Статті в журналах: "Active clay"

1

Gea Pagano, Arianna, Vanessa Magnanimo, and Alessandro Tarantino. "A DEM investigation of the shearing behaviour of non-active clays." E3S Web of Conferences 92 (2019): 14003. http://dx.doi.org/10.1051/e3sconf/20199214003.

Повний текст джерела

Анотація:

This paper presents the numerical DEM simulation of shear tests on two-dimensional clay-like specimens. Clay particles are modelled as rod-shaped elements made of spherical elementary units. The contact laws implemented in the adopted DEM framework account for both the mechanical interaction developing between particles in contact, and the long-range electro-chemical interaction in the form of Coulombian attraction/repulsion between charged particles. Virtual specimens for shear testing are obtained via the one-dimensional compression and unloading of clay-like particle assemblies, in order to study the effect of different over consolidation ratios on the macroscopic mechanical behaviour. The DEM framework is challenged against its ability to reproduce qualitatively key aspects of the macroscopic behaviour of normally consolidated and over consolidated clays during shearing, including contractive and dilative behaviour, and monotonic and non-monotonic stress-strain behaviour.

Стилі APA, Harvard, Vancouver, ISO та ін.

2

Yessengeldi, A. M., A. A. Yessengulova, G. Zh Kayralapova, R. S. Iminova, and M. M. Beysebekov. "Obtaining of surface-active substance sorbents based on acrylate-clay polymers." International Journal of Biology and Chemistry 10, no. 2 (2017): 4–9. http://dx.doi.org/10.26577/2218-7979-2017-10-2-4-9.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

3

Bastianini, Maria, Caterina Faffa, Michele Sisani, and Annarita Petracci. "Caffeic Acid-layered Double Hydroxide Hybrid: A New Raw Material for Cosmetic Applications." Cosmetics 5, no. 3 (August 21, 2018): 51. http://dx.doi.org/10.3390/cosmetics5030051.

Повний текст джерела

Анотація:

Bioactive ingredients from natural sources possess well-known positive effects in cosmetic applications. Among them, phenolic acids have emerged with very interesting potential. Caffeic acid (CAF) is one of the most promising active compounds because it possess antioxidant, anti-inflammatory, antitumoral and anti-wrinkle effects. In order to increase its local bioavailability in topical applications, the vehiculation of caffeic acid can lead to a new raw material of cosmetic interest. For this purpose, clay minerals possess excellent properties, such as low or null toxicity and good biocompatibility. Clays are able to host a wide range of active ingredients in the interlayer region, using a green process known as intercalation reaction. The hosting of cosmetic actives into the layered structure of anionic clays allows the preparation of new materials with enhanced stability towards oxidation and photodegradation, better local bioavailability, and easier workability. In this paper, the successful vehiculation of caffeic acid into anionic clay is presented. The obtained hybrid is very promising for the cosmetic market because of its higher bioavailability and prolonged antioxidant activity.

Стилі APA, Harvard, Vancouver, ISO та ін.

4

Švinka, Ruta, Visvaldis Švinka, Oskars Lescinskis, and Lauma Lindina. "Catalytic Pyrolysis of Wood by Presence of Clay Minerals." Key Engineering Materials 762 (February 2018): 311–16. http://dx.doi.org/10.4028/www.scientific.net/kem.762.311.

Повний текст джерела

Анотація:

Devonian, and Quaternary clays of Latvia together with additive of sawdust after plastic moulding of pellets were used. Partial oxidation of sawdust and formation of active carbon after thermal shock at temperature 800°C were determined. The main clay mineral in all of clays was hydromica with some difference in the structure. Obtained materials with bulk density 1.1 g/cm3 as sorbent for different chemicals such as iodine and methylene blue was used. Dependence of sorption ability of pellets on the type of used clay (clay minerals) was determined. XRD for the determination of phase compositions, nitrogen absorption for the pore size distribution, SEM for the analysis of structure and nanoscale Zetasizer for the determination of surface charge were used.

Стилі APA, Harvard, Vancouver, ISO та ін.

5

De la Morena, Gema, Vicente Navarro, Laura Asensio, and Domenico Gallipoli. "A water retention model accounting for void ratio changes in double porosity clays." Acta Geotechnica 16, no. 9 (March 6, 2021): 2775–90. http://dx.doi.org/10.1007/s11440-020-01126-0.

Повний текст джерела

Анотація:

AbstractThis paper presents a constitutive model that predicts the water retention behaviour of compacted clays with evolving bimodal pore size distributions. In line with previous research, the model differentiates between the water present inside the saturated pores of the clay aggregates (the microstructure) and the water present inside the pores between clay aggregates (the macrostructure). A new formulation is then introduced to account for the effect of the macrostructural porosity changes on the retention behaviour of the soil, which results in a consistent evolution of the air-entry value of suction with volumetric deformations. Data from wetting tests on three different active clays (i.e. MX-80 bentonite, FEBEX bentonite, and Boom clay), subjected to distinct mechanical restraints, were used to formulate, calibrate, and validate the proposed model. Results from free swelling tests were also modelled by using both the proposed double porosity model and a published single porosity model, which confirmed the improvement in the predictions of degree of saturation by the present approach. The proposed retention model might be applied, for example, to the simulation of the hydromechanical behaviour of engineered bentonite barriers in underground nuclear waste repositories, where compacted active clays are subjected to changes of both suction and porosity structure under restrained volume conditions.

Стилі APA, Harvard, Vancouver, ISO та ін.

6

Al-Ani, Faris, and Ghayda Al-Kindi. "Suitability of the Iraqi natural clay for the preparation of Al-Fe pillared-clays." MATEC Web of Conferences 162 (2018): 05017. http://dx.doi.org/10.1051/matecconf/201816205017.

Повний текст джерела

Анотація:

Some organic pollutant in aqueous wastewater inhabitant biological treatment, catalyst wet air oxidation is a method to treat this waste. Al-Fe pillared Iraqi clays with different Fe content were prepared. Aluminum was mixed with iron in different molar ratio Fe/Al (1:9- 2:8- 3:7- 4-6- 5:5) for each regions. These clays collected from different location in Iraq (Anbar, Erbil, Mosel, Baghdad, and Basra), the results of some properties studied for natural and pillared clay, from X-Ray- Fluorescence (XRF) show that iron cation replaces some Ca in the clay, and from X-Ray Diffraction (XRD) show the Calcite types of Iraqi clays. constructs clusters of active ingredient which dramatically clear on the catalytic surface for all catalyst types show through photos of catalysts by Scanning Electron Microscopy (SEM), the best molar ratio of Fe/Al in which give strong interaction between Fe and Al in the pillared were (0.5-0.4-0.3-0.3 and 0.2) for (Mosul-Basra -Anbar-Baghdad and Erbil) respectively. This ratio gives high surface area, and pore size in mesopore. It is concluded that clay and silty clay (Mosul clay) consider the best catalyst due to higher activity and stability through experiment of CWAO in batch reactor, with operation condition 150°C, 2.5 Mpa, Ccat equal to 7 mg/l.

Стилі APA, Harvard, Vancouver, ISO та ін.

7

Balykbayeva, G. T., K. H. Darmagambet, A. S. Tapalova, G. M. Abizbekova, and Sh O. Espenbetova. "FLOCCULATION OF SUSPENSIONS BENTONIT CLAY SURFACE –ACTIVE POLYMERS." Bulletin of Korkyt Ata Kyzylorda University 56, no. 1 (2021): 116–24. http://dx.doi.org/10.52081/bkaku.2021.v56.i1.015.

Повний текст джерела

Анотація:

Мақалада табиғи сорбенттерді практикада пайдалану олардың жоғары сорбциялық сыйымдылығына, әр түрлі агрегаттық күйдегі заттарды сіңіруіне, таңдамалы сорбциясына, жеткілікті механикалық беріктігіне байланысты екенін ескере отырып, олардың суспензиясын тазалау қарастырылады. Табиғи сорбенттерді пайдаланудың тиімділігіне сорбенттердің арзандығы мен жергілікті материал ретінде оңай табылуы маңызды факторлардың бірі болып саналады. Шығыс Қазақстан облысы Таған кен орнының монтмориллонитті бентониттері, құрамының мономинералдылығымен ерекшеленеді, алмасу кешенінде натрий катиондарының мөлшері кальций мен магний катиондарының құрамынан жоғары, бірақ олардың қосындысынан төмен. Су және топырақты тазалауда Таған бентонитін қолдану арқылы жоғары нәтижелер алуға болады. Суда бентониттер ісінеді немесе ұсақ бөлшектерге бөлінеді. Сондықтан, бентонитті саз супензиясына беттік белсенді полимерлердің әсері зерттелінді. Суспензияларды тазартуда коагулянттармен бірге флокулянттар қолдану арқылы жоғары нәтижеге қол жеткізіледі. Ең тиімді флокуляциялық агенттер-жоғары молекулалық салмағы бар полиэлектролиттер. Флокулянттарды қолдану коагулянттардың дозасын азайтуға, коагуляция процесінің ұзақтығын азайтуға және пайда болған ұлпалардың тұндыру жылдамдығын арттыруға мүмкіндік береді. Екі жағдайда да дисперсті жүйенің тұндыру сипаттамаларын жақсартып қана қоймай, қымбат реагенттерді тұтынуды азайтуға болады. Сонымен, алынған мәліметтерді талдау нәтижесіне дисперсті жүйелерді беттік белсенді полимерлермен флокуляциялау кезінде көпір түзілу механизмінің маңызды рөлін көрсетеді.

Стилі APA, Harvard, Vancouver, ISO та ін.

8

HAYASHI, Masao. "Occurrence of clay minerals in active geothermal fields." Journal of the Mineralogical Society of Japan 17 (1986): 9–16. http://dx.doi.org/10.2465/gkk1952.17.special_9.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

9

Pillon, Lilianna Z. "SURFACE ACTIVE PROPERTIES OF CLAY TREATED JET FUELS." Petroleum Science and Technology 19, no. 9-10 (November 30, 2001): 1109–18. http://dx.doi.org/10.1081/lft-100108297.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

10

Gravenor, C. P., and D. A. Coyle. "Origin and magnetic fabric of glacial varves, Nottawasaga River, Ontario, Canada." Canadian Journal of Earth Sciences 22, no. 2 (February 1, 1985): 291–94. http://dx.doi.org/10.1139/e85-025.

Повний текст джерела

Анотація:

An examination of the glacial varved clays that crop out in the banks of the Nottawasaga River, Ontario, shows that both the silt and clay layers are composed of sublaminae.An analysis of the magnetic fabric and remanent magnetization of the varves shows that the current directions are the same for the clay and silt layers and that the magnetic fabric in the clay layer was not influenced by the Earth's magnetic field. This indicates that bottom currents were active during the winter period and were of sufficient strength to align the particles of magnetite parallel to the current directions. This conclusion is not unique to the Nottawasaga varves but serves to illustrate that the conceptual model of glacial varve deposition requires modification.

Стилі APA, Harvard, Vancouver, ISO та ін.

11

Lakshmy, M., B. M. Chandrasekhar, B. S. Jai Prakash, and Y. S. Bhat. "Zeolitic behaviour of paratoluenesulfonic acid-modified clay in Friedel-Crafts synthesis of raspberry ketone." Clay Minerals 50, no. 5 (December 2015): 573–81. http://dx.doi.org/10.1180/claymin.2015.050.5.02.

Повний текст джерела

Анотація:

AbstractDuring solventless alkylation of phenol with 4-hydroxy-2-butanone under microwave irradiation, paratoluenesulfonic acid (pTSA)-modified montmorillonite clays gave, regioselectively, 4-(4′-hydroxyphenyl)-2-butanone (raspberry ketone). The duration for this reaction under microwave irradiation is much shorter than that of the conventional method. A comparative study of the alkylation reaction over a montmorillonite clay sample treated with 0.5 M-pTSA (0.5 M-pTSA clay) with that of Al-exchanged montmorillonite (Al3+-Mont) and beta-zeolite (HB) was carried out. The results show that the reaction time to reach equilibrium and the product distribution pattern for the reaction over 0.5 M-pTSA clay were similar to those values for the HB. Micropores formed on the clay surface during the pTSA treatment were found to enhance the rate of formation of C-alkylation. Micropores appear to enable better access to the active sites during the course of reaction.

Стилі APA, Harvard, Vancouver, ISO та ін.

12

Konrad, J. M., and J. T. C. Seto. "Frost heave characteristics of undisturbed sensitive Champlain Sea clay." Canadian Geotechnical Journal 31, no. 2 (April 1, 1994): 285–98. http://dx.doi.org/10.1139/t94-033.

Повний текст джерела

Анотація:

Undisturbed Champlain Sea clay samples were subjected to laboratory freezing tests with pore-pressure measurements in order to determine the freezing characteristics of a structured compressible soil. Step-freezing and ramped-freezing tests with applied back pressure were conducted on 10 cm high samples in open-system conditions. Significant pore-pressure reductions in the unfrozen soil induce important frost-induced consolidation and destructuration of the clay. It was found that the freezing characteristics of Saint-Alban clay are best defined by the segregation potential at the active ice lens, SPℓ, which includes water fluxes generated within the frozen fringe and within the unfrozen soil as excess water is expelled during consolidation, and finally water from an external source. For the Saint-Alban clay, SPℓ values of the intact clay ranged between 450 and 600 × 10−5 mm2/(s °C), whereas those of destructured clay at a lower void ratio were significantly smaller. Back-calculating the segregation potential solely from surface heave measurements in laboratory tests may underestimate considerably the frost susceptibility of compressible structured clays. Segregation potential inferred from instrumented field sites was 430 × 10−5 mm2/(s °C) and is consistent with the laboratory tests results. Key words : freezing, frost heave, structured clay, undisturbed, consolidation.

Стилі APA, Harvard, Vancouver, ISO та ін.

13

Chuaicham, Chitiphon, Jirawat Trakulmututa, Kaiqian Shu, Sulakshana Shenoy, Assadawoot Srikhaow, Li Zhang, Sathya Mohan, Karthikeyan Sekar, and Keiko Sasaki. "Recent Clay-Based Photocatalysts for Wastewater Treatment." Separations 10, no. 2 (January 22, 2023): 77. http://dx.doi.org/10.3390/separations10020077.

Повний текст джерела

Анотація:

Photocatalysis is a remarkable methodology that is popular and applied in different interdisciplinary research areas such as the degradation of hazardous organic contaminants in wastewater. In recent years, clay-based photocatalyst composites have attracted significant attention in the field of photocatalysis owing to their abundance, excellent light response ability, and stability. This review describes the combination of clay with focusing photocatalysts such as TiO2, g-C3N4, and Bi-based compounds for degrading organic pollutants in wastewater. Clay-based composites have more active surface sites, resulting in inhibited photocatalyst particle agglomeration. Moreover, clay enhances the creation of active radicals for organic pollutant degradation by separating photogenerated electrons and holes. Thus, the functions of clay in clay-based photocatalysts are not only to act as a template to inhibit the agglomeration of the main photocatalysts but also to suppress charge recombination, which may lengthen the electron–hole pair’s lifespan and boost degrading activity. Moreover, several types of clay-based photocatalysts, such as the clay type and main photocatalyst, were compared to understand the function of clay and the interaction of clay with the main photocatalyst. Thus, this study summarizes the recent clay-based photocatalysts for wastewater remediation and concludes that clay-based photocatalysts have considerable potential for low-cost, solar-powered environmental treatment.

Стилі APA, Harvard, Vancouver, ISO та ін.

14

Carretero, M. Isabel, and Manuel Pozo. "Clay and non-clay minerals in the pharmaceutical and cosmetic industries Part II. Active ingredients." Applied Clay Science 47, no. 3-4 (February 2010): 171–81. http://dx.doi.org/10.1016/j.clay.2009.10.016.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

15

Couillard, Martin, Daniel D. Tyo, David M. Kingston, Bussaraporn Patarachao, Andre Zborowski, Samson Ng, and Patrick H. J. Mercier. "Structure and Mineralogy of Hydrophilic and Biwettable Sub-2 µm Clay Aggregates in Oil Sands Bitumen Froth." Minerals 10, no. 11 (November 21, 2020): 1040. http://dx.doi.org/10.3390/min10111040.

Повний текст джерела

Анотація:

A primary concern of commercial mined oil sands operations is the extent to which one can minimize the content of water and solids contaminants in the solvent-diluted bitumen products resulting from the bitumen production processes. During bitumen production, particles of about 2 µm or less may be responsible for the stabilization of water-in-bitumen emulsions that form during aqueous extraction of bitumen and purification of bitumen froth subsequently during the froth treatment processes, thus leading to the presence of those contaminants in solvent-diluted bitumen products. In this study, we separate and analyze sub-2 µm clay solids isolated from typical bitumen froth fed to a froth treatment plant at a commercial mined oil sands operation. Analytical transmission electron microscopy (TEM) with spatially-resolved energy-dispersive X-ray spectroscopy (EDX) and electron energy-loss spectroscopy (EELS) demonstrate key differences in morphology and composition between sub-2 µm clay aggregates with two distinct wettability characteristics: hydrophilic vs. biwettable particle surfaces. In particular, clay platelets with <200 nm lateral dimensions and thicknesses of a few atomic layers, which are intermixed within coarser sub-2 µm clay aggregates, are found to confer clear differences in morphological characteristics and wettability behaviors to the sub-2 µm clay aggregates. The <200 nm clay platelets found within sub-2 µm biwettable clays tend to arrange themselves with random orientations, whereas <200 nm clay platelets within sub-2 µm hydrophilic clays typically form well-ordered face-to-face stacks. Moreover, in biwettable sub-2 µm clay aggregates, <200 nm clay platelets often cover the surfaces of ~1–2 µm sized mineral particles, whereas similarly sized mineral particles in hydrophilic sub-2 µm clay aggregates, in contrast, generally have exposed surfaces without clay platelet coverage. These biwettable vs. hydrophilic behaviors are attributed to a difference in the surface characteristics of the <200 nm clay platelets caused by toluene-unextractable organic carbon coatings. Nanometer-scale carbon mapping reveals an inhomogeneous toluene-unextractable organic carbon coating on the surfaces of <200 nm platelets in biwettable clays. In contrast, hydrophilic clays have a significantly lower amount of toluene-unextractable organic carbon, which tends to be concentrated at steps or near metal oxide nanoparticles on clay particle surfaces. Mixing surface-active organic species, such as asphaltene, resin, or carboxylic organic acids of various types with inorganic solids can lead to a dramatically enhanced emulsion stability. Consequently, understanding the origin and characteristics of sub-2 µm clay solids in bitumen froth is important to (i) clarify their potential role in the formation of stable water-in-oil emulsions during bitumen production and (ii) improve froth treatment process performance to further reduce contaminant solids in solvent-diluted bitumen products. We discuss the implications of our results from these two perspectives.

Стилі APA, Harvard, Vancouver, ISO та ін.

16

Baranchiyeva, Zarina, Gulziya Seilkhanova, and Akmaral Rakhym. "Analysis of the physicochemical and sorption characteristics of composites based on zeolite and chamotte clay." MATEC Web of Conferences 340 (2021): 01027. http://dx.doi.org/10.1051/matecconf/202134001027.

Повний текст джерела

Анотація:

Clays and aluminosilicate materials are known as effective sorbents for purification of wastewater from various types of contaminants. Some properties and sorption activity of materials based on the zeolite of Shankanai deposit and Chamotte clay towards Cd2+ ions were analyzed in the present work. The structural characteristics of the studied objects, their qualitative and quantitative composition were determined by the SEM and EDAX methods. It was found that maximum adsorption capacity (qe) of the initial zeolite for extraction Cd2+ ions is (7.3±0.11) mg/g, while for Chamotte clay this value equals to (5.3±0.12) mg/g. After modification with polyvinylpyrrolidone, qe increased to (10.1±0.08) mg/g for zeolite, and (8.5±0.15) mg/g for Chamotte clay. Developed specific surface of the composite material (sorbent) and complexation with the active centres of thepolymer couldbe a resultof Cd2+ ions binding.

Стилі APA, Harvard, Vancouver, ISO та ін.

17

Galan, E. "Properties and applications of palygorskite-sepiolite clays." Clay Minerals 31, no. 4 (December 1996): 443–53. http://dx.doi.org/10.1180/claymin.1996.031.4.01.

Повний текст джерела

Анотація:

AbstractThe palygorskite-sepiolite group of clay minerals has a wide range of industrial applications derived mainly from its sorptive, rheological and catalytic properties which are based on the fabric, surface area, porosity, crystal morphology, structure and composition of these minerals. For assessing potential industrial uses, the mineralogical and chemical composition of the clay and its basic physical and physico-chemical parameters must be determined. Then some particular properties of commercial interest can be modified and improved by appropriate thermal, mechanical and acid treatments, surface active agents, organo-mineral derivatives formation, etc. In this paper, a revision of the principal characteristics of commercial palygorskite-sepiolite clays is presented, and potential uses are suggested according to these data. New products and applications are being investigated and those concerning environmental protection in particular, are noted. Finally, possible health effects of these elongate clay minerals are discussed.

Стилі APA, Harvard, Vancouver, ISO та ін.

18

Neuzil, C. E. "Permeability of Clays and Shales." Annual Review of Earth and Planetary Sciences 47, no. 1 (May 30, 2019): 247–73. http://dx.doi.org/10.1146/annurev-earth-053018-060437.

Повний текст джерела

Анотація:

The low permeability of clays, shales, and other argillaceous lithologies makes them key controls of transport and deformation processes in the crust but is known for being challenging to characterize. As muds are modified by compaction and diagenesis to low-porosity shales, permeability can decrease by six or more orders of magnitude, but at large scales it is often dramatically and unpredictably increased by fractures, faults, and other features. Testing and inverse modeling show that petrophysical properties and the geological environment are dominant controls of clay and shale matrix permeability and its scale dependence. Active sedimentation and tectonism on continental margins cause large-scale permeability to vary with time, but in stable continent interiors it is unclear how regional permeability of argillaceous formations changes over time or, in most cases, what controls it. Although rarely considered, it is also unknown whether Darcian permeability adequately describes flow in clay-rich materials. ▪ Critical for problems in energy, water supply, waste isolation, and geologic hazards, clay and shale permeability remains problematic. ▪ Test data and inverse model analyses are beginning to reveal where and how permeability of clay and shale changes with scale. ▪ In clays and shales, causes of permeability scale effects, their time dependence, and even flow behavior continue to raise questions.

Стилі APA, Harvard, Vancouver, ISO та ін.

19

Gawecka, Klementyna A., David M. G. Taborda, David M. Potts, Wenjie Cui, Lidija Zdravković, and Muhamad S. Haji Kasri. "Numerical modelling of thermo-active piles in London Clay." Proceedings of the Institution of Civil Engineers - Geotechnical Engineering 170, no. 3 (June 2017): 201–19. http://dx.doi.org/10.1680/jgeen.16.00096.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

20

Liu, Xu, Xingyu Lu, Yongchao Su, Eucharist Kun, and Feng Zhang. "Clay-Polymer Nanocomposites Prepared by Reactive Melt Extrusion for Sustained Drug Release." Pharmaceutics 12, no. 1 (January 7, 2020): 51. http://dx.doi.org/10.3390/pharmaceutics12010051.

Повний текст джерела

Анотація:

Clay–polymer nanocomposites have exhibited a great potential as carriers for controlled release drug delivery. This study aims to prepare exfoliated montmorillonite–Eudragit RS nanocomposites using reactive melt extrusion and investigate the influence of claying loading, clay types (sodium montmorillonite (Cloisite Na) vs. organomodified montmorillonite (Cloisite 20)) on clay–polymer interactions and drug release properties. The clays were used as the filler material at various levels in Eudragit RS and theophylline was used as the active pharmaceutical ingredient. The resulting structure of the nanocomposites was characterized using TEM (transmission electron microscopy) and XRPD (X-ray powder diffraction). The hygroscopicity of the nanocomposites was investigated using DVS (dynamic vapor sorption). The effect of the interfacial interaction between the polymer and clay sheet, the clay loading as well as the clay type on the drug release behavior were further studied by dissolution testing. TEM and XRPD data show that when the clay content is increased from 5% to 15% by weight, the nanocomposite’s structure switches from a fully exfoliated state to intercalated structures or partial exfoliation with stacked clay layers. FT-IR (fourier transform infrared spectroscopy) and ssNMR (solid-state NMR) results suggest that Cloisite Na and Cloisite 20 layers exhibit different interaction strengths with polymer networks by creating compacted complex structures. The addition of nanoclay in the formulation could robustly adjust drug release profiles, and the clay concentration and type are important factors that affect the crossing-linking density of the nanocomposites by adjusting the drug release properties. This study indicates that the clay–Eudragit RS nanocomposites provide an improved oral controlled drug delivery system that minimizes the drug dosing frequency, potentially leading to improved patient compliance.

Стилі APA, Harvard, Vancouver, ISO та ін.

21

hmunsiama, Lal, and Seung-Mok Lee. "Potential of Iron Pillared Clay as Active Nanocatalyst for Rapid Decolorization of Methylene Blue." Science & Technology Journal 7, no. 2 (July 1, 2019): 46–53. http://dx.doi.org/10.22232/stj.2019.07.02.05.

Повний текст джерела

Анотація:

In this study, the iron-pillared clay nanocatalyst (ICN) was employed as a nanocatalyst for decolorization of methylene blue (MB) in aqueous solutions without hydrogen peroxide. The changes in clay structure after the incorporation of iron-oxide particles was studied with the help of XRD analytical data. The SEM micrographs showed higher heterogeneous structure of ICN compared to pristine clay and the specific surface area of ICN (82.54 m2/g) is considerably higher than the unmodified clay (63.41 m2/g). Further, the EDX analytical data indicate the successful incorporation of iron-oxide into bentonite clay. Batch experiments showed that ICN could degrade MB within pH 3.0 to 11.0 and it is efficient even at higher concentrations. The degradation is very fast and more than 90% is removed within 30 mins. A small amount of ICN is effective for degradation of MB and the reusability test showed that ICN can be reuse for several times for the degradation of MB in aqueous solutions. The effect of scavengers studies indicate that the ·OH radicals generated from the ICN are responsible in the degradation of MB. This study indicates that ICN must be low cost and environmentally friendly active nanocatalyst for degradation of MB present in aquatic environment.

Стилі APA, Harvard, Vancouver, ISO та ін.

22

Mörtl, Mária, Orsolya Kereki, Béla Darvas, Szandra Klátyik, Ágnes Vehovszky, János Győri, and András Székács. "Study on Soil Mobility of Two Neonicotinoid Insecticides." Journal of Chemistry 2016 (2016): 1–9. http://dx.doi.org/10.1155/2016/4546584.

Повний текст джерела

Анотація:

Movement of two neonicotinoid insecticide active ingredients, clothianidin (CLO) and thiamethoxam (TMX), was investigated in different soil types (sand, clay, or loam) and in pumice. Elution profiles were determined to explore differences in binding capacity. Soil characterized by high organic matter content retained the ingredients, whereas high clay content resulted in long release of compounds. Decrease in concentration was strongly influenced by soil types: both CLO and TMX were retained in loam and clay soils and showed ready elution through sandy soil and pumice. Elution capability of the active ingredients in sandy soil correlated with their water solubility, indicating approximately 30% higher rapidity for TMX than for CLO. Soil organic carbon-water partitioning coefficients (Koc) determined were in good agreement with literature values with somewhat lower value for CLO in sandy soil and substantially higher values for TMX in clay soil. High mobility of these neonicotinoid active ingredients in given soil types urges stronger precautionary approach taken during their application.

Стилі APA, Harvard, Vancouver, ISO та ін.

23

Mangoni, Ana Paula, Patrícia Moura Dias, and Vera Leopoldo Constantino. "A versatilidade das argilas e as propriedades dos sítios superficiais de interação." Eclética Química Journal 40, no. 1 (September 26, 2015): 192. http://dx.doi.org/10.26850/1678-4618eqj.v40.1.2015.p192-203.

Повний текст джерела

Анотація:

This article presents in a simplified and introductory way, the active sites present on the surfaces of clays that make them so versatile. These sites are responsible for interactions between the clay and organic or inorganic species, and the chemical transformations of substrates that occur on the surface, allowing to understand either natural processes in the environment or those performed on an industrial scale. It is proposed that this text can illustrate, in the classroom, fundamental concepts (types of chemical reactions, electrostatic interactions and other ones) from processes on solid surfaces. The correlation between the active sites of clays and their properties is a rich topic to be explored in chemistry disciplines.

Стилі APA, Harvard, Vancouver, ISO та ін.

24

Kashiri, Mahboobeh, Yahya Maghsoudlo, and Morteza khomeiri. "Incorporating Zataria multiflora Boiss. essential oil and sodium bentonite nano-clay open a new perspective to use zein films as bioactive packaging materials." Food Science and Technology International 23, no. 7 (May 26, 2017): 582–96. http://dx.doi.org/10.1177/1082013217708526.

Повний текст джерела

Анотація:

Active zein films with different levels of Zataria multiflora Boiss. essential oil were produced successfully. To enhance properties of this biopolymer for food packaging applications, sodium bentonite clay was used at two levels (2 and 4%). The results indicated that the addition of Z. multiflora Boiss. essential oil caused a reduction in tensile strength and Young’s modulus and slight increase in the percent of elongation at break of the films. Maximum solubility in water and water vapor permeability was observed by incorporation of 10% Z. multiflora Boiss. essential oil in the zein matrix. Transmission electron microscopy micrographs of zein film were verified by the exfoliation of the layers of sodium bentonite clay in the zein matrix. Stronger films with lower water vapor permeability and water solubility were evident of good distribution of sodium bentonite clay in the zein matrix. According to the results, 2% sodium bentonite clay was selected for evaluation of nano active film properties. Water vapor permeability, UV light barrier, tensile strength, and Young’s modulus values of active films were improved by incorporation of 2% sodium bentonite clay. The antibacterial activity of different contents of Z. multiflora Boiss. essential oil in vapor phase demonstrated that use of Z. multiflora Boiss. essential oil in the liquid phase was more effective than in vapor phase. The antibacterial zein-based films showed that active zein film with 5 and 10% Z. multiflora Boiss. essential oil had reductions of 1.68 log and 2.99 log, respectively, against Listeria monocytogenes and 1.39 and 3.07 log against Escherichia coli. Nano active zein film containing 10% Z. multiflora Boiss. essential oil and 2% sodium bentonite clay showed better antibacterial properties against L. monocytogenes (3.23 log) and E. coli (3.17 log).

Стилі APA, Harvard, Vancouver, ISO та ін.

25

Abedi, Sadegh, Majid Abdouss, Mehdi Nekoomanesh-Haghighi, and Naser Sharifi-Sanjani. "PE/clay nanocomposites produced via in situ polymerization by highly active clay-supported Ziegler–Natta catalyst." Polymer Bulletin 70, no. 4 (September 25, 2012): 1313–25. http://dx.doi.org/10.1007/s00289-012-0856-1.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

26

Malūnavičius, Saulius. "INFLUENCE OF ACTIVE SURFACE MATERIALS FOR SHEAR STRENGTH OF CLAY SOIL / PAVIRŠIAUS AKTYVIŲJŲ MEDŽIAGŲ ĮTAKA MOLINIŲ GRUNTŲ KERPAMAJAM STIPRIUI." Mokslas - Lietuvos ateitis 3, no. 2 (June 7, 2011): 71–75. http://dx.doi.org/10.3846/mla.2011.035.

Повний текст джерела

Анотація:

The article deals with the active surface materials (ASM) on the clay soil shear strength parameters, which are used in calculating the building base strength and stability of soil pressure in to supporting surface and slope stability. From the known mineral composition of clay soil was partially removed calcium compounds and were polluted of different concentration of pollutants and the values were compared. The analysis of active surface material substance influence on clay soil shows that higher concetration of pollutants in solution results in decreased soil cohesion, where the angle of internal friction remains various values.

Стилі APA, Harvard, Vancouver, ISO та ін.

27

Castro, Julia, Maria P. Asta, Jorge P. Galve, and José Miguel Azañón. "Formation of Clay-Rich Layers at The Slip Surface of Slope Instabilities: The Role of Groundwater." Water 12, no. 9 (September 21, 2020): 2639. http://dx.doi.org/10.3390/w12092639.

Повний текст джерела

Анотація:

Some landslides around the world that have low-angle failure planes show exceptionally poor mechanical properties. In some cases, an extraordinarily pure clay layer has been detected on the rupture surface. In this work, a complex landslide, the so-called Diezma landslide, is investigated in a low- to moderate-relief region of Southeast Spain. In this landslide, movement was concentrated on several surfaces that developed on a centimeter-thick layer of smectite (montmorillonite-beidellite) clay-rich level. Since these clayey levels have a very low permeability, high plasticity, and low friction angle, they control the stability of the entire slide mass. Specifically, the triggering factor of this landslide seems to be linked to the infiltration of water from a karstic aquifer located in the head area. The circulation of water through old failure planes could have promoted the active hydrolysis of marly soils to produce new smectite clay minerals. Here, by using geophysical, mineralogical, and geochemical modelling methods, we reveal that the formation and dissolution of carbonates, sulfates, and clay minerals in the Diezma landslide could explain the elevated concentrations of highly plastic secondary clays in its slip surface. This study may help in the understanding of landslides that show secondary clay layers coinciding to their low-angle failure planes.

Стилі APA, Harvard, Vancouver, ISO та ін.

28

Fulignati, Paolo. "Clay Minerals in Hydrothermal Systems." Minerals 10, no. 10 (October 16, 2020): 919. http://dx.doi.org/10.3390/min10100919.

Повний текст джерела

Анотація:

The study of active and fossil hydrothermal systems shows clay minerals to be a fundamental tool for the identification and characterization of hydrothermal alteration facies. The occurrence and composition of hydrothermal alteration facies could provide useful information on the physicochemical conditions of the hydrothermal activity affecting a rock volume. In particular, clay minerals (i.e., smectite group, chlorite, illite, kaoline group, pyrophyllite, biotite) are pivotal for extrapolating important parameters that strongly affect the development of water/rock interaction processes such as the temperature and pH of the hydrothermal environment. This work aims to give a general reference scheme concerning the occurrence of clay minerals in hydrothermal alteration paragenesis, their significance, and the information that can be deduced by their presence and chemical composition, with some examples from active and fossil hydrothermal systems around the world. The main mineralogical geothermometers based on chlorite and illite composition are presented, together with the use of hydrogen and oxygen isotope investigation of clay minerals in hydrothermal systems. These techniques provide a useful tool for the reconstruction of the origin and evolution of fluids involved in hydrothermal alteration. Finally, a list of oxygen and hydrogen fractionation factor equations between the main clay minerals and water is also provided.

Стилі APA, Harvard, Vancouver, ISO та ін.

29

O’Loughlin, Edward J., Maxim I. Boyanov, Kenneth M. Kemner, and Korbinian O. Thalhammer. "Reduction of Hg(II) by Fe(II)-Bearing Smectite Clay Minerals." Minerals 10, no. 12 (December 1, 2020): 1079. http://dx.doi.org/10.3390/min10121079.

Повний текст джерела

Анотація:

Aluminosilicate clay minerals are often a major component of soils and sediments and many of these clays contain structural Fe (e.g., smectites and illites). Structural Fe(III) in smectite clays is redox active and can be reduced to Fe(II) by biotic and abiotic processes. Fe(II)-bearing minerals such as magnetite and green rust can reduce Hg(II) to Hg(0); however, the ability of other environmentally relevant Fe(II) phases, such as structural Fe(II) in smectite clays, to reduce Hg(II) is largely undetermined. We conducted experiments examining the potential for reduction of Hg(II) by smectite clay minerals containing 0–25 wt% Fe. Fe(III) in the clays (SYn-1 synthetic mica-montmorillonite, SWy-2 montmorillonite, NAu-1 and NAu-2 nontronite, and a nontronite from Cheney, Washington (CWN)) was reduced to Fe(II) using the citrate-bicarbonate-dithionite method. Experiments were initiated by adding 500 µM Hg(II) to reduced clay suspensions (4 g clay L−1) buffered at pH 7.2 in 20 mM 3-morpholinopropane-1-sulfonic acid (MOPS). The potential for Hg(II) reduction in the presence of chloride (0–10 mM) and at pH 5–9 was examined in the presence of reduced NAu-1. Analysis of the samples by Hg LIII-edge X-ray absorption fine structure (XAFS) spectroscopy indicated little to no reduction of Hg(II) by SYn-1 (0% Fe), while reduction of Hg(II) to Hg(0) was observed in the presence of reduced SWy-2, NAu-1, NAu-2, and CWN (2.8–24.8% Fe). Hg(II) was reduced to Hg(0) by NAu-1 at all pH and chloride concentrations examined. These results suggest that Fe(II)-bearing smectite clays may contribute to Hg(II) reduction in suboxic/anoxic soils and sediments.

Стилі APA, Harvard, Vancouver, ISO та ін.

30

Massaro, Marina, Carmelo Colletti, Giuseppe Lazzara, and Serena Riela. "The Use of Some Clay Minerals as Natural Resources for Drug Carrier Applications." Journal of Functional Biomaterials 9, no. 4 (October 19, 2018): 58. http://dx.doi.org/10.3390/jfb9040058.

Повний текст джерела

Анотація:

The goal of modern research is to use environmentally preferable materials. In this context, clay minerals are emerging candidates for their bio- and ecocompatibility, low cost and natural availability. Clay minerals present different morphologies according to their layer arrangements. The use of clay minerals, especially in biomedical applications is known from ancient times and they are regaining attention in recent years. The most representative clay minerals are kaolinit, montmorillonite, sepiolites and halloysite. This review summarizes some clay minerals and their derivatives for application as nanocontainer for biologically active species.

Стилі APA, Harvard, Vancouver, ISO та ін.

31

SAHDI, F., C. GAUDIN, D. J. WHITE, N. BOYLAN, and M. F. RANDOLPH. "Centrifuge modelling of active slide–pipeline loading in soft clay." Géotechnique 64, no. 1 (January 2014): 16–27. http://dx.doi.org/10.1680/geot.12.p.191.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

32

Heller-Kallai, L. "Active Components in Clay Condensates and Extracts as Potential Geocatalysts." Clays and Clay Minerals 44, no. 3 (1996): 393–97. http://dx.doi.org/10.1346/ccmn.1996.0440308.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

33

Koster, R. M., M. Bogert, B. de Leeuw, E. K. Poels, and A. Bliek. "Active sites in the clay catalysed dimerisation of oleic acid." Journal of Molecular Catalysis A: Chemical 134, no. 1-3 (September 1998): 159–69. http://dx.doi.org/10.1016/s1381-1169(98)00032-6.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

34

Chen, Xiaole, Naifei Hu, Yonghuai Zeng, James F. Rusling, and Jing Yang. "Ordered Electrochemically Active Films of Hemoglobin, Didodecyldimethylammonium Ions, and Clay." Langmuir 15, no. 20 (September 1999): 7022–30. http://dx.doi.org/10.1021/la990239x.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

35

Altun, Gursat, and Ali Ettehadi Osgouei. "Investigation and remediation of active-clay contaminated sepiolite drilling muds." Applied Clay Science 102 (December 2014): 238–45. http://dx.doi.org/10.1016/j.clay.2014.10.002.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

36

Varade, Dharmesh, and Kazutoshi Haraguchi. "Synthesis of Highly Active and Thermally Stable Nanostructured Pt/Clay Materials by Clay-Mediated in Situ Reduction." Langmuir 29, no. 6 (February 2013): 1977–84. http://dx.doi.org/10.1021/la3044945.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

37

Bazhenova, Olga, Sofia Bazhenova, V. Nemirova, and Dmitriy Bazhenov. "The clays after heat treatment as the concrete active mineral additive." MATEC Web of Conferences 170 (2018): 03021. http://dx.doi.org/10.1051/matecconf/201817003021.

Повний текст джерела

Анотація:

Active mineral additives are one of the most common components of cement systems now. They are entered cements of increase in extent of hydration, the directed formation of structure of a cement stone from more stable hydrate phases of the lowered basicity, for the purpose of improvement of construction and technical properties of cements, by cutting of costs of fuel raw material resources for their production, giving to cements of some specific properties. In work the possibility of use as active mineral additives not only the granulated slags, but also local clays which industrially can give certain puzzolan properties are considered. It is proved that heat treatment of clay breeds significantly increases their puzzolan activity that does them suitable for use as active mineral additive instead of the domain granulated slag by production of the portland cement.

Стилі APA, Harvard, Vancouver, ISO та ін.

38

Boominathan, A., and R. Ayothiraman. "Measurement and Analysis of Horizontal Vibration Response of Pile Foundations." Shock and Vibration 14, no. 2 (2007): 89–106. http://dx.doi.org/10.1155/2007/869184.

Повний текст джерела

Анотація:

Pile foundations are frequently used in very loose and weak deposits, in particular soft marine clays deposits to support various industrial structures, power plants, petrochemical complexes, compressor stations and residential multi-storeyed buildings. Under these circumstances, piles are predominantly subjected to horizontal dynamic loads and the pile response to horizontal vibration is very critical due to its low stiffness. Though many analytical methods have been developed to estimate the horizontal vibration response, but they are not well validated with the experimental studies. This paper presents the results of horizontal vibration tests carried out on model aluminium single piles embedded in a simulated Elastic Half Space filled with clay. The influence of various soil and pile parameters such as pile length, modulus of clay, magnitude of dynamic load and frequency of excitation on the horizontal vibration response of single piles was examined. Measurement of various response quantities, such as the load transferred to the pile, pile head displacement and the strain variation along the pile length were done using a Data Acquisition System. It is found that the pile length, modulus of clay and dynamic load, significantly influences the natural frequency and peak amplitude of the soil-pile system. The maximum bending moment occurs at the fundamental frequency of the soil-pile system. The maximum bending moment of long piles is about 2 to 4 times higher than that of short piles and it increases drastically with the increase in the shear modulus of clay for both short and long piles. The active or effective pile length is found to be increasing under dynamic load and empirical equations are proposed to estimate the active pile length under dynamic loads.

Стилі APA, Harvard, Vancouver, ISO та ін.

39

da Silva, Carla Dantas, Rosa do Carmo de Oliveira Lima, Julliana Marques Rocha Costa, Gelmires Araújo Neves, and Heber Carlos Ferreira. "Influence of Organophilization Process Variables in Bentonite Clays from Cubati-PB." Materials Science Forum 727-728 (August 2012): 1467–72. http://dx.doi.org/10.4028/www.scientific.net/msf.727-728.1467.

Повний текст джерела

Анотація:

This work aims at the development of organoclay from two varieties of bentonite for use in organic media using ionic surfactants, studying the influence of process variables in the organophilization process. We used the following materials: natural bentonite clay from Cubati-PB District, and the ionic quaternary ammonium salt: Praepagen WB® with 45% active matter. The clays were benefited and then turned into sodium form and subsequently into organoclays. The bentonites were characterized by laser diffraction (GA) X-ray fluorescence chemical composition (EDX), thermogravimetric analysis (TGA), thermogravimetry (DTA) and X-ray diffraction (XRD). The organoclays were characterized by (XRD) thermogravimetric analysis (TGA) and thermogravimetry (DTA). The results showed that the clay has potential for application in the organophilization process and that there is influence of process variables.

Стилі APA, Harvard, Vancouver, ISO та ін.

40

Vilarinho, Fernanda, Malia Fátima Vaz, and Ana Sanches Silva. "The Use of Montmorillonite (MMT) in Food Nanocomposites: Methods of Incorporation, Characterization of MMT/Polymer Nanocomposites and Main Consequences in the Properties." Recent Patents on Food, Nutrition & Agriculture 11, no. 1 (April 29, 2020): 13–26. http://dx.doi.org/10.2174/2212798410666190401160211.

Повний текст джерела

Анотація:

Background: The clay Montmorillonite (MMT) is among the nanofillers more frequently used in food packaging. The uniform dispersion of nanoparticles in polymers confers considerable improvement of mechanical, thermal, optical, and/or barrier properties in polymer/clay nanocomposites. Objective: The aim is to ascertain the state of the art of the use of MMT for packaging purposes, with special emphasis on food applications. Methods: A literature review was carried out through recent papers and patents that focused on the incorporation of MMT in polymers. Results: This review emphasizes the interaction of MMT with polymers and their levels of incorporation in the nanocomposites. This work also highlights the analytical methodologies used for the characterization of the polymer/clay nanocomposites and the main consequences of the fillers in the properties of nanocomposites. Challenges remain about increasing the compatibility between clays and biopolymers to promote their utilization in food packaging. New strategies for immobilization of oxides, enzymes, essential oils, and other bioactive compounds are needed. Conclusion: MMT-based composite materials are promising to be used in intelligent and active packaging.

Стилі APA, Harvard, Vancouver, ISO та ін.

41

Quigley, R. M., A. J. Sethi, P. Boonsinsuk, D. E. Sheeran, and R. N. Yong. "Geologic control on soil composition and properties, Lake Ojibway clay plain, Matagami, Quebec." Canadian Geotechnical Journal 22, no. 4 (November 1, 1985): 491–500. http://dx.doi.org/10.1139/t85-069.

Повний текст джерела

Анотація:

Varved clays deposited in proglacial Lake Ojibway at Matagami, Quebec, were derived from two source areas: carbonate-deficient, Precambrian crystalline igneous rocks from New Quebec to the east and carbonate-rich Palaeozoic rocks from the James Bay lowlands in Ontario to the west. About 50% of the 12–15 m thick clay section consists of varved clays containing less than 3% carbonate, reflecting the New Quebec source. The remaining 50% of the section consists of two pulses of carbonate-enriched varves (15–30% carbonate) derived from rock flour in two glacial advances known as Cochrane I and Cochrane II, which advanced to within 20 km of Matagami.The clays are preconsolidated at the site by a combination of desiccation, groundwater level drawdown, and bonding, in such a way that σp′ is almost constant at 70 kPa at depths from 3.5 to 10 m.High in situ water contents correlate with thinner, low-carbonate, distal varves of high activity. The est correlations are obtained for relative activity, Ac(rel), defined as plasticity index ÷ specific surface area (Ip ÷ SS). Carbonate seems to have effectively neutralized smectite in the Cochrane proximal varves, rendering the distal varves (of New Quebec source) the most active clays at the site. Key words: varved clay, activity, carbonate, turbidity currents, glacial geology.

Стилі APA, Harvard, Vancouver, ISO та ін.

42

García-Villén, Fátima, and César Viseras. "Clay-Based Pharmaceutical Formulations and Drug Delivery Systems." Pharmaceutics 12, no. 12 (November 25, 2020): 1142. http://dx.doi.org/10.3390/pharmaceutics12121142.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

43

Rigault, Cécile, Patricia Patrier, and Daniel Beaufort. "Clay minerals related to circulation of near neutral to weakly acidic fluids in active high energy geothermal systems." Bulletin de la Société Géologique de France 181, no. 4 (July 1, 2010): 337–47. http://dx.doi.org/10.2113/gssgfbull.181.4.337.

Повний текст джерела

Анотація:

Abstract Clay minerals are widespread alteration products in most hydrothermal systems and are considered as efficient petrogenetic guides. Their distribution in active geothermal fields depends on the ability of the fluid to approach equilibrium with host rocks at any scale during the hydrothermal processes. Both illitization and chloritization reactions depend on factors such as time, water-rock ratio, deformation history... as well as the variables used to define equilibrium (i.e., temperature, composition). This paper is focussed on how the properties of clay minerals change with respect to the evolution of hydrogeological conditions during the life time of geothermal systems. The presented data are based on comparative studies performed in productive and non productive zones of several active geothermal systems related to subduction plate tectonics (Chipilapa, Milos and Bouillante). The temporal sequence of clay crystallizations can be summarized as follows. The opening stage of the geothermal system promotes a massive crystallization of metastable smectites in conditions of strong thermodynamic disequilibrium. As time and alteration progress, clay minerals of the newly sealed parts of the reservoir are transformed in more stable phases (via dissolution crystallization processes). Metastable smectites continue to precipitate in the permeable zones still subjected to strong physico-chemical disequilibrium such as boiling or mixing of fluids of contrasted composition and/or temperature, whereas clay minerals close to those predicted by thermodynamic calculations (illite, chlorite) crystallize in other zones in which the geothermal fluid can reach chemical equilibrium with the altered host rock. Downward infiltration of surficial water led to crystallization of montmorillonite in the outer part of geothermal fields. Collapsing of hydrothermal activity leads to a change in the heat flow regime with predominance of a depth dependant conductive thermal gradient. Even if such thermal conditions promote the transformation of the previously formed smectite rich metastable clay minerals and lead to a progressive emplacement of depth dependant conversion series of di- and trioctahedral smectites to respectively illite and chlorite, signatures of the ancient geothermal reservoirs are preserved in the textural or microstructural properties of the clay particles which sealed them.

Стилі APA, Harvard, Vancouver, ISO та ін.

44

Khuzhaniezov, Sh, and M. Siddikov. "Durability of Clay Architecture Monuments of Khorezm Oasis." Bulletin of Science and Practice 6, no. 12 (December 15, 2020): 472–76. http://dx.doi.org/10.33619/2414-2948/61/58.

Повний текст джерела

Анотація:

The results of the experimental study of MG, the possibility of using modified clay with a new composition was established, a method of heat treatment is recommended for the restoration of architectural clay-raw monuments and the construction of new low-rise residential buildings in seismically active regions.

Стилі APA, Harvard, Vancouver, ISO та ін.

45

Bondarev, A. V., E. T. Zhilyakova, N. B. Demina, and E. Yu Timoshenko. "Prospects for the Use of Medical Clays (Review)." Drug development & registration 8, no. 4 (November 26, 2019): 27–31. http://dx.doi.org/10.33380/2305-2066-2019-8-4-27-31.

Повний текст джерела

Анотація:

Introduction. The article deals with the aspects of the use of Medical Clays in Pharmaceutical Technology. A review of the traditional areas of application of Medical Clay, as well as highlighting new directions.Text. One of the main problems of domestic industrial pharmacy is a narrow nomenclature of active pharmaceutical substances and excipients. Replenishment of the nomenclature occurs in two ways-through the synthesis of new chemical compounds or through the processing of natural raw materials of animal, plant or mineral origin. In the process of purification and processing of mineral raw materials, Medical Clays are obtained, which are now widely used as active pharmaceutical substances for the production of Enterosorbents, as well as auxiliary substances.Conclusion. A review of perspectives and areas of use of Medicinal Clays have shown that at present, Medical Clays used in the three traditional areas: cutaneous application, application per os, application in pharmaceutical and food technology. A promising direction is the use of Medical Clays as transport drug systems. The study of this information array and its generalization has undoubted practical and scientific significance in modern pharmaceutical technology.

Стилі APA, Harvard, Vancouver, ISO та ін.

46

Porten, Kristin W., Michał J. Warchoł, and Ian A. Kane. "Formation of detrital clay grain coats by dewatering of deep-water sands and significance for reservoir quality." Journal of Sedimentary Research 89, no. 12 (December 20, 2019): 1231–49. http://dx.doi.org/10.2110/jsr.2019.65.

Повний текст джерела

Анотація:

ABSTRACT Well-developed detrital clay grain coats are observed in deep-marine sandstones of the Upper Cretaceous Springar Formation of the Vøring Basin in the Norwegian Sea. The detrital clay coats form thin and compact rims on individual sand grains and meniscus-shaped bridges between grains. These well-developed coats are found in high-density turbidites and proximal hybrid event beds with common to pervasive dewatering structures deposited in proximity to the base of a syndepositionally active basin high. Here, in one exploration well, detrital clay grain coats are common throughout a sandstone package 100 m thick. High-density turbidites and proximal and distal hybrid event beds drilled in mid- to distal-fan settings unaffected by seismically resolved seafloor topography show common dewatering features, but have only scattered detrital clay coats confined to individual dewatering pipes or dish structures. Hence, we propose that intense sediment dewatering has the potential to form detrital clay coats in deep-marine sandstones by a combination of elutriation and reorganization of clays during fluid escape from sediment bodies with pore fluid pressures significantly higher than the hydrostatic pressure. In submarine fan systems, deposition of sediment with coeval trapping of large volumes of interstitial pore fluid is most likely to occur where gravity flows undergo rapid deceleration in response to an abrupt decrease in confinement or gradient. Such environments include the channel–lobe transition and settings in proximity to seabed topography. The investigated sandstones are quartz arenites and subarkoses, with minor to moderate volumes of quartz cement (up to 6%). However, strongly to completely quartz-cemented intergranular pore space is observed where detrital clay coats or matrix does not cover quartz grains in the deepest part of the studied formation. Modeling of quartz cementation predicts that most intergranular macroporosity in the lower part of the Springar Formation would be quartz cemented if the sandstones were free of detrital clays. Based on our observations and modeling results we propose that intense sediment dewatering has the potential to form detrital clay coats, which can be important for retaining porosity in deeply buried sandstones and in basins with high present or past heat flow.

Стилі APA, Harvard, Vancouver, ISO та ін.

47

Leiten, K., H. Sirelpuu, and M. Kiviste. "Desalination using clay and lime sacrificial plasters with additives on field stone wall and fired clay bricks." Journal of Physics: Conference Series 2069, no. 1 (November 1, 2021): 012087. http://dx.doi.org/10.1088/1742-6596/2069/1/012087.

Повний текст джерела

Анотація:

Abstract Salt deteriorations can ruin the appearance as well as the structure of buildings. Salt deteriorations can be mitigated by passive and active methods. Common active methods include sprinkling water on the structure, scraping off the concentrated salts from the surface and the use of sacrificial plasters. Sacrificial plasters are traditionally used for desalination. Two tests at different sites were performed in order to determine the effectiveness of desalination of different sacrificial plasters. The first test site was a two hundred years old stable wall in Mooste county, Estonia. Salt percentage by mass in the test wall was determined in 2017 and again in 2019. In December 2019 different plasters of local natural clay and lime with additives such as hemp flax, charcoal and turf were tested on the wall. The second test was performed on burnt clay bricks that were placed into salt solution until efflorescence appeared. For desalination process again, different clay and lime based sacrificial plasters were used. After removing the sacrificial plaster, samples from the mortar and bricks were taken to measure the salt content by using Ion chromatography. Clay and hemp flax based sacrificial plasters were the most suitable for desalination and removal.

Стилі APA, Harvard, Vancouver, ISO та ін.

48

Fayyadh, M. A., and S. A. F. Rekani. "Distribution Path of Total and Active Carbonates, and Iron Oxides under Two Different Forest Tree Species." IOP Conference Series: Earth and Environmental Science 1120, no. 1 (December 1, 2022): 012038. http://dx.doi.org/10.1088/1755-1315/1120/1/012038.

Повний текст джерела

Анотація:

Abstract The research area was in Iraq’s Kurdistan region’s Duhok province. Oak and pine were chosen as the two woodland tree species. At each location, five pedons were dug, and soil horizons were then sampled. Because both types of forest soil were formed from limestone parent materials and the soil of Pine trees was substantially more carbonate than the soil of oak trees, and the calcium carbonate concentration of both forest types increased. The active carbonate varies from horizon to horizon, but it is often lower on the surface horizons, and its distribution pattern matches that of clay. Iron oxides in soils generally fluctuated between increasing and decreasing in the studied pedons, with the highest value of iron oxides in soil being discovered at the Sarke location. In contrast, the distribution pattern of iron oxides in clay fraction increased with increasing depth and was correlated with an increase in clay content. This study came to the conclusion that the distribution of active carbonate follows a similar pattern to that of total carbonate and is consistent with that of clay. The movement from surface soil horizons to subsurface due to gain was associated with the translocation of iron oxides in the investigated soils. The purpose of this study was to clarify the distribution pathways of free iron oxides, total and active carbonates in soil, under two different tree species.

Стилі APA, Harvard, Vancouver, ISO та ін.

49

Leal, Artur S. C., Carlos José de Araújo, Suédina Maria L. Silva, and Antônio Gilson Barbosa de Lima. "Thermal Behavior of Clay/Epoxy Nanocomposites." Journal of Nano Research 21 (December 2012): 23–28. http://dx.doi.org/10.4028/www.scientific.net/jnanor.21.23.

Повний текст джерела

Анотація:

In this work, the effect of curing agent, curing conditions and the incorporation of small amounts of organoclay on the thermal properties of DGEBA (diglycidyl ether of bisphenol A) epoxy resin was evaluated in order to develop an epoxy system for application as the matrix in active composites whose dispersed phase consists of shape memory alloy wires. The DGEBA resin was prepared using three amine derivatives as hardeners (triethylenetetramine - TETA, diethylenetriamine - DETA and diaminodiphenylsulfone - DDS) under varied curing conditions, in the absence and presence of organoclay. Epoxy systems were characterized by dynamic mechanical analysis (DMA), optical microscopy and X-ray diffraction. According to the obtained results, the cured DETA and DDS epoxy systems at elevated temperatures, above 180°C, showed a higher glass transition temperature (Tg) and thermal stability values than the system cured at low temperature (TETA). In addition, when the post-cure treatment was used, an improvement of the thermal stability was verified. When 1 phr (parts hundred resin) of organoclay was incorporated in DETA and DDS cured epoxy systems and post-cured, either the increase in the Tg and thermal stability values were more significant, especially for the system cured with DDS. Hence, the epoxy/DDS/organoclay system (exfoliated nanocomposite) is the most appropriate to be used as the matrix in the preparation of active composites since this matrix is thermally stable in the Ni-Ti shape memory alloy working range whose phase transformation occurs between 70 and 80 °C.

Стилі APA, Harvard, Vancouver, ISO та ін.

50

Islam, M. N., and A. F. M. Sanaullah. "Physico-chemical Properties of Soil of Rangapani Tea Estate of Bangladesh." Journal of Scientific Research 3, no. 3 (August 30, 2011): 683–88. http://dx.doi.org/10.3329/jsr.v3i3.7503.

Повний текст джерела

Анотація:

Bangladesh is one of the tea producing countries of the world. It has 163 tea estates. Rangapani is a low yielding tea estate relative to other neighboring tea estates of Chittagong district in Bangladesh. A total 54 soil samples were collected from six different hills and three topographic positions having different depths of Rnagapanni Tea-Estate. Physico-Chemical properties of soils such as active acidity, reserve acidity, cation exchange capacity and clay content of the collected soil samples were determined. The measured parameters of the soil samples were plotted and analyzed with reference to site and topography. The parameters have been found to vary with sampling sites, depths and topography. Active acidity and reserve acidity were very low, with some exceptions compared to the optimum range for tea cultivation. Sand, silt, clay and cation exchange capacity (CEC) were found in reasonable range Keywords: Soil; Active acidity; Reserve acidity; Cation exchange capacity; Clay content. © 2011 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: 10.3329/jsr.v3i3.7503 J. Sci. Res. 3 (3), 683-688 (2011)

Стилі APA, Harvard, Vancouver, ISO та ін.

Статті в журналах з теми "Active clay"

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями