Ultrafine portland cement performance

Directory of Open Access Journals (Sweden)

C. Argiz

2018-04-01

Full Text Available By mixing several binder materials and additions with different degrees of fineness, the packing density of the final product may be improved. In this work, ultrafine cement and silica fume mixes were studied to optimize the properties of cement-based materials. This research was performed in mortars made of two types of cement (ultrafine Portland cement and common Portland cement and two types of silica fume with different particle-size distributions. Two Portland cement replacement ratios of 4% and 10% of silica fume were selected and added by means of a mechanical blending method. The results revealed that the effect of the finer silica fume mixed with the coarse cement enhances the mechanical properties and pore structure refinement at a later age. This improvement is somewhat lower in the case of ultrafine cement with silica fume.

Basalt waste added to Portland cement

Directory of Open Access Journals (Sweden)

Thiago Melanda Mendes

2016-08-01

Full Text Available Portland cement is widely used as a building material and more than 4.3 billion tons were produced in 2014, with increasing environmental impacts by this industry, mainly through CO2 emissions and consumption of non-removable raw materials. Several by-products have been used as raw materials or fuels to reduce environmental impacts. Basaltic waste collected by filters was employed as a mineral mixture to Portland cement and two fractions were tested. The compression strength of mortars was measured after 7 days and Scanning Electron Microscopy (SEM and Electron Diffraction Scattering (EDS were carried out on Portland cement paste with the basaltic residue. Gains in compression strength were observed for mixtures containing 2.5 wt.% of basaltic residue. Hydration products observed on surface of basaltic particles show the nucleation effect of mineral mixtures. Clinker substitution by mineral mixtures reduces CO2 emission per ton of Portland cement.

Chemical constitution, physical properties, and biocompatibility of experimentally manufactured Portland cement.

Science.gov (United States)

Hwang, Yun-Chan; Kim, Do-Hee; Hwang, In-Nam; Song, Sun-Ju; Park, Yeong-Joon; Koh, Jeong-Tae; Son, Ho-Hyun; Oh, Won-Mann

2011-01-01

An experimental Portland cement was manufactured with pure raw materials under controlled laboratory conditions. The aim of this study was to compare the chemical constitution, physical properties, and biocompatibility of experimentally manufactured Portland cement with those of mineral trioxide aggregate (MTA) and Portland cement. The composition of the cements was determined by scanning electron microscopy (SEM) and energy-dispersive x-ray analysis (EDAX). The setting time and compressive strength were tested. The biocompatibility was evaluated by using SEM and XTT assay. SEM and EDAX revealed the experimental Portland cement to have a similar composition to Portland cement. The setting time of the experimental Portland cement was significantly shorter than that of MTA and Portland cement. The compressive strength of the experimental Portland cement was lower than that of MTA and Portland cement. The experimental Portland cement showed a similar biocompatibility to MTA. The experimental Portland cement might be considered as a possible substitute for MTA in clinical usage after further testing. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Lithofacies and petrophysical properties of Portland Base Bed and Portland Whit Bed limestone as related to durability

NARCIS (Netherlands)

Dubelaar, C.W.; Engering, S.; Hees, R.P.J. van; Koch, R.; Lorenz, H.G.

2003-01-01

This study focuses on the differences in lithofacies and petrophysical properties of Base Bed and Whit Bed Portland limestone and the presumed relationships between these characteristics and the durability of this building stone. As Portland limestone probably will be used as a stone for several

Lithofacies and Petrophysical Properties of Portland Base Bed and Portland Whit Bed Limestone as Related to Durability

NARCIS (Netherlands)

Dubelaar, C.W.; Engering, S.; Van Hees, R.P.J.; Koch, R.; Lorenz, H.G.

2003-01-01

This study focuses on the differences in lithofacies and petrophysical properties of Base Bed and Whit Bed Portland limestone and the presumed relationships between these characteristics and the durability of this building stone. As Portland limestone probably will be used as a stone for several

Nuevos conglomerantes complementarios del cemento portland

OpenAIRE

Argiz, Cristina; Menéndez, Esperanza; Moragues, Amparo; Sanjuan-Barbudo, Miguel

2012-01-01

El desarrollo de nuevos conglomerantes complementarios al cemento portland se presenta como una alternativa que permitirá reciclar residuos, entre otros posibles beneficios. Estos nuevos materiales difícilmente podrán competir con el cemento portland ya que sus aplicaciones son limitadas y su coste, en general, más elevado.

7 CFR 27.11 - Area Director, Marketing Services Office; responsibility.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Area Director, Marketing Services Office... MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE COMMODITY... Regulations Administration § 27.11 Area Director, Marketing Services Office; responsibility. Subject to this...

Office Requirements in the Portland Standard Metropolitan Area

Science.gov (United States)

Robertson, Leonard

1975-01-01

The findings evolved from questionnaires received from 204 firms pertaining to needed skills in spelling, typewriting, automatic typewriting, calculating machines, transcription machines, shorthand, and work processing, as well as to attributes of job attendance, cooperation, courtesy, telephone personality and appearance. (Author)

Energy edge post-occupancy evaluation project: the Hollywood Office Building, Portland, Oregon

Energy Technology Data Exchange (ETDEWEB)

1990-06-01

The Hollywood Office Park Building Survey for the Energy Post- Occupancy Project was administered to nine building occupants. The nine respondents answered the questions which rated building features in the areas of (1) thermal factors; (2) air quality; (3) lighting; (4) acoustics; and, (5) overall workspace satisfaction. In addition to rating these ambient environmental features, these respondents also rated their satisfaction of various functional and aesthetic features and specific kinds of workspaces. Data was also collected on heath characteristics and occupational demographics of the respondents. No analysis is made of the survey findings which are reported in graphic format. 15 figs. (BN)

Poet Portland Approval

Science.gov (United States)

This update August 9, 2016 letter from EPA approves the petition, with modifications, from Poet Biorefining-Portland, LLC, regarding non-grandfathered ethanol produced through a dry mill process, qualifying under the Clean Air Act for renewable fuel

INFLUENCE OF SUBSTITUTION OF ORDINARY PORTLAND CEMENT BY SILICA FUME ON THE HYDRATION OF SLAG-PORTLAND CEMENT PASTES

Directory of Open Access Journals (Sweden)

E.A. El-Alfi

2011-06-01

Full Text Available Effect of gradual substitution of ordinary Portland cement by a few percent of silica fume (0.0, 2.5, 5.0 and 7.5 wt.% on the hydration properties of slag-Portland cement pastes up to 12 months was investigated. The results show that the composite cement pastes containing silica fume give the higher physico-mechanical properties than that of the slag-Portland cement. Also, the XRD results reveal that the peak of Ca(OH2 shows higher intensity in the sample without silica fume and completely disappears in the sample containing 7.5 wt.% silica fume content. Also, the intensity peaks of C4AH13 sharply increase with silica fume content.

Comparison of the physical and mechanical properties of MTA and portland cement.

Science.gov (United States)

Islam, Intekhab; Chng, Hui Kheng; Yap, Adrian U Jin

2006-03-01

This study evaluated and compared the pH, radiopacity, setting time, solubility, dimensional change, and compressive strength of ProRoot MTA (PMTA), ProRoot MTA (tooth colored formula) (WMTA), white Portland cement (WP), and ordinary Portland cement (OP). The results showed that PMTA and Portland cement have very similar physical properties. However, the radiopacity of Portland cement is much lower than that of PMTA. The compressive strength of PMTA was greater than Portland cement at 28 days. The major constituent of PMTA is Portland cement. Given the low cost of Portland cement and similar properties when compared to PMTA, it is reasonable to consider Portland cement as a possible substitute for PMTA in endodontic applications. However, industrially manufactured Portland cement is not approved currently for use in the United States and therefore no clinical recommendation can be made for its use in the human body. Further in vitro and in vivo tests, especially with regards its biocompatibility, should be conducted to ascertain if it meets the FDA requirements for use as a medical device.

Radiopacity of portland cement associated with different radiopacifying agents.

Science.gov (United States)

Húngaro Duarte, Marco Antonio; de Oliveira El Kadre, Guâniara D'arc; Vivan, Rodrigo Ricci; Guerreiro Tanomaru, Juliane Maria; Tanomaru Filho, Mário; de Moraes, Ivaldo Gomes

2009-05-01

This study evaluated the radiopacity of Portland cement associated with the following radiopacifying agents: bismuth oxide, zinc oxide, lead oxide, bismuth subnitrate, bismuth carbonate, barium sulfate, iodoform, calcium tungstate, and zirconium oxide. A ratio of 20% radiopacifier and 80% white Portland cement by weight was used for analysis. Pure Portland cement and dentin served as controls. Cement/radiopacifier and dentin disc-shaped specimens were fabricated, and radiopacity testing was performed according to the ISO 6876/2001 standard for dental root sealing materials. Using Insight occlusal films, the specimens were radiographed near to a graduated aluminum stepwedge varying from 2 to 16 mm in thickness. The radiographs were digitized and radiopacity compared with the aluminum stepwedge using Digora software (Orion Corporation Soredex, Helsinki, Finland). The radiographic density data were converted into mmAl and analyzed statistically by analysis of variance and Tukey-Kramer test (alpha = 0.05). The radiopacity of pure Portland cement was significantly lower (p cement/radiopacifier mixtures were significantly more radiopaque than dentin and Portland cement alone (p cement/bismuth oxide and Portland cement/lead oxide presented the highest radiopacity values and differed significantly from the other materials (p cement/zinc oxide presented the lowest radiopacity values of all mixtures (p cement as radiopacifying agents. However, the possible interference of the radiopacifiers with the setting chemistry, biocompatibility, and physical properties of the Portland cement should be further investigated before any clinical recommendation can be done.

Microstructure and durability of Portland cement-carbon nanotube composites

OpenAIRE

MacLeod, Alastair James Neil

2017-01-01

The incorporation of carbon nanotubes (CNTs), fibres with diameters less than 100 nanometres that exhibit a tensile strength in excess of ten times greater than steel, into Portland cement (OPC) is a relatively novel, yet promising, development for next-generation construction materials exhibiting enhanced strength and ductility, even multifunctionality. When added to Portland cement, creating a Portland cement-CNT nanocomposite material (OPC-CNT), CNTs promote the nucleation of the princi...

Mineral trioxide aggregate and Portland cement promote biomineralization in vivo.

Science.gov (United States)

Dreger, Luonothar Antunes Schmitt; Felippe, Wilson Tadeu; Reyes-Carmona, Jessie Fabiola; Felippe, Gabriela Santos; Bortoluzzi, Eduardo Antunes; Felippe, Mara Cristina Santos

2012-03-01

Mineral trioxide aggregate (MTA) and Portland cement have been shown to be bioactive because of their ability to produce biologically compatible carbonated apatite. This study analyzed the interaction of MTA and white Portland cement with dentin in vivo. Seventy-two human dentin tubes were filled with MTA Branco, MTA BIO, and white Portland cement + 20% bismuth oxide (PC1) or PC1 + 10% of calcium chloride (PC2) and implanted subcutaneously in 18 rats at 4 sites from the dorsal area. Empty dentin tubes, implanted in rats of a pilot study, were used as control. After 30, 60, and 90 days, the animals were killed, and the dentin tubes were retrieved for scanning electron microscope analysis. In the periods of 30 and 60 days, the mineral deposition in the material-dentin interface (interfacial layer) and in the interior of dentinal tubules was detected in more tubes filled with MTA Branco and MTA BIO than in tubes filled with PC1 and PC2. After 90 days, the interfacial layer and intratubular mineralization were detected in all tubes except for 3 and 1 of the tubes filled with PC2, respectively. It was concluded that all the cements tested were bioactive. The cements released some of their components in the tissue capable of stimulating mineral deposition in the cement-dentin interface and in the interior of the dentinal tubules. MTA BIO and MTA Branco were more effective in promoting the biomineralization process than Portland cements, mainly after 30 and 60 days. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Urban Flooding Analysis Using Radar Rainfall Data and 2-D Hydrodynamic Model: A Pilot Study of Back Cover Area, Portland, Maine

Energy Technology Data Exchange (ETDEWEB)

Yan, Eugene [Argonne National Lab. (ANL), Argonne, IL (United States); Pierce, Julia [Argonne National Lab. (ANL), Argonne, IL (United States); Mahat, Vinod [Argonne National Lab. (ANL), Argonne, IL (United States); Jared, Alissa [Argonne National Lab. (ANL), Argonne, IL (United States); Collis, Scott [Argonne National Lab. (ANL), Argonne, IL (United States); Verner, Duane [Argonne National Lab. (ANL), Argonne, IL (United States); Wall, Thomas [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-11-01

This project is a part of the Regional Resiliency Assessment Program, led by the Department of Homeland Security, to address flooding hazards of regional significance for Portland, Maine. The pilot study was performed by Argonne National Laboratory to identify differences in spatial rainfall distributions between the radar-derived and rain-gauge rainfall datasets and to evaluate their impacts on urban flooding. The flooding impact analysis utilized a high-resolution 2-dimensional (2-D) hydrodynamic model (15 ft by 15 ft) incorporating the buildings, streets, stream channels, hydraulic structures, an existing city storm drain system, and assuming a storm surge along the coast coincident with a heavy rainfall event. Two historical storm events from April 16, 2007, and September 29, 2015, were selected for evaluation. The radar-derived rainfall data at a 200-m resolution provide spatially-varied rainfall patterns with a wide range of intensities for each event. The resultant maximum flood depth using data from a single rain gauge within the study area could be off (either under- or over-estimated) by more than 10% in the 2007 storm and more than 60% in the 2015 storm compared to the radar-derived rainfall data. The model results also suggest that the inundation area with a flow depth at or greater than 0.5 ft could reach 11% (2007 storm) and 17% (2015 storm) of the total study area, respectively. The lowland areas within the neighborhoods of North Deering, East Deering, East and West Baysides and northeastern Parkside, appear to be more vulnerable to the flood hazard in both storm events. The high-resolution 2-D hydrodynamic model with high-resolution radar-derived rainfall data provides an excellent tool for detailed urban flood analysis and vulnerability assessment. The model developed in this study could be potentially used to evaluate any proposed mitigation measures and optimize their effects in the future for Portland, ME.

76 FR 28315 - Security Zone; Portland Rose Festival on Willamette River

Science.gov (United States)

2011-05-17

... Zone; Portland Rose Festival on Willamette River AGENCY: Coast Guard, DHS. ACTION: Notice of enforcement of regulation. SUMMARY: The Coast Guard will enforce the Portland Rose Festival Security Zone in... River during the Portland Rose festival. During the enforcement period, no person or vessel may enter or...

2014 Oregon Department of Geology and Mineral Industries (DOGAMI) Oregon Lidar: Metro Portland, OR

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The dataset encompasses 1221.6 square miles in portions of the greater Portland Metro area in the state of Oregon. The highest hit digital surface models (DSM)...

7 CFR 600.9 - Major land resource area soil survey offices.

Science.gov (United States)

2010-01-01

... 7 Agriculture 6 2010-01-01 2010-01-01 false Major land resource area soil survey offices. 600.9 Section 600.9 Agriculture Regulations of the Department of Agriculture (Continued) NATURAL RESOURCES CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE GENERAL ORGANIZATION § 600.9 Major land resource area soil survey offices. The United States is divide...

Carlsbad Area Office strategic plan

International Nuclear Information System (INIS)

1995-10-01

This edition of the Carlsbad Area Office Strategic Plan captures the U.S. Department of Energy's new focus, and supercedes the edition issued previously in 1995. This revision reflects a revised strategy designed to demonstrate compliance with environmental regulations earlier than the previous course of action; and a focus on the selected combination of scientific investigations, engineered alternatives, and waste acceptance criteria for supporting the compliance applications. An overview of operations and historical aspects of the Waste Isolation Pilot Plant near Carlsbad, New Mexico is presented

Preterm delivery among people living around Portland cement plants

International Nuclear Information System (INIS)

Yang, C.-Y.; Chang, C.-C.; Tsai, S.-S.; Huang, H.-Y.; Ho, C.-K.; Wu, T.-N.; Sung, F.-C.

2003-01-01

The Portland cement industry is the main source of particulate air pollution in Kaohsiung city. Data in this study concern outdoor air pollution and the health of individuals living in communities in close proximity to Portland cement plants. The prevalence of delivery of preterm birth infants as significantly higher in mothers living within 0-2 km of a Portland cement plant than in mothers living within 2-4 km. After controlling for several possible confounders (including maternal age, season, marital status, maternal education, and infant sex), the adjusted odds ratio was 1.30 (95% I=1.09-1.54) for the delivery of preterm infants for mothers living close to he Portland cement plants, chosen at the start to be from 0 to 2 km. These data provide further support for the hypothesis that air pollution can affect he outcome of pregnancy

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...

2014 Oregon Department of Geology and Mineral Industries (DOGAMI) Oregon Lidar DEM: Metro Portland, OR

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The dataset encompasses 1221.6 square miles in portions of the greater Portland Metro area in the state of Oregon. The highest hit digital surface models (DSM)...

Understanding mineral trioxide aggregate/Portland-cement: a review of literature and background factors.

Science.gov (United States)

Steffen, R; van Waes, H

2009-06-01

This was to carry out a review of the literature concerning mineral trioxide aggregate (MTA) and Portland cement with regards to clinical, biological and mechanical findings and a possible substitution of MTA through Portland cement for endodontic use. Electronic literature search of scientific papers from January 1993 to January 2009 was carried out on the MEDLINE and Scopus databases using specific key words. In total, 57 papers were identified that dealt with MTA and Portland cement in a relevant way. The review of 50 papers conforming to the applied criteria showed that MTA and Portland cements have the same clinical, biological and mechanical properties. In animal experiments and technical characterisations both materials seemed to have very similar properties. The only difference is bismuth oxide in MTA added for better radio opacity. It seems likely that MTA materials are based on industrial Portland cements mixed with bismuth oxide. More studies, especially some long-term studies comparing MTA and Portland cement, are necessary. The existing literature gives a solid base for clinical studies with Portland cement in order to replace MTA as an endodontic material. Portland cement could be a substitute for most endodontic materials used in primary teeth.

Analyses of heavy metals in mineral trioxide aggregate and Portland cement.

Science.gov (United States)

Schembri, Matthew; Peplow, George; Camilleri, Josette

2010-07-01

Portland cement is used in the construction industry as a binder in concrete. It is manufactured from chalk, limestone, and clay, which are clinkered at very high temperatures and ground with gypsum to form Portland cement. The raw materials and the manufacturing process can result in the inclusion of heavy metals in Portland cement. Portland cement with a four to one addition of bismuth oxide is marketed as mineral trioxide aggregate (MTA), which is used mainly as a dental material. Heavy metal inclusion can be of concern because MTA is in contact with hard and soft tissues. Measurements of arsenic, lead, and chromium in hydrated gray and white Portland cement, ProRoot MTA, and MTA Angelus were conducted with graphite furnace atomic absorption spectrophotometry after acid digestion on the hydrated material. The leaching of the metal ions from the solid material in water and simulated body fluid (SBF) was also determined. All cement types showed high relative values of leached chromium compared with arsenic and lead in both the total metal content and leached species. The gray Portland cement showed the highest total amount of metal. The white Portland and both MTAs had lower values for all the leached metal ions. Both MTAs released more arsenic than the amount specified in ISO 9917-1 (2007). Portland cements and MTAs showed evidence of heavy metals in the acid-soluble form as well as leaching in deionized water and SBF. MTA contained levels of arsenic higher than the safe limit specified by the ISO 9917-1 (2007). Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Effect of blended materials on U(VI) retention characteristics for portland cement solidification product

International Nuclear Information System (INIS)

Tan Hongbin; Ma Xiaoling; Li Yuxiang

2006-01-01

Using the simulated groundwater as leaching liquid, the retention capability of U(VI) in solidification products with Portland cement, the Portland cement containing silica fume, the Portland cement containing metakaolin and the Portland cement containing fly ash was researched by leaching experiments at 25 degree C for 42 d. The results indicate silica fume and metakaolin as blended materials can improve the U(VI) retention capability of Portland cement solidification product, but fly ash can not. (authors)

76 FR 28318 - National Emission Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing...

Science.gov (United States)

2011-05-17

... Cement Manufacturing Industry and Standards of Performance for Portland Cement Plants AGENCY... Emission Standards for Hazardous Air Pollutants from the Portland Cement Manufacturing Industry Response to... by the Portland Cement Industry and the New Source Performance Standards for Portland Cement Plants...

76 FR 2832 - National Emission Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing...

Science.gov (United States)

2011-01-18

... Cement Manufacturing Industry and Standards of Performance for Portland Cement Plants AGENCY...) from the Portland Cement Manufacturing Industry and Standards of Performance (NSPS) for Portland Cement... Standards for Hazardous Air Pollutant From the Portland Cement Manufacturing Industry Docket, Docket ID No...

Effect of three natural pozzolans in portland cement hydration

Directory of Open Access Journals (Sweden)

Rahhal, V.

2003-03-01

Full Text Available Natural pozzolans have been used since ancient times and continues to be used today. The chemistry and morphological composition of natural pozzolans and their particle size distribution allows classifying them as more or less reactive pozzolan. In this research several techniques have been used to study the influence of pozzolan on portland cement hydration as much as to evaluate the mechanical and durable properties of concretes, mortars and pastes containing pozzolans. This paper describes the effect of incorporating three natural pozzolans to two cements with very different mineralogical composition. The techniques used were: conduction calorimetry and Fratini test. Results proved that pozzolanic activity and the acceleration and retardation of hydration reaction depend on the mineralogical composition of the portland cernent used. Effects of dilution, stimulation, acceleration or retardation reactions, behavior into areas of heat dissipation and pozzolanic activity depend on the percentage of pozzolan used and the age in which it has been analyzed.

El uso de las puzolanas naturales se remonta a la antigüedad, no obstante, actualmente continúa su utilización. La composición química y morfológica de las puzolanas naturales, sumado al tamaño de sus partículas, las califican como más o menos reactivas. En el estudio de las mismas, se han aplicado variadas técnicas para el análisis de sus interferencias en las reacciones de hidratación de los cementos portland; así como para la evaluación de las propiedades resistentes y duraderas que pueden conferirle a los hormigones, morteros o pastas de los que formen parte. Este trabajo versará sobre los efectos que produce la incorporación de tres puzolanas naturales a dos cementos portland de muy diferente composición mineralógica. Las técnicas aplicadas para su estudio han sido: la calorimetría de conducción y el ensayo de Fratini. Los resultados obtenidos permiten determinar

77 FR 46371 - National Emission Standards for Hazardous Air Pollutants for the Portland Cement Manufacturing...

Science.gov (United States)

2012-08-03

...-AQ93 National Emission Standards for Hazardous Air Pollutants for the Portland Cement Manufacturing... Portland Cement Manufacturing Industry and Standards of Performance for Portland Cement Plants,'' which was... Manufacturing Industry and Standards of Performance for Portland Cement Plants'' under Docket ID No. EPA-HQ-OAR...

Immediate and delayed solubility of mineral trioxide aggregate and Portland cement

Directory of Open Access Journals (Sweden)

Augusto Bodanezi

2008-04-01

Full Text Available This study investigated the solubility of mineral trioxide aggregate (MTA and Portland cement since its mixture until 672 hours, by means of two complimentary methods. Metal ring molds filled with the cements were covered with distilled water and, at each experimental time (3, 24, 72, 168, 336 and 672 hours, were weighed as soon as the plates in which the samples have been placed. Empty rings served as the control group (n=8. Mean weight gain and loss was determined and analyzed statistically by two-way ANOVA and Tukey's test for all pairwise comparisons. Only Portland cement showed less than 3% weight loss through 24 hours. Detached MTA residues were heavier than those of Portland cement over the 3 to 168 hours. The weight of MTA rings increased more than that of Portland rings within 672 hours (p=0.05. The findings of the present study indicate that, in an aqueous environment MTA is more soluble than Portland cement and exceeds the maximum weight loss considered acceptable by ISO 6876 standard (2001.

Immediate and delayed solubility of mineral trioxide aggregate and Portland cement.

Science.gov (United States)

Bodanezi, Augusto; Carvalho, Nara; Silva, Daniela; Bernardineli, Norberti; Bramante, Clovis Monteiro; Garcia, Roberto Brandão; de Moraes, Ivaldo Gomes

2008-01-01

This study investigated the solubility of mineral trioxide aggregate (MTA) and Portland cement since its mixture until 672 hours, by means of two complimentary methods. Metal ring molds filled with the cements were covered with distilled water and, at each experimental time (3, 24, 72, 168, 336 and 672 hours), were weighed as soon as the plates in which the samples have been placed. Empty rings served as the control group (n=8). Mean weight gain and loss was determined and analyzed statistically by two-way ANOVA and Tukey's test for all pairwise comparisons. Only Portland cement showed less than 3% weight loss through 24 hours. Detached MTA residues were heavier than those of Portland cement over the 3 to 168 hours. The weight of MTA rings increased more than that of Portland rings within 672 hours (p=0.05). The findings of the present study indicate that, in an aqueous environment MTA is more soluble than Portland cement and exceeds the maximum weight loss considered acceptable by ISO 6876 standard (2001).

Electrically conductive Portland cement concrete.

Science.gov (United States)

1986-01-01

There is a need for an effective, simple-to-install secondary anode system for use in the cathodic protection of reinforced concrete bridge decks. In pursuit of such a system, carbon fibers and carbon black were incorporated in portland cement concre...

Thermophysical properties of blends from Portland and sulfoaluminate-belite cements

International Nuclear Information System (INIS)

Mojumdar, S.C.; Janotka, I.

2002-01-01

The behavior of mortars with blends consisting of sulfoaluminate-belite cements and ordinary Portland cement made with cement to sand ratio of 1:3 by weight and w/c = 0.5 maintained for 90 days at 20 0 C either at 60% relative humidity - dry air or 100% relative humidity - wet air. The results show insufficient character of hydraulic activity of sulfoaluminate-belite cements. Their quality has been improved. The replacement of 15 wt % of sulfoaluminate-belite cement by ordinary Portland cement influences strength positively and elasticity modulus values as well as hydrated phases and pore structure development of sulfoaluminate-belite/ordinary Portland cement blends relative to pure sulfoaluminate-belite cement systems. The above statements confirm the possible making technologies, when improvements in sulfoaluminate-belite cements quality will be achieved. One would then anticipate the competition in usages between sulfoaluminate-belite/ordinary Portland cement and blast furnace-slag Portland cement systems in the practice. It is important to consider because sulfoaluminate-belite cements are of great advantage from the viewpoint of energy savings and quantity of CO 2 released during their production. Thermal characteristics of the samples were studied by thermogravimetry and differential thermal analysis from room temperature to 1000 0 C in air atmosphere. Generally, four significant temperature regions on thermogravimetry curves with the respective differential thermal analysis peak temperature for all types of samples are observed (Authors)

The Development of the Academic Administration Model of Basic Primary Educational Institutions under the Office of Sakon Nakhon Educational Service Area Office 3

Directory of Open Access Journals (Sweden)

Kamonlrat Kaenchan

2017-09-01

Full Text Available The research aimed to 1 examine the current conditions, problems and academic administration of basic education schools under the office of Sakon Nakhon educational service area office 3, 2 develop the academic administration model of basic educational schools under the office of Sakon Nakhon educational service area office 3. The study was divided into 2 phases. Phase 1: Study the researches and literatures concerning the framework, the current conditions and the problems of academic administration to gain the concept for constructing a set of questionnaire. The questionnaire was then used to collect data from 50 administrators, 83 heads of academic sections and 198 heads of learning areas ; and interviewed the administrators of 5 schools that ranked top-five of the national education test scores (O-NET and were certified by the office of educational standard assurance and quality assessment in the third-round inspection. Phase 2: Construct the model of educational administration of basic education schools under the office of Sakon Nakhon educational service area office 3, held a focus group discussion of which the participants were 2 educational administrators and 5 school directors on the constructed model, evaluated the educational administration models of the schools under the office of Sakon Nakhon educational service area office 3 by 30 school administrators and teachers. The instruments used to collect data were a set of questionnaire, interviewing forms, recording forms and evaluating forms. The data were analyzed by a computer application. The statistics used to analyze the data were percentage, mean and standard deviation. The results were as follows: 1 The current conditions of academic administration of basic education schools under the office of Sakon Nakhon educational service area office 3, overall, were at a high level. The highest mean was the development of the learning process. The problems of academic administration, overall

Portland cement versus MTA as a root-end filling material. A pilot study.

Science.gov (United States)

da Silva, Sérgio Ribeiro; da Silva Neto, José Dias; Veiga, Daniela Francescato; Schnaider, Taylor Brandão; Ferreira, Lydia Masako

2015-02-01

To assess periradicular lesions clinically and by computed tomography (CT) after endodontic surgery using either Portland cement or mineral trioxide aggregate (MTA) as a root-end filling material. Three patients diagnosed with periradicular lesions by cone-beam CT underwent endodontic surgery with root-end filling. Patient A was treated with MTA as the root-end filling material, patient B was treated with Portland cement and patient C had two teeth treated, one with MTA and the other with Portland cement. Six months after surgery, the patients were assessed clinically and by CT scan and the obtained results were compared. Periradicular tissue regeneration was observed in all cases, with no significant differences in bone formation when comparing the use of MTA and Portland cement as root-end filling materials. Both mineral trioxide aggregate and Portland cement were successful in the treatment of periradicular lesions.

E-cigarettes forbidden in offices and closed areas

CERN Document Server

2013-01-01

Be reminded that all people on the CERN site must comply with the following notice from the Medical Service: “In the same manner as for ordinary cigarettes, the use of e-cigarettes is forbidden in all offices and closed areas.” If you have any question, please write to medical.service@cern.ch HSE Unit/ GS-ME Department

Performance Characteristics of Waste Glass Powder Substituting Portland Cement in Mortar Mixtures

Science.gov (United States)

Kara, P.; Csetényi, L. J.; Borosnyói, A.

2016-04-01

In the present work, soda-lime glass cullet (flint, amber, green) and special glass cullet (soda-alkaline earth-silicate glass coming from low pressure mercury-discharge lamp cullet and incandescent light bulb borosilicate glass waste cullet) were ground into fine powders in a laboratory planetary ball mill for 30 minutes. CEM I 42.5N Portland cement was applied in mortar mixtures, substituted with waste glass powder at levels of 20% and 30%. Characterisation and testing of waste glass powders included fineness by laser diffraction particle size analysis, specific surface area by nitrogen adsorption technique, particle density by pycnometry and chemical analysis by X-ray fluorescence spectrophotometry. Compressive strength, early age shrinkage cracking and drying shrinkage tests, heat of hydration of mortars, temperature of hydration, X-ray diffraction analysis and volume stability tests were performed to observe the influence of waste glass powder substitution for Portland cement on physical and engineering properties of mortar mixtures.

Biocompatibility of Portland cement combined with different radiopacifying agents.

Science.gov (United States)

Lourenço Neto, Natalino; Marques, Nádia C T; Fernandes, Ana Paula; Rodini, Camila O; Duarte, Marco A H; Lima, Marta C; Machado, Maria A A M; Abdo, Ruy C C; Oliveira, Thais M

2014-03-01

The aim of this study was to evaluate the response of rat subcutaneous tissue to Portland cement combined with two different radiopacifying agents, iodoform (CHI3) and zirconium oxide (ZrO2). These materials were placed in polyethylene tubes and implanted into the dorsal connective tissue of Wistar rats for 7 and 15 days. The specimens were then stained with hematoxylin and eosin, and inflammatory reaction parameters were evaluated by light microscopy. The intensity of the inflammatory response to the sealants was analyzed by two blind calibrated observers throughout the experimental period. Histological analysis showed that all the materials caused a moderated inflammatory reaction at 7 days, which then diminished with time. At 15 days, the inflammatory reaction was almost absent, and fibroblasts and collagen fibers were observed indicating normal tissue healing. The degrees of the inflammatory reaction on different days throughout the experimental period were compared using the non-parametric Kruskal-Wallis test. Statistical analysis demonstrated no significant differences amongst the groups, and Portland cement associated with radiopacifying agents gave satisfactory results. Therefore, Portland cement used in combination with radiopacifying agents can be considered a biocompatible material. Although our results are very encouraging, further studies are needed in order to establish safe clinical indications for Portland cement combined with radiopacifying agents.

Influence of ultrasonic radiation on the amorphous zeolite - Portland cement system

NARCIS (Netherlands)

Jakevicius, L.; Vaiciukyniene, D.; Demcenko, A.

2012-01-01

This paper considers the investigation of influence of an amorphous synthetic zeolite with inserted $Ca^{2+}$ ions additive (ASZ) on the hydration temperature of Portland cement paste. In this investigation the sonicated Portland cement paste is compared to the non-sonicated paste; and then the

Portland-pfa cement: a comparison between intergrinding and blending

Energy Technology Data Exchange (ETDEWEB)

Monk, M

1983-09-01

Portland-pfa cements containing 20-40% (by weight) pfa have been prepared in the laboratory both by intergrinding the ashes with clinker and by blending with cement. Cement properties have been assessed according to BS 4550 and scanning electron microscopy was used to examine the effects of grinding upon the pfa particles. The work has shown that intergrinding leads to an improvement in the water-reducing properties of coarse pfas and also in their pozzolanic activity as indicated by compressive strength development at later ages. Setting times have been found to be essentially the same for blended and interground cements, both being considerably longer than for typical ordinary Portland cements. Thus the results of this investigation indicate that, provided pfa's are chemically acceptable, they can be used for Portland-pfa cement manufacture by intergrinding irrespective of their coarseness.

77 FR 42367 - National Emission Standards for Hazardous Air Pollutants for the Portland Cement Manufacturing...

Science.gov (United States)

2012-07-18

... and 63 National Emission Standards for Hazardous Air Pollutants for the Portland Cement Manufacturing... Standards for Hazardous Air Pollutants for the Portland Cement Manufacturing Industry and Standards of... manufacturing plants. Federal government Not affected. State/local/tribal government.... Portland cement...

Recycled materials in Portland cement concrete

Science.gov (United States)

2000-06-01

This report pertains to a comprehensive study involving the use of recycled materials in Portland cement concrete. Three different materials were studied including crushed glass (CG), street sweepings (SS), and recycled concrete (RC). Blast furnace s...

2015 City of Portland, Maine, Lidar

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — 2015 City of Portland Maine Lidar Data Acquisition and Processing Woolpert Order No. 75564 Contractor: Woolpert, Inc. This task is for a high resolution data set of...

Analysis of Chemical Composition of Portland Cement in Ghana: A Key to Understand the Behavior of Cement

OpenAIRE

Bediako, Mark; Amankwah, Eric Opoku

2015-01-01

The performance of Portland cement in concrete or mortar formation is very well influenced by chemical compositions among other factors. Many engineers usually have little information on the chemical compositions of cement in making decisions for the choice of commercially available Portland cement in Ghana. This work analyzed five different brands of Portland cement in Ghana, namely, Ghacem ordinary Portland cement (OPC) and Portland limestone cement (PLC), CSIR-BRRI Pozzomix, Dangote OPC, a...

75 FR 54969 - National Emission Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing...

Science.gov (United States)

2010-09-09

... Hazardous Air Pollutants From the Portland Cement Manufacturing Industry and Standards of Performance for... Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing Industry and Standards of... (NESHAP) from the Portland Cement Manufacturing Industry and to the New Source Performance Standards (NSPS...

76 FR 2860 - National Emission Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing...

Science.gov (United States)

2011-01-18

... Cement Manufacturing Industry and Standards of Performance for Portland Cement Plants AGENCY... Portland Cement Manufacturing Industry Docket, Docket ID No. EPA-HQ-OAR-2002-0051, 1200 Pennsylvania Ave... Portland Cement Manufacturing Industry Docket, EPA West, Room 3334, 1301 Constitution Ave., NW., Washington...

76 FR 78240 - Gray Portland Cement and Clinker From Japan: Continuation of Antidumping Duty Order

Science.gov (United States)

2011-12-16

... DEPARTMENT OF COMMERCE International Trade Administration [A-588-815] Gray Portland Cement and... Department) initiated the third sunset review of the antidumping duty order on gray portland cement and... of the antidumping duty order on gray portland cement and clinker from Japan would likely lead to...

39 CFR 223.2 - Channels of communication, headquarters with area offices.

Science.gov (United States)

2010-07-01

... RELATIONSHIPS AND COMMUNICATION CHANNELS § 223.2 Channels of communication, headquarters with area offices. (a... 39 Postal Service 1 2010-07-01 2010-07-01 false Channels of communication, headquarters with area...). Whether published on paper or online, such policies must be coordinated with other appropriate...

Tabular data base construction and analysis from thematic classified Landsat imagery of Portland, Oregon

Science.gov (United States)

Bryant, N. A.; George, A. J., Jr.; Hegdahl, R.

1977-01-01

A systematic verification of Landsat data classifications of the Portland, Oregon metropolitan area has been undertaken on the basis of census tract data. The degree of systematic misclassification due to the Bayesian classifier used to process the Landsat data was noted for the various suburban, industrialized and central business districts of the metropolitan area. The Landsat determinations of residential land use were employed to estimate the number of automobile trips generated in the region and to model air pollution hazards.

Portland cement concrete air content study.

Science.gov (United States)

1987-04-20

This study took the analysis of Portland cement concrete air content. Based on the information gathered, this study hold the results were : 1) air-entrained concrete was more durable than non-air entrained concrete all other factors being equal; 2) A...

Biological evaluation of a new pulp capping material developed from Portland cement.

Science.gov (United States)

Negm, Ahmed M; Hassanien, Ehab E; Abu-Seida, Ashraf M; Nagy, Mohamed M

2017-03-02

This study evaluates the biological properties of a new pulp capping material developed from Portland cement. This study was conducted on 48 teeth in 4 dogs (12 teeth/dog). The dogs were classified into two equal groups (n=24 teeth) according to the evaluation period including: group A (3 weeks) and group B (3 months). Each group was further subdivided into three equal subgroups (n=8 teeth) according to the capping material including: subgroup 1: mineral trioxide aggregate (MTA), subgroup2: Portland cement+10% calcium hydroxide+20% bismuth oxide (Port Cal) and subgroup 3: Portland cement+bismuth oxide. After general anesthesia, a class V buccal cavity was prepared coronal to the gingival margin. After pulp exposure and hemostasis,the capping materials and glass ionomer filling were placed on the exposure sites. All histopathological findings, inflammatory cell count and dentin bridge formation were recorded. Data were analyzed statistically. After 3 months, the histopathological picture of the pulp in subgroup 1 showed normal pulp, continuous odontoblastic layer and complete dentin bridge formation while subgroup 2 showed partial and complete dentin bridge over a normal and necrotic pulps. Subgroup 3 showed loss of normal architecture, areas of necrosis, complete, or incomplete dentin bridge formation, attached and detached pulp stones and fatty degeneration in group B. For group A, MTA subgroup showed the least number of inflammatory cell infiltrate followed by Port Cal subgroup. While subgroup 3 showed the highest number of inflammatory cell infiltrate. For group B, the mean inflammatory cell count increased with the three tested materials with no statistical difference. Regarding dentin bridge formation at group A, no significant differences was found between subgroups, while at group B, MTA subgroup exhibited significantly higher scores than other subgroups. In conclusion, addition of calcium hydroxide to Portland cement improves the dentin bridge formation

32 CFR 536.9 - Responsibilities and operations of area claims offices.

Science.gov (United States)

2010-07-01

... detachment, recruiting company or station, or DOD agency) within the area appoints a claims officer to... their areas of jurisdiction, appropriate legal publications on state or territorial law and precedent... understanding between the affected commands. (3) Normally, claims that cannot be settled by a COE ACO will be...

Characterization of floodflows along the Arkansas River without regulation by Pueblo Reservoir, Portland to John Martin Reservoir, Southeastern Colorado

Science.gov (United States)

Little, John R.; Bauer, Daniel P.

1981-01-01

The need for a method for estimating flow characteristics of flood hydrographs between Portland, Colo., and John Martin Reservoir has been promoted with the construction of the Pueble Reservoir. To meet this need a procedure was developed for predicting floodflow peaks, traveltimes, and volumes at any point along the Arkansas River between Portland and John Martin Reservoir without considering the existing Pueble Reservoir detention effects. A streamflow-routing model was calibrated initially and then typical flood simulations were made for the 164.8-mile study reach. Simulations were completed for varying magnitudes of floods and antecedent streamflow conditions. Multiple regression techniques were then used with simulation results as input to provide predictive relationships for food peak, volume, and traveltime. Management practices that may be used to benefit water users in the area include providing methods for the distribution and allotment of the flood waters upstream of Portland to different downstream water users according to Colorado water law and also under the Arkansas River Compact. (USGS)

33 CFR 165.1315 - Safety Zones: Fireworks displays in the Captain of the Port Portland Zone.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety Zones: Fireworks displays... Coast Guard District § 165.1315 Safety Zones: Fireworks displays in the Captain of the Port Portland Zone. (a) Safety zones. The following areas are designated safety zones: (1) Cinco de Mayo Fireworks...

Effect of mineral trioxide aggregates and Portland cements on inflammatory cells.

Science.gov (United States)

Shahi, Shahriar; Rahimi, Saeed; Yavari, Hamid Reza; Mokhtari, Hadi; Roshangar, Leila; Abasi, Mehran Mesgary; Sattari, Sahar; Abdolrahimi, Majid

2010-05-01

Recently, some studies have compared mineral trioxide aggregate (MTA) with Portland cements, concluding that the principal ingredients of Portland cements are similar to those of MTA. The purpose of the present study was to evaluate the effect of gray MTA, white MTA, and gray and white Portland cements on inflammatory cells in rats. Fresh mixtures mixed with distilled water were placed in polyethylene tubes, which were implanted in the dorsal subcutaneous connective tissue of 60 Sprague-Dawley rats along with empty tubes as controls. Tissue specimens were collected after the rats were sacrificed after 7, 15, 30, 60, and 90 days. The specimens were fixed, stained, processed, and histologically evaluated under a light microscope. Inflammatory reactions were classified as grade 0: without inflammatory cells, grade I: sporadic infiltration of inflammatory cells, grade II: moderate infiltration (125 cells). Data were analyzed with the nonparametric (two factor) analysis of variance and Kruskal-Wallis H-test. All the groups showed grade III inflammation after 7 and 15 days; there was a decrease in the inflammatory process after 30, 60, and 90 days. After 90 days, gray MTA, white MTA, and control groups had grade 0 inflammatory process, but gray Portland cement and white Portland cement groups showed grade 0 to grade I inflammatory processes. MTAs were more biocompatible; however, more studies are required. Copyright (c) 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

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

Science.gov (United States)

Chen, Irvin Allen

Portland cement concrete, the most widely used manufactured material in the world, is made primarily from water, mineral aggregates, and portland cement. The production of portland cement is energy intensive, accounting for 2% of primary energy consumption and 5% of industrial energy consumption globally. Moreover, portland cement manufacturing contributes significantly to greenhouse gases and accounts for 5% of the global CO2 emissions resulting from human activity. The primary objective of this research was to explore methods of reducing the environmental impact of cement production while maintaining or improving current performance standards. Two approaches were taken, (1) incorporation of waste materials in portland cement synthesis, and (2) optimization of an alternative environmental friendly binder, calcium sulfoaluminate-belite cement. These approaches can lead to less energy consumption, less emission of CO2, and more reuse of industrial waste materials for cement manufacturing. In the portland cement part of the research, portland cement clinkers conforming to the compositional specifications in ASTM C 150 for Type I cement were successfully synthesized from reagent-grade chemicals with 0% to 40% fly ash and 0% to 60% slag incorporation (with 10% intervals), 72.5% limestone with 27.5% fly ash, and 65% limestone with 35% slag. The synthesized portland cements had similar early-age hydration behavior to commercial portland cement. However, waste materials significantly affected cement phase formation. The C3S--C2S ratio decreased with increasing amounts of waste materials incorporated. These differences could have implications on proportioning of raw materials for cement production when using waste materials. In the calcium sulfoaluminate-belite cement part of the research, three calcium sulfoaluminate-belite cement clinkers with a range of phase compositions were successfully synthesized from reagent-grade chemicals. The synthesized calcium sulfoaluminate

78 FR 4331 - Safety Zone; Sellwood Bridge Move; Willamette River, Portland, OR

Science.gov (United States)

2013-01-22

... Sellwood Bridge as it is being moved. This safety zone will also allow full maneuverability for... 1625-AA00 Safety Zone; Sellwood Bridge Move; Willamette River, Portland, OR AGENCY: Coast Guard, DHS... the Sellwood Bridge, located on the Willamette River in Portland, Oregon, while it is being relocated...

Portland Energy Centre: Securing supply and clearing the air

International Nuclear Information System (INIS)

2003-02-01

The rationale for, and benefits derivable from the proposed Portland natural gas-fired cogeneration plant, to be located beside the former Hearn power station near the Leslie Street Spit in Toronto, are discussed. The justification for and the single most important benefit promised by the proposed plant is that it could help Ontario achieve its coal phase-out target by displacing 100 per cent of the annual output of the Lakeview coal--fired power plant in Mississauga, as well as six per cent of the annual output of the Nanticoke coal-fired power plant, in total supplying about 10 per cent of Toronto's electricity needs and providing steam to heat several office towers in downtown Toronto. Other benefits discussed include substantially improved air quality, reduced incidence of asthma and heart attacks, a more reliable power supply for Toronto, some 500 new jobs during construction, and 25 to 35 permanent jobs to operate the plant. The Fact Sheet also offers suggestions on how to generate political support for this project in particular and for renewable power sources in general

The existence state of uranium(VI) in portland cement matrix material immobilization body

International Nuclear Information System (INIS)

Tan Hongbin; Li Yuxiang

2005-01-01

The basis of Portland cement material reaction with uranium, the corrosion of uranium minerals in nature and the state of study on immobilization of uranium by Portland cement matrix material are introduced, and some considerations are presented. (authors)

Waste-form development for conversion to portland cement at Los Alamos National Laboratory (LANL) Technical Area 55 (TA-55)

International Nuclear Information System (INIS)

Veazey, G.W.; Schake, A.R.; Shalek, P.D.; Romero, D.A.; Smith, C.A.

1996-10-01

The process used at TA-55 to cement transuranic (TRU) waste has experienced several problems with the gypsum-based cement currently being used. Specifically, the waste form could not reliably pass the Waste Isolation Pilot Plant (WIPP) prohibition for free liquid and the Environmental Protection Agency (EPA)-Toxicity Characteristic Leaching Procedure (TCLP) standard for chromium. This report describes the project to develop a portland cement-based waste form that ensures compliance to these standards, as well as other performance standards consisting of homogeneous mixing, moderate hydration temperature, timely initial set, and structural durability. Testing was conducted using the two most common waste streams requiring cementation as of February 1994, lean residue (LR)- and oxalate filtrate (OX)-based evaporator bottoms (EV). A formulation with a pH of 10.3 to 12.1 and a minimum cement-to-liquid (C/L) ratio of 0.80 kg/l for OX-based EV and 0.94 kg/L for LR-based EV was found to pass the performance standards chosen for this project. The implementation of the portland process should result in a yearly cost savings for raw materials of approximately $27,000 over the gypsum process

Carlsbad Area Office strategic plan, March 1995. Revision 1

International Nuclear Information System (INIS)

1995-03-01

This edition of the Carlsbad Area Office Strategic Plan captures the US Department of Energy's (DOE's) new focus, and supersedes the edition issued previously (DOE, 1993a). This revision reflects: a revised strategy designed to demonstrate compliance with environmental regulations earlier than the previous course of action; and a focus on establishment of standardized transuranic waste characterization and acceptance criteria for disposal facilities

Formula of Moulding Sand, Bentonite and Portland Cement toImprove The Quality of Al-Si Cast Alloy

OpenAIRE

Andoko Andoko; Poppy Puspitasari; Avita Ayu Permanasari; Didin Zakaria Lubis

2017-01-01

A binder is any material used to strengthen the bonding of moulding sand grains. The primary function of the binder is to hold the moulding sand and other materialstogether to produce high-quality casts. In this study, there were four binder compositions being tested, i.e. 5% bentonite + 5% Portland cement, 4% bentonite + 6% Portland cement, 6% bentonite + 4% Portland cement, and 7% bentonite + 3% Portland cement. Each specimen was measured for its compressive strength, shear strength, tensil...

Development of Mix Design Method in Efforts to Increase Concrete Performance Using Portland Pozzolana Cement (PPC)

Science.gov (United States)

Krisnamurti; Soehardjono, A.; Zacoeb, A.; Wibowo, A.

2018-01-01

Earthquake disaster can cause infrastructure damage. Prevention of human casualties from disasters should do. Prevention efforts can do through improving the mechanical performance of building materials. To achieve high-performance concrete (HPC), usually used Ordinary Portland Cement (OPC). However, the most widely circulating cement types today are Portland Pozzolana Cement (PPC) or Portland Composite Cement (PCC). Therefore, the proportion of materials used in the HPC mix design needs to adjust to achieve the expected performance. This study aims to develop a concrete mix design method using PPC to fulfil the criteria of HPC. The study refers to the code/regulation of concrete mixtures that use OPC based on the results of laboratory testing. This research uses PPC material, gravel from Malang area, Lumajang sand, water, silica fume and superplasticizer of a polycarboxylate copolymer. The analyzed information includes the investigation results of aggregate properties, concrete mixed composition, water-binder ratio variation, specimen dimension, compressive strength and elasticity modulus of the specimen. The test results show that the concrete compressive strength achieves value between 25 MPa to 55 MPa. The mix design method that has developed can simplify the process of concrete mix design using PPC to achieve the certain desired performance of concrete.

Lift : Special Needs Transportation in Portland, Oregon

Science.gov (United States)

1978-01-01

The report covers Portland, Oregon's Special Needs Transportation (SNT) project - the Lift - during its first year of operation. The purposes of this UMTA Service and Methods Demonstration (SMD) is to: (1) test a transit operator's ability to provide...

Utilization of Iron Ore Tailings as Raw Material for Portland Cement Clinker Production

Directory of Open Access Journals (Sweden)

Li Luo

2016-01-01

Full Text Available The cement industry has for some time been seeking alternative raw material for the Portland cement clinker production. The aim of this research was to investigate the possibility of utilizing iron ore tailings (IOT to replace clay as alumina-silicate raw material for the production of Portland cement clinker. For this purpose, two kinds of clinkers were prepared: one was prepared by IOT; the other was prepared by clay as a reference. The reactivity and burnability of raw meal, mineralogical composition and physical properties of clinker, and hydration characteristic of cement were studied by burnability analysis, differential thermal analysis, X-ray diffraction, and hydration analysis. The results showed that the raw meal containing IOT had higher reactivity and burnability than the raw meal containing clay, and the use of IOT did not affect the formation of characteristic mineralogical phases of Portland cement clinker. Furthermore, the physical and mechanical performance of two cement clinkers were similar. In addition, the use of IOT was found to improve the grindability of clinker and lower the hydration heat of Portland cement. These findings suggest that IOT can replace the clay as alumina-silicate raw material for the preparation of Portland cement clinker.

Modelling porewater chemistry in hydrated Portland cement

International Nuclear Information System (INIS)

Berner, U.R.

1987-01-01

Extensive employment of concrete is foreseen in radioactive waste repositories. A prerequisite for modelling the interactions between concrete and formation waters is characterization of the concrete system. Available experimental data from high pressure squeezing of cement pore-water indicate that, besides the high pH due to alkali hydroxide dissolution, cement composition itself influences the solubility determining solid phases. A model which simulates the hydration of Portland cement assuming complete hydration of the main clinker minerals is presented. The model also includes parameters describing the reactions between the cement and blending agents. Comparison with measured pore-water data generally gives a consistent picture and, as expected, the model gives correct predictions for pure Portland cements. For blended cements, the required additional parameters can, to some extent, be derived from pore-water analysis. 14 references, 1 figure, 4 tables

Immobilization of citric acid solutions in portland cement; Imobilizacao de solucoes de acido citrico em cimento Portland

Energy Technology Data Exchange (ETDEWEB)

Lopes, Valdir M.; Rzyski, Barbara M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

1997-12-01

Decontamination processes by using citric acid on certain items used in the nuclear area, can result in large volumes of liquid wastes with low activity or effluents, contaminated with uranium and some elements dangerous to the environment. A great number of installations that have decontamination processes adopt the zero discharge philosophy. So, one of the forms to isolate the solutions is by reducing its volume through the evaporation process. The generated must can be neutralized and encapsulated or immobilized in Portland cement. This work propose a chemical technique to destroy the citric acid in the decontamination solutions instead of neutralization and, depending on the installation convenience, a direct cement immobilization of these solutions or of the evaporation mud. The results obtained in this work involve data about the workability, setting time and mechanical resistance, after 28 days of sealed cure, for samples with water-cement ratios of 4, 0.5 and 0.6, by weight. (author). 5 refs., 2 tabs.

Analysis on Zero Energy Consumption Strategy for Office Buildings Lighting in Lianyungang Area

Science.gov (United States)

Wu, Dongmei

2018-01-01

In recent years, the energy-saving environmental protection has aroused the people’s high concern, and set off a new application practice in China. By analyzing the advantages of the illumination condition in Lianyungang area and combining the content and form of office space, the author puts forward a series of ways and means of energy saving in office building lighting, in order to provide a way for reference to the goal of building Zero energy consumption in the office space environment under the background of green architecture.

Hospital waste ashes in Portland cement mortars

International Nuclear Information System (INIS)

Genazzini, C.; Zerbino, R.; Ronco, A.; Batic, O.; Giaccio, G.

2003-01-01

Nowadays, most concretes incorporate mineral additions such as pozzolans, fly ash, silica fume, blast furnace slag, and calcareous filler among others. Although the technological and economical benefits were the main reasons for the use of mineral additions, the prevention of environmental contamination by means of proper waste disposal becomes a priority. The chance of incorporating hospital waste ashes in Portland cement-based materials is presented here. Ash characterization was performed by chemical analysis, X-ray diffraction, radioactive material detection, and fineness and density tests. Conduction calorimetry and setting time tests were developed on pastes including ash contents from 0% to 100%. Mortars were prepared including ash contents up to 50% of cement. The results of setting time, temperature development, flexural and compressive strengths, water absorption, density, and leachability are analyzed. Results indicate that Portland cement systems could become an alternative for the disposal of this type of ashes

Radiopacity evaluation of Portland and MTA-based cements by digital radiographic system.

Science.gov (United States)

Borges, Alvaro Henrique; Pedro, Fabio Luiz Miranda; Semanoff-Segundo, Alex; Miranda, Carlos Eduardo Saraiva; Pécora, Jesus Djalma; Cruz Filho, Antônio Miranda

2011-01-01

The aim of the present study was to evaluate the radiopacity of Portland and MTA-based cements using the Digora TM digital radiographic system. The performed tests followed specification number 57 from the American National Standard Institute/American Dental Association (2000) for endodontic sealing materials. The materials were placed in 5 acrylic plates, especially designed for this experiment, along with a graduated aluminum stepwedge varying from 1 to 10 mm in thickness. The set was radiographed at a 30 cm focus-object distance and with 0.2 s exposure time. After the radiographs were taken, the optical laser readings of radiographs were performed by Digora TM system. Five radiographic density readings were performed for each studied material and for each step of the aluminum scale. White ProRoot MTA (155.99±8.04), gray ProRoot MTA (155.96±16.30) and MTA BIO (143.13±16.94) presented higher radiopacity values (pPortland (119.76±22.34), gray Portland (109.71±4.90) and white structural Portland (99.59±12.88) presented lower radiopacity values (pcements were the only materials presenting radiopacity within the ANSI/ADA specifications.

Partial replacement of Portland cement by red ceramic waste in mortars: study of pozzolanic activity; Substituicao parcial do cimento Portland por residuo de ceramica vermelha em argamassas: estudo da atividade pozolonica

Energy Technology Data Exchange (ETDEWEB)

Silva, A.R. da; Cabral, K.C.; Pinto, E.N. de M.G.l., E-mail: kleber.cabral@ufersa.edu.br [Universidade Federal Rural do Semi-Arido (UFERSA), Mossoro, RN (Brazil)

2016-07-01

The objective of this study is to analyze the pozzolanic activity of red ceramic residue on the partial replacement of Portland cement in mortars. The mortars were prepared by substituting 25% of the Portland cement for ground of ceramic residue with water cement’s factor of 0.48. The concrete used to construct the reference mortars and those with addiction was CPII-Z-32 (compound of Portland pozzolana cement). The chemical analysis and physical ceramic waste showed that this meets the requirements of NBR12653 (2014) for use as pozzolanic material. The pozzolanic activity index (IAP) obtained for the ceramic waste to twenty-eight days cure rate was 80.28%. (author)

A comparative evaluation of compressive strength of Portland cement with zinc oxide eugenol and Polymer-reinforced cement: an in vitro analysis.

Science.gov (United States)

Prakasam, S; Bharadwaj, Prakasam; Loganathan, S C; Prasanth, B Krishna

2014-01-01

The purpose of this study is to evaluate the ultimate compressive strength of 50% and 25% Portland cement mixed with Polymer-reinforced zinc oxide eugenol and zinc oxide eugenol cement after 1 hour, 24 hours, and 7 days. One hundred and eighty samples were selected. The samples were made cylindrical of size 6 × 8 mm and were divided into six groups as follows with each group consisting of 10 samples. Group 1: Polymer-reinforced zinc oxide eugenol with 50% Portland cement (PMZNPC 50%) Group 2: Polymer-reinforced zinc oxide eugenol with 25% Portland cement (PMZNPC 25%) Group 3: Polymer-reinforced zinc oxide eugenol with 0% Portland cement (PMZNPC 0%) Group 4: Zinc oxide eugenol with 50% Portland cement (ZNPC 50%) Group 5: Zinc oxide eugenol with 25% Portland cement (ZNPC 25%) Group 6: Zinc oxide eugenol with 0% Portland cement (ZNPC 0%) These samples were further subdivided based on time interval and were tested at 1 hour, 24 hours and at 7 th day. After each period of time all the specimens were tested by vertical CVR loaded frame with capacity of 5 tones/0473-10kan National Physical laboratory, New Delhi and the results were statistically analyzed using ANOVA and Scheffe test. Polymer-reinforced cement with 50% Portland cement, Zinc oxide with 50% Portland cement, Polymer-reinforced cement with 25% Portland cement and Zinc oxide with 25% Portland cement exhibited higher compressive strength when compared to Zinc oxide with 0% Portland cement and Polymer-reinforced cement with 0% Portland cement, at different periods of time. The difference between these two groups were statistically significant (P Portland cement in Zinc oxide eugenol and Polymer-modified zinc oxide cement can be used as core build up material and permanent filling material. It is concluded that 50% and 25% Portland cement in zinc oxide eugenol and polymer-modified zinc oxide eugenol results in higher compressive strength and hence can be used as permanent filling material and core built

Interfacial morphology and domain configurations in 0-3 PZT-Portland cement composites

International Nuclear Information System (INIS)

Jaitanong, N.; Zeng, H.R.; Li, G.R.; Yin, Q.R.; Vittayakorn, W.C.; Yimnirun, R.; Chaipanich, A.

2010-01-01

Cement-based piezoelectric composites have attracted great attention recently due to their promising applications as sensors in smart structures. Lead zirconate titanate (PZT) and Portland cement (PC) composite were fabricated using 60% of PZT by volume. Scanning Electron Microscope and piezoresponse force microscope were used to investigate the morphology and domain configurations at the interfacial zone of PZT-Portland cement composites. Angular PZT ceramic grains were found to bind well with the cement matrix. The submicro-scale domains were clearly observed by piezoresponse force microscope at the interfacial regions between the piezoelectric PZT phase and Portland cement phase, and are clearer than the images obtained for pure PZT. This is thought to be due to the applied internal stress of cement to the PZT ceramic particle which resulted to clearer images.

78 FR 4381 - Foreign-Trade Zone 45-Portland, Oregon; Application for Reorganization and Expansion Under...

Science.gov (United States)

2013-01-22

... following sites: Site 1 (1,830 acres)--Rivergate Industrial Park, Port Terminal Nos. 5 and 6, and the... Way and NE Alderwood Road, Portland; Site 3 (254 acres)--Portland Ship Repair Yard, 5555 N. Channel...

The Portland Basin: A (big) river runs through it

Science.gov (United States)

Evarts, Russell C.; O'Connor, Jim E.; Wells, Ray E.; Madin, Ian P.

2009-01-01

Metropolitan Portland, Oregon, USA, lies within a small Neogene to Holocene basin in the forearc of the Cascadia subduction system. Although the basin owes its existence and structural development to its convergent-margin tectonic setting, the stratigraphic architecture of basin-fill deposits chiefly reflects its physiographic position along the lower reaches of the continental-scale Columbia River system. As a result of this globally unique setting, the basin preserves a complex record of aggradation and incision in response to distant as well as local tectonic, volcanic, and climatic events. Voluminous flood basalts, continental and locally derived sediment and volcanic debris, and catastrophic flood deposits all accumulated in an area influenced by contemporaneous tectonic deformation and variations in regional and local base level.

76 FR 54206 - Gray Portland Cement and Clinker From Japan: Final Results of the Expedited Third Sunset Review...

Science.gov (United States)

2011-08-31

... DEPARTMENT OF COMMERCE International Trade Administration [A-588-815] Gray Portland Cement and... portland cement and clinker from Japan. As a result of this third sunset review, the Department finds that... initiation of the third sunset review of the antidumping duty order on gray portland cement and clinker from...

Chemical composition, radiopacity, and biocompatibility of Portland cement with bismuth oxide.

Science.gov (United States)

Hwang, Yun-Chan; Lee, Song-Hee; Hwang, In-Nam; Kang, In-Chol; Kim, Min-Seok; Kim, Sun-Hun; Son, Ho-Hyun; Oh, Won-Mann

2009-03-01

This study compared the chemical constitution, radiopacity, and biocompatibility of Portland cement containing bismuth oxide (experimental cement) with those of Portland cement and mineral trioxide aggregate (MTA). The chemical constitution of materials was determined by scanning electron microscopy and energy-dispersive X-ray analysis. The radiopacity of the materials was determined using the ISO/6876 method. The biocompatibility of the materials was tested by MTT assay and tissue reaction. The constitution of all materials was similar. However, the Portland cement and experimental cement were more irregular and had a larger particle size than MTA. The radiopacity of the experimental cement was similar to MTA. The MTT assay revealed MTA to have slightly higher cell viability than the other materials. However, there were no statistically significant differences between the materials, with the exception of MTA at 24 h. There was no significant difference in the tissue reaction between the experimental groups. These results suggest that the experimental cement may be used as a substitute for MTA.

Potencialidades da metacaolinita e do tijolo queimado moído como substitutos parciais do cimento Portland Potentialities of metakaolin and crushed waste calcined clay brick as partial replacement of Portland cement

Directory of Open Access Journals (Sweden)

João de Farias Filho

2000-12-01

Full Text Available Avalia-se, neste trabalho, a potencialidade do uso da metacaolinita e dos resíduos de produção de tijolos cerâmicos queimados finamente moídos, como substitutos parciais do cimento Portland. Os materiais foram caracterizados física, química e mineralogicamente, além de determinado o índice de atividade pozolânica com cimento Portland. A evolução da resistência a compressão e a flexão das argamassas foi avaliada até as idades de, respectivamente, 365 e 208 dias. As porcentagens de substituição do cimento Portland, em peso, pelos materiais pozolânicos, variaram de 20 a 50%, enquanto o fator água/cimento variou de 0,37 a 0,45. Os resultados obtidos indicaram que a metacaolinita e o tijolo moído queimado possuem elevada atividade pozolânica e que a resistência a compressão, aos 28 dias, das argamassas mistas, foi superior à das argamassas de cimento Portland para os níveis de substituição e fatores água/cimento estudados. Um modelo matemático para predição da resistência à compressão das argamassas mistas é proposto com base em um desenho fatorial de experimentos.This paper evaluates the potentiality of metakaolin and crushed waste fired clay brick as cement replacement materials. They were characterised physically, chemically and mineralogically and their activity with Portland cement determined. The influence of the partial replacement of Portland cement on the development of compressive and flexural strength was evaluated until the age of, respectively, 365 and 208 days. The percentage of cement replacement, in weight, ranged from 20 to 50%, whereas the water/cement ratio ranged from 0.37 to 0.45. The results obtained show that the metakaolin and crushed calcined clay brick presented a good pozolanic activity and that the compressive strength of the blended mortars after 28 days of cure was higher than that observed for the reference Portland cement for all levels of cement replacement and water/cement ratio. A

Optimization of calcium chloride content on bioactivity and mechanical properties of white Portland cement

International Nuclear Information System (INIS)

Torkittikul, Pincha; Chaipanich, Arnon

2012-01-01

This research investigates the optimization of calcium chloride content on the bioactivity and mechanical properties of white Portland cement. Calcium chloride was used as an addition of White Portland cement at 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10% by weight. Calcium chloride was dissolved in sterile distilled water and blended with White Portland cement using a water to cement ratio of 0.5. Analysis of the bioactivity and pH of white Portland cement pastes with calcium chloride added at various amounts was carried out in simulated body fluid. Setting time, density, compressive strength and volume of permeable voids were also investigated. The characteristics of cement pastes were examined by X-ray diffractometer and scanning electron microscope linked to an energy-dispersive X-ray analyzer. The result indicated that the addition of calcium chloride could accelerate the hydration of white Portland cement, resulting in a decrease in setting time and an increase in early strength of the pastes. The compressive strength of all cement pastes with added calcium chloride was higher than that of the pure cement paste, and the addition of calcium chloride at 8 wt.% led to achieving the highest strength. Furthermore, white Portland cement pastes both with and without calcium chloride showed well-established bioactivity with respect to the formation of a hydroxyapatite layer on the material within 7 days following immersion in simulated body fluid; white Portland cement paste with added 3%CaCl 2 exhibited the best bioactivity. - Highlights: ► Optimization CaCl 2 content on the bioactivity and mechanical properties. ► CaCl 2 was used as an addition at 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10% by weight. ► CaCl 2 resulted in a decrease in setting time and an increase in early strength. ► Addition of 3%CaCl 2 exhibited the optimum formation of hydroxyapatite.

Binding of chloride and alkalis in Portland cement systems

International Nuclear Information System (INIS)

Nielsen, Erik P.; Herfort, Duncan; Geiker, Mette R.

2005-01-01

A thermodynamic model for describing the binding of chloride and alkalis in hydrated Portland cement pastes has been developed. The model is based on the phase rule, which for cement pastes in aggressive marine environment predicts multivariant conditions, even at constant temperature and pressure. The effect of the chloride and alkalis has been quantified by experiments on cement pastes prepared from white Portland cements containing 4% and 12% C 3 A, and a grey Portland cement containing 7% C 3 A. One weight percent calcite was added to all cements. The pastes prepared at w/s ratio of 0.70 were stored in solutions of different Cl (CaCl 2 ) and Na (NaOH) concentrations. When equilibrium was reached, the mineralogy of the pastes was investigated by EDS analysis on the SEM. A well-defined distribution of chloride was found between the pore solution, the C-S-H phase, and an AFm solid solution phase consisting of Friedel's salt and monocarbonate. Partition coefficients varied as a function of iron and alkali contents. The lower content of alkalis in WPC results in higher chloride contents in the C-S-H phase. High alkali contents result in higher chloride concentrations in the pore solution

Contribución al estudio de los reacciones de hidratación del cemento portland por espectroscopia infrarroja II. Estudio de clínkeres y de cementos portland anhidros

Directory of Open Access Journals (Sweden)

Vázquez-Moreno, Tomás

1976-06-01

Full Text Available Not availableEn un artículo anterior (1 se dio cuenta de los trabajos realizados sobre la aplicación de la espectroscopia IR al estudio de las principales fases sintetizadas del clínker de cemento portland como fase previa al estudio de diversos clínkeres, obtenidos por nosotros en el laboratorio a partir de crudos industriales, y de distintos cementos portland comerciales anhidros.

Stabilization of chromium salt in ordinary portland cement

Indian Academy of Sciences (India)

Ordinary Portland cement (OPC) samples containing the chromium salt have been investigated using differential microcalorimetry, conductometry and Fourier transform infrared spectroscopic analysis. The effect of chromium on OPC hydration was evaluated by continuous observing of early hydration.

Evaluation of the strength and radiopacity of Portland cement with varying additions of bismuth oxide.

Science.gov (United States)

Saliba, E; Abbassi-Ghadi, S; Vowles, R; Camilleri, J; Hooper, S; Camilleri, J

2009-04-01

To study the effect of addition of various proportions of bismuth oxide on compressive strength and radiopacity of Portland cement. The compressive strength of white Portland cement and cement replaced with 10, 15, 20, 25 and 30% bismuth oxide was evaluated by testing cylinders 6 mm in diameter and 12 mm high. Twelve cylinders were tested for each material under study. The radiopacity of the cements tested was evaluated using an aluminium step-wedge and densitometer. The optical density was compared with the relevant thickness of aluminium (Al). Statistical analysis was performed using Analysis of Variance (ANOVA) with P = 0.05 and Tukey test to perform multiple comparison tests. Various additions of bismuth oxide had no significant effect on the strength of the material when compared with the unmodified Portland cement (P > 0.05). The radiopacity of the cements tested ranged from 2.02 mm Al for Portland cement to 9.79 mm Al for the highest bismuth replacement. Addition of bismuth oxide did not affect the compressive strength of Portland cement. All the bismuth oxide cement mixtures had radio-opacities higher than 3 mm thickness of aluminium.

EnviroAtlas - Portland, ME - Ecosystem Services by Block Group

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 146 block groups in Portland, Maine. Carbon attributes, temperature reduction,...

EnviroAtlas - Portland, OR - Ecosystem Services by Block Group

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 1176 block groups in Portland, Oregon. Carbon attributes, temperature reduction,...

Silica fume effect on retention characteristics of portland cement for uranium (VI)

International Nuclear Information System (INIS)

Tan Hongbin; Ma Xiaoling; Li Yuxiang

2005-01-01

With simulated groundwater as leachant, the retention capabilities of the portland cement, which contains different amount of silica fume, are investigated under 25 degree C and 42 days. The results indicate that silica fume can improve the retention capabilities of portland cement for uranium. When the cement contains 15% silica fume, the diffusion coefficient is 7 x 10 -3 cm 3 · -1 . It is only 5.5% of the cement without containing fume. (authors)

Food mirages: geographic and economic barriers to healthful food access in Portland, Oregon.

Science.gov (United States)

Breyer, Betsy; Voss-Andreae, Adriana

2013-11-01

This paper investigated the role of grocery store prices in structuring food access for low-income households in Portland, Oregon. We conducted a detailed healthful foods market basket survey and developed an index of store cost based on the USDA Thrifty Food Plan. Using this index, we estimated the difference in street-network distance between the nearest low-cost grocery store and the nearest grocery store irrespective of cost. Spatial regression of this metric in relation to income, poverty, and gentrification at the census tract scale lead to a new theory regarding food access in the urban landscape. Food deserts are sparse in Portland, but food mirages are abundant, particularly in gentrifying areas where poverty remains high. In a food mirage, grocery stores are plentiful but prices are beyond the means of low-income households, making them functionally equivalent to food deserts in that a long journey to obtain affordable, nutritious food is required in either case. Results suggested that evaluation of food environments should, at a minimum, consider both proximity and price in assessing healthy food access for low-income households. © 2013 Elsevier Ltd. All rights reserved.

Sealing ability of mineral trioxide aggregate and Portland cement for furcal perforation repair: a protein leakage study.

Science.gov (United States)

Shahi, Shahriar; Rahimi, Saeed; Hasan, Maryam; Shiezadeh, Vahab; Abdolrahimi, Majid

2009-12-01

The purpose of this study was to compare the sealing ability of gray mineral trioxide aggregate (GMTA), white MTA (WMTA), and both white and gray Portland cement as furcation perforation repair materials. A total of 120 human mandibular first molars were used. After root canal obturation and preparation of furcal perforations the specimens were randomly divided into four groups of 25 teeth each. In groups A, B, C, and D furcation perforations were filled with WMTA, GMTA, white Portland cement, and type II Portland cement, respectively. Ten teeth were used as positive controls with no filling materials in the perforations and 10 teeth with complete coverage with two layers of nail varnish were used as negative controls. A protein leakage model utilizing 22% bovine serum albumin (BSA) was used for evaluation. Leakage was noted when color conversion of the protein reagent was observed. The controls behaved as expected. Leakage was found in the samples from group A (WMTA), group B (GMTA), and in the two other groups (white and gray Portland cement). There were no statistically significant differences between GMTA and WMTA or white and gray Portland cement, but significant differences were observed between the MTA groups and the Portland cement groups. It was concluded that Portland cements have better sealing ability than MTA, and can be recommended for repair of furcation perforation if the present results are supported by other in vivo and in vitro studies.

Alkali binding in hydrated Portland cement paste

NARCIS (Netherlands)

Chen, Wei; Brouwers, Jos

2010-01-01

The alkali-binding capacity of C–S–H in hydrated Portland cement pastes is addressed in this study. The amount of bound alkalis in C–S–H is computed based on the alkali partition theories firstly proposed by Taylor (1987) and later further developed by Brouwers and Van Eijk (2003). Experimental data

Hydration of Blended Portland Cements Containing Calcium-Aluminosilicate Glass Powder and Limestone

DEFF Research Database (Denmark)

Moesgaard, M; Poulsen, Søren Lundsted; Herfort, D

2012-01-01

M. MOESGAARD, S.L. POULSEN, D. HERFORT, M. STEENBERG, L.F. KIRKEGAARD, J. SKIBSTED, Y. YUE, Hydration of Blended Portland Cements Containing Calcium-Aluminosilicate Glass Powder and Limestone, Journal of the American Ceramic Society 95, 403 – 409 (2012).......M. MOESGAARD, S.L. POULSEN, D. HERFORT, M. STEENBERG, L.F. KIRKEGAARD, J. SKIBSTED, Y. YUE, Hydration of Blended Portland Cements Containing Calcium-Aluminosilicate Glass Powder and Limestone, Journal of the American Ceramic Society 95, 403 – 409 (2012)....

Sulfatos en el cemento portland y su incidencia sobre el falso fraguado: Estado actual del conocimiento

Directory of Open Access Journals (Sweden)

de la Cruz, Ignacio

1983-12-01

Full Text Available A bibliographical study is carried out of the sulphates which may be present in the clinker and Portland cement, as likewise the effects of the aeration and temperature on the setting. This work is a prior phase of a wide experimental investigation carried out in the IETCC, on anomalies or setting and phenomena of "lumping" in Portland cement.

Se realiza un estudio bibliográfico de los sulfatos que pueden estar presentes en el clínker y cemento portland, así como de los efectos de la aireación y temperatura sobre el fraguado. Este trabajo es la fase previa de una amplia investigación experimental realizada en el IETCC, sobre anomalías de fraguado y fenómenos de "aterronamiento" en el cemento portland.

Physicochemical Properties of MTA and Portland Cement after Addition of Aloe Vera.

Science.gov (United States)

Henrique Borges, Alvaro; Aguirre Guedes, Orlando; Evaristo Ricci Volpato, Luiz; Siebert Filho, Gilberto; Meireles Borba, Alexandre; Zina, Omar; Piva, Evandro; Estrela, Carlos

2017-01-01

The aim of this in vitro study was to determine the liquid-powder ratio, setting time, solubility, dimensional change, pH, and radiopacity of white structural and non-structural Portland cement, ProRoot MTA and MTA Bio, associated with a 2% glycolic solution containing Aloe Vera, as vehicle. Five samples of each material were used for each test, according to the American National Standards Institute/American Dental Association (ANSI/ADA) specification No. 57. Statistical analyses were performed using ANOVA and Tukey's test at 5% significance. When sample distribution was not normal, non-parametric analysis of variance and the Kruskal-Wallis test were used ( α =0.05). No statistical differences were found in liquid-powder ratios among the tested materials. ProRoot MTA showed the longest setting time. Dimensional change values were acceptable in all groups. Also, no significant differences were found in pH values and pH was alkaline in all samples throughout the experiment. Mean radiopacity results obtained for white Portland cements did not meet ANSI/ADA requirements, and were significantly lower than those obtained for MTA-based cements. Finally, Portland cements showed significantly higher mean solubility values compared to the other samples. The physicochemical properties of the tested materials in association with Aloe Vera were compatible with ANSI/ADA requirements, except for the white Portland cements, which failed to meet the radiopacity specification.

Hydration characteristics of zirconium oxide replaced Portland cement for use as a root-end filling material.

Science.gov (United States)

Camilleri, J; Cutajar, A; Mallia, B

2011-08-01

Zirconium oxide can be added to dental materials rendering them sufficiently radiopaque. It can thus be used to replace the bismuth oxide in mineral trioxide aggregate (MTA). Replacement of Portland cement with 30% zirconium oxide mixed at a water/cement ratio of 0.3 resulted in a material with adequate physical properties. This study aimed at investigating the microstructure, pH and leaching in physiological solution of Portland cement replaced zirconium oxide at either water-powder or water-cement ratios of 0.3 for use as a root-end filling material. The hydration characteristics of the materials which exhibited optimal behavior were evaluated. Portland cement replaced by zirconium oxide in varying amounts ranging from 0 to 50% in increments of 10 was prepared and divided into two sets. One set was prepared at a constant water/cement ratio while the other set at a constant water/powder ratio of 0.3. Portland cement and MTA were used as controls. The materials were analyzed under the scanning electron microscope (SEM) and the hydration products were determined. X-ray energy dispersive analysis (EDX) was used to analyze the elemental composition of the hydration products. The pH and the amount of leachate in Hank's balanced salt solution (HBSS) were evaluated. A material that had optimal properties that satisfied set criteria and could replace MTA was selected. The microstructure of the prototype material and Portland cement used as a control was assessed after 30 days using SEM and atomic ratio diagrams of Al/Ca versus Si/Ca and S/Ca versus Al/Ca were plotted. The hydration products of Portland cement replaced with 30% zirconium oxide mixed at water/cement ratio of 0.3 were calcium silicate hydrate, calcium hydroxide and minimal amounts of ettringite and monosulphate. The calcium hydroxide leached in HBSS solution resulted in an increase in the pH value. The zirconium oxide acted as inert filler and exhibited no reaction with the hydration by-products of Portland

Administrative Strategies of School Management Effectiveness, Buriram Office of Primary Educational Service Area 4

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Khanintipparat Prommaraj

2017-09-01

Full Text Available The objectives of this research were 1 to study the current and the expected Conditions of school management effectiveness, Buriram Office of Primary Educational Service Area 4 and 2 to construct administrative strategies of such schools. Eighty of directors, board chairpersons, teachers and parents were sampled. The instruments for data collection were 5-level rating scale questionnaires with the IOC value between 0.60–1.00 and the reliability value of 0.88 and in-depth interview forms. Quantitative data were analyzed by computer and qualitative data were inductively analyzed. The findings were as follows: 1. The current conditions school management effectiveness, Buriram Office of Primary Educational Service Area 4 was moderate while the expected conditions was high. By means of expected condition can be listed from high to low were atmosphere and environment management, administration, learning management and participation. 2. Strategies for effective management of schools under the Office of Educational Service Area 4 consists of four elementary Bachelor’s strategy is the first strategic development, management efficiency. 2 learners develop strategies to meet educational standards. Strategy 3: create an atmosphere and environment conducive to development. Strategy 4 and the joint cooperation of network.

Presence of arsenic in different types of MTA and white and gray Portland cement.

Science.gov (United States)

Monteiro Bramante, Clóvis; Demarchi, Ana Claudia Cardoso Oliveira; de Moraes, Ivaldo Gomes; Bernadineli, Norberti; Garcia, Roberto Brandão; Spångberg, Lars S W; Duarte, Marco Antonio Hungaro

2008-12-01

The presence of arsenic in various types of mineral trioxide aggregate (MTA) and Portland cements were evaluated to verify if they comply with the ISO-recommended limit for water-based cements of 2 mg arsenic/kg material. An amount of 5 mL of hydrochloric acid was added to 2 g each of MTA and Portland cement to be analyzed. After 15 minutes, the material was filtered and the volume of supernatant was diluted with reagent-grade water up to 40 mL. Atomic absorption spectrophotometry readings were performed in triplicate. The following mean values were obtained: CPM (Egeo, Buenos Aires, Argentina) 11.06 mg/kg; CPM sealer (Egeo) 10.30 mg/kg; MTA-Obtura (Angelus, Londrina, PR, Brazil) 0.39 mg/kg; Experimental MTA: 10.30 mg/kg; White MTA-Angelus (Angelus) 1.03 mg/kg; Gray MTA-Angelus (Angelus) 5.91 mg/kg; ProRoot-MTA (Dentsply/Tulsa Dental Specialties, Tulsa, OK) 5.25 mg/kg; Gray Portland cement (Votorantim Cimentos, Cubatão, SP, Brazil): 34.27 mg/kg; and White Portland cement (Cimento Rio Branco, Rio de Janeiro, RJ, Brazil) 0.52 mg/kg. All tested materials presented arsenic in their composition. The form of arsenic was not analyzed nor the toxicity of the arsenic found. Only MTA-Obtura, White MTA-Angelus, and White Portland cement presented arsenic levels below the limit set in the ISO 9917-1 standard.

PULPOTOMIES WITH PORTLAND CEMENT IN HUMAN PRIMARY MOLARS

Science.gov (United States)

Conti, Taísa Regina; Sakai, Vivien Thiemy; Fornetti, Ana Paula Camolese; Moretti, Ana Beatriz Silveira; Oliveira, Thais Marchini; Lourenço, Natalino; Machado, Maria Aparecida Andrade Moreira; Abdo, Ruy Cesar Camargo

2009-01-01

Two clinical cases in which Portland cement (PC) was applied as a medicament after pulpotomy of mandibular primary molars in children are presented. Pulpotomy using PC was carried out in two mandibular first molars and one mandibular second molar, which were further followed-up. At the 3, 6 and 12-month follow-up appointments, clinical and radiographic examinations of the pulpotomized teeth and their periradicular area revealed that the treatments were successful in maintaining the teeth asymptomatic and preserving pulpal vitality. Additionally, the formation of a dentin bridge immediately below the PC could be observed in the three molars treated. PC may be considered as an effective alternative for primary molar pulpotomies, at least in a short-term period. Randomized clinical trials with human teeth are required in order to determine the suitability of PC before unlimited clinical use can be recommended. PMID:19148409

Research on the nanolevel influence of surfactants on structure formation of the hydrated Portland cement compositions

Directory of Open Access Journals (Sweden)

Guryanov Alexander

2016-01-01

Full Text Available The research of the structure formation process on a nanolevel of the samples of hydrated Portland cement compositions containing the modifying additives has been conducted with the help of small angle neutron scattering method. Carbonate and aluminum alkaline slimes as well as the complex additives containing surfactants were used as additives. The influence of slimes and surfactants on structural parameters change of Portland cement compositions of the average size of the disseminating objects, fractal dimension samples is considered. These Portland cement compositions are shown to be fractal clusters.

Pulp tissue response to Portland cement associated with different radio pacifying agents on pulpotomy of human primary molars.

Science.gov (United States)

Marques, N; Lourenço Neto, N; Fernandes, A P; Rodini, C; Hungaro Duarte, M; Rios, D; Machado, M A; Oliveira, T

2015-12-01

The objective of this research was to evaluate the response of Portland cement associated with different radio pacifying agents on pulp treatment of human primary teeth by clinical and radiographic exams and microscopic analysis. Thirty mandibular primary molars were randomly divided into the following groups: Group I - Portland cement; Group II - Portland cement with iodoform (Portland cement + CHI3 ); Group III - Portland cement with zirconium oxide (Portland cement + ZrO2 ); and treated by pulpotomy technique (removal of a portion of the pulp aiming to maintain the vitally of the remaining radicular pulp tissue using a therapeutic dressing). Clinical and radiographic evaluations were recorded at 6, 12 and 24 months follow-up. The teeth at the regular exfoliation period were extracted and processed for histological analysis. Data were tested using statistical analysis with a significance level of 5%. The microscopic findings were descriptively analysed. All treated teeth were clinically and radiographically successful at follow-up appointments. The microscopic analysis revealed positive response to pulp repair with hard tissue barrier formation and pulp calcification in the remaining roots of all available teeth. The findings of this study suggest that primary teeth pulp tissue exhibited satisfactory biological response to Portland cement associated with radio pacifying agents. However, further studies with long-term follow-up are needed to determine the safe clinical indication of this alternative material for pulp therapy of primary teeth. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

Partial replacement of Portland cement by red ceramic waste in mortars: study of pozzolanic activity

International Nuclear Information System (INIS)

Silva, A.R. da; Cabral, K.C.; Pinto, E.N. de M.G.l.

2016-01-01

The objective of this study is to analyze the pozzolanic activity of red ceramic residue on the partial replacement of Portland cement in mortars. The mortars were prepared by substituting 25% of the Portland cement for ground of ceramic residue with water cement’s factor of 0.48. The concrete used to construct the reference mortars and those with addiction was CPII-Z-32 (compound of Portland pozzolana cement). The chemical analysis and physical ceramic waste showed that this meets the requirements of NBR12653 (2014) for use as pozzolanic material. The pozzolanic activity index (IAP) obtained for the ceramic waste to twenty-eight days cure rate was 80.28%. (author)

Alternatieven voor Portland Cement in ontwikkelingslanden onderzocht : continue-kalkoven maakt toepassing van kalk pozzolaan cement mogelijk

NARCIS (Netherlands)

Egmond - de Wilde De Ligny, van E.L.C.; Jongsma, Ivo

1995-01-01

In de discussie over bouwmaterialen in ontwikkelingslanden wordt vaak gepleit voor alternatieven voor Portland Cement. De productie van Portland Cement is kapitaal- en energie-intensief en draagt weinig bij aan de ontwikkeling van deze landen. De klein schaliger productie van alternatieven voor

Developing an Implementation Guideline to International Standard School for Schools under Secondary Educational Service Area Office 25

Directory of Open Access Journals (Sweden)

Worawut Poltree

2017-09-01

Full Text Available The objectives of developing an implementation guideline to international standard school for schools under secondary educational service area office 25 were ; 1 to study present and problem an implementation guideline to international standard school for schools under secondary educational service area office 25 and 2 to develop an implementation guideline to international standard school for schools under secondary educational service area office 25. There were 68 samples ; administrators, deputy administrators, head of quality management systems, and academic teachers by purposive sampling. The tools used to collect the data were the five level scale questionnaire and structured interviews. Data were analyzed using mean, standard deviation, and descriptive analysis. The researcher set the research by 2 phase. The first phase educated present and problem an implementation guideline to international standard school for schools under secondary educational service area office 25. The research was assessed feasibility of developing an implementation guideline to international standard school for schools under secondary educational service area office 25 by 5 experts. The research results were: 1. The present and problem an implementation guideline to international standard school for schools under secondary educational service area office 25 found that the overall present were at the high level and each one was at the high level. The overall problem were at the low and each one was at the moderate 2 aspects ; The leadership and the focus on personnel. Then it was at the low level. 2. Developing an implementation guideline to international standard school for schools under secondary educational service area office 25 found that 1 the leadership had set with the vision, values, performance of the school’s senior leadership, including good governance of the school, implementation of the ethics law, and responsibility for the community, 2 strategic

Exploratory characterization of volcanic ash sourced from Uganda as a pozzolanic material in portland cement concrete

NARCIS (Netherlands)

Buregyeya, A.; Quercia Bianchi, G.; Spiesz, P.R.; Florea, M.V.A.; Nassingwa, R.; Uzoegbo, H.C.; Schmidt, W.

2013-01-01

The need for alternative cementing materials to ordinary Portland cement (OPC) has promoted characterization research on pozzolana as an important ingredient in cement production. In Uganda, natural pozzolana application in cement production is done by only two producers of Portland cement and at a

Physical and Thermodynamical Properties of Water Phases in Hardening Portland Cement Systems

DEFF Research Database (Denmark)

Hansen, T. Bæk

The present study is devoted to the description of water phases in hardening portland cement paste systems containing a significant amount of micro-filler and having a low to moderate water/powder ratio. Emphasis has been placed on the early stages of the hardening process.......The present study is devoted to the description of water phases in hardening portland cement paste systems containing a significant amount of micro-filler and having a low to moderate water/powder ratio. Emphasis has been placed on the early stages of the hardening process....

Structure investigations on Portland cement paste by small angle neutron scattering

International Nuclear Information System (INIS)

Dragolici, C.A.; Lin, A.

2004-01-01

Hydrated Portland cement is a very complex material. Cement paste consists of many crystalline and non-crystalline phases in various ranges of sizes (μm and nm scale). The crystalline phases are embedded in amorphous phases of hydration products. We investigated the structural changes of hydrating phases in a time interval up to 18 days, at Budapest Neutron Center's SANS spectrometer. The small angle neutron scattering of Portland cements prepared with a various water-to-cement ratios, gave us information about the microstructure changes in the material. Fractals were a suitable way for structure modelling. Some comments regarding the opportunity of using the most common models are pointed out. (authors)

Reaction of rat subcutaneous tissue to mineral trioxide aggregate and Portland cement: a secondary level biocompatibility test.

Science.gov (United States)

Karanth, P; Manjunath, M K; Kuriakose, E S

2013-01-01

This secondary-level animal study was conducted to assess and compare the subcutaneous tissue reaction to implantation of white mineral trioxide aggregate (MTA) and white Portland cement. Polyethylene tubes filled with either freshly mixed white MTA (Group I) or white Portland cement (Group II) were implanted subcutaneously into 12 Wistar Albino rats. Each animal also received an empty polyethylene tube as the control (Group III). After 7, 14, 21 and 30 days, the implants, together with surrounding tissues were excised. Two pathologists blinded to the experimental procedure, evaluated sections taken from the biopsy specimens for the severity of the inflammatory response, calcification and the presence and thickness of fibrous capsule surrounding the implant. Statistical analysis was performed using the Cross-tabs procedure, Univariate analysis of the variance two-way and the Pearson product moment correlation to assess inter-rater variability between the two evaluators. At 7 days, there was no significant difference in the severity of inflammation between the control group, white MTA, and white Portland cement groups. In the 14 day, 21 day and 30 day test periods, control group had significantly less inflammation than white MTA and white Portland cement. There was no significant difference in the grading of inflammation between white MTA and white Portland cement. All materials exhibited thick capsule at 7 days and thin capsule by 30 days. Both white MTA and white Portland cement were not completely non-irritating at the end of 30 days as evidenced by the presence of mild inflammation. However, the presence of a thin capsule around the materials, similar to the control group, indicates good tissue tolerance. White MTA and white Portland cement seem to be materials of comparable biocompatibility.

Immobilization of citric acid solutions in portland cement

International Nuclear Information System (INIS)

Lopes, Valdir M.; Rzyski, Barbara M.

1997-01-01

Decontamination processes by using citric acid on certain items used in the nuclear area, can result in large volumes of liquid wastes with low activity or effluents, contaminated with uranium and some elements dangerous to the environment. A great number of installations that have decontamination processes adopt the zero discharge philosophy. So, one of the forms to isolate the solutions is by reducing its volume through the evaporation process. The generated must can be neutralized and encapsulated or immobilized in Portland cement. This work propose a chemical technique to destroy the citric acid in the decontamination solutions instead of neutralization and, depending on the installation convenience, a direct cement immobilization of these solutions or of the evaporation mud. The results obtained in this work involve data about the workability, setting time and mechanical resistance, after 28 days of sealed cure, for samples with water-cement ratios of 4, 0.5 and 0.6, by weight. (author). 5 refs., 2 tabs

EnviroAtlas - Portland, ME - BenMAP Results by Block Group

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset demonstrates the effect of changes in pollution concentration on local populations in 146 block groups in Portland, Maine. The US EPA's...

EnviroAtlas - Portland, OR - BenMAP Results by Block Group

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset demonstrates the effect of changes in pollution concentration on local populations in 1176 block groups in Portland, Oregon. The US EPA's...

Assessment of Pollution Potentialities of some Portland Cement ...

African Journals Online (AJOL)

Chemical analysis of some Portland cement commonly used in Nigeria was carried out. All the cement studies were found to be good for concrete work especially where no special property is required. The concentration levels of heavy metals in all the cement samples were above the tolerance limit and therefore need to ...

Winter Storm Jupiter of January 2017: Meteorological Drivers, Synoptic Evolution, and Climate Change Considerations in Portland, Oregon

Science.gov (United States)

Dean, S.; Loikith, P. C.

2017-12-01

Although the Pacific Northwest has some of the highest wintertime precipitation in the United States, most urban areas receive little in the way of snow. While 37 inches of wintertime rain fall in Portland on average annually, the city only receives four inches of snow on average. Although wintertime extreme snowstorm events are rare in Portland, in the last century they have occurred about once every ten years. On January 10-12th, 2017, winter storm Jupiter brought 11 inches of snow to downtown Portland within a 12-hour period, making it the largest snowstorm for the city in twenty years. The city declared a state of emergency, over 30,000 citizens lost power, and thousands of businesses were forced to shut down. The anomalously cold air and high amounts of snowfall in a short amount of time made the storm different from others in recent years. This study aims to discover the meteorological drivers behind the January 2017 snowstorm in Portland, Oregon. We also aim to understand how this storm compared with other local storms in the past, and assess the likelihood of a similar event occurring in the future. To do this, reanalysis data were used to display the synoptic evolution of the January 2017 storm. We compared this storm with two other extreme snowfall events from December 2008 and January 1980, assessing meteorological similarities and differences between storms. Results show that the 2017 event was associated with a slow moving, strong low-pressure system accompanied by a 500 hPa trough. These large-scale features helped drive slow moving, locally heavy snow bands over the city of Portland. At the same time, an unusually strong Arctic high-pressure system moved into the interior Pacific Northwest allowing for strong cold air advection west through the Cascade Mountain Range and Columbia River Gorge. Temperature trends show warming of 1-2 °C in the Pacific Northwest since the middle of the last century. Because of this, uncertainty associated with

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

Science.gov (United States)

2011-03-07

... Production Act of 1993--Portland Cement Association Notice is hereby given that, on February 02, 2011... seq. (``the Act''), Portland Cement Association (``PCA'') has filed written notifications..., Praxair, Danbury, CT; Metso Minerals, York, PA; Lehigh Cement Company LLC, Allentown, PA; Lehigh Northwest...

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

Science.gov (United States)

2011-06-13

... Production Act of 1993; Portland Cement Association Notice is hereby given that, on May 12, 2011, pursuant to.... (``the Act''), Portland Cement Association (``PCA'') has filed written notifications simultaneously with... plaintiffs to actual damages under specified circumstances. Specifically, Drake Cement, LLC, Scottsdale, AZ...

NOAA Office for Coastal Management Coastal Inundation Digital Elevation Model: Gray/Portland Weather Forecast Office (GYX WFO) - Maine and New Hampshire

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These data were created as part of the National Oceanic and Atmospheric Administration Office for Coastal Management's efforts to create an online mapping viewer...

Structure investigations on Portland cement paste by small angle neutron scattering

International Nuclear Information System (INIS)

Dragolici, C. A.; Len, A.

2003-01-01

Portland cement pastes consist of many crystalline and non-crystalline phases in various ranges of sizes (nm and mm scale). The crystalline phases are embedded in amorphous phases of the hydration products. We investigated the structural changes of hydrating phases in the time interval of 1-30 days at Budapest Neutron Center's SANS diffractometer. The small angle neutron scattering of Portland cements prepared with a water-to-cement ratio from 0,3 to 0,8 gave us information about the microstructure changes in the material. Fractals were a suitable way for structure modelling. The variation of fractals size depending on the preparation-to-measurement time interval and water-to-cement ratio could be observed. (authors)

The Social Acceptance of Community Solar: A Portland Case Study

Science.gov (United States)

Weaver, Anne

Community solar is a renewable energy practice that's been adopted by multiple U.S. states and is being considered by many more, including the state of Oregon. A recent senate bill in Oregon, called the "Clean Electricity and Coal Transition Plan", includes a provision that directs the Oregon Public Utility Commission to establish a community solar program for investor-owned utilities by late 2017. Thus, energy consumers in Portland will be offered participation in community solar projects in the near future. Community solar is a mechanism that allows ratepayers to experience both the costs and benefits of solar energy while also helping to offset the proportion of fossil-fuel generated electricity in utility grids, thus aiding climate change mitigation. For community solar to achieve market success in the residential sector of Portland, ratepayers of investor-owned utilities must socially accept this energy practice. The aim of this study was to forecast the potential social acceptance of community solar among Portland residents by measuring willingness to participate in these projects. Additionally, consumer characteristics, attitudes, awareness, and knowledge were captured to assess the influence of these factors on intent to enroll in community solar. The theory of planned behavior, as well as the social acceptance, diffusion of innovation, and dual-interest theories were frameworks used to inform the analysis of community solar adoption. These research objectives were addressed through a mixed-mode survey of Portland residents, using a stratified random sample of Portland neighborhoods to acquire a gradient of demographics. 330 questionnaires were completed, yielding a 34.2% response rate. Descriptive statistics, binomial logistic regression models, and mean willingness to pay were the analyses conducted to measure the influence of project factors and demographic characteristics on likelihood of community solar participation. Roughly 60% of respondents

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

Science.gov (United States)

2010-01-27

... Production Act of 1993--Portland Cement Association Notice is hereby given that, on December 14, 2009... seq. (``the Act''), Portland Cement Association (``PCA'') has filed written notifications... Cement, Hannibal, MO has been added as a party to this venture. Also, the following parties have...

Nanotechnology-Based Performance Improvements For Portland Cement Concrete - Phase I

Science.gov (United States)

2012-08-16

A fundamental understanding of the nano-structure of Portland cement concrete (PCC) is the key to realizing significant breakthroughs regarding high performance and susta : (MBTC 2095/3004) using molecular dynamics (MD) provided new understanding of ...

Study of the bismuth oxide concentration required to provide Portland cement with adequate radiopacity for endodontic use.

Science.gov (United States)

Bueno, Carlos Eduardo da Silveira; Zeferino, Eduardo Gregatto; Manhães, Luiz Roberto Coutinho; Rocha, Daniel Guimarães Pedro; Cunha, Rodrigo Sanches; De Martin, Alexandre Sigrist

2009-01-01

The purpose of this study was to determine the ideal concentration of bismuth oxide in white Portland cement to provide it with sufficient radiopacity for use as an endodontic material (ADA specification #57). 2-mm thick standardized test specimens of white MTA and of white Portland cement, as controls, and of white Portland cement with the experimental addition of 5%, 10%, 15%, 20%, 25% or 30% of bismuth oxide were radiographed and compared with various thicknesses of pure aluminum, using optic density to determine the observed grayscale levels of radiopacity in a scale ranging from 0 to 255. The data was submitted to ANOVA (pcement with 0%, 5%, 10%, 15%, 20%, 25% and 30% of bismuth oxide presented mean readings of 63.3, 95.7, 110.7, 142.7, 151.3, 161.0 and 180.0 respectively. MTA presented a mean reading of 157.3. The readings of MTA and white Portland cement with 15% bismuth oxide did not differ significantly from the reading observed for a thickness of 4 mm of aluminum (145.3), which is considered ideal for a test specimen by ADA specification #57 (2 mm above the thickness of the test specimen). White MTA and white Portland cement with 15% bismuth oxide presented the radiopacity required for an endodontic cement.

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

Science.gov (United States)

2012-02-03

... Production Act of 1993--Portland Cement Association Notice is hereby given that, on January 6, 2012, pursuant... seq. (``the Act''), Portland Cement Association (``PCA'') has filed written notifications..., Newark, DE, has been added as a party to this venture. Also, Texas-Lehigh Cement Company, Buda, TX...

Toxicity and Histopathological Effects of Portland Cement Powder in ...

African Journals Online (AJOL)

Hepatic lesions in the liver tissues of fish exposed to Portland cement powder in solution were characterized by degeneration of hepatocyte, vascuolization of cell cytoplasm, fatty degeneration and hypertrophy of hepatocytes. Histological comparison of tissues indicated that most damage occurred in the gill rather than in ...

Utilization of steel slag for Portland cement clinker production.

Science.gov (United States)

Tsakiridis, P E; Papadimitriou, G D; Tsivilis, S; Koroneos, C

2008-04-01

The aim of the present research work is to investigate the possibility of adding steel slag, a by-product of the conversion of iron to steel process, in the raw meal for the production of Portland cement clinker. Two samples of raw meals were prepared, one with ordinary raw materials, as a reference sample ((PC)(Ref)), and another with 10.5% steel slag ((PC)(S/S)). Both raw meals were sintered at 1450 degrees C. The results of chemical and mineralogical analyses as well as the microscopic examination showed that the use of the steel slag did not affect the mineralogical characteristics of the so produced Portland cement clinker. Furthermore, both clinkers were tested by determining the grindability, setting times, compressive strengths and soundness. The hydration products were examined by XRD analysis at 2, 7, 28 and 90 days. The results of the physico-mechanical tests showed that the addition of the steel slag did not negatively affect the quality of the produced cement.

Radiopacity and histological assessment of Portland cement plus bismuth oxide.

Science.gov (United States)

Coutinho-Filho, Tauby; De-Deus, Gustavo; Klein, Leila; Manera, Gisele; Peixoto, Carla; Gurgel-Filho, Eduardo Diogo

2008-12-01

The present study evaluated the subcutaneous connective tissue reactions and the radiopacity of MTA, Portland cement (PC), and Portland cement plus bismuth oxide (BO). Forty rats were divided into 5 groups (n = 8 per group): A1: Control (empty capsule); A2: Pro-Root MTA; A3: PC; A4: PC + BO 1:1; and A5: PC + BO 2:1. Polyethylene tubes were filled with the test materials and standardized radiographic images were taken. Histological evaluation was done after 7 and 60 days. Student t test and Fisher's test were used in the statistical analysis (P A4 > A5 > A3. No differences were found for the tissue response in the 2 experimental periods. A positive correlation between BO concentration and radiopacity of PC was determined. The histological evaluation suggests that all studied materials were biocompatible at 7 and 60 days.

Comparative study of the properties of ordinary portland cement ...

African Journals Online (AJOL)

The study explored metakaolin as alternative material to cement. It compares the properties of Ordinary Portland Cement (OPC) concrete and binary concrete containing metakaolin as partial replacement of OPC. Two set of concrete samples; one with 10% Metakaolin (MK) replacing OPC by weight, and the other without ...

Developing the Conflicts Management Model for School Administrators of Secondary School under the Office of Secondary Educational Service Area 20

Directory of Open Access Journals (Sweden)

Pornpan Ruangrit

2017-09-01

Full Text Available This study aimed to 1 investigate the cause of conflict which in the secondary schools under the Secondary School under the Office of Secondary Educational Service Area 20, 2 study the conflict management method which administrators applied in Secondary School under the Office of Secondary Educational Service Area 20, and 3 develop conflict management model for Secondary School under the Office of Secondary Educational Service Area 20. The participants were 115 school administrators (44 school directors and 71 deputy directors which were selected by random sampling technique. The research instruments included a questionnaire, which reliability value was 0.97, and an interview schedule that were administered to the respondents. The data were analyzed by frequency, percentage, mean, and standard deviation. The result of the study showed that: 1. the causes of conflict in Secondary School under the Office of Secondary Educational Service Area 20 in overall was at the high level with the mean of 4.21, the internal conflict was at the high level with the mean of 4.22, and the external conflict was at the high level with the mean of 4.19. 2. Overall, conflict management method used by administrators in Secondary School under the Office of Secondary Educational Service Area 20was at a high level. Considering each aspect, the compromising method was the highest level at 4.48. 3. Developing conflict management model in Secondary School under the Office of Secondary Educational Service Area 20 were the collaboration and making understand method. These should be used for conflict management to achieve the success and to reach the standard which including responsibility, accountability, equality, teamwork, and communication competence.

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

... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-461 (Third Review)] 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 States International...

Ettringite and C-S-H Portland cement phases for waste ion immobilization: A review

International Nuclear Information System (INIS)

Gougar, M.L.D.; Scheetz, B.E.; Roy, D.M.

1996-01-01

The formation, structure and chemistry of the ettringite and C-S-H phases of Portland cement have been reviewed as they relate to waste ion immobilization. The purpose of this review was to investigate the use of Portland cement as a host for priority metallic pollutants as identified by the Environmental Protection Agency and as a host for radioactive waste ions as identified in 40 CFR 191. Ettringite acts as host to a number of these ions in both the columnar and channel sections of the crystal structure. Substitutions have been made at the calcium, aluminum, hydroxide and sulfate sites. C-S-H also hosts a number of the waste species in both ionic and salt form. Immobilization mechanisms for C-S-H include sorption, phase mixing and substitution. The following ions have not apparently been reported as specifically immobilized by one of these phases: Ag, Am, Np, Pu, Ra, Tc, Th and Sn; however, some of these ions are immobilized by Portland cement

Una nota sobre los Hormigones de Cemento Portland (HCP y Hormigones de Cemento Portland con Adiciones (HCPA

Directory of Open Access Journals (Sweden)

Talero Morales, Rafael

1993-09-01

Full Text Available El hombre contemporáneo ha dividido el proceso evolutivo de la humanidad en macroperíodos de tiempo relacionados con avances significativos obtenidos en el campo de los materiales. Así se define la edad de piedra, bronce, hierro, cobre, etc. Y siguiendo esta tendencia, probablemente las generaciones futuras podrán hablar de esta época como la "edad del hormigón" y mostrar los monumentales vestigios que, en su mayor parte, se han construido con hormigón de cemento portland.

Portland cement hydration in the presence of admixtures: black gram pulse and superplasticizer

Directory of Open Access Journals (Sweden)

Viveka Nand Dwivedi

2008-12-01

Full Text Available Effect of admixtures such as black gram pulse (BGP and sulfonated naphthalene based superplasticizer (SP on the hydration of Portland cement has been studied. The hydration characteristics of OPC in the presence of BGP and SP were studied with the help of non evaporable water content determinations, calorimetric method, Mössbauer spectroscopic and atomic force microscopic techniques. Results have shown that both BGP and SP get adsorbed at the surface of cement and its hydration products. The hydration of Portland cement is retarded in the presence of both the admixtures and nanosize hydration products are formed.

Properties of Portland-Composite Cements with metakaolin: Commercial and manufactured by Thermal Activation of Serbian Kaolin Clay

Directory of Open Access Journals (Sweden)

Mitrovic A.

2012-09-01

Full Text Available Portland-composite cements (CEM II were prepared with addition of 5 to 35% of metakaolin (MK, manufactured by thermal activation/calcination of Serbian kaolin clay, and commercial matakaolin (CMK. Performance of the composite cements was evaluated, through the setting time (initial and final, compressive strengths (for ages 2, 7, 28, 90 and 180 days and soundness, and compared with control cement (Portland cement – CEM I. Setting time (initial and final is accelerated in Portlandcomposite cements, for both metakaolins used. The acceleration is higher in cement with addition of commercial metakaolin. Lower compressive strength is obtained after 2 days of curing for all Portland-composite cements in comparison with control cement, since pozzolanic reaction still did not show its effect. After 7 days, pozzolanic reaction show its effect, manifested as compressive strength increase of Portland-composite cements with addition of up to 35% of CMK, and 25% in the case of cements with MK. After 28 days compressive strength was higher than that for control cement for cements prepared with addition of CMK, and with addition of up to 25% MK. After 90 days increased compressive strength was noticed with addition of 10 - 20% of CMK, and with 10 and 15% of MK, while after 180 days addition of both metakaolins influences compressive strength decrease. The results of the soundness, 0.5 mm for CEM I, and 1.0 mm in most Portland-composite cements indicate soundness increase with addition of metakaolins. Generally, better performance of Portland-composite cements was obtained with addition of commercial metakaolin, which may be attributed to the differences in the pozzolanic activity of the applied metakaolins, 20.5 MPa and 14.9 MPa for CMK and MK, respectively. By our previous findings pozzolanic activity of the thermally activated clay may be increased by subsequent milling of the metakaolin manufactured by thermal activation process.

Experimental and modeling study of Portland cement paste degradation in boric acid

International Nuclear Information System (INIS)

Benakli, A.; Chomat, L.; Le Bescop, P.; Wall, J.

2015-01-01

In the framework of Spent Fuel Pools (SFP) lifetime studies, an investigation of the Portland cement degradation in boric acid has been requested by the Electric Power Research Institute. The main goal of this study is to identify the physico-chemical degradation mechanisms involved in boric acid media. Both experimental and modeling approaches are considered. Concerning degradation experiments, sample of cement paste are immersed during three and nine months in a boric acid solution at 2400 ppm that is periodically renewed. Boric acid concentration has been chosen to be representative of SFP solution. Results will be confronted with reactive transport numerical calculations performed by the reactive transport code HYTEC associated with a dedicated extended database called Thermoddem. The analysis of degradation solution revealed a main ions release mechanism driven by diffusion especially for calcium, nitrate, sodium and sulfate. Leaching behavior of magnesium seems to be more complex. Decalcification is the major degradation process involved, even if a non-negligible contribution of further cations (Mg 2+ , Na + ) and anions (SO 4 2- ) has been noticed. Analysis of degradation soution also revealed that kinetic of Portland cement paste degradation in boric acid is higher than in pure water, regarding the degraded depths measured and calcium leaching rate. This observation has been confirmed by solid characterization. Microstructure analysis of degraded Portland cement paste showed a global porosity increase in the degraded zone that might be mainly attributed to Portlandite dissolution. An Ettringite reprecipitation in the degraded zone has been suspected but could also be Ettringite-like phases containing boron. The analysis techniques used did not allow us to differentiate it, and no others specific mineral phases containing boron has been identified. Profile pattern by XRD analysis allowed us to identify four zones composing the degraded Portland cement paste

Use of red mud as addition for portland cement mortars

International Nuclear Information System (INIS)

Ribeiro, D.V.; Morelli, M.R.

2011-01-01

The aim of the present research work was to investigate the possibility of adding red mud, an alkaline leaching waste that is obtained from bauxite during the Bayer process for alumina production, in the raw meal of Portland cement mortars. The red mud is classified as dangerous, according to NBR 10004/2004, and world while generation reached over 117 million tons/year. This huge production requires high consuming products to be used as incorporation matrix and we studied the influence of red mud addition on the characteristics of cement mortars and concrete. In this paper the properties of Portland cement mortars incorporating high amounts of red mud was evaluated: pH variation, fresh (setting time, workability or normal consistency and water retention), and hardened state (mechanical strength, capillary water absorption, density and apparent porosity). Results seem promising for red mud additions up to 20 wt%. (author)

Study of irradiation damage by fast neutrons in samples of Portland cement

International Nuclear Information System (INIS)

Lucki, G.; Rosa Junior, A.A.

1984-01-01

The effect of neutron irradiation in samples of Portland cement was evaluated, using the resonance frequency method and pulse velocity of ultra-sound techniques. The samples were divided in three groups: 1) monitoring samples; 2) samples submitted to gamma heating; 3) Irradiated samples. In the sample preparation, it was used the Portland Santa Rita CP 320 cement, and water-cement rate of 0.40 l/Kg. The irradiation was done in the research reactor IEA-R1, at IPEN - CNEN/SP, with an integrated flux of 7.2 x 10 18 n/cm 2 (E approx. 1 MeV). Some damage were detected, due to the neutron flux, and by the thermal effect of gamma heating. (E.G.) [pt

Hydration kinetics modeling of Portland cement considering the effects of curing temperature and applied pressure

International Nuclear Information System (INIS)

Lin Feng; Meyer, Christian

2009-01-01

A hydration kinetics model for Portland cement is formulated based on thermodynamics of multiphase porous media. The mechanism of cement hydration is discussed based on literature review. The model is then developed considering the effects of chemical composition and fineness of cement, water-cement ratio, curing temperature and applied pressure. The ultimate degree of hydration of Portland cement is also analyzed and a corresponding formula is established. The model is calibrated against the experimental data for eight different Portland cements. Simple relations between the model parameters and cement composition are obtained and used to predict hydration kinetics. The model is used to reproduce experimental results on hydration kinetics, adiabatic temperature rise, and chemical shrinkage of different cement pastes. The comparisons between the model reproductions and the different experimental results demonstrate the applicability of the proposed model, especially for cement hydration at elevated temperature and high pressure.

Ecological indices of manufacture of Portland cement clinker and production of the dolomite clinker

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Vinnichenko Varvara

2017-01-01

Full Text Available It is shown that the production of dolomite clinker in comparison with that of Portland cement is environmentally appropriate. When calcining dolomite for cementitious binder, the pollution of the atmosphere by carbon dioxide is reduced due to its isolation during decarbonization reactions of calcium carbonates. Reducing fuel consumption for clinker burning provides less carbon dioxide emissions from combustion products. Reducing the firing temperature creates obstacles to the formation of nitrogen oxides. The production of binders from dolomite in comparison with the production of Portland cement helps to protect the environment from contamination

Portland Public Schools Project Chrysalis: Year 2 Evaluation Report.

Science.gov (United States)

Mitchell, Stephanie J.; Gabriel, Roy M.; Hahn, Karen J.; Laws, Katherine E.

In 1994, the Chrysalis Project in Portland Public Schools received funding to prevent or delay the onset of substance abuse among a special target population: high-risk, female adolescents with a history of childhood abuse. Findings from the evaluation of the project's second year of providing assistance to these students are reported here. During…

Comfort Study of Office Buildings with Large Glazed Areas

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Violeta Motuzienė

2017-09-01

Full Text Available In the buildings with large glazed areas the biggest problem is the space overheating during the warm season. This causes increased energy demand for cooling. The survey was carried out during the warm and cold seasons in two office buildings with large glazed areas. The methodology was prepared for evaluating indoor climate parameters using objective and subjective evaluation. The measurements have shown that there are problems with lighting in workplaces of both buildings during both the warm and cold seasons. The biggest problem is too dry air during the cold period, an acceptable temperature is also not always in the building No. 2. The survey has shown that some employees are dissatisfied with the indoor climate in the workplace, the bigger dissatisfaction is in building No. 2. Assessing according to the O. Fanger methodology was obtained that the number of PPD is in the normal range during the cold period, whereas close to the limit when the building can not be operated in the warm period.

Microstructure engineering of Portland cement pastes and mortars through addition of ultrafine layer silicates

DEFF Research Database (Denmark)

Lindgreen, Holger; Geiker, Mette; Krøyer, Hanne

2008-01-01

Pozzolanic submicron-sized silica fume and the non-pozzolanic micron- and nano-sized layer silicates (clay minerals) kaolinite, smectite and palygorskite have been used as additives in Portland cement pastes and mortars. These layer silicates have different particle shape (needles and plates......), surface charge, and size (micron and nano). The structure of the resulting cement pastes and mortars has been investigated by atomic force microscopy (AFM), helium porosimetry, nitrogen adsorption (specific surface area and porosity), low-temperature calorimetry (LTC) and thermal analysis. The main result...... is that the cement paste structure and porosity can be engineered by addition of selected layer silicates having specific particle shapes and surface properties (e.g., charge and specific surface area). This seems to be due to the growth of calcium-silicate hydrates (C-S-H) on the clay particle surfaces...

Regional economic impact assessment: Evaluating remedial alternatives for the Portland Harbor Superfund Site, Portland, Oregon, USA.

Science.gov (United States)

Harrison, David; Coughlin, Conor; Hogan, Dylan; Edwards, Deborah A; Smith, Benjamin C

2018-01-01

The present paper describes a methodology for evaluating impacts of Superfund remedial alternatives on the regional economy in the context of a broader sustainability evaluation. Although economic impact methodology is well established, some applications to Superfund remedial evaluation have created confusion because of seemingly contradictory results. This confusion arises from failure to be explicit about 2 opposing impacts of remediation expenditures: 1) positive regional impacts of spending additional money in the region and 2) negative regional impacts of the need to pay for the expenditures (and thus forgo other expenditures in the region). The present paper provides a template for economic impact assessment that takes both positive and negative impacts into account, thus providing comprehensive estimates of net impacts. The paper also provides a strategy for identifying and estimating major uncertainties in the net impacts. The recommended methodology was applied at the Portland Harbor Superfund Site, located along the Lower Willamette River in Portland, Oregon, USA. The US Environmental Protection Agency (USEPA) developed remedial alternatives that it estimated would cost up to several billion dollars, with construction durations possibly lasting decades. The economic study estimated regional economic impacts-measured in terms of gross regional product (GRP), personal income, population, and employment-for 5 of the USEPA alternatives relative to the "no further action" alternative. Integr Environ Assess Manag 2018;14:32-42. © 2017 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC). © 2017 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Solving a problem of establishing a connection between post offices in the area of a city

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Biljana GRGUROVIC

2015-03-01

Full Text Available According to The General Plan of Post Network and in accordance with the criteria for opening branches of postal services for customers numerous postal offices which perform delivery services are located on the territory of every large city area. In case of using the system for combined decentralization one of the offices is assigned the role of the central deliverance post office. If the central office cannot be connected to some other unit directly, their connection is realized through one or more other units which are located in between them. Aside from the idea of the most economical management, the organization of postal offices is limited by some other actors, from the number of available vehicles, their capacity, to the question of the place and time of realizing a transaction. This paper provides information about how the money-saving algorithm for solving the problem of time interval routing can be used in a suitable way in these situations as well.

Influencia del yeso sobre la velocidad de hidratación del cemento portland

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Yamaguchi, G.

1961-12-01

Full Text Available Not availablePara esclarecer la Influencia del yeso sobre el fraguado y endurecimiento del cemento, los autores estudiaron el grado de hidratación de los cuatro principales minerales del clínker de cemento Portland y el efecto del yeso sobre ellas. Haciendo uso del análisis cuantitativo de rayos X, se determinó la porción no hidratada. Simultáneamente, se determinaron los tiempos de fraguado y las resistencias. Los ensayos se llevaron a cabo sobre tres clínkeres sintéticos de diferentes composiciones y sobre dos clínkeres de cemento Portland comerciales.

Rheological Properties of Very High-Strength Portland Cement Pastes: Influence of Very Effective Superplasticizers

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Adriano Papo

2010-01-01

Full Text Available The influence of the addition of very effective superplasticizers, that are commercially available, employed for maximising the solid loading of very high-strength Portland cement pastes, has been investigated. Cement pastes were prepared from deionized water and a commercially manufactured Portland cement (Ultracem 52.5 R. Cement and water were mixed with a vane stirrer according to ASTM Standard C305. The 0.38 to 0.44 water/cement ratio range was investigated. Three commercial superplasticizing agents produced by Ruredil S.p.a. were used. They are based on a melamine resin (Fluiment 33 M, on a modified lignosulphonate (Concretan 200 L, and on a modified polyacrylate (Ergomix 1000. Rheological tests were performed at 25°C by using the rate controlled coaxial cylinder viscometer Rotovisko-Haake 20, system M5-osc., measuring device MV2P with serrated surfaces. The tests were carried out under continuous flow conditions. The results of this study were compared with those obtained in a previous article for an ordinary Portland cement paste.

Thermodynamic modelling of the effect of temperature on the hydration and porosity of Portland cement

International Nuclear Information System (INIS)

Lothenbach, Barbara; Matschei, Thomas; Moeschner, Goeril; Glasser, Fred P.

2008-01-01

The composition of the phase assemblage and the pore solution of Portland cements hydrated between 0 and 60 deg. C were modelled as a function of time and temperature. The results of thermodynamic modelling showed a good agreement with the experimental data gained at 5, 20, and 50 deg. C. At 5 and at 20 deg. C, a similar phase assemblage was calculated to be present, while at approximately 50 deg. C, thermodynamic calculations predicted the conversion of ettringite and monocarbonate to monosulphate. Modelling showed that in Portland cements which have an Al 2 O 3 /SO 3 ratio of > 1.3 (bulk weight), above 50 deg. C monosulphate and monocarbonate are present. In Portland cements which contain less Al (Al 2 O 3 /SO 3 < 1.3), above 50 deg. C monosulphate and small amounts of ettringite are expected to persist. A good correlation between calculated porosity and measured compressive strength was observed

STABILISASI TANAH LIAT SANGAT LUNAK DENGAN GARAM DAN PC (PORTLAND CEMENT

Directory of Open Access Journals (Sweden)

Tirta Djusman Arief

2006-01-01

Full Text Available Adding sodium chloride, as admixture, and Portland Cement, as stabilizer, to a very soft clay increase its plasticity index (PI, Californian Bearing Ratio (CBR, and Unconfined Compression Strength (UCS. This paper presents the results of testings done to very soft clay from Margomulyo, Surabaya. The results show a promising tendency. Anyhow a wider and comprehensive research is still needed to ensure the long-term effect of the soil stabilization. Abstract in Bahasa Indonesia : Penambahan garam (sodium chloride dan PC (Portland Cement meningkatkan PI (Plasticity Index, CBR (Californian Bearing Ratio, dan UCS (Unconfined Compression Strength dari tanah lempung sangat lunak. Dalam makalah ini disajikan hasil pengujian yang dilakukan terhadap lempung sangat lunak dari daerah Margomulyo, Surabaya. Hasilnya menunjukkan kecenderungan yang menggembirakan, namun penelitian yang luas dan komprehensif masih diperlukan untuk peningkatan stabilitas tanah dalam jangka panjang.

Ex vivo assessment of genotoxicity and cytotoxicity in murine fibroblasts exposed to white MTA or white Portland cement with 15% bismuth oxide.

Science.gov (United States)

Zeferino, E G; Bueno, C E S; Oyama, L M; Ribeiro, D A

2010-10-01

To evaluate whether white mineral trioxide aggregate (MTA) or white Portland cement with 15% bismuth oxide were able to induce genetic damage and cellular death ex vivo. Aliquots of 1 × 10(4) murine fibroblasts were incubated at 37 °C for 3 h with MTA (white) or white Portland cement with 15% bismuth oxide, at final concentrations ranging from 10 to 1000 μg mL(-1) individually. Data of three independent repeats from the comet assay and the trypan blue exclusion test were assessed by the one-way anova followed by Tukey's test. Mineral trioxide aggregate or Portland cement containing bismuth oxide did not produce genotoxic effects with respect to the single-cell gel (comet) assay data for all concentrations evaluated. Furthermore, no cytotoxicity was observed for MTA or Portland cement. White MTA or white Portland cement containing 15% bismuth oxide were not genotoxic and cytotoxic. © 2010 International Endodontic Journal.

EnviroAtlas - Portland, ME - Meter-Scale Urban Land Cover (MULC) Data (2010)

Data.gov (United States)

U.S. Environmental Protection Agency — The EnviroAtlas Portland, ME Meter-Scale Urban Land Cover (MULC) data was generated from USDA NAIP (National Agricultural Imagery Program) four band (red, green,...

Wireless local area network for the dental office.

Science.gov (United States)

Mupparapu, Muralidhar

2004-01-01

Dental offices are no exception to the implementation of new and advanced technology, especially if it enhances productivity. In a rapidly transforming digital world, wireless technology has a special place, as it has truly "retired the wire" and contributed to the ease and efficient access to patient data and other software-based applications for diagnosis and treatment. If the office or the clinic is networked, access to patient management software, imaging software and treatment planning tools is enhanced. Access will be further enhanced and unrestricted if the entire network is wireless. As with any new, emerging technology, there will be issues that should be kept in mind before adapting to the wireless environment. Foremost is the network security involved in the installation and use of these wireless networks. This short, technical manuscript deals with standards and choices in wireless technology currently available for implementation within a dental office. The benefits of each network security protocol available to protect patient data and boost the efficiency of a modern dental office are discussed.

INFLUENCE OF BARIUM OXIDE ADDITIONS ON PORTLAND CLINKER

Directory of Open Access Journals (Sweden)

Anezka Zezulova

2016-12-01

Full Text Available Nowadays, nuclear power plants are widespread around the world and research is of great interest. Together with nuclear research, shielding of different types of radiation is an important current topic of research aiming at their safety. Portland cement has been an elementary building material for centuries. Since barium is very efficient in shielding different types of radiation, it can be assumed that the radiation shielding capability of cement can be improved by incorporation of barium. This work deals with the influence of barium oxide, added in the form of barium carbonate and sulphate, on the formation and properties of Portland clinker. The structure of burnt clinkers and the ratio of clinker phases were studied by polarizing microscopy and by X-ray diffraction. With increasing barium content, the alite-belite ratio decreases and the content of free lime gradually increases. Moreover, sulphates induce the growth of alite crystals. The ability of barium to be a part of the clinker minerals was observed by scanning electron microscopy. Belite and clinker melt contain the highest amount of barium, but aggregates of barium oxide are formed in the clinker melt. Furthermore, the rate of alite crystallization was studied under isothermal conditions.

Setting time and flowability of accelerated Portland cement mixed with polycarboxylate superplasticizer.

Science.gov (United States)

Wongkornchaowalit, Norachai; Lertchirakarn, Veera

2011-03-01

Important limitations of mineral trioxide aggregate for use in clinical procedures are extended setting time and difficult handling characteristics. The removal of gypsum at the end stage of the Portland cement manufacturing process and polycarboxylate superplasticizer admixture may solve these limitations. Different concentrations of polycarboxylate superplasticizer (0%, 1.2%, 1.8%, and 2.4% by volume) and liquid-to-powder ratios (0.27, 0.30, and 0.33 by weight) were mixed with white Portland cement without gypsum (AWPC-experimental material). Type 1 ordinary white Portland cement mixed with distilled water at the same ratios as the experimental material was used as controls. All samples were tested for setting time and flowability according to the International Organization for Standardization 6876:2001 guideline. The data were analyzed by two-way analysis of variance. Then, one-way analysis of variance and multiple comparison tests were used to analyze the significance among groups. The data are presented in mean ± standard deviation values. In all experimental groups, the setting times were in the range of 4.2 ± 0.4 to 11.3 ± 0.2 minutes, which were significantly (p setting time and increased flowability of cement, which would be beneficial for clinical use. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Planning, zoning and financial incentives for ecoroofs in Portland, Oregon

Energy Technology Data Exchange (ETDEWEB)

Liptan, T. [City of Portland, OR (United States). Bureau of Environmental Services

2003-07-01

Approximately 35 to 90 per cent of the surface area of various city neighbourhoods is composed of rooftops and pavement. The City of Portland has suffered from several infrastructure and environmental problems as a result of these rooftops and pavement. In response, the City created a program to address storm water related problems and to provide other environmental benefits. This program promotes the use of Ecoroofs or vegetated roofs. City officials are investigating three specific concerns regarding Ecoroofs: (1) the extent to which Ecoroofs can manage precipitation and water quality, (2) the design, construction and maintenance issues to be addressed in order to ensure Ecoroofs are viable, and (3) the policies and economic concerns that must be addressed to determine the appropriate incentives and potential regulations for Ecoroofs. The overall city program was described in this presentation. The incentives and assistance provided by the city were reviewed, and the practical lessons learned were discussed. 1 tab., 1 fig.

Improved quantification of alite and belite in anhydrous Portland cements by 29Si MAS NMR: Effects of paramagnetic ions

DEFF Research Database (Denmark)

Poulsen, Søren Lundsted; Kocaba, Vanessa; Le Saoût, Gwenn

2009-01-01

The applicability, reliability, and repeatability of 29Si MAS NMR for determination of the quantities of alite (Ca3SiO5) and belite (Ca2SiO4) in anhydrous Portland cement was investigated in detail for 11 commercial Portland cements and the results compared with phase quantifications based...

Prediction of potential compressive strength of Portland clinker from its mineralogy

DEFF Research Database (Denmark)

Svinning, K.; Høskuldsson, Agnar; Justnes, H.

2010-01-01

Based on a statistical model first applied for prediction of compressive strength up to 28 d from the microstructure of Portland cement, potential compressive strength of clinker has been predicted from its mineralogy. The prediction model was evaluated by partial least squares regression...

Development of the Portland cement slurries with diatomaceous earth to the oil industry; Desenvolvimento de pastas de cimento Portland com adicao de diatomita para a industria do petroleo

Energy Technology Data Exchange (ETDEWEB)

Brito, Roseane A; Melo, Dulce M.A.; Martinelli, Antonio E.; Simao, Cristina A.; Paiva, Maria D.M. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Melo, Marcus A.F. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

2004-07-01

The class-G Portland cement has been used with success in oil well cementing. The material is usually shipped to the Northeast Brazil, because the only plant that manufactures class-G is located in Cantagalo/RJ. The present work investigates the influence of the partial substitution of Portland cement by diatomaceous earth, aiming at reducing the costs in oil well cementing, improving the slurry properties and using local raw material. The diatomaceous earth has pozzolanic properties and can be used as extenders of cement slurries. This properties added to the lower cost and availability of this material in Northeast Brazil, make the diatomaceous earth a candidate material to produce light cements, to well conditions in advanced phases of production. It were evaluated the rheological properties of the slurries (at 25 and 52 deg C), volume of free water, compressive strength after curing for 8, 24 and 48 h at 38 deg C, and consistometry tests. The results show that the diatomaceous earth maintain the viscosity values and gel force suitable for use in oil well cementing. No free water was observed in the formulations. It was also verified that the compressive strength of slurries hardened with diatomaceous earth is similar to those with only Portland cement and that the minimum compressive strength of 300 psi, after curing for 8 h was reached. The thickening time was longer than the average value and the application value. (author)

Production of portland cement using Moroccan oil shale and comparative study between conventional cement plant and cement plant using oil shale

International Nuclear Information System (INIS)

Doumbouya, M.; Kacemi, K.E.; Kitane, S.

2012-01-01

Like the use of coal ash from power plants as an addition to cement, oil shale are used for cement production on an industrial scale in Estonia, China, USA and Germany. Oil shale can be utilized in manufacturing the cement. In addition to the utilization of these by-products after combustion, it can also reduce the required temperature for the clinkering reactions during the production of Portland clinker. We performed a study on the Moroccan oil shale to maximize the use of oil shale ash in the manufacturing of Portland cement. We found that Moroccan oil shale ash can be used up to 30% with 70% Portland clinker without altering its principle properties. The corresponding temperature required to generate the required liquid for the clinkering reactions as well as the essential ingredients for clinker was found to be around 850 to 1000 deg. C. The operating temperatures for this optimized blend ratio were found to 1000 deg. C. The resulting Portland clinker from this ratio will need further testing in accordance with international standards for Portland cement to examine properties like strength and setting time. (author)

7 CFR 2003.14 - Field Offices.

Science.gov (United States)

2010-01-01

...) ADMINISTRATIVE REGULATIONS ORGANIZATION Functional Organization of the Rural Development Mission Area § 2003.14... Office Program Directors. State Directors may organizationally structure their offices based on the... tier program delivery structure. In a three tier system, Local offices report to an Area office, that...

Source segregation of food waste in office areas: Factors affecting waste generation rates and quality

DEFF Research Database (Denmark)

Edjabou, Vincent Maklawe Essonanawe; Boldrin, Alessio; Scheutz, Charlotte

2015-01-01

Existing legislation mandates that the amount of waste being recycled should be increased. Among others, in its Resource Strategy Plan, the Danish Government decided that at least 60% of food waste generated by the service sector, including in office areas, should be source-sorted and collected...... separately by 2018. To assess the achievability of these targets, source-sorted food waste and residual waste from office areas was collected and weighed on a daily basis during 133 working days. Waste composition analyses were conducted every week to investigate the efficiency of the source-sorting campaign...... and the purity of the source-sorted food waste. The moisture content of source-sorted food waste and residual waste fractions, and potential methane production from source-sorted food waste, was also investigated.Food waste generation equated to 23. ±. 5. kg/employee/year, of which 20. ±. 5. kg...

Zero Energy With an Affordable Price Tag: Friends School of Portland

Energy Technology Data Exchange (ETDEWEB)

Torcellini, Paul A [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-08-09

More than half of all operating school districts in the U.S. are in rural areas. These small schools operate at a different scale and have different needs than their city counterparts. In 2003-2004, 20% of public schools in the U.S. served fewer than 200 students(1). Although the Friends School of Portland - which was designed to achieve both zero energy performance and Passivhaus certification - is an independent school, it faced financial constraints similar to those faced by many other small schools throughout the country. The project was financed through a capital campaign and a mortgage that forced a hard cost cap on the project, so the project team had to be diligent about every dollar that was spent. In its first year of operation, the school site energy use intensity was just 12 kbtu/ft2, a bit more than the 9 kbtu/ft2 predicted.

Final Rule: NESHAP for the Portland Cement Manufacturing Industry: Alternative Monitoring Method

Science.gov (United States)

EPA is extending its approval for the use of an alternative method to show compliance with hydrogen chloride (HCl) emissions limits in the National Emission Standards for Hazardous Air Pollutants for the Portland Cement Manufacturing Industry

High-volume natural volcanic pozzolan and limestone powder as partial replacements for portland cement in self-compacting and sustainable concrete

KAUST Repository

Celik, Kemal; Jackson, Marie D.; Mancio, Mauricio; Meral, Cagla; Emwas, Abdul-Hamid M.; Mehta, P. Kumar; Monteiro, Paulo José Meleragno

2014-01-01

A laboratory study demonstrates that high volume, 45% by mass replacement of portland cement (OPC) with 30% finely-ground basaltic ash from Saudi Arabia (NP) and 15% limestone powder (LS) produces concrete with good workability, high 28-day compressive strength (39 MPa), excellent one year strength (57 MPa), and very high resistance to chloride penetration. Conventional OPC is produced by intergrinding 95% portland clinker and 5% gypsum, and its clinker factor (CF) thus equals 0.95. With 30% NP and 15% LS portland clinker replacement, the CF of the blended ternary PC equals 0.52 so that 48% CO2 emissions could be avoided, while enhancing strength development and durability in the resulting self-compacting concrete (SCC). Petrographic and scanning electron microscopy (SEM) investigations of the crushed NP and finely-ground NP in the concretes provide new insights into the heterogeneous fine-scale cementitious hydration products associated with basaltic ash-portland cement reactions. © 2013 Published by Elsevier Ltd.

Analysis of heavy metal contents in gray and white MTA and 2 kinds of Portland cement: a preliminary study.

Science.gov (United States)

Chang, Seok Woo; Shon, Won Jun; Lee, WooCheol; Kum, Kee Yeon; Baek, Seung Ho; Bae, Kwang Shik

2010-04-01

The levels of 10 heavy metals (arsenic, bismuth, cadmium, chromium, copper, iron, lead, manganese, nickel, and zinc) in gray Portland cement (GPC), white Portland cement (WPC), gray MTA (GMTA), and white MTA (WMTA) were analyzed by inductively coupled plasma-atomic emission spectrometry (ICP-AES). One gram of each material was digested with 80 degrees C "aqua-regia" (7 mL of 60% HNO3 and 21 mL of 35% HCl), filtered, and analyzed by ICP-AES. The analysis was performed 6 times and the data were analyzed statistically. Arsenic and lead concentrations were the highest in GPC (P cements (P Portland cement versus MTA, the differences in purity may be considered. Copyright 2010 Mosby, Inc. All rights reserved.

Evaluation of physico-chemical properties of Portland cements and MTA

Directory of Open Access Journals (Sweden)

Jorge Luis Gonçalves

2010-09-01

Full Text Available The purpose of this study was to evaluate the hydrogenionic potential and electrical conductivity of Portland cements and MTA, as well as the amount of arsenic and calcium released from these materials. In Teflon molds, samples of each material were agitated and added to plastic flasks containing distilled water for 3, 24, 72 and 168 h. The results were analyzed with a Kruskal-Wallis non-parametric test for global comparisons and a Dunn-Tukey test for pairwise comparisons. The results revealed no significant differences in the pH of the materials (p > 0.05. The electrical conductivity of the cements were not statistically different (p > 0.05. White non-structural cement and MTA BIO released the largest amount of calcium ions into solution (p 0.05. The results indicated that the physico-chemical properties of Portland cements and MTA were similar. Furthermore, all materials produced an alkaline environment and can be considered safe for clinical use because arsenic was not released. The electrical conductivity and the amount of calcium ions released into solution increased over time.

Evaluation of physico-chemical properties of Portland cements and MTA.

Science.gov (United States)

Gonçalves, Jorge Luis; Viapiana, Raqueli; Miranda, Carlos Eduardo Saraiva; Borges, Alvaro Henrique; Cruz Filho, Antônio Miranda da

2010-01-01

The purpose of this study was to evaluate the hydrogenionic potential and electrical conductivity of Portland cements and MTA, as well as the amount of arsenic and calcium released from these materials. In Teflon molds, samples of each material were agitated and added to plastic flasks containing distilled water for 3, 24, 72 and 168 h. The results were analyzed with a Kruskal-Wallis non-parametric test for global comparisons and a Dunn-Tukey test for pairwise comparisons. The results revealed no significant differences in the pH of the materials (p > 0.05). The electrical conductivity of the cements were not statistically different (p > 0.05). White non-structural cement and MTA BIO released the largest amount of calcium ions into solution (p 0.05). The results indicated that the physico-chemical properties of Portland cements and MTA were similar. Furthermore, all materials produced an alkaline environment and can be considered safe for clinical use because arsenic was not released. The electrical conductivity and the amount of calcium ions released into solution increased over time.

Experimental study of chloride diffusivity in unsaturated ordinary Portland cement mortar

NARCIS (Netherlands)

Zhang, Y.; Ye, G.; Santhanam, M.

2017-01-01

Experiments are carried out to investigate the chloride diffusivity in partially saturated ordinary Portland cement mortars with water-to-cement (w/c) ratios of 0.4, 0.5 and 0.6. Based on resistivity measurement and Nernst-Einstein equation, the chloride diffusivities of cement mortars at various

X-ray diffractometry of steam cured ordinary Portland and blast-furnace-slag cements

International Nuclear Information System (INIS)

Camarini, G.; Djanikian, J.G.

1994-01-01

This work studies some aspects of the phases produced by hydration of ordinary and blast-furnace-slag cements, at normal conditions and steam cured (60 and 95 0 C), using an X-ray diffraction technique. The blast-furnace-slag cement was a mixture of 50% of ordinary Portland cement and 50% of blast-furnace-slag (separately grinding). After curing the X-ray diffraction reveals that, in relation to ordinary Portland cement, the main phases in blast-furnace-slag cement are hydrated silicates and aluminates, hydro garnet, etringitte and mono sulphate. After steam curing the hydration of blast-furnace-slag cement proceeds. This is a result of the slag activation by the curing temperature. (author). 8 refs., 3 figs., 1 tab

Comparative Study of Portland Cement-based and Zeolite-based Concretes in Terms of Hexavalent Chromium Leaching

Directory of Open Access Journals (Sweden)

Oravec Jozef

2016-12-01

Full Text Available The paper presents the results of the leaching study of Portland cement-based and zeolite-based concretes regarding water soluble hexavalent chromium. Three leaching water media (distilled water, rain water, and Britton-Robinson buffer of various pH values were under investigation. The correlation between pH and leached-out concentrations of chromium was not confirmed. The content of hexavalent water-soluble chromium in leachates of zeolite-based concretes was found to be higher than that in leachates of Portland cement-based samples.

Portland cement concrete pavement review of QC/QA data 2000 through 2009.

Science.gov (United States)

2011-04-01

This report analyzes the Quality Control/Quality Assurance (QC/QA) data for Portland cement concrete pavement : (PCCP) awarded in the years 2000 through 2009. Analysis of the overall performance of the projects is accomplished by : reviewing the Calc...

Natural cement as the precursor of Portland cement: Methodology for its identification

International Nuclear Information System (INIS)

Varas, M.J.; Alvarez de Buergo, M.; Fort, R.

2005-01-01

When cements appeared in the 19th century, they took the place of traditional binding materials (lime, gypsum, and hydraulic lime) which had been used until that time. Early cements can be divided into two groups, natural and artificial (Portland) cements. Natural cements were introduced first, but their widespread usage was short-lived as they were quickly replaced by artificial cements (Portland), still the most important and predominant today. The main differences between natural and artificial cements arise during the manufacturing process. The final properties of the cements are greatly influenced by differences in the raw materials and burning temperatures employed. The aim of this paper is to assess the efficiency of traditional analytical techniques (petrographic microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR)) used to differentiate natural and artificial cements

Four Decades of Systems Science Teaching and Research in the USA at Portland State University

Directory of Open Access Journals (Sweden)

Wayne Wakeland

2014-04-01

Full Text Available Systems science is defined in general fashion, and a brief background is provided that lists some of the systems science-related societies, conferences, journals, research institutes, and educational programs. The Systems Science Graduate Program at Portland State University in Portland, OR, USA, is described in detail, including its history, curriculum, students, faculty, and degrees granted. Dissertation topics are summarized via word diagrams created from dissertation titles over the years. MS degrees, student placement, and undergraduate courses are also mentioned, and future plans for the program are described including its support for sustainability education.

Office Hysteroscopy

OpenAIRE

Hikmet Hassa; Basar Tekin; H. Mete Tanir; Bulent Cakmak

2007-01-01

Although hysteroscopy has evolved in recent years, its use in the office setting was not made practical until early 1980s with the introduction of small caliber hysteroscopes of less than 5- mm outer diameter.This innovation simplifies ambulatory uterine exploration and the office evaluation of patients with abnormal uterine bleeding. This article reviews current trends in office hysteroscopy and its areas of application in different forms of gynecological problems.

X-ray diffractometry of steam cured ordinary Portland and blast-furnace-slag cements; Difratometria de raios X de pastas de cimento Portland comum e de alto-forno submetidas a cura termica

Energy Technology Data Exchange (ETDEWEB)

Camarini, G [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia; Djanikian, J G [Sao Paulo Univ., SP (Brazil). Escola Politecnica

1994-12-31

This work studies some aspects of the phases produced by hydration of ordinary and blast-furnace-slag cements, at normal conditions and steam cured (60 and 95{sup 0} C), using an X-ray diffraction technique. The blast-furnace-slag cement was a mixture of 50% of ordinary Portland cement and 50% of blast-furnace-slag (separately grinding). After curing the X-ray diffraction reveals that, in relation to ordinary Portland cement, the main phases in blast-furnace-slag cement are hydrated silicates and aluminates, hydro garnet, etringitte and mono sulphate. After steam curing the hydration of blast-furnace-slag cement proceeds. This is a result of the slag activation by the curing temperature. (author). 8 refs., 3 figs., 1 tab.

Recycled Portland cement concrete pavements : Part II, state-of-the art summary.

Science.gov (United States)

1979-01-01

This report constitutes a review of the literature concerning recycling of portland cement concrete pavements by crushing the old pavement and reusing the crushed material as aggregate in a number of applications. A summary of the major projects cond...

Prediction of water vapour sorption isotherms and microstructure of hardened Portland cement pastes

International Nuclear Information System (INIS)

Burgh, James M. de; Foster, Stephen J.; Valipour, Hamid R.

2016-01-01

Water vapour sorption isotherms of cementitious materials reflect the multi-scale physical microstructure through its interaction with moisture. Our ability to understand and predict adsorption and desorption behaviour is essential in the application of modern performance-based approaches to durability analysis, along with many other areas of hygro-mechanical and hygro-chemo-mechanical behaviour. In this paper, a new physically based model for predicting water vapour sorption isotherms of arbitrary hardened Portland cement pastes is presented. Established thermodynamic principles, applied to a microstructure model that develops with hydration, provide a rational basis for predictions. Closed-form differentiable equations, along with a rational consideration of hysteresis and scanning phenomena, makes the model suitable for use in numerical moisture simulations. The microstructure model is reconciled with recently published 1 H NMR and mercury intrusion porosimetry results.

Thermal analysis of borogypsum and its effects on the physical properties of Portland cement

International Nuclear Information System (INIS)

Elbeyli, Iffet Yakar; Derun, Emek Moeroeydor; Guelen, Jale; Piskin, Sabriye

2003-01-01

Borogypsum, which consists mainly of gypsum crystals, B 2 O 3 and some impurities, is formed during the production of boric acid from colemanite, which is an important borate ore. In this study, the effect of borogypsum and calcined borogypsum on the physical properties of ordinary Portland cement (OPC) has been investigated. The calcination temperature and transformations in the structures of borogypsum and natural gypsum were determined by differential thermal analysis (DTA), thermogravimetric analysis (TGA) and X-ray diffraction (XRD) techniques. Thermal experiments were carried out between ambient temperature and 500 deg. C in an air atmosphere at a heating rate of 10 deg. C min -1 . After calculation of enthalpy and determination of conversion temperatures, borogypsum (5% and 7%), hemihydrate borogypsum (5%) and natural gypsum (5%) were added separately to Portland cement clinker and cements were ground in the laboratory. The final products were tested for chemical analysis, compressive strength, setting time, Le Chatelier expansion and fineness properties according to the European Standard (EN 196). The results show that increasing the borogypsum level in Portland cement from 5% to 7% caused an increase in setting time and a decrease in soundness expansion and compressive strength. The cement prepared with borogypsum (5%) was found to have similar strength properties to those obtained with natural gypsum, whereas a mixture containing 5% of hemihydrate borogypsum was found to develop 25% higher compressive strength than the OPC control mixtures at 28 days. For this reason, utilization of calcined borogypsum in cement applications is expected to give better results than untreated borogypsum. It is concluded that hemihydrate borogypsum could be used as a retarder for Portland cement as an industrial side. This would play an important role in reducing environmental pollution

Portland blended cements: demolition ceramic waste management

International Nuclear Information System (INIS)

Trezza, M.A.; Zito, S.; Tironi, A.; Irassar, E.F.; Rahhal, V.F.

2017-01-01

Demolition ceramic wastes (DCWs) were investigated in order to determine their potential use as supplementary cementitious materials in Portland Blended Cements (PBCs). For this purpose, three ceramic wastes were investigated. After characterization of the materials used, the effect of ceramic waste replacement (8, 24 and 40% by mass) was analyzed. Pozzolanic activity, hydration progress, workability and compressive strength were determined at 2, 7 and 28 days. The results showed that the ground wastes behave as filler at an early age, but as hydration progresses, the pozzolanic activity of ceramic waste contributes to the strength requirement. [es

Office Hysteroscopy

Directory of Open Access Journals (Sweden)

Hikmet Hassa

2007-06-01

Full Text Available Although hysteroscopy has evolved in recent years, its use in the office setting was not made practical until early 1980s with the introduction of small caliber hysteroscopes of less than 5- mm outer diameter.This innovation simplifies ambulatory uterine exploration and the office evaluation of patients with abnormal uterine bleeding. This article reviews current trends in office hysteroscopy and its areas of application in different forms of gynecological problems.

Influence of limestone on the hydration of Portland cements

International Nuclear Information System (INIS)

Lothenbach, Barbara; Le Saout, Gwenn; Gallucci, Emmanuel; Scrivener, Karen

2008-01-01

The influence of the presence of limestone on the hydration of Portland cement was investigated. Blending of Portland cement with limestone was found to influence the hydrate assemblage of the hydrated cement. Thermodynamic calculations as well as experimental observations indicated that in the presence of limestone, monocarbonate instead of monosulfate was stable. Thermodynamic modelling showed that the stabilisation of monocarbonate in the presence of limestone indirectly stabilised ettringite leading to a corresponding increase of the total volume of the hydrate phase and a decrease of porosity. The measured difference in porosity between the 'limestone-free' cement, which contained less than 0.3% CO 2 , and a cement containing 4% limestone, however, was much smaller than calculated. Coupling of thermodynamic modelling with a set of kinetic equations which described the dissolution of the clinker, predicted quantitatively the amount of hydrates. The quantities of ettringite, portlandite and amorphous phase as determined by TGA and XRD agreed well with the calculated amounts of these phases after different periods of time. The findings in this paper show that changes in the bulk composition of hydrating cements can be followed by coupled thermodynamic models. Comparison between experimental and modelled data helps to understand in more detail the dominating processes during cement hydration

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

Science.gov (United States)

2011-12-08

... and Cement Clinker From Japan Determination On the basis of the record \\1\\ developed in the subject... duty order on gray Portland cement and cement clinker from Japan would be likely to lead to... and Cement Clinker from Japan: Investigation No. 731- TA-461 (Third Review). By order of the...

Durabilidad de un suelo contaminado y tratado con cemento portland Durability of a contaminated soil treated with portland cement

OpenAIRE

José W Jiménez Rojas; Nilo C Consoli; Karla Salvagni Heineck

2008-01-01

Este trabajo tiene por objetivo la aplicación de la técnica de solidificación/estabilización de suelos contaminados, analizando específicamente el comportamiento físico del suelo a través de ensayos de durabilidad. El suelo fue contaminado en laboratorio con residuo oleoso y la aplicación de la técnica tuvo cómo agente de encapsulamiento el cemento Portland CP V-ARI. Los ensayos de durabilidad, realizados según la NBR 13554 (1996), tuvieron como objetivo estudiar el grado de desagregación y v...

Evaluation of dynamic elasticity module in samples of Portland (type 1) cement paste exposed to neutronic irradiation

International Nuclear Information System (INIS)

Rosa Junior, A.A.; Lucki, G.

1986-01-01

The fast neutron radiation effects and temperature on Portland cement are studied. The Dynamic Elasticity Module (Ed) in samples of Portland cement paste was evaluated. Ultrassonic technics were applied (resonance frequency and pulse velocity). The samples were irradiated with fast neutrons to fluence of 7,2 x 10 18 n/cm 2 (E approx. 1 MeV), at temperature of 120 + - 5 0 C, due to gamma heating. This temperature was simulated in laboratory in a microwave oven. (Author) [pt

Portland cement hydration and early setting of cement stone intended for efficient paving materials

Science.gov (United States)

Grishina, A.

2017-10-01

Due to the growth of load on automotive roads, modern transportation engineering is in need of efficient paving materials. Runways and most advanced highways require Portland cement concretes. This makes important the studies directed to improvement of binders for such concretes. In the present work some peculiarities of the process of Portland cement hydration and early setting of cement stone with barium hydrosilicate sol were examined. It was found that the admixture of said sol leads to a shift in the induction period to later times without significant change in its duration. The admixture of a modifier with nanoscale barium hydrosilicates increases the degree of hydration of the cement clinker minerals and changes the phase composition of the hydration products; in particular, the content of portlandite and tricalcium silicate decreases, while the amount of ettringite increases. Changes in the hydration processes of Portland cement and early setting of cement stone that are caused by the nanoscale barium hydrosilicates, allow to forecast positive technological effects both at the stage of manufacturing and at the stage of operation. In particular, the formwork age can be reduced, turnover of molds can be increased, formation of secondary ettringite and corrosion of the first type can be eliminated.

Mineral Trioxide Aggregate and Portland Cement for Direct Pulp Capping in Dog: A Histopathological Evaluation

Directory of Open Access Journals (Sweden)

Maryam Bidar

2014-09-01

Full Text Available Background and aims. Mineral trioxide aggregate and calcium hydroxide are considered the gold standard pulp-capping materials. Recently, Portland cement has been introduced with properties similar to those of mineral trioxide aggregate. His-topathological effects of direct pulp capping using mineral trioxide aggregate and Portland cements on dog dental pulp tis-sue were evaluated in the present study. Materials and methods. This histopatological study was carried out on 64 dog premolars. First, the pulp was exposedwith a sterile bur. Then, the exposed pulp was capped with white or gray mineral trioxide aggregates and white or gray Port-land cements in each quadrant and sealed with glass-ionomer. The specimens were evaluated under a light microscope after 6 months. Statistical analysis was carried out using Kruskal-Wallis test. Statistical significance was defined at α=5%. Results. There was no acute inflammation in any of the specimens. Chronic inflammation in white and gray mineral triox-ide aggregates and white and gray Portland cements was reported to be 45.5%, 27.3%, 57.1% and 34.1%, respectively. Al-though the differences were not statistically significant, severe inflammation was observed mostly adjacent to white mineral trioxide aggregate. The largest extent of increased vascularization (45% and the least increase in fibrous tissue were ob-served adjacent to white mineral trioxide aggregate, with no significant differences. In addition, the least calcified tissue formed adjacent to white mineral trioxide aggregate, although the difference was not significant. Conclusion. The materials used in this study were equally effective as pulp protection materials following direct pulp cap-ping in dog teeth.

Predicting the durability of Portland cement systems in aggressive environments--Laboratory validation

International Nuclear Information System (INIS)

Maltais, Y.; Samson, E.; Marchand, J.

2004-01-01

Portland cement systems are often exposed to severe environments, and their long-term performance is of concern. The main results of a comprehensive investigation of deterioration processes that may affect the behavior of Portland cement systems exposed to chemically aggressive environments is presented. As part of this investigation, well-cured cement paste discs were fully characterized and exposed to deionized water and sodium sulfate solutions. Degradation experiments were conducted under saturated and unsaturated conditions. At the end of the exposure period, microstructural alterations were investigated by microprobe analyses, scanning electron microscope observations and energy-dispersive X-ray analyses. Test results provide information on the basic aspects of various degradation phenomena, such as decalcification and external sulfate attack. Experimental results were also compared with results obtained by a numerical model. The analysis reveals that the intricate microstructural features of the degraded samples could be accurately reproduced by the model

PCB usage at the Grand Junction Area Office Facility. Final report

International Nuclear Information System (INIS)

Miller, M.E.; Donivan, S.

1982-06-01

The development, implementation, and results of the polychlorinated biphenyl (PCB) identification project at the Grand Junction Area Office (GJAO) are summarized. Methodology for the PCB analysis is described, and results are tabulated. Of the 51 transformers and disconnects in use at GJAO, 15 unites were determined to be PCB-contaminated or filled with PCBs. This number falls within EPA's estimate of 25 to 40 percent of all transformers in use being at least contaminated. Approximately 324 gallons of PCBs and 515 gallons of PCB-contaminated fluids are being used currently. No contaminated transformers or disconnects are in a position to contaminate food or feed products at the facility

NESHAP for the Portland Cement Manufacturing Industry: Fact Sheets for Actions Since 2015

Science.gov (United States)

EPA is extending its approval for the use of an alternative method to show compliance with hydrogen chloride (HCl) emissions limits in the National Emission Standards for Hazardous Air Pollutants for the Portland Cement Manufacturing Industry

Healing of apical rarefaction of three nonvital open apex anterior teeth using a white portland cement apical plug

Directory of Open Access Journals (Sweden)

Amitabha Chakraborty

2012-01-01

Full Text Available The major challenge of performing root canal treatment in an open apex pulp-less tooth is to obtain a good apical seal. MTA has been successfully used to achieve a good apical seal, wherein the root canal obturation can be done immediately. MTA and White Portland Cement has been shown similarity in their physical, chemical and biological properties and has also shown similar outcome when used in animal studies and human trials. In our study, open apex of three non vital upper central incisors has been plugged using modified white Portland cement. 3 to 6 months follow up revealed absence of clinical symptoms and disappearance of peri-apical rarefactions. The positive clinical outcome may encourage the future use of white Portland cement as an apical plug material in case of non vital open apex tooth as much cheaper substitute of MTA.

Elemental atmospheric pollution assessment via moss-based measurements in Portland, Oregon

Science.gov (United States)

Demetrios Gatziolis; Sarah Jovan; Geoffrey Donovan; Michael Amacher; Vicente Monleon

2016-01-01

Mosses accumulate pollutants from the atmosphere and can serve as an inexpensive screening tool for mapping air quality and guiding the placement of monitoring instruments. We measured 22 elements using 346 moss samples collected across Portland, Oregon, in December 2013. Our objectives were to develop citywide maps showing concentrations of each element in moss and...

Trees in the city: valuing street trees in Portland, Oregon

Science.gov (United States)

G.H. Donovan; D.T. Butry

2010-01-01

We use a hedonic price model to simultaneously estimate the effects of street trees on the sales price and the time-on-market (TOM) of houses in Portland. Oregon. On average, street trees add $8,870 to sales price and reduce TOM by 1.7 days. In addition, we found that the benefits of street trees spill over to neighboring houses. Because the provision and maintenance...

Effects of chemical and mineral additives and the water/cement ratio on the thermal resistance of Portland cement concrete

International Nuclear Information System (INIS)

Cesar, Leandro Cesar Dias; Morelli, Arnaldo C.; Baldo, Joao Baptista

1998-01-01

The exposure of Portland concrete to high temperatures (>250 deg C) can damage drastically the microstructural integrity of the material. Since the water/cement ratio as well as the inclusion of superplasticizers and mineral additives (silica fume) can alter constitutively and micro structurally the material, in this work it was investigated per effect of these additions on the damage resistance of portland concrete after exposure to high temperatures. (author)

Recycling of porcelain tile polishing residue in portland cement: hydration efficiency.

Science.gov (United States)

Pelisser, Fernando; Steiner, Luiz Renato; Bernardin, Adriano Michael

2012-02-21

Ceramic tiles are widely used by the construction industry, and the manufacturing process of ceramic tiles generates as a major residue mud derived from the polishing step. This residue is too impure to be reused in the ceramic process and is usually discarded as waste in landfills. But the analysis of the particle size and concentration of silica of this residue shows a potential use in the manufacture of building materials based on portland cement. Tests were conducted on cement pastes and mortars using the addition of 10% and 20% (mass) of the residue. The results of compressive strength in mortars made up to 56 days showed a significant increase in compressive strength greater than 50%. The result of thermogravimetry shows that portlandite is consumed by the cement formed by the silica present in the residue in order to form calcium silicate hydrate and featuring a pozzolanic reaction. This effect improves the performance of cement, contributes to research and application of supplementary cementitious materials, and optimizes the use of portland cement, reducing the environmental impacts of carbon dioxide emissions from its production.

D90: The Strongest Contributor to Setting Time in Mineral Trioxide Aggregate and Portland Cement.

Science.gov (United States)

Ha, William N; Bentz, Dale P; Kahler, Bill; Walsh, Laurence J

2015-07-01

The setting times of commercial mineral trioxide aggregate (MTA) and Portland cements vary. It was hypothesized that much of this variation was caused by differences in particle size distribution. Two gram samples from 11 MTA-type cements were analyzed by laser diffraction to determine their particle size distributions characterized by their percentile equivalent diameters (the 10th percentile, the median, and the 90th percentile [d90], respectively). Setting time data were received from manufacturers who performed indentation setting time tests as specified by the standards relevant to dentistry, ISO 6786 (9 respondents) or ISO 9917.1 (1 respondent), or not divulged to the authors (1 respondent). In a parallel experiment, 6 samples of different size graded Portland cements were produced using the same cement clinker. The measurement of setting time for Portland cement pastes was performed using American Society for Testing and Materials C 191. Cumulative heat release was measured using isothermal calorimetry to assess the reactions occurring during the setting of these pastes. In all experiments, linear correlations were assessed between setting times, heat release, and the 3 particle size parameters. Particle size varied considerably among MTA cements. For MTA cements, d90 was the particle size characteristic showing the highest positive linear correlation with setting time (r = 0.538). For Portland cement, d90 gave an even higher linear correlation for the initial setting time (r = 0.804) and the final setting time (r = 0.873) and exhibited a strong negative linear correlation for cumulative heat release (r = 0.901). Smaller particle sizes result in faster setting times, with d90 (the largest particles) being most closely correlated with the setting times of the samples. Copyright © 2015 American Association of Endodontists. All rights reserved.

Fermilab Education Office - Contacts

Science.gov (United States)

Search The Office of Education and Public Outreach: Contacts All telephone numbers require area code Presentations for Presenters 840-3094 Office of Education and Public Outreach Spencer Pasero spasero@fnal.gov Education Office 840-3076 Fermilab Friends for Science Education General Questions Susan Dahl sdahl@fnal.gov

Portland cement for SO.sub.2 control in coal-fired power plants

Science.gov (United States)

Steinberg, Meyer

1985-01-01

There is described a method of removing oxides of sulfur from the emissions of fossil fuel combustion by injecting portland cement into the boiler with the fuel, the combustion air, or downstream with the combustion gases. There is also described the cement products that result from this method.

Portland cement for SO/sub 2/ control in coal-fired power plants

Science.gov (United States)

Steinberg, M.

1984-10-17

A method is described for removing oxides of sulfur from the emissions of fossil fuel combustion by injecting portland cement into the boiler with the fuel, the combustion air, or downstream with the combustion gases. The cement products that result from this method is also described. 1 tab.

Influence Of Cement Kiln Dust As Partial Replacement On Some Properties Of Ordinary And White Portland Cement

Directory of Open Access Journals (Sweden)

Salah Sharif

2013-04-01

Full Text Available Cement Kiln Dust (CKD is produced as a solid waste with large quantities during manufacturing of Portland cement clinker. The possibility of utilizing CKD as partial replacement for Ordinary Portland Cement (OPC and White Portland Cement (WPC produced in factories of the Iraqi cement state company has been examined in this study to fulfil the environmental and economical aims. Different percentages of CKD were blended with OPC and WPC mixes. The results show that the amount of water for normal consistency were increased with about 39 % and 31 % for OPC and WPC blended with 25 % CKD. The setting time (initial and final decreases with increasing percent of CKD added. Compressive strength decreases slightly with increasing CKD content up to 10 %. For 7- day curing time, it decreases 7 % and 9 % for OPC and WPC mixes, respectively. As percent of added CKD increases to more than 10 %, the compressive strength and other parameters where affected significantly. Overall results proved that OPC and WPC blended with up to 10 % CKD are admissible for passing relevant specification requirements.

Physicochemical and mechanical properties of zirconium oxide and niobium oxide modified Portland cement-based experimental endodontic sealers.

Science.gov (United States)

Viapiana, R; Flumignan, D L; Guerreiro-Tanomaru, J M; Camilleri, J; Tanomaru-Filho, M

2014-05-01

To evaluate the physicochemical and mechanical properties of Portland cement-based experimental sealers (ES) with different radiopacifying agents (zirconium oxide and niobium oxide micro- and nanoparticles) in comparison with the following conventional sealers: AH Plus, MTA Fillapex and Sealapex. The materials were tested for setting time, compressive strength, flow, film thickness, radiopacity, solubility, dimensional stability and formaldehyde release. Data were subjected to anova and Tukey tests (P 0.05) and lower solubility when compared with MTA Fillapex and Sealapex (P Portland cement-based experimental endodontic sealers presented physicochemical properties according to the specifications no 57 ANSI/ADA (ADA Professional Product Review, 2008) and ISO 6876 (Dentistry - Root Canal Sealing Materials, 2012, British Standards Institution, London, UK). The sealers had setting times and flow ability that was adequate for clinical use, satisfactory compressive strength and low solubility. Additional studies should be carried out with the purpose of decreasing the film thickness and to determine the ideal ratio of radiopacifying agents in Portland cement-based root canal sealers. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

CACTUS SPRING ROADLESS AREA, CALIFORNIA.

Science.gov (United States)

Matti, Jonathan C.; Kuizon, Lucia

1984-01-01

Geologic, geochemical, and geophysical studies together with a review of historic mining and prospecting activities indicate that the Cactus Spring Roadless Area in California has little promise for the occurrence of mineral or energy resources. Marble bodies occur in the northern part of the roadless area and are possible resources for building stone, crushed and quarried aggregate, and lime and magnesium for Portland cement and industrial applications. It is recommended that the terrane of marble be mapped and sampled carefully in order to evaluate the quantity and quality of the carbonate resources.

Hydration kinetics for the alite, belite, and calcium aluminate phase in Portland cements from 27Al and 29Si MAS NMR spectroscopy

DEFF Research Database (Denmark)

Skibsted, Jørgen; Jensen, Ole Mejlhede; Jakobsen, Hans Jørgen

1997-01-01

29Si magic-angle spinning (MAS) NMR spectroscopy is shown to be a valuable tool for obtaining the quantities of alite and belite in hydrated Portland cements. The hydration (1-180 days) of a white Portland cement with 10 wt.% silica fume added is investigated and the degrees of hydration for alite...

The biomineralization ability of mineral trioxide aggregate and Portland cement on dentin enhances the push-out strength.

Science.gov (United States)

Reyes-Carmona, Jessie F; Felippe, Mara S; Felippe, Wilson T

2010-02-01

Recently, it was shown that the interaction of each of mineral trioxide aggregate (MTA) and Portland cement with dentin in phosphate-buffered saline (PBS) promotes a biomineralization process that leads to the formation of an interfacial layer with tag-like structures at the cement-dentin interface. This study analyzes the influence of the biomineralization process on the push-out strength of ProRoot MTA (Dentsply Tulsa Dental, Tulsa, OK), MTA Branco (Angelus Soluções Odontológicas, Londrina, PR, Brazil), MTA BIO (Angelus Soluções Odontológicas), or Portland cement with and without calcium chloride. Dentin discs with standardized cavities were filled with ProRoot MTA, MTA Branco, MTA BIO, white Portland cement + 20% bismuth oxide (PC1), or PC1 + 10% of calcium chloride (PC2). The specimens were randomly divided into two groups: cement in contact with a wet cotton pellet for 72 hours or immersed in PBS for 2 months. The bond strengths were measured with the Instron Testing machine (Model 4444; Instron Corp, Canton, MA), and the fractured surfaces on the root walls were observed by scanning electron microscopy. All samples immersed in PBS displayed a significantly greater resistance to displacement than that observed for the samples in contact with a wet cotton pellet for 72 hours (p Portland cements. It was concluded that the biomineralization process positively influenced the push-out bond strength of the cements, particularly the MTA groups. Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Experimental investigation of the multiple scatter peak of gamma rays in portland cement in the energy range 279-1332 keV

International Nuclear Information System (INIS)

Singh, Tejbir; Singh, Parjit S

2011-01-01

The pulse height spectra for different thicknesses of portland cement in the reflected geometry has been recorded with the help of a NaI(Tl) scintillator detector and 2 K MCA card using different gamma-ray sources such as Hg 203 (279 keV), Cs 137 (662 keV) and Co 60 (1173 and 1332 keV). It has been observed that the multiple scatter peak for portland cement appears at 110 (±7) keV in all the spectra irrespective of different incident photon energies in the range 279-1332 keV from different gamma-ray sources. Further, the variation in the intensity of the multiple scatter peak with the thickness of portland cement in the backward semi-cylinders has been investigated.

XRF analysis of portland cement for major and trace elements

International Nuclear Information System (INIS)

Abdunnabi, A. R.

2012-12-01

Libyan portland cement produced in several factories around the country, in Lip tis, Zoltan, Souq-Elkamis, Dernah and El-Fatach, were analyzed for quantitative major and trace elements and mineral content, which were compered with those imported from Spain, Romania, Cyprus, and Egypt. X-ray fluorescence spectro X lab 2000 spectrometer equipped with Rh-and X-ray tube was used for the analysis of various samples. The detector Si(Li) with a resolution of 148 eV at Mn K-a=5.9 keV facilitates the determination of a wide range of elements from sodium to uranium, with a detection limit at sub levels. Cement samples in the powder form were analyzed using the pellet-technique. The pellets were prepared by mixing 4g of the cement powder with 0.9 g of binder (HWC) and pressed at high pressure. A ful analysis including, background counting, matrix correction and all relevant corrections were achieved automatically by XLAB 2000 software package. For major and trace elements X RF results were higher for most of the elements than those analyzed with atomic absorption spectrometry. The mineral content showed that Libyan cement is comparable to the imported ones, also the Libyan cement meets the requirements of the international specifications of the portland cement. (Author)

A Histologic Evaluation on Tissue Reaction to Three Implanted Materials (MTA, Root MTA and Portland Cement Type I in the Mandible of Cats

Directory of Open Access Journals (Sweden)

F. Sasani

2004-09-01

Full Text Available Statement of Problem: Nowadays Mineral Trioxide aggregate (MTA is widely used for root end fillings, pulp capping, perforation repair and other endodontic treatments.Investigations have shown similar physical and chemical properties for Portland cement and Root MTA with those described for MTA.Purpose: The aim of this in vitro study was to evaluate the tissue reaction to implanted MTA, Portland cement and Root MTA in the mandible of cats.Materials and Methods: Under asepsis condition and general anesthesia, a mucoperiosteal flap, following the application of local anesthesia, was elevated to expose mandibular symphysis. Two small holes in both sides of mandible were drilled. MTA, Portland cement and Root MTA were mixed according to the manufacturers, recommendation and placed in bony cavities. In positive control group, the test material was Zinc oxide powder plus tricresoformalin. In negative control group, the bony cavities were left untreated. After 3,6 and 12 weeks, the animals were sacrificed and the mandibular sections were prepared for histologic examination under light microscope. The presence and thickness of inflammation, presence of fibrosis capsule, the severity of fibrosis and bone formation were investigated. The data were submitted to Exact Fisher test, chi square test and Kruskal-Wallis test for statistical analysis.Results: No statistically significant differences were found in the degree of inflammation,presence of fibrotic capsule, severity of fibrosis and inflammation thickness between Root MTA, Portland cement and MTA (P>0.05. There was no statistical difference in boneformation between MTA and Portland cement (P>0.05. However, bone formation was not found in any of the Root MTA specimens and the observed tissue was exclusively of fibrosis type.Conclusion: The physical and histological results observed with MTA are similar to those of Root MTA and Portland cement. Additionally, all of these three materials are biocompatible

Development of a participatory Management approach of the Committee for Basic Education School under the Nongbualamphu Primary Educational Service Area Office 2

Directory of Open Access Journals (Sweden)

Jirayu Prommajak

2016-10-01

Full Text Available This study aimed: 1 study the present state and adverse conditions of administration with the participation of the basic education in schools. 2 Development of a participatory Management approach of the Committee for Basic Education school under the Nongbualamphu Primary Educational Service Area Office 2. Split data into 2 phases. Phase 1: The sample used for this research consisted of 128 members of the committee on basic education in school under the Nongbualamphu Primary Educational Service Area Office 2. Selected by using stratified random sampling. Instruments used included a set of rating scale questionnaires. Phase 2: Data from the interviews using a structured questionnaire and focus group discussion. The basic statistics used for analyzing the collected data were percentage, means and standard deviation. The results of this study were as follows: 1. On the present state administration with the participation of the basic education commission in schools underunder the Nongbualamphu Primary Educational Service Area Office 2 overall participation in management is moderate. Considering the individual aspects, found that the academic administration overall participation in management and budget management were moderate. The personnel management and general and administrative overall participation in management at a high level. 2. Adverse conditions of administration with the participation of the school board for basic education in schools underunder the Nongbualamphu Primary Educational Service Area Office 2 overall in a high level. Considering the individual aspects, found that the school board in basic education is desirable to participate in the management of all aspects. 3. Development of a participatory management approach of the committee for basic education school under the Nongbualamphu Primary Educational Service Area Office 2 is a developmental process management principles PDCA, 5 steps. Step 1: Creating a common understanding Step

Determination of coefficient of thermal expansion for Portland Cement Concrete pavements for MEPDG Implementation

Science.gov (United States)

2012-10-01

The Coefficient of Thermal Expansion (CTE) is an important parameter in Portland Cement Concrete (PCC) pavement analysis and design as it is directly proportional to the magnitude of temperature-related pavement deformations throughout the pavement s...

The influence of shrinkage-cracking on the drying behaviour of White Portland cement using Single-Point Imaging (SPI).

Science.gov (United States)

Beyea, S D; Balcom, B J; Bremner, T W; Prado, P J; Cross, A R; Armstrong, R L; Grattan-Bellew, P E

1998-11-01

The removal of water from pores in hardened cement paste smaller than 50 nm results in cracking of the cement matrix due to the tensile stresses induced by drying shrinkage. Cracks in the matrix fundamentally alter the permeability of the material, and therefore directly affect the drying behaviour. Using Single-Point Imaging (SPI), we obtain one-dimensional moisture profiles of hydrated White Portland cement cylinders as a function of drying time. The drying behaviour of White Portland cement, is distinctly different from the drying behaviour of related concrete materials containing aggregates.

United States Coast Guard: Officer Corps Military Professional Development Program

Science.gov (United States)

2011-06-10

captain relieved of command after viewing porn on computer,‖ 10 July 2010, http://www.thenewstribune.com/2010/07/ 10/1259108/portland-coast-guard...Coast Guard captain relieved of command after viewing porn on computer,‖ 10 July 2010. http://www.thenewstribune.com/2010/07/ 10/1259108/portland

Study irradiation damage by fast neutrons in Portland cement by means of ultra-sound

International Nuclear Information System (INIS)

Rosa Junior, A.A.

1988-01-01

The effect of neutron irradiation in samples of Portland cement paste was evaluated, using the resonance frequency method and pulse velocity of ultra-sound technique. The samples were divide in three groups: 1) Monitoring samples; 2) Samples to gamma heating simulation; 3) Fast neutron irradiated samples in reactor core. Santa Rita Portland cement was utilized for samples preparation with water-cement rate of 0,40 l/kg. The irradiation was performed in the research reactor IEA-R1, at IPEN-CNEN/SP, with an integrated flux of 7,2 X 10 sup(18) n/cm sup(2) (E approx. 1 Mev). The samples of group 2 were submitted to special micro-waves heat treatment-with the same number of cycles of the reactor-which allowed the detection of fast neutron radiation effects within the predominant thermal effects. (author)

Ordinary Portland Cement matrix for solidification of cellulosic protective clothes hazardous wastes

International Nuclear Information System (INIS)

Shatta, H.A.; Saleh, H.M.

2006-01-01

The used cellulosic protective clothes constitutes considerable fraction of the hazardous and radioactive wastes accumulated during the practical daily life. The direct solidification of these wastes with ordinary Portland cement resulted in waste forms having undesired characters, therefore, it is recommended to immobilize the secondary waste solutions coming from the oxidative degradation of the used protective clothes waste simulates rather than direct imbedding. IR analyses, X-ray diffraction and thermal characteristics for products of both direct encapsulation of the waste and the cementation of its degradation products were performed to evaluate the properties of the final waste cemented form before their disposal. Based on the results reached from X-ray diffraction, IR spectrograms and thermal analyses reports, it could be stated that no detectable changes in hydration and curing coarse of ordinary Portland cement when mixing the residual secondary waste solution resulting from the oxidative degradation of the used protective clothes waste simulate compared with mixing cement with water and in reverse with imbedding the unprocessed waste in cement matrix

Bioactive coatings on Portland cement substrates: Surface precipitation of apatite-like crystals

International Nuclear Information System (INIS)

Gallego, Daniel; Higuita, Natalia; Garcia, Felipe; Ferrell, Nicholas; Hansford, Derek J.

2008-01-01

We report a method for depositing bioactive coatings onto cement materials for bone tissue engineering applications. White Portland cement substrates were hydrated under a 20% CO 2 atmosphere, allowing the formation of CaCO 3 . The substrates were incubated in a calcium phosphate solution for 1, 3, and 6 days (CPI, CPII, and CPIII respectively) at 37 deg. C to induce the formation of carbonated apatite. Cement controls were prepared and hydrated with and without CO 2 atmosphere (C+ and C- respectively). The presence of apatite-like crystals was verified by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The substrate cytocompatibility was evaluated via SEM after 24 hour cell cultures. SEM revealed the presence Ca(OH) 2 on C-, and CaCO 3 on C+. Apatite-like crystals were detected only on CPIII, confirmed by phosphorus EDS peaks only for CPIII. Cells attached and proliferated similarly well on all the substrates except C-. These results prove the feasibility of obtaining biocompatible and bioactive coatings on Portland cement for bone tissue engineering applications

Portland cement with additives in the repair of furcation perforations in dogs.

Science.gov (United States)

Silva Neto, José Dias da; Schnaider, Taylor Brandão; Gragnani, Alfredo; Paiva, Anderson Paulo de; Novo, Neil Ferreira; Ferreira, Lydia Masako

2012-11-01

To evaluate the use of Portland cements with additives as furcation perforation repair materials and assess their biocompatibility. The four maxillary and mandibular premolars of ten male mongrel dogs (1-1.5 years old, weighing 10-15 kg) received endodontic treatment (n=80 teeth). The furcations were perforated with a round diamond bur (1016 HL). The perforations involved the dentin, cementum, periodontal ligament, and alveolar bone. A calcium sulfate barrier was placed into the perforated bone to prevent extrusion of obturation material into the periradicular space. The obturation materials MTA (control), white, Type II, and Type V Portland cements were randomly allocated to the teeth. Treated teeth were restored with composite resin. After 120 days, the animals were sacrificed and samples containing the teeth were collected and prepared for histological analysis. There were no significant differences in the amount of newly formed bone between teeth treated with the different obturation materials (p=0.879). Biomineralization occurred for all obturation materials tested, suggesting that these materials have similar biocompatibility.

Effect of radiopaque Portland cement on mineralization in human dental pulp cells.

Science.gov (United States)

Min, Kyung-San; Lee, Sang-Im; Lee, Yoon; Kim, Eun-Cheol

2009-10-01

The aim of this study was to investigate whether radiopaque Portland cement (RPC) facilitates the mineralization process in human dental pulp cells (HDPCs) compared with pure Portland cement (PC). Under a scanning electron microscope (SEM), cellular morphology was evaluated. Alkaline phosphatase (ALP) activity was analyzed, and nodule formation was assessed by performing Alizarin Red S staining. In addition, the mRNA expressions of mineralization-related proteins were evaluated by performing a real-time polymerase chain reaction. On SEM evaluation, healthy HDPCs were found adhering to the surfaces of PC and RPC. The ALP activity increased in the PC and RPC groups compared with the control group at 1 day. Alizarin Red stain increased in the PC and RPC groups compared with the control group at 2 and 3 weeks. The mRNA expression of dentin sialophosphoprotein increased at 14 days in the PC and RPC groups. These results show that PC and RPC have similar effects in terms of mineralization and suggest that RPC also has the potential to be used as a clinically suitable pulp-capping material.

Effect of wastewater on properties of Portland pozzolana cement

Science.gov (United States)

Babu, G. Reddy

2017-07-01

This paper presents the effect of wastewaters on properties of Portland pozzolana cement (PPC). Fourteen water treatment plants were found out in the Narasaraopet municipality region in Guntur district, Andhra Pradesh, India. Approximately, from each plant, between 3500 and 4000 L/day of potable water is selling to consumers. All plants are extracting ground water and treating through Reverse Osmosis (RO) process. During water treatment, plants are discharging approximately 1,00,000 L/day as wastewater in side drains in Narasaraopet municipality. Physical and chemical analysis was carried out on fourteen plants wastewater and distilled water as per producer described in APHA. In the present work, based on the concentrations of constituent's in wastewater, four typical plants i.e., Narasaraopeta Engineering College (NECWW), Patan Khasim Charitable Trust (PKTWW), Mahmadh Khasim Charitable Trust (MKTWW) and Amara (ARWW) were considered. The performance of four plants wastewater on physical properties i.e., setting times, compressive strength, and flexural strength of Portland pozzolana Cement (PPC) were performed in laboratories and compared same with reference specimens i.e., made with Distilled Water (DW) as mixing water. No significant change was observed in initial and finial setting time but setting times of selected wastewaters were retarded as compared to that of reference water. Almost, no change was observed in 90 days compressive and flexural strengths in four plants wastewaters specimens compared to that of reference water specimens. XRD technique was employed to find out main hydration compounds formed in the process.

Description of the structural evolution of a hydrating portland cement paste by SANS

International Nuclear Information System (INIS)

Haeussler, F.; Eichhorn, F.; Baumbach, H.

1994-01-01

On the spectrometer MURN at the pulsed reactor IBR-2 dry Portland cement, silica fume, and a hydrating Portland cement paste were studied by small-angle neutron scattering (SANS). By using the TOF-method a momentum transfer from 0.07 nm -1 to 7 nm -1 is detectable. Every component (dry cement powder, clinker minerals, hydrating cement pastes) shows a different scattering behaviour. In the measured Q-region the hardening cement paste does not show a Porod-like behaviour of SANS-curves. In contrast the Porod's potential law holds for dry powder samples of clinker minerals and silica fume. In experiments carried out to observe the hydration progress within the first 321 days the characteristics of the scattering curves (potential behaviour, the radius of gyration, and the macroscopic scattering cross section at Q = 0 nm -1 were measured. Some evolution of the inner structure of the hardened cement paste was noted. (orig.)

Effect of blastfurnace slag addition to Portland cement for cationic exchange resins encapsulation

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Stefan L.

2013-07-01

Full Text Available In the nuclear industry, cement-based materials are extensively used to encapsulate spent ion exchange resins (IERs before their final disposal in a repository. It is well known that the cement has to be carefully selected to prevent any deleterious expansion of the solidified waste form, but the reasons for this possible expansion are not clearly established. This work aims at filling the gap. The swelling pressure of IERs is first investigated as a function of ions exchange and ionic strength. It is shown that pressures of a few tenths of MPa can be produced by decreases in the ionic strength of the bulk solution, or by ion exchanges (2Na+ instead of Ca2+, Na+ instead of K+. Then, the chemical evolution of cationic resins initially in the Na+ form is characterized in CEM I (Portland cement and CEM III (Portland cement + blastfurnace slag cements at early age and an explanation is proposed for the better stability of CEM III material.

Effect of addition of Sikament-R superplasticizer on the hydration characteristics of portland cement pastes

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Safaa.M. El Gamal

2012-08-01

Full Text Available The effect of addition of Sikament-R superplasticizer (modified lignosulphonate base on the hydration characteristics of hardened Portland cement pastes were studied at different curing conditions. Four mixtures were prepared using 0, 0.2, 0.4 and 0.6 wt% addition of Sikament-R superplasticizer (SR of cement. These pastes were hydrated under two different conditions; (i normal curing at room temperature; 25 °C up to 90 days periods and (ii hydrothermal curing at a pressure of 8 atm. of saturated steam up to 24 h. The compressive strength, combined water content, free lime content, gel/space ratio and microstructure of hardened cement pastes were studied. The results revealed that addition of SR superplasticizer promote the dispersion of cement particles and interacts with Ca(OH2. The addition of SR superplasticizer exhibits Portland cement better workability during the preparation of pastes. In addition, amore compact structure were obtained leading to higher values of compressive strength for all the hardened hydrated pastes under both normal and hydrothermal curing. The results indicated that the addition of SR superplasticizer to Portland cement does not alter the types of hydration products formed during normal or hydrothermal conditions; only it caused a decrease in the degree of the porosity of the formed pastes.

Possibility of using waste tire rubber and fly ash with Portland cement as construction materials.

Science.gov (United States)

Yilmaz, Arin; Degirmenci, Nurhayat

2009-05-01

The growing amount of waste rubber produced from used tires has resulted in an environmental problem. Recycling waste tires has been widely studied for the last 20 years in applications such as asphalt pavement, waterproofing systems and membrane liners. The aim of this study is to evaluate the feasibility of utilizing fly ash and rubber waste with Portland cement as a composite material for masonry applications. Class C fly ash and waste automobile tires in three different sizes were used with Portland cement. Compressive and flexural strength, dry unit weight and water absorption tests were performed on the composite specimens containing waste tire rubber. The compressive strength decreased by increasing the rubber content while increased by increasing the fly ash content for all curing periods. This trend is slightly influenced by particle size. For flexural strength, the specimens with waste tire rubber showed higher values than the control mix probably due to the effect of rubber fibers. The dry unit weight of all specimens decreased with increasing rubber content, which can be explained by the low specific gravity of rubber particles. Water absorption decreased slightly with the increase in rubber particles size. These composite materials containing 10% Portland cement, 70% and 60% fly ash and 20% and 30% tire rubber particles have sufficient strength for masonry applications.

NOAA Office for Coastal Management Coastal Inundation Digital Elevation Model: Portland (OR) WFO - Tillamook, Lincoln, and Lane Counties

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This digital elevation model (DEM) is a part of a series of DEMs produced for the National Oceanic and Atmospheric Administration Office for Coastal Management's Sea...

Characterization and chemical activity of Portland cement and two experimental cements with potential for use in dentistry.

Science.gov (United States)

Camilleri, J

2008-09-01

To evaluate the chemical activity of Portland cement and two other cement types with similar chemical composition to mineral trioxide aggregate with the aim of developing these cements for further applications in dentistry. The chemical composition of the three cement types namely Portland cement, calcium sulpho-aluminate cement and calcium fluoro-aluminate cement was evaluated by elemental analysis using energy dispersive analysis with X-ray under the scanning electron microscope and by X-ray diffraction analysis (XRD) to determine the phases. The constituents of the hydration reaction by-products were evaluated by XRD analysis of the set cements at 1, 7, 28 and 56 days and by analysis of the leachate by ion chromatography. The pH of both cements and leachate was determined at different time intervals. Cements admixed with micro-silica were also tested to determine the effect of micro-silica on the reaction by-products. All three cement types were composed of tricalcium silicate as the main constituent phase. The hydration reaction of Portland cement produced calcium hydroxide. However, this was not present in the other cements tested at all ages. Admixed micro-silica had little or no effect on the cements with regard to reaction by-products. The pH of all cements tested was alkaline. Both the experimental calcium sulpho-aluminate cement and calcium fluoro-aluminate cement had different hydration reactions to that of Portland cement even though calcium silicate was the major constituent element of both cement types. No calcium hydroxide was produced as a by-product to cement hydration. Micro-silica addition to the cement had no effect on the hydration reaction.

Clinical and computed tomographic evaluation of portland cement pulpotomy in primary molar: A case report

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Kamrun Nahar

2016-08-01

Full Text Available The present case describes the clinical & radiographic outcome of a Portland Cement pulpotomy. The 5 years old girl presenting extensive carious exposure in her mandibular left 2nd deciduous molar and was suffering pain in her left lower jaw only on exposure to cold for last 2 days. She was ultimately diagnosed clinic-radio-graphically as a case of irreversible pulpitis. Coronal pulpotomy procedure was carried out in the responsible tooth and Portland cement (PC was applied as a medicament after pulpotomy. At the 3 & 6-months follow-up appointments, treated tooth was asymptomatic clinically and radiographic examinations revealed no sign of periradicular pathosis in the pulpotomized teeth. Additionally, the formation of a dentin bridge immediately below the PC in the treated tooth was confirmed by RVG and CBCT.

Pacific Northwest National Laboratory Annual Site Environmental Report for Calendar Year 2013

Energy Technology Data Exchange (ETDEWEB)

Duncan, Joanne P. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Sackschewsky, Michael R. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Tilden, Harold T. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Barnett, J. Matthew [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Su-Coker, Jennifer [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Ballinger, Marcel Y. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Fritz, Brad G. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Stoetzel, Gregory A. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Lowry, Kami L. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Moon, Thomas W. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Becker, James M. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Mendez, Keith M. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Raney, Elizabeth A. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Chamness, Michele A. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Larson, Kyle B. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

2014-09-30

Pacific Northwest National Laboratory (PNNL), one of the U.S. Department of Energy (DOE) Office of Science’s 10 national laboratories, provides innovative science and technology development in the areas of energy and the environment, fundamental and computational science, and national security. DOE’s Pacific Northwest Site Office (PNSO) is responsible for oversight of PNNL at its Campus in Richland, Washington, as well as its facilities in Sequim, Seattle, and North Bonneville, Washington, and Corvallis and Portland, Oregon.

Solidification of ion exchange resins saturated with Na+ ions: Comparison of matrices based on Portland and blast furnace slag cement

International Nuclear Information System (INIS)

Lafond, E.; Cau dit Coumes, C.; Gauffinet, S.; Chartier, D.; Stefan, L.; Le Bescop, P.

2017-01-01

This work is devoted to the conditioning of ion exchange resins used to decontaminate radioactive effluents. Calcium silicate cements may have a good potential to encapsulate spent resins. However, certain combinations of cement and resins produce a strong expansion of the final product, possibly leading to its full disintegration. The focus is placed on the understanding of the behaviour of cationic resins in the Na + form in Portland or blast furnace slag (CEM III/C) cement pastes. During hydration of the Portland cement paste, the pore solution exhibits a decrease in its osmotic pressure, which causes a transient expansion of small magnitude of the resins. At 20 °C, this expansion takes place just after setting in a poorly consolidated material and is sufficient to induce cracks. In the CEM III/C paste, swelling of the resins also occurs, but before the end of setting, and induces limited stress in the matrix which is still plastic. - Highlights: • Solidification of cationic resins in the Na + -form is investigated. • Portland and blast furnace slag cements are compared. • Deleterious expansion is observed with Portland cement only. • Resin swelling is due to a decrease in the osmotic pressure of the pore solution. • The consolidation rate of the matrix is a key parameter to prevent damage.

Puzzolanic cements of greater resistance at the attack of selenitic waters than the high sulfate resistance portland cements, and viceverse

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Talero, Rafael

1987-09-01

Full Text Available This work confirms the certainty of the predictions of useful service given by Kaluosek and al. for the sulphate resistant portland cements (type V, USA, subject to severe selenitic attack. Two sulphate resistant portland cements, were tested by means of the Le Chatelier Anstett method. The tarts were destroyed at ages of three years, having detected in them the presence of thaumasite by XRD. Even so, the impossibility and possibility thaumasite formation was confirmed in pozzolanic cements tarts, which either had or did not have adequate amount of pozzolana (diatomite for such purpose.

Este trabajo confirman las predicciones de vida útil dadas por Kalousek y colaboradores, para los cementos portland de elevada resistencia al ataque de los iones sulfato (tipo V, USA, sometidos a un severo ataque selenitoso. Se ensayaron dos cementos portland de elevada resistencia al ataque del yeso, mediante el ensayo de Le Chatelier-Anstett. Sus tortas correspondientes se destruyeron a la edad de tres años, habiéndose detectado en las mismas la presencia de thaumasita por DRX. Asimismo se confirmó la imposibilidad y posibilidad de formación de thaumasita en tortas de cementos puzolánicos, los cuales tenían, o no, respectivamente, una adecuada cantidad de puzolana (diatomita para tales fines.

The Arabic Version of the Mayo-Portland Adaptability Inventory 4: A Validation Study

Science.gov (United States)

Hamed, Razan; Tariah, Hashem Abu; Malkawi, Somaya; Holm, Margo B.

2012-01-01

The Mayo-Portland Adaptability Inventory 4 (MPAI-4) is a valid and reliable assessment tool to detect clinical impairments in patients with acquired brain injury. The tool is widely used by rehabilitation therapists worldwide, given its good psychometric properties and its availability in several languages. The purpose of this study was to…

Relation between Portland cement carbonation, range of clinker burning and some expansive phenomena in the autoclave test

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Ruiz de Cauna, A.

1975-12-01

Full Text Available Not availableEn este trabajo se estudia el doble pico que aparece en la región de altas temperaturas de las curvas derivatométricas, realizadas en atmósfera de vapor de agua, de los cementos portland anhidros e hidratados y en general el efecto de la carbonatación sobre los silicatos y aluminatos presentes en los cementos portland, especialmente sobre el perfil de las curvas derivatométricas de los cementos portland anhidros e hidratados. Se recogen y examinan los cambios experimentados en el doble pico al someter los cementos a la acción de diversos tratamientos y de agentes modificantes, tales como el tiempo, el CO2, la hidratación normal, las hidrataciones bajo agua a ebullición, en autoclave y en suspensión acuosa con agitación, la adición de puzolana y de fuertes proporciones de S04Ca. Se estudia y compara, asimismo, el comportamiento al análisis térmico bajo vapor de agua y al ensayo de autoclave de algunos clínkeres y cementos que presentan el doble pico en forma acusada y poco apreciable, respectivamente. De los resultados obtenidos se deducen conclusiones que explican los comportamientos experimentales observados. Las principales conclusiones se refieren a la interpretación de los picos que aparecen en las curvas derivatométricas o de velocidad de pérdida de peso de los cementos portland anhidros e hidratados, y a algunos aspectos de su carbonatación, a la probable existencia de un compuesto intermedio, consecuencia de la incompleta formación del silicato tricálcico y a la explicación de determinadas grandes expansiones producidas en el ensayo de autoclave.

A thermodynamic approach to the hydration of sulphate-resisting Portland cement

International Nuclear Information System (INIS)

Lothenbach, Barbara; Wieland, Erich

2006-01-01

A thermodynamic approach is used to model changes in the hydrate assemblage and the composition of the pore solution during the hydration of calcite-free and calcite-containing sulphate-resisting Portland cement CEM I 52.5 N HTS. Modelling is based on thermodynamic data for the hydration products and calculated hydration rates for the individual clinker phases, which are used as time-dependent input parameters. Model predictions compare well with the composition of the hydrate assemblage as observed by TGA and semi-quantitative XRD and with the experimentally determined compositions of the pore solutions. The calculations show that in the presence of small amounts of calcite typically associated with Portland cement, C-S-H, portlandite, ettringite and calcium monocarbonate are the main hydration products. In the absence of calcite in the cement, however, siliceous hydrogarnet instead of calcium monocarbonate is observed to precipitate. The use of a higher water-to-cement ratio for the preparation of a calcite-containing cement paste has a minor effect on the composition of the hydrate assemblage, while it significantly changes the composition of the pore solution. In particular, lower pH value and higher Ca concentrations appear that could potentially influence the solubility and uptake of heavy metals and anions by cementitious materials

Effectiveness of shrinkage-reducing admixtures on Portland pozzolan cement concrete

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Videla, C.

2005-06-01

Full Text Available Drying shrinkage causes tensile stress in restrained concrete members. Since all structural elements are subject to some degree of restraint, drying shrinkage is regarded to be one of the main causes of concrete cracking. The purpose of the present study was to evaluate the effectiveness of SRA in reducing drying shrinkage strain in Portland pozzolan cement concrete. The major variables examined included slump, admixture type and dose, and specimen size. The measured results indicate that any of the admixtures used in the study significantly reduced shrinkage. Concrete manufactured with shrinkage reducing admixtures shrank an average of 43% less than concrete without admixtures. As a rule, the higher the dose of admixture, the higher was its shrinkage reduction performance. The experimental results were compared to the shrinkage strain estimated with the ACI 209, CEB MC 90, B3, GL 2000, Sakata 1993 and Sakata 2001 models. Although none of these models was observed to accurately describe the behaviour of Portland pozzolan cement concrete with shrinkage reducing admixtures, the Sakata 2001 model, with a weighted coefficient of variation of under 30%, may be regarded to be roughly adequate.

La retracción por secado es un fenómeno intrínseco del hormigón que produce tensiones de tracción en elementos restringidos de hormigón. Puesto que todos los elementos presentan algún grado de retracción, se considera a la retracción por secado como una de las principales causas de agrietamiento en proyectos de construcción en hormigón. Por lo tanto, el objetivo de esta investigación fue evaluar la efectividad de los aditivos reductores de retracción (SRA en hormigones fabricados con cemento Portland puzolánico. Las variables principales estudiadas incluyen el asentamiento de cono de Abrams, marca y dosis de aditivo reductor de retracción, y tamaño de espécimen de hormigón. Los resultados obtenidos permiten concluir que el uso de

Application of probabilistic risk assessment: Evaluating remedial alternatives at the Portland Harbor Superfund Site, Portland, Oregon, USA.

Science.gov (United States)

Ruffle, Betsy; Henderson, James; Murphy-Hagan, Clare; Kirkwood, Gemma; Wolf, Frederick; Edwards, Deborah A

2018-01-01

A probabilistic risk assessment (PRA) was performed to evaluate the range of potential baseline and postremedy health risks to fish consumers at the Portland Harbor Superfund Site (the "Site"). The analysis focused on risks of consuming fish resident to the Site containing polychlorinated biphenyls (PCBs), given that this exposure scenario and contaminant are the primary basis for US Environmental Protection Agency's (USEPA's) selected remedy per the January 2017 Record of Decision (ROD). The PRA used probability distributions fit to the same data sets used in the deterministic baseline human health risk assessment (BHHRA) as well as recent sediment and fish tissue data to evaluate the range and likelihood of current baseline cancer risks and noncancer hazards for anglers. Areas of elevated PCBs in sediment were identified on the basis of a geospatial evaluation of the surface sediment data, and the ranges of risks and hazards associated with pre- and postremedy conditions were calculated. The analysis showed that less active remediation (targeted to areas with the highest concentrations) compared to the remedial alternative selected by USEPA in the ROD can achieve USEPA's interim risk management benchmarks (cancer risk of 10 -4 and noncancer hazard index [HI] of 10) immediately postremediation for the vast majority of subsistence anglers that consume smallmouth bass (SMB) fillet tissue. In addition, the same targeted remedy achieves USEPA's long-term benchmarks (10 -5 and HI of 1) for the majority of recreational anglers. Additional sediment remediation would result in negligible additional risk reduction due to the influence of background. The PRA approach applied here provides a simple but adaptive framework for analysis of risks and remedial options focused on variability in exposures. It can be updated and refined with new data to evaluate and reduce uncertainty, improve understanding of the Site and target populations, and foster informed remedial decision

Addition of polyurethane dispersions to Portland G for oil wells steam injection submitted to vapor injection; Adicao de poliuretana em dispersao a Portland G para cimentacao de pocos de petroleo sujeitos a injecao de vapor

Energy Technology Data Exchange (ETDEWEB)

Silva, L.B. da; Lima, F.M. de; Martinelli, A.M.; Bezerra, U.T.; Mello, D.M.A. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Araujo, R.G.S. [PETROBRAS, Rio de Janeiro, RJ (Brazil)

2004-07-01

Portland cement is by far the most important binding material used in oil well cementing. The cement sheath is responsible for both the mechanical stability of the wellbore and zonal isolation. During primary cementing and the production lifespan of the well, the cement sheath is exposed to adverse thermo-mechanical conditions, which may crack the intrinsically brittle cement material. Cracking affects the mechanical integrity of the sheath resulting in the contamination of oil or gas pay zones, as well as in the increase of producing costs related to the extraction of pebble and water. This scenario is especially encountered in wells containing heavy oils, typical of the Northeastern region of Brazil. The objective of the present study was to improve the fracture toughness of hardened Special Portland Cement slurries by the addition of aqueous polyurethane to Portland-based slurries used in primary cementing, plug backs and squeeze operations, improving environmental and economical impacts. The results revealed that the addition of polyurethane increased the viscosity of the slurry but still within the limits established by oil well cement guidelines. No significant increase was observed in the compressive strength of the cement. However, the addition of polyurethane improved the toughness of the cement increasing its ability to withstand thermo-mechanical cycles typical of heavy oil recovery. In addition, significant reduction in permeability was observed as the contents of polyurethane increased, contributing to the reduction in set time and gas migration through the cement sheath. (author)

Influence of bismuth oxide concentration on the pH level and biocompatibility of white Portland cement.

Science.gov (United States)

Marciano, Marina Angélica; Garcia, Roberto Brandão; Cavenago, Bruno Cavalini; Minotti, Paloma Gagliardi; Midena, Raquel Zanin; Guimarães, Bruno Martini; Ordinola-Zapata, Ronald; Duarte, Marco Antonio Hungaro

2014-01-01

To investigate if there is a relation between the increase of bismuth oxide and the decrease of pH levels and an intensification of toxicity in the Portland cement. White Portland cement (WPC) was mixed with 0, 15, 20, 30 and 50% bismuth oxide, in weight. For the pH level test, polyethylene tubes were filled with the cements and immersed in Milli-Q water for 15, 30 and 60 days. After each period, the increase of the pH level was assessed. For the biocompatibility, two polyethylene tubes filled with the cements were implanted in ninety albino rats (n=6). The analysis of the intensity of the inflammatory infiltrate was performed after 15, 30 and 60 days. The statistical analysis was performed using the Kruskal-Wallis, Dunn and Friedman tests for the pH level and the Kruskal-Wallis and Dunn tests for the biological analysis (p0.05). For the inflammatory infiltrates, no significant statistical differences were found among the groups in each period (p>0.05). The 15% WPC showed a significant decrease of the inflammatory infiltrate from 15 to 30 and 60 days (pPortland cement did not affect the pH level and the biological response. The concentration of 15% of bismuth oxide resulted in significant reduction in inflammatory response in comparison with the other concentrations evaluated.

The Influence of Diatomite on the Strength and Microstructure of Portland Cement

Directory of Open Access Journals (Sweden)

Liu Jun

2016-01-01

Full Text Available To study the influence of the types and mixing amount of diatomite on the Portland cement, we prepared the cement specimen doped with the calcined first-grade, first-grade and second-grade diatomite ,tested the 3d, 7d, 14d compressive strength, and studied and discussed phase, structure and morphology of diatomite in the binary system by the method of XRD, SEM . Experimental results show that with the addition of diatomite, the strength of cement paste increase; the optimal contents of calcined first-grade ,first-grade and second-grade diatomite in Portland cement are 5%,Compared to the blank group, the strength of specimen can be increased by 54.6%, 15.4% and 10.2%, respectively; At the same time ,the 7d microscopic hydration of different diatomite particles were analyzed through the experiment , and the shell of calcined diatomite particles were better hydrated than that of first-grade and second-grade diatomite particles. The results indicate that the diatomite can improve the strength of cement paste, the hydration of different diatomite particles can influence the growth of cement paste strength.

Office of Technology Development FY 1993 program summary: Office of Research and Development, Office of Demonstration, Testing and Evaluation. Revision 1

Energy Technology Data Exchange (ETDEWEB)

1994-02-01

This report summarizes significant FY93 programmatic information and accomplishments relevant to the individual activities within the Office of Technology Development Program for Research, Development, Demonstration, Testing, and Evaluation (RDDT&E). A brief discussion of the mission of the Office of Environmental Restoration and Waste Management (EM) and the Office of Technology Development is presented. An overview is presented of the major problem areas confronting DOE. These problem areas include: groundwater and soils cleanup; waste retrieval and processing; and pollution prevention. The organizational elements within EM are highlighted. An EM-50 Funding Summary for FY92 and FY93 is also provided. RDDT&E programs are discussed and their key problem areas are summarized. Three salient program-formulating concepts are explained. They are: Integrated Demonstrations, Integrated Programs, and the technology window of opportunity. Detailed information for each of the programs within RDDT&E is presented and includes a fact sheet, a list of technical task plans and an accomplishments and objectives section.

Office of Technology Development FY 1993 program summary: Office of Research and Development, Office of Demonstration, Testing and Evaluation. Revision 1

International Nuclear Information System (INIS)

1994-02-01

This report summarizes significant FY93 programmatic information and accomplishments relevant to the individual activities within the Office of Technology Development Program for Research, Development, Demonstration, Testing, and Evaluation (RDDT ampersand E). A brief discussion of the mission of the Office of Environmental Restoration and Waste Management (EM) and the Office of Technology Development is presented. An overview is presented of the major problem areas confronting DOE. These problem areas include: groundwater and soils cleanup; waste retrieval and processing; and pollution prevention. The organizational elements within EM are highlighted. An EM-50 Funding Summary for FY92 and FY93 is also provided. RDDT ampersand E programs are discussed and their key problem areas are summarized. Three salient program-formulating concepts are explained. They are: Integrated Demonstrations, Integrated Programs, and the technology window of opportunity. Detailed information for each of the programs within RDDT ampersand E is presented and includes a fact sheet, a list of technical task plans and an accomplishments and objectives section

Characteristics of novel root-end filling material using epoxy resin and Portland cement.

Science.gov (United States)

Lee, Sang-Jin; Chung, Jin; Na, Hee-Sam; Park, Eun-Joo; Jeon, Hyo-Jin; Kim, Hyeon-Cheol

2013-04-01

The aim of this study was to evaluate the physical properties and cytotoxicity of a novel root-end filling material (EPC) which is made from epoxy resin and Portland cement as a mineral trioxide aggregate (MTA) substitute. EPC, developed as a root-end filling material, was compared with MTA and a mixture of AH Plus sealer and MTA (AMTA) with regard to the setting time, radio-opacity, and microleakage. Setting times were evaluated using Vicat apparatus. Digital radiographs were taken to evaluate the aluminium equivalent radio-opacity using an aluminium step wedge. Extracted single-rooted teeth were used for leakage test using methylene blue dye. After canal shaping and obturation, the apical 3-mm root was resected, and a root-end cavity with a depth of 3 mm was prepared. The root-end cavities were filled with MTA, AMTA, and EPC for 15 specimens in each of three groups. After setting in humid conditions for 24 h, the specimens were tested for apical leakage. For evaluation of the biocompatibility of EPC, cell (human gingival fibroblast) viability was compared for MTA and Portland cement by MTT assay, and cell morphological changes were compared for MTA and AH Plus by fluorescence microscopy using DAPI and F-actin staining. The setting time, radio-opacity, and microleakage were compared using one-way ANOVA and Scheffe's post hoc comparison, and the cytotoxicity was compared using the nonparametric Kruskal-Wallis rank sum test. Statistical significance was set at 95%. EPC had a shorter setting time and less microleakage compared with MTA (p Portland cement, was found to be a useful material for root-end filling, with favourable radio-opacity, short setting time, low microleakage, and clinically acceptable low cytotoxicity. The novel root-end filling material would be a potentially useful material for a surgical endodontic procedure with favourable properties.

Effect of calcium/silicon ratio on retention of uranium (VI) in portland cement materials

International Nuclear Information System (INIS)

Tan Hongbin; Li Yuxiang

2005-01-01

Calcium silicate hydrate (CSH) materials of varied calcium to silicon (Ca/Si) ratios were prepared by hydrothermal synthesis at 80 degree C, with calcium oxide and micro-silicon employed. These products were determined to be of gel phase by XRD. Leaching tests with 1% hydrochloric acid indicated that more Uranium (VI) was detained by CSH with lower Ca/Si ratios. Alkali-activated slag cement (with a lower Ca/Si ratio) was found to have a stronger retention capacity than Portland cement (with a higher Ca/Si ratio), at 25 degree C in 102-days leaching tests with simulated solidified forms containing Uranium (VI). The accumulative leaching fraction of Uranium (VI) for Alkali-activated slag cement solidified forms is 17.6% lower than that for Portland cement. The corresponding difference of diffusion coefficients is 40.6%. This could be correlated with the difference of Ca/Si ratios between cements of two kinds. (authors)

Measurement of the leaching rate of radionuclide 134Cs from the solidified radioactive sources in Portland cement mixed with microsilica and barite matrixes

International Nuclear Information System (INIS)

Shaaban, Ismail; Assi, Nasim

2011-01-01

Portland cement was mixed with radionuclide 134 Cs to produce low-level radioactive sources. These sources were surrounded with cement mixed with different materials like microsilica and barite. The leaching rate of 134 Cs from the solidified radioactive source in Portland cement alone was found to be 4.481 x 10 -4 g/cm 2 per day. Mixing this Portland cement with microsilica and with barite reduced significantly the leaching rate to 1.091 x 10 -4 g/cm 2 per day and 3.153 x 10 -4 g/cm 2 per day for 1 wt.% mixing, and to 1.401 x 10 -5 g/cm 2 per day and 1.703 x 10 -4 g/cm 2 per day for 3 wt.% mixing, respectively. It was also found that the application of a latex paint reduced these leaching rates by about 6.5%, 20.3% and 13.3% for Portland cement, cement mixed with microsilica and with barite, respectively. The leaching data were also analyzed using the polynomial method. The obtained results showed that cement mixed with microsilica and with barite can be effectively used for radioactive sources solidification.

Durabilidad de un suelo contaminado y tratado con cemento portland Durability of a contaminated soil treated with portland cement

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José W Jiménez Rojas

2008-01-01

Full Text Available Este trabajo tiene por objetivo la aplicación de la técnica de solidificación/estabilización de suelos contaminados, analizando específicamente el comportamiento físico del suelo a través de ensayos de durabilidad. El suelo fue contaminado en laboratorio con residuo oleoso y la aplicación de la técnica tuvo cómo agente de encapsulamiento el cemento Portland CP V-ARI. Los ensayos de durabilidad, realizados según la NBR 13554 (1996, tuvieron como objetivo estudiar el grado de desagregación y vulnerabilidad del material con diversas combinaciones de dosificaciones de cemento y residuo oleoso, así cómo estudiar la variación volumétrica de los mismos. A partir de los resultados es posible observar que cuanto mayor la cantidad de contaminante, mayor es la pérdida de masa. Sin embargo, cuánto mayor es la cantidad de cemento, menor es la pérdida de masa y menor la variación volumétrica.This work seeks the application of solidification/stabilization techniques to contaminated soils analyzing specifically de physical behavior of the soil through tests of durability. The soil was contaminated in laboratory with acidic oily sludge industrial residues and the application of that technique had an encapsulate agent, the Portland cement CP V-ARI. The tests were carried out according to NBR 13.554 (1996, and they aimed to study the level of degradation and the vulnerability of the material with several combinations of cement and acidic oily sludge as well as study their volumetric variations. Starting from the results, it is possible to observe that the larger the contamination the larger the mass loss; however the larger the amount of cement, the smaller the mass loss and the more stable the volumetric variation.

Properties of expansive cements, made with Portland cement, gypsum and high alumina cement

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Monfore, G. E.

1966-03-01

Full Text Available Not availableLos cementos expansivos se han desarrollado durante las tres décadas pasadas, principalmente por las investigaciones llevadas a cabo en Francia, URSS y Estados Unidos. Los cementos expansivos que fueron utilizados en los estudios de los cuales se da cuenta en el presente trabajo se obtuvieron mediante la mezcla de cemento Portland, cemento aluminoso y yeso. En las investigaciones se utilizaron morteros con los cuales se pudo determinar los efectos de la composición, tiempo y temperatura de curado sobre las resistencias, dilatación libre, retracción y desarrollo de resistencias en probetas pretensadas. Se hace una revisión sobre los estudios hechos con cementos expansivos y desarrollados en la Universidad de California. Las propiedades de taIes hormigones son, en términos generales, comparables a aquellos obtenidos con mezclas de cementos portland, cemento aluminoso y yeso. Es necesaria más información sobre pérdidas de tensión en los aceros y durabilidad de los hormigones autopretensados.

Radioactive waste-Portland cement systems: I, radionuclide distribution

International Nuclear Information System (INIS)

Jantzen, C.M.; Glasser, F.P.; Lachowski, E.E.

1984-01-01

Crystal chemical stabilization of radioactive wastes can be achieved during clinkering of, or with, ordinary portland cement. Waste loadings of 20 to 30 wt% are achieved by dilute solid solution of waste ions into cementitious host lattices. Higher waste loadings result in compatible noncementitious radiophases. The cementitious phases hydrate without loss of compressive strength. Crystallochemical relationships predict that the radionuclide partitioning in the anhydrous clinkered phases will be maintained in the hydration products. These cementitious hydroxylated radiophases would be in internal equilibrium under anticipated repository conditions. The radionuclide distributions observed are described in the context of established phase equilibria for commercial waste cement systems, but are applicable to transuranic, medium- and low-level wastes

Evaluation of the effect of intrinsic material properties and ambient conditions on the dimensional stability of white mineral trioxide aggregate and Portland cement.

Science.gov (United States)

Camilleri, Josette

2011-02-01

A number of factors affect the dimensional stability of a material. These factors include curing conditions, material solubility, leaching, and time. The aim of this study was to evaluate the restrained dimensional change in the vertical direction as a function of the ambient conditions, fluid uptake, solubility, and leaching of white mineral trioxide aggregate (MTA) and Portland cement stored in Hank's balanced salt solution (HBSS) over a period of 28 days. The dimensional change in the vertical direction over a 28-day period was determined using a linear variable differential transducer (LVDT) on laterally restrained test samples. The fluid uptake and solubility of both MTA and Portland cement was also evaluated. The leaching in water and HBSS was assessed using inductively coupled plasma. MTA was more soluble than Portland cement. Both materials absorbed water and physiological solution, with Portland cement displaying a lower uptake than MTA. Both cements exhibited a net expansion when in contact with a physiological solution and released high levels of calcium. MTA leached bismuth. Both calcium and bismuth ion release was higher in HBSS than in water. Phosphorus ions in HBSS were depleted when in contact with both MTA and Portland cement. The MTA was very susceptible to ambient conditions. The addition of bismuth oxide to MTA reduced the leaching of calcium hydroxide, increased the material solubility, and caused deterioration in material dimensional stability. Further research is necessary to establish the material porosity and its effect on the dimensional stability. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Solidification of ion exchange resins saturated with Na{sup +} ions: Comparison of matrices based on Portland and blast furnace slag cement

Energy Technology Data Exchange (ETDEWEB)

Lafond, E. [CEA, DEN, DTCD, SPDE, F-30207 Bagnols-sur-Cèze cedex (France); Cau dit Coumes, C., E-mail: celine.cau-dit-coumes@cea.fr [CEA, DEN, DTCD, SPDE, F-30207 Bagnols-sur-Cèze cedex (France); Gauffinet, S. [Laboratoire Interdisciplinaire Carnot de Bourgogne UMR 6303 CNRS-Université de Bourgogne, Dijon, France, 9 Av Alain Savary, BP 47870, 21078 Dijon cedex (France); Chartier, D. [CEA, DEN, DTCD, SPDE, F-30207 Bagnols-sur-Cèze cedex (France); Stefan, L. [AREVA, Back End Business Group, Dismantling & Services, 1 Place Jean Millier, 92084 Paris La Défense (France); Le Bescop, P. [CEA, DEN, DPC, SECR, F-91192 Gif-sur-Yvette (France)

2017-01-15

This work is devoted to the conditioning of ion exchange resins used to decontaminate radioactive effluents. Calcium silicate cements may have a good potential to encapsulate spent resins. However, certain combinations of cement and resins produce a strong expansion of the final product, possibly leading to its full disintegration. The focus is placed on the understanding of the behaviour of cationic resins in the Na{sup +} form in Portland or blast furnace slag (CEM III/C) cement pastes. During hydration of the Portland cement paste, the pore solution exhibits a decrease in its osmotic pressure, which causes a transient expansion of small magnitude of the resins. At 20 °C, this expansion takes place just after setting in a poorly consolidated material and is sufficient to induce cracks. In the CEM III/C paste, swelling of the resins also occurs, but before the end of setting, and induces limited stress in the matrix which is still plastic. - Highlights: • Solidification of cationic resins in the Na{sup +}-form is investigated. • Portland and blast furnace slag cements are compared. • Deleterious expansion is observed with Portland cement only. • Resin swelling is due to a decrease in the osmotic pressure of the pore solution. • The consolidation rate of the matrix is a key parameter to prevent damage.

Preparation and Physical Assessment of Portland Cement Base Composites Containing Nano Particles

OpenAIRE

Amir Mahmoudi

2015-01-01

In this research the effects of adding silica and alumina nanoparticles on flow ability and compressive strength of cementitious composites based on Portland cement were investigated. In the first stage, the rheological behavior of different samples containing nanosilica, nanoalumina and polypropylene, polyvinyl alcohol and polyethylene fibers were evaluated. With increasing of nanoparticles in fresh samples, the slump flow diameter reduced. Fibers reduced the flow abilit...

Factor analysis of the Mayo-Portland Adaptability Inventory: structure and validity.

Science.gov (United States)

Bohac, D L; Malec, J F; Moessner, A M

1997-07-01

Principal-components (PC) factor analysis of the Mayo-Portland Adaptability Inventory (MPAI) was conducted using a sample of outpatients (n = 189) with acquired brain injury (ABI) to evaluate whether outcome after ABI is multifactorial or unifactorial in nature. An eight-factor model was derived which explained 64-4% of the total variance. The eight factors were interpreted as representing Activities of Daily Living, Social Initiation, Cognition, Impaired-Self-awareness/Distress, Social Skills/ Support, Independence, Visuoperceptual, and Psychiatric, respectively. Validation of the Cognition factor was supported when factor scores were correlated with various neuropsychological measures. In addition, 117 patient self-rating total scores were used to evaluate the Impaired Self-awareness/Distress factor. An inverse relationship was observed, supporting this factor's ability to capture the two-dimensional phenomena of diminished self-awareness or enhanced emotional distress. A new subscale structure is suggested, that may allow greater clinical utility in understanding how ABI manifests in patients, and may provide clinicians with a better structure for implementing treatment strategies to address specific areas of impairment and disability for specific patients. Additionally, more precise measurement of treatment outcomes may be afforded by this reorganization.

Manufacturing of mortars and concretes non-traditionals, by Portland cement, metakaoline and gypsum (15.05%

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Talero, R.

1999-12-01

Full Text Available In a thorough previous research (1, it appeared that creation, evolution and development of the values of compressive mechanical strength (CS and flexural strength (FS, measured in specimens 1x1x6cm of mortar type ASTM C 452-68 (2, manufactured by ordinary Portland cement P-1 (14.11% C₃A or PY-6 (0.00% C₃A, metakaolin and gypsum (CaSO₄∙2H₂O -or ternary cements, CT-, were similar to the ones commonly developed in mortars and concretes of OPC. This paper sets up the experimental results obtained from non-traditional mortars and concretes prepared with such ternary cements -TC-, being the portland cement/metakaolin mass ratio, as follows: 80/20, 70/30 and 60/40. Finally, the behaviour of these cements against gypsum attack, has been also determined, using the following parameters: increase in length (ΔL%, compressive, CS, and flexural, FS, strengths, and ultrasound energy, UE. Experimental results obtained from these non-traditional mortars and concretes, show an increase in length (ΔL, in CS and FS, and in UE values, when there is addition of metakaolin.

En una exhaustiva investigación anterior (1, se pudo comprobar que la creación, evolución y desarrollo de los valores de resistencias mecánicas a compresión, RMC, y flexotracción, RMF, proporcionados por probetas de 1x1x6 cm, de mortero 1:2,75, selenitoso tipo ASTM C 452-68 (2 -que habían sido preparadas con arena de Ottawa, cemento portland, P-1 (14,11% C₃A o PY- 6 (0,00% C₃A, metacaolín y yeso (CaSO₄∙2H₂O-, fue semejante a la que, comúnmente, desarrollan los morteros y hormigones tradicionales de cemento portland. En el presente trabajo se exponen los resultados experimentales obtenidos de morteros y hormigones no tradicionales, preparados con dichos cementos ternarios, CT, siendo las proporciones porcentuales en masa ensayadas, cemento portland/metacaolín, las siguientes: 80/20, 70

Hydration rate and strength development of low-heat type portland cement mortar mixed with pozzolanic materials

International Nuclear Information System (INIS)

Matsui, Jun

1998-01-01

Recently, low-heat type Portland cement was specified in Japan Industrial Standards (JIS). Its hydration proceeds slowly. The results of the research so far obtained indicate that slow hydration of cement and mixing of pozzolanic materials with cement make micro-structure of harded cement paste dense and durable. In this study, a blended cement using low-heat type Portland cement and some of pozzolanic materials has been newly developed and its strength property and hydration ratio were checked. The followings are conclusion. (1) Hydration rate of cement paste varies with the replacement ratio of pozzolanic materials. (2) A good liner relationship between strength and total hydration rate of cement paste was observed. (3) A proper replacement ratio of both base-cement and pozzolanic material for manufacturing a blended cement is 50%. (author)

Phased-Resolved Strain Measuremetns in Hydrated Ordinary Portland Cement Using Synchrotron x-Rays (Prop. 2003-033)

International Nuclear Information System (INIS)

Biernacki, Joseph J.; Watkins, Thomas R.; Parnham, C.J.; Hubbard, Camden R.; Bai, J.

2006-01-01

X-ray diffraction methods developed for the determination of residual stress states in crystalline materials have been applied to study residual strains and strains because of mechanical loading of ordinary portland cement paste. Synchrotron X-rays were used to make in situ measurements of interplanar spacings in the calcium hydroxide (CH) phase of hydrated neat portland cement under uniaxial compression. The results indicate that strains on the order of 1/100 000 can be resolved providing an essentially new technique by which to measure the phase-resolved meso-scale mechanical behavior of cement under different loading conditions. Evaluation of these strain data in view of published elastic parameters for CH suggests that the CH carries a large fraction of the applied stress and that plastic interactions with the matrix are notable.

Parameters of Alumina Cement and Portland Cement with Addition of Chalcedonite Meal

Science.gov (United States)

Kotwa, Anna

2017-10-01

Aluminous cement is a quick binder with special properties. It is used primarily to make non-standard monolithic components exposed to high temperatures, + 1300°C. It is also a component of adhesives and mortars. It has a very short setting time. It is characterized by rapid increase in mechanical strength and resistance to aggressive sulphates. It can be used in reinforced concrete structures. Laying of concrete, construction mortar made of alumina cement can be carried out even at temperatures of -10°C. This article discusses a comparison of the parameters of hardened mortar made of alumina cement GÓRKAL 40 and Portland cement CEM I 42.5R. The mortars contain an addition of chalcedonite meal with pozzolanic properties, with particle size of less than 0.063μm. The meal was added in amounts of 5% and 20% of cement weight. Chalcedonite meal used in the laboratory research is waste material, resulting from chalcedonite aggregate mining. It has the same properties as the rock from which it originates. We have compared the parameters of hardened mortar i.e. compressive strength, water absorption and capillarity. The addition of 20% chalcedonite meal to mortars made from aluminous cement will decrease durability by 6.1% relative to aluminous cement mortar without addition of meal. Considering the results obtained during the absorbency tests, it can be stated that the addition of chalcedonite meal reduces weight gains in mortars made with cement CEM I 42.5 R and alumina cement. Use of alumina cement without addition of meal in mortars causes an increase of mass by 248% compared to Portland cement mortars without additions, in the absorption tests. The addition of chalcedonite meal did not cause increased weight gain in the capillary action tests. For the alumina cement mortars, a lesser weight gains of 24.7% was reported, compared to the Portland cement mortar after 28 days of maturing.

Alkali segregation in Portland cement pastes

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Triviño, F.

1966-09-01

Full Text Available Not availableEn el presente trabajo se pone de manifiesto experimentalmente la formación y presencia de aphthitalita -sulfato doble de potasio y sodio en la relación S04K2/S04Na2 = 3/1 en las pastas puras de cemento portland, desde el comienzo del fraguado de las mismas. Se estudia el mecanismo de la citada formación, íntimamente relacionada con el proceso general de formación de eflorescencias salinas, a base de una emigración de sulfatos alcalinos hacia las partes externas de las pastas, en virtud de fenómenos de exudación equivalentes a arrastres capilares. Se sintetiza y aísla la aphthitalita por dos procedimientos y se obtiene su difractograma.de rayos· X, a efectos de su identificación y de la confirmación de los resultados experimentales obtenidos, así como de la interpretación de los mismos.

Portland's experience with land use tools to promote green roofs

International Nuclear Information System (INIS)

Johnson, M.

2004-01-01

In the late 1990s, the City of Portland, Oregon faced environmental challenges that prompted the City to mandate environmentally sensitive development. Several programs were developed in response to these challenges, some of which resulted in the creation of land use policies and incentives that promote green roofs. Zoning code provisions were adopted in 2001 to promote eco-roofs in an effort to reduce stormwater runoff, mitigate urban heat island effects, provide habitat for birds, and improve air quality and energy efficiency. The Central City Fundamental Design Guidelines were also revised to encourage eco-roof development. In 2002, the South Waterfront Plan was created to integrate ecological design into an urban environment through sustainability principles and practices. Land use tools were developed to introduce developers to an approach that reduced energy costs and stormwater costs, while also contributing to a project's marketability. These tools were created with the support of programs and policies such as the CSO (Combined Sewer Overflow) Program; eco-roof research which began in 1995 to determine the stormwater management potential of eco-Green roofs; technical assistance to encourage and highlight sustainable development practices; the Stormwater Management Manual that set standards for the amount and quality of stormwater runoff leaving development sites; the G/Rated Program that offers resources for green building practices; the Green Investment Fund that supports the G/Rated Program; and, the Portland Development Commission Green Building Policy financing tool for earth-friendly designs and materials. 34 refs., 2 figs

Flow properties of MK-based geopolymer pastes. A comparative study with standard Portland cement pastes.

Science.gov (United States)

Favier, Aurélie; Hot, Julie; Habert, Guillaume; Roussel, Nicolas; d'Espinose de Lacaillerie, Jean-Baptiste

2014-02-28

Geopolymers are presented in many studies as alternatives to ordinary Portland cement. Previous studies have focused on their chemical and mechanical properties, their microstructures and their potential applications, but very few have focussed on their rheological behaviour. Our work highlights the fundamental differences in the flow properties, which exist between geopolymers made from metakaolin and Ordinary Portland Cement (OPC). We show that colloidal interactions between metakaolin particles are negligible and that hydrodynamic effects control the rheological behaviour. Metakaolin-based geopolymers can then be described as Newtonian fluids with the viscosity controlled mainly by the high viscosity of the suspending alkaline silicate solution and not by the contribution of direct contacts between metakaolin grains. This fundamental difference between geopolymers and OPC implies that developments made in cement technology to improve rheological behaviour such as plasticizers will not be efficient for geopolymers and that new research directions need to be explored.

Comparative evaluation of antimicrobial action of MTA, calcium hydroxide and Portland cement Avaliação comparativa da ação antimicrobiana do MTA, hidróxido de cálcio e cimento Portland

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Caroline Sousa Ribeiro

2006-10-01

Full Text Available The present study aimed to evaluate and compare the antimicrobial effect of MTA Dentsply, MTA Angelus, Calcium Hydroxide and Portland cement. Four reference bacterial strains were used: Pseudomonas aeruginosa, Escherichia coli, Bacteroides fragilis, and Enterococcus faecalis. Plates containing Mueller-Hinton agar supplemented with 5% sheep blood, hemin, and menadione were inoculated with the bacterial suspensions. Subsequently, wells were prepared and immediately filled with materials and incubated at 37ºC for 48 hours under anaerobic conditions, except P. aeruginosa. The diameters of inhibition zones were measured, and data analyzed using ANOVA and the Tukey test with 1% level of significance. MTA Dentsply, MTA Angelus and Portland cement inhibited the growth of P. aeruginosa. Calcium Hydroxide was effective against P. aeruginosa and B. fragillis. Under anaerobic conditions, which may hamper the formation of reactive oxygen species, the materials failed to inhibit E. faecalis, and E. coli.O objetivo do presente trabalho foi avaliar e comparar o efeito antimicrobiano do MTA Dentsply, MTA Angelus, hidróxido de cálcio e cimento Portland sobre quatro cepas bacterianas: Pseudomonas aeruginosa, Escherichia coli, Bacteroides fragilis, e Enterococcus faecalis. Placas contendo agar Muller-Hinton suplementadas com 5% de sangue de carneiro, hemina e menadiona foram inoculadas com as suspensões bacterianas. Poços foram confeccionados com auxílio de perfuradores e imediatamente preenchidos com os materiais, e incubados a 37ºC por 48 horas em atmosfera de anaerobiose, exceto P. aeruginosa. O diâmetro dos halos de inibição foi medido e os dados analisados usando o teste estatístico ANOVA e o de Tukey com nível de significância de 1%. O MTA Dentsply, MTA Angelus e Cimento Portland inibiram o crescimento da P.aeruginosa. O hidróxido de cálcio foi efetivo contra P. aeruginosa e B. fragillis. Sob atmosfera de anaerobiose, condição que pode

Influence of moisture condition on chloride diffusion in partially saturated ordinary Portland cement mortar

NARCIS (Netherlands)

Zhang, Y.; Zhang, M.; Ye, G.

2018-01-01

Experiments have been carried out to study the influence of moisture condition, including moisture content and its distribution, on the chloride diffusion in partially saturated ordinary Portland cement mortar. The mortar samples with water-to-cement (w/c) ratios of 0.4, 0.5 and 0.6, cured for 1

The impact of zirconium oxide radiopacifier on the early hydration behaviour of white Portland cement

International Nuclear Information System (INIS)

Coleman, Nichola J.; Li, Qiu

2013-01-01

Zirconium oxide has been identified as a candidate radiopacifying agent for use in Portland cement-based biomaterials. During this study, the impact of 20 wt.% zirconium oxide on the hydration and setting reactions of white Portland cement (WPC) was monitored by powder X-ray diffraction (XRD), 29 Si and 27 Al magic angle spinning nuclear magnetic resonance spectroscopy (MAS NMR), transmission electron microscopy (TEM) and Vicat apparatus. The presence of 20 wt.% zirconium oxide particles in the size-range of 0.2 to 5 μm was found to reduce the initial and final setting times of WPC from 172 to 147 min and 213 to 191 min, respectively. Zirconium oxide did not formally participate in the chemical reactions of the hydrating cement; however, the surface of the zirconium oxide particles presented heterogeneous nucleation sites for the precipitation and growth of the early C-S-H gel products which accelerated the initial setting reactions. The presence of zirconium oxide was found to have little impact on the development of the calcium (sulpho)aluminate hydrate phases. - Highlights: ► This is the first study of Portland cement-based biomaterials by 27 Al and 29 Si NMR. ► 20 wt.% ZrO 2 radiopacifier accelerates the early cement hydration reactions. ► Extent of hydration after 6 h is increased from 5.7% to 15% in the presence of ZrO 2 . ► Initial and final setting times are reduced by 25 and 22 min, respectively. ► ZrO 2 provides nucleation sites for the precipitation of early hydration products.

Pembuatan dan Pengujian Kualitas Semen Portland Yang Diperkaya Silikat Abu Ampas Tebu

OpenAIRE

Suci Wulandari, Indah Pratama

2015-01-01

Penelitian ini mengkaji pengaruh penambahan abu ampas tebu terhadap kuat tekan mortar dan sifat fisis semen portland komposit, meliputi: kehalusan semen, kebutuhan air semen, waktu pengikatan semen, pemuaian dan komposisi kimia semen. Dari hasil penelitian, besar kuat tekan pada penggunaan abu ampas tebu dengan kadar 9% merupakan penambahan optimum pada mortar yang direndam larutan kapur jenuh Sedangkan dari hasil pengujian fisis yang meliputi kehalusan semen, kebutuhan air semen, waktu pengi...

The influence of the amount addition and kind of the active silica fume in the mechanical properties of the cement Portland concrete

International Nuclear Information System (INIS)

Silva, I.J. da; Melo, A.B. de; Liborio, J.B.L.; Souza, M.F. de

1998-01-01

This study presents an evaluation of the influence of the amount addition and of active silica type deriving from residues of the production of Iron-Silicon alloys of brasilian industries, on the mechanical properties of the concrete made with basaltic aggregates with D max ≥9,5 mm using Portland cements CP II E 32. The study has for objective to evaluate the efficiency of the active silica on the mechanical resistance of the high performance concrete (CAD), when used in substitution of the Portland cement, even so maintaining the same amount of agglomerant material. They are appraised amount of 5%, 8%, 10%, 12% and 15% of active silica in relation to Portland cement mass. The results suggest that for the appraised silicas there is little efficiency. Other aspects related to the mixtures just with addictive water reducers are commented with the purpose of also providing a high performance concrete. (author)

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.

Developing Guidelines to Enhance Students Desirable Characteristics for Schools under the Office of Udornthani Primary Education Service Area 1

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Aroonsiri Janlon

2017-09-01

Full Text Available The purposes of this research were 1 to study the elements and indicators students desirable characteristics for schools ; 2 to study the present condition and the desirable of students desirable characteristics for schools ; and 3 to develop guidelines to enhance students desirable characteristics for schools under the office of Udornthani primary education service area 1. Research and development. Method was divided into three phases for the purposes of research. The samples were 296 teachers and school administrators, using stratified random sampling. Instruments used were questionnaire, assessment elements and indicators, interview form and assessment guidelines. Data were analyzed using mean, standard devitation and modified priority needs index. Research findings were as follows: 1. There were 3 elements of students desirable characteristics for schools consisted of discipline, learning and commitment to work. Discipline consisted of four indicators, learning consisted of indicators and commitment to work consisted of two indicators. 2. The current situation of students desirable characteristics for schools under the office of Udornthani primary education service area 1, overall at a high level, considering each element, discipline was the highest, followed by learning and the lowest was commitment to work as well. In desirable situation the same relults on the current situation. 3. Guidelines to enhance students desirable characteristics for schools under the office of Udornthani primary education service area 1 consisted of 7 guidelines: 1 the policy clearly ; 2 providing specialized committees ; 3 creating a common understanding ; 4 targeting clearly ; 5 the environmental moral ; 6 supervision, monitoring and evaluation ; and 7 creating a network of parents and the community.

Symmetry or asymmetry -- Comfort is the question. (A study of the second floor of the west office wing of the Water Pollution Control Laboratory in Portland, Oregon.)

Energy Technology Data Exchange (ETDEWEB)

Gonzalez, A.F.; Gaba, P.; Kowitanupong, C.

1999-07-01

This article explores the effects of an asymmetric distribution of building components, and their relation to human comfort. The studied building was the Water Pollution Control Laboratory in Portland, Oregon. This project, designed by the Miller/Hull Partnership, provides the perfect conditions to do such a study since it has very different ceiling heights within the same space, and an asymmetric distribution of the fenestration as well. Findings show that: (a) Variable ceiling heights affect the quantity of daylight received, and also affect the quality and distribution of electric light; (b) An asymmetric distribution of the fenestration creates very different conditions in both the luminous and thermal environments; and (c) The design of lighting and HVAC systems must take into consideration variations in ceiling height and the position of the fenestration into the space.

Influence of bismuth oxide concentration on the pH level and biocompatibility of white Portland cement

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Marina Angélica MARCIANO

2014-07-01

Full Text Available Objectives: To investigate if there is a relation between the increase of bismuth oxide and the decrease of pH levels and an intensification of toxicity in the Portland cement. Material and Methods: White Portland cement (WPC was mixed with 0, 15, 20, 30 and 50% bismuth oxide, in weight. For the pH level test, polyethylene tubes were filled with the cements and immersed in Milli-Q water for 15, 30 and 60 days. After each period, the increase of the pH level was assessed. For the biocompatibility, two polyethylene tubes filled with the cements were implanted in ninety albino rats (n=6. The analysis of the intensity of the inflammatory infiltrate was performed after 15, 30 and 60 days. The statistical analysis was performed using the Kruskal-Wallis, Dunn and Friedman tests for the pH level and the Kruskal-Wallis and Dunn tests for the biological analysis (p0.05. For the inflammatory infiltrates, no significant statistical differences were found among the groups in each period (p>0.05. The 15% WPC showed a significant decrease of the inflammatory infiltrate from 15 to 30 and 60 days (p<0.05. Conclusions: The addition of bismuth oxide into Portland cement did not affect the pH level and the biological response. The concentration of 15% of bismuth oxide resulted in significant reduction in inflammatory response in comparison with the other concentrations evaluated.

Low porosity portland cement pastes based on furan polymers

International Nuclear Information System (INIS)

Darweesh, H.H.M.

2005-01-01

The effect of three different types of Furan polymers on the porosity, mechanical properties, mechanism of hydration and microstructure of Ordinary Portland cement (OPC) pastes was investigated. The results showed that mixing the OPC with Furan polymers, the standard water of consistency of the different cement pastes decreases and therefore the setting times (initial and final) are shortened. The total porosity of the hardened cement pastes decreased, while the mechanical properties improved and enhanced at all curing ages of hydration compared with those of the pure OPC pastes. The hydration process with Furan polymers proceeded according to the following decreasing order: F.ac. > F.ph. > F.alc. > OPC

Strategic Planning to Advance Equity on Campus: A Case Study at Portland State University

Science.gov (United States)

Zapata, Marisa; Percy, Stephen; Andrews, Sona

2018-01-01

Propelled by many factors, including a newly appointed Board of Trustees responsible for governance of our university, resource shortages, and enrollment swings, Portland State University embarked on a strategic planning effort in 2014 with the intent of reunifying a divided campus and creating a bold vision for moving forward in the next five…

Biocompatibility and setting time of CPM-MTA and white Portland cement clinker with or without calcium sulfate.

Science.gov (United States)

Bramante, Clovis Monteiro; Kato, Marcia Magro; Assis, Gerson Francisco de; Duarte, Marco Antonio Hungaro; Bernardineli, Norberti; Moraes, Ivaldo Gomes de; Garcia, Roberto Brandão; Ordinola-Zapata, Ronald; Bramante, Alexandre Silva

2013-01-01

To evaluate the biocompatibility and the setting time of Portland cement clinker with or without 2% or 5% calcium sulfate and MTA-CPM. Twenty-four mice (Rattus norvegicus) received subcutaneously polyethylene tubes filled with Portland cement clinker with or without 2% or 5% calcium sulfate and MTA. After 15, 30 and 60 days of implantation, the animals were killed and specimens were prepared for microscopic analysis. For evaluation of the setting time, each material was analyzed using Gilmore needles weighing 113.5 g and 456.5 g, according to the ASTM specification Number C266-08 guideline. Data were analyzed by ANOVA and Tukey's test for setting time and Kruskal-Wallis and Dunn test for biocompatibility at 5% significance level. Histologic observation showed no statistically significant difference of biocompatibility (p>0.05) among the materials in the subcutaneous tissues. For the setting time, clinker without calcium sulfate showed the shortest initial and final setting times (6.18 s/21.48 s), followed by clinker with 2% calcium sulfate (9.22 s/25.33 s), clinker with 5% calcium sulfate (10.06 s/42.46 s) and MTA (15.01 s/42.46 s). All the tested materials showed biocompatibility and the calcium sulfate absence shortened the initial and final setting times of the white Portland cement clinker.

Comparative study of physico-chemical properties of MTA-based and Portland cements.

Science.gov (United States)

Borges, Alvaro H; Pedro, Fábio L M; Miranda, Carlos E S; Semenoff-Segundo, Alex; Pécora, Jesus D; Filho, Antônio M Cruz

2010-01-01

The purpose of this investigation was to evaluate the physicochemical properties of gray and white structural and nonstructural Portland cement, gray and white ProRoot MTA and MTA BIO. The water/powder ratio, setting time, solubility and pH (hydrogen-ion potential) changes of the materials were evaluated. Tests followed specification #57 from the American National Standard Institute/American Dental Association (2000) for endodontic sealing materials and pH was determined by a digital pH meter. The test results were statistically analyzed by variance analyses for global comparison and by the complementary Tukey's test for pairwise comparisons (5%). Considering the water/powder ratio, no significant difference (p > 0.05) was observed among the cements. MTA BIO (33.10 +/- 2.30) had the lowest setting time (p Portland cement (2.55 +/- 0.08) had the highest solubility (p 0.05) was observed among materials when considering pH evaluation. The pH levels were highly alkaline immediately after immersion in solution, remaining stable throughout the test period. The authors conclude that the cements had similar water/powder proportions. MTA BIO had the shortest setting time and gray ProRoot MTA had the lowest solubility. All cements had similar behavior in the pH analysis.

Tribal Grant Program Area Polygons with Project Officer and Tribal Contact Information, US EPA Region 9, 2015, Regional Tribal Operations Committee

Data.gov (United States)

U.S. Environmental Protection Agency — This dataset contains information pertaining to EPA Region 9 project officers and their areas of oversight, EPA Region 9 grant program recipients and grant types,...

Elementary characterization of samples of Portland cement, natural gypsum and phosphogypsum mortars from Brazil

Energy Technology Data Exchange (ETDEWEB)

Narloch, Danielle Cristine; Paschuk, Sergei Anatolyevich; Corrêa, Janine Nicolosi; Torres, Catarina Alzira Peddis; Mazer, Wellington; Macioski, Gustavo [Universidade Tecnologica Federal do Parana (UTFPR), PR (Brazil); Lara, Alessandro [Universidade de Sao Paulo (USP), SP (Brazil). Departamento de Fisica; Casali, Juliana Machado, E-mail: janine_nicolosi@hotmail.com, E-mail: alellara@hotmail.com, E-mail: jucasali@gmail.com [Instituto Federal de Santa Catarina (IFSC), Florianópolis, SC (Brazil)

2017-07-01

Portland cement, the basic ingredient of concrete and is manufactured by crushing, milling and proportioning limestone, sand, clay, iron ore and secondary materials such as shells, chalk or marl combined with shale slate or blast furnace slag, fly ash, gypsum, phosphogypsum, and some others. Evaluating the physical and mineralogical characteristics of the cement and its chemical composition is essential to establish the quality of the product. Therefore, the objective of this work was to characterize and quantify the most common chemical elements in the samples of Brazilian Portland cement, natural gypsum, and phosphogypsum mortars by means of X-ray dispersive energy spectroscopy (EDXRF), as well as to evaluate the strength of these mortars. For analysis of the compressive strength, initially prepared samples were submitted to a destructive mechanical test. Subsequently samples were milled and compacted to form thin tablets, which were submitted to the EDXRF analysis. The qualitative and quantitative analyzes showed that for phosphogypsum mortar the largest mass fractions were found of 49.8±2.5% (Si), 24.66±0.96% (S) and 22.10±0.42% (Ca). For gypsum mortar those values were found of 43.41±0.45% (Ca), 33.8 ± 0.8% (S) and 18.9±1.2% (Si), respectively; and for Portland cement mortar, the predominant elements in those samples have the mass fractions of 64.20±0.52% (Ca) and 27.3±1.5% (Si). The results showed that obtained values of mass fraction of the elements Si, S, K, Ca, Ti, Fe are in rather good agreement with quantities indicated for manufacture. Besides, gypsum and phosphogypsum presented almost the same composition and compressive strength. (author)

Elementary characterization of samples of Portland cement, natural gypsum and phosphogypsum mortars from Brazil

International Nuclear Information System (INIS)

Narloch, Danielle Cristine; Paschuk, Sergei Anatolyevich; Corrêa, Janine Nicolosi; Torres, Catarina Alzira Peddis; Mazer, Wellington; Macioski, Gustavo; Lara, Alessandro

2017-01-01

Portland cement, the basic ingredient of concrete and is manufactured by crushing, milling and proportioning limestone, sand, clay, iron ore and secondary materials such as shells, chalk or marl combined with shale slate or blast furnace slag, fly ash, gypsum, phosphogypsum, and some others. Evaluating the physical and mineralogical characteristics of the cement and its chemical composition is essential to establish the quality of the product. Therefore, the objective of this work was to characterize and quantify the most common chemical elements in the samples of Brazilian Portland cement, natural gypsum, and phosphogypsum mortars by means of X-ray dispersive energy spectroscopy (EDXRF), as well as to evaluate the strength of these mortars. For analysis of the compressive strength, initially prepared samples were submitted to a destructive mechanical test. Subsequently samples were milled and compacted to form thin tablets, which were submitted to the EDXRF analysis. The qualitative and quantitative analyzes showed that for phosphogypsum mortar the largest mass fractions were found of 49.8±2.5% (Si), 24.66±0.96% (S) and 22.10±0.42% (Ca). For gypsum mortar those values were found of 43.41±0.45% (Ca), 33.8 ± 0.8% (S) and 18.9±1.2% (Si), respectively; and for Portland cement mortar, the predominant elements in those samples have the mass fractions of 64.20±0.52% (Ca) and 27.3±1.5% (Si). The results showed that obtained values of mass fraction of the elements Si, S, K, Ca, Ti, Fe are in rather good agreement with quantities indicated for manufacture. Besides, gypsum and phosphogypsum presented almost the same composition and compressive strength. (author)

Effect of addition of opaline siliceous rocks at different proportions to portland cement

Directory of Open Access Journals (Sweden)

de Luxan, M. P.

1989-03-01

Full Text Available En este trabajo se estudia la influencia de la presencia de rocas silíceas opalinas, procedentes de las provincias de Salamanca, Zamora y Avila, en las propiedades de los cementos mixtos fabricados con cemento portland y proporciones variables de estas rocas utilizadas como adiciones activas. La caracterización de estos materiales y el estudio de las propiedades de los cementos preparados revelan la capacidad puzolánica de las rocas opalinas, y su singularidad respecto a otras puzolanas naturales, así como su posibilidad de empleo en la fabricación de cementos con adiciones.

En este trabajo se estudia la influencia de la presencia de rocas silíceas opalinas, procedentes de las provincias de Salamanca, Zamora y Avila, en las propiedades de los cementos mixtos fabricados con cemento portland y proporciones variables de estas rocas utilizadas como adiciones activas. La caracterización de estos materiales y el estudio de las propiedades de los cementos preparados revelan la capacidad puzolánica de las rocas opalinas, y su singularidad respecto a otras puzolanas naturales, así como su posibilidad de empleo en la fabricación de cementos con adiciones.

Evaluation of the use of red mud as a pozzolanic additive in Portland cement

International Nuclear Information System (INIS)

Fortes, Gustavo Mattos; Balbino, Thiago Gabriel Ferreira; Lourenco, Rafaela Roberta; Rodrigues, Jose de Anchieta

2011-01-01

It is estimated that the aluminum industry generates approximately 13.7 million tones/year of red mud (RB) in Brazil. Although, being the RB rich in Al 2 O 3 and SiO 2 and partially amorphous, a potential pozzolanic activity is suggested. Thus, this work aims to evaluate the application of 15w-% of RB, as a pozzolanic additive, to the ordinary Portland cement (CPI), simulating a pozzolanic compost Portland cement (CPII-Z). To study the pozzolanic activation of the RB, this one was added without calcination, calcinated at 400°C and at 600°C. The compressive strength was measured in mortars of CPI with additions of RB, of CPI and CPII (references), after 28 days of curing. The analysis of the apparent porosity and the characterization of the hydration products were done to complement the evaluation. The mortars with calcinated RB showed good results of mechanical strength, reaching more than 85% (45 MPa) of the CPI's strength and higher values than the CPII-Z32. (author)

Potencialidades de um caulim calcinado como material de substituição parcial do cimento portland em argamassas Potentialities of a calcined kaolin as material of partial replacement of portland cement in mortars

Directory of Open Access Journals (Sweden)

Marilia P. de Oliveira

2006-06-01

Full Text Available A utilização de argilas calcinadas na forma de metacaulinita, como material pozolânico para argamassas e concretos, tem recebido atenção considerável nos últimos anos. Este trabalho objetivou avaliar o desempenho mecânico de argamassas, nas quais foi utilizado um caulim calcinado proveniente do Estado da Paraíba, como material de substituição parcial do cimento Portland. Utilizaram-se duas finuras do caulim: passando nas peneiras ABNT 200 (0,074 mm e 325 (0,044 mm e calcinados nas temperaturas de 700, 800 e 900 ºC pelo tempo de 2 h. As amostras foram caracterizadas através de análise química, análise térmica diferencial, difração de raios-X e área específica. Obteve-se o índice de atividade pozolânica com a cal e o cimento Portland. O percentual de substituição adotado foi de 0, 10, 20, 30 e 40%. A relação aglomerante: areia foi de 1:1,5 e a relação água/aglomerante fixada igual 0,4. O efeito da substituição parcial do cimento na argamassa foi avaliado através da resistência à compressão simples, nas idades de 7, 28 e 90 dias. As argamassas estudadas apresentaram resistência superior em relação à da referência, até o nível de 30% de substituição.The use of burnt clays, in the metakaolin form, as pozzolanic material for mortars and concretes has received a remarkable attention in the last years. This paper aimed to evaluate the mechanical property of mortars, in which a calcined kaolin originating from the State of Paraiba, was used as partial cement replacement material. Two finess of the kaolin were used: ABNT 200 (0.074 mm and 325 (0.044 mm and burnt at temperatures of 700, 800 and 900 ºC for a period of 2 h. Both materials were characterized by chemical analysis, differential thermal analysis, X-ray diffraction, specific area tests. The pozolanic activity index was obtanied using lime and cement Portland. The amounts of replacement were 10, 20, 30 and 40%, besides the reference mortar. The binder

Microscopic analysis of dog dental pulp after pulpotomy and pulp protection with mineral trioxide aggregate and white Portland cement Análise microscópica da polpa dental de cães após pulpotomia e proteção pulpar com agregado de trióxido mineral e cimento Portland branco

Directory of Open Access Journals (Sweden)

Renato Menezes

2004-06-01

Full Text Available Considering previous studies on the similarity between the chemical composition of the mineral trioxide aggregate and the Portland cement, the purpose of this study was to investigate the pulp response of dog's teeth after pulpotomy and direct pulp protection with MTA Angelus and white Portland cement. Thirty eight pulp remnants were protected with these materials. One hundred and twenty days after treatment, the animals were sacrificed and the specimens removed and prepared for histological analysis. Both materials demonstrated the same results when used as pulp capping materials, inducing hard tissue bridge formation and maintaining pulp vitality in all specimens. The MTA Angelus and the white Portland cement showed to be effective as pulp protection materials following pulpotomy.Considerando estudos anteriores sobre a similaridade entre a composição química do agregado de trióxido mineral e o cimento Portland, o objetivo deste estudo foi investigar a resposta pulpar de dentes de cães após pulpotomia e proteção pulpar direta com MTA Angelus e cimento Portland branco. Trinta e oito remanescentes pulpares foram recobertos com esses materiais. Cento e vinte dias após o tratamento, os animais foram sacrificados e os espécimes removidos e preparados para análise histológica. Ambos os materiais demonstraram os mesmos resultados quando utilizados como materiais de capeamento pulpar, induzindo a formação de ponte de tecido mineralizado e mantendo a vitalidade pulpar em todos os espécimes. Ambos matérias se mostraram efetivos como protetores pulpares após pulpotomia em dentes de cães.

The origins of American industrial success: Evidence from the US portland cement industry

OpenAIRE

Prentice, David

2008-01-01

The contributions of innovations, factor endowments and institutions to American industrialization are examined through analysing the rise of the American portland cement industry. Minerals abundance contributed in multiple ways to the spectacular rise of the industry from the 1890s. However, the results of a structural econometric analysis of entry suggests geological surveys, institutions highlighted by David and Wright, played a contributing rather than critical rol...

Early hydration of portland cement with crystalline mineral additions

International Nuclear Information System (INIS)

Rahhal, V.; Talero, R.

2005-01-01

This research presents the effects of finely divided crystalline mineral additions (quartz and limestone), commonly known as filler, on the early hydration of portland cements with very different mineralogical composition. The used techniques to study the early hydration of blended cements were conduction calorimeter, hydraulicity (Fratini's test), non-evaporable water and X-ray diffraction. Results showed that the stimulation and the dilution effects increase when the percentage of crystalline mineral additions used is increased. Depending on the replacement proportion, the mineralogical cement composition and the type of crystalline addition, at 2 days, the prevalence of the dilution effect or the stimulation effect shows that crystalline mineral additions could act as sites of heat dissipation or heat stimulation, respectively

Rat subcutaneous tissue response to MTA Fillapex® and Portland cement.

Science.gov (United States)

Marques, Nádia Carolina Teixeira; Lourenço Neto, Natalino; Fernandes, Ana Paula; Rodini, Camila de Oliveira; Duarte, Marco Antônio Hungaro; Oliveira, Thais Marchini

2013-01-01

The aim of this study was to evaluate the response of rat subcutaneous tissue to MTA Fillapex® (Angelus), an experimental root canal filling material based on Portland cement and propylene glycol (PCPG), and a zinc oxide, eugenol and iodoform (ZOEI) paste. These materials were placed in polyethylene tubes and implanted into the dorsal connective tissue of Wistar rats for 7 and 15 days. The specimens were stained with hematoxylin and eosin, and evaluated regarding inflammatory reaction parameters by optical microscopy. The intensity of inflammatory response against the sealers was analyzed by two blinded and previously calibrated examiners for all experimental periods (kappa=0.96). The histological evaluation showed that all materials caused a moderate inflammatory reaction at 7 days, which subsided with time. A greater inflammatory reaction was observed at 7 days in the tubes filled with ZOEI paste. Tubes filled with MTA Fillapex presented some giant cells, macrophages and lymphocytes after 7 days. At 15 days, the presence of fibroblasts and collagen fibers was observed indicating normal tissue healing. The tubes filled with PCPG showed similar results to those observed in MTA Fillapex. At 15 days, the inflammatory reaction was almost absent at the tissue, with several collagen fibers indicating normal tissue healing. Data were analyzed by the nonparametric Kruskal-Wallis test (α=0.05). Statistically significant difference (p0.05). MTA Fillapex and Portland cement added with propylene glycol had greater tissue compatibility than the PCPG paste.

The regulation of hazardous air pollutants under the Clean Air Act Amendments of 1990: Effects on the Portland cement industry

International Nuclear Information System (INIS)

Mikols, E.H.; Gill, A.S.; Dougherty, A.

1996-01-01

Title III of the 1990 Clean Air Act Amendments (CAAA) addresses the control of hazardous air pollutants (HAPs) from major sources of air pollution in the US. In the CAAA, Congress defined 189 compounds as hazardous air pollutants in need of additional control by the Environmental Protection Agency (EPA). Congress directed EPA to identify the major source categories which emit HAPs and to prepare regulations that would reduce and control future HAP emissions. This paper outlines the activities undertaken by EPA to regulate HAP emissions from Portland cement plants and the program developed by the Portland cement manufacturing industry to cope with Title III

Effect of the use nickeliferous laterite and pumice as additives in the performance and durability of the Portland cement

Directory of Open Access Journals (Sweden)

María Carolina Rueda-Gualdrón

2016-01-01

Full Text Available En este trabajo se evalúa el comportamiento puzolánico de la laterita niquelífera de Cerromatoso (Córdoba y la pumita de Cemex (Boyacá en la preparación de morteros según normas NTC para agregados finos. Los morteros se prepararon con adiciones de 2,5%, 5% y 10% como sustitutos del cemento Portland tipo I, los cuales fueron sometidos a ensayos de resistencia mecánica antes y después de ser sometidos a ambientes extremos (altas temperaturas y ataques químicos como H2 SO4 y MgSO4 . Los resultados demuestran cómo estos materiales alternativos incrementan o disminuyen su grado de puzolanidad, así como el efecto de estos aditivos al interior de las mezclas de mortero en el tiempo, demostrando propiedades similares con relación a los morteros preparados con cemento Portland tipo I. Por lo tanto, los morteros tienen una respuesta aceptable ante las condiciones evaluadas, aunque es posible mejorar su desempeño y durabilidad, colaborando no solo con el ahorro energético en la producción del cemento Portland tipo I sino también en el uso de aditivos alternativos que permitan mitigar el impacto ambiental provocado por la industria cementera.

A randomized clinical trial on the use of medical Portland cement, MTA and calcium hydroxide in indirect pulp treatment.

Science.gov (United States)

Petrou, Marina Agathi; Alhamoui, Fadi Alhaddad; Welk, Alexander; Altarabulsi, Mohammed Basel; Alkilzy, Mohammed; H Splieth, Christian

2014-01-01

Studies on indirect pulp treatment (IPT) show varying success rates of 73 to 97 %. The necessity of re-opening the cavity and the question of the optimal capping material is still under debate. The aim of this prospective in vivo study was to compare the clinical and microbiological outcomes of mineral trioxide aggregate (MTA), medical Portland cement, and calcium hydroxide on the dentin-pulp complex of permanent and primary teeth treated with two-step IPT. In 86 regular patients (51 % men; 49 % women; age 17.2 years ±13.8), one deep carious lesion each was treated with incomplete caries removal, randomly selected capping with either calcium hydroxide (n = 31), medical Portland cement (29) or white MTA (26), and re-entry (6.3 months ±1.0). Clinical (color, humidity, and consistency of dentin) and microbiological (Lactobacilli/Mutans Strep. counts) parameters were recorded at the first and second treatment. The IPT had a high success rate of 90.3 % regardless of the material used (p = 0.72). The arrested lesions showed consistently darker, dry, and therefore, sclerotic dentine (p Portland cement. The findings of this study could promote the improvement of the IPT as a one-step treatment of deep carious lesions when the remaining demineralized dentin would be sealed with durable restorations.

Comparative evaluation of antimicrobial activity of three cements: new endodontic cement (NEC), mineral trioxide aggregate (MTA) and Portland.

Science.gov (United States)

Hasan Zarrabi, Mohammad; Javidi, Maryam; Naderinasab, Mahboube; Gharechahi, Maryam

2009-09-01

Using the agar diffusion method, we conducted an in vitro study to evaluate the antimicrobial activity of mineral trioxide aggregate (MTA), new endodontic cement (NEC) and Portland cement at different concentrations against five different microorganisms. A base layer was made using Muller-Hinton agar for Escherichia coli (ATCC 10538) and Candida (ATCC 10231). For Actinomyces viscosus (ATCC 15987), Enterococcus faecalis (ATCC 10541) and Streptococcus mutans (ATCC 25175) blood agar medium was used. Wells were formed by removing the agar, and the materials were placed in the well immediately after manipulation. The plates were kept at room temperature for 2 h for prediffusion, and then incubated at 37 degrees C for 72 h. The inhibition zones were then measured. The data were analyzed using ANOVA and the Tukey test to compare the differences among the three cements at different concentrations. The positive controls showed bacterial growth, while the negative controls showed no bacterial growth. All materials showed antimicrobial activity against the tested strains except for Enterococcus faecalis. NEC created larger inhibition zones than MTA and Portland cement. This difference was significant for Portland cement (P 0.05). Among the examined microorganisms, the largest inhibition zone was observed for Actinomyces group (P < 0.05). The antimicrobial activity of the materials increased with time and concentration (P < 0.05). It was concluded that NEC is a potent inhibitor of microorganism growth.

National Emission Standards for Hazardous Air Pollutants (NESHAP) for the Portland Cement Manufacturing Industry Subpart LLL Rule Guidance

Science.gov (United States)

This Spring 2016 document is intended for the use of EPA staff, State and Local regulatory agencies and their staff, and industry plant managers for the NESHAP for the Portland Cement Manufacturing Industry.

Incorporation of phosphorus guest ions in the calcium silicate phases of Portland cement from 31P MAS NMR spectroscopy.

Science.gov (United States)

Poulsen, Søren L; Jakobsen, Hans J; Skibsted, Jørgen

2010-06-21

Portland cements may contain small quantities of phosphorus (typically below 0.5 wt % P(2)O(5)), originating from either the raw materials or alternative sources of fuel used to heat the cement kilns. This work reports the first (31)P MAS NMR study of anhydrous and hydrated Portland cements that focuses on the phase and site preferences of the (PO(4))(3-) guest ions in the main clinker phases and hydration products. The observed (31)P chemical shifts (10 to -2 ppm), the (31)P chemical shift anisotropy, and the resemblance of the lineshapes in the (31)P and (29)Si MAS NMR spectra strongly suggest that (PO(4))(3-) units are incorporated in the calcium silicate phases, alite (Ca(3)SiO(5)) and belite (Ca(2)SiO(4)), by substitution for (SiO(4))(4-) tetrahedra. This assignment is further supported by a determination of the spin-lattice relaxation times for (31)P in alite and belite, which exhibit the same ratio as observed for the corresponding (29)Si relaxation times. From simulations of the intensities, observed in inversion-recovery spectra for a white Portland cement, it is deduced that 1.3% and 2.1% of the Si sites in alite and belite, respectively, are replaced by phosphorus. Charge balance may potentially be achieved to some extent by a coupled substitution mechanism where Ca(2+) is replaced by Fe(3+) ions, which may account for the interaction of the (31)P spins with paramagnetic Fe(3+) ions as observed for the ordinary Portland cements. A minor fraction of phosphorus may also be present in the separate phase Ca(3)(PO(4))(2), as indicated by the observation of a narrow resonance at delta((31)P) = 3.0 ppm for two of the studied cements. (31)P{(1)H} CP/MAS NMR spectra following the hydration of a white Portland cement show that the resonances from the hydrous phosphate species fall in the same spectral range as observed for (PO(4))(3-) incorporated in alite. This similarity and the absence of a large (31)P chemical shift ansitropy indicate that the hydrous (PO(4

National Institutes of Health, Office of AIDS Research

Science.gov (United States)

... Search Term(s): Main Navigation for the Office of AIDS Research Homepage ABOUT OAR SCIENTIFIC AREAS STRATEGIC PLAN ... HIV/AIDS INFORMATION Welcome to the Office of AIDS Research. Welcome to the Office of AIDS Research ...

Temperature Characteristics of Porous Portland Cement Concrete during the Hot Summer Session

Directory of Open Access Journals (Sweden)

Liqun Hu

2017-01-01

Full Text Available Pavement heats the near-surface air and affects the thermal comfort of the human body in hot summer. Because of a large amount of connected porosity of porous Portland cement concrete (PPCC, the thermal parameters of PPCC are much different from those of traditional Portland cement concrete (PCC. The temperature change characteristics of PPCC and the effects on surrounding environment are also different. A continuous 48-hour log of temperature of a PCC and five kinds of PPCC with different porosity were recorded in the open air in the hot summer. The air temperatures at different heights above concrete specimens were tested using self-made enclosed boxes to analyze the characteristics of near-surface air temperature. The output heat flux of different concrete specimens was calculated. The results show that the PPCC has higher temperature in the daytime and lower temperature in the nighttime and larger temperature gradient than the PCC. The air temperature above PPCC is lower than that of PCC after solar radiation going to zero at night. The total output heat flux of PPCC is slightly smaller in the daytime and significantly smaller at night than that of PCC. The results of tests and calculations indicate that PPCC contributes to the mitigation of heating effect of pavement on the near-surface air.

50 CFR 10.22 - Law enforcement offices.

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Law enforcement offices. 10.22 Section 10... GENERAL PROVISIONS Addresses § 10.22 Law enforcement offices. Service law enforcement offices and their areas of responsibility follow. Mail should be addressed: “Assistant Regional Director, Division of Law...

An Analysis of Naval Officer Accession Programs

National Research Council Canada - National Science Library

Lehner, William D

2008-01-01

... Training Corps, and Officer Candidate School. Three areas are covered: historical patterns in officer accessions and historical changes in Navy pre-commissioning training and education philosophy and policy...

Effect of ProRoot MTA, Portland cement, and amalgam on the expression of fibronectin, collagen I, and TGFβ by human periodontal ligament fibroblasts in vitro.

Science.gov (United States)

Fayazi, Sara; Ostad, Seyed Nasser; Razmi, Hasan

2011-01-01

Today many materials have been introduced for root-end filling materials. One of them is mineral trioxide aggregate (MTA) that is mentioned as a gold standard. The purpose of this in vitro study was to evaluate the reaction of human periodontal ligament fibroblasts to the root-end filling materials, such as ProRoot MTA, Portland cement, and amalgam. Eight impacted teeth were extracted in aseptic condition. The tissues around the roots were used to obtain fibroblast cells. After cell proliferation, they were cultured in the chamber slides and the extracts of the materials were added to the wells. Immunocytochemical method for measuring the expression of Fibronectin, collagen I and transforming growth factor beta (TGF®) was performed by Olysia Bioreport Imaging Software. The results were analyzed by SPSS 13.0 and Tukey post hoc test with PPortland cement group showed the most expression of collagen significantly and after 1 week, Portland cement and MTA groups had the most expression of collagen but there was no significant difference between these 2 groups. After 1 week, the Portland cement group demonstrated a higher amount of TGF® and fibronectin. The results suggest that Portland cement can be used as a less expensive root filling material with low toxicity. It has better effects than amalgam on the fibroblasts.

The Influence of Diatomite on the Strength and Microstructure of Portland Cement

OpenAIRE

Liu Jun; Shao Peng; Wang Shihao

2016-01-01

To study the influence of the types and mixing amount of diatomite on the Portland cement, we prepared the cement specimen doped with the calcined first-grade, first-grade and second-grade diatomite ,tested the 3d, 7d, 14d compressive strength, and studied and discussed phase, structure and morphology of diatomite in the binary system by the method of XRD, SEM . Experimental results show that with the addition of diatomite, the strength of cement paste increase; the optimal contents of calcin...

Quantitative study of Portland cement hydration by X-Ray diffraction/Rietveld analysis and geochemical modeling

Science.gov (United States)

Coutelot, F.; Seaman, J. C.; Simner, S.

2017-12-01

In this study the hydration of Portland cements containing blast-furnace slag and type V fly ash were investigated during cement curing using X-ray diffraction, with geochemical modeling used to calculate the total volume of hydrates. The goal was to evaluate the relationship between the starting component levels and the hydrate assemblages that develop during the curing process. Blast furnace-slag levels of 60, 45 and 30 wt.% were studied in blends containing fly ash and Portland cement. Geochemical modelling described the dissolution of the clinker, and predicted quantitatively the amount of hydrates. In all cases the experiments showed the presence of C-S-H, portlandite and ettringite. The quantities of ettringite, portlandite and the amorphous phases as determined by XRD agreed well with the calculated amounts of these phases after different periods of time. These findings show that changes in the bulk composition of hydrating cements can be described by geochemical models. Such a comparison between experimental and modelled data helps to understand in more detail the active processes occurring during cement hydration.

Stress distribution in a semi-infinite body symmetrically loaded over a circular area

Science.gov (United States)

Mcginness, H.

1980-01-01

Algorithms are developed for computing stresses in a semi-infinite body when loaded by a uniform pressure acting over a circular area. The algorithm allows easy determination of any stress component in a semi-infinite body having a known Poisson's ratio. Example curves are plotted for Portland cement grout and metal representative values.

U.S. Department of Energy, Carlsbad Area Office quality assurance program document. Revision 1

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-04-01

Mission of the Carlsbad Area Office (CAO) is to protect human health and the environment by opening and operating the Waste Isolation Pilot Plant (WIPP) for safe disposal of TRU waste, and establishing an effective system for management of TRU waste from generation to disposal. To help in fulfilling this mission and to ensure that risks and environmental impacts are identified and minimized, and that safety, reliability, and performance are optimized, CAO`s policy is to establish and maintain an effective quality assurance (QA) program that supports compliance with applicable Federal, State, and local regulations, and DOE orders and requirements. This document establishes QA program requirements for all programs, projects, and activities sponsored by CAO.

Effect of silica fume on reaction products of uranium (VI) with portland cement

International Nuclear Information System (INIS)

Tan Hongbin; Shaanxi Univ. of Technology, Hanzhong; Li Yuxiang

2005-01-01

Simulation of radioactive waste of U(VI) by uranyl nitrate and the effects of different additive quantities (12%, 20%, 30%, 35%, 40%) of silica fume on the products of U(VI) with Portland cement were studied at a hydrothermal condition of 180 degree C for a duration of one week. The X-ray powder diffraction examination results showed that the calcium uranate would be transformed into uranophane when the cement contained 30% silica fume. (authors)

7 CFR 2003.6 - Office of the Under Secretary.

Science.gov (United States)

2010-01-01

... public communication and information services related to the Rural Development. The office maintains a... Secretary. This office submits Paperwork Reduction Act public burden clearances to OMB, administers all... Training and Mission Area Personnel Services Division, and Labor Relations Staff offices. The office is...

Problems and Guidelines of Strategy Implementation in Basic Educational Institutions under the Supervision of KhonKaen Primary Educational Service Area Office 4

Directory of Open Access Journals (Sweden)

Sasiwan Tonkanya

2016-09-01

Full Text Available The research aimed to 1 study problems of strategy implementation in basic educational institutions under Khonkaen Primary Educational Service Area Office 4 ; and 2 propose the guidelines for strategy implementation in basic educational institutions under Khonkaen Primary Educational Service Area Office 4. The study was carried out in 2 phases. In phase 1, it focused on the study and analysis of the strategic implementation problems and phase 2 studied the best practice schools. The informants for the interview in phase 1 comprised 6 school administrators and teachers who were involved in strategy implementation from small-sized, medium-sized, and large-sized schools. They were selected by the use of purposive sampling technique. The population in the study of the strategic implementation problems in basic educational institutions in phase 1 consisted of 543 school administrators and teachers who were involved in strategy implementation from 181 schools under Khonkaen Primary Educational Service Area Office 4 in academic year 2014. The study samples were 217 school administrators and teachers who were involved in strategy implementation from small-sized, medium-sized, and large-sized schools under Khonkaen Primary Educational Service Area Office 4. The samples were selected by the use of stratified sampling technique. The informants of the phase 2 study were 6 school administrators and teachers who were involved in strategy implementation from small-sized, medium-sized, and large-sized best practice schools obtained from purposive sampling technique. The research instruments used for data collection consisted of 2 sets of questionnaires. The Set 1 questionnaire was the 5-point Likert scale on the levels of the problems in implementation with item discrimination at 0.60 – 1.00 and reliability of the whole questionnaire at .9359. The questionnaire contained 3 parts with 65 items. The Set 2 questionnaire comprised 2 parts with 10 items regarding

A new aluminium-hydrate species in hydrated Portland cements characterized by 27Al and 29Si MAS NMR spectroscopy

International Nuclear Information System (INIS)

Andersen, Morten Daugaard; Jakobsen, Hans J.; Skibsted, Jorgen

2006-01-01

Recent 27 Al MAS NMR studies of hydrated Portland cements and calcium-silicate-hydrate (C-S-H) phases have shown a resonance from Al in octahedral coordination, which cannot be assigned to the well-known aluminate species in hydrated Portland cements. This resonance, which exhibits the isotropic chemical shift δ iso = 5.0 ppm and the quadrupole product parameter P Q = 1.2 MHz, has been characterized in detail by 27 Al MAS and 27 Al{ 1 H} CP/MAS NMR for different hydrated white Portland cements and C-S-H phases. These experiments demonstrate that the resonance originates from an amorphous or disordered aluminate hydrate which contains Al(OH) 6 3- or O x Al(OH) 6-x (3+x)- units. The formation of the new aluminate hydrate is related to the formation of C-S-H at ambient temperatures, however, it decomposes by thermal treatment at temperatures of 70-90 o C. From the experiments in this work it is proposed that the new aluminate hydrate is either an amorphous/disordered aluminate hydroxide or a calcium aluminate hydrate, produced as a separate phase or as a nanostructured surface precipitate on the C-S-H phase. Finally, the possibilities of Al 3+ for Ca 2+ substitution in the principal layers and interlayers of the C-S-H structure are discussed

Arsenic Encapsulation Using Portland Cement With Ferrous Sulfate/Lime And Terra-BondTM Technologies - Microcharacterization And Leaching Studies

Science.gov (United States)

This work reports the results of an investigation on the treatment and encapsulation of arsenic-containing materials by Portland cement with ferrous sulfate and lime (PFL) and Terra-BondTM, a commercially available patented technology. The arsenic materials treated we...

33 CFR 165.1318 - Security and Safety Zone Regulations, Large Passenger Vessel Protection, Portland, OR Captain of...

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Security and Safety Zone Regulations, Large Passenger Vessel Protection, Portland, OR Captain of the Port Zone 165.1318 Section 165.1318 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND...

The influence of calcium nitrate on setting and hardening rate of Portland cement concrete at different temperatures

Science.gov (United States)

Kičaitė, A.; Pundienė, I.; Skripkiūnas, G.

2017-10-01

Calcium nitrate in mortars and concrete is used as a multifunctional additive: as set accelerator, plasticizer, long term strength enhancer and as antifreeze admixture. Used binding material and the amount of calcium nitrate, affect the characteristics of the concrete mixture and strength of hardened concrete. The setting time of the initial and the final binding at different temperatures of hardening (+ 20 °C and + 5 °C) of the pastes made of different cements (Portland cement CEM I 42.5 R and Portland limestone cement CEM II/A-LL 42.5 R) and various amounts of calcium nitrate from 1 % until 3 % were investigated. The effect of calcium nitrate on technological characteristics of concrete mixture (the consistency of the mixture, the density, and the amount of air in the mixture), on early concrete strength after 2 and 7 days, as well as on standard concrete strength after 28 days at different temperatures (at + 20 °C and + 5 °C) were analysed.

2017 Building Technologies Office Peer Review Report

Energy Technology Data Exchange (ETDEWEB)

None, None

2017-11-01

The 2017 Building Technologies Office Peer Review Report summarizes the feedback submitted by reviewers for the 109 Building Technologies Office (BTO) projects presented at the 2017 BTO Peer Review. The report presents an overview of the goals and activities under each technology program area, a summary of project scores for each program, and a brief analysis of general evaluation trends within each program area or its constituent subprograms.

Estudo para o aproveitamento de resíduos pétreos de marmorarias, como agregados para concreto de cimento Portland

Directory of Open Access Journals (Sweden)

Fábio Conrado de Queiroz

2008-01-01

Full Text Available In this paper, it is presented a study for the utilization of marble shops waste (stone by-products as aggregate of Portland cement concrete. First, the material were separated and classified by lithologic type. After that, they were mixed in a crusher, producing the required aggregates. Several tests for technological characterization of the material were done, intending to evaluate the use of the material as aggregate. Some simulations of Portland cement concrete dosage were done with variation in fine and coarse aggregate composition, water/cement ratio and mortar percentage. The materials were submitted to uniaxial compression test at 7th, 14th and 28th days, showing similar resistances, around to 35 MPa, independent of the aggregate mix and concrete dosage.

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

Imaging a fossil oolitic system with GPR, insights into the exposures of the Isle of Portland (UK)

Science.gov (United States)

Moreau, Julien; Hansen, Trine L.; Nielsen, Lars

2015-04-01

The Isle of Portland shows exposure of uppermost Jurassic oolitic carbonate all along its coast. The stone of Portland properties are famous as standards for concrete composition, as building material but also for sculpture. As a consequence, the Isle has been quarried intensively for hundreds of years. The regional exposure quality is very high with a potential 3D control. The site has seen generations of geologist trainees coming for field work. The Wessex Basin where the Isle is sitting contains an active petroleum system and the geologists visiting/training there use the carbonates of Portland as an analogue to equivalent Middle-East oil and gas reservoir. Surprisingly, although the site has a tremendous potential to understand the 3D architecture and the sedimentary dynamic of an oolitic system, only punctual observations of logs (1D), sometimes correlated have been published. Several studies place a shore line between the Isle and the continent striking NEE-SWW and facing towards the Channel. Facies changes are attributed to rapid sea-level variations and Walter's Law. We have collected an extensive GPR survey of the same stratigraphic interval (The Portland Freestone). With a total of 99 GPR profiles, we have produced grids on top of most of the coastal cliffs and quarry faces. We have encountered 3 main architectures: 2-m-high bars with steep clinoforms, 10s of metres-wide channels plugged with a variety of organisms and stacked aggrading bundles of multidirectional dunesets. Our dataset does not illustrate any major unconformity which could be attributed to a sharp sea-level drop. We have interpreted our sedimentary architecture to be the result of various hydrodynamic conditions associated with a mix of wave and tide influences. The Isle shows an island barrier complex which progrades into the basin but also expands laterally filling up the available space and cannibalising itself. More proximal facies are effectively observed in the north of the island

Resistance to acid attack of portland cement mortars produced with red mud as a pozzolanic additive

International Nuclear Information System (INIS)

Balbino, Thiago Gabriel Ferreira; Fortes, Gustavo Mattos; Lourenco, Rafaela Roberta; Rodrigues, Jose de Anchieta

2011-01-01

Portland cement structures are usually exposed to aggressive environments, which requires the knowledge of the performance of these materials under deleterious conditions. In this study, it was evaluated the resistance to acid attack of mortars that contain ordinary (CPI) and compost (CPII-Z) Portland cements, adding to the first red mud (RB) as a pozzolanic additive in different conditions: without calcination, calcined at 400 ° C and at 600 ° C. The specimens were subjected to HCl and H 2 SO 4 solutions, both with concentration of 1.0 Mol L -1 for 28 days, monitoring the weight loss and leached material nature by atomic emission inductively coupled plasma (ICP). The hydration products were studied by thermogravimetric analysis (TGA) and X-ray diffraction (XRD) of the hydrated cement pastes. It was observed a reduction of portlandite amount in the RB containing cement pastes, indicating a possible pozzolanic activity of the red mud. The mortars prepared with RB were more resistant to HCl, while that ones with calcined RB present a better performance in H 2 SO 4 attack. (author)

78 FR 8493 - Foreign-Trade Zone 45-Portland, OR; Notification of Proposed Production Activity; SoloPower Inc...

Science.gov (United States)

2013-02-06

...; Notification of Proposed Production Activity; SoloPower Inc. (Thin Film Photovoltaic Solar Panels); Portland... of FTZ 45. The facility is used for the production of thin film photovoltaic solar panels. Pursuant... procedures that applies to the thin film solar panels (duty-free) for the foreign status inputs noted below...

Red mud addition in the raw meal for the production of Portland cement clinker.

Science.gov (United States)

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

2004-12-10

The aim of the present research work was to investigate the possibility of adding red mud, an alkaline leaching waste, which is obtained from bauxite during the Bayer process for alumina production, in the raw meal for the production of Portland cement clinker. For that reason, two samples of raw meals were prepared: one with ordinary raw materials, as a reference sample ((PC)Ref), and another with 3.5% red mud ((PC)R/M). The effect on the reactivity of the raw mix was evaluated on the basis of the unreacted lime content in samples sintered at 1350, 1400 and 1450 degrees C. Subsequently, the clinkers were produced by sintering the two raw meals at 1450 degrees C. The results of chemical and mineralogical analyses as well as the microscopic examination showed that the use of the red mud did not affect the mineralogical characteristics of the so produced Portland cement clinker. Furthermore, both clinkers were tested by determining the grindability, setting time, compressive strength and expansibility. The hydration products were examined by XRD analysis at 2, 7, 28 and 90 days. The results of the physico-mechanical tests showed that the addition of the red mud did not negatively affect the quality of the produced cement.

The impact of zirconium oxide radiopacifier on the early hydration behaviour of white Portland cement.

Science.gov (United States)

Coleman, Nichola J; Li, Qiu

2013-01-01

Zirconium oxide has been identified as a candidate radiopacifying agent for use in Portland cement-based biomaterials. During this study, the impact of 20 wt.% zirconium oxide on the hydration and setting reactions of white Portland cement (WPC) was monitored by powder X-ray diffraction (XRD), (29)Si and (27)Al magic angle spinning nuclear magnetic resonance spectroscopy (MAS NMR), transmission electron microscopy (TEM) and Vicat apparatus. The presence of 20 wt.% zirconium oxide particles in the size-range of 0.2 to 5 μm was found to reduce the initial and final setting times of WPC from 172 to 147 min and 213 to 191 min, respectively. Zirconium oxide did not formally participate in the chemical reactions of the hydrating cement; however, the surface of the zirconium oxide particles presented heterogeneous nucleation sites for the precipitation and growth of the early C-S-H gel products which accelerated the initial setting reactions. The presence of zirconium oxide was found to have little impact on the development of the calcium (sulpho)aluminate hydrate phases. Copyright © 2012 Elsevier B.V. All rights reserved.

Mechanical characterization of Portland cement mortars containing petroleum or coal tar

Directory of Open Access Journals (Sweden)

Garcés, P.

2007-08-01

Full Text Available This article discusses experimental data on the flexural and compressive strength of Portland cement mortars containing additions or cement replacements consisting in petroleum or coal tar, by-products of the oil and coal industries. The materials studied were two coal (BACA and BACB and two petroleum (BPP and BPT tars. The results show that it is feasible to use such materials as a partial replacement for cement in mortar manufacture. This should lead to the design of a new sustainable product that will contribute to lowering the environmental impact of construction materials while at the same time opening up an avenue for the re-use of this type of industrial by-products.En este artículo se presentan datos experimentales de resistencia a flexión y a compresión de morteros de cemento Portland con adición y sustitución de breas de petróleo y de alquitrán de carbón, que son subproductos de la industria del carbón o del petróleo. Los materiales estudiados son breas de alquitrán de carbón A (BACA y B (BACB, y dos breas de petróleo (BPP y (BPT. Los datos demuestran la viabilidad del uso de estas breas en la fabricación de morteros con menores contenidos de cemento, permitiendo diseñar un nuevo material sostenible con el medio ambiente y que contribuya a reducir el impacto ambiental de los materiales de construcción, hecho que permite abrir una nueva vía de valorización de estos subproductos.

Environmental justice and factors that influence participation in tree planting programs in Portland, Oregon, U.S

Science.gov (United States)

Geoffrey H. Donovan; John Mills

2014-01-01

Many cities have policies encouraging homeowners to plant trees. For these policies to be effective, it is important to understand what motivates a homeowner’s tree-planting decision. Researchers address this question by identifying variables that influence participation in a tree-planting program in Portland, Oregon, U.S. According to the study, homeowners with street...

Evolution of porosity in a Portland cement paste studied through positron annihilation lifetime spectroscopy

International Nuclear Information System (INIS)

Consolati, G.; Quasso, F.

2003-01-01

Positron annihilation lifetime spectroscopy experiments were carried out in an ordinary Portland cement paste characterized by a water-to-cement ratio w/c=0.8, in order to monitor the porosity of the paste. It was found that ortho-positronium intensity is a suitable quantity to this purpose, being sensitive to the amount of water contained in the pores. The experimental data show good agreement with the porosity calculated according to the Powers' thin filmsodel

Analysis of Minority Officer Recruiting in the U.S. Marine Corps

Science.gov (United States)

2011-03-01

Selection Officer ( OSO ) ..........................11  b.  Officer Recruiting Impact on Minority Officer Accessions ..12  B.  LITERATURE REVIEW...Serve Data..............................................39  c.  Officer Selection Officer ( OSO ) Area of Operation Data .....41  2.  Phase 2 and Phase 3...School OSO Officer Selection Officer OSS Officer Selection Station PLC Platoon Leaders Course PW-QCP Propensity-Weighted Qualified Candidate

Petrographic Analysis of Portland Cement Concrete Cores from Pease Air National Guard Base, New Hampshire

Science.gov (United States)

2016-11-01

Petrographic Analysis of Portland Cement Concrete Cores from Pease Air National Guard Base, New Hampshire E n g in e e r R e s e a rc h a n d...id, age of the concrete being evaluated and tests performed...4 3 Preface This study was conducted in support of the Air Force Civil Engineer Center (AFCEC) to assess concrete obtained from Pease

The AFm phase in Portland cement

International Nuclear Information System (INIS)

Matschei, T.; Lothenbach, B.; Glasser, F.P.

2007-01-01

The AFm phase of Portland cements refers to a family of hydrated calcium aluminates based on the hydrocalumite-like structure of 4CaO.Al 2 O 3 .13-19 H 2 O. However OH - may be replaced by SO 4 2- and CO 3 2- . Except for limited replacement (50 mol%, maximum) of sulfate by hydroxide, these compositions do not form solid solutions and, from the mineralogical standpoint, behave as separate phases. Therefore many hydrated cements will contain mixtures of AFm phases. AFm phases have been made from precursors and experimentally-determined phase relationships are depicted at 25 deg. C. Solubility data are reported and thermodynamic data are derived. The 25 deg. C stability of AFm phases is much affected by the nature of the anion: carbonate stabilises AFm and displaces OH and SO 4 at species activities commonly encountered in cement systems. However in the presence of portlandite, and as carbonate displaces sulfate in AFm, the reaction results in changes in the amount of both portlandite and ettringite: specimen calculations are presented to quantify these changes. The scheme of phase balances enables calculation of the mineralogical balances of a hydrated cement paste with greater accuracy than hitherto practicable

Large-scale Meteorological Patterns Associated with Extreme Precipitation Events over Portland, OR

Science.gov (United States)

Aragon, C.; Loikith, P. C.; Lintner, B. R.; Pike, M.

2017-12-01

Extreme precipitation events can have profound impacts on human life and infrastructure, with broad implications across a range of stakeholders. Changes to extreme precipitation events are a projected outcome of climate change that warrants further study, especially at regional- to local-scales. While global climate models are generally capable of simulating mean climate at global-to-regional scales with reasonable skill, resiliency and adaptation decisions are made at local-scales where most state-of-the-art climate models are limited by coarse resolution. Characterization of large-scale meteorological patterns associated with extreme precipitation events at local-scales can provide climatic information without this scale limitation, thus facilitating stakeholder decision-making. This research will use synoptic climatology as a tool by which to characterize the key large-scale meteorological patterns associated with extreme precipitation events in the Portland, Oregon metro region. Composite analysis of meteorological patterns associated with extreme precipitation days, and associated watershed-specific flooding, is employed to enhance understanding of the climatic drivers behind such events. The self-organizing maps approach is then used to characterize the within-composite variability of the large-scale meteorological patterns associated with extreme precipitation events, allowing us to better understand the different types of meteorological conditions that lead to high-impact precipitation events and associated hydrologic impacts. A more comprehensive understanding of the meteorological drivers of extremes will aid in evaluation of the ability of climate models to capture key patterns associated with extreme precipitation over Portland and to better interpret projections of future climate at impact-relevant scales.

Immobilisation Of Spent Ion Exchange Resins Using Portland Cement Blending With Organic Material

International Nuclear Information System (INIS)

Zalina Laili; Mohd Abdul Wahab; Nur Azna Mahmud

2014-01-01

Immobilisation of spent ion exchange resins (spent resins) using Portland cement blending with organic material for example bio char was investigated. The performance of cement-bio char matrix for immobilisation of spent ion exchange resins was evaluated based on their compression strength and leachability under different experimental conditions. The results showed that the amount of bio char and spent resins loading effect the compressive strength of the waste form. Several factors affecting the leaching behaviour of immobilised spent resins in cement-bio char matrix. (author)

Concentration of electrolyte reserves of the juvenile african catfish clarias gariepinus (burchell, 1822) exposed to sublethal concentrations of portland cement powder in solution

International Nuclear Information System (INIS)

Adamu, M.K.; Francis, O.A.

2008-01-01

The study investigated the effect of sublethal concentrations (39.10, 19.55, 9.87 and 0.00 mg/l) of Portland cement powder in solution on the electrolyte reserves (sodium, potassium, calcium, chloride and inorganic phosphorus) in the serum, liver and kidney of the juvenile African catfish Clarias gariepinus after a 15 day exposure period. The basic function of the determined electrolyte reserves in the body lies in controlling fluid distribution, intra and extra cellular acidobasic equilibrium, maintaining osmotic pressure of body fluid and normal neuro-muscular irritability. The result revealed significant (P 0.05) changes in inorganic phosphorus. Sodium, calcium, chloride and inorganic phosphorus and potassium were significantly (P 0.05) different in liver and kidney, respectively. Ipso-facto, the effector organs viz: liver and kidney of teleost species - Clarias gariepinus which are primarily responsible for regulating water and ionic movement between external and internal milieu of fishes are susceptible to deleterious effects of Portland cement powder thus sublethal concentration (39.10 mg/l) of Portland cement powder in solution after a 15 day exposure has been most toxic and debilitating to the test fish. (author)

Influence of Ba2+ and Sr2+ ions on the hydration process of portland cement and blended cements

Directory of Open Access Journals (Sweden)

Živanović, B. M.

1987-12-01

Full Text Available This study concerns the influence of the concentration of Sr2+ and Ba2+ ions in mortar batch waters upon the hydration process of various Portland and additive cements. An increase in the mechanical resistence of said cements is observed, after 28 days, when the concentration of Ba2+ and Sr2+ ions in the mortar batch waters increases. This suggests a possible microstructural explanation of said phenomenon.En el presente trabajo se estudia la influencia de la concentración de los iones Sr2+ y Ba2+ en las aguas de amasado sobre el proceso de hidratación de varios cementos portland y de adición. Se comprueba un incremento de las resistencias mecánicas de dichos cementos, a los 28 días, cuando aumenta la concentración de los iones Ba2+ y Sr2+ en las aguas de amasado, lo cual sugiere una posible explicación microestructural a dicho fenómeno.

Evolution and quantification of the main Sensitisers in commercial portland cements

Directory of Open Access Journals (Sweden)

Frías, M.

2002-03-01

Full Text Available The commercial Portland cements contain minor elements in their chemical compositions. The presence of these elements has a direct incidence in different aspects: rheological behaviour, reaction kinetics, environmental, etc. Some of them also have a negative effect on the human health; so, chromium (Cr, nickel (Ni and cobalt (Co are the main allergens present in Portland cements, causing of Professional Dermatitis in construction workers. The current study is focussed on the quantification of total and soluble chromium, nickel and cobalt in a wide range of Spanish commercial cements. These values can represent a contribution to the establishing of possible limitations or reductions of these elements in forthcoming standards. Analytical data show that clinkers are the main responsibles of the presence of soluble chromium in commercial cements. This fact could be indicating that chromium solubility (from inert Cr III to soluble Cr VI would be closely related to the clinkerisation conditions. On the other hand, there is not a direct ratio between total chromium and soluble chromium; it means that analytical results are punctual and not any case can be extrapolating ones. Ni and Co solubility in water is practically negligible either raw as clinkers.

Los cementos Portland comerciales contienen elementos minoritarios en su composición química. La presencia de estos elementos tiene una incidencia directa en diferentes aspectos: comportamiento reológico, cinética de reacción, contaminación ambiental, etc. Algunos de ellos, aparte de su incidencia mencionada anteriormente, tienen un efecto negativo en la salud humana. Así, el cromo (Cr, níquel (Ni y cobalto (Co son los principales alérgenos contenidos en los cementos y, por lo tanto, los principales causantes de la Dermatitis Profesional. Este trabajo se centra en la cuantifîcación de los contenidos totales y solubles de cromo, níquel y cobalto presentes en los cementos comerciales

"Why Is This the Only Place in Portland I See Black People?": Teaching Young Children about Redlining

Science.gov (United States)

Johnson, Katharine

2012-01-01

As in many historically black neighborhoods in the United States, the gentrification of northeast Portland rests on an older history of economic injustice perpetrated by banks, realtors, governments, and white property owners. Redlining was one piece of an elaborate puzzle denying people of color access to housing and to wealth. The term refers to…

CALCIUM ORTHOPHOSPHATES HYDRATES: FORMATION, STABILITY AND INFLUENCE ON STANDARD PROPERTIES OF PORTLAND CEMENT

Directory of Open Access Journals (Sweden)

Kaziliunas A.

2013-12-01

Full Text Available Preparation of phosphogypsum to produce the binders requires a much higher input than preparation of natural gypsum stone. This makes it uncompetitive material. The investigations presented therein are meant to reduce this input by looking for the ways of rendering impurities harmless. Soluble acid orthophosphates are the main harmful impurity of phosphogypsum. The studies show that dry insoluble calcium orthophosphates hydrates (1.09 % and 2.18 % P2O5 in gypsum have little effect on W/C, setting times and soundness of Portland cement pastes. Insoluble calcium orthophosphates hydrates {CaHPO4∙2H2O, Ca8(HPO42(PO44∙5H2O and Ca9(HPO4(PO45(OH∙4H2O} formed in acidic medium (pH = 4.2 - 5.9 have been destroyed in alkaline medium and reduce standard compressive strength of cement up to 28 %. Calcium orthophosphates hydrates of hydroxyapatite group are stable in alcaline medium, while in dry state they reduce the standard compressive strength of cement until 10 %, but their suspensions prolong setting times of Portland cement as soluble orthophosphates – 2 - 3 times. Alkalis in cement increase pH of paste, but do not change the process of formation of calcium orthophosphates hydrates of hydroxyapatite group: it takes place through an intermediate phase - CaHPO4·2H2O, whose transformation into apatite lasts for 2 - 3 months.

The Development of Rally Activities to Environmental Conservationfor Social Education Teachers of Mathayom Suksa Education Area Office 27 Roi-Et Province

Directory of Open Access Journals (Sweden)

Phiphop Sinthuphong

2016-09-01

Full Text Available The purposes of this research on the development of rally activities to environmental conservation for social education teachers of Mathayom suksa education area office 27 Roi-et province were ; 1 to study and analyze the place organized rally to environmental conservation, 2 to develop activities rally to environmental conservation for social education teachers 3 and compare knowledge and attitude toward environmental conservation, before and after the activity 4 to study participation in activities rally to environmental conservation after the activities. The samples used in the study and analysis of the event was social Education Teachers of Mathayom Suksa Education Area Office 27 Roi-Et Province were 77 and sample used in the event of 50 people. Social education teachers under the office of the secondary area 27 province. The tools used in this study were manual and brochures of Green activities Car Rally to environmental conservation, knowledge test, attitudes test and participating questionnaire manuals. The statistical analysis of data were percentage, mean, standard deviation and Paired t-test The results showed that there were proper place in activity all 9 points include 1. Wat Burapharam, 2. Pralanchai Swamp, 3.Roi-Et aquarium, 4. Ku Ka Sing ancient park, 5. Ku Phra Kona ancient park, 6. Jasmine rice learning source (land development station , 7. Chi river, 8.Don Swamp and 9. Rai Dakdea and dodo scouts camp. The tool in rally activities environmental conservation had suitability at more level. After participation of rally activities environmental conservation, social education teachers had mean score of knowledge and attitude to environmental conservation at more than before the participation at statistical significant level .05. And the score of knowledge and attitude toward environmental conservation, before and after the organized activities, it was found that, according to the hypothesis .05 and They had participation in

77 FR 39793 - Notice of Intent To Rule on Request To Release Airport Property at Portland-Hillsboro Airport...

Science.gov (United States)

2012-07-05

... To Release Airport Property at Portland--Hillsboro Airport, Hillsboro, OR AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of Proposal to Release Airport Property. SUMMARY: The FAA proposes to... provisions of Section 125 of the Wendell H. Ford Aviation Investment Reform Act for the 21st Century (AIR 21...

Estudo do reaproveitamento do cimento Portland de alta resistência inicial

Directory of Open Access Journals (Sweden)

A. G. de Araújo Jr.

Full Text Available Resumo Devido aos impactos ambientais gerados pela construção civil, muitos pesquisadores têm estudado os resíduos de construção e demolição. É possível encontrar na literatura científica trabalhos focados na pasta de cimento endurecido. Neste estudo, pasta de cimento Portland hidratada (PCH preparada a partir de cimento Portland CP V-ARI (CP-V foi desidratada via tratamento térmico a 700 °C (700-PCD e a 900 °C (900-PCD, sendo em seguida reidratada. A estrutura e microestrutura durante hidratação, desidratação e reidratação foram investigadas. Para a caracterização das mudanças morfológicas, difração de raios X, espectroscopia no infravermelho com transformada de Fourier e microscopia eletrônica de varredura foram utilizadas. A análise termogravimétrica foi utilizada para estudar as etapas de desidratação da pasta de cimento hidratada original. O estudo de desidratação da PCH mostrou que a 700 e 900 °C os novos nesossilicatos e CaO estão claramente presentes nas amostras. Durante a reidratação das amostras de 700-PCD e o 900-PCD, ocorreram reidratação parcial e carbonatação. Corpos de prova a partir de CP-V e 0%, 2%, 10%, 40% e 60% de pó de cimento desidratado (PCD foram preparados. Corpos de prova preparados com até 40% de PCD apresentaram propriedades semelhantes, quando comparado com corpos de prova de pasta de cimento puro preparados com CP-V, enquanto adições de 60% de PCD resultaram em um decréscimo da resistência à compressão.

Determination of the Apical Sealing Abilities of Mineral Trioxide Aggregate, Portland Cement, and Bioaggregate After Irrigation with Different Solutions.

Science.gov (United States)

Bayram, H Melike; Saklar, Feridun; Bayram, Emre; Orucoglu, Hasan; Bozkurt, Alperen

2015-06-01

The purpose of this study was to investigate the sealing ability of root-end filling materials such as mineral trioxide aggregate (MTA), Portland cement, and bioaggregate (BA) after irrigation with different solutions. We examined 130 human maxillar central teeth. After cutting the teeth at the cementoenamel junction, the root canals were expanded using nickel-titanium rotary instruments. Root canals were filled with AH-plus and gutta-percha. Then, the roots were cut apically, and 3 mm deep retrograde cavities were prepared. The roots were divided 12 experimental groups, consisting 10 teeth each; the positive and negative control groups contained five teeth each. The retrograde cavities were rinsed using ethylenediaminetetraacetic acid (EDTA), chlorhexidine (CHX), BioPure(™) mixture of a tetracycline isomer, an acid, and a detergent (MTAD), or distilled water. Next, groups 1, 2, 3, and 4 were sealed with MTA; groups 5, 6, 7, and 8 were sealed with Portland cement; and groups 9, 10, 11, and 12 were sealed with BA. Then, apical microleakage was evaluated by using a computerized fluid filtration method. The results of the leakage test were statistically evaluated by the post-hoc Tukey's test. MTA, Portland cement, and BA root-end filling materials showed the least leakage in the CHX and distilled water groups. The highest leakage was observed in the EDTA and MTAD groups. The sealing ability of BA was as good as that of MTA. EDTA and MTAD increased the apical leakage and CHX and distilled water decreased the leakage of the root-end filling materials examined in this study.

Oiling and cleanup issues in wetlands, M/T Julie N spill, Portland, Maine

International Nuclear Information System (INIS)

Michel, J.; Lehmann, S.M.; Henry, C.B.Jr.

1998-01-01

The clean up and environmental assessment techniques which were used following the September 1996 oil spill from the M/T Julie N in Portland Harbor, Maine were reviewed and documented. The spill resulted in heavy oiling of wetland. Aerial photography, ground-truth surveys, transects and chemical sampling were conducted to try to assess the impact to wetlands and to decide on appropriate cleanup options. A range of cleanup methods were attempted including low-pressure flushing, shoreline cleaning agents, vegetation cutting, and natural recovery. 9 refs., 3 tabs., 1 fig

The Estimation of Compaction Parameter Values Based on Soil Properties Values Stabilized with Portland Cement

Science.gov (United States)

Lubis, A. S.; Muis, Z. A.; Pasaribu, M. I.

2017-03-01

The strength and durability of pavement construction is highly dependent on the properties and subgrade bearing capacity. This then led to the idea of the selection methods to estimate the density of the soil with the proper implementation of the system, fast and economical. This study aims to estimate the compaction parameter value namely the maximum dry unit weight (γd max) and optimum moisture content (wopt) of the soil properties value that stabilized with Portland Cement. Tests conducted in the laboratory of soil mechanics to determine the index properties (fines and liquid limit) and Standard Compaction Test. Soil samples that have Plasticity Index (PI) between 0-15% then mixed with Portland Cement (PC) with variations of 2%, 4%, 6%, 8% and 10%, each 10 samples. The results showed that the maximum dry unit weight (γd max) and wopt has a significant relationship with percent fines, liquid limit and the percentation of cement. Equation for the estimated maximum dry unit weight (γd max) = 1.782 - 0.011*LL + 0,000*F + 0.006*PS with R2 = 0.915 and the estimated optimum moisture content (wopt) = 3.441 + 0.594*LL + 0,025*F + 0,024*PS with R2 = 0.726.

Assessment of diabetic teleretinal imaging program at the Portland Department of Veterans Affairs Medical Center.

Science.gov (United States)

Tsan, Grace L; Hoban, Keely L; Jun, Weon; Riedel, Kevin J; Pedersen, Amy L; Hayes, John

2015-01-01

We conducted a retrospective chart review of 200 diabetic patients who had teleretinal imaging performed between January 1, 2010, and January 1, 2011, at Portland Department of Veterans Affairs (VA) Medical Center outpatient clinics to assess the effectiveness of the diabetic teleretinal imaging program. Twenty patients (10%) had diabetic retinopathy. Ninety percent of the available teleretinal imaging studies were of adequate quality for interpretation. In accordance with local VA policy at that time, all teleretinal imaging patients should have been referred for a dilated retinal examination the following year. Image readers referred 97.5% of the patients to eye clinics for subsequent eye examinations, but the imagers scheduled appointments for only 80% of these patients. The redundancy rate, i.e., patients who had an eye examination within the past 6 mo, was 11%; the duplicate recall rate, i.e., patients who had a second teleretinal imaging performed within 1 yr of the eye examination, was 37%. Rates of timely diabetic eye examinations at clinics with teleretinal imaging programs, particularly when teleretinal imaging and eye clinics were colocated at the same community-based outpatient clinic, were higher than those without a teleretinal imaging program. We concluded that the Portland VA Medical Center's teleretinal imaging program was successful in increasing the screening rate for diabetic retinopathy.

Special considerations for hiring an office manager.

Science.gov (United States)

Sachs Hills, Laura

2004-01-01

Medical practice office managers come in many varieties. They can be hired from the outside or promoted from within. They can have a great deal of experience working in medical practices or practically none. Which type of office manager is the best choice for your practice? This article will help you decide. It describes three types of office managers and considers the pros and cons of each. It explores the characteristics, advantages, and disadvantages of lay administrators hired from the outside, office managers promoted from the ranks, and "super-aides" who are asked to manage while doing their old jobs. This article also offers a list of 10 characteristics to look for in office manager candidates, as well as six areas of overall responsibility for your office manager. Finally, it includes a quick checklist of 20 required duties of typical medical practice office managers that can help you shape your office manager's job description.

The effect of urban trees on the rental price of single-family homes in Portland, Oregon

Science.gov (United States)

Geoffrey H. Donovan; David T. Butry

2011-01-01

Few studies have estimated the effect of environmental amenities on the rental price of houses. We address this gap in the literature by quantifying the effect of urban trees on the rental price of single-family homes in Portland, Oregon, USA. We found that an additional tree on a house's lot increased monthly rent by $5.62, and a tree in the public right of way...

Effect of saliva and blood contamination on the bi-axial flexural strength and setting time of two calcium-silicate based cements: Portland cement and biodentine.

Science.gov (United States)

Alhodiry, W; Lyons, M F; Chadwick, R G

2014-03-01

This study evaluated the effect of contamination with saliva and blood on the bi-axial flexural strength and setting time of pure gray Portland cement and Biodentine (Septodont, Allington, UK). A one-way ANOVA showed that contamination caused no significant difference between the cements in bi-axial flexural strength (P> 0.05). However there was a significant difference in setting time (PPortland cement taking longer than Biodentine, regardless of the contaminant, and contamination with blood increased the setting time of both materials. Biodentine was similar in strength to Portland cement, but had a shorter setting time for both contaminated and non-contaminated samples.

Office Rental Determinants in WUSE Commercial District of Abuja ...

African Journals Online (AJOL)

This paper examines the determinants of office rents in Wuse commercial district of Abuja, Nigeria. Primary and secondary data were utilized for the study. Primary data obtained for the study include office rental levels and office space data in the study area for the period between 2001 and 2012. Secondary data obtained ...

A Development of Academic Management on Small School Model Under The Office of Udonthani Educational Service Area 2

Directory of Open Access Journals (Sweden)

Theerachai Saenkaew

2017-03-01

Full Text Available The purpose of study were ; 1 to determine the Academic Management on small school Model ; 2 to Develop of Academic Management on small school model Under the office of Udonthani Educational Service Area 2. The research Methodology consisted of four steps ; 1 Analyzing the documentary research ; 2 developing the academic management on small school factors and Indicators with Delphi Technique by verifying of 21 experts ; 3 seeking the advices and the feedbacks from nine experts in Udonthani using focus group discussion ; 4 evaluating the 110 school Administrators opinions in Udonthani. The analysis of the data was accomplished by computation of percentage, mean, standard deviation, median and interquartile ranges. Based on the findings to the study; it was concluded that: 1 The group of experts represented the three factors were ; a A development school Record of students ; b A development attribute of student ; c care forward successes with 15 Indicators. 2 Based on group discussion, all experts strongly agreed with the used and Integration of three factors of academic management on small school Model. 3 Overall, the at 110 school demonstrations in Udonthani agreed with academic management on small school model at high level. 4 A development of academic management on small school model in the office of Udonthani Educational Service Area 2 ; a A development school Record of students with 5 indicators ; b A development attribute of student with 6 indicators ; c Care Forward Successes with 4 indicators.

Utilization of the national Portland cement for immobilizing radioactive wastes - Physical characteristics

International Nuclear Information System (INIS)

Rzyski, B.M.; Suarez, A.A.

1988-01-01

This paper shows the results obtained in the study of the national Portland cement, P320, as matrix for radioactive nitric waste incorporation. Cement use practice in other countries is common for this purposes and demonstrates to be cheap and accessible when low and medium level wastes are immobilized. Some of physical characteristics as: homogeneity,mechanical strenght, setting and porosity are analysed due to water-cement ratio and salt contents. Those characteristics which are proper of the final product, must be controlled in such way to assure a long time integrity of the wasteform. The establishment of process and quality control criteria are based in such kind of data. (author) [pt

Microstructure Development and Transport Properties of Portland Cement-fly Ash Binary Systems : In view of service life predictions

NARCIS (Netherlands)

Yu, Z.

2015-01-01

Fly ash is a by-product of burning coal in electric power generating plants. It is commonly known that owing to its pozzolanic properties fly ash is widely used as a partial replacement for Portland cement in concrete. The use of fly ash in concrete not only reduces the landfill costs of fly ash,

Senior Strategic Outreach and Engagement Officer | IDRC ...

International Development Research Centre (IDRC) Digital Library (Canada)

The Senior Strategic Outreach and Engagement Officer provides strategic advice ... the third one in the area of knowledge management and the forth one in the area ... or the International Research Initiative on Adaptation to Climate Change.

Decontamination & decommissioning focus area

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-08-01

In January 1994, the US Department of Energy Office of Environmental Management (DOE EM) formally introduced its new approach to managing DOE`s environmental research and technology development activities. The goal of the new approach is to conduct research and development in critical areas of interest to DOE, utilizing the best talent in the Department and in the national science community. To facilitate this solutions-oriented approach, the Office of Science and Technology (EM-50, formerly the Office of Technology Development) formed five Focus AReas to stimulate the required basic research, development, and demonstration efforts to seek new, innovative cleanup methods. In February 1995, EM-50 selected the DOE Morgantown Energy Technology Center (METC) to lead implementation of one of these Focus Areas: the Decontamination and Decommissioning (D & D) Focus Area.

Hydration of Portland cement with additions of calcium sulfoaluminates

International Nuclear Information System (INIS)

Le Saoût, Gwenn; Lothenbach, Barbara; Hori, Akihiro; Higuchi, Takayuki; Winnefeld, Frank

2013-01-01

The effect of mineral additions based on calcium aluminates on the hydration mechanism of ordinary Portland cement (OPC) was investigated using isothermal calorimetry, thermal analysis, X-ray diffraction, scanning electron microscopy, solid state nuclear magnetic resonance and pore solution analysis. Results show that the addition of a calcium sulfoaluminate cement (CSA) to the OPC does not affect the hydration mechanism of alite but controls the aluminate dissolution. In the second blend investigated, a rapid setting cement, the amorphous calcium aluminate reacts very fast to ettringite. The release of aluminum ions strongly retards the hydration of alite but the C–S–H has a similar composition as in OPC with no additional Al to Si substitution. As in CSA–OPC, the aluminate hydration is controlled by the availability of sulfates. The coupling of thermodynamic modeling with the kinetic equations predicts the amount of hydrates and pore solution compositions as a function of time and validates the model in these systems.

Operating plan for the Office of International Health Programs

International Nuclear Information System (INIS)

1996-01-01

In this report unified ideas are presented about what the Office of International Health Programs does, what the individual contributions are, and how the organization connects to the Department of Energy. The planning efforts have focused on the office's three areas of responsibility: Europe, Japan, and the Marshall Islands. Common to each technical program area are issues related to the following: health of populations exposed to radiation incidents and the associated medical aspects of exposure; dose reconstruction; training; and public involvement. Each of the program areas, its customers, and primary customer interests are described

Reuse of a residue from petrochemical industry with portland cement Reutilización de un residuo de la industria petroquímica como adición al cemento portland

Directory of Open Access Journals (Sweden)

Janneth Torres Agredo

2012-06-01

Full Text Available In this article the possibility of using waste from the petrochemical industry,as partial replacement of Portland cement is studied, evaluating the presenceof contaminants in the waste and the encapsulation, once it is confined on the cement. This has been done, in order to find a use to this residue without cause damage to the environment. This residue, called spent fluid catalytic cracking catalyst (FCC, is mainly formed by a type Y zeolite, which is dispersing in an inorganic oxides matrix. The toxicity characteristic leaching proceeding was applied, in mortars adding with 20% of FCC as Portland cement replacement. The results showed that the residue does not represent a problem from the point of view of the leaching of elements, such as As, Pb, Zn, Cr, and La, which were below to the permissible limits. Additionally, the pozzolanic activity of FCC was evaluated according to ASTM C311, where the efficiency of the residue as pozzolanic addition is demonstrated. With the results the importance of reusing a residue of the petrochemical industry is emphasized, that decreases the amount of cement to be used and improves the mechanical resistance of the materials containing it.En el presente artículo se estudia la posibilidad de utilizar un residuo de la industria petroquímica, como sustitución parcial del cemento Portland, evaluando la presencia de elementos contaminantes en el residuo y su encapsulación, una vez se haya confinado con el cemento. Lo anterior, con el fin de determinar si su uso como material de construcción, puede o no causar un efecto negativo al medio ambiente. El residuo, denominado catalizador usado de craqueo catalítico (FCC, es un material que está compuesto por una zeolita tipo Y, dispersa en una matriz de óxidos inorgánicos. Se aplicó la técnica de TCLP (del inglés Toxicity Characteristic Leaching Procedure, en morteros adicionados con un 20%, de FCC con respecto a la cantidad de cemento. Los resultados

In Vitro Bioactivity and Setting Times of White Portland Cement Combined with Different Radio Pacifying Agents

Directory of Open Access Journals (Sweden)

Coleman Nichola Jayne

2017-01-01

Full Text Available Commercial formulations based on 80:20 mixtures of Portland cement and bismuth oxide (a radiopacifying agent are used in dentistry as root-filling materials. This study compares the impact of two alternative radiopacifiers, barium sulphate and zirconium oxide, with that of bismuth oxide, on the setting times and bioactivity of white Portland cement. The findings indicate that bismuth oxide prolongs both the initial and final setting times of the cement, and that barium sulphate and zirconium oxide have no effect on this parameter. Hydroxyapatite (HA formed on the surfaces of all test samples within 7 days of exposure to simulated body fluid, indicating that they possess the potential to stimulate new hard tissue formation. Fourier transform infrared spectroscopy, the traditional technique for the identification of HA, was not appropriate for the analysis of these cement systems owing to the overlap of signals from each of the radiopacifiers with the characteristic P-O bending modes of HA in the 570 – 610 cm−1 region. In this respect, the P-O band at 965 cm−1 of HA in the Raman spectrum was found to be a suitable means of detection since it is discrete with respect to all signals arising from the radiopacifying agents and cement phases.

Clinical and Radiographic Evaluation of the Effectiveness of Formocresol, Mineral Trioxide Aggregate, Portland Cement, and Enamel Matrix Derivative in Primary Teeth Pulpotomies: A Two Year Follow-Up.

Science.gov (United States)

Yildirim, Ceren; Basak, Feridun; Akgun, Ozlem Marti; Polat, Gunseli Guven; Altun, Ceyhan

2016-01-01

The aim of this study was to evaluate and to compare clinical and radiographic outcomes of 4 materials (formocresol, mineral trioxide aggregate (MTA), Portland cement and enamel matrix derivative) using in primary teeth pulpotomies. Sixty-five patients aged 5-9 years (32 female, 33 male) were included in this study. A total of 140 primary first and second molars with deep caries were treated with pulpotomy. All teeth were then restored with stainless steel crowns. The treated teeth were evaluated clinically and radiographically at 3, 6, 12, 18 and 24 months. At 24 months, the clinical success rates of formocresol, MTA, Portland cement, and enamel matrix derivative were 96.9%, 100%, 93.9%, and 93.3%, respectively. The corresponding radiographic success rates were 84.4%, 93.9%, 86.7% and 78.1%, respectively. Although there were no statistically significant differences in clinical and radiographic success rates among the 4 groups, MTA appears to be superior to formocresol, Portland cement, and enamel matrix derivative as a pulpotomy agent in primary teeth.

Multi-angled Façade System for Office Building Renovation

DEFF Research Database (Denmark)

Hannoudi, Loay Akram; Christensen, Jørgen Erik; Lauring, Michael

renovating office buildings. The architectural potential is presented with the help of AutoCAD software. The energy efficiency and indoor climate are investigated and evaluated by using correlational research and simulation research methods with the software IDA ICE. From a functional perspective, the multi......-angled façade increases the area of the office room and provides more space. There are many potential aesthetic benefits provided by multi-angled façades such as improved optical and visual quality from inside the office room and the possibility for daylight penetration and a view to outside from one part...... compared to a renovated flat façade varies between 4.9 and 6.5 kWh/(m2.year), depending on the orientation of the façade. The increase in the office room area, when renovated with a multi-angled façade, is by 19%, while the increase of the yearly primary energy consumption (not area weighted), is by 4...

Properties of SiMn slag as apozzolanic material in portland cement manufacture

Directory of Open Access Journals (Sweden)

Frías, M.

2005-12-01

Full Text Available The primary purpose of this study was to evaluate the behaviour of SiMn slag as a pozzolanic material in commercial Portland cement manufacture. This necessitated exploring different scientific and technical aspects to ensure a correct valuation. The results obtained revealed that silica and calcium are the main components of SiMn slag, whose pozzolanic activity occupies an intermediate position between silica fume and fly ash; it reduces heat of hydration and mortars made with cement containing SiMn slag exhibit compressive strength values similar to the figures for standard mortar. Consequently, the use of SiMn slag as an active addition to cement is feasible, inasmuch as the resulting product meets the requirements laid down in the present legislation.

El objetivo principal de este trabajo es evaluar el comportamiento de la escoria de SiMn como material puzolánico en la fabricación de cementos Portland comerciales. Para ello, resulta necesario investigar diferentes aspectos científicos y técnicos que conlleven a una correcta valorización de las mismas. Los resultados obtenidos en el presente trabajo han puesto de manifiesto que la escoria de SiMn presenta una naturaleza sílico-cálcica, actividad puzolúnica intermedia entre el humo de sílice y ceniza volante, reduce el calor de hidratación y los morteros con escoria de SiMn muestra alcanzan resistencias a compresión similares a las del mortero patrón. Por lo tanto, la utilización de la escoria de SiMn como adición activa al cemento es viable, cumpliendo con las exigencias recogidas en la norma vigente.

Immobilisation of strontium, nickel and iodide by a sulphate-resisting Portland cement

International Nuclear Information System (INIS)

Wieland, E.; Tits, J.; Spieler, P.; Dobler, J.-P.

1998-01-01

The interaction of Sr(II), Ni(II) and I(-I) with sulphate-resisting Portland cement was investigated under highly alkaline conditions. Batch-sorption studies were performed by contacting HTS cement (haute teneur en silice, sulphate-resisting Portland cement, Lafarge, France) with artificial cement pore water (ACW). The composition of ACW was 0.18 M KOH, 0.114 M NaOH and 1.2 mM Ca(OH) 2 . 85 Sr, 63 Ni and 125 I were used as tracers. In the experiments with Sr(II) and Ni(II), isosaccharinic acid (ISA) was added to ACW at 10 -5 M to 10 -2 M in order to study the effect of complexing ligands on radionuclide retention. The stability of the tracer solutions and the cement suspensions were first assessed. Moreover, the inventory of the stable elements were determined in cement and cement pore water. We then studied the kinetics of the radionuclide-cement interaction process and measured the dependence of the distribution ratio (R d ) on the concentration of ISA and on the concentration of cement particles (S:L ratio). In the case of 63 Ni and 125 I a strong decrease in the distribution ratio (R d ) with increasing S:L ratio was observed. There is strong indication that the inventory of the stable fraction of an element present in cement pore water accounts for the retention of the radioisotope fraction. The results further indicate that phase transformations may occur in non-pre-equilibrated cement systems (non-equilibrium conditions) which affect 63 Ni uptake by HTS cement. The distribution ratios measured on HTS cement were compared with values obtained from measurements on important cement components (portlandite, CSH/C(A)SH-phases)

10 CFR 1.37 - Office of Small Business and Civil Rights.

Science.gov (United States)

2010-01-01

... consideration is given to Labor Surplus Area firms and Women Business Enterprises, and conducts an outreach... 10 Energy 1 2010-01-01 2010-01-01 false Office of Small Business and Civil Rights. 1.37 Section 1... Headquarters Staff Offices § 1.37 Office of Small Business and Civil Rights. The Office of Small Business and...

Industrial Wastes as Alternative Mineral Addition in Portland Cement and as Aggregate in Coating Mortars

OpenAIRE

Oliveira, Kamilla Almeida; Nazário, Bruna Inácio; Oliveira, Antonio Pedro Novaes de; Hotza, Dachamir; Raupp-Pereira, Fabiano

2017-01-01

This paper presents an evaluation study of wastes from pulp and paper as well as construction and demolition industries for application in cement-based materials. The alternative raw materials were used as a source of calcium carbonate (CaCO3) and as pozzolanic material (water-reactive SiO2) in partial replacement of Portland cement. In addition to the hydraulic binder, coating mortars were composed by combining the pulp and paper fluidized bed sand residue with construction and demolition wa...

Solidification of ion exchange resins saturated with Na+ ions: Comparison of matrices based on Portland and blast furnace slag cement

Science.gov (United States)

Lafond, E.; Cau dit Coumes, C.; Gauffinet, S.; Chartier, D.; Stefan, L.; Le Bescop, P.

2017-01-01

This work is devoted to the conditioning of ion exchange resins used to decontaminate radioactive effluents. Calcium silicate cements may have a good potential to encapsulate spent resins. However, certain combinations of cement and resins produce a strong expansion of the final product, possibly leading to its full disintegration. The focus is placed on the understanding of the behaviour of cationic resins in the Na+ form in Portland or blast furnace slag (CEM III/C) cement pastes. During hydration of the Portland cement paste, the pore solution exhibits a decrease in its osmotic pressure, which causes a transient expansion of small magnitude of the resins. At 20 °C, this expansion takes place just after setting in a poorly consolidated material and is sufficient to induce cracks. In the CEM III/C paste, swelling of the resins also occurs, but before the end of setting, and induces limited stress in the matrix which is still plastic.

33 CFR 165.103 - Safety and Security Zones; LPG Vessel Transits in Portland, Maine, Captain of the Port Zone...

Science.gov (United States)

2010-07-01

... within a 500-yard radius of any Liquefied Petroleum Gas (LPG) vessel while it is moored at the LPG... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety and Security Zones; LPG... and Security Zones; LPG Vessel Transits in Portland, Maine, Captain of the Port Zone, Portsmouth...

20 CFR 658.415 - Transferring complaints to proper JS office.

Science.gov (United States)

2010-04-01

... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Transferring complaints to proper JS office... Agency Js Complaint System § 658.415 Transferring complaints to proper JS office. (a) Where a JS-related... local office serving the area in which the employer is located. Where a JS-related complaint deals with...

Metabolic Syndrome. Diagnosis in women of five doctor's office. North Area. November 2007-2008.

Directory of Open Access Journals (Sweden)

Yaneisy Triana Toledo

2011-11-01

Full Text Available The morbility for Metabolic-Syndrome in five doctor's office of the north health area in the municipality Accomplished a descriptive transverse cut investigation in 151 adult women's probabilistic sign to characterize itself Sancti - Spíritus, among 1ro of Noviembre of the 2007 and the November 30 the 2008. Morbility, the antecedent factors personnels of risk and of chronic illnesses were variables gone into no transmissible, they gathered data in a fill-out form, statistical analysis included percentages calculation, parameters esteem and tests them of proportions difference (x2. The main things aftermaths were Metabolic Syndrome prevalence of 33,3 % In the patients with metabolic syndrome the risk factor of chronic illnesses no transmissible that predominate was in order not to accomplish physical activity (96,1 %, her hiperlipidemia (27,3 %, as well as the obesity (24,4 % in this entity's bearers. The antecedent pathological personals for chronic illnesses no transmissible registered hypertension went with 64,7 %.

THE CONTEXT OF ESTABLISHING PROJECT MANAGEMENT OFFICES IN THE IT AREA: TWO CASE STUDIES

Directory of Open Access Journals (Sweden)

Andrea Giovanni Spelta

2010-01-01

Full Text Available Completing strategic Information Technology (IT projects as planned is certainly an important objective for large firms. One of the measures adopted to reach this goal systematically is to create a Project Management Office in the IT area (PMO-IT. However, many firms consider the possibility of creating a PMO-IT, but decide not to do it. This paper presents the results of an exploratory research about the contextual drivers that determine the decision to create PMO-Its. Through two case studies of large Brazilian firms – one that created the entity and another which believes does not need it –, the drivers of the decision to create or not to create a PMO-IT were identified, and it was possible to confirm some of the drivers mentioned in the literature. This paper increases the undertstanding about this topic, which is important in the Management Information Systems field, as well as indicates paths for future research.

Propriedades mecânicas de materiais compósitos à base de cimento Portland e resina epoxi Mechanical properties of composite materials based on portland cement and epoxy resin

Directory of Open Access Journals (Sweden)

T. H. Panzera

2010-03-01

Full Text Available O estudo de materiais de alto desempenho e multifuncionais, como os compósitos poliméricos cimentícios, tem sido o foco de inúmeras pesquisas na indústria da construção civil. Este trabalho investiga o efeito da combinação de uma fase polimérica termorrígida, uma resina epóxi, com cimento Portland branco estrutural, seguido da avaliação da resistência à compressão e módulo de elasticidade. Este compósito, quando comparado individualmente com as suas matérias-prima originais, promove um aumento da resistência mecânica à compressão, redução da massa específica e, também uma mudança significativa do comportamento mecânico. As mudanças nas propriedades mecânicas estão associadas à hidratação da fase cimentícia na presença da resina, fato comprovado através da análise espectroscópica na região do infravermelho.The study of multi-functional materials of high performance, as the polymeric-cementitious composites, has been the focus of several researches in the industry of the civil engineering. This work investigates the effect of the combination of a thermorigid epoxy phase and the white Portland cement, followed by the evaluation of its compressive strength and modulus of elasticity. This composite, when the phases are individually compared, provides an increase of the compressive strength, a reduction of the density, and a significant change of the mechanical behaviour. The changes in mechanical behaviour are associated with the hydration of cement in the presence of resin, which was evident after infrared spectroscopy analysis.

Hydration study of ordinary portland cement in the presence of zinc ions

Directory of Open Access Journals (Sweden)

Monica Adriana Trezza

2007-12-01

Full Text Available Hydration products of Portland cement pastes, hydrated in water and in the presence of zinc ions were studied comparatively at different ages. Hydration products were studied by X ray diffractions (XRD and infrared spectroscopy (IR. Although IR is not frequently used in cement chemistry, it evidenced a new phase Ca(Zn(OH32. 2H2O formed during cement hydration in the presence of zinc. The significant retardation of early cement hydration in the presence of zinc is assessed in detail by differential calorimetry as a complement to the study carried out by IR and XRD, providing evidence that permits to evaluate the kinetic of the early hydration.

Programs of the Office of Energy Research

International Nuclear Information System (INIS)

1990-01-01

The Office of Energy Research sponsors long-term research in certain fundamental areas and in technical areas associated with energy resources, production, use, and resulting health and environmental effects. This document describes these activities, including recent accomplishments, types of facilities, and gives some impacts on energy, science, and scientific manpower development. The document is intended to respond to the many requests from diverse communities --- such as government, education, and public and private research --- for a summary of the types of research sponsored by the Department of Energy's Office of Energy Research. This is important since the Office relies to a considerable extent on unsolicited proposals from capable university and industrial groups, self-motivated interested individuals, and organizations that may wish to use the Department's extensive facilities and resources. By describing our activities and facilities, we hope not only to inform, but to also encourage interest and participation

5 CFR 591.207 - Which areas are COLA areas?

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Which areas are COLA areas? 591.207 Section 591.207 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS ALLOWANCES AND DIFFERENTIALS Cost-of-Living Allowance and Post Differential-Nonforeign Areas Cost-Of-Living...

Aplicaciones prácticas de la espectroscopía de absorción infrarroja en el estudio de los crudos, del clínker y del cemento portland anhidro

OpenAIRE

Vázquez, Tomás

1980-01-01

En la primera parte de este trabajo (*) se trató brevemente y de una manera fundamentalmente práctica el estudio por espectroscopía infrarroja de calizas, arcillas, clínker portland y sus fases constituyentes. En, el presente trabajo finalizará esta exposición con una visión general de algunas posibilidades que tiene la espectroscopía IR en el estudio del cemento portland anhidro, así como el estudio breve de puzolanas, escorias y cenizas volantes, como adiciones activas.

Underdiagnosis and Lower Rates of Office Visits for Overweight/Obese Pediatric Patients in Rural Compared with Urban Areas.

Science.gov (United States)

SanGiovanni, Christine; McElligott, James; Morella, Kristen; Basco, William

2017-07-01

This study compared the number of children enrolled in Medicaid in rural and urban areas of South Carolina with an overweight/obesity diagnosis and the mean rates of office visits with overweight/obesity diagnosed. Medicaid claims data from 2012 for children in three South Carolina counties, categorized as urban, rural high resource, and rural low resource, were used to identify those who had been diagnosed as being overweight/obese during any encounter. Logistic and Poisson regressions were performed to predict whether overweight/obese children in each county would receive an overweight/obesity visit diagnosis and to calculate the mean rate of total office visits with an overweight/obesity diagnosis in each county. A total of 1233 children enrolled in Medicaid were diagnosed as being overweight/obese at any encounter in the designated counties. Well visits with overweight/obesity diagnosed varied significantly, with 42.6%, 28%, and 11% in urban, rural high-resource counties, and rural low-resource counties, respectively ( P overweight/obese at a well visit. All of the children had a low number of total office visits with overweight/obesity diagnosed. When comparing the counties, urban children (1.22 visits per year) had more visits than rural low-resource children (0.75 visits per year, P Overweight/obesity is underdiagnosed in rural children enrolled in Medicaid in South Carolina, which affects the number of children who receive help to manage their weight. Interventions to overcome barriers of diagnosis and management are necessary to address childhood obesity properly.

Quantitative study on the effect of high-temperature curing at an early age on strength development of concrete. Experiment with mortar using moderate-heat portland cement

International Nuclear Information System (INIS)

Sugiyama, Hisashi; Chino, Shigeo

1999-01-01

The effect of high-temperature curing at an early age on the strength development of concrete using moderate-heat portland cement was quantitatively studied. High-temperature curing conditions were set so as to give systematic variations in the temperature-time factors. As a result, the integrated value of curing temperature during the period having a significant effect on the strength development was proposed as a parameter that expressed the degree of high-temperature curing. The effect of high-temperature curing on the strength development of concrete using moderate-heat portland cement could be exactly predicted with the integrated value of curing temperature during the period from 0 to 3 days. (author)

Determination of the leaching rate of radionuclide 134Cs from the solidified radioactive wastes in Syrian Portland cement and cement-microsilica matrixes

International Nuclear Information System (INIS)

Ismail Shaaban; Nasim Assi

2010-01-01

The suitability of Syrian Portland cement for disposal of solidified low-level radioactive waste was assessed by measuring the leaching rate of 134 Cs. In ordinary cement concrete, a leaching rate of 1.309 x 10 -3 g/cm 2 per day was measured. Mixing this concrete with microsilica reduced significantly the leaching rate to 3.106 x 10 -4 g/cm 2 per day for 1% mixing, and to 9.645 x 10 -5 g/cm 2 per day for 3% mixing. It was also found that the application of a latex paint reduced these leaching rates by about 10%. These results, along with mechanical strength tests (under radiation exposure, high temperature, long water immersion and freeze-thaw cycling) indicate that Syrian Portland cement is suited for the disposal of low-level radioactive waste. (author)

Utility of the Mayo-Portland adaptability inventory-4 for self-reported outcomes in a military sample with traumatic brain injury.

Science.gov (United States)

Kean, Jacob; Malec, James F; Cooper, Douglas B; Bowles, Amy O

2013-12-01

To investigate the psychometric properties of the Mayo-Portland Adaptability Inventory-4 (MPAI-4) obtained by self-report in a large sample of active duty military personnel with traumatic brain injury (TBI). Consecutive cohort who completed the MPAI-4 as a part of a larger battery of clinical outcome measures at the time of intake to an outpatient brain injury clinic. Medical center. Consecutively referred sample of active duty military personnel (N=404) who suffered predominantly mild (n=355), but also moderate (n=37) and severe (n=12), TBI. Not applicable. MPAI-4 RESULTS: Initial factor analysis suggested 2 salient dimensions. In subsequent analysis, the ratio of the first and second eigenvalues (6.84:1) and parallel analysis indicated sufficient unidimensionality in 26 retained items. Iterative Rasch analysis resulted in the rescaling of the measure and the removal of 5 additional items for poor fit. The items of the final 21-item Mayo-Portland Adaptability Inventory-military were locally independent, demonstrated monotonically increasing responses, adequately fit the item response model, and permitted the identification of nearly 5 statistically distinct levels of disability in the study population. Slight mistargeting of the population resulted in the global outcome, as measured by the Mayo-Portland Adaptability Inventory-military, tending to be less reflective of very mild levels of disability. These data collected in a relatively large sample of active duty service members with TBI provide insight into the ability of patients to self-report functional impairment and the distinct effects of military deployment on outcome, providing important guidance for the meaningful measurement of outcome in this population. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Microstructure: Surface and cross-sectional studies of hydroxyapatite formation on the surface of white Portland cement paste in vitro

International Nuclear Information System (INIS)

Chaipanich, Arnon; Torkittikul, Pincha

2011-01-01

The formation of hydroxyapatite was investigated at the surface and at the cross-section of white Portland cement paste samples before and after immersion in simulated body fluid. Scanning electron microscope images showed that hydroxyapatite were found at the surface of white Portland cement after immersion in simulated body fluid. Hydroxyapatite grains of mostly ∼1 μm size with some grain size of ∼2-3 μm were seen after 4 days immersion period. More estabilshed hydroxyapatite grain size of ∼3 μm grains were observed at longer period of immersion at 7 and 10 days. The cross-section of the samples was investigated using line scanning technique and was used to determine the hydroxyapatite layer. A strong spectrum of phosphorus is detected up to 6-8 μm depth for samples after 4, 7 and 10 days immersion in simulated body fluid when compared to weak spectrum detected before immersion. The increase in the phosphorus spectrum corresponds to the hydroxyapatite formation on the surface of the samples after the samples were placed in simulated body fluid.

Estimating the availability of LLEA officers

International Nuclear Information System (INIS)

Berkbigler, K.P.

1977-07-01

An important element in the analysis of transportation safeguards systems is the determination of the availability of local law enforcement agents. Such information is necessary to identify areas where there are few officers available and to make comparisons of alternative routes. A computerized model, COPS, has been developed which rapidly estimates the total number of officers along a highway route. This paper briefly describes the model and presents example results for several routes in California and Nevada

Normal and refractory concretes for LMFBR applications. Volume 1. Review of literature on high-temperature behavior of portland cement and refractory concretes. Final report

International Nuclear Information System (INIS)

Bazant, Z.P.; Chern, J.C.; Abrams, M.S.; Gillen, M.P.

1982-06-01

The extensive literature on the properties and behavior at elevated temperature of portland cement concrete and various refractory concretes was reviewed to collect in concise form the physical and chemical properties of castable refractory concretes and of conventional portland cement concretes at elevated temperature. This survey, together with an extensive bibliography of source documents, is presented in Volume 1. A comparison was made of these properties, the relative advantages of the various concretes was evaluated for possible liquid metal fast breeder reactor applications, and a selection was made of several materials of interest for such applications. Volume 2 concludes with a summary of additional knowledge needed to support such uses of these materials together with recommendations on research to provide that knowledge

Applications of solid-state Nuclear Magnetic Resonance (NMR) in studies of Portland cements-based materials

DEFF Research Database (Denmark)

Skibsted, Jørgen; Andersen, Morten Daugaard; Jakobsen, Hans Jørgen

2007-01-01

Solid-state NMR spectroscopy represents an important research tool in the characterization of a range of structural properties for cement-based materials. Different approaches of the technique can be used to obtain information on hydration kinetics, mobile and bound water, porosity, and local...... atomic structures. After a short introduction to these NMR techniques, it is exemplified how magic-angle spinning (MAS) NMR can provide quantitative and structural information about specific phases in anhydrous and hydrated Portland cements with main emphasis on the incorporation of Al3+ ions...

Introducción a la fabricación y normalización del cemento portland

OpenAIRE

Sanjuán Barbudo, Miguel Ángel; Chinchón Yepes, Servando

2014-01-01

El cemento portland es un conglomerante hidráulico cuya principal propiedad es la de formar masas pétreas resistentes y duraderas cuando se mezcla con áridos y agua. El endurecimiento de la mezcla ocurre transcurrido un cierto tiempo desde el momento en que se realiza el amasado, lo que permite dar forma a la piedra artificial resultante. Estas tres cualidades (moldeable, resistente, duradero) hacen que los productos derivados del cemento tengan una gran aplicación en la construcción de edifi...

Relationships between environmental governance and water quality in a growing metropolitan area of the Pacific Northwest, USA

Science.gov (United States)

Chang, H.; Thiers, P.; Netusil, N. R.; Yeakley, J. A.; Rollwagen-Bollens, G.; Bollens, S. M.; Singh, S.

2014-04-01

We investigate relationships between environmental governance and water quality in two adjacent growing metropolitan areas in the western US. While the Portland, Oregon and Vancouver, Washington metro areas share many common biophysical characteristics, they have different land development histories and water governance structures, providing a unique opportunity for examining how differences in governance might affect environmental quality. We conceptualize possible linkages in which water quality influences governance directly, using monitoring efforts as a metric, and indirectly by using the change in the sale price of single-family residential properties. Governance may then influence water quality directly through riparian restoration resulting from monitoring results and indirectly through land use policy. We investigate evidence to substantiate these linkages. Our results showed that changes in monitoring regimes and land development patterns differed in response to differences in growth management policy and environmental governance systems. Our results also showed similarities in environmental quality responses to varying governance systems. For example, we found that sales prices responded positively to improved water quality (e.g., increases in DO and reductions in bacteria counts) in both cities. Furthermore, riparian restoration efforts improved over time for both cities, indicating the positive effect of governance on this land-based resource that may result in improved water quality. However, as of yet, there were no substantial differences across study areas in water temperature over time, despite an expansion of these urban areas of more than 20 % over 24 years. The mechanisms by which water quality was maintained was similar in the sense that both cities benefited from riparian restoration, but different in the sense that Portland benefited indirectly from land use policy. A combination of long-term legacy effects of land development, and a

Aplicaciones prácticas de la espectroscopía de absorción infrarroja en el estudio de los crudos, del clínker y del cemento portland anhidro

Directory of Open Access Journals (Sweden)

Vázquez, Tomás

1980-09-01

Full Text Available Not available

En la primera parte de este trabajo (* se trató brevemente y de una manera fundamentalmente práctica el estudio por espectroscopía infrarroja de calizas, arcillas, clínker portland y sus fases constituyentes. En, el presente trabajo finalizará esta exposición con una visión general de algunas posibilidades que tiene la espectroscopía IR en el estudio del cemento portland anhidro, así como el estudio breve de puzolanas, escorias y cenizas volantes, como adiciones activas.

31st August 2011 - Government of Japan R. Chubachi, Executive Member of the Council for Science and Technology Policy, Cabinet Office, Vice Chairman, Representative Corporate Executive Officer and Member of the Board, Sony Corporation, visiting the ATLAS experimental area with Former Collaboration Spokesperson P. Jenni and Senior physicist T. Kondo.

CERN Multimedia

Raphaël Piguet

2011-01-01

31st August 2011 - Government of Japan R. Chubachi, Executive Member of the Council for Science and Technology Policy, Cabinet Office, Vice Chairman, Representative Corporate Executive Officer and Member of the Board, Sony Corporation, visiting the ATLAS experimental area with Former Collaboration Spokesperson P. Jenni and Senior physicist T. Kondo.

Combining Ordinary Kriging with wind directions to identify sources of industrial odors in Portland, Oregon.

Science.gov (United States)

Eckmann, Ted C; Wright, Samantha G; Simpson, Logan K; Walker, Joe L; Kolmes, Steven A; Houck, James E; Velasquez, Sandra C

2018-01-01

This study combines Ordinary Kriging, odor monitoring, and wind direction data to demonstrate how these elements can be applied to identify the source of an industrial odor. The specific case study used as an example of how to address this issue was the University Park neighborhood of Portland, Oregon (USA) where residents frequently complain about industrial odors, and suspect the main source to be a nearby Daimler Trucks North America LLC manufacturing plant. We collected 19,665 odor observations plus 105,120 wind measurements, using an automated weather station to measure winds in the area at five-minute intervals, logging continuously from December 2014 through November 2015, while we also measured odors at 19 locations, three times per day, using methods from the American Society of the International Association for Testing and Materials. Our results quantify how winds vary with season and time of day when industrial odors were observed versus when they were not observed, while also mapping spatiotemporal patterns in these odors using Ordinary Kriging. Our analyses show that industrial odors were detected most frequently to the northwest of the Daimler plant, mostly when winds blew from the southeast, suggesting Daimler's facility is a likely source for much of this odor.

Effects of the super plasticizers and the water/cement ratio on the mini-slump of Portland cement pastes

International Nuclear Information System (INIS)

Meirelles, J.R.; Morelli, A.C.; Baldo, J.B.

1998-01-01

The rheology of Portland cement concrete is dominated by the cement paste rheology. In general the rheological behavior of cement pastes is evaluated by means of the mini-slump test. In the present paper it was investigated the effect of the water/cement ratio was as of two types of superplasticizers (melamine and naftalen based) on the mini-slump of pastes of common cement pastes. (author)

Implementing lean office: a successful case in public sector

OpenAIRE

Monteiro, Mónica F. J. R.; Pacheco, Claudia C. L.; Dinis-Carvalho, José; Paiva, Francisco C.

2015-01-01

Applying lean approaches in office areas can lead to performance improvements and other benefits as achieved in traditional manufacturing environments. The intangibility of office operations may appear as a major difficulty for lean implementations but in fact the benefits achievable are as important as the ones achieved in manufacturing environments. This paper reports a successful case of lean office implementation in a public sector organization giving emphasis to its major performance imp...

Análises do comportamento físico de um solo contaminado por borra oleosa ácida e encapsulado com cimento Portland Analyses of physical behavior of a soil contaminated by acidic oily sludge and encapsulated with cement Portland

Directory of Open Access Journals (Sweden)

José Waldomiro Jiménez Rojas

2008-06-01

Full Text Available Este trabalho tem como objetivo aplicar a técnica de encapsulamento em um solo contaminado com crescentes quantidades do resíduo industrial borra oleosa ácida, utilizando como agente encapsulante o cimento Portland CP-V ARI. A aplicação da técnica de encapsulamento consistiu na realização de estudos pós-tratamento, analisando fisicamente o solo contaminado através de ensaios de resistência à compressão simples e durabilidade. Os resultados apontam que quanto maior a quantidade de borra oleosa ácida presente no solo encapsulado, menor a resistência à compressão simples e maior a perda de massa.The objective of this study is applying the encapsulation technique in soil contaminated with increasing amounts of acidic oily sludge industrial residues, using Portland cement CP-V ARI as the encapsulating agent. The application of the encapsulation technique consisted in the accomplishment of post-treatment studies, analyzing the contaminated soil physically through unconfined compressive strength and durability tests. The results showed that an increasing amount of acidic oily sludge in the encapsulated soil ends up lowering the unconfined compressive strength as well as increasing the mass loss.

An Experimental Study of Portland Cement and Superfine Cement Slurry Grouting in Loose Sand and Sandy Soil

OpenAIRE

Weijing Yao; Jianyong Pang; Yushan Liu

2018-01-01

Grouting technology is widely applied in the fields of geotechnical engineering in infrastructure. Loose sand and sandy soil are common poor soils in tunnel and foundation treatments. It is necessary to use superfine cement slurry grouting in the micro-cracks of soil. The different effectiveness of Portland cement slurry and superfine cement slurry in sandy soil by the laboratory grouting experiment method were presented in this paper. The grouting situations of superfine cement slurry inject...

Análisis cuantitativo de cuarzo-alfa en mezclas de cemento portland anhidro y calcita sintética por difracción de rayos X con equipo Philips PW-1700

Directory of Open Access Journals (Sweden)

Sagrera-Moreno, J. L.

1985-09-01

Full Text Available In this article there are explained the necessary steps to make up a quantitative analysis of alpha-quartz applying the technique of rays X diffraction, in artificial mixtures of anhydrous portland cement and synthetic calcite, which contents are known.

En el presente artículo se explican los pasos necesarios para realizar un análisis cuantitativo de cuarzo-alfa aplicando la técnica de difracción de rayos X en mezclas artificiales de cemento portland anhidro y calcita sintética, cuyos contenidos son conocidos.

Chemical and morphological characteristics of mineral trioxide aggregate and Portland cements.

Science.gov (United States)

Khan, Shahbaz; Kaleem, Muhammad; Fareed, Muhammad Amber; Habib, Amir; Iqbal, Kefi; Aslam, Ayesha; Ud Din, Shahab

2016-01-01

The purpose of this study was to investigate the chemical composition and particle morphology of white mineral trioxide aggregate (WMTA) and two white Portland cements (CEM 1 and CEM 2). Compositional analysis was performed by energy dispersive X-ray spectroscopy, X-ray fluorescence spectrometry and X-ray diffraction whereas, morphological characteristics were analyzed by scanning electron microscope and Laser scattering particle size distribution analyzer. The elemental composition of WMTA, CEM 1 and CEM 2 were similar except for the presence of higher amounts of bismuth in WMTA. Calcium oxide and silicon oxide constitute the major portion of the three materials whereas, tricalcium silicate was detected as the major mineral phase. The particle size distribution and morphology of WMTA was finer compared to CEM 1 and CEM 2. The three tested materials had relatively similar chemical composition and irregular particle morphologies.

The Office of Environmental Management technical reports: A bibliography

International Nuclear Information System (INIS)

1996-01-01

The Office of Environmental Management's (EM) technical reports bibliography is an annual publication that contains information on scientific and technical reports sponsored by the Office of Environmental Management added to the Energy Science and Technology Database from July 1, 1994 through June 30, 1995. This information is divided into the following categories: Focus Areas, Cross-Cutting Programs, and Support Programs. In addition, a category for general information is included. EM's Office of Science and Technology sponsors this bibliography

The Relative Benefits of Green Versus Lean Office Space : Three Field Experiments

NARCIS (Netherlands)

Nieuwenhuis, Marlon; Knight, Craig; Postmes, Tom; Haslam, S. Alexander

Principles of lean office management increasingly call for space to be stripped of extraneous decorations so that it can flexibly accommodate changing numbers of people and different office functions within the same area. Yet this practice is at odds with evidence that office workers' quality of

Plutonium focus area

International Nuclear Information System (INIS)

1996-08-01

To ensure research and development programs focus on the most pressing environmental restoration and waste management problems at the U.S. Department of Energy (DOE), the Assistant Secretary for the Office of Environmental Management (EM) established a working group in August 1993 to implement a new approach to research and technology development. As part of this new approach, EM developed a management structure and principles that led to the creation of specific Focus Areas. These organizations were designed to focus the scientific and technical talent throughout DOE and the national scientific community on the major environmental restoration and waste management problems facing DOE. The Focus Area approach provides the framework for intersite cooperation and leveraging of resources on common problems. After the original establishment of five major Focus Areas within the Office of Technology Development (EM-50, now called the Office of Science and Technology), the Nuclear Materials Stabilization Task Group (EM-66) followed the structure already in place in EM-50 and chartered the Plutonium Focus Area (PFA). The following information outlines the scope and mission of the EM, EM-60, and EM-66 organizations as related to the PFA organizational structure

Portland 10 x 20 NTMS area, Maine and New Hampshire: data release

International Nuclear Information System (INIS)

Koller, G.R.

1979-02-01

Stream sediment and stream water samples were collected from small streams at 1094 sites for a nominal density of one site per 13 square kilometers (five square miles) in rural areas. Ground water samples were collected at 560 sites for a nominal density of one site per 26 square kilometers (ten square miles). Neutron activation analysis (NAA) results are given for uranium and 16 other elements in sediments, and for uranium and 9 other elements in ground water and surface water

Análise microscópica da polpa dental de cães após pulpotomia e proteção pulpar com agregado de trióxido mineral e cimento Portland branco

OpenAIRE

Menezes, Renato; Bramante, Clóvis Monteiro; Garcia, Roberto Brandão; Letra, Ariadne; Carvalho, Vanessa Graciela Gomes; Carneiro, Everdan; Brunini, Sérgio; Oliveira, Rodrigo Cardoso; Canova, Giovana Calichio; Moraes, Fernanda Gomes de

2004-01-01

Considering previous studies on the similarity between the chemical composition of the mineral trioxide aggregate and the Portland cement, the purpose of this study was to investigate the pulp response of dog's teeth after pulpotomy and direct pulp protection with MTA Angelus and white Portland cement. Thirty eight pulp remnants were protected with these materials. One hundred and twenty days after treatment, the animals were sacrificed and the specimens removed and prepared for histological ...

76 FR 10926 - Self-Regulatory Organizations; Municipal Securities Rulemaking Board; Notice of Filing of...

Science.gov (United States)

2011-02-28

..., Chief Financial Officer dated September 8, 2010 (``Georgetown, Texas Letter''); and Portland Letter... the financial advisor are separate, adversarial roles and cannot be provided by the same party.'' One..., President and Chief Executive Officer dated September 29, 2010 (``D.A. Davidson Letter''); and J.J.B...

The Office of Environmental Management technical reports: a bibliography

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-07-01

The Office of Environmental Management`s (EM) technical reports bibliography is an annual publication that contains information on scientific and technical reports sponsored by the Office of Environmental Management added to the Energy Science and Technology Database from July 1, 1995 through Sept. 30, 1996. This information is divided into the following categories: Focus Areas and Crosscutting Programs. Support Programs, Technology Integration and International Technology Exchange are now included in the General category. EM`s Office of Science and Technology sponsors this bibliography.

The Office of Environmental Management technical reports: a bibliography

International Nuclear Information System (INIS)

1997-07-01

The Office of Environmental Management''s (EM) technical reports bibliography is an annual publication that contains information on scientific and technical reports sponsored by the Office of Environmental Management added to the Energy Science and Technology Database from July 1, 1995 through Sept. 30, 1996. This information is divided into the following categories: Focus Areas and Crosscutting Programs. Support Programs, Technology Integration and International Technology Exchange are now included in the General category. EM''s Office of Science and Technology sponsors this bibliography

Final report of the decontamination and decommissioning of the exterior land areas at the Grand Junction Projects Office facility

Energy Technology Data Exchange (ETDEWEB)

Widdop, M.R.

1995-09-01

The US Department of Energy (DOE) Grand Junction Projects Office (GJPO) facility occupies approximately 56.4 acres (22.8 hectares) along the Gunnison River near Grand Junction, Colorado. The site was contaminated with uranium ore and mill tailings during uranium-refining activities conducted by the Manhattan Engineer District and during pilot-milling experiments conducted for the US Atomic Energy Commission`s (AEC`s) domestic uranium procurement program. The GJPO facility was the collection and assay point for AEC uranium and vanadium oxide purchases until the early 1970s. The DOE Decontamination and Decommissioning Program sponsored the Grand Junction Projects Office Remedial Action Project (GJPORAP) to remediate the facility lands, site improvements, and the underlying aquifer. The site contractor, Rust Geotech, was the Remedial Action Contractor for GJPORAP. The exterior land areas of the facility assessed as contaminated have been remediated in accordance with identified standards and can be released for unrestricted use. Restoration of the aquifer will be accomplished through the natural flushing action of the aquifer during the next 50 to 80 years. The remediation of the DOE-GJPO facility buildings is ongoing and will be described in a separate report.

Arsenic content in Portland cement: a literature review.

Science.gov (United States)

Tenório de Franca, Talita Ribeiro; da Silva, Raphaela Juvenal; Sedycias de Queiroz, Michellini; Aguiar, Carlos Menezes

2010-01-01

Portland cement (PC) is a hydraulic binding material widely used in the building industry. The main interest in its use in dentistry is focused on a possible alternative to mineral trioxide aggregate (MTA) because PC is less expensive and is widely available. In dentistry, PC has been used in dental procedures such as pulpotomy, pulp capping, repair of root perforation and root-end filling. The purpose of this article is review the dental literature about the PC, its composition with special attention to arsenic content, properties, and application in dentistry. A bibliographic research was performed in Bireme, PubMed, LILACS and Scopus data bases looking for national and international studies about the PC composition, properties and clinical use. It was observed that PC has favorable biological properties very similar to those of MTA. The PC has shown good cell proliferation induction with formation of a monolayer cell, satisfactory inflammatory response, inhibitory effect of prostaglandin and antimicrobial effect. Studies have shown that PC is not cytotoxic, stimulates the apposition of reparative dentin and permits cellular attachment and growth. Regarding arsenic presence, its levels and release are low. PC has physical, chemical and biological properties similar to MTA. Arsenic levels and release are low, therefore, unable to cause toxic effects.

Arsenic content in Portland cement: A literature review

Directory of Open Access Journals (Sweden)

Tenorio de Franca Talita

2010-01-01

Full Text Available Portland cement (PC is a hydraulic binding material widely used in the building industry. The main interest in its use in dentistry is focused on a possible alternative to mineral trioxide aggregate (MTA because PC is less expensive and is widely available. In dentistry, PC has been used in dental procedures such as pulpotomy, pulp capping, repair of root perforation and root-end filling. The purpose of this article is review the dental literature about the PC, its composition with special attention to arsenic content, properties, and application in dentistry. A bibliographic research was performed in Bireme, PubMed, LILACS and Scopus data bases looking for national and international studies about the PC composition, properties and clinical use. It was observed that PC has favorable biological properties very similar to those of MTA. The PC has shown good cell proliferation induction with formation of a monolayer cell, satisfactory inflammatory response, inhibitory effect of prostaglandin and antimicrobial effect. Studies have shown that PC is not cytotoxic, stimulates the apposition of reparative dentin and permits cellular attachment and growth. Regarding arsenic presence, its levels and release are low. PC has physical, chemical and biological properties similar to MTA. Arsenic levels and release are low, therefore, unable to cause toxic effects.

Development of a CE-QUAL-W2 temperature model for Crystal Springs Lake, Portland, Oregon

Science.gov (United States)

Buccola, Norman L.; Stonewall, Adam J.

2016-05-19

During summer 2014, lake level, streamflow, and water temperature in and around Crystal Springs Lake in Portland, Oregon, were measured by the U.S. Geological Survey and the City of Portland Bureau of Environmental Services to better understand the effect of the lake on Crystal Springs Creek and Johnson Creek downstream. Johnson Creek is listed as an impaired water body for temperature by the Oregon Department of Environmental Quality (ODEQ), as required by section 303(d) of the Clean Water Act. A temperature total maximum daily load applies to all streams in the Johnson Creek watershed, including Crystal Springs Creek. Summer water temperatures downstream of Crystal Springs Lake and the Golf Pond regularly exceed the ODEQ numeric criterion of 64.4 °F (18.0 °C) for salmonid rearing and migration. To better understand temperature contributions of this system, the U.S. Geological Survey developed two-dimensional hydrodynamic water temperature models of Crystal Springs Lake and the Golf Pond. Model grids were developed to closely resemble the bathymetry of the lake and pond using data from a 2014 survey. The calibrated models simulated surface water elevations to within 0.06 foot (0.02 meter) and outflow water temperature to within 1.08 °F (0.60 °C). Streamflow, water temperature, and lake elevation data collected during summer 2014 supplied the boundary and reference conditions for the model. Measured discrepancies between outflow and inflow from the lake, assumed to be mostly from unknown and diffuse springs under the lake, accounted for about 46 percent of the total inflow to the lake.

Effect of different radiopacifying agents on the physicochemical properties of white Portland cement and white mineral trioxide aggregate.

Science.gov (United States)

Hungaro Duarte, Marco Antonio; Minotti, Paloma Gagliardi; Rodrigues, Clarissa Teles; Zapata, Ronald Ordinola; Bramante, Clovis Monteiro; Tanomaru Filho, Mário; Vivan, Rodrigo Ricci; Gomes de Moraes, Ivaldo; Bombarda de Andrade, Flaviana

2012-03-01

The aim of this study was to evaluate the pH, calcium ion release, setting time, and solubility of white mineral trioxide aggregate (WMTA) and white Portland cement (WPC) combined with the following radiopacifying agents: bismuth oxide (BO), calcium tungstate (CT), and zirconium oxide (ZO). Fifty acrylic teeth with root-end filling material were immersed in ultrapure water for measurement of pH and calcium release (atomic absorption spectrophotometry) at 3, 24, 72, and 168 hours. For evaluation of setting time, each material was analyzed according to the American Society for Testing and Materials guidelines 266/08. The solubility test was performed according to American National Standards Institute/American Dental Association specification no. 57/2000. Solubility, setting time, and pH values were compared by using analysis of variance and Tukey test, and the values of calcium release were compared by the Kruskal-Wallis and Miller tests. The significance level was set at 5%. The pH and calcium release were higher at 3 and 24 hours. WPC was the material with the higher values for both properties. WMTA had the greatest solubility among all materials (P Portland cement. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Microbial leakage of MTA, Portland cement, Sealapex and zinc oxide-eugenol as root-end filling materials.

Science.gov (United States)

Estrela, Carlos; Estrada-Bernabé, Pedro-Felício; de Almeida-Decurcio, Daniel; Almeida-Silva, Julio; Rodrigues-Araújo-Estrela, Cyntia; Poli-Figueiredo, José-Antonio

2011-05-01

The aim of this study was to compare the microbial leakage of mineral trioxide aggregate (MTA), Portland cement (PC), Sealapex and zinc oxide-eugenol (ZOE) as root-end filling materials. An in vitro microbial leakage test (MLT) with a split chamber was used in this study. A mixture of facultative bacteria and one yeast (S. aureus+E. faecalis+P. aeruginosa+B. subtilis+C. albicans) was placed in the upper chamber and it could only reach the lower chamber containing Brain Heart Infusion broth by way of leakage through the root-end filling. Microbial leakage was observed daily for 60 days. Sixty maxillary anterior human teeth were randomly assigned to different groups--MTA and PC (gray and white), Sealapex+zinc oxide and ZOE, control groups and subgroups to evaluate the influence of EDTA for smear layer removal. These materials were further evaluated by an agar diffusion test (ADT) to verify their antimicrobial efficacy. Data were analyzed statistically by Kruskal-Wallis and Mann-Whitney test. In the MLT, Sealapex+zinc oxide and ZOE did not show evidence of microbial leakage over the 60-day experimental period. The other materials showed leakage from the 15th day. The presence of smear layer influenced microbial leakage. Microbial inhibition zones were not observed in all samples tested by ADT. Sealapex+zinc oxide and ZOE did not show microbial leakage over the experimental period, whereas it was verified within 15 to 45 days in MTA and Portland cement.

An Experimental Study of Portland Cement and Superfine Cement Slurry Grouting in Loose Sand and Sandy Soil

Directory of Open Access Journals (Sweden)

Weijing Yao

2018-04-01

Full Text Available Grouting technology is widely applied in the fields of geotechnical engineering in infrastructure. Loose sand and sandy soil are common poor soils in tunnel and foundation treatments. It is necessary to use superfine cement slurry grouting in the micro-cracks of soil. The different effectiveness of Portland cement slurry and superfine cement slurry in sandy soil by the laboratory grouting experiment method were presented in this paper. The grouting situations of superfine cement slurry injected into sand and sandy soil were explored. The investigated parameters were the dry density, wet density, moisture content, internal friction angle, and cohesion force. The results show that the consolidation effect of superfine cement is better than that of Portland cement due to the small size of superfine cement particles. The superfine cement can diffuse into the sand by infiltration, extrusion, and splitting. When the water–cement ratio of superfine cement slurry is less than 2:1 grouting into loose sand, the dry and wet density decrease with the increase in the water–cement ratio, while the moisture content and cohesive force gradually increase. When the water–cement ratio of superfine cement slurry is 1:1 grouting into loose sand and sandy soil, the dry density, wet density, and cohesive force of loose sand are larger than those of sandy soil. The results of the experiment may be relevant for engineering applications.

Modeling the degradation of Portland cement pastes by biogenic organic acids

International Nuclear Information System (INIS)

De Windt, Laurent; Devillers, Philippe

2010-01-01

Reactive transport models can be used to assess the long-term performance of cement-based materials subjected to biodegradation. A bioleaching test (with Aspergillus niger fungi) applied to ordinary Portland cement pastes during 15 months is modeled with HYTEC. Modeling indicates that the biogenic organic acids (acetic, butyric, lactic and oxalic) strongly accelerate hydrate dissolution by acidic hydrolysis whilst their complexation of aluminum has an effect on the secondary gel stability only. The deepest degradation front corresponds to portlandite dissolution and decalcification of calcium silicate hydrates. A complex pattern of sulfate phases dissolution and precipitation takes place in an intermediate zone. The outermost degraded zone consists of alumina and silica gels. The modeling accurateness of calcium leaching, pH evolution and degradation thickness is consistently enhanced whilst considering increase of diffusivity in the degraded zones. Precipitation of calcium oxalate is predicted by modeling but was hindered in the bioleaching reactor.

Efeito do tempo de cura na rigidez de argamassas produzidas com cimento Portland Effect of the curing time on the stiffness of mortars produced with Portland cement

Directory of Open Access Journals (Sweden)

G. C. R. Garcia

2011-03-01

Full Text Available O concreto de cimento Portland é um dos materiais mais usados no mundo inteiro, entretanto, devido a sua estrutura ser muito complexa, torna-se imprescindível estudar suas propriedades com bastante profundidade. O concreto é produzido a partir de uma argamassa, de areia e cimento, com adição de agregados graúdos, sendo que suas propriedades estão basicamente suportadas nessa argamassa de constituição. O objetivo deste trabalho foi estudar a variação da rigidez de duas argamassas de composições com razão cimento:areia de 1:2 e 1:3 em função do tempo de cura, tendo como parâmetro a variação do módulo de Young. Os resultados mostraram que o módulo de Young cresce até atingir o valor máximo no oitavo dia, sendo que nos três primeiros dias esse crescimento é mais acentuado. A análise dos resultados indica que grande parte do processo de hidratação do cimento, com formação das ligações químicas responsáveis pela rigidez da argamassa, acontece nos primeiros dias de cura.Concrete produced with Portland cement is one of building materials most widely used worldwide. However, due to its highly complex structure, its properties require in-depth studies. Concrete is a mortar consisting of a mixture of cement, sand and coarse aggregates, and its properties are represented basically by the mortar base. The aim of this work was to study the change in stiffness of two mortar compositions cured at 25 ºC with a cement-to-sand ratio of 1:2 and 1:3, as a function of curing time using the variation of Young modulus as the measuring parameter. The results showed that Young modulus increases up to a maximum value on the 8th day, and that this increase is more pronounced during the first three days. An analysis of the results indicates that a large part of the cement hydration process, involving the formation of chemical bonds that are responsible for the mortar stiffness, takes place in the early days of curing.

DOE Office of Environmental Management, 2016 Year in Review

Energy Technology Data Exchange (ETDEWEB)

None

2016-12-01

2016 accomplishments and primary areas of focus for the Department of Energy's (DOE's) Office of Environmental Management and EM sites are presented. For DOE EM, these include Focusing on the Field, Teaming with Cleanup Partners, Developing New Technology, and Maximizing Cleanup Dollars. Major 2016 achievements are highlighted for EM, Richland Operations Office, Office of River Protection, Savannah River Site, Oak Ridge, Idaho, Waste Isolation Pilot Plant, Los Alamos, Portsmouth, Paducah, West Valley Demonstration Project, and the Nevada National Security Site,

Evaluating the freeze-thaw durability of portland cement-stabilized-solidified heavy metal waste using acoustic measurements

International Nuclear Information System (INIS)

El-Korchi, T.; Gress, D.; Baldwin, K.; Bishop, P.

1989-01-01

The use of stress wave propagation to assess freeze-thaw resistance of portland cement solidified/stabilized waste is presented. The stress wave technique is sensitive to the internal structure of the specimens and would detect structural deterioration independent of weight loss or visual observations. The freeze-thaw resistance of a cement-solidified cadmium waste and a control was evaluated. The control and cadmium wastes both showed poor freeze-thaw resistance. However, the addition of cadmium and seawater curing increased the resistance to more cycles of freezing and thawing. This is attributed to microstructural changes

Transfer Pricing; Charging of head office costs

Energy Technology Data Exchange (ETDEWEB)

Andersen, Joergen

1998-07-01

The key issues discussed in this presentation are (1) What are head office costs?, (2) Why is the charging an area of concern for international companies?, (3) Which part of head office costs should be charged?, (4) OECD guidelines on charging. Head office costs are classified as Shareholder costs, Stewardship costs, Costs related to a specific subsidiary or group of subsidiaries (on call), and Costs related to operational activities in the parent company. The OECD reports of 1984 and 1996 are discussed. In Norsk Hydro's experience, the practising of the OECD guidelines by national authorities are confusing and not consistent over time or across borders. To get a better understanding of how charging of corporate head office costs are dealt with on an international level, Norsk Hydro asked Deloitte and Touche in London to carry out a study on international companies' behaviour. Their conclusions are included.

Costs and benefits of bicycling investments in Portland, Oregon.

Science.gov (United States)

Gotschi, Thomas

2011-01-01

Promoting bicycling has great potential to increase overall physical activity; however, significant uncertainty exists with regard to the amount and effectiveness of investment needed for infrastructure. The objective of this study is to assess how costs of Portland's past and planned investments in bicycling relate to health and other benefits. Costs of investment plans are compared with 2 types of monetized health benefits, health care cost savings and value of statistical life savings. Levels of bicycling are estimated using past trends, future mode share goals, and a traffic demand model. By 2040, investments in the range of $138 to $605 million will result in health care cost savings of $388 to $594 million, fuel savings of $143 to $218 million, and savings in value of statistical lives of $7 to $12 billion. The benefit-cost ratios for health care and fuel savings are between 3.8 and 1.2 to 1, and an order of magnitude larger when value of statistical lives is used. This first of its kind cost-benefit analysis of investments in bicycling in a US city shows that such efforts are cost-effective, even when only a limited selection of benefits is considered.

Standard Test Method for Bond Strength of Ceramic Tile to Portland Cement Paste

CERN Document Server

American Society for Testing and Materials. Philadelphia

2002-01-01

1.1 This test method covers the determination of the ability of glazed ceramic wall tile, ceramic mosaic tile, quarry tile, and pavers to be bonded to portland cement paste. This test method includes both face-mounted and back-mounted tile. 1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Analysis by X-Ray images of wind blandes waste incorporated in Portland cement

International Nuclear Information System (INIS)

Marques, M.A.

2011-01-01

The wind blandes wastes can be reused in the incorporation in Portland cement, to be used in non-structural constructions. This work shows X-rays images to assessment the space distribution of the wastes in the cement and to evaluate the use of this methodology. Cylindrical specimens were produced according to ABNT NBR 5738 standards. The mass relation of sand, pebbles and cement was 3:2:1 and 10%, 20% and 50% of waste was incorporated in cement specimens. Frontal and upper projections were obtained in X-Rays images. The images showed that the distribution of the waste is homogeneous, consistent with what was intended in this type of incorporation, which can provide uniformity in test results of compressive strength. (author)

Office 2010 For Seniors For Dummies

CERN Document Server

Wempen, Faithe

2010-01-01

Clear, easy-to-understand instructions for seniors who want to get the most out of Microsoft Office 2010. Seniors are buying computers—both desktops and laptops—in record numbers to stay in touch with family and friends, connect with peers, research areas of interest, make purchases online, or learn a new skill. Assuming no prior knowledge of Microsoft Office, this book is aimed at seniors who are interested in maximizing the capabilities of Microsoft Word, Excel, PowerPoint, and Outlook. Written in large typeface and featuring enlarged figures and drawings to make the book easier to read, thi

Influence of citric acid as setting retarder in CPV portland cement pastes and mortars; Influencia do acido citrico como retardador de pega em pastas e argamassas de cimento portland CPV ARI

Energy Technology Data Exchange (ETDEWEB)

Mendes, B.C.; Lopes, M.M.S.; Alvarenga, R.C.S.S.; Fassoni, D.P.; Pedroti, L.G. [Universidade Federal de Vicosa (UFV), MG (Brazil); Azevedo, A.R.G. de, E-mail: afonso.garcez91@gmail.com [Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ (Brazil)

2016-07-01

This work aims to study the availability of using and the influence of citric acid in the properties of pastes and mortars made with Portland cement CPV ARI both in fresh and hardened form. The citric acid dosages were 0, 0.4%, and 0.8% relative to the cement mass. The produced cement pastes were tested to determine normal consistency water and initial and final setting times. Mortars were tested to determine the consistency index, specific gravity, air entrained content in the fresh stage, hardened bulk density, compressive strength at ages 7, 14, and 28 days, and analysis by XRD technique. The results show that citric acid, besides improve the mortar workability, contribute to an increase in mechanical strength in older than 14 days. (author)

Effect of sewage sludge ash (SSA on the mechanical performance and corrosion levels of reinforced Portland cement mortars

Directory of Open Access Journals (Sweden)

Andión, L. G.ª

2006-06-01

Full Text Available The article describes a study conducted to determinecorrosion in reinforcement embedded in Portland cement(PC mortars with different percentages of sewage sludgeash (SSA admixtures. The polarization resistancetechnique was used to determine the steel corrosion rate(Icorr in the test specimens. The samples were subjectedto different environmental conditions and aggressiveagents: 100% relative humidity (RH, accelerated carbonationat 70% RH and seawater immersion. Portlandcement was partially substituted for SSA in the mixes atrates of 0, 10, 20, 30 and 60% (by mass to make thedifferent mortars. The results show that where cementwas replaced by SSA at rates of up to 10% by mass,mortar corrosion performance was comparable to thebehaviour observed in SSA-free mortars (control mortar:0% SSA. Data for higher rates are also shown. From themechanical standpoint, SSA exhibited moderate pozzolanicactivity and the best performance when SSA wasadded at a rate of 10% to mixes with a water/(binder:PC + SSA (w/b ratio of 0.5.Se ha estudiado el nivel de corrosion que presentan lasarmaduras embebidas en morteros fabricados con cementoPortland (CP con diferentes porcentajes de sustitucion deceniza de lodo de depuradora (CLD. Se ha utilizado la tecnicade la Resistencia a la Polarizacion para determinar lavelocidad de corrosion del acero embebido en las muestrasestudiadas. Las muestras se han sometido a diferentes condicionesambientales y agentes agresivos: 100% de humedadrelativa (HR, carbonatacion acelerada al 70% HR einmersion en agua de mar. Para la fabricacion de los distintosmorteros, el cemento Portland ha sido parcialmente sustituidopor CLD en los siguientes porcentajes en masa: 0,10, 20, 30 y 60%. Los resultados muestran que sustitucionesde cemento por CLD de hasta el 10% en masa no alteranel comportamiento frente a la corrosion de los morterosal compararlos con los morteros libres de CLD (morteroscontrol: 0% de sustitucion de cemento por CLD. Se

Resistência à compressão do solo-cimento com substituição parcial do cimento Portland por resíduo cerâmico moído Compressive strength of soil-cement with partial replacement of the Portland cement by crushed ceramic waste

Directory of Open Access Journals (Sweden)

Rivanildo Dallacort

2002-12-01

Full Text Available Neste trabalho, apresenta-se o estudo experimental da resistência à compressão do solo-cimento, com substituição parcial do cimento Portland por resíduo cerâmico moído. Para tanto, foram ensaiados 81 espécimenes cilíndricos desse material à compressão, em que parte do cimento foi substituída por material cerâmico moído. Realizou-se uma programação fatorial, na qual três variáveis foram selecionadas para estudo: o teor de material ligante (cimento + resíduo cerâmico, a umidade do solo e o teor de resíduo cerâmico adicionado. É apresentado um estudo estatístico através de análise de variância da massa específica do material e da resistência a compressão. Tal estudo permitiu concluir-se que substituições de 25 e 57% do teor de cimento por material cerâmico podem produzir blocos de solo-cimento com resistências superiores a 2 MPa, com teor de material ligante de 6 e 8%, respectivamente.In this paper, an experimental study of the compressive strength of soil-cement with partial replacement of the Portland cement by crushed ceramic waste is presented and discussed. For this, eighty-one cylindrical specimens of soil-cement were tested, where part of cement percentage was replaced by crushed ceramic waste. The experiment was conducted in factorial design and three variables were selected and studied: the binding material content (cement + ceramic waste, soil moisture content and the ratio of ceramic waste. A statistical study using variance analysis of the specific mass and compressive strength of the material is presented. This study concluded that replacement ratios of 25 and 57% of the Portland cement by crushed ceramic material can be used to fabricate soil-cement bricks with strength higher than 2 MPa, for a binding material content of 6 and 8% respectively.

Physical and microstructural aspects of sulfate attack on ordinary and limestone blended Portland cements

International Nuclear Information System (INIS)

Schmidt, Thomas; Lothenbach, Barbara; Romer, Michael; Neuenschwander, Juerg; Scrivener, Karen

2009-01-01

The consequences of external sulfate attack were investigated by traditional test methods, i.e. length and mass change, as well as by a newly developed, surface sensitive ultrasonic method, using Leaky Rayleigh waves (1 MHz). The macroscopic changes are discussed and compared with thermodynamic calculations and microstructural findings (SEM/EDS). The results show that the main impact of limestone additions on resistance to sulfate degradation are physical - i.e. addition of a few percent in Portland cement reduces the porosity and increases the resistance of Portland cement systems to sulfate; but higher addition of 25% increase porosity and lower resistance to sulfate. The kinetics of degradation were dramatically affected by the solution concentration (4 or 44 g Na 2 SO 4 /l) and the higher concentration also resulted in the formation of gypsum, which did not occur at the low concentration. However the pattern of cracking was similar in both cases and it appears that gypsum precipitates opportunistically in pre-formed cracks so it is not considered as making a significant contribution to the degradation. At 8 deg. C limited formation of thaumasite occurred in the surface region of the samples made from cement with limestone additions. This thaumasite formation led to loss of cohesion of the paste and loss of material from the surface of the samples. However thaumasite formation was always preceded by expansion and cracking of the samples due to ettringite formation and given the very slow kinetics of thaumasite formation it was probably facilitated by the opening up of the structure due to ettringite induced cracking. The expansion of the samples showed a steady stage, followed by a rapidly accelerating stage, with destruction of the samples. The onset of the rapidly accelerating stage occurred when the thickness of the cracked surface layer reached about 1-1.5 mm-10-15% of the total specimen thickness (10 mm).

Diffusion of He in OPC paste and low-heat Portland cement paste containing fly-ash in contact with aqueous phase

International Nuclear Information System (INIS)

Sato, Fuminori; Miwata, Chikanori; Noda, Natsuko; Sato, Seichi; Kozaki, Tamotsu; Higashihara, Tomohiro; Hironaga, Michihiko; Kawanishi, Motoi

2008-01-01

As a part of gas migration studies in concrete package for nuclear waste surrounded by water-saturated rock, the helium diffusion in ordinary Portland cement paste (OPC) was studied using disk form specimen at various water-to-cement (w/c) ratios. The helium diffusion in low-heat Portland cement paste containing fly-ash (LPF) was also studied. Apparent diffusion coefficients of helium in OPC paste were ∼1 x 10 -10 m 2 s -1 at 0.4 w/c ratio, independent of increase of w/c ratio. It is likely that the materials formation such as C-S-H and CH in capillary pores in OPC plays an important role on the helium diffusion rather than porosity increase. Apparent diffusion coefficient of helium in LPF was two orders of magnitude smaller than that in OPC. It is quite possible that the addition of fly-ash contributes to the formation of hydration products which markedly enhance discontinuity of capillary pore. The results of the present study on the two kinds of cement pastes give us valuable information about alternatives to release gas from cement package. (author)

Development of a Knowledge Management Model for the Development of a Quality Public Sector Management System for the Office of the Primary Educational Service Area

Science.gov (United States)

Khotbancha, Wijitra; Chantarasombat, Chalard; Sriampai, Anan

2015-01-01

The objectives of this research were: 1) to study the current situation and problem of Knowledge Management of the office of the primary education service area, 2) to develop a Knowledge Management model, 3) to study the success of the implementation of the Knowledge Management system. There were 25 persons in the target group. There were 2 kinds…

Utilización de ladrillos de adobe estabilizados con cemento portland al 6% y reforzados con fibra de coco, para muros de carga en Tampico

Directory of Open Access Journals (Sweden)

Olivares Santiago, Manuel

2002-04-01

Full Text Available In this article conclusions are presented about adobe bricks stabilized with 6% portland cement and reinforced with different percentages of coconut fibers. The author, has developed an experimental plan in laboratory and has built in situ several walls with different bricks, different joints and different orientations, to analyze the behaviour ofthe brick prototypes for the weather conditions in Tampico.En este artículo se presentan las conclusiones acerca del refuerzo Ide ladrillos de adobe, estabilizados con cemento portland al 6% con diferentes porcentajes de fibra de coco. El autol; para llegar a estas conclusiones, desarrolla un plan experimental en laboratorio asi como construye in situ muestras de muros con diferentes clases de ladrillos, diferentes uniones entre ellos y distintas orientaciones, para analizar el comportamiento de prototipos ante las condiciones climáticas de la zona de Tampico.

Contribution to the determination of gypsum and hemihydrates content in Portland cements

Directory of Open Access Journals (Sweden)

Moreno Arús, Fernando

1975-09-01

Full Text Available Not availableLa mayoría de los técnicos de cemento, aceptan, que las anormalidades del fraguado, conocidas como "falso fraguado" en el cemento portland, se deben primordialmente a la presencia de yeso parcialmente deshidratado (S04Ca1/2H20. Si el clínker que se muele está enriquecido en cal libre, o la temperatura del molino es elevada (superior a los 110 °C o hay escasa ventilación de éste, se llega a originar una parcial deshidratación del yeso, que se mantiene durante el proceso de ensilado y que origina las anormalidades del fraguado al que anteriormente nos hemos referido. Por esta razón creemos muy importante poder conocer el grado de deshidratación en que se encuentra el yeso en un cemento.

Design and manufacture of Portland cement - application of sensitivity analysis in exploration and optimisation Part II. Optimisation

DEFF Research Database (Denmark)

Svinning, K.; Høskuldsson, Agnar

2006-01-01

A program for a model-based optimisation has been developed. The program contains two subprograms. The first one does minimising or maximising constrained by one original PLS-component or one equal to a combination of several. The second one does searching for the optimal combination of PLS-compo......-components, which gives max or min y. The program has proved to be applicable for achieving realistic results for implementation in the design of Portland cement with respect to performance and in the quality control during production....

700 Area

Data.gov (United States)

Federal Laboratory Consortium — The 700 Area of the Hanford Site is located in downtown Richland.Called the Federal Office Building, the Richland Operations Site Manager and the Richland Operations...

Will musculoskeletal and visual stress change when Visual Display Unit (VDU) operators move from small offices to an ergonomically optimized office landscape?

Science.gov (United States)

Helland, Magne; Horgen, Gunnar; Kvikstad, Tor Martin; Garthus, Tore; Aarås, Arne

2011-11-01

This study investigated the effect of moving from small offices to a landscape environment for 19 Visual Display Unit (VDU) operators at Alcatel Denmark AS. The operators reported significantly improved lighting condition and glare situation. Further, visual discomfort was also significantly reduced on a Visual Analogue Scale (VAS). There was no significant correlation between lighting condition and visual discomfort neither in the small offices nor in the office landscape. However, visual discomfort correlated significantly with glare in small offices i.e. more glare is related to more visual discomfort. This correlation disappeared after the lighting system in the office landscape had been improved. There was also a significant correlation between glare and itching of the eyes as well as blurred vision in the small offices, i.e. more glare more visual symptoms. Experience of pain was found to reduce the subjective assessment of work capacity during VDU tasks. There was a significant correlation between visual discomfort and reduced work capacity in small offices and in the office landscape. When moving from the small offices to the office landscape, there was a significant reduction in headache as well as back pain. No significant changes in pain intensity in the neck, shoulder, forearm, and wrist/hand were observed. The pain levels in different body areas were significantly correlated with subjective assessment of reduced work capacity in small offices and in the office landscape. By careful design and construction of an office landscape with regard to lighting and visual conditions, transfer from small offices may be acceptable from a visual-ergonomic point of view. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Effect of mixes made of coal bottom ash and fly ash on the mechanical strength and porosity of Portland cement

Directory of Open Access Journals (Sweden)

Argiz, C.

2013-03-01

Full Text Available New additions to the cement are needed to achieve a more sustainable and durable construction material. Within this context, bottom ashes can be used as a main constituent of Portland cements when it is mixed in an optimized proportion with fly ashes. The mechanical characteristics of standarized mortars made of mixes of pulverized coal combustion bottom and fly ashes are studied. The mortars were made of ordinary Portland cement (CEM I 42.5 N and mixes of bottom ashes with fly ashes in similar proportions to those of CEM II/A-V, CEM II/B-V and CEM IV/A (V. Summing up, it can be said that the utilization of bottom ashes mixed with fly ashes in replacement levels from 0% to 100% do not affect significantively on the mechanical caracteristics of the mortars considered in the present study which had an addition maximum content of 35%.

La utilización de nuevas adiciones en el cemento es necesaria con el fin de obtener un material más sostenible y durable. En este sentido, las cenizas de fondo o cenicero de las centrales termoeléctricas de carbón se podrían reciclar siendo empleadas como un componente principal de los cementos Portland. Se han estudiado las propiedades mecánicas de unos morteros normalizados elaborados con mezclas de cenizas volantes con cenizas de fondo fabricados con unos porcentajes similares a los correspondientes de los CEM II/A-V, CEM II/B-V y CEM IV/A (V. En conclusión, la utilización de mezclas de cenizas de fondo o cenicero con cenizas volantes sustituyendo a éstas últimas entre el 0% y el 100%, no influye significativamente en el comportamiento mecánico de los morteros estudiados en los que el contenido máximo de adición ha sido del 35%, si bien afecta a determinados aspectos microestructurales, como la cantidad y distribución de poros capilares.

Avaliação preliminar do emprego de arenito zeolítico da região nordeste do Brasil como material pozolânico para cimento Portland Preliminary evaluation of sandstones from northeastern Brazil with pozzolanic properties for Portland cement

Directory of Open Access Journals (Sweden)

M. S. Picanço

2011-12-01

Full Text Available As zeolitas possuem atividade pozolânica normalmente sem a necessidade de ativação térmica, por isto têm sido empregadas na produção de cimento e concreto hidráulicos desde a época do império romano. Hoje em dia são utilizadas na fabricação do cimento Portland através da substituição do clinquer em percentuais que variam entre 5 e 20%, dependendo da reatividade e da finura da zeólita. Em razão disto, são muito importantes do ponto de vista econômico e ambiental, principalmente quando não necessitam de tratamento térmico para adquirirem caráter pozolânico satisfatório, porque reduzem significativamente a energia de produção do clinquer e a liberação de CO2 proveniente tanto da descarbonatação da calcita como da combustão de combustíveis fósseis. Contudo, dados sobre reservas de zeólitas naturais são escassos e imprecisos. No Brasil, não existe conhecimento sobre depósitos naturais de zeólitas que possam ser explorados comercialmente. No nordeste do Brasil existe a ocorrência de zeolitas sedimentares relacionadas a arenitos descoberta nos anos 2000. Estes arenitos são constituídos de quartzo, argilominerais e zeolitas naturais (estilbita. O objetivo geral desse trabalho foi avaliar se esta zeólita natural presente no arenito possui atividade pozolânica satisfatória para ser empregada como adição mineral em cimentos Portland. No programa experimental o arenito zeolítico passou por beneficiamento através da remoção, por peneiramento, do quartzo e outros minerais inertes, de modo a concentrar a zeólita estilbita e com isto verificar as propriedades pozolânicas deste mineral. No estudo experimental foram empregadas as técnicas de difração de raios X, calorimetria, ensaios químicos e de determinação da atividade pozolânica em argamassas de cal hidratada e cimento Portland. Os resultados mostraram que o arenito zeolítico acelerou a hidratação do cimento Portland devido a extrema finura do

76 FR 80890 - Pacific Fishery Management Council; Public Meeting

Science.gov (United States)

2011-12-27

... Airport Hotel, 7900 NE 82nd Avenue, Portland, OR 97220. Council address: Pacific Fishery Management.... Kerry Griffin, Staff Officer, Pacific Council; (503) 820-2280. SUPPLEMENTARY INFORMATION: The purpose of...

Avaliação de pastas de cimento Portland contendo cinza pesada moída

OpenAIRE

Pilar, Ronaldo; Schankoski, Rudiele Aparecida; Moro, Agostinho João Dal; Repette, Wellington Longuini

2016-01-01

Neste trabalho avalia-se a influência da incorporação de cinza pesada moída, obtida da combustão de carvão mineral, em pastas de cimento Portland. A cinza pesada foi incorporada as pastas de cimento em três distribuições granulométricas distintas e dosadas para teores de substituição ao cimento, em volume, de 10%, 30% e 50%. As pastas foram dosadas com duas relações água/aglomerante, em massa, de 0,35 e 0,40. As primeiras idades foram investigadas por calorimetria isotérmica. Após passarem po...

Preparation of composites of national rubber latex (NRL) - portland cement mould. Vol. 3

International Nuclear Information System (INIS)

Dessouki, A.M.; Taher, N.H.; El-Nahas, H.H.

1996-01-01

The aim of this study is to prepare some polymeric mould using national rubber latex (NRL) - portland cement composites based on a delayed- action mechanism. Factors affecting the preparation process such as concentration, mixing percentage, additives and their effect on what is regarded as a delayed action coacervant combination was studied. Composites of national latex (NRL) - portland cement would were prepared as two separate parts. The stabilized natural rubber latex (NRL) 100 parts with hydroxy ethyl cellulose (HEC) 2 parts as stabilizer and a delayed - action coacervant (sodium meta silicate as a delaying agent) 5 parts on one hand and the dry blend of cement 65 parts soluble in 65 parts of water as a paste on the other hand were mixed thoroughly on site. (HEC) was added to the rubber latex to prevent the coagulation of the rubber latex with the electrolyte (sodium meta silicate) present in the rubber mixture. Two kinds of stabilization occurred in the rubber part, namely steric stabilization and the stabilization against electrolyte. The effect of delayed - action coacervant (sodium meta silicate) on the initial setting time of rubber - cement mould showed that the molding process did not occur at sodium meta silicate concentration less than 2.66 parts per 100 parts of rubber latex (phr), and the optimum concentration used was 5% parts of rubber latex. It was observed that addition of a delaying agent (Sodium meta silicate) to the rubber part enhanced the delaying mechanism in the time needed for the molding process, while the addition of the delaying agent to the cement part did not have any effect on retardation of the molding process. Chemical coacervants function mainly by reducing the ζ potential which is associated with the electrical double layer surrounding the latex particle. This reduction may brought about in at least three distinct ways which take place in the system studied. 5 figs., 3 tabs

Preparation of composites of national rubber latex (NRL) - portland cement mould. Vol. 3

Energy Technology Data Exchange (ETDEWEB)

Dessouki, A M; Taher, N H; El-Nahas, H H [National Center for Radiation Research and Technology, Atomic Energy Athority, Cairo (Egypt)

1996-03-01

The aim of this study is to prepare some polymeric mould using national rubber latex (NRL) - portland cement composites based on a delayed- action mechanism. Factors affecting the preparation process such as concentration, mixing percentage, additives and their effect on what is regarded as a delayed action coacervant combination was studied. Composites of national latex (NRL) - portland cement would were prepared as two separate parts. The stabilized natural rubber latex (NRL) 100 parts with hydroxy ethyl cellulose (HEC) 2 parts as stabilizer and a delayed - action coacervant (sodium meta silicate as a delaying agent) 5 parts on one hand and the dry blend of cement 65 parts soluble in 65 parts of water as a paste on the other hand were mixed thoroughly on site. (HEC) was added to the rubber latex to prevent the coagulation of the rubber latex with the electrolyte (sodium meta silicate) present in the rubber mixture. Two kinds of stabilization occurred in the rubber part, namely steric stabilization and the stabilization against electrolyte. The effect of delayed - action coacervant (sodium meta silicate) on the initial setting time of rubber - cement mould showed that the molding process did not occur at sodium meta silicate concentration less than 2.66 parts per 100 parts of rubber latex (phr), and the optimum concentration used was 5% parts of rubber latex. It was observed that addition of a delaying agent (Sodium meta silicate) to the rubber part enhanced the delaying mechanism in the time needed for the molding process, while the addition of the delaying agent to the cement part did not have any effect on retardation of the molding process. Chemical coacervants function mainly by reducing the {zeta} potential which is associated with the electrical double layer surrounding the latex particle. This reduction may brought about in at least three distinct ways which take place in the system studied. 5 figs., 3 tabs.

Mobile Monitoring of Diesel Particulate Matter Exposure within Five Urban Microenvironments, Portland, OR

Science.gov (United States)

Orlando, P. J.; Bennett, B. A.; George, L. A.

2016-12-01

Diesel particulate matter (DPM) is a hazardous air pollutant linked to mortality and morbidity outcomes including cancer, cardiovascular disease, and adverse respiratory effects. The EPA's Air Toxics Assessment indicated that more than 50% of Oregonians are exposed to 10 times the ambient benchmark concentration (ABC) of 0.1 μgm-3 for DPM. These model estimates have not been verified with measurements, potentially limiting policy action. We developed a mobile monitoring platform to ground-truth model predictions and characterize DPM spatial variation. Using black carbon (BC) as a marker, concentrations within five urban microenvironments (a construction site, an arterial, a bus mall, a city park, and an indoor workspace) were sampled within Portland, OR. The mobile monitoring platform consisted of a bicycle and trailer equipped with an aethalometer measuring BC mass, a Data Ram 4 measuring total PM2.5 mass, and a Q-Starz GPS recording location; each instrument was monitoring in 1 second intervals. Concentrations of BC were used as an indicator of DPM. The construction site had the highest DPM concentration (7 μg m-3). The indoor workspace and the park had the lowest DPM (0.3 μg m-3). Near the construction site, DPM constituted approximately 50% of the total PM2.5. However, at the park, DPM was attributed to only 6% of the total PM2.5, while the indoor space constituted 15%. Concentrations of BC near construction sites were observed to exceed 67 times the state ABC of 0.1 μg m-3 (Figure). These results signify the need to better characterize the urban exposure to DPM, as even the cleanest microenvironments may be 3 times above the ABC. Our mobile monitoring platform will help further elucidate how local-scale sources contribute to the broader distribution of DPM within Portland, while providing a tool for both residents and DEQ to effectively mitigate the health impacts from DPM exposure.

78 FR 46525 - Application Procedures, Execution and Filing of Forms: Correction of State Office Address for...

Science.gov (United States)

2013-08-01

... Address for Filings and Recordings, Including Proper Offices for Recording of Mining Claims; New Mexico...) * * * STATE OFFICES AND AREAS OF JURISDICTION * * * * * New Mexico State Office, 310 Dinosaur Trail, Santa Fe...

2016 Building Technologies Office Peer Review Report

Energy Technology Data Exchange (ETDEWEB)

Building Technologies Office

2016-12-01

The 2016 Building Technologies Office Peer Review Report summarizes the feedback submitted by reviewers of the 67 BTO projects presented at the 2016 BTO Peer Review. The report presents an overview of the goals and activities under each technology program area, a summary of project scores for each program, and a brief analysis of general evaluation trends within each program area or its constituent subprograms.

Evaluation of bacterial leakage of four root- end filling materials: Gray Pro Root MTA, White Pro Root MTA, Root MTA and Portland Cement (type I

Directory of Open Access Journals (Sweden)

Zarabian M.

2005-07-01

Full Text Available Background and Aim: Today several materials have been used for root- end filling in endodontic surgery. Optimal properties of Pro Root MTA in in-vitro and in-vivo studies has been proven. On the other hand, based on some studies, Root MTA (Iranian Pro Root MTA and Portland cement are similar to Pro Root MTA in physical and biologic properties. The aim of this study was to evaluate bacterial leakage (amount and mean leakage time of four root- end filling materials. Materials and Methods: In this experimental in-vitro study, seventy six extracted single- rooted human teeth were randomly divided into six groups for root-end filling with gray Pro Root MTA, white Pro Root MTA, Root MTA (Iranian Pro Root MTA, Portland Cement (type I and positive and negative control groups. Root canals were instrumented using the step- back technique. Root- end filling materials were placed in 3mm ultra sonic retro preparations. Samples and microleakage model system were sterilized in autoclave. The apical 3-4 mm of the roots were immersed in phenol red with 3% lactose broth culture medium. The coronal access of each specimen was inoculated every 24h with a suspension of Streptococcus sanguis (ATCC 10556. Culture media were observed every 24h for colour change indicating bacterial contamination for 60 days. Statistical analysis was performed using log- rank test with P<0.05 as the limit of significance. Results: At the end of study 50%, 56.25%, 56.25% and 50% of specimens filled with Gray Pro Root MTA, White Pro Root MTA. Root MTA and Portland Cement (type I had evidence of leakage respectively. The mean leakage time was 37.19±6.29, 36.44±5.81, 37.69±5.97 and 34.81±6.67 days respectively. Statistical analysis of data showed no significant difference among the leakage (amount and mean leakage time of the four tested root- end filling materials (P=0.9958. Conclusion: Based on the results of this study, there were no significant differences in leakage among the four

EFFECT OF SEA WATER ON THE STRENGTH OF POROUS CONCRETE CONTAINING PORTLAND COMPOSITE CEMENT AND MICROFILAMENT POLYPROPYLENE FIBER

OpenAIRE

TJARONGE, M.W

2011-01-01

The aim of this research is to study the influence of sea water on the strength of porous concrete containing Portland Composite cement and micro monofilament polypropylene fibre. The specimens of porous concrete were immersed in the sea water up to 28 days. The compressive strength test and flexural strength test were carried out at 3, 7 and 28 days in order to investigate the strength development. The test result indicated that the strength of porous concrete can develop in t...

32 CFR Appendix A to Part 552 - DPCA Recreational Areas in Training Areas

Science.gov (United States)

2010-07-01

... guests. Boat launch adjacent to Officer's Club Beach on American Lake/Beachwood area Cat Lake Picnic and Fishing Area—Training Area 19 Chambers Lake Picnic and *Fishing Area—Training Area 12 (See para 2 below) Ecology Park Hiking Path—North Fort, CTA A West Fiander Lake Picnic and Fishing Area—Training Area 20...

Physical chemistry of portland-cement hydrate, radioactive-waste hosts: Final report, January 16, 1987--December 31, 1987

International Nuclear Information System (INIS)

Grutzeck, M.W.

1989-01-01

This is a final report summarizing the results of a study of the physical and crystal chemistry of potential hydroxylated radioactive waste hosts compatible with portland cement. Research has focussed on the identification and evaluation of hydrated host phases for four ions: cesium, strontium, iodine and boron. These ions were chosen because they are among the most long lived of the radioactive waste ions as well as the most difficult to immobilize with cement-based materials. Results show that such phases do indeed exist, and that they are excellent host phases for the above ions

32 CFR Appendix A to Subpart M of... - DPCA Recreational Areas in Training Areas

Science.gov (United States)

2010-07-01

... launch adjacent to Officer's Club Beach on American Lake—Beachwood area Cat Lake Picnic and Fishing Area—Training Area 19 Chambers Lake Picnic and Fishing Area—Training Area 12 (See Para 3 below) Fiander lake Picnic and Fishing Area—Training Area 20 Johnson Marsh—Training Area 10 Lewis Lake Picnic and Fishing...

Green ethic takes root: how a US city is changing its ways

Energy Technology Data Exchange (ETDEWEB)

Cohn, L.

2005-10-01

The green power utility programme, sustainable architecture and public attitudes in the city of Portland in the northwest US state have made it one of North America's greenest cities. Portland has adopted a goal of purchasing all the electricity to supply municipal facilities from renewable resources by 2010 and the city has nearly 30,000 residential customers buying green power. Portland has a number of community gathering places such as community bulletin boards powered by solar energy and an increasing number of building projects registered with the US Green Building Council as LEEd (Leadership in Energy and Environmental Design) buildings. A number of organisations that support sustainable projects are based in Portland, including Portland's own Office of Sustainable Development (one of the first of its kind in the USA), Renewable Northwest Project (RNP), Bonneville Energy Foundation (BEF) and City Repair. RNP promotes the use of renewable energy while BEF and City Repair offer creative ideas to put renewable energy into practice. Incentives to fuel the growth of solar energy in Oregon are examined in a side box.

Energy use in office buildings

Energy Technology Data Exchange (ETDEWEB)

None

1980-10-01

This is the report on Task IB, Familiarization with Additional Data Collection Plans of Annual Survey of BOMA Member and Non-Member Buildings in 20 Cities, of the Energy Use in Office Buildings project. The purpose of the work was to monitor and understand the efforts of the Building Owners and Managers Association International (BOMA) in gathering an energy-use-oriented data base. In order to obtain an improved data base encompassing a broad spectrum of office space and with information suitable for energy analysis in greater detail than is currently available, BOMA undertook a major data-collection effort. Based on a consideration of geographic area, climate, population, and availability of data, BOMA selected twenty cities for data collection. BOMA listed all of the major office space - buildings in excess of 40,000 square feet - in each of the cities. Tax-assessment records, local maps, Chamber of Commerce data, recent industrial-development programs, results of related studies, and local-realtor input were used in an effort to assemble a comprehensive office-building inventory. In order to verify the accuracy and completeness of the building lists, BOMA assembled an Ad-Hoc Review Committee in each city to review the assembled inventory of space. A questionnaire on office-building energy use and building characteristics was developed. In each city BOMA assembled a data collection team operating under the supervision of its regional affiliate to gather the data. For each city a random sample of buildings was selected, and data were gathered. Responses for over 1000 buildings were obtained.

Analysis by X-Ray images of EVA waste incorporated in Portland Cement

International Nuclear Information System (INIS)

Marques, M.A.; Antunes, M.L.P.; Montagnoli, R.M.; Mancini, S.D.

2012-01-01

The EVA is a copolymer used by Brazilian shoes industries. This material is cut for the manufacture of insoles. This operation generates about 18% of waste. The EVA waste can be reused in incorporation in Portland cement to construction without structural purposes. The aim of this work is to show X-rays images to assessment the space distribution of the wastes in the cement and to evaluate the use of this methodology. Cylindrical specimens were produced according to ABNT - NBR 5738 standards. The volume relation of sand and cement was 3:1, 10% and 30% of waste was incorporated in cement specimens. X-Rays images were obtained of cylindrical specimens in front projection. The images showed that the distribution of the waste is homogeneous, consistent with what was intended in this type of incorporation, which can provide uniformity in test results of compressive strength. (author)

Increasing the compressive strength of portland cement concrete using flat glass powder

Energy Technology Data Exchange (ETDEWEB)

Miranda Junior, Edson Jansen Pedrosa de; Bezerra, Helton de Jesus Costa Leite; Politi, Flavio Salgado; Paiva, Antonio Ernandes Macedo, E-mail: edson.jansen@ifma.edu.br [Instituto Federal de Educacao, Ciencia e Tecnologia do Maranha (IFMA), Sao Luis, MA (Brazil). Dept. de Mecanica e Materiais

2014-08-15

This paper analyzes the compressive strength of Portland cement concrete in response to the incorporation of 5%, 10% and 20% of flat glass powder in place of sand, at w/c (water/cement) ratios of 0.50, 0.55 and 0.58. A statistical analysis of variance (ANOVA) was performed after 7, 14 and 28 days of curing. The compressive strength test results indicate that the concrete containing a w/c ratio of 0.50 can be used for structural applications, regardless of the waste glass content, as can that with a w/c ratio of 0.55 containing 20% of waste glass. We suggest that the use of flat glass powder in place of sand in the above mentioned percentages is feasible for the production of an environmentally appropriate and structurally applicable concrete. However, the concrete's fluidity and void content must be taken into account. (author)

4th February 2011- Polish Ambassador to the United Nations Office R. A. Henczel visiting CMS control room and underground experimental area with his daughter, guided by Collaboration Spokesperson G. Tonelli.

CERN Multimedia

Maximilien Brice

2011-01-01

4th February 2011- Polish Ambassador to the United Nations Office R. A. Henczel visiting CMS control room and underground experimental area with his daughter, guided by Collaboration Spokesperson G. Tonelli.

Corrosion rate of steel embedded in blended Portland and fluid catalytic cracking catalyst residue (FC3R cement mortars

Directory of Open Access Journals (Sweden)

Payá, J.

2008-12-01

Full Text Available This paper reports on a study of the corrosion levels in steel bars embedded in mortars made with a blend of Portland cement and (0-20% spent fluid catalytic cracking catalyst residue (FC3R, with a variable (0.3-0.7 water/binder (w/b ratio. The specimens were stored in the following conditions: relative humidity of 40, 80 or 100% and CO2 concentrations of 5 and 100%. The steel corrosion rate was measured with polarization resistance techniques. In the absence of aggressive agents, the steel was found to remain duly passivated in mortars with an FC3R content of up to 15% under all the conditions of relative humidity tested. The reinforcement corrosion level in mortars with a w/b ratio of 0.3 and 15% FC3R subjected to accelerated carbonation was similar to the level observed in the unblended Portland cement control mortar.En este trabajo se ha estudiado el nivel de corrosión de barras de acero embebidas en morteros de cemento Portland con relación agua/material cementante (a/mc variable (0,3-0,7, en los que parte del cemento (0-20% se sustituyó por catalizador de craqueo usado (FC3R. Las condiciones de conservación de las probetas elaboradas fueron las siguientes: distintas humedades relativas (40, 80 y 100% y dos concentraciones de CO2 (5 y 100%. La velocidad de corrosión de los aceros se midió mediante la técnica de resistencia de polarización. Se ha podido determinar que, bajo las distintas condiciones de humedad relativa y ausencia de agresivo, los aceros se mantuvieron correctamente pasivados en los morteros con contenidos de FC3R de hasta el 15%. El nivel de corrosión que presenta el refuerzo embebidos en morteros con sustitución de un 15% de cemento por FC3R y relación a/mc 0,3, al ser sometidos a un proceso de carbonatación acelerada, era muy similar al mostrado por el mortero patrón, sin FC3R.

75 FR 2549 - Office of Biotechnology Activities; Office of Science Policy; Office of the Director; Notice of a...

Science.gov (United States)

2010-01-15

... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology... Coordinator, Office of Biotechnology Activities, Office of Science Policy, Office of the Director, National..., Office of Biotechnology Activities, National Institutes of Health. [FR Doc. 2010-730 Filed 1-14-10; 8:45...

Push-out strength of modified Portland cements and resins.

Science.gov (United States)

Iacono, Francesco; Gandolfi, Maria Giovanna; Huffman, Bradford; Sword, Jeremy; Agee, Kelli; Siboni, Francesco; Tay, Franklin; Prati, Carlo; Pashley, David

2010-02-01

Modified calcium-silicate cements derived from white Portland cement (PC) were formulated to test their push-out strength from radicular dentin after immersion for 1 month. Slabs obtained from 42 single-rooted extracted teeth were prepared with 0.6 mm diameter holes, then enlarged with rotary instruments. After immersion in EDTA and NaOC1, the holes were filled with modified PCs or ProRoot MTA, Vitrebond and Clearfil SE. Different concentrations of phyllosilicate (montmorillonite-MMT) were added to experimental cements. ProRoot MTA was also included as reference material. Vitrebond and Clearfil SE were included as controls. Each group was tested after 1 month of immersion in water or PBS. A thin-slice push-out test on a universal testing machine served to test the push-out strength of materials. Results were statistically analyzed using the least squares means (LSM) method. The modified PCs had push-out strengths of 3-9.5 MPa after 1 month of immersion in water, while ProRoot MTA had 4.8 MPa. The push-out strength of PC fell after incubation in PBS for 1 month, while the push-out strength of ProRoot MTA increased. There were no significant changes in Clearfil SE Bond or Vitrebond after water or PBS storage.

77 FR 70381 - General Schedule Locality Pay Areas

Science.gov (United States)

2012-11-26

... 3206-AM51 General Schedule Locality Pay Areas AGENCY: U.S. Office of Personnel Management. ACTION: Proposed rule with request for comments. SUMMARY: On behalf of the President's Pay Agent, the Office of Personnel Management is issuing proposed regulations to tie the metropolitan area portion of locality pay...

Development of Guidelines for Mentoring Internal Supervision for the Schools under Roi-Et Office of Primary Education Service Area 2

Directory of Open Access Journals (Sweden)

Natchana Sahunil

2017-06-01

Full Text Available The research aimed to 1 study the factors and indicators of mentoring internal supervision for schools, 2 study the current state and the desirable state of mentoring internal supervision for schools, and 3 study the guidelines on the operation of mentoring internal supervision for the schools under Roi-Et Office of Primary Education Service Area 2. The research was divided into 3 phases. In phase 1 the informants comprised 5 certified experts. In phase 2 the sample comprised 488 government teachers under Roi-Et Office of Primary Education Service Area 2, btained through multi-stage random sampling. In phase 3 the informants comprised school directors, school deputy directors and supervisor teachers under Roi-Et Office of Primary Education Service Area 2, totally 9 persons. The research instruments onsisted of 1 a questionnaire having the discrimination from 0.34 to 0.79 and the total reliability of 0.87, 2 a structured interview form, and 3 a suitability and feasibility assessment form for the guidelines on the operation of mentoring internal supervision. The analysis of data employed percentage, the mean and standard deviation. The results are as follows: 1. There are 4 factors of the guidelines on mentoring internal supervision for schools. They are: preparation of mentoring supervision, with 12 indicators ; management of mentoring supervision, with 12 indicators ; operation of mentoring supervision, with 14 indicators ; and evaluation of mentoring supervision, with 10 indicators, all of which had been evaluated by the experts as, on the whole, very suitable. 2. The current state of the mentoring internal supervision for schools, on the whole and factor by factor, was in the moderate level in every factor. Meanwhile, the desirable state of mentoring internal supervision for schools, on the whole, was in the high level. When considered factor by factor, the factor with the highest mean is management of mentoring supervision. The factor with

Influence of citric acid as setting retarder in CPV portland cement pastes and mortars

International Nuclear Information System (INIS)

Mendes, B.C.; Lopes, M.M.S.; Alvarenga, R.C.S.S.; Fassoni, D.P.; Pedroti, L.G.; Azevedo, A.R.G. de

2016-01-01

This work aims to study the availability of using and the influence of citric acid in the properties of pastes and mortars made with Portland cement CPV ARI both in fresh and hardened form. The citric acid dosages were 0, 0.4%, and 0.8% relative to the cement mass. The produced cement pastes were tested to determine normal consistency water and initial and final setting times. Mortars were tested to determine the consistency index, specific gravity, air entrained content in the fresh stage, hardened bulk density, compressive strength at ages 7, 14, and 28 days, and analysis by XRD technique. The results show that citric acid, besides improve the mortar workability, contribute to an increase in mechanical strength in older than 14 days. (author)

Effect of water curing duration on strength behaviour of portland composite cement (PCC) mortar

Science.gov (United States)

Caronge, M. A.; Tjaronge, M. W.; Hamada, H.; Irmawaty, R.

2017-11-01

Cement manufacturing of Indonesia has been introduced Portland Composite Cement (PCC) to minimize the rising production cost of cement which contains 80% clinker and 20% mineral admixture. A proper curing is very important when the cement contains mineral admixture materials. This paper reports the results of an experimental study conducted to evaluate the effect of water curing duration on strength behaviour of PCC mortar. Mortar specimens with water to cement ratio of (W/C) 0.5 were casted. Compressive strength, flexural strength and concrete resistance were tested at 7, 28 and 91 days cured water. The results indicated that water curing duration is essential to continue the pozzolanic reaction in mortar which contributes to the development of strength of mortar made with PCC.

Plant-Wide Energy Efficiency Assessment at the Arizona Portland Cement Plant in Rillito, Arizona

Energy Technology Data Exchange (ETDEWEB)

Stephen J. Coppinger, P.E.; Bruce Colburn, Ph.D., P.E., CEM

2007-05-17

A Department of Energy Plant-wide Assessment was undertaken by Arizona Portland Cement (APC) beginning in May 2005. The assessment was performed at APC’s cement production facility in Rillito, Arizona. The assessment included a compressed air evaluation along with a detailed process audit of plant operations and equipment. The purpose of this Energy Survey was to identify a series of energy cost savings opportunities at the Plant, and provide preliminary cost and savings estimates for the work. The assessment was successful in identifying projects that could provide annual savings of over $2.7 million at an estimated capital cost of $4.3 million. If implemented, these projects could amount to a savings of over 4.9 million kWh/yr and 384,420 MMBtu/year.

49 CFR 800.25 - Delegation to the Directors of Office of Aviation Safety, Office of Railroad Safety, Office of...

Science.gov (United States)

2010-10-01

... Office of Aviation Safety, Office of Railroad Safety, Office of Highway Safety, Office of Marine Safety... Offices of Aviation, Railroad, Highway, Marine, and Pipeline and Hazardous Materials Safety, the authority... 49 Transportation 7 2010-10-01 2010-10-01 false Delegation to the Directors of Office of Aviation...

Evaluation of physical stability and leachability of Portland Pozzolona Cement (PPC) solidified chemical sludge generated from textile wastewater treatment plants

International Nuclear Information System (INIS)

Patel, Hema; Pandey, Suneel

2012-01-01

Highlights: ► Stabilization/solidification of chemical sludge from textile wastewater treatment plants using Portland Pozzolona Cement (PPC) containing fly ash. ► Physical engineering (compressive strength and block density) indicates that sludge has potential to be reused for construction purpose after stabilization/solidification. ► Leaching of heavy metals from stabilized/solidified materials were within stipulated limits. ► There is a modification of microstructural properties of PPC with sludge addition as indicated by XRD and SEM patterns. - Abstract: The chemical sludge generated from the treatment of textile dyeing wastewater is a hazardous waste as per Indian Hazardous Waste Management rules. In this paper, stabilization/solidification of chemical sludge was carried out to explore its reuse potential in the construction materials. Portland Pozzolona Cement (PPC) was selected as the binder system which is commercially available cement with 10–25% fly ash interground in it. The stabilized/solidified blocks were evaluated in terms of unconfined compressive strength, block density and leaching of heavy metals. The compressive strength (3.62–33.62 MPa) and block density (1222.17–1688.72 kg/m 3 ) values as well as the negligible leaching of heavy metals from the stabilized/solidified blocks indicate that there is a potential of its use for structural and non-structural applications.

Portland cement induces human periodontal ligament cells to differentiate by upregulating miR-146a

Directory of Open Access Journals (Sweden)

Min-Ching Wang

2018-04-01

Full Text Available Background/Purpose: Bioaggregates such as Portland cement (PC can be an economical alternative for mineral trioxide aggregate (MTA with additional benefit of less discoloration. MTA has been known to induce differentiations of several dental cells. MicroRNAs are important regulators of biological processes, including differentiation, physiologic homeostasis, and disease progression. This study is to explore how PC enhances the differentiation of periodontal ligament (PDL cells in microRNAs level. Methods: PDL cells were cultured in a regular PC- or MTA-conditioned medium or an osteoinduction medium (OIM. Alizarin red staining was used to evaluate the extent of mineralization. Transfection of microRNA mimics induced exogenous miR-31 and miR-146a expression. The expression of microRNAs and differentiation markers was assayed using reverse-transcriptase polymerase chain reaction. Results: PC enhanced the mineralization of PDL cells in a dose-dependent manner in the OIM. Exogenous miR-31 and miR-146a expression upregulated alkaline phosphatase (ALP, bone morphogenic protein (BMP, and dentin matrix protein 1 (DMP1 expression. However, miR-31 and miR-146a modulates cementum protein 1 (CEMP1 expression in different ways. PC also enhanced ALP and BMP but attenuated CEMP1 in the OIM. Although the OIM or PC treatment upregulated miR-21, miR-29b, and miR-146a, only miR-146a was able to be induced by PC in combination with OIM. Conclusion: This study demonstrated that PC enhances the differentiation of PDL cells, especially osteogenic through miR-146a upregulation. In order to control the ankylosis after regenerative endodontics with the usage of bioaggregates, further investigations to explore these differentiation mechanisms in the miRNA level may be needed. Keywords: Portland cement, Bioaggregate, miR-146a, Osteogenic differentiation, Periodontal ligament (PDL

76 FR 28793 - Office of Biotechnology Activities, Office of Science Policy, Office of the Director; Notice of...

Science.gov (United States)

2011-05-18

... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology Activities, Office of Science Policy, Office of the Director; Notice of Meeting Pursuant to section 10(a) of... Hill, NSABB Program Assistant, NIH Office of Biotechnology Activities, 6705 Rockledge Drive, Suite 750...

76 FR 3918 - Office of Biotechnology Activities, Office of Science Policy, Office of the Director; Notice of...

Science.gov (United States)

2011-01-21

... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology Activities, Office of Science Policy, Office of the Director; Notice of Meeting Pursuant to section 10(a) of... Assistant NIH Office of Biotechnology Activities, 6705 Rockledge Drive, Suite 750, Bethesda, Maryland 20892...

76 FR 77240 - Office of Biotechnology Activities, Office of Science Policy, Office of the Director; Notice of...

Science.gov (United States)

2011-12-12

... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology Activities, Office of Science Policy, Office of the Director; Notice of Meeting Pursuant to section 10(d) of..., NSABB Program Assistant, NIH Office of Biotechnology Activities, 6705 Rockledge Drive, Suite 750...

77 FR 66624 - Office of Biotechnology Activities, Office of Science Policy, Office of the Director; Notice of...

Science.gov (United States)

2012-11-06

... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology Activities, Office of Science Policy, Office of the Director; Notice of Meeting Pursuant to section 10(a) of..., Maryland 20892. Contact Person: Ronna Hill, NSABB Program Assistant, NIH Office of Biotechnology Activities...

75 FR 58410 - Office of Biotechnology Activities, Office of Science Policy, Office of the Director; Notice of...

Science.gov (United States)

2010-09-24

... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology Activities, Office of Science Policy, Office of the Director; Notice of Meeting Pursuant to section 10(a) of..., NSABB Program Assistant, NIH Office of Biotechnology Activities, 6705 Rockledge Drive, Suite 750...

Cell attachment properties of Portland cement-based endodontic materials: biological and methodological considerations.

Science.gov (United States)

Ahmed, Hany Mohamed Aly; Luddin, Norhayati; Kannan, Thirumulu Ponnuraj; Mokhtar, Khairani Idah; Ahmad, Azlina

2014-10-01

The attachment and spreading of mammalian cells on endodontic biomaterials are an area of active research. The purpose of this review is to discuss the cell attachment properties of Portland cement (PC)-based materials by using scanning electron microscope (SEM). In addition, methodological aspects and technical challenges are discussed. A PubMed electronic search was conducted by using appropriate key words to identify the available investigations on the cell attachment properties of PC-based endodontic materials. After retrieving the full text of related articles, the cross citations were also identified. A total of 23 articles published between January 1993 and October 2013 were identified. This review summarizes the cell attachment properties of commercial and experimental PC-based materials on different cell cultures by using SEM. Methodological procedures, technical challenges, and relevance of SEM in determining the biological profile of PC-based materials are discussed. SEM observations demonstrate that commercial MTA formulations show favorable cell attachment properties, which is consistent with their successful clinical outcomes. The favorable cell attachment properties of PC and its modified formulations support its potential use as a substitute for mineral trioxide aggregate. However, researchers should carefully select cell types for their SEM investigations that would be in contact with the proposed PC-based combinations in the clinical situation. Despite being a technical challenge, SEM provides useful information on the cell attachment properties of PC-based materials; however, other assays for cell proliferation and viability are essential to come up with an accurate in vitro biological profile of any given PC-based formulation. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Assessment the potential of using Carbon nanotubes reinforcements for improving the tensile/flexural strength and fracture toughness of Portland cement paste for damage resistant concrete transportation infrastructures.

Science.gov (United States)

2010-09-01

The focus of this study was on exploring the use of nanotechnology-based nano-filaments, such as carbon : nanotubes (CNTs) and nanofibers (CNFs), as reinforcement in improving the mechanical properties of Portland : cement paste as a construction mat...

Performance of portland limestone cements: Cements designed to be more sustainable that include up to 15% limestone addition

Science.gov (United States)

Barrett, Timothy J.

In 2009, ASTM and AASHTO permitted the use of up to 5% interground limestone in ordinary portland cement (OPC) as a part of a change to ASTM C150/AASHTO M85. When this work was initiated a new proposal was being discussed that would enable up to 15% interground limestone cement to be considered in ASTM C595/AASHTO M234. This work served to provide rapid feedback to the state department of transportation and concrete industry for use in discussions regarding these specifications. Since the time this work was initiated, ASTM C595/AASHTO M234 was passed (2012c) and PLCs are now able to be specified, however they are still not widely used. The proposal for increasing the volume of limestone that would be permitted to be interground in cement is designed to enable more sustainable construction, which may significantly reduce the CO2 that is embodied in the built infrastructure while also extending the life of cement quarries. Research regarding the performance of cements with interground limestone has been conducted by the cement industry since these cements became widely used in Europe over three decades ago, however this work focuses on North American Portland Limestone Cements (PLCs) which are specifically designed to achieve similar performance as the OPCs they replace.This thesis presents a two-phase study in which the potential for application of cements containing limestone was assessed. The first phase of this study utilized a fundamental approach to determine whether cement with up to 15% of interground or blended limestone can be used as a direct substitute to ordinary portland cement. The second phase of the study assessed the concern of early age shrinkage and cracking potential when using PLCs, as these cements are typically ground finer than their OPC counterparts. For the first phase of the study, three commercially produced PLCs were obtained and compared to three commercially produced OPCs made from the same clinker. An additional cement was tested

An Alternative Quality Control Technique for Mineral Chemistry Analysis of Portland Cement-Grade Limestone Using Shortwave Infrared Spectroscopy

Directory of Open Access Journals (Sweden)

Nasrullah Zaini

2016-11-01

Full Text Available Shortwave infrared (SWIR spectroscopy can be applied directly to analyze the mineral chemistry of raw or geologic materials. It provides diagnostic spectral characteristics of the chemical composition of minerals, information that is invaluable for the identification and quality control of such materials. The present study aims to investigate the potential of SWIR spectroscopy as an alternative quality control technique for the mineral chemistry analysis of Portland cement-grade limestone. We used the spectroscopic (wavelength position and depth of absorption feature and geochemical characteristics of limestone samples to estimate the abundance and composition of carbonate and clay minerals on rock surfaces. The depth of the carbonate (CO3 and Al-OH absorption features are linearly correlated with the contents of CaO and Al2O3 in the samples, respectively, as determined by portable X-ray fluorescence (PXRF measurements. Variations in the wavelength position of CO3 and Al-OH absorption features are related to changes in the chemical compositions of the samples. The results showed that the dark gray and light gray limestone samples are better suited for manufacturing Portland cement clinker than the dolomitic limestone samples. This finding is based on the CaO, MgO, Al2O3, and SiO2 concentrations and compositions. The results indicate that SWIR spectroscopy is an appropriate approach for the chemical quality control of cement raw materials.

Acompanhamento da hidratação de cimento Portland simples com resíduo de bauxita

Directory of Open Access Journals (Sweden)

R. C. O. Romano

Full Text Available Resumo A substituição parcial de cimento Portland por resíduo de bauxita (RB resulta em produtos com, no mínimo, propriedades similares às dos produtos fabricados com o ligante puro. No entanto, as interações físico-químicas entre os diferentes tipos de cimento e o RB durante a reação de hidratação ainda é pouco explorada em literatura. A elevada quantidade de sódio e a presença de Al2O3, SiO2 e Fe2O3 são fatores que afetam a formação dos produtos hidratados e dependem do tipo de cimento utilizado na mistura. Sendo assim, este trabalho foi realizado com o objetivo de avaliar o impacto da presença do resíduo de bauxita em associação ao cimento Portland simples nas primeiras idades de hidratação. Calorimetria de condução isotérmica, difração de raios X, análise termogravimétrica e espectroscopia de infravermelho foram as técnicas escolhidas para o monitoramento. Os resultados ilustraram que a presença do resíduo coletado na planta da Alcoa (Poços de Caldas aumenta o tempo de indução, o consumo de portlandita, e as quantidades de etringita e monossulfoaluminato formadas. Ao mesmo tempo, houve formação de silicoaluminato de sódio e bicarbonato de sódio, devido às reações com silicatos, aluminatos e com o carbonato do cimento.

Blasted copper slag as fine aggregate in Portland cement concrete.

Science.gov (United States)

Dos Anjos, M A G; Sales, A T C; Andrade, N

2017-07-01

The present work focuses on assessing the viability of applying blasted copper slag, produced during abrasive blasting, as fine aggregate for Portland cement concrete manufacturing, resulting in an alternative and safe disposal method. Leaching assays showed no toxicity for this material. Concrete mixtures were produced, with high aggregate replacement ratios, varying from 0% to 100%. Axial compressive strength, diametrical compressive strength, elastic modulus, physical indexes and durability were evaluated. Assays showed a significant improvement in workability, with the increase in substitution of fine aggregate. With 80% of replacement, the concrete presented lower levels of water absorption capacity. Axial compressive strength and diametrical compressive strength decreased, with the increase of residue replacement content. The greatest reductions of compressive strength were found when the replacement was over 40%. For tensile strength by diametrical compression, the greatest reduction occurred for the concrete with 80% of replacement. After the accelerated aging, results of mechanic properties showed a small reduction of the concrete with blasted copper slag performance, when compared with the reference mixture. Results indicated that the blasted copper slag is a technically viable material for application as fine aggregate for concrete mixtures. Copyright © 2017 Elsevier Ltd. All rights reserved.

Guidelines of the Development and the Supporting Learning Resources by the Community Participatory of Case Study for the Schools Under Secondary Education Service Area Office 24

Directory of Open Access Journals (Sweden)

Wisan Payungwong

2017-06-01

Full Text Available This research aimed 1 to study the components of guidelines of the development and the supporting learning resources by the community participatory of case study for the schools under Secondary Education Service Area Office 24 and 2 to investigate guidelines of guidelines of the development and the supporting learning resources by the community participatory of case study for the schools under Secondary Education Service Area Office 24. This research was conducted into two phases. The first phase was investigated the components and indicators of guidelines of the development and the supporting learning resources by the community participatory of case study for the schools under Secondary Education Service Area Office 24. The samples group were five respondents to provide the information by an assessment form. The second phase was conducted to find out the guidelines of development and supporting learning resources by community participatory of case study which included four steps. The first step was the focus group of case study schools with best practice. The samples were fourteen key informants from 2 schools. There were school directors, deputy director of academic administration, head of learning, village leaders, wisdom villagers and religious leaders. The data were collected by using focus group discussion form. The second step was draft the develop management guideline of academic administration. The sample group were 7 professionals. The data were collected by using the evaluation from of propriety/feasibility/utility of the develop management guideline of academic administration. The data were analyzed in average ( and standard deviation (S.D.. The third step was group discussion for evaluated the applying of the develop management guideline of academic administration. The samples group were 14 key informants from 2 schools. There were school directors, deputy director of academic administration, head of learning, village leaders

PSD Determination, Portland Cement Plant

Science.gov (United States)

This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

Office of the Chief Financial Officer Annual Report 2009

Energy Technology Data Exchange (ETDEWEB)

Fernandez, Jeffrey

2009-12-15

Presented is the 2009 Chief Financial Officer's Annual Report. The data included in this report has been compiled from the Budget Office, the Controller, Procurement and Property Management and the Sponsored Projects Office.

76 FR 5391 - Office of Biotechnology Activities, Office of Science Policy, Office of the Director

Science.gov (United States)

2011-01-31

... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology Activities, Office of Science Policy, Office of the Director Amended Notice of Meeting Notice is hereby given of a change in the meeting of the National Science Advisory Board for Biosecurity (NSABB), February...

A study of photon interaction in some building materials: High-volume admixture of blast furnace slag into Portland cement

International Nuclear Information System (INIS)

Kurudirek, Murat; Tuerkmen, Ibrahim; Ozdemir, Yueksel

2009-01-01

Total mass attenuation coefficients, mean free paths (MFP), half-value (HVT) and tenth-value (TVT) thicknesses of Portland cement and three mixtures have been calculated in function of the energy from 1 keV to 100 GeV. Both in the low- and high-energy region there were significant variations in those parameters where photoelectric process and pair production partially dominates, respectively. In general, the attenuation parameters were found to vary with chemical composition, density of given material and photon energy.

A study of photon interaction in some building materials: High-volume admixture of blast furnace slag into Portland cement

Energy Technology Data Exchange (ETDEWEB)

Kurudirek, Murat [Faculty of Science, Department of Physics, Ataturk University, 25240 Erzurum (Turkey)], E-mail: mkurudirek@gmail.com; Tuerkmen, Ibrahim [Faculty of Engineering, Department of Civil Engineering, Ataturk University, 25240 Erzurum (Turkey); Ozdemir, Yueksel [Faculty of Science, Department of Physics, Ataturk University, 25240 Erzurum (Turkey)

2009-09-15

Total mass attenuation coefficients, mean free paths (MFP), half-value (HVT) and tenth-value (TVT) thicknesses of Portland cement and three mixtures have been calculated in function of the energy from 1 keV to 100 GeV. Both in the low- and high-energy region there were significant variations in those parameters where photoelectric process and pair production partially dominates, respectively. In general, the attenuation parameters were found to vary with chemical composition, density of given material and photon energy.

Lime kiln dust as a potential raw material in portland cement manufacturing

Science.gov (United States)

Miller, M. Michael; Callaghan, Robert M.

2004-01-01

In the United States, the manufacture of portland cement involves burning in a rotary kiln a finely ground proportional mix of raw materials. The raw material mix provides the required chemical combination of calcium, silicon, aluminum, iron, and small amounts of other ingredients. The majority of calcium is supplied in the form of calcium carbonate usually from limestone. Other sources including waste materials or byproducts from other industries can be used to supply calcium (or lime, CaO), provided they have sufficiently high CaO content, have low magnesia content (less than 5 percent), and are competitive with limestone in terms of cost and adequacy of supply. In the United States, the lime industry produces large amounts of lime kiln dust (LKD), which is collected by dust control systems. This LKD may be a supplemental source of calcium for cement plants, if the lime and cement plants are located near enough to each other to make the arrangement economical.

Portland blended cements: demolition ceramic waste management; Cementos Portland con adiciones: manejo de residuos cerámicos de demolición.

Energy Technology Data Exchange (ETDEWEB)

Trezza, M.A.; Zito, S.; Tironi, A.; Irassar, E.F.; Rahhal, V.F.

2017-07-01

Demolition ceramic wastes (DCWs) were investigated in order to determine their potential use as supplementary cementitious materials in Portland Blended Cements (PBCs). For this purpose, three ceramic wastes were investigated. After characterization of the materials used, the effect of ceramic waste replacement (8, 24 and 40% by mass) was analyzed. Pozzolanic activity, hydration progress, workability and compressive strength were determined at 2, 7 and 28 days. The results showed that the ground wastes behave as filler at an early age, but as hydration progresses, the pozzolanic activity of ceramic waste contributes to the strength requirement. [Spanish] Se estudiaron residuos cerámicos de demolición (DCWs) a fin de determinar su potencial uso como materiales cementicios suplementarios en cementos mezcla (PBC). Para este propósito, se investigaron tres residuos cerámicos. Luego de la caracterización de los materiales a utilizar, se analizó el efecto del reemplazo por residuos cerámico (8, 24 y 40% en peso). Se estudió la actividad puzolánica, el progreso de la hidratación, la trabajabilidad y la resistencia a compresión a 2, 7 y 28 días. Los resultados mostraron que los residuos molidos se comportaron como fillers a edades tempranas, pero con el progreso de la hidratación, la actividad puzolánica de los residuos cerámicos contribuye a los requerimientos de resistencia.

75 FR 15713 - Office of Biotechnology Activities; Office of Science Policy; Office of the Director; Notice of a...

Science.gov (United States)

2010-03-30

... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology... Lewallen, Advisory Committee Coordinator, Office of Biotechnology Activities, Office of Science Policy..., Director, Office of Biotechnology Activities, National Institutes of Health. [FR Doc. 2010-6970 Filed 3-29...

2005 HI Office of Planning Lidar: Kilauea Crater

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The State of Hawaii Planning Office contracted the Airborne 1 Corporation to collect, process and deliver several areas in Hawaii in the later part of 2005. 3,000...

A Firsthand Comparison of a System Office to a College Office

Science.gov (United States)

Hom, Willard C.

2010-01-01

System offices for community college institutional research differ in many ways from campus offices for community college institutional research. The other chapters in this volume describe salient characteristics of system IR offices, but many readers may want to see a direct comparison of system IR offices to campus IR offices in the community…

Office lighting systems: Optimization

Energy Technology Data Exchange (ETDEWEB)

Dagnino, U. (ENEL, Milan (Italy))

1990-09-01

Relative to office lighting systems, in particular, those making use of tubular fluorescent lamps, currently available on the international market, this paper tries to develop lighting system, design optimization criteria. The comparative assessment of the various design possibilities considers operating cost, energy consumption, and occupational comfort/safety aspects such as lighting level uniformity and equilibrium, reduction of glare and reflection, natural/artificial lighting balance, programmed switching, computerized control systems for multi-use requirements in large areas, programmed maintenance for greater efficiency and reliability.

Manganese substitutions into the portland cement clinker phases

Directory of Open Access Journals (Sweden)

Puertas, F.

1989-06-01

Full Text Available The effect of manganese substitution into the crystal structures of the main Portland cement clinker phases (3CaO.SiO₂, 2CaO.SiO₂, 3CaO.Al₂O₃, 2CaO.Fe₂O₃ y 4CaO.Al₂O₃.Fe₂O₃ has been studied by X-ray and analytical electron microscopy. In oxidizing conditions, the limit of solid solution in 3CaO.SiO₂ is about 0.72 ±0.11% (wt, while in 2CaO.SiO₂ is 1.53±0,12%(wt. Mn solid solubility on 3CaO.Al₂O₃structure, in oxidizing conditions is close to 0.78 ± 0,12% (wt. In identical atmosphere, the proportion of Mn in the ferrite phases (2CaO.Fe₂O₃ and 4CaO.Al₂O₃.Fe₂O₃ is 6.80 ± 0.87% (wt and 6.7% (wt, respectively. To each mentioned clinker phases a solid solution formula has been proposed. In these formula, the manganese substitutions and also the different oxidation states which this element can be introduced in those crystalline structure are defined.

Se ha estudiado, por difracción de rayos X y microanálisis por espectroscopia de energías dispersivas, el efecto de la sustitución del manganeso en las estructuras cristalinas de las fases más importantes del clinker del cemento portland (3CaO.SiO₂, 2CaO.SiO₂, 3CaO.Al₂O₃, 2CaO.Fe₂O₃ y 4CaO.Al₂O₃.Fe₂O₃. En condiciones oxidantes, el límite de solubilidad sólida en 3CaO.SiO₂ es del orden de 0,72 ± 0,11% en peso; mientras que en 2CaO.SiO₂ es de 1,53 ±0,12% en peso. La solución sólida del Mn en la estructura del 3CaO.Al₂O₃, en condiciones oxidantes, es próxima al 0,78 ±0,12% en peso. En idéntica atmósfera, la proporción del Mn en las fases terríficas (2CaO.Fe₂O₃ y 4CaO.Al₂

Performance test results of noninvasive characterization of RCRA surrogate waste by prompt gamma neutron activation analysis

International Nuclear Information System (INIS)

Gehrke, R.J.; Propp, W.A.

1997-11-01

A performance evaluation to determine the feasibility of using prompt gamma neutron activation analysis (PGNAA) for noninvasive, quantitative assay of mixed waste containers was sponsored by DOE's Office of Technology Development (OTD), the Mixed Waste Focus Area (MWFA), and the Idaho National Engineering and Environmental Laboratory (INEEL). The evaluation was conducted using a surrogate waste, based on Portland cement, that was spiked with three RCRA metals, mercury, cadmium, and lead. The results indicate that PGNAA has potential as a process monitor. However, further development is required to improve its sensitivity to meet regulatory requirements for determination of these RCRA metals

Programs of the Office of the Science Advisor (OSA)

Science.gov (United States)

Office of the Science Advisor provides leadership in cross-Agency science and science policy. Program areas: Risk Assessment, Science and Technology Policy, Human Subjects Research, Environmental Measurement and Modeling, Scientific Integrity.

Numerical simulation of heat and mass transport during hydration of Portland cement mortar in semi-adiabatic and steam curing conditions

OpenAIRE

Hernandez-Bautista, E.; Bentz, D. P.; Sandoval-Torres, S.; de Cano-Barrita, P. F. J.

2016-01-01

A model that describes hydration and heat-mass transport in Portland cement mortar during steam curing was developed. The hydration reactions are described by a maturity function that uses the equivalent age concept, coupled to a heat and mass balance. The thermal conductivity and specific heat of mortar with water-to-cement mass ratio of 0.30 was measured during hydration, using the Transient Plane Source method. The parameters for the maturity equation and the activation energy were obtaine...

Acción del agua de mar sobre un cemento portland de alta resistencia inicial y sobre un cemento portland resistente a los sulfatos: influencia de la adición de escoria. Estudio de la concentración iónica

Directory of Open Access Journals (Sweden)

Gaspar-Tébar, Demetrio

1987-06-01

Full Text Available Not available

En este trabajo se estudia la variación del pH, así como la de la concentración de los iones Ca (II, Mg (II, SO₄ (II y Cl (I del agua de mar artificial (ASTM D 1141-75, en donde las probetas de mortero (1 : 3 de 1 X 1 X 6 cm fabricadas con un cemento portland industrial de alta resistencia inicial (cemento 1, con un cemento portland industrial resistente a los sulfatos (cemento 2 y con las mezclas cemento (1 ó 2/escoria = 85/15, 65/35, 40/60 y 30/70 (en peso han estado sumergidas, durante 56 - 90 - 180 y 360 días, después del período de curado (1 día en cámara húmeda y 21 días en agua potable; así mismo se estudia la evolución del contenido de Ca (II, Mg (II y SO₄ (II en la nueva fase sólida formada en el agua de mar artificial mencionada en donde han estado las probetas de mortero. En el agua de mar artificial se produce un aumento de la concentración de Ca (II y del valor del pH, una disminución de las cantidades de Mg (II, SO₄ (II y Cl (I, así como la formación de una nueva fase sólida, que son función de las mezclas cemento/escoria utilizadas para elaborar las probetas de mortero y del tiempo de conservación-ataque. El contenido de Ca (II, que procede del Ca(0H₂ disuelto del cemento hidratado, en el agua de mar artificial responde, prácticamente, a las cantidades calculadas a partir del Ca (II correspondientes al medio (agua de mar artificial en donde han estado las probetas fabricadas con los dos cementos estudiados, sin adición de escoria. La evolución de los contenidos de Ca (II y de Mg (II en el agua de mar artificial, en donde han estado las probetas, están íntimamente ligados, de tal modo que si la concentración de uno de ellos aumenta, la del otro disminuye y viceversa. Hay un sistema cemento/escoria - agua de mar artificial, para una mezcla determinada, en donde tiene lugar el equilibrio Ca (II que pasa a la disolución ⇌ Mg (II que

Effectiveness of inorganic membrane mixture of natural zeolite and portland white cement in purifying of peat water based on turbidity parameter

Science.gov (United States)

Elfiana; Fuadi, A.; Diana, S.

2018-04-01

Peat water is water surface that brownish red colour caused by the contained constituents. Solving the peat watercolor problem requires special attention considering the quantity of peat water and suitable to be used to meet the daily needs. This study aims to know the inorganic membrane capability of mix nature zeolite and white Portland cement to purifying the peat water based on turbidity parameter. The study was conducted by varying the composition of nature zeolite (Za) and white Portland cement (Sp) in the ratio of Za: Sp is (25%:75%; 50%:50%; 75%:25%) with zeolite condition activated using HCl 2M and nonactivated zeolite treatments. The result of the characteristic test on membrane morphology using SEM (Scanning Electron Microscope) showed that the pore surface size of the membrane is 2 μm that could classified in microfiltration membrane an organic type. The characteristic test showed also resulted in the density of 0.77 to 0.86 gr/cm3, porosity 26.22% to 35.93%, and permeability 2736.19 to 8428.15. While the water retention capacity is in range of 30.64% to 46.46%, The result of inorganic membrane application on peat water showed turbidity of peat water decreased 94.17%, from 10.3 NTU to 0.6 NTU.

Chemical composition, effective atomic number and electron density study of trommel sieve waste (TSW), Portland cement, lime, pointing and their admixtures with TSW in different proportions

International Nuclear Information System (INIS)

Kurudirek, Murat; Aygun, Murat; Erzeneoglu, Salih Zeki

2010-01-01

The trommel sieve waste (TSW) which forms during the boron ore production is considered to be a promising building material with its use as an admixture with Portland cement and is considered to be an alternative radiation shielding material, also. Thus, having knowledge on the chemical composition and radiation interaction properties of TSW as compared to other building materials is of importance. In the present study, chemical compositions of the materials used have been determined using a wavelength dispersive X-ray fluorescence spectrometer (WDXRFS). Also, TSW, some commonly used building materials (Portland cement, lime and pointing) and their admixtures with TSW have been investigated in terms of total mass attenuation coefficients (μ/ρ), photon interaction cross sections (σ t ), effective atomic numbers (Z eff ) and effective electron densities (N e ) by using X-rays at 22.1, 25 keV and γ-rays at 88 keV photon energies. Possible conclusions were drawn with respect to the variations in photon energy and chemical composition.

Effect of the use nickeliferous laterite and pumice as additives in the performance and durability of the Portland cement

OpenAIRE

Rueda-Gualdrón, María Carolina; Vega-Nuñez, Karen Milena; Ríos-Reyes, Carlos Alberto

2016-01-01

This work evaluated the pozzolanic behavior of the niqueliferous laterite of Cerromatoso (Córdoba) and the pumice of Cemex (Boyacá), based on the NTC standards for fine aggregates. The mortars were prepared with additions of 2.5%, 5% and 10% as substitutes of type I Portland cement, which tested to extreme environments (high temperatures and chemical attacks with H2SO4 y MgSO4). Results demonstrates how these alternative materials increase or decrease their puzolanic degree, as well as the ef...

Clinical use of the Mayo-Portland Adaptability Inventory in rehabilitation after paediatric acquired brain injury.

Science.gov (United States)

Oddson, Bruce; Rumney, Peter; Johnson, Patricia; Thomas-Stonell, Nancy

2006-11-01

The Mayo-Portland Adaptability Inventory (MPAI; designed to be administered by clinicians) is a popular measure of disability following head injury in adults. Its acceptability, validity, and reliability were assessed for use with children. There were 335 children and adolescents (215 males, 120 females) aged between 1 and 19 years at injury (median age 9y 8mo [SD 5y]) in our sample. The test was acceptable to respondents, rapidly and easily administered, and required only small modifications. It demonstrated validity against client and parent reports of major symptoms. It demonstrated test-retest reliability within the limitations of our data and excellent interrater accord. Consequently, the MPAI is recommended for paediatric use for evaluating rehabilitation needs and therapy outcome.

Clinical and radiographic evaluation of Portland cement added to radiopacifying agents in primary molar pulpotomies.

Science.gov (United States)

Lourenço Neto, N; Marques, N C T; Fernandes, A P; Hungaro Duarte, M A; Abdo, R C C; Machado, M A A M; Oliveira, T M

2015-10-01

This was to evaluate the clinical and radiographic outcomes of Portland cement (PC) added to radiopacifying agents in primary molar pulpotomies. Thirty primary mandibular molars of children aged between 5 and 9 years were randomly assigned to the following groups: PC; PC with iodoform (PC + CHI(3)); PC with zirconium oxide (PC + ZrO(2)) and treated by pulpotomy technique. Clinical and radiographic follow-up assessments were performed at 6, 12 and 24 months. Statistical analysis was performed by Fisher's exact test (P < 0.05). The clinical and radiographic evaluations showed 100 % success rates, and the results showed no statistically significant difference between groups. According to this study, PC added to radiopacifying agents exhibited satisfactory clinical and radiographic results in primary molar pulpotomies.

Stakeholder value-linked sustainability assessment: Evaluating remedial alternatives for the Portland Harbor Superfund Site, Portland, Oregon, USA.

Science.gov (United States)

Apitz, Sabine E; Fitzpatrick, Anne G; McNally, Amanda; Harrison, David; Coughlin, Conor; Edwards, Deborah A

2018-01-01

Regulatory decisions on remediation should consider affected communities' needs and values, and how these might be impacted by remedial options; this process requires that diverse stakeholders are able to engage in a transparent consideration of value trade-offs and of the distribution of risks and benefits associated with remedial actions and outcomes. The Stakeholder Values Assessment (SVA) tool was developed to evaluate remedial impacts on environmental quality, economic viability, and social equity in the context of stakeholder values and priorities. Stakeholder values were linked to the pillars of sustainability and also to a range of metrics to evaluate how sediment remediation affects these values. Sediment remedial alternatives proposed by the US Environmental Protection Agency (USEPA) for the Portland Harbor Superfund Site were scored for each metric, based upon data provided in published feasibility study (FS) documents. Metric scores were aggregated to generate scores for each value; these were then aggregated to generate scores for each pillar of sustainability. In parallel, the inferred priorities (in terms of regional remediation, restoration, planning, and development) of diverse stakeholder groups (SGs) were used to evaluate the sensitivity and robustness of the values-based sustainability assessment to diverse SG priorities. This approach, which addresses social indicators of impact and then integrates them with indicators of environmental and economic impacts, goes well beyond the Comprehensive Environmental Response, Compensation and Liability Act's (CERCLA) 9 criteria for evaluating remedial alternatives because it evaluates how remedial alternatives might be ranked in terms of the diverse values and priorities of stakeholders. This approach identified trade-offs and points of potential contention, providing a systematic, semiquantitative, transparent valuation tool that can be used in community engagement. Integr Environ Assess Manag 2018

75 FR 52780 - Designation of Nine Counties as High Intensity Drug Trafficking Areas

Science.gov (United States)

2010-08-27

... EXECUTIVE OFFICE OF THE PRESIDENT Office of National Drug Control Policy Designation of Nine Counties as High Intensity Drug Trafficking Areas ACTION: Notice. SUMMARY: The Director of the Office of National Drug Control Policy designated nine additional counties as High Drug Trafficking Areas pursuant to...

75 FR 21368 - Designation of Five Counties as High Intensity Drug Trafficking Areas

Science.gov (United States)

2010-04-23

... EXECUTIVE OFFICE OF THE PRESIDENT Office of National Drug Control Policy Designation of Five Counties as High Intensity Drug Trafficking Areas ACTION: Notice. SUMMARY: The Director of the Office of National Drug Control Policy designated five additional counties as High Drug Trafficking Areas pursuant to...

Proceedings of the International Symposium on Detonation (9th) Held in Portland, Oregon on 28 August - 1 September 1989. Volume 1

Science.gov (United States)

1989-09-01

compaction andeation pres wace , mixture (the loss of pressurization is due to the In the series of experiments investigat- venting into undisturbed...Detonation was held at the Red Lion Inn, Columbia River, Portland, Oregon, from August 28 through September 1, 1989. The Symposium was one of a series ...Francis Ree and Katsumi Tanaka The Detonation Parameters of New Powerful Explosive Compounds Predicted with a Revised VLW Equation of State W u Xiong

Act concerning the establishment of a Federal Office for Radiation Protection

International Nuclear Information System (INIS)

1989-01-01

The Federal Office for Radiation Protection shall be placed under the competence of the Federal Minister for the Environment, Nature Conservation and Reactor Safety, and shall have the powers of a higher federal authority. The Office shall have its seat in Salzgitter. The Office shall fulfil administrative tasks within the federal powers in the fields of radiation protection including preventive radiation protection, nuclear safety, transport of radioactive materials, and nuclear waste management including the construction and operation of installations under the competence of the Federal Covernment, for the collection and ultimate disposal of nuclear wastes. The Office shall fulfil such Federal tasks as are defined in these areas by the Atomic Energy Act, the Act on Preventive Radiation Protection, or any other federal act, or such tasks as will be assigned to the Office on the basis of said acts. Any amendments of the above acts required for proper fulfilment of tasks by the Federal Office for Radiation Protection shall be duly announced. (orig./HP) [de

Freeze-Thaw Performance and Moisture-Induced Damage Resistance of Base Course Stabilized with Slow Setting Bitumen Emulsion-Portland Cement Additives

Directory of Open Access Journals (Sweden)

Mojtaba Shojaei Baghini

2015-01-01

Full Text Available Freeze-thaw (FT cycles and moisture susceptibility are important factors influencing the geotechnical characteristics of soil-aggregates. Given the lack of published information on the behavior of cement-bitumen emulsion-treated base (CBETB under environmental conditions, especially freezing and thawing, this study investigated the effects of these additives on the CBETB performance. The primary goal was to evaluate the resistance of CBETB to moisture damage by performing FT, Marshall conditioning, and AASHTO T-283 tests and to evaluate the long-term stripping susceptibility of CBETB while also predicting the liquid antistripping additives to assess the mixture’s durability and workability. Specimens were stabilized with Portland cement (0%–6%, bitumen emulsion (0%–5%, and Portland cement-bitumen emulsion mixtures and cured for 7 days, and their short- and long-term performances were studied. Evaluation results of both the Marshall stability ratio and the tensile strength ratio show that the additions of additives increase the resistance of the mixtures to moisture damage. Results of durability tests performed for determining the resistance of compacted specimens to repeated FT cycles indicate that the specimen with the 4% cement-3% bitumen emulsion mixture significantly improves water absorption, volume changes, and weight losses. This indicates the effectiveness of this additive as a road base stabilizer with excellent engineering properties for cold regions.

37 CFR 1.414 - The United States Patent and Trademark Office as a Designated Office or Elected Office.

Science.gov (United States)

2010-07-01

... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false The United States Patent and Trademark Office as a Designated Office or Elected Office. 1.414 Section 1.414 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES International Processing...

Report of the Office of Nuclear Reactor Regulation technical assistance task force

International Nuclear Information System (INIS)

1981-11-01

In 1981, the Director of the Office of Nuclear Reactor Regulation (NRR) of the Nuclear Regulatory Commission (NRC) chartered a task force to assess the office program of technical assistance and to recommend improvements. The task force divided the technical assistance program into four areas, and the practices in each area were assessed through a series of surveys of staff, management, and contractor personnel. The task force placed emphasis in its interview and assessment process on the problem areas that exist in the technical assistance program. The report thus reflects a weight on the faults found as a result of the inquiries made. The four major areas of technical assistance contracting studied were program planning, program management and execution, program control and management information systems, and program administration and coordination

Biomineralization ability and interaction of mineral trioxide aggregate and white portland cement with dentin in a phosphate-containing fluid.

Science.gov (United States)

Reyes-Carmona, Jessie F; Felippe, Mara S; Felippe, Wilson T

2009-05-01

Mineral trioxide aggregate (MTA) has been shown to be bioactive because of its ability to produce biologically compatible carbonated apatite. This study analyzed the interaction of MTA and white Portland cement with dentin after immersion in phosphate-buffered saline (PBS). Dentin disks with standardized cavities were filled with ProRoot MTA, MTA Branco, MTA BIO, white Portland cement + 20% bismuth oxide (PC1), or PC1 + 10% of calcium chloride (PC2) and immersed in 15 mL of PBS for 2 months. The precipitates were weighed and analyzed by scanning electron microscopy (SEM) and x-ray diffraction. The calcium ion release and pH of the solutions were monitored at 5, 15, 25, and 35 days. The samples were processed for SEM observations. Data were analyzed by using analysis of variance or Kruskall-Wallis tests. Our findings revealed the presence of amorphous calcium phosphate precipitates with different morphologies. The apatite formed by the cement-PBS system was deposited within collagen fibrils, promoting controlled mineral nucleation on dentin, observed as the formation of an interfacial layer with tag-like structures. All the cements tested were bioactive. The cements release some of their components in PBS, triggering the initial precipitation of amorphous calcium phosphates, which act as precursors during the formation of carbonated apatite. This spontaneous precipitation promotes a biomineralization process that leads to the formation of an interfacial layer with tag-like structures at the cement-dentin interface.

Modelling of Pb release during Portland cement alteration

Energy Technology Data Exchange (ETDEWEB)

Benard, A. [INERIS Mediterrannee, F-13545 Aix En Provence 04 (France); Rose, J.; Borschneck, D.; Bottero, J.Y. [Univ Paul Cezanne, CNRS, UMR 6635, CEREGE, IFR PMSE 112, F-13545 Aix En Provence, (France); Hazemann, J.L. [CNRS, Cristallog Lab, F-38042 Grenoble 09 (France); Proux, O. [Univ Grenoble 1, CNRS, UMR, LGIT, F-38400 St Martin Dheres (France); Trotignon, L. [CEA Cadarache, DTN, SMTM, Lab Modelisat Transferts Environm, 13 - Saint Paul lez Durance (France); Nonat, A. [Univ Bourgogne, CNRS, UMR 5613, Fac Sci Mirande, Lab Rech Reactivite Solides, F-21078 Dijon (France); Chateau, L. [ADEME, F-49004 Angers (France)

2009-07-01

Complex cementitious matrices undergo weathering with environmental exchange and can release metallic pollutants during alteration. The molecular mechanisms responsible for metal release are difficult to identify, though this is necessary if such processes are to be controlled. The present study determines and models the molecular mechanisms of Pb release during Portland cement leaching. As Pb release is strongly related to its speciation (i.e. atomic environment and the nature of bearing phases), the first objective of the present study was to investigate the evolution of Pb retention sites together with the evolution of the cement mineralogy during leaching. Complementary and efficient investigation tools were used, namely X-ray diffraction, micro-X-ray fluorescence and X-ray absorption fine structures. The second objective was to reproduce our results with a reactive transport code (CHESS/HYTEC) in order to test the proposed speciation model of Pb. Combined results indicate that in both the unaltered core and the altered layer of the leached cement, Pb(II) would be retained through C-S-H 'nano-structure', probably linked to a Q(1) or Q(2P) silicate tetrahedra. Moreover in the altered layer, the presence of Fe atoms in the atomic environment of Pb is highly probable. Unfortunately little is known about Fe phases in cement, which makes the interpretation difficult. Can Fe-substituted hydrogranet (C(3)AH(6)) be responsible for Pb retention? Modelling results were consistent with Pb retention through C-S-H in layers and also in an additional, possibly Fe-containing, Pb-retention phase in the altered layer. (authors)

The relative benefits of green versus lean office space: three field experiments.

Science.gov (United States)

Nieuwenhuis, Marlon; Knight, Craig; Postmes, Tom; Haslam, S Alexander

2014-09-01

Principles of lean office management increasingly call for space to be stripped of extraneous decorations so that it can flexibly accommodate changing numbers of people and different office functions within the same area. Yet this practice is at odds with evidence that office workers' quality of life can be enriched by office landscaping that involves the use of plants that have no formal work-related function. To examine the impact of these competing approaches, 3 field experiments were conducted in large commercial offices in The Netherlands and the U.K. These examined the impact of lean and "green" offices on subjective perceptions of air quality, concentration, and workplace satisfaction as well as objective measures of productivity. Two studies were longitudinal, examining effects of interventions over subsequent weeks and months. In all 3 experiments enhanced outcomes were observed when offices were enriched by plants. Implications for theory and practice are discussed. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Workability and mental wellbeing among therapeutic prison officers.

Science.gov (United States)

Walker, E J; Jackson, C A; Egan, H H; Tonkin, M

2015-10-01

Previous research has examined how age and health can shape workability (WA). This study seeks to explore how a lack of WA (inability) may affect the health of the employee. To explore the effects of work inability on mental wellbeing among therapeutic prison officers. An anonymous cross-sectional study of prison officers conducted in a category B English prison using the Work Ability Index (WAI) and General Health Questionnaire-28 (GHQ). Fifty-seven officers (59%) participated and of those 95% achieved GHQ caseness. Officers with poorer WA reported significantly higher GHQ scores. Work inability for mental demands had significant associations with anxiety (β = -0.58, 95% CI -4.21 to -1.88, particularly sleep loss; Pearson's r = -0.66). Our findings present clear associations between poor WA and its impact upon mental wellbeing. The results of this study may help to focus on areas for intervention such as improving WA and promoting mental wellbeing. © The Author 2015. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Influence of the waste glass in the axial compressive strength of Portland cement concrete; Influencia dos residuos vitreos na resistencia a compressao axial do concreto de cimento Portland

Energy Technology Data Exchange (ETDEWEB)

Miranda Junior, E.J.P.; Paiva, A.E.M., E-mail: edson.jansen@hotmail.com [Instituto Federal de Educacao, Ciencia e Tecnologia do Maranhao (PPGEM/IFMA), Sao Luis, MA (Brazil). Programa de Pos-Graduacao em Engenharia de Materiais

2012-07-01

In this work, was studied the influence of the incorporation of waste glass, coming from the stage of thinning and polishing of a company of thermal glass treatments, in the axial compressive strength of Portland cement concrete. The coarse and ground aggregates used was crushed stone and sand, respectively. For production of the concrete, percentages of glass residues of 5%, 10% and 20% had been used in substitution to the sand, and relations water/cement (a/c) 0,50, 0,55 and 0,58. The cure of the test bodies was carried through in 7, 14 and 28 days. The statistics analysis of the results was carried out through of the analysis of variance for each one of the cure times. From the results of the compressive strength of the concrete, it could be observed that the concrete has structural application for the relation a/c 0,5, independently of waste glass percentage used, and for the relation a/c 0,55 with 20% of waste glass. (author)