Interface actions between TiO{sub 2} and porous diatomite on the structure and photocatalytic activity of TiO{sub 2}-diatomite

Energy Technology Data Exchange (ETDEWEB)

Xia, Yue; Li, Fangfei; Jiang, Yinshan, E-mail: jiangys@jlu.edu.cn; Xia, Maosheng; Xue, Bing; Li, Yanjuan

2014-06-01

TiO{sub 2}-diatomite photocatalysts were prepared by sol–gel process with various pre-modified diatomite. In order to obtain diatomite with different surface characteristics, two modification approaches including calcination and phosphoric acid treatment on the micro-structure of diatomite are introduced. The photocatalysts were characterized by XRD, XPS, nitrogen adsorption–desorption isotherms and micromorphology analysis. The results indicate that, compared with pure TiO{sub 2}, the anatase-to-rutile phase transition temperature of TiO{sub 2} loaded on diatomite carrier is significantly increased to nearly 900 °C, depending on the different pretreatment method of diatomite. The photocatalytic activities of different samples were evaluated by their degradation rate of methyl orange (MO) dye under UV and visible-light irradiation. The samples prepared by phosphoric acid pretreatment method exhibit the highest photocatalytic activity. After 90 min of UV irradiation, about 90% of MO is decomposed by the best effective photocatalyst. And after 8 h visible-light irradiation, nearly 60% of MO is decomposed by the same sample. Further mechanism investigation reveals that the H{sub 3}PO{sub 4} pretreatment process can obviously change the surface features of diatomite carrier, cause the formation of Si–O–Ti bond, increase the binding strength between TiO{sub 2} and diatomite, restrain crystal growth of loaded TiO{sub 2}, and thus form thermal-stable mesoporous structure at the granular spaces. It helps to build micro-, meso- and macro-porous hierarchical porous structure in TiO{sub 2}-diatomite, and improves the charge and mass transfer efficiency during catalyzing process, resulting in the significantly increased photocatalytic activity of TiO{sub 2}-diatomite pretreated by phosphoric acid.

Immobilization of uranium from aqueous solutions by using natural diatomites

International Nuclear Information System (INIS)

Mokhambetbakr, Kh.E.; Burkitbaev, M.

2008-01-01

In this study, the adsorption of uranium on natural diatomite (as high abundant and low-cost material) obtained from Aktyubinsk (Kazakhstan) has been investigated. The main purpose of this work is the immobilization of uranium from liquid waste by using diatomites. The diatomites under study were subjected to treatment with various conditions. The first sample is the natural sample (D) Natural Diatomite, the second (D H CL) is purified 0,5 N HCl and the third is the Calcined Diatomite (D 9 00). The effects of concentration of uranium, contact time and type of diatomite treatment on the adsorption process were examined.

Development and characterization of ferrihydrite-modified diatomite as a phosphorus adsorbent.

Science.gov (United States)

Xiong, Wenhui; Peng, Jian

2008-12-01

A novel phosphorus adsorbent, ferrihydrite-modified diatomite was developed and characterized in this study. The ferrihydrite-modified diatomite was made through surface modification treatments including NaOH treatment and ferrihydrite deposition on raw diatomite. In the NaOH treatment, surface SiO(2) of diatomite was partially dissolved in the NaOH solution. The dissolved Si contributed to form the stable 2-line ferrihydrite which deposited into the macropores and mesopores of diatomite. Blocking macropores and larger mesopores of diatomite with 0.24g Fe/g of 2-line ferrihydrite resulted in a specific surface area of 211.1m(2)/g for the ferrihydrite-modified diatomite, which is 8.5-fold increase than the raw diatomite (24.77m(2)/g). The surface modification also increased the point of zero charge (pH(PZC)) values to 10 for the ferrihydrite-modified diatomite from 5.8 for the raw diatomite. Because of the increased surface area and surface charge, the maximum adsorption capacity of ferrihydrite-modified diatomite at pH 4 and pH 8.5 was increased from 10.2mgP/g and 1.7mgP/g of raw diatomite to 37.3mgP/g and 13.6mgP/g, respectively.

Sonocatalytic Degradation of Antibiotics Tetracycline by Mn-Modified Diatomite

OpenAIRE

Guo, Yiping; Mi, Xiao; Li, Guoting; Chen, Xi

2017-01-01

Mn-modified diatomite was prepared by wet impregnation and subsequent calcinations processes. It was used as catalyst for sonocatalytic degradation of antibiotics tetracycline. Characterizations by scanning electron microscopy and X-ray diffraction pattern showed that the morphology and crystal structure of the modified diatomite were similar to these of raw diatomite. Despite containing very limited amount of Mn oxides, the Mn-modified diatomite showed much higher sonocatalytic activity than...

Lime finishing compounds using modified diatomite

OpenAIRE

Логаніна, Валентина Іванівна; Камбург, Володимир Григорович; Давидова, Ольга Олександрівна; Симонов, Євген Євгенович

2012-01-01

It provides information on the impact of modification of diatomite sol silicon-ing acid on the rheological properties of calcareous composition with the introduction of plasticizers. It is shown that modification of diatomite promotes the improvement exists a plasticizing properties of calcareous composition

Detection of mineral impurities in diatomite ores

OpenAIRE

Guatame Garcia, L.A.; Buxton, M.W.N.; Fiore, Saverio

2017-01-01

Diatomaceous Earth (DE) is commonly used in the industry for the manufacturing of filters, where diatomite is preferred due to its low chemical reactivity and high porosity. Diatomite deposits with major amounts of mineral impurities, such as carbonates, present a problem in the production DE. In this study, samples from a diatomite deposit with known presence of carbonate were analysed. With the aim of estimating the carbonate content, the samples were analysed with infrared (IR) spectroscop...

Performance Evaluation and Improving Mechanisms of Diatomite-Modified Asphalt Mixture.

Science.gov (United States)

Yang, Chao; Xie, Jun; Zhou, Xiaojun; Liu, Quantao; Pang, Ling

2018-04-27

Diatomite is an inorganic natural resource in large reserve. This study consists of two phases to evaluate the effects of diatomite on asphalt mixtures. In the first phase, we characterized the diatomite in terms of mineralogical properties, chemical compositions, particle size distribution, mesoporous distribution, morphology, and IR spectra. In the second phase, road performances, referring to the permanent deformation, crack, fatigue, and moisture resistance, of asphalt mixtures with diatomite were investigated. The characterization of diatomite exhibits that it is a porous material with high SiO₂ content and large specific surface area. It contributes to asphalt absorption and therefore leads to bonding enhancement between asphalt and aggregate. However, physical absorption instead of chemical reaction occurs according to the results of FTIR. The resistance of asphalt mixtures with diatomite to permanent deformation and moisture are superior to those of the control mixtures. But, the addition of diatomite does not help to improve the crack and fatigue resistance of asphalt mixture.

Performance Evaluation and Improving Mechanisms of Diatomite-Modified Asphalt Mixture

Directory of Open Access Journals (Sweden)

Chao Yang

2018-04-01

Full Text Available Diatomite is an inorganic natural resource in large reserve. This study consists of two phases to evaluate the effects of diatomite on asphalt mixtures. In the first phase, we characterized the diatomite in terms of mineralogical properties, chemical compositions, particle size distribution, mesoporous distribution, morphology, and IR spectra. In the second phase, road performances, referring to the permanent deformation, crack, fatigue, and moisture resistance, of asphalt mixtures with diatomite were investigated. The characterization of diatomite exhibits that it is a porous material with high SiO2 content and large specific surface area. It contributes to asphalt absorption and therefore leads to bonding enhancement between asphalt and aggregate. However, physical absorption instead of chemical reaction occurs according to the results of FTIR. The resistance of asphalt mixtures with diatomite to permanent deformation and moisture are superior to those of the control mixtures. But, the addition of diatomite does not help to improve the crack and fatigue resistance of asphalt mixture.

Advanced tertiary treatment of municipal wastewater using raw and modified diatomite.

Science.gov (United States)

Wu, Jinlu; Yang, Y S; Lin, Jinhua

2005-12-09

Advanced technology for more efficient and effective wastewater treatment is always timely needed. The feasibility of using raw and modified diatomite for advanced treatment of secondary sewage effluents (SSE) was investigated in this study. Raw diatomite at a dosing rate of 300 mg/l showed a similar potential as activated carbon for removing most organic pollutants and toxic metals from SSE. Its performance was found poor in removal of arsenic and crop nutrient constituents (e.g. ammoniacal nitrogen and phosphate) and remained unsatisfactory even when the dosing rate increased up to 500 mg/l. Where modified diatomite was in lieu of raw diatomite, the removal efficiency for all target constituents was improved by 20-50%. At the dosing rate of 150 mg/l, modified diatomite enabled the post-treated effluents to satisfy the discharge consents, with the levels of all target constituents below the regulatory limits. Modified diatomite has advantages over raw diatomite in improving removal efficiency and reducing the dosing rate required for satisfactory treatment of SSE. It is concluded that modified diatomite is much more effective and efficient than raw diatomite, as an alternative to activated carbon, for economic treatment of SSE.

The Influence of Diatomite on the Strength and Microstructure of Portland Cement

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Liu Jun

2016-01-01

Full Text Available To study the influence of the types and mixing amount of diatomite on the Portland cement, we prepared the cement specimen doped with the calcined first-grade, first-grade and second-grade diatomite ,tested the 3d, 7d, 14d compressive strength, and studied and discussed phase, structure and morphology of diatomite in the binary system by the method of XRD, SEM . Experimental results show that with the addition of diatomite, the strength of cement paste increase; the optimal contents of calcined first-grade ,first-grade and second-grade diatomite in Portland cement are 5%,Compared to the blank group, the strength of specimen can be increased by 54.6%, 15.4% and 10.2%, respectively; At the same time ,the 7d microscopic hydration of different diatomite particles were analyzed through the experiment , and the shell of calcined diatomite particles were better hydrated than that of first-grade and second-grade diatomite particles. The results indicate that the diatomite can improve the strength of cement paste, the hydration of different diatomite particles can influence the growth of cement paste strength.

Detection of mineral impurities in diatomite ores

NARCIS (Netherlands)

Guatame Garcia, L.A.; Buxton, M.W.N.; Fiore, Saverio

2017-01-01

Diatomaceous Earth (DE) is commonly used in the industry for the manufacturing of filters, where diatomite is preferred due to its low chemical reactivity and high porosity. Diatomite deposits with major amounts of mineral impurities, such as carbonates, present a problem in the production DE. In

Sonocatalytic Degradation of Antibiotics Tetracycline by Mn-Modified Diatomite

Directory of Open Access Journals (Sweden)

Yiping Guo

2017-01-01

Full Text Available Mn-modified diatomite was prepared by wet impregnation and subsequent calcinations processes. It was used as catalyst for sonocatalytic degradation of antibiotics tetracycline. Characterizations by scanning electron microscopy and X-ray diffraction pattern showed that the morphology and crystal structure of the modified diatomite were similar to these of raw diatomite. Despite containing very limited amount of Mn oxides, the Mn-modified diatomite showed much higher sonocatalytic activity than the raw diatomite. The increases in both MnSO4 concentration of the wet impregnation solution and the catalyst dosage could enhance the degradation of antibiotics tetracycline significantly. Kapp values for ultrasonication, catalyst adsorption, and both processes combined (0.10 mol/L MnSO4-modified diatomite were 1.22 × 10−4, 0.00193, and 0.00453 min−1, respectively, while the corresponding values of R2 were 0.956, 0.986, and 0.953, respectively. These results demonstrated the significant synergetic effect by combining ultrasonication and catalyst adsorption processes. The presence of isopropanol, KBr, and NaN3 quenched a series of reactive oxygen species sharply, indicating the dominant role of reactive oxygen species in the sonocatalytic process. In contrast, the addition of Fe(II enhanced the degradation due to the generation of more OH∙ radicals in the concurrent Fenton reaction. All the results indicated that Mn-modified diatomite had the great potential for water treatment by sonocatalytic oxidation.

Turning the volume down on heavy metals using tuned diatomite. A review of diatomite and modified diatomite for the extraction of heavy metals from water.

Science.gov (United States)

Danil de Namor, Angela F; El Gamouz, Abdelaziz; Frangie, Sofia; Martinez, Vanina; Valiente, Liliana; Webb, Oliver A

2012-11-30

Contamination of water by heavy metals is a global problem, to which an inexpensive and simple solution is required. Within this context the unique properties of diatomite and its abundance in many regions of the world have led to the current widespread interest in this material for water purification purposes. Defined sections on articles published on the use of raw and modified diatomite for the removal of heavy metal pollutants from water are critically reviewed. The capability of the materials as extracting agents for individual species and mixtures of heavy metals are considered in terms of the kinetics, the thermodynamics and the recyclability for both, the pollutant and the extracting material. The concept of 'selectivity' for the enrichment of naturally occurring materials such as diatomite through the introduction of suitable functionalities in their structure to target a given pollutant is emphasised. Suggestions for further research in this area are given. Copyright © 2012 Elsevier B.V. All rights reserved.

Removal of aniline and phenol from water using raw and aluminum hydroxide-modified diatomite.

Science.gov (United States)

Wu, C D; Zhang, J Y; Wang, L; He, M H

2013-01-01

The feasibility of using raw diatomite and aluminum hydroxide-modified diatomite (Al-diatomite) for removal of aniline and phenol from water was investigated. Their physicochemical characteristics such as pHsolution, point of zero charge (pHPZC), surface area, Fourier transform infrared (FT-IR) and scanning electron microscopy was determined. After the raw diatomite was modified, the surface area of Al-diatomite increases from 26.67 to 82.65 m(2) g(-1). The pHPZC and pHsolution (10%) occurred around pH 5.2 and pH 8.6, respectively. The removal rates of aniline and phenol on diatomite and Al-diatomite decreased with increasing solution pH, while surface charge density decreased. The adsorption of aniline and phenol on diatomite presented a good fit to the Langmuir and Freundlich models, but the models are not fit to forecast the adsorption of aniline and phenol on Al-diatomite. The study indicated that electrostatic interaction was a dominating mechanism of aniline and phenol sorption onto Al-diatomite.

Freshwater diatomite deposits in the western United States

Science.gov (United States)

Wallace, Alan R.; Frank, David G.; Founie, Alan

2006-01-01

Freshwater diatomite deposits in the Western United States are found in lake beds that formed millions of years ago. These diatom-rich sediments are among the Nation's largest commercial diatomite deposits. Each deposit contains billions of tiny diatom skeletons, which are widely used for filtration, absorption, and abrasives. New studies by the U.S. Geological Survey (USGS) are revealing how ancient lakes in the Western States produced such large numbers of diatoms. These findings can be used by both land-use managers and mining companies to better evaluate diatomite resources in the region.

Inorganically modified diatomite as a potential prolonged-release drug carrier.

Science.gov (United States)

Janićijević, Jelena; Krajišnik, Danina; Calija, Bojan; Dobričić, Vladimir; Daković, Aleksandra; Krstić, Jugoslav; Marković, Marija; Milić, Jela

2014-09-01

Inorganic modification of diatomite was performed with the precipitation product of partially neutralized aluminum sulfate solution at three different mass ratios. The starting and the modified diatomites were characterized by SEM-EDS, FTIR, thermal analysis and zeta potential measurements and evaluated for drug loading capacity in adsorption batch experiments using diclofenac sodium (DS) as a model drug. In vitro drug release studies were performed in phosphate buffer pH6.8 from comprimates containing: the drug adsorbed onto the selected modified diatomite sample (DAMD), physical mixture of the drug with the selected modified diatomite sample (PMDMD) and physical mixture of the drug with the starting diatomite (PMDD). In vivo acute toxicity testing of the modified diatomite samples was performed on mice. High adsorbent loading of the selected modified diatomite sample (~250mg/g in 2h) enabled the preparation of comprimates containing adsorbed DS in the amount near to its therapeutic dose. Drug release studies demonstrated prolonged release of DS over a period of 8h from both DAMD comprimates (18% after 8h) and PMDMD comprimates (45% after 8h). The release kinetics for DAMD and PMDMD comprimates fitted well with Korsmeyer-Peppas and Bhaskar models, indicating that the release mechanism was a combination of non-Fickian diffusion and ion exchange process. Copyright © 2014 Elsevier B.V. All rights reserved.

Photocatalytic Degradation of Methylene Blue Using TiO2 Impregnated Diatomite

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Ranfang Zuo

2014-01-01

Full Text Available Nano-TiO2 showed a good catalytic activity, but it is easy to agglomerate, resulting in the reduction or even complete loss of photocatalytic activity. The dispersion of TiO2 particles on porous materials was a potential solution to this problem. Diatomite has high specific surface and absorbability because of its particular shell structure. Thus, TiO2/diatomite composite, prepared by loading TiO2 on the surface of diatomite, was a good photocatalyst, through absorbing organic compounds with diatomite and degrading them with TiO2. Scanning electron microscopy (SEM, energy dispersive spectrum (EDS, X-ray diffraction (XRD, chemical analysis, and Fourier transform infrared spectrometry (FTIR indicated that TiO2 was impregnated well on the surface of diatomite. Furthermore, TiO2/diatomite was more active than nano-TiO2 for the degradation of methylene blue (MB in solution. MB at concentrations of 15 and 35 ppm can be completely degraded in 20 and 40 min, respectively.

A new green methodology for surface modification of diatomite filler in elastomers

Energy Technology Data Exchange (ETDEWEB)

Lamastra, F.R. [Italian Interuniversity Consortium on Materials Science and Technology (INSTM), Research Unit Roma Tor Vergata, Via del Politecnico 1, 00133, Rome (Italy); Mori, S.; Cherubini, V. [Italian Interuniversity Consortium on Materials Science and Technology (INSTM), Research Unit Roma Tor Vergata, Via del Politecnico 1, 00133, Rome (Italy); Department of Enterprise Engineering, University of Rome ' Tor Vergata' , Via del Politecnico 1, 00133, Rome (Italy); Scarselli, M. [Department of Physics, University of Rome ' Tor Vergata' , Via della Ricerca Scientifica 1, 00133, Rome (Italy); Nanni, F., E-mail: fnanni@ing.uniroma2.it [Italian Interuniversity Consortium on Materials Science and Technology (INSTM), Research Unit Roma Tor Vergata, Via del Politecnico 1, 00133, Rome (Italy); Department of Enterprise Engineering, University of Rome ' Tor Vergata' , Via del Politecnico 1, 00133, Rome (Italy)

2017-06-15

In this work a new, simple and green protocol to introduce a limited content of silanol groups on the surface of an hydrophobic diatomite, in order to be slightly hydrophilic and susceptible to be silanized by bifunctional, sulfur-containing organosilanes for rubber applications, is proposed. The chemical modification was carried out at 85 °C in a solution of H{sub 2}O:NaOH:H{sub 2}O{sub 2}. The modified diatomite was then silanized with bis(triethoxysilylpropyl) disulfide by a procedure that does not involve toxic solvent. Morphological features and elemental composition of diatomite were investigated by Field emission scanning electron microscopy coupled with Energy dispersive X-ray spectroscopy. The surface modification and silanization process were assessed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Diatomite was composed by micrometric frustules from different diatom species with pore size ranging from 25 nm to 1 μm. The spectroscopic characterizations confirmed the surface modification of diatomite with some silanols that acted as sites for silanization reaction. The silanized diatomite and the untreated one were used as filler in unvulcanized solvent-cast SBR films in order to verify that the modification does not negatively affect the polymer/filler interface and as consequence the mechanical properties. Mechanical properties of the realized samples were assessed by uniaxial tensile tests. Films filled with 10 wt% of diatomite (untreated or silanized) showed an increase of Elastic Modulus about of 50% and a decrease of the strain at break with respect to SBR samples, while the tensile strength was not significantly affected by the diatomite addition. SEM images of fracture surfaces of tested specimens showed a fine dispersion of both untreated and silanized diatomite in the polymeric matrix and the achieving of a good interfacial adhesion SBR/fillers. The silanized diatomite, as it is potentially able to bind

A new green methodology for surface modification of diatomite filler in elastomers

International Nuclear Information System (INIS)

Lamastra, F.R.; Mori, S.; Cherubini, V.; Scarselli, M.; Nanni, F.

2017-01-01

In this work a new, simple and green protocol to introduce a limited content of silanol groups on the surface of an hydrophobic diatomite, in order to be slightly hydrophilic and susceptible to be silanized by bifunctional, sulfur-containing organosilanes for rubber applications, is proposed. The chemical modification was carried out at 85 °C in a solution of H_2O:NaOH:H_2O_2. The modified diatomite was then silanized with bis(triethoxysilylpropyl) disulfide by a procedure that does not involve toxic solvent. Morphological features and elemental composition of diatomite were investigated by Field emission scanning electron microscopy coupled with Energy dispersive X-ray spectroscopy. The surface modification and silanization process were assessed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Diatomite was composed by micrometric frustules from different diatom species with pore size ranging from 25 nm to 1 μm. The spectroscopic characterizations confirmed the surface modification of diatomite with some silanols that acted as sites for silanization reaction. The silanized diatomite and the untreated one were used as filler in unvulcanized solvent-cast SBR films in order to verify that the modification does not negatively affect the polymer/filler interface and as consequence the mechanical properties. Mechanical properties of the realized samples were assessed by uniaxial tensile tests. Films filled with 10 wt% of diatomite (untreated or silanized) showed an increase of Elastic Modulus about of 50% and a decrease of the strain at break with respect to SBR samples, while the tensile strength was not significantly affected by the diatomite addition. SEM images of fracture surfaces of tested specimens showed a fine dispersion of both untreated and silanized diatomite in the polymeric matrix and the achieving of a good interfacial adhesion SBR/fillers. The silanized diatomite, as it is potentially able to bind chemically to

Natural diatomite process for removal of radioactivity from liquid waste

Energy Technology Data Exchange (ETDEWEB)

Osmanlioglu, Ahmet Erdal [Radioactive Waste Management Unit (RWMU), Turkish Atomic Energy Authority, Cekmece Nuclear Research and Training Center, Altinsehir Yolu 5 km. Halkali, 34303K Cekmece, Istanbul (Turkey)]. E-mail: Erdal.Osmanlioglu@taek.gov.tr

2007-01-15

Diatomite has a number of unique physical properties and has found diversified industrial utilization. The filtration characteristics are particularly significant in the purification of liquids. The purpose of this study was to test natural diatomaceous earth (diatomite) as an alternative material that could be used for removal of radioactivity from liquid waste. A pilot-scale column-type device was designed. Natural diatomite samples were ground, sieved and prepared to use as sorption media. In this study, real waste liquid was used as radioactive liquid having special conditions. The liquid waste contained three radionuclides (Cs-137, Cs-134 and Co-60). Following the treatment by diatomite, the radioactivity of liquid waste was reduced from the initial 2.60 Bq/ml to less than 0.40 Bq/ml. The results of this study show that most of the radioactivity was removed from the solution by processing with diatomite.

Natural diatomite process for removal of radioactivity from liquid waste

International Nuclear Information System (INIS)

Osmanlioglu, Ahmet Erdal

2007-01-01

Diatomite has a number of unique physical properties and has found diversified industrial utilization. The filtration characteristics are particularly significant in the purification of liquids. The purpose of this study was to test natural diatomaceous earth (diatomite) as an alternative material that could be used for removal of radioactivity from liquid waste. A pilot-scale column-type device was designed. Natural diatomite samples were ground, sieved and prepared to use as sorption media. In this study, real waste liquid was used as radioactive liquid having special conditions. The liquid waste contained three radionuclides (Cs-137, Cs-134 and Co-60). Following the treatment by diatomite, the radioactivity of liquid waste was reduced from the initial 2.60 Bq/ml to less than 0.40 Bq/ml. The results of this study show that most of the radioactivity was removed from the solution by processing with diatomite

Natural diatomite process for removal of radioactivity from liquid waste.

Science.gov (United States)

Osmanlioglu, Ahmet Erdal

2007-01-01

Diatomite has a number of unique physical properties and has found diversified industrial utilization. The filtration characteristics are particularly significant in the purification of liquids. The purpose of this study was to test natural diatomaceous earth (diatomite) as an alternative material that could be used for removal of radioactivity from liquid waste. A pilot-scale column-type device was designed. Natural diatomite samples were ground, sieved and prepared to use as sorption media. In this study, real waste liquid was used as radioactive liquid having special conditions. The liquid waste contained three radionuclides (Cs-137, Cs-134 and Co-60). Following the treatment by diatomite, the radioactivity of liquid waste was reduced from the initial 2.60 Bq/ml to less than 0.40 Bq/ml. The results of this study show that most of the radioactivity was removed from the solution by processing with diatomite.

Synthesis and characterization of silver/diatomite nanocomposite by electron beam irradiation

Science.gov (United States)

Hanh, Truong Thi; Thu, Nguyen Thi; Quoc, Le Anh; Hien, Nguyen Quoc

2017-10-01

Silver nanoparticles (AgNPs) with diameter about 9 nm were deposited on diatomite by irradiation under electron beam of diatomite suspension containing 10 mM AgNO3 in 1% chitosan solution, at the dose of 20.2 kGy. The AgNPs/diatomite nanocomposite was characterized by UV-Vis spectroscopy, TEM image and energy dispersive X-ray spectroscopy (EDX). The antibacterial activity of the AgNPs/diatomite against E. coli and S. aureus was evaluated by reduction of bacterial colonies on spread plates and inhibition zone diameter on diffusion disks.

Performance Evaluation and Improving Mechanisms of Diatomite-Modified Asphalt Mixture

OpenAIRE

Chao Yang; Jun Xie; Xiaojun Zhou; Quantao Liu; Ling Pang

2018-01-01

Diatomite is an inorganic natural resource in large reserve. This study consists of two phases to evaluate the effects of diatomite on asphalt mixtures. In the first phase, we characterized the diatomite in terms of mineralogical properties, chemical compositions, particle size distribution, mesoporous distribution, morphology, and IR spectra. In the second phase, road performances, referring to the permanent deformation, crack, fatigue, and moisture resistance, of asphalt mixtures with diato...

Study on Purification Diatomite with nitric acid by Thermal Closed System

Directory of Open Access Journals (Sweden)

Kuang Meng

2016-01-01

Full Text Available In this research, a purification approach using nitric acid leaching at thermal closed system was developed to improve the porous structure of raw diatomite by removal of impurities from its surface and clogged pores. The feasibility and efficiency of this approach were determined by XRF for chemical constitution of diatomite, SEM for morphology and BET for specific surface area of purified diatomite. The investigations indicated that the content of SiO2 was in order of 85.14% for raw diatomite and 98% for purified diatomite, the content of Fe2O3 decreases after purified; the integrity of the porous structure was confirmed by SEM, and increase in specific surface area from 18m2·g-1 to 36m2·g-1.

3-Mercaptopropyltrimethoxysilane Modified Diatomite: Preparation and Application for Voltammetric Determination of Lead (II and Cadmium (II

Directory of Open Access Journals (Sweden)

Dinh Quang Khieu

2017-01-01

Full Text Available In this study, functionalized diatomite was prepared by grafting of 3-mercaptopropyltrimethoxysilane (MPTMS to diatomite (MPTMS-diatomite. The diatomite with thermal treatment from 100 to 700°C was functionalized by MPTMS under dry and humid conditions. The obtained MPTMS-diatomite was characterized by X-ray diffraction (XRD, thermal gravity-differential scanning calorimeter (TG-DSC, and Fourier transformation infrared (FT-IR. The results showed that an increase in treatment temperature seems to reduce the loading of MPTMS onto diatomite. The humidity of diatomite was favorable for the grafting of functional groups on the surface. The possible mechanisms of MPTMS loading to diatomite (MPTMS-diatomite were also proposed. The performance of a carbon paste electrode (CPE modified with MPTMS-diatomite in the simultaneous determination of Cd(II and Pb(II ions was addressed.

Organic-inorganic hybrid foams with diatomite addition: Effect on functional properties

Science.gov (United States)

Verdolotti, L.; D'Auria, M.; Lavorgna, M.; Vollaro, P.; Iannace, S.; Capasso, I.; Galzerano, B.; Caputo, D.; Liguori, B.

2016-05-01

Organic-inorganic hybrid foams were prepared by using metakaolin, diatomite as a partial (or total) replacement of metakaolin, as matrix, silicon and whipped protein as pore forming. The foamed systems were hardened at defined temperature and time and then characterized by mechanical point of view through compression tests and by functional point of view through fire reaction and acoustic tests. The experimental findings highlighted that the replacement of diatomite in the formulation affected the morphological structure of the foams and consequently their mechanical properties. In particular, the consolidation mechanism in the diatomite based-hybrid foams changed from geopolymerization to a silicate polycondensation mechanism. Therefore, mechanical performances enhanced with increasing of the diatomite content. Fire reaction tests, such as non-combustibility and cone calorimeter tests, showed positive thermal inertia of samples regardless of the content of diatomite.

The Influence of Diatomite on the Strength and Microstructure of Portland Cement

OpenAIRE

Liu Jun; Shao Peng; Wang Shihao

2016-01-01

To study the influence of the types and mixing amount of diatomite on the Portland cement, we prepared the cement specimen doped with the calcined first-grade, first-grade and second-grade diatomite ,tested the 3d, 7d, 14d compressive strength, and studied and discussed phase, structure and morphology of diatomite in the binary system by the method of XRD, SEM . Experimental results show that with the addition of diatomite, the strength of cement paste increase; the optimal contents of calcin...

Diagenesis of diatomite from the Kolubara Coal Basin, Barosevac, Serbia

Energy Technology Data Exchange (ETDEWEB)

Obradovic, J; Hein, J R; Djurdjevic, J [University of Belgrade, Belgrade (Yugoslavia). Faculty of Mining and Geology

1994-09-01

Diatomite associated with the Kolubara Coal Basin was studied to better understand early stage silica diagenesis of shallow water deposits. The Kolubara Basin consists of Neogene siliciclastic rocks, diatomite, marlstone and rare carbonates. Palaeozoic metamorphic and Mesozoic sedimentary and igneous basement rocks are transgressively overlain by Upper Miocene sandstone, siltstone, shale and mudstone. This Upper Miocene section is transgressively overlain by the Pontian section, which contains diatomite and coal beds. White and grey diatomite form beds 0.7-2.2 m thick that are continuous over an area of about 2 km[sup 2]. Siliceous rocks vary in composition from diatomite (81-89% SiO[sub 2]) to diatom-bearing shale (58-60% SiO[sub 2]). Siliceous deposits are laminated in places, with the laminae defined by variations in clay minerals, organic matter and diatoms. Diatomite shows only incipient diagenesis characterized by the fragmentation of diatom frustules, the minor to moderate corrosion of frustules and the formation of minor amounts of opal-A (X-ray amorphous inorganic opal) cement. The low degree of diagenesis results from the young age of the deposits, low burial temperatures and possibly also from the presence of abundant organic matter and the dissolution of kaolinite. The presence of only weak diagenesis is also reflected by the characteristically poor consolidation of the rocks and low rank of the associated coal.

Biocompatible Silver Nanoparticle-Modified Natural Diatomite with Anti-Infective Property

Directory of Open Access Journals (Sweden)

Haolin Sun

2018-01-01

Full Text Available Nanosilver as an alternative antibacterial agent of antibiotics has been researched for possible applications in various orthopedic implants. However, it is imperative to achieve controllable release of Ag+ to reduce its cytotoxic effect on normal tissue. Here, a nanosilver release system that has potential to be used in anti-infective bone cement was reported. Nanosilver modified diatomite was developed through the reaction of Tollens’ reagent to improve the antibacterial effect and natural diatomite was used as the carrier of Ag+ ions for controlled release. Cytotoxicity and the antibacterial activities of the nanosilver release system were characterized. After 3 days, the NIH3T3 cells cultured in the extract of nanosilver modified diatomite with an initial concentration of 0.5 mg/ml showed better cell viability than cells cultured in α-MEM. The density of MC3T3-E1 cells cultured in the extract of nanosilver modified diatomite at the same concentration did not differ significantly from the density of cells cultured in α-MEM. The nanosilver modified diatomite exhibited antibacterial effect against E. coli and S. aureus when the concentration was higher than 0.5 mg/ml. With appropriate selection of Ag+ concentration, the nanosilver modified diatomite is promising for improving the antibacterial effect while not affecting the biocompatibility of reinforced calcium phosphate bone cement.

Diatomite biosilica nanocarriers for siRNA transport inside cancer cells.

Science.gov (United States)

Rea, Ilaria; Martucci, Nicola M; De Stefano, Luca; Ruggiero, Immacolata; Terracciano, Monica; Dardano, Principia; Migliaccio, Nunzia; Arcari, Paolo; Taté, Rosarita; Rendina, Ivo; Lamberti, Annalisa

2014-12-01

Diatomite is a natural porous biomaterial of sedimentary origin, formed by fragments of diatom siliceous skeletons, called "frustules". Due to large availability in many areas of the world, chemical stability, and non-toxicity, these fossil structures have been widespread used in lot of industrial applications, such as food production, water extracting agent, production of cosmetics and pharmaceutics. However, diatomite is surprisingly still rarely used in biomedical applications. In this work, we exploit diatomite nanoparticles for small interfering ribonucleic acid (siRNA) transport inside human epidermoid cancer cells (H1355). Morphology and composition of diatomite microfrustules (average size lower than 40μm) are investigated by scanning electron microscopy equipped by energy dispersive X-ray spectroscopy, Fourier transform infrared analysis, and photoluminescence measurements. Nanometric porous particles (average size lower than 450nm) are obtained by mechanical crushing, sonication, and filtering of micrometric frustules. siRNA bioconjugation is performed on both micrometric and nanometric fragments by silanization. In-vitro experiments show very low toxicity on exposure of the cells to diatomite nanoparticle concentration up to 300μg/ml for 72h. Confocal microscopy imaging performed on cancer cells incubated with siRNA conjugated nanoparticles demonstrates a cytoplasmatic localization of vectors. Gene silencing by delivered siRNA is also demonstrated. Our studies endorse diatomite nanoparticles as non-toxic nanocarriers for siRNA transport in cancer cells. siRNA is a powerful molecular tool for cancer treatment but its delivery is inefficient due to the difficulty to penetrate the cell membrane. siRNA-diatomite nanoconjugate may be well suited for delivery of therapeutic to cancer cells. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis and characterization of antimicrobial nanosilver/diatomite nanocomposites and its water treatment application

Energy Technology Data Exchange (ETDEWEB)

Xia, Yijie [Institute of Materials Research and Engineering (IMRE), Agency of Science, Technology, and Research - A*STAR, 3 Research Link, 117602 (Singapore); School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai 200093 (China); Jiang, Xiaoyu; Zhang, Jing [AGplus Technologies Pte Ltd, 10 Jalan Besar #10-06 Sim Lim Tower, 208787 (Singapore); Lin, Ming [Institute of Materials Research and Engineering (IMRE), Agency of Science, Technology, and Research - A*STAR, 3 Research Link, 117602 (Singapore); Tang, Xiaosheng [AGplus Technologies Pte Ltd, 10 Jalan Besar #10-06 Sim Lim Tower, 208787 (Singapore); Zhang, Jie, E-mail: zhangj@imre.a-star.edu.sg [Institute of Materials Research and Engineering (IMRE), Agency of Science, Technology, and Research - A*STAR, 3 Research Link, 117602 (Singapore); Liu, Hongjun, E-mail: hjliu@henu.edu.cn [Key Laboratory of Natural Medicine and Immuno-Engineering of Henan Province, Henan University, Kaifeng, Henan 475004 (China); AGplus Technologies Pte Ltd, 10 Jalan Besar #10-06 Sim Lim Tower, 208787 (Singapore)

2017-02-28

Highlights: • Nanosilver diatomite has been developed with a facile, easy and effective in–situ reduction method. • The nanosilver diatomite demonstrated great antibacterial properties to gram positive and gram–negative bacterial. • A small amount of the nanosilver diatomite could kill >99.999% of E. Coli within half an hour time. • Low cost nano–composite antimicrobial material for water purification industry. - Abstract: Nanotechnology for water disinfection application gains increasing attention. Diatomite is one kind of safe natural material, which has been widely used as absorbent, filtration agents, mineral fillers, especially in water treatment industry. Nanosilver/diatomite nanocomposites were developed in this publication with a facile, effective in-situ reduction method. The as-prepared nanosilver/diatomite nanocomposites demonstrated amazing antibacterial properties to gram-positive and gram-negative bacteria. The corresponding property has been characterized by UV–vis absorbance, Transmission Electron Microscopy (TEM), Energy Dispersive X-ray (EDX) and X-ray Photoelectron Spectroscopy (XPS). Moreover, the detailed bacteria killing experiments further displayed that 0.5 g of the nanosilver diatomite could kill >99.999% of E. Coli within half an hour time. And the silver leaching test demonstrated that the concentrations of silver in the filtered water under varies pH environment were below the limit for silver level of WHO standard. Considering the low price of natural diatomite, it is believed that the nanosilver/diatomite nanocomposites have potential application in water purification industry due to its excellent antimicrobial property.

Synthesis and characterization of antimicrobial nanosilver/diatomite nanocomposites and its water treatment application

International Nuclear Information System (INIS)

Xia, Yijie; Jiang, Xiaoyu; Zhang, Jing; Lin, Ming; Tang, Xiaosheng; Zhang, Jie; Liu, Hongjun

2017-01-01

Highlights: • Nanosilver diatomite has been developed with a facile, easy and effective in–situ reduction method. • The nanosilver diatomite demonstrated great antibacterial properties to gram positive and gram–negative bacterial. • A small amount of the nanosilver diatomite could kill >99.999% of E. Coli within half an hour time. • Low cost nano–composite antimicrobial material for water purification industry. - Abstract: Nanotechnology for water disinfection application gains increasing attention. Diatomite is one kind of safe natural material, which has been widely used as absorbent, filtration agents, mineral fillers, especially in water treatment industry. Nanosilver/diatomite nanocomposites were developed in this publication with a facile, effective in-situ reduction method. The as-prepared nanosilver/diatomite nanocomposites demonstrated amazing antibacterial properties to gram-positive and gram-negative bacteria. The corresponding property has been characterized by UV–vis absorbance, Transmission Electron Microscopy (TEM), Energy Dispersive X-ray (EDX) and X-ray Photoelectron Spectroscopy (XPS). Moreover, the detailed bacteria killing experiments further displayed that 0.5 g of the nanosilver diatomite could kill >99.999% of E. Coli within half an hour time. And the silver leaching test demonstrated that the concentrations of silver in the filtered water under varies pH environment were below the limit for silver level of WHO standard. Considering the low price of natural diatomite, it is believed that the nanosilver/diatomite nanocomposites have potential application in water purification industry due to its excellent antimicrobial property.

Mechanical properties of dental resin composites by co-filling diatomite and nanosized silica particles

International Nuclear Information System (INIS)

Wang Hua; Zhu Meifang; Li Yaogang; Zhang Qinghong; Wang Hongzhi

2011-01-01

The aim of this study was to investigate the mechanical property effects of co-filling dental resin composites with porous diatomite and nanosized silica particles (OX-50). The purification of raw diatomite by acid-leaching was conducted in a hot 5 M HCl solution at 80 deg. C for 12 h. Both diatomite and nanosized SiO 2 were silanized with 3-methacryloxypropyltrimethoxysilane. The silanized inorganic particles were mixed into a dimethacrylate resin. Purified diatomite was characterized by X-ray diffraction, UV-vis diffuse reflectance spectroscopy and an N 2 adsorption-desorption isotherm. Silanized inorganic particles were characterized using Fourier transform infrared spectroscopy and a thermogravimetric analysis. The mechanical properties of the composites were tested by three-point bending, compression and Vicker's microhardness. Scanning electron microscopy was used to show the cross-section morphologies of the composites. Silanization of diatomite and nanosized silica positively reinforced interactions between the resin matrix and the inorganic particles. The mechanical properties of the resin composites gradually increased with the addition of modified diatomite (m-diatomite). The fracture surfaces of the composites exhibited large fracture steps with the addition of m-diatomite. However, when the mass fraction of m-diatomite was greater than 21 wt.% with respect to modified nanosized silica (mOX-50) and constituted 70% of the resin composite by weight, the mechanical properties of the resin composites started to decline. Thus, the porous structure of diatomite appears to be a crucial factor to improve mechanical properties of resin composites.

Adsorption of p-cresol on novel diatomite/carbon composites.

Science.gov (United States)

Hadjar, H; Hamdi, B; Ania, C O

2011-04-15

Hybrid inorganic/organic adsorbents were synthesized using mixtures of diatomite and carbon charcoal as precursors, and explored for the removal of p-cresol from aqueous solution. The carbon/diatomite composites displayed a bimodal and interconnected porous structure which was partially inherited from both precursors. They display moderate surface areas (between 100 and 400 m(2)g(-1)) due to their large inorganic content (between 70 and 90 wt.%), since the diatomite is a non-porous material. Compared to activated carbons with a more developed porosity, p-cresol adsorption on the prepared carbon/diatomite composites was much faster, showing adsorption capacities similar to those of conventional adsorbents over a wide pH range. These results show a good affinity of p-cresol molecules towards the hybrid inorganic/organic composites, and demonstrate the suitability of these novel materials for the removal of aromatic (polar) molecules, despite their dominant inorganic character. Copyright © 2011 Elsevier B.V. All rights reserved.

Adsorption behaviour of methylene blue onto Jordanian diatomite: a kinetic study.

Science.gov (United States)

Al-Ghouti, Mohammad A; Khraisheh, Majeda A M; Ahmad, Mohammad N M; Allen, Stephen

2009-06-15

The effect of initial concentration, particle size, mass of the adsorbent, pH and agitation speed on adsorption behaviour of methylene blue (MB) onto Jordanian diatomite has been investigated. The maximum adsorption capacity, q, increased from 75 to 105 mg/g when pH of the dye solution increased from 4 to 11. It is clear that the ionisable charge sites on the diatomite surface increased when pH increased from 4 to 11. When the solution pH was above the pH(ZPC), the diatomite surface had a negative charge, while at low pH (pHdiatomite did not follow the pseudo-first order model and had low correlation coefficients (R(2)diatomite when the particle size distribution is less than 250-500 microm. While at larger particle size 250-500 microm, the maximum uptake capacity was dependent on the particle size. It would imply that the MB adsorption is limited by the external surface and that intraparticle diffusion is reduced. The effect of the agitation speeds on the removal of MB from aqueous solution using the diatomite is quite low. The MB removal increased from 43 to 100% when mass of the diatomite increased from 0.3 to 1.7 g.

Mechanical properties of dental resin composites by co-filling diatomite and nanosized silica particles

Energy Technology Data Exchange (ETDEWEB)

Wang Hua; Zhu Meifang [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620 (China); Li Yaogang [Engineering Research Center of Advanced Glasses Manufacturing Technology, MOE, Donghua University, Shanghai 201620 (China); Zhang Qinghong, E-mail: zhangqh@dhu.edu.cn [Engineering Research Center of Advanced Glasses Manufacturing Technology, MOE, Donghua University, Shanghai 201620 (China); Wang Hongzhi, E-mail: wanghz@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620 (China)

2011-04-08

The aim of this study was to investigate the mechanical property effects of co-filling dental resin composites with porous diatomite and nanosized silica particles (OX-50). The purification of raw diatomite by acid-leaching was conducted in a hot 5 M HCl solution at 80 deg. C for 12 h. Both diatomite and nanosized SiO{sub 2} were silanized with 3-methacryloxypropyltrimethoxysilane. The silanized inorganic particles were mixed into a dimethacrylate resin. Purified diatomite was characterized by X-ray diffraction, UV-vis diffuse reflectance spectroscopy and an N{sub 2} adsorption-desorption isotherm. Silanized inorganic particles were characterized using Fourier transform infrared spectroscopy and a thermogravimetric analysis. The mechanical properties of the composites were tested by three-point bending, compression and Vicker's microhardness. Scanning electron microscopy was used to show the cross-section morphologies of the composites. Silanization of diatomite and nanosized silica positively reinforced interactions between the resin matrix and the inorganic particles. The mechanical properties of the resin composites gradually increased with the addition of modified diatomite (m-diatomite). The fracture surfaces of the composites exhibited large fracture steps with the addition of m-diatomite. However, when the mass fraction of m-diatomite was greater than 21 wt.% with respect to modified nanosized silica (mOX-50) and constituted 70% of the resin composite by weight, the mechanical properties of the resin composites started to decline. Thus, the porous structure of diatomite appears to be a crucial factor to improve mechanical properties of resin composites.

COMPOSITION OF MINERAL PHASES OF THE GHIDIRIM DIATOMITE

Directory of Open Access Journals (Sweden)

Vasile Rusu

2007-06-01

Full Text Available Studies of the mineralogical composition of diatomite from the Ghidirim location of RM, as well as of the extracted clay phase are presented. The mineral phase of the diatomite contains a number of clay minerals, like montmorillonite (in a mixture with insignificant quantities of slightly chloritized montmorillonite, illite and kaolinite. Diatomite contains also non-clay components as fine-dispersed quartz and amorphous material, the more probable sources of which are opal, amorphous alumosilicates, aluminum and iron hydroxides. The applied procedure for separation of clay fractions by sizing settling in liquid media proves to be very useful, enabling possibilities for more accurate identification of the clay constituents of diatomic material. Procedure allows to separate very clean clay fraction especially rich in montmorillonite, which can be utilized itself as mineral adsorbent for practical purposes.

Modified natural diatomite and its enhanced immobilization of lead, copper and cadmium in simulated contaminated soils

International Nuclear Information System (INIS)

Ye, Xinxin; Kang, Shenghong; Wang, Huimin; Li, Hongying; Zhang, Yunxia; Wang, Guozhong; Zhao, Huijun

2015-01-01

Highlights: • We modify natural diatomite using the facile acid treatment and ultrasonication. • Modification add pore volume, surface area and electronegativity of natural diatomite. • Modified diatomite is superior to natural diatomite in soil heavy metal remediation. • Modified diatomite can be promising for in-situ immobilization of heavy metal in soil. - Abstract: Natural diatomite was modified through facile acid treatment and ultrasonication, which increased its electronegativity, and the pore volume and surface area achieved to 0.211 cm 3 g −1 and 76.9 m 2 g −1 , respectively. Modified diatomite was investigated to immobilize the potential toxic elements (PTEs) of Pb, Cu and Cd in simulated contaminated soil comparing to natural diatomite. When incubated with contaminated soils at rates of 2.5% and 5.0% by weight for 90 days, modified diatomite was more effective in immobilizing Pb, Cu and Cd than natural diatomite. After treated with 5.0% modified diatomite for 90 days, the contaminated soils showed 69.7%, 49.7% and 23.7% reductions in Pb, Cu and Cd concentrations after 0.01 M CaCl 2 extraction, respectively. The concentrations of Pb, Cu and Cd were reduced by 66.7%, 47.2% and 33.1% in the leaching procedure, respectively. The surface complexation played an important role in the immobilization of PTEs in soils. The decreased extractable metal content of soil was accompanied by improved microbial activity which significantly increased (P < 0.05) in 5.0% modified diatomite-amended soils. These results suggested that modified diatomite with micro/nanostructured characteristics increased the immobilization of PTEs in contaminated soil and had great potential as green and low-cost amendments

3-Mercaptopropyltrimethoxysilane Modified Diatomite: Preparation and Application for Voltammetric Determination of Lead (II) and Cadmium (II)

OpenAIRE

Quang Khieu, Dinh; Dang Son, Bui Hai; Thi Thanh Chau, Vo; Dinh Du, Pham; Hai Phong, Nguyen; Thi Diem Chau, Nguyen

2017-01-01

In this study, functionalized diatomite was prepared by grafting of 3-mercaptopropyltrimethoxysilane (MPTMS) to diatomite (MPTMS-diatomite). The diatomite with thermal treatment from 100 to 700°C was functionalized by MPTMS under dry and humid conditions. The obtained MPTMS-diatomite was characterized by X-ray diffraction (XRD), thermal gravity-differential scanning calorimeter (TG-DSC), and Fourier transformation infrared (FT-IR). The results showed that an increase in treatment temperature ...

Modified natural diatomite and its enhanced immobilization of lead, copper and cadmium in simulated contaminated soils

Energy Technology Data Exchange (ETDEWEB)

Ye, Xinxin, E-mail: xxye@issp.ac.cn [Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Kang, Shenghong; Wang, Huimin [Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Li, Hongying [Institute of Soil and Fertilizer, Anhui Academy of Agricultural Sciences, Hefei 230031 (China); Zhang, Yunxia [Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Wang, Guozhong, E-mail: gzhwang@issp.ac.cn [Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Zhao, Huijun [Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Centre for Clean Environment and Energy, Gold Coast Campus, Griffith University, Queensland 4222 (Australia)

2015-05-30

Highlights: • We modify natural diatomite using the facile acid treatment and ultrasonication. • Modification add pore volume, surface area and electronegativity of natural diatomite. • Modified diatomite is superior to natural diatomite in soil heavy metal remediation. • Modified diatomite can be promising for in-situ immobilization of heavy metal in soil. - Abstract: Natural diatomite was modified through facile acid treatment and ultrasonication, which increased its electronegativity, and the pore volume and surface area achieved to 0.211 cm{sup 3} g{sup −1} and 76.9 m{sup 2} g{sup −1}, respectively. Modified diatomite was investigated to immobilize the potential toxic elements (PTEs) of Pb, Cu and Cd in simulated contaminated soil comparing to natural diatomite. When incubated with contaminated soils at rates of 2.5% and 5.0% by weight for 90 days, modified diatomite was more effective in immobilizing Pb, Cu and Cd than natural diatomite. After treated with 5.0% modified diatomite for 90 days, the contaminated soils showed 69.7%, 49.7% and 23.7% reductions in Pb, Cu and Cd concentrations after 0.01 M CaCl{sub 2} extraction, respectively. The concentrations of Pb, Cu and Cd were reduced by 66.7%, 47.2% and 33.1% in the leaching procedure, respectively. The surface complexation played an important role in the immobilization of PTEs in soils. The decreased extractable metal content of soil was accompanied by improved microbial activity which significantly increased (P < 0.05) in 5.0% modified diatomite-amended soils. These results suggested that modified diatomite with micro/nanostructured characteristics increased the immobilization of PTEs in contaminated soil and had great potential as green and low-cost amendments.

Photocatalytic Degradation of Methylene Blue Using TiO2 Impregnated Diatomite

OpenAIRE

Zuo, Ranfang; Du, Gaoxiang; Zhang, Weiwei; Liu, Lianhua; Liu, Yanming; Mei, Lefu; Li, Zhaohui

2014-01-01

Nano-TiO2 showed a good catalytic activity, but it is easy to agglomerate, resulting in the reduction or even complete loss of photocatalytic activity. The dispersion of TiO2 particles on porous materials was a potential solution to this problem. Diatomite has high specific surface and absorbability because of its particular shell structure. Thus, TiO2/diatomite composite, prepared by loading TiO2 on the surface of diatomite, was a good photocatalyst, through absorbing organic compounds with ...

[Preparation and structural analysis of diatomite-supported SPFS flocculant].

Science.gov (United States)

Zheng, Huai-li; Fang, Hui-li; Jiang, Shao-jie; Yang, Chun; Ma, Jiang-ya; Zhang, Zhao-qing

2011-07-01

In the presetn study, polymerized ferric sulphate (PFS) flocculant was prepared and tested. In the preparation of PFS flocculant, industrial by-product ferrous sulfate heptahydrate (FeSO4.7H2O) was reused as the main material. By composition with diatomite and drying up at certain temperature in vacuum drying oven, solid PFS flocculant was produced. Structural characteristics of the new flocculant product were examined through infrared spectroscopy and scanning electron microscopy (SEM), which showed that by compositing with diatomite, new group bridging emerged in the structure of PFS, which made the bond of groups stronger. In addition, part of the metalic contents in diatomite was polymerized with PFS, the product of which was polymerized ferric complex. Furthermore, the absorbing and agglomerating capacity of the diatomite carrier was significant. Considering the factors listed above, the new solid polymerized ferric sulphate (SPFS) flocculant was characterized with a larger molecule structure and enhanced absorbing, bridging and rolling sweep capacities. Through orthogonal experiment, optimum conditions of synthesis were as follows: the ratio of FeSO4.7H2O/diatomite in weight was 43/1, the reaction time is 1 h and the reaction temperature is 55 degrees C. By wastewater treatment experiment, it was found that the synthetic products showed good flocculation performance in the treatment of domestic sewage, the removal of COD was 80.00% and the removal of turbidity was 99.98%.

Synthesis and characterization of antimicrobial nanosilver/diatomite nanocomposites and its water treatment application

Science.gov (United States)

Xia, Yijie; Jiang, Xiaoyu; Zhang, Jing; Lin, Ming; Tang, Xiaosheng; Zhang, Jie; Liu, Hongjun

2017-02-01

Nanotechnology for water disinfection application gains increasing attention. Diatomite is one kind of safe natural material, which has been widely used as absorbent, filtration agents, mineral fillers, especially in water treatment industry. Nanosilver/diatomite nanocomposites were developed in this publication with a facile, effective in-situ reduction method. The as-prepared nanosilver/diatomite nanocomposites demonstrated amazing antibacterial properties to gram-positive and gram-negative bacteria. The corresponding property has been characterized by UV-vis absorbance, Transmission Electron Microscopy (TEM), Energy Dispersive X-ray (EDX) and X-ray Photoelectron Spectroscopy (XPS). Moreover, the detailed bacteria killing experiments further displayed that 0.5 g of the nanosilver diatomite could kill >99.999% of E. Coli within half an hour time. And the silver leaching test demonstrated that the concentrations of silver in the filtered water under varies pH environment were below the limit for silver level of WHO standard. Considering the low price of natural diatomite, it is believed that the nanosilver/diatomite nanocomposites have potential application in water purification industry due to its excellent antimicrobial property.

40 CFR 436.240 - Applicability; description of the diatomite subcategory.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the diatomite subcategory. 436.240 Section 436.240 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS MINERAL MINING AND PROCESSING POINT SOURCE CATEGORY Diatomite Subcategory § 436.240 Applicability;...

Synthesis of ZnFe2O4/SiO2 composites derived from a diatomite template.

Science.gov (United States)

Liu, Zhaoting; Fan, Tongxiang; Zhou, Han; Zhang, Di; Gong, Xiaolu; Guo, Qixin; Ogawa, Hiroshi

2007-03-01

A novel porous ZnFe2O4/SiO2 composite product has been generated with a template-directed assembly method from porous diatomite under different synthesis conditions, such as precursor concentrations (metallic nitrates), calcination temperature and diatomite type. The phase composition and morphology of all the materials were examined by x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The results indicated that an inherited hierarchical porous structure from the diatomite template can be obtained, and the synthesis conditions were found to have clear effects on the formation of the ZnFe2O4/SiO2 composite. The ideal composite of ZnFe2O4/SiO2 can be obtained through optimization of diatomite template type, precursor solution and calcination temperature. Furthermore, the adsorption abilities of two types of diatomites were analyzed in detail using FTIR spectra and nitrogen adsorption measurements etc, which proved that A-diatomite (Shengzhou-diatomite) is better than B-diatomite (Changbai-diatomite) on the aspect of adsorbing Zn and Fe ions, and of forming the ZnFe2O4.

Fe-Mn binary oxide incorporated into diatomite as an adsorbent for arsenite removal: preparation and evaluation.

Science.gov (United States)

Chang, Fangfang; Qu, Jiuhui; Liu, Huijuan; Liu, Ruiping; Zhao, Xu

2009-10-15

Fe-Mn binary oxide incorporated into diatomite (FMBO-diatomite) was prepared by a simple coating method, and exhibited high oxidation and adsorption ability for arsenite [As(III)]. After being incorporated by Fe-Mn binary oxide, the surface area of diatomite increased 36%, and the pore volume increased five times. The pHzpc of FMBO-diatomite was determined to be 8.1. These characteristics are responsible for the increased As(III) adsorption efficiency. The adsorption equilibria of As(III) on FMBO-diatomite were described well by a Langmuir isotherm model due to the homogeneous distribution of Fe-Mn binary oxide on a diatomite surface. As(III) was oxidized into As(V), and then adsorbed by FMBO-diatomite. The oxidation and adsorption efficiencies for As(III) depended deeply on the pH of solution. When the pH was raised to 8.1, the As(III) adsorption efficiency of FMBO-diatomite was almost equal to the As(III) oxidation efficiency. Silicate and phosphate had negative effects on As(III) adsorption. Also the influence of silicate and phosphate with the pH variation was different.

Preparation, characterization and antimicrobial efficiency of Ag/PDDA-diatomite nanocomposite.

Science.gov (United States)

Panáček, Aleš; Balzerová, Anna; Prucek, Robert; Ranc, Václav; Večeřová, Renata; Husičková, Vendula; Pechoušek, Jiří; Filip, Jan; Zbořil, Radek; Kvítek, Libor

2013-10-01

Nanocomposites consisting of diatomaceous earth particles and silver nanoparticles (silver NPs) with high antimicrobial activity were prepared and characterized. For the purpose of nanocomposite preparation, silver NPs with an average size of 28nm prepared by modified Tollens process were used. Nanocomposites were prepared using poly(diallyldimethylammonium) chloride (PDDA) as an interlayer substance between diatomite and silver NPs which enables to change diatomite original negative surface charge to positive one. Due to strong electrostatic interactions between negatively charged silver NPs and positively charged PDDA-modified diatomite, Ag/PDDA-diatomite nanocomposites with a high content of silver (as high as 46.6mgAg/1g of diatomite) were prepared. Because of minimal release of silver NPs from prepared nanocomposites to aqueous media (<0.3mg Ag/1g of nanocomposite), the developed nanocomposites are regarded as a potential useful antimicrobial material with a long-term efficiency showing no risk to human health or environment. All the prepared nanocomposites exhibit a high bactericidal activity against Gram-negative and Gram-positive bacteria and fungicidal activity against yeasts at very low concentrations as low as 0.11g/L, corresponding to silver concentration of 5mg/L. Hence, the prepared nanocomposites constitute a promising candidate suitable for the microbial water treatment in environmental applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Microwave absorption property of the diatomite coated by Fe-CoNiP films

International Nuclear Information System (INIS)

Yan, Zhenqiang; Cai, Jun; Xu, Yonggang; Zhang, Deyuan

2015-01-01

Highlights: • The bio-absorbent coated Fe-CoNiP was fabricated by electroless and CVD. • The EM parameters were enlarged as Fe coated on the diatomite. • The coating CIPs play a key role in the enhancement mechanism. • The Fe-CoNiP diatomite had a better absorbing and shielding properties. - Abstract: A bio-absorbent of Fe-CoNiP coated on the diatomite was fabricated by way of electroless plating of CoNiP and subsequent chemical vapor deposition of Fe. The surface morphology and composition of the above-mentioned diatomite particles at different stage were characterized with the scanning electron microscopy and the energy spectrum analysis respectively, and the results showed that the diatomite was successfully coated with CoNoP and Fe (carbony iron). The complex permittivity and permeability of composites filled with the bio-absorbent and paraffin was measured in frequency range of 2–18 GHz, and then the microwave reflection loss (RL) and the shielding effectiveness (SE) were calculated. The results showed that the permittivity and the permeability were both enlarged as Fe films were coated onto the CoNiP-coated diatomite, which was attributed to the excellent electromagnetic property of carbonyl irons. The composites made with the Fe-CoNiP diatomite had a better absorbing property (minimum RL −11.0 dB) as well as the shielding property (maximum SE 5.6 dB) at thickness 2 mm. It indicated the absorption property was mainly due to the attenuation on the microwave, and the Fe-CoNiP diatomite could be an effective absorbent with low-density

Microwave absorption property of the diatomite coated by Fe-CoNiP films

Energy Technology Data Exchange (ETDEWEB)

Yan, Zhenqiang; Cai, Jun; Xu, Yonggang, E-mail: xuyonggang221@163.com; Zhang, Deyuan

2015-08-15

Highlights: • The bio-absorbent coated Fe-CoNiP was fabricated by electroless and CVD. • The EM parameters were enlarged as Fe coated on the diatomite. • The coating CIPs play a key role in the enhancement mechanism. • The Fe-CoNiP diatomite had a better absorbing and shielding properties. - Abstract: A bio-absorbent of Fe-CoNiP coated on the diatomite was fabricated by way of electroless plating of CoNiP and subsequent chemical vapor deposition of Fe. The surface morphology and composition of the above-mentioned diatomite particles at different stage were characterized with the scanning electron microscopy and the energy spectrum analysis respectively, and the results showed that the diatomite was successfully coated with CoNoP and Fe (carbony iron). The complex permittivity and permeability of composites filled with the bio-absorbent and paraffin was measured in frequency range of 2–18 GHz, and then the microwave reflection loss (RL) and the shielding effectiveness (SE) were calculated. The results showed that the permittivity and the permeability were both enlarged as Fe films were coated onto the CoNiP-coated diatomite, which was attributed to the excellent electromagnetic property of carbonyl irons. The composites made with the Fe-CoNiP diatomite had a better absorbing property (minimum RL −11.0 dB) as well as the shielding property (maximum SE 5.6 dB) at thickness 2 mm. It indicated the absorption property was mainly due to the attenuation on the microwave, and the Fe-CoNiP diatomite could be an effective absorbent with low-density.

[Preliminary study of bonding strength between diatomite-based dental ceramic and veneering porcelains].

Science.gov (United States)

Lu, Xiao-li; Gao, Mei-qin; Cheng, Yu-ye; Zhang, Fei-min

2015-04-01

In order to choose the best veneering porcelain for diatomite-based dental ceramic substrate, the bonding strength between diatomite-based dental ceramics and veneering porcelains was measured, and the microstructure and elements distribution of interface were analyzed. The coefficient of thermal expansion (CTE) of diatomite-based dental ceramics was detected by dilatometry. Three veneering porcelain materials were selected with the best CTE matching including alumina veneering porcelain (group A), titanium porcelain veneering porcelain (group B), and E-max veneering porcelain (group C). Shear bonding strength was detected. SEM and EDS were used to observe the interface microstructure and element distribution. Statistical analysis was performed using SPSS 17.0 software package. The CTE of diatomite-based dental ceramics at 25-500 degrees centigrade was 8.85×10-6K-1. The diatomite-based substrate ceramics combined best with group C. Shear bonding strength between group A and C and group B and C both showed significant differences(P<0.05). SEM and EDS showed that the interface of group C sintered tightly and elements permeated on both sides of the interface. The diatomite-based substrate ceramics combines better with E-max porcelain veneer.

Synthesis and photocatalytic activity of ytterbium-doped titania/diatomite composite photocatalysts

International Nuclear Information System (INIS)

Tang, Wenjian; Qiu, Kehui; Zhang, Peicong; Yuan, Xiqiang

2016-01-01

Graphical abstract: - Highlights: • Yb-doped TiO_2/diatomite composite photocatalysts were prepared by a sol-gel method. • Yb-doped TiO_2/diatomite photocatalysts show much higher photocatalytic activity. • The higher photodegradation rate is due to the effect of diatomite and Yb doping. - Abstract: Ytterbium-doped titanium dioxide (Yb-TiO_2)/diatomite composite materials with different Yb concentrations were prepared by sol–gel method. The phase structure, morphology, and chemical composition of the as-prepared composites were well characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), and ultraviolet–visible (UV–vis) diffuse reflection spectroscopy. The XRD and Raman spectroscopy analysis indicated that the TiO_2 existed in the form of pure anatase in the composites. The SEM images exhibited the well deposition and dispersion of TiO_2 nanoparticles with little agglomeration on the surfaces of diatoms. The UV–vis diffuse reflection spectra showed that the band gap of TiO_2 could be narrowed by the introduction of Yb species, which was further affected by doping concentration of Yb. The photocatalytic activity of synthesized samples was investigated by the degradation of methylene blue (MB) under UV light irradiation. It was observed that the photocatalytic degradation followed a pseudo-first-order kinetics according to the Langmuir–Hinshelwood model. Compared to TiO_2 and TiO_2/diatomite, the Yb-TiO_2/diatomite composites exhibited higher photocatalytic activity toward degradation of MB using UV light irradiation.

Synthesis and photocatalytic activity of ytterbium-doped titania/diatomite composite photocatalysts

Energy Technology Data Exchange (ETDEWEB)

Tang, Wenjian; Qiu, Kehui; Zhang, Peicong; Yuan, Xiqiang

2016-01-30

Graphical abstract: - Highlights: • Yb-doped TiO{sub 2}/diatomite composite photocatalysts were prepared by a sol-gel method. • Yb-doped TiO{sub 2}/diatomite photocatalysts show much higher photocatalytic activity. • The higher photodegradation rate is due to the effect of diatomite and Yb doping. - Abstract: Ytterbium-doped titanium dioxide (Yb-TiO{sub 2})/diatomite composite materials with different Yb concentrations were prepared by sol–gel method. The phase structure, morphology, and chemical composition of the as-prepared composites were well characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), and ultraviolet–visible (UV–vis) diffuse reflection spectroscopy. The XRD and Raman spectroscopy analysis indicated that the TiO{sub 2} existed in the form of pure anatase in the composites. The SEM images exhibited the well deposition and dispersion of TiO{sub 2} nanoparticles with little agglomeration on the surfaces of diatoms. The UV–vis diffuse reflection spectra showed that the band gap of TiO{sub 2} could be narrowed by the introduction of Yb species, which was further affected by doping concentration of Yb. The photocatalytic activity of synthesized samples was investigated by the degradation of methylene blue (MB) under UV light irradiation. It was observed that the photocatalytic degradation followed a pseudo-first-order kinetics according to the Langmuir–Hinshelwood model. Compared to TiO{sub 2} and TiO{sub 2}/diatomite, the Yb-TiO{sub 2}/diatomite composites exhibited higher photocatalytic activity toward degradation of MB using UV light irradiation.

Degradation of simazine from aqueous solutions by diatomite-supported nanosized zero-valent iron composite materials

Energy Technology Data Exchange (ETDEWEB)

Sun, Zhiming [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia); Zheng, Shuilin [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Ayoko, Godwin A.; Frost, Ray L. [Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia); Xi, Yunfei, E-mail: y.xi@qut.edu.au [Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia)

2013-12-15

Graphical abstract: Nanosized zero-valent iron (nZVI) particles were deposited onto acid-leached diatomite through centrifugation or rotary evaporation. The synthesis schematic diagram and morphology of the prepared nZVI/diatomite composites are shown in the illustration. The removal efficiency for herbicide simazine by nZVI/diatomite composites was compared with that of the pristine nZVI and the commercial iron powder. -- Highlights: • Diatomite-supported nanosized zero-valent iron composite was synthesised. • The obtained composites were characterised by XRD, SEM–EDS, TEM and XPS. • The removal efficiency for simazine in water were studied. • The prepared composite showed potential prospects in environmental remediation. -- Abstract: A novel composite material based on deposition of nanosized zero-valent iron (nZVI) particles on acid-leached diatomite was synthesised for the removal of a chlorinated contaminant in water. The nZVI/diatomite composites were characterised by X-ray diffraction, scanning electron microscopy, elemental analysis, transmission electron microscopy and X-ray photoelectron spectroscopy. Compared with the pure nZVI particles, better dispersion of nZVI particles on the surface or inside the pores of diatom shells was observed. The herbicide simazine was selected as the model chlorinated contaminant and the removal efficiency by nZVI/diatomite composite was compared with that of the pristine nZVI and commercial iron powder. It was found that the diatomite supported nZVI composite material prepared by centrifugation exhibits relatively better efficient activity in decomposition of simazine than commercial Fe, lab synthesised nZVI and composite material prepared via rotary evaporation, and the optimum experimental conditions were obtained based on a series of batch experiments. This study on immobilising nZVI particles onto diatomite opens a new avenue for the practical application of nZVI and the diatomite-supported nanosized zero

Fabrication and characterization of flaky core-shell particles by magnetron sputtering silver onto diatomite

Science.gov (United States)

Wang, Yuanyuan; Zhang, Deyuan; Cai, Jun

2016-02-01

Diatomite has delicate porous structures and various shapes, making them ideal templates for microscopic core-shell particles fabrication. In this study, a new process of magnetron sputtering assisted with photoresist positioning was proposed to fabricate lightweight silver coated porous diatomite with superior coating quality and performance. The diatomite has been treated with different sputtering time to investigate the silver film growing process on the surface. The morphologies, constituents, phase structures and surface roughness of the silver coated diatomite were analyzed with SEM, EDS, XRD and AFM respectively. The results showed that the optimized magnetron sputtering time was 8-16 min, under which the diatomite templates were successfully coated with uniform silver film, which exhibits face centered cubic (fcc) structure, and the initial porous structures were kept. Moreover, this silver coating has lower surface roughness (RMS 4.513 ± 0.2 nm) than that obtained by electroless plating (RMS 15.692 ± 0.5 nm). And the infrared emissivity of coatings made with magnetron sputtering and electroless plating silver coated diatomite can reach to the lowest value of 0.528 and 0.716 respectively.

Influence of diatomite addition on membrane fouling and performance in a submerged membrane bioreactor.

Science.gov (United States)

Yang, Xiao-Li; Song, Hai-Liang; Lu, Ji-Lai; Fu, Da-Fang; Cheng, Bing

2010-12-01

This paper examined the effect of diatomite addition on membrane fouling and process performance in an anoxic/oxic submerged membrane bioreactor (A/O MBR). Particle size distribution, molecular weight distribution and microbial activity have been investigated to characterize the sludge mixed liquor. Results show that diatomite addition is a reliable and effective approach in terms of both membrane fouling mitigation and pollutants removal improvement. The MBR system with diatomite addition of 50 mg/L enhanced the removal of COD, TN and TP by 0.9%, 6.9% and 31.2%, respectively, as compared to the control MBR (without diatomite addition). The NH(4)-N removal always maintained at a high level of over 98% irrespective of diatomite addition. Due to the hybrid effect of adsorption and co-precipitation on fine colloids and dissolved organic matter (DOM) from the addition of diatomite, a reduction in foulants amount, an increase in microbial floc size and an improvement in sludge settleability have been achieved simultaneously. As a result, the membrane fouling rate was mitigated successfully. 2010 Elsevier Ltd. All rights reserved.

A Study on Astrazon Black AFDL Dye Adsorption onto Vietnamese Diatomite

Directory of Open Access Journals (Sweden)

Bui Hai Dang Son

2016-01-01

Full Text Available In the present paper, the adsorption of Astrazon Black AFDL dye onto Vietnamese diatomite has been demonstrated. The diatomite was characterized by XRD, SEM, TEM, EDS, and nitrogen adsorption/desorption isotherms. The results show that diatomite mainly constituted centric type frustules characterized by pores as discs or as cylindrical shapes. The adsorption kinetics and isotherms of dye onto Vietnam diatomite were investigated. The experimental data were fitted well to both Freundlich and Langmuir in the initial concentration range of 400–1400 mg L−1. The average value of maximum adsorption capacity, qm, calculated from Freundlich equation is statistically similar to the average value of maximum monolayer adsorption capacity calculated from Langmuir equation. The thermodynamic parameters evaluated from the temperature dependent on adsorption isotherms in the range of 303–343 K show that the adsorption process was spontaneous and endothermic. The Webber and pseudo-first/second-order kinetic models were used to analyze the mechanism of adsorption. The piecewise linear regression and Akaike’s Information Criterion were used to analyze experimental data. The results show that the dye adsorption onto diatomite was film diffusion controlled and the goodness of fit of experimental data for kinetics modes was dependent on the initial concentration.

Adsorption of BTEX, MTBE and TAME on natural and modified diatomite.

Science.gov (United States)

Aivalioti, Maria; Papoulias, Panagiotis; Kousaiti, Athanasia; Gidarakos, Evangelos

2012-03-15

The removal of BTEX (benzene, toluene, ethyl-benzene and m-,p-,o-xylenes), MTBE (methyl tertiary butyl ether) and TAME (tertiary amyl methyl ether) from aqueous solutions by raw, thermally, chemically and both chemically and thermally treated diatomite was studied, through batch adsorption experiments. In total, 14 different diatomite samples were created and tested. Selected physical characteristics of the adsorbents, such as specific surface area and pore volume distribution, were determined. Matrix and competitive adsorption effects were also explored. It was proved that the diatomite samples were effective in removing BTEX, MTBE and TAME from aqueous solutions, with the sample treated with HCl being the most effective, as far as its adsorption capacity and equilibrium time are concerned. Among the contaminants, BTEX appeared to have the strongest affinity, based on mass uptake by the diatomite samples. Matrix effects were proved to be strong, significantly decreasing the adsorption of the contaminants onto diatomite. The kinetics data proved a closer fit to the pseudo second order model, while the isotherm experimental data were a better fit to the Freundlich model. However, the latter produced values of the isotherm constant 1/n greater than one, indicating unfavorable adsorption. Copyright © 2011 Elsevier B.V. All rights reserved.

Prediction of Splitting Tensile Strength of Concrete Containing Zeolite and Diatomite by ANN

Directory of Open Access Journals (Sweden)

E. Gülbandılar

2017-01-01

Full Text Available This study was designed to investigate with two different artificial neural network (ANN prediction model for the behavior of concrete containing zeolite and diatomite. For purpose of constructing this model, 7 different mixes with 63 specimens of the 28, 56 and 90 days splitting tensile strength experimental results of concrete containing zeolite, diatomite, both zeolite and diatomite used in training and testing for ANN systems was gathered from the tests. The data used in the ANN models are arranged in a format of seven input parameters that cover the age of samples, Portland cement, zeolite, diatomite, aggregate, water and hyper plasticizer and an output parameter which is splitting tensile strength of concrete. In the model, the training and testing results have shown that two different ANN systems have strong potential as a feasible tool for predicting 28, 56 and 90 days the splitting tensile strength of concrete containing zeolite and diatomite.

Kinetics of in situ combustion. SUPRI TR 91

Energy Technology Data Exchange (ETDEWEB)

Mamora, D.D.; Ramey, H.J. Jr.; Brigham, W.E.; Castanier, L.M.

1993-07-01

Oxidation kinetic experiments with various crude oil types show two reaction peaks at about 250{degree}C (482{degree}F) and 400{degree}C (725{degree}F). These experiments lead to the conclusion that the fuel during high temperature oxidation is an oxygenated hydrocarbon. A new oxidation reaction model has been developed which includes two partially-overlapping reactions: namely, low-temperature oxidation followed by high-temperature oxidation. For the fuel oxidation reaction, the new model includes the effects of sand grain size and the atomic hydrogen-carbon (H/C) and oxygen-carbon (O/C) ratios of the fuel. Results based on the new model are in good agreement with the experimental data. Methods have been developed to calculate the atomic H/C and O/C ratios. These methods consider the oxygen in the oxygenated fuel, and enable a direct comparison of the atomic H/C ratios obtained from kinetic and combustion tube experiments. The finding that the fuel in kinetic tube experiments is an oxygenated hydrocarbon indicates that oxidation reactions are different in kinetic and combustion tube experiments. A new experimental technique or method of analysis will be required to obtain kinetic parameters for oxidation reactions encountered in combustion tube experiments and field operations.

Microwave absorption property of the diatomite coated by Fe-CoNiP films

Science.gov (United States)

Yan, Zhenqiang; Cai, Jun; Xu, Yonggang; Zhang, Deyuan

2015-08-01

A bio-absorbent of Fe-CoNiP coated on the diatomite was fabricated by way of electroless plating of CoNiP and subsequent chemical vapor deposition of Fe. The surface morphology and composition of the above-mentioned diatomite particles at different stage were characterized with the scanning electron microscopy and the energy spectrum analysis respectively, and the results showed that the diatomite was successfully coated with CoNoP and Fe (carbony iron). The complex permittivity and permeability of composites filled with the bio-absorbent and paraffin was measured in frequency range of 2-18 GHz, and then the microwave reflection loss (RL) and the shielding effectiveness (SE) were calculated. The results showed that the permittivity and the permeability were both enlarged as Fe films were coated onto the CoNiP-coated diatomite, which was attributed to the excellent electromagnetic property of carbonyl irons. The composites made with the Fe-CoNiP diatomite had a better absorbing property (minimum RL -11.0 dB) as well as the shielding property (maximum SE 5.6 dB) at thickness 2 mm. It indicated the absorption property was mainly due to the attenuation on the microwave, and the Fe-CoNiP diatomite could be an effective absorbent with low-density.

Synthesis of nano-TiO2/diatomite composite and its photocatalytic degradation of gaseous formaldehyde

Science.gov (United States)

Zhang, Guangxin; Sun, Zhiming; Duan, Yongwei; Ma, Ruixin; Zheng, Shuilin

2017-08-01

The TiO2/diatomite composite was synthesized through a mild hydrolysis of titanyl sulfate. The prepared composite was characterized by X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and UV-vis diffused reflectance spectroscopy. The results demonstrate that the anatase TiO2 nanopartilces anchored on the surface of diatomite with Ti-O-Si bonds between diatomite and TiO2. The photodegradation of gaseous formaldehyde under UV irradiation by the TiO2/diatomite composite was studied under various operating conditions, including relative humidity, illumination intensity and catalyst amount, which have significant influence on the degradation process. The TiO2/diatomite composite exhibited better photocatalytic activity than pure TiO2, which could be attributed to the favorable nanoparticles dispersibility and strong formaldehyde adsorption capacity. In addition, the composite exhibited outstanding reusability over five cycles. The TiO2/diatomite composite shows great promising application foreground in formaldehyde degradation.

Facile decolorization of methylene blue by morphology-dependence δ-MnO2 nanosheets -modified diatomite

Science.gov (United States)

Yu, Ting Ting; Li, Kai Lin; Guo, Xiao Long; Li, Fei; Huang, Jia Mu; Zhang, Yu Xin

2015-12-01

In this work, coscinodiscus-diatomite and melosira-diatomite have been decorated by ultrathin birnessite MnO2 (δ-MnO2) nanosheets through a one-pot hydrothermal method without using any surfactants. The δ-MnO2 nanosheets are observed to grow vertically on the purified melosira-diatomite as well as coscinodiscus-diatomite. Moreover, the two composites exhibit high efficiency for decomposing methylene blue (MB) in the presence of H2O2. The coscinodiscus-diatmite@MnO2 achieves a removal rate of 81.8% (2 h), and yet melosira-diatomite@MnO2 reaches a higher degradation rate of 91.3% in 2 h. Additionally, the effects of catalyst amount, catalysis reaction temperature, preparing time have also been investigated. In principle, the diverse diatomite@MnO2 nanostructures not only present an environmentally friendly and low cost with a good cycling stability, but also offer a simple way for the catalytic degradation of dye waste water in practical applications.

Diatomite-immobilized BiOI hybrid photocatalyst: Facile deposition synthesis and enhanced photocatalytic activity

International Nuclear Information System (INIS)

Li, Baoying; Huang, Hongwei; Guo, Yuxi; Zhang, Yihe

2015-01-01

Graphical abstract: - Highlights: • A novel diatomite-immobilized BiOI hybrid photocatalyst has been prepared by a facile one-step deposition process for the first time. • The diatomite-immobilized BiOI hybrid photocatalyst exhibits much better photocatalytic performance. • This enhancement should be attributed to that diatomite can play as an excellent carrier platform to increase the reactive sites and promote the separation of photogenerated electron–hole pairs. • This work shed new light on facile fabrication of novel composite photocatalyst based on natural mineral. - Abstract: A novel diatomite-immobilized BiOI hybrid photocatalyst has been prepared by a facile one-step deposition process for the first time. The structure, morphology and optical property of the products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and UV–vis diffuse reflectance spectroscopy (DRS). The photocatalytic performance of the as-prepared BiOI/diatomite photocatalysts was studied by photodegradation of Rhodamine B (RhB) and methylene blue (MB) and monitoring photocurrent generation under visible light (λ > 420 nm). The results revealed that BiOI/diatomite composites exhibit enhanced photocatalytic activity compared to the pristine BiOI sample. This enhancement should be attributed to that diatomite can play as an excellent carrier platform to increase the reactive sites and promote the separation of photogenerated electron–hole pairs. In addition, the corresponding photocatalytic mechanism was proposed based on the active species trapping experiments. This work shed new light on facile fabrication of novel composite photocatalyst based on natural mineral.

Diatomite-immobilized BiOI hybrid photocatalyst: Facile deposition synthesis and enhanced photocatalytic activity

Energy Technology Data Exchange (ETDEWEB)

Li, Baoying; Huang, Hongwei, E-mail: hhw@cugb.edu.cn; Guo, Yuxi; Zhang, Yihe, E-mail: zyh@cugb.edu.cn

2015-10-30

Graphical abstract: - Highlights: • A novel diatomite-immobilized BiOI hybrid photocatalyst has been prepared by a facile one-step deposition process for the first time. • The diatomite-immobilized BiOI hybrid photocatalyst exhibits much better photocatalytic performance. • This enhancement should be attributed to that diatomite can play as an excellent carrier platform to increase the reactive sites and promote the separation of photogenerated electron–hole pairs. • This work shed new light on facile fabrication of novel composite photocatalyst based on natural mineral. - Abstract: A novel diatomite-immobilized BiOI hybrid photocatalyst has been prepared by a facile one-step deposition process for the first time. The structure, morphology and optical property of the products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and UV–vis diffuse reflectance spectroscopy (DRS). The photocatalytic performance of the as-prepared BiOI/diatomite photocatalysts was studied by photodegradation of Rhodamine B (RhB) and methylene blue (MB) and monitoring photocurrent generation under visible light (λ > 420 nm). The results revealed that BiOI/diatomite composites exhibit enhanced photocatalytic activity compared to the pristine BiOI sample. This enhancement should be attributed to that diatomite can play as an excellent carrier platform to increase the reactive sites and promote the separation of photogenerated electron–hole pairs. In addition, the corresponding photocatalytic mechanism was proposed based on the active species trapping experiments. This work shed new light on facile fabrication of novel composite photocatalyst based on natural mineral.

Surface complexation modeling calculation of Pb(II) adsorption onto the calcined diatomite

Science.gov (United States)

Ma, Shu-Cui; Zhang, Ji-Lin; Sun, De-Hui; Liu, Gui-Xia

2015-12-01

Removal of noxious heavy metal ions (e.g. Pb(II)) by surface adsorption of minerals (e.g. diatomite) is an important means in the environmental aqueous pollution control. Thus, it is very essential to understand the surface adsorptive behavior and mechanism. In this work, the Pb(II) apparent surface complexation reaction equilibrium constants on the calcined diatomite and distributions of Pb(II) surface species were investigated through modeling calculations of Pb(II) based on diffuse double layer model (DLM) with three amphoteric sites. Batch experiments were used to study the adsorption of Pb(II) onto the calcined diatomite as a function of pH (3.0-7.0) and different ionic strengths (0.05 and 0.1 mol L-1 NaCl) under ambient atmosphere. Adsorption of Pb(II) can be well described by Freundlich isotherm models. The apparent surface complexation equilibrium constants (log K) were obtained by fitting the batch experimental data using the PEST 13.0 together with PHREEQC 3.1.2 codes and there is good agreement between measured and predicted data. Distribution of Pb(II) surface species on the diatomite calculated by PHREEQC 3.1.2 program indicates that the impurity cations (e.g. Al3+, Fe3+, etc.) in the diatomite play a leading role in the Pb(II) adsorption and dominant formation of complexes and additional electrostatic interaction are the main adsorption mechanism of Pb(II) on the diatomite under weak acidic conditions.

Fabrication and excellent conductive performance of antimony-doped tin oxide-coated diatomite with porous structure

International Nuclear Information System (INIS)

Du Yucheng; Yan Jing; Meng Qi; Wang Jinshu; Dai Hongxing

2012-01-01

Graphical abstract: Antimony-doped tin oxide (ATO)-coated diatomite with porous structures are fabricated using the co-precipitation method. The porous ATO-coated diatomite material shows excellent conductive performance. Highlights: ► Sb-doped SnO 2 (ATO)-coated diatomite materials with porous structures are prepared. ► Sn/Sb ratio, ATO coating amount, pH value, and temperature influence resistivity. ► Porous ATO-coated diatomite materials show excellent conductive performance. ► The lowest resistivity of the porous ATO-coated diatomite sample is 10 Ω cm. - Abstract: Diatomite materials coated with antimony-doped tin oxide (ATO) were prepared by the co-precipitation method, and characterized by means of the techniques, such as X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, selected-area electron diffraction, X-ray fluorescence spectroscopy, and N 2 adsorption–desorption measurement. It was shown that the coated ATO possessed a tetragonal rutile crystal structure, and the ATO-coated diatomite materials had a multi-pore (micro- meso-, and macropores) architecture. The porous ATO-coated diatomite materials exhibited excellent electrical conductive behaviors. The best conductive performance (volume resistivity = 10 Ω cm) was achieved for the sample that was prepared under the conditions of Sn/Sb molar ratio = 5.2, Sn/Sb coating amount = 45 wt%, pH = 1.0, and reaction temperature = 50 °C. Such a conductive porous material is useful for the applications in physical and chemical fields.

Removal of Azo Dye from Synthetic Wastewater Using Immobilized Nano-Diatomite Within Calcium Alginate

Directory of Open Access Journals (Sweden)

AA Khodabandelou

2016-03-01

Full Text Available Introduction: The presence of organic dyes, discharged by textile industries, in aqueous environments can cause detrimental effects on aquatic life and subsequently human health. Therefore, the decolorization of aquatic environments is mandatory to protect the environment. For this reason, in the present study, nano-sized diatomite was immobilized within calcium alginate as a nanocomposite adsorbent for removing organic azo dye (Direct blue 15 from aqueous solutions.  Methods: First of all, Iranian diatomite was grinded in a planetary ball mill equipped with tungsten carbide cup for 20 h to achieve nanoparticles of the diatomite. For the immobilization of nanostructured diatomite, a 2% sodium alginate solution was used. Scanning electron microscopy (SEM, X-ray diffraction (XRD and Fourier transform infra-red (FT-IR spectroscopy were used to characterize immobilized nano-diatomite. Fifty milliliter Erlenmeyer flasks were used as batch flow mode experimental reactors. Working solutions were prepared by the dilution of stock solution (1 g/L to desired concentrations. The effect of different operational parameters including contact time, initial pH, adsorbent dosage and initial dye concentration along with kinetic and isotherm of the adsorption were evaluated. After each experiment, the residual concentration of the dyes was measured spectrophotometrically. Results: As results, the adsorption of organic dye increased with increasing contact time and adsorbent dosage, while increasing initial dye concentrations resulted in decreasing the adsorption. The adsorption of DB-15 was favored at basic PH. The immobilization of diatomite led to enhancing the adsorption of  DB-15 compared to diatomite alone. According to the obtained correlation coefficient, the adsorption of DB-15 obeyed pseudo-second order kinetic model and Langmuir isotherm model. The maximum adsorption capacity of diatomite/alginate nanocomposite for the adsorption of DB-15 were found

Influence of diatomite microstructure on its adsorption capacity for Pb(II

Directory of Open Access Journals (Sweden)

Nenadović S.

2009-01-01

Full Text Available The effect of microstructural changes caused by mechanical modification on adsorption properties of diatomite samples were investigated. The microstructure has been characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM and atomic force microscopy (AFM while the degree of metal adsorption was evaluated by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP AES. The results show that metal sorption capacity of diatomite is considerably improved after mechanical modification and it can be attributed to amorphysation of the material. Immobilization efficiency increased from 22% for untreated to 81% for the treated sample after 5h at BPR 4.This qualifies natural diatomite as a material for wastewater remediation.

The role of diatomite particles in the activated sludge system for treating coal gasification wastewater

Energy Technology Data Exchange (ETDEWEB)

Zhang, W.Q.; Rao, P.H.; Zhang, H.; Xu, J.L. [Shanghai University of Engineering Science, Shanghai (China)

2009-02-15

Diatomite is a kind of natural low-cost mineral material. It has a number of unique physical properties and has been widely used as an adsorbent in wastewater treatment. This study was conducted to investigate the aerobic biodegradation of coal gasification wastewater with and without diatomite addition. Experimental results indicated that diatomite added in the activated sludge system could promote the biomass and also enhance the performance of the sludge settling. The average mixed-liquor volatile suspended solids (MLVSS) is increased from 4055 mg.L{sup -1} to 4518 mg.L{sup -1} and the average settling volume (SV) are changed only from 45.9% to 47.1%. Diatomite additive could enhance the efficiency of chemical oxygen demand (COD) and total phenols removal from the wastewater. The COD removal increased from 73.3% to near 80% and the total phenols removal increased from 81.4% to 85.8%. The mechanisms of the increase of biomass and pollutants removal may correlated to the improvement of bioavailability and sludge settlement characteristics by diatomite added. Micrograph of the sludge in the diatomite-activated sludge system indicated that the diatomite added could be the carrier of the microbe and also affect the biomass and pollutant removal.

Influence of Diatomite and Mineral Powder on Thermal Oxidative Ageing Properties of Asphalt

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Yongchun Cheng

2015-01-01

Full Text Available Ageing of asphalt affects the performances of asphalt pavement significantly. Therefore, effects of diatomite and mineral powder on ageing properties of asphalt were investigated systematically in order to improve the antiageing property of mixture. Thin film oven test (TFOT was used to conduct the short term ageing in laboratory. Softening points, penetrations, force ductility, low temperature creep properties, and viscosities of asphalt mastics were tested before and after TFOT, respectively. Results indicated that percent retained penetration (PRP increased with the increasing of fillers. Increment of softening point (ΔT, ductility retention rate (DRR, deformation energy ageing index (JAI, and viscosity ageing index (VAI of asphalt mastics nonlinearly decreased with the increasing of fillers. Ageing of asphalt was reduced by diatomite and mineral powder. And the antiageing effect of diatomite was better than that of mineral powder as a result of its porous structure. It is suggested that the mineral powder could be reasonably replaced by diatomite in order to reduce thermal oxidative ageing of asphalt mixture. The optimal content of diatomite 12.8% is also suggested for engineering.

Light-refractory radiation shielding materials using diatomites and zeolites

International Nuclear Information System (INIS)

Murakami, Hideki

2005-01-01

It has been recently shown that diatomites and zeolites have some useful characteristics for radiation shielding materials. In this study, the availability of these materials for unexpected accidents in the nuclear sites is examined. The diatomites and zeolites, compared to existing shielding materials, have superior characteristics; low density and light weight, low in radiation-induced problem, high-heat resistance, remain unaltered by the addition of an acid except hydrofluoric acid, porous and large specific surface area, and also excellent water-absorbing property. These porous materials could also expand the shielding energy range applied and be used for fast- and thermal-neutrons, and γ ray. In addition, these materials are easy to store for long periods of time against emergency because of their natural rocks. From the examinations, it is cleared that diatomites and zeolites have excellent properties as radiation shielding materials for emergency use. (author)

Improved performance of diatomite-based dental nanocomposite ceramics using layer-by-layer assembly.

Science.gov (United States)

Lu, Xiaoli; Xia, Yang; Liu, Mei; Qian, Yunzhu; Zhou, Xuefeng; Gu, Ning; Zhang, Feimin

2012-01-01

To fabricate high-strength diatomite-based ceramics for dental applications, the layer-by-layer technique was used to coat diatomite particles with cationic [poly(allylamine hydrochloride)] and anionic [poly(sodium 4-styrenesulfonate)] polymers to improve the dispersion and adsorption of positively charged nano-ZrO(2) (zirconia) as a reinforcing agent. The modified diatomite particles had reduced particle size, narrower size distribution, and were well dispersed, with good adsorption of nano-ZrO(2). To determine the optimum addition levels for nano-ZrO(2), ceramics containing 0, 20, 25, 30, and 35 wt% nano-ZrO(2) were sintered and characterized by the three-point bending test and microhardness test. In addition to scanning electron microscopy, propagation phase-contrast synchrotron X-ray microtomography was used to examine the internal structure of the ceramics. The addition of 30 wt% nano-ZrO(2) resulted in the highest flexural strength and fracture toughness with reduced porosity. Shear bond strength between the core and veneer of our diatomite ceramics and the most widely used dental ceramics were compared; the shear bond strength value for the diatomite-based ceramics was found to be significantly higher than for other groups (P < 0.05). Our results show that diatomite-based nanocomposite ceramics are good potential candidates for ceramic-based dental materials.

Synthesis of nano-TiO{sub 2}/diatomite composite and its photocatalytic degradation of gaseous formaldehyde

Energy Technology Data Exchange (ETDEWEB)

Zhang, Guangxin; Sun, Zhiming, E-mail: zhimingsun@cumtb.edu.cn; Duan, Yongwei; Ma, Ruixin; Zheng, Shuilin, E-mail: shuilinzheng8@gmail.com

2017-08-01

Highlights: • TiO{sub 2}/diatomite composite was synthesized by hydrolysis deposition method. • The composite displayed higher photocatalytic performance for formaldehyde. • The dispersion effect of diatomite was a key factor for high photoactivity. • The composite is a promising photocatalyst for the indoor air purification. - Abstract: The TiO{sub 2}/diatomite composite was synthesized through a mild hydrolysis of titanyl sulfate. The prepared composite was characterized by X-ray diffraction, N{sub 2} adsorption–desorption, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and UV–vis diffused reflectance spectroscopy. The results demonstrate that the anatase TiO{sub 2} nanopartilces anchored on the surface of diatomite with Ti–O–Si bonds between diatomite and TiO{sub 2}. The photodegradation of gaseous formaldehyde under UV irradiation by the TiO{sub 2}/diatomite composite was studied under various operating conditions, including relative humidity, illumination intensity and catalyst amount, which have significant influence on the degradation process. The TiO{sub 2}/diatomite composite exhibited better photocatalytic activity than pure TiO{sub 2}, which could be attributed to the favorable nanoparticles dispersibility and strong formaldehyde adsorption capacity. In addition, the composite exhibited outstanding reusability over five cycles. The TiO{sub 2}/diatomite composite shows great promising application foreground in formaldehyde degradation.

Preparation and Photocatalytic Property of TiO2/Diatomite-Based Porous Ceramics Composite Materials

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Shuilin Zheng

2012-01-01

Full Text Available The diatomite-based porous ceramics was made by low-temperature sintering. Then the nano-TiO2/diatomite-based porous ceramics composite materials were prepared by hydrolysis deposition method with titanium tetrachloride as the precursor of TiO2 and diatomite-based porous as the supporting body of the nano-TiO2. The structure and microscopic appearance of nano-TiO2/diatomite-based porous ceramics composite materials was characterized by XRD and SEM. The photocatalytic property of the composite was investigated by the degradation of malachite green. Results showed that, after calcination at 550°C, TiO2 thin film loaded on the diatomite-based porous ceramics is anatase TiO2 and average grain size of TiO2 is about 10 nm. The degradation ratio of the composite for 5 mg/L malachite green solution reached 86.2% after irradiation for 6 h under ultraviolet.

Fabrication and excellent conductive performance of antimony-doped tin oxide-coated diatomite with porous structure

Energy Technology Data Exchange (ETDEWEB)

Du Yucheng, E-mail: ychengdu@bjut.edu.cn [Key Lab of Advanced Functional Materials, Ministry of Education, College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124 (China); Yan Jing; Meng Qi; Wang Jinshu [Key Lab of Advanced Functional Materials, Ministry of Education, College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124 (China); Dai Hongxing, E-mail: hxdai@bjut.edu.cn [Laboratory of Catalysis Chemistry and Nanoscience, Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China)

2012-04-16

Graphical abstract: Antimony-doped tin oxide (ATO)-coated diatomite with porous structures are fabricated using the co-precipitation method. The porous ATO-coated diatomite material shows excellent conductive performance. Highlights: Black-Right-Pointing-Pointer Sb-doped SnO{sub 2} (ATO)-coated diatomite materials with porous structures are prepared. Black-Right-Pointing-Pointer Sn/Sb ratio, ATO coating amount, pH value, and temperature influence resistivity. Black-Right-Pointing-Pointer Porous ATO-coated diatomite materials show excellent conductive performance. Black-Right-Pointing-Pointer The lowest resistivity of the porous ATO-coated diatomite sample is 10 {Omega} cm. - Abstract: Diatomite materials coated with antimony-doped tin oxide (ATO) were prepared by the co-precipitation method, and characterized by means of the techniques, such as X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, selected-area electron diffraction, X-ray fluorescence spectroscopy, and N{sub 2} adsorption-desorption measurement. It was shown that the coated ATO possessed a tetragonal rutile crystal structure, and the ATO-coated diatomite materials had a multi-pore (micro- meso-, and macropores) architecture. The porous ATO-coated diatomite materials exhibited excellent electrical conductive behaviors. The best conductive performance (volume resistivity = 10 {Omega} cm) was achieved for the sample that was prepared under the conditions of Sn/Sb molar ratio = 5.2, Sn/Sb coating amount = 45 wt%, pH = 1.0, and reaction temperature = 50 Degree-Sign C. Such a conductive porous material is useful for the applications in physical and chemical fields.

Modified local diatomite as potential functional drug carrier--A model study for diclofenac sodium.

Science.gov (United States)

Janićijević, Jelena; Krajišnik, Danina; Čalija, Bojan; Vasiljević, Bojana Nedić; Dobričić, Vladimir; Daković, Aleksandra; Antonijević, Milan D; Milić, Jela

2015-12-30

Diatomite makes a promising candidate for a drug carrier because of its high porosity, large surface area, modifiable surface chemistry and biocompatibility. Herein, refined diatomite from Kolubara coal basin, which complied with the pharmacopoeial requirements for heavy metals content and microbiological quality, was used as a starting material. Inorganic modification of the starting material was performed through a simple, one-step procedure. Significant increase in adsorbent loading with diclofenac sodium (DS) was achieved after the modification process (∼373mg/g) which enabled the preparation of comprimates containing therapeutic dose of the adsorbed drug. Adsorption of DS onto modified diatomite resulted in the alteration of the drug's XRD pattern and FTIR spectrum. In vitro drug release studies in phosphate buffer pH 7.5 demonstrated prolonged DS release over 8h from comprimates containing DS adsorbed on modified diatomite (up to 37% after 8h) and those containing physical mixture of the same composition (up to 45% after 8h). The results of in vivo toxicity testing on mice pointed on potential safety of both unmodified (starting) and modified diatomite. All these findings favor the application of diatomite as a potential functional drug carrier. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of Mesoporous Diatomite Particles on the Kinetics of SR&NI ATRP of Styrene and Butyl Acrylate

Science.gov (United States)

Khezri, Khezrollah; Ghasemi, Moosa; Fazli, Yousef

2018-05-01

Mesoporous diatomite particles were employed to prepare different poly(styrene-co-butyl acrylate)/diatomite nanocomposites. Diatomite nanoplatelets were used for in situ copolymerization of styrene and butyl acrylate by SR&NI ATRP to synthesize well-defined poly(styrene-co-butyl acrylate) nanocomposites. Nitrogen adsorption/desorption isotherm is applied to examine surface area and structural characteristics of the diatomite nanoplatelets. Evaluation of pore size distribution and morphological studies were also performed by SEM and TEM. Conversion and molecular weight determinations were carried out using gas and size exclusion chromatography respectively. Addition of 3 wt% pristine mesoporous diatomite nanoplatelets leads to increase of conversion from 73 to 89%. Molecular weight of poly(styrene-co-butyl acrylate) chains increases from 17,115 to 20,343 g·mol-1 by addition of 3 wt% pristine mesoporous diatomite; however, polydispersity index values increases from 1.14 to 1.37. Increasing thermal stability of the nanocomposites is demonstrated by TGA. Differential scanning calorimetry shows an increase in glass transition temperature from 35.26 to 39.61°C by adding 3 wt% of mesoporous diatomite nanoplatelets.

Formation of siliceous sediments in brandy after diatomite filtration.

Science.gov (United States)

Gómez, J; Gil, M L A; de la Rosa-Fox, N; Alguacil, M

2015-03-01

Brandy is quite a stable spirit but sometimes light sediment appears. This sediment was separated and analysed by IR and SEM-EDX. It was revealed that the sediment is composed mostly of silica and residual organic matter. Silica was present as an amorphous phase and as microparticles. In an attempt to reproduce the formation of the sediment, a diatomite extract was prepared with an ethanol/water mixture (36% vol.) and a calcined diatomite similar to that used in brandy filtration. This extract was added to unfiltered brandy in different amounts. After 1 month, the Si concentration decreased in all samples and sediments with similar compositions and features to those found in the unstable brandy appeared. The amounts of sediment obtained were directly related to the decrease in Si concentration in solution. Consequently, it can be concluded that siliceous sediment in brandy originates from Si released during diatomite filtration. Copyright © 2014 Elsevier Ltd. All rights reserved.

Improved performance of diatomite-based dental nanocomposite ceramics using layer-by-layer assembly

Directory of Open Access Journals (Sweden)

Lu X

2012-04-01

Full Text Available Xiaoli Lu1,2, Yang Xia1, Mei Liu1, Yunzhu Qian3, Xuefeng Zhou4, Ning Gu4, Feimin Zhang1,41Institute of Stomatology, Nanjing Medical University, Nanjing, 2Nantong Stomatological Hospital, Nantong, 3Center of Stomatology, The Second Affiliated Hospital of Suzhou University, Suzhou, 4Suzhou Institute, Southeast University, Suzhou, People's Republic of ChinaAbstract: To fabricate high-strength diatomite-based ceramics for dental applications, the layer-by-layer technique was used to coat diatomite particles with cationic [poly(allylamine hydrochloride] and anionic [poly(sodium 4-styrenesulfonate] polymers to improve the dispersion and adsorption of positively charged nano-ZrO2 (zirconia as a reinforcing agent. The modified diatomite particles had reduced particle size, narrower size distribution, and were well dispersed, with good adsorption of nano-ZrO2. To determine the optimum addition levels for nano-ZrO2, ceramics containing 0, 20, 25, 30, and 35 wt% nano-ZrO2 were sintered and characterized by the three-point bending test and microhardness test. In addition to scanning electron microscopy, propagation phase-contrast synchrotron X-ray microtomography was used to examine the internal structure of the ceramics. The addition of 30 wt% nano-ZrO2 resulted in the highest flexural strength and fracture toughness with reduced porosity. Shear bond strength between the core and veneer of our diatomite ceramics and the most widely used dental ceramics were compared; the shear bond strength value for the diatomite-based ceramics was found to be significantly higher than for other groups (P < 0.05. Our results show that diatomite-based nanocomposite ceramics are good potential candidates for ceramic-based dental materials.Keywords: layer-by-layer, diatomite, nanoceramics, zirconia (ZrO2, dental materials

Diatomite as high performance and environmental friendly catalysts for phenol hydroxylation with H2O2

Directory of Open Access Journals (Sweden)

Yuxin Jia et al

2007-01-01

Full Text Available A series of diatomite catalysts were treated and characterized. For the first time, the resulting materials were used in catalysis for the hydroxylation of phenol with H2O2 and showed very high hydroxylation activity due to the Fe species in the diatomite. The effect of HCl treatment, contents of catalysts and H2O2 were investigated and the active components of diatomite were discussed. The results show that diatomite is the promising candidate for industrial output due to their high catalytic activity, easy physical separation and very low costs.

Comparative research on tillable properties of diatomite-improved soils in the Yangtze River Delta region, China.

Science.gov (United States)

Qu, Ji-Li; Zhao, Dong-Xue

2016-10-15

To improve soil texture and structure, techniques associated with physical, biological or chemical aspects are generally adopted, among which diatomite is an important soil conditioner. However, few studies have been conducted to investigate the physical, hydraulic and tillage performance of diatomite-improved soils. Consistency limits and compaction properties were investigated in this study, and several performance indicators were compared, such as the liquid limit, plastic limit and compactability, of silt, silt loam and silty-clay loam soils to which diatomite was added at volumetric ratios of 0%, 10%, 20%, and 30%. The results showed that diatomite significantly (pdiatomite lowered the maximum dry bulk density (MBD) of the classified soils, the optimum moisture content (OMC) was increased overall. The trend was consistent with the proportion of diatomite, and MBD decreased by 8.7%, 10.3%, and 13.2% in the silt, silt loam and silty-clay loam soils when 30% diatomite was mixed, whereas OMC increased by 28.7%, 22.4%, and 25.3%, respectively. Additionally, aggregate stability was negatively correlated with MBD but positively correlated with OMC. Diatomite exerts positive effects on soil mechanical strength, suggesting that soils from sludge farms are more tillable with a larger stabilized and workable matrix. Copyright © 2016 Elsevier B.V. All rights reserved.

Chapter E: History and Overview of the U.S. Diatomite Mining Industry, with Emphasis on the Western United States

Science.gov (United States)

Moyle, Phillip R.; Dolley, Thomas P.

2003-01-01

The United States is the largest producer and consumer of diatomite in the world. In 2001, the United States produced about a third of the estimated global production of 1.95 million metric tons (Mt) of diatomite (Dolley, 2003). In any given year, the United States accounts for at least 50 percent of all the diatomite exported in the world (Roskill, 1994). Seven diatomite companies operating in the United States produce diatomite in various grades for a range of applications, including filtration, absorbents, fillers, insulation, and cement manufacture. Economic deposits of diatomite within the United States depend on variations in the physical and chemical properties between and within deposits, potential end uses, and proximity to suitable markets. On the basis of historical production figures, estimated U.S. diatomite-production capacity is currently about 800,000 metric tons per year (t/yr).

Microporous nano-MgO/diatomite ceramic membrane with high positive surface charge for tetracycline removal.

Science.gov (United States)

Meng, Xian; Liu, Zhimeng; Deng, Cheng; Zhu, Mengfu; Wang, Deyin; Li, Kui; Deng, Yu; Jiang, Mingming

2016-12-15

A novel microporous nano-MgO/diatomite ceramic membrane with high positive surface charge was prepared, including synthesis of precursor colloid, dip-coating and thermal decomposition. Combined SEM, EDS, XRD and XPS studies show the nano-MgO is irregularly distributed on the membrane surface or pore walls and forms a positively charged nano coating. And the nano-MgO coating is firmly attached to the diatomite membrane via SiO chemical bond. Thus the nano-MgO/diatomite membrane behaves strong electropositivity with the isoelectric point of 10.8. Preliminary filtration tests indicate that the as-prepared nano-MgO/diatomite membrane could remove approximately 99.7% of tetracycline in water through electrostatic adsorption effect. The desirable electrostatic property enables the nano-MgO/diatomite membrane to be a candidate for removal of organic pollutants from water. And it is convinced that there will be a great application prospect of charged ceramic membrane in water treatment field. Copyright © 2016 Elsevier B.V. All rights reserved.

Characterization of diatomite and its application for the retention of radiocobalt: role of environmental parameters.

Science.gov (United States)

Sheng, Guodong; Dong, Huaping; Li, Yimin

2012-11-01

Clay minerals have been extensively studied because of their strong sorption and complexation ability. In this work, diatomite was characterized by using acid-base titration. Retention of radionuclide (60)Co(II) from aqueous solution by sorption onto diatomite was investigated by using batch technique under various environmental conditions such as pH, ionic strength, humic acid (HA), fulvic acid (FA), and temperature. The results indicated that the sorption of Co(II) onto diatomite was strongly dependent on pH. At low pH value, the sorption of Co(II) was dominated by outer-sphere surface complexation and ion exchange with Na(+)/H(+) on diatomite surfaces, whereas inner-sphere surface complexation was the main sorption mechanism at high pH value. The D-R model fitted the sorption isotherms better than the Langmuir and Freundlich models. The thermodynamic parameters (ΔH(0), ΔS(0) and ΔG(0)) calculated from the temperature-dependent sorption isotherms suggested that the sorption of Co(II) was an endothermic and spontaneous process. In addition, diatomite showed higher sorption capacity than that of lots of the sorbents reported in the literatures we surveyed. From the results of Co(II) removal by diatomite, the optimum reaction conditions can be obtained for the maximum removal of Co(II) from water. It is clear that the best pH values of the system to remove Co(II) from solution by using diatomite are 7-8. Considering the low cost and effective disposal of Co(II)-contaminated wastewaters, the best condition for Co(II) removal is at room temperature and solid content of 0.5 g/L. The results might be important for assessing the potential of practical application of diatomite in Co(II) and related radionuclide pollution management. Copyright © 2012 Elsevier Ltd. All rights reserved.

Modified natural diatomite and its enhanced immobilization of lead, copper and cadmium in simulated contaminated soils.

Science.gov (United States)

Ye, Xinxin; Kang, Shenghong; Wang, Huimin; Li, Hongying; Zhang, Yunxia; Wang, Guozhong; Zhao, Huijun

2015-05-30

Natural diatomite was modified through facile acid treatment and ultrasonication, which increased its electronegativity, and the pore volume and surface area achieved to 0.211 cm(3) g(-1) and 76.9 m(2) g(-1), respectively. Modified diatomite was investigated to immobilize the potential toxic elements (PTEs) of Pb, Cu and Cd in simulated contaminated soil comparing to natural diatomite. When incubated with contaminated soils at rates of 2.5% and 5.0% by weight for 90 days, modified diatomite was more effective in immobilizing Pb, Cu and Cd than natural diatomite. After treated with 5.0% modified diatomite for 90 days, the contaminated soils showed 69.7%, 49.7% and 23.7% reductions in Pb, Cu and Cd concentrations after 0.01 M CaCl2 extraction, respectively. The concentrations of Pb, Cu and Cd were reduced by 66.7%, 47.2% and 33.1% in the leaching procedure, respectively. The surface complexation played an important role in the immobilization of PTEs in soils. The decreased extractable metal content of soil was accompanied by improved microbial activity which significantly increased (Psoils. These results suggested that modified diatomite with micro/nanostructured characteristics increased the immobilization of PTEs in contaminated soil and had great potential as green and low-cost amendments. Copyright © 2015 Elsevier B.V. All rights reserved.

Diatomite Type Filters for Swimming Pools. Standard No. 9, Revised October, 1966.

Science.gov (United States)

National Sanitation Foundation, Ann Arbor, MI.

Pressure and vacuum diatomite type filters are covered in this standard. The filters herein described are intended to be designed and used specifically for swimming pool water filtration, both public and residential. Included are the basic components which are a necessary part of the diatomite type filter such as filter housing, element supports,…

Degradation of simazine from aqueous solutions by diatomite-supported nanosized zero-valent iron composite materials.

Science.gov (United States)

Sun, Zhiming; Zheng, Shuilin; Ayoko, Godwin A; Frost, Ray L; Xi, Yunfei

2013-12-15

A novel composite material based on deposition of nanosized zero-valent iron (nZVI) particles on acid-leached diatomite was synthesised for the removal of a chlorinated contaminant in water. The nZVI/diatomite composites were characterised by X-ray diffraction, scanning electron microscopy, elemental analysis, transmission electron microscopy and X-ray photoelectron spectroscopy. Compared with the pure nZVI particles, better dispersion of nZVI particles on the surface or inside the pores of diatom shells was observed. The herbicide simazine was selected as the model chlorinated contaminant and the removal efficiency by nZVI/diatomite composite was compared with that of the pristine nZVI and commercial iron powder. It was found that the diatomite supported nZVI composite material prepared by centrifugation exhibits relatively better efficient activity in decomposition of simazine than commercial Fe, lab synthesised nZVI and composite material prepared via rotary evaporation, and the optimum experimental conditions were obtained based on a series of batch experiments. This study on immobilising nZVI particles onto diatomite opens a new avenue for the practical application of nZVI and the diatomite-supported nanosized zero-valent iron composite materials have potential applications in environmental remediation. Copyright © 2013 Elsevier B.V. All rights reserved.

Improved performance of diatomite-based dental nanocomposite ceramics using layer-by-layer assembly

Science.gov (United States)

Lu, Xiaoli; Xia, Yang; Liu, Mei; Qian, Yunzhu; Zhou, Xuefeng; Gu, Ning; Zhang, Feimin

2012-01-01

To fabricate high-strength diatomite-based ceramics for dental applications, the layer-by-layer technique was used to coat diatomite particles with cationic [poly(allylamine hydrochloride)] and anionic [poly(sodium 4-styrenesulfonate)] polymers to improve the dispersion and adsorption of positively charged nano-ZrO2 (zirconia) as a reinforcing agent. The modified diatomite particles had reduced particle size, narrower size distribution, and were well dispersed, with good adsorption of nano-ZrO2. To determine the optimum addition levels for nano-ZrO2, ceramics containing 0, 20, 25, 30, and 35 wt% nano-ZrO2 were sintered and characterized by the three-point bending test and microhardness test. In addition to scanning electron microscopy, propagation phase-contrast synchrotron X-ray microtomography was used to examine the internal structure of the ceramics. The addition of 30 wt% nano-ZrO2 resulted in the highest flexural strength and fracture toughness with reduced porosity. Shear bond strength between the core and veneer of our diatomite ceramics and the most widely used dental ceramics were compared; the shear bond strength value for the diatomite-based ceramics was found to be significantly higher than for other groups (P ceramics are good potential candidates for ceramic-based dental materials. PMID:22619551

Diatomite as a novel composite ingredient for chitosan film with enhanced physicochemical properties.

Science.gov (United States)

Akyuz, Lalehan; Kaya, Murat; Koc, Behlul; Mujtaba, Muhammad; Ilk, Sedef; Labidi, Jalel; Salaberria, Asier M; Cakmak, Yavuz Selim; Yildiz, Aysegul

2017-12-01

Practical applications of biopolymers in different industries are gaining considerable increase day by day. But still, these biopolymers lack important properties in order to meet the industrial demands. In the same regard, in the current study, chitosan composite films are produced by incorporating diatomite soil at two different concentrations. In order to obtain a homogeneous film, glutaraldehyde was supplemented to chitosan solution as a cross-linker. Compositing diatomaceous earth to chitosan film resulted in improvement of various important physicochemical properties compared to control such as; enhanced film wettability, increase elongation at break and improved thermal stability (264-277°C). The microstructure of the film was observed to haveconsisted of homogeneously distributed blister-shaped structures arised due to the incorporation of diatomite. The incorporation of diatomite did not influence the overall antioxidant activity of the composite films, which can be ascribe to the difficulty radicals formation. Chitosan film incorporated with increasing fraction of diatomite revealed a notable enhancement in the antimicrobial activity. Additionally with the present study, for the first time possible interactions between chitosan/diatomite were determined via quantum chemical calculations. Current study will be helpful in giving a new biotechnological perspective to diatom in terms of its successful application in hydrophobic composite film production. Copyright © 2017 Elsevier B.V. All rights reserved.

Fibrillar polyaniline/diatomite composite synthesized by one-step in situ polymerization method

International Nuclear Information System (INIS)

Li Xingwei; Li Xiaoxuan; Wang Gengchao

2005-01-01

A fibrillar polyaniline/diatomite composite was prepared by one-step in situ polymerization of aniline in the dispersed system of diatomite, and was characterized via Fourier-transform infrared spectra (FT-IR), UV-vis-NIR spectra, wide-angle X-ray diffraction (WXRD), thermogravimetric analysis (TGA) and transmission electron microscopy (TEM), as well as conductivity. Morphology of the composite is uniform nanofibers, which the diameters of nanofibers are about 50-80 nm. The conductivity of polyaniline/diatomite composite contained 28% polyaniline is 0.29 S cm -1 at 25 deg. C, and temperature of thermal degradation has reached 493 deg. C in air. The composite has potential commercial applications as fillers for electromagnetic shielding materials and conductive coatings

Possible mechanism of structural incorporation of Al into diatomite during the deposition process I. Via a condensation reaction of hydroxyl groups.

Science.gov (United States)

Liu, Dong; Yu, Wenbin; Deng, Liangliang; Yuan, Weiwei; Ma, Lingya; Yuan, Peng; Du, Peixin; He, Hongping

2016-01-01

The structural incorporation of aluminium (Al) into diatomite is investigated by preparing several Al-diatomite composites by loading an Al precursor, hydroxyl aluminum polymer (Al13), onto the surface of diatomite and heating at various temperatures. The results indicate that Al was incorporated and implanted into the structure of diatomite by the condensation reaction of the hydroxyl groups of Al13 and diatomite, and the Si-O-Al(OH) groups were formed during the condensation reaction. Al incorporation by the condensation reaction of hydroxyl groups of Al13 with single silanols of diatomite occurred more readily than that with geminal silanols. The Al incorporation increased solid acidity of diatomite after Al incorporation. The acidity improvement was various for different types of acid sites, depending on the preparation temperature of the Al-incorporated diatomite. Both Brønsted and Lewis acid sites increased greatly after heating at 250 and 350 °C, but only L acid sites significantly improved after heating at 500 °C. These results demonstrate that the structural incorporation of Al(3+) ions into diatomite can occur by the condensation reaction of the hydroxyl groups of the Al precursors and diatomite. Moreover, the rich solid acid sites of Al-incorporated diatomite show its promising application as a solid acid catalyst. Copyright © 2015 Elsevier Inc. All rights reserved.

Prediction of equilibrium parameters of adsorption of lead (II) ions onto diatomite

Science.gov (United States)

Salman, Taylan; Ardalı, Yüksel; Gamze Turan, N.

2013-04-01

Heavy metals from industrial wastewaters are one of the most important environmental issues to be solved today. Due to their toxicity and nonbiodegradable nature, heavy metals cause environmental and public health problems. Various techniques have been developed to remove heavy metals from aqueous solutions. These include chemical precipitation, reverse osmosis, ion Exchange and adsorption. Among them, adsorption is considered to be a particularly competitive and effective process for the removal of heavy metals from aqueous solutions. There is growing interest in using low cost, commercially available materials for the adsorption of heavy metals. Diatomite is a siliceous sedimentary rock having an amorphous form of silica (SiO2. nH2O) containing a small amount of microcrystalline material. It has unique combination of physical and chemical properties such as high porosity, high permeability, small particle size, large surface area, and low thermal conductivity. In addition, it is available in Turkey and in various locations around the world. Therefore, diatomite has been successfully used as adsorbent for the removal of heavy metals. The aim of the study is to investigate the adsorption properties of diatomite. The equilibrium adsorption data were applied to the Langmuir, Freundlich and Dubinin-Radushkevic (D-R) isotherm models. Adsorption experiments were performed under batch process, using Pb (II) initial concentration, pH of solution and contact time as variables. The results demonstrated that the adsorption of Pb (II) was strongly dependent on pH of solution. The effect of pH on adsorption of Pb(II) on diatomite was conducted by varying pH from 2 to 12 at 20 oC. In the pH range of 2.0-4.0, the adsorption percentage increases slightly as the pH increasing. At pH>4, the adsorption percentage decreases with increasing pH because hydrolysis product and the precipitation begin to play an important role in the sorption of Pb (II). At pH4, the maximum adsorption

Possible Use of Diatomite and Pumice-Amended Mortar and Plaster in Agricultural Structures

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Serkan Yazarel

2017-12-01

Full Text Available This study was conducted to investigate the potential use of diatomite (a natural pozzolana and pumice in plasters and mortars to be used in agricultural buildings. Compacted and loose unit weights, specific weight, water absorption, organic matter content, abrasion resistance of aggregate (sand and pumice and pozzolana were investigated and materials were found to comply with the relevant standards. Test results on fresh (unit weight and slum test and hardened (unit weight, capillary water absorption, total water absorption, bending and compressive strength, vapor diffusion test mortar samples revealed that pumice and diatomite could be used in agricultural structures. Diatomite and pumice should be heat-treated and grounded before to use in mortars. In plasters to be made with abundant pumice and diatomite sources, high water holding capacity of the materials should be taken into consideration and further researches should be carried out about their compliance with the other materials.

Diatomite-immobilized BiOI hybrid photocatalyst: Facile deposition synthesis and enhanced photocatalytic activity

Science.gov (United States)

Li, Baoying; Huang, Hongwei; Guo, Yuxi; Zhang, Yihe

2015-10-01

A novel diatomite-immobilized BiOI hybrid photocatalyst has been prepared by a facile one-step deposition process for the first time. The structure, morphology and optical property of the products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and UV-vis diffuse reflectance spectroscopy (DRS). The photocatalytic performance of the as-prepared BiOI/diatomite photocatalysts was studied by photodegradation of Rhodamine B (RhB) and methylene blue (MB) and monitoring photocurrent generation under visible light (λ > 420 nm). The results revealed that BiOI/diatomite composites exhibit enhanced photocatalytic activity compared to the pristine BiOI sample. This enhancement should be attributed to that diatomite can play as an excellent carrier platform to increase the reactive sites and promote the separation of photogenerated electron-hole pairs. In addition, the corresponding photocatalytic mechanism was proposed based on the active species trapping experiments. This work shed new light on facile fabrication of novel composite photocatalyst based on natural mineral.

BIOSILICA NANOVECTOR FROM DIATOMITE FOR siRNA TRANSPORT IN CANCER CELL

OpenAIRE

Migliaccio, Nunzia

2015-01-01

Diatomite is a natural porous biomaterial of sedimentary origin, formed by fragments of diatom siliceous skeletons, called "frustules". Due to large availability in many areas of the world, chemical stability, and non-toxicity, these fossil structures have been widespread used in a lot of industrial applications, such as food production, water extracting agent, production of cosmetics and pharmaceutics. However, diatomite is surprisingly still rarely used in biomedical ap...

Sorption of Cr(III) ion from aqueous solution by two kinds of modified diatomite.

Science.gov (United States)

Li, Er; Zeng, Xiangying

2012-01-01

Raw diatomite modified by microemulsion (DMM) and manganese oxide (MnD) were used for the removal of Cr(III) ions from aqueous solution. The characteristics and performance of these two types of modified diatomite on Cr(III) ion adsorption were compared. The results indicate that the Cr(III) ion adsorption capacities of diatomite were considerably improved after modifications by manganese oxide (MnO) and microemulsion. The surface area of MnD was increased because of the formation of MnO on the diatomite surface, and that of DMM was promoted owing to the existence of the hydrolyzed aromatic acid. Because of the stronger surface ionized function, the adsorption performance of Cr(III) ions in DMM was better than that in MnD. Within the experimental range of pH (i.e. 2.2-6.3), the Cr(III) ion removal of DMM (35-70%) was higher than that of MnD (33-59%) owing to the different electrostatic forces between the Cr(III) ion and the surface of the modified diatomite. The Cr(III) ion removal in MnD and DMM was improved with the increase of synthetic solution concentration in volumes from 0 to 2,500 mL.

Pore structure modification of diatomite as sulfuric acid catalyst support by high energy electron beam irradiation and hydrothermal treatment

Science.gov (United States)

Li, Chong; Zhang, Guilong; Wang, Min; Chen, Jianfeng; Cai, Dongqing; Wu, Zhengyan

2014-08-01

High energy electron beam (HEEB) irradiation and hydrothermal treatment (HT), were applied in order to remove the impurities and enlarge the pore size of diatomite, making diatomite more suitable to be a catalyst support. The results demonstrated that, through thermal, charge, impact and etching effects, HEEB irradiation could make the impurities in the pores of diatomite loose and remove some of them. Then HT could remove rest of them from the pores and contribute significantly to the modification of the pore size distribution of diatomite due to thermal expansion, water swelling and thermolysis effects. Moreover, the pore structure modification improved the properties (BET (Brunauer-Emmett-Teller) specific surface area, bulk density and pore volume) of diatomite and the catalytic efficiency of the catalyst prepared from the treated diatomite.

Manipulating surface wettability and oil absorbency of diatomite depending on processing and ambient conditions

Science.gov (United States)

Özen, İlhan; Şimşek, Süleyman; Okyay, Gamze

2015-03-01

In this study, a diatomite sample, which is a natural inorganic mineral with inherently high water and oil absorption capacity, was subjected to grinding before surface modification. Afterwards, the diatomite surface was modified via facile methods using a fluorocarbon (FC) chemical and stearic acid (SA) in addition to the sol-gel fluorosilanization (FS) process. The water and oil wettability, and oil absorbency properties of the unmodified and modified diatomites were investigated in addition to diatomite characterizations such as chemical content, surface area, particle size distribution, morphology, and modification efficiency. It was revealed that the wettability was changed completely depending on the surface modification agent and the media used, while the oil absorbency property surprisingly did not change. On the other hand, the oil absorbency was worsened by the grinding process, whereas the wettability was not affected.

Characterization of diatomite and its application for the retention of radiocobalt: role of environmental parameters

International Nuclear Information System (INIS)

Sheng, Guodong; Dong, Huaping; Li, Yimin

2012-01-01

Clay minerals have been extensively studied because of their strong sorption and complexation ability. In this work, diatomite was characterized by using acid–base titration. Retention of radionuclide 60 Co(II) from aqueous solution by sorption onto diatomite was investigated by using batch technique under various environmental conditions such as pH, ionic strength, humic acid (HA), fulvic acid (FA), and temperature. The results indicated that the sorption of Co(II) onto diatomite was strongly dependent on pH. At low pH value, the sorption of Co(II) was dominated by outer-sphere surface complexation and ion exchange with Na + /H + on diatomite surfaces, whereas inner-sphere surface complexation was the main sorption mechanism at high pH value. The D–R model fitted the sorption isotherms better than the Langmuir and Freundlich models. The thermodynamic parameters (ΔH 0 , ΔS 0 and ΔG 0 ) calculated from the temperature-dependent sorption isotherms suggested that the sorption of Co(II) was an endothermic and spontaneous process. In addition, diatomite showed higher sorption capacity than that of lots of the sorbents reported in the literatures we surveyed. From the results of Co(II) removal by diatomite, the optimum reaction conditions can be obtained for the maximum removal of Co(II) from water. It is clear that the best pH values of the system to remove Co(II) from solution by using diatomite are 7–8. Considering the low cost and effective disposal of Co(II)-contaminated wastewaters, the best condition for Co(II) removal is at room temperature and solid content of 0.5 g/L. The results might be important for assessing the potential of practical application of diatomite in Co(II) and related radionuclide pollution management. - Highlights: ► The sorption of Co(II) was strongly dependent on ionic strength at low pH, but independent of ionic strength at high pH. ► A positive effect of HA/FA on Co(II) sorption was found at low pH, whereas a negative effect

Experimental study on the effect of calcination on the volcanic ash activity of diatomite

Science.gov (United States)

Xiao, Liguang; Pang, Bo

2017-09-01

The volcanic ash activity of diatomite was studied under the conditions of aerobic calcination and vacuum calcination by the combined water rate method, it was characterized by XRD, BET and SEM. The results showed that the volcanic ash activity of diatomite under vacuum conditions was higher than that of aerobic calcination, 600°C vacuum calcination 2h, the combined water rate of diatomite-Ca(OH)2-H2O system was increased from 6.24% to 71.43%, the volcanic ash activity reached the maximum value, the specific surface

Pore structure modified diatomite-supported PEG composites for thermal energy storage

Science.gov (United States)

Qian, Tingting; Li, Jinhong; Deng, Yong

2016-09-01

A series of novel composite phase change materials (PCMs) were tailored by blending PEG and five kinds of diatomite via a vacuum impregnation method. To enlarge its pore size and specific surface area, different modification approaches including calcination, acid treatment, alkali leaching and nano-silica decoration on the microstructure of diatomite were outlined. Among them, 8 min of 5 wt% NaOH dissolution at 70 °C has been proven to be the most effective and facile. While PEG melted during phase transformation, the maximum load of PEG could reach 70 wt.%, which was 46% higher than that of the raw diatomite. The apparent activation energy of PEG in the composite was 1031.85 kJ·mol-1, which was twice higher than that of the pristine PEG. Moreover, using the nano-silica decorated diatomite as carrier, the maximum PEG load was 66 wt%. The composite PCM was stable in terms of thermal and chemical manners even after 200 cycles of melting and freezing. All results indicated that the obtained composite PCMs were promising candidate materials for building applications due to its large latent heat, suitable phase change temperature, excellent chemical compatibility, improved supercooling extent, high thermal stability and long-term reliability.

Pore structure modified diatomite-supported PEG composites for thermal energy storage.

Science.gov (United States)

Qian, Tingting; Li, Jinhong; Deng, Yong

2016-09-01

A series of novel composite phase change materials (PCMs) were tailored by blending PEG and five kinds of diatomite via a vacuum impregnation method. To enlarge its pore size and specific surface area, different modification approaches including calcination, acid treatment, alkali leaching and nano-silica decoration on the microstructure of diatomite were outlined. Among them, 8 min of 5 wt% NaOH dissolution at 70 °C has been proven to be the most effective and facile. While PEG melted during phase transformation, the maximum load of PEG could reach 70 wt.%, which was 46% higher than that of the raw diatomite. The apparent activation energy of PEG in the composite was 1031.85 kJ·mol(-1), which was twice higher than that of the pristine PEG. Moreover, using the nano-silica decorated diatomite as carrier, the maximum PEG load was 66 wt%. The composite PCM was stable in terms of thermal and chemical manners even after 200 cycles of melting and freezing. All results indicated that the obtained composite PCMs were promising candidate materials for building applications due to its large latent heat, suitable phase change temperature, excellent chemical compatibility, improved supercooling extent, high thermal stability and long-term reliability.

Electromagnetic properties of core–shell particles by way of electroless Ni–Fe–P alloy plating on flake-shaped diatomite

Energy Technology Data Exchange (ETDEWEB)

Zhang, Deyuan [Bionic and Micro/Nano/Bio Manufacturing Technology Research Center, School of Mechanical Engineering and Automation, Beihang University, Beijing 100191 (China); Yuan, Liming, E-mail: lming_y@163.com [Bionic and Micro/Nano/Bio Manufacturing Technology Research Center, School of Mechanical Engineering and Automation, Beihang University, Beijing 100191 (China); Lan, Mingming; Hu, Yanyan; Cai, Jun [Bionic and Micro/Nano/Bio Manufacturing Technology Research Center, School of Mechanical Engineering and Automation, Beihang University, Beijing 100191 (China); Zhang, Wenqiang [College of Engineering, China Agricultural University, Beijing 100083 (China); Li, Haiyang [China Aerospace Science and Technology Corporation, Beijing 100854 (China)

2013-11-15

Flake-shaped diatomite particles coated by Ni–Fe–P alloy were prepared by electroless plating technique and processed by heat treatment. The samples were characterized by SEM, EDS and XRD. The results indicated that the magnetic diatomite particles had continuous and homogeneous Ni–Fe–P coating, and the phase constitution of the Ni–Fe–P coating was transformed from an amorphous structure to a crystalline structure during heat treatment. The measured electromagnetic parameters and the calculated reflection loss suggested that heat treatment was able to enhance the microwave absorption performance of the paraffin wax based composites. In a word, the Ni–Fe–P coated diatomite particle obtained in this paper is a promising candidate for lightweight microwave absorbing inclusions. - Highlights: • We used the flake-shaped diatomite particles as forming template to fabricate the core–shell ferromagnetic particles. • The diatomite particles were deposited Ni–Fe–P alloy by way of electroless plating methods. • The coated diatomite particles were lightweight ferromagnetic fillers. • The composites containing coated diatomite particles with heat treatment exhibited great potential in the field of electromagnetic absorbing.

Electromagnetic properties of core–shell particles by way of electroless Ni–Fe–P alloy plating on flake-shaped diatomite

International Nuclear Information System (INIS)

Zhang, Deyuan; Yuan, Liming; Lan, Mingming; Hu, Yanyan; Cai, Jun; Zhang, Wenqiang; Li, Haiyang

2013-01-01

Flake-shaped diatomite particles coated by Ni–Fe–P alloy were prepared by electroless plating technique and processed by heat treatment. The samples were characterized by SEM, EDS and XRD. The results indicated that the magnetic diatomite particles had continuous and homogeneous Ni–Fe–P coating, and the phase constitution of the Ni–Fe–P coating was transformed from an amorphous structure to a crystalline structure during heat treatment. The measured electromagnetic parameters and the calculated reflection loss suggested that heat treatment was able to enhance the microwave absorption performance of the paraffin wax based composites. In a word, the Ni–Fe–P coated diatomite particle obtained in this paper is a promising candidate for lightweight microwave absorbing inclusions. - Highlights: • We used the flake-shaped diatomite particles as forming template to fabricate the core–shell ferromagnetic particles. • The diatomite particles were deposited Ni–Fe–P alloy by way of electroless plating methods. • The coated diatomite particles were lightweight ferromagnetic fillers. • The composites containing coated diatomite particles with heat treatment exhibited great potential in the field of electromagnetic absorbing

Alumina Coating To Realize Desired Pore Characteristics Of Sintered Diatomite Membrane

Directory of Open Access Journals (Sweden)

Ha J.-H.

2015-06-01

Full Text Available Porous ceramic membranes prepared from natural materials such as diatomite, have lately attracted great interest in industrial applications due to their cost-effectiveness. In this study, we attempted to prepare an alumina coating to be deposited over a sintered diatomite-kaolin composite support layer in order to reduce the largest pore size to below 0.4 μm; such a coating could be potentially used in water treatment applications for bacterial removal.

AgBr/diatomite for the efficient visible-light-driven photocatalytic degradation of Rhodamine B

Science.gov (United States)

Fang, Jing; Zhao, Huamei; Liu, Qinglei; Zhang, Wang; Gu, Jiajun; Su, Yishi; Abbas, Waseem; Su, Huilan; You, Zhengwei; Zhang, Di

2018-03-01

The treatment of organic pollution via photocatalysis has been investigated for a few decades. However, earth-abundant, cheap, stable, and efficient substrates are still to be developed. Here, we prepare an efficient visible-light-driven photocatalyst via the deposition of Ag nanoparticles (light intensity. For comparison, AgBr/SiO2 ( κ = 0.04 min-1) and commercial AgBr nanoparticles ( κ = 0.05 min-1) were measured as well. The experimental results reveal that diatomite acted more than a substrate benefiting the dispersion of AgBr nanoparticles, as well as a cooperator to help harvest visible light and adsorb dye molecules, leading to the efficient visible-light-driven photocatalytic performance of AgBr/diatomite. Considering the low cost (10 per ton) and large-scale availability of diatomite, our study provides the possibility to prepare other types of diatomite-based efficient photocatalytic composites with low-cost but excellent photocatalytic performance.

Synthesis and Performances of Phase Change Microcapsules with a Polymer/Diatomite Hybrid Shell for Thermal Energy Storage

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Yanli Sun

2018-05-01

Full Text Available The mechanical behavior of phase-change microcapsules (microPCMs is of vital significance for practical applications in thermal energy storage. Hence, a new type of microPCMs based on an n-octadecane (C18 core and a melamine-urea-formaldehyde (MUF/diatomite hybrid shell was developed through in situ polymerization. Based on SEM micrographs, most microPCMs exhibited a nearly spherical and smooth microstructure, with broadened particle size distributions. It was confirmed by Fourier transform infrared (FTIR that successful polymerization of diatomite into the microPCMs occurred, and that additional diatomite had no effect on the core coated by the shell. In addition, the results of the differential scanning calorimeter (DSC and Atomic Force Microscopy (AFM demonstrated that the mechanical properties of the microPCMs were remarkably improved by the addition of a moderate amount of diatomite, but that the heat enthalpy and encapsulated efficiency (η decreased slightly. The incorporation of 2 wt % diatomite resulted in the average Young’s modulus of microPCMs, which was 1.64 times greater than those of microPCMs without diatomite. Furthermore, the melting and crystallization enthalpies and the encapsulated efficiency of the microPCMs were as high as 237.6 J/g, 234.4 J/g and 77.90%, respectively. The microPCMs with a polymer/diatomite hybrid shell may become the potential materials in the application of thermal energy storage.

Foams in porous media

Energy Technology Data Exchange (ETDEWEB)

Marsden, S.S.

1986-07-01

In 1978 a literature search on selective blocking of fluid flow in porous media was done by Professor S.S. Marsden and two of his graduate students, Tom Elson and Kern Huppy. This was presented as SUPRI Report No. TR-3 entitled ''Literature Preview of the Selected Blockage of Fluids in Thermal Recovery Projects.'' Since then a lot of research on foam in porous media has been done on the SUPRI project and a great deal of new information has appeared in the literature. Therefore we believed that a new, up-to-date search should be done on foam alone, one which would be helpful to our students and perhaps of interest to others. This is a chronological survey showing the development of foam flow, blockage and use in porous media, starting with laboratory studies and eventually getting into field tests and demonstrations. It is arbitrarily divided into five-year time periods. 81 refs.

Preparation and thermal energy storage properties of paraffin/calcined diatomite composites as form-stable phase change materials

International Nuclear Information System (INIS)

Sun, Zhiming; Zhang, Yuzhong; Zheng, Shuilin; Park, Yuri; Frost, Ray L.

2013-01-01

Highlights: ► Composite phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite. ► The optimum mixed proportion was obtained through differential scanning calorimetry. ► Thermal energy storage properties of the composite PCMs were determined by DSC. ► Thermal cycling test showed that the prepared PCMs are thermally reliable and chemically stable. - Abstract: A composite paraffin-based phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite through the fusion adsorption method. In this study, raw diatomite was purified by thermal treatment in order to improve the adsorption capacity of diatomite, which acted as a carrier material to prepare shape-stabilized PCMs. Two forms of paraffin (paraffin waxes and liquid paraffin) with different melting points were blended together by the fusion method, and the optimum mixed proportion with a suitable phase-transition temperature was obtained through differential scanning calorimetry (DSC) analysis. Then the prepared composite paraffin was adsorbed in calcined diatomite. The prepared paraffin/calcined diatomite composites were characterized by the scanning electron microscope (SEM) and Fourier transformation infrared (FT-IR) analysis techniques. Thermal energy storage properties of the composite PCMs were determined by DSC method. DSC results showed that there was an optimum adsorption ratio between composite paraffin and calcined diatomite and the phase-transition temperature and the latent heat of the composite PCMs were 33.04 °C and 89.54 J/g, respectively. Thermal cycling test of composite PCMs showed that the prepared material is thermally reliable and chemically stable. The obtained paraffin/calcined diatomite composites have proper latent heat and melting temperatures, and show practical significance and good potential application value

Preparation and thermal energy storage properties of paraffin/calcined diatomite composites as form-stable phase change materials

Energy Technology Data Exchange (ETDEWEB)

Sun, Zhiming [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia); Zhang, Yuzhong [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Zheng, Shuilin, E-mail: shuilinzh@yahoo.com.cn [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Park, Yuri [Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia); Frost, Ray L., E-mail: r.frost@qut.edu.au [Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia)

2013-04-20

Highlights: ► Composite phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite. ► The optimum mixed proportion was obtained through differential scanning calorimetry. ► Thermal energy storage properties of the composite PCMs were determined by DSC. ► Thermal cycling test showed that the prepared PCMs are thermally reliable and chemically stable. - Abstract: A composite paraffin-based phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite through the fusion adsorption method. In this study, raw diatomite was purified by thermal treatment in order to improve the adsorption capacity of diatomite, which acted as a carrier material to prepare shape-stabilized PCMs. Two forms of paraffin (paraffin waxes and liquid paraffin) with different melting points were blended together by the fusion method, and the optimum mixed proportion with a suitable phase-transition temperature was obtained through differential scanning calorimetry (DSC) analysis. Then the prepared composite paraffin was adsorbed in calcined diatomite. The prepared paraffin/calcined diatomite composites were characterized by the scanning electron microscope (SEM) and Fourier transformation infrared (FT-IR) analysis techniques. Thermal energy storage properties of the composite PCMs were determined by DSC method. DSC results showed that there was an optimum adsorption ratio between composite paraffin and calcined diatomite and the phase-transition temperature and the latent heat of the composite PCMs were 33.04 °C and 89.54 J/g, respectively. Thermal cycling test of composite PCMs showed that the prepared material is thermally reliable and chemically stable. The obtained paraffin/calcined diatomite composites have proper latent heat and melting temperatures, and show practical significance and good potential application value.

Laboratory Study on Properties of Diatomite and Basalt Fiber Compound Modified Asphalt Mastic

Directory of Open Access Journals (Sweden)

Yongchun Cheng

2017-01-01

Full Text Available In order to improve the performance of asphalt mastic, some researchers have added diatomite or basalt fiber as a modifier to the asphalt mastic, and the results show that some properties of the asphalt mastic were improved. For the simultaneous addition of diatomite and basalt fiber, two kinds of modifier, compound modified asphalt mastic had not been reported; in this paper, thirteen groups of diatomite and basalt fiber (DBFCMAM compound modified asphalt mastic with different content were prepared to study the performance. Softening point, cone penetration, viscosity, and DSR tests were conducted, for the high temperature performance evaluation of DBFCMAM, whereas force ductility and BBR tests were used in the low temperature performance study of the DBFCMAM. The results demonstrated that the high temperature performance of DBFCMAM was increased; moreover, the low temperature performance of DBFCMAM improved by diatomite and basalt fiber according to the results of the force ductility test; however, the conclusion of the BBR test data was inconsistent with the force ductility test. In summary, the high temperature and low temperature properties of DBFCMAM had been improved.

Chapter B: Regional Geologic Setting of Late Cenozoic Lacustrine Diatomite Deposits, Great Basin and Surrounding Region: Overview and Plans for Investigation

Science.gov (United States)

Wallace, Alan R.

2003-01-01

Freshwater diatomite deposits are present in all of the Western United States, including the Great Basin and surrounding regions. These deposits are important domestic sources of diatomite, and a better understanding of their formation and geologic settings may aid diatomite exploration and land-use management. Diatomite deposits in the Great Basin are the products of two stages: (1) formation in Late Cenozoic lacustrine basins and (2) preservation after formation. Processes that favored long-lived diatom activity and diatomite formation range in decreasing scale from global to local. The most important global process was climate, which became increasingly cool and dry from 15 Ma to the present. Regional processes included tectonic setting and volcanism, which varied considerably both spatially and temporally in the Great Basin region. Local processes included basin formation, sedimentation, hydrology, and rates of processes, including diatom growth and accumulation; basin morphology and nutrient and silica sources were important for robust activity of different diatom genera. Only optimum combinations of these processes led to the formation of large diatomite deposits, and less than optimum combinations resulted in lakebeds that contained little to no diatomite. Postdepositional processes can destroy, conceal, or preserve a diatomite deposit. These processes, which most commonly are local in scale, include uplift, with related erosion and changes in hydrology; burial beneath sedimentary deposits or volcanic flows and tuffs; and alteration during diagenesis and hydrothermal activity. Some sedimentary basins that may have contained diatomite deposits have largely been destroyed or significantly modified, whereas others, such as those in western Nevada, have been sufficiently preserved along with their contained diatomite deposits. Future research on freshwater diatomite deposits in the Western United States and Great Basin region should concentrate on the regional

MODELLING OF KINETICS OF FLUORINE ADSORPTION ONTO MODIFIED DIATOMITE

Directory of Open Access Journals (Sweden)

VEACESLAV ZELENTSOV

2017-03-01

Full Text Available The paper presents kinetics modelling of adsorption of fluorine onto modified diatomite, its fundamental characteristics and mathematical derivations. Three models of defluoridation kinetics were used to fit the experimental results on adsorption fluorine onto diatomite: the pseudo-first order model Lagergren, the pseudo-second order model G. McKay and H.S. Ho and intraparticle diffusion model of W.J. Weber and J.C. Morris. Kinetics studies revealed that the adsorption of fluorine followed second-order rate model, complimented by intraparticle diffusion kinetics. The adsorption mechanism of fluorine involved three stages – external surface adsorption, intraparticle diffusion and the stage of equilibrium.

The use of infrared spectroscopy to determine product quality of carbonate-rich diatomite ores

NARCIS (Netherlands)

Guatame Garcia, L.A.; Buxton, M.W.N.

2018-01-01

Diatomite, a rock formed by the accumulation of opaline diatom frustules, is a preferred raw material for the manufacturing of filters. Its uniqueness relies on the high porosity and inertness of the frustules. The presence of carbonates in some diatomite ores hinders these properties. The~purpose

Characterization and improved solar light activity of vanadium doped TiO2/diatomite hybrid catalysts

International Nuclear Information System (INIS)

Wang, Bin; Zhang, Guangxin; Leng, Xue; Sun, Zhiming; Zheng, Shuilin

2015-01-01

Highlights: • V-doped TiO 2 /diatomite composite photocatalyst was synthesized. • The physiochemical property and solar light photoactivity were characterized. • The presence and influence of V ions in TiO 2 matrix was systematically analyzed. • The photocatalysis for Rhodamine B were studied under solar light illumination. - Abstract: V-doped TiO 2 /diatomite composite photocatalysts with different vanadium concentrations were synthesized by a modified sol–gel method. The diatomite was responsible for the well dispersion of TiO 2 nanoparticles on the matrix and consequently inhibited the agglomeration. V-TiO 2 /diatomite hybrids showed red shift in TiO 2 absorption edge with enhanced absorption intensity. Most importantly, the dopant energy levels were formed in the TiO 2 bandgap due to V 4+ ions substituted to Ti 4+ sites. The 0.5% V-TiO 2 /diatomite photocatalyst displayed narrower bandgap (2.95 eV) compared to undoped sample (3.13 eV) and other doped samples (3.05 eV) with higher doping concentration. The photocatalytic activities of V doped TiO 2 /diatomite samples for the degradation of Rhodamine B under stimulated solar light illumination were significantly improved compared with the undoped sample. In our case, V 4+ ions incorporated in TiO 2 lattice were responsible for increased visible-light absorption and electron transfer to oxygen molecules adsorbed on the surface of TiO 2 to produce superoxide radicals ·O 2 – , while V 5+ species presented on the surface of TiO 2 particles in the form of V 2 O 5 contributed to e – –h + separation. In addition, due to the combination of diatomite as support, this hybrid photocatalyst could be separated from solution quickly by natural settlement and exhibited good reusability

Pore structure modification of diatomite as sulfuric acid catalyst support by high energy electron beam irradiation and hydrothermal treatment

International Nuclear Information System (INIS)

Li, Chong; Zhang, Guilong; Wang, Min; Chen, Jianfeng; Cai, Dongqing; Wu, Zhengyan

2014-01-01

Highlights: • High energy electron beam (HEEB) irradiation and hydrothermal treatment were used. • HEEB irradiation could make the impurities in the pores of diatomite loose. • Hydrothermal treatment (HT) could remove these impurities from the pores. • They could effectively improve pore size distribution and decrease the bulk density. • Catalytic performance of the corresponding catalyst was significantly improved. - Abstract: High energy electron beam (HEEB) irradiation and hydrothermal treatment (HT), were applied in order to remove the impurities and enlarge the pore size of diatomite, making diatomite more suitable to be a catalyst support. The results demonstrated that, through thermal, charge, impact and etching effects, HEEB irradiation could make the impurities in the pores of diatomite loose and remove some of them. Then HT could remove rest of them from the pores and contribute significantly to the modification of the pore size distribution of diatomite due to thermal expansion, water swelling and thermolysis effects. Moreover, the pore structure modification improved the properties (BET (Brunauer–Emmett–Teller) specific surface area, bulk density and pore volume) of diatomite and the catalytic efficiency of the catalyst prepared from the treated diatomite

Pore structure modification of diatomite as sulfuric acid catalyst support by high energy electron beam irradiation and hydrothermal treatment

Energy Technology Data Exchange (ETDEWEB)

Li, Chong [Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, Beijing 100029 (China); Zhang, Guilong; Wang, Min [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031 (China); Chen, Jianfeng [Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, Beijing 100029 (China); Cai, Dongqing, E-mail: dqcai@ipp.ac.cn [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031 (China); Wu, Zhengyan, E-mail: zywu@ipp.ac.cn [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031 (China)

2014-08-15

Highlights: • High energy electron beam (HEEB) irradiation and hydrothermal treatment were used. • HEEB irradiation could make the impurities in the pores of diatomite loose. • Hydrothermal treatment (HT) could remove these impurities from the pores. • They could effectively improve pore size distribution and decrease the bulk density. • Catalytic performance of the corresponding catalyst was significantly improved. - Abstract: High energy electron beam (HEEB) irradiation and hydrothermal treatment (HT), were applied in order to remove the impurities and enlarge the pore size of diatomite, making diatomite more suitable to be a catalyst support. The results demonstrated that, through thermal, charge, impact and etching effects, HEEB irradiation could make the impurities in the pores of diatomite loose and remove some of them. Then HT could remove rest of them from the pores and contribute significantly to the modification of the pore size distribution of diatomite due to thermal expansion, water swelling and thermolysis effects. Moreover, the pore structure modification improved the properties (BET (Brunauer–Emmett–Teller) specific surface area, bulk density and pore volume) of diatomite and the catalytic efficiency of the catalyst prepared from the treated diatomite.

Interaction of radionickel with diatomite as a function of pH, ionic strength and temperature

International Nuclear Information System (INIS)

Xue Wang

2013-01-01

Sequestration of Ni(II) on diatomite as a function of reaction time, pH, ionic strength, foreign ions and temperature were investigated by batch sorption technique. The results indicated that the sorption of Ni(II) on diatomite was quickly in the first contact time of 2 h and then slowly with increasing contact time. The interaction of Ni(II) with diatomite was strongly pH- and ionic strength-dependent at low pH values (i.e., which was dominated by ion exchange or outer-sphere surface complexation), while the pH-dependent and ionic strength-independent sorption at high pH suggested that inner-sphere or multinuclear surface complexation was the main sorption mechanism. With increasing temperature, the sorption of Ni(II) on diatomite increased and the experimental data were well fitted by Langmuir model. The sorption samples at pH 6.8 and 10.0 were also characterized by XPS spectroscopy, and the results suggested that Si atoms also participated in Ni(II) sorption on diatomite. The results are important to evaluate the physicochemical behavior of Ni(II) and other similar radionuclides and heavy metal ions in the environment. (author)

Prussian blue caged in spongiform adsorbents using diatomite and carbon nanotubes for elimination of cesium

Energy Technology Data Exchange (ETDEWEB)

Hu, Baiyang [Graduate School of Environmental Science, Hokkaido University, Sapporo 060-0810 (Japan); Fugetsu, Bunshi, E-mail: hu@ees.hokudai.ac.jp [Graduate School of Environmental Science, Hokkaido University, Sapporo 060-0810 (Japan); Yu, Hongwen [Graduate School of Environmental Science, Hokkaido University, Sapporo 060-0810 (Japan); Abe, Yoshiteru [Kyoei Engineering Corporation, Niigata 959-1961 (Japan)

2012-05-30

Highlights: Black-Right-Pointing-Pointer Prussian blue was sealed in cavities of diatomite using carbon nanotubes. Black-Right-Pointing-Pointer The caged Prussian blue after being permanently immobilized in polyurethane spongy showed a 167 mg/g capability for absorbing cesium. Black-Right-Pointing-Pointer Cesium elimination was accomplished by simply adding the Prussian-blue based spongiform adsorbent to radioactive water. - Abstract: We developed a spongiform adsorbent that contains Prussian blue, which showed a high capacity for eliminating cesium. An in situ synthesizing approach was used to synthesize Prussian blue inside diatomite cavities. Highly dispersed carbon nanotubes (CNTs) were used to form CNT networks that coated the diatomite to seal in the Prussian blue particles. These ternary (CNT/diatomite/Prussian-blue) composites were mixed with polyurethane (PU) prepolymers to produce a quaternary (PU/CNT/diatomite/Prussian-blue), spongiform adsorbent with an in situ foaming procedure. Prussian blue was permanently immobilized in the cell walls of the spongiform matrix and preferentially adsorbed cesium with a theoretical capacity of 167 mg/g cesium. Cesium was absorbed primarily by an ion-exchange mechanism, and the absorption was accomplished by self-uptake of radioactive water by the quaternary spongiform adsorbent.

Prussian blue caged in spongiform adsorbents using diatomite and carbon nanotubes for elimination of cesium.

Science.gov (United States)

Hu, Baiyang; Fugetsu, Bunshi; Yu, Hongwen; Abe, Yoshiteru

2012-05-30

We developed a spongiform adsorbent that contains Prussian blue, which showed a high capacity for eliminating cesium. An in situ synthesizing approach was used to synthesize Prussian blue inside diatomite cavities. Highly dispersed carbon nanotubes (CNTs) were used to form CNT networks that coated the diatomite to seal in the Prussian blue particles. These ternary (CNT/diatomite/Prussian-blue) composites were mixed with polyurethane (PU) prepolymers to produce a quaternary (PU/CNT/diatomite/Prussian-blue), spongiform adsorbent with an in situ foaming procedure. Prussian blue was permanently immobilized in the cell walls of the spongiform matrix and preferentially adsorbed cesium with a theoretical capacity of 167 mg/g cesium. Cesium was absorbed primarily by an ion-exchange mechanism, and the absorption was accomplished by self-uptake of radioactive water by the quaternary spongiform adsorbent. Copyright © 2012 Elsevier B.V. All rights reserved.

Enhanced oxidation of naphthalene using plasma activation of TiO2/diatomite catalyst.

Science.gov (United States)

Wu, Zuliang; Zhu, Zhoubin; Hao, Xiaodong; Zhou, Weili; Han, Jingyi; Tang, Xiujuan; Yao, Shuiliang; Zhang, Xuming

2018-04-05

Non-thermal plasma technology has great potential in reducing polycyclic aromatic hydrocarbons (PAHs) emission. But in plasma-alone process, various undesired by-products are produced, which causes secondary pollutions. Here, a dielectric barrier discharge (DBD) reactor has been developed for the oxidation of naphthalene over a TiO 2 /diatomite catalyst at low temperature. In comparison to plasma-alone process, the combination of plasma and TiO 2 /diatomite catalyst significantly enhanced naphthalene conversion (up to 40%) and CO x selectivity (up to 92%), and substantially reduced the formation of aerosol (up to 90%) and secondary volatile organic compounds (up to near 100%). The mechanistic study suggested that the presence of the TiO 2 /diatomite catalyst intensified the electron energy in the DBD. Meantime, the energized electrons generated in the discharge activated TiO 2 , while the presence of ozone enhanced the activity of the TiO 2 /diatomite catalyst. This plasma-catalyst interaction led to the synergetic effect resulting from the combination of plasma and TiO 2 /diatomite catalyst, consequently enhanced the oxidation of naphthalene. Importantly, we have demonstrated the effectiveness of plasma to activate the photocatalyst for the deep oxidation of PAH without external heating, which is potentially valuable in the development of cost-effective gas cleaning process for the removal of PAHs in vehicle applications during cold start conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization and improved solar light activity of vanadium doped TiO2/diatomite hybrid catalysts.

Science.gov (United States)

Wang, Bin; Zhang, Guangxin; Leng, Xue; Sun, Zhiming; Zheng, Shuilin

2015-03-21

V-doped TiO2/diatomite composite photocatalysts with different vanadium concentrations were synthesized by a modified sol-gel method. The diatomite was responsible for the well dispersion of TiO2 nanoparticles on the matrix and consequently inhibited the agglomeration. V-TiO2/diatomite hybrids showed red shift in TiO2 absorption edge with enhanced absorption intensity. Most importantly, the dopant energy levels were formed in the TiO2 bandgap due to V(4+) ions substituted to Ti(4+) sites. The 0.5% V-TiO2/diatomite photocatalyst displayed narrower bandgap (2.95 eV) compared to undoped sample (3.13 eV) and other doped samples (3.05 eV) with higher doping concentration. The photocatalytic activities of V doped TiO2/diatomite samples for the degradation of Rhodamine B under stimulated solar light illumination were significantly improved compared with the undoped sample. In our case, V(4+) ions incorporated in TiO2 lattice were responsible for increased visible-light absorption and electron transfer to oxygen molecules adsorbed on the surface of TiO2 to produce superoxide radicals ˙O2(-), while V(5+) species presented on the surface of TiO2 particles in the form of V2O5 contributed to e(-)-h(+) separation. In addition, due to the combination of diatomite as support, this hybrid photocatalyst could be separated from solution quickly by natural settlement and exhibited good reusability. Copyright © 2014 Elsevier B.V. All rights reserved.

Comparative Potential Protect Effect of HSCAS, Diatomite and ...

African Journals Online (AJOL)

mdenli

bentonite (Rosa et al., 2001), zeolite (Miazzo et al., 2000), hydrated sodium calcium aluminosilicate. (HSCAS) ... Due to these properties diatomite was selected for use in this experiment to compare ..... Aflatoxins in animal and human health.

Flower-, wire-, and sheet-like MnO2-deposited diatomites: Highly efficient absorbents for the removal of Cr(VI).

Science.gov (United States)

Du, Yucheng; Wang, Liping; Wang, Jinshu; Zheng, Guangwei; Wu, Junshu; Dai, Hongxing

2015-03-01

Flower-, wire-, and sheet-like MnO2-deposited diatomites have been prepared using a hydrothermal method with Mn(Ac)2, KMnO4 and/or MnSO4 as Mn source and diatomite as support. Physical properties of the materials were characterized by means of numerous analytical techniques, and their behaviors in the adsorption of chromium(VI) were evaluated. It is shown that the MnO2-deposited diatomite samples with different morphologies possessed high surface areas and abundant surface hydroxyl groups (especially the wire-like MnO2/diatomite sample). The wire-like MnO2/diatomite sample showed the best performance in the removal of Cr(VI), giving the maximum Cr(VI) adsorption capacity of 101 mg/g. Copyright © 2014. Published by Elsevier B.V.

Effects of Diatomite Organic Fertilizer on Cd and Zn Forms and Availability of Cd-Zn Polluted Soil

OpenAIRE

LIN Ji; CHENG Chen; HAN Ming-qiang; LI Song-xing; MA Xiao-rui; LI Yan

2014-01-01

An indoor soil cultivation experiment was carried out to study the effects of diatomite organic fertilizer on the forms and the avail-ability of Cd, Zn in soil. The results showed that the soil pH increased, the soil available Cd and Zn reduced after diatomite organic fertilizer application in contaminated soil. Diatomite organic fertilizer application decreased the contents of exchangeable form and weakly-bound-to organic form of Cd and Zn significantly, but increased the contents of strongl...

BTEX and MTBE adsorption onto raw and thermally modified diatomite.

Science.gov (United States)

Aivalioti, Maria; Vamvasakis, Ioannis; Gidarakos, Evangelos

2010-06-15

The removal of BTEX (benzene, toluene, ethyl-benzene and xylenes) and MTBE (methyl tertiary butyl ether) from aqueous solution by raw (D(R)) and thermally modified diatomite at 550, 750 and 950 degrees C (D(550), D(750) and D(950) respectively) was studied. Physical characteristics of both raw and modified diatomite such as specific surface, pore volume distribution, porosity and pH(solution) were determined, indicating important structural changes in the modified diatomite, due to exposure to high temperatures. Both adsorption kinetic and isotherm experiments were carried out. The kinetics data proved a closer fit to the pseudo-second order model. Maximum values for the rate constant, k(2), were obtained for MTBE and benzene (48.9326 and 18.0996 g mg(-1)h(-1), respectively) in sample D(550). The isotherm data proved to fit the Freundlich model more closely, which produced values of the isotherm constant 1/n higher than one, indicating unfavorable adsorption. The highest adsorption capacity, calculated through the values of the isotherm constant k(F), was obtained for MTBE (48.42 mg kg(-1) (mg/L)(n)) in sample D(950). Copyright 2010 Elsevier B.V. All rights reserved.

Diatomite reinforced chitosan composite membrane as potential scaffold for guided bone regeneration.

Science.gov (United States)

Tamburaci, Sedef; Tihminlioglu, Funda

2017-11-01

In this study, natural silica source, diatomite, incorporated novel chitosan based composite membranes were fabricated and characterized for bone tissue engineering applications as possible bone regeneration membrane. The effect of diatomite loading on the mechanical, morphological, chemical, thermal and surface properties, wettability and in vitro cytotoxicity and cell proliferation on of composite membranes were investigated and observed by tensile test, atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), protein adsorption assay, air/water contact angle analysis and WST-1 respectively. Swelling studies were also performed by water absorption capacity determination. Results showed that incorporation of diatomite to the chitosan matrix increased the surface roughness, swelling capacity and tensile modulus of membranes. An increase of about 52% in Young's modulus was achieved for 10wt% diatomite composite membranes compared with chitosan membranes. High cell viability results were obtained with indirect extraction method. Besides, in vitro cell proliferation and ALP activity results showed that diatom incorporation significantly increased the ALP activity of Saos-2 cells cultured on chitosan membranes. The novel composite membranes prepared in the present study with tunable properties can be considered as a potential candidate as a scaffold in view of its enhanced physical & chemical properties as well as biological activities for bone tissue engineering applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Facile preparation of hierarchically porous carbon using diatomite as both template and catalyst and methylene blue adsorption of carbon products.

Science.gov (United States)

Liu, Dong; Yuan, Peng; Tan, Daoyong; Liu, Hongmei; Wang, Tong; Fan, Mingde; Zhu, Jianxi; He, Hongping

2012-12-15

Hierarchically porous carbons were prepared using a facile preparation method in which diatomite was utilized as both template and catalyst. The porous structures of the carbon products and their formation mechanisms were investigated. The macroporosity and microporosity of the diatomite-templated carbons were derived from replication of diatom shell and structure-reconfiguration of the carbon film, respectively. The macroporosity of carbons was strongly dependent on the original morphology of the diatomite template. The macroporous structure composed of carbon plates connected by the pillar- and tube-like macropores resulted from the replication of the central and edge pores of the diatom shells with disk-shaped morphology, respectively. And another macroporous carbon tubes were also replicated from canoe-shaped diatom shells. The acidity of diatomite dramatically affected the porosity of the carbons, more acid sites of diatomite template resulted in higher surface area and pore volume of the carbon products. The diatomite-templated carbons exhibited higher adsorption capacity for methylene blue than the commercial activated carbon (CAC), although the specific surface area was much smaller than that of CAC, due to the hierarchical porosity of diatomite-templated carbons. And the carbons were readily reclaimed and regenerated. Copyright © 2012 Elsevier Inc. All rights reserved.

Effect of cathode vibration and heat treatment on electromagnetic properties of flake-shaped diatomite coated with Ni–Fe alloy by electroplating

Energy Technology Data Exchange (ETDEWEB)

Lan, Mingming, E-mail: lan_mingming@163.com; Li, Huiqin; Huang, Weihua; Xu, Guangyin; Li, Yan

2015-03-01

In this paper, flake-shaped diatomite particles were used as forming templates for the fabrication of the ferromagnetic functional fillers by way of electroplating Ni–Fe alloy method. The effects of cathode vibration frequency on the content of Ni–Fe alloy in the coating and the surface morphologies of the coatings were evaluated. The electromagnetic properties of the coated diatomite particles before and after heat treatment were also investigated in detail. The results show that the core-shell flake-shaped diatomite particles with high content of Ni–Fe alloy and good surface qualities of the coatings can be obtained by adjusting cathode vibration frequency. The coated diatomite particles with heat treatment filled paraffin wax composites exhibit a superior microwave absorbing and electromagnetic properties compared to the non-heat treated samples. Additionally, the peaks of reflection loss are found to be able to shift to lower frequency by the heat treatment process, which indicates the heat treatment can adjust microwave absorbing frequency band. - Highlights: • We used the diatomite particles as template to fabricate the flake-shaped ferromagnetic fillers. • The diatomite particles were deposited pure magnetic Ni–Fe alloy by electroplating methods. • The coated diatomite particles were lightweight ferromagnetic fillers. • The composites containing coated diatomite particles with heat treatment exhibited great potential in the field of electromagnetic absorbing.

Effect of cathode vibration and heat treatment on electromagnetic properties of flake-shaped diatomite coated with Ni–Fe alloy by electroplating

International Nuclear Information System (INIS)

Lan, Mingming; Li, Huiqin; Huang, Weihua; Xu, Guangyin; Li, Yan

2015-01-01

In this paper, flake-shaped diatomite particles were used as forming templates for the fabrication of the ferromagnetic functional fillers by way of electroplating Ni–Fe alloy method. The effects of cathode vibration frequency on the content of Ni–Fe alloy in the coating and the surface morphologies of the coatings were evaluated. The electromagnetic properties of the coated diatomite particles before and after heat treatment were also investigated in detail. The results show that the core-shell flake-shaped diatomite particles with high content of Ni–Fe alloy and good surface qualities of the coatings can be obtained by adjusting cathode vibration frequency. The coated diatomite particles with heat treatment filled paraffin wax composites exhibit a superior microwave absorbing and electromagnetic properties compared to the non-heat treated samples. Additionally, the peaks of reflection loss are found to be able to shift to lower frequency by the heat treatment process, which indicates the heat treatment can adjust microwave absorbing frequency band. - Highlights: • We used the diatomite particles as template to fabricate the flake-shaped ferromagnetic fillers. • The diatomite particles were deposited pure magnetic Ni–Fe alloy by electroplating methods. • The coated diatomite particles were lightweight ferromagnetic fillers. • The composites containing coated diatomite particles with heat treatment exhibited great potential in the field of electromagnetic absorbing

[Differential Effect and Mechanism of in situ Immobilization of Cadmium Contamination in Soil Using Diatomite Produced from Different Areas].

Science.gov (United States)

Zhu, Jian; Wang, Ping; Lin, Yan; Lei, Ming-jing; Chen, Yang

2016-02-15

In order to understand the difference of in situ immobilization effect and mechanism of Cd contamination in soil using diatomite produced from different areas, the test was conducted using diatomite produced from Yunnan Tengchong, Jilin Linjiang, Zhejiang Shengzhou and Henan Xinyang of China as modifiers to immobilize cadmium contamination in simulated soil. The results indicated that the diatomite from all the four producing areas could effectively immobilize available Cd in soil, decreasing the available Cd content in soil by 27.7%, 28.5%, 30.1% and 57.2%, respectively when the adding concentration was 30 g x kg(-1). Their ability for immobilizing available Cd in soil followed the sequence of Henan Xinyang > Zhejiang Shengzhou > Jilin Linjiang > Yunnan Tengchong. It was also found that the physical and chemical properties of diatomite played a main role in soil cadmium immobilization, lower bulk density, larger specific surface area, more micro pores and wider distribution range of aperture were more favorable for available Cd immobilization. The results also showed that, the diatomite could control Cd contamination by changing soil physical and chemical properties, among these properties, pH and organic matter content were the key factors, increasing soil pH value and organic matter content was favorable for available cadmium immobilization, while the soil water content had little effect on available cadmium immobilization. The control of soil cadmium contamination by using diatomite to change cation exchange capacity was limited by time in some degree. The diatomite produced from Henan Xinyang, Zhejiang Shengzhou and Yunnan Tengchong increased the soil pH value and organic matter content, and was favorable for available Cd immobilization, while the diatomite from Jilin Linjiang showed converse effect.

Preparation and investigation of structural properties of magnetic diatomite nanocomposites formed with different iron content

Energy Technology Data Exchange (ETDEWEB)

Yusan, Sabriye, E-mail: sabriye.doyurum@ege.edu.tr [Ege University, Institute of Nuclear Sciences, 35100 Bornova, Izmir (Turkey); Korzhynbayeva, Kuralay [Al-Farabi Kazakh National University, Faculty of Chemistry and Chemical Technology, 050040 Almaty (Kazakhstan); Aytas, Sule [Ege University, Institute of Nuclear Sciences, 35100 Bornova, Izmir (Turkey); Tazhibayeva, Sagdat; Musabekov, Kuanyshbek [Al-Farabi Kazakh National University, Faculty of Chemistry and Chemical Technology, 050040 Almaty (Kazakhstan)

2014-09-01

Highlights: • Magnetic diatomite nanocomposites were generated by partial reduction co-precipitation method. • VSM results showed that nanocomposites have superparamagnetic behaviour. • The nanocomposites were also characterized by XRD, FTIR, SEM, DTA/TGA and BET. - Abstract: Magnetic diatomite nanocomposites (MDNC) were synthesized successfully by partial reduction co-precipitation method from iron salt solution at different concentrations and characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermal analyses (DTA/TGA), vibrating sample magnetometry (VSM) and surface area measurements (BET). The XRD pattern of magnetic diatomite nanocomposites is face centered cubic with an average diameter of 4.67, 4.11 and 4. 82 nm as MDNC-1, MDNC-2 and MDNC-3, respectively. The saturation magnetization values for magnetic diatomite composites (diatomite/Fe ratio 1:1.5, 1:2.0 and 1:3.0) were found to be 13.81, 13.37 and 16.42 emu/g, respectively. By FT-IR spectra it was found that the main features of the silica framework were maintained after magnetite incorporation and some peak intensities were increased with magnetite loading. The cell parameter increase and the surface area decrease with increase in Fe content, observed by N{sub 2} adsorption–desorption technique, were considered as evidence of metal concentration effect in the synthesis procedure.

Fast degradation of dyes in water using manganese-oxide-coated diatomite for environmental remediation

Science.gov (United States)

Dang, Trung-Dung; Banerjee, Arghya Narayan; Tran, Quang-Tung; Roy, Sudipta

2016-11-01

By a simple wet-chemical procedure using a permanganate in the acidic medium, diatomite coated with amorphous manganese oxide nanoparticles was synthesized. The structural, microstructural and morphological characterizations of the as-synthesized catalysts confirmed the nanostructure of MnO2 and its stabilization on the support - diatomite. The highly efficient and rapid degradation of methylene blue and methyl orange over synthesized MnO2 coated Diatomite has been carried out. The results revealed considerably faster degradation of the dyes against the previously reported data. The proposed mechanism of the dye-degradation is considered to be a combinatorial effect of chemical, physicochemical and physical processes. Therefore, the fabricated catalysts have potential application in waste water treatment, and pollution degradation for environmental remediation.

Diatomite based ceramics macro- and microscopic characterization

Science.gov (United States)

Aderdour, H.; Bentayeb, A.; Nadiri, A.; Ouammou, A.; Sangleboeuf, J.-C.; Lucas-Girot, A.; Carel, C.

2005-03-01

A Moroccan diatomite is characterized chemically and physically. Mechanical properties of ceramics prepared by sintering at different temperatures ranging from 1050 to 1350° C are studied. Compressive strength and Young modulus are determined by compression tests. Densification and evolution of the microstructure are followed by SEM and other tests.

Adsorption of arsenic(V) by iron-oxide-coated diatomite (IOCD).

Science.gov (United States)

Pan, Yi-Fong; Chiou, Cary T; Lin, Tsair-Fuh

2010-09-01

PURPOSES AND AIMS: Economically efficient methods for removing arsenic from the drinking water supply are urgently needed in many parts of the world. Iron oxides are known to have a strong affinity for arsenic in water. However, they are commonly present in the forms of fine powder or floc, which limits their utility in water treatment. In this study, a novel granular adsorbent, iron-oxide-coated diatomite (IOCD), was developed and examined for its adsorption of arsenic from water. An industrial-grade diatomite was used as the iron oxide support. The diatomite was first acidified and dried and then coated with iron oxide up to five times. The prepared IOCD samples were characterized for their morphology, composition, elemental content, and crystal properties by various instruments. Experiments of equilibrium and kinetic adsorption of As(V) on IOCD were conducted using 0.1- and 2-L polyethylene bottles, respectively, at different pH and temperatures. Iron oxide (alpha-Fe(2)O(3) hematite) coated onto diatomite greatly improves (by about 30 times) the adsorption of As(V) from water by IOCD as compared to using raw diatomite. This improvement was attributed to increases in both surface affinity and surface area of the IOCD. The surface area of IOCD increased to an optimal value. However, as the IOCD surface area (93 m(2)/g) was only 45% higher than that of raw diatomite (51 m(2)/g), the enhanced As(V) adsorption resulted primarily from the enhanced association of negatively charged As(V) ions with the partial positive surface charge of the iron oxide. The As(V) adsorption decreased when the solution pH was increased from 3.5 to 9.5, as expected from the partial charge interaction between As(V) and IOCD. The adsorption data at pH 5.5 and 7.5 could be well fitted to the Freundlich equation. A moderately high exothermic heat was observed for the As(V) adsorption, with the calculated molar isosteric heat ranging from -4 to -9 kcal/mol. The observed heats fall between those

Preparation and characterization of silica aerogels from diatomite via ambient pressure drying

Science.gov (United States)

Wang, Baomin; Ma, Hainan; Song, Kai

2014-07-01

The silica aerogels were successfully fabricated under ambient pressure from diatomite. The influence of different dilution ratios of diatomite filtrate on physical properties of aerogels were studied. The microstructure, surface functional groups, thermal stability, morphology and mechanical properties of silica aerogels based on diatomite were investigated by BET adsorption, FT-IR, DTA-TG, FESEM, TEM, and nanoindentation methods. The results indicate that the filtrate diluted with distilled water in a proportion of 1: 2 could give silica aerogels in the largest size with highest transparency. The obtained aerogels with density of 0.122-0.203 g/m3 and specific surface area of 655.5-790.7 m2/g are crack free amorphous solids and exhibited a sponge-like structure. Moreover, the peak pore size resided at 9 nm. The initial aerogels were hydrophobic, when being heat-treated around 400°C, the aerogels were transformed into hydrophilic ones. The obtained aerogel has good mechanical properties.

Porous Diatomite-Immobilized Cu–Ni Bimetallic Nanocatalysts for Direct Synthesis of Dimethyl Carbonate

Directory of Open Access Journals (Sweden)

Yong Chen

2012-01-01

Full Text Available A series of diatomite-immobilized Cu–Ni bimetallic nanocatalysts was prepared under ultrasonication and evaluated for the direct synthesis of dimethyl carbonate under various conditions. Upon being fully characterized by TPR, TPD, BET, SEM, XRD, and XPS methodologies, it is found that the bimetallic composite is effectively alloyed and well immobilized inside or outside the pore of diatomite. Under the optimal conditions of 1.2 MPa and 120∘C, the prepared catalyst with loading of 15% exhibited the highest methanol conversion of 6.50% with DMC selectivity of 91.2% as well as more than 10-hour lifetime. The possible reaction mechanism was proposed and discussed in detail. To our knowledge, this is the first report to use diatomite as a catalyst support for direct DMC synthesis from methanol and CO2.

Enhanced coagulation for improving coagulation performance and reducing residual aluminum combining polyaluminum chloride with diatomite.

Science.gov (United States)

Hu, Wenchao; Wu, Chunde

2016-01-01

The feasibility of using enhanced coagulation, which combined polyaluminum chloride (PAC) with diatomite for improving coagulation performance and reducing the residual aluminum (Al), was discussed. The effects of PAC and diatomite dosage on the coagulation performance and residual Al were mainly investigated. Results demonstrated that the removal efficiencies of turbidity, dissolved organic carbon (DOC), and UV254 were significantly improved by the enhanced coagulation, compared with PAC coagulation alone. Meaningfully, the five forms of residual Al (total Al (TAl), total dissolved Al (TDAl), dissolved organic Al (DOAl), dissolved monomeric Al (DMAl), and dissolved organic monomeric Al (DOMAl)) all had different degrees of reduction in the presence of diatomite and achieved the lowest concentrations (0.185, 0.06, 0.053, 0.014, and 0 mg L(-1), respectively) at a PAC dose of 15 mg L(-1) and diatomite dose of 40 mg L(-1). In addition, when PAC was used as coagulant, the majority of residual Al existed in dissolved form (about 31.14-70.16%), and the content of DOMAl was small in the DMAl.

Effects of inherent/enhanced solid acidity and morphology of diatomite templates on the synthesis and porosity of hierarchically porous carbon.

Science.gov (United States)

Liu, Dong; Yuan, Peng; Tan, Daoyong; Liu, Hongmei; Fan, Mingde; Yuan, Aihua; Zhu, Jianxi; He, Hongping

2010-12-21

The inherent or enhanced solid acidity of raw or activated diatomite is found to have significant effects on the synthesis of hierarchically porous diatomite-templated carbon with high surface area and special porous structure. The solid acidity makes raw/activated diatomite a catalyst for the generation of porous carbon, and the porous parameters of the carbon products are strongly dependent on the solid acidity of diatomite templates. The morphology of diatomite also dramatically affects the textural structure of porous carbon. Two types of macroporous structures in the carbon product, the partially solid pillars and the ordered hollow tubes, derive from the replication of the central and the edge pores of diatom shell, respectively. The hierarchically porous carbon shows good capability for the adsorption of solvent naphtha and H(2), enabling potential applications in adsorption and gas storage.

Sorption properties of Th(IV) on the raw diatomite-Effects of contact time, pH, ionic strength and temperature

International Nuclear Information System (INIS)

Sheng Guodong; Hu Jun; Wang Xiangke

2008-01-01

Diatomite has a number of unique physicochemical properties and has diversified industrial uses. Natural diatomite has been tested as a potential sorbent for the removal of Th(IV) from aqueous solutions. The results indicate that sorption of Th(IV) is strongly dependent on ionic strength at pH 3. Outer-sphere complexation or ion exchange may be the main sorption mechanism of Th(IV) to diatomite at low pH values, whereas the sorption of Th(IV) at pH>3 is mainly dominated by inner-sphere complexation or precipitation. The competition for Th(IV) between aqueous or surface adsorbed anions (e.g., herein ClO 4 - , NO 3 - and Cl - ) and surface functional groups of diatomite is important for Th(IV) sorption. The thermodynamic data (ΔH 0 , ΔS 0 , ΔG 0 ) are calculated from the temperature-dependent sorption isotherms. The results suggest that sorption process of Th(IV) on diatomite is spontaneous and endothermic

Sorption properties of Th(IV) on the raw diatomite--effects of contact time, pH, ionic strength and temperature.

Science.gov (United States)

Sheng, Guodong; Hu, Jun; Wang, Xiangke

2008-10-01

Diatomite has a number of unique physicochemical properties and has diversified industrial uses. Natural diatomite has been tested as a potential sorbent for the removal of Th(IV) from aqueous solutions. The results indicate that sorption of Th(IV) is strongly dependent on ionic strength at pH3. Outer-sphere complexation or ion exchange may be the main sorption mechanism of Th(IV) to diatomite at low pH values, whereas the sorption of Th(IV) at pH>3 is mainly dominated by inner-sphere complexation or precipitation. The competition for Th(IV) between aqueous or surface adsorbed anions (e.g., herein ClO(4)(-), NO(3)(-) and Cl(-)) and surface functional groups of diatomite is important for Th(IV) sorption. The thermodynamic data (DeltaH(0), DeltaS(0), DeltaG(0)) are calculated from the temperature-dependent sorption isotherms. The results suggest that sorption process of Th(IV) on diatomite is spontaneous and endothermic.

Characterization and improved solar light activity of vanadium doped TiO{sub 2}/diatomite hybrid catalysts

Energy Technology Data Exchange (ETDEWEB)

Wang, Bin, E-mail: b.wang6@uq.edu.au [School of Chemical and Environmental Engineering, China University of Mining & Technology, Beijing 100083 (China); School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072 (Australia); Zhang, Guangxin, E-mail: z111@163.com [School of Chemical and Environmental Engineering, China University of Mining & Technology, Beijing 100083 (China); Leng, Xue, E-mail: xue.leng@uq.net.au [School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072 (Australia); Sun, Zhiming, E-mail: zhiming.baxia@163.com [School of Chemical and Environmental Engineering, China University of Mining & Technology, Beijing 100083 (China); Zheng, Shuilin, E-mail: shuilinzheng8@gmail.com [School of Chemical and Environmental Engineering, China University of Mining & Technology, Beijing 100083 (China)

2015-03-21

Highlights: • V-doped TiO{sub 2}/diatomite composite photocatalyst was synthesized. • The physiochemical property and solar light photoactivity were characterized. • The presence and influence of V ions in TiO{sub 2} matrix was systematically analyzed. • The photocatalysis for Rhodamine B were studied under solar light illumination. - Abstract: V-doped TiO{sub 2}/diatomite composite photocatalysts with different vanadium concentrations were synthesized by a modified sol–gel method. The diatomite was responsible for the well dispersion of TiO{sub 2} nanoparticles on the matrix and consequently inhibited the agglomeration. V-TiO{sub 2}/diatomite hybrids showed red shift in TiO{sub 2} absorption edge with enhanced absorption intensity. Most importantly, the dopant energy levels were formed in the TiO{sub 2} bandgap due to V{sup 4+} ions substituted to Ti{sup 4+} sites. The 0.5% V-TiO{sub 2}/diatomite photocatalyst displayed narrower bandgap (2.95 eV) compared to undoped sample (3.13 eV) and other doped samples (3.05 eV) with higher doping concentration. The photocatalytic activities of V doped TiO{sub 2}/diatomite samples for the degradation of Rhodamine B under stimulated solar light illumination were significantly improved compared with the undoped sample. In our case, V{sup 4+} ions incorporated in TiO{sub 2} lattice were responsible for increased visible-light absorption and electron transfer to oxygen molecules adsorbed on the surface of TiO{sub 2} to produce superoxide radicals ·O{sub 2}{sup –}, while V{sup 5+} species presented on the surface of TiO{sub 2} particles in the form of V{sub 2}O{sub 5} contributed to e{sup –}–h{sup +} separation. In addition, due to the combination of diatomite as support, this hybrid photocatalyst could be separated from solution quickly by natural settlement and exhibited good reusability.

Liquid Phase adsorption kinetics and equilibrium of toluene by novel modified-diatomite.

Science.gov (United States)

Sheshdeh, Reza Khalighi; Abbasizadeh, Saeed; Nikou, Mohammad Reza Khosravi; Badii, Khashayar; Sharafi, Mohammad Sadegh

2014-01-01

The adsorption equilibria of toluene from aqueous solutions on natural and modified diatomite were examined at different operation parameters such as pH, contact time, initial toluene concentration was evaluated and optimum experimental conditions were identified. The surface area and morphology of the nanoparticles were characterized by SEM, BET, XRD, FTIR and EDX analysis. It was found that in order to obtain the highest possible removal of toluene, the experiments can be carried out at pH 6, temperature 25°C, an agitation speed of 200 rpm, an initial toluene concentration of 150 mg/L, a centrifugal rate of 4000 rpm, adsorbent dosage = 0.1 g and a process time of 90 min. The results of this work show that the maximum percentage removal of toluene from aqueous solution in the optimum conditions for NONMD was 96.91% (145.36 mg/g). Furthermore, under same conditions, the maximum adsorption of natural diatomite was 71.45% (107.18 mg/g). Both adsorption kinetic and isotherm experiments were carried out. The experimental data showed that the adsorption follows the Langmuir model and Freundlich model on natural and modified diatomite respectively. The kinetics results were found to conform well to pseudo-second order kinetics model with good correlation. Thus, this study demonstrated that the modified diatomite could be used as potential adsorbent for removal of toluene from aqueous solution.

Preparation of porous diatomite-templated carbons with large adsorption capacity and mesoporous zeolite K-H as a byproduct.

Science.gov (United States)

Liu, Dong; Yuan, Weiwei; Deng, Liangliang; Yu, Wenbin; Sun, Hongjuan; Yuan, Peng

2014-06-15

In this study, KOH activation was performed to enhance the porosity of the diatomite-templated carbon and to increase its adsorption capacity of methylene blue (MB). In addition to serving as the activation agent, KOH was also used as the etchant to remove the diatomite templates. Zeolite K-H was synthesized as a byproduct via utilization of the resultant silicon- and potassium-containing solutions created from the KOH etching of the diatomite templates. The obtained diatomite-based carbons were composed of macroporous carbon pillars and tubes, which were derived from the replication of the diatomite templates and were well preserved after KOH activation. The abundant micropores in the walls of the carbon pillars and tubes were derived from the break and reconfiguration of carbon films during both the removal of the diatomite templates and KOH activation. Compared with the original diatomite-templated carbons and CO2-activated carbons, the KOH-activated carbons had much higher specific surface areas (988 m(2)/g) and pore volumes (0.675 cm(3)/g). Moreover, the KOH-activated carbons possessed larger MB adsorption capacity (the maximum Langmuir adsorption capacity: 645.2 mg/g) than those of the original carbons and CO2-activated carbons. These results showed that KOH activation was a high effective activation method. The zeolite K-H byproduct was obtained by utilizing the silicon- and potassium-containing solution as the silicon and potassium sources. The zeolite exhibited a stick-like morphology and possessed nanosized particles with a mesopore-predominant porous structure which was observed by TEM for the first time. Copyright © 2014 Elsevier Inc. All rights reserved.

Natural diatomite (Rudovci, Serbia as adsorbent for removal Cs from radioactive waste liquids

Directory of Open Access Journals (Sweden)

Nenadović S.

2015-01-01

Full Text Available The removal of Cs (I ions from aqueous solution was studied using natural diatomite as adsorption materials originated from Rudovci, Serbia. The microstructure of natural diatomite has been characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM while the degree of Cs adsorption was evaluated by atomic emission spectroscopy. The cation exchange capacity (CEC values for natural diatomite was 50 meq/100g. Depending on whether the Cs adsorption occurred in the acidic and alkaline media at a temperature of 298.15 K in acidic media ΔG0 values was -12.674 kJ/mol, while in alkaline media ΔG0 was - 13.142 kJ/mol and a change of ΔS0 to 42.51 J/molK in acidic media and 44.08 J/molK in alkaline medium. [Projekat Ministarstva nauke Republike Srbije, br. 45012

Preparation of Diatomite Supported Nano Zinc Oxide Composite Photocatalytic Material and Study on its Formaldehyde Degradation

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Xiao, Liguang; Pang, Bo

2017-09-01

This experiment used zinc nitrate as precursor, ethanol as solvent and polyethylene glycol as dispersant, diatomite as carrier, diatomite loaded nano Zinc Oxide was prepared by sol-gel method, in addition, the formaldehyde degradation was studied by two kinds of experimental methods: preparation and loading, preparation and post loading, The samples were characterized by SEM, XRD, BET and IR. Experimental results showed that: Diatomite based nano Zinc Oxide had a continuous adsorption and degradation of formaldehyde, formaldehyde gas with initial concentration was 0.7mg/m3, after 36h degradation, the concentration reached 0.238mg/m3, the degradation rate reached to 66%.

Easy and industrially applicable impregnation process for preparation of diatomite-based phase change material nanocomposites for thermal energy storage

International Nuclear Information System (INIS)

Konuklu, Yeliz; Ersoy, Orkun; Gokce, Ozgur

2015-01-01

The high porosity, high oil and water absorption capacity and low density of diatomite make it ideal for industrial applications. The porous structure of diatomite protects phase change materials (PCMs) from environmental factors as a supporting matrix and phase changes occur in nanopores of diatomite. Previous research on diatomite/PCMs composites aimed optimal composite preparation but many methods were feasible only in laboratory scale. In large scale industrial fabrication, easy, continuous and steady state methods are need to be performed. The main purpose of this study was to prepare leakage-free, thermally stable nanocomposite PCMs (nanoCPCMs) by an easy, continuous and steady state method for high temperature thermal energy storage applications. A series of nanoCPCMs with different paraffin:diatomite mass ratios were prepared. The properties of nanoCPCMs have been characterized via scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The leak (exudation) test was performed on prepared composites at higher temperatures (95 °C) in comparison with literature. As the optimum composite for thermal energy storage applications, thermal reliability of nanoCPCM was evaluated after 400 cycles of melting and freezing. NanoCPCM melted at 36.55 °C with latent heat of 53.1 J/g. - Highlights: • Diatomite-based phase change material nanocomposites were prepared. • An easy and industrially applicable impregnation process was developed. • Influence of diatomite: PCM mass ratio on thermal properties reported.

Bio-diatomite dynamic membrane reactor for micro-polluted surface water treatment.

Science.gov (United States)

Chu, Huaqiang; Cao, Dawen; Dong, Bingzhi; Qiang, Zhimin

2010-03-01

This work investigated the feasibility of treating micro-polluted surface water for drinking water production with a bio-diatomite dynamic membrane reactor (BDDMR) at lab-scale in continuous-flow mode. Results indicate that the BDDMR was effective in removing COD(Mn), DOC, UV(254), NH(3)-N and trihalomethanes' formation potential (THMFP) at a hydraulic retention time (HRT) of 3.5h due to its high concentrations of mixed liquor suspended solids (MLSS) and mixed liquor volatile suspended solids (MLVSS). The removal of pollutants was mainly ascribed to microbial degradation in BDDMR because the dynamic membrane alone was much less effective in pollutant removal. Though the diatomite particles (5-20microm) were much smaller in size than the aperture of the stainless steel support mesh (74microm), microorganisms and their extracellular polymer substances could bind these particles tightly to form bio-diatomite particles which were completely retained by the support mesh. The analysis of molecular weight (MW) distribution by gel permeation chromatography (GPC) shows that the BDDMR could effectively remove the hydrophilic fraction of dissolved organic materials present in the raw water. Copyright 2009 Elsevier Ltd. All rights reserved.

Sorption properties of Th(IV) on the raw diatomite-Effects of contact time, pH, ionic strength and temperature

Energy Technology Data Exchange (ETDEWEB)

Sheng Guodong; Hu Jun [Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei 230031 (China); Wang Xiangke [Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei 230031 (China)], E-mail: xkwang@ipp.ac.cn

2008-10-15

Diatomite has a number of unique physicochemical properties and has diversified industrial uses. Natural diatomite has been tested as a potential sorbent for the removal of Th(IV) from aqueous solutions. The results indicate that sorption of Th(IV) is strongly dependent on ionic strength at pH<3, and is independent of ionic strength at pH>3. Outer-sphere complexation or ion exchange may be the main sorption mechanism of Th(IV) to diatomite at low pH values, whereas the sorption of Th(IV) at pH>3 is mainly dominated by inner-sphere complexation or precipitation. The competition for Th(IV) between aqueous or surface adsorbed anions (e.g., herein ClO{sub 4}{sup -}, NO{sub 3}{sup -} and Cl{sup -}) and surface functional groups of diatomite is important for Th(IV) sorption. The thermodynamic data ({delta}H{sup 0}, {delta}S{sup 0}, {delta}G{sup 0}) are calculated from the temperature-dependent sorption isotherms. The results suggest that sorption process of Th(IV) on diatomite is spontaneous and endothermic.

Diatomite Photonic Crystals for Facile On-Chip Chromatography and Sensing of Harmful Ingredients from Food.

Science.gov (United States)

Kong, Xianming; Yu, Qian; Li, Erwen; Wang, Rui; Liu, Qing; Wang, Alan X

2018-03-31

Diatomaceous earth-otherwise called diatomite-is essentially composed of hydrated biosilica with periodic nanopores. Diatomite is derived from fossilized remains of diatom frustules and possesses photonic-crystal features. In this paper, diatomite simultaneously functions as the matrix of the chromatography plate and the substrate for surface-enhanced Raman scattering (SERS), by which the photonic crystal-features could enhance the optical field intensity. The on-chip separation performance of the device was confirmed by separating and detecting industrial dye (Sudan I) in an artificial aqueous mixture containing 4-mercaptobenzoic acid (MBA), where concentrated plasmonic Au colloid was casted onto the analyte spot for SERS measurement. The plasmonic-photonic hybrid mode between the Au nanoparticles (NP) and the diatomite layer could supply nearly 10 times the increment of SERS signal (MBA) intensity compared to the common silica gel chromatography plate. Furthermore, this lab-on-a-chip photonic crystal device was employed for food safety sensing in real samples and successfully monitored histamine in salmon and tuna. This on-chip food sensor can be used as a cheap, robust, and portable sensing platform for monitoring for histamine or other harmful ingredients at trace levels in food products.

Heavy and Thermal Oil Recovery Production Mechanisms, SUPRI TR-127

Energy Technology Data Exchange (ETDEWEB)

Kovscek, Anthony R.; Brigham, William E.; Castanier, Louis M.

2001-09-07

The program spans a spectrum of topics and is divided into five categories: (i) multiphase flow and rock properties, (ii) hot fluid injection, (iii) primary heavy-oil production, (iv) reservoir definition, and (v) in-situ combustion.

Layer-by-layer assembly of TiO(2) colloids onto diatomite to build hierarchical porous materials.

Science.gov (United States)

Jia, Yuxin; Han, Wei; Xiong, Guoxing; Yang, Weishen

2008-07-15

TiO(2) colloids with the most probably particle size of 10 nm were deposited on the surface of macroporous diatomite by a layer-by-layer (LBL) assembly method with using phytic acid as molecular binder. For preparation of colloidal TiO(2), titanium(IV) isopropoxide (Ti(C(3)H(7)O)(4)) was used as titanium precursor, nitric acid (HNO(3)) as peptizing agent and deionized water and isopropanol (C(3)H(7)OH) as solvent. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), N(2) adsorption-desorption, and UV-vis spectra are used to assess the morphology and physical chemistry properties of the resulting TiO(2) coated diatomite. It was shown that the mesoporosity has been introduced into macroporous diatomite by LBL deposition. The mesoporosity was originated from close-packing of the uniform TiO(2) nanoparticles. More TiO(2) could be coated on the surface of diatomite by increasing the deposition cycles. This hierarchical porous material has potential for applications in catalytic reactions involved diffusion limit, especially in photocatalytic reactions.

Development of a dielectric ceramic based on diatomite-titania part two: dielectric properties characterization

Directory of Open Access Journals (Sweden)

Medeiros Jamilson Pinto

1998-01-01

Full Text Available Dielectric properties of sintered diatomite-titania ceramics are presented. Specific capacitance, dissipation factor, quality factor and dielectric constant were determined as a function of sintering temperature, titania content and frequency; the temperature coefficient of capacitance was measured as a function of frequency. Besides leakage current, the dependence of the insulation resistance and the dielectric strength on the applied dc voltage were studied. The results show that diatomite-titania compositions can be used as an alternative dielectric.

Diatom community and palaeoenvironmental properties of Karacaören diatomite deposits (Nevşehir, Central Anatolia, Turkey)

Science.gov (United States)

Yıldız, Ayşegül; Gürel, Ali; Dursun, Yusuf Gökhan

2017-10-01

The diatom community and palaeoenvironmental properties of volcano genetic diatomite deposits that outcrop in the Karacaören (Nevşehir) area are described. Two stratigraphic sections were measured in the study area. One of these sections was measured in Quaternary lake units (K1), and the other in lacustrine sediments of the late Miocene-Pliocene Ürgüp Formation's Bayramhacılı Member (K2). According to stratigraphic and chemical characteristics of the sections, two distinct paleogeographic domains were determined in the study area. One of these, the shallow lacustrine to fluvial area (Quaternary) which is represented by an alternating sequence of diatomite, silt/mud, and tuffite. The other was the deeper lacustrine stage (late Miocene) which is represented by diatomites with some interbedded mud facies, chert and volcanics. From the diatomite samples of these sections, twenty-five species of 10 different diatom genera were identified. When evaluated together, the ecological properties and the distribution of numerical values of the determined diatom genera and species, showed that the study area's diatomite was generally deposited in shallow, high temperature, nutrient-rich water, where nitrogen and phosphorus were abundant and which was an alkaline (pH > 7) freshwater lake environment. Over time the pH value of the environment decreased (pH < 7), and the environment became acidic.

Fabrication and electromagnetic properties of flake ferrite particles based on diatomite

International Nuclear Information System (INIS)

Zhang Deyuan; Zhang Wenqiang; Cai Jun

2011-01-01

Hexagonal ferrite BaZn 1.1 Co 0.9 Fe 16 O 27 coated surfaces of diatomite flakes of low density were synthesized by a sol-gel method. The phase structures, morphologies, particle size and chemical compositions of the composites were characterized by X-ray diffraction, scanning electron microscope and energy dispersive X-ray spectroscopy. The results show that hexagonal ferrite coated diatomite flakes can be achieved, and that the coating consisted of BaZn 1.1 Co 0.9 Fe 16 O 27 nanoparticles. The vibranting sample magnetometer results reveal that the flake ferrite particles have static magnetic properties. The complex permeability and permittivity of the composites were measured in the frequency range of 1-18 GHz. The microwave absorption properties of these ferrite particles are discussed. The results indicate that the flake ferrites have the potential to be used as a lightweight broad band microwave absorber. - Highlights: → We synthesize the flake ferrite particles using diatomite as a template. → Flake ferrite particles' coating layers are constituted by BaZn 1.1 Co 0.9 Fe 16 O 27 nanoparticles. → Flake ferrite particles have good static magnetic properties.→ Flake ferrites are a kind lightweight broad band microwave absorber.

Fabrication and electromagnetic properties of flake ferrite particles based on diatomite

Energy Technology Data Exchange (ETDEWEB)

Zhang Deyuan [Bionic and Micro/Nano/Bio Manufacturing Technology Research Center, Beihang University, Beijing 100191 (China); Zhang Wenqiang, E-mail: zwqzwqzwqzwq@126.com [Bionic and Micro/Nano/Bio Manufacturing Technology Research Center, Beihang University, Beijing 100191 (China); Cai Jun, E-mail: jun_cai@buaa.edu.cn [Bionic and Micro/Nano/Bio Manufacturing Technology Research Center, Beihang University, Beijing 100191 (China)

2011-09-15

Hexagonal ferrite BaZn{sub 1.1}Co{sub 0.9}Fe{sub 16}O{sub 27} coated surfaces of diatomite flakes of low density were synthesized by a sol-gel method. The phase structures, morphologies, particle size and chemical compositions of the composites were characterized by X-ray diffraction, scanning electron microscope and energy dispersive X-ray spectroscopy. The results show that hexagonal ferrite coated diatomite flakes can be achieved, and that the coating consisted of BaZn{sub 1.1}Co{sub 0.9}Fe{sub 16}O{sub 27} nanoparticles. The vibranting sample magnetometer results reveal that the flake ferrite particles have static magnetic properties. The complex permeability and permittivity of the composites were measured in the frequency range of 1-18 GHz. The microwave absorption properties of these ferrite particles are discussed. The results indicate that the flake ferrites have the potential to be used as a lightweight broad band microwave absorber. - Highlights: > We synthesize the flake ferrite particles using diatomite as a template. > Flake ferrite particles' coating layers are constituted by BaZn{sub 1.1}Co{sub 0.9}Fe{sub 16}O{sub 27} nanoparticles. > Flake ferrite particles have good static magnetic properties. > Flake ferrites are a kind lightweight broad band microwave absorber.

Synthesis and photocatalytic activity of ytterbium-doped titania/diatomite composite photocatalysts

Science.gov (United States)

Tang, Wenjian; Qiu, Kehui; Zhang, Peicong; Yuan, Xiqiang

2016-01-01

Ytterbium-doped titanium dioxide (Yb-TiO2)/diatomite composite materials with different Yb concentrations were prepared by sol-gel method. The phase structure, morphology, and chemical composition of the as-prepared composites were well characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), and ultraviolet-visible (UV-vis) diffuse reflection spectroscopy. The XRD and Raman spectroscopy analysis indicated that the TiO2 existed in the form of pure anatase in the composites. The SEM images exhibited the well deposition and dispersion of TiO2 nanoparticles with little agglomeration on the surfaces of diatoms. The UV-vis diffuse reflection spectra showed that the band gap of TiO2 could be narrowed by the introduction of Yb species, which was further affected by doping concentration of Yb. The photocatalytic activity of synthesized samples was investigated by the degradation of methylene blue (MB) under UV light irradiation. It was observed that the photocatalytic degradation followed a pseudo-first-order kinetics according to the Langmuir-Hinshelwood model. Compared to TiO2 and TiO2/diatomite, the Yb-TiO2/diatomite composites exhibited higher photocatalytic activity toward degradation of MB using UV light irradiation.

[Removal Kinetics and Mechanism of Aniline by Manganese-oxide-modified Diatomite].

Science.gov (United States)

Xiao, Shao-dan; Liu, Lu; Jiang, Li-ying; Chen, Jian-meng

2015-06-01

A novel rapid green one-step method was developed for the preparation of manganese modified diatomite (Mn-D) by treating roasted diatomite with an acidic permanganate solution. The effects of calcination temperature and mass ratio of KMnO4 and diatomite (p) on aniline removal efficiency of Mn-D were investigated. The removal kinetics and mechanism of aniline by Mn-D were also discussed. The results showed that when the optimal calcination temperature was 450 degrees C, p was 1.6, and the loading amounts of δ-MnO2 was 0.82 g x g(-1), Mn-D had a great performance for aniline removal, and more than 80% of aniline was adsorbed within 10 minutes, accompanied with the release of Mn2+. In acidic conditions, the adsorption process on Mn-D followed pseudo-second-order and was mainly controlled by intra-particle diffusion. The best fitting of the experimental adsorption data was given by the Freundlich equation. Gas chromatograph-mass spectrometer was applied to identify the reaction intermediates at different times, and azobenzene was found to be the main reaction intermediate in the degradation system. Based on the above observations, the possible degradation pathway of aniline by Mn-D was proposed.

Adsorption of methyl orange from aqueous solution using chitosan/diatomite composite.

Science.gov (United States)

Zhao, Peng; Zhang, Runhu; Wang, Jianglin

2017-04-01

A novel chitosan/diatomite composite was prepared by a simple mixture in the mass ratio to remove methyl orange (MO) from aqueous media in this study. The composite adsorbent was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy analysis. The parameters to influence the adsorption of MO were studied under such conditions as kinetics, adsorption isotherm, pH effect, and thermodynamics. The results revealed that adsorption of MO was initially rapid and the equilibrium time was reached after 40 min. The optimal value of the pH was 5.0 for better adsorption. The equilibrium data were well fitted to the Langmuir isotherm compared to the Freundlich isotherm, and exhibited the highest capacity and a removal rate of 88.37% under an initial dye concentration of 50 mg/L. The kinetic data were well described by the pseudo-second order model. The thermodynamic calculations revealed that the sorption was viable, spontaneous, and exothermic under the conditions studied. In addition, the chitosan/diatomite composite had good adsorption and desorption performance with respect to reusability after six cycles. These results showed that the chitosan/diatomite could be considered as a potential adsorbent for the removal of MO in aqueous solution.

Surface silylation of natural mesoporous/macroporous diatomite for adsorption of benzene.

Science.gov (United States)

Yu, Wenbin; Deng, Liangliang; Yuan, Peng; Liu, Dong; Yuan, Weiwei; Liu, Peng; He, Hongping; Li, Zhaohui; Chen, Fanrong

2015-06-15

Naturally occurring porous diatomite (Dt) was functionalized with phenyltriethoxysilane (PTES), and the PTES-modified diatomite (PTES-Dt) was characterized using diffuse reflectance Fourier transform infrared spectroscopy, nitrogen adsorption, nuclear magnetic resonance spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. After silylation, a functional group (-C6H5, phenyl) was successfully introduced onto the surface of Dt. PTES-Dt exhibited hydrophobic properties with a water contact angle (WCA) as high as 120°±1°, whereas Dt was superhydrophilic with a WCA of 0°. The benzene adsorption data on both Dt and PTES-Dt fit well with the Langmuir isotherm equation. The Langmuir adsorption capacity of benzene on PTES-Dt is 28.1 mg/g, more than 4-fold greater than that on Dt. Moreover, the adsorption kinetics results show that equilibrium was achieved faster for PTES-Dt than for Dt, over the relative pressure range of 0.118-0.157. The excellent benzene adsorption performance of PTES-Dt is attributed to strong π-system interactions between the phenyl groups and the benzene molecules as well as to the macroporosity of the PTES-Dt. These results show that the silylated diatomite could be a new and inexpensive adsorbent suitable for use in benzene emission control. Copyright © 2015 Elsevier Inc. All rights reserved.

Diatomite-supported Pd-M (M=Cu, Co, Ni) bimetal nanocatalysts for selective hydrogenation of long-chain aliphatic esters.

Science.gov (United States)

Huang, Changliang; Zhang, Hongye; Zhao, Yanfei; Chen, Sha; Liu, Zhimin

2012-11-15

Diatomite supported Pd-M (M=Cu, Co, Ni) bimetal nanocatalysts with various metal compositions were prepared and characterized by means of X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. It was demonstrated that the metal nanoparticles were uniformly distributed on the support, and their size was centered around 8 nm with a relatively narrow size distribution. The catalysts were used to catalyze hydrogenation of long-chain aliphatic esters, including methyl palmitate, methyl stearate, and methyl laurate. It was indicated that the all diatomite-supported Pd-based bimetal catalysts were active to the selective hydrogenation of long-chain esters to corresponding alcohols at 270°C, originated from the synergistic effect between the metal particles and the diatomite support. For the selective hydrogenation of methyl palmitate, Pd-Cu/diatomite with metal loading of 1% and Pd/Cu=3 displayed the highest performance, giving a 1-hexadecanol yield of 82.9% at the substrate conversion of 98.8%. Copyright © 2012 Elsevier Inc. All rights reserved.

Investigation of Diatomite Properties from Ankara-Kızılcahamam and Çankırı-Çerkeş Regions

OpenAIRE

ARUNTAŞ, H. Yılmaz

1998-01-01

The physical properties, chemical and mineralogical compositions and microscopic structures of diatomites collected from Ankara-Kızılcahamam and Çankırı-Çerkeş regions were examined in this study. The diatomites were found to be pure, amorphous, usually soft and easily friable with particle size of 5-50 mm. It was determined that the diatomites were highly with a high water absorption capacity and contained plagioclase, smectite, and quartz minerals. The specific gravity was less th...

Effect of sulfate ions on the crystallization and photocatalytic activity of TiO2/diatomite composite photocatalyst

Science.gov (United States)

Zhang, Jinjun; Wang, Xiaoyan; Wang, Jimei; Wang, Jing; Ji, Zhijiang

2016-01-01

TiO2 nanoparticles were immobilized on diatomite by hydrolysis-deposition method using titanium tetrachloride as precursor. The effect of sulfate ions on the crystallization and photocatalytic activity of TiO2/diatomite composite photocatalyst was characterized by TG-DSC, XRD, BET surface area, SEM, FT-IR spectroscopy, XPS and UV-vis diffuse reflectance spectra. The results indicate that addition of a small amount of sulfate ions promotes the formation of anatase phase and inhibits the transformation from anatase to rutile. On the other hand, sulfate ions immobilized on the surface of TiO2/diatomite have strong affinity for electrons, capturing the photo-generated electrons, which hinders the recombination of electrons and holes.

Development of a dielectric ceramic based on diatomite-titania. Part one: powder preparation and sintering study

Directory of Open Access Journals (Sweden)

Tavares Elcio Correia de Souza

1997-01-01

Full Text Available This work presents powder preparation and sintering experiments of a mixture diatomite-titania. X-ray diffraction, DTA, TGA as well as chemical and microstructural analyses were made. The sintering process was investigated as a function of sintering temperature and time, mass variation, linear shrinkage and activation energy. The results show that sintering of diatomite-titania could be described by a viscous flow mechanism.

Diatomite: A promising natural candidate as carrier material for low, middle and high temperature phase change material

International Nuclear Information System (INIS)

Qian, Tingting; Li, Jinhong; Min, Xin; Deng, Yong; Guan, Weimin; Ning, Lei

2015-01-01

Graphical abstract: Low-temperature PCMs are always the objects of prime investigations, however, the field of PCMs’ applications is not limited to low temperatures only. In the present study, three kinds of PCMs: polyethylene glycol (PEG), lithium nitrate, and sodium sulfate were respectively employed as the low-, middle- and high-temperature storage medium. A series of novel form-stable phase change materials (fs-PCMs) were tailor-made by blending diatomite and the three kinds of PCMs via a vacuum impregnation method or a facile mixing and sintering method. Various techniques were employed to characterize their structural and thermal properties. - Highlights: • Low-temperature PEG/diatomite was prepared. • Middle-temperature LiNO 3 /diatomite was prepared. • High-temperature Na 2 SO 4 /diatomite was prepared. - Abstract: Low-temperature PCMs are always the objects of prime investigations, however, the field of PCM’s application is not only limited to low temperatures. In this study, polyethylene glycol (PEG), lithium nitrate (LiNO 3 ), and sodium sulfate (Na 2 SO 4 ) were respectively employed as the low-, middle- and high-temperature storage medium. A series of novel form-stable phase change materials (fs-PCMs) were tailor-made by blending diatomite and the three PCMs via a vacuum impregnation method or a facile mixing and sintering method. Various techniques were employed to characterize their structural and thermal properties. The maximum loads of PEG, LiNO 3 , and Na 2 SO 4 in diatomite powder could respectively reach 58%, 60%, and 65%, while PCM melts during the solid–liquid phase transformation. SEM, XRD, and FT-IR results indicated that PCMs were well dispersed into diatomite pores and no chemical changes took place during the heating and cooling process. The prepared fs-PCMs were quite stable in terms of thermal and chemical manner even after a 200-cycle of melting and freezing. The resulting composite fs-PCMs were promising candidates to

Diatomite and re-use coal waste as promising alternative for fertilizer to environmental improvement

OpenAIRE

Mohammad Hassan Sayyari-Zahan; AbdolHamid Gholami; Somayeh Rezaeepour

2015-01-01

Application of conventional fertilizers has been contributing much pollutant to the environment. This study aimed to assess the potential of diatomite and re-use coal waste as a non chemical fertilizer to environmental improvement. The experiments were evaluated in 2kg pots under greenhouse conditions at 4 levels of diatomite powder including 0, 10, 20, 40 g/kg soil as well as 5 levels of coal waste powder including 0, 20, 40, 80, 160 g/kg soil based on completely randomized design with three...

Aggregation and transport of rutile titanium dioxide nanoparticles with montmorillonite and diatomite in the presence of phosphate in porous sand.

Science.gov (United States)

Guo, Peng; Xu, Nan; Li, Duo; Huangfu, Xinxing; Li, Zuling

2018-08-01

Crop soil is inevitably contaminated by the excess of phosphate (P) fertilizers. A large amount of nanoparticle titanium dioxide (nTiO 2 ) entered soils as well due to the wide use of engineered nanomaterials. It is of great urgency and a high priority to investigate the mechanisms of nTiO 2 deposition with the presence of P in crop soils. This study investigated the transport behavior of (1.0 g L -1 ) rutile nTiO 2 with two representative clay particles (montmorillonite or diatomite) in the presence of P through the saturated quartz sand. In 10 mM NaCl electrolyte solution at pH 6.0, the recovery percentage of nTiO 2 was 36.3% from sand column. Nevertheless, it was reduced to 18.6% and 11.1% while montmorillonite and diatomite present in suspensions, respectively. Obviously, the improvement of nTiO 2 retention in sand was more pronounced by diatomite than montmorillonite. The likely mechanism for this result was that large aggregates were formed due to the attachment of nTiO 2 to montmorillonite and diatomite. Moreover, the surface of diatomite with the larger hydrodynamic radius was less negatively charged by comparison with montmorillonite. However, this phenomenon disappeared with the addition of P. P adsorption increases the repulsive force between particles and sand and the fast release of attached nTiO 2 -montmorillonite and diatomite from sand. The two-site kinetic retention model and the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory suggested that the combination of k 1/ k 1d , k 2 and secondary minimum energy can be used to accurately describe the attachment of nTiO 2 -montmorillonite and diatomite to sand in the presence of P. Copyright © 2018 Elsevier Ltd. All rights reserved.

Colloidal diatomite, radionickel, and humic substance interaction: a combined batch, XPS, and EXAFS investigation.

Science.gov (United States)

Sheng, Guodong; Shen, Runpu; Dong, Huaping; Li, Yimin

2013-06-01

This work determined the influence of humic acid (HA) and fulvic acid (FA) on the interaction mechanism and microstructure of Ni(II) onto diatomite by using batch experiments, X-ray photoelectron spectroscopy (XPS), and extended X-ray absorption fine structure (EXAFS) methods. Macroscopic and spectroscopic experiments have been combined to see the evolution of the interaction mechanism and microstructure of Ni(II) in the presence of HA/FA as compared with that in the absence of HA/FA. The results indicated that the interaction of Ni(II) with diatomite presents the expected solution pH edge at 7.0, which is modified by addition of HA/FA. In the presence of HA/FA, the interaction of Ni(II) with diatomite increased below solution pH 7.0, while Ni(II) interaction decreased above solution pH 7.0. XPS analysis suggested that the enrichment of Ni(II) onto diatomite may be due to the formation of (≡SO)2Ni. EXAFS results showed that binary surface complexes and ternary surface complexes of Ni(II) can be simultaneously formed in the presence of HA/FA, whereas only binary surface complexes of Ni(II) are formed in the absence of HA/FA, which contribute to the enhanced Ni(II) uptake at low pH values. The results observed in this work are important for the evaluation of Ni(II) and related radionuclide physicochemical behavior in the natural soil and water environment.

Impact of diatomite on the slightly polluted algae-containing raw water treatment process using ozone oxidation coupled with polyaluminum chloride coagulation.

Science.gov (United States)

Hu, Wenchao; Wu, Chunde; Jia, Aiyin; Zhang, Zhilin; Chen, Fang

2014-01-01

The impact of adding diatomite on the treatment performance of slightly polluted algae-containing raw water using ozone pre-oxidation and polyaluminum chloride (PAC) coagulation was investigated. Results demonstrated that the addition of diatomite is advantageous due to reduction of the PAC dose (58.33%) and improvement of the removal efficiency of algae, turbidity, and dissolved organic matter (DOM) in raw water. When the ozone concentration was 1.0 mg L⁻¹ and the PAC dosage was 2.5 mg L⁻¹, the removal rates of algae, turbidity, UV254, and TOC were improved by 6.39%, 7.06%, 6.76%, and 4.03%, respectively, with the addition of 0.4 g L⁻¹ diatomite. It has been found that the DOM presented in the Pearl River raw water mainly consisted of small molecules ( 50 kDa). After adding diatomite (0.4 g L⁻¹), the additional removal of 5.77% TOC and 14.82% UV254 for small molecules (50 kDa) could be achieved, respectively, at an ozone concentration of 1.0 mg L⁻¹ and a PAC dose of 2.5 mg L⁻¹. The growth of anabaena flos-aquae (A.F.) was observed by an atomic force microscope (AFM) before and after adding diatomite. AFM images demonstrate that diatomite may have a certain adsorption on A.F.

Effects of Diatomite Organic Fertilizer on Cd and Zn Forms and Availability of Cd-Zn Polluted Soil

Directory of Open Access Journals (Sweden)

LIN Ji

2014-08-01

Full Text Available An indoor soil cultivation experiment was carried out to study the effects of diatomite organic fertilizer on the forms and the avail-ability of Cd, Zn in soil. The results showed that the soil pH increased, the soil available Cd and Zn reduced after diatomite organic fertilizer application in contaminated soil. Diatomite organic fertilizer application decreased the contents of exchangeable form and weakly-bound-to organic form of Cd and Zn significantly, but increased the contents of strongly-bound-to organic form and residual form of Cd and Zn in con-taminated soil. Statistics analysis showed that the contents of exchangeable and weakly-bound-to organic form of Cd and Zn had highly sig-nificant relation to the content of soil available Cd and Zn(P<0.01. The contents of Mn oxide-occluded Cd had significant relation to the con-tent of soil available Cd(P<0.05. Comparing the treatments of diatomite organic fertilizer with the rate of 5%and 10%soil weight, there was no significant difference in soil pH, the contents of soil available Cd, Zn and the forms of Cd, Zn.

[The effect of core veneer thickness ratio on the flexural strength of diatomite-based dental ceramic].

Science.gov (United States)

Jiang, Jie; Zhang, Xin; Gao, Mei-qin; Zhang, Fei-min; Lu, Xiao-li

2015-06-01

To evaluate the effect of different core veneer thickness ratios on the flexural strength and failure mode of bilayered diatomite-based dental ceramics. Diatomite-based dental ceramics blocks (16 mm×5.4 mm×1 mm) were sintered with different thickness of veneer porcelains: 0 mm (group A), 0.6 mm (group B), 0.8 mm (group C) and 1.0 mm (group D). Flexural strength was detected and scanning electron microscope was used to observe the interface microstructure. Statistical analysis was performed using SPSS 17.0 software package. With the increase of the thickness of the veneer porcelain, flexural strength of group C showed highest flexural strength up to (277.24±5.47) MPa. Different core veneer thickness ratios can significantly influence the flexural strength of bilayered diatomite-based dental ceramics. Supported by Science and Technology Projects of Nantong City (HS2013010).

Performance and enhanced mechanism of a novel bio-diatomite biofilm pretreatment process treating polluted raw water.

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Yang, Guang-feng; Feng, Li-juan; Wang, Sha-fei; Yang, Qi; Xu, Xiang-yang; Zhu, Liang

2015-09-01

A lab-scale novel bio-diatomite biofilm process (BDBP) was established for the polluted raw water pretreatment in this study. Results showed that a shorter startup period of BDBP system was achieved under the completely circulated operation mode, and the removal efficiencies of nitrogen and disinfection by-product precursor were effective at low hydraulic retention time of 2-4 h due to high biomass attached to the carrier and diatomite. A maximum NH4(+)-N oxidation potential predicted by modified Stover-Kincannon model was 333.3 mg L(-1) d(-1) in the BDBP system, which was 4.7 times of that in the control reactor. Results demonstrated that the present of bio-diatomite favors the accumulation of functional microbes in the oligotrophic niche, and the pollutants removal performance of this novel process was enhanced for polluted raw water pretreatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Application of classical isothermal adsorption models in heavy metal ions/ diatomite system and related problems].

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Zhu, Jian; Wu, Qing-Ding; Wang, Ping; Li, Ke-Lin; Lei, Ming-Jing; Zhang, Wei-Li

2013-11-01

In order to fully understand adsorption nature of Cu2+, Zn2+, Pb2+, Cd2+, Mn2+, Fe3+ onto natural diatomite, and to find problems of classical isothermal adsorption models' application in liquid/solid system, a series of isothermal adsorption tests were conducted. As results indicate, the most suitable isotherm models for describing adsorption of Pb2+, Cd2+, Cu2+, Zn2+, Mn2+, Fe3+ onto natural diatomite are Tenkin, Tenkin, Langmuir, Tenkin, Freundlich and Freundlich, respectively, the adsorption of each ion onto natural diatomite is mainly a physical process, and the adsorption reaction is favorable. It also can be found that, when using classical isothermal adsorption models to fit the experimental data in liquid/solid system, the equilibrium adsorption amount q(e) is not a single function of ion equilibrium concentration c(e), while is a function of two variables, namely c(e) and the adsorbent concentration W0, q(e) only depends on c(e)/W(0). Results also show that the classical isothermal adsorption models have a significant adsorbent effect, and their parameter values are unstable, the simulation values of parameter differ greatly from the measured values, which is unhelpful for practical use. The tests prove that four-adsorption-components model can be used for describing adsorption behavior of single ion in nature diatomite-liquid system, its parameters k and q(m) have constant values, which is favorable for practical quantitative calculation in a given system.

Bioinspired Diatomite Membrane with Selective Superwettability for Oil/Water Separation.

Science.gov (United States)

Lo, Yu-Hsiang; Yang, Ching-Yu; Chang, Haw-Kai; Hung, Wei-Chen; Chen, Po-Yu

2017-05-03

Membranes with selective superwettability for oil/water separation have received significant attention during the past decades. Hierarchical structures and surface roughness are believed to improve the oil repellency and the stability of Cassie-Baxter state. Diatoms, unicellular photosynthetic algae, possess sophisticated skeletal shells (called frustules) which are made of hydrated silica. Motivated by the hierarchical micro- and nanoscale features of diatom, we fabricate a hierarchical diatomite membrane which consists of aligned micro-sized channels by the freeze casting process. The fine nano-porous structures of frustules are well preserved after the post sintering process. The bioinspired diatomite membrane performs both underwater superoleophobicity and superhydrophobicity under various oils. Additionally, we demonstrate the highly efficient oil/water separation capabililty of the membranes in various harsh environments. The water flux can be further adjusted by tuning the cooling rates. The eco-friendly and robust bioinspired membranes produced by the simple, cost-effective freeze casting method can be potentially applied for large scale and efficient oil/water separation.

Visualization of Solution Gas Drive in Viscous Oil, SUPRI TR-126

Energy Technology Data Exchange (ETDEWEB)

George, D.S.; Kovscek, A.R.

2001-07-23

Several experimental studies of solution gas drive are available in this report. Almost all of the studies have used light oil. Solution gas drive behavior, especially in heavy oil reservoirs, is poorly understood. Experiments were performed in which pore-scale solution gas drive phenomena were viewed in water/carbon dioxide and viscous oil/carbon dioxide systems. A new pressure vessel was designed and constructed to house silicon-wafer micromodels that previously operated at low (<3 atm) pressure. The new apparatus is used for the visual studies. Several interesting phenomena were viewed. The repeated nucleation of gas bubbles was observed at a gas-wet site occupied by dirt. Interestingly, the dissolution of a gas bubble into the liquid phase was previously recorded at the same nucleation site. Gas bubbles in both systems grew to span one ore more pore bodies before mobilization. Liquid viscosity affected the ease with which gas bubbles coalesced. More viscous solutions result in slower rates of coalescence. The transport of solid particles on gas-liquid interfaces was also observed.

Plasmonic nanoparticles-decorated diatomite biosilica: extending the horizon of on-chip chromatography and label-free biosensing.

Science.gov (United States)

Kong, Xianming; Li, Erwen; Squire, Kenny; Liu, Ye; Wu, Bo; Cheng, Li-Jing; Wang, Alan X

2017-11-01

Diatomite consists of fossilized remains of ancient diatoms and is a type of naturally abundant photonic crystal biosilica with multiple unique physical and chemical functionalities. In this paper, we explored the fluidic properties of diatomite as the matrix for on-chip chromatography and, simultaneously, the photonic crystal effects to enhance the plasmonic resonances of metallic nanoparticles for surface-enhanced Raman scattering (SERS) biosensing. The plasmonic nanoparticle-decorated diatomite biosilica provides a lab-on-a-chip capability to separate and detect small molecules from mixture samples with ultra-high detection sensitivity down to 1 ppm. We demonstrate the significant potential for biomedical applications by screening toxins in real biofluid, achieving simultaneous label-free biosensing of phenethylamine and miR21cDNA in human plasma with unprecedented sensitivity and specificity. To the best of our knowledge, this is the first time demonstration to detect target molecules from real biofluids by on-chip chromatography-SERS techniques. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

The separation of uranium ions by natural and modified diatomite from aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Sprynskyy, Myroslav, E-mail: sprynsky@yahoo.com [Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, 7 Gagarina Str., 87-100 Torun (Poland); Kovalchuk, Iryna [Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, 7 Gagarina Str., 87-100 Torun (Poland); Institute of Adsorption and Problem of Endoecology, National Academy of Sciences of Ukraine, 13 General Naumov Str., 03164 Kyiv (Ukraine); Buszewski, Boguslaw [Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, 7 Gagarina Str., 87-100 Torun (Poland)

2010-09-15

In this work the natural and the surfactant modified diatomite has been tested for ability to remove uranium ions from aqueous solutions. Such controlling factors of the adsorption process as initial uranium concentration, pH, contact time and ionic strength have been investigated. Effect of ionic strength of solution has been examined using the solutions of NaCl, Na{sub 2}CO{sub 3} and K{sub 2}SO{sub 4}. The pseudo-first order and the pseudo-second order models have been used to analyze the adsorption kinetic results, whereas the Langmuir and the Freundlich isotherms have been used to the equilibrium adsorption data. The effects of the adsorbent modification as well as uranium adsorption on the diatomite surface have been studied using X-ray powder diffraction, scanning electron microscopy and FTIR spectroscopy. The maximum adsorption capacities of the natural and the modified diatomite towards uranium were 25.63 {mu}mol/g and 667.40 {mu}mol/g, respectively. The desorptive solutions of HCl, NaOH, Na{sub 2}CO{sub 3}, K{sub 2}SO{sub 4}, CaCO{sub 3}, humic acid, cool and hot water have been tested to recover uranium from the adsorbent. The highest values of uranium desorption (86%) have been reached using 0.1 M HCl.

The separation of uranium ions by natural and modified diatomite from aqueous solution.

Science.gov (United States)

Sprynskyy, Myroslav; Kovalchuk, Iryna; Buszewski, Bogusław

2010-09-15

In this work the natural and the surfactant modified diatomite has been tested for ability to remove uranium ions from aqueous solutions. Such controlling factors of the adsorption process as initial uranium concentration, pH, contact time and ionic strength have been investigated. Effect of ionic strength of solution has been examined using the solutions of NaCl, Na(2)CO(3) and K(2)SO(4). The pseudo-first order and the pseudo-second order models have been used to analyze the adsorption kinetic results, whereas the Langmuir and the Freundlich isotherms have been used to the equilibrium adsorption data. The effects of the adsorbent modification as well as uranium adsorption on the diatomite surface have been studied using X-ray powder diffraction, scanning electron microscopy and FTIR spectroscopy. The maximum adsorption capacities of the natural and the modified diatomite towards uranium were 25.63 micromol/g and 667.40 micromol/g, respectively. The desorptive solutions of HCl, NaOH, Na(2)CO(3), K(2)SO(4), CaCO(3), humic acid, cool and hot water have been tested to recover uranium from the adsorbent. The highest values of uranium desorption (86%) have been reached using 0.1M HCl. Copyright 2010 Elsevier B.V. All rights reserved.

Sorption of DNA by diatomite-Zn(II) embedded supermacroporous monolithic p(HEMA) cryogels.

Science.gov (United States)

Tozak, Kabil Özcan; Erzengin, Mahmut; Sargin, Idris; Ünlü, Nuri

2013-01-01

In this study, the DNA sorption performance of diatomite-Zn(II) embedded supermacroporous monolithic p(HEMA) cryogels were investigated for the purpose of designing a novel adsorbent that can be utilized for DNA purification, separation and immunoadsorption studies such as removal of anti-dsDNA antibodies from systemic lupus erythematosus (SLE) patient plasma. Poly(2-hydroxyethyl methacrylate) [p(HEMA)]-based monolithic cryogel column embedded with Zn(2+)-diatomite particles was prepared by free radical cryo-copolymerization of 2-hydroxyethyl methacrylate (HEMA) with N,N'-methylene-bis-acrylamide (MBAAm). The polymerization reaction was initiated by N,N,N',N'-tetramethylene diamine (TEMED) and ammonium persulfate (APS) pair in an ice bath. After thawing, the monolithic composite cryogels were used for affinity sorption and then subsequent desorption of DNA molecules from aqueous solutions. Diatomite (DA) particles were characterized by XRF and BET method. The characterization of composite cryogel was done through SEM imaging. The effects of pH of the solution, initial DNA concentration, ionic strength, temperature and flow rates on adsorption were investigated to determine the optimum conditions for adsorption/desorption experiments. The particle embedding procedure was shown to yield significantly enhanced adsorption of DNA on the adsorbent. Furthermore, considering its excellent bio-compatibility, p(HEMA) cryogels are promising a candidate for further DNA sorption studies.

Effect of cathode vibration and heat treatment on electromagnetic properties of flake-shaped diatomite coated with Ni-Fe alloy by electroplating

Science.gov (United States)

Lan, Mingming; Li, Huiqin; Huang, Weihua; Xu, Guangyin; Li, Yan

2015-03-01

In this paper, flake-shaped diatomite particles were used as forming templates for the fabrication of the ferromagnetic functional fillers by way of electroplating Ni-Fe alloy method. The effects of cathode vibration frequency on the content of Ni-Fe alloy in the coating and the surface morphologies of the coatings were evaluated. The electromagnetic properties of the coated diatomite particles before and after heat treatment were also investigated in detail. The results show that the core-shell flake-shaped diatomite particles with high content of Ni-Fe alloy and good surface qualities of the coatings can be obtained by adjusting cathode vibration frequency. The coated diatomite particles with heat treatment filled paraffin wax composites exhibit a superior microwave absorbing and electromagnetic properties compared to the non-heat treated samples. Additionally, the peaks of reflection loss are found to be able to shift to lower frequency by the heat treatment process, which indicates the heat treatment can adjust microwave absorbing frequency band.

Chapter D: With or Without Salt-a Comparison of Marine and Continental-Lacustrine Diatomite Deposits

Science.gov (United States)

Moyle, Phillip R.; Dolley, Thomas P.

2003-01-01

Diatoms in sedimentary deposits of marine and continental, especially lacustrine, origin have similar nutrient (for example, phosphate, nitrate, and silica) and light requirements; however, their geologic ranges and physiographic environments vary. Marine diatoms range in age from Early Cretaceous to Holocene, and continental diatoms range in age from Eocene to Holocene; however, most commercial diatomites, both marine and lacustrine, were deposited during the Miocene. Marine deposits of commercial value generally accumulated along continental margins with submerged coastal basins and shelves where wind-driven boundary currents provided the nutrient-rich upwelling conditions capable of supporting a productive diatom habitat. Commercial freshwater diatomite deposits occur in volcanic terrains associated with events that formed sediment-starved drainage basins, such as the Basin and Range Province, particularly in Nevada. Marine habitats generally are characterized by stable conditions of temperature, salinity, pH, nutrients, and water currents, in contrast to lacustrine habitats, which are characterized by wide variations in these conditions. Marine deposits generally are of higher quality and contain larger resources, owing to their greater areal extent and thickness, whereas most of the world's known diatomites are of lacustrine origin. Both types of deposit are commonly mined by open-pit methods and subjected to processing designed to remove organic matter, CO2, pore water, and inorganic contaminants in order to produce purified products. The highest quality diatomites, predominantly from marine sources, are used in filtration, although both types of deposit produce filter grades, and additional end uses include fillers, additives, absorbents, and abrasives.

Study on The Application of Composed TiO2-diatomite in The Removal of Phenol in Water

Science.gov (United States)

Liu, S.; Li, J.

2017-10-01

As an environmentally friendly pollution control technology, TiO2 photocatalytic technology has a broad prospect in the field of environmental protection. In this paper, composed nano-TiO2-diatomite were prepared by depositing TiO2 nanoparticles on the surface of diatomite microparticles. The nano-TiO2/diatomite composed photocatalyst is used to remove phenol in water in a specific designed reaction box under 4 different operation factors such as different reaction time, different pollutant concentration, different UV light powers and different amount of catalytic powder. The experimental results indicate that the phenol removal percentages are influenced by the reaction time most significantly, the second is the phenol concentration, the next one is the photocatalyst amount and the UV light powers’ effect is quite limited. Tthe degradation of phenol typically slows down at the reaction time about 30 or 60 minutes. Besides that, the phenol removal kinetic removal rates were also investigated.

The Use of Infrared Spectroscopy to Determine the Quality of Carbonate-Rich Diatomite Ores

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Adriana Guatame-Garcia

2018-03-01

Full Text Available Diatomite, a rock formed by the accumulation of opaline diatom frustules, is a preferred raw material for the manufacturing of filters. Its uniqueness relies on the high porosity and inertness of the frustules. The presence of carbonates in some diatomite ores hinders these properties. The purpose of this study was to identify the type of carbonates and their association with the ore in a diatomite deposit, and to assess the suitability of determining the quality of the ore using techniques with potential for in-pit implementation. For this, run-of-mine samples were analysed using environmental scanning electron microscopy (ESEM and infrared spectroscopy. The ESEM images showed that carbonate is present as cement and laminae. The infrared data revealed that the carbonate minerals correspond to aragonite and calcite, and that their occurrence is linked to the total amount of carbonate in the sample. By using a portable spectral instrument that uses diffuse reflectance, it was possible to classify the spectra of the ore samples based on the carbonate content. These results indicate that infrared technology could be used on-site for determining the quality of the ore, thus providing relevant information to assist the optimisation of mining and beneficiation activities.

Biological marker distribution in coexisting kerogen, bitumen and asphaltenes in Monterey Formation diatomite, California

Science.gov (United States)

Tannenbaum, E.; Ruth, E.; Huizinga, B. J.; Kaplan, I. R.

1986-01-01

Organic-rich (18.2%) Monterey Formation diatomite from California was studied. The organic matter consist of 94% bitumen and 6% kerogen. Biological markers from the bitumen and from pyrolysates of the coexisting asphaltenes and kerogen were analyzed in order to elucidate the relationship between the various fractions of the organic matter. While 17 alpha(H), 18 alpha(H), 21 alpha(H)-28,30-bisnorhopane was present in the bitumen and in the pryolysate of the asphaltenes, it was not detected in the pyrolysates of the kerogen. A C40-isoprenoid with "head to head" linkage, however, was present in pyrolysates of both kerogen and asphaltenes, but not in the bitumen from the diatomite. The maturation level of the bitumen, based on the extent of isomerization of steranes and hopanes, was that of a mature oil, whereas the pyrolysate from the kerogen showed a considerably lower maturation level. These relationships indicate that the bitumen may not be indigenous to the diatomite and that it is a mature oil that migrated into the rock. We consider the possibility, however, that some of the 28,30-bisnorhopane-rich Monterey Formation oils have not been generated through thermal degradation of kerogen, but have been expelled from the source rock at an early stage of diagenesis.

Diatomite Photonic Crystals for Facile On-Chip Chromatography and Sensing of Harmful Ingredients from Food

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Xianming Kong

2018-03-01

Full Text Available Diatomaceous earth—otherwise called diatomite—is essentially composed of hydrated biosilica with periodic nanopores. Diatomite is derived from fossilized remains of diatom frustules and possesses photonic-crystal features. In this paper, diatomite simultaneously functions as the matrix of the chromatography plate and the substrate for surface-enhanced Raman scattering (SERS, by which the photonic crystal-features could enhance the optical field intensity. The on-chip separation performance of the device was confirmed by separating and detecting industrial dye (Sudan I in an artificial aqueous mixture containing 4-mercaptobenzoic acid (MBA, where concentrated plasmonic Au colloid was casted onto the analyte spot for SERS measurement. The plasmonic-photonic hybrid mode between the Au nanoparticles (NP and the diatomite layer could supply nearly 10 times the increment of SERS signal (MBA intensity compared to the common silica gel chromatography plate. Furthermore, this lab-on-a-chip photonic crystal device was employed for food safety sensing in real samples and successfully monitored histamine in salmon and tuna. This on-chip food sensor can be used as a cheap, robust, and portable sensing platform for monitoring for histamine or other harmful ingredients at trace levels in food products.

Dewatering of Chlorella pyrenoidosa using diatomite dynamic membrane: filtration performance, membrane fouling and cake behavior.

Science.gov (United States)

Zhang, Yalei; Zhao, Yangying; Chu, Huaqiang; Zhou, Xuefei; Dong, Bingzhi

2014-01-01

The diatomite dynamic membrane (DDM) was utilized to dewater Chlorella pyrenoidosa of 2 g dry weight/L under continuous-flow mode, whose ultimate algae concentration ranged from 43 g to 22 g dry weight/L of different culture time. The stable flux of DDM could reach 30 L/m(2) h over a 24 h operation time without backwash. Influences of extracellular organic matters (EOM) on filtration behavior and membrane fouling were studied. The DDM was divided into three sub-layers, the slime layer, the algae layer and the diatomite layer from the outside to the inside of the cake layer based on components and morphologies. It was found that EOM caused membrane fouling by accumulating in the slime and algae layers. The DDM intercepted polysaccharides, protein-like substances, humic-like substances and some low-MW organics. Proteins were indicated the major membrane foulants with increased protein/polysaccharide ratio from the slime layer to the diatomite layer as culture time increased. This method could be applied to subsequent treatment of microalgae coupling technology of wastewater treatment or microalgae harvesting for producing biofuel. Copyright © 2013 Elsevier B.V. All rights reserved.

Effect Factors of Benzene Adsorption and Degradation by Nano-TiO2 Immobilized on Diatomite

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Lijun Cheng

2012-01-01

Full Text Available Difference between adsorption of benzene by diatomite and nano-TiO2 immobilized on diatomite was investigated. And effects of temperature, light intensity, relative humidity, and initial benzene concentration on adsorption and degradation of benzene by nano-TiO2 immobilized on diatomite were also studied. The experimental results showed that when initial benzene concentration was 2.2×10−3 mg L−1, it could be degraded to below safe concentration (1.1×10−4 mg L−1 after 50 h when temperature was 20°C, but it just needed 30 h at 35°C. When light intensity was 6750 Lx, it needed 30 h for benzene to be degraded to below safe concentration, but benzene could barely be degraded without light. When relative humidity was 50%, benzene could be degraded to 1.0×10−4 mg L−1 after 30 h, while its concentration could be reduced to 7.0×10−5 mg L−1 at the relative humidity of 80%.

Chapter F: Preliminary Bibliography of Lacustrine Diatomite Deposits in the Western United States and Related Topics

Science.gov (United States)

Bolm, Karen S.; Wallace, Alan R.; Moyle, Phillip R.; Bliss, James D.; Orris, Greta J.

2003-01-01

Introduction As part of the assessment of lacustrine diatomite resources in the Western United States (fig. 1), U.S. Geological Survey (USGS) project members conducted a review of literature relating to the formation, location, and nature of deposits in the study area. This preliminary bibliography consists of selected publications to identify, locate, and describe the deposits to be studied, to characterize common geologic factors about the deposits, and to better understand the factors that control their formation, preservation, or destruction. The bibliography also serves as a resource for other workers to research the topic. References included in the preliminary bibliography were gathered by searching existing bibliographic data bases and library collections. Project researchers also contributed references that they found during the course of their work. This bibliography should be considered a working document that will grow as research and literature searches continue. Clearly, many significant publications may be missing from this preliminary list; therefore, USGS staff members intend to issue a revised bibliography as project work progresses. To assure completeness, input from other researchers and industry is welcome. Although the focus of this bibliography is lacustrine diatomite deposits of the Western United States, additional references that provide a foundation of knowledge for the study of diatomites, diatoms, and diatom-related processes (ecology, geology, geochemistry) and for the uses and behavior of diatomite have also been included. An index of keywords has been added to this bibliography, designed to help the user locate reports by topic or by geographic location. The letter 'A' following a number indicates that the report referenced is an abstract.

Detection analysis of surface hydroxyl active sites and simulation calculation of the surface dissociation constants of aqueous diatomite suspensions

International Nuclear Information System (INIS)

Ma, Shu-Cui; Wang, Zhi-Gang; Zhang, Ji-Lin; Sun, De-Hui; Liu, Gui-Xia

2015-01-01

Highlights: • To examine surface hydroxyl functional groups of the calcined diatomite by TGA-DSC, FTIR, and XPS. • To calculate the optimized log K 1 , log K 2 and log C values and the surface species distribution of each surface reactive site using ProtoFit and PHREEQC, respectively. - Abstract: The surface properties of the diatomite were investigated using nitrogen adsorption/deadsorption isotherms, TG-DSC, FTIR, and XPS, and surface protonation–deprotonation behavior was determined by continuous acid–base potentiometric titration technique. The diatomite sample with porous honeycomb structure has a BET specific surface area of 10.21 m 2 /g and large numbers of surface hydroxyl functional groups (i.e. ≡Si-OH, ≡Fe-OH, and ≡Al-OH). These surface hydroxyls can be protonated or deprotonated depending on the pH of the suspension. The experimental potentiometric data in two different ionic strength solutions (0.1 and 0.05 mol/L NaCl) were fitted using ProtoFit GUI V2.1 program by applying diffuse double layer model (DLM) with three amphoteric sites and minimizing the sum of squares between a dataset derivative function and a model derivative function. The optimized surface parameters (i.e. surface dissociation constants (log K 1 , log K 2 ) and surface site concentrations (log C)) of the sample were obtained. Based on the optimized surface parameters, the surface species distribution was calculated using Program-free PHREEQC 3.1.2. Thus, this work reveals considerable new information about surface protonation–deprotonation processes and surface adsorptive behaviors of the diatomite, which helps us to effectively use the cheap and cheerful diatomite clay adsorbent

Detection analysis of surface hydroxyl active sites and simulation calculation of the surface dissociation constants of aqueous diatomite suspensions

Energy Technology Data Exchange (ETDEWEB)

Ma, Shu-Cui [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Key Laboratory of Applied Chemistry and Nanotechnology at Universities of Jilin Province, Changchun University of Science and Technology, Changchun 130022 (China); Wang, Zhi-Gang [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Zhang, Ji-Lin, E-mail: zjl@ciac.ac.cn [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Sun, De-Hui [Changchun Institute Technology, Changchun 130012 (China); Liu, Gui-Xia, E-mail: liuguixia22@163.com [Key Laboratory of Applied Chemistry and Nanotechnology at Universities of Jilin Province, Changchun University of Science and Technology, Changchun 130022 (China)

2015-02-01

Highlights: • To examine surface hydroxyl functional groups of the calcined diatomite by TGA-DSC, FTIR, and XPS. • To calculate the optimized log K{sub 1}, log K{sub 2} and log C values and the surface species distribution of each surface reactive site using ProtoFit and PHREEQC, respectively. - Abstract: The surface properties of the diatomite were investigated using nitrogen adsorption/deadsorption isotherms, TG-DSC, FTIR, and XPS, and surface protonation–deprotonation behavior was determined by continuous acid–base potentiometric titration technique. The diatomite sample with porous honeycomb structure has a BET specific surface area of 10.21 m{sup 2}/g and large numbers of surface hydroxyl functional groups (i.e. ≡Si-OH, ≡Fe-OH, and ≡Al-OH). These surface hydroxyls can be protonated or deprotonated depending on the pH of the suspension. The experimental potentiometric data in two different ionic strength solutions (0.1 and 0.05 mol/L NaCl) were fitted using ProtoFit GUI V2.1 program by applying diffuse double layer model (DLM) with three amphoteric sites and minimizing the sum of squares between a dataset derivative function and a model derivative function. The optimized surface parameters (i.e. surface dissociation constants (log K{sub 1}, log K{sub 2}) and surface site concentrations (log C)) of the sample were obtained. Based on the optimized surface parameters, the surface species distribution was calculated using Program-free PHREEQC 3.1.2. Thus, this work reveals considerable new information about surface protonation–deprotonation processes and surface adsorptive behaviors of the diatomite, which helps us to effectively use the cheap and cheerful diatomite clay adsorbent.

Characterizations of nano-TiO{sub 2}/diatomite composites and their photocatalytic reduction of aqueous Cr (VI)

Energy Technology Data Exchange (ETDEWEB)

Sun, Qing; Li, Hui; Zheng, Shuilin, E-mail: shuilinzh@sina.com; Sun, Zhiming, E-mail: szmcumtb@hotmail.com

2014-08-30

Graphical abstract: Nano-TiO{sub 2}/diatomite (DIA) composites were successfully synthesized by a typical hydrolysis precipitation method. The composites show good photocatalytic activity and stability for aqueous Cr (VI) removal. - Highlights: • TiO{sub 2} nanoparticles/diatomite composite was synthesized and characterized. • The composite exhibited a good photocatalytic performance in Cr (VI) reduction. • The photocatalyst showed good photocatalytic stability. • The composite is a promising material for Cr (VI) photocatalytic reduction. - Abstract: In this paper, the TiO{sub 2} nanoparticles were immobilized on diatomite (DIA) via a typical hydrolysis precipitation process using TiCl{sub 4} as precursor. The as-prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). TiO{sub 2} nanoparticles with the average grain size of around 7–14 nm were well deposited on the surface of diatomite. The photocatalytic activity toward the reduction of aqueous Cr (VI) was demonstrated under UV light. The influence of initial pH values, catalyst amount, illumination intensity and initial concentration of Cr (VI) on photocatalytic reduction of Cr (VI) were investigated. Compared with the commercial TiO{sub 2} (P25, Degussa), the TiO{sub 2}/DIA composites had better reactive activity because of their relatively higher adsorption capacity. Furthermore, the prepared photocatalyst exhibited relatively good photocatalytic stability depending on the reusability tests.

Cyanide Containing Wastewater Treatment by Ozone Enhanced Catalytic Oxidation over Diatomite Catalysts

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Lin Mingguo

2018-01-01

Full Text Available Cyanide containing wastewater that discharged from gold mining process creates environmental problems due to the toxicity of cyanide. As one of the promising advanced oxidation process, catalytic oxidation with ozone is considered to be effective on the purification of cyanide. Diatomite, a natural mineral, was used as catalyst in this study. The effect of O3 dosage, salinity, initial cyanide concentration and initial pH condition were investigated. It was observed that the removal rate of cyanide was much higher in the catalytic oxidation with ozone process than the one in zone alone process. Alkaline condition was especially favorable for cyanide in catalytic oxidation with ozone. The ozone and catalytic oxidation with ozone were simulated by pseudo-first-order kinetics model. The apparent first-order rate constant contribution of the diatomite catalyst was 0.0757 min-1, and the contribution percentage was 65.77%.

Facile synthesis of three-dimensional diatomite/manganese silicate nanosheet composites for enhanced Fenton-like catalytic degradation of malachite green dye

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Jiang, De Bin; Yuan, Yunsong; Zhao, Deqiang; Tao, Kaiming; Xu, Xuan; Zhang, Yu Xin

2018-05-01

In this work, we demonstrate a novel and simple approach for fabrication of the complex three-dimensional (3D) diatomite/manganese silicate nanosheet composite (DMSNs). The manganese silicate nanosheets are uniformly grown on the inner and outer surface of diatomite with controllable morphology using a hydrothermal method. Such structural features enlarged the specific surface area, resulting in more catalytic active sites. In the heterogeneous Fenton-like reaction, the DMSNs exhibited excellent catalytic capability for the degradation of malachite green (MG). Under optimum condition, 500 mg/L MG solution was nearly 93% decolorized at 70 min in the reaction. The presented results show an enhanced catalytic behavior of the DMSNs prepared by the low-cost natural diatomite material and simple controllable process, which indicates their potential for environmental remediation applications. [Figure not available: see fulltext.

Depth Filters Containing Diatomite Achieve More Efficient Particle Retention than Filters Solely Containing Cellulose Fibers.

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Buyel, Johannes F; Gruchow, Hannah M; Fischer, Rainer

2015-01-01

The clarification of biological feed stocks during the production of biopharmaceutical proteins is challenging when large quantities of particles must be removed, e.g., when processing crude plant extracts. Single-use depth filters are often preferred for clarification because they are simple to integrate and have a good safety profile. However, the combination of filter layers must be optimized in terms of nominal retention ratings to account for the unique particle size distribution in each feed stock. We have recently shown that predictive models can facilitate filter screening and the selection of appropriate filter layers. Here we expand our previous study by testing several filters with different retention ratings. The filters typically contain diatomite to facilitate the removal of fine particles. However, diatomite can interfere with the recovery of large biopharmaceutical molecules such as virus-like particles and aggregated proteins. Therefore, we also tested filtration devices composed solely of cellulose fibers and cohesive resin. The capacities of both filter types varied from 10 to 50 L m(-2) when challenged with tobacco leaf extracts, but the filtrate turbidity was ~500-fold lower (~3.5 NTU) when diatomite filters were used. We also tested pre-coat filtration with dispersed diatomite, which achieved capacities of up to 120 L m(-2) with turbidities of ~100 NTU using bulk plant extracts, and in contrast to the other depth filters did not require an upstream bag filter. Single pre-coat filtration devices can thus replace combinations of bag and depth filters to simplify the processing of plant extracts, potentially saving on time, labor and consumables. The protein concentrations of TSP, DsRed and antibody 2G12 were not affected by pre-coat filtration, indicating its general applicability during the manufacture of plant-derived biopharmaceutical proteins.

Depth filters containing diatomite achieve more efficient particle retention than filters solely containing cellulose fibers

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Johannes Felix Buyel

2015-12-01

Full Text Available The clarification of biological feed stocks during the production of biopharmaceutical proteins is challenging when large quantities of particles must be removed, e.g. when processing crude plant extracts. Single-use depth filters are often preferred for clarification because they are simple to integrate and have a good safety profile. However, the combination of filter layers must be optimized in terms of nominal retention ratings to account for the unique particle size distribution in each feed stock. We have recently shown that predictive models can facilitate filter screening and the selection of appropriate filter layers. Here we expand our previous study by testing several filters with different retention ratings. The filters typically contain diatomite to facilitate the removal of fine particles. However, diatomite can interfere with the recovery of large biopharmaceutical molecules such as virus-like particles and aggregated proteins. Therefore, we also tested filtration devices composed solely of cellulose fibers and cohesive resin. The capacities of both filter types varied from 10 to 50 L m-2 when challenged with tobacco leaf extracts, but the filtrate turbidity was ~500-fold lower (~3.5 NTU when diatomite filters were used. We also tested pre coat filtration with dispersed diatomite, which achieved capacities of up to 120 L m-2 with turbidities of ~100 NTU using bulk plant extracts, and in contrast to the other depth filters did not require an upstream bag filter. Single pre-coat filtration devices can thus replace combinations of bag and depth filters to simplify the processing of plant extracts, potentially saving on time, labor and consumables. The protein concentrations of TSP, DsRed and antibody 2G12 were not affected by pre-coat filtration, indicating its general applicability during the manufacture of plant-derived biopharmaceutical proteins.

Direct Evidence of Reduction of Cloud Water after Spreading Diatomite Particles in Stratus Clouds in Beijing, China

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Qiang Zhang

2010-01-01

Full Text Available Artificial weather modification experiments have been intensively practiced in many years over China, and some progresses have been made, including more methodologies and advanced instruments. However, a challenge question still remains for providing convincing scientific evidence during these practices and experiments. This is a very difficult scientific issue, which is related to complicated cloud physical science, such as to accurately predict the large natural variability of cloud formation and precipitation. In this study, we report a clear evidence that the cloud water is reduced after spreading diatomite particles in stratus clouds during a field experiment in Beijing, China. The analysis shows that the diatomite particles (15–20 μm in radius are large and have strong hygroscopic property (absorbing cloud water. As a result, during the experiment, spreading large diatomite particles lead to downward motion (producing more stable atmospheric condition and reduction of cloud water. It is noted that due to lacks of instruments, this designed experiment only can provide a qualitative result (such as photo evidence, and no quantitative result can be drawn from this experiment.

SORPTION OF Cu2+ IONS ONTO DIATOMITE CONSTITUENTS

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Vasile Rusu

2009-06-01

Full Text Available Studies of the sorption capacity towards Cu2+ ions of diatomite from the Ghidirim location of RM, as well as of the extracted clay phase are presented. Separated clay fraction from diatomic material is clean enough, and especially is rich in montmorillonite. Maximum sorption capacity for studied clay fraction is achieved by rising the temperature of calcination treatment up to 200oC. At higher temperatures the lattice of montmorillonite is contracted and its sorption capacity towards Cu2+ ions decreases strongly.

Experimental Study on Purification of Low Grade Diatomite

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Xiao, Liguang; Pang, Bo

2017-04-01

This paper presented an innovation for purification of low grade diatomite(DE) by grinding, ultrasonic pretreatment, acid leaching of closed stirring and calcination. The optimum process parameters of DE purification were obtained, the characterizations of original and purified DE were determined by SEM and BET. The results showed that the specific surface area of DE increased from 12.65m2/g to 23.23m2/g, which increased by 45.54%. SEM analysis revealed that the pore structure of purified DE was dredged highly.

Preparation Parameter Analysis and Optimization of Sustainable Asphalt Binder Modified by Waste Rubber and Diatomite

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Hanbing Liu

2018-01-01

Full Text Available In this study, crumb rubber and diatomite were used to modify asphalt binder. Wet process was adopted as a preparation method, and the corresponding preparation process was determined firstly. The effects of six preparation parameters (crumb rubber concentration, diatomite concentration, shear time, shear speed, shear temperature, and storing time on properties of modified asphalt binder (penetration at 25°C, softening point, ductility, viscosity at 135°C, elastic recovery, and penetration index were investigated, and multiresponse optimization was conducted using the response surface method. The results revealed that softening points, viscosity, elastic recovery, and penetration index increase, while penetration and ductility decrease with the increase of crumb rubber concentration. Softening points, viscosity, and penetration index increase, while penetration and ductility decrease with the increase of diatomite concentration, which presents little influence on elastic recovery of binder. Shear temperature presented significant effects on penetration, softening point, viscosity, and ductility. Shear speed, shear time, and storing time have similar effects on binder properties because of their similar mechanism of action. Based on the model obtained from the response surface method, optimized preparation parameters corresponding to specific criteria can be determined, which possess favorable accuracy compared with experimental results.

[Determination of Heavy Metal Elements in Diatomite Filter Aid by Inductively Coupled Plasma Mass Spectrometry].

Science.gov (United States)

Nie, Xi-du; Fu, Liang

2015-11-01

This study established a method for determining Be, Cr, Ni, As, Cd, Sb, Sn, Tl, Hg and Pb, total 10 heavy metals in diatomite filter aid. The diatomite filter aid was digested by using the mixture acid of HNO₃ + HF+ H₃PO₄ in microwave system, 10 heavy metals elements were determined by inductively coupled plasma mass spectrometry (ICP-MS). The interferences of mass spectrometry caused by the high silicon substrate were optimized, first the equipment parameters and isotopes of test metals were selected to eliminate these interferences, the methane was selected as reactant gas, and the mass spectral interferences were eliminated by dynamic reaction cell (DRC). Li, Sc, Y, In and Bi were selected as the internal standard elements to correct the interferences caused by matrix and the drift of sensitivity. The results show that the detection limits for analyte is in the range of 3.29-15.68 ng · L⁻¹, relative standard deviations (RSD) is less than 4.62%, and the recovery is in the range of 90.71%-107.22%. The current method has some advantages such as, high sensitivity, accurate, and precision, which can be used in diatomite filter aid quality control and safety estimations.

High-temperature adsorption layers based on fluoridated polyimide and diatomite carrier

Science.gov (United States)

Yakovleva, E. Yu.; Shundrina, I. K.; Gerasimov, E. Yu.

2017-09-01

A way of preparing separation layers by the pyrolysis of fluorinated polyimide obtained from 2,4,6-trimethyl- m-phenylenediamine (2,4,6-TM mPDA) and 2,2-bis(3',4'-dicarboxyphenyl)hexafluoropropane (6FDA) applied onto a diatomite carrier is described. Thermogravimetry, elemental analysis, low-temperature nitrogen adsorption, high-resolution electron microscopy, and gas chromatography are used to study changes in the texture and chromatographic characteristics of these layers. It is found that changes in the structure and the effectivity of separation characteristic of the layers depend on the temperature of pyrolysis, which ranges from 250 to 1100°C. It is established that a layer of separation is formed at 250-350°C, and the order of elution of hydrocarbons is similar to their chromatographic behavior on such stationary phases as OV-101. Layers of amorphous carbon formed on the surfaces of individual particles on a diatomite surface at 500-700°C. These layers ensure highly stable and selective separation of permanent gases and hydrocarbons when they are present together.

Detection analysis of surface hydroxyl active sites and simulation calculation of the surface dissociation constants of aqueous diatomite suspensions

Science.gov (United States)

Ma, Shu-Cui; Wang, Zhi-Gang; Zhang, Ji-Lin; Sun, De-Hui; Liu, Gui-Xia

2015-02-01

The surface properties of the diatomite were investigated using nitrogen adsorption/deadsorption isotherms, TG-DSC, FTIR, and XPS, and surface protonation-deprotonation behavior was determined by continuous acid-base potentiometric titration technique. The diatomite sample with porous honeycomb structure has a BET specific surface area of 10.21 m2/g and large numbers of surface hydroxyl functional groups (i.e. tbnd Si-OH, tbnd Fe-OH, and tbnd Al-OH). These surface hydroxyls can be protonated or deprotonated depending on the pH of the suspension. The experimental potentiometric data in two different ionic strength solutions (0.1 and 0.05 mol/L NaCl) were fitted using ProtoFit GUI V2.1 program by applying diffuse double layer model (DLM) with three amphoteric sites and minimizing the sum of squares between a dataset derivative function and a model derivative function. The optimized surface parameters (i.e. surface dissociation constants (log K1, log K2) and surface site concentrations (log C)) of the sample were obtained. Based on the optimized surface parameters, the surface species distribution was calculated using Program-free PHREEQC 3.1.2. Thus, this work reveals considerable new information about surface protonation-deprotonation processes and surface adsorptive behaviors of the diatomite, which helps us to effectively use the cheap and cheerful diatomite clay adsorbent.

Response surface modeling of acid activation of raw diatomite using in sunflower oil bleaching by: Box-Behnken experimental design.

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Larouci, M; Safa, M; Meddah, B; Aoues, A; Sonnet, P

2015-03-01

The optimum conditions for acid activation of diatomite for maximizing bleaching efficiency of the diatomite in sun flower oil treatment were studied. Box-Behnken experimental design combining with response surface modeling (RSM) and quadratic programming (QP) was employed to obtain the optimum conditions of three independent variables (acid concentration, activation time and solid to liquid) for acid activation of diatomite. The significance of independent variables and their interactions were tested by means of the analysis of variance (ANOVA) with 95 % confidence limits (α = 0.05). The optimum values of the selected variables were obtained by solving the quadratic regression model, as well as by analyzing the response surface contour plots. The experimental conditions at this global point were determined to be acid concentration = 8.963 N, activation time = 11.9878 h, and solid to liquid ratio = 221.2113 g/l, the corresponding bleaching efficiency was found to be about 99 %.

Hydrous iron oxide modified diatomite as an active filtration medium for phosphate capture.

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Wang, Zhe; Lin, Yan; Wu, Deyi; Kong, Hainan

2016-02-01

A simple method to functionalize diatomite with hydrous iron oxide was attempted and its performance as a new active filtration material to remove and recover phosphate from water was investigated under varying solution conditions. The Langmuir phosphate adsorption capacity increased from 0.6 mgP/g for raw diatomite to 4.89, 14.71, 25.02 mgP/g for hydrous iron oxide modified diatomite (HIOMD), depending on the amount of iron loaded. Loading of hydrous iron oxide caused the increase in true and bulk density and a decline in filtration rate, but to a lesser extent. It was shown that the HIOMD product with suitable iron content could retain a good filtration performance with a greatly increased adsorption capacity for phosphate. The phosphate adsorption increased by decreasing pH and by increasing ionic strength at high pH levels. The adsorption process was interpreted by ligand exchange. Coexisting oxyanions of sulfate, nitrate, citrate, carbonate, silicate and humic acid showed different effects on phosphate fixation but it was presumed that their influence at their concentrations and pH levels commonly encountered in effluent or natural waters was limited, i.e., HIOMD had a reasonably good selectivity. Results in repeated adsorption, desorption and regeneration experiment showed that the adsorbed phosphate could be recovered and the material could be reused after regeneration. The column test showed that HIOMD could be potentially utilized as an adsorption filtration medium for phosphate removal and recovery from water. Copyright © 2015 Elsevier Ltd. All rights reserved.

Characterization of the diatomite binding domain in the ribosomal protein L2 from E. coli and functions as an affinity tag.

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Li, Junhua; Zhang, Yang; Yang, Yanjun

2013-03-01

The ribosomal protein L2, a constituent protein of the 50S large ribosomal subunit, can be used as Si-tag using silica particles for the immobilization and purification of recombinant proteins (Ikeda et al. (Protein Expr Purif 71:91-95, 2010); Taniguchi et al. (Biotechnol Bioeng 96:1023-1029, 2007)). We applied a diatomite powder, a sedimentary rock mainly composed with diatoms silica, as an affinity solid phase and small ubiquitin-like modifier (SUMO) technology to release a target protein from the solid phase. The L2 (203-273) was the sufficient region for the adsorption of ribosomal protein L2 on diatomite. We comparatively analyzed the different adsorption properties of the two deleted proteins of L2 (L2 (1-60, 203-273) and L2 (203-273)) on diatomite. The time required to reach adsorption equilibrium of L2 (203-273) fusion protein on diatomite was shorter than that of L2 (1-60, 203-273) fusion protein. The maximum adsorption capacity of L2 (203-273) fusion protein was larger than that of L2 (1-60, 203-273) fusion protein. In order to study whether the L2 (203-273) can function as an affinity purification tag, SUMO was introduced as one specific protease cleavage site between the target protein and the purification tags. The L2 (203-273) and SUMO fusion protein purification method was tested using enhanced green fluorescent protein as a model protein; the result shows that the purification performance of this affinity purification method was good. The strong adsorption characteristic of L2 (203-273) on diatomite also provides a potential protein fusion tag for the immobilization of enzyme.

Synthesis, characterization and activity of an immobilized photocatalyst: natural porous diatomite supported titania nanoparticles.

Science.gov (United States)

Wang, Bin; de Godoi, Fernanda Condi; Sun, Zhiming; Zeng, Qingcong; Zheng, Shuilin; Frost, Ray L

2015-01-15

Diatomite, a porous non-metal mineral, was used as support to prepare TiO2/diatomite composites by a modified sol-gel method. The as-prepared composites were calcined at temperatures ranging from 450 to 950 °C. The characterization tests included X-ray powder diffraction (XRD), scanning electron microscopy (SEM) with an energy-dispersive X-ray spectrometer (EDS), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption/desorption measurements. The XRD analysis indicated that the binary mixtures of anatase and rutile exist in the composites. The morphology analysis confirmed the TiO2 particles were uniformly immobilized on the surface of diatom with a strong interfacial anchoring strength, which leads to few drain of photocatalytic components during practical applications. In further XPS studies of hybrid catalyst, we found the evidence of the presence of Ti-O-Si bond and increased percentage of surface hydroxyl. In addition, the adsorption capacity and photocatalytic activity of synthesized TiO2/diatomite composites were evaluated by studying the degradation kinetics of aqueous Rhodamine B under UV-light irradiation. The photocatalytic degradation was found to follow pseudo-first order kinetics according to the Langmuir-Hinshelwood model. The preferable removal efficiency was observed in composites by 750 °C calcination, which is attributed to a relatively appropriate anatase/rutile mixing ratio of 90/10. Copyright © 2014 Elsevier Inc. All rights reserved.

Facile Preparation of Nano-Bi₂MoO₆/Diatomite Composite for Enhancing Photocatalytic Performance under Visible Light Irradiation.

Science.gov (United States)

Cai, Lu; Gong, Jiuyan; Liu, Jianshe; Zhang, Hailong; Song, Wendong; Ji, Lili

2018-02-09

In this work, a new nano-Bi₂MoO₆/diatomite composite photocatalyst was successfully synthesized by a facile solvothermal method. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and UV-vis diffuse reflection spectroscopy (DRS) were employed to investigate the morphology, crystal structure, and optical properties. It was shown that nanometer-scaled Bi₂MoO₆ crystals were well-deposited on the surface of Bi₂MoO₆/diatomite. The photocatalytic activity of the obtained samples was evaluated by the degradation of rhodamine B (RhB) under the visible light (λ > 420 nm) irradiation. Moreover, trapping experiments were performed to investigate the possible photocatalytic reaction mechanism. The results showed that the nano-Bi₂MoO₆/diatomite composite with the mass ratio of Bi₂MoO₆ to diatomaceous earth of 70% exhibited the highest activity, and the RhB degradation efficiency reached 97.6% within 60 min. The main active species were revealed to be h⁺ and•O 2- . As a photocatalytic reactor, its recycling performance showed a good stability and reusability. This new composite photocatalyst material holds great promise in the engineering field for the environmental remediation.

Regioselective oxyalkylation of vinylarenes catalyzed by diatomite-supported manganese oxide nanoparticles.

Science.gov (United States)

Sun, Huayin; Zhang, Yonghui; Guo, Fengfeng; Zha, Zhenggen; Wang, Zhiyong

2012-04-06

A regioselective oxyalkylation reaction of vinylarenes with cyclic ethers was developed under the catalysis of a new heterogeneous catalyst, the diatomite-supported Mn(3)O(4) nanoparticles (SMONP-1). The use of this heterogeneous catalyst provided a novel approach for the synthesis of α-carbonyled β-alkylated aryl derivatives via a sp(3) C-H bond functionalization under mild aerobic conditions.

Effects of Diatomite and SBS on Freeze-Thaw Resistance of Crumb Rubber Modified Asphalt Mixture

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Haibin Wei

2017-01-01

Full Text Available Asphalt mixture is susceptible to moisture damage under the effect of freeze-thaw (F-T cycles. In this paper, crumb rubber (CR was used to modify stone mastic asphalt (SMA and the effects of diatomite and styrene butadiene styrene (SBS on antifreezing performances of crumb rubber modified SMA (CRSMA were investigated. Regression analysis and modified grey model (MGM were used to construct the prediction models for properties of modified mixtures. CRSMA, CR and diatomite modified SMA (CRDSMA, and CR and SBS modified SMA (CRSSMA were prepared in laboratory, respectively. Process of F-T cycles was designed. Air void, indirect tensile strength (ITS, and indirect tensile stiffness modulus (ITSM were measured to evaluate the antifreezing performances of CRSMA, CRDSMA, and CRSSMA. Results indicate that air voids increase with the increasing of F-T cycles. ITS and ITSM all decrease with the increasing of F-T cycles. The addition of diatomite and SBS can reduce the air void and improve the ITS and ITSM of CRSMA. CRSSMA presents the lowest air void, highest tensile strength, and largest stiffness modulus, which reveals that CRSSMA has the best F-T resistance among three different kinds of mixtures. Moreover, MGM (1, 2 models present more favorable accuracy in prediction of air void and ITS compared with regression ones.

Removal of hexavalent chromium [Cr(VI)] from aqueous solutions by the diatomite-supported/unsupported magnetite nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Yuan Peng, E-mail: yuanpeng@gig.ac.cn [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Liu Dong; Fan Mingde; Yang Dan [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Zhu Runliang; Ge Fei [College of Chemical Engineering, Xiangtan University, Xiangtan 411105 (China); Zhu Jianxi; He Hongping [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

2010-01-15

Diatomite-supported/unsupported magnetite nanoparticles were prepared by co-precipitation and hydrosol methods, and characterized by X-ray diffraction, nitrogen adsorption, elemental analysis, differential scanning calorimetry, transmission electron microscopy and X-ray photoelectron spectroscopy. The average sizes of the unsupported and supported magnetite nanoparticles are around 25 and 15 nm, respectively. The supported magnetite nanoparticles exist on the surface or inside the pores of diatom shells, with better dispersing and less coaggregation than the unsupported ones. The uptake of hexavalent chromium [Cr(VI)] on the synthesized magnetite nanoparticles was mainly governed by a physico-chemical process, which included an electrostatic attraction followed by a redox process in which Cr(VI) was reduced into trivalent chromium [Cr(III)]. The adsorption of Cr(VI) was highly pH-dependent and the kinetics of the adsorption followed a pseudo-second-order model. The adsorption data of diatomite-supported/unsupported magnetite fit well with the Langmuir isotherm equation. The supported magnetite showed a better adsorption capacity per unit mass of magnetite than unsupported magnetite, and was more thermally stable than their unsupported counterparts. These results indicate that the diatomite-supported/unsupported magnetite nanoparticles are readily prepared, enabling promising applications for the removal of Cr(VI) from aqueous solution.

Removal of hexavalent chromium [Cr(VI)] from aqueous solutions by the diatomite-supported/unsupported magnetite nanoparticles.

Science.gov (United States)

Yuan, Peng; Liu, Dong; Fan, Mingde; Yang, Dan; Zhu, Runliang; Ge, Fei; Zhu, JianXi; He, Hongping

2010-01-15

Diatomite-supported/unsupported magnetite nanoparticles were prepared by co-precipitation and hydrosol methods, and characterized by X-ray diffraction, nitrogen adsorption, elemental analysis, differential scanning calorimetry, transmission electron microscopy and X-ray photoelectron spectroscopy. The average sizes of the unsupported and supported magnetite nanoparticles are around 25 and 15 nm, respectively. The supported magnetite nanoparticles exist on the surface or inside the pores of diatom shells, with better dispersing and less coaggregation than the unsupported ones. The uptake of hexavalent chromium [Cr(VI)] on the synthesized magnetite nanoparticles was mainly governed by a physico-chemical process, which included an electrostatic attraction followed by a redox process in which Cr(VI) was reduced into trivalent chromium [Cr(III)]. The adsorption of Cr(VI) was highly pH-dependent and the kinetics of the adsorption followed a pseudo-second-order model. The adsorption data of diatomite-supported/unsupported magnetite fit well with the Langmuir isotherm equation. The supported magnetite showed a better adsorption capacity per unit mass of magnetite than unsupported magnetite, and was more thermally stable than their unsupported counterparts. These results indicate that the diatomite-supported/unsupported magnetite nanoparticles are readily prepared, enabling promising applications for the removal of Cr(VI) from aqueous solution.

INVESTIGATION OF THERMO‐PHYSICAL PROPERTIES OF DIATOMITE/WATER NANOFLUID

OpenAIRE

ÖZTAŞ, Sinan; KARAKAYA, Uğur; İSKENDER, Ümit

2016-01-01

In this study, the thermo physical properties of the nanofluid obtained with prepared solution by adding as basic fluid 1.3% the diatomite nanoparticles into water were determined. Many researchers are working to improve the performance of heat transfer fluids. One of the methods used, if we want to increase the overall thermal conductivity of the fluid, the high thermal conductive materials such as metal oxides, metals and carbon should be added to heat transfer fluids as nano‐sized particle...

Study on preparation and thermal property of binary fatty acid and the binary fatty acids/diatomite composite phase change materials

International Nuclear Information System (INIS)

Li, Min; Kao, Hongtao; Wu, Zhishen; Tan, Jinmiao

2011-01-01

This study prepared a series of binary phase change materials by mixing decanoic acid, dodecanoic acid, hexadecanoic acid and octadecanoic acid each other. The phase-transition temperature of binary fatty acid and its corresponding mixing proportion are calculated with phase diagram thermodynamic method. The results are verified by the experimental result of the heat absorption curve and the Differential Scanning Calorimetry (DSC) analysis curve. The results show that the calculation method of phase diagram thermodynamic calculation can be taken as a basis for mixing proportion of binary fatty acid phase change materials. In addition, the decanoic-dodecanoic acid/diatomite composite phase change material (PCM) are prepared and its microstructure, thermal property and thermal reliability are characterized. The result shows that the decanoic-dodecanoic acid is uniformly adsorbed into diatomite and the form-stable PCM are formed. The phase-transition temperature and the latent heat of the decanoic-dodecanoic acid/diatomite composite PCMs is 16.74 o C and 66.8114 J/g, respectively.

Preliminary geological investigation of the Bir Hayzan diatomite deposit, Kingdom of Saudi Arabia, with a section on selected physical properties and implications for future geophysical exploration

Science.gov (United States)

Whitney, J.W.; Gettings, M.E.

1982-01-01

A 2.2-m-thick lake bed composed entirely of diatomite was found in the southwestern arm of the Nafud sand sea, about 67 km east of Tayma in northwestern Saudi Arabia. Its stratigraphic position above eolian sand and below a large barchanoid dune indicates deposition during an exceptional period of pluvial climate in an otherwise arid sand desert. Radiocarbon-dated carbonate lake beds found in similar stratigraphic settings in other parts of the Nafud suggest that the diatomite was deposited in the late Pleistocene epoch sometime between 32,000 and 20,000 years ago. Diatomite of the same pluvial episode has also been found in the Afar region of Ethiopia. Four samples of the diatomite were analyzed for major chemical components and 32 minor and trace elements. Two of the samples appeared to be representative of the lake bed. These samples contained about 85 percent SiO2, 2.34 percent Fe2O3, 1 4 percent Al2O3, and 8.27 percent ignition loss, with only traces of CaO, P2O5, MgO, Na2O, and TiO2. The high content of silica and low contents of alumina, iron oxide, lime, and other constituents indicate low contamination. Analyses of samples from the two atypical units indicate a small amount of contamination, probably clay or mica, in the basal unit and addition of iron oxide and carbonate by ground water in an isolated green-colored unit. Chemically the Bi'r Hayzan diatomite compares favorably with commercial deposits from other parts of the world. Low bulk densities of 0.64 g/cm3 (30-40 lbs/ft3) and an average porosity of 63 percent for five samples also suggest the deposit is of industrial grade. Further studies are recommended to determine: (1) the size and extent of the deposit and (2) the suitability of the diatomite for commercial applications. As means to these ends, electrical-resistivity surveys following winter rains are suggested to determine both the extent and thickness of the lake bed beneath the overlying sand dunes. A complete species identification of the

Adsorption of p-Nitrophenol (PNP) on new adsorbents prepared from diatomite and charcoal

International Nuclear Information System (INIS)

Hamdi, B.; Khelifa, N.; Chernai-Hamdi, S.; Hadjari, H.

2009-01-01

Increasing attention has been paid to mesoporous materials with high surface area and narrow pore size distribution because of their diverse applications (e. g., adsorbents, catalysts, and host materials). Inorganic composite materials (ICM) prepared by a mixture of natural diatomite (macroporous materials) and charcoal (microporous material) in particular operative conditions. (Author)

Thermal conductivity of wood ash diatomite composites using the transient hot strip method

International Nuclear Information System (INIS)

Muia, L.M.; Gaitho, F.

2003-08-01

The transient Hot Strip method (THS) was used to determine the thermal conductivities of pure Wood Ash (WA), two kinds of diatomite i.e., DB and DF, and their composites. The effects of grain size and temperature on the thermal conductivities of the three systems and their composites were also determined. The lowest thermal conductivities of 0.02x10 -2 Wm -1 K -1 for wood ash and ∼ 3x10 -2 Wm -1 K -1 for the diatomites are found in the particle size range 60 -80μm. The thermal conductivities of the various composites range between 1.3x10 -3 and 6.8x10 -2 Wm -1 K -1 . These values are a factor of 10 lower than those of the pure materials. The thermal conductivity of the three composites is independent of temperature in the range 26-350 deg. C, in contrast to those pure materials which increase with temperature. Generally, the thermal conductivites of the pure materials which increase as their porosity or moisture contents are increased. (author)

Egyptian diatomite as high fluid loss squeeze slurry in sealing fractures and

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A.M. Al-Sabagh

2016-09-01

Full Text Available Lost circulation is the most costly mud related drilling problem, and induced fracture. Water slurry of diatomite is used as the high fluid loss squeeze slurry in the treatment of lost circulation and in decreasing fluid loss. Egypt has diatomite deposits, especially in El-Fayuom Depression. Fourteen samples were collected from Qasr El-Sagha at the northern shore of Birket Qarun. Samples were examined to identify the diatom species then subjected to X-ray fluorescence, XRD and grain size distribution tests. A total of 38 species related to 13 diatom genera were identified. Cocconeis, Epithemia and Rhopalodia were the predominant genera. The diatomaceous earth which acts as a filter aid material was tested with different additives; bentonite, lime, finely divided paper, polymer, barite and different concentrations with different types of lost circulation materials (LCM to form a high fluid loss squeeze slurry. As a result the required time for collecting the filtrate was decreased to be in the range of 50 s to 1 min and 49 s comparing with the international standard which recommended the filtrate should be collected maximum within 2–3 min.

The effect of zeolite and diatomite on the corrosion of reinforcement steel in 1 M HCl solution

Directory of Open Access Journals (Sweden)

Husnu Gerengi

2015-01-01

Full Text Available The greatest disadvantage of reinforced concrete structures is the corrosion occurring in the reinforcement which, over time, causes a reduction in the reinforcement-concrete adherence and eventual sectional loss. The purpose of this study was to reveal the corrosion mechanism of ribbed reinforcement inside additive-free (reference, 20% zeolite-doped and 20% diatomite-doped concrete samples after exposure to 1 M HCl over 240 days. Electrochemical impedance spectroscopy (EIS measurements were made every 10 days. Consequently, it was determined that the 20% zeolite-doped concrete samples had higher concrete and reinforcement resistance compared to the 20% diatomite-doped and the reference concrete, i.e. they exhibited less corrosion.

Effect of preparation conditions on the characteristics and photocatalytic activity of TiO2/purified diatomite composite photocatalysts

International Nuclear Information System (INIS)

Sun, Zhiming; Hu, Zhibo; Yan, Yang; Zheng, Shuilin

2014-01-01

Highlights: • TiO 2 /purified diatomite composites were synthesized under different conditions. • The optimum preparation conditions of composites were obtained. • The obtained photocatalyst showed good photocatalytic activity. • The dispersity and grain size of loaded TiO 2 NPs are the critical factors. - Abstract: TiO 2 /purified diatomite composite materials were prepared through a modified hydrolysis-deposition method under low temperature using titanium tetrachloride as precursor combined with a calcination crystallization process. The microstructure and crystalline phases of the obtained composites prepared under different preparation conditions were characterized by high resolution scanning electron microscope (SEM) and X-ray diffraction (XRD), respectively. The photocatalytic performance of TiO 2 /purified diatomite composites was evaluated by Rhodamine B as the target pollutant under UV irradiation, and the optimum preparation conditions of composites were obtained. The TiO 2 crystal form in composites prepared under optimum conditions was anatase, the grain size of which was 34.12 nm. The relationships between structure and property of composite materials were analyzed and discussed. It is indicated that the TiO 2 nanoparticles uniformly dispersed on the surface of diatoms, and the photocatalytic performance of the composite materials was mainly determined by the dispersity and grain size of loaded TiO 2 nanoparticles

The sorption of lead, cadmium, copper and zinc ions from aqueous solutions on a raw diatomite from Algeria.

Science.gov (United States)

Safa, Messaouda; Larouci, Mohammed; Meddah, Boumediene; Valemens, Pierre

2012-01-01

The adsorption of Cu(2+), Zn(2+), Cd(2+) and Pb(2+) ions from aqueous solution by Algerian raw diatomite was studied. The influences of different sorption parameters such as contact pH solution, contact time and initial metal ions concentration were studied to optimize the reaction conditions. The metals ions adsorption was strictly pH dependent. The maximum adsorption capacities towards Cu(2+), Zn(2+), Cd(2+) and Pb(2+) were 0.319, 0.311, 0.18 and 0.096 mmol g(-1), respectively. The kinetic data were modelled using the pseudo-first-order and pseudo-second-order kinetic equations. Among the kinetic models studied, the pseudo-second-order equation was the best applicable model to describe the sorption process. Equilibrium isotherm data were analysed using the Langmuir and the Freundlich isotherms; the results showed that the adsorption equilibrium was well described by both model isotherms. The negative value of free energy change ΔG indicates feasible and spontaneous adsorption of four metal ions on raw diatomite. According to these results, the high exchange capacities of different metal ions at high and low concentration levels, and given the low cost of the investigated adsorbent in this work, Algerian diatomite was considered to be an excellent adsorbent.

The natural diatomite from caldiran-van (Turkey): electroanalytical application to antimigraine compound naratriptan at modified carbon paste electrode.

Science.gov (United States)

Calışkan, Necla; Sögüt, Eda; Saka, Cafer; Yardım, Yavuz; Sentürk, Zuhre

2010-09-01

This paper is the first report describing the characterization of local diatomite of Caldiran-Van region (Eastern Anatolia, Turkey). Special attention was paid to the ability of its electroanalytical performance at modified electrodes and to the potential application of diatomite-modified electrode. For this purpose, the determination of Naratriptan which is a novel oral triptan (5-hydroxytryptamine receptor agonist) in migraine treatment, by means of a carbon paste electrode modified with 10% (w/w) of diatomite was studied using cyclic and square-wave voltammetry. The experimental conditions that affect the electrode reaction process were studied in terms of pH of the supporting electrolyte, scan rate, accumulation variables, modifier composition and square-wave parameters. Using square-wave stripping mode, the drug yielded a well-defined voltammetric response in Britton-Robinson buffer, pH 4.0 at 0.84 V (vs. Ag/AgCl) (a pre-concentration step being carried out with an open circuit at 120 s). The process could be used to determine Naratriptan concentrations in the range 5x10(-7)-9x10(-7) M, with a detection limit of 1.25x10(-7) M (46.5 mug L(-1)). The applicability of the method to spiked human urine samples was illustrated.

Macroscopic and microscopic investigation of Ni(II) sequestration on diatomite by batch, XPS, and EXAFS techniques.

Science.gov (United States)

Sheng, Guodong; Yang, Shitong; Sheng, Jiang; Hu, Jun; Tan, Xiaoli; Wang, Xiangke

2011-09-15

Sequestration of Ni(II) on diatomite as a function of time, pH, and temperature was investigated by batch, XPS, and EXAFS techniques. The ionic strength-dependent sorption at pH < 7.0 was consistent with outer-sphere surface complexation, while the ionic strength-independent sorption at pH = 7.0-8.6 was indicative of inner-sphere surface complexation. EXAFS results indicated that the adsorbed Ni(II) consisted of ∼6 O at R(Ni-O) ≈ 2.05 Å. EXAFS analysis from the second shell suggested that three phenomena occurred at the diatomite/water interface: (1) outer-sphere and/or inner-sphere complexation; (2) dissolution of Si which is the rate limiting step during Ni uptake; and (3) extensive growth of surface (co)precipitates. Under acidic conditions, outer-sphere complexation is the main mechanism controlling Ni uptake, which is in good agreement with the macroscopic results. At contact time of 1 h or 1 day or pH = 7.0-8.0, surface coprecipitates occur concurrently with inner-sphere complexes on diatomite surface, whereas at contact time of 1 month or pH = 10.0, surface (co)precipitates dominate Ni uptake. Furthermore, surface loading increases with temperature increasing, and surface coprecipitates become the dominant mechanism at elevated temperature. The results are important to understand Ni interaction with minerals at the solid-water interface, which is helpful to evaluate the mobility of Ni(II) in the natural environment.

Performance of diatomite/iron oxide modified nonwoven membrane used in membrane bioreactor process for wastewater reclamation.

Science.gov (United States)

He, Yueling; Zhang, Wenqi; Rao, Pinhua; Jin, Peng

2014-01-01

This study describes an approach for surface modification of a nonwoven membrane by diatomite/iron oxide to examine its filterability. Analysis results showed that nonwoven hydrophilicity is enhanced. Static contact angle decreases dramatically from 122.66° to 39.33°. Scanning electron micrograph images show that diatomite/iron oxide is attached on nonwoven fiber. X-ray diffraction analysis further proves that the compound is mostly magnetite. Fourier transformed infrared spectra results reveal that two new absorption peaks might be attributed to Si-O and Fe-O, respectively. Modified and original membranes were used in double nonwoven membrane bioreactors (MBRs) for synthetic wastewater treatment. High critical flux, long filtration time, slow trans-membrane pressure rise and stable sludge volume index confirmed the advantages of modified nonwoven. Comparing with original nonwoven, similar effluent qualities are achieved, meeting the requirements for wastewater reclamation.

Gravity filtration performances of the bio-diatomite dynamic membrane reactor for slightly polluted surface water purification.

Science.gov (United States)

Chu, Huaqiang; Dong, Bingzhi; Zhang, Yalei; Zhou, Xuefei

2012-01-01

A bio-diatomite dynamic membrane (BDDM) reactor for surface water treatment under a water head of 30, 40, 50, 60 and 70 cm, respectively, was investigated, which was very effective for pollutants removal. The water head exerted strong influences on filtration flux of BDDM during the precoating process, as well as on the formation of BDDM and turbidity variations. A high filtration flux (approximately 200-300 L/m2 h) could be achieved in the long filtration times of BDDM with a stable effluent turbidity of approximately 0.11-0.25 NTU. The BDDM could remove particles larger than 25 μm completely. The adopted sintered diatomite mainly consisted of macro pores, which were beneficial for improving the filtration flux of BDDM. During the backwash stage, the BDDM could be removed completely by the air backwash.

Preparation of diatomite/Ca(OH){sub 2} sorbents and modelling their sulphation reaction Istanbul Technical University, Istanbul (Turkey). Chemical and Metallurgical Engineering Faculty

Energy Technology Data Exchange (ETDEWEB)

Nilgun Karatepe; Nilufer Erdoan; Aysegul Ersoy-Mericboyu; Sadriye Kucukbayrak

2004-09-01

Mixtures of Ca(OH){sub 2} and diatomite were hydrated at different conditions to produce reactive SO{sub 2} sorbents. Two different hydration techniques were used; namely, atmospheric and pressure hydration. The effect of the hydration temperature, time and diatomite/Ca(OH){sub 2} weight ratio on the physical properties of the activated sorbents were investigated. In atmospheric hydration, it was found that increasing the temperature and hydration time caused an increase in the total surface area of the sorbents. However, surface area values of the sorbents prepared from mixtures which have different diatomite/Ca(OH){sub 2} weight ratio were generally not changed significantly. In pressure hydration, the surface area of the activated sorbents was positively affected from the hydration temperature and pressure. Finally, Ca(OH){sub 2} and two diatomite/Ca(OH){sub 2} sorbents were sulphated at constant temperature (338 K) using a synthetic gaseous mixture consisting of 5% O{sub 2}, 10% CO{sub 2}, 5000 ppm SO{sub 2} and the balance of nitrogen with a 55% relative humidity. The sulphation reaction of these sorbents were investigated and modelled. The unreacted shrinking core model was chosen to describe this non-catalytic solid/gas (hydrated sorbent/SO{sub 2}) reaction mechanism. The experimental results were found to be correlated successfully by this model.

The hydroxyl species and acid sites on diatomite surface: a combined IR and Raman study

Science.gov (United States)

Yuan, P.; Wu, D. Q.; He, H. P.; Lin, Z. Y.

2004-04-01

Diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), Raman spectroscopy of adsorbed pyridine molecules (Py-Raman) and in situ Py-IR have been used to investigate the hydroxyl species and acid sites on diatomite surfaces. The Lewis (L) and Brønsted (B) acid sites, and various hydroxyl species, including isolated hydroxyl groups, H-bonded hydroxyl groups and physically adsorbed water, are identified. The L acid sites in diatomite samples are resulted from the clay impurities, and the B acid sites are resulted from some moderate strength H-bonded hydroxyl groups. At room temperature, both of the isolated and H-bonded silanols associate with the physically adsorbed water by hydrogen bond. After calcination treatment, physically adsorbed water will be desorbed from the silanols, and the silanols will condense with the increase of temperature. Generally, the H-bonded silanols condense more easily than the isolated ones. The properties of surface hydroxyl species of diatomaceous silica are more similar to precipitated silica rather than fumed silica.

Adsorption of Streptococcus faecalis on diatomite carriers for use in biotransformations.

Science.gov (United States)

Anderson, W A; Bay, P; Legge, R L; Moo-Young, M

1990-01-01

Adsorption of cells on particulate carriers is potentially one of the most cost-effective immobilization techniques available. Diatomite carriers, such as Celite, have desirable physical properties, are inexpensive, and are suitable for both mycelial and bacterial systems. This work investigated the use of diatomite carriers as a biocatalyst support in a packed-bed reactor where L-tyrosine was enzymatically decarboxylated using adsorbed, non-growing cells of Streptococcus faecalis. Composition of microbial adsorption on different Celite types, with mean pore sizes ranging from 0.55 to 22 microns, showed there was no significant difference in biomass loading capacity under the conditions used. Using Celite 560, biomass loadings in a packed-bed reactor varied from 10 to 30 g dm-3 of reactor volume, which compares favourably with other adsorption methods. When used to decarboxylate L-tyrosine, the reactor was found to have a half-life of 15-20 h. A combination of enzyme activity loss and slow leakage of biomass from the packed-bed reactor was responsible for the decline in conversion. Treatment of the S. faecalis cells with glutaraldehyde significantly reduced the enzyme activity loss and extended the reactor half-life to 65 h, but had little effect on the rate of cell leakage from the reactor. Further work on reduction of cell leakage rate seems necessary for evaluation of the system's practicality.

Facile Preparation of Nano-Bi2MoO6/Diatomite Composite for Enhancing Photocatalytic Performance under Visible Light Irradiation

Directory of Open Access Journals (Sweden)

Lu Cai

2018-02-01

Full Text Available In this work, a new nano-Bi2MoO6/diatomite composite photocatalyst was successfully synthesized by a facile solvothermal method. Scanning electron microscopy (SEM, Fourier transform infrared spectroscopy (FTIR, X-ray diffraction (XRD, and UV-vis diffuse reflection spectroscopy (DRS were employed to investigate the morphology, crystal structure, and optical properties. It was shown that nanometer-scaled Bi2MoO6 crystals were well-deposited on the surface of Bi2MoO6/diatomite. The photocatalytic activity of the obtained samples was evaluated by the degradation of rhodamine B (RhB under the visible light (λ > 420 nm irradiation. Moreover, trapping experiments were performed to investigate the possible photocatalytic reaction mechanism. The results showed that the nano-Bi2MoO6/diatomite composite with the mass ratio of Bi2MoO6 to diatomaceous earth of 70% exhibited the highest activity, and the RhB degradation efficiency reached 97.6% within 60 min. The main active species were revealed to be h+ and•O2−. As a photocatalytic reactor, its recycling performance showed a good stability and reusability. This new composite photocatalyst material holds great promise in the engineering field for the environmental remediation.

Facile Preparation of Nano-Bi2MoO6/Diatomite Composite for Enhancing Photocatalytic Performance under Visible Light Irradiation

Science.gov (United States)

Gong, Jiuyan; Liu, Jianshe; Song, Wendong; Ji, Lili

2018-01-01

In this work, a new nano-Bi2MoO6/diatomite composite photocatalyst was successfully synthesized by a facile solvothermal method. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and UV-vis diffuse reflection spectroscopy (DRS) were employed to investigate the morphology, crystal structure, and optical properties. It was shown that nanometer-scaled Bi2MoO6 crystals were well-deposited on the surface of Bi2MoO6/diatomite. The photocatalytic activity of the obtained samples was evaluated by the degradation of rhodamine B (RhB) under the visible light (λ > 420 nm) irradiation. Moreover, trapping experiments were performed to investigate the possible photocatalytic reaction mechanism. The results showed that the nano-Bi2MoO6/diatomite composite with the mass ratio of Bi2MoO6 to diatomaceous earth of 70% exhibited the highest activity, and the RhB degradation efficiency reached 97.6% within 60 min. The main active species were revealed to be h+ and•O2−. As a photocatalytic reactor, its recycling performance showed a good stability and reusability. This new composite photocatalyst material holds great promise in the engineering field for the environmental remediation. PMID:29425138

PHYSICOCHEMICAL PROPERTIES AND USES OF KARACAÖREN AREA (NEVŞEHİR DIATOMITE

Directory of Open Access Journals (Sweden)

Ayşegül YILDIZ

2016-12-01

Full Text Available In this study, physicochemical properties and the area of use of diatomites that occur in association with Central Anatolian volcanism in the Karacaören region (Ürgüp country, Nevşehir are investigated. In the investigated area two stratigraphic sections were measured, one is in Quaternary lake units (K1 and another section is in the lacustrine sediments of Bayramhacılı Member within Ürgüp Formation of late Miocene-Pliocene age (K2. In order to specify physicochemical properties and the area of use of diato- mites, various analyses were carried out at the Laboratories of General Directorate of Mineral Research and Exploration including loss on ignition (at 1050 °C, XRD, amount of acid and water-insoluble matter, thermal conductivity (in the range of 101; 150 °C and ± 10 °C, XRF, pH, total porosity, specific gravity, specific surface area, pore volume, pore size, whiteness, particle size and SEM analysis. The evaluation of the analyses results showed that the studied diatomites have a commercial value and can be used directly in percolator, as filler and structuring agents and in silicate manufacturing. In addition, once processed, they can also be used as mild abrasive and cleaner in production of isolation material.

Microfluidic Diatomite Analytical Devices for Illicit Drug Sensing with ppb-Level Sensitivity.

Science.gov (United States)

Kong, Xianming; Chong, Xinyuan; Squire, Kenny; Wang, Alan X

2018-04-15

The escalating research interests in porous media microfluidics, such as microfluidic paper-based analytical devices, have fostered a new spectrum of biomedical devices for point-of-care (POC) diagnosis and biosensing. In this paper, we report microfluidic diatomite analytical devices (μDADs), which consist of highly porous photonic crystal biosilica channels, as an innovative lab-on-a-chip platform to detect illicit drugs. The μDADs in this work are fabricated by spin-coating and tape-stripping diatomaceous earth on regular glass slides with cross section of 400×30µm 2 . As the most unique feature, our μDADs can simultaneously perform on-chip chromatography to separate small molecules from complex biofluidic samples and acquire the surface-enhanced Raman scattering spectra of the target chemicals with high specificity. Owing to the ultra-small dimension of the diatomite microfluidic channels and the photonic crystal effect from the fossilized diatom frustules, we demonstrate unprecedented sensitivity down to part-per-billion (ppb) level when detecting pyrene (1ppb) from mixed sample with Raman dye and cocaine (10 ppb) from human plasma. This pioneering work proves the exclusive advantage of μDADs as emerging microfluidic devices for chemical and biomedical sensing, especially for POC drug screening.

Trækonstruktioner

DEFF Research Database (Denmark)

Larsen, H.J.; Riberholt, H.

Denne anvisning behandler materialer til trækonstruktioner og beregning af sædvanlige elementer og konstruktioner i henhold til Trænormen fra 2003 med tillæg. Forbindelser behandles i SBI-anvisning 194: Trækonstruktioner. Forbindelser. Anvisningen er tænkt anvendt af projekterende og som lærebog på...

Characterizations of nano-TiO2/diatomite composites and their photocatalytic reduction of aqueous Cr (VI)

Science.gov (United States)

Sun, Qing; Li, Hui; Zheng, Shuilin; Sun, Zhiming

2014-08-01

In this paper, the TiO2 nanoparticles were immobilized on diatomite (DIA) via a typical hydrolysis precipitation process using TiCl4 as precursor. The as-prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). TiO2 nanoparticles with the average grain size of around 7-14 nm were well deposited on the surface of diatomite. The photocatalytic activity toward the reduction of aqueous Cr (VI) was demonstrated under UV light. The influence of initial pH values, catalyst amount, illumination intensity and initial concentration of Cr (VI) on photocatalytic reduction of Cr (VI) were investigated. Compared with the commercial TiO2 (P25, Degussa), the TiO2/DIA composites had better reactive activity because of their relatively higher adsorption capacity. Furthermore, the prepared photocatalyst exhibited relatively good photocatalytic stability depending on the reusability tests.

Fabrication of Ce/N co-doped TiO_2/diatomite granule catalyst and its improved visible-light-driven photoactivity

International Nuclear Information System (INIS)

Chen, Yan; Liu, Kuiren

2017-01-01

Highlights: • Ce/N co-doped TiO_2/diatomite granule (CNTD-G) was prepared via sol-gel method. • The optimal doping amount of Ce was determined. • The effects of impurity ions on photodegradation process were studied. • The intermediates generated during photodegradation process were deduced. • The mechanism of photodegradation process was proposed. - Abstract: Eliminating antibiotic remnants in aquatic environment has become one of the hottest topics among current research works. Thus, we prepared Ce, N co-doped TiO_2/diatomite granule (CNTD-G) catalyst to provide a new method. As one typical antibiotics, oxytetracycline (OTC) was selected as the target pollutant to be degradated under visible light irradiation. The carrier diatomite helped the spread of TiO_2 nanoparticles onto its surface, and inhibited their agglomeration. The synergy of Ce and N dopants highly improved the visible-light-driven photoactivity of TiO_2. The optimal doping amount and degradation conditions were determined. Besides, the effects of impurity ions were also investigated, including cations: Ca"2"+, Mg"2"+; or anions: NO_3"−, SO_4"2"− and PO_4"3"−. The intermediates generated during degradation process were studied, and the mechanism of the photodegradation process was proposed. CNTD-G could be easily collected from the reactor, and showed excellent recyclability.

Sorption of Th(IV) onto ZnO nanoparticles and diatomite-supported ZnO nanocomposite. Kinetics, mechanism and activation parameters

Energy Technology Data Exchange (ETDEWEB)

Yusan, Sabriye; Aslani, Mahmut A.A.; Aytas, Sule [Ege Univ., Izmir (Turkey). Inst. of Nuclear Sciences; Bampaiti, Anastasia; Noli, Fotini [Aristotle University of Thessaloniki (Greece). Dept. of Chemistry; Erenturk, Sema [Istanbul Technical Univ., Ayazaga Campus, Maslak-Istanbul (Turkey). Energy Inst.

2016-11-01

In this study, for the first time ZnO nanoparticles and diatomite-supported ZnO nanocomposite have been utilized as adsorbent for the removal of Th(IV) ions from aqueous solutions under different experimental conditions. The Langmuir, Freundlich, Temkin and Dubinin- Radushkevich (D-R) isotherms were used to analyze the equilibrium data. The sorption equilibrium data were fitted well to the Langmuir isotherm with maximum sorption capacities values was found to be 1.105 mmol/g and 0.320 mmol/g for ZnO nanoparticles and diatomite supported ZnO nanocomposite, respectively. Pseudo-first and pseudo-second order equations, Intraparticle diffusion and Bangham's models were considered to evaluate the rate parameters and sorption mechanism. Sorption kinetics were better reproduced by the pseudo-second order model (R{sup 2} > 0.999), with an activation energy (E{sub a}) of +99.74 kJ/mol and +62.95 kJ/mol for ZnO nanoparticles and diatomite-supported ZnO nanocomposite, respectively. In order to specify the type of sorption reaction, thermodynamic parameters were also determined. The evaluated ΔG* and ΔH* indicate the non-spontaneous and endothermic nature of the reactions. The results of this work suggest that both of the used materials are fast and effective adsorbents for removing Th(IV) from aqueous solutions and chemical sorption plays a role in controlling the sorption rate.

Effect of preparation conditions on the characteristics and photocatalytic activity of TiO{sub 2}/purified diatomite composite photocatalysts

Energy Technology Data Exchange (ETDEWEB)

Sun, Zhiming, E-mail: szmcumtb@hotmail.com; Hu, Zhibo; Yan, Yang; Zheng, Shuilin, E-mail: shuilinzh@sina.com

2014-09-30

Highlights: • TiO{sub 2}/purified diatomite composites were synthesized under different conditions. • The optimum preparation conditions of composites were obtained. • The obtained photocatalyst showed good photocatalytic activity. • The dispersity and grain size of loaded TiO{sub 2} NPs are the critical factors. - Abstract: TiO{sub 2}/purified diatomite composite materials were prepared through a modified hydrolysis-deposition method under low temperature using titanium tetrachloride as precursor combined with a calcination crystallization process. The microstructure and crystalline phases of the obtained composites prepared under different preparation conditions were characterized by high resolution scanning electron microscope (SEM) and X-ray diffraction (XRD), respectively. The photocatalytic performance of TiO{sub 2}/purified diatomite composites was evaluated by Rhodamine B as the target pollutant under UV irradiation, and the optimum preparation conditions of composites were obtained. The TiO{sub 2} crystal form in composites prepared under optimum conditions was anatase, the grain size of which was 34.12 nm. The relationships between structure and property of composite materials were analyzed and discussed. It is indicated that the TiO{sub 2} nanoparticles uniformly dispersed on the surface of diatoms, and the photocatalytic performance of the composite materials was mainly determined by the dispersity and grain size of loaded TiO{sub 2} nanoparticles.

Effect of Rice Husk and Diatomite on the Insulating Properties of Kaolin - Clay Firebricks

Directory of Open Access Journals (Sweden)

Emmanuel Ogo ONCHE

2007-09-01

Full Text Available This work was carried out to investigate the effect of rice husk and diatomite on the insulating properties of kaolin-clay firebrick. Five firebrick samples of different compositions were fired at 900°C, 1000°C, 1100°C, and 1200°C. Samples A-E are all insulating firebricks that can withstand temperatures ranging from 900°C to 1200°C since none of the samples crumbled during firing. The results showed that they all had good insulating characteristics with their highly porous structure making them suitable for backup insulation. Mixing ratios of 3:2:4:1 representing weight in grams of kaolin, plastic clay, rice husk and diatomite respectively for sample D gave the optimum performance values in terms of modulus of rupture, apparent porosity, apparent density, bulk density, and thermal conductivity at all temperatures. At 1200°C, the values are 22.57kgf/cm2 for modulus of rupture, 98.25% for apparent porosity, 2.38g/cm3 for apparent density, 1.11g/cm3 for bulk density, and 0.038w/mK for thermal conductivity.

Nanoscale zero-valent iron incorporated with nanomagnetic diatomite for catalytic degradation of methylene blue in heterogeneous Fenton system.

Science.gov (United States)

Zha, Yiming; Zhou, Ziqing; He, Haibo; Wang, Tianlin; Luo, Liqiang

2016-01-01

Nanoscale zero-valent iron (nZVI) incorporated with nanomagnetic diatomite (DE) composite material was prepared for catalytic degradation of methylene blue (MB) in heterogeneous Fenton system. The material was constructed by two facile steps: Fe3O4 magnetic nanoparticles were supported on DE by chemical co-precipitation method, after which nZVI was incorporated into magnetic DE by liquid-phase chemical reduction strategy. The as-prepared catalyst was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, magnetic properties measurement and nitrogen adsorption-desorption isotherm measurement. The novel nZVI@Fe3O4-diatomite nanocomposites showed a distinct catalytic activity and a desirable effect for degradation of MB. MB could be completely decolorized within 8 min and the removal efficiency of total organic carbon could reach to 90% after reaction for 1 h.

Multicurie, transportable, integrally shielded 123Xe → 123I generator and processing system for high-purity iodine-123 production

International Nuclear Information System (INIS)

Lagunas-Solar, M.C.; Thibeau, H.L.; Goodart, C.E.; Little, F.E.; Navarro, N.J.; Hartnett, D.E.

1985-01-01

An integrally shielded 123 Xe → 123 I generator system has been designed and tested under production conditions for its suitability as a multicurie handling device from which to produce radiopharmaceutical-quality high-purity no-carrier-added (NCA) 123 I. The 123 Xe → 123 I generator system is expected to provide an alternative to current techniques and to increase the availability and reliability of high-purity 123 I made via the 127 I(p,5n) 123 Xe → 123 I nuclear reaction. The generator system is based on the Crocker Nuclear Laboratory's continuous-flow production system which has been operating since 1974 for the multicurie production of 123 I. The generator system, which consists of an integrally shielded xenon trap and separate loading and processing apparatuses, is simple and reliable to operate, can be adapted to computerized control, and provides a safe working environment for the repeated handling of multicurie amounts of Xe-I radioactivities

Diatomite Modified Immobilized Delftia sp. for the Bio-Abiotic Removal of Antibiotics Amoxicillin in the Aqueous System

Science.gov (United States)

Gao, Lijuan; Sun, Jing; Guan, Kai; Shen, Tingting; Wang, Xikui

2017-05-01

Diatomite modified sodium alginate (Si/SA) immobilized Delftia sp. A2(2011) (STT01) was applied to degrade amoxicillin. The immobilized pellets provided a direct and visual probe for the degradation process due to their intrinsic bright colour. The results demonstrated that 100% of amoxicillin and 68.5% of CODcr removal were achieved after 72 h, comparing with the cases of sodium alginate (SA) system (81.2%, 46.9%) and the free cells system (60.5%, 35.5%). The degradation kinetics was in good agreement with Michaelis-Menten equation. The maximum rate (Vm ) and Michaelis constant (Km ) were calculated as 9.09 mg L-1 h-1 and 228 mg L-1, respectively. The results further revealed that diatomite not only acted as immobilization support to improve the mechanical strength and lifetime of the pellets but also as absorbent to promote the treatment efficiency. Therefore, both enzymatic catalysis and chemisorption were responsible for the removal of amoxicillin.

Fabrication of Ce/N co-doped TiO{sub 2}/diatomite granule catalyst and its improved visible-light-driven photoactivity

Energy Technology Data Exchange (ETDEWEB)

Chen, Yan; Liu, Kuiren, E-mail: liukr@smm.neu.edu.cn

2017-02-15

Highlights: • Ce/N co-doped TiO{sub 2}/diatomite granule (CNTD-G) was prepared via sol-gel method. • The optimal doping amount of Ce was determined. • The effects of impurity ions on photodegradation process were studied. • The intermediates generated during photodegradation process were deduced. • The mechanism of photodegradation process was proposed. - Abstract: Eliminating antibiotic remnants in aquatic environment has become one of the hottest topics among current research works. Thus, we prepared Ce, N co-doped TiO{sub 2}/diatomite granule (CNTD-G) catalyst to provide a new method. As one typical antibiotics, oxytetracycline (OTC) was selected as the target pollutant to be degradated under visible light irradiation. The carrier diatomite helped the spread of TiO{sub 2} nanoparticles onto its surface, and inhibited their agglomeration. The synergy of Ce and N dopants highly improved the visible-light-driven photoactivity of TiO{sub 2}. The optimal doping amount and degradation conditions were determined. Besides, the effects of impurity ions were also investigated, including cations: Ca{sup 2+}, Mg{sup 2+}; or anions: NO{sub 3}{sup −}, SO{sub 4}{sup 2−} and PO{sub 4}{sup 3−}. The intermediates generated during degradation process were studied, and the mechanism of the photodegradation process was proposed. CNTD-G could be easily collected from the reactor, and showed excellent recyclability.

In situ hydrothermal synthesis of a novel hierarchically porous TS-1/modified-diatomite composite for methylene blue (MB) removal by the synergistic effect of adsorption and photocatalysis.

Science.gov (United States)

Yuan, Weiwei; Yuan, Peng; Liu, Dong; Yu, Wenbin; Laipan, Minwang; Deng, Liangliang; Chen, Fanrong

2016-01-15

Hierarchically porous TS-1/modified-diatomite composites with high removal efficiency for methylene blue (MB) were prepared via a facile in situ hydrothermal route. The surface charge state of the diatomite was modified to enhance the electrostatic interactions, followed by in situ hydrothermal coating with TS-1 nanoparticles. The zeolite loading amount in the composites could be adjusted by changing the hydrothermal time. The highest specific surface area and micropore volume of the obtained composites were 521.3m(2)/g and 0.254cm(3)/g, respectively, with an optimized zeolite loading amount of 96.8%. Based on the synergistic effect of efficient adsorption and photocatalysis resulting from the newly formed hierarchically porous structure and improved dispersion of TS-1 nanoparticles onto diatomite, the composites' removal efficiency for MB reached 99.1% after 2h of photocatalytic reaction, even higher than that observed using pure TS-1 nanoparticles. Moreover, the superior MB removal kinetics of the composites were well represented by a pseudo-first-order model, with a rate constant (5.28×10(-2)min(-1)) more than twice as high as that of pure TS-1 nanoparticles (2.43×10(-2)min(-1)). The significant dye removal performance of this novel TS-1/modified-diatomite composite indicates that it is a promising candidate for use in waste water treatment. Copyright © 2015 Elsevier Inc. All rights reserved.

Comparison of a novel TiO₂/diatomite composite and pure TiO₂ for the purification of phosvitin phosphopeptides.

Science.gov (United States)

Zhang, Yang; Li, Junhua; Niu, Fuge; Sun, Jun; Dou, Yuan; Liu, Yuntao; Su, Yujie; Zhou, Bei; Xu, Qinqin; Yang, Yanjun

2014-06-01

A novel TiO2/diatomite composite (TD) was prepared and then characterized by scanning electron microscope (SEM) and Fourier Transform Infrared (FTIR). The results of SEM showed that after modification, the porous surface of diatomite was covered with TiO2. Both diatomite and TD had clear disc-shaped structures with average grain diameters of around 25 μm. Then TD and pure TiO2 were applied in the purification of phosvitin phosphopeptides (PPPs) from the digest of egg yolk protein, and a comparative study of adsorption properties of PPPs on TD and TiO2 was performed. In the study of adsorption kinetics, the adsorption equilibrium of PPPs on TD and TiO2 fitted well with the Langmuir model, and the time needed to reach adsorption equilibrium were both around 10 min. The maximum dynamic adsorption capacity of TD (8.15 mg/g) was higher than that of TiO2 (4.96 mg/g). The results of repeated use showed that TD and TiO2 were very stable after being subjected to ten repeated adsorption-elution cycles, and TD could easily be separated from aqueous solution by filtration. On the other hand, the present synthetic technology of TD was very simple, cost-effective, organic solvent-free and available for large-scale preparation. Thus, this separation method not only brings great advantages in the purification of PPPs from egg yolk protein but also provides a promising purification material for the enrichment of phosphopeptides in proteomic researches. Copyright © 2014 Elsevier B.V. All rights reserved.

Magnetic diatomite(Kieselguhr)/Fe2O3/TiO2 composite as an efficient photo-Fenton system for dye degradation

Science.gov (United States)

Barbosa, Isaltino A.; Zanatta, Lucas D.; Espimpolo, Daniela M.; da Silva, Douglas L.; Nascimento, Leandro F.; Zanardi, Fabrício B.; de Sousa Filho, Paulo C.; Serra, Osvaldo A.; Iamamoto, Yassuko

2017-10-01

We explored the potential use of diatomite/Fe2O3/TiO2 composites as catalysts for heterogeneous photo-Fenton degradation of methylene blue under neutral pH. Such system consists in magnetic solids synthesized by co-precipitation with Fe2+/Fe3+ in the presence of diatomite, followed by impregnation of TiO2. The results showed that the optimal amount of the catalyst was 2.0 g L-1, since aggregation phenomena become significant above this concentration, which decreases the photodegradation activity. The catalyst is highly efficient in the degradation of methylene blue and shows an easy recovery by an external magnetic field. This allows for an effective catalyst reuse without significant loss of activity in catalytic cycles, which is a highly interesting prospect for recyclable dye degradation systems.

Effect of preparation conditions on the characteristics and photocatalytic activity of TiO2/purified diatomite composite photocatalysts

Science.gov (United States)

Sun, Zhiming; Hu, Zhibo; Yan, Yang; Zheng, Shuilin

2014-09-01

TiO2/purified diatomite composite materials were prepared through a modified hydrolysis-deposition method under low temperature using titanium tetrachloride as precursor combined with a calcination crystallization process. The microstructure and crystalline phases of the obtained composites prepared under different preparation conditions were characterized by high resolution scanning electron microscope (SEM) and X-ray diffraction (XRD), respectively. The photocatalytic performance of TiO2/purified diatomite composites was evaluated by Rhodamine B as the target pollutant under UV irradiation, and the optimum preparation conditions of composites were obtained. The TiO2 crystal form in composites prepared under optimum conditions was anatase, the grain size of which was 34.12 nm. The relationships between structure and property of composite materials were analyzed and discussed. It is indicated that the TiO2 nanoparticles uniformly dispersed on the surface of diatoms, and the photocatalytic performance of the composite materials was mainly determined by the dispersity and grain size of loaded TiO2 nanoparticles.

Calibration And Performance Verification Of LSC Packard 1900TR AFTER REPAIRING

International Nuclear Information System (INIS)

Satrio; Evarista-Ristin; Syafalni; Alip

2003-01-01

Calibration process and repeated verification of LSC Packard 1900TR at Hydrology Section-P3TlR has been done. In the period of middle 1997 to July 2000, the counting system of the instrument has damaged and repaired for several times. After repairing, the system was recalibrated and then verified. The calibration and verification were conducted by using standard 3 H, 14 C and background unquenched. The result of calibration shows that background count rates of 3 H and 14 C is 12.3 ± 0.79 cpm and 18.24 ± 0.69 cpm respectively; FOM 3 H and 14 C is 285.03 ± 15.95 and 641.06 ± 16.45 respectively; 3 H and 14 C efficiency is 59.13 ± 0.28 % and 95.09 ± 0.31 %. respectively. From the verification data's, the parameter of SIS and tSIE for 14 C is to be in range of limit. And then 3 H and 14 C efficiency is still above minimum limit. Whereas, the background fluctuation still show normal condition. It could be concluded that until now the performance of LSC Packard 1900TR is well condition and could be used for counting. (author)

Elimination of nitrate in secondary effluent of wastewater treatment plants by Fe0 and Pd-Cu/diatomite

Directory of Open Access Journals (Sweden)

Yupan Yun

2018-03-01

Full Text Available Because total nitrogen (TN, in which nitrate (NO3– is dominant in the effluent of most wastewater treatment plants, cannot meet the requirement of Chinese wastewater discharge standard (<15 mg/L, NO3– elimination has attracted considerable attention. In this research, the novel diatomite-supported palladium-copper catalyst (Pd-Cu/diatomite with zero-valent iron (Fe0 was tried to use for catalytic reduction of nitrate in wastewater. Firstly, specific operational conditions (such as mass ratio of Pd:Cu, catalyst amounts, reaction time and pH of solution were optimized for nitrate reduction in artificial solution. Secondly, the selected optimal conditions were further employed for nitrate elimination of real effluent of a wastewater treatment plant in Beijing, China. Results showed that 67% of nitrate removal and 62% of N2 selectivity could be obtained under the following conditions: 5 g/L Fe0, 3:1 mass ratio (Pd:Cu, 4 g/L catalyst, 2 h reaction time and pH 4.3. Finally, the mechanism of catalytic nitrate reduction was also proposed.

Iodine-123 (123I) is promising radiopharmaceutical in the radionuclide diagnostics

International Nuclear Information System (INIS)

Tazhedinov, I.T.

2003-01-01

In the paper some advantages of the radiopharmaceuticals with 123 I against 99m Tc preparations are shown. It is noted that the 123 I is the most favourable among cyclotron radionuclides for radionuclide diagnostics by it nuclear-physical characteristics. With application of 123 I it is possible to attain a significant progress in the thyroid examination. 123 I labelled preparations should have a high bond strength providing the high information valuation of examinations

Macrolide resistance gene erm(TR) and erm(TR)-carrying genetic elements in Streptococcus agalactiae: characterization of ICESagTR7, a new composite element containing IMESp2907.

Science.gov (United States)

Mingoia, Marina; Morici, Eleonora; Marini, Emanuela; Brenciani, Andrea; Giovanetti, Eleonora; Varaldo, Pietro E

2016-03-01

The objective of this study was to investigate macrolide-resistant Streptococcus agalactiae isolates harbouring erm(TR), an erm(A) gene subclass, with emphasis on their erm(TR)-carrying genetic elements. Four erm(TR)-carrying elements have been described to date: three closely related (ICE10750-RD.2, Tn1806 and ICESp1108) in Streptococcus pyogenes, Streptococcus pneumoniae and S. pyogenes, respectively; and one completely different (IMESp2907, embedded in ICESp2906 to form ICESp2905) in S. pyogenes. Seventeen macrolide-resistant erm(TR)-positive S. agalactiae isolates were phenotypically and genotypically characterized. Their erm(TR)-carrying elements were explored by analysing the distinctive recombination genes of known erm(TR)-carrying integrative and conjugative elements (ICEs) and by PCR mapping. The new genetic context and organization of IMESp2907 in S. agalactiae were explored using several experimental procedures and in silico analyses. Five isolates harboured ICE10750-RD.2/Tn1806, five isolates harboured ICESp1108 and five isolates bore unknown erm(TR)-carrying elements. The remaining two isolates, exhibiting identical serotypes and pulsotypes, harboured IMESp2907 in a new genetic environment, which was further investigated in one of the two isolates, SagTR7. IMESp2907 was circularizable in S. agalactiae, as described in S. pyogenes. The new IMESp2907 junctions were identified based on its site-specific integration; the att sites were almost identical to those in S. pyogenes. In strain SagTR7, erm(TR)-carrying IMESp2907 was embedded in an erm(TR)-less internal element related to ICE10750-RD.2/Tn1806, which, in turn, was embedded in an ICESde3396-like element. The resulting whole ICE, ICESagTR7 (∼129 kb), was integrated into the chromosome downstream of the rplL gene, and was excisable in circular form and transferable by conjugation. This is the first study exploring erm(TR)-carrying genetic elements in S. agalactiae. © The Author 2015. Published by

Caracterização de argilas bentonitas e diatomitas e sua aplicação como adsorventes Bentonites and diatomites clays characterization and aplication in adsorption

Directory of Open Access Journals (Sweden)

Enéderson Rossetto

2009-01-01

Full Text Available Five samples of natural clays denominated: diatomite, CN-20, CN-29, CN-40 and CN-45 from Aliança Latina LTDA were characterized by differents supplementary techniques such as: XRD, chemical analysis, adsorption N2 measurements, infrared spectroscopy analysis, thermogravimetric analysis. Clays were tested in adsorption of blue methylene. All of isotherms adjust in a model of physics adsorption with formation of multilayers, however in the case of diatomite was a favorable adsorption (type II and the CNs were a not favorable adsorption (type III. In the case of CNs had flocculation of clay in high concentration of coloring.

Production of 123I

International Nuclear Information System (INIS)

Britto, J.L.Q. de; Silva, A.G. da; Teixeira, F.C.M.; Costa e Silva, A.; Souza, A.S.F. de

1981-01-01

The 12 I is prepared by 122 Te( 3 He, 2n) 123 Xe sup(β+) → 123 I reaction. The remotization of the Xe diffusion and capture system and the retired of the 123 I produced by the 123 Xe precursory decaying. (E.G.) [pt

Fabrication of Ce/N co-doped TiO2/diatomite granule catalyst and its improved visible-light-driven photoactivity.

Science.gov (United States)

Chen, Yan; Liu, Kuiren

2017-02-15

Eliminating antibiotic remnants in aquatic environment has become one of the hottest topics among current research works. Thus, we prepared Ce, N co-doped TiO 2 /diatomite granule (CNTD-G) catalyst to provide a new method. As one typical antibiotics, oxytetracycline (OTC) was selected as the target pollutant to be degradated under visible light irradiation. The carrier diatomite helped the spread of TiO 2 nanoparticles onto its surface, and inhibited their agglomeration. The synergy of Ce and N dopants highly improved the visible-light-driven photoactivity of TiO 2 . The optimal doping amount and degradation conditions were determined. Besides, the effects of impurity ions were also investigated, including cations: Ca 2+ , Mg 2+ ; or anions: NO 3 - , SO 4 2- and PO 4 3- . The intermediates generated during degradation process were studied, and the mechanism of the photodegradation process was proposed. CNTD-G could be easily collected from the reactor, and showed excellent recyclability. Copyright © 2016 Elsevier B.V. All rights reserved.

Stabilization of heavy metals in municipal sewage sludge by freeze-thaw treatment with a blend of diatomite, FeSO4, and Ca(OH)2.

Science.gov (United States)

Wang, Jing; Fu, Rongbing; Xu, Zhen

2017-08-01

In this work, the effects of diatomite with 15% FeSO 4 •7H 2 O and 7.5% Ca(OH) 2 on sludge stabilization were investigated using batch leaching tests. The influence of cell rupture caused by freezing and thawing on stabilization was also evaluated. The results indicated that the optimal diatomite percentage was 2%. Cell rupture by freezing and thawing reduced heavy metal leachability, followed by cell death and decrease of organic groups. The concentration of heavy metals in sludge leachate increased after cell rupture, indicating that the heavy metal leachability was reduced after freezing and thawings. Moreover, the stabilization effects were generally improved after freezing and thawing. As compared with the stabilization of the original sludge, the unstable fractions decreased and the residual fractions of the heavy metals increased in the stabilized sludge after cell rupture. This study developed a method to stabilize heavy metals in municipal sewage sludge. Diatomite combined with FeSO 4 ·7H 2 O and Ca(OH) 2 improved the treatment of sewage sludge contaminated by heavy metals. Cell lysis by freeze-thaw treatment reduced the risk of leaching heavy metals caused by cell death and decreased major organic groups in the sludge.

Surface bioengineering of diatomite based nanovectors for efficient intracellular uptake and drug delivery

Science.gov (United States)

Terracciano, Monica; Shahbazi, Mohammad-Ali; Correia, Alexandra; Rea, Ilaria; Lamberti, Annalisa; de Stefano, Luca; Santos, Hélder A.

2015-11-01

Diatomite is a natural porous silica material of sedimentary origin. Due to its peculiar properties, it can be considered as a valid surrogate of synthetic porous silica for nano-based drug delivery. In this work, we exploit the potential of diatomite nanoparticles (DNPs) for drug delivery with the aim of developing a successful dual-biofunctionalization method by polyethylene glycol (PEG) coverage and cell-penetrating peptide (CPP) bioconjugation, to improve the physicochemical and biological properties of the particles, to enhance the intracellular uptake in cancer cells, and to increase the biocompatibility of 3-aminopropyltriethoxysilane (APT) modified-DNPs. DNPs-APT-PEG-CPP showed hemocompatibility for up to 200 μg mL-1 after 48 h of incubation with erythrocytes, with a hemolysis value of only 1.3%. The cytotoxicity of the modified-DNPs with a concentration up to 200 μg mL-1 and incubation with MCF-7 and MDA-MB-231 breast cancer cells for 24 h, demonstrated that PEGylation and CPP-bioconjugation can strongly reduce the cytotoxicity of DNPs-APT. The cellular uptake of the modified-DNPs was also evaluated using the above mentioned cancer cell lines, showing that the CPP-bioconjugation can considerably increase the DNP cellular uptake. Moreover, the dual surface modification of DNPs improved both the loading of a poorly water-soluble anticancer drug, sorafenib, with a loading degree up to 22 wt%, and also enhanced the drug release profiles in aqueous solutions. Overall, this work demonstrates that the biofunctionalization of DNPs is a promising platform for drug delivery applications in cancer therapy as a result of its enhanced stability, biocompatibility, cellular uptake, and drug release profiles.Diatomite is a natural porous silica material of sedimentary origin. Due to its peculiar properties, it can be considered as a valid surrogate of synthetic porous silica for nano-based drug delivery. In this work, we exploit the potential of diatomite nanoparticles

Removal of zearalenone toxin from synthetics gastric and body fluids using talc and diatomite: a batch kinetic study.

Science.gov (United States)

Sprynskyy, Myroslav; Gadzała-Kopciuch, Renata; Nowak, Karolina; Buszewski, Bogusław

2012-06-01

Adsorption kinetics of zearalenone (ZEA) toxin from synthetic gastric fluid (SGF) and synthetic body fluid (SBF) by talc and diatomite was studied in the batch experiments. Chemical composition, morphology and structure of the used adsorbents were examined by scanning electron microscopy, FTIR spectroscopy and low-temperature nitrogen adsorption/desorption method. High performance liquid chromatography (HPLC) method was used for ZEA determining. The study results showed that ZEA is more effectively adsorbed on the talc (73% and 54% from SGF and SBF respectively). The efficiency on the diatomite was lower (53% and 42% from SGF and SBF respectively). The first order kinetics model was applied to describe the adsorption process. Rate of the ZEA adsorption from SGF is very rapid initially with about 95% of amount of the toxin adsorbed during first 5 min, while ZEA is adsorbed from SBF in two steps. The values of determined Gibbs free energy of adsorption (from -13 to -17 kJ/mol) indicated that adsorption of ZEA toxin by the both adsorbents are spontaneous and exothermic. Copyright © 2012 Elsevier B.V. All rights reserved.

Cyclotron production of high-purity 123I for medical applications via the 127I(p,5n)123Xe → 123I nuclear reaction

International Nuclear Information System (INIS)

Lagunas-Solar, M.C.

1985-01-01

The use of iodine-123 in nuclear medicine procedures is well documented in the scientific literature. Also, several methods for its production based on accelerator techniques have been described. Indirectly made 123 I via the 127 I(p,5n) 123 Xe → 123 I reaction produces 123 I of > 99.9% radionuclidic purity, with only 125 I ( 123 I production were developed at the University of California at Davis, where since 1974 the 76-in. isochronous cyclotron of the Crocker Nuclear Laboratory has been used for routine biweekly production of high-purity no-carrier-added 123 I

Safety features of TR-2 reactor

International Nuclear Information System (INIS)

Tuerker, T.

2001-01-01

TR-2 is a swimming pool type research reactor with 5 MW thermal power and uses standard MTR plate type fuel elements. Each standard fuel element consist of 23 fuel plates with a meat + cladding thickness of 0.127 cm, coolant channel clearance is 0.21 cm. Originally TR-2 is designed for %93 enriched U-Al. Alloy fuel meat.This work is based on the preparation of the Final Safety Analyses Report (FSAR) of the TR-2 reactor. The main aspect is to investigate the behaviour of TR-2 reactor under the accident and abnormal operating conditions, which cowers the accident spectrum unique for the TR-2 reactor. This presentation covers some selected transient analyses which are important for the safety aspects of the TR-2 reactor like reactivity induced startup accidents, pump coast down (Loss of Flow Accident, LOFA) and other accidents which are charecteristic to the TR-2

Friluftsinstallationer i træer

DEFF Research Database (Denmark)

Skov, Simon; Thomsen, Iben Margrete

2015-01-01

Abebaner, treetop walking, high rope adventure, slackline, træhuse og parkour-baner er alle installationer, som bruger træerne som støtte, enten midlertidigt eller permanent. Den nye sport, turistattraktionen eller team building-redskabet sætter i alle tilfælde træerne på prøve. Der følger positiv...

Facile preparation of hierarchically porous diatomite/MFI-type zeolite composites and their performance of benzene adsorption: the effects of NaOH etching pretreatment.

Science.gov (United States)

Yu, Wenbin; Yuan, Peng; Liu, Dong; Deng, Liangliang; Yuan, Weiwei; Tao, Bo; Cheng, Hefa; Chen, Fanrong

2015-03-21

Hierarchically porous diatomite/MFI-type zeolite (Dt/Z) composites with excellent benzene adsorption performance were prepared. The hierarchical porosity was generated from the microporous zeolite coated at the surface of diatom frustules and from the macroporous diatomite support. A facile NaOH etching method was employed for the first time to treat the frustule support, followed by hydrothermal growth of MFI-type zeolite at the surface of frustules previously seeded with nanocrystalline silicalite-1 (Sil-1). NaOH etching enlarged the pores on diatom frustules and further increased the coated zeolite contents (W(z)). The central macropore size of the diatom frustules increased from approximately 200-500 nm to 400-1000 nm after NaOH etching. The W(z) could reach 61.2%, while the macroporosity of the composites was largely preserved due to more voids for zeolite coating being formed by NaOH etching. The Dt/Z composites exhibited higher benzene adsorption capacity per unit mass of zeolite and less mass transfer resistance than Sil-1, evaluated via a method of breakthrough curves. These results demonstrate that etching of a diatomite support is a facile but crucial process for the preparation of Dt/Z composites, enabling the resulting composites to become promising candidates for uses in volatile organic compounds emission control. Copyright © 2014 Elsevier B.V. All rights reserved.

Thermal Properties of Algerian Diatomite, Study of the Possibility to Its Use in the Thermal Insulation

Science.gov (United States)

Hamdi, Boualem; Hamdi, Safia

The chemical and physical properties of a Algerian diatomite were given before and after heat treatment and chemical with an aim of a use in the heat insulation of constructions. The preliminary results obtained showed that this material is extremely porous (porosity >70 %), characterized of a low density and a very low thermal conductivity. These promising properties support the use of this local material in the thermal insulation.

Separation of aflatoxin B1 from synthetic physiological fluids using talc and diatomite: Kinetic and isotherm aspects.

Science.gov (United States)

Sprynskyy, Myroslav; Krzemień-Konieczka, Iwona; Gadzała-Kopciuch, Renata; Buszewski, Bogusław

2018-01-01

The objective of the study was to examine adsorption of the aflatoxin B1 from synthetic gastric fluid and synthetic intestinal fluid by talc, raw and calcined diatomite. The kinetic and equilibrium adsorption processes were studied in the batch adsorption experiments applying high performance liquid chromatography for the aflatoxin B1 determination. The kinetic study showed a very fast adsorption of the aflatoxin B1 onto the selected adsorbents from the both physiological fluids with reaching equilibrium within 1-15min. The aflatoxin B1 was almost completely adsorbed in initial linear step of the kinetic process that can be described well by the zero-order kinetics model. The experimental data of the equilibrium adsorption were characterized using the Langmuir and Freundlich isotherm models. The high adsorption effectiveness was found in a range of 90%-100% and 60%-100% for the diatomite samples and the talc respectively at the initial concentrations of the aflatoxin B1 as 31-300ng/mL. The possible mechanisms of the aflatoxin adsorption onto the used mineral adsorbents are also discussed in the work. Copyright © 2017 Elsevier B.V. All rights reserved.

Fixed-bed column studies of total organic carbon removal from industrial wastewater by use of diatomite decorated with polyethylenimine-functionalized pyroxene nanoparticles.

Science.gov (United States)

Hethnawi, Afif; Manasrah, Abdallah D; Vitale, Gerardo; Nassar, Nashaat N

2018-03-01

In this study, a fixed-bed column adsorption process was employed to remove organic pollutants from a real industrial wastewater effluent using polyethylenimine-functionalized pyroxene nanoparticles (PEI-PY) embedded into Diatomite at very low mass percentage. Various dynamic parameters (e.g., inlet concentration, inlet flow rate, bed height, and PEI-nanoparticle concentration in Diatomite, (%nps)) were investigated to determine the breakthrough behavior. The obtained breakthrough curves were fit with a convection-dispersion model to determine the characteristic parameters based on mass transfer phenomena. The axial dispersion coefficient (D L ) and group of dimensionless numbers; including Renold number (Re), Schmidt number (Sc), and Sherwood number (Sh) were all determined and correlated by Wilson-Geankoplis correlation that was used to estimate the external film diffusion coefficients (Kc) at 0.0015 < Re<55. Copyright © 2017 Elsevier Inc. All rights reserved.

Eco-sustainable systems based on poly(lactic acid), diatomite and coffee grounds extract for food packaging.

Science.gov (United States)

Cacciotti, Ilaria; Mori, Stefano; Cherubini, Valeria; Nanni, Francesca

2018-06-01

In the food packaging sector many efforts have been (and are) devoted to the development of new materials in order to reply to an urgent market demand for green and eco-sustainable products. Particularly a lot of attention is currently devoted both to the use of compostable and biobased polymers as innovative and promising alternative to the currently used petrochemical derived polymers, and to the re-use of waste materials coming from agriculture and food industry. In this work, multifunctional eco-sustainable systems, based on poly(lactic acid) (PLA) as biopolymeric matrix, diatomaceous earth as reinforcing filler and spent coffee grounds extract as oxygen scavenger, were produced for the first time, in order to provide a simultaneous improvement of mechanical and gas barrier properties. The influence of the diatomite and the spent coffee grounds extract on the microstructural, mechanical and oxygen barrier properties of the produced films was deeply investigated by means of X-Ray diffraction (XRD), infrared spectroscopy (FT-IR, ATR), scanning electron microscopy (SEM), uniaxial tensile tests, O 2 permeabilimetry measurements. An improvement of both mechanical and oxygen barrier properties was recorded for systems characterised by the co-presence of diatomite and coffee grounds extract, suggesting a possible synergic effect of the two additives. Copyright © 2018 Elsevier B.V. All rights reserved.

Water Influx, and Its Effect on Oil Recovery: Part 1. Aquifer Flow, SUPRI TR-103

Energy Technology Data Exchange (ETDEWEB)

Brigham, William E.

1999-08-09

Natural water encroachment is commonly seen in many oil and gas reservoirs. In fact, overall, there is more water than oil produced from oil reservoirs worldwide. Thus it is clear that an understanding of reservoir/aquifer interaction can be an important aspect of reservoir management to optimize recovery of hydrocarbons. Although the mathematics of these processes are difficult, they are often amenable to analytical solution and diagnosis. Thus this will be the ultimate goal of a series of reports on this subject. This first report deals only with aquifer behavior, so it does not address these important reservoir/aquifer issues. However, it is an important prelude to them, for the insight gained gives important clues on how to address reservoir/aquifer problems. In general when looking at aquifer flow, there are two convenient inner boundary conditions that can be considered; constant pressure or constant flow rate. There are three outer boundary conditions that are convenient to consider; infinite, closed and constant pressure. And there are three geometries that can be solved reasonably easily; linear, radial and spherical. Thus there are a total of eighteen different solutions that can be analyzed.

Landbrugets trædemølle

DEFF Research Database (Denmark)

Hansen, Henning Otte

2016-01-01

Teorien om landbrugets trædemølle siger, at teknologi medfører stigende produktivitet, stigende udbud og dermed faldende priser. Dermed øges behovet for ny teknologi. Det vedvarende teknologipres gavner de innovative landmænd, mens de mere afventende landmænd kun oplever de negative virkninger i...... form af prisfald. I denne artikel beskrives nærmere de enkelte elementer i trædemøllen. Samtidig vurderes trædemøllens betydning og mulige påvirkning. Det konkluderes, at trædemøllen, dens forudsætninger og afledte virkninger stadig er fuldt gældende. Det er ikke muligt for et enkelt land eller region...... af bremse trædemøllen på lang sigt. På lokalt plan kan man løse nogle sociale og økonomiske problemer skabt af trædemøllen gennem nemmere afvandring....

Evaluation of an up-flow anaerobic sludge bed (UASB) reactor containing diatomite and maifanite for the improved treatment of petroleum wastewater.

Science.gov (United States)

Chen, Chunmao; Liang, Jiahao; Yoza, Brandon A; Li, Qing X; Zhan, Yali; Wang, Qinghong

2017-11-01

Novel diatomite (R1) and maifanite (R2) were utilized as support materials in an up-flow anaerobic sludge bed (UASB) reactor for the treatment of recalcitrant petroleum wastewater. At high organic loadings (11kg-COD/m 3 ·d), these materials were efficient at reducing COD (92.7% and 93.0%) in comparison with controls (R0) (88.4%). Higher percentages of large granular sludge (0.6mm or larger) were observed for R1 (30.3%) and R2 (24.6%) compared with controls (22.6%). The larger portion of granular sludge provided a favorable habitat that resulted in greater microorganism diversity. Increased filamentous bacterial communities are believed to have promoted granular sludge formation promoting a conductive environment for stimulation methanogenic Archaea. These communities had enhanced pH tolerance and produced more methane. This study illustrates a new potential use of diatomite and maifanite as support materials in UASB reactors for increased efficiency when treating refractory wastewaters. Copyright © 2017 Elsevier Ltd. All rights reserved.

Surface bioengineering of diatomite based nanovectors for efficient intracellular uptake and drug delivery.

Science.gov (United States)

Terracciano, Monica; Shahbazi, Mohammad-Ali; Correia, Alexandra; Rea, Ilaria; Lamberti, Annalisa; De Stefano, Luca; Santos, Hélder A

2015-12-21

Diatomite is a natural porous silica material of sedimentary origin. Due to its peculiar properties, it can be considered as a valid surrogate of synthetic porous silica for nano-based drug delivery. In this work, we exploit the potential of diatomite nanoparticles (DNPs) for drug delivery with the aim of developing a successful dual-biofunctionalization method by polyethylene glycol (PEG) coverage and cell-penetrating peptide (CPP) bioconjugation, to improve the physicochemical and biological properties of the particles, to enhance the intracellular uptake in cancer cells, and to increase the biocompatibility of 3-aminopropyltriethoxysilane (APT) modified-DNPs. DNPs-APT-PEG-CPP showed hemocompatibility for up to 200 μg mL(-1) after 48 h of incubation with erythrocytes, with a hemolysis value of only 1.3%. The cytotoxicity of the modified-DNPs with a concentration up to 200 μg mL(-1) and incubation with MCF-7 and MDA-MB-231 breast cancer cells for 24 h, demonstrated that PEGylation and CPP-bioconjugation can strongly reduce the cytotoxicity of DNPs-APT. The cellular uptake of the modified-DNPs was also evaluated using the above mentioned cancer cell lines, showing that the CPP-bioconjugation can considerably increase the DNP cellular uptake. Moreover, the dual surface modification of DNPs improved both the loading of a poorly water-soluble anticancer drug, sorafenib, with a loading degree up to 22 wt%, and also enhanced the drug release profiles in aqueous solutions. Overall, this work demonstrates that the biofunctionalization of DNPs is a promising platform for drug delivery applications in cancer therapy as a result of its enhanced stability, biocompatibility, cellular uptake, and drug release profiles.

Photocatalytic Degradation Property of NANO-TiO2/DIATOMITE for Rodamine B Dye Wastewater

Science.gov (United States)

Liu, Yue; Zheng, Shuilin; Du, Gaoxiang; Shu, Feng; Chen, Juntao

The Nano-TiO2/Diatomite compound photocatalyst is used to degrade rhodamine B dye wastewater in photochemical reactor. The test result indicates that the rate of photodegradation of rhodamine B is influenced by reactive conditions. The best technical conditions are concentration of rhodamine B solution 10mg/L, ultraviolet light 300W, the compound photocatalyst amount used 1g/L, the pH 5.8, reaction time 20min. Under these conditions the rate of photodegradation of rhodamine B may reach as high as 97.80%. And the efficiency of photodegradation of catalyst only has a little changed in recycling.

Clinical uses of I-123 produced by 127I(p, 5n)123Xe to 123I reaction in NIRS

International Nuclear Information System (INIS)

Saegusa, Kenji; Arimizu, Noboru; Uchiyama, Guio; Tateno, Yukio; Rikitake, Tomoyuki.

1978-01-01

123 I capsules produced by NIRS which are believed to be uncontaminated by radioactive impurities other than 125 I were compared with commercial 123 I capsules regarding gamma-ray spectra, thyroid phantoms and clinical scintigrams. Absorbed radiation doses of 123 I contaminated with nuclides other than 123 I to thyroid and whole body were also estimated. Regarding gamma-ray spectra, any nuclides other than 125 I(0.53%) did not contaminate in 123 I produced by NIRS, and it was superior to commercial capsules. Regarding phantoms and clinical scintigrams, background counts around the thyroid gland seemed to be slightly higher in commercial capsules than that produced by NIRS because of contamination with other nuclides. Exposed doses in thyroid and whole body were counted. Ratios in thyroid and whole body were increased by 30% and 9%, respectively in 123 I produced by NIRS because of contamination with 0.53% of 125 I in the event that the intake ratio of thyroid was determined as 25%. In commercial capsules the doses in thyroid and whole body were increased by 500% and 150%, respectively. Doses of commercial capsules and NIRS capsules were 7.87 rad and 1.72 rad, respectively per 100 μCi in thyroid. The ratio of NIRS capsules to commercial capsules in thyroid was 1/4.6, and that in the whole body was less than 1/2. (Ichikawa, K.)

Blog.tr.ee ei anna alla / Raigo Neudorf

Index Scriptorium Estoniae

Neudorf, Raigo

2007-01-01

Veebikeskkonna blog.tr.ee arengust ja majandamisest räägivad keskkonna looja Andris Reinmann ja firma OÜ Tr.ee osaniku Mobi Solutions'i esindaja Rain Rannu. Vt. samas: Mis on blog.tr.ee; Kaljundi: blog.tr.ee on hobiprojekt. Kommenteerib nagi.ee juhataja Jüri Kaljundi. Lisatud joonis: Blog.tr.ee unikaalsete külastajate arv nädalas

The interstellar extinction in the open clusters Tr 14, Tr 15, Tr 16/Cr 232 and Cr 228 in NGC 3372. New near-infrared photometry

International Nuclear Information System (INIS)

Tapia, M.; Roth, M.; Ruiz, M.T.

1988-01-01

Near-infrared JHKL photometry of more than 200 stars, members of the open clusters Tr14, Tr15, Tr16, Cr228 and Cr232 in the Carina Nebula are presented. From comparing these results with the available visual photometry and spectroscopy, it is found that, except in Tr15, the intracluster reddening is characterized by a 'normal' extinction law at λ > 0.5μm but is highly anomalous and variable in the U- and B-bands. This behaviour may be explained by the presence of intracluster interstellar grains 'processed' by shock waves presumably associated with the explosive history of η Carinae. All clusters are found to be at the same distance from the Sun at d = 2.4 ± 0.2 kpc or Vsub(o) - Msub(v) 11.9 ± 0.2. The total amount of reddening, though, differs significantly from cluster to cluster. (author)

Efeito do carvedilol a curto prazo na atividade simpática cardíaca pela cintilografia com 123I-MIBG Effects of short-term carvedilol on the cardiac sympathetic activity assessed by 123I-MIBG scintigraphy

Directory of Open Access Journals (Sweden)

Sandra Marina Ribeiro de Miranda

2010-03-01

Full Text Available FUNDAMENTO: Alterações autonômicas na insuficiência cardíaca estão associadas a um aumento da morbimortalidade. Vários métodos não invasivos têm sido empregados para avaliar a função simpática, incluindo a imagem cardíaca com 123I-MIBG. OBJETIVO: Avaliar a atividade simpática cardíaca, por meio da cintilografia com 123I-MIBG, antes e após três meses de terapia com carvedilol em pacientes com insuficiência cardíaca com fração de ejeção do VE BACKGROUND: Autonomic alterations in heart failure are associated with an increase in morbimortality. Several noninvasive methods have been employed to evaluate the sympathetic function, including the Meta-Iodobenzylguanidine (123I-MIBG scintigraphy imaging of the heart. OBJECTIVE: to evaluate the cardiac sympathetic activity through 123I-MIBG scintigraphy, before and after three months of carvedilol therapy in patients with heart failure and left ventricular ejection fraction (LVEF < 45%. PATIENTS AND METHODS: Sixteen patients, aged 56.3 ± 12.6 years (11 males, with a mean LVEF of 28% ± 8% and no previous use of beta-blockers were recruited for the study. Images of the heart innervation were acquired with 123I-MIBG, and the serum levels of catecholamines (epinephrine, dopamine and norepinephrine were measured; the radioisotope ventriculography (RIV was performed before and after a three-month therapy with carvedilol. RESULTS: Patients' functional class showed improvement: before the treatment, 50% of the patients were FC II and 50% were FC III. After 3 months, 7 patients were FC I (43.8% and 9 were FC II (56.2%, (p = 0.0001. The mean LVEF assessed by RIV increased from 29% to 33% (p = 0.017. There was no significant variation in cardiac adrenergic activity assessed by 123I-MIBG (early and late resting images and washout rate. No significant variation was observed regarding the measurement of catecholamines. CONCLUSION: The short-term treatment with carvedilol promoted the clinical

7 CFR 1280.123 - State.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false State. 1280.123 Section 1280.123 Agriculture... INFORMATION ORDER Lamb Promotion, Research, and Information Order Definitions § 1280.123 State. State means each of the 50 States and the District of Columbia. ...

Understanding TR binding to pMHC complexes: how does a TR scan many pMHC complexes yet preferentially bind to one.

Directory of Open Access Journals (Sweden)

Javed Mohammed Khan

Full Text Available Understanding the basis of the binding of a T cell receptor (TR to the peptide-MHC (pMHC complex is essential due to the vital role it plays in adaptive immune response. We describe the use of computed binding (free energy (BE, TR paratope, pMHC epitope, molecular surface electrostatic potential (MSEP and calculated TR docking angle (θ to analyse 61 TR/pMHC crystallographic structures to comprehend TR/pMHC interaction. In doing so, we have successfully demonstrated a novel/rational approach for θ calculation, obtained a linear correlation between BE and θ without any "codon" or amino acid preference, provided an explanation for TR ability to scan many pMHC ligands yet specifically bind one, proposed a mechanism for pMHC recognition by TR leading to T cell activation and illustrated the importance of the peptide in determining TR specificity, challenging the "germline bias" theory.

7 CFR 1260.123 - Research.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false Research. 1260.123 Section 1260.123 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE BEEF PROMOTION AND RESEARCH Beef Promotion and Research Order Definitions § 1260.123 Research. Research means studies relative to the...

Properties of silica fume procured from natural diatomite and its usage in the production of vacuum insulation panels

OpenAIRE

V.P. Selyaev; V.A. Neverov; O.G. Mashtaev; A.V. Kolotushkin

2013-01-01

The article shows the results of the research of silica fume particles procured from diatomite from Atemar deposit by means of separating silicic acid from colloidal dissolved state into the sediment. The objective of the work was to define thermal-physical and structural characteristics of the silica fume. The research included IR-spectrometry, granulometry, thermal gravimetric analysis, X-ray structural analysis, optical microscopy, and small angle X-Ray scattering. As a result of the resea...

Investigating the taste in the city : Très très bon, gourmet stroll in Paris

Directory of Open Access Journals (Sweden)

Camille BRACHET

2015-12-01

Full Text Available In this paper, will be examined the potential of television regarding the representation of food and taste. The analysis focuses on a particular TV show, Très très bon, a weekend program broadcast on the channel Paris Première. Since the success of many TV programs has already shown that cooking and television can go together, it is interesting to try to understand the terms of staging which are very specific to Très très bon. For this purpose, the apparatus behind this TV program will be analysed in order to understand how the TV show seduces the viewer for whom any form of tasting remains technically impossible.

Iodine-123 iodobenzofuran (I-123 IBF) SPECT in patients with parkinsonism

Energy Technology Data Exchange (ETDEWEB)

Nakabeppu, Yoshiaki; Nakajo, Masayuki; Mitsuda, Mitsuru; Tsuchimochi, Shinsaku; Tani, Atsushi; Osame, Mitsuhiro [Kagoshima Univ. (Japan). Faculty of Medicine

1999-12-01

Iodine-123 benzofuran (I-123 IBF) is a dopaminergic antagonist which is suitable for SPECT imaging of D2 receptors. The purpose of this study is to evaluate the potential usefulness of semi-quantitative parameters obtained from brain SPECT data of I-123 IBF for differential diagnosis in patients with parkinsonism (PN). Subjects were 10 patients with PN: 2 patients with striato-nigral degeneration (SND), 5 patients with Parkinson's disease (PD), 2 patients with progressive supranuclear palsy (PSP) and one patient with olivo-ponto-cerebellar atrophy (OPCA). The data were acquired with a triple-head gamma camera at 2 hours after intravenous injection of 167 MBq of I-123 IBF. Transverse images were reconstructed by means of filtered backprojection, and attenuation correction was performed by Chang's method ({mu}=0.08). The basal ganglia-to-frontal cortex ratio (GFR) and the basal ganglia-to-occipital cortex ratio (GOR) on slices of 5 different thicknesses were calculated. The GFR and GOR were lower in the SND group than in the other disease groups in all slices with different thicknesses (7.2 mm, 14.4 mm, 21.6 mm, 28.8 mm and 43.2 mm). The semiquantitative parameters (GFR and GOR) obtained from brain SPECT data at 2 hours after intravenous injection of I-123 IBF may be useful for differential diagnosis in patients with PN. (author)

Iodine-123 iodobenzofuran (I-123 IBF) SPECT in patients with parkinsonism

International Nuclear Information System (INIS)

Nakabeppu, Yoshiaki; Nakajo, Masayuki; Mitsuda, Mitsuru; Tsuchimochi, Shinsaku; Tani, Atsushi; Osame, Mitsuhiro

1999-01-01

Iodine-123 benzofuran (I-123 IBF) is a dopaminergic antagonist which is suitable for SPECT imaging of D2 receptors. The purpose of this study is to evaluate the potential usefulness of semi-quantitative parameters obtained from brain SPECT data of I-123 IBF for differential diagnosis in patients with parkinsonism (PN). Subjects were 10 patients with PN: 2 patients with striato-nigral degeneration (SND), 5 patients with Parkinson's disease (PD), 2 patients with progressive supranuclear palsy (PSP) and one patient with olivo-ponto-cerebellar atrophy (OPCA). The data were acquired with a triple-head gamma camera at 2 hours after intravenous injection of 167 MBq of I-123 IBF. Transverse images were reconstructed by means of filtered backprojection, and attenuation correction was performed by Chang's method (μ=0.08). The basal ganglia-to-frontal cortex ratio (GFR) and the basal ganglia-to-occipital cortex ratio (GOR) on slices of 5 different thicknesses were calculated. The GFR and GOR were lower in the SND group than in the other disease groups in all slices with different thicknesses (7.2 mm, 14.4 mm, 21.6 mm, 28.8 mm and 43.2 mm). The semiquantitative parameters (GFR and GOR) obtained from brain SPECT data at 2 hours after intravenous injection of I-123 IBF may be useful for differential diagnosis in patients with PN. (author)

Businnes Model of Cors-Tr Tusaga-Aktif

Science.gov (United States)

Bakici, S.; Erkek, B.; İlbey, A.; Kulaksiz, E.

2017-11-01

CORS-TR (TUSAGA-Aktif (Turkish National Permanent GNSS Network - Active)), serves location information at cm level accuracy in Turkey and TR Northern Cyprus in few seconds, where adequate numbers of GNSS satellites are observed and communication possibilities are present. No ground control points and benchmarks are necessary. There are 146 permanent GNSS stations within the CORS-TR System. Station data are transferred online to the main control center located in the Mapping Department of the General Directorate of Land Registry and Cadastre. CORS-TR System was established in 2008 and has been updated in software, hardware, communication and pricing areas from technical and administrative point of view in order to improve the system and provide better service to the users. Thus, the added value obtained from the CORS-TR System has been increased and contributed to the more efficient use of country resources. In this paper, how the technical, administrative and financial studies in the operation of the CORS-TR System were managed with a sustainable business model, studies for solving problems encountered in operating of the system, the cost / benefit analysis of the system and the sharing of experience gained from the perspective of how web-based applications are managed and the business model of the CORS-TR System are explained in detail.

29 CFR 570.123 - Agriculture.

Science.gov (United States)

2010-07-01

... 29 Labor 3 2010-07-01 2010-07-01 false Agriculture. 570.123 Section 570.123 Labor Regulations... Provisions of the Fair Labor Standards Act of 1938, as Amended Exemptions § 570.123 Agriculture. (a) Section... agriculture outside of school hours for the school district where such employee is living while he is so...

BUSINNES MODEL OF CORS-TR (TUSAGA-AKTIF

Directory of Open Access Journals (Sweden)

S. Bakici

2017-11-01

Full Text Available CORS-TR (TUSAGA-Aktif (Turkish National Permanent GNSS Network – Active, serves location information at cm level accuracy in Turkey and TR Northern Cyprus in few seconds, where adequate numbers of GNSS satellites are observed and communication possibilities are present. No ground control points and benchmarks are necessary. There are 146 permanent GNSS stations within the CORS-TR System. Station data are transferred online to the main control center located in the Mapping Department of the General Directorate of Land Registry and Cadastre. CORS-TR System was established in 2008 and has been updated in software, hardware, communication and pricing areas from technical and administrative point of view in order to improve the system and provide better service to the users. Thus, the added value obtained from the CORS-TR System has been increased and contributed to the more efficient use of country resources. In this paper, how the technical, administrative and financial studies in the operation of the CORS-TR System were managed with a sustainable business model, studies for solving problems encountered in operating of the system, the cost / benefit analysis of the system and the sharing of experience gained from the perspective of how web-based applications are managed and the business model of the CORS-TR System are explained in detail.

Late Pliocene diatoms in a diatomite from Prydz Bay, East Antarctica

Science.gov (United States)

Mahood, A.D.; Barron, J.A.

1996-01-01

Very well-preserved Pliocene diatoms from a diatomite unit interbedded within glacial sediments at Ocean Drilling Program Site 742 in Prydz Bay, Antarctica are documented and illustrated. The presence of Thalassiosira kolbei, T. torokina, Actinocyclus actinochilus, A. karstenii and the absence of Nitzschia interfrigidaria. T. insigna and T. vulnifica in Sample 119-742A-15R-4, 44-46cm constrain its age to ca. 2.2-1.8 Ma (late Pliocene). Diatoms associated with sea ice constitute 35% of the Pliocene diatom assemblage, compared with 71% of the modern sediment assemblage at the site, suggesting that sea ice was present during the late Pliocene period of deposition of the sample, although it probably was not the significant feature it is today. Thalassiosira ellitipora (Donahue) Fenner is described and illustrated in detail and is validly published. An expanded description and numerous illustrations are also presented for T. torokina Brady.

Metabolism of 123I-FP-CIT in humans

International Nuclear Information System (INIS)

Tanaka, Akihiro; Okano, Kyoko; Tamagami, Hiroshi

1999-01-01

The metabolism of N-(3-fluoropropyl)-2β-carbomethoxy-3β-(4-iodophenyl)nortropane ( 123 I) ( 123 I-FP-CIT) in healthy humans was studied. Plasma and urine samples, obtained after i.v. administration of 123 I-FP-CIT, were analyzed using the two-dimensional thin-layer chromatography technique. Eleven radiochemical components were detected in both plasma and urine, and four of them were the parent 123 I-FP-CIT and its metabolites, N-(3-fluoropropyl)-2β-carboxy-3β-(4-iodophenyl)nortropane ( 123 I) ( 123 I-acid), 2β-carboxy-3β-(4-iodophenyl)nortropane ( 123 I) ( 123 I-nor-acid) and 2β-carbomethoxy-3β-(4-iodophenyl)nortropane ( 123 I) ( 123 I-nor-CIT). These four identified radiochemical components occupied about 80% or more in ratio of the radiochemical components in the plasma and urine. In the metabolites of 123 I-FP-CIT, the high polar metabolites- 123 I-acid and 123 I-nor-acid-were found to be the major components, while lipophilic 123 I-nor-CIT was a minor component. Free iodide ( 123 I - ) was not found in the plasma or urine. Thus, the main metabolic reactions which 123 I-FP-CIT undergoes in humans seem to be hydrolysis of the ester bond and N-dealkylation. In vivo deiodination of 123 I-FP-CIT was found to be minimum. Current results suggest that the metabolites of 123 I-FP-CIT hardly influence evaluation of the dopamine transporter in the human brain. (author)

Hydraulic Fracturing of 403 Shallow Diatomite Wells in South Belridge Oil Field, Kern County, California, in 2014

Science.gov (United States)

Wynne, D. B.; Agusiegbe, V.

2015-12-01

We examine all 403 Hydraulic Fracture (HF) jobs performed by Aera Energy, LLC, in the South Belridge oil field, Kern County, CA in 2014. HFs in the South Belridge oil field are atypical amongst North American plays because the reservoir is shallow and produced via vertical wells. Our data set constitutes 88% of all HF jobs performed in CA oil fields in calendar-2014. The South Belridge field produces 11% of California's oil and the shallow HFs performed here differ from most HFs performed elsewhere. We discuss fracture modeling and methods and summary statistics, and modelled dimensions of fractures and their relationships to depth and reservoir properties. The 403 HFs were made in the diatomite-dominated Reef Ridge member of the Monterey Formation. The HFs began at an average depth of 1047 feet below ground (ft TVD) and extended an average of 626 ft vertically downward. The deepest initiation of HF was at 2380 ft and the shallowest cessation was at 639 ft TVD. The average HF was performed using 1488 BBL (62,496 gallons) of water. The HFs were performed in no more than 6 stages and nearly all were completed within one day. We (1) compare metrics of the South Belridge sample group with recent, larger "all-CA" and nationwide samples; and (2) conclude that if relationships of reservoir properties, well completion and HF are well understood, shallow diatomite HF may be optimized to enhance production while minimizing environmental impact.

[A Phase 1 study of beta-methyl-p-(123I)-iodophenyl-pentadecanoic acid (123I-BMIPP)].

Science.gov (United States)

Torizuka, K; Yonekura, Y; Nishimura, T; Tamaki, N; Uehara, T; Ikekubo, K; Hino, M

1991-07-01

Phase 1 study of beta-methyl-p-(123I)-iodophenylpentadecanoic acid (123I-BMIPP), a new radiopharmaceutical developed for the evaluation of myocardial fatty acid metabolism, was performed in six normal volunteers to evaluate its biodistribution and safety. After intravenous injection of 111 MBq of 123I-BMIPP, the agent accumulated to the myocardium rapidly (5.4 +/- 0.6% at 1.5 hr after injection) and was washed-out slowly (5.1 +/- 0.4% at 3.0hr). 123I-BMIPP demonstrated no significant accumulation to any specific organs other than myocardium, liver and muscle. Myocardium was clearly visualized in the planar and SPECT images obtained 30 min and 3 hrs after injection. The absorption doses from 123I-BMIPP estimated by MIRD method were lower than those from 201Tl in all organs. Neither adverse reactions nor abnormal clinical laboratory findings were found in the safety evaluation. These results suggest 123I-BMIPP is a promising agent for evaluating myocardial fatty acid metabolism.

Dopamine transporter SPECT using fast kinetic ligands: 123I-FP-β-CIT versus 99mTc-TRODAT-1

International Nuclear Information System (INIS)

Laere, K. van; Ceuninck, L. de; Eynden, J. van den; Dupont, P.; Mortelmans, L.; Dom, R.; Vanbilloen, H.; Cleynhens, J.; Bormans, G.; Verbruggen, A.

2004-01-01

A comparative study was carried out on two promising presynaptic dopamine transporter single-photon emission tomography (SPECT) radioligands with a fast pharmacokinetic profile, 123 I-FP-β-CIT (FP) and 99m Tc-TRODAT-1 (TR), in order to assess their differential diagnostic power in early parkinsonism and their sensitivity for detection of disease progression. This cross-sectional study was conducted on 96 patients with early-stage parkinsonism referred in a tertiary clinical setting. Mean disease duration was 2.0±1.3 years, and patients had a modified Hoehn and Yahr (H and Y) stage of 1-2 (average 1.2). Forty-seven patients received TR, and 49 received FP. In both groups, ten patients with normal presynaptic function were included as a control population; all other patients were clinically diagnosed as having idiopathic Parkinson's disease. Groups were matched for gender, age, disease duration and modified H and Y stage. Triple-head gamma camera SPECT was analysed using a semiquantitative index of transporter binding (BI). Discriminant analysis with cross-validation resulted in a maximal classification accuracy for FP of 93% (sensitivity 95% and specificity 86%) for the contralateral putamen BI. For TR, the corresponding values were 87% accuracy, 92% sensitivity and 70% specificity. For FP, disease duration was correlated with both the putamen BI (-8.8%/year, ρ=-0.41, P=0.025) and the putamen/caudate ratio (-7.4%/year, ρ=-0.51, P=0.004), but for TR no significant correlation was found (all P values >0.5). In conclusion, both FP and TR show high sensitivity in a clinically relevant setting, but FP has superior accuracy for early differential diagnosis of idiopathic parkinsonism and non-degenerative extrapyramidal disorders, as well as better sensitivity for disease follow-up. (orig.)

N-isopropyl-p-[I[sup 123

Energy Technology Data Exchange (ETDEWEB)

Tada, Hiroshi; Morooka, Keiichi; Arimoto, Kiyoshi; Matsuo, Takiko; Takagi, Kazue; Yanagawa, Etsuko (Toho Univ., Tokyo (Japan). School of Medicine)

1992-09-01

We studied the clinical usefulness of I[sup 123]-IMP SPECT in 50 pediatric patients with CNS disorders, which were categorized into the convulsive disorder group (n=20), the cerebrovascular disorder group (n=10), the acute encephalopathy or CNS infection group (n=10), the metabolic or degenerative disorder group (n=6), the congenital abnormality group (n=2) and the migraine group (n=2). The findings obtained were compared with those of cranial CT. I[sup 123]-IMP SPECT revealed abnormal findings in 45 out of the 50 patients (90%), although cranial CT showed abnormal findings in only 24 patients (48%). This difference was statistically significant (p<0.01). In all groups except the migraine, we could find abnormal findings in more than 90% of the patients. Out of 28 patients without focal findings on the initial CT scanning. I[sup 123]-IMP SPECT showed focal abnormalities in 26 patients (93%). Moreover in many patients with focal neurological abnormalities, we found focal abnormalities of I[sup 123]-IMP SPECT related with neurological abnormalities of the patients. From these findings, we think I[sup 123]-IMP SPECT might be superior to CT scanning in examining a localized lesion. It was found that in many patients with focal abnormalities in CT scanning, I[sup 123]-IMP SPECT showed larger abnormalities in CT scanning. By using I[sup 123]-IMP SPECT we might be able to study the blood perfusional state surrounding the abnormal area shown by CT. In 3 patients with acute cerebrovascular disorders, I[sup 123]-IMP SPECT revealed abnormal findings 3 to 11 days earlier than cranial CT. I[sup 123]-IMP SPECT might be useful for early recognition of the pathological state. From these experiences, we concluded that I[sup 123]-IMP SPECT was useful for studying the pathophysiology of CNS disorders in children. (author).

Production and application of 123I-labeled M-iodobenzylguanidine (123I-MIBG)

International Nuclear Information System (INIS)

Washburn, L.C.; Khosla, R.C.; Williams, C.C.; Gelfand, M.J.; Maxon, H.R.

1993-01-01

For the past two years the authors have been producing 123 I-MIBG for diagnosis and evaluation of neural crest tumors in both pediatric and adult patients. The method of Mock and Weiner (Appl. Radiat. Isot. 39:939-942, 1988) was used. Out of 89 attempted runs, 87 were successful in meeting the 90% radiochemical purity required for patient administration; both failures occurred during the first six months of the project. The 87 runs provided 144 pediatric doses and 48 adult doses. The radiochemical yield, not corrected for decay, was 67.7 ± 10.3% (mean ± S.D.). The radiochemical purity of the successful runs was 99.3 ± 1.3%, with 71 of the 87 runs giving a radiochemical purity of >99%. The radionuclidic purity of the I-123, obtained as sodium [ 123 I]iodide from Nordion International, was 99.985 ± 0.008%. Bacterial endotoxins, determined by the Limulus amebocyte lysate technique, were below the detectable level of 0.31 EU/mL for all batches of 123 I-MIBG. Sterility tests using both trypticase soy broth and fluid thioglycollate medium were negative for all batches except two, which showed growth of nonpathogenic microorganisms probably introduced during inoculation of the culture medium. 123 I-MIBG has thus been reliably prepared in high yield and excellent purity, and it has proved to be a valuable agent for diagnosis and evaluation of neural crest tumors in both children and adults

Renovascular hypertension screening with iodine-123 orthoiodohippurate

International Nuclear Information System (INIS)

Oppenheim, B.E.; Appledorn, C.R.; Mock, B.H.; Yune, H.Y.; Grim, C.E.

1985-01-01

Screening of 123 hypertensive patients for renovascular disease was carried out through renal studies, performed with iodine-123 ortho-iodohippurate (OIH), consisting of 214 studies performed with high-purity 123 I-OIH and 10 studies performed with 123 I-OIH contaminated with 124 I. Standard dynamic renal images and renogram curves were supplemented by functional renal images generated by computer. For the same radiation dose to the bladder, the number of detected photons with contaminated 123 I-OIH is only about one-third of that for high-purity 123 I-OIH so that for comparable studies one must use at least twice the dose with the former agent as compared with the latter. The study was hampered by erratic delivery of 123 I-OIH, which demonstrated the need for a reliable source

Trükitööstuste TOP 50

Index Scriptorium Estoniae

2002-01-01

Trükitööstuste TOP 50. Käibe TOP 30. Käibe kasum TOP 30. Kasvu TOP 30. Kasumi kasvu TOP 30. Rentaabluse TOP. Varade tootlikkuse TOP. Trükitööstusettevõtete üldandmed. Trükitööstusettevõtete finantsandmed

10 CFR 71.123 - Test control.

Science.gov (United States)

2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false Test control. 71.123 Section 71.123 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PACKAGING AND TRANSPORTATION OF RADIOACTIVE MATERIAL Quality Assurance § 71.123 Test control. The licensee, certificate holder, and applicant for a CoC shall establish a test...

N-isopropyl-p-[I123] iodoamphetamine single photon emission computed tomography (I123-IMP SPECT) and child neurology

International Nuclear Information System (INIS)

Tada, Hiroshi; Morooka, Keiichi; Arimoto, Kiyoshi; Matsuo, Takiko; Takagi, Kazue; Yanagawa, Etsuko

1992-01-01

We studied the clinical usefulness of I 123 -IMP SPECT in 50 pediatric patients with CNS disorders, which were categorized into the convulsive disorder group (n=20), the cerebrovascular disorder group (n=10), the acute encephalopathy or CNS infection group (n=10), the metabolic or degenerative disorder group (n=6), the congenital abnormality group (n=2) and the migraine group (n=2). The findings obtained were compared with those of cranial CT. I 123 -IMP SPECT revealed abnormal findings in 45 out of the 50 patients (90%), although cranial CT showed abnormal findings in only 24 patients (48%). This difference was statistically significant (p 123 -IMP SPECT showed focal abnormalities in 26 patients (93%). Moreover in many patients with focal neurological abnormalities, we found focal abnormalities of I 123 -IMP SPECT related with neurological abnormalities of the patients. From these findings, we think I 123 -IMP SPECT might be superior to CT scanning in examining a localized lesion. It was found that in many patients with focal abnormalities in CT scanning, I 123 -IMP SPECT showed larger abnormalities in CT scanning. By using I 123 -IMP SPECT we might be able to study the blood perfusional state surrounding the abnormal area shown by CT. In 3 patients with acute cerebrovascular disorders, I 123 -IMP SPECT revealed abnormal findings 3 to 11 days earlier than cranial CT. I 123 -IMP SPECT might be useful for early recognition of the pathological state. From these experiences, we concluded that I 123 -IMP SPECT was useful for studying the pathophysiology of CNS disorders in children. (author)

40 CFR 123.61 - Approval process.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Approval process. 123.61 Section 123... REQUIREMENTS Program Approval, Revision, and Withdrawal § 123.61 Approval process. (a) After determining that a...; and (6) Briefly outline the fundamental aspects of the State's proposed program, and the process for...

Renal function study using I-123-OIH

International Nuclear Information System (INIS)

Yamashita, Masato; Osaka, Yosio; Aikawa, Ichiro

1989-01-01

Twenty-eight renal function studies were performed in 24 patients with renal diseases with I-123 orthoiodohippurate (I-123 OIH). Neither side effects nor abnormal laboratory values were attributable to I-123 OIH. Imaging with Tc-99m diethylene triaminepentaacetic acid (DTPA) was also performed in 20 patients within one week after I-123 imaging. Findings with I-123 OIH and Tc-99m DTPA were similar in all except for two patients. The two patients had received cadaveric renal transplantation. One patient presented with acute tubular necrosis and the other with chronic renal rejection. In these patients, I-123 imaging showed vascular stricture and Tc-99m imaging showed a decreased glomerular function. Because I-123 OIH and Tc-99m DTPA had different pharmacodynamics, combined use of the two imaging agents may be useful in evaluating renal rejection or acute tubular necrosis. (N.K.)

Striatal uptake of I-123-β-CIT and I-123-IBZM in patients with extrapyramidal symptoms

International Nuclear Information System (INIS)

Bettin, S.; Kaempfer, I.; Seese, A.; Schaefer, A.; Reuter, M.; Loessner, J.; Dietrich, J.; Wagner, A.; Knapp, W.H.

1997-01-01

Aim: This pilot study deals with the question whether characteristic changes in local cerebral dopamine transporter function and D 2 -receptor binding capacity can be shown with SPET, in idiopathic Parkinson syndrome (IPS) and secondary Parkinson syndrome (SPS). Methods: In 16 patients (6 with IPS, 6 with SPS except Wilsons's disease, and 4 with Wilson's disease) SPET studies were performed using I-123-β-CIT and I-123-IBZM and a dual-head gamma camera. Images were obtained 20-24 h and 2 h post injection, respectively. For semiquantitative analysis count density ratios of basal ganglia (BG) and cerebellum (CER) were determined for I-123-β-CIT and ratios between BG and medial frontal cortex (MFC) for I-123-IBZM. Results: The BG/CER ratio in the I-123-β-CIT studies averaged 3.04±0.83 in IPS and 7.73±3.28 in SPS (p [de

Characterization of SGN-CD123A, A Potent CD123-Directed Antibody-Drug Conjugate for Acute Myeloid Leukemia.

Science.gov (United States)

Li, Fu; Sutherland, May Kung; Yu, Changpu; Walter, Roland B; Westendorf, Lori; Valliere-Douglass, John; Pan, Lucy; Cronkite, Ashley; Sussman, Django; Klussman, Kerry; Ulrich, Michelle; Anderson, Martha E; Stone, Ivan J; Zeng, Weiping; Jonas, Mechthild; Lewis, Timothy S; Goswami, Maitrayee; Wang, Sa A; Senter, Peter D; Law, Che-Leung; Feldman, Eric J; Benjamin, Dennis R

2018-02-01

Treatment choices for acute myelogenous leukemia (AML) patients resistant to conventional chemotherapies are limited and novel therapeutic agents are needed. IL3 receptor alpha (IL3Rα, or CD123) is expressed on the majority of AML blasts, and there is evidence that its expression is increased on leukemic relative to normal hematopoietic stem cells, which makes it an attractive target for antibody-based therapy. Here, we report the generation and preclinical characterization of SGN-CD123A, an antibody-drug conjugate using the pyrrolobenzodiazepine dimer (PBD) linker and a humanized CD123 antibody with engineered cysteines for site-specific conjugation. Mechanistically, SGN-CD123A induces activation of DNA damage response pathways, cell-cycle changes, and apoptosis in AML cells. In vitro , SGN-CD123A-mediated potent cytotoxicity of 11/12 CD123 + AML cell lines and 20/23 primary samples from AML patients, including those with unfavorable cytogenetic profiles or FLT3 mutations. In vivo , SGN-CD123A treatment led to AML eradication in a disseminated disease model, remission in a subcutaneous xenograft model, and significant growth delay in a multidrug resistance xenograft model. Moreover, SGN-CD123A also resulted in durable complete remission of a patient-derived xenograft AML model. When combined with a FLT3 inhibitor quizartinib, SGN-CD123A enhanced the activity of quizartinib against two FLT3-mutated xenograft models. Overall, these data demonstrate that SGN-CD123A is a potent antileukemic agent, supporting an ongoing trial to evaluate its safety and efficacy in AML patients (NCT02848248). Mol Cancer Ther; 17(2); 554-64. ©2017 AACR . ©2017 American Association for Cancer Research.

32 CFR 701.123 - PA fees.

Science.gov (United States)

2010-07-01

... 32 National Defense 5 2010-07-01 2010-07-01 false PA fees. 701.123 Section 701.123 National... OFFICIAL RECORDS AVAILABILITY OF DEPARTMENT OF THE NAVY RECORDS AND PUBLICATION OF DEPARTMENT OF THE NAVY DOCUMENTS AFFECTING THE PUBLIC DON Privacy Program § 701.123 PA fees. The PA fee schedule is only applicable...

The roles of testicular nuclear receptor 4 (TR4 in male fertility-priapism and sexual behavior defects in TR4 knockout mice

Directory of Open Access Journals (Sweden)

Bao Bo-Ying

2011-10-01

Full Text Available Abstract Background Successful reproductive efforts require the establishment of a situation favorable for reproduction that requires integration of both behavior and internal physiological events. TR4 nuclear receptor is known to be involved in male fertility via controlling spermatogenesis, yet its roles in regulating other biological events related to reproduction have not been completely revealed. Methods Male TR4 knockout (TR4-/- and wild type mice were used for the sexual behavior and penile dysfunction studies. Mice were sacrificed for histological examination and corresponding genes profiles were analyzed by quantitative RT-PCR. Reporter gene assays were performed. Results We describe an unexpected finding of priapism in TR4-/- mice. As a transcriptional factor, we demonstrated that TR4 transcriptionally modulates a key enzyme regulating penis erection and neuronal nitric oxide synthese NOS (nNOS. Thereby, elimination of TR4 results in nNOS reduction in both mRNA and protein levels, consequently may lead to erectile dysfunction. In addition, male TR4-/- mice display defects in sexual and social behavior, with increased fear or anxiety, as well as reduced mounting, intromission, and ejaculation. Reduction of ER alpha, ER beta, and oxytocin in the hypothalamus may contribute to defects in sexual behavior and stress response. Conclusions Together, these results provide in vivo evidence of important TR4 roles in penile physiology, as well as in male sexual behavior. In conjunction with previous finding, TR4 represents a key factor that controls male fertility via regulating behavior and internal physiological events.

Dosimetry of iodine-123 for newborn and infant

International Nuclear Information System (INIS)

Guilhem, M.T.; Therain, F.

1987-01-01

Iodine-123 ( 123 I) is a radionuclide of choice of neonatal hypothyroidism diagnosis. It is important to know infant main organs adsorbed doses during a thyroid scan with 123 I. Absorbed doses are already available for adults: for infants, they must be transformed taking account of organs sizes and inter-organs distances. Calculations are done for commercially available 123 I(p,2n) and 123 I(p,5n). Important contamination of 124 I in 123 I(p,2n) increases considerably the absorbed-dose during thyroid scan of a newborn (the ratio 124 I/ 123 I doubles every 15h). For routinely used activities, thyroid absorbed dose, 24 h after end of production, is fifteen times higher with 123 I(p,5n) than with 99m Tc: for one month old child; total body absorbed dose is of the same order of magnitude [fr

Industrial system for producing iodine-123

International Nuclear Information System (INIS)

Brantley, J.C.

1985-01-01

An industrial system to produce iodine-123 required a complex set of steps involving new approaches by the Food and Drug Administration, difficult distribution procedures, and evidence from potential users that either very pure iodine-123 or inexpensive iodine-123 is needed. Industry has shown its willingness to invest in new radionuclides but needs strong evidence as to product potential to justify those investments

Tallinna linna- ja gümnaasiumi trükikoda ehk 380 aastat trükikunsti Tallinnas / Aija Sakova-Merivee

Index Scriptorium Estoniae

Sakova-Merivee, Aija, 1980-

2015-01-01

Alanud aasta alguses esitlesid Tallinna Ülikooli Akadeemiline Raamatukogu ja Tallinna Linnaarhiiv ühist trükist „Tallinna linna- ja gümnaasiumi trükikoda (1634–1828). Näituse kataloog”. Autor annab ülevaate nii näitusest kui selle kataloogist

18 CFR 284.123 - Rates and charges.

Science.gov (United States)

2010-04-01

... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Rates and charges. 284.123 Section 284.123 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION... AUTHORITIES Certain Transportation by Intrastate Pipelines § 284.123 Rates and charges. (a) General rule...

49 CFR 38.123 - Restrooms.

Science.gov (United States)

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false Restrooms. 38.123 Section 38.123 Transportation Office of the Secretary of Transportation AMERICANS WITH DISABILITIES ACT (ADA) ACCESSIBILITY... measured to the top of the toilet seat. Seats shall not be sprung to return to a lifted position. (3) A...

19 CFR 123.31 - Merchandise in transit.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Merchandise in transit. 123.31 Section 123.31... TREASURY CUSTOMS RELATIONS WITH CANADA AND MEXICO Shipments in Transit Through the United States § 123.31 Merchandise in transit. (a) From one contiguous country to another. Merchandise may be transported in transit...

19 CFR 123.21 - Merchandise in transit.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Merchandise in transit. 123.21 Section 123.21... TREASURY CUSTOMS RELATIONS WITH CANADA AND MEXICO Shipments in Transit Through Canada or Mexico § 123.21 Merchandise in transit. (a) Status. Merchandise may be transported from one port to another in the United...

29 CFR 780.123 - Raising of bees.

Science.gov (United States)

2010-07-01

... 29 Labor 3 2010-07-01 2010-07-01 false Raising of bees. 780.123 Section 780.123 Labor Regulations... Raising of Livestock, Bees, Fur-Bearing Animals, Or Poultry § 780.123 Raising of bees. The term “raising of * * * bees” refers to all of those activities customarily performed in connection with the...

A novel adsorbent obtained by inserting carbon nanotubes into cavities of diatomite and applications for organic dye elimination from contaminated water.

Science.gov (United States)

Yu, Hongwen; Fugetsu, Bunshi

2010-05-15

A novel approach is described for establishing adsorbents for elimination of water-soluble organic dyes by using multi-walled carbon nanotubes (MWCNTs) as the adsorptive sites. Agglomerates of MWCNTs were dispersed into individual tubes (dispersed-MWCNTs) using sodium n-dodecyl itaconate mixed with 3-(N,N-dimethylmyristylammonio)-propanesulfonate as the dispersants. The resultant dispersed-MWCNTs were inserted into cavities of diatomite to form composites of diatomite/MWCNTs. These composites were finally immobilized onto the cell walls of flexible polyurethane foams (PUF) through an in situ PUF formation process to produce the foam-like CNT-based adsorbent. Ethidium bromide, acridine orange, methylene blue, eosin B, and eosin Y were chosen to represent typical water-soluble organic dyes for studying the adsorptive capabilities of the foam-like CNT-based adsorbent. For comparisons, adsorptive experiments were also carried out by using agglomerates of the sole MWCNTs as adsorbents. The foam-like CNT-based adsorbents were found to have higher adsorptive capacities than the CNT agglomerates for all five dyes; in addition, they are macro-sized, durable, flexible, hydrophilic and easy to use. Adsorption isotherms plotted based on the Langmuir equation gave linear results, suggesting that the foam-like CNT-based adsorbent functioned in the Langmuir adsorption manner. The foam-like CNT-based adsorbents are reusable after regeneration with aqueous ethanol solution. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Kronisk træthedssyndrom, en usynlig sygdom?

DEFF Research Database (Denmark)

Jentoft Olsen, Rikke Katrine; Martlev, Lasse; Fernandez Guerra, Paula

2018-01-01

Seahorse XF-teknologi kan måle cellers evne til at producere energi under stress og afslører dysfunktionelle energisystemer i kronisk træthedssyndrom......Seahorse XF-teknologi kan måle cellers evne til at producere energi under stress og afslører dysfunktionelle energisystemer i kronisk træthedssyndrom...

Clinical utility of N-isopropyl-p-[123I] iodoamphetamine (123I-IMP) for SPECT in epileptic children

International Nuclear Information System (INIS)

Taki, Kuniyasu; Seto, Hikaru; Futatsuya, Ryusuke; Kakishita, Masao; Seki, Hiroyasu.

1989-01-01

A regional cerebral perfusion study was performed in epileptic children using single photon emission computed tomography (SPECT) and N-isopropyl-p-[ 123 I] iodoamphetamine ( 123 I-IMP). A total of 22 patients with epilepsy underwent both a 123 I-IMP brain perfusion study and X-ray CT. Eighteen had positive and four had negative perfusion study results. Of the eighteen patients with positive perfusion study results, two were positive on X-ray CT. In these two patients, the areas of perfusion defects were larger than those of low density on X-ray CT. In only four patients did the areas of perfusion defects correspond to the sites of abnormal EEG. In conclusion, 123 I-IMP perfusion study is of great clinical value in pediatric epileptic cases. (author)

Production of 123 I for medical diagnosis application

International Nuclear Information System (INIS)

Britto, J.L.Q. de.

1982-01-01

A method for production of carrier free 123 I with high radionuclidic purity in which the processing is done remotely was developed at Instituto de Engenharia Nuclear in Rio de Janeiro. The 123 I is produced in the decay of 123 Xe which is obtained through the reaction 122 Te ( 3 He, 2 n) 123 Xe with 30 MeV 3 He beams of IEN's variable energy cyclotron. The irradiated natural Te O 2 target is heated in a furnace at 675 0 C and the diffused out 123 Xe is adsorbed in a copper trap maintained at -196 0 C. The 123 Xe is allowed to decay during 6.3 hours and the 123 I produced washed out of the trap with a 0.1 N solution of NaOH. All the process is remotely controlled by using electric and pneumatic systems as well as manipulators and tongs. The quality control was achieved by atomic absorption and gamma-ray spectroscopy. (author)

Synthesis and structural characterization of the Zintl phases Na{sub 3}Ca{sub 3}TrPn{sub 4}, Na{sub 3}Sr{sub 3}TrPn{sub 4}, and Na{sub 3}Eu{sub 3}TrPn{sub 4} (Tr=Al, Ga, In; Pn=P, As, Sb)

Energy Technology Data Exchange (ETDEWEB)

Wang, Yi [Department of Chemistry & Biochemistry, University of Delaware, 304A Drake Hall, Newark, DE 19716 (United States); Suen, Nian-Tzu [Department of Chemistry & Biochemistry, University of Delaware, 304A Drake Hall, Newark, DE 19716 (United States); College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002 (China); Kunene, Thabiso; Stoyko, Stanislav [Department of Chemistry & Biochemistry, University of Delaware, 304A Drake Hall, Newark, DE 19716 (United States); Bobev, Svilen, E-mail: bobev@udel.edu [Department of Chemistry & Biochemistry, University of Delaware, 304A Drake Hall, Newark, DE 19716 (United States)

2017-05-15

15 new quaternary Zintl phases have been synthesized by solid-state reactions from the respective elements, and their structures have been determined by single-crystal X-ray diffraction. Na{sub 3}E{sub 3}TrPn{sub 4} (E=Ca, Sr, Eu; Tr=Al, Ga, In; Pn=P, As, Sb) crystallize in the hexagonal crystal system with the non-centrosymmetric space group P6{sub 3}mc (No. 186). The structure represents a variant of the K{sub 6}HgS{sub 4} structure type (Pearson index hP22) and features [TrPn{sub 4}]{sup 9–} tetrahedral units, surrounded by Na{sup +} and Ca{sup 2+}, Sr{sup 2+}, Eu{sup 2+} cations. The nominal formula rationalization [Na{sup +}]{sub 3}[E{sup 2+}]{sub 3}[TrPn{sub 4}]{sup 9–} follows the octet rule, suggesting closed-shell configurations for all atoms and intrinsic semiconducting behavior. However, structure refinements for several members hint at disorder and mixing of cations that potentially counteract the optimal valence electron count. - Graphical abstract: The hexagonal, non-centrosymmetric structure of Na{sub 3}E{sub 3}TrPn{sub 4} (E=Ca, Sr, Eu; Tr=Al, Ga, In; Pn=P, As, Sb) features [TrPn{sub 4}]{sup 9–} tetrahedral units, surrounded by Na{sup +} and Ca{sup 2+}, Sr{sup 2+}, Eu{sup 2+} cations. - Highlights: • 15 quaternary phosphides, arsenides, and antimonides are synthesized and structurally characterized. • The structure is a variant of the hexagonal K{sub 6}HgS{sub 4}-type, with distinctive pattern for the cations. • Occupational and/or positional disorder of yet unknown origin exists for some members of the series.

A ironia trágica de Machado de Assis

Directory of Open Access Journals (Sweden)

Patrick Pessoa

2007-04-01

Full Text Available O texto defende, a partir de uma análise das Memórias póstumas de Brás Cubas, de Machado de Assis, que a ironia do autor deve ser lida como uma espécie de ironia trágica. A fundamentação dessa hipótese é realizada em três etapas: na primeira, apresenta-se o conceito de ironia trágica, como tematizado por Christoph Menke e Wayne Booth; na segunda, mostra-se como a noção de ironia trágica permite compreender a célebre definição de Lukács de que “a ironia é a objetividade do romance”; finalmente, o texto discute como o conceito de ironia trágica ao mesmo tempo esclarece e subverte as interpretações tradicionais da obra de Machado de Assis.

Aasta trükise 2000 võitjad selgunud

Index Scriptorium Estoniae

2000-01-01

Rahvusvaheline žürii valis välja 6 raamatut, reklaam- ja väiketrükist ning etiketiseeria. Parimad trükised, trükikojad, kujundajad. Publikuauhinna võitsid üliõpilased Terje Homutov, Monika Eensalu, Tim Kolk

Assessment of cerebral benzodiazepine receptor distribution in anxiety disorders by 123I-iomazenil-SPECT. Comparison to cerebral perfusion scintigraphy by 123I-IMP

International Nuclear Information System (INIS)

Uchiyama, Mayuki; Sue, Hironari; Fukumitsu, Nobuyoshi; Mori, Yutaka; Kawakami, Kenji

1997-01-01

123 I-Iomazenil ( 123 I-IMZ) and 123 I-IMP imaging were performed in 5 patients with anxiety disorder (PAD) and 6 normal volunteers (NV). On 123 I-IMZ delayed imaging, the 2 PAD showed abnormally decreased findings. In anxiety disorder, decreased accumulation on 123 I-IMZ delayed images was seen in left hippocampus and parahippocampal gyrus in one patient, in right frontal and temporal lobe and left occipital pole in the other. Compared with NV, PAD had lower 123 I-IMZ uptake on delayed image in right upper and left lower frontal cortices, indicating the involvement of the benzodiazepine receptor complex in anxiety disorder. Compared with grading for anxiety disorder with Hamilton anxiety scale (HAS) and delayed to early count ratios of 123 I-IMZ, negative correlation (R 123 I-IMP image, positive correlation (R>0.7) was recognized in the hippocampus, the parahippocampal gyrus, the lower outer temporal cortex and the lower frontal cortex. (author)

The earth grind or ''diatomite'' as the removal of chemicals in the laboratory

International Nuclear Information System (INIS)

Alfaro Vargas, Ariel

2007-01-01

Experiments were carried out to determine the capability of diatomite for the disposal of laboratory residues. Experimentation with different organic solvents (ethyl ether, acetone, ethyl acetate, hexane and ethanol) verified that there is no solvent absorption in the mineral material. Experiments were also carried out with heavy metal cations, in order to quantify their absorption or adsorption in the porous mineral. Ion sequestration was determined and the following order resulted: Cr 3+ > Pb 2+ > Ag + > Ni 2+ > Zn 2+ > Cr 2 O 7 2- . The effect of pH was also studied with nickel, 99,5% removal was observed at pH 7, SO 4 2- was 98% removed, followed by Cl - and NO 3 - . The ideal cation concentration was 4 ppm with a removal efficiency of 99,5%. It is possible to conclude that the absorption material can be used as effusion containment system, rather than a material to eliminate laboratory residues. (author) [es

Clarification of sodium silicate solutions derived from diatomites, to improve their industrial expectations

International Nuclear Information System (INIS)

Aguilar Cantillano, Eduardo

2000-01-01

solutions of soluble silicates synthesized have been clarified in Costa Rica from diatomite in almost 50% of their initial coloration. Clarification and removal of iron oxides have been achieved in a higher order of 50% m/m expressed as Fe 2 O 3 . Activated carbon treatment has clarified the scope of [31-57]%, but not significantly decreases the iron content. The application of NaClO to 3% m/m clarifies the scope of [28-51]%, and reduced iron by 48% m/m. The land alone has been shown that is not very effective filter to clarify, [0-14]%, but is effective for the stripping of iron by 68% m/m. Other procedures are effective in clarifying the scope of [42-51]% and reduced the amount of iron in the field of [48-66]%. The synthesis of soluble glasses is possible to clarify for conditioning with commercial purposes diverse, treatment methodologies and analytical control, simple and economical. (author) [es

40 CFR 123.3 - Coordination with other programs.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Coordination with other programs. 123.3 Section 123.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS STATE PROGRAM REQUIREMENTS General § 123.3 Coordination with other programs. Issuance of State permits...

Labeling of indocyanine green with carrier-free iodine-123

International Nuclear Information System (INIS)

Ansari, A.N.; Lambrecht, R.M.; Redvanly, C.S.; Wolf, A.P.

1976-01-01

The method is described for labeling indocyanine green (ICG) with carrier-free iodine-123 by condensing xenon-123 on crystals of ICG followed by permitting decay of the 123 Xe a sufficient length of time to produce 123 I-electronically excited ions and atoms which subsequently label ICG. 4 claims, no drawings

Quantitative SPECT reconstruction of iodine-123 data

International Nuclear Information System (INIS)

Gilland, D.R.; Jaszczak, R.J.; Greer, K.L.; Coleman, R.E.

1991-01-01

Many clinical and research studies in nuclear medicine require quantitation of iodine-123 ( 123 I) distribution for the determination of kinetics or localization. The objective of this study was to implement several reconstruction methods designed for single-photon emission computed tomography (SPECT) using 123 I and to evaluate their performance in terms of quantitative accuracy, image artifacts, and noise. The methods consisted of four attenuation and scatter compensation schemes incorporated into both the filtered backprojection/Chang (FBP) and maximum likelihood-expectation maximization (ML-EM) reconstruction algorithms. The methods were evaluated on data acquired of a phantom containing a hot sphere of 123 I activity in a lower level background 123 I distribution and nonuniform density media. For both reconstruction algorithms, nonuniform attenuation compensation combined with either scatter subtraction or Metz filtering produced images that were quantitatively accurate to within 15% of the true value. The ML-EM algorithm demonstrated quantitative accuracy comparable to FBP and smaller relative noise magnitude for all compensation schemes

Ginkgo biloba extract alters the binding of the sodium [123I] iodide (Na123I) on blood constituents

International Nuclear Information System (INIS)

Aleixo, Luiz Cláudio Martins; Moreno, Silvana Ramos Farias; Freitas, Rosimeire de Souza; Thomaz, Hélio; Santos-Filho, Sebastião David

2012-01-01

We evaluated the in vitro effect of an aqueous extract of Ginkgo biloba (EGb) on the distribution in blood cells (BC) and plasma (P) and on the binding of Na 123 I to the blood constituents using precipitation with trichloroacetic acid. The radioactivity percentages insoluble (SF) and insoluble fraction (IF) of blood constituents were determined. The EGb interfered (p 123 I in the P (from 69.64 to 86.13) and BC (from 30.36 to 13.87) and altered the fixation of the Na 123 I in IF-P and in IF-BC. - Highlights: ► Interaction between the Ginkgo biloba and blood constituents radiolabeled. ► Modification of the binding of sodium iodide (Na 123 I) to the blood constituents. ► This alteration should have influence in a diagnosis of nuclear medicine.

Preparation of Si3N4 Form Diatomite via a Carbothermal Reduction-Nitridation Process

Science.gov (United States)

Ma, Bin; Huang, Zhaohui; Mei, Lefu; Fang, Minghao; Liu, Yangai; Wu, Xiaowen; Hu, Xiaozhi

2016-05-01

Si3N4 was produced using diatomite and sucrose as silicon and carbon sources, respectively. The effect of the C/SiO2 molar ratio, heating temperature and soaking time on the morphology and phase compositions of the final products was investigated by scanning electron microscopy, x-ray diffraction analysis and energy dispersive spectroscopy. The phase equilibrium relationships of the system at different heating temperatures were also investigated based on the thermodynamic analysis. The results indicate that the phase compositions depended on the C/SiO2 molar ratio, heating temperature and soaking time. Fabrication of Si3N4 from the precursor via carbothermal reduction nitridation was achieved at 1550°C for 1-8 h using a C/SiO2 molar ratio of 3.0. The as-prepared Si3N4 contained a low amount of Fe3Si (<1 wt.%).

Diatomite-Templated Synthesis of Freestanding 3D Graphdiyne for Energy Storage and Catalysis Application.

Science.gov (United States)

Li, Jiaqiang; Xu, Jing; Xie, Ziqian; Gao, Xin; Zhou, Jingyuan; Xiong, Yan; Chen, Changguo; Zhang, Jin; Liu, Zhongfan

2018-05-01

Graphdiyne (GDY), a new kind of two-dimensional (2D) carbon allotropes, has extraordinary electrical, mechanical, and optical properties, leading to advanced applications in the fields of energy storage, photocatalysis, electrochemical catalysis, and sensors. However, almost all reported methods require metallic copper as a substrate, which severely limits their large-scale application because of the high cost and low specific surface area (SSA) of copper substrate. Here, freestanding three-dimensional GDY (3DGDY) is successfully prepared using naturally abundant and inexpensive diatomite as template. In addition to the intrinsic properties of GDY, the fabricated 3DGDY exhibits a porous structure and high SSA that enable it to be directly used as a lithium-ion battery anode material and a 3D scaffold to create Rh@3DGDY composites, which would hold great potential applications in energy storage and catalysts, respectively. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

10 CFR 1040.123 - Consolidated or joint hearings.

Science.gov (United States)

2010-01-01

... ACTIVITIES Enforcement Opportunity for Hearing § 1040.123 Consolidated or joint hearings. In cases in which... 10 Energy 4 2010-01-01 2010-01-01 false Consolidated or joint hearings. 1040.123 Section 1040.123... departments or agencies, where applicable, provide for the conduct of consolidated or joint hearings and for...

15-(para-[123I]iodophenyl) pentadecanoic acid obtained using mercuration and subsequent [123I] radioiodination

International Nuclear Information System (INIS)

Dougan, H.; Vincent, J.S.; Lyster, D.M.

1989-01-01

The present work explores the basic reactions necessary for the preparation of [ 123 I] 15-(paraiodophenyl)-pentadecanoic acid (IPPA) from organo mercury compounds. It was found that the essential reactions occur readily and with good yield. The steps were as follows: phenyl pentadecanoic acid or its ethyl ester may be mercurated using Hg(TFA) 2 in TFA solvent, and the para-chloromercury compounds may be recovered. [ 123 I] radioiodination may be carried out in a variety of solvents in the presence of chloramine T. When radioiodination was conducted at room temperature the isomeric purity of the ester or fatty acid was found to be 99.9% para. The results indicate that poor solubility of certain mercurated pentadecanoic acid compounds will limit the development of a kit for [ 123 I]IPPA. (author) 16 refs.; 2 tabs

A New Type of Synthesis of 1,2,3-Thiadiazole and 1,2,3-Diazaphosphole Derivatives Via-Hurd-Mori Cyclization

Directory of Open Access Journals (Sweden)

Mona A. Hosny

2012-01-01

Full Text Available We present a short and efficient synthesis of the title compounds starting with cheap and readily available camphor and derivatives of acetophenone. The optimized sequence allows the large-scale preparation of this new type of synthesis in a few steps. New 1,2,3-thiadiazole and 1,2,3-diazaphosphole derivatives 11-20, were prepared from the ketones 1-5 via the corresponding semicarbazones 6-10. The Hurd-Mori and Lalezari methods were used, respectively, for the preparation of these 1,2,3-thiadiazole and 1,2,3-diazaphospholene derivatives. These derivatives exhibit anticancer effect due to their high potential biological activity.

27 CFR 28.123 - Export marks.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.123..., or Transportation to a Manufacturing Bonded Warehouse § 28.123 Export marks. (a) General. In addition... filled under the provisions of part 24 of this chapter, the proprietor shall mark the word “Export” on...

21 CFR 123.7 - Corrective actions.

Science.gov (United States)

2010-04-01

... of their HACCP plans in accordance with § 123.6(c)(5), by which they predetermine the corrective... in accordance with § 123.10, to determine whether the HACCP plan needs to be modified to reduce the risk of recurrence of the deviation, and modify the HACCP plan as necessary. (d) All corrective actions...

27 CFR 31.123 - New corporation.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false New corporation. 31.123... Requiring Registration As A New Business § 31.123 New corporation. Where a new corporation is formed to take over and conduct the business of one or more corporations that have registered under this part, the new...

Production of 123I for medical use with small accelerators

International Nuclear Information System (INIS)

Beyer, G.J.; Pimentel, G.; Solin, O.; Heselius, S.J.; Taka, T.

1988-01-01

The possibilities of 123 I production with small accelerators are discussed. Among the possible nuclear reactions the 122 Te(d,n) 123 I and the 123 Te(p,n) 123 I reaction are of particular interest for those institutions, who do not run a cyclotron with particle energies for protons above 18-20 MeV. The use of TeO 2 as target material is advantaged over Te. The 123 I preparations contain resonable amounts of 130 I and 124 I. The most 'dangerous' impurity is 130 I due to its high energy gamma radiation. Nevertheless, high quality imagings may be obtained using medium or high energy collimators loosing some of the advantages of 123 I. The proposed approach is the only way to make 123 I available for a number of institutions or countries running small cyclotrons and for which commercial 123 I is difficult or impossible to obtain for economical or geographical reasons. (author)

TrED: the Trichophyton rubrum Expression Database

Directory of Open Access Journals (Sweden)

Liu Tao

2007-07-01

Full Text Available Abstract Background Trichophyton rubrum is the most common dermatophyte species and the most frequent cause of fungal skin infections in humans worldwide. It's a major concern because feet and nail infections caused by this organism is extremely difficult to cure. A large set of expression data including expressed sequence tags (ESTs and transcriptional profiles of this important fungal pathogen are now available. Careful analysis of these data can give valuable information about potential virulence factors, antigens and novel metabolic pathways. We intend to create an integrated database TrED to facilitate the study of dermatophytes, and enhance the development of effective diagnostic and treatment strategies. Description All publicly available ESTs and expression profiles of T. rubrum during conidial germination in time-course experiments and challenged with antifungal agents are deposited in the database. In addition, comparative genomics hybridization results of 22 dermatophytic fungi strains from three genera, Trichophyton, Microsporum and Epidermophyton, are also included. ESTs are clustered and assembled to elongate the sequence length and abate redundancy. TrED provides functional analysis based on GenBank, Pfam, and KOG databases, along with KEGG pathway and GO vocabulary. It is integrated with a suite of custom web-based tools that facilitate querying and retrieving various EST properties, visualization and comparison of transcriptional profiles, and sequence-similarity searching by BLAST. Conclusion TrED is built upon a relational database, with a web interface offering analytic functions, to provide integrated access to various expression data of T. rubrum and comparative results of dermatophytes. It is devoted to be a comprehensive resource and platform to assist functional genomic studies in dermatophytes. TrED is available from URL: http://www.mgc.ac.cn/TrED/.

More on the TR-OSL signal from BeO ceramics

International Nuclear Information System (INIS)

Bulur, Enver

2014-01-01

Time Resolved Optically Stimulated Luminescence (TR-OSL) from BeO ceramics was investigated using blue (445 nm) and near-IR light (852 nm) for stimulation. Stimulation spectrum of the TR-OSL signal – as measured in the interval 700 to 420 nm- was observed to increase monotonically with the decreasing stimulation wavelength. In addition to the “fast” and “slow” components observed with blue light stimulation, IR stimulated TR-OSL spectra of irradiated BeO ceramics were observed to have two components with average lifetimes around ∼2.5 μs and ∼17 μs. Emission spectra of the both IR stimulated TR-OSL components were observed to have a broad emission band peaking around 330 nm. Thermal stability of the IR stimulated TR-OSL signal was studied by making preheating experiments in the range from 100 °C to 190 °C. It was observed that the IR stimulated OSL signal is stable up to ∼150 °C and decay afterwards. Radiation dose response of the IR stimulated luminescence signal was obtained in the range from 5 to 500 Gy. Both blue and IR stimulated TR-OSL signals grew up to 100 Gy and exhibited saturation for higher doses. Additionally, measurement temperature dependence of the components was also investigated and for the ∼2 μs component thermal assistance with activation energy around 0.16 eV was observed. It seems that the fast component of the blue stimulated TR-OSL component can be correlated to the ∼2 μs IR stimulated TR-OSL component. - Highlights: • IR Stimulated Time-Resolved OSL from BeO was studied. • Two components with lifetimes ∼2 and ∼17us were observed. • IR stimulated TR-OSL signal is found to be stable up to 150 °C. • Thermal quenching energy of the 2us component was found as 0.16 eV

Rhodamine-123: a p-glycoprotein marker complex with sodium lauryl sulfate.

Science.gov (United States)

Al-Mohizea, Abdullah M; Al-Jenoobi, Fahad Ibrahim; Alam, Mohd Aftab

2015-03-01

Aim of this study was to investigate the role of sodium lauryl sulfate (SLS) as P-glycoprotein inhibitor. The everted rat gut sac model was used to study in-vitro mucosal to serosal transport of Rhodamine-123 (Rho-123). Surprisingly, SLS decreases the serosal absorption of Rho-123 at all investigated concentrations. Investigation reveals complex formation between Rhodamine-123 and sodium lauryl sulfate. Interaction profile of SLS & Rho-123 was studied at variable SLS concentrations. The SLS concentration higher than critical micelle concentration (CMC) increases the solubility of Rho-123 but could not help in serosal absorption, on the contrary the absorption of Rho-123 decreased. Rho-123 and SLS form pink color complex at sub-CMC. The SLS concentrations below CMC decrease the solubility of Rho-123. For further studies, Rho-123 & SLS complex was prepared by using solvent evaporation technique and characterized by using differential scanning calorimeter (DSC). Thermal analysis also proved the formation of complex between SLS & Rho-123. The P values were found to be significant (<0.05) except group comprising 0.0001% SLS, and that is because 0.0001% SLS is seems to be very low to affect the solubility or complexation of Rho-123.

Preparation of chitosan/amine modified diatomite composites and adsorption properties of Hg(II) ions.

Science.gov (United States)

Fu, Yong; Huang, Yue; Hu, Jianshe; Zhang, Zhengjie

2018-03-01

A green functional adsorbent (CAD) was prepared by Schiff base reaction of chitosan and amino-modified diatomite. The morphology, structure and adsorption properties of the CAD were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and Brunauer Emmett Teller measurements. The effect of pH value, contact time and temperature on the adsorption of Hg(II) ions for the CAD is discussed in detail. The experimental results showed that the CAD had a large specific surface area and multifunctional groups such as amino, hydroxyl and Schiff base. The optimum adsorption effect was obtained when the pH value, temperature and contact time were 4, 25 °C and 120 min, respectively, and the corresponding maximum adsorption capacity of Hg(II) ions reached 102 mg/g. Moreover, the adsorption behavior of Hg(II) ions for the CAD followed the pseudo-second-order kinetic model and Langmuir model. The negative ΔG 0 and ΔH 0 suggested that the adsorption was a spontaneous exothermic process.

Adsorption characteristics of Cs"+ onto artificial zeolites synthesized from coal fly ash and diatomite

International Nuclear Information System (INIS)

Johan, Erni; Yoshida, Kohei; Itagaki, Yoshiteru; Aono, Hiromichi; Munthali, Moses Wazingwa; Matsue, Naoto

2015-01-01

The radioactive decontamination of water, soil and other materials requires cheap and effective adsorbents. Artificial zeolites synthesized from an industrial waste (coal fly ash: Na-P1 type zeolite) and a natural material (diatomite: mordenite type zeolite) have a high Cs"+ adsorptivity in the adsorption experiments using 0.1 g of the zeolite and 50 mL of up to 7.5 mM CsCl. The coexisting cation suppressed the Cs"+ adsorption onto the zeolites, and the effect of the suppression was in the order, K"+ > Na"+ > Ca"2"+ > Mg"2"+. A thermodynamic analysis proved that the Cs"+ adsorption onto the two zeolites was exothermic favoring a lower temperature. The artificial mordenite showed a greater Cs"+ adsorption strength, higher distribution coefficient and lower ΔG°, especially at low Cs"+ concentrations. Adsorption isotherm analysis by the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich models showed a greater Cs"+ adsorption selectivity for the artificial mordenite even at a low pH. (author)

Myocardial scintigraphy with I-123 labeled fatty acids

International Nuclear Information System (INIS)

Dudczak, R.

1983-01-01

This study presents experimental and clinical data in the use of I-123 labeled aromatic and aliphatic fatty acids. I-123 p-phenylpentadecanoic acid (p-IPPA) and I-123 heptadecanoic acid (HDA) were applied for myocardial scintigraphy. The feasibility of p-IPPA and HDA for myocardial scintigraphy was substantiated in animal experiments. Clinical studies were performed in patients with coronary artery disease (CAD) and cardiomyopathy (CMP). In CAD the results of fatty acid studies were compared with those of Tl-201. I-123 labeled fatty acids proved to be a useful tool for myocardial scintigraphy. The possibility to evaluate non invasively the myocardial metabolic function in man may add a complementary diagnostic tool in the clinical follow up of patients with heart disease. In CAD studies with I-123 p-IPPA and I-123 HDA might provide a means to assess the degree of myocardial viability and to identify a subgroup of patients who are at increased risk for irreversible myocardial damage. In patients with CMP it is probable that these studies may be used as a means of separating groups of patients with this disease. (Author)

Ion chemistry of 1H-1,2,3-triazole.

Science.gov (United States)

Ichino, Takatoshi; Andrews, Django H; Rathbone, G Jeffery; Misaizu, Fuminori; Calvi, Ryan M D; Wren, Scott W; Kato, Shuji; Bierbaum, Veronica M; Lineberger, W Carl

2008-01-17

A combination of experimental methods, photoelectron-imaging spectroscopy, flowing afterglow-photoelectron spectroscopy and the flowing afterglow-selected ion flow tube technique, and electronic structure calculations at the B3LYP/6-311++G(d,p) level of density functional theory (DFT) have been employed to study the mechanism of the reaction of the hydroxide ion (HO-) with 1H-1,2,3-triazole. Four different product ion species have been identified experimentally, and the DFT calculations suggest that deprotonation by HO- at all sites of the triazole takes place to yield these products. Deprotonation of 1H-1,2,3-triazole at the N1-H site gives the major product ion, the 1,2,3-triazolide ion. The 335 nm photoelectron-imaging spectrum of the ion has been measured. The electron affinity (EA) of the 1,2,3-triazolyl radical has been determined to be 3.447 +/- 0.004 eV. This EA and the gas-phase acidity of 2H-1,2,3-triazole are combined in a negative ion thermochemical cycle to determine the N-H bond dissociation energy of 2H-1,2,3-triazole to be 112.2 +/- 0.6 kcal mol-1. The 363.8 nm photoelectron spectroscopic measurements have identified the other three product ions. Deprotonation of 1H-1,2,3-triazole at the C5 position initiates fragmentation of the ring structure to yield a minor product, the ketenimine anion. Another minor product, the iminodiazomethyl anion, is generated by deprotonation of 1H-1,2,3-triazole at the C4 position, followed by N1-N2 bond fission. Formation of the other minor product, the 2H-1,2,3-triazol-4-ide ion, can be rationalized by initial deprotonation of 1H-1,2,3-triazole at the N1-H site and subsequent proton exchanges within the ion-molecule complex. The EA of the 2H-1,2,3-triazol-4-yl radical is 1.865 +/- 0.004 eV.

Kompleksnost vzvodov strategije prodajnih poti v izvoznem trženju

OpenAIRE

Tominc, Polona; Jurše, Milan; Jager, Jerneja

2015-01-01

Distribucije v raziskavi ne obravnavamo zgolj kot ene od sestavin trženjskega spleta podjetja, temveč kot strateško razsežnost razvoja tržne pozicije na izbranih tujih trgih, katere cilj ni zagotoviti zgolj prodajo izdelkov podjetja, temveč ustvariti distribucijski sistem, ki bo podjetju zagotavljal rast prodaje in krepil konkurenčne prednosti na trgu. Na izbranem vzorcu slovenskih proizvodnih podjetij smo preverjali povezanost med izvozno tržno naravnanostjo podjetja, inovativnostjo, odnosi ...

Hot seeding using large Y-123 seeds

International Nuclear Information System (INIS)

Scruggs, S J; Putman, P T; Zhou, Y X; Fang, H; Salama, K

2006-01-01

There are several motivations for increasing the diameter of melt textured single domain discs. The maximum magnetic field produced by a trapped field magnet is proportional to the radius of the sample. Furthermore, the availability of trapped field magnets with large diameter could enable their use in applications that have traditionally been considered to require wound electromagnets, such as beam bending magnets for particle accelerators and electric propulsion. We have investigated the possibility of using large area epitaxial growth instead of the conventional point nucleation growth mechanism. This process involves the use of large Y123 seeds for the purpose of increasing the maximum achievable Y123 single domain size. The hot seeding technique using large Y-123 seeds was employed to seed Y-123 samples. Trapped field measurements indicate that single domain samples were indeed grown by this technique. Microstructural evaluation indicates that growth can be characterized by a rapid nucleation followed by the usual peritectic grain growth which occurs when large seeds are used. Critical temperature measurements show that no local T c suppression occurs in the vicinity of the seed. This work supports the suggestion of using an iterative method for increasing the size of Y-123 single domains that can be grown

12 CFR 225.123 - Activities closely related to banking.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Activities closely related to banking. 225.123 Section 225.123 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL... Holding Companies Interpretations § 225.123 Activities closely related to banking. (a) Effective June 15...

Labeling and quality control of 123I-MIBG

International Nuclear Information System (INIS)

Figols de Barboza, Marycel Rosa

2002-01-01

This report describes a method to facilitate routine production of 123 I-MIBG in Radiopharmacy Centre of IPEN-CNEN/SP. Iodine-123 radioisotope is produced in the form of sodium iodide in Cyclone-30 (IBA) at IPEN-CNEN/SP through proton irradiation of gaseous 124 Xe target. The labelling procedure uses MIBG-sulphate and leads to 123 I-MIBG with radiochemical purity at least 98% and specific activity of 300-380 MBq/mg

Dicty_cDB: SFC123 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available SF (Link to library) SFC123 (Link to dictyBase) - - - Contig-U16368-1 SFC123E (Link...) Clone ID SFC123 (Link to dictyBase) Atlas ID - NBRP ID - dictyBase ID - Link to Contig Contig-U16368-1 Ori...CVPHHDGCGNIQCPWGHYCVNEHGKCRCVPHRPPPRPPVDQCRNQHCPH GYSCRVIKGCATCVRDARPPHNLCRGFGCPEGSHCEVLEKHPVCVRNHVPPHPPPPPQIC GSVNCGPGYICT...CRCVPHRPPPRPPVDQCRNQHCPH GYSCRVIKGCATCVRDARPPHNLCRGFGCPEGSHCEVLEKHPVCVRNHVPPHPPPPPQIC GSVNCGPGYICTIINGHPTCIR...(bits) Value N D13973 |D13973.1 Dictyostelium discoideum DNA for Dp87 protein, complete cds. 1643 0.0 5 BJ17

The effect of aging and smoking on N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) accumulation in the human lung

International Nuclear Information System (INIS)

Hara, Masafumi; Tomiguchi, Seiji; Kojima, Akihiro; Nakashima, Rumi; Ooyama, Youichi; Takahashi, Mutsumasa; Matsumoto, Masanori.

1994-01-01

123 I-IMP clearance on dynamic lung scintigraphy was studied by two exponential compartments analysis in order to evaluate the effects of aging and smoking on the pulmonary function. Twenty-four patients (14 smokers and 10 non-smokers), referred for 123 I-IMP brain perfusion study, underwent lung dynamic scintigraphy for 42 min immediately after 123 I-IMP injection. In the non-smoking group 123 I-IMP lung clearance was delayed with aging. A significant correlation was found between aging and clearance rate in the lung. There was also a significant difference in the clearance rates between smoker and non-smoker groups. These findings suggest that smoking and aging affect the pulmonary function. (author)

Magnetic fluctuations on TR{sub 3}Ba{sub 5}Cu{sub 8}O{sub δ} (TR=Ho, Y and Yb) superconducting system

Energy Technology Data Exchange (ETDEWEB)

Supelano, G.I., E-mail: ivan.supelano@uptc.edu.co [Grupo de Superficies Electroquímica y Corrosión, Universidad Pedagógica y Tecnológica de Colombia (Colombia); Sarmiento Santos, A. [Grupo de Superficies Electroquímica y Corrosión, Universidad Pedagógica y Tecnológica de Colombia (Colombia); Parra Vargas, C.A. [Grupo de Física de Materiales, Universidad Pedagógica y Tecnológica de Colombia (Colombia)

2014-12-15

In this work, we report the production of TR{sub 3}Ba{sub 5}Cu{sub 8}O{sub δ} (TR=Ho, Y and Yb) superconducting system using a usual solid state reaction method. The irreversibility line and the analysis of magnetization fluctuations for TR{sub 3}Ba{sub 5}Cu{sub 8}O{sub δ} (TR=Ho, Y and Yb) system were investigated. The curves of magnetization ZFC–FC were measured in magnetic fields of the 100–4000 Oe to obtain the values for T{sup ⁎} and T{sub C} temperatures. The penetration depth and the coherence length parameters as a function of the applied magnetic field were obtained. The data of the magnetization excess ΔM(T, H) was analyzed from the curves of magnetization as a function of logarithm of applied field for different values of temperature in the corresponding range. The Bulavskii, Ledvij and Kogan theory was employed for this purpose which considers fluctuations effects in the free energy and into the equilibrium magnetization.

Recent developments in the field of 123I-radiopharmaceuticals

International Nuclear Information System (INIS)

Machulla, H.J.; Knust, E.J.

1984-01-01

Due to its advantageous nuclear physical properties iodine-123 is an excellent label for radiopharmaceuticals very well suited for measurements by γ-cameras and single-photon emission tomography. The development of 123 I-radiopharmaceuticals should be based on a clear biochemical concept, reliable labelling procedures and careful pharmacokinetic studies in order to evaluate the physiological behaviour of the radioiodinated compounds being analogues of metabolic substrates. The development of 123 I-labelled fatty acids and biogenic amines clearly proved the successful use of 123 I for labelling compounds applied in medical diagnosis. (orig.) [de

Canal de Mensagens de Trânsito

OpenAIRE

Egon Cervieri Guterres

2010-01-01

Informe Setorial: O Canal de Mensagens de Trânsito (Traffic Message Channel - TMC) é uma padronização internacional para a distribuição de informações (conteúdo) sobre a situação do trânsito urbano local e inter-regional, em tempo real, de forma eletrônica e diretamente aos motoristas. Traz para os cidadãos, em mensagens eletrônicas simples e acessíveis, informações sobre congestionamentos, acidentes, obras na pista, problemas climáticos (alagamentos, asfalto escorregadio, nevoeiro...) e desv...

40 CFR 123.46 - Individual control strategies.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Individual control strategies. 123.46... PROGRAM REQUIREMENTS Transfer of Information and Permit Review § 123.46 Individual control strategies. (a..., approval, and implementation an individual control strategy for each point source identified by the State...

Synergistic effect of manganese dioxide and diatomite for fast decolorization and high removal capacity of methyl orange.

Science.gov (United States)

Peng, Hui Hua; Chen, Jie; Jiang, De Yi; Li, Min; Feng, Li; Losic, Dusan; Dong, Fan; Zhang, Yu Xin

2016-12-15

MnO 2 nanostructures with two different morphologies (nanowires and nanosheets) were uniformly deposited on diatomite via a one-pot hydrothermal method. The fast decolorization and high removal capacity for anionic dye-MO over synthesized composites had been clarified. The results revealed that the equilibrium time was shortened to as low as 10-30min, and the maximum adsorption capacities were 325mgg -1 and 420mgg -1 for nanowires and nanosheets composites, respectively, under the condition of initial pH 3 and ambient temperature. Indeed, the proposed decolorization mechanism was considered to be simultaneous multi-processes during the dye removal, including physical, physicochemical and chemical process. In principle, well-controlled cost-effective composites have promising ability to remove anionic dye pollutants for environmental remediation. Copyright © 2016 Elsevier Inc. All rights reserved.

Investigation of 123I production using electron accelerator

International Nuclear Information System (INIS)

Avetisyan, Albert; Avagyan, Robert; Dallakyan, Ruben; Avdalyan, Gohar; Dobrovolsky, Nikolay; Gavalyan, Vasak; Kerobyan, Ivetta; Harutyunyan, Gevorg

2017-01-01

The possibility of 123 I isotope production with the help of the high-intensity bremsstrahlung photons produced by the electron beam of the LUE50 linear electron accelerator at the A.I. Alikhanyan National Science Laboratory (Yerevan Physics Institute [YerPhI]) is considered. The production method has been established and shown to be successful. The 124 Xe(γ,n) 123 Xe → 123 I nuclear reaction has been investigated and the cross-section was calculated by nuclear codes TALYS 1.6 and EMPIRE 3.2. The optimum parameter of the thickness of the target was determined by GEANT4 code. For the normalized yield of 123 I, the value of 143 Bq/(mg·μA·h) has been achieved.

Assessment of cerebral benzodiazepine receptor distribution in anxiety disorders by {sup 123}I-iomazenil-SPECT. Comparison to cerebral perfusion scintigraphy by {sup 123}I-IMP

Energy Technology Data Exchange (ETDEWEB)

Uchiyama, Mayuki; Sue, Hironari; Fukumitsu, Nobuyoshi; Mori, Yutaka; Kawakami, Kenji [Jikei Univ., Tokyo (Japan). School of Medicine

1997-01-01

{sup 123}I-Iomazenil ({sup 123}I-IMZ) and {sup 123}I-IMP imaging were performed in 5 patients with anxiety disorder (PAD) and 6 normal volunteers (NV). On {sup 123}I-IMZ delayed imaging, the 2 PAD showed abnormally decreased findings. In anxiety disorder, decreased accumulation on {sup 123}I-IMZ delayed images was seen in left hippocampus and parahippocampal gyrus in one patient, in right frontal and temporal lobe and left occipital pole in the other. Compared with NV, PAD had lower {sup 123}I-IMZ uptake on delayed image in right upper and left lower frontal cortices, indicating the involvement of the benzodiazepine receptor complex in anxiety disorder. Compared with grading for anxiety disorder with Hamilton anxiety scale (HAS) and delayed to early count ratios of {sup 123}I-IMZ, negative correlation (R<-0.7) was recognized hippocampus and parahippocampal gyrus, frontal and occipital cortices. Compared between HAS and the count ratio to the cerebellum on {sup 123}I-IMP image, positive correlation (R>0.7) was recognized in the hippocampus, the parahippocampal gyrus, the lower outer temporal cortex and the lower frontal cortex. (author)

7 CFR 1955.123 - Sale procedures (chattel).

Science.gov (United States)

2010-01-01

... 7 Agriculture 14 2010-01-01 2009-01-01 true Sale procedures (chattel). 1955.123 Section 1955.123 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS... be notified of the opportunity to appeal in accordance with subpart B of part 1900 of this chapter...

40 CFR 123.23 - Attorney General's statement.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Attorney General's statement. 123.23... PROGRAM REQUIREMENTS State Program Submissions § 123.23 Attorney General's statement. (a) Any State that seeks to administer a program under this part shall submit a statement from the State Attorney General...

9 CFR 113.123 - Salmonella Dublin Bacterin.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Salmonella Dublin Bacterin. 113.123... Inactivated Bacterial Products § 113.123 Salmonella Dublin Bacterin. Salmonella Dublin Bacterin shall be prepared from a culture of Salmonella dublin which has been inactivated and is nontoxic. Each serial of...

Preliminary mineralogical and paleoenvironmental study of the diatomites from Adamclisi, South Dobrogea, Romania

Science.gov (United States)

Dumitras, Delia-Georgeta; Sebe-Radoi, Oana-Gabriela; Marincea, Stefan; Costea, Constantin

2017-04-01

Diatomite samples taken from the Urluia - Adamclisi localities, South Dobrogea region (Romania) have been studied by X-ray fluorescence, wet-chemical analysis, scanning electron microscopy (SEM), FTIR and X-ray powder diffraction. The diatomaceous earth from Adamclisi occurs as beds and lenses in alternance with bentonitic clays and limestones. The diatomite levels are chalk-like, soft, friable, earthy, very fine-grained, and have a white - yellow color. The mineralogy of all but one sample is characterized by the presence of quartz, amorphous silica, feldspars and clay minerals. Based on the broad hump registered between 15 and 20° 2 theta on XRD patterns and on the characters and intensities of the bands centered around 3350 and 1630 cm-1 in the FTIR spectra, the amorphous silica from the diagenesis-affected diatom frustules was identified as opal-A. The associated mineral species are quartz (up to 5 wt.%), opal-Ct (up to 15 wt%), clay minerals (up to 60 wt.%), and minor feldspar (up to 20 wt.%). The micro-paleontological study shows that benthic pennate diatoms prevail (more than 60%), with a low rate of species diversity. Large chain-forming centric diatoms also occur together with other microfossils (dinoflagellates, phytolites, sponge spicules, different types of fish teeth) assemblages common for the Sarmatian (middle Miocene) marine deposits of Eastern Paratethys. The diatomaceous formation afforded exceptional fossilization. The diatom assemblages characterize a shallow marine basin environment, with littoral or freshwater contributions. Both at the basis and on the top of the profile, the marine diatoms prevail. At the basis of profile, the marine species (e.g., Actinocyclus ehrenbergii, Amphora crassa, Amphora crassa-punctata, Caloneis liber, Camylodiscus kutzingii, Grammatophora stricta, etc.) form up to 80 % of the rock volume, being associated with marine-brackish species such as Achnanthes brevipes and Cocconeis scutelum (up to 25 %) and with

16 CFR 1.23 - Quantity limit rules.

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Quantity limit rules. 1.23 Section 1.23 Commercial Practices FEDERAL TRADE COMMISSION ORGANIZATION, PROCEDURES AND RULES OF PRACTICE GENERAL... Robinson-Patman Act. These rules have the force and effect of law. [32 FR 8444, June 13, 1967. Redesignated...

V123 Beam Synchronous Encoder Module

International Nuclear Information System (INIS)

Kerner, T.; Conkling, C. R.; Oerter, B.

1999-01-01

The V123 Synchronous Encoder Module transmits events to distributed trigger modules and embedded decoders around the RHIC rings where they are used to provide beam instrumentation triggers [1,2,3]. The RHIC beam synchronous event link hardware is mainly comprised of three VMEbus board designs, the central input modules (V201), and encoder modules (V123), and the distributed trigger modules (V124). Two beam synchronous links, one for each ring, are distributed via fiberoptic and fanned out via twisted wire pair cables. The V123 synchronizes with the RF system clock derived from the beam bucket frequency and a revolution fiducial pulse. The RF system clock is used to create the beam synchronous event link carrier and events are synchronized with the rotation fiducial. A low jitter RF clock is later recovered from this carrier by phase lock loops in the trigger modules. Prioritized hardware and software triggers fill up to 15 beam event code transmission slots per revolution while tracking the ramping RF acceleration frequency and storage frequency. The revolution fiducial event is always the first event transmitted which is used to synchronize the firing of the abort kicker and to locate the first bucket for decoders distributed about the ring

Iodine-123 metaiodobenzylguanidine scintigraphy and iodine-123 ioflupane single photon emission computed tomography in Lewy body diseases: complementary or alternative techniques?

Science.gov (United States)

Treglia, Giorgio; Cason, Ernesto; Cortelli, Pietro; Gabellini, Anna; Liguori, Rocco; Bagnato, Antonio; Giordano, Alessandro; Fagioli, Giorgio

2014-01-01

To compare myocardial sympathetic imaging using (123)I-Metaiodobenzylguanidine (MIBG) scintigraphy and striatal dopaminergic imaging using (123)I-Ioflupane (FP-CIT) single photon emission computed tomography (SPECT) in patients with suspected Lewy body diseases (LBD). Ninety-nine patients who performed both methods within 2 months for differential diagnosis between Parkinson's disease (PD) and other parkinsonism (n = 68) or between dementia with Lewy bodies (DLB) and other dementia (n = 31) were enrolled. Sensitivity, specificity, accuracy, positive and negative predictive values of both methods were calculated. For (123) I-MIBG scintigraphy, the overall sensitivity, specificity, accuracy, positive and negative predictive values in LBD were 83%, 79%, 82%, 86%, and 76%, respectively. For (123)I-FP-CIT SPECT, the overall sensitivity, specificity, accuracy, positive and negative predictive values in LBD were 93%, 41%, 73%, 71%, and 80%, respectively. There was a statistically significant difference between these two methods in patients without LBD, but not in patients with LBD. LBD usually present both myocardial sympathetic and striatal dopaminergic impairments. (123)I-FP-CIT SPECT presents high sensitivity in the diagnosis of LBD; (123)I-MIBG scintigraphy may have a complementary role in differential diagnosis between PD and other parkinsonism. These scintigraphic methods showed similar diagnostic accuracy in differential diagnosis between DLB and other dementia. Copyright © 2012 by the American Society of Neuroimaging.

50 CFR 14.123 - Care in transit.

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Care in transit. 14.123 Section 14.123 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR TAKING... transit. (a) A primate shall be observed for signs of distress and given food and water according to the...

27 CFR 22.123 - Losses on premises.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Losses on premises. 22.123... OF THE TREASURY LIQUORS DISTRIBUTION AND USE OF TAX-FREE ALCOHOL Losses § 22.123 Losses on premises. (a) Recording of losses. A permittee shall determine and record, in the records prescribed by subpart...

17 CFR 12.3 - Business address; hours.

Science.gov (United States)

2010-04-01

... REPARATIONS General Information and Preliminary Consideration of Pleadings § 12.3 Business address; hours. The... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Business address; hours. 12.3..., DC 20581. It is open each day, except Saturdays, Sundays, and legal public holidays, from 8:15 a.m...

Adsorption of crystal violet with diatomite earth&carbon by a modification of hydrothermal carbonization process.

Science.gov (United States)

Zhang, Yanzhuo; Li, Jun; Chen, Guanghui; Bian, Wei; Lu, Yun; Li, Wenjing; Zheng, Zhaoming; Cheng, Xiaojie

2016-01-01

The high colority and difficulty of decolorization are the most important tasks on printing and dyeing wastewater. This study investigates the ability of diatomite earth&carbon (DE&C) as an adsorbent to removal crystal violet (CV) from aqueous solutions. Fourier transform infrared spectroscopy results indicate the importance of functional groups during the adsorption of CV. The obtained N2 adsorption-desorption isotherm values accord with well IUPAC type II. Our calculations determined a surface area of 73.15 m(2) g(-1) for DE&C and an average pore diameter of 10.56 nm. Equilibrium data of the adsorption process fitted very well to the Langmuir model (R(2) > 0.99). The results of kinetics study showed that the pseudo-second-order model fitted to the experimental data well. The thermodynamic parameters were also evaluated. ΔH° 0 and ΔG° < 0 demonstrated that the adsorption process was spontaneous and exothermic for dye. Furthermore the positive value of ΔS° reflected good affinity of the CV dye.

Growing three-dimensional biomorphic graphene powders using naturally abundant diatomite templates towards high solution processability

Science.gov (United States)

Chen, Ke; Li, Cong; Shi, Liurong; Gao, Teng; Song, Xiuju; Bachmatiuk, Alicja; Zou, Zhiyu; Deng, Bing; Ji, Qingqing; Ma, Donglin; Peng, Hailin; Du, Zuliang; Rümmeli, Mark Hermann; Zhang, Yanfeng; Liu, Zhongfan

2016-11-01

Mass production of high-quality graphene with low cost is the footstone for its widespread practical applications. We present herein a self-limited growth approach for producing graphene powders by a small-methane-flow chemical vapour deposition process on naturally abundant and industrially widely used diatomite (biosilica) substrates. Distinct from the chemically exfoliated graphene, thus-produced biomorphic graphene is highly crystallized with atomic layer-thickness controllability, structural designability and less noncarbon impurities. In particular, the individual graphene microarchitectures preserve a three-dimensional naturally curved surface morphology of original diatom frustules, effectively overcoming the interlayer stacking and hence giving excellent dispersion performance in fabricating solution-processible electrodes. The graphene films derived from as-made graphene powders, compatible with either rod-coating, or inkjet and roll-to-roll printing techniques, exhibit much higher electrical conductivity (~110,700 S m-1 at 80% transmittance) than previously reported solution-based counterparts. This work thus puts forward a practical route for low-cost mass production of various powdery two-dimensional materials.

The Orphan Nuclear Receptor TR4 Is a Vitamin A-activated Nuclear Receptor

Energy Technology Data Exchange (ETDEWEB)

Zhou, X. Edward; Suino-Powell, Kelly M.; Xu, Yong; Chan, Cee-Wah; Tanabe, Osamu; Kruse, Schoen W.; Reynolds, Ross; Engel, James Douglas; Xu, H. Eric (Michigan-Med); (Van Andel)

2015-11-30

Testicular receptors 2 and 4 (TR2/4) constitute a subgroup of orphan nuclear receptors that play important roles in spermatogenesis, lipid and lipoprotein regulation, and the development of the central nervous system. Currently, little is known about the structural features and the ligand regulation of these receptors. Here we report the crystal structure of the ligand-free TR4 ligand binding domain, which reveals an autorepressed conformation. The ligand binding pocket of TR4 is filled by the C-terminal half of helix 10, and the cofactor binding site is occupied by the AF-2 helix, thus preventing ligand-independent activation of the receptor. However, TR4 exhibits constitutive transcriptional activity on multiple promoters, which can be further potentiated by nuclear receptor coactivators. Mutations designed to disrupt cofactor binding, dimerization, or ligand binding substantially reduce the transcriptional activity of this receptor. Importantly, both retinol and retinoic acid are able to promote TR4 to recruit coactivators and to activate a TR4-regulated reporter. These findings demonstrate that TR4 is a ligand-regulated nuclear receptor and suggest that retinoids might have a much wider regulatory role via activation of orphan receptors such as TR4.

Medical necessity for shorter lived radionuclides, specifically pure Iodine-123

International Nuclear Information System (INIS)

DeNardo, G.L.; DeNardo, S.J.; Hines, H.H.; Lagunas-Solar, M.C.; Jungerman, J.A.

1985-01-01

Iodine-123 has physical and radiochemical characteristics ideal for most tracer procedures performed in patients. Its use is generally preferable to the use of 131 I for diagnosis. The potential for 123 I can be realized only if a radiopharmaceutical of lesser radionuclide contamination is generally and economically available. Iodine-123 produced by direct methods has significant disadvantages relative to quality of procedure and radiation dosimetry. Our experience with 123 I(p,5n) during the past 12 years causes us to vigorously encourage general availability of an 123 I radiopharmaceutical of this quality. Using this product, the authors have prepared radiopharmaceuticals for use in the study of cancer, coagulation, and renal and thyroid diseases

40 CFR 90.123 - Denial, revocation of certificate of conformity.

Science.gov (United States)

2010-07-01

... conformity. 90.123 Section 90.123 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Emission Standards and Certification Provisions § 90.123 Denial, revocation of certificate of conformity... conformity if the Administrator finds any one of the following infractions to be substantial: (1) The engine...

Radioiodinated Rhodamine-123: a potential cationic hepatobiliary imaging agent

International Nuclear Information System (INIS)

Moonen, P.; Gorree, G.C.M.; Hoekstra, A.

1987-01-01

The labelling of the cationic dye Rhodamine-123 with 125 I is described. The biodistribution of the iodinated Rhodamine-123 has been determined at different time intervals after intravenous injection into fasted rats. It turned out that the dye is predominantly cleared by the liver and discharged into the bile. The bile acid taurocholate did not enhance the rate of excretion of 125 I-Rhodamine-123. (author)

21 CFR 123.11 - Sanitation control procedures.

Science.gov (United States)

2010-04-01

... records are subject to the requirements of § 123.9. (d) Relationship to HACCP plan. Sanitation controls may be included in the HACCP plan, required by § 123.6(b). However, to the extent that they are monitored in accordance with paragraph (b) of this section they need not be included in the HACCP plan, and...

Imaging with 123I labelled fatty acids

International Nuclear Information System (INIS)

Dudczak, R.

1985-01-01

This report describes the clinical results obtained with radioiodinated aromatic and aliphatic fatty acids. The radiopharmaceuticals were 123 I labelled p-phenylpentadecanoic (p-IPPA) and 123 I labelled heptadecanoic acid (HDA). The possibility to evaluate the myocardial metabolic function in man noninvasively add a complementary diagnostic tool in the clinical follow-up of patients with heart disease. (Auth.)

Human absorbed dose calculations for 123I labeled phenyl pentadecanoic acid

International Nuclear Information System (INIS)

Kulkarni, P.V.; Clark, G.; Corbett, J.R.; Willerson, J.T.; Parkey, R.W.

1986-01-01

I-123 labeled fatty acids have been proposed for studying myocardial metabolism by scintigraphic methods. With the availability of clean I-123 and the advent of single photon emission tomography, I-123 labeled fatty acids would be well suited to study regional myocardial viability or metabolism in humans. The authors have studied I-125 and I-123 labeled iodophenyl pentadecanoic acid (IPPA) in rats and dogs. Clinical studies are in progress with I-123 (IPPA). They have studied the pharmacokinetics of this tracer in male Sprague-Dawley rats at 0.25, 0.5, 1, 3, 6, and 24 hours postinjection. The cumulated doses, due to both pure I-123 and a version contaminated with 1.4% I-125, in various organs and the total body in humans are estimated. The average dose to organs for humans injected with I-123 IPPA with pure I-123 and contaminated I-123 respectively, are (rads to organ per mCi injected): heart wall (0.0507, 0.0514), liver (0.0792, 0.0875), kidneys (0.0479, 0.0561), thyroid (0.0517, 0.0638), ovaries (0.0427, 0.0561), testes (0.0307, 0.0309), total body (0.0386, 0.0392). 12 references, 9 figures, 5 tables

A novel poly(acrylic acid-co-acrylamide)/diatomite composite flocculant with outstanding flocculation performance.

Science.gov (United States)

Xu, Kun; Liu, Yao; Wang, Yang; Tan, Ying; Liang, Xuecheng; Lu, Cuige; Wang, Haiwei; Liu, Xiusheng; Wang, Pixin

2015-01-01

Series of anionic flocculants with outstanding flocculation performance, poly(acrylic acid-co-acrylamide)/diatomite composite flocculants (PAAD) were successfully prepared through aqueous solution copolymerization and applied to flocculate from oil-field fracturing waste-water. The structure of PAAD was characterized by Fourier transform infra-red spectroscopy, (13)C nuclear magnetic resonance and X-ray diffraction tests, and its properties were systematically evaluated by viscometer, thermogravimetry analysis and flocculation measurements. Furthermore, the influences of various reaction parameters on the apparent viscosity of flocculant solution were studied, and the optimum synthesis condition was determined. The novel composite flocculants exhibited outstanding flocculation properties. Specifically, the dosage of composite flocculants that could make the transmittance of treated wastewater exceed 90% was only approximately 12-35 ppm, which was far lower than that of conventional flocculants. Meanwhile, the settling time was lower than 5 s, which was similar to that of conventional flocculants. This was because PAAD flocculants had a higher absorption capacity, and larger chain extending space than conventional linear flocculants, which could refrain from the entanglement of linear polymer chains and significantly improve flocculation capacity.

Dynamic myocardial scintigraphy with 123I-labelled free fatty acids

International Nuclear Information System (INIS)

Wall, E.E. van der.

1981-01-01

In this thesis, long-chain radioiodinated free fatty acids ( 123 I-FFA), 16-iodo- 123 I-cis-Δ 9 -hexadecenoic acid ( 123 I-HA) and 17-iodo- 123 I-heptade-canoic acid ( 123 I-Hsup(o)A), were employed for myocardial scintigraphy in patients with coronary artery disease. The results indicate that clearance of 123 I-FFA from the myocardium is dependent on the nature of ischemic injury. Clearance is delayed if the injury is reversible and accelerated in case of irreversible ischemia. Mechanisms responsible for divergent behaviour of FFA in patients with acute myocardial infarction versus patients with angina pectoris are purely speculative. This differential clearance from normally perfused, transiently ischemic and infarcted myocardium has practical application. The test provides a means to assess the nature of ischemic injury rapidly. These findings may have major consequences for logical management of patients presenting with chest pain and suspected coronary artery disease. (Auth.)

(123I)-IMP SPECT findings in Machado-Joseph disease

International Nuclear Information System (INIS)

Suzuki, Masahiko

1997-01-01

Single photon emission computed tomography (SPECT) with N-isopropyl-p-( 123 I)iodoamphetamine (IMP) was used to study the dynamics of cerebellar and brainstem metabolic function in patients with Mochado-Joseph disease (MJD), the diagnosis of which was confirmed with genetic analysis. The SPECT data obtained was analyzed semiquantitatively. In patients with MJD, ( 123 I)-IMP accumulation in the cerebellum and brainstem was decreased, and the degree of decrease reflected the clinical severity of MJD. When MJD was mild, the decrease in ( 123 I)-IMP accumulation was much greater in the brainstem than in the cerebellum. However, the decrease in ( 123 I)-IMP accumulation in the cerebellum and brainstem was not correlated with the severity of atrophy or with the number of CAG repeats. ( 123 I)-IMP SPECT was useful for evaluating the decrease in cerebellum and brainstem function in patients with MJD. Results of this study suggest that the functional decrease in MJD may begin in the brainstem. (author)

[11 C]Rhodamine-123: Synthesis and biodistribution in rodents

International Nuclear Information System (INIS)

Bao Xiaofeng; Lu Shuiyu; Liow, Jeih-San; Morse, Cheryl L.; Anderson, Kacey B.; Zoghbi, Sami S.; Innis, Robert B.; Pike, Victor W.

2012-01-01

Introduction: Rhodamine-123 is a known substrate for the efflux transporter, P-glycoprotein (P-gp). We wished to assess whether rhodamine-123 might serve as a useful substrate for developing probes for imaging efflux transporters in vivo with positron emission tomography (PET). For this purpose, we aimed to label rhodamine-123 with carbon-11 (t 1/2 = 20.4 min) and to study its biodistribution in rodents. Methods: [ 11 C]Rhodamine-123 was prepared by treating rhodamine-110 (desmethyl-rhodamine-123) with [ 11 C]methyl iodide. The biodistribution of this radiotracer was studied with PET in wild-type mice and rats, in efflux transporter knockout mice, in wild-type rats pretreated with DCPQ (an inhibitor of P-gp) or with cimetidine (an inhibitor of organic cation transporters; OCT), and in P-gp knockout mice pretreated with cimetidine. Unchanged radiotracer in forebrain, plasma and peripheral tissues was also measured ex vivo at 30 min after radiotracer administration to wild-type and efflux transporter knockout rodents. Results: [ 11 C]Rhodamine-123 was obtained in 4.4% decay-corrected radiochemical yield from cyclotron-produced [ 11 C]carbon dioxide. After intravenous administration of [ 11 C]rhodamine-123 to wild-type rodents, PET and ex vivo measurements showed radioactivity uptake was very low in brain, but relatively high in some other organs such as heart, and especially liver and kidney. Inhibition of P-gp increased uptake in brain, heart, kidney and liver, but only by up to twofold. Secretion of radioactivity from kidney was markedly reduced by OCT knockout or pretreatment with cimetidine. Conclusions: [ 11 C]Rhodamine-123 was unpromising as a PET probe for P-gp function and appears to be a strong substrate of OCT in kidney. Cimetidine appears effective for blocking OCT in kidney in vivo.

40 CFR 91.123 - Denial, revocation of certificate of conformity.

Science.gov (United States)

2010-07-01

... conformity. 91.123 Section 91.123 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Certification Provisions § 91.123 Denial, revocation of certificate of conformity. (a) If, after review of the... conformity if the Administrator finds any one of the following infractions to be substantial: (1) The engine...

Influence of revascularization on myocardial perfusion, metabolism and function evaluated with I-123-IPPA

International Nuclear Information System (INIS)

Kropp, J.; Krois, M.; Eichhorn, B.; Feske, W.; Likungu, J.; Kirchhoff, P.J.; Luederitz, B.; Biersack, H.J.; Knapp, F.F. Jr.

1993-01-01

Patients with coronary artery disease (CAD) were investigated with sequential SPECT-scintigraphy after administration of 200 MBq of 15-(p-[I-123]iodophenyl)pentadecanoic acid (IPPA) at peak submaximal exercise. Twenty patients underwent coronary angioplasty (PTCA) from which 14 had control coronary arteriography (CA) and left ventricular cineventriculography (LVCV). Nineteen pts underwent bypass graft surgery (ACB) and stress sonagraphy. Semi-quantification of uptake (Up related to perfusion) and turnover (Tr) was obtained by segmental comparison of oblique slices. About 90% of the reperfused myocardial segments in the PTCA-group and 76% in the ACB-group showed an improvement of uptake after therapy (RUp). Of these, 50% and 66% exhibited increased turnover (RTr) after PTCA or ACB. Pathologic RTr was highly correlated with regional wall motion abnormalities after therapy in both groups. In the ACB-group presence of improvement of RTr was correlated with improved RWM at rest and stress. IPPA-studies show potential to provide information about changes of perfusion and metabolism after reperfusion and IPPA-turnover is a good predictor of the pattern of contractile function

Myocardial kinetics of 123I-labeled-16-hexadecanoic acid

International Nuclear Information System (INIS)

Okada, R.D.; Elmaleh, D.; Werre, G.S.; Strauss, H.W.; Massachusetts General Hospital, Boston

1983-01-01

To determine if the myocardial clearance of omega 123 I-16-hexadecanoic acid ( 123 I-HDA) is affected by decreased coronary blodood flow, six anesthetized dogs had partial occlusion of the left anterior descending coronary artery. One hour later, 113 Sn-microspheres were injected into the left atrium, followed immediately by the IV administration of 123 I-HDA. Following injection, regional myocardial 123 I activities were monitored continuously with miniature cadmium telluride radiation detectors placed against the endocardium in both ischemic and nonischemic zones. After 3 h continuous monitoring, 46 Sc-microspheres were injected into the left atrium and the dogs were killed. Ischemic and nonischemic areas of myocardium were sectioned and counted in a well counter. (orig./WL)

The Test Reactor Embrittlement Data Base (TR-EDB)

International Nuclear Information System (INIS)

Stallmann, F.W.; Kam, F.B.K.; Wang, J.A.

1993-01-01

The Test Reactor Embrittlement Data Base (TR-EDB) is part of an ongoing program to collect test data from materials irradiations to aid in the research and evaluation of embrittlement prediction models that are used to assure the safety of pressure vessels in power reactors. This program is being funded by the US Nuclear Regulatory Commission (NRC) and has resulted in the publication of the Power Reactor Embrittlement Data Base (PR-EDB) whose second version is currently being released. The TR-EDB is a compatible collection of data from experiments in materials test reactors. These data contain information that is not obtainable from surveillance results, especially, about the effects of annealing after irradiation. Other information that is only available from test reactors is the influence of fluence rates and irradiation temperatures on radiation embrittlement. The first version of the TR-EDB will be released in fall of 1993 and contains published results from laboratories in many countries. Data collection will continue and further updates will be published

The anti-inflammatory effect of TR6 on LPS-induced mastitis in mice.

Science.gov (United States)

Hu, Xiaoyu; Fu, Yunhe; Tian, Yuan; Zhang, Zecai; Zhang, Wenlong; Gao, Xuejiao; Lu, Xiaojie; Cao, Yongguo; Zhang, Naisheng

2016-01-01

[TRIAP]-derived decoy peptides have anti-inflammatory properties. In this study, we synthesized a TRIAP-derived decoy peptide (TR6) containing, the N-terminal portion of the third helical region of the [TIRAP] TIR domain (sequence "N"-RQIKIWFQNRRMKWK and -KPGFLRDPWCKYQML-"C"). We evaluated the effects of TR6 on lipopolysaccharide-induced mastitis in mice. In vivo, the mastitis model was induced by LPS administration for 24h, and TR6 treatment was initiated 1h before or after induction of LPS. In vitro, primary mouse mammary epithelial cells and neutrophils were used to investigate the effects of TR6 on LPS-induced inflammatory responses. The results showed that TR6 significantly inhibited mammary gland hisopathologic changes, MPO activity, and LPS-induced production of TNF-α, IL-1β and IL-6. In vitro, TR6 significantly inhibited LPS-induced TNF-α and IL-6 production and phosphorylation of NF-κB and MAPKs. In conclusion, this study demonstrated that the anti-inflammatory effect of TR6 against LPS-induced mastitis may be due to its ability to inhibit TLR4-mediated NF-κB and MAPK signaling pathways. TR6 may be a promising therapeutic reagent for mastitis treatment. Copyright © 2015. Published by Elsevier B.V.

Iodine-123 and bromine-75 production and development program at Juelich

International Nuclear Information System (INIS)

Stoecklin, G.

1985-01-01

The iodine-123 and bromine-75 production and development program at the Nuclear Research Center in Juelich as of 1982 is described, and examples of recent 123 I- and 75 Br-analogue tracers that have been developed to the level of clinical trial are given. Iodine-123 is produced via the 127 I(d,6n) 123 Xe → 123 I process and by the 124 Te(p,2n) 123 I and 122 Te(d,n) 123 I reactions. These production methods are critically reviewed. Bromine-75-labeled benzodiazenes have been prepared for in vivo mapping of benzodiazepine receptor sites. The 7-( 75 Br)-5-(2-fluorophenyl)-1-methyl-1,3-dihydro-2H-1,4-benzodiazepine-2-one (BFB) was prepared with a specific activity of > 10 4 Ci/mmole. Finally, preparation and applications of the halogenated amino acid L-3-( 123 I)-iodo-α-methyltyrosine (IMT) and the analogous 75 Br compound (BMT) are reported. Both IMT and BMT have been successfully applied for pancreas imaging and tomography, and IMT has been used for imaging both melanotic and amelanotic malignant melanoma of the eye

123I research and production at Brookhaven

International Nuclear Information System (INIS)

Mausner, L.F.; Srivastava, S.C.; Mirzadeh, S.; Meinken, G.E.; Prach, T.

1985-01-01

The procedures for preparing high purity 123 I at the BLIP using the 127 I(p,5n) 123 Xe reaction on an NaI target are described. The activity is supplied in a glass ampoule with anhydrous 123 I deposited on the interior walls, allowing maximum flexibility in subsequent iodinations. Preliminary experience with a continuous flow target is also described. The results of a series of measurements of specific activity by neutron activation, x-ray fluorescence, uv absorption, and wet chemistry generally showed no detectable carrier. HPLC methods to analyse the chemical form of radioiodine and to characterize various iodinated radiopharmaceuticals have been developed. These methods provide higher sensitivity, speed and resolution than commonly used techniques. 19 refs., 6 figs., 2 tabs

Melt processing of Yb-123 tapes

International Nuclear Information System (INIS)

Athur, S. P.; Balachandran, U.; Salama, K.

2000-01-01

The innovation of a simple, scalable process for manufacturing long-length conductors of HTS is essential to potential commercial applications such as power cables, magnets, and transformers. In this paper the authors demonstrate that melt processing of Yb-123 tapes made by the PIT route is an alternative to the coated conductor and Bi-2223 PIT tape fabrication techniques. Ag-clad Yb-123 tapes were fabricated by groove rolling and subsequently, melt processed in different oxygen partial pressures in a zone-melting furnace with a gradient of 140 C/cm. The transition temperatures measured were found to be around 81 K undermost processing conditions. EPMA of the tapes processed under different conditions show the 123 phase to be Ba deficient and Cu and Yb rich. Critical current was measured at various temperatures from 77 K to 4.2 K. The J c increased with decrease in pO 2 . The highest I c obtained was 52 A at 4.2 K

TR32DB - Management of Research Data in a Collaborative, Interdisciplinary Research Project

Science.gov (United States)

Curdt, Constanze; Hoffmeister, Dirk; Waldhoff, Guido; Lang, Ulrich; Bareth, Georg

2015-04-01

The management of research data in a well-structured and documented manner is essential in the context of collaborative, interdisciplinary research environments (e.g. across various institutions). Consequently, set-up and use of a research data management (RDM) system like a data repository or project database is necessary. These systems should accompany and support scientists during the entire research life cycle (e.g. data collection, documentation, storage, archiving, sharing, publishing) and operate cross-disciplinary in interdisciplinary research projects. Challenges and problems of RDM are well-know. Consequently, the set-up of a user-friendly, well-documented, sustainable RDM system is essential, as well as user support and further assistance. In the framework of the Transregio Collaborative Research Centre 32 'Patterns in Soil-Vegetation-Atmosphere Systems: Monitoring, Modelling, and Data Assimilation' (CRC/TR32), funded by the German Research Foundation (DFG), a RDM system was self-designed and implemented. The CRC/TR32 project database (TR32DB, www.tr32db.de) is operating online since early 2008. The TR32DB handles all data, which are created by the involved project participants from several institutions (e.g. Universities of Cologne, Bonn, Aachen, and the Research Centre Jülich) and research fields (e.g. soil and plant sciences, hydrology, geography, geophysics, meteorology, remote sensing). Very heterogeneous research data are considered, which are resulting from field measurement campaigns, meteorological monitoring, remote sensing, laboratory studies and modelling approaches. Furthermore, outcomes like publications, conference contributions, PhD reports and corresponding images are regarded. The TR32DB project database is set-up in cooperation with the Regional Computing Centre of the University of Cologne (RRZK) and also located in this hardware environment. The TR32DB system architecture is composed of three main components: (i) a file-based data

49 CFR 37.123 - ADA paratransit eligibility: Standards.

Science.gov (United States)

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false ADA paratransit eligibility: Standards. 37.123... INDIVIDUALS WITH DISABILITIES (ADA) Paratransit as a Complement to Fixed Route Service § 37.123 ADA... complementary paratransit service shall provide the service to the ADA paratransit eligible individuals...

I-123 IMP SPECT in Parkinson's disease

International Nuclear Information System (INIS)

Kawabata, Keita; Tachibana, Kyudai; Sugita, Minoru

1990-01-01

To examine semiquantitatively regional cerebral blood flow, SPECT with N-isopropyl-p-[I-123]iodoamphetamine (I-123 IMP) was undertaken in 17 patients with Parkinson's disease. Seven patients with Alzheimer's disease and 9 senile control subjects were also imaged for comparison. Both the Parkinson's disease group and the Alzheimer's disease group had a decreased uptake of I-123 IMP in the frontal lobe, in comparison with the control group. A remarkably decreased uptake was seen in the lateral and parietal lobes in the group of Parkinson's disease associated with dementia, as well as in the Alzheimer's disease group. A significantly decreased uptake was observed in the frontal lobe, lateral lobe, thalamus, and basal ganglia in the Parkinson's disease group, irrespective of the presence or absence of dementia. For Parkinson's disease associated with dementia, there was much more significant decrease in I-123 IMP uptake. The pattern of regional cerebral blood flow in the Alzheimer's disease group was analogous to that in the Parkinson's disease group associated with dementia. This supports the hypothesis that Alzheimer's disease may be somewhat involved in the occurrence of dementia for Parkinson's disease. (N.K.)

23 CFR 771.123 - Draft environmental impact statements.

Science.gov (United States)

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Draft environmental impact statements. 771.123 Section... ENVIRONMENT ENVIRONMENTAL IMPACT AND RELATED PROCEDURES § 771.123 Draft environmental impact statements. (a) A... significant impacts on the environment. When the applicant, after consultation with any project sponsor that...

[sup 123]I-iodobenzoylglucosamines: glucose analogues for heart imaging

Energy Technology Data Exchange (ETDEWEB)

Lutz, T [British Columbia Univ., Vancouver, BC (Canada). Dept. of Pharmaceutical Sciences; Dougan, H [TRIUMF, Vancouver, BC (Canada); Rihela, T; Vo, C V [Vancouver General Hospital (Canada). Div. of Nuclear Medicine; Lyster, D M [British Columbia Univ., Vancouver, BC (Canada). Dept. of Pharmaceutical Sciences Vancouver General Hospital (Canada). Div. of Nuclear Medicine

1993-01-01

The ortho-, meta- and para-[[sup 123]I]-2-deoxy-2-N-(iodobenzoyl)-D-glucosamine (BGA) derivatives were investigated to determine the effect of iodine position and lipophilicity on tissue distribution. There was no correlation between tissue uptake and lipophilicity. Maximum uptake was observed for o-BGA displaying a heart:blood ratio of 36.0 at 18 hours post injection. Yeast hexokinase phosphorylation studies in vitro and an in vivo insulin experiment were carried out on o-BGA. No phosphorylation was detected, but the insulin study indicated that o-BGA uses the glucose transporter. o-BGA showed maximum tissue uptake in mice at an optimal specific activity of 0.004mg/[mu]Ci. Mouse biodistribution studies of o-[[sup 123]I]-iodobenzamide(o-[sup 123]IBA) indicated that the glucose moiety of o-BGA may be involved in the heart accumulation process in mice. Heart tissue extraction studies showed unmetabolized o-[[sup 123]I]BGA was the predominant species. A rabbit image of o-[[sup 123]I]BGA, recorded at 14 hours post injection, showed significant heart uptake. (author).

21 CFR 123.5 - Current good manufacturing practice.

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2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Current good manufacturing practice. 123.5 Section...) FOOD FOR HUMAN CONSUMPTION FISH AND FISHERY PRODUCTS General Provisions § 123.5 Current good manufacturing practice. (a) Part 110 of this chapter applies in determining whether the facilities, methods...

19 CFR 123.41 - Truck shipments transiting Canada.

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2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Truck shipments transiting Canada. 123.41 Section... OF THE TREASURY CUSTOMS RELATIONS WITH CANADA AND MEXICO United States and Canada In-Transit Truck Procedures § 123.41 Truck shipments transiting Canada. (a) Manifest required. Trucks with merchandise...

7 CFR 457.123 - Almond crop insurance provisions.

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2010-01-01

... 7 Agriculture 6 2010-01-01 2010-01-01 false Almond crop insurance provisions. 457.123 Section 457... CORPORATION, DEPARTMENT OF AGRICULTURE COMMON CROP INSURANCE REGULATIONS § 457.123 Almond crop insurance provisions. The Almond Crop Insurance Provisions for the 2008 and succeeding crop years are as follows: FCIC...

I-123-insulin: A new marker for hepatoma

International Nuclear Information System (INIS)

Sodoyez, J.C.; Goffaux, F.S.; Fallais, C.; Bourgeois, P.

1984-01-01

Previous studies have demonstrated that carrier-free I-123-Tyr Al4 insulin was taken up by the liver (by a saturable mechanism) and by the kidneys (by a non saturable mechanism). Autoradiographs of rat liver after injection of I-125-insulin showed that binding specifically occurred at the plasma membrane of the hepatocytes. I-123-Insulin binding to the hepatocyte plasma membrane appeared mediated by specific receptors. Indeed it was blocked by antibodies to the insulin receptors and by an excess of native insulin. Futhermore insulin derivatives with low biological potency (proinsulin and desoctapeptide insulin) did not inhibit I-123-insulin binding to the hepatocytes. I-123-Insulin (1.3 mCi) was I.V. injected into a patient in whom the right liver lobe was normal (normal uptake of Tc-99m-colloid sulfur) but the left liver lobe was occupied by a voluminous hepatoma (no uptake of Tc-99m-colloid sulfur). Liver blood supply was also studied by Tc-99m-pyrophosphate-labeled red cells. Computer analysis of the data revealed that compared to the normal liver lobe, binding of I-123-insulin to the hepatoma was more precocious (vascularization through the hepatic artery and not the portal vein), more intense and more prolonged (half-lives were 6 min in the normal liver and 14 min in the hepatoma). These results are consistent with characteristics of hepatoma cells in culture in which high insulin binding capacity contrasts with a markedly decreased insulin degrading activity. It is concluded that I-123-insulin may be used as a specific marker of hepatoma in man

Switchable Synthesis of 4,5-Functionalized 1,2,3-Thiadiazoles and 1,2,3-Triazoles from 2-Cyanothioacetamides under Diazo Group Transfer Conditions.

Science.gov (United States)

Filimonov, Valeriy O; Dianova, Lidia N; Galata, Kristina A; Beryozkina, Tetyana V; Novikov, Mikhail S; Berseneva, Vera S; Eltsov, Oleg S; Lebedev, Albert T; Slepukhin, Pavel A; Bakulev, Vasiliy A

2017-04-21

High yield solvent-base-controlled, transition metal-free synthesis of 4,5-functionalized 1,2,3-thiadiazoles and 1,2,3-triazoles from 2-cyanothioacetamides and sulfonyl azides is described. Under diazo transfer conditions in the presence of a base in an aprotic solvent 2-cyanothioacetamides operating as C-C-S building blocks produce 5-amino-4-cyano-1,2,3-thiadiazoles exclusively. The use of alkoxide/alcohol system completely switches the reaction course due to the change of one of the reaction centers in the 2-cyanothioacetamide (C-C-N building block) resulting in the formation of 5-sulfonamido-1,2,3-triazole-4-carbothioamide sodium salts as the only products. The latter serve as good precursors for 5-amino-1,2,3-thiadiazole-4-carboximidamides, the products of Cornforth-type rearrangement occurring in neutral protic medium or under acid conditions. According to DFT calculations (B3LYP/6-311+G(d,p)) the rearrangement proceeds via intermediate formation of a diazo compound, and can be catalyzed by acids via the protonation of oxygen atom of the sulfonamide group.

14 CFR 415.123 - Computing systems and software.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Computing systems and software. 415.123... Launch Vehicle From a Non-Federal Launch Site § 415.123 Computing systems and software. (a) An applicant's safety review document must describe all computing systems and software that perform a safety...

Diagnosis of pheochromocytoma using (123I)-compared with (131I)-metaiodobenzylguanidine scintigraphy

International Nuclear Information System (INIS)

Furuta, Nozomu; Kiyota, Hiroshi; Yoshigoe, Fukuo; Hasegawa, Norio; Ohishi, Yukihiko

1999-01-01

Patient with pheochromocytoma (PCT) cannot be cured without operation, therefore, preoperative determination of the localization of PCT should be performed accurately. ( 131 I)-Metaiodobenzylguanidine (MIBG) scintigraphy is a gold standard for the diagnosis of PCT. However, ( 123 I)-MIBG is also found to accumulate in PCT. In order to clarify the usefulness of ( 123 I)-MIBG scintigraphy for the local detection of PCT, we compared the distribution of ( 123 I)- and ( 131 I)-MIBG in patients with or without PCT. ( 131 I)- and ( 123 I)-MIBG scintigraphy was performed in 29 and 16 patients, respectively. In the former group, 14 patients had PCT, 12 had hypertension without any adrenal disorder and three had other diseases. In the latter group, eight patients had PCT, two had hypertension without any adrenal disorder and six had other diseases. The sensitivity, specificity and accuracy of ( 123 I)- with ( 131 I)-MIBG scintigraphy were compared. The sensitivity of ( 131 I)- and ( 123 I)-MIBG scintigraphy was 85.7 and 90%, respectively. The specificity of each test was 100%. The accuracy of ( 131 I)- and ( 123 I)-MIBG scintigraphy was 93.1 and 95%, respectively. The quality of images obtained using ( 123 I)-MIBG was better than with ( 131 I)-MIBG, because ( 123 I)-MIBG generated a higher dose of γ-rays with a higher specificity than ( 131 I)-MIBG. In addition, normal adrenal grands were visualized in 50% of patients tested with ( 123 I)-MIBG scintigraphy. These results indicate that ( 123 I)-MIBG scintigraphy is a valuable tool for the local detection of PCT, as is ( 131 I)-MIBG scintigraphy. Furthermore, it is possible that ( 123 I)-MIBG can be used as an alternative to ( 131 I)-MIBG for the detection of PCT. Our study was not a prospective study and the background of the patients was not matched. Further prospective studies are needed in order to determine the efficacy of ( 123 I)-MIBG scintigraphy for the diagnosis of PCT. (author)

Effect of light rare earth doping in 123 high temperature supercoductors

Directory of Open Access Journals (Sweden)

M. Mirzadeh

2006-09-01

Full Text Available   We have studied the structural and electrical properties of Gd(Ba2-xLaxCu3O7+δ [Gd(BaLa123], Gd(Ba2-xNdxCu3O7+δ [Gd(BaNd123], and Nd(Ba2-xPrxCu3O7+δ [Nd(BaPr123] compounds with 0.0≤x≤0.8 prepared by the standard solid-state reaction. The XRD patterns show that all of the samples with x≤0.5 are isosructure 123 phase, but in Gd(BaNd123 and Nd(BaPr123 there are several impurity peaks in the XRD patterns for x≥0.6. We estimated the xcsolubility=1.1, 0.6 and 0.55 in Gd(BaLa123, Nd(BaPr123, and Gd(BaNd123, respectively. The resistivity increases with the increase of doping. The decrease of Tc with the increase of Pr doping is faster than Nd and La doping. The normal-state resistivity is fitted for two and three dimensional variable range hopping (2D&amp3D-VRH and Coulomb gap (CG regimes, separately. Our results indicate that the dominant mechanism for x≥xcSIT is 3D-VRH. The broadening of magnetoresistance have been investigated by TAFC and AH models. The pinning energy and Josephson coupling energy, decrease with the increase of applied magnetic field as U~H-β, these values also decrease with doping concentration Pr is more effective than Nd and La.

40 CFR 81.123 - Southeastern Oklahoma Intrastate Air Quality Control Region.

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2010-07-01

... Quality Control Region. 81.123 Section 81.123 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.123 Southeastern Oklahoma Intrastate Air Quality Control Region. The Southeastern Oklahoma Intrastate Air Quality Control Region consists of the territorial area encompassed by the...

Localization of mitochondria in living cells with rhodamine 123.

Science.gov (United States)

Johnson, L V; Walsh, M L; Chen, L B

1980-01-01

The laser dye rhodamine 123 is shown to be a specific probe for the localization of mitochondria in living cells. By virtue of its selectivity for mitochondria and its fluorescent properties, the detectability of mitochondria stained with rhodamine 123 is significantly improved over that provided by conventional light microscopic techniques. With the use of rhodamine 123, it is possible to detect alterations in mitochondrial distribution following transformation by Rous sarcoma virus and changes in the shape and organization of mitochondria induced by colchicine treatment. Images PMID:6965798

Internalization kinetics and cytoplasmic localization of functionalized diatomite nanoparticles in cancer cells by Raman imaging.

Science.gov (United States)

Managò, Stefano; Migliaccio, Nunzia; Terracciano, Monica; Napolitano, Michela; Martucci, Nicola M; De Stefano, Luca; Rendina, Ivo; De Luca, Anna Chiara; Lamberti, Annalisa; Rea, Ilaria

2018-04-01

Porous biosilica nanoparticles obtained from diatomites (DNPs) have been recently demonstrated to be non-toxic nanovectors of therapeutic agents in cancer cells. In this work, the internalization kinetics and intracellular spatial distribution of functionalized DNPs incubated with human lung epidermoid carcinoma cell line (H1355) up to 72 hours are investigated by Raman imaging. The label-free Raman results are compared with confocal fluorescence microscopy and photoluminescence (PL) data. Raman bands specifically assigned to DNPs and cellular components provide evidence that the nanovectors are internalized and co-localize with lipid environments. A considerable DNPs uptake in cells is observed within 6 hours, with equilibrium being achieved after 18 hours. The obtained data show the presence of DNPs up to 72 hours, without damage to cell viability or morphology. The PL measurements performed on DNPs not penetrating the cells at different incubation times are strongly correlated with the results obtained by Raman imaging and confocal microscopy analyses. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Growing three-dimensional biomorphic graphene powders using naturally abundant diatomite templates towards high solution processability.

Science.gov (United States)

Chen, Ke; Li, Cong; Shi, Liurong; Gao, Teng; Song, Xiuju; Bachmatiuk, Alicja; Zou, Zhiyu; Deng, Bing; Ji, Qingqing; Ma, Donglin; Peng, Hailin; Du, Zuliang; Rümmeli, Mark Hermann; Zhang, Yanfeng; Liu, Zhongfan

2016-11-07

Mass production of high-quality graphene with low cost is the footstone for its widespread practical applications. We present herein a self-limited growth approach for producing graphene powders by a small-methane-flow chemical vapour deposition process on naturally abundant and industrially widely used diatomite (biosilica) substrates. Distinct from the chemically exfoliated graphene, thus-produced biomorphic graphene is highly crystallized with atomic layer-thickness controllability, structural designability and less noncarbon impurities. In particular, the individual graphene microarchitectures preserve a three-dimensional naturally curved surface morphology of original diatom frustules, effectively overcoming the interlayer stacking and hence giving excellent dispersion performance in fabricating solution-processible electrodes. The graphene films derived from as-made graphene powders, compatible with either rod-coating, or inkjet and roll-to-roll printing techniques, exhibit much higher electrical conductivity (∼110,700 S m -1 at 80% transmittance) than previously reported solution-based counterparts. This work thus puts forward a practical route for low-cost mass production of various powdery two-dimensional materials.

5 CFR 610.123 - Travel on official time.

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2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Travel on official time. 610.123 Section... DUTY Weekly and Daily Scheduling of Work Work Schedules § 610.123 Travel on official time. Insofar as practicable travel during nonduty hours shall not be required of an employee. When it is essential that this...

Preparation and solar-light photocatalytic activity of TiO2 composites: TiO2/kaolin, TiO2/diatomite, and TiO2/zeolite

Science.gov (United States)

Li, Y.; Li, S. G.; Wang, J.; Li, Y.; Ma, C. H.; Zhang, L.

2014-12-01

Three TiO2 loaded composites, TiO2/kaolin, TiO2/diatomite, and TiO2/zeolite, were prepared in order to improve the solar-light photocatalytic activity of TiO2. The results showed that the photocatalytic activity could obviously be enhanced by loading appropriate amount of inorganic mineral materials. Meanwhile, TiO2 content, heat-treatment temperature and heat-treatment time on the photocatalytic activity were reviewed. Otherwise, the effect of solar light irradiation time and dye concentration on the photocatalytic degradation of Acid Red B was investigated. Furthermore, the degradation mechanism and adsorption process were also discussed.

/sup 123m/Te-labeled biochemicals and method of preparation

International Nuclear Information System (INIS)

Knapp, F.

1980-01-01

A process for preparing a /sup 123m/Te-labeled organic compound of the formula R-/sup 123m/Te-CH 2 -R', R being alkyl, substituted alkyl, aryl or substituted aryl and R' being a steroidal side chain, alkyl amino acid or amino acid group, said process comprising the steps of: (A) reaching a /sup 123m/Te-symmetric diorgano ditelluride, R 2 /sup 123m/Te 2 , R being alkyl, substituted alkyl, aryl or substituted aryl, with a hydride reducing agent and a source of alkali metal ions to form an alkali metal organo telluride M-/sup 123m/Te-R; (B) reacting said alkali metal organo telluride with a primary halogenated organic compound R/sub a/'-X, R/sub a/' being a 17 alkyl steroid group having 1-4 carbon atoms in said alkyl group, an alkyl amino acid group, or a group hydrolyzable to an alkyl amino acid group

Herpesvirus telomerase RNA (vTR with a mutated template sequence abrogates herpesvirus-induced lymphomagenesis.

Directory of Open Access Journals (Sweden)

Benedikt B Kaufer

2011-10-01

Full Text Available Telomerase reverse transcriptase (TERT and telomerase RNA (TR represent the enzymatically active components of telomerase. In the complex, TR provides the template for the addition of telomeric repeats to telomeres, a protective structure at the end of linear chromosomes. Human TR with a mutation in the template region has been previously shown to inhibit proliferation of cancer cells in vitro. In this report, we examined the effects of a mutation in the template of a virus encoded TR (vTR on herpesvirus-induced tumorigenesis in vivo. For this purpose, we used the oncogenic avian herpesvirus Marek's disease virus (MDV as a natural virus-host model for lymphomagenesis. We generated recombinant MDV in which the vTR template sequence was mutated from AATCCCAATC to ATATATATAT (vAU5 by two-step Red-mediated mutagenesis. Recombinant viruses harboring the template mutation replicated with kinetics comparable to parental and revertant viruses in vitro. However, mutation of the vTR template sequence completely abrogated virus-induced tumor formation in vivo, although the virus was able to undergo low-level lytic replication. To confirm that the absence of tumors was dependent on the presence of mutant vTR in the telomerase complex, a second mutation was introduced in vAU5 that targeted the P6.1 stem loop, a conserved region essential for vTR-TERT interaction. Absence of vTR-AU5 from the telomerase complex restored virus-induced lymphoma formation. To test if the attenuated vAU5 could be used as an effective vaccine against MDV, we performed vaccination-challenge studies and determined that vaccination with vAU5 completely protected chickens from lethal challenge with highly virulent MDV. Taken together, our results demonstrate 1 that mutation of the vTR template sequence can completely abrogate virus-induced tumorigenesis, likely by the inhibition of cancer cell proliferation, and 2 that this strategy could be used to generate novel vaccine candidates

Effect of growth anisotropy on the morphology and property of directionally solidified RE123

International Nuclear Information System (INIS)

Nakamura, Yuichi; Shibusawa, Akira; Ooishi, Yoshihiro; Misu, Tomohiko; Inada, Ryoji; Oota, Akio

2005-01-01

The REBa 2 Cu 3 O y (RE123: RE = Y, Sm, Gd etc.) superconducting current lead is a favorable application due to the high J c properties and low thermal conductivity. Since the RE123 crystal shows the anisotropy in the J c properties as well as the mechanical properties, the ab-plane of the crystal parallel to the growth direction is preferable. The preferential growth direction during directional solidification is determined by the growth anisotropy in the early stage of the growth. In order to get the fundamental information to control the growth orientation, we investigated the growth rates of the Gd123 and Sm123 crystals against the undercooling and the continuous growth condition of Sm123 in directional solidification process. The growth rates of Sm123 and Gd123 were found to be about 5-10 times larger than that of Y123 at the same undercooling. The Sm123 showed the continuous growth structure up to 15 mm/h for fiber samples and up to 10 mm/h for 2 mm circle rods by the zone melting process. These pulling rates for continuous growth are larger than those of Y123 although the difference in growth rates between Sm123 and Y123 is much larger than this difference

[Evaluation of myocardial uptake of beta-methyl-(123I)-iodophenylpentadecanoic acid (123I-BMIPP)].

Science.gov (United States)

Momose, M; Kobayashi, H; Saito, K; Matsumoto, N; Maki, M; Hosoda, S; Kusakabe, K

1994-12-01

To evaluate the myocardial uptake of beta-methyl-(123I)-iodophenylpentadecanoic acid (123I-BMIPP), nineteen patients with ischemic heart disease including left ventricular hypertrophy (mean age 63 +/- 7.8, 14 males and 5 females) underwent BMIPP myocardial scintigraphy. Myocardial uptake (MU) of BMIPP to the total injected dose was calculated from anterior view of the planar image in all subjects, and was compared with plasma glucose (BS), triglyceride (TG), and free fatty acid (FFA). It was also compared with left ventricular mass (LVM) calculated with echocardiography. MU was not related to BS, TG, and FFA, however had the positive correlation with LVM (r = 0.676, p < 0.01). Myocardial uptake per left ventricular mass (MU/LVM) had the negative correlation with LVM (r = -0.671, p < 0.01). Further studies for the significance of MU/LVM will be required.

Evaluation of myocardial uptake of β-methyl-(123I)-iodophenylpentadecanoic acid (123II-BMIPP)

International Nuclear Information System (INIS)

Momose, Mitsuru; Kobayashi, Hideki; Matsumoto, Nobusuke; Maki, Masako; Kusakabe, Kiyoko; Saito, Katsumi; Hosoda, Saichi.

1994-01-01

To evaluate the myocardial uptake of β-methyl-( 123 I)-iodophenylpentadecanoic acid ( 123 I-BMIPP), nineteen patients with ischemic heart disease including left ventricular hypertrophy (mean age 63±7.8, 14 males and 5 females) underwent BMIPP myocardial scintigraphy. Myocardial uptake (MU) of BMIPP to the total injected dose was calculated from anterior veiw of the planar image in all subjects, and was compared with plasma glucose (BS), triglyceride (TG), and free fatty acid (FFA). It was also compared with left ventricular mass (LVM) calculated with echocardiography. MU was not related to BS, TG, and FFA, however had the positive correlation with LVM (r=0.676, p<0.01). Myocardial uptake per left ventricular mass (MU/LVM) had the negative correlation with LVM (r=-0.671, p<0.01). Further studies for the significance of MU/LVM will be required. (author)

Feasibility of dual radionuclide brain imaging with I-123 and Tc-99m

International Nuclear Information System (INIS)

Ivanovic, M.; Weber, D.A.; Loncaric, S.; Franceschi, D.

1994-01-01

A study was conducted to evaluate the feasibility of simultaneous dual radionuclide brain imaging with 123 I and 99m Tc using photopeak image subtraction techniques or offset photopeak image acquisition. The contribution of the photons from one radionuclide to a second radionuclide's photopeak energy window (crosstalk) was evaluated for SPECT and planar imaging of a brain phantom containing 123 I and 99m Tc for a range of activity levels and distribution properties approximating those in rCBF images of the adult human brain. Crosstalk was evaluated for 10% symmetrical energy windows centered on the 123 I and 99m Tc photopeaks and for 10% energy windows asymmetrically placed to the left and right of the center of the respective photopeaks. It was observed that the centered photopeak windows, 99m Tc crosstalk in the 123 I window is 8.9% of the 99m Tc seen in the 99m Tc window and ranges from 37.5% to 75.0% of the 123 I in the 123 I window. 123 I crosstalk is 37.8% of the 123 I seen in the 123 I window and ranges from 4.4% to 8.9% of the 99m Tc seen in the 99m Tc window. The spatial distribution of a radionuclide's crosstalk photons differs from that observed in the radionuclide's photopeak window. A 99m Tc photopeak window offset to the left does not decrease 123 I crosstalk, and the percentage of 99m Tc scattered photons is significantly increased in the window. Offsetting the 123 I window to the right decreases 99m Tc crosstalk to 9.0% to 17.9% of the 123 I counts, but decreases 123 I sensitivity by 39.9%. Offsetting both photopeak windows to the right decreases the 99m Tc scattered photons in the 99m Tc window, but increases 123 I crosstalk to 17.0% to 33.8% of the 99m Tc counts

Utjecaj liberalizacije na tržište stočarskih proizvoda

Directory of Open Access Journals (Sweden)

Ružica Lončarić

2004-01-01

Full Text Available Ulaskom u Svjetsku trgovinsku organizaciju Republika Hrvatska je dokazala spremnost za izazove liberalizacije i globalizacije svjetskoga tržišta. Ovom je koraku prethodilo i potpisivanju drugih značajnih dokumenata za uključenje u europski integracijski proces, kao što je Pakt o stabilizaciji u istočnoj Europi, Sporazum o stabilizaciji i Pridruživanju EU i RH, službeno priključenje CEFTA-i, te službena prijava za članstvo u EU, koji na provođenje određenih reformi i prilagodbu u političkome, gospodarskom i pravnom smislu. Kako se hrvatska poljoprivreda, pogotovo grana stočarstva, od osamostaljenja i prihvaćanja tržišnog sustava gospodarenja, nalazi u velikoj krizi, u radu se analizira položaj stočarstva s obzirom na uvjete proizvodnje i brojno stanje stoke, tržište stočarskih proizvoda uz pomoć dinamičke raščlambe sustava proizvodnje stočarskih proizvoda, te se daju prognoze na koji će se način odvijati adaptacija stočarstva u uvjetima EU s obzirom na konkurentnost naših stočarskih proizvoda u europskom okruženju tes obzirom na liberalizacijske obveze. Rezultati analizirani u radu pokazuju kako je hrvatska proizvodnja i tržište stočarskih proizvoda u dubokoj krizi, te da bi bilo potrebno poduzeti niz tržišno-cjenovnih mjera agrarne politike koje bi uredilo navedeno tržište s obzirom na obveze i pravila o liberalizaciji trgovine unutar europskog tržišta.

Clinical evaluation of 123I-BMIPP myocardial scintigraphy in patients with hypertrophic cardiomyopathy

International Nuclear Information System (INIS)

Ohtsuki, Katsuichi; Sugihara, Hiroki; Umamoto, Ikuo

1992-01-01

123 I-β-methyl-p-iodophenylpentadecanoic acid ( 123 I-BMIPP) myocardial scintigraphy was performed in 13 patients with hypertrophic cardiomyopathy and compared with 201 Tl myocardial scintigraphy performed within 3 months for evaluating the clinical significance of 123 I-BMIPP myocardial scintigraphy. SPECT images were divided into 13 segments and segmental images were visually scored on a 4 (increased tracer uptake) to 0 (severely decreased tracer uptake) scale according to the tracer uptake. In comparison of 123 I-BMIPP early images and 201 Tl perfusion images, mismatches were seen in about 70% of all segments. The number of segments demonstrating lower myocardial uptake of 123 I-BMIPP was larger than that of 201 Tl. In hypertrophic regions, the tracer uptake of 123 I-BMIPP early images was significantly lower than that of 201 Tl images and the lower uptake of 123 I-BMIPP delayed images was more marked. In non-hypertrophic regions, no significant difference was seen between the tracer uptakes of 123 I-BMIPP early images and 201 Tl images but the tracer uptake of 123 I-BMIPP delayed images was significantly lower than that of 201 Tl images. The mismatch between the tracer uptakes of 123 I-BMIPP images and 201 Tl images was thought to be a reflection of disordered myocardial fatty acid metabolism. 'Washout', the difference between the tracer uptakes of 123 I-BMIPP early images and delayed images was also thought to be a reflection of disordered myocardial fatty acid metabolism. These results suggest that 123 I-BMIPP is a promising radiopharmaceutical for evaluating disordered myocardial fatty acid metabolism in patients with HCM. (author)

[(123)I]FP-CIT ENC-DAT normal database

DEFF Research Database (Denmark)

Tossici-Bolt, Livia; Dickson, John C; Sera, Terez

2017-01-01

BACKGROUND: [(123)I]FP-CIT is a well-established radiotracer for the diagnosis of dopaminergic degenerative disorders. The European Normal Control Database of DaTSCAN (ENC-DAT) of healthy controls has provided age and gender-specific reference values for the [(123)I]FP-CIT specific binding ratio...... quantifications methods, BRASS and Southampton, and explores the performance of the striatal phantom calibration in their harmonisation. RESULTS: BRASS and Southampton databases comprising 123 ENC-DAT subjects, from gamma cameras with parallel collimators, were reconstructed using filtered back projection (FBP......) and iterative reconstruction OSEM without corrections (IRNC) and compared against the recommended OSEM with corrections for attenuation and scatter and septal penetration (ACSC), before and after applying phantom calibration. Differences between databases were quantified using the percentage difference...

Fragmentation patterns in the diatom genus Rouxia and their potential for identifying latent depositional hiatuses in the early Pliocene diatomite of the ANDRILL AND-1B core

Science.gov (United States)

Konfirst, M. A.; Scherer, R. P.; Winter, D.; Sjunneskog, C.; Warnock, J.; Kuhn, G.; Niessen, F.; Helling, D.; Magens, D.

2009-04-01

Diatom genera have traditionally been split into two primary groupings based upon the symmetry of the siliceous frustule. Diatoms symmetric about a point are classified as centrics, while those symmetric about a line are classified as pennates. This fundamental difference in shape has consequences for preservation in ice proximal settings, where an overriding ice sheet can create shearing in the upper meters of the sediment column. This leads to preferential breakage in pennate forms, and results in a higher ratio of undamaged centric to pennate frustules (Scherer et al., 2004). Similarly, an ice sheet grounded over highly porous diatomite results in significant diatom fragmentation resulting from normal load compaction. The diatom genus Rouxia is a pennate form with a relatively wide raphe, making it particularly susceptible to breakage during ice advance and retreat, and offering the opportunity to evaluate ice advance stages in sedimentary units where glacial erosion may have removed upper depositional units. In the ANDRILL AND-1B core, a long interval of nearly pure diatomite was recovered from 382.98-459.24 mbsf. Construction of an age model during this interval has relied primarily on age ranges provided by presence or absence of key diatom species. However, questions still remain as to the continuity of deposition. In this study, samples were collected at an average of 50-cm spacing for the length of the long diatom unit as well as for 20 meters of the silica-rich diamictite unit directly overlaying the diatomite. Fragments of specimens from the genus Rouxia were counted and classified into categories based on the size of the fragment in relation to total frustule length. These data were then used to develop a quantitative index, which was examined for changes in fragmentation through time. Preliminary data are presented that indicate increased fragmentation at the top of the section under study, which we interpret to indicate evidence for increased glacial

40 CFR 96.123 - CAIR permit contents and term.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false CAIR permit contents and term. 96.123 Section 96.123 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... necessary to facilitate coordination of the renewal of the CAIR permit with issuance, revision, or renewal...

Cardiac Iodine-123 metaiodobenzylguanidine (123I-MIBG) scintigraphy parameter predicts cardiac and cerebrovascular events in type 2 diabetic patients without structural heart disease

International Nuclear Information System (INIS)

Yufu, Kunio; Takahashi, Naohiko; Okada, Norihiro; Shinohara, Tetsuji; Nakagawa, Mikiko; Hara, Masahide; Yoshimatsu, Hironobu; Saikawa, Tetsunori

2012-01-01

Cardiac iodine-123 metaiodobenzylguanidine ( 123 I-MIBG) scintigraphy is an established method of assessment of cardiovascular sympathetic function. The aim of the present study was to investigate the long-term cardiovascular predictive value of cardiac 123 I-MIBG scintigraphy parameters in Japanese type 2 diabetic patients without structural heart disease. Cardiac 123 I-MIBG scintigraphy in 108 patients with type 2 diabetes who did not have structural heart disease, was evaluated. The washout rate (WR) was considered enhanced if it was ≥40%. Accurate follow-up information for 4.6 years was obtained in 54 enhanced WR patients (27 male; mean age, 61±11 years) and in 54 sex- and age-matched preserved WR patients (27 male; mean age, 61±10 years). Major adverse cardiac and cerebrovascular events (MACCE) were investigated. During follow-up, 10 enhanced WR patients developed MACCE including cardiac death, coronary revascularization, stroke, and congestive heart failure, while MACCE occurred in only 3 male patients. The Kaplan-Meier curves indicated that enhanced WR patients had higher incidence of MACCE than those with preserved WR (P 123 I-MIBG scintigraphy at baseline has long-term cardiovascular predictive value in Japanese patients with type 2 diabetes without structural heart disease. (author)

Apparatus of hot cell for iodine-123 production

International Nuclear Information System (INIS)

Almeida, G.L. de; Rautenberg, F.A.; Souza, A.S.F. de.

1986-01-01

The hot cell installation at IEN cyclotron (Brazilian-CNEN) for sup(123)I production is presented. Several devices, such as, tube furnace coupling system, tube furnace driving system, sup(123)I target transfer system, product extraction system, furnace control system, and effluent systems, were constructed and modified for implanting process engineering. The requirements of safety engineering for operation process were based on ALARA concept. (M.C.K.)

47 CFR 80.123 - Service to stations on land.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Service to stations on land. 80.123 Section 80... STATIONS IN THE MARITIME SERVICES Operating Requirements and Procedures Special Procedures-Public Coast Stations § 80.123 Service to stations on land. Marine VHF public coast stations, including AMTS coast...

40 CFR 97.123 - CAIR permit contents and term.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false CAIR permit contents and term. 97.123 Section 97.123 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... facilitate coordination of the renewal of the CAIR permit with issuance, revision, or renewal of the CAIR NOX...

Clinical applications of brain spect with N-isopropyl-123I-p-iodoamphetamine

International Nuclear Information System (INIS)

Moretti, J.L.; Sergent, A.; Raynaud, C.; Baron, J.C.; Samson, Y.; Lassen, N.; Bourdoiseau, M.

1985-01-01

Single-photon emission computed tomography (SPECT) with N-isopropyl- 123 I-p-iodoamphetamine (IAMP-I-123) was used for 250 patients suffering from brain disorders, comprising brain tumours (36), normal-pressure hydrocephalus (NPH) (23), cerebrovascular pathologies (127) and partial epilepsy (64). Brain tumours were found to be hypoactive, whatever the grade and nature. Frontal hypoactivity was found in NPH patients, and IAMP-I-123 perfusion was improved after cerebral spinal fluid (CSF) lumbar drainage, giving a good predictive criterion of clinical outcome after CSF diversion. For cerebrovascular disorders, it was possible to obtain with IAMP-I-123 SPECT larger pictures of hypoactive areas than the pictures of hypodense lesions obtained with X-ray CT scans; other hypoactive areas that could not be observed with CT were also delineated by IAMP-I-123 SPECT. The hypoactive areas found in constituted infarctions can present two types of kinetics - those which are 'persistent' (still present on delayed scans performed 5 h after IAMP-I-123 injection) and those which disappear with time, thereby suggesting hypofunctional parenchyma without tissue impairment. IAMP-I-123 SPECT was proved to be useful in assessing ischaemia, especially in reversible ischaemia patients, by defining the affected arterial territory and guiding complementary arteriographic exploration in view of surgical procedures. IAMP-I-123 SPECT was able to accurately delineate the affected parenchymal areas. It could also be of help in the follow-up of the efficiency of drug therapy and surgery, and it can be regarded as a good predictive criterion for stroke rehabilitation. The results obtained with IAMP-I-123 indicate that the lesional and epileptogenic areas in epileptic patients are hypoactive. The localization of these territories by IAMP-I-123 SPECT correlates well with other, more accurate, neuroradiological and stereotactic techniques. (author)

Naturlig ventilation og træk

DEFF Research Database (Denmark)

Nielsen, Peter Vilhelm

2002-01-01

Nye ventilationsprincipper som naturlig ventilation er med til at sætte fokus på de strømningselementer, der skal anvendes til dimensionering af luftfordelingen i et rum. Artiklen anviser, hvordan træk fra vinduer og tagåbninger i rum med naturlig ventilation kan beregnes ved hjælp af...

DNA and chromosome breaks induced by 123I-estrogen in CHO cells

International Nuclear Information System (INIS)

Schwartz, J.L.

1997-01-01

The effects of the Auger electron-emitting isotope I-123, covalently bound to estrogen, on DNA single- and double-strand breakage and on chromosome breakage was determined in estrogen positive Chinese hamster ovary (CHO-ER) cells. Exposure to the 123 I-estrogen induced both single- and double-strand breaks with a ratio of single- to double-strand breaks of 2.2. The corresponding ratio with 60 Co gamma rays was 15.6. The dose-response was biphasic suggesting that either receptor sites are saturated at high does, or that there is a nonrandom distribution of breaks induced by the 123 I-estrogen. The 123 I-estrogen treatment induced chromosome aberrations with an efficiency of about 1 aberration for each 1,000 disintegrations per cell. This corresponds to the mean lethal dose of 123 I-estrogen for these cells suggesting that the lethal event induced by the Auger electron emitter bound to estrogen is a chromosome aberration. Most of the chromosome-type aberrations were dicentrics and rings, suggesting that 123 I-estrogen-induced chromosome breaks are rejoined. The F-ratio, the ratio of dicentrics to centric rings, was 5.8 ± 1.7, which is similar to that seen with high LET radiations. Their results suggest that I-123 bound to estrogen is an efficient clastogenic agent, that the cytotoxic damage produced by I-123 bound to estrogen is very like high LET-induced damage, and the I-123 in the estrogen-receptor-DNA complex is probably in close proximity to the sugar-phosphate backbone of the DNA

I-123 IMP brain scintigraphies in asphyxiated newborns

International Nuclear Information System (INIS)

Maeda, Hisatoshi; Konishi, Yukuo; Kuriyama, Masanori; Ishii, Yasushi; Sudo, Masakatsu

1987-01-01

Brain scintigraphies with N-Isopropyl (I-123) p-Iodoamphetamine (I-123 IMP) were conducted in eight patients who had asphyxia at the time of birth. Two patients, 15 and 26 year-old, had local defects and diffuse low cerebral uptakes. Two children, 70 day and 2 year-old, had no cerebral uptake. Brain scintigraphies were carried out twice in three among four newborns. Only slight I-123 IMP brain uptakes were observed in the first 10 days. The lateral views of the brain scintigraphies showed increased uptake in the middle region of the brain between 10 to 30 days and reached almost equally distributed in frontal, middle and posterior regions after 30 days. These results were thought to represent rather developmental changes of the cerebral blood flow after ischemic attacks at birth. (author)

Forbruget af træer og buske i Danmark

DEFF Research Database (Denmark)

Jensen, Jan Svejgaard; Laursen, Allan Bach; Kjær, Erik Dahl

Træer og buske er vigtige elementer i byen og landskabet, og i Danmark bruges der mellem 60 og 80 millioner vedplanter hvert år. Forbruget har været konstant stigende og der er sket store forskydninger i forbrugsmønstret i retning af større fokus på mangfoldighed og autencitet. Undersøgelsen...... klarlægger forbrugsmønstret for træer og buske og undersøger, hvad brugerne lægger vægt på i deres valg af planter....

Successful therapy with hemoperfusion and plasma exchange in acute 1,2,3-trichloropropane poisoning.

Science.gov (United States)

Liu, P; Liang, Y-G; Meng, Q-Y; Zhang, C-G; Wang, H-C; Zhang, X-G; Li, G; Liu, Z-Y; He, Y-Z

2012-05-01

1,2,3-trichloropropane (1,2,3-TCP) is commonly used as an intermediate in pesticide and an industrial specialty solvent. Acute 1,2,3-TCP poisoning is rare but a medical emergency. Sporadic cases of toxic hepatic injury from 1,2,3-TCP in humans have been reported. Liver is a target organ for 1,2,3-TCP toxicity, which may ensue in a short period after ingestion. A specific antidote against 1,2,3-TCP is not available. So it is important to distinguish that a patient with 1,2,3-TCP poisoning constitutes a medical emergency. In this case study, the poisoned patient's clinical condition and laboratory values improved gradually after she received hemoperfusion (HP) and plasma exchange, which indicated that the therapy with HP and plasma exchange were helpful in the treatment of 1,2,3-TCP poisoning.

Clinical evaluation of 123I-IMP SPECT in patients with various neurological diseases

International Nuclear Information System (INIS)

Yoneda, Naoto

1993-01-01

Single photon emission computed tomography with N-isopropyl-p-[ 123 I] iodoamphetamine ( 123 I-IMP SPECT) was performed in 57 patients with various neurological disease, and compared with the findings of brain CT, MRI, and EEG. The author also evaluated the relationship between the findings on 123 I-IMP SPECT and the condition of the control of the attack after treatment with antiepileptic drugs in idiopathic epileptic patients. Abnormality of accumulation of 123 I-IMP SPECT was observed in 62.3% of all cases. Focal abnormality was detected in 28.3% of all cases by brain CT and 54.1% by MRI. The detectability of focal abnormality in brain CT and MRI was found to be lower than that of 123 I-TMP SPECT. There was very little significance in detectability between 123 I-IMP SPECT and EEG. But it infers that 123 I-IMP SPECT can detect the subictal state in epileptic patients. One comparative study of the relationship between the findings on 123 I-IMP SPECT and the condition of the control of the attack by antiepileptic drugs in patients with idiopathic epilepsy, abnormality of 123 I-IMP SPECT findings was found to be higher in patients who were not controlled sufficiently than in patients who were controlled sufficiently, and a significant difference is found by X 2 test. 123 I-IMP SPECT is useful for the evaluation of treatment in patients with epilepsy. (author)

Labeling of 3H11 With 123I and Its Biodistribution

International Nuclear Information System (INIS)

Qin Hongbin; Yin Wei; Gao Huibo; Chen Daming; Qi Benzhong; Jin Xiaohai; Bai Hongsheng; Zhang Wenhui; Yang Zhi

2010-01-01

3H11 was labeled with 123 I by Iodogen method,and the labeling product were purified with PD-10 column. The labeling yield and the radiochemical purity of the product was determined by paper chromatography. The biodistribution of 123 I-3H11 in normal mice was car ride out as well. The optimal experimental conditions of 123 I-3H11 was as follow: Iodogen 10 μg, 3H11 30 μg, Na 123 I solution 20 μL (13.3 MBq), PBS 100 μL (pH 7.4, 0.2 mol/L), the normal temperature for 8 min. The labeling yield of 123 I-3H11 was 70%-80%. After stored at 4 degree C for 48 h in human serum,the radiochemical purity was more than 92%. The results of biodistribution showed that the clearance of radiolabeled antibody in blood (half time, T 1/2 ) was 12.25±0.25 h, and the radioactivity in the stomach was up taken obviously. The above results indicated that 123 I-3H11 appears to show some potential as gastric cancer imaging diagnostic agent. (authors)

Basic studies on the hepatobiliary scintigraphy with 123I-rose bengal

International Nuclear Information System (INIS)

Narabayashi, Isamu; Ito, Yasuhiko; Otsuka, Nobuaki; Muranaka, Akira; Konno, Katsunobu.

1979-01-01

The purpose of this investigation is to evaluate the values of 123 I-rose bengal. sup(99m)Tc-labels for the hepatobiliary radiopharmaceutical are not fully satisfied because of greater urinary excretion, especially in cases of hyperbilirubinemia. 123 I is a lower gamma ray energy emitter more suitable for imaging and has a short half life with 13 hours. Commercially obtained rose bengal was purified using Sephadex G-25 column on gelfiltration. 123 I-rose bengal was prepared using iodine exchange reaction between nonradioactive rose bengal and Na 123 I. Radiochemical purity of 123 I-rose bengal was examined by paper chromatography. Biological distribution of 123 I-rose bengal in rabbits at 1 hours after intravenous injection indicated that the tracer was cleared from the blood to the liver, thereafter excreted into the small intestine through the common bile duct. Hepatic uptake and excretion of activity has been measured for 60 minutes using a scintillation camera in conjunction with a VTR system. There existed no significant relative to those of 131 I-rose bengal. Serial scintigraphic images showed satisfactorily better images even in a rabbit with complete obstructive jaundice. (author)

Effects of cigarette smoking on I-123 IMP clearance from the lung

International Nuclear Information System (INIS)

Katoh, Kunihiko; Takahashi, Tsuneo

1990-01-01

N-isopropyl-p-I-123-iodoamphetamine (I-123 IMP), originally developed as a brain scanning agent, is also taken up by the lung. To evaluate the cigarette smoking on the uptake of IMP by the lung, we studied I-123 IMP clearance from the lung on 14 volunteers; 5 non-smokers and 9 smokers. After the injection of 111 MBq (3mCi) of I-123 IMP into the medial cubital vein, the time-activity curve for 60 minutes and the regional activity using 1 frame per minute and a 64 x 64 matrix was obtained. I-123 IMP clearance curve was described as follows: C(t)=A 1 e -k1t +A 2 e -k2t (A 1 , A 2 : intercepts, and k 1 , k 2 : slopes of the exponential components). I-123 IMP clearance was delayed in smokers, and k 2 was smaller in smokers. Also a significant correlations between k 1 , k 2 , and the number of cigarettes smoked per day were found. In conclusion, this study suggests that the delayed clearance and retention of I-123 IMP in the lung indicate the lung metabolic disorders due to cigarette smoking. (author)

Regulation of mitosis-meiosis transition by the ubiquitin ligase β-TrCP in male germ cells.

Science.gov (United States)

Nakagawa, Tadashi; Zhang, Teng; Kushi, Ryo; Nakano, Seiji; Endo, Takahiro; Nakagawa, Makiko; Yanagihara, Noriko; Zarkower, David; Nakayama, Keiko

2017-11-15

The mitosis-meiosis transition is essential for spermatogenesis. Specific and timely downregulation of the transcription factor DMRT1, and consequent induction of Stra8 expression, is required for this process in mammals, but the molecular mechanism has remained unclear. Here, we show that β-TrCP, the substrate recognition component of an E3 ubiquitin ligase complex, targets DMRT1 for degradation and thereby controls the mitosis-meiosis transition in mouse male germ cells. Conditional inactivation of β-TrCP2 in male germ cells of β-TrCP1 knockout mice resulted in sterility due to a lack of mature sperm. The β-TrCP-deficient male germ cells did not enter meiosis, but instead underwent apoptosis. The induction of Stra8 expression was also attenuated in association with the accumulation of DMRT1 at the Stra8 promoter in β-TrCP-deficient testes. DMRT1 contains a consensus β-TrCP degron sequence that was found to bind β-TrCP. Overexpression of β-TrCP induced the ubiquitylation and degradation of DMRT1. Heterozygous deletion of Dmrt1 in β-TrCP-deficient spermatogonia increased meiotic cells with a concomitant reduction of apoptosis. Collectively, our data indicate that β-TrCP regulates the transition from mitosis to meiosis in male germ cells by targeting DMRT1 for degradation. © 2017. Published by The Company of Biologists Ltd.

Diagnostic value of asymmetric striatal D2 receptor upregulation in Parkinson's disease: an [123I]IBZM and [123I]FP-CIT SPECT study

International Nuclear Information System (INIS)

Verstappen, C.C.P.; Bloem, B.R.; Haaxma, C.A.; Horstink, M.W.I.M.; Oyen, W.J.G.

2007-01-01

Striatal postsynaptic D 2 receptors in Parkinson's disease (PD) are thought to be upregulated in the first years of the disease, especially contralateral to the clinically most affected side. The aim of this study was to evaluate whether the highest striatal D 2 binding is found contralateral to the most affected side in PD, and whether this upregulation can be used as a diagnostic tool. Cross-sectional survey was undertaken of 81 patients with clinically asymmetric PD, without antiparkinsonian drugs and with a disease duration of ≤5 years and 26 age-matched controls. Striatal D 2 binding was assessed with [ 123 I]IBZM SPECT, and severity of the presynaptic dopaminergic lesion with [ 123 I]FP-CIT SPECT. The mean striato-occipital ratio of [ 123 I]IBZM binding was significantly higher in PD patients (1.56 ±0.09) than in controls (1.53 ±0.06). In PD patients, higher values were found contralateral to the clinically most affected side (1.57 ±0.09 vs 1.55 ±0.10 ipsilaterally), suggesting D 2 receptor upregulation, and the reverse was seen using [ 123 I]FP-CIT SPECT. However, on an individual basis only 56% of PD patients showed this upregulation. Our study confirms asymmetric D 2 receptor upregulation in PD. However, the sensitivity of contralateral higher striatal [ 123 I]IBZM binding is only 56%. Therefore, the presence of contralateral higher striatal IBZM binding has insufficient diagnostic accuracy for PD, and PD cannot be excluded in patients with parkinsonism and no contralateral upregulation of D 2 receptors, assessed with [ 123 I]IBZM SPECT. (orig.)

A short proof of a conjecture on the Tr-choice number of even cycles

NARCIS (Netherlands)

Sitters, R. A.

In this note we prove that the Tr-choice number of the cycle C2n is equal to the Tr-choice number of the path (tree) on 4n - 1 vertices, i.e. Tr-ch(C2n) = [((4n - 2)/(4n - 1))(2r + 2)] + 1. This solves a recent conjecture of Alon and Zaks.

Gåsetrekket i Vesterålen og Nord-Trøndelag 2004

DEFF Research Database (Denmark)

Tombre, I.; Madsen, J.; Bakken, J.

for the goose species pink-footed goose Anser brachyrhynchus, barnacle goose Branta leucopsis and greylag goose Anser anser. The present report summarises goose registrations in some of the municipalities involved; Steinkjer and Inderøy in Nord-Trøndelag, Mid-Norway (pink-footed goose), and Sortland...... in Vesterålen, Northern Norway (pink-footed goose and barnacle goose). Registrations in the Nord-Trøndelag municipalities, Verdal and Levanger, are also included. Pink-footed and barnacle geese stage in Norway during spring on their way to their breeding grounds in Svalbard. In Trøndelag, the spring...... estimate of 43 000). This is probably an underestimate due to all hiding possibilities in the region, and it is assumed that at least 75 % of the Svalbard population of pink-footed goose stayed in Nord-Trøndelag in early May. Intensive scaring of geese registered at several locations in the county...

Iodine-123-labelled serum amyloid P component scintigraphy in amyloidosis

International Nuclear Information System (INIS)

Saile, R.; Deveaux, M.; Marchandise, X.; Duquesnoy, B.

1993-01-01

This study describes the results of scintigraphy with iodine-123-labelled serum amyloid P component (SAP) as a means of establishing the distribution of organ involvement in amyloidosis. The significance of 123 I-SAP scans obtained in 15 patients with biopsy-proven AA or AL amyloidosis is discussed. Biopsy-proven amyloidosis was typically confirmed by scintigraphy, though such confirmation was not obtained in the kidneys in six patients with histological proof of extensive renal amyloid deposition. This lack of uptake may have been due to the accumulation of a major part of the 123 I-SAP in the spleen and/or liver. Twenty-four hour whole-body retention of 123 I-SAP was higher in patients with amyloidosis than in controls. Twenty-four hour tracer accumulation of the radioactivity in the extravascular compartment was notably greater in patients than in controls and appeared to be a good diagnostic criterion. We conclude that 123 I-SAP scintigraphy may be helpful for the evaluation of organ involvement not only in patients with biopsy-proven amyloidosis but also when a biopsy cannot be performed or when a strong suspicion of amyloidosis exists in spite of repeated negative biopsises. (orig.)

Some observations on the use of iodine-123 for thyroid imaging

International Nuclear Information System (INIS)

Ryo, U.Y.; Pinsky, S.

1985-01-01

Efficacy of /sup 99m/Tc and 123 I for thyroid imaging was studied in 122 subjects with a variety of thyroid abnormalities. Both agents produced images that were equivalent in quality in 51 subjects, the image with 123 I was in better quality in 22, and the /sup 99m/Tc image was better in 9. In the remaining 40 cases, discordant findings existed between the 123 I image and /sup 99m/Tc image. In the majority of cases, i.e., 32 or 40, the discrepancy was caused by hot or warm lesions on the /sup 99m/Tc image that became cold or normal (nonvisualization) on the 123 I image. Advantages with /sup 99m/Tc appeared to be (1) the saving of time and cost for patients and physicians and (2) superior sensitivity in detecting thyroid lesions, whereas the advantages with 123 I appeared to be better quality of thyroid images and accurate representation of function of thyroid nodules

Optimization and Verification of the TR-MAC Protocol for Wireless Sensor Networks

NARCIS (Netherlands)

Morshed, S.; Heijenk, Geert

2015-01-01

Energy-efficiency is an important requirement in the design of communication protocols for wireless sensor networks (WSN). TR-MAC is an energy-efficient medium access control (MAC) layer protocol for low power WSN that exploits transmitted-reference (TR) modulation in the physical layer. The

Myocardial turnover rates of I-123 heptadecanoic acid (HDA)

International Nuclear Information System (INIS)

Dudczak, R.; Schmoliner, R.; Kletter, K.; Derfler, D.K.; Frischauf, H.; Angelberger, P.; Losert, U.

1982-01-01

Myocardial scintigraphy was performed with I-123 labeled HDA in patients with coronary artery disease (CAD, n=37), cardiomyopathy (COCM, n=7) and controls (n=10). These results were compared with coronary angiography, Tl 201 scintigraphy and radionuclide angiography. Results from animal experiments (intracoronary application in calfes) and patient studies supported the assumption that myocardial scintigraphy with I-123 HDA reveals information about myocardial fatty acid utilisation. Summarizing all clinical results using I-123 HDA showed that from the myocardial accumulation pattern of the labeled fatty acid, as well as from Tl 201 perfusion scintigraphy, the value of the regional elimination rate (t/2) could not be predicted. In patients with COCM the mean t/2 was prolonged, but overlapped with controls. In ischemic regions ''shortened'', normal and prolonged elimination rates were found. These findings were related to the observed wall motion and the calculated regional ejection fraction (r=0.73, p<0.001). This data indicate, that I-123 HDA add a further aspect in nuclear cardiology; the results obtained bear a relation to the functional state of the diseased heart

30 CFR 250.123 - Will MMS allow gas storage on unleased lands?

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Will MMS allow gas storage on unleased lands? 250.123 Section 250.123 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR... § 250.123 Will MMS allow gas storage on unleased lands? You may not store gas on unleased lands unless...

In-site coatings to reduce H and Tr permeation

International Nuclear Information System (INIS)

Stoever, D.; Buchkremer, H.P.; Hecker, R.; Jonas, H.; Schaefer, J.; Zink, U.; Forsyth, N.; Thiele, W.

1982-01-01

The main goal of this project is the development of protective coatings to reduce or prevent Tr and H permeation through the heat exchanger walls of HTR components. The tasks of the project are: Measurement of the permeation inhibition efficiency of oxidic coatings on the high-temperature- resistant heat exchanger walls; establishing the parameters influencing permeation by variation of the process gas and steam parameters, temperature and mechanical stress; characterisation of coatings and correlation of coating characteristics with permeation measurements; investigation of permeation and corrosion mechanisms; quantitative description of H and Tr permeation by means of mathematical/physical models. (orig./IHOE) [de

Síndrome de Isaacs: relato de três casos

Directory of Open Access Journals (Sweden)

SCOLA ROSANA HERMÍNIA

1999-01-01

Full Text Available Relatamos três casos de síndrome de Isaacs, que apresentavam mioquímia clínica, cãibras, dificuldades para o relaxamento muscular, hipertrofia muscular e aumento da sudorese. A eletromiografia de agulha mostrou atividade muscular contínua involuntária, caracterizada como descargas mioquímicas. Os estudos da condução nervosa foram normais. Biópsia de músculo, realizado nos três casos, mostrou atrofia de fibras do tipo 2. Dois casos apresentaram melhora clínica com a utilização de carbamazepina e um com prednisona.

123I and 13I purification for biomolecules labelling

International Nuclear Information System (INIS)

Catanoso, Marcela Forli

2011-01-01

The 123 I and 131 I are iodine radioisotopes widely used in Nuclear Medicine. The radioisotope 123 I is used in diagnosis through the SPECT technique and is routinely produced at IPEN in cyclotron through the reaction: '1 24 Xe (p, 2n) '1 23 Cs -> 123 Xe -> 123 I. The radioisotope 131 I is used both in diagnosis and therapy due to its physical characteristics of decay by β - and its γ-ray emissions that are softened with the use of specific collimators for diagnosis. It is routinely produced at IPEN using the nuclear reactor through the indirect reaction: 130 Te (n, γ) -> 131 Te -> 131 I, irradiating compounds containing Te. The radiopharmaceuticals prepared with these radioisotopes go through rigorous quality control tests and the chemical purity of the primary radioisotopes 123 I and 131 I are within the permissible limits currently defined. However, the presence of some chemical contaminants can prejudice the biomolecules labeling (monoclonal antibodies and peptides), that will produce radiopharmaceuticals of first generation to the oncology area. The aim of this work was to obtain a new purification method of these radioisotopes, allowing the labeling of biomolecules and also to established a process control on those radioisotopes. The methodology was separated on 3 steps: Evaluation of '1 23 I e 131 I radionuclidic purity using a hyper pure germanium detector, chemical purity using ICP-OES and the retention and elution study of 131 I in several absorbers to choose the most appropriate for the purification tests analyzing the behavior of the possible contaminants. The radionuclidic analyses showed the presence of Te and Co on 131 I samples and Te, Tc e Co on 123 I samples. The chemical purity analyses showed the presence of Al and Mo in 123 I, coming from the window material of the target holder and the presence of Al and Te in 131 I samples, coming from the target holder and the target, respectively. The retention and elution study selected the most

Realization of an integrated VDF/TrFE copolymer-on-silicon pyroelectric sensor

NARCIS (Netherlands)

Setiadi, D.; Setiadi, D.; Regtien, Paulus P.L.; Sarro, P.M.

1995-01-01

An integrated pyroelectric sensor based on a vinylidene fluoride trifluoroethylene (VDF/TrFE) copolymer is presented. A silicon substrate that contains FET readout electronics is coated with the VDF/TrFE copolymer film using a spin-coating technique. On-chip poling of the copolymer has been applied

Acute 1,2,3-trichloropane poisoning: a case report and literature review.

Science.gov (United States)

Han, Hui

2010-12-01

1,2,3-Trichloropropane is widely used in industrial and agricultural production. However 1,2,3-trichloropropane poisoning has been rarely encountered in clinical practices. Here, a 45-year-old farmer who suffered fulminant hepatic failure due to ingestion of 1,2,3-trichloropropane has been reported and literature about 1,2,3-trichloropane poisoning has been reviewed. For this case, reduced glutathione, vitamin K, pantoprazole were infused intravenously, and transfusion of blood plasma, platelets and red blood cells were carried out. Unfortunately, the patient's family gave up treatment and they left the hospital with the patient because of the low chance of recovery 20 hr after admission. Based on blood toxicology screening, patient history and rapid deterioration of the patient, the cause of fulminant hepatic failure was determined to be acute intoxication of 1,2,3-trichloropropane by unintentional toxicity. 1,2,3-trichloropropane has histopathological toxic effects on many organs and this toxic effect occurs within a short period after ingestion, with liver as the major affected organ. © 2010 The Author. Basic & Clinical Pharmacology & Toxicology © 2010 Nordic Pharmacological Society.

I-123(131)-metyrapone for imaging of the adrenal cortex

International Nuclear Information System (INIS)

Zolle, I.; Bergmann, H.; Hoefer, R.; Robien, W.

1982-01-01

Attempts to label metyrapone with radioiodine resulted in the synthesis of 4'-bromometyrapone that is labelled with I-123(131) by halogen exchange before use. The synthesis of I-123(131)-metyrapone involves 4 intermediate compounds. 4'-bromometyrapone serves as a precursor with indefinite shelf-life that is labelled selectively in the 4'-position of ring B. Studies of the biodistribution of I-131-metyrapone indicate the highest concentration in the adrenal gland 10-20 min after injection, peak uptake in the normal adrenal corresponds to 0.2% of the administered dose. In hyperfunctioning adrenals the uptake is higher. In a patient with bilateral modular hyperplasia, 0.8% of the injected radioactivity were measured in the enlarged adrenals at 2 resp. 2.8 hrs after injection of I-123-metyrapone. We have performed the first adrenal scintigram on the same patient with 1.25 mCi of I-123-metyrapone. (Author)

Synthesis of 123I-16 iodo estradiol

International Nuclear Information System (INIS)

Therain, F.; Gros, J.; Souchu, A.

1982-01-01

16α iodo estradiol has been demonstrated to have as good an affinity as estradiol for estrogen-receptors and, labeled with iodine 123, may provide a good scanning agent fot visualisation of tissues containing estrogen-repectors, especially mammary tumors. 123 I-16α iodo estradiol has been synthesized by an halogen exchange of 16ν bromo estradiol according to the procedure described by Hochberg for 125 I-16α iodo estradiol labeling. Radiochemical yields are much lower than with iodine 125 (1 to 30%) and extremely variable. Specific activity range from 1,000 to 2,000 Ci/mmole [fr

Iodine-123 program at the TRIUMF laboratory

International Nuclear Information System (INIS)

Vincent, J.S.

1985-01-01

A research program for the production and utilization of iodine-123 is described. From 1979 to 1982 the spallation of elemental cesium by 500-MeV protons was used to provide 100 mCi/hr at the end of bombardment (EOB). Contaminants were 3% iodine-125 and 0.15% tellurium-121 at EOB + 36 hr. The material from weekly runs was used by remote clinics in Canada for evaluation as a radiochemical and for labeling studies. A new facility at TRIUMF will be operational in 1983 to produce iodine-123 by the (p,5n) reaction

Maximum credible accident analysis for TR-2 reactor conceptual design

International Nuclear Information System (INIS)

Manopulo, E.

1981-01-01

A new reactor, TR-2, of 5 MW, designed in cooperation with CEN/GRENOBLE is under construction in the open pool of TR-1 reactor of 1 MW set up by AMF atomics at the Cekmece Nuclear Research and Training Center. In this report the fission product inventory and doses released after the maximum credible accident have been studied. The diffusion of the gaseous fission products to the environment and the potential radiation risks to the population have been evaluated

Coulomb excitation of {sup 123}Cd

Energy Technology Data Exchange (ETDEWEB)

Hartig, Anna-Lena; Kroell, Thorsten; Ilieva, Stoyanka; Boenig, Sabine; Thuerauf, Michael [IKP, TU Darmstadt (Germany); Simpson, Gary; Drouet, Floriane; Ramdhane, Mourad [LPSC, Grenoble (France); Georgiev, Georgi [CSNSM, Orsay (France); Kesteloot, Nele; Wrzosek-Lipska, Kasia [KU, Leuven (Belgium); Jungclaus, Andrea; Illana Sison, Andres [CSIC, Madrid (Spain); Balabanski, Dimiter [INRNE-BAS, Sofia (Bulgaria); Warr, Nigel [Koeln Univ. (Germany). IKP; Voulot, Didier; Wenander, Fredrik; Marsh, Bruce [CERN, Geneva (Switzerland)

2013-07-01

On the neutron-rich side of the valley of stability in the vicinity of the double magic nucleus {sup 132}Sn one can find the {sup 123}Cd isotope. Surprisingly the neutron-rich even-A Cd isotopes in this region are showing signs of collectivity beyond that calculated by modern shell-model predictions. In order to gain a deeper insight in this phenomenon we started to extend these studies to odd-A Cd isotopes. As first isotope the exotic nucleus {sup 123}Cd was produced for safe Coulomb excitation by the ISOLDE facility at CERN and post-accelerated by REX-ISOLDE. The γ-decay from excited states was detected with the MINIBALL array. A report on the status of the ongoing analysis is given.

Clinical evaluation of sup 123 I-BMIPP myocardial scintigraphy in patients with hypertrophic cardiomyopathy

Energy Technology Data Exchange (ETDEWEB)

Ohtsuki, Katsuichi; Sugihara, Hiroki; Umamoto, Ikuo (Kyoto Prefectural Univ. of Medicine (Japan)) (and others)

1992-02-01

{sup 123}I-{beta}-methyl-p-iodophenylpentadecanoic acid ({sup 123}I-BMIPP) myocardial scintigraphy was performed in 13 patients with hypertrophic cardiomyopathy and compared with {sup 201}Tl myocardial scintigraphy performed within 3 months for evaluating the clinical significance of {sup 123}I-BMIPP myocardial scintigraphy. SPECT images were divided into 13 segments and segmental images were visually scored on a 4 (increased tracer uptake) to 0 (severely decreased tracer uptake) scale according to the tracer uptake. In comparison of {sup 123}I-BMIPP early images and {sup 201}Tl perfusion images, mismatches were seen in about 70% of all segments. The number of segments demonstrating lower myocardial uptake of {sup 123}I-BMIPP was larger than that of {sup 201}Tl. In hypertrophic regions, the tracer uptake of {sup 123}I-BMIPP early images was significantly lower than that of {sup 201}Tl images and the lower uptake of {sup 123}I-BMIPP delayed images was more marked. In non-hypertrophic regions, no significant difference was seen between the tracer uptakes of {sup 123}I-BMIPP early images and {sup 201}Tl images but the tracer uptake of {sup 123}I-BMIPP delayed images was significantly lower than that of {sup 201}Tl images. The mismatch between the tracer uptakes of {sup 123}I-BMIPP images and {sup 201}Tl images was thought to be a reflection of disordered myocardial fatty acid metabolism. 'Washout', the difference between the tracer uptakes of {sup 123}I-BMIPP early images and delayed images was also thought to be a reflection of disordered myocardial fatty acid metabolism. These results suggest that {sup 123}I-BMIPP is a promising radiopharmaceutical for evaluating disordered myocardial fatty acid metabolism in patients with HCM. (author).

Effekter af træstøv; inflammation, gentoksicitet og cancer

DEFF Research Database (Denmark)

Lange, Jette Bornholdt

2008-01-01

lokaliseret i næse og bihuler. Især erhvervsmæssig udsæt-telse for hårde træsorter som eg, birk, bøg eller teak er associeret med sinonasal cancer og luftvejssymptomer. Trods talrige epidemiologiske studier af træstøvs helbredseffekter er forståelsen af de bagvedliggende mekanismer meget begrænset. I år 2000...

The design of an asynchronous Tiny RISC TM/TR4101 microprocessor core

DEFF Research Database (Denmark)

Christensen, Kåre Tais; Jensen, P.; Korger, P.

1998-01-01

This paper presents the design of an asynchronous version of the TR4101 embedded microprocessor core developed by LSI Logic Inc. The asynchronous processor, called ARISC, was designed using the same CAD tools and the same standard cell library that was used to implement the TR4101. The paper repo...

Clinical significance of I-123 IMP brain SPECT in children with brain diseases

International Nuclear Information System (INIS)

Takishima, Teruo; Machida, Kikuo; Honda, Norinari; Mamiya, Toshio; Takahashi, Taku; Kamano, Tsuyoshi; Hasegawa, Noriko

1990-01-01

Single photon emission computed tomography (SPECT) of the brain using N-isopropyl p-I-123-iodoamphetamine (I-123 IMP) was performed in 43 children with suspected brain diseases. Forty-three children (25 males and 18 females), with an age range of 24 days-15 years (mean: 6.6 years), were included in the study. Six patients were subsequently diagnosed as normal. Early SPECT of the brain was performed 30 minutes after intravenous administration of 74-111 MBq (2-3 mCi) I-123 IMP using a rotating gamma camera equipped with a 30-degree slant hole and medium energy collimator. Transverse images were reconstructed by Shepp-Logan filtered back projection method with attenuation correction after spatial filtering using an 8th order Butterworth-Wiener filter. Findings of I-123 IMP SPECT were compared with those of X-ray computed tomography (CT) and electroencephalography (EEG). The results showed that in I-123 IMP SPECT, abnormality was found in 30 out of 37 children with brain diseases. The incidence of abnormal findings in the 37 patients was 81% in I-123 IMP SPECT, 61% in X-ray CT, and 78% in EEG; in both cryptogenic and secondary epilepsy, the incidence of abnormality was higher in I-123 IMP SPECT than in X-ray CT. (70% and 94% vs 50% and 81% respectively), and epileptic foci detected by EEG did not correspond with defects found using I-123 IMP SPECT in 27% of the patients; and in asphyxiated infants, a high incidence of abnormality was observed on both I-123 IMP SPECT (86%) and X-ray CT (86%). In conclusion, I-123 IMP SPECT is a clinically useful examination in children with brain disease. (author)

Short TR imaging with refocusing of the steady-state transverse magnetization

International Nuclear Information System (INIS)

Zur, Y.; Stokar, S.; Bendel, P.

1987-01-01

Repetitive application of a sequence with repetition time (TR) shorter than T2 results in a steady state in which the transverse magnetization Mt reaches a nonzero value at the end of the sequence. This value depends on the TR and flip angle as well as on the frequency offset ν of each spin isochromat. The authors present a detailed analysis of the time domain and image domain signals for sequences with short TR that employ gradient reversal echoes. Because of the dependence of Mt on ν, two distinct echos appear in the time domain. With proper adjustment of the view gradients, each echo can be sampled separately. Image intensities derived for spins in a liquid (i.e., T1 -- T2) suggest enhanced signal intensity for the cerebrospinal fluid. This was confirmed experimentally

Radiosynthesis of 123I-labeled hesperetin for biodistribution study of orally administered hesperetin

International Nuclear Information System (INIS)

Jongho Jeon; So-Young Ma; Dae Seong Choi; Beom-Su Jang; Jung Ae Kang; You Ree Nam; Seonhye Yoon; Sang Hyun Park; Korea University of Science and Technology, Daejeon

2015-01-01

The purpose of this study is to synthesize 123 I-labeled hesperetin and to investigate its in vivo behavior. The optimized labeling condition provided two isomers of 123 I-labeled hesperetin with high radiochemical yields and radiochemical purities. Both 123 I-labeled products were orally administered to normal ICR mice, and the initial result showed that most of 123 I activity was detected in the stomach and the intestines. A part of 123 I-labeled hesperetin was absorbed from the small intestine to bloodstream and then it was distributed in normal organs. The results in the present study provided an efficient radiolabeling method of flavonoid and quantitative organ distribution of orally administered hesperetin. (author)

Iodine-123 in Western Europe

International Nuclear Information System (INIS)

Qaim, S.M.; Stoecklin, G.; Weinreich, R.

1976-08-01

The major object of this panel was to obtain information on the state of art of Iodine-123 production in Western Europe. Technical, medical and organizational problems were discussed extensively during the one-day meeting and a stimulating exchange of information between the various 123 I-producers and users has been initiated. Some specific examples of medical application were also included in order to get a feeling of the degree of acceptance by the medical community and the demand for this isotope. The meeting clearly demonstrated the great demand for this isotope but it also showed that the present rate of production is well below the demand. In order to fill this gap, not only further technical development is needed but also the organizational question of distribution has to be solved, perhaps within a network of collaborating cyclotrons, a task which is considerably more difficult in Western Europe than in the USA. (orig./HP) [de

Monitoração de tráfego par-a-par em tempo real

OpenAIRE

Tiago Alves Macambira

2005-01-01

O tráfego devido a aplicações P2P tem aumentado consideravelmente nos últimos anos e, apesar de ser hoje o responsável pela maior parte de todo o tráfego da Internet, não existem muitas ferramentas que auxiliem na monitoração e portanto no entendimento desse tráfego, tanto sob um ponto de vista acadêmico como sob um ponto de vista prático. Nesse trabalho abordamos as dificuldades em se construir umasolução que viabilize a análise e a caracterização de tráfego de aplicações em tempo real, tend...

A case report and brief literature review of Klippel-Trénaunay syndrome

Directory of Open Access Journals (Sweden)

Choudhary MG

2012-05-01

Full Text Available Madan Gopal Choudhary, Zia Ul Haq, Ram Narayan Sehra, Chandra Kumar ChaharDepartment of Paediatrics, Sardar Patel Medical College and P.B.M Hospital, Rajasthan, IndiaAbstract: Klippel-Trénaunay syndrome is a rare disorder characterized by the triad of vascular malformations, venous varicosities, and bone and soft-tissue hypertrophy. We present a case of Klippel-Trénaunay syndrome with limb hypertrophy, port-wine stains, angiokeratoma, and venous varicosities in the limbs.Keywords: Klippel-Trénaunay syndrome, sporadic, venous varicosities, port-wine stain, angiokeratoma

21 CFR 516.123 - Informal conferences regarding agency administrative actions.

Science.gov (United States)

2010-04-01

... exemption, determining that a qualified expert panel does not meet the selection criteria, denying a request... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Informal conferences regarding agency administrative actions. 516.123 Section 516.123 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH...

Evaluation of myocardial uptake of {beta}-methyl-({sup 123}I)-iodophenylpentadecanoic acid ({sup 123}II-BMIPP)

Energy Technology Data Exchange (ETDEWEB)

Momose, Mitsuru; Kobayashi, Hideki; Matsumoto, Nobusuke; Maki, Masako; Kusakabe, Kiyoko [Tokyo Women`s Medical Coll. (Japan); Saito, Katsumi; Hosoda, Saichi

1994-12-01

To evaluate the myocardial uptake of {beta}-methyl-({sup 123}I)-iodophenylpentadecanoic acid ({sup 123}I-BMIPP), nineteen patients with ischemic heart disease including left ventricular hypertrophy (mean age 63{+-}7.8, 14 males and 5 females) underwent BMIPP myocardial scintigraphy. Myocardial uptake (MU) of BMIPP to the total injected dose was calculated from anterior veiw of the planar image in all subjects, and was compared with plasma glucose (BS), triglyceride (TG), and free fatty acid (FFA). It was also compared with left ventricular mass (LVM) calculated with echocardiography. MU was not related to BS, TG, and FFA, however had the positive correlation with LVM (r=0.676, p<0.01). Myocardial uptake per left ventricular mass (MU/LVM) had the negative correlation with LVM (r=-0.671, p<0.01). Further studies for the significance of MU/LVM will be required. (author).

Kinetics of 17-(123I) iodoheptadecanoic acid in myocardium of rats

International Nuclear Information System (INIS)

Reske, S.N.; Auner, G.; Winkler, C.

1983-01-01

Myocardial uptake and turnover of 17-( 123 I)-iodoheptadecanoic acid, injected i.v., was studied in rats. Kinetics of radioactivity incorporated into myocardial tissue and heart lipids as well as myocardial radioactivity recovered as 123 I iodide were determined. Maximal heart uptake of IHA (7.9% dose/g) heart was observed as early as 30 sec., p.i., followed by monocomponent elimination period. Already 10 to 30 sec p.i. 70 to 80% of total myocardial radioactivity was recovered as 123 I iodide. IHA was incorporated only in modest amounts into myocardial phospholipids and triglycerides. Time course of total myocardial radioactivity grossly paralleled to that recovered as 123 I iodide. These findings indicate stringent limitations in utility of IHA as a tracer for assessment of β-oxidation. (author)

Iodine-123-labeled meta-iodobenzylguanidine myocardial scintigraphy evaluation of Machado-Joseph disease

International Nuclear Information System (INIS)

Kazuta, Toshinari; Hayashi, Michiyuki; Yoshita, Mitsuhiro; Hirai, Shunsaku

1998-01-01

Iodine-123-labeled meta-iodobenzylguanidine (( 123 I)MIBG), an analogue of guanetidine, is used as a tracer for evaluation of the function of sympathetic neurons. To investigate cardiac sympathetic function in Machado-Joseph disease (MJD), ( 123 I)MIBG myocardial scintigraphy was performed in 12 patients with MJD and 20 controls. In planar imaging studies, the heart to the mediastinum of the average count ratio (H/M) was calculated for both early and delayed images. The mean values of H/M in delayed images of MJD was lower than those of controls (p 123 I)MIBG myocardial scintigraphy in MJD can be seen earlier than abnormal sudomotor system detected by SSR. (author)

21 CFR 163.123 - Sweet chocolate.

Science.gov (United States)

2010-04-01

... CONSUMPTION CACAO PRODUCTS Requirements for Specific Standardized Cacao Products § 163.123 Sweet chocolate. (a... specified in paragraph (b)(3) of this section are used in the breakfast cocoa, the label shall bear an...

Myocardial imaging with 9-[Te-123m]tellurapheptadecanoic acid

International Nuclear Information System (INIS)

Elmaleh, D.R.; Knapp, F.F.; Yasuda, T.; Coffey, J.L.; Kopiwoda, S.; Okada, R.; Strauss, W.H.

1981-01-01

The distribution of radioactivity in the myocardium of rats and dogs infarcted by ligation of the left anterior coronary artery has been determined after intravenous injection of 9-[Te-123m]telluraheptadecanoic acid (Te-123m HDA). In rats the normal myocardium concentrated radioactivity (3.7% +/- 0.28 injected dose/g) to nearly three times that in the zones of infarction (1.12% +/- 0.18 dose/g). The focal defects detected in the gamma-camera images of rats and dogs correspond well with areas of infarction identified in the excised hearts by staining with triphenyltetrazolium chloride. The distribution of radioactivity from Te-123m HDA in dog hearts sectioned at autopsy showed a linear correlation (r = 0.94) with blood flow as determined with scandium-46-labeled microspheres