Diffusion behavior of Se(IV) in Tamusu clayrock core by through-diffusion method

2021 ◽  
Author(s):  
Yuzhen Sun ◽  
Hui Zhang ◽  
Chuan-Pin Lee ◽  
Mingbiao Luo ◽  
Rong Hua ◽  
...  
Keyword(s):  
Diffusion Method ◽  
Diffusion Behavior ◽  
Through Diffusion

Through-and Out-Diffusion of Se(IV) and Re(VII) in Compacted Bentonite

2014 ◽  
Vol 953-954 ◽  
pp. 614-620
Author(s):  
Hai Wang ◽  
Tao Wu ◽  
Jiang Chen ◽  
Yao Lin Zhao ◽  
Chao Hui He ◽  
...  
Keyword(s):  
Diffusion Method ◽  
Gmz Bentonite ◽  
Porosity Distribution ◽  
Diffusion Behavior ◽  
Compacted Bentonite ◽  
Anion Diffusion ◽  
Through Diffusion

Through-diffusion and out-diffusion are good way to understand anion diffusion behavior in compacted bentonite. In the present work we investigated Re (VII) and Se (IV) diffusion behavior in 2000 kg/m3 compacted GMZ bentonite. The De values of Re (VII) and Se (IV) are 0.29 ± 0.02 and 0.77 ± 0.05× 10-11 m2/s. The result obtained from out-diffusion method was not agreed with predicted data due to the heterogeneous porosity distribution in clay boundaries and species changed when the diffusion occurred in GMZ bentonite. Comparing the Da values of Se, Tc and I in GMZ and Kunigel-F bentonites, it showed that Kunigel-F bentonite hindered the mobilities of anion more efficiently than GMZ bentonite because of the higher content of montmorillonite.

Investigation of Re(VII) diffusion in Tamusu clayrock core by through-diffusion method

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yuzhen Sun ◽  
Hui Zhang ◽  
Rong Hua ◽  
Mingbiao Luo ◽  
Chuan-Pin Lee ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Radioactive Waste ◽  
Diffusion Mechanism ◽  
Effective Diffusion ◽  
Diffusion Method ◽  
Migration Behavior ◽  
Diffusion Behavior ◽  
High Level Radioactive Waste ◽  
Through Diffusion ◽  
High Level

Abstract Tamusu area is the primary pre-selection site of clayrock disposal repository for high-level radioactive waste (HLW) in China. However, the research on the migration behavior of nuclides in Tamusu clayrock is still in its infancy. For the first time in laboratory, the diffusion behavior of Re(VII) in Tamusu clayrock core was studied by means of through-diffusion method. The effects of pH, ionic strength and humic acid on the diffusion behavior of Re(VII) in clayrock were studied. The effective diffusion coefficient, apparent diffusion coefficient and rock capacity factor value were obtained. All the experimental conditions of Re(VII) diffusion in Tamusu clayrock are compared with other geological samples under the same conditions in literature data. The diffusion mechanism of radionuclide in Tamusu clay is discussed, which can provide experimental data for site selection and safety assessment of high-level radioactive waste repository in China. The experimental results showed an effective application and reference for the countries disposed HLW in mudrocks or clayrocks, such as France, Belgium etc. in Europe. Moreover, this research can provide the original data support for the metallogenic regularity and prospecting prognosis of rare element rhenium in different geological environments.

Effective diffusivity of neptunium and plutonium in granite from Inada, Ibaraki, Japan under anaerobic conditions

2002 ◽  
Vol 90 (12) ◽  
Author(s):  
Tetsuji Yamaguchi ◽  
S. Nakayama ◽  
H. Okamoto
Keyword(s):  
Effective Diffusivity ◽  
Diffusion Method ◽  
Anaerobic Conditions ◽  
Through Diffusion ◽  
Effective Diffusivities

SummaryThe effective diffusivities of neptunium and plutonium in Inada granite have been determined using the through–diffusion method. Experiments were performed under anaerobic conditions in the presence of carbonate. The actinides are expected to be present as carbonato or carbonatohydroxo complexes. Effective diffusivity (D

Evaluation of sorption and diffusion behavior of selenium in crushed granite by through-diffusion column tests

2010 ◽  
Vol 285 (3) ◽  
pp. 733-739 ◽  
Author(s):  
Tsuey-Lin Tsai ◽  
Chuan-Pin Lee ◽  
Tzung-Yi Lin ◽  
Hwa-Jou Wei ◽  
Lee-Chung Men
Keyword(s):  
Column Tests ◽  
Diffusion Behavior ◽  
Crushed Granite ◽  
Diffusion Column ◽  
Through Diffusion ◽  
And Diffusion

Mineralogical Changes of Cement and Bentonite Accompanied ith Their Interactions

2009 ◽  
Vol 1193 ◽  
Author(s):  
Seiichi Hoshino ◽  
Tetsuji Yamaguchi ◽  
Toshikatsu Maeda ◽  
Masayuki Mukai ◽  
Tadao Tanaka ◽  
...  
Keyword(s):  
Tritiated Water ◽  
Effective Diffusivity ◽  
Diffusion Method ◽  
Hardened Cement ◽  
Computational Studies ◽  
Secondary Phases ◽  
Hardened Cement Paste ◽  
Xrd Pattern ◽  
Through Diffusion ◽  
Primary Minerals

AbstractMineralogical changes of cement and bentonite accompanied with their interaction wereexperimentally studied by mixing granulated hardened cement paste and bentonite, and aging the mixture for91 days at 50° C. Mineralogical changes of cement and bentonite were identified by XRD. Hydratedcalcium-silicate phases (C-S-H), Ca(OH)2, ettringite and monosulfate were identified in the unalteredhardened cement. While Ca(OH)2 and monosulfate decreased with aging and disappeared after 91 days,calcite and katoite (Ca3Al2(SiO4)(OH)8) were formed concurrently. Montmorillonite, quartz (and/orchalcedony), clinoptilolite, plagioclase, calcite, analcime and pyrite were identified in the unaltered bentonite.The XRD pattern showed that diffraction intensities of these minerals decreased with aging. It seems thatthese primary minerals dissolved in the course of the alteration. C-S-H appeared in bentonite during the agingas secondary phases, indicating the participation of silicon dissolved from the bentonite and calcium from thecement formed the C-S-H. The formation of C-S-H that had been predicted by previous modeling studieswas confirmed by the present experiments.In addition, diffusivity of tritiated water in mixed specimen with granulated hardened cement andbentonite was determined by a through-diffusion method. The effective diffusivity of tritiated water decreasedwith aging. The result suggests that the mass diffusivity in the interface of cement-bentonite system willdecrease with their interactions. The results of the diffusion experiments are qualitatively consistent with thediffusivity change in cement-bentonite systems predicted by some computational studies.

Experimental evaluation of personal protection devices against graphite nanoaerosols: fibrous filter media, masks, protective clothing, and gloves

2009 ◽  
Vol 28 (6-7) ◽  
pp. 353-359 ◽  
Author(s):  
L. Golanski ◽  
A. Guiot ◽  
F. Rouillon ◽  
J. Pocachard ◽  
F. Tardif
Keyword(s):  
Protective Clothing ◽  
Particle Diameter ◽  
Diffusion Method ◽  
Personal Protection ◽  
Electrical Mobility ◽  
Filter Media ◽  
Specific Test ◽  
Graphite Nanoparticles ◽  
Protection Devices ◽  
Through Diffusion

In this study, different conventional personal protection devices (fibrous filters, cartridges for respirators, protective clothing, and gloves) well qualified for micron particles were tested with graphite nanoparticles ranging from 10 to 100 nm (electrical mobility diameter). For this purpose, two specific test benches were designed: one for filter-based devices which are tested under a controlled air flow and other for gloves and protective clothing based on the “through diffusion method.” The penetration versus particle size shows for most tested filter media the behavior predicted by the theoretical Brownian capture: penetration decreases when particle diameter decreases. No thermal rebound was detected until 10 nm for graphite nanoparticles. Protective clothes were tested by two methods and same trends were obtained. Nonwoven fabrics (air-tight materials) are much more efficient against nanoparticles than cotton and paper. Gloves tested by “through diffusion technique,” in static condition seem to efficiently protect against graphite nanoparticles in spite of their important porosity.

Development of simplified biofilm sorption and diffusion experiment method using Bacillus sp. isolated from Horonobe Underground Research Laboratory

2014 ◽  
Vol 1665 ◽  
pp. 171-177
Author(s):  
Kotaro Ise ◽  
Tomofumi Sato ◽  
Yoshito Sasaki ◽  
Hideki Yoshikawa
Keyword(s):  
Bacillus Cereus ◽  
Diffusion Method ◽  
Cellulose Acetate Membrane ◽  
Diffusion Experiment ◽  
Biofilm Growth ◽  
Experiment Method ◽  
Measure Diffusion Coefficient ◽  
Through Diffusion ◽  
Underground Research Laboratory ◽  
And Diffusion

ABSTRACTWe developed a simplified biofilm sorption and diffusion experiment method. The biofilms of the Bacillus cereus were incubated on cellulose acetate membrane filters (pore size 0.2 µm, diameter 47 mm) placed on thick NB broth agar medium (thickness was about 30 mm) to support sufficient biofilm growth of the Bacillus cereus. The thickness of the formed biofilms was about 1 mm. The formed biofilms were applied to through-diffusion method, which has been used to measure diffusion coefficient of crystalline and sedimentary rocks and clay minerals. The obtained copper sorption coefficient by batch experiments was about 100 ml/g (wet weight) at the case of the concentration of cupper ion was over 0.074mmol/L. And diffusion coefficients by through diffusion experiment was De=1.1 x 10-10 (m2/s). From these results, this simplified biofilm sorption and diffusion experiment may make possible to obtain these parameters with ease.

Diffusion of Cs, Np, Am and Co in compacted sand-bentonite mixtures: evidence for surface diffusion of Cs cations

Clay Minerals ◽  
2013 ◽  
Vol 48 (2) ◽  
pp. 411-422 ◽  
Author(s):  
T. Sawaguchi ◽  
T. Yamaguchi ◽  
Y. Iida ◽  
T. Tanaka ◽  
I. Kitagawa
Keyword(s):  
Surface Diffusion ◽  
Pore Water ◽  
Concentration Gradient ◽  
Unit Volume ◽  
Effective Diffusivity ◽  
The Other ◽  
Diffusion Method ◽  
Diffusive Flux ◽  
Diffusive Transport ◽  
Through Diffusion

AbstractWe studied the diffusive transport of Cs, Np, Am and Co in compacted sandbentonite mixtures by using the through-diffusion method. The experiments for Cs were performed under various aqueous compositions. Effective diffusivity (De) values of 4.7×10–10 to 5.9×10–9 m2 s–1 were obtained with a somewhat large variation. Apparent diffusivity (Da) values, on the other hand, showed less variation, ranging from 2.0×10–12 to 6.2×10–12 m2 s–1. The results indicated that diffusive flux was proportional to the concentration gradient on the basis of the amount of Cs in the unit volume of the compacted sand-bentonite mixtures rather than the Cs concentration gradient in pore water. Because the former concentration gradient in the mixtures was nearly equal to that of adsorbed Cs, the diffusion of Cs in the mixtures was probably dominated by the concentration gradient of the Cs adsorbed on the mixtures. In addition, the effective/apparent diffusivity of 237Np(IV) and apparent diffusivity of 241Am(III) and 60Co(II) in the mixtures were determined in 0.3/0.03 mol l–1 (NH4)2CO3/Na2S2O4 solution.

Therapeutic efficacy of some extracts of hot pepper fruits (Capsicum annuum) and Sumac seeds (Rhus coriaria) on the growth of some isolated dermatophytes species

2018 ◽  
Vol 1 (3) ◽  
pp. 52-62
Author(s):  
Sara Omran ◽  
Abdulghani Alsamarai ◽  
Firas Razzzaq
Keyword(s):  
Antifungal Activity ◽  
Fungal Infection ◽  
Aqueous Extract ◽  
Plant Extracts ◽  
Therapeutic Efficacy ◽  
Diffusion Method ◽  
Quantitative Detection ◽  
Hot Pepper ◽  
Alcoholic Extract ◽  
Dermatology Clinic

Background: Fungal infections are one of the common skin diseases with difficulty in their treatment approach. The present efficient drugs for fungal infection are limited. Aim: To determine the therapeutic efficacy of plant extracts as alternative antifungal agents. Materials and methods: 100 clinical samples [68 from female and 32 from male] were collected during the period from March to July 2017 from subjects attending Dermatology Clinic in Salah Uldean General Hospital. Fungal infection was diagnosed with using KOH wet preparation. Fungal species identified by using conventional approach. The active ingredients existing in the plant extracts were detected and analyzed through qualitative and quantitative detection technique of chemical compounds using a high performance liquid chromatographic device (HPLC). Agar diffusion method was used to determine antifungal activity of plant extracts. Results: Direct microscopic examination showed that there were (75%) positive samples, while culture shows (67%) positive samples. The isolated dermatophytes belong to Epidermophyoton, Microsporum, and Trichophyton genus. The predominant dermatophytes were T. rubrum (25%) species. The highest frequency of infection was in the age group of 11-20 years. The sensitivity of the tested fungi to the aqueous and alcoholic plant extracts varies. Alcoholic extract of the hot pepper plant was more effective as antifungal than the aqueous extract of the same plant. However, aqueous hot pepper extracts was more effective against T. mentagrophyte than that of alcoholic extract. Additionally, alcoholic Sumac extract shows higher efficacy that aqueous extract. Conclusion: Hot pepper and Sumac extracts show antifungal activity against Microsporum canis, Trichophyton rubrum and T. mentagrophyte.

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