scholarly journals Swelling Properties and Permeability of GMZ Bentonite-Sand Mixtures during Different Solutions Infiltration

2021 ◽  
Vol 13 (4) ◽  
pp. 1622
Author(s):  
Yu-Ping Wang ◽  
Zhe Wang ◽  
Yu Zhao ◽  
Fa-Cheng Yi ◽  
Bao-Long Zhu
Keyword(s):  
Swelling Pressure ◽  
Development Stage ◽  
Gmz Bentonite ◽  
Test Results ◽  
X Ray Diffraction ◽  
Swelling Properties ◽  
Swelling Capacity ◽  
Slow Expansion ◽  
Expansion Stage ◽  
Chemical Solutions

In China, Gaomiaozi (GMZ) bentonite is recognized as a barrier material for isolating nuclear waste. Different chemical solutions may change the hydraulic conductivity and swelling capacity of bentonite. Consequently, a series of swelling pressure and permeability experiments was carried out on bentonite-sand mixtures with various dry densities and infiltrating solutions. X-ray diffraction (XRD) and the field emission scanning electron microscope (FESEM) were carried out on the samples experiencing the tests to identify the influence of chemistry pore solutions upon the mineralogical and microstructure changes. The results show that the swelling pressure experienced rapid swelling, slow expansion, and the stable expansion stage for the specimens of infiltrating solutions except for NaOH. For the specimens infiltrated with NaOH solutions, the swelling pressure experienced rapid increases, slow decreases, and a stable development stage. With hyper-alkaline and hyper-salinity infiltration, the swelling pressure decreased, and the permeability increased. In addition, swelling pressure attained stability more quickly on contact with hyper-alkaline and hyper-salinity solutions. Comparing the test results, the results indicate that the influence of NaOH on the expansion and permeability was higher than NaCl-Na2SO4 at the same concentration.

Swelling of Brazilian Organoclays in Some Solvents with Application in the Petroleum Industry

2010 ◽  
Vol 660-661 ◽  
pp. 1031-1036 ◽  
Author(s):  
M.B. Queiroz ◽  
Simone C.Gallani Rodrigues ◽  
Herve M. Laborde ◽  
Meiry Glaúcia Freire Rodrigues
Keyword(s):  
Quaternary Ammonium ◽  
Petroleum Industry ◽  
Diesel Oil ◽  
Basal Spacing ◽  
Test Results ◽  
X Ray Diffraction ◽  
Treated Sample ◽  
Swelling Capacity ◽  
Dimethylammonium Chloride ◽  
Aqueous Effluents

Brasgel clay has been modified via cation exchange reaction using quaternary ammonium chlorides (stearyl dimethylammonium chloride, Praepagen). Basal spacing, interlamellar structure clay have been characterized using X-ray diffraction (XRD) technique. The organoclay was characterized by the Foster Swelling test. The results indicated that the quaternary ammonium salts were intercalated between the layers of clay. The Foster Swelling Test results indicated that the affinity of stearyl dimethylammonium chloride, Praepagen occurred in the treated clay tested in all organic solvents (diesel, gasoline, toluene and p-xylene), without and with agitation. the treated sample presented a high swelling capacity (with and without agitation) when tested in gasoline. On the other hand, when inserted in diesel oil without agitation, the treated samples presented low swelling capacity, but when the assay was performed under agitation, it yielded an intermediate swelling capacity. In Toluene, the samples presented intermediate swelling, both without and with agitation. In p-xylene, the samples presented low swelling, without and intermediate swelling, with agitation. Therefore, this clay can be used for the removal of oils and greases from polluted aqueous effluents of the petroleum industry.

PENGEMBANGAN PERANGKAT PEMBELAJARAN MENGGUNAKAN PENDEKATAN CONTEXTUAL TEACHING AND LEARNING (CTL) DENGAN INTEGRASI NILAI-NILAI KARAKTER DI SMAN I TUGUMULYO

2014 ◽  
Vol 13 (3) ◽  
Author(s):  
Sri Wahyu Widyaningsih ◽  
Irfan Yusuf
Keyword(s):  
Teaching And Learning ◽  
Lesson Plan ◽  
Development Stage ◽  
Design Stage ◽  
Learning Tools ◽  
Test Results ◽  
Learning Materials ◽  
Is Research ◽  
Efficacy Trials

<p>The research is motivated not yet using CTL approach. In addition, the study provided yet foster the character value of students. This study aimed to the development of learning materials by using CTL approach with the integration of character value are valid, practical, and effective. The type of this research is research and development by using 4-D models. The stages of this research are define, design, and development. The define stage consists of analyzing of curriculum, students, and concept. Then, the learning materials as lesson plan, handout, student’s worksheet, and evaluation, were designed at design stage. The development stage was doing validity, practicality, and effectiveness test. The data of this research was collected by using validation instruments, questionnaire of students and teacher, observation and test instruments. The result of research with validity of the test results showed that the syllabus, lesson plans, teaching materials, worksheets and assessment sheets (cognitive, affective and psychomotor) developed very valid. The test results showed that the learning practicalities developed very practical. Based on the results of efficacy trials, it was stated that the developed learning very effectively used as learning tools are developed to improve the activity and competence of students in the cognitive, affective and psychomotor and behavioral character. And Those, learning materials by using CTL approach with the integration of character values are classification of very valid, very practical, and effective.</p>

Transient liquid phase bonding of Cu and Al using metallic particles interlayers

2021 ◽  
pp. 095440542098823
Author(s):  
Alireza Zaheri ◽  
Mohammadreza Farahani ◽  
Alireza Sadeghi ◽  
Naser Souri
Keyword(s):  
Liquid Phase ◽  
Mechanical Test ◽  
Transient Liquid Phase ◽  
Transient Liquid Phase Bonding ◽  
Joint Interface ◽  
Test Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metallic Particles ◽  
Powder Interlayer

The bonding strength, and microstructures of Cu and Al couples using metallic powders as interlayer during transient liquid phase bonding (TLP bonding) were investigated. The interfacial morphologies and microstructures were studied by scanning electron microscopy equipped with energy dispersive X-ray spectroscopy, and X-ray diffraction. First, to explore the optimum bonding time and temperature, nine samples were bonded without interlayers in a vacuum condition. Mechanical test results indicated that bonding at 560°C in 20 min returns the highest bond strength (84% of Al). This bonding condition was used to join ten samples with powder interlayers. Powders were prepared by mixing different combinations of Cu, Al (+Fe nanoparticles) and Zn. In the bonding zone, different Cu9Al4, CuAl, and CuAl2 intermetallic co-precipitate. The strongest bonding is formed in the sample with the 70Al (+Fe)-30Cu powder interlayer. Powder interlayers present thinner and more uniform intermetallic layers at the joint interface.

scholarly journals The Influence Of NO/O2 On The NOx Storage Properties Over A Pt-Ba-Ce/γ-Al2O3 Catalyst

2019 ◽  
Vol 17 (1) ◽  
pp. 1459-1465
Author(s):  
Xuedong Feng ◽  
Jing Yi ◽  
Peng Luo
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
No Oxidation ◽  
Test Results ◽  
X Ray Diffraction ◽  
Storage Performance ◽  
Transmission Electron ◽  
Temperature Programmed ◽  
Physical And Chemical ◽  
Al2o3 Catalyst

AbstractWith the purpose of studying the influence of NO/O2 on the NOx storage activity, a Pt-Ba-Ce/γ-Al2O3 catalyst was synthesized by an acid-aided sol-gel method. The physical and chemical properties of the catalyst were characterized by X-ray diffraction (XRD) and Transmission Electron Microscope (TEM) methods. The results showed that the composition of the catalyst was well-crystallized and the crystalline size of CeO2 (111) was about 5.7 nm. The mechanism of NO and NO2 storage and NOx temperature programmed desorption (NO-TPD) experiments were investigated to evaluate the NOx storage capacity of the catalyst. Pt-Ba-Ce/γ-Al2O3 catalyst presented the supreme NOx storage performance at 350℃, and the maximum value reached to 668.8 μmol / gcat. Compared with O2-free condition, NO oxidation to NO2 by O2 had a beneficial effect on the storage performance of NOx. NO-TPD test results showed that the NOx species stored on the catalyst surface still kept relatively stable even below 350℃.

scholarly journals Combined effect of mineralogical and chemical parameters on swelling behaviour of expansive soils

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bendadi Hanumantha Rao ◽  
Peddireddy Sreekanth Reddy ◽  
Bijayananda Mohanty ◽  
Krishna R. Reddy
Keyword(s):  
Expansive Soils ◽  
Research Work ◽  
Swelling Pressure ◽  
Combined Effect ◽  
Practical Significance ◽  
Chemical Compositions ◽  
Chemical Parameters ◽  
Swelling Behaviour ◽  
Mineral Contents ◽  
Swelling Properties

AbstractMicrolevel properties such as mineralogical and chemical compositions greatly control the macro behaviour of expansive soils. In this paper, the combined effect of mineral (i.e. montmorillonite, MMC) and chemical contents (i.e. Ca and Na in their total (T), leachable (L) and exchangeable form (CEC)) on swelling behaviour is investigated in a comprehensive way. Several 3-dimensional (3D) graphs correlating MMC and Ca/Na ratio, together, with swelling property (swelling potential, Sa, and swelling pressure, Sp) are developed. 3D plots, in general, portrayed a non-linear relationship of Sa and Sp with MMC and Ca/Na ratio, together. It is hypothesized that swelling initially is triggered by chemical parameters due to their quick and rapid ionization capability, but the overall swelling phenomenon is largely controlled by MMC. It is importantly found that expansive soils are dominant with divalent Ca++ ions up to MMC of 67% and beyond this percentage, monovalent Na+ ions are prevalent. From the interpretation of results, the maximum Sa of 18% and Sp of 93 kPa is measured at MMC of 43%, (Ca/Na)T of 10–14 and (Ca/Na)L of 2–7. It is concluded from study that total CEC + MMC for determining Sa and (Ca/Na)T + MMC for determining Sp are superior parameters to be considered. The findings of the study also excellently endorsed the results of Foster32, who stated that ionization of Na or Ca depends on the constituent mineral contents. The findings presented herein are unique, interesting and bear very practical significance, as no earlier research work reported such findings by accounting for chemical and mineralogical parameters impact, in tandem, on swelling properties.

Experimental Research on the Engineering Properties of Foam-Improved Red Clay Soil

2011 ◽  
Vol 261-263 ◽  
pp. 1831-1835
Author(s):  
Guo Gang Qiao ◽  
Da Jun Yuan ◽  
Bo Liu
Keyword(s):  
Experimental Research ◽  
Clay Soil ◽  
Soil Improvement ◽  
Engineering Properties ◽  
Screw Conveyor ◽  
Test Results ◽  
X Ray Diffraction ◽  
Shield Tunneling ◽  
Red Clay ◽  
Improvement Measures

Red clay soil is widely distributed in south China, the microstructure of red clay soil was studied applying scanning electron microscopy (SEM), and the X-ray diffraction analysis (XRD) test found that a large number of swelling inducing minerals, for example, montmorillonite, illite-montmorillonite or chlorite-smectite were contained in the red clay soil. Shield tunneling in this kind of stratum is prone to arising “cake” and “arch” phenomena and it prone to lead screw conveyor device unsmooth dumping, so soil improvement measures must be taken. Foam as the most advanced soil conditioner has been widely used in shield construction. Using self-developed foam agent, experimental research on foam conditioning red clay soil was carried out, test results show that foam can not only significantly reduce the soil shear strength, but also can greatly enhance the soil's compressibility and fluidity, which is significant for the smooth dumping and excavation face stability maintenance.

Effects of Laumontite Hydration/Dehydration on Swelling Deformation and Slake Durability of Altered Granodiorite

2020 ◽  
Vol 26 (4) ◽  
pp. 507-516
Author(s):  
Junsong Yan ◽  
Junhui Shen ◽  
Kaizhen Zhang ◽  
Jianjun Xu ◽  
Weifeng Duan ◽  
...  
Keyword(s):  
Axial Strain ◽  
Test Results ◽  
X Ray Diffraction ◽  
Dam Foundation ◽  
Hydro Power ◽  
Slake Durability Index ◽  
Slake Durability ◽  
Dehydration Reactions ◽  
Short Period ◽  
Durability Index

ABSTRACT The mineral laumontite can undergo hydration/dehydration reactions at room temperature. The hydration/dehydration produces a 3 to 6 percent volume change in the unit cell. The effects of laumontite hydration/dehydration on swelling and slake durability were investigated using altered granodiorite containing laumontite from the dam foundation of Yangfanggou Hydro Power Station, Sichuan, China. The occurrence of laumontite in altered rocks was first determined by petrological analysis. Typical samples were then collected for laboratory X-ray diffraction (XRD) analyses, free swelling tests, and slake durability index (SDI) tests. The test results were analyzed to determine the quantitative relationships between laumontite content, maximum axial strain, and slake durability index. We found that hydration of laumontite led to rock swelling. As laumontite content increased, maximum axial strain increased linearly; if water penetrated the rock quickly, swelling occurred over a short period. The hydration/dehydration of laumontite decreased slake durability of the rock; the SDI decreased approximately linearly as laumontite content increased.

scholarly journals Perancangan E-Modul “ALKI” Pada Mata Pelajaran Kimia Bagi Siswa Kelas X Berbasis Mobile di SMAN 1 Mapat Tunggul

2021 ◽  
Vol 6 (2) ◽  
pp. 93-104
Author(s):  
Aisyah Amini ◽  
Riri Okra
Keyword(s):  
Mobile Application ◽  
Development Stage ◽  
Test Results ◽  
Research Model ◽  
Design Development ◽  
Process Testing ◽  
Development Life Cycle ◽  
Multimedia Development ◽  
The Media ◽  
Chemical Materials

ALKI is an e-module that serves as a learning medium for grade X students majoring in MIA at SMAN 1 MAPAT TUNGGUL. E-module ALKI was created with the aim of assisting teachers in delivering materials and helping students understand more about chemical materials by repeating lessons, working on exercises, and strengthening memory by playing flashcards. The thing behind the design of alki e-module is the lack of motivation to learn students, difficulty and the absence of internet network in Mapat Tunggul area, students should not take home the package book, the smartphone owned by students is not used to study, and when doing homework with the help of the internet most students just copy the answer without understanding the origin of the answer. This research method is Research and Development (R&D) with a 4-D research model (four-D) that is with define, Design, Development, and Disseminate stages. In the Development stage, the development stage of ALKI e-module media is carried out. The media development model used in this study is MDLC(Multimedia Development Life Cycle) luther-sutopo version which consists of 6 stages, namely conception, design, material collection, manufacturing process, testing and distribution. The result of the research is a mobile-based ALKI e-module product. With 0.81 validity test results declared valid,0.93 Practicality test results are practiced very practically,and 0.80 effectiveness test results are declared very effective. So, it can be concluded that alki e-module based on mobile application as a learning medium has been valid, practical and effective.

scholarly journals SYNTHESIS AND PROTECTIVE PROPERTIES OF PECTIN/MONTMORILLONITE COMPOSITES AGAINST ASPIRIN-INDUCED ENTEROCOLITIS

2020 ◽  
Vol 17 (35) ◽  
pp. 897-907
Author(s):  
Assemgul S. AUYEZKHANOVA ◽  
Eldar T. TALGATOV ◽  
Sandugash N. AKHMETOVA ◽  
Unzira N. KAPYSHEVA ◽  
Alima K. ZHARMAGAMBETOVA
Keyword(s):  
Gastrointestinal Tract ◽  
Adverse Effects ◽  
Hybrid Composites ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Swelling Properties ◽  
Protective Properties ◽  
Pectin Content ◽  
Water Ph

Long term use of aspirin for prevention of cardiovascular events is limited by its gastrointestinal adverse effects, and, therefore, patients at high risk should receive gastroprotective agents. However, gastroprotective drugs also have a few adverse effects that require searching for safe and effective alternatives. The composites combining the swelling properties of clays and the biological activity of polysaccharides seem to be promising candidates for gastrointestinal protection. This study aimed to characterize pectin/montmorillonite composites and evaluate their protective effect on the gastrointestinal tract of rats taking aspirin over a long period. A series of composites based on montmorillonite (ММТ) and low esterified pectin (Pec) was synthesized using the adsorption-precipitation method. The polysaccharide to clay weight ratios were 1:19, 1:9, and 1:4. The composites were characterized using Thermogravimetric Analysis (TGA), Infrared Spectroscopy (IR), Scanning Electron Microscopy (SEM), and X-Ray Diffraction (XRD). Pectin was completely fixed on MMT, and the polysaccharide content in the composites was approximately 5, 10, and 20 wt%, respectively. The shifting of the absorption band of the C=O group of the pectin indicated the interaction of the polysaccharide with the clay, confirming effective immobilization of Pec on MMT. Modification with pectin changed the morphology and structure of the MMT due to the surface coating and intercalation into the interlayer space. The composites swelled in acidified water (pH = 2.0), and their swelling ability was higher to compare with unmodified MMT. The sorption capacity of Pec/MMT composites towards acetylsalicylic acid (ASA) was decreased from 6.8 to 1.0 mg g-1 with increasing of pectin content from 5 to 20 wt%. The hybrid composites promoted the protection of the gastrointestinal tract of rats, which were administered ASA with Pec/MMTs for 16 days. Protective properties of the Pec/MMT have been improved with increasing pectin content from 5 to 20 wt%.

Synthesis, Applications and Swelling Properties of Poly (Sodium Acrylate-Coacrylamide) Based Superabsorbent Hydrogels

2019 ◽  
Vol 41 (4) ◽  
pp. 668-668
Author(s):  
Saud Hashmi Saud Hashmi ◽  
Saad Nadeem Saad Nadeem ◽  
Zahoor Awan Zahoor Awan ◽  
Adeel ur Rehman Adeel ur Rehman ◽  
Ahsan Abdul Ghani Ahsan Abdul Ghani
Keyword(s):  
Rate Constant ◽  
Polymeric Materials ◽  
Water Soluble ◽  
Ion Concentration ◽  
Copolymer Composition ◽  
Swelling Properties ◽  
Swelling Capacity ◽  
Swelling Rate ◽  
Crosslinker Concentration ◽  
Superabsorbent Hydrogels

Superabsorbent hydrogels constitute a group of polymeric materials with three-dimensional network structure, which can swell to absorb an enormous amount of water or aqueous solutions. This property enables various commercial applications of hydrogels such as water holding capability in agriculture and superabsorbent material for baby diapers. Several novel superabsorbent hydrogels based on acrylic acid-co-acrylamide copolymers were synthesized under variation of copolymer compositions through free radical polymerization. N,N’methylenebisacrylamide (MBA) was used as a water soluble crosslinker and potassium persulphate (KPS) as an initiator. Effect of varying the copolymer composition, change in crosslinker concentration, and effect of environmental parameters (pH, temperature, and ion concentration) on both swelling capacity and swelling rate were examined. These gel shows maximum swelling at neutral pH-7, whereas increasing salt concentration in water decrease the swelling capacity. It was found interesting that an increase in crosslinker concentration from 0.020% to 0.16%, the swelling capacity decreases up to 70% while the swelling rate increases from 0.007g water/g dry hydrogel sec to 0.024g water/g dry hydrogel sec, respectively because there is a compromise exists between entropic spring forces between network connection points and the hydrostatic pressure of the water diffusing into the gels. Dynamic swelling curve obtained were fitted to the three different kinetic models namely Peleg’s kinetic model, pseudo 1st order as proposed by Lagergen and pseudo 2nd order kinetics. All these models provided a good agreement with the experimental data; However on the bases of statistical parameters (RMSE, R2 and X2) the Peleg’s model was selected as the most appropriate model for this study. Analyzing rate constant for Peleg’s models at different swelling temperatures disclosed that increasing temperature could only increase the swelling rate without affecting the swelling capacity of the hydrogels. Experimental values for rate constant k1 of Peleg’s model at different temperature shows a sharp decrease from 0.57545 at 30 oC to 0.1535 at 75 oC that contemplated the rate of swelling at 75 oC was 65% faster than that of 30 oC. The diffusion mechanisms in hydrogels were proven to be tailorable by increasing cross-linker concentration and temperature, leading towards the Fickian type diffusion behavior. The synthesized superabsorbent hydrogels were also tested for water retention applications in agriculture.

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