Journal articles: 'Cement chemistry'

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Mason, Patricia. "Chemistry of Cement." Journal of Chemical Education 83, no. 10 (October 2006): 1472A. http://dx.doi.org/10.1021/ed083p1472a.

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Venkatesh, B., D. W. Pigott, A. Fernandez, and S. P. Hendry. "Continuous Measurement of Arterial Blood Gas Status during Total Hip Replacement: A Prospective Study." Anaesthesia and Intensive Care 24, no. 3 (June 1996): 334–41. http://dx.doi.org/10.1177/0310057x9602400306.

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The arterial blood gas chemistry was measured continuously in ten patients during primary cemented total hip replacement in order to define more precisely the patterns of changes in blood gases during various stages of the operation. All ten patients demonstrated significant drops in PaO2 after femoral cement implantation and nine of the ten after acetabular cement implanation. The mean drop in PaO2 following acetabular cement expressed as mean ± SD was 18±8 mmHg (16±6%) (P<0.05) and femoral cement application was 25±11 mmHg (23±9%) (P<0.05). For changes in PaO2 there were corresponding drops in SpO2 in all patients with the femoral cement and in eight patients with the acetabular cement. The mean drop in SpO2 following the application of acetabular and femoral cements respectively were 1.7±1.5% and 3±2.45%. No changes in blood PaO2 were observed during dislocation of the hip joint or reaming of acetabulum and femur. In vitro studies revealed no effect of the liquid monomer or the cured cement on the performance of the Clark electrode of the sensor. We suggest that significant drops in PaO2 occur with both acetabular and femoral cement implantation and that the derangements in blood PaO2 last longer than detected by pulse oximetry following cement implantation.

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Pike, Jack, Andrew Patterson, and Marvin S. Arons. "Chemistry of Cement Burns." Journal of Burn Care & Rehabilitation 9, no. 3 (May 1988): 258–60. http://dx.doi.org/10.1097/00004630-198805000-00004.

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Marangu, Joseph Mwiti, Joseph Karanja Thiong’o, and Jackson Muthengia Wachira. "Review of Carbonation Resistance in Hydrated Cement Based Materials." Journal of Chemistry 2019 (January 1, 2019): 1–6. http://dx.doi.org/10.1155/2019/8489671.

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Blended cements are preferred to Ordinary Portland Cement (OPC) in construction industry due to costs and technological and environmental benefits associated with them. Prevalence of significant quantities of carbon dioxide (CO2) in the atmosphere due to increased industrial emission is deleterious to hydrated cement materials due to carbonation. Recent research has shown that blended cements are more susceptible to degradation due to carbonation than OPC. The ingress of CO2 within the porous mortar matrix is a diffusion controlled process. Subsequent chemical reaction between CO2 and cement hydration products (mostly calcium hydroxide [CH] and calcium silicate hydrate [CSH]) results in degradation of cement based materials. CH offers the buffering capacity against carbonation in hydrated cements. Partial substitution of OPC with pozzolanic materials however decreases the amount of CH in hydrated blended cements. Therefore, low amounts of CH in hydrated blended cements make them more susceptible to degradation as a result of carbonation compared to OPC. The magnitude of carbonation affects the service life of cement based structures significantly. It is therefore apparent that sufficient attention is given to carbonation process in order to ensure resilient cementitious structures. In this paper, an indepth review of the recent advances on carbonation process, factors affecting carbonation resistance, and the effects of carbonation on hardened cement materials have been discussed. In conclusion, carbonation process is influenced by internal and external factors, and it has also been found to have both beneficial and deleterious effects on hardened cement matrix.

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Askar Zhambulovich, Aimenov, Khudyakova Tatyana Mikhailovna, Sarsenbayev Bakytzhan Kudaibergenovich, Dzhakipbekova Nagima Ormanovna, Ali Khalid Abdul Khalim Kheidar, and Alvein Yaser Mukhamed Ali. "Studying the Mineral Additives Effect on a Composition and Properties of a Composite Binding Agent." Oriental Journal of Chemistry 34, no. 4 (August 20, 2018): 1945–55. http://dx.doi.org/10.13005/ojc/3404031.

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A Portland cement is a basic initial component for concrete and reinforced concrete manufacture, which defines their technical-economic and operational properties. One of a perspective ways of increase in the efficiency of cement production without essential change of its technology is inclusion of various mineral additives influencing on a structure and properties of a cement stone. As power inputs make the most part of the costs necessary for cement manufacture, the cement industry is interested in decrease in fuel and electric power expenditures per 1 tonne of cement. To reach the decrease in power inputs and at the same time to raise the environmental safety of cement production the cement industry is recently focused on increase in output of composite cements. Composite cements not only promote optimization of the production in terms of ecology, but also can provide such technical advantages as lower hydration heat, higher chemical resistance and placeability.

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6

MacLaren, Douglas C., and Mary Anne White. "Cement: Its Chemistry and Properties." Journal of Chemical Education 80, no. 6 (June 2003): 623. http://dx.doi.org/10.1021/ed080p623.

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Viani, A., A. F. Gualtieri, M. Secco, L. Peruzzo, G. Artioli, and G. Cruciani. "Crystal chemistry of cement-asbestos." American Mineralogist 98, no. 7 (July 1, 2013): 1095–105. http://dx.doi.org/10.2138/am.2013.4347.

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van Breugel, K. "Modelling of cement-based systems—the alchemy of cement chemistry." Cement and Concrete Research 34, no. 9 (September 2004): 1661–68. http://dx.doi.org/10.1016/j.cemconres.2004.02.016.

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AGZAMOV, Farit A., Arman KABDUSHEV, Elvira TOKUNOVA, BAUYRZHAN Zh MANAPBAYEV, and Bolat Zh KOZHAGELDI. "MAGNESIA CORROSION OF GROUTING MATERIALS." Periódico Tchê Química 17, no. 34 (March 20, 2020): 951–61. http://dx.doi.org/10.52571/ptq.v17.n34.2020.975_p34_pgs_951_961.pdf.

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The issue of magnesia corrosion of grouting materials in oil and gas wells is very relevant in the construction of oil and gas wells since magnesia salts can lead to the destruction of Portland cement-based cement stone within few months. When fastening powerful intervals of salt deposits represented by magnesium salts, the use of magnesia cements is effective. However, individual layers and interlayers containing dissolved magnesium salts are not individually cemented, but overlap over the entire interval of the open hole with cement Portland cement, which can be destroyed due to magnesia corrosion. The main aim of the paper is to analyze the corrosion of Portland cement stone in aggressive environments of magnesia. As the quantitative indicators characterizing the degree of stone damage, the thickness of the damaged layer and the stone resistance coefficient are taken, characterized by the ratio of the compressive strength or bending strength of stone samples after being in an aggressive environment to the strength of control samples at the same hardening time. The corrosion resistance of cement stone was assessed after 8 weeks in an aggressive magnesia environment. Also, the role of MgCl2 concentration on the mechanism of corrosion damage to cement stone was studied. The use of reducing the water-cement ratio and adding palygorskite clay to reduce the porosity of cement stone and reduce the rate of corrosion damage is proposed. The kinetics and the main factors affecting the corrosion process were considered, an X-ray diffraction analysis of corrosion products and unaffected cement stone was carried out.

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10

Saito, T. "Cement Chemistry by Dr. Renichi Kondo." Concrete Journal 51, no. 9 (2013): 764–68. http://dx.doi.org/10.3151/coj.51.764.

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Herfort, D., G. K. Moir, V. Johansen, F. Sorrentino, and H. Bolio Arceo. "The chemistry of Portland cement clinker." Advances in Cement Research 22, no. 4 (October 2010): 187–94. http://dx.doi.org/10.1680/adcr.2010.22.4.187.

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Ludwig, Horst-Michael, and Wensheng Zhang. "Research review of cement clinker chemistry." Cement and Concrete Research 78 (December 2015): 24–37. http://dx.doi.org/10.1016/j.cemconres.2015.05.018.

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13

Prathumsuwan, Thitarat, Alfred A. Christy, and Rein Terje Thorstensen. "Hydration Chemistry of Cement Studied by Near Infrared Spectroscopy." Key Engineering Materials 765 (March 2018): 309–13. http://dx.doi.org/10.4028/www.scientific.net/kem.765.309.

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Cement is a complex mixture of inorganic compounds which mainly composed of calcium silicates and calcium aluminates. Cement is mixed with water to form concrete. During the mixing calcium silicate hydrate (CSH) and calcium hydroxide are formed. The ratio of water/cement (w/c ratio) is important to obtain a mixture that gives optimum strength to the concrete. In this work, three different cement samples were mixed with water in four different ratios, including 0.35, 0.40, 0.45 and 0.55, respectively. The hydration process of cement was investigated by using near infrared (NIR) spectroscopy over a period of 28 days. The combination frequency of OH stretching and bending of water molecules gives rise to an absorption around 5200 cm-1. This peak contains contributions of overtones from several types of water molecules in the cement. Fourth derivatives spectra of all cement samples showed three peaks in the combination band region of 5300-5100 cm-1. These peaks indicated the presence of three distinct types of water molecules in the system. First, the characteristic peak at 5260-5240 cm-1 represented the hydrogen bond between water molecules and silinol group of calcium silicates. This peak indicated the formation of CSH from hydration of cement. Furthermore, this peak experienced a slight red shift after a period of seven days indicating stronger hydrogen bonding of water molecules with silinol groups. The peak at 5130 cm-1 corresponded to hydrogen bonding between water molecules and the peak at 5165 cm-1 corresponded to hydrogen bonding between free water and bound water. The suitable w/c ratio for cement-1 is at 0.35-0.45, cement-2, and cement-3 are 0.45. In addition, real concrete sample showed two characteristic peaks at 5250 cm-1 and 5165 cm-1, demonstrating the presence of CSH and free water within concrete, respectively. Near infrared spectroscopy in combination with fourth derivative technique can be used to investigate the hydration chemistry of cement and concrete.

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14

Ren, Jie, Zhengxiang Lv, Honghui Wang, Jianmeng Wu, and Shunli Zhang. "The Origin of Quartz Cement in the Upper Triassic Second Member of the Xujiahe Formation Sandstones, Western Sichuan Basin, China." Water 13, no. 14 (July 8, 2021): 1890. http://dx.doi.org/10.3390/w13141890.

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High-precision in situ δ18O values obtained using secondary ion mass spectrometry (SIMS) for μm-size quartz cement are applied to constrain the origin of the silica in the deep-buried Upper Triassic second member of Xujiahe Formation tight sandstones, western Sichuan Basin, China. Petrographic, cathodoluminescence (CL), and fluid inclusion data from the quartz cements in the Xu2 sandstones indicate three distinct, separate quartz precipitation phases (referred to as Q1, Q2, and Q3). The Q1 quartz cement was formed at temperatures of approximately 56–85 °C and attained the highest δ18O values (ranging from 18.3 to 19.05‰ Vienna Standard Mean Ocean Water (VSMOW)). The Q2 quartz cement was generated at temperatures of approximately 90–125 °C, accompanying the main phase of hydrocarbon fluid inclusions, with the highest Al2O3 content and high δ18O values (ranging from 15 to 17.99‰ VSMOW). The Q3 quartz cement was formed at temperatures of approximately 130–175 °C, with the lowest δ18O values (ranging from 12.79 to 15.47‰ VSMOW). A portion of the Q2 and Q3 quartz cement has a relatively high K2O content. The dissolution of feldspar and volcanic rock fragments was likely the most important source of silica for the Q1 quartz cement. The variations in δ18O(water) and trace element composition from the Q2 quartz cement to the Q3 quartz cement suggest that hydrocarbon emplacement and water-rock interactions greatly altered the chemistry of the pore fluid. Feldspar dissolution by organic acids, clay mineral reactions (illitization and chloritization of smectite), and pressure dissolution were the main sources of silica for the Q2 and Q3 quartz cements, while transformation of the clay minerals in the external shale unit was a limited silica source.

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15

Fei, Aiping, Wensheng Zhang, and Tiezhi Zhang. "Research on Shrinkage Chemical Properties of Cement Stabilized Macadam Material Based on a Multi-dimensional Expansion and Shrinkage Tester." Revista de Chimie 71, no. 6 (July 1, 2020): 418–28. http://dx.doi.org/10.37358/rc.20.6.8208.

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In order to find out the shrinkage law of cement stabilized macadam material under specific conditions, this paper studied the expansion and shrinkage properties of cement stabilized macadam material under two environmental conditions, five kinds of cement dosage conditions, suspended compacted type and skeleton compaced type based on the multi-dimensional expansion and shrinkage tester. Through the test comparison, it is confirmed that the water loss rate of cement stabilized macadam material increases with the increase of cement dosage, showing a general change rule of rising first and then stabilizing. The average increase of the total water loss rate of suspended compacted cement stabilized macadam at room temperature was greater than that of the skeleton compacted cement stabilized macadam. The dry shrinkage strain also follows the above trend. Either at room temperature or under the conditions of dry shrinkage box, the water loss rate of suspended compacted cemeny stabilized macadam is higher than that of skeleton compacted cement stabilized macadam , which can be up to 3.23% higher. By comparing the temperature shrinkage coefficient under the high and low temperature environment, the temperature coefficient of the skeleton compacted cement stabilized macadam is smaller than that of the suspended compacted cement stabilized macadam. The temperature shrinkage coefficient of the suspended compacted cement stabilized macadam increases by 5.56% on average for each 0.5% increase of the cement dosage, and the temperature shrinkage coefficient of the skeleton compacted cement stabilized macadam increases by 6.33% on average. Through the comparative analysis of tests, it can be found that the anti-reflection crack ability of the skeleton compacted cement stabilized macadam material is better, and the fine aggregate content should be strictly controlled in the construction.

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Opoczky, Ludmilla, and László Sas. "Cement chemistry and –technology issues in the production of low-chromate cements (I)." Epitoanyag - Journal of Silicate Based and Composite Materials 59, no. 4 (2007): 102–5. http://dx.doi.org/10.14382/epitoanyag-jsbcm.2007.14.

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17

Khalil, N. M., and Yousif Algamal. "Utilization of petroleum sludge wastes for increasing productivity of ordinary portland cement." Main Group Chemistry 19, no. 4 (January 23, 2021): 315–28. http://dx.doi.org/10.3233/mgc-200967.

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This work aims at maximum exploitation of petroleum waste sludge as additive to portland cement to prepare blended cements and hence increasing its production capacity without further firing. This will decrease the main cement industry problems involving environmental pollution such as releasing gases and high-energy consumption during industry and hence maximizes the production economics. Six batches of ordinary portland cement (OPC) mixed with different proportions of petroleum waste sludge (PWS) donated as C1 (control batch contains no PWS), C2 (contains 90 wt.% of OPC+10 wt.% of PWS), C3 (contains 80 wt.% of OPC+20 wt.% of PWS), C4 (contains 70 wt.% of OPC+30 wt.% of PWS), C4 (contains 60 wt.% of OPC+40 wt.% of PWS) and C6 (contains 50 wt.% of OPC+50 wt.% of PWS), were prepared and mixed individually with the suitable amount of mixing water. Cement mixes C2, C3 and C4 showed improved cementing and physicomechanical properties compared with pure cement (C1) with special concern of mix C4. Such improvement is due to the relatively higher surface area as well as the high content of kaolinite and quartz in the added PWS (high pozzalanity) favoring the hydration process evidenced by the increase in the cement hydration product (portlandite mineral (Ca (OH) 2).

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Hanein, Theodore, Tristana Y. Duvallet, Robert B. Jewell, Anne E. Oberlink, Thomas L. Robl, Yongmin Zhou, Fredrik P. Glasser, and Marcus N. Bannerman. "Alite calcium sulfoaluminate cement: chemistry and thermodynamics." Advances in Cement Research 31, no. 3 (March 2019): 94–105. http://dx.doi.org/10.1680/jadcr.18.00118.

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19

Barnes, P. "Dynamic characterization of cement and ceramic chemistry." Acta Crystallographica Section A Foundations of Crystallography 52, a1 (August 8, 1996): C398. http://dx.doi.org/10.1107/s0108767396083602.

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20

Aragaw, Tadele Assefa. "Concise Introduction to Cement Chemistry and Manufacturing." Synthesis Lectures on Engineering 12, no. 2 (April 30, 2018): 1–81. http://dx.doi.org/10.2200/s00839ed1v01y201803eng031.

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21

Hanting, Cheng, Liu Hanxing, and Zhang Guoqing. "The setting chemistry of glass ionomer cement." Journal of Wuhan University of Technology-Mater. Sci. Ed. 20, no. 4 (December 2005): 110–12. http://dx.doi.org/10.1007/bf02841298.

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Jungan, Xue. "Recent developments of cement chemistry in China." Ceramics International 11, no. 4 (October 1985): 150. http://dx.doi.org/10.1016/0272-8842(85)90240-8.

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Oduniyi, Odumade Adegboyega, Ezeah Chukwunonye, Charles Nnamdi Ezugwu, and Ekeoma Emmanuel. "Influence of Cement Chemistry on the Performance of Cement Stabilized Tropical Lateritic Soil." American Journal of Engineering and Applied Sciences 11, no. 2 (February 1, 2018): 783–91. http://dx.doi.org/10.3844/ajeassp.2018.783.791.

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Zhang, Shaokang, Ru Wang, Linglin Xu, Andreas Hecker, Horst-Michael Ludwig, and Peiming Wang. "Properties of Calcium Sulfoaluminate Cement Mortar Modified by Hydroxyethyl Methyl Celluloses with Different Degrees of Substitution." Molecules 26, no. 8 (April 8, 2021): 2136. http://dx.doi.org/10.3390/molecules26082136.

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This paper studies the influence of hydroxyethyl methyl cellulose (HEMC) on the properties of calcium sulfoaluminate (CSA) cement mortar. In order to explore the applicability of different HEMCs in CSA cement mortars, HEMCs with higher and lower molar substitution (MS)/degree of substitution (DS) and polyacrylamide (PAAm) modification were used. At the same time, two kinds of CSA cements with different contents of ye’elimite were selected. Properties of cement mortar in fresh and hardened states were investigated, including the fluidity, consistency and water-retention rate of fresh mortar and the compressive strength, flexural strength, tensile bond strength and dry shrinkage rate of hardened mortar. The porosity and pore size distribution were also analyzed by mercury intrusion porosimetry (MIP). Results show that HEMCs improve the fresh state properties and tensile bond strength of both types of CSA cement mortars. However, the compressive strength of CSA cement mortars is greatly decreased by the addition of HEMCs, and the flexural strength is decreased slightly. The MIP measurement shows that HEMCs increase the amount of micron-level pores and the porosity. The HEMCs with different MS/DS have different effects on the improvement of tensile bond strength in different CSA cement mortars. PAAm modification can improve the tensile bond strength of HEMC-modified CSA cement mortar.

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Cheng, Qiangqiang, Jixiong Zhang, Nan Zhou, Yu Guo, and Shining Pan. "Experimental Study on Unconfined Compression Strength of Polypropylene Fiber Reinforced Composite Cemented Clay." Crystals 10, no. 4 (March 26, 2020): 247. http://dx.doi.org/10.3390/cryst10040247.

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The effects of three main factors, including polypropylene fiber content, composite cement content and curing time on the unconfined compressive strength of fiber-reinforced cemented clay were studied through a series of unconfined compressive strength tests. The experimental results show that the incorporation of fibers can increase the compressive strength and residual strength of cement-reinforced clay as well as the corresponding axial strain when the stress peak is reached compared with cement-reinforced clay. The compressive strength of fiber-reinforced cement clay decreases first, then increases with small-composite cement at curing time 14 d and 28 d. However, fiber-reinforced cement clay’s strength increases with the increase of fiber content for heavy-composite cement. The compressive strength of fiber-composite cement-reinforced marine clay increases with the increase of curing time and composite cement content. The growth rate increases with the increase of curing time. The failure mode of composite cement-reinforced clay is brittle failure, while the failure mode of fiber-reinforced cemented clay is plastic failure.

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Rakandenu, I. Gede Made Gani, and Dyah Kusuma Wardhani. "KAJIAN PENGARUH PENGGUNAAN SEMEN EKSPOS SEBAGAI FINISHING DINDING INTERIOR TERHADAP PSIKOLOGIS PENGGUNA RUANG." AKSEN 5, no. 2 (May 24, 2021): 43–51. http://dx.doi.org/10.37715/aksen.v5i2.1870.

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The use of exposed cement materials as wall finishing lately is in great demand and is becoming a designtrend at the moment. Many property buildings ranging from commercial buildings such as cafes, restaurants,to hotels to residential buildings such as houses, apartments and condos use exposed cement as one ofthe interior wall finishing. Exposed cement as wall finishing is usually associated with industrial designstyles. In Indonesia, exposed cement is applied as finishing material after bricks. Using exposed cementas wall finish that nowadays has been trending in architecture and interior applicants gives a differentambience of space, home or building yet still economically acceptable. The using of exposed cement aswall finish are close to the using of industrial style. As known, industrial style is an interior architecturedesign style that adopting industries elements such as the using of metal, bricks and pipe material thenbe exposed on purpose. Industrial style has color palette such as black and greyish. Therefore the usingof exposed cement as wall finish often used in industrial design style. However with the popular use ofexposed cement as wall finish does not mean that it can freely acceptable in all situations, because it canaffect the comfort of the room user.

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Honda, Michiyo, Yusuke Kawanobe, Kohei Nagata, Ken Ishii, Morio Matsumoto, and Mamoru Aizawa. "Bactericidal and Bioresorbable Calcium Phosphate Cements Fabricated by Silver-Containing Tricalcium Phosphate Microspheres." International Journal of Molecular Sciences 21, no. 11 (May 26, 2020): 3745. http://dx.doi.org/10.3390/ijms21113745.

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Bacterial adhesion to the calcium phosphate surface is a serious problem in surgery. To prevent bacterial infection, the development of calcium-phosphate cements (CPCs) with bactericidal properties is indispensable. The aim of this study was to fabricate antibacterial CPCs and evaluate their biological properties. Silver-containing tricalcium phosphate (Ag-TCP) microspheres consisting of α/β-TCP phases were synthesized by an ultrasonic spray-pyrolysis technique. The powders prepared were mixed with the setting liquid to fabricate the CPCs. The resulting cements consisting of β-TCP and hydroxyapatite had a porous structure and wash-out resistance. Additionally, silver and calcium ions could be released into the culture medium from Ag-TCP cements for a long time accompanied by the dissolution of TCP. These data showed the bioresorbability of the Ag-TCP cement. In vitro antibacterial evaluation demonstrated that both released and immobilized silver suppressed the growth of bacteria and prevented bacterial adhesion to the surface of CPCs. Furthermore, histological evaluation by implantation of Ag-TCP cements into rabbit tibiae exhibited abundant bone apposition on the cement without inflammatory responses. These results showed that Ag-TCP cement has a good antibacterial property and good biocompatibility. The present Ag-TCP cements are promising for bone tissue engineering and may be used as antibacterial biomaterials.

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Wang, Lei, and Qi Chen. "Study on the Stabilization of Heavy Metal by Cement with Quantum Chemistry." Advanced Materials Research 955-959 (June 2014): 2935–39. http://dx.doi.org/10.4028/www.scientific.net/amr.955-959.2935.

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The quantum chemistry is a kind of efficient theoretical research methodology; it has become an important foundation and core technology to the computational materials science. The researches of melting mechanism, doping mechanism, mechanism of hydration activity can be used in the related areas of stabilization of heavy metal by cement. Density functional theory is reviewed in the study of the affective mechanism of cement hydration activity and the intensity of hydration by heavy metal, the mechanism of fixating heavy metals by mineral and the mechanism of lowering melting temperature. It is considered that quantum chemistry can be used to make a simulation at the micro level to explore the mechanism of cement-enclosed heavy metals and has a perfect theoretical guiding significance for further research.

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Marangu, Joseph Mwiti, Cyprian Muturia M’thiruaine, and Mark Bediako. "Physicochemical Properties of Hydrated Portland Cement Blended with Rice Husk Ash." Journal of Chemistry 2020 (December 7, 2020): 1–10. http://dx.doi.org/10.1155/2020/5304745.

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In the presence of significant quantities of carbon dioxide (CO2) and elevated temperatures in the atmosphere due to climate change, cement-based materials are susceptible to carbonation. Blended cements are more prone to carbonation attack than Portland cement. There is a need to evaluate the carbonation resistance of blended cements in a carbonation-prone environment. This paper presents experimental findings obtained from an evaluation of carbonation resistance tests on Rice Husk Ash- (RHA-) blended cement. The blended cement was made by intergrinding of Portland Cement (PC) and RHA to make the test cement (PC-RHA). The RHA dosage in the PC-RHA was varied from 0 to 30% by mass of PC. Pozzolanicity, standard consistency, and setting time tests were conducted on PC-RHA. Mortar prisms measuring 160 mm × 40 mm x 40 mm were separately cast at a water/cement ratio ( w / c ) of 0.50 and 0.60 and cured in water for 2, 7, 14, 28, and 90 days. Compressive strength tests were conducted on the mortar prisms at each of the testing ages. The prepared mortars were also subjected to accelerated carbonation tests in two Relative Humidity (RH) curing regimes, one maintained at an RH greater than 90% and the other between 50–60%. Carbonation resistance of the mixtures was evaluated in terms of the changes in carbonation depth using a phenolphthalein test at the age of 7, 14, 28, and 56 days of curing in a continuous flow of CO2. Compressive strength measurements were also taken during each of the carbonation testing ages. For comparison, similar tests were conducted using commercial PC. The results showed that PC-RHA was pozzolanic while PC was nonpozzolanic. Higher water demand and longer setting times were observed in PC-RHA than in PC. Moreover, there was increased strength development in water-cured samples with increased curing duration. Carbonation results indicated that there was a marked increase in carbonation depth with increased dosage of RHA in PC-RHA binders, increased duration of exposure to CO2, and decreased RH (RH between 50–60%). PC-RHA binders exhibited lower carbonation resistance than PC. In conclusion, for mortars at any w / c ratio, carbonation resistance decreased with increase in RHA dosage and increased w / c ratio.

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Mihailescu, Dan, Dana Nicoleta Mihai, Liliana Savin, Lavinia Vasiliu, Victor Grigorescu, Alexandru Patrascu, and Marcel Ionel Popa. "Polymeric Biomaterials with Complimentary Role in Joint Endoprosthesis. II. Compositional and morpho-structural analysis." Materiale Plastice 56, no. 3 (September 30, 2019): 611–15. http://dx.doi.org/10.37358/mp.19.3.5239.

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Successfully used in bone surgery for more than 65 years, self-hardening organic cements (CCOs), in particular acrylic cements, are today, the most advanced complementary biomaterials used in articular endoprosthesis. One of the strategies for obtaining of performing anchorage of artificial implants is to develop new acrylic cements with improved physical, chemical and biomechanical characteristics. The aim of this paper was to identify the compositional and morpho-structural changes of acrylic cements induced by the composition of the liquid phase of the material. Such changes influence the potential to generate the physical bonds responsible for fixation and stabilization of endoprosthesis. The samples studied had different compositions due to the mixture of acrylic monomers, methyl methacrylate (MMA) and butyl acrylate (BuA) in the liquid component of cement. The MMA / BuA ratio varied between 1/0 v / v and 1/4 v / v. Changes in the composition and morphology of cement samples have been highlighted by ESCA (Electron Spectroscopy for Chemical Analysis), EDX (Energy-Dispersive X-ray Spectroscopy), IR spectroscopy and SEM images. The obtained data show that minor changes in cement composition can significantly influence morpho-structural characteristics such as pore size and their distribution in the mass of fixing material.

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Aleisa, Khalil, Syed Rashid Habib, Abdul Sadekh Ansari, Ragad Altayyar, Shahad Alharbi, Sultan Ali S. Alanazi, and Khalid Tawfik Alduaiji. "Effect of Luting Cement Film Thickness on the Pull-Out Bond Strength of Endodontic Post Systems." Polymers 13, no. 18 (September 13, 2021): 3082. http://dx.doi.org/10.3390/polym13183082.

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Optimal bond strength between the prefabricated post/dowel to the surrounding dentin is essential. The present study aimed to analyze and compare the effect of three different cement film thicknesses on the pull-out bond strength of three different prefabricated post systems. Extracted natural teeth (N = 90) with similar root dimensions were acquired. Teeth were mounted in resin blocks, endodontically treated, sectioned at cemento-enamel junction, divided into three groups (A: Parapost Fiber Lux plus; B: 3M ESPE Relyx fiber post; and C: Parapost XP), and stored. Uniform post spaces were prepared for the groups (A and C: Length = 8 mm, Width = 1.5 mm; B: Length = 8 mm, Width = 1.6 mm). Each group (N = 30) was further subdivided into three subgroups (n = 10) based on the size (4, 5, and 6) of the post and cemented with resin cement (MultiLink-N, Ivoclar Vivadent). After thermocycling, the specimens were subjected to a pull-out test using a universal testing machine, and tensile force was recorded (MPa). Digital microscopic evaluations were performed for modes of failure. ANOVA and Tukey-HSD tests were used for statistics. Significant differences were observed for each tested material (p = 0.000). The lowest and highest bond strength values were recorded for Group C (Titanium post) and Group A (000), respectively. Multiple comparisons showed significance (p < 0.05) among all the groups, except for space 1 and space 2 (p = 0.316) for Group A. Most of the failures occurred within the cement-dentin and post-cement interface (Adhesive failures, 73.5%). An increase in the luting cement film thickness results in the decrease in pull-out bond strength of prefabricated posts luted with resin cement, irrespective of the type/material/shape of the post. The serrated fiber posts showed the highest pull-out bond strength compared to the smooth surfaced fiber posts or serrated metal posts. Increased pull-out bond strengths were observed when appropriate post space was created with the same sized drill as the post size.

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Hökfors, Bodil, Dan Boström, Erik Viggh, and Rainer Backman. "On the phase chemistry of Portland cement clinker." Advances in Cement Research 27, no. 1 (January 2015): 50–60. http://dx.doi.org/10.1680/adcr.13.00071.

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Bland, C. H., and J. H. Sharp. "The chemistry of Portland cement-gasifier slag interactions." Advances in Cement Research 3, no. 11 (July 1990): 91–98. http://dx.doi.org/10.1680/adcr.1990.3.11.91.

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34

Phair, John W. "Green chemistry for sustainable cement production and use." Green Chemistry 8, no. 9 (2006): 763. http://dx.doi.org/10.1039/b603997a.

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35

Chandra, S. "10th International congress on the chemistry of cement." Cement and Concrete Research 27, no. 10 (October 1997): 1613–17. http://dx.doi.org/10.1016/s0008-8846(97)00198-1.

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36

Costantino, P. D., C. D. Friedman, K. Jones, L. C. Chow, H. J. Pelzer, and G. A. Sisson. "Hydroxyapatite Cement: I. Basic Chemistry and Histologic Properties." Archives of Otolaryngology - Head and Neck Surgery 117, no. 4 (April 1, 1991): 379–84. http://dx.doi.org/10.1001/archotol.1991.01870160033004.

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Devasahayam, Sheila. "Decarbonising the Portland and other Cements—Via Simultaneous Feedstock Recycling and Carbon Conversions Sans External Catalysts." Polymers 13, no. 15 (July 27, 2021): 2462. http://dx.doi.org/10.3390/polym13152462.

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The current overarching global environmental crisis relates to high carbon footprint in cement production, waste plastic accumulation, and growing future energy demands. A simultaneous solution to the above crises was examined in this work. The present study focused on decarbonizing the calcination process of the cement making using waste plastics and biowastes as the reactants or the feedstock, to reduce the carbon footprint and to simultaneously convert it into clean energy, which were never reported before. Other studies reported the use of waste plastics and biowastes as fuel in cement kilns, applicable to the entire cement making process. Calcination of calcium carbonate and magnesium carbonate is the most emission intensive process in cement making in Portland cements and Novacem-like cements. In the Novacem process, which is based on magnesium oxide and magnesium carbonates systems, the carbon dioxide generated is recycled to carbonate magnesium silicates at elevated temperatures and pressures. The present study examined the Novacem-like cement system but in the presence of waste plastics and biomass during the calcination. The carbon dioxide and the methane produced during calcination were converted into syngas or hydrogen in Novacem-like cements. It was established that carbon dioxide and methane emissions were reduced by approximately 99% when plastics and biowastes were added as additives or feedstock during the calcination, which were converted into syngas and/or hydrogen. The reaction intermediates of calcination reactions (calcium carbonate–calcium oxide or magnesium carbonate–magnesium oxide systems) can facilitate the endothermic carbon conversion reactions to syngas or hydrogen acting as non-soot forming catalysts. The conventional catalysts used in carbon conversion reactions are expensive and susceptible to carbon fouling. Two criteria were established in this study: first, to reduce the carbon dioxide/methane emissions during calcination; second, to simultaneously convert the carbon dioxide and methane to hydrogen. Reduction and conversion of carbon dioxide and methane emissions were facilitated by co-gasification of plastics and bio-wastes.

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Oproiu, Carmen-Lidia, Marius-George Parvan, Georgeta Voicu, Alina-Ioana Badanoiu, and Roxana Trusca. "Influence of a Chromium-rich Industrial Waste on the Hydration and Hardening Processes of Portland Cements with Slag and Limestone Additions." Revista de Chimie 71, no. 2 (March 3, 2020): 252–61. http://dx.doi.org/10.37358/rc.20.2.7923.

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This research work assesses the influence of a chromium-rich waste (from potassium dichromate manufacture) on the hydration and hardening processes of two types of Portland cements with limestone filler and slag additions. Therefore, mixtures of Portland cement and chromium-rich waste, corresponding to 0.5% wt. and 1% wt. Cr, were prepared and tested. The analyses performed on cement pastes with chromium waste content, showed that chromium immobilization is mainly due to the formation of Ca6Al2Cr3O18�32H2O (CrEt); this compound results by the substitution of [SO4]2- groups from ettringite lattice of with [CrO4]2-. CrEt crystals growth on the surface of clinker particles forms a diffusion barrier which explains longer setting times for cements with chromium content. The increase of chromium content in the studied systems decreases the compressive strength values but these remain above the lower limits imposed for this type of materials. The chromium content in leachates prepared according to the method described in SR EN 12457-2, was well below the legal limit of 70 mg/Kg established by Romanian legislation. A better chromium immobilisation was achieved in the cement with slag content, in good correlation with the nature and amount of formed hydrates.

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Presa, Leticia, Jorge L. Costafreda, Domingo A. Martín, and Isabel Díaz. "Natural Mordenite from Spain as Pozzolana." Molecules 25, no. 5 (March 9, 2020): 1220. http://dx.doi.org/10.3390/molecules25051220.

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This work deals with anomalous concentrations of natural mordenite in the southeast of Spain. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies evidenced that the samples contain mainly monomineral zeolitic phase of mordenite (70% to 74%), usually accompanied by smectite (montmorillonite), the principal component of bentonite. A study of the applicability of these zeolites is presented to establish the potential use as pozzolanic cements. For comparative purposes, synthetic commercial mordenite is also characterized and tested. The initial mixtures were prepared using cement and mordenite at a 75:25 ratio. Chemical analysis and a pozzolanicity test showed the high pozzolanic character. These mixtures were further added to sand and water, yielding the cement specimens to be used as concrete. Mechanical test results showed that the mechanical compression at 7 and 28 days fall into the range of 19.23 to 43.05 MegaPascals (MPa) for the cement specimens built with natural mordenites. The obtained results fall in the same range of cement specimens prepared with natural clinoptilolite, using mixtures within the European requirement for commercial concretes. Thus, these results and the low cost of natural mordenite of San José de los Escullos deposit supports the potential use of natural mordenite as pozzolanic cement.

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Marina, Biljana, Snezana Brezovska, Donco Burevski, and Biljana Panova. "Porous and adsorption properties of hydrated cement paste." Chemical Industry 58, no. 1 (2004): 6–9. http://dx.doi.org/10.2298/hemind0401006m.

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

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Marina, Biljana, Snezana Brezovska, Donco Burevski, and Biljana Angjuseva. "Monolayer capacity and specific surface area of cement pastes determined from benzene adsorption isotherms." Chemical Industry 59, no. 1-2 (2005): 28–31. http://dx.doi.org/10.2298/hemind0502028m.

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Hydrated cement pastes, prepared from Portland cements with different degrees of dispersity obtained by adding small quantities of triethanol amine and ethylene glycol as a grinding aids were investigated. The adsorption isotherms of benzene vapor on the pastes were interpreted by means of the Brunauer - Emmet - Teller (BET), N - layer Brunauer - Emmet -Teller (N - BET) and Huttig equations. The monolayer capacity and specific surface areas of the pastes after 28 days of hydration were determined. By comparison of the results obtained using different equations, the most suitable equation could be selected and used to determine the monolayer capacity and specific surface area. The influence of the dispersity of the cement on the specific surface area of the cement gel in the pastes could also be analyzed from the obtained results. The investigations were in accordance with the results of the physical mechanical properties of cement plasters.

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42

Moncif, N., E. L. H. Gourri, A. B. A. Elouahli, M. Ezzahmouly, K. Nayme, M. Timinouni, and Z. Hatim. "Characterization of Bio-composite Apatite/Chitosan Cement and its Antibacterial Activity." Oriental Journal of Chemistry 34, no. 4 (August 27, 2018): 1765–73. http://dx.doi.org/10.13005/ojc/340408.

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In this work, we report the physico-chemical properties and antibacterial activity of apatite/chitosan composite cements. The biocomposite was prepared by reaction between dihydrated dicalcium phosphate and calcium hydroxide in the presence of chitosan. The characterization of cement was carried out by Infrared Spectroscopy, X-ray diffraction, Transmission Electron Microscopy and X-ray Scanner with computational image processing. The results show that the setting of the paste is due to the formation of a hydrated tri-calcium phosphate that evolves into a hard calcium-apatite. In the presence of chitosan, the fastness of setting time is attributed to the precipitation of chitosan that strengthens the cohesion between grains. The formed complex evolves into hard Apatite-chitosan composite. In an induced bone defect, the hard composite shows radiopaque homogenous microstructure and intimate contact bone/implant. The antibacterial tests of hard cements show a significant reduction in Staphylococci bacterial growth on the surface of composite grains. This reduction is highly dependent on the type of bacteria, and the percentage of the added antibacterial agent. Bio-composite cement shows total inhibition of Staphylococci aureus and low resistance to Staphylococci epidermidis. The apatite/chitosan composite prepared by the way of cements can have interesting applications as bone substitute material.

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43

Prodjosantoso, Antikolonial, Wahyu Widiyati, Wafin Wafin, Ani Widyawati, and Maximus Pranjoto Utomo. "Cement Chemisrty: Hydration of Ca2-Xsrxsio4 Compound." Oriental Journal Of Chemistry 37, no. 3 (June 30, 2021): 589–93. http://dx.doi.org/10.13005/ojc/370310.

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Dicalcium silicate (Ca2SiO4) isan importantcomponent of cement. The compound ofCa2-xSrxSiO4 can be formed if the Sr containing precursorsare used to synthesize the cement. The presence of Sr may alter the hydrationof the product. The hydration chemistry ofCa2-xSrxSiO4 compounds is reported. The hydration of Ca2-xSrxSiO4was conducted uder nitrogen atmosphere for about 6 months. The dry samples were characterized usingXRD, FTIR, TGA-DSC, andSEM-EDXmethods. It is confirmed that the hydration ofCa2-xSrxSiO4produces mainlyCa3Si2O7.3H2O and Ca(OH)2. However, the Sr doped Ca3Si2O7.3H2O andCa(OH)2 are possibly formed.The compound of CaCO3,as the result ofinteractions between Ca(OH)2 and atmospheric CO2gas during the sample handling,is also observed.

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Radosavljevic, Radivoje, Sasa Stankovic, Zorica Ajdukovic, Danimir Jevremovic, and Jelena Todic. "Scanning electron microscopy analysis of dental cements." Chemical Industry 63, no. 4 (2009): 281–88. http://dx.doi.org/10.2298/hemind0904281r.

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The aim of this study was to compare in vitro the characteristics of different types of luting cements (zinc phosphate, glass-ionomer and resin based composite cement) using scanning electron microscopy (SEM) analysis and microleakage for the quality range of materials. Dental cements were mixed in accordance with the manufacturer's instructions and formed with posts in dental root canals of extracted teeth. The quality of cement was determined by SEM observation on horizontal sectioned roots with fixed posts according to specific pore and marginal gap diameter. The microleakage was measured on specimens immersed in Lofler (methylene blue) solution. The mean values of the maximal diameter of pores, marginal gaps and microleakage of conventional cements are remarkably larger in comparison with composite luting agents. In conclusion, the quality and efficiency of composite luting agents in comparison with conventional cements are more successful in protecting the interior of tooth from penetration of oral fluids, bacteria and bacterial toxins into unprotected dentine.

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Yamazaki, Yuto, Jihoon Kim, Keisuke Kadoya, and Yukio Hama. "Physical and Chemical Relationships in Accelerated Carbonation Conditions of Alkali-Activated Cement Based on Type of Binder and Alkali Activator." Polymers 13, no. 4 (February 23, 2021): 671. http://dx.doi.org/10.3390/polym13040671.

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Alkali-activated cements prepared from aluminosilicate powders, such as blast furnace slag and fly ash, are rapidly attracting attention as alternatives to cement because they can significantly reduce CO2 emissions compared to conventional cement concrete. In this study, we investigated the relationship between the physical and chemical changes by accelerated carbonation conditions of alkali-activated cements. Alkali-activated cements were prepared from binders composed of blast furnace slag and fly ash as well as alkali activators sodium silicate and sodium hydroxide. Physical changes were analyzed from compressive strength, pH, and neutralization depth, and chemical changes were analyzed from XRD, TG-DTG, and 29Si MAS NMR. The C–(N)–A–S–H structure is noted to change via carbonation, and the compressive strength is observed to decrease. However, in the case of Na-rich specimens, the compressive strength does not decrease by accelerated carbonation. This work is expected to contribute to the field of alkali-activated cements in the future.

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Yakerson, Vladimir I., and E. Z. Golosman. "Cement-containing catalysts." Russian Chemical Reviews 59, no. 5 (May 31, 1990): 450–68. http://dx.doi.org/10.1070/rc1990v059n05abeh003536.

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Ohama, Yoshihiko. "Carbon-cement composites." Carbon 27, no. 5 (1989): 729–37. http://dx.doi.org/10.1016/0008-6223(89)90206-6.

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48

Pilo, Raphael, Sharon Agar-Zoizner, Shaul Gelbard, and Shifra Levartovsky. "The Retentive Strength of Laser-Sintered Cobalt-Chromium-Based Crowns after Pretreatment with a Desensitizing Paste Containing 8% Arginine and Calcium Carbonate." International Journal of Molecular Sciences 19, no. 12 (December 17, 2018): 4082. http://dx.doi.org/10.3390/ijms19124082.

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The retention of laser-sintered cobalt-chromium (Co-Cr)-based crowns were examined after dentin pretreatment with desensitizing paste containing 8% arginine and calcium carbonate (DP-ACC). Forty lower first molars were prepared using a standardized protocol. The Co-Cr crowns were produced using selective laser melting. The teeth were either pretreated with the desensitizing paste or not pretreated. After one week, each group was cemented with glass ionomer cement (GIC) or zinc phosphate cement (ZPC). Surface areas of the teeth were measured before cementation. After aging, a universal testing machine was used to test the retentive strength of the cemented crown-tooth assemblies. The debonded surfaces of the teeth and crowns were examined at 2.7× magnification. Pretreating the dentin surfaces with the desensitizing paste before cementation with GIC or ZPC did not affect the retention of the Co-Cr crowns. The retention of the GIC group (6.04 ± 1.10 MPa) was significantly higher than that of the ZPC group (2.75 ± 1.25 MPa). The predominant failure mode for the ZPC and the nontreated GIC group was adhesive cement-dentin failure; for the treated GIC group, it was adhesive cement-crown failure. The desensitizing paste can be safely used to reduce post-cementation sensitivity without reducing the retentive strength of Co-Cr crowns cemented with GIC or ZPC.

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Xie, Ping, Ping Gu, and J. J. Beaudoin. "Application of electrical conductivity methods in interfacial cement chemistry." Advances in Cement Research 5, no. 17 (January 1993): 41–45. http://dx.doi.org/10.1680/adcr.1993.5.17.41.

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Worthington, J. C., D. G. Bonner, and D. V. Nowell. "Influence of cement chemistry on chloride attack of concrete." Materials Science and Technology 4, no. 4 (April 1988): 305–13. http://dx.doi.org/10.1179/mst.1988.4.4.305.

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Journal articles on the topic 'Cement chemistry'

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