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Journal articles on the topic 'Alkalis'

Author: Grafiati

Published: 4 June 2021

Last updated: 25 July 2025

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1

Doroshenko, O. "Use of modified basalt fiber in transport construction." Collection of scientific works of the State University of Infrastructure and Technologies series "Transport Systems and Technologies", no. 42 (December 12, 2023): 58–68. http://dx.doi.org/10.32703/2617-9059-2023-42-5.

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Basalt fiber is a promising material that can be used to create a new class of building materials. It has a number of advantages, including high strength, low weight and resistance to chemicals. One of the disadvantages of basalt fiber is its low alkali resistance. In an alkaline environment, the fiber is destroyed, which limits its use in building materials exposed to alkalis. The paper investigates the effect of heat treatment on the alkali resistance of basalt fiber. It was found that heat treatment at a temperature of 500 0C increases the alkali resistance of the fiber by 80%. This is due

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2

Liu, Kai Qiang, Hui Tang, Yan Nian Rui, and Guo Qiang Chen. "Alkali Resistance of the Silk/PLA Mixture." Advanced Materials Research 441 (January 2012): 687–90. http://dx.doi.org/10.4028/www.scientific.net/amr.441.687.

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As a new textile material, silk/PLA mixture combines the outstanding characteristics of silk and PLA fibers, but this mixture is subjected to some problems owing to the poor alkali resistance of PLA fiber during the pretreatment and reactive dyeing processes. In the present work, the alkali resistance of silk/PLA mixture was tested with three alkalis, namely sodium hydroxide, sodium carbonate and sodium bicarbonate. It was found that silk component was less influenced by sodium carbonate and sodium bicarbonate, whereas PLA component was more or less influenced by three alkalis. Silk/PLA mixtur

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3

Jang, Ju-Woong, Byung Soo Kim, Hak Kwan Kim, and Deuk Yong Lee. "Correlation between Thermal Expansion Coefficients of La₂O₃-Al₂O₃-SiO₂ Glasses and Strength of the Glass Infiltrated Alumina for all Ceramic Crown." Materials Science Forum 449-452 (March 2004): 1193–96. http://dx.doi.org/10.4028/www.scientific.net/msf.449-452.1193.

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16 different lanthanum-aluminosilicate glasses were prepared to evaluate the effect of alkalis (Na2O, K2O) and alkaline earths (MgO, CaO) on thermal expansion coefficients (CTEs) of the glasses. Analysis was performed with an aid of the Taguchi method and orthogonal arrays to elucidate four factor interactions between 4 two-level factors using two level L16(215) orthogonal arrays. The observed CTEs were in the range of 6.29×10-6 C-1 to 8.22×10-6 C-1. The addition of alkalis was more influential to CTE of the glass than that of alkaline earth, however, co-addition of the mixed alkalis was detri

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4

Bavasso, Irene, Umberto Costa, Teresa Mangialardi, and Antonio Evangelista Paolini. "Assessment of Alkali–Silica Reactivity of Aggregates by Concrete Expansion Tests in Alkaline Solutions at 38 °C." Materials 13, no. 2 (2020): 288. http://dx.doi.org/10.3390/ma13020288.

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A new accelerated concrete prism expansion test at 38 °C (accelerated CPT) is proposed for assessing the alkali-reactivity of concrete aggregates. In this test, concrete prisms with a standardized mix composition and different alkali contents are immersed in alkaline solutions with compositions simulating the pore liquid of hardened concretes. The concrete prism expansion test at 38 °C and RH > 95% (traditional CPT) was taken as a reference test, in order to define the appropriate expansion limit criterion for the proposed accelerated CPT. Three natural aggregates of known field performance

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5

Procházka, Lukáš, and Jana Boháčová. "The Role of Alkalis in Hydraulic Mixtures." Materials Science Forum 955 (May 2019): 62–67. http://dx.doi.org/10.4028/www.scientific.net/msf.955.62.

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Alkali substances are present in cements used as a binder in concrete only in a minimum content. The most known process that alkali causes is the alkali-silica reaction. In this reaction, the alkali contained in the cement or supplied from the outside with an inappropriately selected aggregate containing amorphous SiO2. This reaction results in the development of hydration products, resulting in an increase in the volume of the original components, which can cause a breakage of the concrete structure and subsequent disintegration. The range of alkali-silica reaction can be reduced by the use o

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6

Breitenbücher, Rolf, and Robin Przondziono. "Sustainability of concrete pavements considering traffic and de-icing agents." Acta Polytechnica CTU Proceedings 33 (March 3, 2022): 45–51. http://dx.doi.org/10.14311/app.2022.33.0045.

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In concrete pavements, special conditions, that increase the likeliness of damaging reactions, as for example an alkali-silica reaction (ASR), prevail. Especially to the superposition of microstructural degradation caused by cyclic loading with an external alkali supply can influence the sustainability negatively. Concrete pavements are subjected to cyclic loadings by traffic and climate changes. These cause microcracks (about 5 μm) within the concrete matrix during service. Additionally, an ASR in pavements is promoted by externally supplied alkalis (de-icing agents). By superposition of both

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Menéndez, E., R. García-Rovés, and B. Aldea. "Incidence of Alkali Release in Concrete Dams. Evaluation of Alkalis Releasable by Feldspars." MATEC Web of Conferences 199 (2018): 03006. http://dx.doi.org/10.1051/matecconf/201819903006.

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Alkali release from aggregates can constitute a source of alkalis in concrete exposed to wet environments for long periods of time. Feldspars are one of the minerals that can release alkalis to the concrete with time. The formation of reaction products in the interface with the paste due to the alkali release from sodium and potassium feldspars has been observed in a concrete with granite aggregates. This has been observed after more than 25 years of exposure. It is necessary to evaluate the amount of alkalis releasable to define the formulation of concrete before manufacturing. Different test

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8

Jiang, Xiao Jun, Yan Yun, and Zhi Hua Hu. "Development of Non-Autoclaved Aerated Concrete by Alkali Activated Phosphorus Slag." Advanced Materials Research 250-253 (May 2011): 1147–52. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.1147.

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The feasibility of manufacturing non-autoclaved aerated concrete using alkali activated phosphorus slag as a cementitious material was investigated in this paper. Liquid sodium silicate with various modules (the molar ratio between SiO2 and Na2O) was used as alkali activator and a part of phosphorus slag was replaced with fly ash which was used to control the setting time of aerated concrete. The influences of the fly ash, curing procedure, modulus of sodium silicate solution and concentration of alkalis on the compressive strength and bulk density of non-autoclaved aerated concrete have been

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9

Seo, Dong-Cheon, Ruifeng Guo, and Dong-Hoon Lee. "Performance of alkaline impregnated biochar derived from rice hull for hydrogen sulfide removal from gas." Environmental Engineering Research 26, no. 6 (2020): 200452–0. http://dx.doi.org/10.4491/eer.2020.452.

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Hydrogen sulfide (H2S) causes malodor, health disorders, and equipment corrosion, but is a constituent of a wide range of valuable gases. For efficient H2S removal, biochars derived from rice hull and loaded with four alkalis (NaOH, KOH, Na2CO3, and K2CO3) were prepared by impregnation. The H2S removal characteristics were investigated by continuous adsorption column tests. The alkaline impregnated biochars (IBCs) showed superior H2S removal performance compared to that of coconut shell activated carbon (AC) due to the enhanced chemical adsorption. The removal capacity varied depending on the

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10

Gillott, J. E., and C. A. Rogers. "Alkali – aggregate reaction and internal release of alkalis." Magazine of Concrete Research 46, no. 167 (1994): 99–112. http://dx.doi.org/10.1680/macr.1994.46.167.99.

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11

Ryabkova, E. A., L. A. Sokura, A. Yu Ivanov, I. M. Sosnin, A. V. Kremleva та М. V. Dorogov. "Effect of Solution Composition on the Morphology of Synthesized β-Ga2O3 Particles". Reviews on Advanced Materials and Technologies 5, № 1 (2023): 22–25. http://dx.doi.org/10.17586/2687-0568-2023-5-1-22-25.

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Micro- and nanoparticles of β-Ga2O3 are synthesized as a result of chemical reaction of an aqueous solution of gallium nitrate and various alkalis: ammonia, sodium, potassium, and lithium hydroxides. It is shown that particles morphology depends on the type and concentration of alkali. The use of microwave treatment of ammonia containing solutions made it possible to change the shape of particles from ellipsoidal to parallelepiped while maintaining their size. In contrast to the synthesis with ammonia, for other alkalis dispersed particles were obtained only at a ratio of alkali to gallium nit

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12

Osabohien, Emmanuel, Paul N. Diagboya, and Alexander A. Odagwe. "Comparative Characterization of Soaps Prepared from Plant-sourced Alkali Solutions and Caustic Soda." Unidel Journal of Science, Technology and Innovations 1, no. 1 (2024): 1–6. https://doi.org/10.5281/zenodo.15316527.

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<strong>Abstract</strong> One of the basic ingredients of modern soap making is synthetic alkali such as caustic soda or lye (NaOH). The utilization of plant-based alkalis to make soap has been compared to the use of synthetic caustic alkalis (sodium hydroxide). Synthetic alkalis cause significant adverse effects on the environment which may be drastically reduced by using plant-based alkalis. Nigeria is an agrarian economy ranked among the first five largest producers of both plantain (<em>Musa paradisiaca</em>) and oil palm (<em>Elaeis guineensis</em>) in the world, thus generating large amo

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13

Amalate Ann Obuebite, Obumneme Onyeka Okwonna, and Jeffrey Randy Gbonhinbor. "Design of salinity tolerant in alkaline surfactant systems for high salinity reservoirs." GSC Advanced Research and Reviews 14, no. 3 (2023): 193–208. http://dx.doi.org/10.30574/gscarr.2023.14.3.0076.

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Chemical oil recovery from offshore reservoirs which are usually characterised by harsh conditions such as high salinities have remained a source of concern. This study assesses chemical compatibilities of alkalis –surfactant systems under high salinity and divalent ions (Ca2+ and Mg2+). It analysed the synergy between alkali-surfactant slugs and crude oil, leading to the design of an optimal low-cost alkaline- surfactant flooding. Three alkali systems: sodium hydroxide, sodium metaborate and ethylene-diamine-tetracetic acid-(EDTA/NaOH) were evaluated with two high salinity synthetic brines; o

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14

Sanjuán, Miguel, Esteban Estévez, and Cristina Argiz. "Alkali Ion Concentration Estimations in Cement Paste Pore Solutions." Applied Sciences 9, no. 5 (2019): 992. http://dx.doi.org/10.3390/app9050992.

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The alkalinity of the pore solution is of great interest for evaluating the rising of the alkali–silica reaction (ASR) when reactive amorphous silica is found in some aggregates in some cement-based composites. This reaction is not desirable because it generates swelling gel materials around the aggregates, which produce an expansive pressure inside concrete over time, and can cause the cracking of concrete, leading to serious structural problems. The purpose of this study is to develop a quick, easy and reliable method to estimate the available alkali concentrations in the pore solution of ce

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15

Manninger, Tanja, Daniel Jansen, Jürgen Neubauer, and Friedlinde Goetz-Neunhoeffer. "Phase Solubility Changes during Hydration of Monocalciumaluminate and Calcite—The Influence of Alkali Accumulation." Materials 13, no. 6 (2020): 1406. http://dx.doi.org/10.3390/ma13061406.

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The reaction of CA (monocalcium aluminate) with calcite was closely monitored with regard to phase development, pore water ion content and heat flow. Calcite acts as filler and reactant, finally leading to thermodynamically stable products after hydration at ambient conditions. For better understanding the mechanism taking place, a CA-cement and a commercial calcite mix were compared to a pure CA and pure calcite mix. Both reaction paths were compared. Thermodynamic modeling with PhreeqC gave insight about factors that can influence the course of the hydration reaction. Alkali ions in pore sol

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16

Amalate, Ann Obuebite, Onyeka Okwonna Obumneme, and Randy Gbonhinbor Jeffrey. "Design of salinity tolerant in alkaline surfactant systems for high salinity reservoirs." GSC Advanced Research and Reviews 14, no. 3 (2023): 193–208. https://doi.org/10.5281/zenodo.7928788.

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Chemical oil recovery from offshore reservoirs which are usually characterised by harsh conditions such as high salinities have remained a source of concern. This study assesses chemical compatibilities of alkalis –surfactant systems under high salinity and divalent ions (Ca<sup>2+</sup> and Mg<sup>2+</sup>). It analysed the synergy between alkali-surfactant slugs and crude oil, leading to the design of an optimal low-cost alkaline- surfactant flooding. Three alkali systems: sodium hydroxide, sodium metaborate and ethylene-diamine-tetracetic acid-(EDTA/NaOH) were evaluated with two

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17

Anenburg, Michael, John A. Mavrogenes, Corinne Frigo, and Frances Wall. "Rare earth element mobility in and around carbonatites controlled by sodium, potassium, and silica." Science Advances 6, no. 41 (2020): eabb6570. http://dx.doi.org/10.1126/sciadv.abb6570.

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Carbonatites and associated rocks are the main source of rare earth elements (REEs), metals essential to modern technologies. REE mineralization occurs in hydrothermal assemblages within or near carbonatites, suggesting aqueous transport of REE. We conducted experiments from 1200°C and 1.5 GPa to 200°C and 0.2 GPa using light (La) and heavy (Dy) REE, crystallizing fluorapatite intergrown with calcite through dolomite to ankerite. All experiments contained solutions with anions previously thought to mobilize REE (chloride, fluoride, and carbonate), but REEs were extensively soluble only when al

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18

Bettencourt Ribeiro, António, João Custódio, and Sofia Real. "Influence of alkali on the drying shrinkage of cement pastes." MATEC Web of Conferences 409 (2025): 08001. https://doi.org/10.1051/matecconf/202540908001.

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Concrete shrinkage remains a relevant topic of study due to the increased use of high- performance concrete. Understanding shrinkage mechanisms is essential for developing non-shrinking concrete and reducing cracking problems. During concrete curing, substantial quantities of alkalis dissolve in the pore solution, and their influence on shrinkage is not fully understood. This paper gives further insight into the role of the alkalis, by monitoring the length changes and mass variations of hardened cement pastes with pore structures saturated with solutions containing potassium hydroxide (KOH) i

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19

Kalina, Lukáš, Vlastimil Bílek, Lada Bradová, and Libor Topolář. "Blastfurnace Hybrid Cement with Waste Water Glass Activator: Alkali–Silica Reaction Study." Materials 13, no. 16 (2020): 3646. http://dx.doi.org/10.3390/ma13163646.

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Hybrid systems represent a new sustainable type of cement combining the properties of ordinary Portland cement and alkali-activated materials. In this study, a hybrid system based on blast furnace slag and Portland clinker was investigated. The economic aspects and appropriate waste management resulted in the usage of technological waste from water glass production (WG-waste) as an alkaline activator. Although the Portland clinker content was very low, the incorporation of this by-product significantly improved the mechanical properties. Nevertheless, the high amount of alkalis in combination

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20

Fang, Hong, and Puru Jena. "Super-ion inspired colorful hybrid perovskite solar cells." Journal of Materials Chemistry A 4, no. 13 (2016): 4728–37. http://dx.doi.org/10.1039/c5ta09646d.

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Hybrid perovskites viewed as super alkali halides with alkali and halogen ions replaced by super alkalis and super halogens, respectively. The basic properties of these materials are determined by the bonding ionicity and effective ionic radii of the super-ions. New colorful hybrid perovskites can be invented with super-ions as the building block.

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21

Greenwood, John E., Jin Lin Tan, Justin Choong Tzen Ming, and Andrew D. Abell. "Alkalis and Skin." Journal of Burn Care & Research 37, no. 2 (2016): 135–41. http://dx.doi.org/10.1097/bcr.0000000000000222.

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22

Kim, Taewan, Sungnam Hong, and Choonghyun Kang. "The Effects of Aluminium Sulphate on Slag Paste Activated with Sodium Hydroxide and Sodium Silicate." Materials 13, no. 10 (2020): 2286. http://dx.doi.org/10.3390/ma13102286.

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This study investigates the characteristics of alkali-activated slag cement using aluminium sulphate (ALS) as an activator. The alkalis NaOH and Na2SiO3 were used as additional activators (denoted by alkali) at 5% and 10% of the weight of the ground granulated blast furnace slag (GGBFS). Three types of activators were considered. The first was when ALS was used alone. For the second, ALS and 5% alkali were used together. The third was when ALS and 10% alkali were used. ALS was used at concentrations of 2%, 4%, 6%, 8%, and 10% based on binder weight. Experimental results show that when ALS was

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23

Bumanis, G., and D. Bajare. "Porous alkali activated materials with slow alkali release dynamic. Role of composition." Materiales de Construcción 68, no. 329 (2018): 145. http://dx.doi.org/10.3989/mc.2018.14016.

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Alkali activated materials (AAM) based on calcined metakaolin or illite clay together with waste by-products, such as waste glass or aluminium scrap recycling waste, were tested as value-added materials for pH stabilization in biogas technology where decrease of pH should be avoided. Porous materials with ability to slowly leach alkalis in the water media thus providing continuous control of the pH level were obtained. XRD, FTIR, SEM and titration methods were used to characterize AAM and their leaching properties. It is clear that composition of the material has an important effect on the dif

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Anenburg, Michael, Sam Broom-Fendley, and Wei Chen. "Formation of Rare Earth Deposits in Carbonatites." Elements 17, no. 5 (2021): 327–32. http://dx.doi.org/10.2138/gselements.17.5.327.

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Carbonatites and related rocks are the premier source for light rare earth element (LREE) deposits. Here, we outline an ore formation model for LREE-mineralised carbonatites, reconciling field and petrological observations with recent experimental and isotopic advances. The LREEs can strongly partition to carbonatite melts, which are either directly mantle-derived or immiscible from silicate melts. As carbonatite melts evolve, alkalis and LREEs concentrate in the residual melt due to their incompatibility in early crystal-lising minerals. In most carbonatites, additional fractionation of calci

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Liu, Kai Qiang, Yan Lian Rui, and Guo Qiang Chen. "Dyeing of Silk/PLA Mixture with Reactive Dyes." Advanced Materials Research 239-242 (May 2011): 1739–42. http://dx.doi.org/10.4028/www.scientific.net/amr.239-242.1739.

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Silk/PLA mixture is a new textile material, and it combines the outstanding characteristics of silk and PLA fibers. During the wet process, this mixture is subjected to some problems owing to the poor resistance of PLA fiber to alkali. The silk component in this mixture can be dyed with acid dyes under acidic condition, and with reactive dyes under alkaline condition. In the present work, silk/PLA mixture was dyed with Everzol ED reactive dyes in the case of the use of sodium carbonate and sodium bicarbonate as alkalis for the fixation of dyes. The alkali dosage and dyeing temperature on the u

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26

Li, Ke Liang, Guo Hong Huang, Lin Hua Jiang, Yue Bo Cai, Jian Chen, and Jian Tong Ding. "Study on Abilities of Mineral Admixtures and Geopolymer to Restrain ASR." Key Engineering Materials 302-303 (January 2006): 248–54. http://dx.doi.org/10.4028/www.scientific.net/kem.302-303.248.

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This paper deals with the effect of mineral admixtures and Geopolymer on preventing excessive expansion due to alkali-silica reaction (ASR). The test method used was ASTM C 441-97. Expansions of mortar-bars were measured at 14, 56, 90 days. The results prove that mineral admixtures can effectively restrain ASR. When three kinds of mineral admixtures, silica fume, fly ash, and ground granulated blast-furnace slag (GGBS), were used together, they bring about a compound effect which is more effective to restrain ASR. Mortar expansion can be reduced 81.9 % by this compound effect. Chemical analysi

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27

Michael Ioelovich. "Thermochemistry of alkalization and etherification of cellulose." World Journal of Advanced Research and Reviews 20, no. 3 (2023): 1166–74. http://dx.doi.org/10.30574/wjarr.2023.20.3.2566.

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In this research, the process of alkalization of cotton cellulose with solutions of sodium hydroxide of different concentrations has been studied. It was found that the enthalpy of cellulose alkalization is exothermic. Moreover, the exothermic enthalpy value of cellulose alkalization with 30-40% NaOH solutions is higher than with 16-20% alkalis. Thus, the cellulose treatment with 30-40% alkalis provides the formation of more reactive alkali cellulose. In addition, the determination of the formation enthalpy of alkali celluloses showed that this thermochemical characteristic is also exothermic,

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Michael, Ioelovich. "Thermochemistry of alkalization and etherification of cellulose." World Journal of Advanced Research and Reviews 20, no. 3 (2023): 1166–74. https://doi.org/10.5281/zenodo.12755243.

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In this research, the process of alkalization of cotton cellulose with solutions of sodium hydroxide of different concentrations has been studied. It was found that the enthalpy of cellulose alkalization is exothermic. Moreover, the exothermic enthalpy value of cellulose alkalization with 30-40% NaOH solutions is higher than with 16-20% alkalis. Thus, the cellulose treatment with 30-40% alkalis provides the formation of more reactive alkali cellulose. In addition, the determination of the formation enthalpy of alkali celluloses showed that this thermochemical characteristic is also exothermic,

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29

Kaushik, Sakshi, and Ajay Kumar Gupta. "A CRITICAL REVIEW ON KSHARA- DOSHA." October 2023 11, no. 10 (2023): 2504–7. http://dx.doi.org/10.46607/iamj1811102023.

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In the context of Shalya Tantra, Acharya Sushruta, popularly known as ‘The Father of Indian Surgery’ has devised a number of surgical instruments and appliances for the ailments requiring some sort of minor or major surgeries. More importantly, in the cases that require Chhedana (incising), Bhedana (excising) and Lekhana (scraping), the concept of Kshara (alkalis or alkaline preparations) given by Acharya Sushruta is of great importance than surgical instruments and appliances (both principal and secondary or substitutive); as they possess of the virtue of subduing the three deranged bodily hu

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Nusbaum, Robert L., and S. Kerry Gant. "Alkali Metasomatism and Fossil Geothermal Activity: Wah Wah Springs Tuff, Utah." Mountain Geologist 24, no. 1 (1987): 26–29. http://dx.doi.org/10.31582/rmag.mg.24.1.26.

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Variable degrees of widespread alkali metasomatism have been detected within Wah Wah Springs Tuff samples collected in southwestern Utah. Highly altered samples show (1) strong periodic enrichment trends for alkali metals (except Na) at the expense of alkaline earth elements (except Ba), and (2) complete to partial replacement of andesine phenocrysts by K-feldspar: Mildly altered samples show (1) similar but less extreme enrichments and depletions compared to highly altered samples, and (2) no megascopic evidence of alteration. Cs is the most sensitive of the elements enriched by the alteratio

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Kovalchuk, O., and V. Zozulunets. "Use of active aggregates in concrete as a guarantee of expansion of raw material base and reduction of cost of products." Ways to Improve Construction Efficiency 1, no. 48 (2021): 100–107. http://dx.doi.org/10.32347/2707-501x.2021.48(1).100-107.

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Traditional natural materials (mainly granite and quartz) are usually used as aggregates for the manufacture of concrete products and structures. This raw material is tested, reliable and does not cause destruction during operation of structures. However, it is exhaustive and characterized by high cost. That is why it is advisable to consider the use of reactive (active) aggregates. Especially if you consider ways to eliminate alkaline corrosion. The development of alkaline concrete compositions with the use of active aggregates is the key to expanding the raw material base for the manufacture

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Ergashov, A.A., and A.A. Abrolov. "Adsorbents used in industry and problems in their use." Research and implementation 2, no. 7 (2024): 26–31. https://doi.org/10.5281/zenodo.11379099.

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Catharinoids are resistant to alkalis and therefore are not released during alkaline cleaning. If the concentration of the alkaline solution is high, during neutralization the carotenoids are absorbed by the soap stock and the oil is partially bleached (lightened). Carotenoids are actively sorbed on the surface of a solid sorbent.

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Nahara, Annisa Ridha, Erlinda Ningsih, Raden Darmawan, and Sri Rachmania Juliastuti. "Optimization of Sidoarjo Mud Akaline Fusion Process Using Taguchi Method." Diffusion Foundations and Materials Applications 37 (December 24, 2024): 61–68. https://doi.org/10.4028/p-phldd4.

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Sidoarjo mud contains 48.3% silica which is considered as the biggest impurity when compared to the content of rare earth metals which are 0.3% Eu and 0.02% Yb. The hydrothermal process is used to bind silica as a form of silica extraction activity in the Sidoarjo mud so that the Rare Earth Elements are purified further because their uses are urgently needed. This process compares the alkalis in the form of Na2CO3 and K2CO3 which are basic salts which will then be compared to the most optimum conditions of the two alkalis. Each alkali will be processed under operating conditions following the

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34

Sharygin, V. V., and L. N. Pospelova. "MELT EVOLUTION DURING CRYSTALLIZATION OF FERGUSITE PORPHYRIES (Eastern Pamir)." Russian Geology and Geophysics 35, no. 1 (1994): 93–99. https://doi.org/10.2113/rgg.1994.35.1.93.

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Leucite fergusite porphyries from diatremes are produced during crystallization of initial parent undifferentiated magma generated under the upper mantle conditions. Study of melt inclusions in phenocrysts (leucite, apatite, clinopyroxene) has shown that phenocrysts were formed at 1300-1100 °C. Inclusion glasses in the earliest mineral (leucite) approximately correspond to bulk rock composition and are rich in BaO and TiO2. Melt evolution during the crystallization was directed toward its enrichment by SiO2, Al2O3, alkalis and depletion in femic components. Being differentiates of the parent m

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Wigum, Børge Johannes, and Jan Lindgård. "Three decades of international RILEM activities to combat deleterious Alkali-Silica Reactions (ASR) in concrete." MATEC Web of Conferences 199 (2018): 03001. http://dx.doi.org/10.1051/matecconf/201819903001.

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Since 1988, the International Union of Laboratories and Experts in Construction Materials, Systems and Structures (RILEM) Technical Committees (TCs) have been seeking to establish universally applicable test methods for assessing the alkali-reactivity potential of aggregates, and from later on, for concrete mixes. TC 106 (1988 – 2001) focused on accelerated aggregate tests. The successor committee TC 191-ARP (2001 – 2006) also included work on diagnosis/appraisal & specification. TC 219-ACS (2006 – 2014) introduced work on performance testing & modelling. The major recommendations were

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Neidich, Gary. "Ingestion of Caustic Alkali Farm Products." Journal of Pediatric Gastroenterology and Nutrition 16, no. 1 (1993): 75–77. http://dx.doi.org/10.1002/j.1536-4801.1993.tb10805.x.

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SummarySince the Poison Prevention Packaging Act took effect, the number of ingestions of caustic alkali from household products has been significantly reduced. Commercial caustic alkalis used on farms, however, were not included in this legislation. Fourteen children over a 5 year period were seen after ingestion of commercial caustic alkalis used on farms. Seven of the children had ingested liquid pipeline cleaners and seven had ingested solid agents used for a variety of reasons. Six of seven children ingesting liquid agents did so from nonoriginal containers into which the caustic had been

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Savoye, Liliane, Michel Petit-Conil, and Valérie Meyer. "Alternative alkalis for peroxide bleaching of chemithermomechanical pulp." Nordic Pulp & Paper Research Journal 27, no. 1 (2012): 42–49. http://dx.doi.org/10.3183/npprj-2012-27-01-p042-049.

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Abstract A total substitution of sodium hydroxide by weak alkali sources, namely Mg(OH)2, MgCO3 and Ca(OH)2, was studied in a two-stage peroxide bleaching of a maple chemithermomechanical pulp. For the same brightness, the optimised bleaching conditions for Mg(OH)2, MgCO3- and Ca(OH)2- based P1-P2 processes enabled to decrease the COD to more than 25%. Moreover, the biodegradability of bleaching effluents was enhanced, as reflected by the reduction of 1/3 of the recalcitrant COD remaining after the secondary wastewater treatment with activated sludge. Additionally, alternative alkali-based ble

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Vora, Aditya M. "Lattice Dynamics of Alkalis." Journal of Advanced Physics 5, no. 1 (2016): 29–35. http://dx.doi.org/10.1166/jap.2016.1222.

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Talabér, József. "Alkalis and the cement." Epitoanyag - Journal of Silicate Based and Composite Materials 54, no. 4 (2002): 112–15. http://dx.doi.org/10.14382/epitoanyag-jsbcm.2002.19.

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Rozental, N. K., G. V. Chekhnii, and A. N. Rozental. "Alkali-reactive aggregates: corrosion and protection of concrete." Bulletin of Science and Research Center of Construction 43, no. 4 (2024): 141–55. https://doi.org/10.37538/2224-9494-2024-4(43)-141-155.

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Introduction. One type of concrete corrosion is caused by the chemical interaction of amorphous silica in aggregates with alkalis in the cement paste. This process develops slowly, and damage to the concrete is often detected only several years after construction is completed. Initially, damage caused by alkali-silica reaction was observed in large structures such as dams, bridges, and road pavements. Repairing and protecting damaged concrete structures is considered a complex process. The present paper addresses issues related to the prevention and protection of structures affected by this ty

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Yahya, Devi Puspita Amartha. "PENGARUH APLIKASI PUPUK HAYATI DAN PUPUK PELENGKAP ALKALIS DALAM MENINGKATKAN PRODUKSI CABAI MERAH KERITING (Capsicum annuum L.)." Inovasi Pembangunan : Jurnal Kelitbangan 10, no. 01 (2022): 1–14. http://dx.doi.org/10.35450/jip.v10i01.270.

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Penelitian bertujuan untuk mengetahui pengaruh aplikasi pupuk hayati dan pupuk pelengkap terhadap pertumbuhan dan produksi tanaman cabai merah keriting (Capsicum annuum L.). Penelitian menggunakan Rancangan Acak Kelompok (RAK), terdiri atas dua faktor dan tiga pengulangan. Faktor pertama adalah aplikasi pupuk hayati yang terdiri atas 3 taraf, yaitu H0 = tanpa aplikasi pupuk hayati; H1 = dosis 4 ml/tanaman; H2 = dosis 8 ml/tanaman. Faktor kedua adalah pupuk pelengkap alkalis yang terdiri atas tiga taraf, yaitu P0 = tanpa pupuk pelengkap alkalis; P1 = dosis 0,05 gr/tanaman; P2 = dosis 0,1 gr/tan

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Kotsay, Galyna, and Wiktor Szewczenko. "Extraction of Alkalis from Silicate Materials PART 2—Crystalline Silicate Materials." Materials 15, no. 17 (2022): 6059. http://dx.doi.org/10.3390/ma15176059.

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A feature of silicate materials is that they can exist in two antagonistic states—amorphous and crystalline. In both cases, alkalis, which are always present in chemical compositions, play an important role. A feature of alkalis in the composition of silicate materials is that at certain stages of the synthesis of products, they play a positive role, reducing the temperature of synthesis, but worsening the properties of these products at the stage of their operation. Synthesis products should be understood as important building materials such as building glass and cement. It is known that the

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RAMOS, V., I. FERNANDES, A. S. SILVA, D. SOARES, and F. NORONHA. "Potential reactivity of granitic rocks. Petrographic characterization vs accelerated expansion tests." Revista IBRACON de Estruturas e Materiais 9, no. 1 (2016): 66–74. http://dx.doi.org/10.1590/s1983-41952016000100005.

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Several cases of alkali-silica reaction involving granitic aggregates have been diagnosed in damaged concrete structures in Portugal. Nonetheless, this kind of rock is usually regarded as slow/late reactive or even non-reactive to alkalis. Granitic rocks are widely exploited in Northern and Central Portugal, representing almost half of the produced aggregates in this country. Project IMPROVE rose from the need to accurately diagnose the potential reactivity of granites to alkalis. The study involved about forty granites collected from different regions in Portugal, from which the results of ei

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Anenburg, Michael, and Izzan Nur Aslam. "Calcite-saturated natrocarbonatites: composition, crystal morphology, and weathering." Volcanica 7, no. 2 (2024): 813–33. https://doi.org/10.30909/vol.07.02.813833.

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Interpretation of calcite-dominated fossil carbonatite volcanoes is complicated by the instability of many igneous carbonatite materials on Earth’s surface. One hypothesis suggests that they originate by eruption of alkali-free calcic carbonatite lavas. However, liquid calcite is not thermodynamically stable at atmospheric pressure. A second hypothesis suggests that calcite is secondary and formed after primary nyerereite lost its alkalis to surface water. Here, we experimentally test a combined hypothesis in which solid calcite phenocrysts are suspended in natrocarbonatite lava that solidifie

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Krivenko, Pavlо, Hai Lin Cao, Lu Qian Weng, and Еlena Kаvalerova. "Mineralogical Aspects of Durable Geocement Matrix Formation - Role of Alkali." Advanced Materials Research 1004-1005 (August 2014): 1523–30. http://dx.doi.org/10.4028/www.scientific.net/amr.1004-1005.1523.

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Less than half a century ago just an idea of presence of free alkalis in a ceramic matrix was considered by ordinary Portland cement people as an absurd one and this was a basic postulate accepted in chemistry of cements. In 1957 a scientist from Ukraine (USSR) Viktor Glukhovsky put forward an assumption which was taken as a base for development and bringing into practice of construction a principally new class of cementitious materials which first appeared in the field under a name of alkaline (now also known under a general name of alkali-activated) cementitious materials. A validity of thes

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Li, Pei Yi, Mei Yun Zhang, Xin Xing Xia, and Chun Tao Lin. "Reinforcement of Hydrogen Peroxide Bleaching of Bamboo Pulp." Advanced Materials Research 476-478 (February 2012): 2071–74. http://dx.doi.org/10.4028/www.scientific.net/amr.476-478.2071.

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Magnesium-based alkalis and the Chelants (tetra acetyl ethylene diamine (TAED), Sodium Citrate and Opal) for hydrogen peroxide bleaching of bamboo pulp were investigated in this paper. The results showed that the optimal conditions of hydrogen peroxide bleaching of bamboo pulp were as follows: H2O2 4%, Mg(OH)2:NaOH=25%, Sodium Citrate 1%, Opal 1.5%, TAED:H2O2=0.67, temperature 60°C, and time 90 minutes. Under the optimum conditions, the brightness of bamboo pulp can be enhanced from 41.2% ISO to 78.2% ISO, while the brightness of bleached pulp by using the Mg(OH)2-based alkalis was higher than

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Olague, C., G. Wenglas, and P. Castro. "Influencia de los álcalis provenientes de fuentes distintas al cemento en la evolución de la reacción álcali-sílice." Materiales de Construcción 53, no. 271-272 (2003): 189–98. http://dx.doi.org/10.3989/mc.2003.v53.i271-272.303.

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Zăvoianu, Rodica, Mădălina Tudorache, Vasile I. Parvulescu, Bogdan Cojocaru, and Octavian D. Pavel. "New MgFeAl-LDH Catalysts for Claisen–Schmidt Condensation." Molecules 27, no. 23 (2022): 8391. http://dx.doi.org/10.3390/molecules27238391.

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A rapid, cheap and feasible new approach was used to synthesize the Mg0.375Fe0.375Al0.25-LDH in the presence of tetramethylammonium hydroxide (TMAH), as a nontraditional hydrolysis agent, applying both mechano-chemical (MC) and co-precipitation methods (CP). For comparison, these catalysts were also synthesized using traditional inorganic alkalis. The mechano-chemical method brings several advantages since the number of steps and the energy involved are smaller than in the co-precipitation method, while the use of organic alkalis eliminates the possibility of contaminating the final solid with

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Dumańska-Słowik, Magdalena, and Wiesław Heflik. "Ultramafic and Mafic Rocks Found in the Near Vicinity of Mariupolites within the Alkaline Oktiabrski Massif (SE Ukraine) – Preliminary Investigations." Gospodarka Surowcami Mineralnymi 32, no. 2 (2016): 63–78. http://dx.doi.org/10.1515/gospo-2016-0015.

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AbstractThe preliminary results of the mineralogical and geochemical investigations of ultramafic (peridotite and pyroxenite) and mafic (olivine gabbro) rocks from the Mazurovski Field of the Oktiabrski Massif in South-eastern Ukraine are presented in this paper. Peridotite is mainly composed of olivine (forsterite), pyroxene (diallage), plagioclase (labradorite) and ore minerals such as magnetite, ilmenite and pyrite. Antigorite and talk are secondary components. Diallage with subordinate plagioclase, olivine and Fe compounds (oxides/sulphides) are found in pyroxenite. Gabro is made of two ge

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Dias, D. P., Amilcar Soares, C. E. Viana, J. C. Soares, and P. H. B. Azevedo. "Alkaline Activation of Kaolinitic Soils for the Production of Special Binders." Materials Science Forum 498-499 (November 2005): 394–400. http://dx.doi.org/10.4028/www.scientific.net/msf.498-499.394.

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The alkaline activation of Portland cement based materials, ground granulated blast furnace slag and pozzolans has been accomplished with success since the decade of 40, in several countries. The practicability of the use of the alkalis opens new opportunities for the production of special binders with properties different from those presented by the ordinary Portland cement. Besides the chemical composition, the mechanical strength of these alkali-activated materials depends a lot on the reactivity of the raw material, property that is influenced mainly by the specific surface area and crysta

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