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Sample records for hdpb modified natural

  1. Natural radiation exposure modified by human activities

    International Nuclear Information System (INIS)

    Fujimoto, Kenzo

    1995-01-01

    We are now living in the radiation environment modified by our technology. It is usually called 'Technologically Enhanced Natural Radiation' and have been discussed in the UNSCEAR Reports as an important source of exposure. The terrestrial radionuclide concentrations as well as the intensity of cosmic rays are considered to have been constant after our ancestors came down from trees and started walking on their two feet. However, we have been changing our environment to be more comfortable for our life and consequently ambient radiation levels are nomore what used to be. In this paper exposures due to natural radiation modified by our following activities are discussed: housing, balneology, cave excursion, mountain climbing, skiing, swimming, smoking and usage of mineral water, well water, coal, natural gas, phosphate rocks and minerals. In the ICRP Publication No. 39, it is clearly mentioned that even natural radiation should be controlled as far as it is controllable. We have to pay more attention to our activities not to enhance the exposure due to unnecessary, avoidable radiation. (author)

  2. Natural products as radiation response modifiers

    International Nuclear Information System (INIS)

    Colin Seymour; Carmel Mothersill

    2007-01-01

    Complete text of publication follows. Protection of cells and organisms against low doses of radiation is a complex issue which must be considered at the level of cells, tissues and organisms. 'Protection' at one level, for example, prevention of cell death, may be adverse at another level, if it allows a damaged cell to survive and form a malignant tumour. Conversely, death of a cell carrying damage can be protective for the organism if it eliminates a damaged cell. Thus, it is important to understand the mechanisms involved in protection against radiation damage at several hierarchical levels. The use of natural products as radiation response modifiers is very attractive. Many of these compounds are readily available and their function and pharmacology is well understood. Some derive from venoms or natural defenses and are currently used in medicine, others include vitamins, antioxidants or cofactors, which are tried and tested nutritional supplements. Radiation effects may be targeted or untargeted. Radiation may interact directly within a cell causing a direct DNA lesion or it may elicit a bystander response from the irradiated cell. A bystander effect is produced when the irradiated cell apparently exhibits no damage from the radiation, but passes on a biochemical signal which induces neighbouring cells to apoptose or undergo a number of other responses usually associated with irradiation such as mutation induction, transformation, induction of ROS responses etc.. Effects induced in progeny of non-targeted cells in receipt of bystander signals include genetic instability, mini and microsatellite mutations and carcinogenesis. A key characteristic of these non targeted effects is that they occur at very low acute doses (of the order of 5mGy) and saturate so that effective prevention requires an agent which can effectively shut off the mechanism. While the mechanism is not fully known, it is thought to involve signals from irradiated cells communicating via

  3. Environmental application of modified natural zeolites

    International Nuclear Information System (INIS)

    Nikashina, V.A.; Myasoedov, B.F.

    1998-01-01

    The following techniques were used for the chemical modification of the natural zeolites: (1) treatment of natural zeolites with organic substances. Examples of applications of these sorbents to the decontamination and disinfection of solutions of different composition and surface waters are presented. (2) Treatment of the natural zeolites with a inorganic substances. (2.1) The clinoptilolite-rich tuffs were treated with a hot suspensions of freshly precipitated magnetite. This leads to the preparation of sorbents possessing magnetic properties. The radionuclides and heavy metals recovery from soils and silts was investigated using different soil and ferromagnetic zeolite weights ratios and contact times. Different soils and sorbent of varying capacities were used for these investigations. As example, the recovery 137 Cs and 85 Sr from soils of different nature is presented. (2.2) Treatment of natural zeolites with Fe-containing solutions of Fe-containing natural waters. The filtration of these solutions through clinoptilolite-rich tuffs makes leads to preparation of materials possessing high selectivity to PO 4 3- ions. The properties of these sorbents can be utilized for the PO 4 3+ decontamination of waters (e.g. waste waters) and for the subsequent use of these materials in agriculture as fertilizers.(author)

  4. Immobilization of catalase via adsorption into natural and modified ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-03

    Jun 3, 2009 ... and modified active carbon obtained from walnut in various methods ... area of food technology. In this industrial ... The amount of the enzyme activity adsorbed on the clay was calculated as ..... Application of natural kaolin as ...

  5. Technologically modified exposures to natural radiation. Annex C

    International Nuclear Information System (INIS)

    1982-01-01

    This Annex deals with some examples of technologically modified exposures to natural radiation. Radiation exposures due to coal-fired power plants, geothermal energy production, exploitation of phosphate rock, aircraft travel, and consumer products are discussed. The present state of knowledge does not allow an accurate estimate of the collective effective dose equivalent from technologically modified exposures to natural radiation to be made. This annex has an extensive bibliography with at least 200 references.

  6. Natural gums and modified natural gums as sustained-release carriers.

    Science.gov (United States)

    Bhardwaj, T R; Kanwar, M; Lal, R; Gupta, A

    2000-10-01

    Although natural gums and their derivatives are used widely in pharmaceutical dosage forms, their use as biodegradable polymeric materials to deliver bioactive agents has been hampered by the synthetic materials. These natural polysaccharides do hold advantages over the synthetic polymers, generally because they are nontoxic, less expensive, and freely available. Natural gums can also be modified to have tailor-made materials for drug delivery systems and thus can compete with the synthetic biodegradable excipients available in the market. In this review, recent developments in the area of natural gums and their derivatives as carriers in the sustained release of drugs are explored.

  7. Natural diatomite modified as novel hydrogen storage material

    Science.gov (United States)

    Jin, Jiao; Zheng, Chenghui; Yang, Huaming

    2014-03-01

    Natural diatomite, subjected to different modifications, is investigated for hydrogen adsorption capacities at room temperature. An effective metal-modified strategy is developed to disperse platinum (Pt) and palladium (Pd) nanoparticles on the surface of diatomite. Hydrogen adsorption capacity of pristine diatomite (diatomite) is 0.463 wt.% at 2.63 MPa and 298 K, among the highest of the known sorbents, while that of acid-thermally activated diatomite (A-diatomite) could reach up to 0.833 wt.% due to the appropriate pore properties by activation. By incorporation with a small amount of Pt and Pd ( 0.5 wt.%), hydrogen adsorption capacities are enhanced to 0.696 wt.% and 0.980 wt.%, respectively, indicating that activated diatomite shows interesting application in the field of hydrogen storage at room temperature.

  8. The introduction of tritium label into natural and modified prostaglandins

    International Nuclear Information System (INIS)

    Shevchenko, V.P.; Bezuglov, V.V.; Nagayev, I.Y.; Myasoedov, N.F.

    1989-01-01

    Studies on the role of the nature of both heterogeneous catalysts and the solvent on the reduction selectively of 5,6-double bonds showed that the largest yield could be obtained by using the Lindlar catalyst and ethyl acetate. The use of different isotopes of hydrogen in the protium-deuterium-tritium series markedly decreased the hydrogenation reaction rate, but the selectivity of the process practically remained unaltered. Homogeneous catalysts were also used in the production of natural tritium-labelled prostaglandins and of their fluorine and deoxy analogues. The label was introduced by selective hydrogenation in the presence of (Ph 3 P) 3 RhCl and dioxane as solvent. Different ways have been studied of tritium-label introduction into prostaglandins modified at the carboxyl group. The synthesis of similar preparations was performed either by selective dehalogenation in the presence of heterogeneous catalysts treated with quinoline or triethylamine, or by condensation of prostaglandins at the carboxyl group by tritium-labelled amino acid. (author). 4 refs.; 1 fig

  9. The increase of compressive strength of natural polymer modified concrete with Moringa oleifera

    Science.gov (United States)

    Susilorini, Rr. M. I. Retno; Santosa, Budi; Rejeki, V. G. Sri; Riangsari, M. F. Devita; Hananta, Yan's. Dianaga

    2017-03-01

    Polymer modified concrete is one of some concrete technology innovations to meet the need of strong and durable concrete. Previous research found that Moringa oleifera can be applied as natural polymer modifiers into mortars. Natural polymer modified mortar using Moringa oleifera is proven to increase their compressive strength significantly. In this resesearch, Moringa oleifera seeds have been grinded and added into concrete mix for natural polymer modified concrete, based on the optimum composition of previous research. The research investigated the increase of compressive strength of polymer modified concrete with Moringa oleifera as natural polymer modifiers. There were 3 compositions of natural polymer modified concrete with Moringa oleifera referred to previous research optimum compositions. Several cylinder of 10 cm x 20 cm specimens were produced and tested for compressive strength at age 7, 14, and, 28 days. The research meets conclusions: (1) Natural polymer modified concrete with Moringa oleifera, with and without skin, has higher compressive strength compared to natural polymer modified mortar with Moringa oleifera and also control specimens; (2) Natural polymer modified concrete with Moringa oleifera without skin is achieved by specimens contains Moringa oleifera that is 0.2% of cement weight; and (3) The compressive strength increase of natural polymer modified concrete with Moringa oleifera without skin is about 168.11-221.29% compared to control specimens

  10. Gold nanoparticles applications in natural polymer modified for UV protection

    International Nuclear Information System (INIS)

    Silva, Iris O. da; Ladchumananandasivam, Rasiah; Nascimento, Jose H. O. do; Silva, Francisco C. da; Sa, Christiane S. de A.

    2015-01-01

    The protein-based polymers such as milk, such as polylactic acid (PLA) and soya can be cited as examples of substrates used in various fields of engineering, mainly due to its character of biodegradability, generating low environmental impact when compared to chemical polymers to petroleum-based, which take years to decompose in nature. Among these, soy fiber has great application potential because it is a manufactured material base of a residue obtained from the existing folder in the soybean seeds after oil extraction, using resins and chemicals for structural modification. In this work, soy mesh was used to develop a material with ultraviolet protection properties, through the use of nanotechnology. Thus, to connect the gold nanoparticles (NPAu), the fabric had a surface charge modified with the use of chitosan, using 20% of the weight of the material, followed by nanomaterials exhaust process. The NPAu were synthesized via chemical synthesis with sodium nitrate as reducing and stabilizing agent. The analysis of the solution samples were evaluated by absorbance spectroscopy and solid materials through diffuse reflectance spectroscopy and XRD X-ray diffraction. The size of NPAu was evaluated in equipment Zetasizer nanoseries / nanoZ, finding nanoparticles with an average size of 34.59 nm, and also underlined plasmon resonance phenomenon, with peaks between 530 nm and red coloration, and good results from the soundness washes, compared to conventional dyeing. It was found that soy polymer treated with NPAu presented an excellent property with ultraviolet protection factor (UPF) of +50, considered excellent, proving its potential application in the biomedical field. (author)

  11. Application of natural seaweed modified mortar for sustainable concrete production

    Science.gov (United States)

    Siddique, M. N. I.; Zularisam, A. W.

    2018-04-01

    The effect of seaweed such as Eucheuma Cottonii (gel) and Gracilaria Sp. modified mortar on the properties of sustainable concrete was investigated. Pre-experiment and main-experiment was conducted to carry out this study. Pre-experiment was conducted to study the compressive strength of the sustainable concrete. The main-experiment studied the compressive and splitting strength. Results showed that seaweed modified mortar yielded satisfactory compressive and splitting strength of 30 MPa and 5 MPa at 28 days.

  12. High performance natural rubber composites with a hierarchical reinforcement structure of carbon nanotube modified natural fibers

    International Nuclear Information System (INIS)

    Tzounis, Lazaros; Debnath, Subhas; Rooj, Sandip; Fischer, Dieter; Mäder, Edith; Das, Amit; Stamm, Manfred; Heinrich, Gert

    2014-01-01

    A simple and facile method for depositing multiwall carbon nanotubes (MWCNTs) onto the surface of naturally occurring short jute fibers (JFs) is reported. Hierarchical multi-scale structures were formed with CNT-networks uniformly distributed and fully covering the JFs (JF–CNT), as depicted by the scanning electron microscopy (SEM) micrographs. The impact of these hybrid fillers on the mechanical properties of a natural rubber (NR) matrix was systematically investigated. Pristine JFs were cut initially to an average length of 2.0 mm and exposed to an alkali treatment (a-JFs) to remove impurities existing in the raw jute. MWCNTs were treated under mild acidic conditions to generate carboxylic acid moieties. Afterward, MWCNTs were dispersed in an aqueous media and short a-JFs were allowed to react with them. Raman spectroscopy confirmed the chemical interaction between CNTs and JFs. The JF–CNT exposed quite hydrophobic behavior as revealed by the water contact angle measurements, improving the wettability of the non-polar NR. Consequently, the composite interfacial adhesion strength was significantly enhanced while a micro-scale “mechanical interlocking” mechanism was observed from the interphase-section transmission electron microscopy (TEM) images. SEM analysis of the composite fracture surfaces demonstrated the interfacial strength of NR/a-JF and NR/JF–CNT composites, at different fiber loadings. It can be presumed that the CNT-coating effectively compatibillized the composite structure acting as a macromolecular coupling agent. A detailed analysis of stress-strain and dynamic mechanical spectra confirmed the high mechanical performance of the hierarchical composites, consisting mainly of materials arising from natural resources. - Highlights: • Natural rubber (NR) composites reinforced with CNT-modified short jute fibers. • MWCNTs deposited to the surface of jute fibers via non-covalent interactions. • Hierarchical reinforcement structure with

  13. Modified natural nanoparticles as contrast agents for medical imaging

    NARCIS (Netherlands)

    Cormode, David P.; Jarzyna, Peter A.; Mulder, Willem J. M.; Fayad, Zahi A.

    2010-01-01

    The development of novel and effective contrast agents is one of the drivers of the ongoing improvement in medical imaging. Many of the new agents reported are nanoparticle-based. There are a variety of natural nanoparticles known, e.g. lipoproteins, viruses or ferritin. Natural nanoparticles have

  14. Nanocomposites of natural rubber and polyaniline-modified cellulose nanofibrils

    Science.gov (United States)

    Cellulose nanofibrils (CNF) were isolated from cotton microfibrils (CM) by acid hydrolysis and coated with polyaniline (PANI) by in situ polymerization of aniline onto CNF in the presence of hydrochloride acid and ammonium peroxydisulfate to produce CNF/PANI. Nanocomposites of natural rubber (NR) re...

  15. Radiation exposure by man-modified materials containing natural radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Becker, D.E. [Technical Inspection Agency of Bavaria, Munich (Germany); Eder, E. [Government of Bavaria, Ministry for State Development and Environmental Affairs Development, Munich (Germany); Reichelt, A. [Technical Inspection Agency of Bavaria, Munich (Germany)

    1992-07-01

    More than one hundred materials, containing natural radioactive nuclides, are being investigated due to radiation exposure to people. This paper deals with thoriated gas mantles and shows that the radiation exposure by inhalation of radionuclides released while burning and exchange is not negligible. (author)

  16. Investigation of surface properties of physico-chemically modified natural fibres using inverse gas chromatography

    CSIR Research Space (South Africa)

    Cordeiro, N

    2011-01-01

    Full Text Available Inverse gas chromatography (IGC) is a suitable method to determine surface energy of natural fibres when compared to wetting techniques. In the present study, the surface properties of raw and modified lignocellulosic fibres have been investigated...

  17. Particle reinforced composites from acrylamide modified blend of styrene-butadiene and natural rubber

    Science.gov (United States)

    Blends of styrene-butadiene rubber and natural rubber that provide balanced properties were modified with acrylamide and reinforced with soy protein particles. The rubber composites show improved mechanical properties. Both modified rubber and composites showed a faster curing rate. The crosslinking...

  18. Study of vitamin A derivative complexation in natural and modified cyclodextrins

    International Nuclear Information System (INIS)

    Weisse, Sandrine

    1999-01-01

    This research thesis reports a test of solubilisation and stabilisation of retinol, a highly hydrophobic and unsteady molecule, by natural or modified cyclodextrins. The author first recalls retinol physical-chemical characteristics, and then evokes the different techniques (other than cyclodextrins) used to modify these characteristics. Then, the author addresses the complexes of inclusion of retinol in cyclodextrins, and the associated characterization techniques [fr

  19. Ion exchange of radionuclides on natural and modified micaceous minerals

    International Nuclear Information System (INIS)

    Kojvula, R.; Lekhto, Yu.

    1998-01-01

    Interaction of 134 Cs, 85 Sr and 60 Co with three micaceous minerals: muscovites, biotites and phlogopite is studied. Two types of micaceous minerals: natural ones, wherein potassium is an exchange cation, and samples, converted into sodium form, are studied/ It is found that biotite and phlogopite in the sodium form are specified by high selectivity to cobalt with distribution coefficient above 10 5 ml/g, whereas the muscovite potassium form is characterized by high selectivity to cesium. Neither of the micaceous minerals is characterized by selectivity to strontium. Distribution coefficients strongly depend on pH of the medium

  20. 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

  1. 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.

  2. 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.

  3. Effectiveness of indometacin to prevent ovulation in modified natural-cycle IVF : A randomized controlled trial

    NARCIS (Netherlands)

    Rijken-Zijlstra, T. M.; Haadsma, M. L.; Hammer, C.; Burgerhof, J. G. M.; Pelinck, M. J.; Simons, A. H. M.; van Echten-Arends, J.; Arts, J. G. E. M.; Land, J. A.; Groen, H.; Hoek, A.

    Modified natural-cycle IVF has a lower pregnancy rate per started cycle as compared with IVF with ovarian stimulation due to, for example, premature ovulation. Indometacin administered before ovulation prevents follicle rupture. Therefore, addition of indometacin may improve the effectiveness of

  4. Removal of lead from aqueous solutions by using the natural and Fe(III)-modified zeolite

    International Nuclear Information System (INIS)

    Kragović, Milan; Daković, Aleksandra; Sekulić, Živko; Trgo, Marina; Ugrina, Marin; Perić, Jelena; Gatta, G. Diego

    2012-01-01

    In the present study, the sorption of lead by the natural and Fe(III)-modified zeolite (clinoptilolite) is described. The characterization of the natural zeolite-rich rock and the Fe(III)-modified form was performed by chemical analysis, point of the zero charge (pH pzc ), X-ray powder diffraction, applying the Rietveld/RIR method for the quantitative phase analysis, and scanning electron microscopy. The effects of sorbents dose and the initial lead concentrations on its sorption by two sorbents were investigated. For both sorbents, it was determined that at lower initial concentrations of lead, ion exchange of inorganic cations in zeolites with lead, together with uptake of hydrogen dominated, while at higher initial lead concentrations beside these processes, chemisorption of lead occurred. Significantly higher sorption of lead was achieved with Fe(III)-modified zeolite. From sorption isotherms, maximum sorbed amounts of lead, under the applied experimental conditions, were 66 mg/g for the natural and 133 mg/g for Fe(III)-modified zeolite. The best fit of experimental data was achieved with the Freundlich model (R 2 ≥ 0.94).

  5. Semi-conducting material obtained from natural fiber modified with PAni

    International Nuclear Information System (INIS)

    Rocha, Eli V. da; Silva Junior, Fernando Gomes; Oliveira, Geiza E.; Pinto, Jose Carlos

    2009-01-01

    The surface of natural Brazilian Amazonic fibers (curaua, Ananas erectifolius) was modified with polyaniline nanoparticles, through in-situ preparation of polyaniline nanoparticles in presence of the curaua fibers. As it was shown here, this modification allowed a very significant increase of the electrical conductivity of the fibers (about 2.500 times). The modified materials were also characterized by FTIR (Fourier Transform Infrared Spectroscopy), AFM (Atomic Force Microscopy) and SAXS (Small Angle X-ray Scattering) and the obtained results were used to explain some of the chemical and morphological aspects of the materials. (author)

  6. Properties of diclofenac sodium sorption onto natural zeolite modified with cetylpyridinium chloride.

    Science.gov (United States)

    Krajišnik, Danina; Daković, Aleksandra; Milojević, Maja; Malenović, Anđelija; Kragović, Milan; Bogdanović, Danica Bajuk; Dondur, Vera; Milić, Jela

    2011-03-01

    In this study an investigation of a model drug sorption onto cationic surfactant-modified natural zeolites as a drug formulation excipient was performed. Natural zeolite was modified with cetylpyridinium chloride in amounts equivalent to 100, 200 and 300% of its external cation-exchange capacity. The starting material and obtained organozeolites were characterized by Fourier transform infrared spectroscopy, zeta potential measurements and thermal analysis. In vitro sorption of diclofenac sodium as a model drug was studied for all surfactant/zeolite composites by means of sorption isotherm measurements in aqueous solutions (pH 7.4). The modified zeolites with three levels of surfactant coverage within the short activation time were prepared. Zeta potential measurements and thermal analysis showed that when the surfactant loading level was equal to external cation-exchange value, almost monolayer of organic phase were present at the zeolitic surface while higher amounts of surfactant produced less extended bilayers, ordered bilayers or admicelles at the zeolitic surface. Modified zeolites, obtained in this manner, were effective in diclofenac sodium sorption and the organic phase derived from adsorbed cetylpyridinium chloride was the primary sorption phase for the model drug. The Langmuir isotherm was found to describe the equilibrium sorption data well over the entire concentration range. The separate contributions of the adsorption and partition to the total sorption of DS were analyzed mathematically. Results revealed that that adsorption and partitioning of the model drug take place simultaneously. 2010 Elsevier B.V. All rights reserved.

  7. A modified protocol for myocardial perfusion SPECT using natural plant extracts for enbancement of biliorg excretion

    International Nuclear Information System (INIS)

    Jeong, Hwan Jeong; Kim, Chang Guhn

    2003-01-01

    For good quality of myocardial perfusion images, an approximately 30 min to 1 hour of waiting time after radiopharmaceutical injection of fatty meal are asked of the patients. The aim of this study was to investigate the shortening of waiting time after radiopharmaceutical injection and improvement of image quality using natural plant extracts that promote bile excretion. Ten volunteers participated in protocol 1 (7 men, 3 women; mean age, 24.1±2.4 years) and protocol 2 (8 men, 2 women; mean age, 26.1±2.9 years), respectively. For the modified method of both protocols, subjects took natural plant extracts 15 minutes before the first injection of 99m Tc MIBI without taking fatty meals. Control (Conventional) methods were performed with intake of a fatty meal 20 to 30 minutes after 99m Tc MIBI injection. As the results of protocol 1 and 2, the ratio of myocardial to lung ratio were not different between modified and conventional method. Liver to lung ratio of modified method showed significantly lower value than that of conventional method. In modified method, myocardial to liver ratio was higher persistently. In protocol 2, natural plant extracts took before the first injection of 99m Tc MIBI exerted accelerating effect of excretion of bile juice into intestine until the end of examination. These results represent that natural plant extracts for facilitation of bile excretion before injection of 99m Tc MIBI may provide better quality of myocardial perfusion images without the need for preparations such as ingestion of fatty meal within the 2 hours compared with conventional method

  8. 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.

  9. Sorption of nonpolar aromatic contaminants by chlorosilane surface modified natural minerals.

    Science.gov (United States)

    Huttenloch, P; Roehl, K E; Czurda, K

    2001-11-01

    The efficacy of the surface modification of natural diatomite and zeolite material by chlorosilanes is demonstrated. Chlorosilanes used were trimethylchlorosilane (TMSCI), tert-butyldimethylchlorosilane (TBDMSCI), dimethyloctadecylchlorosilane (DMODSCI), and diphenyldichlorosilane (DPDSCI) possessing different headgroups and chemical properties. Silanol groups of the diatomite and zeolite were modified by chemical reaction with the chlorosilanes resulting in a stable covalent attachment of the organosilanes to the mineral surface. The alteration of surface properties of the modified material was proved by measurements of water adsorption capacity, total organic carbon (TOC) content, and thermoanalytical data. The surface modified material showed great stability even when exposed to extremes in ionic strength, pH, and to pure organic solvents. Sorption of toluene, o-xylene, and naphthalene from water was greatly enhanced by the surface modification compared to the untreated materials which showed no measurable sorption of these compounds. The enhanced sorption was dependent on the organic carbon content as well as on chemical characteristics of the chlorosilanes used. Batch sorption experiments showed that the phenyl headgroups of DPDSCI have the best affinity for aromatic compounds. Removal from an aqueous solution of 10 mg/L of naphthalene, o-xylene, and toluene was 71%, 60%, and 30% for surface modified diatomite and 51%, 30%, and 16% for modified clinoptilolite, respectively. Sorption data were well described by the Freundlich isotherm equation, which indicated physical adsorption onto the lipophilic surface rather than partitioning into the surface organic phase. The chlorosilane modified materials have an apparent potential for application in environmental technologies such as permeable reactive barriers (PRB) or wastewater treatment.

  10. Characterization of natural and modified zeolites using ion beam analysis techniques

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, E. [Instituto de Fisica, Departamento de Fisica Experimental, Universidad Nacional Autonoma de Mexico, Apdo. Postal 20-364, 01000 (Mexico)], E-mail: andrade@fisica.unam.mx; Solis, C. [Instituto de Fisica, Departamento de Fisica Experimental, Universidad Nacional Autonoma de Mexico, Apdo. Postal 20-364, 01000 (Mexico); Aceves, J.M.; Miranda, R. [Facultad de Estudios Superiores Cuautitlan Itzcalli, Departamento de Quimica, Universidad Nacional Autonoma de Mexico, 1 de Mayo S/N, Cuatitlan Itzcalli, Edo. de Mexico, C.P. 74540 (Mexico); Cruz, J. [Instituto de Fisica, Departamento de Fisica Experimental, Universidad Nacional Autonoma de Mexico, Apdo. Postal 20-364, 01000 (Mexico); Rocha, M.F. [Escuela Superior de Ingenieria Mecanica y Electrica, Instituto Politecnico Nacional, U.P. ' Adolfo Lopez Mateos' , Zacatenco, Del. Gustavo A. Madero, Mexico D.F. 07738 (Mexico); Zavala, E.P. [Instituto de Fisica, Departamento de Fisica Experimental, Universidad Nacional Autonoma de Mexico, Apdo. Postal 20-364, 01000 (Mexico)

    2008-05-15

    Zeolites are very important materials in catalytic and industrial processes. Natural, modified and synthetic zeolites have a wide range of uses because of their good adsorption, ion exchange capacity and catalytic properties. Mexico is an import source of natural zeolites, however their utilization in the natural form is limited due to the presence of trace metallic impurities. For example, metals such as vanadium and chromium inhibit the elimination of sulfur in hydrocarbons. Therefore, it is important to know the precise composition of the zeolite material. In this work, we report the elemental characterization of zeolites using various IBA techniques. {sup 3}He{sup +} and {sup 2}H{sup +} beams were used to measure the major element concentrations (Si, Al, O, C) by RBS and NRA. PIXE and SEM-EDS were used to measure the total trace element content (V, Cr, Fe, Ni, Cu, Zn, Rb, Sr, Zr, Pb, etc). Additionally, XRD was used to study the zeolite crystal structure.

  11. Modified natural zeolite as heterogeneous Fenton catalyst in treatment of recalcitrants in industrial effluent

    Directory of Open Access Journals (Sweden)

    Milton M. Arimi

    2017-04-01

    Full Text Available Industrial effluents with high recalcitrants should undergo post-treatment after biological treatment. The aim of this study was to use cheap and abundantly available natural materials to develop heterogeneous Fenton catalysts for the removal of colored recalcitrants in molasses distillery wastewater (MDW. The pellets of zeolite, which is naturally available in many countries, were modified by pre-treatment with sulphuric acid, nitric acid and hydrochloric acid, before embedding on them the ferrous ions. The effects of pH and temperature on heterogeneous Fenton were studied using the modified catalysts. The sulphuric acid-ferrous modified catalysts showed the highest affectivity which achieved 90% color and 60% TOC (total organic carbon removal at 150 g/L pellet catalyst dosage, 2 g/L H2O2 and 25 °C. The heterogeneous Fenton with the same catalyst caused improvement in the biodegradability of anaerobic effluent from 0.07 to 0.55. The catalyst was also applied to pre-treat the raw MDW and increased it's biodegradability by 4%. The color of the resultant anaerobic effluent was also reduced. The kinetics of total TOC removal was found to depend on operation temperature. It was best described by simultaneous first and second order kinetics model for the initial reaction and second order model for the rest of the reaction.

  12. Engineering characterisation of epoxidized natural rubber-modified hot-mix asphalt.

    Directory of Open Access Journals (Sweden)

    Ramez A Al-Mansob

    Full Text Available Road distress results in high maintenance costs. However, increased understandings of asphalt behaviour and properties coupled with technological developments have allowed paving technologists to examine the benefits of introducing additives and modifiers. As a result, polymers have become extremely popular as modifiers to improve the performance of the asphalt mix. This study investigates the performance characteristics of epoxidized natural rubber (ENR-modified hot-mix asphalt. Tests were conducted using ENR-asphalt mixes prepared using the wet process. Mechanical testing on the ENR-asphalt mixes showed that the resilient modulus of the mixes was greatly affected by testing temperature and frequency. On the other hand, although rutting performance decreased at high temperatures because of the increased elasticity of the ENR-asphalt mixes, fatigue performance improved at intermediate temperatures as compared to the base mix. However, durability tests indicated that the ENR-asphalt mixes were slightly susceptible to the presence of moisture. In conclusion, the performance of asphalt pavement can be enhanced by incorporating ENR as a modifier to counter major road distress.

  13. Evaluation of permanent deformation and durability of epoxidized natural rubber modified asphalt mix

    Science.gov (United States)

    Al-Mansob, Ramez A.; Ismail, Amiruddin; Rahmat, Riza Atiq O. K.; Nazri Borhan, Muhamad; Alsharef, Jamal M. A.; Albrka, Shaban Ismael; Rehan Karim, Mohamed

    2017-09-01

    The road distresses have caused too much in maintenance cost. However, better understandings of the behaviours and properties of asphalt, couples with greater development in technology, have allowed paving technologists to examine the benefits of introducing additives and modifiers. As a result, modifiers such as polymers are the most popular modifiers used to improve the performance of asphalt mix. This study was conducted to investigate the use of epoxidized natural rubber (ENR) to be mixed with asphalt mix. Tests were conducted to investigate the performance characteristics of ENR-asphalt mixes, where the mixes were prepared according to the wet process. Mechanical testing on the ENR-asphalt mixes have demonstrated that the asphalt mix permanent deformation performance at high temperature was found to be improved compared to the base mixes. However, the durability studies have indicated that ENR-asphalt mixes are slightly susceptible with the presence of moisture. The durability of the ENR-asphalt mixes were found to be enhanced in term of permanent deformation at high and intermediate temperatures compared to the base asphalt mixes. As conclusion, asphalt pavement performance can be enhanced by using ENR as modifier to face the major road distresses.

  14. X-ray diffraction characterization of epitaxial CVD diamond films with natural and isotopically modified compositions

    Energy Technology Data Exchange (ETDEWEB)

    Prokhorov, I. A., E-mail: igor.prokhorov@mail.ru [Russian Academy of Sciences, Space Materials Science Laboratory, Shubnikov Institute of Crystallography, Federal Scientific Research Centre “Crystallography and Photonics”, Kaluga Branch (Russian Federation); Voloshin, A. E. [Russian Academy of Sciences, Shubnikov Institute of Crystallography, Federal Scientific Research Centre “Crystallography and Photonics” (Russian Federation); Ralchenko, V. G.; Bolshakov, A. P. [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation); Romanov, D. A. [Bauman Moscow State Technical University, Kaluga Branch (Russian Federation); Khomich, A. A. [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation); Sozontov, E. A. [National Research Centre “Kurchatov Institute” (Russian Federation)

    2016-11-15

    Comparative investigations of homoepitaxial diamond films with natural and modified isotopic compositions, grown by chemical vapor deposition (CVD) on type-Ib diamond substrates, are carried out using double-crystal X-ray diffractometry and topography. The lattice mismatch between the substrate and film is precisely measured. A decrease in the lattice constant on the order of (Δa/a){sub relax} ∼ (1.1–1.2) × 10{sup –4} is recorded in isotopically modified {sup 13}C (99.96%) films. The critical thicknesses of pseudomorphic diamond films is calculated. A significant increase in the dislocation density due to the elastic stress relaxation is revealed by X-ray topography.

  15. Optimization of uranyl ions removal from aqueous solution by natural and modified kaolinites

    Energy Technology Data Exchange (ETDEWEB)

    Elhefnawy, O.A.; Elabd, A.A. [Nuclear and Radiological Regulatory Authority (NRRA), Cairo (Egypt). Nuclear Safeguards and Physical Protection Dept.

    2017-10-01

    The paper addresses the modifications of the most common mineral clay ''kaolinite'' for U(VI) removal from aqueous solutions. A new modified Egyptian natural kaolinite (Ca-MK) was prepared by coating kaolinite with calcium oxide. Another modification process was utilized by calcination and acid activation of kaolinite (E-MK). The Egyptian natural kaolinite (E-NK) and the two modified kaolinites were characterized by different techniques SEM, EDX, XRD, and FTIR. The removal process were investigated in batch experiments as a function of pH, contact time, initial U(VI) concentration, effect of temperature, and recovery of U(VI) were studied. The equilibrium stage was achieved after 60 min and the kinetic data was described well by pseudo-second order model. Isothermal data was better described by the Langmuir isotherm model, indicating the homogeneous removal process. Also the removal process was studied on different temperature 293, 313, and 323 K. The thermodynamic parameters ΔH , ΔS , and ΔG were calculated. The thermodynamic results pointed to the endothermic and favorable nature of the U(VI) removal process in the three kaolinite adsorbents. This study indicated that (Ca-MK) has higher CEC and can be used as a new adsorbent for highly efficient removal of U(VI) from aqueous solutions.

  16. Modified lysozymes as novel broad spectrum natural antimicrobial agents in foods.

    Science.gov (United States)

    Aminlari, Ladan; Hashemi, Marjan Mohammadi; Aminlari, Mahmoud

    2014-06-01

    In recent years much attention and interest have been directed toward application of natural antimicrobial agents in foods. Some naturally occurring proteins such as lactoperoxidase, lactoferrin, and lysozyme have received considerable attention and are being considered as potential antimicrobial agents in foods. Lysozyme kills bacteria by hydrolyzing the peptidoglycan layer of the cell wall of certain bacterial species, hence its application as a natural antimicrobial agent has been suggested. However, limitations in the action of lysozyme against only Gram-positive bacteria have prompted scientists to extend the antimicrobial effects of lysozyme by several types of chemical modifications. During the last 2 decades extensive research has been directed toward modification of lysozyme in order to improve its antimicrobial properties. This review will report on the latest information available on lysozyme modifications and examine the applicability of the modified lysozymes in controlling growth of Gram-positive and Gram-negative bacteria in foods. The results of modifications of lysozyme using its conjugation with different small molecule, polysaccharides, as well as modifications using proteolytic enzymes will be reviewed. These types of modifications have not only increased the functional properties of lysozyme (such as solubility and heat stability) but also extended the antimicrobial activity of lysozyme. Many examples will be given to show that modification can decrease the count of Gram-negative bacteria in bacterial culture and in foods by as much as 5 log CFU/mL and in some cases essentially eliminated Escherichia coli. In conclusion this review demonstrates that modified lysozymes are excellent natural food preservatives, which can be used in food industry. The subject described in this review article can lead to the development of methods to produce new broad-spectrum natural antimicrobial agents, based on modification of chicken egg white lysozyme, which

  17. Assessment of the Resistance to External Factors of Low-Density Polyethylene Modified with Natural Fillers

    Directory of Open Access Journals (Sweden)

    Karolina Głogowska

    2017-12-01

    Full Text Available The study reports the results of investigation of basic processing and thermal properties of low-density polyethylene modified with two types of natural filler: wheat bran and pumpkin seed hulls, their content ranging from 5% to 15% relative to the matrix. In addition, the physical properties of the produced granulates are determined, i.e. the relationship between their density and the applied contents of the tested fillers. Furthermore, the study reports the results concerning the longitudinal shrinkage, abrasion resistance and cold water absorption of injection molded tensile specimens.

  18. Restoring Natural Streamflow Variability by Modifying Multi-purpose Reservoir Operation

    Science.gov (United States)

    Shiau, J.

    2010-12-01

    Multi-purpose reservoirs typically provide benefits of water supply, hydroelectric power, and flood mitigation. Hydroelectric power generations generally do not consume water. However, temporal distribution of downstream flows is highly changed due to hydro-peaking effects. Associated with offstream diversion of water supplies for municipal, industrial, and agricultural requirements, natural streamflow characteristics of magnitude, duration, frequency, timing, and rate of change is significantly altered by multi-purpose reservoir operation. Natural flow regime has long been recognized a master factor for ecosystem health and biodiversity. Restoration of altered flow regime caused by multi-purpose reservoir operation is the main objective of this study. This study presents an optimization framework that modifying reservoir operation to seeking balance between human and environmental needs. The methodology presented in this study is applied to the Feitsui Reservoir, located in northern Taiwan, with main purpose of providing stable water-supply and auxiliary purpose of electricity generation and flood-peak attenuation. Reservoir releases are dominated by two decision variables, i.e., duration of water releases for each day and percentage of daily required releases within the duration. The current releasing policy of the Feitsui Reservoir releases water for water-supply and hydropower purposes during 8:00 am to 16:00 pm each day and no environmental flows releases. Although greater power generation is obtained by 100% releases distributed within 8-hour period, severe temporal alteration of streamflow is observed downstream of the reservoir. Modifying reservoir operation by relaxing these two variables and reserve certain ratio of streamflow as environmental flow to maintain downstream natural variability. The optimal reservoir releasing policy is searched by the multi-criterion decision making technique for considering reservoir performance in terms of shortage ratio

  19. 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.

  20. 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.

  1. Removal of selenium species from waters using various surface-modified natural particles and waste materials

    Energy Technology Data Exchange (ETDEWEB)

    Yigit, Nevzat O.; Tozum, Seda [Department of Environmental Engineering, Suleyman Demirel University, Isparta (Turkey)

    2012-07-15

    Waste red mud and natural pumice/volcanic slag particles were surface modified and their selenium adsorption from waters was investigated. Acid activation/heat treatment of original red mud (ORM) particles significantly increased their micropore and external surface area and cumulative volume of pores. Iron oxide coating of pumice/slags and acid activation of ORM decreased their pH{sub pzc} values and increased surface acidity. Selenite/selenate adsorption on iron oxide surfaces and acid activated red mud (AARM) was very fast with approximately first-order adsorption kinetics. Iron oxide coating of pumice/slag and acid activation of ORM particles significantly enhanced their selenite and selenate uptakes. Maximum Se adsorption capacities as high as 6.3 (mg Se/g adsorbent) were obtained by AARM. The extent of selenate uptakes by the surface modified particles was generally lower than those of selenite. Due to competition among Se species and other background water matrix for iron oxide adsorption sites, reduced selenite/selenate uptakes were found in natural water compared to single solute tests. Higher Se uptakes by iron oxide surfaces were found at pH 7.5 compared to pH 8.9, due to increased electrostatic repulsion among iron oxides and Se species at higher pH. The most effective adsorbents among the tested 17 different particles for Se uptake were AARM and iron oxide coated pumice. Se concentrations less than drinking water standards (5-10 {mu}g/L) can be achieved by these particles. These low-cost, natural, or recyclable waste particles appear to be promising adsorbents for Se removal after their surface modification. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Bio-corrosion in synthetic and natural sea water of modified stainless steels by poison elements

    International Nuclear Information System (INIS)

    Hernandez Duque, G.

    1989-09-01

    In seawater, bacteria can modify the behaviour of stainless steels towards corrosion. It can be then considered to control this type of degradation by a better adjustment of the chemical composition of the steels used. In this work, has been studied the influence of the addition of 'poisons' elements for bacteria on the bio-corrosion resistance of an austenitic 316L steel. The added elements were copper, tin and arsenic. After a bibliographic study and a description of the metallographic, electrochemical and surface analyses methods used, the results obtained in the considered media are given: synthetical seawater, natural, or sterilized and then inoculated. The specific role of each addition elements has then been revealed as well as the alteration of the protecting films and of the induced bio-film, and the behaviour differences in aerobic and anaerobic conditions. (O.M.)

  3. Vulcanization characteristics and dynamic mechanical behavior of natural rubber reinforced with silane modified silica.

    Science.gov (United States)

    Chonkaew, Wunpen; Minghvanish, Withawat; Kungliean, Ulchulee; Rochanawipart, Nutthaya; Brostow, Witold

    2011-03-01

    Two silane coupling agents were used for hydrolysis-condensation reaction modification of nanosilica surfaces. The surface characteristics were analyzed using Fourier transform infrared spectroscopy (FTIR). The vulcanization kinetics of natural rubber (NR) + silica composites was studied and compared to behavior of the neat NR using differential scanning calorimetry (DSC) in the dynamic scan mode. Dynamic mechanical analysis (DMA) was performed to evaluate the effects of the surface modification. Activation energy E(a) values for the reaction are obtained. The presence of silica, modified or otherwise, inhibits the vulcanization reaction of NR. The neat silica containing system has the lowest cure rate index and the highest activation energy for the vulcanization reaction. The coupling agent with longer chains causes more swelling and moves the glass transition temperature T(g) downwards. Below the glass transition region, silica causes a lowering of the dynamic storage modulus G', a result of hindering the cure reaction. Above the glass transition, silica-again modified or otherwise-provides the expected reinforcement effect.

  4. Modified natural cycle for embryo transfer using frozen-thawed blastocysts: A satisfactory option.

    Science.gov (United States)

    Le, Quoc V; Abhari, Sina; Abuzeid, Omar M; DeAnna, Jennifer; Satti, Mohamed A; Abozaid, Tarek; Khan, Iqbal; Abuzeid, Mostafa I

    2017-06-01

    To describe pregnancy outcomes of frozen-thawed blastocysts cycles using modified natural cycle frozen embryo transfers (NC-FET) and down-regulated hormonally controlled frozen embryo transfers (HC-FET) protocols. This retrospective cohort study included all patients undergoing either modified NC-FET or down-regulated HC-FET using frozen-thawed day 5 embryos. Cycles with donor blastocysts were excluded. Four hundred twenty eight patients underwent a total of 493 FET cycles. Patients with regular menses and evidence of ovulation underwent modified NC-FET. These patients were given hCG 10,000 IU IM on the day of LH-surge. Vaginal progesterone (P4) was started two days later and blastocyst transfer was planned seven days after detecting the LH surge. Anovulatory patients and some ovulatory patients underwent down-regulated HC-FET. These patients were placed on medroxy-progesterone acetate (10mg) for 10days to bring on menses and were also given a half-dose of GnRH-agonist (GnRH-a) on the third day of medroxy-progesterone acetate. Exogenous estradiol was initiated on the third day of menses. Once serum E2 levels reached >500pg/mL and endometrial lining reached >8mm, intramuscular (IM) P4 in oil was administered. Blastocyst FET was planned 6days after initiating P4. The primary outcomes included clinical pregnancy and delivery rates. There were 197 patients in the modified NC-FET protocol and 181 in the down-regulated HC-FET protocol. Mean age (years), day-3 FSH levels (mIU/mL) and percentage of patients with male factor infertility were significantly higher and mean BMI (kg/m 2 ) was significantly lower in modified NC-FET compared to HC-FET, respectively. Analysis of the first cycle pregnancy outcomes revealed no significant differences in clinical pregnancy rate (54.3% vs. 52.5%) and delivery rate (47.2% vs. 43.6%) between modified NC-FET and HC-FET. Logistic regression analysis showed age (OR=0.939, 95% CI 0.894-0.989, p=0.011), number of blastocysts transferred (OR

  5. Surface modified natural zeolite as a carrier for sustained diclofenac release: A preliminary feasibility study.

    Science.gov (United States)

    de Gennaro, Bruno; Catalanotti, Lilia; Cappelletti, Piergiulio; Langella, Alessio; Mercurio, Mariano; Serri, Carla; Biondi, Marco; Mayol, Laura

    2015-06-01

    In view of zeolite potentiality as a carrier for sustained drug release, a clinoptilolite-rich rock from California (CLI_CA) was superficially modified with cetylpyridinium chloride and loaded with diclofenac sodium (DS). The obtained surface modified natural zeolites (SMNZ) were characterized by confocal scanning laser microscopy (CLSM), powder X-ray diffraction (XRPD) and laser light scattering (LS). Their flowability properties, drug adsorption and in vitro release kinetics in simulated intestinal fluid (SIF) were also investigated. CLI_CA is a Na- and K-rich clinoptilolite with a cationic exchange ability that fits well with its zeolite content (clinoptilolite=80 wt%); the external cationic exchange capacity is independent of the cationic surfactant used. LS and CLSM analyses have shown a wide distribution of volume diameters of SMNZ particles that, along with their irregular shape, make them cohesive with scarce flow properties. CLSM observation has revealed the localization of different molecules in/on SMNZ by virtue of their chemical nature. In particular, cationic and polar probes prevalently localize in SMNZ bulk, whereas anionic probes preferentially arrange themselves on SMNZ surface and the loading of a nonpolar molecule in/on SMNZ is discouraged. The adsorption rate of DS onto SMNZ was shown by different kinetic models highlighting the fact that DS adsorption is a pseudo-second order reaction and that the diffusion through the boundary layer is the rate-controlling step of the process. DS release in an ionic medium, such as SIF, can be sustained for about 5h through a mechanism prevalently governed by anionic exchange with a rapid final phase. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Production of biodiesel from palm oil using modified Malaysian natural dolomites

    International Nuclear Information System (INIS)

    Shajaratun Nur, Z.A.; Taufiq-Yap, Y.H.; Rabiah Nizah, M.F.; Teo, Siow Hwa; Syazwani, O.N.; Islam, Aminul

    2014-01-01

    Highlights: • Transesterification was carried out using modified Malaysian natural dolomite catalyst. • Characterizations of the catalyst were performed by using XRD, TPD-CO 2 , BET and SEM. • Maximum biodiesel conversion of 100% was achieved from SnO 2 /dolomite catalyst. • The yield was affected by the surface are as well as the basicity of catalyst. • The transesterification reaction gave significant conversion with relatively lower amount of catalyst. - Abstract: Calcined dolomite (AD), produced by calcination of Malaysian dolomite (UD) promotes a potential natural catalyst for biodiesel production from palm oil with the conversion of 99.98%. The catalysts were characterized by using X-ray Diffractometer (XRD), Brunauer–Emmet–Teller (BET) surface area, Scanning Electron Microscopy (SEM) and Temperature Programmed Desorption (TPD) of CO 2 . All catalysts were then employed for transesterification reaction under different conditions (time, methanol to oil molar ratio and amount of catalyst). SnO 2 doped on activated dolomite (SD) shows an optimum conversion (99.98%) at conditions, i.e. 15:1 methanol to oil molar ratio in 4 h compared to ZnO doped on activated dolomite (ZD) and AD. The catalytic activities of these catalysts were found to be depending on the basicity as well as the surface area of the catalyst used

  7. Effect of Modified Natural Rubber on PVC-ENR Electrospun Membrane: Thermal and Morphological Studies

    International Nuclear Information System (INIS)

    Mahathir Mohamed; Dahlan Mohd; Ratnam, C.T.; Pairu Ibrahim

    2016-01-01

    Electrospun fibers membrane (EFM) based on modified epoxidized natural rubber (ENR) and polyvinyl chloride (PVC) was successfully prepared by electro spinning technique. Epoxidized natural rubber was firstly prepared in solution by using 5 L flask and exposed to high intensity UV lamp for degradation. The PVC/ ENR mixture solution concentration were about 16 wt% and blended for 5 hours for homogeneity. The PVC/ ENR mixture were electro spun to form fibers membrane. The sample of electro spun fibers membrane were cured by electron beam. The resulting membranes were characterized for thermal and morphological studies. Thermal decomposition behavior of EFM was analyzed by thermogravimetric analysis (TGA). Thermo gram from TGA showed two stages of degradation for all formulation (90:10, 80:20, 70:30 PVC/ ENR) from 240 to 265 degree Celsius and 400 to 410 degree Celsius, respectively. From the DSC thermo gram of PVC/ ENR electro spun fibers showed that the addition of ENR resulted in the shifting of glass transition temperature (Tg) towards lower temperatures. The morphology of electro spun fibers was examined using scanning electron microscopy and it showed a variety of fiber morphologies. (author)

  8. Copolymer natural latex in concrete: Dynamic evaluation through energy dissipation of polymer modified concrete

    Science.gov (United States)

    Andayani, Sih Wuri; Suratman, Rochim; Imran, Iswandi; Mardiyati

    2018-05-01

    Portland cement concrete have been used in construction due to its strength and ecomical value. But it has some limitations, such low flexural strength, low tensile strength, low chemical resistant and etc. Due to its limitations in flexural and tensile strength, Portland cement concrete more susceptible by seismic force. There are some methods for improving its limitations. Polymer addition into concrete mixture could be one of solution for improving the flexural and tensile strength, in aiming to get erthquake resistant properties. Also, the eartquake resistant could be achieved by improving energy dissipation capacity. In this research, the earthquake resistant evalution was approached from dynamic evaluation through energy dissipation capacity, after polymer addition as concrete additives. The polymers were natural latex (Indonesian naural resource) grafted with styrene and methacrylate, forming copolymer - natural latex methacrylate (KOLAM) and copolymer - natural latex styrene (KOLAS). They were added into concrete mixture resulting polymer modified concrete. The composition of polymer are 1%, 5% and 10% weight/weight of cement. The higher capacity of energy dissipation will give more capability in either absorbing or dissipating energy, and it was predicted would give better earthquake resistant.. The use of KOLAM gave better performance than KOLAS in energy dissipation capacity. It gave about 46% for addition of 1% w/w compared to Portland cement concrete. But for addition 5% w/w and 10% w/w, they gave about 7% and 5% higher energy dissipation capacity. The KOLAM addition into concrete mixture would reduce the maximum impact load with maximumabout 35% impact load reducing after 1% w/w addition. The higher concentration of KOLAM in concrete mixture, lower reducing of impact load, they were about 4% and 3% for KOLAM 5% and 10%. For KOLAS addition in any compositions, there were no positive trend either in energy dissipation capacity or impact load properties

  9. THE PREPARATION OF MAGNETICALLY MODIFIED SYNTHETETIC AND NATURAL ZEOLITES AND COMPARISON OF THEIR SOME PHYSICAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Zafer DİKMEN

    2013-06-01

    Full Text Available In this study, magnetically modified zeolites (MMZ has been produced and their adsorption, ion-exchange and magnetic properties have been studied. In this study, natural zeolite mineral, clinoptilolite, which belongs to Gördes (Manisa regions and synthetic 13X zeolite, which has been produced by Sigma-Aldrich firm have been used. In order to modify the surface of these minerals, magnetite sample which belongs to Divriği (Sivas region has been used. The engagement of magnetite particles on zeolite particles has been studied. For this reason, measuring, visualization and analysis techniques as DTA-TG, XRD, XRF, SEM and EDX have been used. As a result of these procedures, it has been observed that magnetite particles get engaged on the surface of zeolite particles and magnetite contribu-tion on MMZ has changed adsorption, ion-exchange and magnetic properties.In order to determine how magnetite contribution affects adsorption, ion exchange and magnetic properties of MMZ, weightily magnetite contribution ratio (zeolite/magnetite has been applied in three different forms (1/1, 1/2, 1/3.As a result of nitrogen adsorption of MMZ, it has been observed that as the weightily magnetite contribution ratio goes up, specific surface area goes down and average pore diameter rises. It has been identified that total cation exchange capacity rises as the weightily magnetite contribution ratio goes up. It has been observed that pure zeolites, which have no magnetic properties, as a result of magnetically modification process, they have got magnetically character, and they change their magnetic properties positively as the weightily magnetite contribution goes up. It has been determined that as a result of magnetic measurements; the optimum value of applied outer magnetic field is 0.5T.

  10. Comparative analysis of modified PMV models and SET models to predict human thermal sensation in naturally ventilated buildings

    DEFF Research Database (Denmark)

    Gao, Jie; Wang, Yi; Wargocki, Pawel

    2015-01-01

    In this paper, a comparative analysis was performed on the human thermal sensation estimated by modified predicted mean vote (PMV) models and modified standard effective temperature (SET) models in naturally ventilated buildings; the data were collected in field study. These prediction models were....../s, the expectancy factors for the extended PMV model and the extended SET model were from 0.770 to 0.974 and from 1.330 to 1.363, and the adaptive coefficients for the adaptive PMV model and the adaptive SET model were from 0.029 to 0.167 and from-0.213 to-0.195. In addition, the difference in thermal sensation...... between the measured and predicted values using the modified PMV models exceeded 25%, while the difference between the measured thermal sensation and the predicted thermal sensation using modified SET models was approximately less than 25%. It is concluded that the modified SET models can predict human...

  11. Chimeric antigen receptor (CAR)-modified natural killer cell-based immunotherapy and immunological synapse formation in cancer and HIV.

    Science.gov (United States)

    Liu, Dongfang; Tian, Shuo; Zhang, Kai; Xiong, Wei; Lubaki, Ndongala Michel; Chen, Zhiying; Han, Weidong

    2017-12-01

    Cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells contribute to the body's immune defenses. Current chimeric antigen receptor (CAR)-modified T cell immunotherapy shows strong promise for treating various cancers and infectious diseases. Although CAR-modified NK cell immunotherapy is rapidly gaining attention, its clinical applications are mainly focused on preclinical investigations using the NK92 cell line. Despite recent advances in CAR-modified T cell immunotherapy, cost and severe toxicity have hindered its widespread use. To alleviate these disadvantages of CAR-modified T cell immunotherapy, additional cytotoxic cell-mediated immunotherapies are urgently needed. The unique biology of NK cells allows them to serve as a safe, effective, alternative immunotherapeutic strategy to CAR-modified T cells in the clinic. While the fundamental mechanisms underlying the cytotoxicity and side effects of CAR-modified T and NK cell immunotherapies remain poorly understood, the formation of the immunological synapse (IS) between CAR-modified T or NK cells and their susceptible target cells is known to be essential. The role of the IS in CAR T and NK cell immunotherapies will allow scientists to harness the power of CAR-modified T and NK cells to treat cancer and infectious diseases. In this review, we highlight the potential applications of CAR-modified NK cells to treat cancer and human immunodeficiency virus (HIV), and discuss the challenges and possible future directions of CAR-modified NK cell immunotherapy, as well as the importance of understanding the molecular mechanisms of CAR-modified T cell- or NK cell-mediated cytotoxicity and side effects, with a focus on the CAR-modified NK cell IS.

  12. The myth of natural barriers. Is transgene introgression by genetically modified crops an environmental risk?

    Science.gov (United States)

    Guarnieri, Vincenzo; Benessia, Alice; Camino, Elena; Barbiero, Giuseppe

    2008-01-01

    Genetically modified (GM) crops under open field conditions are a complex and controversial issue. Ecologists are discussing about the possibility that a transgene belonging to GM plants could spread to native populations through a process known as introgression the stable incorporation of a gene in the host genome able to generate a differentiated population. The ecological consequences of a transgene introgression in plants or bacteria are not yet well understood, but could be significant. In this critical review we consider vertical and horizontal introgression. We analyse the biochemical and genetic constraints, and environmental factors that limit the possibility of transgene spread; meanwhile we show cases in which the natural barriers are overcome. Then we discuss the overall management of GM crops, noting the shortcomings and approximations of risk assessment based on linear thinking typical of the biomolecular approach. Finally we suggest to explicitly weight facts together with values and we encourage the undertaking of an ecological perspective, encompassing the complexity of (non-linear) relations between organisms and the environment.

  13. Comparison of gamma radiation effects on natural corn and potato starches and modified cassava starch

    Science.gov (United States)

    Teixeira, Bruna S.; Garcia, Rafael H. L.; Takinami, Patricia Y. I.; del Mastro, Nelida L.

    2018-01-01

    The objective of this work was to evaluate the effect of irradiation treatment on physicochemical properties of three natural polymers, i.e. native potato and corn starches and a typical Brazilian product, cassava starch modified through fermentation -sour cassava- and also to prepare composite hydrocolloid films based on them. Starches were irradiated in a 60Co irradiation chamber in doses up to 15 kGy, dose rate about 1 kGy/h. Differences were found in granule size distribution upon irradiation, mainly for corn and cassava starch but radiation did not cause significant changes in granule morphology. The viscosity of the potato, corn and cassava starches hydrogels decreased as a function of absorbed dose. Comparing non-irradiated and irradiated starches, changes in the Fourier transform infrared (FTIR) spectra in the 2000-1500 cm-1 region for potato and corn starches were observed but not for the cassava starch. Maximum rupture force of the starch-based films was affected differently for each starch type; color analysis showed that doses of 15 kGy promoted a slight rise in the parameter b* (yellow color) while the parameter L* (lightness) was not significantly affected; X-ray diffraction patterns remained almost unchanged by irradiation.

  14. The effect of elevated progesterone levels before HCG triggering in modified natural cycle frozen-thawed embryo transfer cycles

    DEFF Research Database (Denmark)

    Groenewoud, Eva R; Macklon, Nick S; Cohlen, Ben J

    2017-01-01

    follicular phase progesterone levels may occur in unstimulated cycles before frozen-thawed embryo transfer, or what affect they may have on outcomes. In this cohort study, 271 patients randomized to the modified natural cycle arm of a randomized controlled trial comparing two endometrial preparation regimens....... Whether monitoring of progesterone and LH in natural cycle frozen-thawed embryo transfer has added clinical value should studied further....

  15. Antidegradation and reinforcement effects of phenyltrimethoxysilane- or N-[3-(trimethoxysilyl)propyl]aniline-modified silica particles in natural rubber composites

    Energy Technology Data Exchange (ETDEWEB)

    Tunlert, Apinya [Program in Petrochemistry and Polymer Science, Chulalongkorn University, Bangkok 10330 (Thailand); Prasassarakich, Pattarapan [Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Poompradub, Sirilux, E-mail: sirilux.p@chula.ac.th [Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Center for Petroleum, Petrochemical and Advanced Material, Chulalongkorn University Bangkok 10330 (Thailand)

    2016-04-15

    The modification of silica particles with phenyltrimethoxysilane or N-[3-(trimethoxysilyl)propyl]aniline via a sol–gel reaction was performed in order to improve the dispersion of silica and antidegradation in natural rubber (NR). The functional groups on the modified silica surface were characterized by Fourier transform infrared spectroscopy, while the morphology was evaluated by scanning and transmission electron microscopy. The surface properties and antioxidant activity of the modified silica particles were determined by the water contact angle and 2, 2-diphenyl-1-picrylhydrazyl assay, respectively. The modified silica particles exhibited a higher hydrophobicity and a decreased interfacial adhesion energy compared with the unmodified silica particles. The modified silica particles were then incorporated into NR. The better dispersion of the modified silica particles than the unmodified ones in the NR matrix resulted in improved mechanical properties in terms of the modulus at 300% elongation (2.9 ± 0.02 MPa), hardness (52.5 ± 0.2 Shore A), abrasion resistance (241 ± 8 mm{sup 3}) and compression set (20.2 ± 0.6%). In addition, the inclusion of the modified silica particles in the NR matrix gave a high initial temperature of decomposition and retarded the ozone-induced degradation compared with the NR filled with unmodified silica particles. - Highlights: • Silica was surface modified with PhTMS or ATMS via a sol–gel reaction. • Modified silica showed a decreased interfacial adhesion energy. • Modified silica showed an enhanced free radical scavenging activity. • Modified silica improved the mechanical properties, thermal stability and ozone resistance in NR vulcanizates.

  16. Cumulative pregnancy rates after sequential treatment with modified natural cycle IVF followed by IVF with controlled ovarian stimulation

    NARCIS (Netherlands)

    Pelinck, M. J.; Knol, H. M.; Vogel, N. E. A.; Arts, E. G. J. M.; Simons, A. H. M.; Heineman, M. J.; Hoek, A.

    BACKGROUND: In modified natural cycle IVF (MNC-IVF), treatment is aimed at using the one follicle that spontaneously develops to dominance, using a GnRH-antagonist together with gonadotrophins in the late follicular phase only. The MNC-IVF is of interest because of its low-risk and patient-friendly

  17. Cumulative pregnancy rates after sequential treatment with modified natural cycle IVF followed by IVF with controlled ovarian stimulation

    NARCIS (Netherlands)

    Pelinck, M. J.; Knol, H. M.; Vogel, N. E. A.; Arts, E. G. J. M.; Simons, A. H. M.; Heineman, M. J.; Hoek, A.

    2008-01-01

    BACKGROUND: In modified natural cycle IVF (MNC-IVF), treatment is aimed at using the one follicle that spontaneously develops to dominance, using a GnRH-antagonist together with gonadotrophins in the late follicular phase only. The MNC-IVF is of interest because of its low-risk and patient-friendly

  18. Modified natural cycle versus controlled ovarian hyperstimulation IVF: a cost-effectiveness evaluation of three simulated treatment scenarios

    NARCIS (Netherlands)

    Groen, Henk; Tonch, Nino; Simons, Arnold H. M.; van der Veen, Fulco; Hoek, Annemieke; Land, Jolande A.

    2013-01-01

    Can modified natural cycle IVF or ICSI (MNC) be a cost-effective alternative for controlled ovarian hyperstimulation IVF or ICSI (COH)? The comparison of simulated scenarios indicates that a strategy of three to six cycles of MNC with minimized medication is a cost-effective alternative for one

  19. Modified natural cycle versus controlled ovarian hyperstimulation IVF : a cost-effectiveness evaluation of three simulated treatment scenarios

    NARCIS (Netherlands)

    Groen, Henk; Tonch, Nino; Simons, Arnold H. M.; van der Veen, Fulco; Hoek, Annemieke; Land, Jolande A.

    2013-01-01

    STUDY QUESTION: Can modified natural cycle IVF or ICSI (MNC) be a cost-effective alternative for controlled ovarian hyperstimulation IVF or ICSI (COH)? SUMMARY ANSWER: The comparison of simulated scenarios indicates that a strategy of three to six cycles of MNC with minimized medication is a

  20. Presence of bile acids in human follicular fluid and their relation with embryo development in modified natural cycle IVF

    NARCIS (Netherlands)

    Nagy, R. A.; van Montfoort, A. P. A.; Dikkers, A.; van Echten-Arends, J.; Homminga, I.; Land, J. A.; Hoek, A.; Tietge, U. J. F.

    STUDY QUESTION: Are bile acids (BA) and their respective subspecies present in human follicular fluid (FF) and do they relate to embryo quality in modified natural cycle IVF (MNC-IVF)? SUMMARY ANSWER: BAconcentrations are 2-fold higher in follicular fluid than in serum and ursodeoxycholic acid

  1. A randomized controlled, non-inferiority trial of modified natural versus artificial cycle for cryo-thawed embryo transfer

    NARCIS (Netherlands)

    Groenewoud, E. R.; Cohlen, B. J.; Al-Oraiby, A.; Brinkhuis, E. A.; Broekmans, F. J. M.; de Bruin, J. P.; van den Dool, G.; Fleisher, K.; Friederich, J.; Goddijn, M.; Hoek, A.; Hoozemans, D. A.; Kaaijk, E. M.; Koks, C. A. M.; Laven, J. S. E.; van der Linden, P. J. Q.; Manger, A. P.; Slappendel, E.; Spinder, T.; Kollen, B. J.; Macklon, N. S.

    2016-01-01

    Are live birth rates (LBRs) after artificial cycle frozen-thawed embryo transfer (AC-FET) non-inferior to LBRs after modified natural cycle frozen-thawed embryo transfer (mNC-FET)? AC-FET is non-inferior to mNC-FET with regard to LBRs, clinical and ongoing pregnancy rates (OPRs) but AC-FET does

  2. A randomized controlled, non-inferiority trial of modified natural versus artificial cycle for cryo-thawed embryo transfer

    NARCIS (Netherlands)

    Groenewoud, E. R.; Cohlen, B. J.; Al-Oraiby, A.; Brinkhuis, E. A.; Broekmans, F. J. M.; de Bruin, J. P.; van den Dool, G.; Fleisher, K.; Friederich, J.; Goddijn, M.; Hoek, A.; Hoozemans, D. A.; Kaaijk, E. M.; Koks, C. A. M.; Laven, J. S. E.; van der Linden, P. J. Q.; Manger, A. P.; Slappendel, E.; Spinder, T.; Kollen, B. J.; Macklon, N. S.

    STUDY QUESTION: Are live birth rates (LBRs) after artificial cycle frozen-thawed embryo transfer (AC-FET) non-inferior to LBRs after modified natural cycle frozen-thawed embryo transfer (mNC-FET)? SUMMARY ANSWER: AC-FET is non-inferior to mNC-FET with regard to LBRs, clinical and ongoing pregnancy

  3. A randomized controlled, non-inferiority trial of modified natural versus artificial cycle for cryo-thawed embryo transfer

    NARCIS (Netherlands)

    Groenewoud, E. R.; Cohlen, B. J.; Al-Oraiby, A.; Brinkhuis, E. A.; Broekmans, F. J M; De Bruin, J. P.; Van Den Dool, G.; Fleisher, K.; Friederich, J.; Goddijn, M.; Hoek, A.; Hoozemans, D. A.; Kaaijk, E. M.; Koks, C. A M; Laven, J. S E; Van Der Linden, P. J Q; Manger, A. P.; Slappendel, E.; Spinder, T.; Kollen, B. J.; Macklon, N. S.

    2016-01-01

    studyquestion: Are live birth rates (LBRs) after artificial cycle frozen-thawed embryo transfer (AC-FET) non-inferior to LBRs after modified natural cycle frozen-thawed embryo transfer (mNC-FET)? summaryanswer: AC-FET is non-inferior to mNC-FET with regard to LBRs, clinical and ongoing pregnancy

  4. Modified natural cycle IVF and mild IVF: a 10 year Swedish experience.

    Science.gov (United States)

    Aanesen, Arthur; Nygren, Karl-Gösta; Nylund, Lars

    2010-01-01

    Modified natural cycle IVF (mnc-IVF) or mild IVF (m-IVF) was offered to selected patients between 1996 and 2007; 43 patients during 129 cycles were treated with mnc-IVF and 145 couples during 250 cycles were treated with m-IVF. Comparison with outcome from conventional IVF cycles during the same time period and in the same clinic was performed. Although 53.5 and 39.6% of started cycles respectively never reached embryo transfer, the ongoing pregnancy rates per embryo transfer were 26.7% for mnc-IVF and 27.2% for m-IVF. During the same time period, cancellation rate for conventional IVF was 13.7% and the ongoing pregnancy rate per embryo transfer was 34.3%. For patients > or =38years of age, the ongoing pregnancy rate per embryo transfer was 17.5% in the m-IVF group. None of the patients aged > or =38years in the mnc-IVF group achieved an ongoing pregnancy. For patients treated with conventional IVF, the > or =38years of age pregnancy rate per embryo transfer was 27.0%. Costs of medication for m-IVF and mnc-IVF were 96.3 and 97.5% less than for the least expensive conventional IVF cycle respectively. Pregnancy rates per embryo transfer are acceptable for these treatment modalities, the cost for medication is low, risks for complications are dramatically reduced, and the treatments may be more psychologically acceptable to the patients. Copyright (c) 2009 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  5. Adsorption of Cu(II), Hg(II), and Ni(II) ions by modified natural wool chelating fibers

    Energy Technology Data Exchange (ETDEWEB)

    Monier, M., E-mail: monierchem@yahoo.com [Chemistry Department, Drexel University, Philadelphia, PA (United States); Chemistry Department, Faculty of Science, Mansoura University, Mansoura (Egypt); Ayad, D.M.; Sarhan, A.A. [Chemistry Department, Faculty of Science, Mansoura University, Mansoura (Egypt)

    2010-04-15

    The graft copolymerization of ethyl acrylate (EA) onto natural wool fibers initiated by potassium persulphate and Mohr's salt redox initiator system in limited aqueous medium was carried out in heterogeneous media. Ester groups of the grafted copolymers were partially converted into hydrazide function groups followed by hydrazone formation through reaction with isatin. Also the application of the modified fibers for metal ion uptake was studied using Cu(II), Hg(II) and Ni(II). The modified chelating fibers were characterized using FTIR spectroscopy, SEM and X-ray diffraction.

  6. Adsorption of Cu(II), Hg(II), and Ni(II) ions by modified natural wool chelating fibers.

    Science.gov (United States)

    Monier, M; Ayad, D M; Sarhan, A A

    2010-04-15

    The graft copolymerization of ethyl acrylate (EA) onto natural wool fibers initiated by potassium persulphate and Mohr's salt redox initiator system in limited aqueous medium was carried out in heterogeneous media. Ester groups of the grafted copolymers were partially converted into hydrazide function groups followed by hydrazone formation through reaction with isatin. Also the application of the modified fibers for metal ion uptake was studied using Cu(II), Hg(II) and Ni(II). The modified chelating fibers were characterized using FTIR spectroscopy, SEM and X-ray diffraction. 2009 Elsevier B.V. All rights reserved.

  7. Adsorption of Cu(II), Hg(II), and Ni(II) ions by modified natural wool chelating fibers

    International Nuclear Information System (INIS)

    Monier, M.; Ayad, D.M.; Sarhan, A.A.

    2010-01-01

    The graft copolymerization of ethyl acrylate (EA) onto natural wool fibers initiated by potassium persulphate and Mohr's salt redox initiator system in limited aqueous medium was carried out in heterogeneous media. Ester groups of the grafted copolymers were partially converted into hydrazide function groups followed by hydrazone formation through reaction with isatin. Also the application of the modified fibers for metal ion uptake was studied using Cu(II), Hg(II) and Ni(II). The modified chelating fibers were characterized using FTIR spectroscopy, SEM and X-ray diffraction.

  8. Recovery of Renibacterium salmoninarum from naturally infected salmonine stocks in Michigan using a modified culture protocol

    Directory of Open Access Journals (Sweden)

    Mohamed Faisal

    2010-01-01

    Full Text Available Renibacterium salmoninarum, the causative agent of bacterial kidney disease (BKD, is a fastidious and slow-growing bacterium that is extremely difficult to grow in vitro. Herein, we describe a modified primary culture protocol that encompasses a modified bacteriological culture medium and a tissue processing procedure. In order to facilitate the release of R. salmoninarum from granulomatous tissues, kidneys of infected fish were homogenized in a high speed stomacher. The kidney disease medium (KDM2, routinely used for primary culture of R. salmoninarum was modified by the addition of antibiotics and metabolites. When a relatively large inoculum of diluted kidney homogenate was streak-plate inoculated onto the modified KDM2, colonial growth of R. salmoninarum was achieved within 5–7 days, compared to the standard of two weeks or more. The modified procedure was then used to determine the prevalence of R. salmoninarum among representative captive and feral salmonid stocks in Michigan. Prevalence and clinical manifestations varied among species, strains of fish, and locations; however, R. salmoninarum isolates were biochemically homogenous. The improved primary culture procedure described in this study enabled selective and quick isolation of R. salmoninarum. Also, the isolates retrieved in this study constitute a unique biological resource for future studies of R. salmoninarum in the Laurentian Great Lakes.

  9. Genetically modified crops and the scientific paradigms from which they emerge in the light of the rights of nature

    Directory of Open Access Journals (Sweden)

    Elizabeth Bravo Velásquez

    2014-10-01

    Full Text Available In this work the scientific paradigms in which the genetic modified organisms were developed are analysed, and how the right of nature are violated, since in the process of developing then, the DNA structure is altered and consequently, the functions of the manipulated organisms, with impacts on the biological cycles and the processes of evolution. The Constitution of Ecuador on rights of nature is the base to analyse violations occurring at the stage of commercial production and handling of GM crops.

  10. Chemotaxonomic markers of organic, natural, and genetically modified soybeans detected by direct infusion electrospray ionization mass spectrometry

    International Nuclear Information System (INIS)

    Santos, L.S.; Catharino, R.R.; Eberlin, M.N.; Tsai, S.M.

    2006-01-01

    The crude methanolic extracts of a single bean from samples of organic, natural or genetically modified (GM) soybeans [Glycine max. (Merrill) L.] were analyzed by direct infusion electrospray ionization mass spectrometry (ESI-MS). These extracts, containing the most polar natural products of soybeans (free aglycones, monoglucosides, diglucosides and esters including isoflavones and flavones) provide characteristic fingerprinting mass spectra owing to different proportions or sets of components. Spectra distinctiveness is confirmed by chemometric multivariate analysis of the ESIMS data, which place the three-types of beans into well-defined groups. When ESI-MS is applied, these polar components constitute therefore unique chemotaxonomic markers able to provide fast soybean typification. (author)

  11. Natural forest regeneration and ecological restoration in human-modified tropical landscapes

    NARCIS (Netherlands)

    Martínez-Ramos, Miguel; Pingarroni, Aline; Rodríguez-Velázquez, Jorge; Toledo-Chelala, Lilibeth; Zermeño-Hernández, Isela; Bongers, Frans

    2016-01-01

    In human-modified tropical landscapes (HMLs) the conservation of biodiversity, functions and services of forest ecosystems depends on persistence of old growth forest remnants, forest regeneration in abandoned agricultural fields, and restoration of degraded lands. Understanding the impacts of

  12. Biodiesel production from rice bran oil by transesterification using heterogeneous catalyst natural zeolite modified with K2CO3

    Science.gov (United States)

    Taslim; Iriany; Bani, O.; Parinduri, S. Z. D. M.; Ningsih, P. R. W.

    2018-02-01

    In the present study, an effort had been made to use natural zeolite from Tapanuli Utara, North Sumatera as a potential catalyst for biodiesel production. Biodiesel production is usuallythrough transesterification, and a catalyst is employed to improve reaction rate and yield. In this research rice bran oil (RBO) was used as feedstock. The objective of this work was to discover the effectiveness of natural zeolite modified by K2CO3 as catalysts in biodiesel production from RBO. K2CO3/natural zeolite catalyst modification was by impregnation method at various K2CO3 concentrations followed by drying and calcination. Transesterification was conducted at 65°C and 500 rpm. Effect of process variables such as the amount of catalyst, reaction time, and the molar ratio of methanol to RBO was investigated.The maximum yield of 98.18% biodiesel was obtained by using 10:1 molar ratio of methanol to RBO at a reaction time of 3 hours in the presence of 4 w% catalyst. The obtained biodiesel was then characterized by its density, viscosity and ester content. The biodiesel properties met the Indonesia standard (SNI).The results showed that natural zeolite modified by K2CO3 was suitable as a catalyst in the synthesis of biodiesel through transesterification from RBO.

  13. Cellular responses to modified Plasmodium falciparum MSP119 antigens in individuals previously exposed to natural malaria infection

    Directory of Open Access Journals (Sweden)

    Awobode Henrietta O

    2009-11-01

    Full Text Available Abstract Background MSP1 processing-inhibitory antibodies bind to epitopes on the 19 kDa C-terminal region of the Plasmodium falciparum merozoite surface protein 1 (MSP119, inhibiting erythrocyte invasion. Blocking antibodies also bind to this antigen but prevent inhibitory antibodies binding, allowing invasion to proceed. Recombinant MSP119 had been modified previously to allow inhibitory but not blocking antibodies to continue to bind. Immunization with these modified proteins, therefore, has the potential to induce more effective protective antibodies. However, it was unclear whether the modification of MSP119 would affect critical T-cell responses to epitopes in this antigen. Methods The cellular responses to wild-type MSP119 and a panel of modified MSP119 antigens were measured using an in-vitro assay for two groups of individuals: the first were malaria-naïve and the second had been naturally exposed to Plasmodium falciparum infection. The cellular responses to the modified proteins were examined using cells from malaria-exposed infants and adults. Results Interestingly, stimulation indices (SI for responses induced by some of the modified proteins were at least two-fold higher than those elicited by the wild-type MSP119. A protein with four amino acid substitutions (Glu27→Tyr, Leu31→Arg, Tyr34→Ser and Glu43→Leu had the highest stimulation index (SI up to 360 and induced large responses in 64% of the samples that had significant cellular responses to the modified proteins. Conclusion This study suggests that specific MSP119 variants that have been engineered to improve their antigenicity for inhibitory antibodies, retain T-cell epitopes and the ability to induce cellular responses. These proteins are candidates for the development of MSP1-based malaria vaccines.

  14. Dyes adsorption blue vegetable and blue watercolor by natural zeolites modified with surfactants

    International Nuclear Information System (INIS)

    Jardon S, C. C.; Olguin G, M. T.; Diaz N, M. C.

    2009-01-01

    In this work was carried out the dyes removal blue vegetable and blue watercolor of aqueous solutions, to 20 C, at different times and using a zeolite mineral of Parral (Chihuahua, Mexico) modified with hexadecyl trimethyl ammonium bromide or dodecyl trimethyl ammonium bromide. The zeolite was characterized before and after of its adaptation with NaCl and later with HDTMABr and DTMABr. For the materials characterization were used the scanning electron microscopy of high vacuum; elementary microanalysis by X-ray spectroscopy of dispersed energy and X-ray diffraction techniques. It was found that the surfactant type absorbed in the zeolite material influences on the adsorption process of the blue dye. Likewise, the chemical structure between the vegetable blue dye and the blue watercolor, determines the efficiency of the color removal of the water, by the zeolites modified with the surfactants. (Author)

  15. ADSORPSI POLUTAN ION DIKROMAT MENGGUNAKAN ZEOLIT ALAM TERMODIFIKASI AMINA (Adsorption of Dichromate Ions Pollutant Using Ammine Modified-Natural Zeolites

    Directory of Open Access Journals (Sweden)

    Eko Sri Kunarti

    2015-11-01

    24,66 kJ/mol. ABSTRACT Chromium (VI is a heavy metal pollutant that is harmful to health and the environment, therefore Cr(VI ions in aqueous solution removal is important to overcome the environmental pollution. Adsorption process is one of simple techniques that can be used to take metal ions. Adsorption study of dichromate ions as a wastewater model of Cr(VI has been conducted in this research by using ammine modified natural zeolite as adsorbents. The research was initiated by preparation of adsorbent of ammine-modified natural zeolites. The preparation was started by washing the natural zeolite (Z using distilled water and refluxing by 3M hydrochloric acid. Refluxed zeolites (ZA were modified by a quaternary ammonium salt, N-cethyl-N,N,N-trimethylammonium bromide (CTAB, and a primary amine, propylamine (PA. The natural zeolite (Z, acid activated zeolite (ZA and amine-modified zeolites were then applied for adsorption of dichromate ions. Characterization of zeolite samples was performed by infrared spectroscopy and X-ray diffraction methods to confirm the crystal structure, and atomic absorption spectroscopy method to analyze the adsorbed dichromate ions. Results showed that all zeolite samples contain clinoptilolite, mordernite and quartz minerals. The zeolite structure was not changed by heat and chemical treatments. Modification of zeolites enhanced the adsorption efficiency of natural zeolites. The dichromate ions were better adsorbed on ammine modified-zeolites compared to that of unmodified-zeolite with adsorption ability of CTAB modified zeolite (CTAB-Z was greater than that of propylammine modified zeolite (PA-Z. The adsorption of dichromate on zeolite samples was achieved in the order of CTAB-Z > PA-Z > ZA > Z, with the adsorption efficiency was about 1.96; 1.74; 0.90 and 0.48 mg/g, respectively. The dichromate ions adsorption by CTAB modified zeolite is chemical adsorption (chemisorption with the adsorption energy of 24.66 kJ/mol.

  16. Analytical determination of size-dependent natural frequencies of fully clamped rectangular microplates based on the modified couple stress theory

    Energy Technology Data Exchange (ETDEWEB)

    Askari, Amir R.; Tahani, Masoud [Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of)

    2015-05-15

    This paper presents an analytical and size-dependent model for vibrational analysis of fully clamped rectangular microplates. Modified couple stress theory (MCST) and the Kirchhoff plate model are considered, and Hamilton's principle is employed to derive the size dependent equation of motion that accounts for the effect of residual stresses. The natural frequencies of the microplate are extracted analytically by extended Kantorovich method. The present findings are validated with the available results in the literature, and an excellent agreement is observed between them. In addition, a parametric study is conducted to demonstrate the significant effects of couple stress components on the natural frequencies of fully clamped microplates. The ratio of MCST natural frequencies to those obtained with classical theory depends only on the Poisson's ratio of the plate and is independent of the aspect ratio of the plate for cases with no residual stresses.

  17. Analytical determination of size-dependent natural frequencies of fully clamped rectangular microplates based on the modified couple stress theory

    International Nuclear Information System (INIS)

    Askari, Amir R.; Tahani, Masoud

    2015-01-01

    This paper presents an analytical and size-dependent model for vibrational analysis of fully clamped rectangular microplates. Modified couple stress theory (MCST) and the Kirchhoff plate model are considered, and Hamilton's principle is employed to derive the size dependent equation of motion that accounts for the effect of residual stresses. The natural frequencies of the microplate are extracted analytically by extended Kantorovich method. The present findings are validated with the available results in the literature, and an excellent agreement is observed between them. In addition, a parametric study is conducted to demonstrate the significant effects of couple stress components on the natural frequencies of fully clamped microplates. The ratio of MCST natural frequencies to those obtained with classical theory depends only on the Poisson's ratio of the plate and is independent of the aspect ratio of the plate for cases with no residual stresses.

  18. Fluoride ions sorption of the water using natural and modified hematite with aluminium hydroxide

    International Nuclear Information System (INIS)

    Teutli S, E. A.

    2011-01-01

    Fluorine is a mineral known for its dental benefits, but fluoride ions can cause fluoro sis in excessive quantities. There are many epidemiological studies on possible adverse effects resulting from prolonged ingestion of fluoride through drinking water. These studies demonstrate that fluoride mainly affects the bone tissue (bones and teeth), may produce an adverse effect on tooth enamel and can cause mild dental fluoro sis at concentrations from 0.9 to 1.2 mg/L in drinking water. In several states of Mexico, water contaminated with fluoride ions can be found, such as Aguascalientes, Chihuahua, Coahuila, Durango, Guanajuato, Sonora, Zacatecas, San Luis Potosi and Jalisco, where the fluoride ions levels are higher than 1.5 mg/L, established by the Mexican Official Standard (NOM-127-Ssa-2000) which sets the permissible limits of water for human use and consumption. Currently, several technologies have been proposed to remove fluoride ions from water such as precipitation methods which are based on the addition of chemicals to water and sorption methods to removed fluoride ions by sorption or ion exchange reactions by some suitable substrate capable of regenerate and reuse. In this work, the sorption of fluoride ions using unmodified and modified hematite with aluminum hydroxide to remove fluoride ions from water by bath experiments was studied. The hematite was modified by treating it with aluminum hydroxide, NaOH and Al 2 (SO 4 ) 3 solutions. The characterization of hematite before and after modification with aluminum hydroxide was studied by X-ray diffraction, scanning electron microscopy, EDS and Bet. The effect of ph, contact time, concentration of fluoride ions, and the dose of sorbent on the sorption of fluoride ions by the modified hematite were studied. Equilibrium was reached within 48 hours of contact time and the maximum sorption of fluoride ions were in the range pH eq between 2.3 and 6.2. Sorption capacities of fluoride ions as a function of dose of

  19. Rheology behaviour of modified silicone-dammar as a natural resin coating

    Science.gov (United States)

    Zakaria, Rosnah; Ahmad, Azizah Hanom

    2015-08-01

    Modified silicone-dammar (SD) was prepared by various weight percent from 5 - 45 wt% of dammar added. The n-value (viscosity index) of silicone with 5 and 10 % were turn to be 1.6 and 1.3 of viscosity index. While 15, 20, 25 and 30 wt% of dammar added gave 0.7, 0.3, 0.2 and 0.1 of viscosity index. On the other hand, 35, 40 and 45 wt% of dammar gave a fixed value of viscosity index of 0.03. This n-value shows the dispersion quality of paint mixture indicates that the modified silicone-dammar was followed the Bingham's Model. The rheology measurement of SD mixture was analysed by plotting ln shear stress vs shear rate value. Analysis of the graph showed a Bingham plastic model with regression R2 equivalent to 0.99. The linear viscoelastic behaviour of SD samples increased in parallel with increasing dammar content indicate that the suspension of dammar in silicone resin could flow steadily with time giving a pseudoplastic behaviour.

  20. Characterization of natural and modified clay for development of polymers nanocomposites

    International Nuclear Information System (INIS)

    Jarek, Flavia; Reis, Dayane M.; Kloss, Juliana R.; Mauler, Raquel S.; Barbosa, Ronilson V.

    2009-01-01

    Bentonite is a technologic terminology applied to clays of very thin granulation basically composed by mineral of the esmectites group where the montmorilonite is the most common, meaning that it is a filossilicate with layers as thick as 1 nm. Because it is polar, the clay is not compatible with most of polymers that are less polars or apolars, reason why it has to be modified to improve compatibility between the inorganic (polar) and the organic phase (apolar). Aiming to show the potential for the development of nanocomposites, the purpose of this work was to verify the chemical and physical characteristics of the various bentonites by comparing the technical files and performing the water Foster swelling and change chemically the samples, evaluating them by infrared spectroscopy and X-ray diffractometry. The different analyzed samples of bentonite showed an effective intercalation of the modifying agent on the surface of the structure. This evidence will allow the use of this material in the clay-polymer nanocomposites synthesis. (author)

  1. Simultaneous sorption of fluoride and arsenic ions (V) in a naturally occurring material modified with iron and aluminum

    International Nuclear Information System (INIS)

    Vazquez M, G.

    2016-01-01

    In this research, two materials, zeolite and pozzolans from the States of Oaxaca and Mexico, were used respectively, which were modified to evaluate their efficiencies to remove F and As(V) ions from solution and natural water. The materials were modified with iron and aluminum using an electrochemical cell, and with the hydroxides formed with iron and aluminum chloride solutions. The natural and modified materials were characterized by X-ray diffraction, scanning electron microscopy with energy X-ray disperse spectroscopy analysis, specific area and the point of zero charge (pHzpc). F- and As(V) adsorption properties of both materials were investigated. Experimental data on the sorption processes of F- ions by modified zeolite and pozzolans were adjusted to the kinetic models of pseudo-second-order (q e, 0408 mg /g K, 4.33 g / mg h) and Lagergen (q e, 0.807 mg/g K L, 1.83 1/min), respectively. Both materials showed the best fit to the Freundlich isotherm, Kf, 0.33 and 0.64 (mg/g) (L/mg) for pozzolans and zeolite respectively; suggesting a physical adsorption process on a heterogeneous material. Experimental adsorption capacities of pozzolans and modified zeolite for F ions were 0.36 and 0.83 mg/g respectively. The results of the kinetics of adsorption of As(V) were treated with the Largergren, pseudo-second-order and Elovich models; however the adsorption rate was high and consequently the rate constants could not be calculated. The isotherms data were fitted to the Freundlich model and the constants Kf were 6.24 and 11.15 (mg/g) (L/mg) for pozzolans and zeolite respectively. The thermodynamic parameters of the adsorption processes suggest endothermic adsorption for F- ions by both materials and for As(V) by the pozzolans. The free energy values ΔG indicate spontaneous processes and not spontaneous for F- ions by pozzolans. The adsorption of As (V) by the pozzolans presented an exothermic and spontaneous behavior. Finally, a study was performed in columns with

  2. Properties of organo-clay/natural rubber nanocomposites: effects of organophilic modifiers

    Czech Academy of Sciences Publication Activity Database

    Hrachová, J.; Komadel, P.; Jochec-Mošková, D.; Krajči, J.; Janigová, I.; Šlouf, Miroslav; Chodák, I.

    2013-01-01

    Roč. 127, č. 5 (2013), s. 3447-3455 ISSN 0021-8995 R&D Projects: GA ČR GAP205/10/0348 Institutional research plan: CEZ:AV0Z40500505 Keywords : nanocomposite s * natural rubber * morphology Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.640, year: 2013

  3. Study of sorption and desorption characteristics of natural and chemically modified ionexes

    International Nuclear Information System (INIS)

    Foeldesova, M.; Dillinger, P.; Lukac, P.

    2004-01-01

    The aim of this paper was give information for scientific community about not-traditionally, simply, high precise and effective radio-indicator method and possibilities its use for determination of sorption characteristics of naturals and chemically adjusted ionexes. These materials are suitable as barrier materials for water, soil and air cleaning

  4. A comparative study of natural rubber modified with ground tire rubber of truck

    OpenAIRE

    Binti Haridan, Ili Liyana

    2016-01-01

    The recycling of waste rubber has considerable significance in term of environmental protection and energy conservation. Considering that most of the relevant literature is concerned with tire recycling, the aim of this work was to develop and characterize the elastomeric samples of natural rubber (NR) composites filled with ground tire rubber of truck (GTR) devulcanized by microwave (DGTR). The tire rubber was ground under ambient conditions and subjected to microwave exposure for 3, 5 and ...

  5. Application of the natural cellulosic supports modified chemically for the treatment of the industrial effluents

    International Nuclear Information System (INIS)

    Kassale, A.; Elbariji, S.; Lacherai, A.; Elamine, M.; Kabli, H.; Albourine, A.

    2009-01-01

    The process of purification and discoloration of industrial waters (and particularly effluents of the textile industry) can meet major difficulties: certain dyes agents get through the devices of purge without being to stop. the cost of equipment and products of purification is prohibitive. Finally, in many cases, the discoloration can be only partial because waters to be treated containing mixtures of dyes of different nature, the material of purification can be effective only screw/screw of some of them. (Author)

  6. Mimicking mechanical response of natural tissues. Strain hardening induced by transient reticulation in lactose-modified chitosan (chitlac).

    Science.gov (United States)

    Cok, Michela; Sacco, Pasquale; Porrelli, Davide; Travan, Andrea; Borgogna, Massimiliano; Marsich, Eleonora; Paoletti, Sergio; Donati, Ivan

    2018-01-01

    The effect of transient cross-links has been explored on a lactose-modified chitosan, which previously had shown interesting biological features. The presence of galactose side chains and of the polyol spacer resulted particularly appealing for the reticulation by borate ions. The interaction between chitlac and borax was investigated by means of 11 B NMR while rheology pointed to a marked non-linear behavior depending on the amount of borax added to the system. The presence of limited amount of cross-linking ion led to dilatant behavior when the steady flow curve was measured. In addition, strain stiffening was noticed on elastic response upon exceeding a critical stress, indicating a transient nature in the formation of the cross-links. The non-linear response of chitlac in the presence of borax compared surprisingly well with the one showed by proteins composing the natural ECM pointing at a possible role of mechanotransduction in the biological significance of the modified chitosan. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Recognition of Porphyromonas gingivalis gingipain epitopes by natural IgM binding to malondialdehyde modified low-density lipoprotein.

    Directory of Open Access Journals (Sweden)

    S Pauliina Turunen

    Full Text Available OBJECTIVE: Increased risk for atherosclerosis is associated with infectious diseases including periodontitis. Natural IgM antibodies recognize pathogen-associated molecular patterns on bacteria, and oxidized lipid and protein epitopes on low-density lipoprotein (LDL and apoptotic cells. We aimed to identify epitopes on periodontal pathogen Porphyromonas gingivalis recognized by natural IgM binding to malondialdehyde (MDA modified LDL. METHODS AND RESULTS: Mouse monoclonal IgM (MDmAb specific for MDA-LDL recognized epitopes on P. gingivalis on flow cytometry and chemiluminescence immunoassays. Immunization of C57BL/6 mice with P. gingivalis induced IgM, but not IgG, immune response to MDA-LDL and apoptotic cells. Immunization of LDLR(-/- mice with P. gingivalis induced IgM, but not IgG, immune response to MDA-LDL and diminished aortic lipid deposition. On Western blot MDmAb bound to P. gingivalis fragments identified as arginine-specific gingipain (Rgp by mass spectrometry. Recombinant domains of Rgp produced in E. coli were devoid of phosphocholine epitopes but contained epitopes recognized by MDmAb and human serum IgM. Serum IgM levels to P. gingivalis were associated with anti-MDA-LDL levels in humans. CONCLUSION: Gingipain of P. gingivalis is recognized by natural IgM and shares molecular identity with epitopes on MDA-LDL. These findings suggest a role for natural antibodies in the pathogenesis of two related inflammatory diseases, atherosclerosis and periodontitis.

  8. Electrospinning of Nanodiamond-Modified Polysaccharide Nanofibers with Physico-Mechanical Properties Close to Natural Skins

    Directory of Open Access Journals (Sweden)

    Mina Mahdavi

    2016-07-01

    Full Text Available Electrospinning of biopolymers has gained significant interest for the fabrication of fibrous mats for potential applications in tissue engineering, particularly for wound dressing and skin regeneration. In this study, for the first time, we report successful electrospinning of chitosan-based biopolymers containing bacterial cellulous (33 wt % and medical grade nanodiamonds (MND (3 nm; up to 3 wt %. Morphological studies by scanning electron microscopy showed that long and uniform fibers with controllable diameters from 80 to 170 nm were prepared. Introducing diamond nanoparticles facilitated the electrospinning process with a decrease in the size of fibers. Fourier transform infrared spectroscopy determined hydrogen bonding between the polymeric matrix and functional groups of MND. It was also found that beyond 1 wt % MND, percolation networks of nanoparticles were formed which affected the properties of the nanofibrous mats. Uniaxial tensile testing of the woven mats determined significant enhancement of the strength (from 13 MPa to 25 MP by dispersion of 1 wt % MND. The hydrophilicity of the mats was also remarkably improved, which was favorable for cell attachment. The water vapor permeability was tailorable in the range of 342 to 423 µg·Pa−1·s−1·m−1. The nanodiamond-modified mats are potentially suitable for wound healing applications.

  9. Electrospinning of Nanodiamond-Modified Polysaccharide Nanofibers with Physico-Mechanical Properties Close to Natural Skins

    Science.gov (United States)

    Mahdavi, Mina; Mahmoudi, Nafiseh; Rezaie Anaran, Farzad; Simchi, Abdolreza

    2016-01-01

    Electrospinning of biopolymers has gained significant interest for the fabrication of fibrous mats for potential applications in tissue engineering, particularly for wound dressing and skin regeneration. In this study, for the first time, we report successful electrospinning of chitosan-based biopolymers containing bacterial cellulous (33 wt %) and medical grade nanodiamonds (MND) (3 nm; up to 3 wt %). Morphological studies by scanning electron microscopy showed that long and uniform fibers with controllable diameters from 80 to 170 nm were prepared. Introducing diamond nanoparticles facilitated the electrospinning process with a decrease in the size of fibers. Fourier transform infrared spectroscopy determined hydrogen bonding between the polymeric matrix and functional groups of MND. It was also found that beyond 1 wt % MND, percolation networks of nanoparticles were formed which affected the properties of the nanofibrous mats. Uniaxial tensile testing of the woven mats determined significant enhancement of the strength (from 13 MPa to 25 MP) by dispersion of 1 wt % MND. The hydrophilicity of the mats was also remarkably improved, which was favorable for cell attachment. The water vapor permeability was tailorable in the range of 342 to 423 µg·Pa−1·s−1·m−1. The nanodiamond-modified mats are potentially suitable for wound healing applications. PMID:27399726

  10. Electrospinning of Nanodiamond-Modified Polysaccharide Nanofibers with Physico-Mechanical Properties Close to Natural Skins.

    Science.gov (United States)

    Mahdavi, Mina; Mahmoudi, Nafiseh; Rezaie Anaran, Farzad; Simchi, Abdolreza

    2016-07-07

    Electrospinning of biopolymers has gained significant interest for the fabrication of fibrous mats for potential applications in tissue engineering, particularly for wound dressing and skin regeneration. In this study, for the first time, we report successful electrospinning of chitosan-based biopolymers containing bacterial cellulous (33 wt %) and medical grade nanodiamonds (MND) (3 nm; up to 3 wt %). Morphological studies by scanning electron microscopy showed that long and uniform fibers with controllable diameters from 80 to 170 nm were prepared. Introducing diamond nanoparticles facilitated the electrospinning process with a decrease in the size of fibers. Fourier transform infrared spectroscopy determined hydrogen bonding between the polymeric matrix and functional groups of MND. It was also found that beyond 1 wt % MND, percolation networks of nanoparticles were formed which affected the properties of the nanofibrous mats. Uniaxial tensile testing of the woven mats determined significant enhancement of the strength (from 13 MPa to 25 MP) by dispersion of 1 wt % MND. The hydrophilicity of the mats was also remarkably improved, which was favorable for cell attachment. The water vapor permeability was tailorable in the range of 342 to 423 µg·Pa(-1)·s(-1)·m(-1). The nanodiamond-modified mats are potentially suitable for wound healing applications.

  11. Natural asphalt modified binders used for high stiffness modulus asphalt concrete

    Science.gov (United States)

    Bilski, Marcin; Słowik, Mieczysław

    2018-05-01

    This paper presents a set of test results supporting the possibility of replacing, in Polish climate conditions, hard road 20/30 penetration grade bitumen used in the binder course and/or base course made of high stiffness modulus asphalt concrete with binders comprising of 35/50 or 50/70 penetration grade bitumens and additives in the form of natural Gilsonite or Trinidad Epuré asphalts. For the purpose of comparing the properties of the discussed asphalt binders, values of the Performance Grade have been determined according to the American Superpave system criteria.

  12. Modified natural fibrils for structural hybrid composites: Towards an investigation of textile reduction

    Science.gov (United States)

    Ufodike, Chukwuzubelu Okenwa

    Recently, the interest for renewable resources for fibers particularly of plant origin has been increasing. Reduction of use of traditional textile materials is now considered more critical due to the increasing environmental concern. Natural fibers are renewable, biodegradable, recyclable, and lightweight materials with high specific modulus, in competition with man-made fossil materials and fiberglass. Natural fibers are used for preparation of functionalized textiles to achieve smart and intelligent properties. However, the incorporation of these fibers in composite systems has been challenging due to their hydrophilic nature. Nevertheless, the fact that these biodegradable materials can be manipulated at a nano-scale to complement desired objective and application has made them a favorable option. The idea behind this project is to explore ways to convert green waste to high value materials and to utilize natural building blocks to design textile reinforcement materials. In this work, cellulose nanofibrils (CNF) supplied from the University of Maine were hydrophobized by silylation and characterized using Fourier-Transform Infrared (FTIR) spectroscopy, Raman spectroscopy, and Thermogravimetric analysis (TGA). Results from FTIR spectroscopy showed a formation of Si-O-C bonds, indicating better fiber-matrix adhesion. Raman spectroscopy showed disruption of hydrogen bonding which indicates interference of parallel nanocellulose fiber adhesion to neighboring fibrils. The TGA suggests that the thermal stability of the functionalized CNF is higher than that of the corresponding neat sample, which could be a result of stable Si bond formation. The raw materials (neat and functionalized) were encapsulated in a polystyrene matrix through a solvent and non-solvent precipitation process, and then extruded using single and dual heat processing. The extruded thin filaments were tested according to the ASTM D638 (tensile test of plastics). Results showed an increasing

  13. Development of Modified Incompressible Ideal Gas Model for Natural Draft Cooling Tower Flow Simulation

    Science.gov (United States)

    Hyhlík, Tomáš

    2018-06-01

    The article deals with the development of incompressible ideal gas like model, which can be used as a part of mathematical model describing natural draft wet-cooling tower flow, heat and mass transfer. It is shown, based on the results of a complex mathematical model of natural draft wet-cooling tower flow, that behaviour of pressure, temperature and density is very similar to the case of hydrostatics of moist air, where heat and mass transfer in the fill zone must be taken into account. The behaviour inside the cooling tower is documented using density, pressure and temperature distributions. The proposed equation for the density is based on the same idea like the incompressible ideal gas model, which is only dependent on temperature, specific humidity and in this case on elevation. It is shown that normalized density difference of the density based on proposed model and density based on the nonsimplified model is in the order of 10-4. The classical incompressible ideal gas model, Boussinesq model and generalised Boussinesq model are also tested. These models show deviation in percentages.

  14. Development of Modified Incompressible Ideal Gas Model for Natural Draft Cooling Tower Flow Simulation

    Directory of Open Access Journals (Sweden)

    Hyhlík Tomáš

    2018-01-01

    Full Text Available The article deals with the development of incompressible ideal gas like model, which can be used as a part of mathematical model describing natural draft wet-cooling tower flow, heat and mass transfer. It is shown, based on the results of a complex mathematical model of natural draft wet-cooling tower flow, that behaviour of pressure, temperature and density is very similar to the case of hydrostatics of moist air, where heat and mass transfer in the fill zone must be taken into account. The behaviour inside the cooling tower is documented using density, pressure and temperature distributions. The proposed equation for the density is based on the same idea like the incompressible ideal gas model, which is only dependent on temperature, specific humidity and in this case on elevation. It is shown that normalized density difference of the density based on proposed model and density based on the nonsimplified model is in the order of 10-4. The classical incompressible ideal gas model, Boussinesq model and generalised Boussinesq model are also tested. These models show deviation in percentages.

  15. Combination Carbon Nanotubes with Graphene Modified Natural Graphite and Its Electrochemical Performance

    Directory of Open Access Journals (Sweden)

    DENG Ling-feng

    2017-04-01

    Full Text Available The CNTs/rGO/NG composite lithiumion battery anode material was synthesized by thermal reducing, using graphene oxide (GO and carbon nanotubes (CNTs as precursors for a 5 ∶ 3 proportion. The morphology, structure, and electrochemical performance of the composite were characterized by scanning electron microscopy(SEM, X-ray diffractometry(XRD, Fourier transform infrared spectra (FTIR and electrochemical measurements. The results show that reduced graphene oxide and carbon nanotubes form a perfect three-dimensional network structure on the surface of natural graphite. CNTs/rGO/NG composite has good rate performance and cycle life,compared with pure natural graphite.The initial discharge capacity of designed anode is 479mAh/g at 0.1C, the reversible capacity up to 473mAh/g after 100 cycles,the capacity is still 439.5mAh/g, the capacity retention rate is 92%,and the capacity is 457, 433, 394mAh/g at 0.5, 1, 5C, respectively.

  16. Thermal Characterization of Modified Tacca Leontopetaloides Starch and Natural Rubber Based Thermoplastic Elastomer

    International Nuclear Information System (INIS)

    Ainatul Mardhiah Mohd Amin; Nur Shahidah Ab Aziz; Nurul Shuhada Mohd Makhtar; Miradatul Najwa Mohd Rodhi; Suhaila Mohd Sauid

    2014-01-01

    The purpose of this study is to identify the potential of Tacca leontopetaloides starch as bio-based thermoplastic elastomers, TPEs. Starch based polymer had been recognized to have highly potential in replace existing source of conventional elastomeric polymer. The modification process of blending starch with natural rubber, plasticizers, additives, and filler contribute to the enhancement and improvement for the properties of starch in order to produce biopolymers by approaching the properties of TPEs. Thermal properties of starch based thermoplastic was studied to evaluate the decomposition and degradation of the samples by using Thermogravimetric Analysis, TGA while the properties of endothermic reactions of the samples were thermally analyzed via Differential Scanning Calorimetry, DSC. From the analysis, it was found that the thermal properties of samples were revealed by recognizing GM-2 (green materials, GM) has high thermal resistance towards high temperature up to 480.06 degree Celsius with higher amount of residue which is 4.97 mg compared to other samples. This indicates GM-2 comprises of superior combination of ratio between natural rubbers and glycerol (plasticizer) in purpose of approaching the properties of Thermoplastic Elastomers, TPEs. (author)

  17. antimicrobial properties of some natural and synthetic fabrics modified by radiation treatments

    International Nuclear Information System (INIS)

    Mohamed, R.M.A.

    2008-01-01

    natural and synthetic fabrics have been treated with different antimicrobial metal complexes under the effect of gamma radiation . in this regard, cotton, cotton/PET blend and PET were grafted with acrylic acid by gamma radiation and this grafted fabrics were complexed with Cu(ll),Ni(ll)and Co(ll) metal ions . the antimicrobial properties were evaluated by the measurement of tensile strength of fabrics after burring in a soil for one and two weeks as well as the effect of this treatment on the growth of certain bacteria and fungi incubated on a culture for 48 hours. the results showed that the highest protection to cotton, cotton/PET blend and PET fabrics by using Cu(ll) ion in the complexation process, where the order of protection by metals is Cu(ll) > Co(ll)> Ni(ll), moreover, the more grafted fabrics the more complexed fabrics with metal ions and is higher protection against microorganisms . the treatment with the metal ions has nearly no effect on the chemical and physical properties of the natural or the synthetic fabrics as indicated from the analysis by TGA, sem, ion exchange testing and wettability testing.

  18. Preparation and properties of natural rubber reinforced with polydopamine-coating modified carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Y-L. Lu

    2017-01-01

    Full Text Available Multi-walled carbon nanotubes (MWCNTs were functionalized by polydopamine (PDA-coating and mixed with natural rubber (NR via latex compounding. Compared with pristine MWCNTs, the surface of MWCNT-PDA was covered by an amorphous and nanometer-scale PDA layer which had a large amount of oxygenic and nitric functional groups. So the MWCNT-PDA showed a perfect dispersion in NR matrix. The tensile strength of NR/MWCNT-PDA (5 phr composites is 28.6 MPa, compared with the pure NR, which increased by 42%. For the electrical properties, when the content of MWCNTPDA or MWCNTs is 2 phr, the volume resistivity of NR/MWCNT-PDA composites falls to about 2.7·109 Ω·cm, compared with 3.3·1013 Ω·cm of NR/MWCNT composites. The thermal conductivity of NR composites increased only by 28.2% when 5 phr MWCNT-PDA was added. A model proposed by Nan was used to calculate the thermal conductivity of NR/MWCNT composites, and the calculated values were compared with the experimental values, the results showed that the interface thermal resistance is the main reason why MWCNTs could not significantly increase the thermal conductivity of natural rubber.

  19. IR and Raman studies of oil and seedcake extracts from natural and genetically modified flax seeds

    Science.gov (United States)

    Żuk, M.; Dymińska, L.; Kulma, A.; Boba, A.; Prescha, A.; Szopa, J.; Mączka, M.; Zając, A.; Szołtysek, K.; Hanuza, J.

    2011-03-01

    Flax plant of the third generation (F3) overexpressing key genes of flavonoid pathway cultivated in field in 2008 season was used as the plant material throughout this study. The biochemical properties of seed, oil and seedcake extracts from natural and transgenic flax plants were compared. Overproduction of flavonoids (kaempferol), phenolic acids (coumaric, ferulic/synapic) and lignan-secoisolariciresinol diglucoside (SDG) in oil and extracts from transgenic seeds has been revealed providing a valuable source of these compounds for biotechnological application. The changes in fatty acids composition and increase in their stability against oxidation along three plant generations were also detected. The analysis of oil and seedcake extracts was performed using Raman and IR spectroscopy. The wavenumbers and integral intensities of Raman and IR bands were used to identify the components of phenylpropanoid pathway in oil and seedcake extracts from control and transgenic flax seeds. The spectroscopic data were compared to those obtained from biochemical analysis.

  20. Synthesis of chlorophyll-c derivatives by modifying natural chlorophyll-a.

    Science.gov (United States)

    Xu, Meiyun; Kinoshita, Yusuke; Matsubara, Shogo; Tamiaki, Hitoshi

    2016-03-01

    Chlorophyll-a (Chl-a) was extracted from cyanobacterial cells and modified to methyl pyropheophorbide-a. The 3-vinyl-chlorin was transformed to zinc complex of the corresponding 3-acetyl-porphyrin. The zinc porphyrin was oxidized to give cis-7,8- and 17,18-dihydroxy-chlorins as well cis-7,8-cis-17,18-tetrahydroxybacteriochlorin. After zinc-demetallation, the isolated cis-7,8- and 17,18-diols were reduced at the 3-acetyl group and triply dehydrated under acidic conditions to afford two regioisomeric 3-vinyl-porphyrins, methyl divinyl-pyroprotopheophorbide-a possessing the 8-vinyl group and 17-propionate residue (one of the divinyl-protoChl-a derivatives) and methyl pyropheophorbide-c 1 possessing the 8-ethyl group and 17-acrylate residue (one of the Chl-c 1 derivatives), respectively. The resulting 7,8,17,18-tetrol was reduced and then acidically treated, giving five-fold dehydrated free base porphyrin, methyl pyropheophorbide-c 2 possessing the 3,8-divinyl groups and 17-acrylate residue (one of the Chl-c 2 derivatives). The visible absorption and fluorescence emission spectra of the three semi-synthetic 3-vinyl-porphyrins in dichloromethane were compared with those of the corresponding 8-ethyl-porphyrin bearing the 17-propionate residue, methyl pyroprotopheophorbide-a (one of the protoChl-a derivatives). The Soret and Qy absorption maxima were shifted to longer wavelengths with an increase of π-conjugation in a molecule: protoChl-a (8-CH2CH3/17-CH2CH2COOCH3) < divinyl-protoChl-a (8-CH=CH2/17-CH2CH2COOCH3) < Chl-c 1 (8-CH2CH3/17-CH=CHCOOCH3) < Chl-c 2 derivatives (8-CH=CH2/17-CH=CHCOOCH3). The 17(1),17(2)-dehydrogenation broadened the absorption bands. The emission maxima were bathochromically shifted in the same order. The reaction mechanism of the present dehydration indicates that the biosynthetic pathway of Chls-c would include the hydroxylation of the 17-propionate reside at the 17(1)-position and successive dehydration to the 17-acrylate residue.

  1. Nature-based care opportunities and barriers in oncology contexts: a modified international e-Delphi survey.

    Science.gov (United States)

    Blaschke, Sarah; O'Callaghan, Clare C; Schofield, Penelope

    2017-10-16

    To develop recommendations regarding opportunities and barriers for nature-based care in oncology contexts using a structured knowledge generation process involving relevant healthcare and design experts. Four-round modified electronic Delphi study. Oncology patients' nature-based recommendations, uncovered in preceding qualitative investigation, were included in the first round for the expert participants' consideration. Key items (opportunities and barriers) were developed using data aggregation and synthesis, followed by item prioritisation and 10-point Likert scale ranking (1=not important, 10=very important). Descriptive statistics were calculated to assess items of highest importance representing expert recommendations. Online Delphi process constituting an electronic international survey. A purposive sample of 200 potential panellists (recruitment target n=40) comprising healthcare practitioners, managers, designers, architects and researchers were invited to participate; experts were identified via research networks, snowballing and systematic literature review. 38 experts across seven countries (Australia, USA, UK, New Zealand, Canada, Denmark and Sweden) returned questionnaire 1, which determined consent and acceptance for participation. Initial response rate was 19%, and subsequent response rates were 84%, 82% and 84% for rounds 2, 3 and 4, respectively. The Delphi panel developed recommendations consisting of 10 opportunities and 10 barriers. The following opportunities were rated to be of highest importance: window views from clinical areas onto nature; outdoor settings, gardens and courtyards with easy and effortless access; and nature-based physical exercise adapted to patient requirements. Highest-rated barriers for nature-based oncology care included lack of knowledge and awareness about benefits of nature engagement and inaccessibility, not considering access requirements for the very sick and frail. Experts suggested and agreed on a set of

  2. Microstructural Properties of Cement Paste and Mortar Modified by Low Cost Nanoplatelets Sourced from Natural Materials

    Directory of Open Access Journals (Sweden)

    Piao Huang

    2018-05-01

    Full Text Available Nanomaterials have been widely used in cement-based materials. Graphene has excellent properties for improving the durability of cement-based materials. Given its high production budget, it has limited its wide potential for application in the field of engineering. Hence, it is very meaningful to obtain low cost nanoplatelets from natural materials that can replace graphene nanoplatelets (GNPs The purpose of this paper is to improve the resistance to chloride ion penetration by optimizing the pore structure of cement-based materials, and another point is to reduce investment costs. The results illustrated that low cost CaCO3 nanoplatelets (CCNPs were successfully obtained under alkali treatment of seashell powder, and the chloride ion permeability of cement-based materials significantly decreased by 15.7% compared to that of the control samples when CCNPs were incorporated. Furthermore, the compressive strength of cement pastes at the age of 28 days increased by 37.9% than that of the plain sample. Improvement of performance of cement-based materials can be partly attributed to the refinement of the pore structure. In addition, AFM was employed to characterize the nanoplatelet thickness of CCNPs and the pore structures of the cement-based composites were analyzed by MIP, respectively. CCNPs composite cement best performance could lay the foundation for further study of the durability of cement-based materials and the application of decontaminated seashells.

  3. Use of a modified natural-rubber phantom for radiotherapy dosimetry measurements

    International Nuclear Information System (INIS)

    Bradley, D.A.; Ng, K.-H.; Aziz, Y.B.

    1988-01-01

    The utility of a phantom material, based on SMR(L) [Standard Malaysian Rubber] grade natural rubber and a formulation used for the proprietary rubber phantom-material, Temex, has been examined for the 1-MeV photon-energy range using γ radiation from a 60 Co source. Measurement has also been performed with 60-keV photons using the radionuclide 241 Am. At photon-therapy energy levels the measured response, when compared with tabulated central-axis percentage depth doses for defined measuring conditions, produces everywhere (in the range 1-19 cm depth) better than 2% deviation. The favourable measured response characteristics combined with the ease of processing and casting the phantom material provide the basis for useful radiotherapy machine calibration and anthropomorphic dosimetry measurements. The measured mass-attenuation coefficient, at 60 keV, of 0.204 cm 2 g -1 (± 3%) is in close agreement with tabulated values for water (0.2055 cm 2 g -1 ). (author)

  4. Dextran-Catechin: An anticancer chemically-modified natural compound targeting copper that attenuates neuroblastoma growth

    Science.gov (United States)

    Vittorio, Orazio; Brandl, Miriam; Cirillo, Giuseppe; Kimpton, Kathleen; Hinde, Elizabeth; Gaus, Katharina; Yee, Eugene; Kumar, Naresh; Duong, Hien; Fleming, Claudia; Haber, Michelle; Norris, Murray; Boyer, Cyrille; Kavallaris, Maria

    2016-01-01

    Neuroblastoma is frequently diagnosed at advanced stage disease and treatment includes high dose chemotherapy and surgery. Despite the use of aggressive therapy survival rates are poor and children that survive their disease experience long term side effects from their treatment, highlighting the need for effective and less toxic therapies. Catechin is a natural polyphenol with anti-cancer properties and limited side effects, however its mechanism of action is unknown. Here we report that Dextran-Catechin, a conjugated form of catechin that increases serum stability, is preferentially and markedly active against neuroblastoma cells having high levels of intracellular copper, without affecting non-malignant cells. Copper transporter 1 (CTR1) is the main transporter of copper in mammalian cells and it is upregulated in neuroblastoma. Functional studies showed that depletion of CTR1 expression reduced intracellular copper levels and led to a decrease in neuroblastoma cell sensitivity to Dextran-Catechin, implicating copper in the activity of this compound. Mechanistically, Dextran-Catechin was found to react with copper, inducing oxidative stress and decreasing glutathione levels, an intracellular antioxidant and regulator of copper homeostasis. In vivo, Dextran-Catechin significantly attenuated tumour growth in human xenograft and syngeneic models of neuroblastoma. Thus, Dextran-Catechin targets copper, inhibits tumour growth, and may be valuable in the treatment of aggressive neuroblastoma and other cancers dependent on copper for their growth. PMID:27374085

  5. Natural and Modified Zeolite—Alginate Composites. Application for Removal of Heavy Metal Cations from Contaminated Water Solutions

    Directory of Open Access Journals (Sweden)

    Milan Kragović

    2018-01-01

    Full Text Available In present paper, the influence of the initial pH and concentration of Pb2+ on its adsorption by the natural (NZA and Fe(III-modified zeolite-alginate beads (FeA was studied. Results showed that modification of the starting materials have a positive effect on their adsorption capacities (102 and 136 mg/g for the NZA and FeA, respectively. After encapsulation, the mechanism of lead adsorption by both adsorbents was changed and ion exchange dominates. The best adsorption was achieved for initial pH > 3.8. Cation exchange capacity, structural properties, and hydrophobicity of samples were also determined, and the presence of the alginate has no significant influence on investigated properties of samples. Experiments on wastewater from tailings of lead and zinc mine Grot, Serbia, showed that after treatment with both adsorbents, the content of the most abundant heavy metals (Pb, Zn, Hg, and Mn significantly decreased.

  6. Effects of partial replacement of silica with surface modified nanocrystalline cellulose on properties of natural rubber nanocomposites

    Directory of Open Access Journals (Sweden)

    Y. F. Luo

    2012-01-01

    Full Text Available Nanocrystalline cellulose was modified by 3-aminopropyl-triethoxysilane (KH550. The modified nanocrystalline cellulose (MNCC was further investigated to partially replace silica in natural rubber (NR composites via coagulation. NR/MNCC/silica and NR/nanocrystalline cellulose (NCC/silica nanocomposites were prepared. Through the comparison of vulcanization characteristics, processing properties of compounds and mechanical properties, compression fatigue properties, dynamic mechanical performance of NR/MNCC/silica and NR/NCC/silica nanocomposites, MNCC was proved to be more efficient than NCC. MNCC could activate the vulcanization process, suppress Payne effect, increase 300% modulus, tear strength and hardness, and reduce the heat build-up and compression set. Moreover, fine MNCC dispersion and strong interfacial interaction were achieved in NR/MNCC/silica nanocomposites. The observed reinforcement effects were evaluated based on the results of apparent crosslinking density (Vr, thermo-gravimetric (TG and scanning electron microscopic (SEM analyses of NR/MNCC/silica in comparison with NR/NCC/silica nanocomposites.

  7. Preparation And Characterization Of Modified Calcium Oxide From Natural Sources And Their Application In The Transesterification Of Palm Oil

    Directory of Open Access Journals (Sweden)

    Aqliliriana

    2015-08-01

    Full Text Available Abstract Calcium oxide catalysts were prepared from natural calcium sources such as limestone and mud creeper shell and the catalytic activities were evaluated in the transesterification of palm oil. The raw material which mainly composed of calcium carbonate can be easily converted to calcium oxide CaO after calcination above 1000 K for few hours. Abundant cheap sources benign high conversion and nontoxic become main advantages of these catalysts. The catalysts were characterized by XRF TGA XRD CO2-TPD SEM and BET methods. Thermal decomposition of CaCO3 will produced CaO which later will be converted into calcium hydroxide CaOH2 via simple hydration technique. Under optimum reaction condition methanol to oil ratio 151 catalyst loading 3 wt. reaction temperature 338 K for 5 hours the highest conversion of palm oil to methyl ester recorded were 98 and 94 when using modified limestone and mud creeper shell respectively. The results observed an increment up to 80 by using modified catalysts with characterization results showed high in basicity and surface area. Hence promising materials via simple and cheap method can be achieved.

  8. Photocatalytic removal of SO2 using natural zeolite modified by TiO2 and polyoxypropylene surfactant.

    Science.gov (United States)

    Amini, Nasibeh; Soleimani, Mohsen; Mirghaffari, Nourollah

    2018-01-25

    Air pollution due to emission of various hazardous gases such as SO 2 into the atmosphere and its control is an important environmental issue. Application of photocatalysts is considered as a suitable process to control the gaseous pollutants. In this study, the efficiency of clinoptilolite as a natural zeolite (Ze) modified by TiO 2 (Ze-Ti) and a polymeric surfactant polyoxypropylene (Ze-Ti-POP) for removal of SO 2 was investigated. The nanocomposites were characterized by SEM, EDX, and BET analyses. The photocatalytic oxidation experiments of SO 2 by the nanocomposites and natural zeolite were done under UV irradiation with initial SO 2 concentration of 500 ppm in a photoreactor. The effects of different factors including reaction time, catalyst dose, UV irradiation intensity, humidity content, and calcination temperature and dose of TiO 2 were studied. The modification of clinoptilolite by TiO 2 and POP increased considerably the BET specific surface area of the nanocomposites. The results showed that maximum removal efficiencies of SO 2 by Ze-Ti and Ze-Ti-POP under the optimum experimental conditions were 82.1 and 87.4%, respectively. Adsorption kinetics data well fitted with the Langmuir-Hinshelwood model. Moreover, reusing of nanocomposites after three regeneration cycles indicated that application of Ze-Ti and Ze-Ti-POP nanocomposites could be a promising approach for SO 2 removal. Graphical abstract ᅟ.

  9. Environmental remediation of high-level nuclear waste in geological repository. Modified computer code creates ultimate benchmark in natural systems

    International Nuclear Information System (INIS)

    Peter, Geoffrey J.

    2011-01-01

    Isolation of high-level nuclear waste in permanent geological repositories has been a major concern for over 30 years due to the migration of dissolved radio nuclides reaching the water table (10,000-year compliance period) as water moves through the repository and the surrounding area. Repositories based on mathematical models allow for long-term geological phenomena and involve many approximations; however, experimental verification of long-term processes is impossible. Countries must determine if geological disposal is adequate for permanent storage. Many countries have extensively studied different aspects of safely confining the highly radioactive waste in an underground repository based on the unique geological composition at their selected repository location. This paper discusses two computer codes developed by various countries to study the coupled thermal, mechanical, and chemical process in these environments, and the migration of radionuclide. Further, this paper presents the results of a case study of the Magma-hydrothermal (MH) computer code, modified by the author, applied to nuclear waste repository analysis. The MH code verified by simulating natural systems thus, creating the ultimate benchmark. This approach based on processes similar to those expected near waste repositories currently occurring in natural systems. (author)

  10. [Research progress in chemical communication among insect-resistant genetically modified plants, insect pests and natural enemies].

    Science.gov (United States)

    Liu, Qing-Song; Li, Yun-He; Chen, Xiu-Ping; Peng, Yu-Fa

    2014-08-01

    Semiochemicals released by plants or insects play an important role in the communication among plants, phytophagous insects and their natural enemies. They thus form a chemical information network which regulates intra- and inter-specific behaviors and sustains the composition and structure of plant and insect communities. The application of insect-resistant genetically modified (IRGM) crops may affect the chemical communication within and among the tritrophic levels, and thus cause disturbances to the biotic community structure and the stability of the farmland ecosystem. This has raised concerns about the environmental safety of IRGM crops and triggered research worldwide. In the current article we provided a brief summary of the chemical communication among plants, herbivores and natural enemies; analyzed the potential of IRGM crops to affect the chemical communication between plants and arthropods and the related mechanisms; and discussed the current research progress and the future prospects in this field. We hope that this will promote the research in this field by Chinese scientists and increase our understanding of the potential effects of growing of IRGM crops on the arthropod community structure.

  11. Thermodynamics of inclusion complexes of natural and modified cyclodextrins with acetylsalicylic acid and ibuprofen in aqueous solution at 298 K

    Energy Technology Data Exchange (ETDEWEB)

    Castronuovo, Giuseppina, E-mail: giuseppina.castronuovo@unina.it [Department of Chemistry, University Federico II of Naples, Complesso Universitario a Monte S. Angelo, via Cintia, 80126 Naples (Italy); Niccoli, Marcella [Department of Chemistry, University Federico II of Naples, Complesso Universitario a Monte S. Angelo, via Cintia, 80126 Naples (Italy)

    2013-04-10

    Graphical abstract: Complexation forces acting in the association between natural and modified α- and β-cyclodextrins and acetylsalicylic acid (aspirin) or ibuprofen are examined through the analysis of the thermodynamic parameters obtained by isothermal calorimetry. Highlights: ► A calorimetric method is reported to study the association of natural and substituted cyclodextrins with acetylsalicylic acid and ibuprofen. ► The study aims to propose a hypothesis about the forces involved in the interaction. That can be useful for designing new cyclodextrins having suitable characteristics to include specific drugs. ► Enthalpic and entropic contributions on the association are discussed. The differences in the cavity dimensions of the cyclodextrins determine the values of the thermodynamic properties to be very different. - Abstract: Thermodynamic parameters for the association of natural and substituted α-, β-, and γ-cyclodextrins with acetylsalicylic acid, salicylic acid and ibuprofen have been determined by isothermal titration calorimetry. Analysis of the data shows that complexes form, all having 1:1 stoichiometry. The shape-matching between the host and guest is the factor determining the values of the thermodynamic quantities. In the case of the smallest cyclodextrin interacting with acetylsalicylic acid and salicylic acid, the parameters indicate that hydrophobic interactions play the major role. Association occurs through the shallow inclusion of the benzene ring into the cavity. In the case of substituted β-cyclodextrins, instead, inclusion of the benzene ring is deeper and the tight fitting of the guest molecule to the cavity makes the enthalpy and entropy to be both negative. Ibuprofen interacts through its isobutyl group: the values of the association constants are very high for β-cyclodextrins as determined by the large and positive entropies due to the relaxation of water molecules from the cavity and the hydration spheres of the interacting

  12. Thermodynamics of inclusion complexes of natural and modified cyclodextrins with acetylsalicylic acid and ibuprofen in aqueous solution at 298 K

    International Nuclear Information System (INIS)

    Castronuovo, Giuseppina; Niccoli, Marcella

    2013-01-01

    Graphical abstract: Complexation forces acting in the association between natural and modified α- and β-cyclodextrins and acetylsalicylic acid (aspirin) or ibuprofen are examined through the analysis of the thermodynamic parameters obtained by isothermal calorimetry. Highlights: ► A calorimetric method is reported to study the association of natural and substituted cyclodextrins with acetylsalicylic acid and ibuprofen. ► The study aims to propose a hypothesis about the forces involved in the interaction. That can be useful for designing new cyclodextrins having suitable characteristics to include specific drugs. ► Enthalpic and entropic contributions on the association are discussed. The differences in the cavity dimensions of the cyclodextrins determine the values of the thermodynamic properties to be very different. - Abstract: Thermodynamic parameters for the association of natural and substituted α-, β-, and γ-cyclodextrins with acetylsalicylic acid, salicylic acid and ibuprofen have been determined by isothermal titration calorimetry. Analysis of the data shows that complexes form, all having 1:1 stoichiometry. The shape-matching between the host and guest is the factor determining the values of the thermodynamic quantities. In the case of the smallest cyclodextrin interacting with acetylsalicylic acid and salicylic acid, the parameters indicate that hydrophobic interactions play the major role. Association occurs through the shallow inclusion of the benzene ring into the cavity. In the case of substituted β-cyclodextrins, instead, inclusion of the benzene ring is deeper and the tight fitting of the guest molecule to the cavity makes the enthalpy and entropy to be both negative. Ibuprofen interacts through its isobutyl group: the values of the association constants are very high for β-cyclodextrins as determined by the large and positive entropies due to the relaxation of water molecules from the cavity and the hydration spheres of the interacting

  13. Application of walnut shell modified with Zinc Oxide (ZnO nanoparticles in removal of natural organic matters (NOMs from aqueous solution

    Directory of Open Access Journals (Sweden)

    ali naghizadeh

    2015-10-01

    Full Text Available Background & Aims of the Study: Natural organic matters (NOMs are a mixture of chemically complex polyelectrolytes produced mainly from the decomposition of plant and animal residues that are present in all surface and groundwater resources. This paper evaluates the aqueous NOMs adsorption efficiency on walnut shell modified with Zinc Oxide (ZnO. Materials & Methods: This study examined the feasibility of removing NOMs from aqueous solutions using walnut shell modified with ZnO. The effects of NOMs concentration, modified walnut shell with ZnO dosage, and pH on adsorption of NOMs by modified walnut shell with ZnO were evaluated. Results: The adsorption capacities of modified walnut shell with ZnO in the best conditions were 37.93 mg/g. The results also demonstrated that adsorption capacity of NOMs on modified walnut shell with ZnO was higher in lower pHs due to significantly high electrostatic attraction exists between the positively charged surface of the adsorbent and negatively charged NOMs. And finally adsorption capacity decreases as adsorbent dose increase. Conclusion: Walnut shell modified with ZnO can be proposed as a natural adsorbent in the removal of NOMs from aqueous solutions

  14. Natural silica sand modified by calcium oxide as a new adsorbent for uranyl ions removal from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Elhefnawy, O.A.; Elabd, A.A. [Nuclear and Radiological Regulatory Authority (NRRA), Cairo (Egypt). Nuclear Safeguards and Physical Protection Dept.

    2017-07-01

    Calcium oxide modified El-Zafarana silica sand (CMZS) was prepared as a new adsorbent for U(VI) removal from aqueous solutions in a series of batch experiments. The new adsorbent CMZS was characterized by different analysis techniques SEM, EDX, XRD, and FTIR. The influence of many parameters on the removal process like; effect of pH, contact time, U(VI) initial concentration and temperature on U(VI) removal were investigated. Kinetic experiments showed that U(VI) removal on CMZS followed pseudo-second-order kinetics model appropriately and the equilibrium data agreed well with the Langmuir isotherm model. Kinetics and isothermal data reveal the chemisorption process of U(VI) on CMZS. The thermodynamic parameters (ΔH {sup circle}, ΔS {sup circle}, ΔG {sup circle}) were evaluated from temperature dependent adsorption data and the U(VI) removal on CMZS was found to be endothermic and spontaneous in nature. U(VI) desorption from CMZS was studied by a simple acid treatment. The results indicate that CMZS is an effective adsorbent for U(VI) from aqueous solutions.

  15. Preparation and characterization of PbTi03 ceramics modified by a natural mixture of rare earth oxides of xenotime

    International Nuclear Information System (INIS)

    Baltazar-Rodrigues, Jair; Rodrigues Junior, Pedro; Cruz, Gerson K. da; Lente, Manuel H.; Eiras, Jose A.

    2014-01-01

    Lead titanate ceramics modified by xenotime (Xm) with nominal composition (Pb, Xm)TiO 3 , Xm 10 or 15 mol %, were prepared by the conventional oxide mixture technique. Xenotime is a natural mineral consisting of a mixture of rare earth oxides. Thermal, structural and electric properties were investigated through differential and gravimetric thermal analysis, X-ray diffraction and dielectric measurements as a function of temperature. The results of both compositions revealed a higher density and free of cracks ceramic body, compared to pure PbTiO 3 prepared by the same procedure. On the other hand, the structural characteristics and Curie temperature are nearly the same as those of pure PbTiO 3 . The hysteresis loop measured at room temperature revealed a hard ferroelectric material with coercive field of 10.7 kV/cm and a remanent polarization of 0.2 μC/cm 2 . These finding reveal a material with properties that highlight potential to be used as electronic devices that operate at high temperature and high frequencies. (author)

  16. Gold nanoparticles applications in natural polymer modified for UV protection; Aplicacao de nanoparticulas de ouro em polimero natural modificado para protecao ultravioleta

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Iris O. da; Ladchumananandasivam, Rasiah; Nascimento, Jose H. O. do; Silva, Francisco C. da; Sa, Christiane S. de A., E-mail: iris.oliveira@gmail.com.br [Universidade Federal do Rio Grande do Norte (PPGEM/UFRN), Natal, RN (Brazil)

    2015-07-01

    The protein-based polymers such as milk, such as polylactic acid (PLA) and soya can be cited as examples of substrates used in various fields of engineering, mainly due to its character of biodegradability, generating low environmental impact when compared to chemical polymers to petroleum-based, which take years to decompose in nature. Among these, soy fiber has great application potential because it is a manufactured material base of a residue obtained from the existing folder in the soybean seeds after oil extraction, using resins and chemicals for structural modification. In this work, soy mesh was used to develop a material with ultraviolet protection properties, through the use of nanotechnology. Thus, to connect the gold nanoparticles (NPAu), the fabric had a surface charge modified with the use of chitosan, using 20% of the weight of the material, followed by nanomaterials exhaust process. The NPAu were synthesized via chemical synthesis with sodium nitrate as reducing and stabilizing agent. The analysis of the solution samples were evaluated by absorbance spectroscopy and solid materials through diffuse reflectance spectroscopy and XRD X-ray diffraction. The size of NPAu was evaluated in equipment Zetasizer nanoseries / nanoZ, finding nanoparticles with an average size of 34.59 nm, and also underlined plasmon resonance phenomenon, with peaks between 530 nm and red coloration, and good results from the soundness washes, compared to conventional dyeing. It was found that soy polymer treated with NPAu presented an excellent property with ultraviolet protection factor (UPF) of +50, considered excellent, proving its potential application in the biomedical field. (author)

  17. Isotherms and kinetics of lead and cadmium uptake from the waste leachate by natural and modified clinoptilolite

    Directory of Open Access Journals (Sweden)

    Maryam Faraji

    2012-01-01

    Conclusions: The modified zeolite with surfactant can be used as an appropriate adsorbent for the separation of heavy metals from waste Leachate. Lead and cadmium were absorbed in a single layer on the surface of the modified zeolite with surfactant, comparing different isoterm models, indicated that the capacity of the modified zeolite for lead adsorption was more than cadmium adsorption, but cadmium was absorbed with higher energy.

  18. Embryo quality and impact of specific embryo characteristics on ongoing implantation in unselected embryos derived from modified natural cycle in vitro fertilization

    NARCIS (Netherlands)

    Pelinck, Marie-Jose; Hoek, Annemieke; Simons, Arnold H. M.; Heineman, Maas Jan; van Echten-Arends, Janny; Arts, Eus G. J. M.

    Objective: To study the implantation potential of unselected embryos derived from modified natural cycle IVF according to their morphological characteristics. Design: Cohort study. Setting: Academic department of reproductive medicine. Patient(S): A series of 449 single embryo transfers derived from

  19. Staphylococcal phenotypes induced by naturally occurring and synthetic membrane-interactive polyphenolic β-lactam resistance modifiers.

    Directory of Open Access Journals (Sweden)

    Lucia Palacios

    Full Text Available Galloyl catechins, in particular (--epicatechin gallate (ECg, have the capacity to abrogate β-lactam resistance in methicillin-resistant strains of Staphylococcus aureus (MRSA; they also prevent biofilm formation, reduce the secretion of a large proportion of the exoproteome and induce profound changes to cell morphology. Current evidence suggests that these reversible phenotypic traits result from their intercalation into the bacterial cytoplasmic membrane. We have endeavoured to potentiate the capacity of ECg to modify the MRSA phenotype by stepwise removal of hydroxyl groups from the B-ring pharmacophore and the A:C fused ring system of the naturally occurring molecule. ECg binds rapidly to the membrane, inducing up-regulation of genes responsible for protection against cell wall stress and maintenance of membrane integrity and function. Studies with artificial membranes modelled on the lipid composition of the staphylococcal bilayer indicated that ECg adopts a position deep within the lipid palisade, eliciting major alterations in the thermotropic behaviour of the bilayer. The non-galloylated homolog (--epicatechin enhanced ECg-mediated effects by facilitating entry of ECg molecules into the membrane. ECg analogs with unnatural B-ring hydroxylation patterns induced higher levels of gene expression and more profound changes to MRSA membrane fluidity than ECg but adopted a more superficial location within the bilayer. ECg possessed a high affinity for the positively charged staphylococcal membrane and induced changes to the biophysical properties of the bilayer that are likely to account for its capacity to disperse the cell wall biosynthetic machinery responsible for β-lactam resistance. The ability to enhance these properties by chemical modification of ECg raises the possibility that more potent analogs could be developed for clinical evaluation.

  20. Nano-clays from natural and modified montmorillonite with and without added blueberry extract for active and intelligent food nanopackaging materials

    Energy Technology Data Exchange (ETDEWEB)

    Gutiérrez, Tomy J., E-mail: tomy.gutierrez@ciens.ucv.ve [Departamento Químico Analítico, Facultad de Farmacia, Universidad Central de Venezuela, Apartado 40109, Caracas, 1040-A (Venezuela, Bolivarian Republic of); Instituto de Ciencia y Tecnología de Alimentos, Facultad de Ciencias, Universidad Central de Venezuela, Apartado 47097, Caracas, 1041-A (Venezuela, Bolivarian Republic of); Grupo de Materiales Compuestos Termoplásticos (CoMP), Instituto de Investigaciones en Ciencia y Tecnología de Materiales (INTEMA), Facultad de Ingeniería, Universidad Nacional de Mar del Plata UNMdP y Consejo Nacional de Investigaciones Científicas y Técnicas - CONICET, Colón 10850, B7608FLC, Mar del Plata (Argentina); Ponce, Alejandra G. [Grupo de Investigación en Ingeniería en Alimentos, Facultad de Ingeniería, Universidad Nacional de Mar del Plata (UNMdP), Juan B. Justo 4302, 7600, Mar del Plata (Argentina); Alvarez, Vera A. [Grupo de Materiales Compuestos Termoplásticos (CoMP), Instituto de Investigaciones en Ciencia y Tecnología de Materiales (INTEMA), Facultad de Ingeniería, Universidad Nacional de Mar del Plata UNMdP y Consejo Nacional de Investigaciones Científicas y Técnicas - CONICET, Colón 10850, B7608FLC, Mar del Plata (Argentina)

    2017-06-15

    The aim of this study was to evaluate the potential of nano-clays as active and intelligent (A&I) food nanopackaging materials. Nanopackaging is a structured system that allows the storage of certain compounds in a stable form. Nano-clays were prepared from natural and modified montmorillonite (Mnt) with and without added blueberry extract, and characterized in terms of their: X-ray diffraction (XRD) patterns, thermogravimetric (TGA) properties, microstructure, moisture content, water activity (a{sub w}), infrared spectra (FTIR), Raman spectra, color parameters, response to pH changes, and antioxidant and antimicrobial activity. Mnt prepared with added blueberry extract showed antioxidant activity and intelligent behavior under different pH conditions. Modifying the Mnt increased the interlayer spacing, thus allowing more blueberry extract to be incorporated within the system. In conclusion, natural and modified Mnt are eco-friendly resources with potential applications for nano-packaging. The addition of blueberry extract imparted intelligent properties to the nano-clays as regards their responses to changes in pH. - Highlights: • Food nano-packaging were obtained from natural and modified montmorillonite (Mnt). • XRD, TGA and FTIR results suggests the blueberry extract nano-packaging. • Intelligent nanocomposites were obtained. • Greater interlayer spacing of the nano-Mnt allows greater nano-packaging.

  1. Nano-clays from natural and modified montmorillonite with and without added blueberry extract for active and intelligent food nanopackaging materials

    International Nuclear Information System (INIS)

    Gutiérrez, Tomy J.; Ponce, Alejandra G.; Alvarez, Vera A.

    2017-01-01

    The aim of this study was to evaluate the potential of nano-clays as active and intelligent (A&I) food nanopackaging materials. Nanopackaging is a structured system that allows the storage of certain compounds in a stable form. Nano-clays were prepared from natural and modified montmorillonite (Mnt) with and without added blueberry extract, and characterized in terms of their: X-ray diffraction (XRD) patterns, thermogravimetric (TGA) properties, microstructure, moisture content, water activity (a_w), infrared spectra (FTIR), Raman spectra, color parameters, response to pH changes, and antioxidant and antimicrobial activity. Mnt prepared with added blueberry extract showed antioxidant activity and intelligent behavior under different pH conditions. Modifying the Mnt increased the interlayer spacing, thus allowing more blueberry extract to be incorporated within the system. In conclusion, natural and modified Mnt are eco-friendly resources with potential applications for nano-packaging. The addition of blueberry extract imparted intelligent properties to the nano-clays as regards their responses to changes in pH. - Highlights: • Food nano-packaging were obtained from natural and modified montmorillonite (Mnt). • XRD, TGA and FTIR results suggests the blueberry extract nano-packaging. • Intelligent nanocomposites were obtained. • Greater interlayer spacing of the nano-Mnt allows greater nano-packaging.

  2. Presence of bile acids in human follicular fluid and their relation with embryo development in modified natural cycle IVF.

    Science.gov (United States)

    Nagy, R A; van Montfoort, A P A; Dikkers, A; van Echten-Arends, J; Homminga, I; Land, J A; Hoek, A; Tietge, U J F

    2015-05-01

    Are bile acids (BA) and their respective subspecies present in human follicular fluid (FF) and do they relate to embryo quality in modified natural cycle IVF (MNC-IVF)? BA concentrations are 2-fold higher in follicular fluid than in serum and ursodeoxycholic acid (UDCA) derivatives were associated with development of top quality embryos on Day 3 after fertilization. Granulosa cells are capable of synthesizing BA, but a potential correlation with oocyte and embryo quality as well as information on the presence and role of BA subspecies in follicular fluid have yet to be investigated. Between January 2001 and June 2004, follicular fluid and serum samples were collected from 303 patients treated in a single academic centre that was involved in a multicentre cohort study on the effectiveness of MNC-IVF. Material from patients who underwent a first cycle of MNC-IVF was used. Serum was not stored from all patients, and the available material comprised 156 follicular fluid and 116 matching serum samples. Total BA and BA subspecies were measured in follicular fluid and in matching serum by enzymatic fluorimetric assay and liquid chromatography-mass spectrometry, respectively. The association of BA in follicular fluid with oocyte and embryo quality parameters, such as fertilization rate and cell number, presence of multinucleated blastomeres and percentage of fragmentation on Day 3, was analysed. Embryos with eight cells on Day 3 after oocyte retrieval were more likely to originate from follicles with a higher level of UDCA derivatives than those with fewer than eight cells (P IVF were used, which resulted in 14 samples only from women with an ongoing pregnancy, therefore further prospective studies are required to confirm the association of UDCA with IVF pregnancy outcomes. The inter-cycle variability of BA levels in follicular fluid within individuals has yet to be investigated. We checked for macroscopic signs of contamination of follicular fluid by blood but the

  3. Focused library with a core structure extracted from natural products and modified: application to phosphatase inhibitors and several biochemical findings.

    Science.gov (United States)

    Hirai, Go; Sodeoka, Mikiko

    2015-05-19

    Synthesis of a focused library is an important strategy to create novel modulators of specific classes of proteins. Compounds in a focused library are composed of a common core structure and different diversity structures. In this Account, we describe our design and synthesis of libraries focused on selective inhibitors of protein phosphatases (PPases). We considered that core structures having structural and electronic features similar to those of PPase substrates, phosphate esters, would be a reasonable choice. Therefore, we extracted core structures from natural products already identified as PPase inhibitors. Since many PPases share similar active-site structures, such phosphate-mimicking core structures should interact with many enzymes in the same family, and therefore the choice of diversity structures is pivotal both to increase the binding affinity and to achieve specificity for individual enzymes. Here we present case studies of application of focused libraries to obtain PPase inhibitors, covering the overall process from selection of core structures to identification and evaluation of candidates in the focused libraries. To synthesize a library focused on protein serine-threonine phosphatases (PPs), we chose norcantharidin as a core structure, because norcantharidin dicarboxylate shows a broad inhibition profile toward several PPs. From the resulting focused library, we identified a highly selective PP2B inhibitor, NCA-01. On the other hand, to find inhibitors of dual-specificity protein phosphatases (DSPs), we chose 3-acyltetronic acid extracted from natural product RK-682 as a core structure, because its structure resembles the transition state in the dephosphorylation reaction of DSPs. However, a highly selective inhibitor was not found in the resulting focused library. Furthermore, an inherent drawback of compounds having the highly acidic 3-acyltetronic acid as a core structure is very weak potency in cellulo, probably due to poor cell membrane

  4. 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.

  5. Biodegradable polymer nanocomposites based on natural nanotubes: effect of magnetically modified halloysite on the behaviour of polycaprolactone

    Czech Academy of Sciences Publication Activity Database

    Khunová, V.; Šafařík, Ivo; Škrátek, M.; Kelnar, Ivan; Tomanová, K.

    2016-01-01

    Roč. 51, č. 3 (2016), s. 435-444 ISSN 0009-8558 R&D Projects: GA ČR(CZ) GA13-15255S Institutional support: RVO:60077344 ; RVO:61389013 Keywords : magnetically modified HNTs * biodegradable polymer nanocomposites * polycaprolactone Subject RIV: CD - Macromolecular Chemistry ; JI - Composite Materials (UMCH-V) Impact factor: 1.052, year: 2016

  6. Modified natural cycle versus controlled ovarian hyperstimulation IVF: a cost-effectiveness evaluation of three simulated treatment scenarios.

    Science.gov (United States)

    Groen, Henk; Tonch, Nino; Simons, Arnold H M; van der Veen, Fulco; Hoek, Annemieke; Land, Jolande A

    2013-12-01

    Can modified natural cycle IVF or ICSI (MNC) be a cost-effective alternative for controlled ovarian hyperstimulation IVF or ICSI (COH)? The comparison of simulated scenarios indicates that a strategy of three to six cycles of MNC with minimized medication is a cost-effective alternative for one cycle of COH with strict application of single embryo transfer (SET). MNC is cheaper per cycle than COH but also less effective in terms of live birth rate (LBR). However, strict application of SET in COH cycles reduces effectiveness and up to three MNC cycles can be performed at the same costs as one COH cycle. The cost-effectiveness of MNC versus COH was evaluated in three simulated treatment scenarios: three cycles of MNC versus one cycle of COH with SET or double embryo transfer (DET) and subsequent transfer of cryopreserved embryos (Scenario 1); six cycles of MNC versus one cycle of COH with strictly SET and subsequent transfer of cryopreserved embryos (Scenario 2); six cycles of MNC with minimized medication (hCG ovulation trigger only) versus one cycle of COH with SET or DET and subsequent transfer of cryopreserved embryos (Scenario 3). We used baseline data obtained from two retrospective cohorts of consecutive patients (2005-2008) undergoing MNC in the University Medical Center Groningen (n = 499, maximum six cycles per patient) or their first COH cycle with subsequent transfer of cryopreserved embryos in the Academic Medical Center Amsterdam (n = 392). Data from 1994 MNC cycles (958 MNC-IVF and 1036 MNC-ICSI) and 392 fresh COH cycles (one per patient, 196 COH-IVF and 196 COH-ICSI) with subsequent transfer of cryopreserved embryos (n = 72 and n = 94 in MNC and COH cycles, respectively) in ovulatory, subfertile women cost-effectiveness ratio (ICER) was calculated, defined as the ratio of the difference in IVF costs up to 6 weeks postpartum to the difference in LBR. Live birth was the primary outcome measure and was defined as the birth of at least one living child

  7. Green dyeing process of modified cotton fibres using natural dyes extracted from Tamarix aphylla (L.) Karst. leaves.

    Science.gov (United States)

    Baaka, Noureddine; Mahfoudhi, Adel; Haddar, Wafa; Mhenni, Mohamed Farouk; Mighri, Zine

    2017-01-01

    This research work involves an eco-friendly dyeing process of modified cotton with the aqueous extract of Tamarix aphylla leaves. During this process, the dyeing step was carried out on modified cotton by several cationising agents in order to improve its dyeability. The influence of the main dyeing conditions (dye bath pH, dyeing time, dyeing temperature, salt addition) on the performances of this dyeing process were studied. The dyeing performances of this process were appreciated by measuring the colour yield (K/S) and the fastness properties of the dyed samples. The effect of mordant type with different mordanting methods on dyeing quality was also studied. The results showed that mordanting gave deeper shades and enhanced fastness properties. In addition, environmental indicators (BOD 5 , COD and COD/BOD 5 ) were used to describe potential improvements in the biodegradability of the dyebath wastewater. Further, HPLC was used to identify the major phenolic compounds in the extracted dye.

  8. Encapsulation, solid-phases identification and leaching of toxic metals in cement systems modified by natural biodegradable polymers

    International Nuclear Information System (INIS)

    Lasheras-Zubiate, M.; Navarro-Blasco, I.; Fernández, J.M.; Álvarez, J.I.

    2012-01-01

    Highlights: ► Speciation of Zn, Pb and Cr has been studied in chitosan-modified cement mortars. ► Metal retention mechanisms have been clarified by newly identified crystalline forms. ► Native chitosan induced and stabilized newly characterized Pb (IV) species. ► Dietrichite is responsible for the Zn immobilization in the polymer-modified mortar. ► Leaching of Zn decreased by 24% in the presence of low molecular weight chitosan. - Abstract: Cement mortars loaded with Cr, Pb and Zn were modified by polymeric admixtures [chitosans with low (LMWCH), medium (MMWCH) and high (HMWCH) molecular weight and hydroxypropylchitosan (HPCH)]. The influence of the simultaneous presence of the heavy metal and the polymeric additive on the fresh properties (consistency, water retention and setting time) and on the compressive strength of the mortars was assessed. Leaching patterns as well as properties of the cement mortars were related to the heavy metals-bearing solid phases. Chitosan admixtures lessened the effect of the addition of Cr and Pb on the setting time. In all instances, chitosans improved the compressive strength of the Zn-bearing mortars yielding values as high as 15 N mm −2 . A newly reported Zn phase, dietrichite (ZnAl 2 (SO 4 ) 4 ·22H 2 O) was identified under the presence of LMWCH: it was responsible for an improvement by 24% in Zn retention. Lead-bearing silicates, such as plumalsite (Pb 4 Al 2 (SiO 3 ) 7 ), were also identified by XRD confirming that Pb was mainly retained as a part of the silicate network after Ca ion exchange. Also, the presence of polymer induced the appearance and stabilization of some Pb(IV) species. Finally, diverse chromate species were identified and related to the larger leaching values of Cr(VI).

  9. Fish assemblages associated with natural and anthropogenically-modified habitats in a marine embayment: comparison of baited videos and opera-house traps.

    Directory of Open Access Journals (Sweden)

    Corey B Wakefield

    Full Text Available Marine embayments and estuaries play an important role in the ecology and life history of many fish species. Cockburn Sound is one of a relative paucity of marine embayments on the west coast of Australia. Its sheltered waters and close proximity to a capital city have resulted in anthropogenic intrusion and extensive seascape modification. This study aimed to compare the sampling efficiencies of baited videos and fish traps in determining the relative abundance and diversity of temperate demersal fish species associated with naturally occurring (seagrass, limestone outcrops and soft sediment and modified (rockwall and dredge channel habitats in Cockburn Sound. Baited videos sampled a greater range of species in higher total and mean abundances than fish traps. This larger amount of data collected by baited videos allowed for greater discrimination of fish assemblages between habitats. The markedly higher diversity and abundances of fish associated with seagrass and limestone outcrops, and the fact that these habitats are very limited within Cockburn Sound, suggests they play an important role in the fish ecology of this embayment. Fish assemblages associated with modified habitats comprised a subset of species in lower abundances when compared to natural habitats with similar physical characteristics. This suggests modified habitats may not have provided the necessary resource requirements (e.g. shelter and/or diet for some species, resulting in alterations to the natural trophic structure and interspecific interactions. Baited videos provided a more efficient and non-extractive method for comparing fish assemblages and habitat associations of smaller bodied species and juveniles in a turbid environment.

  10. Modifying the dissolved-in-water type natural gas field simulation model based on the distribution of estimated Young's modulus for the Kujukuri region, Japan

    Directory of Open Access Journals (Sweden)

    T. Nakagawa

    2015-11-01

    Full Text Available A simulation model, which covers the part of Southern-Kanto natural gas field in Chiba prefecture, was developed to perform studies and make predictions of land subsidence. However, because large differences between simulated and measured subsidence occurred in the northern modeled area of the gas field, the model was modified with an estimated Young's modulus distribution. This distribution was estimated by the yield value distribution and the correlation of yield value with Young's modulus. Consequently, the simulated subsidence in the north area was improved to some extent.

  11. Bacterial inactivation in water by means of a combined process of pulsed dielectric barrier discharge and silver-modified natural zeolite

    International Nuclear Information System (INIS)

    Rodríguez-Méndez, B G; López-Callejas, R; Olguín, M T; Valencia-Alvarado, R; Peña-Eguiluz, R; Mercado-Cabrera, A; Alcántara-Díaz, D; Muñoz-Castro, A E; Hernández-Arias, A N; De la Piedad-Beneitez, A

    2014-01-01

    We propose a novel combined system of pulsed dielectric barrier discharges (PDBDs) and silver-modified natural zeolite (Ag–zeolite) in liquid in bubbles. The system was tested with the Escherichia coli bacteria immersed in water. In order to evaluate the efficiency of the system in bacterial inactivation a microbiological analysis was carried out; 9.82-ln of bacterial reduction was obtained using the combined system, whereas 0.43-ln of bacterial reduction was obtained using Ag–zeolite alone, and 6.26-ln with PDBD. The elapsed time was 10 minutes for the three treatments. (paper)

  12. Natural regeneration of Douglas-fir and associated species using modified clear-cutting systems in the Oregon Cascades.

    Science.gov (United States)

    Jerry F. Franklin

    1963-01-01

    Clear cutting is the standard harvesting system in old-growth Douglas-fir (Pseudotsuga menziesii) forests in the Pacific Northwest. Usually these clear cuts are in "staggered settings" of 15 to 80 acres with the surrounding stand left uncut to provide seed and serve as a firebreak. However, satisfactory natural regeneration of Douglas-fir...

  13. Radiotracer study of the adsorption of Fe(III), Cr(III) and Cd(II) on natural and chemically modified Slovak zeolite

    International Nuclear Information System (INIS)

    Foeldesova, M.; Dillinger, P.; Lukac, P.

    1998-01-01

    In order to minimize the contamination of environment with metals in ionic form the more types of natural and chemically modified zeolites were examined to their uptake of Fe(III), Cr(III) and Cd(II) from water solutions by batch radio-exchange equilibration method. In this study was used zeolitic tuff from deposit Nizny Hrabovec (content of clinoptilolite 50-70%) with the grain size from 1.2 to 2.2 mm. The granules of zeolite were modified with the following NaOH solutions: ).5, 1, 2 and 4 mol.l -1 at 80 grad C for 4 hours. The sorption of Fe, Cr and Cd ions on all types of zeolites was studied by radio-exchange method and the sorption of Fe and Cr also flame atomic absorption method. From sorption curves the sorption coefficients were calculated. The results obtained in this work show that zeolites modified with NaOH solution are suitable for adsorption of Fe(III), Cr(III) and Cd(II) from underwater, waste water, feed water and coolant water from nuclear plants. The adsorbed zeolites can be solidified by conventional way

  14. Solid phase extraction-inductively coupled plasma spectrometry for adsorption of Co(II) and Ni(II) from radioactive wastewaters by natural and modified zeolites

    International Nuclear Information System (INIS)

    Akbar Malekpour; Mohammad Edrisi; Shamsollah Shirzadi; Saeed Hajialigol

    2011-01-01

    Natural and modified clinoptilolite as low-cost adsorbents have been used for adsorption of Co(II) and Ni(II) from nuclear wastewaters both in batch and continuous experiments. Zeolite X was also synthesized and its ability towards the selected cations was examined. Kinetic and thermodynamic behaviors for the process were investigated and adsorption equilibrium was interpreted in term of Langmuir and Freundlich equations. The effect of various parameters including the initial concentration, temperature, ionic strength and pH of solution were examined to achieve the optimized conditions. The clinoptilolite was shown good sorption potential for Co(II) and Ni(II) ions at pH values 4-6. Based on desorption studies, nearly 74 and 85% of adsorbed Co(II) and Ni(II) were removed from clinoptilolite by HCl. The Na + and NH 4 + forms of clinoptilolite were the best modified forms for the removal of investigated cations. It is concluded that the selectivity of clinoptilolite is higher for Co(II) than Ni(II). The synthesized zeolite showed more ability to remove cobalt and nickel ions from aqueous solution than the natural clinoptilolite. The microwave irradiation was found to be more rapid and effective for ion exchange compared to conventional ion exchange process. (author)

  15. Simultaneous sorption of fluoride and arsenic ions (V) in a naturally occurring material modified with iron and aluminum; Sorcion simultanea de iones fluoruros y arsenico (V) en un material de origen natural modificado con hierro y aluminio

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez M, G.

    2016-07-01

    In this research, two materials, zeolite and pozzolans from the States of Oaxaca and Mexico, were used respectively, which were modified to evaluate their efficiencies to remove F and As(V) ions from solution and natural water. The materials were modified with iron and aluminum using an electrochemical cell, and with the hydroxides formed with iron and aluminum chloride solutions. The natural and modified materials were characterized by X-ray diffraction, scanning electron microscopy with energy X-ray disperse spectroscopy analysis, specific area and the point of zero charge (pHzpc). F- and As(V) adsorption properties of both materials were investigated. Experimental data on the sorption processes of F- ions by modified zeolite and pozzolans were adjusted to the kinetic models of pseudo-second-order (q e, 0408 mg /g K, 4.33 g / mg h) and Lagergen (q e, 0.807 mg/g K L, 1.83 1/min), respectively. Both materials showed the best fit to the Freundlich isotherm, Kf, 0.33 and 0.64 (mg/g) (L/mg) for pozzolans and zeolite respectively; suggesting a physical adsorption process on a heterogeneous material. Experimental adsorption capacities of pozzolans and modified zeolite for F ions were 0.36 and 0.83 mg/g respectively. The results of the kinetics of adsorption of As(V) were treated with the Largergren, pseudo-second-order and Elovich models; however the adsorption rate was high and consequently the rate constants could not be calculated. The isotherms data were fitted to the Freundlich model and the constants Kf were 6.24 and 11.15 (mg/g) (L/mg) for pozzolans and zeolite respectively. The thermodynamic parameters of the adsorption processes suggest endothermic adsorption for F- ions by both materials and for As(V) by the pozzolans. The free energy values ΔG indicate spontaneous processes and not spontaneous for F- ions by pozzolans. The adsorption of As (V) by the pozzolans presented an exothermic and spontaneous behavior. Finally, a study was performed in columns with

  16. Alexandria's Eastern Harbor, Egypt: Pollen, microscopic charcoal, and the transition from natural to human-modified basin

    Science.gov (United States)

    Stanley, J.-D.; Bernhardt, C.E.

    2010-01-01

    Pollen and microscopic charcoal examined in Holocene sediment core samples record major environmental modifications affecting Alexandria's Eastern Harbor through time. We assess whether such changes on Egypt's coastal margin were influenced primarily by natural, or natural plus human, or primarily human factors. We focus on (1) the times when pollen assemblages and microscopic charcoal content changed in the core, (2) how they changed, and (3) why this occurred. The analysis takes into account the core's stratigraphy, regional climate variability, human history, and local archaeological record. Four pollenmicroscopic charcoal zones are identified. The earliest change occurred at ca. 6000 YBP, during Egypt's earlier Predynastic (Neolithic) period, coinciding with a lithologic break from sand to muddy sand. Pollen during this time indicates a transition to a much drier climate rather than effects of human activity. The second change in pollen occurred 3600-2900 YBP, during a period of continued aridity with no lithologic variation in this core interval. Pollen (cereal taxa, agricultural weeds, grape) and a sharp increase in microscopic charcoal indicate that human activity became prevalent at least 700 y before Alexander the Great's arrival in this region, and these results highlight the transition from a largely natural climatecontrolled environment to one influenced by both climate and anthropogenic activity. The third shift up-core in pollen assemblages is dated at ca. 2300 YBP, at the boundary between a sand and mud unit. It coincides with construction by the Ptolemies of the Heptastadion between Alexandria and Pharos Island. From this time onward, harbor sediment in the nearly enclosed catchment basin indicates a near-continuous record of dominant proximal human activity. ?? 2010 Coastal Education and Research Foundation.

  17. Naturally occurring mutations in the human 5-lipoxygenase gene promoter that modify transcription factor binding and reporter gene transcription.

    Science.gov (United States)

    In, K H; Asano, K; Beier, D; Grobholz, J; Finn, P W; Silverman, E K; Silverman, E S; Collins, T; Fischer, A R; Keith, T P; Serino, K; Kim, S W; De Sanctis, G T; Yandava, C; Pillari, A; Rubin, P; Kemp, J; Israel, E; Busse, W; Ledford, D; Murray, J J; Segal, A; Tinkleman, D; Drazen, J M

    1997-03-01

    Five lipoxygenase (5-LO) is the first committed enzyme in the metabolic pathway leading to the synthesis of the leukotrienes. We examined genomic DNA isolated from 25 normal subjects and 31 patients with asthma (6 of whom had aspirin-sensitive asthma) for mutations in the known transcription factor binding regions and the protein encoding region of the 5-LO gene. A family of mutations in the G + C-rich transcription factor binding region was identified consisting of the deletion of one, deletion of two, or addition of one zinc finger (Sp1/Egr-1) binding sites in the region 176 to 147 bp upstream from the ATG translation start site where there are normally 5 Sp1 binding motifs in tandem. Reporter gene activity directed by any of the mutant forms of the transcription factor binding region was significantly (P < 0.05) less effective than the activity driven by the wild type transcription factor binding region. Electrophoretic mobility shift assays (EMSAs) demonstrated the capacity of wild type and mutant transcription factor binding regions to bind nuclear extracts from human umbilical vein endothelial cells (HUVECs). These data are consistent with a family of mutations in the 5-LO gene that can modify reporter gene transcription possibly through differences in Sp1 and Egr-1 transactivation.

  18. Crosslinkable mixed matrix membranes with surface modified molecular sieves for natural gas purification: II. Performance characterization under contaminated feed conditions

    KAUST Repository

    Ward, Jason K.

    2011-07-01

    Mixed matrix membranes (MMMs) composed of the crosslinkable polyimide PDMC and surface modified (SM) SSZ-13 have recently been shown to enhance carbon dioxide permeability and carbon dioxide/methane selectivity versus neat PDMC films by as much as 47% and 13%, respectively (Part I). The previous film characterization, however, was performed using ideal, clean mixed gas feeds. In this paper, PDMC/SSZ-13 MMMs are further characterized using more realistic mixed gases containing low concentrations (500 or 1000. ppm) of toluene as a model contaminant. Mixed matrix membranes are shown to outperform pure PDMC films in the presence of toluene with 43% greater carbon dioxide permeability and 12% greater carbon dioxide/selectivity at 35 °C and 700 psia feed pressure. These results suggest that MMMs-in addition to exhibiting enhanced transport properties-may mitigate performance degradation due to antiplasticization effects. Moreover, the analyses presented here show that the reduction in separation performance by trace contaminant-accelerated physical aging can be suppressed greatly with MMMs. © 2011 Elsevier B.V.

  19. Crosslinkable mixed matrix membranes with surface modified molecular sieves for natural gas purification: I. Preparation and experimental results

    KAUST Repository

    Ward, Jason K.

    2011-07-01

    Dense film mixed matrix membranes (MMMs) comprised of SSZ-13 dispersed in a crosslinkable polyimide (PDMC) were fabricated and evaluated for carbon dioxide/methane separations. MMMs containing 25% (w/w) as-received (AR) SSZ-13 exhibited a carbon dioxide permeability of 153 Barrers with a carbon dioxide/methane ideal selectivity of 34.7 at 65. psia and 35 °C. This represents a permeability enhancement of 129% and a decline in selectivity of 4.7% over neat PDMC (PCO2=66.9 Barrers, αCO2/CH4=36.4). A sieve surface modification procedure was developed with the aim of improving SSZ-13/PDMC MMM transport properties. MMMs containing 25% (w/w) surface modified (SM) SSZ-13 exhibited a carbon dioxide permeability of 148 Barrers and carbon dioxide/methane selectivity of 38.9 at 65. psia and 35 °C, representing enhancements in both permeability and selectivity of 121% and 6.9%, respectively. Mixed gas permeation analyses of MMMs containing SM-SSZ-13 using a 10% carbon dioxide/90% methane mixture shows that permeability and selectivity enhancements of 47% and 13%, respectively, over neat PDMC are possible at 700. psia and 35 °C. © 2011 Elsevier B.V.

  20. Penicillamine-modified sensor for the voltammetric determination of Cd(II) and Pb(II) ions in natural samples.

    Science.gov (United States)

    Pérez-Ràfols, Clara; Serrano, Núria; Díaz-Cruz, José Manuel; Ariño, Cristina; Esteban, Miquel

    2015-11-01

    A new penicillamine-GCE was developed based on the immobilization of d-penicillamine on aryl diazonium salt monolayers anchored to the glassy carbon electrode (GCE) surface and it was applied for the first time to the simultaneous determination of Cd(II) and Pb(II) ions by stripping voltammetric techniques. The detection and quantification limits at levels of µg L(-1) suggest that the penicillamine-GCE could be fully suitable for the determination of the considered ions in natural samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. natural

    Directory of Open Access Journals (Sweden)

    Elías Gómez Macías

    2006-01-01

    Full Text Available Partiendo de óxido de magnesio comercial se preparó una suspensión acuosa, la cual se secó y calcinó para conferirle estabilidad térmica. El material, tanto fresco como usado, se caracterizó mediante DRX, área superficial BET y SEM-EPMA. El catalizador mostró una matriz de MgO tipo periclasa con CaO en la superficie. Las pruebas de actividad catalítica se efectuaron en lecho fijo empacado con partículas obtenidas mediante prensado, trituración y clasificación del material. El flujo de reactivos consistió en mezclas gas natural-aire por debajo del límite inferior de inflamabilidad. Para diferentes flujos y temperaturas de entrada de la mezcla reactiva, se midieron las concentraciones de CH4, CO2 y CO en los gases de combustión con un analizador de gases tipo infrarrojo no dispersivo (NDIR. Para alcanzar conversión total de metano se requirió aumentar la temperatura de entrada al lecho a medida que se incrementó el flujo de gases reaccionantes. Los resultados obtenidos permiten desarrollar un sistema de combustión catalítica de bajo costo con un material térmicamente estable, que promueva la alta eficiencia en la combustión de gas natural y elimine los problemas de estabilidad, seguridad y de impacto ambiental negativo inherentes a los procesos de combustión térmica convencional.

  2. A modified Seeded Region Growing algorithm for vessel segmentation in breast MRI images for investigating the nature of potential lesions

    Science.gov (United States)

    Glotsos, D.; Vassiou, K.; Kostopoulos, S.; Lavdas, El; Kalatzis, I.; Asvestas, P.; Arvanitis, D. L.; Fezoulidis, I. V.; Cavouras, D.

    2014-03-01

    The role of Magnetic Resonance Imaging (MRI) as an alternative protocol for screening of breast cancer has been intensively investigated during the past decade. Preliminary research results have indicated that gadolinium-agent administrative MRI scans may reveal the nature of breast lesions by analyzing the contrast-agent's uptake time. In this study, we attempt to deduce the same conclusion, however, from a different perspective by investigating, using image processing, the vascular network of the breast at two different time intervals following the administration of gadolinium. Twenty cases obtained from a 3.0-T MRI system (SIGNA HDx; GE Healthcare) were included in the study. A new modification of the Seeded Region Growing (SRG) algorithm was used to segment vessels from surrounding background. Delineated vessels were investigated by means of their topology, morphology and texture. Results have shown that it is possible to estimate the nature of the lesions with approximately 94.4% accuracy, thus, it may be claimed that the breast vascular network does encodes useful, patterned, information, which can be used for characterizing breast lesions.

  3. Tensile and morphology properties of PLA/LNR blends modified with maleic anhydride grafted-polylactic acid and -natural rubber

    Science.gov (United States)

    Ruf, Mohd Farid Hakim Mohd; Ahmad, Sahrim; Chen, Ruey Shan; Shahdan, Dalila; Zailan, Farrah Diyana

    2018-04-01

    This research was carried out to investigate the addition of grafted copolymers of maleic anhydride grafted-polylactic acid(PLA-g-MA) and maleic anhydride grafted-natural rubber (NR-g-MA) on the tensile and morphology properties of polylactic acid/ liquid natural rubber (PLA/LNR) blends. Prior to blend preparation, the PLA-g-MA and NR-g-MA was first self-synthesized using maleic anhydride (MA) and dicumyl peroxide (DCP) as initiator together with the PLA and NR respectively. The PLA/LNR, PLA/LNR/PLA-g-MA and PLA/LNR/NR-g-MA blends were prepared via melt-blending method. The loading of PLA-g-MA and NR-g-MA was varied by 5, 10 and 15 wt% respectively. The addition of PLA-g-MA led to increment in tensile strength with 5 and 10 wt% while NR-g-MA gives lower than controlled sample (PLA/LNR blend). Scanning electron microscope (SEM) showed the interaction of the components in the blends. The PLA/LNR compatibilized with PLA-g-MA and NR-g-MA shows greater dispersion and adhesion.

  4. Biological effects of several extreme space flight factors (acceleration, magnetically activated water) on mouse natural or modified radiosensitivity

    International Nuclear Information System (INIS)

    Datsov, E.R.

    1979-01-01

    Irradiated and Adeturon-protected mice were used to assess biological effects of several static (magnetically-activated water - MW) and dynamic (acceleration) factors of space flight. The study shows that increased gravitation, 20 G, 5 min, generated by a small radius centrifuge, increases static ability to work, while the number of peripheral blood cells decreases. Continuous exposure of mice to MW induces a decrease in dynamic ability to work, in comparison with the physiological controls, without substantial changes in other indices. Extreme factors in space flight (acceleration MW, radiation, radiation protector), alone or in combination, decrease the animal's growth rate. After administration of 200 mg/kg Adeturone, mouse dynamic ability to work increases, while its capabilities for adaptation and training are lowered, and pronounced leucocytosis is observed. MW, acceleration, or Adeturone pre-treatment of mice increases their survival and dynamic ability to work, following exposure to 600 R, when compared to irradiated animals, but decreases their capabilities for adaptation and training. Acceleration and Adeturone protect peripheral blood from radiation injury, while MW alone intensifies radiation cytopenia. Irradiation does not significantly modify the static ability to work, upon preceding exposure to MW or acceleration. In this case, Adeturone exerts protective effect. ME and Adeturone combined action results in increased survival rate and mean duration of life of irradiated animals, as compared to their single administration. Acceleration reduces MW, Adeturone and MW + Adeturone effect on survival. Peripheral blood parameters do not correlate with survival rates. Combined pre-treatment with two or three of the factors studied increases dynamic ability to work following irradiation, and in many cases the static ability as well. The combination of Adeturone and MW was the only one with negative effect on the static ability to work. (A.B.)

  5. Radiation processing of indigenous natural polymers. Properties of radiation modified blends from sago-starch for biodegradable composite

    International Nuclear Information System (INIS)

    Ghazali, Z.; Dahlan, K.Z.; Wongsuban, B.; Idris, S.; Muhammad, K.

    2001-01-01

    Research and development on biodegradable polymer blends and composites have gained wider interest to offer alternative eco-friendly products. Natural polysaccharide such as sago-starch offers the most promising raw material for the production of biodegradable composites. The potential of sago, which is so abundant in Malaysia, to produce blends for subsequent applications in composite material, was evaluated and explored. Blends with various formulations of sago starch and polyvinyl alcohol (PVA), and polyvinyl pyrrolidone (PVP) polymers were prepared and subjected to radiation modification using electron beam irradiation. The effect of irradiation on the sago and its blends was evaluated and their properties were characterized. The potential of producing composite from sago blends was explored. Foams from these blends were produced using microwave oven while films were produced through casting method. The properties such as mechanical, water absorption, expansion ratio, and biodegradability were characterized and reported in this paper. (author)

  6. Radiation processing of indigenous natural polymers. Properties of radiation modified blends from sago-starch for biodegradable composite

    Energy Technology Data Exchange (ETDEWEB)

    Ghazali, Z.; Dahlan, K.Z. [Malaysian Institute for Nuclear and Technology Research (MINT), Bangi, Kajang (Malaysia); Wongsuban, B.; Idris, S.; Muhammad, K. [Universiti Putra Malaysia, Faculty of Food Science and Biotechnology, Department of Food Science, Serdang (Malaysia)

    2001-03-01

    Research and development on biodegradable polymer blends and composites have gained wider interest to offer alternative eco-friendly products. Natural polysaccharide such as sago-starch offers the most promising raw material for the production of biodegradable composites. The potential of sago, which is so abundant in Malaysia, to produce blends for subsequent applications in composite material, was evaluated and explored. Blends with various formulations of sago starch and polyvinyl alcohol (PVA), and polyvinyl pyrrolidone (PVP) polymers were prepared and subjected to radiation modification using electron beam irradiation. The effect of irradiation on the sago and its blends was evaluated and their properties were characterized. The potential of producing composite from sago blends was explored. Foams from these blends were produced using microwave oven while films were produced through casting method. The properties such as mechanical, water absorption, expansion ratio, and biodegradability were characterized and reported in this paper. (author)

  7. Naturally-occurring changes in social-cognitive factors modify change in physical activity during early adolescence.

    Directory of Open Access Journals (Sweden)

    Rod K Dishman

    Full Text Available To determine whether naturally-occurring changes in children's motives and beliefs are associated with the steep decline in physical activity observed from childhood to early adolescence.Latent growth modeling was applied in longitudinal tests of social-cognitive influences, and their interactions, on physical activity in a large cohort of boys and girls evaluated annually between 5th and 7th grades.Measurement equivalence of motives and beliefs was confirmed between boys and girls. After adjustment for gender and maturity differences, physical activity declined less in children who reported the least decreases in self-efficacy for overcoming barriers to activity and perceived parental support. Physical activity also declined less in students who persistently felt they had more parental and friend support for activity compared to those who reported the largest decrease in support from friends. After further adjustment for race, the decline in physical activity was less in those who had the largest decrease in perceived barriers and maintained a favorable perception of their neighborhood environment. Changes in enjoyment and social motives were unrelated to change in physical activity.Using an objective measure of physical activity, we confirm that naturally-occurring changes in children's beliefs about barriers to physical activity and their ability to overcome them, as well as perceptions of their neighborhood environment and social support, are concurrent with age-related declines in children's physical activity. The longitudinal findings confirm these putative social-cognitive mediators as plausible, interacting targets of interventions designed to mitigate the marked decline in physical activity that occurs during the transition between elementary and middle schools.

  8. Development of Ocular Delivery System for Glaucoma Therapy Using Natural Hydrogel as Film Forming Agent and Release Modifier.

    Science.gov (United States)

    Kulkarni, Giriraj T; Sethi, Nitin; Awasthi, Rajendra; Pawar, Vivek Kumar; Pahuja, Vineet

    2016-01-01

    Glaucoma is characterized by increased intraocular pressure, which results in damage to the optic nerve. The existing therapy with conventional eye drops is inefficient due to nasolachrymal drainage, resulting in a reduced corneal residence of the drug. The objective was to develop controlled-release ocular films of timolol maleate using natural hydrogel from Tamarindus indica seeds as a sustaining and film-forming agent, to overcome the problems associated with eye drops. The hydrogel was isolated using hot aqueous extraction followed by precipitation with ethanol. Six batches of ocular films were prepared and evaluated for drug content, weight variation, thickness, diameter and in vitro release profile. The ideal batch of the films was subjected to stability, pharmacodynamic and ocular safety studies. The yield of the hydrogel was 58.29%. The thickness of the ocular films was in the range of 0.17 to 0.25 mm and the weight of the films was found to increase with the increase in polymer content. The drug release from the films was found to be controlled over a period of 8 h. The films were found to be stable and were able to reduce the intraocular pressure for 24 h in a more efficient manner than the eye drops. The films were found to be practically non-irritating to the eye. It can be concluded that the hydrogel from tamarind seeds can be used as a film-forming and release-controlling agent for the development of an ocular drug delivery system for the effective therapy of glaucoma.

  9. Comparison of the performance of different modified graphene oxide nanosheets for the extraction of Pb(II) and Cd(II) from natural samples

    International Nuclear Information System (INIS)

    Sayar, Omid; Mehrani, Kheirollah; Mehrani, Azadeh; Hoseinzadeh, Fatemeh; Sadeghi, Omid

    2014-01-01

    Graphene nanosheets were modified with amino groups and the resulting material was used as a sorbent for the extraction of cadmium and lead ions. The nanosheets were characterized by IR spectroscopy, transmission electron microscopy, thermal gravimetric analysis and elemental analysis. The effects of sample pH, eluent parameters (type, concentration and volume of eluent), flow rates (of both sample and eluent), and of a variety of other ions on the efficiency of the extraction of Cd(II) and Pb(II) were optimized. Following solid phase extraction, the elements were determined by FAAS. The limits of detection are <0.9 μg L −1 for Pb(II) and <5 ng L −1 for Cd(II). The relative standard deviations are <2.2 %. The method was validated by analyzing several certified reference materials and was then used for Pb(II) and Cd(II) determination in natural waters and vegetables. (author)

  10. Ribosomally Synthesized and Post-translationally Modified Peptide Natural Products: New Insights Into the Role of Leader and Core Peptides During Biosynthesis

    Science.gov (United States)

    Yang, Xiao; van der Donk, Wilfred A.

    2013-01-01

    Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a major class of natural products with a high degree of structural diversity and a wide variety of bioactivities. Understanding the biosynthetic machinery of these RiPPs will benefit the discovery and development of new molecules with potential pharmaceutical applications. In this review, we discuss the features of the biosynthetic pathways to different RiPP classes, and propose mechanisms regarding recognition of the precursor peptide by the posttranslational modification enzymes. We propose that the leader peptides function as allosteric regulators that bind the active form of the biosynthetic enzymes in a conformational selection process. We also speculate how enzymes that generate polycyclic products of defined topologies may have been selected for during evolution. PMID:23666908

  11. Characterization of modified clinoptilolite

    International Nuclear Information System (INIS)

    Novosad, J.; Jandl, J.; Woollins, J.D.

    1992-01-01

    Samples of clinoptilolite were modified using insoluble hexacyanoferrate from aqueous solution. The modified samples were characterized by elemental analysis, powder X-ray diffraction, solid state NMR and vibrational spectroscopy. The sorption properties of modified clinoptilolite were studied, too. Higher affinity for 137 Cs sorption in comparison with the natural clinoptilolite has been proved. (author) 5 refs.; 3 figs.; 2 tabs

  12. Removal of antibiotics from water in the coexistence of suspended particles and natural organic matters using amino-acid-modified-chitosan flocculants: A combined experimental and theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Shuying [School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023 (China); Yang, Zhen, E-mail: yangzhen@njnu.edu.cn [School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023 (China); Ren, Kexin [School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023 (China); Tian, Ziqi [Department of Chemistry, University of California, Riverside, CA 92521 (United States); Dong, Chang; Ma, Ruixue; Yu, Ge [School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023 (China); Yang, Weiben, E-mail: yangwb007@njnu.edu.cn [School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023 (China)

    2016-11-05

    Highlights: • Novel amino-acid-modified-chitosan flocculants are employed to remove antibiotics. • Effects of different structures of amino acids and antibiotics are investigated. • Correlation analysis shows coexisted kaolin and HA have synergistic removal effect. • Theoretical DFT calculation clarifies the interactions in molecular level. - Abstract: Contamination of trace antibiotics is widely found in surface water sources. This work delineates removal of trace antibiotics (norfloxacin (NOR), sulfadiazine (SDZ) or tylosin (TYL)) from synthetic surface water by flocculation, in the coexistence of inorganic suspended particles (kaolin) and natural organic matter (humic acid, HA). To avoid extra pollution caused by petrochemical products-based modification reagents, environmental-friendly amino-acid-modified-chitosan flocculants, Ctrp and Ctyr, with different functional aromatic-rings structures were employed. Jar tests at various pHs exhibited that, Ctyr, owning phenol groups as electron donors, was favored for elimination of cationic NOR (∼50% removal; optimal pH: 6; optimal dosage: 4 mg/L) and TYL (∼60% removal; optimal pH: 7; optimal dosage: 7.5 mg/L), due to π–π electron donator-acceptor (EDA) effect and unconventional H-bonds. Differently, Ctrp with indole groups as electron acceptor had better removal rate (∼50%) of SDZ anions (electron donator). According to correlation analysis, the coexisted kaolin and HA played positive roles in antibiotics’ removal. Detailed pairwise interactions in molecular level among different components were clarified by spectral analysis and theoretical calculations (density functional theory), which are important for both the structural design of new flocculants aiming at targeted contaminants and understanding the environmental behaviors of antibiotics in water.

  13. Removal of antibiotics from water in the coexistence of suspended particles and natural organic matters using amino-acid-modified-chitosan flocculants: A combined experimental and theoretical study

    International Nuclear Information System (INIS)

    Jia, Shuying; Yang, Zhen; Ren, Kexin; Tian, Ziqi; Dong, Chang; Ma, Ruixue; Yu, Ge; Yang, Weiben

    2016-01-01

    Highlights: • Novel amino-acid-modified-chitosan flocculants are employed to remove antibiotics. • Effects of different structures of amino acids and antibiotics are investigated. • Correlation analysis shows coexisted kaolin and HA have synergistic removal effect. • Theoretical DFT calculation clarifies the interactions in molecular level. - Abstract: Contamination of trace antibiotics is widely found in surface water sources. This work delineates removal of trace antibiotics (norfloxacin (NOR), sulfadiazine (SDZ) or tylosin (TYL)) from synthetic surface water by flocculation, in the coexistence of inorganic suspended particles (kaolin) and natural organic matter (humic acid, HA). To avoid extra pollution caused by petrochemical products-based modification reagents, environmental-friendly amino-acid-modified-chitosan flocculants, Ctrp and Ctyr, with different functional aromatic-rings structures were employed. Jar tests at various pHs exhibited that, Ctyr, owning phenol groups as electron donors, was favored for elimination of cationic NOR (∼50% removal; optimal pH: 6; optimal dosage: 4 mg/L) and TYL (∼60% removal; optimal pH: 7; optimal dosage: 7.5 mg/L), due to π–π electron donator-acceptor (EDA) effect and unconventional H-bonds. Differently, Ctrp with indole groups as electron acceptor had better removal rate (∼50%) of SDZ anions (electron donator). According to correlation analysis, the coexisted kaolin and HA played positive roles in antibiotics’ removal. Detailed pairwise interactions in molecular level among different components were clarified by spectral analysis and theoretical calculations (density functional theory), which are important for both the structural design of new flocculants aiming at targeted contaminants and understanding the environmental behaviors of antibiotics in water.

  14. Comparison of greenhouse and 32P isotopic laboratory methods for evaluating the agronomic effectiveness of natural and modified rock phosphates in some acid soils of Ghana

    International Nuclear Information System (INIS)

    Owusu-Bennoah, E.; Zapata, F.; Fardeau, J.C.

    2002-01-01

    Phosphorus deficiency is one of the major constraints for normal plant growth and crop yields in the acid soils of Ghana and therefore addition of P inputs is required for sustainable crop production. This is often difficult, if not impossible for small-scale farmers due to the high cost of mineral P fertilizers and limited access to fertilizer supplies. Direct application of finely ground phosphate rocks (PRs) and their modified forms have been recommended as alternatives for P fertilization. The direct application of the natural and modified PRs to these acid soils implies the need to predict their agronomic effectiveness of the PRs in the simplest and most cost-effective manner. In this study the classical greenhouse pot experiment was compared to the 32 P isotopic kinetics laboratory method for evaluating the agronomic effectiveness of natural and modified Togo PR in six highly weathered Oxisols from southwest Ghana. In the 32 P isotopic kinetics laboratory experiment the six soil samples were each fertilised at the rate of 50 mg P kg -1 soil in the form of triple superphosphate (TSP), Togo PAPR-50%, and Togo PR, respectively. Controls without P amendment were also included. Isotopic exchange kinetics experiments were carried out on two sets of samples, immediately after P fertilizer additions (without incubation) and after 6 weeks of incubation under wet conditions and at a room temperature of 25 deg C. In the greenhouse pot experiment, P fertilizers in the form of Togo PR, Togo PAPR, Mali PR and TSP were each applied to the six soils at rates equivalent to 0, 30, 60, and 120 kg P ha -1 , respectively. The P fertilizers were mixed with the soils and maize (Zea mays L.) variety Obatanpa was grown for 42 days before harvest. The isotopic kinetics data of the control samples indicated that 5 of the studied soils had very low P fertility status as reflected by their low P concentrations in solution (C P -1 ) and low exchangeable P (E 1 min -1 ). The capacity

  15. The role of natural zeolite and of zeolite modified with ammnonium ions to reduce the uptake of lead, zinc, copper and iron ions in Hieracium aurantium and Rumex acetosella grown on tailing ponds

    Directory of Open Access Journals (Sweden)

    Anca PETER

    2011-11-01

    Full Text Available The objective of this research is to determine if zeolite modified with ammonium ions has a higher capacity than natural zeolite to protect Hieracium aurantium and Rumex acetosella growing on tailing ponds, by reducing the quantity of metal ions these plants would accumulate in their roots and leaves. The influence of the amount of zeolite in the substrate (5% and 10% mass percentage was also studied. The experiments were carried out in laboratory and the concentration of the ions of heavy metal in roots and leaves, after 38 days of growth was established by Flame Atomic Adsorption Spectroscopy. The pH, conductivity and redox potential for each of the substrate considered were measured. The results were statistically processed using the one-way analysis of variance (one-way ANOVA. FTIR analyses were performed to establish the structural differences between the natural and modified zeolite. Hieracium aurantium and Rumex acetosella accumulate a smaller quantity of metal ions in roots and leaves in the presence of zeolite modified with ammonium ions than in the presence of natural zeolite. Laboratory tests showed that Hieracium aurantium is more tolerant to ions of heavy metals than Rumex acetosella, as demonstrated by their translocation factors.In terms of reducing the uptake of ions of heavy metals, only the zeolite modified with ammonium has a significant protective effecton Hieracium aurantium, while both natural zeolite and zeolite modified demonstrate a significant role for Rumex acetosella, asrevealed by statistical tests.

  16. Preparation, characterization and application of superparamagnetic iron oxide nanoparticles modified with natural polymers for removal of {sup 60}Co-radionuclides from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Sharaf El-Deen, Gehan E. [Atomic Energy Authority, Cairo (Egypt). Radioactive Waste Management Dept.; Imam, Neama G. [Atomic Energy Authority, Cairo (Egypt). Experimental Physics Dept.; Elettra, Sincrotrone, Trieste (Italy); Ayoub, Refaat R. [Atomic Energy Authority, Cairo (Egypt). Nuclear Chemistry Dept.

    2017-04-01

    Superparamagnetic iron oxide nanoparticles (IO-MNPs) coated with natural polymers, starch (IO-S MNPs) and dextrin (IO-D MNPs), were synthesized by modified co-precipitation method. IO and hybrid-IO-MNPs were characterized by XRD, SEM, HRTEM, FT-IR spectroscopy, vibrating sample magnetometer (VSM) and zeta potential (ZP). IO-S MNPs and IO-D MNPs have IO core-shell structure with core of 10.8 nm and 13.8 nm and shell of 7.5 nm and 5.9 nm, respectively. The efficiency of the hybrid IO-MNPs for sorption of {sup 60}Co(II)-radionuclides from aqueous solution was investigated under varying experimental conditions. Kinetic data were described well by pseudo-second-order mode, sorption isotherms were fitted quite with Freundlich model with maximum adsorption capacity 36.89 (mmol.g{sup -1})/(L.mmol{sup -1}){sup n} for IO-S MNPs and 24.9 (mmol.g{sup -1})/(L.mmol{sup -1}){sup n} for IO-D MNPs. Sorption of {sup 60}Co-radionuclides by IO-S MNPs was suppressed with salinity and most of the adsorbed {sup 60}Co onto IO-S MNPs could be remove with 0.1 M HCl solution. IO-S MNPs exhibits superparamagnetic properties, easier separation according to higher saturation magnetization (47 emu/g) and better adsorption for {sup 60}CO-radionuclides than IO-D MNPs.

  17. Experimental designs applied to desorption of dichromate ions after separation and preconcentration from natural and industrial water by modified Nano-Alumina

    Energy Technology Data Exchange (ETDEWEB)

    Sayar, Omid [Department of Chemical Engineering, Islamic Azad University, Tehran (Iran, Islamic Republic of); Abadi, Iman Jabbari Zahir [Department of Pharmacology and Toxicology, Tehran Medical Unit, Islamic Azad University, Tehran (Iran, Islamic Republic of); Sadeghi, Omid; Zhad, Hamid Reza Lotfi Zadeh; Tavassoli, Najmeh [Department of Chemistry, Islamic Azad University, Shahr-e-Rey Branch, Tehran (Iran, Islamic Republic of)

    2012-03-15

    Nano-alumina modified by 9-aminoacridine was used as a sorbent for separation and determination of dichromate ions from water. Statistical method, based on surface response design, has been used for the optimization of dichromate ions elution from 9-aminoacridine nano-alumina. The adsorbed dichromate ions were found to be eluted quantitatively with 0.8 mol L{sup -1} KCl in 1.6 mol L{sup -1} NaOH which optimized by response surface design. Under optimum conditions, the accuracy, precision (relative standard deviation, RSD%) and R-square of the method were calculated as >98, <3, and >94%, respectively. Remarkable agreement between experimental and theoretical data was confirmed the predicted assumption. The method was applied to the simultaneous determination of dichromate in natural and industrial water samples. We also examined the retention of dichromate anions in the presence of Cl{sup -}, NO{sub 3}{sup -}, and SO{sub 4}{sup 2-} anions at pH 3. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Study on the structure-properties relationship of natural rubber/SiO2 composites modified by a novel multi-functional rubber agent

    Directory of Open Access Journals (Sweden)

    S. Y. Yang

    2014-06-01

    Full Text Available Vulcanization property and structure-properties relationship of natural rubber (NR/silica (SiO2 composites modified by a novel multi-functional rubber agent, N-phenyl- N'-(γ-triethoxysilane-propyl thiourea (STU, are investigated in detail. Results from the infrared spectroscopy (IR and X-ray photoelectron spectroscopy (XPS show that STU can graft to the surface of SiO2 under heating, resulting in a fine-dispersed structure in the rubber matrix without the connectivity of SiO2 particles as revealed by transmission electron microscopy (TEM. This modification effect reduces the block vulcanization effect of SiO2 for NR/SiO2/STU compounds under vulcanization process evidently. The 400% modulus and tensile strength of NR/SiO2/STU composites are much higher than that of NR/SiO2/TU composites, although the crystal index at the stretching ratio of 4 and crosslinking densities of NR/SiO2 composites are almost the same at the same dosage of SiO2. Consequently, a structure-property relationship of NR/SiO2/STU composites is proposed that the silane chain of STU can entangle with NR molecular chains to form an interfacial region, which is in accordance with the experimental observations quite well.

  19. A Successful Pregnancy by Utilization of Gradually Increasing Low Dose Gonadotrophin Stimulation in a Modified Natural Cycle in Vitro Fertilization Procedure: Case Report

    Directory of Open Access Journals (Sweden)

    Serkan Kahyaoğlu

    2016-05-01

    Full Text Available The modified natural cycle in vitro fertilization (MNC-IVF treatment can be a promising method for poor responder patients especially in young patients with poor ovarian reserve. A 34-year-old primary infertile woman presented with a history of poor ovarian response and cycle cancellation following controlled ovarian hyperstimulation during an IVF-ET procedure two months ago. During MNC-IVF treatment with intracytoplasmic sperm injection (ICSI, gradually increasing doses of hMG for three days (totally 675 IU have been administered accompanied by daily 0,25 mg cetrorelix. Following ovulation triggering, one oocyte was picked up and a good quality (grade 1 embryo was transferred on day 2. A clinical pregnancy was established with ultrasonography on sixth weeks of gestation. Acceptable pregnancy rates per embryo transfer, low medication cost, relatively low risk of complications and higher patient acceptability are the main advantages of MNC-IVF treatment as a feasible treatment option especially for poor responder patients.

  20. Preparation and characterization of PbTi0{sub 3} ceramics modified by a natural mixture of rare earth oxides of xenotime

    Energy Technology Data Exchange (ETDEWEB)

    Baltazar-Rodrigues, Jair; Rodrigues Junior, Pedro; Cruz, Gerson K. da, E-mail: jbr@uepg.br [Universidade Estadual de Ponta Grossa (UEPG), PR (Brazil). Departamento de Fisica; Lente, Manuel H.; Eiras, Jose A. [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Fisica

    2014-01-15

    Lead titanate ceramics modified by xenotime (Xm) with nominal composition (Pb, Xm)TiO{sub 3}, Xm 10 or 15 mol %, were prepared by the conventional oxide mixture technique. Xenotime is a natural mineral consisting of a mixture of rare earth oxides. Thermal, structural and electric properties were investigated through differential and gravimetric thermal analysis, X-ray diffraction and dielectric measurements as a function of temperature. The results of both compositions revealed a higher density and free of cracks ceramic body, compared to pure PbTiO{sub 3} prepared by the same procedure. On the other hand, the structural characteristics and Curie temperature are nearly the same as those of pure PbTiO{sub 3}. The hysteresis loop measured at room temperature revealed a hard ferroelectric material with coercive field of 10.7 kV/cm and a remanent polarization of 0.2 μC/cm{sup 2}. These finding reveal a material with properties that highlight potential to be used as electronic devices that operate at high temperature and high frequencies. (author)

  1. Designing and Producing Modified, New-to-Nature Peptides with Antimicrobial Activity by Use of a Combination of Various Lantibiotic Modification Enzymes

    NARCIS (Netherlands)

    van Heel, Auke J.; Mu, Dongdong; Montalban-Lopez, Manuel; Hendriks, Djoke; Kuipers, Oscar P.

    Lanthipeptides are peptides that contain several post-translationally modified amino acid residues and commonly show considerable antimicrobial activity. After translation, the amino acid residues of these peptides are modified by a distinct set of modification enzymes. This process results in

  2. Performance of natural and modified smectite: kinetic and thermodynamics involving arsenic (V adsorption Desempenho de esmectita natural e modificada: cinética e termodinâmica envolvendo adsorção de arsênio (V

    Directory of Open Access Journals (Sweden)

    D. L Guerra

    2010-03-01

    Full Text Available A natural smectite sample has been modified by organofunctionalization process using synthetic route involved the reaction of 2-mercaptopyrimidine with 3-chloropropyltriethoxysilane. The resulting material (S MPY was characterized by SEM, FTIR, textural analysis and 29Si MAS-NMR. The ability of this material to removed As (V from aqueous solution was followed by series of adsorption isotherms adjusted to the Langmuir equation at room temperature and pH 2.0. The kinetic parameters analyzed by Lagergren and Elovich models gave a good fit for a pseudo-second order reaction with k2 in the 4.9 to 14.0 mmol-1 min-1 range for S MPY. The adsorption process was exothermic (ΔintH = -4.09 to -5.79 kJ.mol-1 accompanied by increase in entropy (ΔintS = 41.29 to 61.80 JK-1.mol-1 and Gibbs energy (ΔintG = -22.34 to -24.19 kJmol-1. The energetic effect caused by arsenic cation adsorption was determined through calorimetric titration at the solid-liquid interface and gave a net thermal effect that enabled the calculation of the exothermic values and the equilibrium constant.Uma amostra de esmectita natural foi modificada por processo de organofuncionalização usando rota sintética, envolvendo a reação de 2-mercaptopirimidina com 3-cloropropiltrietoxisilano. O material resultante (S MPY foi caracterizado por microscopia eletrônica de varredura, espectroscopia de infravermelho com transformada de Fourier, análise textural e 29Si MAS-NMR. A habilidade deste material para remover As (V a partir de solução aquosa foi investigada por series de isotermas ajustadas pela equação de Langmuir em temperatura ambiente e pH 2,0. Os parâmetros cinéticos foram analisados por modelos de Lagergren e Elovich, em que um bom ajuste foi obtido para o modelo de reação de pseudo-segunda ordem com k2 em 4,9 para 14,0 mmol-1 min-1 para S MPY. O processo de adsorção foi exotérmico (ΔintH = -4,09 to -5,79 kJmol-1 acompanhado por aumento de entropia (ΔintS = 41,29 to 61

  3. Modified cyanobacteria

    Science.gov (United States)

    Vermaas, Willem F J.

    2014-06-17

    Disclosed is a modified photoautotrophic bacterium comprising genes of interest that are modified in terms of their expression and/or coding region sequence, wherein modification of the genes of interest increases production of a desired product in the bacterium relative to the amount of the desired product production in a photoautotrophic bacterium that is not modified with respect to the genes of interest.

  4. On the nature of gallium species in gallium-modified mordenite and MFI zeolites. A comparative DRIFT study of carbon monoxide adsorption and hydrogen dissociation.

    Science.gov (United States)

    Serykh, Alexander I; Kolesnikov, Stanislav P

    2011-04-21

    The results of a DRIFT study of carbon monoxide molecular adsorption and hydrogen dissociative adsorption on gallium-modified mordenite and MFI (ZSM-5) zeolites are presented. It was found that in the reduced gallium-modified mordenite (Ga-MOR) both Ga(3+) and Ga(+) exchanged cations are present and can be detected by CO adsorption. Ga(3+) cations in Ga-MOR dissociatively adsorb molecular hydrogen at elevated temperatures, resulting in the formation of gallium hydride species and acidic hydroxyl groups. In the reduced Ga-MFI evacuated at 823 K under medium vacuum conditions only Ga(+) exchanged intrazeolite cations were detected. It was found, however, that Ga(3+) intrazeolite exchanged cations which form upon high-temperature disproportionation of Ga(+) cations in the reduced Ga-MFI and Ga-MOR can be stabilized by high-temperature oxidation of these zeolites.

  5. Dyes adsorption blue vegetable and blue watercolor by natural zeolites modified with surfactants;Adsorcion de colorantes azul vegetal y azul acuarela por zeolitas naturales modificadas con surfactantes

    Energy Technology Data Exchange (ETDEWEB)

    Jardon S, C. C.; Olguin G, M. T. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Diaz N, M. C., E-mail: teresa.olguin@inin.gob.m [Instituto Tecnologico de Toluca, Av. Instituto Tecnologico s/n, Ex-Rancho la Virgen, 52140 Metepec, Estado de Mexico (Mexico)

    2009-07-01

    In this work was carried out the dyes removal blue vegetable and blue watercolor of aqueous solutions, to 20 C, at different times and using a zeolite mineral of Parral (Chihuahua, Mexico) modified with hexadecyl trimethyl ammonium bromide or dodecyl trimethyl ammonium bromide. The zeolite was characterized before and after of its adaptation with NaCl and later with HDTMABr and DTMABr. For the materials characterization were used the scanning electron microscopy of high vacuum; elementary microanalysis by X-ray spectroscopy of dispersed energy and X-ray diffraction techniques. It was found that the surfactant type absorbed in the zeolite material influences on the adsorption process of the blue dye. Likewise, the chemical structure between the vegetable blue dye and the blue watercolor, determines the efficiency of the color removal of the water, by the zeolites modified with the surfactants. (Author)

  6. Effect of Organo-Modified Nanoclay on the Thermal and Bulk Structural Properties of Poly(3-hydroxybutyrate-Epoxidized Natural Rubber Blends: Formation of Multi-Components Biobased Nanohybrids

    Directory of Open Access Journals (Sweden)

    Ali Salehabadi

    2014-06-01

    Full Text Available Multi-component nanohybrids comprising of organo-modified montmorillonite (MMT and immiscible biopolymer blends of poly(3-hydroxybutyrate (PHB and epoxidized natural rubber (ENR-50 were prepared by solvent casting technique. The one and three dimensional morphology of PHB/ENR-50/MMT systems were studied using Polarizing Optical Microscopy (POM and Scanning Electron Microscopy (SEM. Differential scanning calorimetry (DSC technique was used to evaluate the thermal properties of the nanohybrids. The melting temperature (Tm and enthalpy of melting (ΔHm of PHB decrease with respect to the increase in ENR-50 as well as MMT content. The non-isothermal decomposition of the nanohybrids was studied using thermogravimetric (TG-DTG analysis. FTIR-ATR spectra supported ring opening of the epoxide group via reaction with carboxyl group of PHB and amines of organic modifier. The reaction mechanism towards the formation of the nanohybrids is proposed.

  7. Bio-based phenolic-branched-chain fatty acid isomers synthesized from vegetable oils and natural monophenols using modified h+-ferrierite zeolite

    Science.gov (United States)

    A new group of phenolic branched-chain fatty acids (n-PBC-FA), hybrid molecules of natural monophenols (i.e., thymol, carvacrol and creosote) and mixed fatty acid (i.e., derived from soybean and safflower oils), were efficiently produced through a process known as arylation. The reaction involves a...

  8. [Validation of the modified algorithm for predicting host susceptibility to viruses taking into account susceptibility parameters of primary target cell cultures and natural immunity factors].

    Science.gov (United States)

    Zhukov, V A; Shishkina, L N; Safatov, A S; Sergeev, A A; P'iankov, O V; Petrishchenko, V A; Zaĭtsev, B N; Toporkov, V S; Sergeev, A N; Nesvizhskiĭ, Iu V; Vorob'ev, A A

    2010-01-01

    The paper presents results of testing a modified algorithm for predicting virus ID50 values in a host of interest by extrapolation from a model host taking into account immune neutralizing factors and thermal inactivation of the virus. The method was tested for A/Aichi/2/68 influenza virus in SPF Wistar rats, SPF CD-1 mice and conventional ICR mice. Each species was used as a host of interest while the other two served as model hosts. Primary lung and trachea cells and secretory factors of the rats' airway epithelium were used to measure parameters needed for the purpose of prediction. Predicted ID50 values were not significantly different (p = 0.05) from those experimentally measured in vivo. The study was supported by ISTC/DARPA Agreement 450p.

  9. Fluoride ions sorption of the water using natural and modified hematite with aluminium hydroxide; Sorcion de iones fluoruro del agua utilizando hematita natural y hematita acondicionada con hidroxido de aluminio

    Energy Technology Data Exchange (ETDEWEB)

    Teutli S, E. A.

    2011-07-01

    Fluorine is a mineral known for its dental benefits, but fluoride ions can cause fluoro sis in excessive quantities. There are many epidemiological studies on possible adverse effects resulting from prolonged ingestion of fluoride through drinking water. These studies demonstrate that fluoride mainly affects the bone tissue (bones and teeth), may produce an adverse effect on tooth enamel and can cause mild dental fluoro sis at concentrations from 0.9 to 1.2 mg/L in drinking water. In several states of Mexico, water contaminated with fluoride ions can be found, such as Aguascalientes, Chihuahua, Coahuila, Durango, Guanajuato, Sonora, Zacatecas, San Luis Potosi and Jalisco, where the fluoride ions levels are higher than 1.5 mg/L, established by the Mexican Official Standard (NOM-127-Ssa-2000) which sets the permissible limits of water for human use and consumption. Currently, several technologies have been proposed to remove fluoride ions from water such as precipitation methods which are based on the addition of chemicals to water and sorption methods to removed fluoride ions by sorption or ion exchange reactions by some suitable substrate capable of regenerate and reuse. In this work, the sorption of fluoride ions using unmodified and modified hematite with aluminum hydroxide to remove fluoride ions from water by bath experiments was studied. The hematite was modified by treating it with aluminum hydroxide, NaOH and Al{sub 2}(SO{sub 4}){sub 3} solutions. The characterization of hematite before and after modification with aluminum hydroxide was studied by X-ray diffraction, scanning electron microscopy, EDS and Bet. The effect of ph, contact time, concentration of fluoride ions, and the dose of sorbent on the sorption of fluoride ions by the modified hematite were studied. Equilibrium was reached within 48 hours of contact time and the maximum sorption of fluoride ions were in the range pH{sub eq} between 2.3 and 6.2. Sorption capacities of fluoride ions as a

  10. Application of natural and modified hectorite clays as adsorbents to removal of Cr(VI) from aqueous solution-Thermodynamic and equilibrium study

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, Denis L., E-mail: dlguerra@iqm.unicamp.br [Chemistry Institute, State University of Campinas, P. O. Box 6154, 13084-971, Campinas, Sao Paulo (Brazil); Viana, Rubia R. [Universidade Federal de Mato Grosso, UFMT, Centro de Recursos Minerais, Cuiaba, Mato Grosso, 768060 900 (Brazil); Airoldi, Claudio [Chemistry Institute, State University of Campinas, P. O. Box 6154, 13084-971, Campinas, Sao Paulo (Brazil)

    2009-12-15

    A hectorite (H) clay sample has been modified with 2-mercaptobenzimidazole (MBI) using homogeneous and heterogeneous routes. Both modification methodologies resulted in similar products, named H{sub HOM} and H{sub HET}, respectively. These materials were characterized by CO{sub 2} gas adsorption, elemental analysis, nuclear magnetic nuclei of carbon-13 and silicon-29. The effect of two variables (contact time and metal concentration) has been studied using batch technique at room temperature and pH 2.0. After achieving the best conditions for Cr(VI) adsorption, isotherms of this adsorbate on using the chosen adsorbents were obtained, which were fitted to non-linear Sips isotherm model. The maximum number of moles adsorbed was determined to be 11.63, 12.85 and 14.01 mmol g{sup -1} for H, H{sub HOM} and H{sub HET}, respectively, reflecting the maximum adsorption order of H{sub HET} > H{sub HOM} > H. The energetic effects ({Delta}{sub int}H{sup o}, {Delta}{sub int}G{sup o} and {Delta}{sub int}S{sup o}) caused by chromium ion adsorption were determined through calorimetric titrations.

  11. Application of natural and modified hectorite clays as adsorbents to removal of Cr(VI) from aqueous solution-Thermodynamic and equilibrium study

    International Nuclear Information System (INIS)

    Guerra, Denis L.; Viana, Rubia R.; Airoldi, Claudio

    2009-01-01

    A hectorite (H) clay sample has been modified with 2-mercaptobenzimidazole (MBI) using homogeneous and heterogeneous routes. Both modification methodologies resulted in similar products, named H HOM and H HET , respectively. These materials were characterized by CO 2 gas adsorption, elemental analysis, nuclear magnetic nuclei of carbon-13 and silicon-29. The effect of two variables (contact time and metal concentration) has been studied using batch technique at room temperature and pH 2.0. After achieving the best conditions for Cr(VI) adsorption, isotherms of this adsorbate on using the chosen adsorbents were obtained, which were fitted to non-linear Sips isotherm model. The maximum number of moles adsorbed was determined to be 11.63, 12.85 and 14.01 mmol g -1 for H, H HOM and H HET , respectively, reflecting the maximum adsorption order of H HET > H HOM > H. The energetic effects (Δ int H o , Δ int G o and Δ int S o ) caused by chromium ion adsorption were determined through calorimetric titrations.

  12. Preparation of Modified Magnetic Nanocomposites Dithiooxamide/Fe3O4 for Preconcentration and Determination of Trace Amounts of Cobalt Ions in Food and Natural Water Samples

    Directory of Open Access Journals (Sweden)

    Ali Mirabi

    2016-09-01

    Full Text Available The first study on the high efficiency of nanometer-sized magnetic nanoparticles (Fe3O4 coated with sodium dodecyl sulfate (SDS and dithiooxamide as a new sorbent solid phase extraction has been reported. Modified magnetic nanicomposites was used to preconcentrate and separate Co (II ions in food and environmental water samples. Magnetic nanoparticles were prepared by chemical precipitation of Fe (II and Fe (III salts from aqueous solution by ammonia solution. These magnetic nanoparticles and nanocomposites were characterized by scanning electron microscopy (SEM, transmission electron microscopy (TEM, thermo gravimetric analysis (TGA and elemental analysis CHNS. A micro sample introduction system was employed for the nebulization micro-volume of diluted solution into flame atomic absorption spectrometry (FAAS. The extraction conditions were optimized by selecting the appropriate extraction parameters including the amount of nanosorbent, pH value, volume of dithiooxamide and condition of eluting solution. The detection limit of this method for Co (II ions was 1.21 ng ml-1 and the R.S.D. was 0.9% (n=6. The advantages of this new method include rapidity, easy preparation of nanosorbents and a high preconcentration factor. The proposed method has been applied to the determination of Co (II ions at trace levels in real samples such as, kiwi, orange, cucumber, apple, green pepper, honey, potato, tap water, river water and sea water with satisfactory results.

  13. Efficient solid-phase microextraction of triazole pesticides from natural water samples using a Nafion-loaded trimethylsilane-modified mesoporous silica coating of type SBA-15

    International Nuclear Information System (INIS)

    Abolghasemi, Mir Mahdi; Hassani, Sona; Bamorowat, Mehdi

    2016-01-01

    A mesoporous silica surface of type SBA-15 was made more hydrophobic by modification with ethoxytrimethylsilane to obtain a hybrid organic–inorganic mesoporous nanocomposite, which then was impregnated with Nafion. The resulting nanocomposite was used as a fiber coating for solid-phase microextraction (SPME). The trimethylsilyl-modified Nafion/SBA-15 nanocomposite with high surface area was characterized by SEM and FTIR. It was immobilized on a stainless steel wire in order to fabricate a fiber for SPME. This fiber was evaluated for its suitability for extracting triazolic agrochemicals from water samples before their quantification through a combination of gas chromatography and mass spectrometry. Experimental conditions for fiber coating, extraction time, stirring rate, ionic strength, pH value, desorption temperature and desorption time were optimized. Under optimum conditions, the repeatability for one fiber (for n = 3) ranges from 4.3 to 5.6 % (relative standard deviation). The detection limits are between 50 and 90 pg⋅mL −1 . The method is simple, fast, low-cost (in terms of equipment), and the fiber used for SPME has high thermal stability and good recovery. (author)

  14. A modified Cournot model of the natural gas market in the European Union: Mixed-motives delegation in a politicized environment

    International Nuclear Information System (INIS)

    Jansen, Thijs; Lier, Arie van; Witteloostuijn, Arjen van; Boon von Ochssée, Tim

    2012-01-01

    With Gazprom gaining prominence as the major supplier of natural gas in the European Union, the European gas market becomes more politicized. We assume that Gazprom's interest as a state monopolist is not only to maximize profit, but also to seek market power, presumably because this contributes to the geopolitical power of Russia at large. We introduce a modeling tool, so-called strategic delegation games, to analyze the implications of Gazprom's operation in the EU. By way of illustration, we model the case where Gazprom competes against two profit-maximizing rivals: Algerian Sonatrach and Norwegian Statoil. We prove that if Gazprom serves any of a comprehensive type of nonprofit objectives, the outcome is beneficial for the EU's consumers, as Gazprom's behavior shifts volumes up and brings prices down. - Highlights: ► We model the natural gas market in the EU. ► The fact that the major gas supplier Russia/Gazprom has nonprofit incentives is beneficial for EU's consumers. ► The nonprofit incentives increase Russia's market share and decrease the profits of its rivals.

  15. Boson peak of alkali and alkaline earth silicate glasses: influence of the nature and size of the network-modifying cation.

    Science.gov (United States)

    Richet, Nicolas F

    2012-01-21

    The influence of the size of the alkaline earth cation on the boson peak of binary metasilicate glasses, MSiO(3) (M = Mg, Ca, Sr, Ba), has been investigated from vibrational densities of states determined by inversion of low-temperature heat capacities. As given both by C(p)/T(3) and g(ω)/ω(2), the intensity of the boson peak undergoes a 7-fold increase from Mg to Ba, whereas its temperature and frequency correlatively decrease from 18 to 10 K and from 100 to 20 cm(-1), respectively. The boson peak results from a combination of librations of SiO(4) tetrahedra and localized vibrations of network-modifying cations with non-bridging oxygens whose contribution increases markedly with the ionic radius of the alkaline earth. As a function of ionic radii, the intensity for Sr and Ba varies in the same way as previously found for alkali metasilicate glasses. The localized vibrations involving alkali and heavy alkaline earth cations appear to be insensitive to the overall glass structure. Although the new data are coherent with an almost linear relationship between the temperature of the boson peak and transverse sound velocity, pure SiO(2) and SiO(2)-rich glasses make marked exceptions to this trend because of the weak transverse character of SiO(4) librations. Finally, the universality of the calorimetric boson peak is again borne out because all data for silicate glasses collapse on the same master curve when plotted in a reduced form (C(P)∕/T(3))/(C(P)/T(3))(b) vs. T/T(b). © 2012 American Institute of Physics

  16. Biological response modifiers

    Energy Technology Data Exchange (ETDEWEB)

    Weller, R.E.

    1991-10-01

    Much of what used to be called immunotherapy is now included in the term biological response modifiers. Biological response modifiers (BRMs) are defined as those agents or approaches that modify the relationship between the tumor and host by modifying the host's biological response to tumor cells with resultant therapeutic effects.'' Most of the early work with BRMs centered around observations of spontaneous tumor regression and the association of tumor regression with concurrent bacterial infections. The BRM can modify the host response in the following ways: Increase the host's antitumor responses through augmentation and/or restoration of effector mechanisms or mediators of the host's defense or decrease the deleterious component by the host's reaction; Increase the host's defenses by the administration of natural biologics (or the synthetic derivatives thereof) as effectors or mediators of an antitumor response; Augment the host's response to modified tumor cells or vaccines, which might stimulate a greater response by the host or increase tumor-cell sensitivity to an existing response; Decrease the transformation and/or increase differentiation (maturation) of tumor cells; or Increase the ability of the host to tolerate damage by cytotoxic modalities of cancer treatment.

  17. Mechanical properties of chemically modified Sansevieria trifasciata/natural rubber/high density polyethylene (STF/NR/HDPE) composites: Effect of silane coupling agent

    Science.gov (United States)

    Zakaria, Nurzam Ezdiani; Baharum, Azizah; Ahmad, Ishak

    2018-04-01

    The main objective of this research is to study the effects of chemical modification on the mechanical properties of treated Sansevieria trifasciata fiber/natural rubber/high density polyethylene (TSTF/NR/HDPE) composites. Processing of STF/NR/HDPE composites was done by using an internal mixer. The processing parameters used were 135°C for temperature and a mixing rotor speed of 55 rpm for 15 minutes. Filler loading was varied from 10% to 40% of STF and the fiber size used was 125 µm. The composite blends obtained then were pressed with a hot press machine to get test samples of 1 mm and 3 mm of thickness. Samples were evaluated via tensile tests, Izod impact test and scanning electron microscopy (SEM). Results showed that tensile strength and strain value decreased while tensile modulus increased when filler loading increased. Impact strength increased when filler loading increased and began to decrease after 10% of filler amount for treated composites. For untreated composites, impact strength began to decrease after 20% of filler loading. Chemical modification by using silane coupling agent has improved certain mechanical properties of the composites such as tensile strength, strain value and tensile modulus. Adding more amount of filler will also increase the viscosity and the stiffness of the materials.

  18. Modified SEAGULL

    Science.gov (United States)

    Salas, M. D.; Kuehn, M. S.

    1994-01-01

    Original version of program incorporated into program SRGULL (LEW-15093) for use on National Aero-Space Plane project, its duty being to model forebody, inlet, and nozzle portions of vehicle. However, real-gas chemistry effects in hypersonic flow fields limited accuracy of that version, because it assumed perfect-gas properties. As a result, SEAGULL modified according to real-gas equilibrium-chemistry methodology. This program analyzes two-dimensional, hypersonic flows of real gases. Modified version of SEAGULL maintains as much of original program as possible, and retains ability to execute original perfect-gas version.

  19. Modeling Natural Selection

    Science.gov (United States)

    Bogiages, Christopher A.; Lotter, Christine

    2011-01-01

    In their research, scientists generate, test, and modify scientific models. These models can be shared with others and demonstrate a scientist's understanding of how the natural world works. Similarly, students can generate and modify models to gain a better understanding of the content, process, and nature of science (Kenyon, Schwarz, and Hug…

  20. Interfacial Modifiers

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Ina; French, Roger H.

    2018-03-19

    Our project objective in the first and only Budget Period was to demonstrate the potential of nm-scale organofunctional silane coatings as a method of extending the lifetime of PV materials and devices. Specifically, the target was to double the lifetime performance of a laminated Cu(In,Ga)Se2 (CIGS) cell under real-world and accelerated aging exposure conditions. Key findings are that modification of aluminum-doped zinc oxide (AZO) films (materials used as transparent conductive oxide (TCO) top contacts) resulted in decreased degradation of optical and electrical properties under damp heat (DH) exposure compared to un-modified AZO. The most significant finding is that modification of the AZO top contact of full CIGS devices resulted in significantly improved properties under DH exposure compared to un-modified devices, by a factor of 4 after 1000 h. Results of this one-year project have demonstrated that surface functionalization is a viable pathway for extending the lifetime of state-of-the-art CIGS devices.

  1. Biodegradable modified Phba systems

    International Nuclear Information System (INIS)

    Aniscenko, L.; Dzenis, M.; Erkske, D.; Tupureina, V.; Savenkova, L.; Muizniece - Braslava, S.

    2004-01-01

    Compositions as well as production technology of ecologically sound biodegradable multicomponent polymer systems were developed. Our objective was to design some bio plastic based composites with required mechanical properties and biodegradability intended for use as biodegradable packaging. Significant characteristics required for food packaging such as barrier properties (water and oxygen permeability) and influence of γ-radiation on the structure and changes of main characteristics of some modified PHB matrices was evaluated. It was found that barrier properties were plasticizers chemical nature and sterilization with γ-radiation dependent and were comparable with corresponding values of typical polymeric packaging films. Low γ-radiation levels (25 kGy) can be recommended as an effective sterilization method of PHB based packaging materials. Purposely designed bio plastic packaging may provide an alternative to traditional synthetic packaging materials without reducing the comfort of the end-user due to specific qualities of PHB - biodegradability, Biocompatibility and hydrophobic nature

  2. A Chemically Modified Curcumin (CMC 2.24) Inhibits Nuclear Factor κB Activation and Inflammatory Bone Loss in Murine Models of LPS-Induced Experimental Periodontitis and Diabetes-Associated Natural Periodontitis.

    Science.gov (United States)

    Elburki, Muna S; Rossa, Carlos; Guimarães-Stabili, Morgana R; Lee, Hsi-Ming; Curylofo-Zotti, Fabiana A; Johnson, Francis; Golub, Lorne M

    2017-08-01

    The purpose of this study was to assess the effect of a novel chemically modified curcumin (CMC 2.24) on NF-κB and MAPK signaling and inflammatory cytokine production in two experimental models of periodontal disease in rats. Experimental model I: Periodontitis was induced by repeated injections of LPS into the gingiva (3×/week, 3 weeks); control rats received vehicle injections. CMC 2.24, or the vehicle, was administered by daily oral gavage for 4 weeks. Experimental model II: Diabetes was induced in adult male rats by streptozotocin injection; periodontal breakdown then results as a complication of uncontrolled hyperglycemia. Non-diabetic rats served as controls. CMC 2.24, or the vehicle, was administered by oral gavage daily for 3 weeks to the diabetics. Hemimaxillae and gingival tissues were harvested, and bone loss was assessed radiographically. Gingival tissues were pooled according to the experimental conditions and processed for the analysis of matrix metalloproteinases (MMPs) and bone-resorptive cytokines. Activation of p38 MAPK and NF-κB signaling pathways was assessed by western blot. Both LPS and diabetes induced an inflammatory process in the gingival tissues associated with excessive alveolar bone resorption and increased activation of p65 (NF-κB) and p38 MAPK. In both models, the administration of CMC 2.24 produced a marked reduction of inflammatory cytokines and MMPs in the gingival tissues, decreased bone loss, and decreased activation of p65 (NF-κB) and p38 MAPK. Inhibition of these cell signaling pathways by this novel tri-ketonic curcuminoid (natural curcumin is di-ketonic) may play a role in its therapeutic efficacy in locally and systemically associated periodontitis.

  3. A natural compromise: a moderate solution to the GMO & "natural" labeling disputes.

    Science.gov (United States)

    Amaru, Stephanie

    2014-01-01

    In the United States, genetically modified (GM) foods are labeled no differently from their natural counterparts, leaving consumers with no mechanism for deciphering genetically modified food content. The Food and Drug Administration (FDA) has not formally defined the term "natural," which is frequently used on food labels despite consumer confusion as to what it means. The FDA should initiate a notice and comment rulemaking addressing the narrow issue of whether use of the word "natural" should be permitted oil GM food labels. Prohibition of the use of"natural" on genetically modified foods would mitigate consumer deception regarding genetically modified food content without significantly disadvantaging genetically modified food producers.

  4. On Modified Bar recursion

    DEFF Research Database (Denmark)

    Oliva, Paulo Borges

    2002-01-01

    Modified bar recursion is a variant of Spector's bar recursion which can be used to give a realizability interpretation of the classical axiom of dependent choice. This realizability allows for the extraction of witnesses from proofs of forall-exists-formulas in classical analysis. In this talk I...... shall report on results regarding the relationship between modified and Spector's bar recursion. I shall also show that a seemingly weak form of modified bar recursion is as strong as "full" modified bar recursion in higher types....

  5. A New Modified Firefly Algorithm

    Directory of Open Access Journals (Sweden)

    Medha Gupta

    2016-07-01

    Full Text Available Nature inspired meta-heuristic algorithms studies the emergent collective intelligence of groups of simple agents. Firefly Algorithm is one of the new such swarm-based metaheuristic algorithm inspired by the flashing behavior of fireflies. The algorithm was first proposed in 2008 and since then has been successfully used for solving various optimization problems. In this work, we intend to propose a new modified version of Firefly algorithm (MoFA and later its performance is compared with the standard firefly algorithm along with various other meta-heuristic algorithms. Numerical studies and results demonstrate that the proposed algorithm is superior to existing algorithms.

  6. Modified Allergens for Immunotherapy.

    Science.gov (United States)

    Satitsuksanoa, Pattraporn; Głobińska, Anna; Jansen, Kirstin; van de Veen, Willem; Akdis, Mübeccel

    2018-02-16

    During the past few decades, modified allergens have been developed for use in allergen-specific immunotherapy (AIT) with the aim to improve efficacy and reduce adverse effects. This review aims to provide an overview of the different types of modified allergens, their mechanism of action and their potential for improving AIT. In-depth research in the field of allergen modifications as well as the advance of recombinant DNA technology have paved the way for improved diagnosis and research on human allergic diseases. A wide range of structurally modified allergens has been generated including allergen peptides, chemically altered allergoids, adjuvant-coupled allergens, and nanoparticle-based allergy vaccines. These modified allergens show promise for the development of AIT regimens with improved safety and long-term efficacy. Certain modifications ensure reduced IgE reactivity and retained T cell reactivity, which facilities induction of immune tolerance to the allergen. To date, multiple clinical trials have been performed using modified allergens. Promising results were obtained for the modified cat, grass and birch pollen, and house dust mite allergens. The use of modified allergens holds promise for improving AIT efficacy and safety. There is however a need for larger clinical studies to reliably assess the added benefit for the patient of using modified allergens for AIT.

  7. Drought in a human-modified world

    NARCIS (Netherlands)

    Loon, van Anne F.; Stahl, Kerstin; Baldassarre, Di Giuliano; Clark, Julian; Rangecroft, Sally; Wanders, Niko; Gleeson, Tom; Dijk, van Albert I.J.M.; Tallaksen, Lena M.; Hannaford, Jamie; Uijlenhoet, Remko; Teuling, Ryan; Hannah, David M.; Sheffield, Justin; Svoboda, Mark; Verbeiren, Boud; Wagener, Thorsten; Lanen, van Henny A.J.

    2016-01-01

    In the current human-modified world, or Anthropocene, the state of water stores and fluxes has become dependent on human as well as natural processes. Water deficits (or droughts) are the result of a complex interaction between meteorological anomalies, land surface processes, and human inflows,

  8. Construction of an Environmentally Sustainable Development on a Modified Coastal Sand Mined and Landfill Site—Part 2. Re-Establishing the Natural Ecosystems on the Reconstructed Beach Dunes

    Directory of Open Access Journals (Sweden)

    Anne-Laure Markovina

    2010-03-01

    Full Text Available Mimicking natural processes lead to progressive colonization and stabilization of the reconstructed beach dune ecosystem, as part of the ecologically sustainable development of Magenta Shores, on the central coast of New South Wales, Australia. The retained and enhanced incipient dune formed the first line of storm defence. Placement of fibrous Leptospermum windrows allowed wind blown sand to form crests and swales parallel to the beach. Burial of Spinifex seed head in the moist sand layer achieved primary colonization of the reconstructed dune and development of a soil fungal hyphae network prior to introduction of secondary colonizing species. Monitoring stakes were used as roosts by birds, promoting re-introduction of native plant species requiring germination by digestive tract stimulation. Bush regeneration reduced competition from weeds, allowing native vegetation cover to succeed. On-going weeding and monitoring are essential at Magenta Shores until bitou bush is controlled for the entire length of beach. The reconstructed dunes provide enhanced protection from sand movement and storm bite, for built assets, remnant significant vegetation and sensitive estuarine ecosystems.

  9. Nanoparticles modified with multiple organic acids

    Science.gov (United States)

    Cook, Ronald Lee (Inventor); Luebben, Silvia DeVito (Inventor); Myers, Andrew William (Inventor); Smith, Bryan Matthew (Inventor); Elliott, Brian John (Inventor); Kreutzer, Cory (Inventor); Wilson, Carolina (Inventor); Meiser, Manfred (Inventor)

    2007-01-01

    Surface-modified nanoparticles of boehmite, and methods for preparing the same. Aluminum oxyhydroxide nanoparticles are surface modified by reaction with selected amounts of organic acids. In particular, the nanoparticle surface is modified by reactions with two or more different carboxylic acids, at least one of which is an organic carboxylic acid. The product is a surface modified boehmite nanoparticle that has an inorganic aluminum oxyhydroxide core, or part aluminum oxyhydroxide core and a surface-bonded organic shell. Organic carboxylic acids of this invention contain at least one carboxylic acid group and one carbon-hydrogen bond. One embodiment of this invention provides boehmite nanoparticles that have been surface modified with two or more acids one of which additional carries at least one reactive functional group. Another embodiment of this invention provides boehmite nanoparticles that have been surface modified with multiple acids one of which has molecular weight or average molecular weight greater than or equal to 500 Daltons. Yet, another embodiment of this invention provides boehmite nanoparticles that are surface modified with two or more acids one of which is hydrophobic in nature and has solubility in water of less than 15 by weight. The products of the methods of this invention have specific useful properties when used in mixture with liquids, as filler in solids, or as stand-alone entities.

  10. Nanoparticles modified with multiple organic acids

    Science.gov (United States)

    Cook, Ronald Lee; Luebben, Silvia DeVito; Myers, Andrew William; Smith, Bryan Matthew; Elliott, Brian John; Kreutzer, Cory; Wilson, Carolina; Meiser, Manfred

    2007-07-17

    Surface-modified nanoparticles of boehmite, and methods for preparing the same. Aluminum oxyhydroxide nanoparticles are surface modified by reaction with selected amounts of organic acids. In particular, the nanoparticle surface is modified by reactions with two or more different carboxylic acids, at least one of which is an organic carboxylic acid. The product is a surface modified boehmite nanoparticle that has an inorganic aluminum oxyhydroxide core, or part aluminum oxyhydroxide core and a surface-bonded organic shell. Organic carboxylic acids of this invention contain at least one carboxylic acid group and one carbon-hydrogen bond. One embodiment of this invention provides boehmite nanoparticles that have been surface modified with two or more acids one of which additional carries at least one reactive functional group. Another embodiment of this invention provides boehmite nanoparticles that have been surface modified with multiple acids one of which has molecular weight or average molecular weight greater than or equal to 500 Daltons. Yet, another embodiment of this invention provides boehmite nanoparticles that are surface modified with two or more acids one of which is hydrophobic in nature and has solubility in water of less than 15 by weight. The products of the methods of this invention have specific useful properties when used in mixture with liquids, as filler in solids, or as stand-alone entities.

  11. Modified Nance palatal button

    Directory of Open Access Journals (Sweden)

    Nitin Arora

    2015-01-01

    Full Text Available This paper describes modified Nance palatal button by which problems encountered in the palatal region around the acrylic button during space closure and molar distalization can be minimized.

  12. Modified microdissection electrocautery needle

    OpenAIRE

    Singh, Virendra; Kumar, Pramod

    2014-01-01

    Electrocautery is routinely used in surgical procedures. The commercially available microdissection electrocautery needles are costly. To overcome this disadvantage, we have modified monopolar electrocautery tip to function as well as commercially available systems.

  13. The natural radiation background

    International Nuclear Information System (INIS)

    Duggleby, J.C.

    1982-01-01

    The components of the natural background radiation and their variations are described. Cosmic radiation is a major contributor to the external dose to the human body whilst naturally-occurring radionuclides of primordial and cosmogenic origin contribute to both the external and internal doses, with the primordial radionuclides being the major contributor in both cases. Man has continually modified the radiation dose to which he has been subjected. The two traditional methods of measuring background radiation, ionisation chamber measurements and scintillation counting, are looked at and the prospect of using thermoluminescent dosimetry is considered

  14. Modified blank ammunition injuries.

    Science.gov (United States)

    Ogunc, Gokhan I; Ozer, M Tahir; Coskun, Kagan; Uzar, Ali Ihsan

    2009-12-15

    Blank firing weapons are designed only for discharging blank ammunition cartridges. Because they are cost-effective, are easily accessible and can be modified to live firearms plus their unclear legal situation in Turkish Law makes them very popular in Turkey. 2004 through 2008, a total of 1115 modified blank weapons were seized in Turkey. Blank firing weapons are easily modified by owners, making them suitable for discharging live firearm ammunition or modified blank ammunitions. Two common methods are used for modification of blank weapons. After the modification, these weapons can discharge the live ammunition. However, due to compositional durability problems with these types of weapons; the main trend is to use the modified blank ammunitions rather than live firearm ammunition fired from modified blank firing weapons. In this study, two types of modified blank weapons and two types of modified blank cartridges were tested on three different target models. Each of the models' shooting side was coated with 1.3+/-2 mm thickness chrome tanned cowhide as a skin simulant. The first model was only coated with skin simulant. The second model was coated with skin simulant and 100% cotton police shirt. The third model was coated with skin simulant and jean denim. After the literature evaluation four high risky anatomic locations (the neck area; the eyes; the thorax area and inguinal area) were pointed out for the steel and lead projectiles are discharged from the modified blank weapons especially in close range (0-50 cm). The target models were designed for these anatomic locations. For the target models six Transparent Ballistic Candle blocks (TCB) were prepared and divided into two test groups. The first group tests were performed with lead projectiles and second group with steel projectile. The shortest penetration depth (lead projectile: 4.358 cm; steel projectile 8.032 cm) was recorded in the skin simulant and jean denim coated block for both groups. In both groups

  15. Natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Fraser, J W

    1967-08-01

    This report on the natural gas industry of Canada includes: composition and uses of natural gas, production statistics, exploration and development, reserve estimates, natural gas processing, transportation, and marketing. For the Canadian natural gas industry, 1966 was a year of moderate expansion in all phases, with a strong demand continuing for sulfur and liquid hydrocarbons produced as by-products of gas processing. Value of natural gas production increased to $199 million and ranked sixth in terms of value of mineral ouput in Canada. Currently, natural gas provides over 70% of Canada's energy requirements. Proved remaining marketable reserves are estimated to be in excess of a 29-yr supply.

  16. Modified nasolacrimal duct stenting

    International Nuclear Information System (INIS)

    Tian Min; Jin Mei; Chen Huanjun; Li Yi

    2008-01-01

    Objective: Traditional nasolacrimal duct stenting possesses some shortcoming including difficulty of pulling ball head guide wire from the nasal cavity with turbinate hypertrophy and nasal septal deviation. The new method of nose-oral tube track establishment can overcome the forementioned and increase the successful rate. Methods: 5 F catheter and arterial sheath were modified to be nasolacrimal duct stent delivery device respectively. Antegrade dacryocystography was taken firstly to display the obstructed site and followed by the modified protocol of inserting the guide wire through nasolacrimal duct and nasal cavity, and establishing the stent delivery track for retrograde stent placement. Results: 5 epiphora patients with failure implantation by traditional method were all succeeded through the modified stenting (100%). During 6-mouth follow-up, no serious complications and reocclusion occurred. Conclusion: The establishment of eye-nose-mouth-nose of external nasal guide wire track can improve the successful rate of nasolacrimal duct stenting. (authors)

  17. Normal modified stable processes

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole Eiler; Shephard, N.

    2002-01-01

    Gaussian (NGIG) laws. The wider framework thus established provides, in particular, for added flexibility in the modelling of the dynamics of financial time series, of importance especially as regards OU based stochastic volatility models for equities. In the special case of the tempered stable OU process......This paper discusses two classes of distributions, and stochastic processes derived from them: modified stable (MS) laws and normal modified stable (NMS) laws. This extends corresponding results for the generalised inverse Gaussian (GIG) and generalised hyperbolic (GH) or normal generalised inverse...

  18. Modified Nanodiamonds for Detoxification

    Science.gov (United States)

    Gibson, Natalie Marie

    Nanodiamonds (NDs) are an emerging class of biomaterials that are reaching worldwide attention due to their biocompatible, nontoxic properties and abundant surface chemistries that lend them to a wide range of biomedical applications. Furthermore, surface functional groups of NDs can easily be tailored to exhibit desirable chemical, physical and biological properties. Such characteristics naturally allow for NDs' surface to be considered as ideal carriers for various molecules and biomolecules intended for the delivery or removal of molecules in vivo. NDs have already shown to have a high affinity for various biological molecules, including DNA and proteins. This dissertation, however, expands NDs' use to the adsorption of carcinogenic mycotoxins, aflatoxin B1 (AfB1) and ochratoxin A (OTA). It has been estimated that myocotoxins are found in approximately 25 % of the world's crops each year. Ingestion of mycotoxins contaminated crops has been linked to hepatocellular carcinoma, disease and death. Therefore, we aim to develop ND enterosorbents, for the binding and removal of mycotoxins within the gastrointestinal (GI) tract, thereby eliminating the effects of these toxins. While NDs are readily available, raw, unmodified NDs, like those typically received from vendors, possess inhomogeneous aggregate sizes and surface characteristics. Our research first explored several ND modification techniques to enhance ND's adsorption of AfB1 and OTA. Modification methods assessed in this research include size reduction techniques, plasma treatments, silane surface coatings and homogenous surface group termination, including carboxylation, hydrogenation and hydroxylation. The effectiveness of these NDs for mycotoxins removal was determined by calculations of maximum capacities and binding constants, as obtained through the Langmuir isotherm and related transform equations. Several of these treatments also showed heightening of the NDs' inherent zeta potentials (ZPs), which were

  19. Natural Gas

    OpenAIRE

    Bakar, Wan Azelee Wan Abu; Ali, Rusmidah

    2010-01-01

    Natural gas fuel is a green fuel and becoming very demanding because it is environmental safe and clean. Furthermore, this fuel emits lower levels of potentially harmful by-products into the atmosphere. Most of the explored crude natural gas is of sour gas and yet, very viable and cost effective technology is still need to be developed. Above all, methanation technology is considered a future potential treatment method for converting the sour natural gas to sweet natural gas.

  20. CONCRETE BASED ON MODIFIED DISPERSE CEMENT SYSTEM

    Directory of Open Access Journals (Sweden)

    D. V. Rudenko

    2016-08-01

    Full Text Available Purpose. The article considers definition of the bond types occurring in a modified cement concrete matrix, and the evaluation of the quality of these links in a non-uniform material to determine the geometrical and physical relationships between the structure and the cement matrix modifiers. Methodology. To achieve this purpose the studies covered the microstructure of dispersed modified concrete cement matrix, the structure formation mechanism of the modified cement concrete system of natural hardening; as well as identification of the methods of sound concrete strength assessment. Findings. The author proposed a model of the spatial structure of the concrete cement matrix, modified by particulate reinforcement crystal hydrates. The initial object of study is a set of volume elements (cells of the cement matrix and the system of the spatial distribution of reinforcing crystallohydrates in these volume elements. It is found that the most dangerous defects such as cracks in the concrete volume during hardening are formed as a result of internal stresses, mainly in the zone of cement matrix-filler contact or in the area bordering with the largest pores of the concrete. Originality. The result of the study is the defined mechanism of the process of formation of the initial strength and stiffness of the modified cement matrix due to the rapid growth of crystallohydrates in the space among the dispersed reinforcing modifier particles. Since the lack of space prevents from the free growth of crystals, the latter cross-penetrate, forming a dense structure, which contributes to the growth of strength. Practical value. Dispersed modifying cement matrix provides a durable concrete for special purposes with the design performance characteristics. The developed technology of dispersed cement system modification, the defined features of its structure formation mechanism and the use of congruence principle for the complex of technological impacts of physical

  1. EAMJ Modifiable 10.indd

    African Journals Online (AJOL)

    2010-02-02

    Feb 2, 2010 ... MODIFIABLE FACTORS ASSOCIATED WITH ACTIVE PULMONARY TUBERCULOSIS IN A KENYAN PRISON. A. S. Amwayi, MBChB, MSc., ... University of Agriculture and Technology, P.O. Box 62000- 0200, Nairobi, Kenya and E. M. Muchiri, MSc, PhD., Division ..... Diabetes and low BMI. 223452.81.

  2. Isotopically modified compounds

    International Nuclear Information System (INIS)

    Kuruc, J.

    2009-01-01

    In this chapter the nomenclature of isotopically modified compounds in Slovak language is described. This chapter consists of following parts: (1) Isotopically substituted compounds; (2) Specifically isotopically labelled compounds; (3) Selectively isotopically labelled compounds; (4) Non-selectively isotopically labelled compounds; (5) Isotopically deficient compounds.

  3. Modifiable Combining Functions

    OpenAIRE

    Cohen, Paul; Shafer, Glenn; Shenoy, Prakash P.

    2013-01-01

    Modifiable combining functions are a synthesis of two common approaches to combining evidence. They offer many of the advantages of these approaches and avoid some disadvantages. Because they facilitate the acquisition, representation, explanation, and modification of knowledge about combinations of evidence, they are proposed as a tool for knowledge engineers who build systems that reason under uncertainty, not as a normative theory of evidence.

  4. Modifying Cookbook Labs.

    Science.gov (United States)

    Clark, Robert, L.; Clough, Michael P.; Berg, Craig A.

    2000-01-01

    Modifies an extended lab activity from a cookbook approach for determining the percent mass of water in copper sulfate pentahydrate crystals to one which incorporates students' prior knowledge, engenders active mental struggling with prior knowledge and new experiences, and encourages metacognition. (Contains 12 references.) (ASK)

  5. Attitudes towards genetically modified and organic foods.

    Science.gov (United States)

    Saher, Marieke; Lindeman, Marjaana; Hursti, Ulla-Kaisa Koivisto

    2006-05-01

    Finnish students (N=3261) filled out a questionnaire on attitudes towards genetically modified and organic food, plus the rational-experiential inventory, the magical thinking about food and health scale, Schwartz's value survey and the behavioural inhibition scale. In addition, they reported their eating of meat. Structural equation modelling of these measures had greater explanatory power for attitudes towards genetically modified (GM) foods than for attitudes towards organic foods (OF). GM attitudes were best predicted by natural science education and magical food and health beliefs, which mediated the influence of thinking styles. Positive attitudes towards organic food, on the other hand, were more directly related to such individual differences as thinking styles and set of values. The results of the study indicate that OF attitudes are rooted in more fundamental personal attributes than GM attitudes, which are embedded in a more complex but also in a more modifiable network of characteristics.

  6. Evaluation of bioadhesive properties of natural and modified ...

    African Journals Online (AJOL)

    Michael

    The bioadhesive property of the starches were not related to the viscosity as the pregelatinised starch ... controlled drug delivery system to improve buccal, nasal and oral ... ceramic tiles and dried in the oven for 24 h at. 100 °C. The dried ...

  7. Solid-Phase Synthesis of Modified Peptides as Putative Inhibitors of Histone Modifying Enzymes

    DEFF Research Database (Denmark)

    Cohrt, Anders Emil O'Hanlon

    to be compatible with all 20 naturally occurring amino acids, and were furthermore feasible on several commonly used polymeric supports. By using dilute SnCl4 for N -Boc deprotection, and NaOH for the release of material from the solid support, N -modified peptides were cleanly obtained in excellent yields...

  8. PLURALIZING NATURE

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2014-01-01

    Denmark is widely recognised for its democratic approach to planning and the idea of planning for the common good. This interest in the common good and common values seems also to be reflected in the way which nature restoration is planned and managed – one common nature directed by the public...... authorities. But nature restoration is far from being a neural undertaking. Just like any other type of heritage production it can be the source of dissonance – ‘our’ nature is not necessary ‘their’ nature. Often this dissonance is managed in ways, which are not particular sensitive to site......-specificity. As exemplified by the Skjern River Restoration Project (1999-2003), one interpretation of the landscape sometimes suppresses other valid interpretations neglecting its diverse history. However, evidence from Switzerland suggests that planning for the common good, in the case of nature restoration, does...

  9. Modified Faraday cup

    Science.gov (United States)

    Elmer, John W.; Teruya, Alan T.; O'Brien, Dennis W.

    1996-01-01

    A tomographic technique for measuring the current density distribution in electron beams using electron beam profile data acquired from a modified Faraday cup to create an image of the current density in high and low power beams. The modified Faraday cup includes a narrow slit and is rotated by a stepper motor and can be moved in the x, y and z directions. The beam is swept across the slit perpendicular thereto and controlled by deflection coils, and the slit rotated such that waveforms are taken every few degrees form 0.degree. to 360.degree. and the waveforms are recorded by a digitizing storage oscilloscope. Two-din-tensional and three-dimensional images of the current density distribution in the beam can be reconstructed by computer tomography from this information, providing quantitative information about the beam focus and alignment.

  10. Tip-modified Propellers

    DEFF Research Database (Denmark)

    Andersen, Poul

    1999-01-01

    The paper deals with tip-modified propellers and the methods which, over a period of two decades, have been applied to develop such propellers. The development is driven by the urge to increase the efficiency of propellers and can be seen as analogous to fitting end plates and winglets to aircraft...... propeller, have efficiency increases of a reasonable magnitude in both open-water and behind-ship conditions....

  11. Viscosity in Modified Gravity 

    Directory of Open Access Journals (Sweden)

    Iver Brevik

    2012-11-01

    Full Text Available A bulk viscosity is introduced in the formalism of modified gravity. It is shownthat, based on a natural scaling law for the viscosity, a simple solution can be found forquantities such as the Hubble parameter and the energy density. These solutions mayincorporate a viscosity-induced Big Rip singularity. By introducing a phase transition inthe cosmic fluid, the future singularity can nevertheless in principle be avoided. 

  12. Modified Firefly Algorithm

    Directory of Open Access Journals (Sweden)

    Surafel Luleseged Tilahun

    2012-01-01

    Full Text Available Firefly algorithm is one of the new metaheuristic algorithms for optimization problems. The algorithm is inspired by the flashing behavior of fireflies. In the algorithm, randomly generated solutions will be considered as fireflies, and brightness is assigned depending on their performance on the objective function. One of the rules used to construct the algorithm is, a firefly will be attracted to a brighter firefly, and if there is no brighter firefly, it will move randomly. In this paper we modify this random movement of the brighter firefly by generating random directions in order to determine the best direction in which the brightness increases. If such a direction is not generated, it will remain in its current position. Furthermore the assignment of attractiveness is modified in such a way that the effect of the objective function is magnified. From the simulation result it is shown that the modified firefly algorithm performs better than the standard one in finding the best solution with smaller CPU time.

  13. Genetically Modified Organisms

    Directory of Open Access Journals (Sweden)

    Claro Llaguno

    2001-06-01

    Full Text Available Recent reports have brought to public attention concerns about Bt corn and genetically modified organisms (GMO in general. The timing, it seems, is most appropriate considering two related developments early this year: the final approval of the Cartagena Protocol on Biosafety in Montreal on January 29, 2001, and the OECD Edinburgh Conference on GM food safety last February 28- March 1, 2001. The protocol makes clear that GMOs include all living modified organisms (LMO defined as "any living organism that possesses a novel combination of genetic material obtained through the use of modern biotechnology". This includes seeds, live fish, and other organisms intentionally obtained for release to the environment. It would seem that the common understanding about GMOs as referring to farm-to-table products is perforce expanded to embrace genetically modified farm animals and aquatic resources. Being a trade agreement, the Montreal accord primarily deals with the safety issues related to the transboundary movement of LMOs around the globe. The OECD conference on the other hand, called for an international body "to address all sides of the GM debate" in response to the public outcry, particularly in Western Europe, regarding the risks the new products pose to human health and the environment. Some points of contention, which remain unresolved, include issues such as whether countries should be allowed to develop their own GM food based on their needs, and whether a global moratorium on GMOs and mandatory labeling should be enforced worldwide.

  14. Natural Philosophy

    OpenAIRE

    Blair, Ann M.

    2006-01-01

    Natural philosophy” is often used by European historians as an umbrella term to designate the study of nature before it can easily be identified with what we call “science” today, to avoid the modern and potentially anachronistic connotations of that term. But “natural philosophy” (and its equivalents in different languages) was also an actor's category, a term commonly used throughout the early modern period and typically defined quite broadly as the study of natural bodies. As the central ...

  15. Dissonant Nature

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2013-01-01

    Nature restoration is far from being a neural undertaking. Just like any other type of heritage production it can be the source of dissonance – ‘our’ nature is not necessary ‘their’ nature. Often this dissonance is managed in ways, which are not particular sensitive to site-specificity. As exempl...... and allows for multiple interpretations to coexist. Evidence can be found in the Re-naturalization of River Aire (2002-2015), a restoration project, which reveals approaches that could be labelled landscape architecture specific....

  16. Temporal naturalism

    Science.gov (United States)

    Smolin, Lee

    2015-11-01

    Two people may claim both to be naturalists, but have divergent conceptions of basic elements of the natural world which lead them to mean different things when they talk about laws of nature, or states, or the role of mathematics in physics. These disagreements do not much affect the ordinary practice of science which is about small subsystems of the universe, described or explained against a background, idealized to be fixed. But these issues become crucial when we consider including the whole universe within our system, for then there is no fixed background to reference observables to. I argue here that the key issue responsible for divergent versions of naturalism and divergent approaches to cosmology is the conception of time. One version, which I call temporal naturalism, holds that time, in the sense of the succession of present moments, is real, and that laws of nature evolve in that time. This is contrasted with timeless naturalism, which holds that laws are immutable and the present moment and its passage are illusions. I argue that temporal naturalism is empirically more adequate than the alternatives, because it offers testable explanations for puzzles its rivals cannot address, and is likely a better basis for solving major puzzles that presently face cosmology and physics. This essay also addresses the problem of qualia and experience within naturalism and argues that only temporal naturalism can make a place for qualia as intrinsic qualities of matter.

  17. Modified asphalt for pavements; Hosoyo kaishitsu asufuaruto ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Tsukagoshi, T. [Nippon Oil Co. Ltd., Yokohama (Japan)

    1997-10-01

    Modified asphalt has been used widely in such applications as countermeasure against rutting, countermeasure against wear caused by tire chains in snowy and cold areas, or bridge deck pavement. Features of various kinds of modified asphalt, standards, and standard properties are introduced. Modified asphalt containing natural asphalt is used for steel plate deck pavement. Semi-blown asphalt is used when emphasis must be given to the countermeasure for flowing resistance of asphalt pavement. Features and standards of asphalt containing rubber, thermoplastic elastomer, and thermoplastic resin are described. Asphalt containing heat-setting resin shows excellent characteristics, which other types of modified asphalt do not possess, in the laboratory resistance test for fatigue, flowing, and wear. Change in the history of modified asphalt in Japan from the initial stage to the present are explained and shown in a table together with time and phenomena, and the change in the production of modified asphalt is shown. 15 refs., 5 figs., 5 tabs.

  18. Matematica Natural.

    Science.gov (United States)

    Lozano, Patricia; Medearis, Linda

    Matematica Natural (Natural Mathematics) is a mathematics curriculum for young children based on the assumption that they learn mathematics through concrete, real life, relevant experiences and that educational differences rather than cultural differences influence math achievement. The curriculum uses hands-on materials and activities to teach…

  19. Natural radiation

    International Nuclear Information System (INIS)

    Feliciano, Vanusa Maria Delage

    2016-01-01

    Cosmic radiation, as well as cosmogenic radiation, terrestrial radiation, radon and thorium are introduced in this chapter 3. The distribution of natural radiation sources is treated, where the percentage distribution of the contribution relative to exposure to radiation from natural and artificial sources is also included

  20. Framing nature

    NARCIS (Netherlands)

    Jansen, Peter

    2017-01-01

    This PhD thesis is about communication concerning nature in the Netherlands. The purpose of this exploratory study is to take both a theoretical and an empirical look at whether (implicit) religious elements play a role in this communication about nature in the Netherlands.

    In this PhD

  1. Natur formet

    DEFF Research Database (Denmark)

    Søberg, Martin

    2011-01-01

    Anmeldelse af Malene Hauxner, "Fra naturlig natur til SUPERNATUR – Europæisk landskabsarkitektur 1967-2007 set fra Danmark", Risskov: Ikaros Press, 2011.......Anmeldelse af Malene Hauxner, "Fra naturlig natur til SUPERNATUR – Europæisk landskabsarkitektur 1967-2007 set fra Danmark", Risskov: Ikaros Press, 2011....

  2. Chemical modifications of liquid natural rubber

    Science.gov (United States)

    Azhar, Nur Hanis Adila; Rasid, Hamizah Md; Yusoff, Siti Fairus M.

    2016-11-01

    Liquid natural rubber (LNR) was synthesized via photosentisized degradation of natural rubber (NR). LNR was modified into epoxidized liquid natural rubber (LENR) and hydroxylated liquid natural rubber (LNR-OH) using Na2WO4/CH3COOH/H2O2 catalytic system. Chemical structures of LNR and modified LNRs were characterized using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) and 1H Nuclear Magnetic Resonance (NMR) spectroscopies. Integration of 1H NMR was used to calculate the epoxy content (%) of LENR. 1H NMR detected the formation of LNR-OH after prolonged heating and increased of catalyst in oxidation reaction.

  3. Biotechnology: Two Decades of Experimentation with Genetically Modified Foods

    Directory of Open Access Journals (Sweden)

    Marjan Ajami

    2016-10-01

    Full Text Available Background and Objective: Over the recent years, genetically modified food in varieties of corn, soybeans, canola and cotton have been introduced to the global market. This study reviews the health and nutritional value of genetically modified foods in the past two decades.Results and Conclusions: Contrary to the present biotechnological claims, transgenic products did not prove to be so flawless, and actually failed to maintain social satisfaction. Genetically modified foods could not gain an increase in the yield potential. Planting natural products and genetically modified products in parallel lines will absolutely result in genetic infection from the side of genetically modified foods. One of the major anxieties of the anti- genetically modified foods activism is the claim that genetically modified crops would alter the consumable parts of the plant quality and safety. Genetically modified foods have shown to have inadequate efficiency and potential adverse effects in both fields of health and biodiversity. This review has presented studies of genetically modified foods performances in the past two decades, and concludes that the wide application and the over generalization of genetically modified foods are not fundamentally recommended.Conflict of interest: Authors declare that there is no conflict of interest.

  4. Modified harmony search

    Science.gov (United States)

    Mohamed, Najihah; Lutfi Amri Ramli, Ahmad; Majid, Ahmad Abd; Piah, Abd Rahni Mt

    2017-09-01

    A metaheuristic algorithm, called Harmony Search is quite highly applied in optimizing parameters in many areas. HS is a derivative-free real parameter optimization algorithm, and draws an inspiration from the musical improvisation process of searching for a perfect state of harmony. Propose in this paper Modified Harmony Search for solving optimization problems, which employs a concept from genetic algorithm method and particle swarm optimization for generating new solution vectors that enhances the performance of HS algorithm. The performances of MHS and HS are investigated on ten benchmark optimization problems in order to make a comparison to reflect the efficiency of the MHS in terms of final accuracy, convergence speed and robustness.

  5. Modified puestow lateral pancreaticojejunostomy.

    Science.gov (United States)

    Ceppa, Eugene P; Pappas, Theodore N

    2009-05-01

    There are various surgical options for the treatment of pain associated with chronic pancreatitis. The modified Puestow lateral pancreaticojejunostomy has been proven to be effective in ameliorating symptoms and expediting return to normal lifestyle while maintaining a low rate of morbidity and mortality. However, the debate regarding which surgical treatment provides the best outcomes is controversial. The aims of this manuscript are to identify the patient population for which the Puestow benefits the most and discuss the pertinent technical aspects of the surgical procedure.

  6. Natural radiation; A radiacao natural

    Energy Technology Data Exchange (ETDEWEB)

    Feliciano, Vanusa Maria Delage

    2016-07-01

    Cosmic radiation, as well as cosmogenic radiation, terrestrial radiation, radon and thorium are introduced in this chapter 3. The distribution of natural radiation sources is treated, where the percentage distribution of the contribution relative to exposure to radiation from natural and artificial sources is also included.

  7. Natural Communities

    Data.gov (United States)

    Kansas Data Access and Support Center — This dataset shows the locations of known tracts of high quality natural communities in Kansas, generalized to the PLSS section. It is not a compehensive dataset of...

  8. Sciences & Nature

    African Journals Online (AJOL)

    AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING AJOL ... Sciences & Nature, the Scientific Journal edited by the University of ... Subjects covered include agronomy, sciences of the earth, environment, biological, ...

  9. Pluralising Nature

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2017-01-01

    suppress other valid perceptions, in conflict with the need for different groups of people to be able to identify with the same territory. However, planning for the common good, in the case of nature restoration, does not necessarily mean planning for one common nature. Understanding and working......Denmark is recognised for its democratic approach to planning, and for the idea of planning for the common good. This interest in the common good and in common values also seems to be reflected in the way that the restoration of nature is planned and managed, suggesting that there is one common...... “nature” that everyone can agree on. But nature restoration is far from being an unproblematic undertaking. As with any other type of heritage production, it can be the source of dissonance. As exemplified by the Skjern River Restoration Project, one perception of a landscape and its value as “nature” can...

  10. Writing Nature

    Directory of Open Access Journals (Sweden)

    Kristin Asdal

    2014-06-01

    Full Text Available This special issue of the Nordic Journal of Science and Technology Studies is interested in how nature, in different versions and forms, is invited into our studies, analyses, and stories. How is it that we “write nature”? How is it that we provide space for, and actually describe the actors, agents, or surroundings, in our stories and analyses? The articles in the issue each deal with different understandings of both the practices of writing and the introduction of various natures into these. In this introduction to the issue the editors engage with actor-network theory as a material semiotic resource for writing nature. We propose to foreground actor-network theory as a writing tool, at the expense of actor-network theory as a distinct vocabulary. In doing this and pointing out the semiotic origins to material-semiotics we also want to problematize a clear-cut material approach to writing nature.

  11. Natural aphrodisiacs.

    Science.gov (United States)

    Shamloul, Rany

    2010-01-01

    The search for a remedy or a prescription that can enhance sexual function and/or treat male erectile dysfunction has been an obsession throughout known history. Whether it was an Eastern civilization or a Western one, religious or atheist, man's aspiration for a better or best "manhood" has been a history-time goal. This review will discuss the current research done on the most popular natural aphrodisiacs and examine the weight of evidence to support or discourage the use of any of these substances to enhance sexual desire and/or function. Review of the current evidence on the use of natural substances as aphrodisiacs. Efficacy of natural aphrodisiacs in enhancing sexual function in men and women. There is little evidence from literature to recommend the usage of natural aphrodisiacs for the enhancement of sexual desire and/or performance. Data on yohimbine's efficacy does not support the wide use of the drug, which has only mild effects in the treatment of psychogenic ED. Although there's a positive trend towards recommending ginseng as an effective aphrodisiac, however, more in depth studies involving large number of subjects and its mechanism of action are needed before definite conclusions could be reached. Data on the use of natural aphrodisiacs in women is limited. The current body of objective evidence does not support the use of any natural aphrodisiac as an effective treatment for male or female sexual dysfunctions. Potent men and men with ED will continue the search for natural aphrodisiacs despite the current disappointing data on their effectiveness. Care should be taken regarding the fraud addition of sildenafil analogues to natural aphrodisiacs.

  12. Lorentz invariance violation in modified gravity

    International Nuclear Information System (INIS)

    Brax, Philippe

    2012-01-01

    We consider an environmentally dependent violation of Lorentz invariance in scalar-tensor models of modified gravity where General Relativity is retrieved locally thanks to a screening mechanism. We find that fermions have a modified dispersion relation and would go faster than light in an anisotropic and space-dependent way along the scalar field lines of force. Phenomenologically, these models are tightly restricted by the amount of Cerenkov radiation emitted by the superluminal particles, a constraint which is only satisfied by chameleons. Measuring the speed of neutrinos emitted radially from the surface of the earth and observed on the other side of the earth would probe the scalar field profile of modified gravity models in dense environments. We argue that the test of the equivalence principle provided by the Lunar ranging experiment implies that a deviation from the speed of light, for natural values of the coupling scale between the scalar field and fermions, would be below detectable levels, unless gravity is modified by camouflaged chameleons where the field normalisation is environmentally dependent.

  13. Lorentz invariance violation in modified gravity

    Energy Technology Data Exchange (ETDEWEB)

    Brax, Philippe, E-mail: philippe.brax@cea.fr [Institut de Physique Theorique, CEA, IPhT, CNRS, URA 2306, F-91191Gif/Yvette Cedex (France)

    2012-06-06

    We consider an environmentally dependent violation of Lorentz invariance in scalar-tensor models of modified gravity where General Relativity is retrieved locally thanks to a screening mechanism. We find that fermions have a modified dispersion relation and would go faster than light in an anisotropic and space-dependent way along the scalar field lines of force. Phenomenologically, these models are tightly restricted by the amount of Cerenkov radiation emitted by the superluminal particles, a constraint which is only satisfied by chameleons. Measuring the speed of neutrinos emitted radially from the surface of the earth and observed on the other side of the earth would probe the scalar field profile of modified gravity models in dense environments. We argue that the test of the equivalence principle provided by the Lunar ranging experiment implies that a deviation from the speed of light, for natural values of the coupling scale between the scalar field and fermions, would be below detectable levels, unless gravity is modified by camouflaged chameleons where the field normalisation is environmentally dependent.

  14. [Genetically modified food--unnecessary controversy?].

    Science.gov (United States)

    Tchórz, Michał; Radoniewicz-Chagowska, Anna; Lewandowska-Stanek, Hanna; Szponar, Elzbieta; Szponar, Jarosław

    2012-01-01

    Fast development of genetic engineering and biotechnology allows use of genetically modified organisms (GMO) more and more in different branches of science and economy. Every year we can see an increase of food amount produced with the use of modification of genetic material. In our supermarkets we can find brand new types of plants, products including genetically modified ingredients or meat from animals fed with food containing GMO. This article presents general information about genetically modified organisms, it also explains the range of genetic manipulation, use of newly developed products and current field area for GMO in the world. Based on scientific data the article presents benefits from development of biotechnology in reference to modified food. It also presents the voice of skeptics who are extremely concerned about the impact of those organisms on human health and natural environment. Problems that appear or can appear as a result of an increase of GMO are very important not only from a toxicologist's or a doctor's point of view but first of all from the point of view of ordinary consumers--all of us.

  15. Bitumen based modified substance

    International Nuclear Information System (INIS)

    Kostolanyi, P.

    1987-01-01

    The necessary amounts of tetrahydrosilicic acid and methyl phenyl silicon oil are added to molten bitumen heated to temperatures of 50 to 200 degC. The mixture is thoroughly mixed and let to cool. The structure of the product comes close to gel and its properties (penetration, softening point, workability time, penetration index) may be changed in dependence on the amount of additions and on the time and temperature of heating. The advantage of the thus prepared modified material is its shorter workability time, its ability to bind materials with a certain water content, and its relatively low price. It may be used for fixing and storing low-and medium-level radioactive organic and thickened waste waters. (E.S.)

  16. Modified Clipped LMS Algorithm

    Directory of Open Access Journals (Sweden)

    Lotfizad Mojtaba

    2005-01-01

    Full Text Available Abstract A new algorithm is proposed for updating the weights of an adaptive filter. The proposed algorithm is a modification of an existing method, namely, the clipped LMS, and uses a three-level quantization ( scheme that involves the threshold clipping of the input signals in the filter weight update formula. Mathematical analysis shows the convergence of the filter weights to the optimum Wiener filter weights. Also, it can be proved that the proposed modified clipped LMS (MCLMS algorithm has better tracking than the LMS algorithm. In addition, this algorithm has reduced computational complexity relative to the unmodified one. By using a suitable threshold, it is possible to increase the tracking capability of the MCLMS algorithm compared to the LMS algorithm, but this causes slower convergence. Computer simulations confirm the mathematical analysis presented.

  17. Modified arthroscopic Brostrom procedure.

    Science.gov (United States)

    Lui, Tun Hing

    2015-09-01

    The open modified Brostrom anatomic repair technique is widely accepted as the reference standard for lateral ankle stabilization. However, there is high incidence of intra-articular pathologies associated with chronic lateral ankle instability which may not be addressed by an isolated open Brostrom procedure. Arthroscopic Brostrom procedure with suture anchor has been described for anatomic repair of chronic lateral ankle instability and management of intra-articular lesions. However, the complication rates seemed to be higher than open Brostrom procedure. Modification of the arthroscopic Brostrom procedure with the use of bone tunnel may reduce the risk of certain complications. Copyright © 2015 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

  18. Modified circular velocity law

    Science.gov (United States)

    Djeghloul, Nazim

    2018-05-01

    A modified circular velocity law is presented for a test body orbiting around a spherically symmetric mass. This law exhibits a distance scale parameter and allows to recover both usual Newtonian behaviour for lower distances and a constant velocity limit at large scale. Application to the Galaxy predicts the known behaviour and also leads to a galactic mass in accordance with the measured visible stellar mass so that additional dark matter inside the Galaxy can be avoided. It is also shown that this circular velocity law can be embedded in a geometrical description of spacetime within the standard general relativity framework upon relaxing the usual asymptotic flatness condition. This formulation allows to redefine the introduced Newtonian scale limit in term of the central mass exclusively. Moreover, a satisfactory answer to the galactic escape speed problem can be provided indicating the possibility that one can also get rid of dark matter halo outside the Galaxy.

  19. Emancipating Nature

    DEFF Research Database (Denmark)

    Munk, Anders Kristian

    2012-01-01

    The issue of riverine flooding in the UK is closely tied up with computer simulations. Arguably, these modelling practices are ripe with the anticipation of nature. They aspire to pre-empt it, hence expect it to be ‘out there’, and ultimately work through formalized distillations of it – hydrodyn......The issue of riverine flooding in the UK is closely tied up with computer simulations. Arguably, these modelling practices are ripe with the anticipation of nature. They aspire to pre-empt it, hence expect it to be ‘out there’, and ultimately work through formalized distillations...... of it – hydrodynamic equations – which have their own anticipations and place their own demands on their modellers. Through the experience of a flood modelling apprenticeship I argue that the taking-place of such anticipations paradoxically relies on the birth of a hybrid, the model-modeller, and thus on a nature...

  20. Natural aerodynamics

    CERN Document Server

    Scorer, R S

    1958-01-01

    Natural Aerodynamics focuses on the mathematics of any problem in air motion.This book discusses the general form of the law of fluid motion, relationship between pressure and wind, production of vortex filaments, and conduction of vorticity by viscosity. The flow at moderate Reynolds numbers, turbulence in a stably stratified fluid, natural exploitation of atmospheric thermals, and plumes in turbulent crosswinds are also elaborated. This text likewise considers the waves produced by thermals, transformation of thin layer clouds, method of small perturbations, and dangers of extra-polation.Thi

  1. Provincialising Nature

    DEFF Research Database (Denmark)

    Provincialising Nature: Multidisciplinary Approaches to the Politics of the Environment in Latin America offers a timely analysis of some of the crucial challenges, contradictions and promises within current environmental discourses and practices in the region. This book shows both challenging...... scenarios and original perspectives that have emerged in Latin America in relation to the globally urgent issues of climate change and the environmental crisis. Two interconnected analytical frameworks guide the discussions in the book: the relationship between nature, knowledge and identity and their role...

  2. Experimental evolution and the dynamics of genomic mutation rate modifiers.

    Science.gov (United States)

    Raynes, Y; Sniegowski, P D

    2014-11-01

    Because genes that affect mutation rates are themselves subject to mutation, mutation rates can be influenced by natural selection and other evolutionary forces. The population genetics of mutation rate modifier alleles has been a subject of theoretical interest for many decades. Here, we review experimental contributions to our understanding of mutation rate modifier dynamics. Numerous evolution experiments have shown that mutator alleles (modifiers that elevate the genomic mutation rate) can readily rise to high frequencies via genetic hitchhiking in non-recombining microbial populations. Whereas these results certainly provide an explanatory framework for observations of sporadically high mutation rates in pathogenic microbes and in cancer lineages, it is nonetheless true that most natural populations have very low mutation rates. This raises the interesting question of how mutator hitchhiking is suppressed or its phenotypic effect reversed in natural populations. Very little experimental work has addressed this question; with this in mind, we identify some promising areas for future experimental investigation.

  3. Nature Watch

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 3. Nature Watch Diversity of Bats. G Marimuthu. Feature Article Volume 1 Issue 3 March 1996 pp 103-110. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/001/03/0103-0110. Author Affiliations.

  4. Nature's Palette

    Science.gov (United States)

    McBride, Brooke B.; Brewer, Carol A.

    2010-01-01

    Flower petals, acorn hats, exoskeletons of beetles, and lichens are just a few of the objects students may find in a surprising array of vivid colors. These tiny examples from nature's palette can be discovered in a school yard, a park, or even along the edges of a paved sidewalk...it simply takes careful observation! This article describes a…

  5. Nature Watch

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 9. Nature Watch - Coral Reefs and their Fauna: An Underwater Fantasyland. Anuradha Bhat. Feature Article Volume 9 Issue 9 September 2004 pp 62-73. Fulltext. Click here to view fulltext PDF. Permanent link:

  6. Nature Watch

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 3. Nature Watch: Symbiosis in Coastal Marine Communities. Neelam Pereira. Feature Article Volume 20 Issue 3 March 2015 pp 245-253. Fulltext. Click here to view fulltext PDF. Permanent link:

  7. Nature Watch

    Indian Academy of Sciences (India)

    ... Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Resonance – Journal of Science Education; Volume 3; Issue 5. Nature Watch - Thinking Like a Tahr: When Males and Females go their Separate Ways. M D Madhusudan. Feature Article Volume 3 Issue 5 May 1998 pp 43-47 ...

  8. Natural Propositions

    DEFF Research Database (Denmark)

    Stjernfelt, Frederik

    Preface -- Introduction -- The generality of signs -- Dicisigns -- Some consequences of the dicisign doctrine -- Dicisigns and cognition -- Natural propositions--the evolution of semiotic self-control -- Dicisigns beyond language -- Operational and optimal iconicity in Peirce's diagrammatology...... -- Cows, red cows, and red herrings -- Corollarial and theorematic experiments with diagrams -- Strategies of research: Peirce's enlightenment maxims -- Perspective -- References -- Index....

  9. Nature Watch

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 7. Nature Watch - Singapore's Jurong BirdPark: A Study Model. Abraham Verghese. Feature Article Volume 6 Issue 7 July 2001 pp 74-88. Fulltext. Click here to view fulltext PDF. Permanent link:

  10. Kritikkens natur

    DEFF Research Database (Denmark)

    Schatz-Jakobsen, Claus

    1999-01-01

    Artiklen introducerer det nye forskningsfelt inden for samtænkning af litteratur, kultur og natur, den såkaldt økologiske kritik, og kaster et kritisk blik på  dens brug af romantisk litteratur som proto-økologisk kanon....

  11. Nature Watch

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 7. Nature Watch - The Odyssey of the Olive Ridley. Kartik Shanker. Feature Article Volume 4 Issue 7 July 1999 pp 68-78. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/004/07/0068-0078 ...

  12. Nature Watch

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 8. Nature Watch - Secrets of the Shieldtails. Kartik Shanker. Feature Article Volume 1 Issue 8 August 1996 pp 64-70. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/001/08/0064-0070 ...

  13. Nature Watch

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... ... 20; Issue 1. Nature Watch: A Tale of Two Turtles. V Deepak. Feature Article Volume 20 Issue 1 January 2015 pp 47-54. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/020/01/0047-0054. Keywords. Ecology; endemic; India; turtles; tortoises; Western Ghats.

  14. Distinguishing modified gravity models

    International Nuclear Information System (INIS)

    Brax, Philippe; Davis, Anne-Christine

    2015-01-01

    Modified gravity models with screening in local environments appear in three different guises: chameleon, K-mouflage and Vainshtein mechanisms. We propose to look for differences between these classes of models by considering cosmological observations at low redshift. In particular, we analyse the redshift dependence of the fine structure constant and the proton to electron mass ratio in each of these scenarios. When the absorption lines belong to unscreened regions of space such as dwarf galaxies, a time variation would be present for chameleons. For both K-mouflage and Vainshtein mechanisms, the cosmological time variation of the scalar field is not suppressed in both unscreened and screened environments, therefore enhancing the variation of constants and their detection prospect. We also consider the time variation of the redshift of distant objects using their spectrocopic velocities. We find that models of the K-mouflage and Vainshtein types have very different spectroscopic velocities as a function of redshift and that their differences with the Λ-CDM template should be within reach of the future ELT-HIRES observations

  15. MODIFIED GYPSUM BINDER

    Directory of Open Access Journals (Sweden)

    KONDRATEVA N. V.

    2017-02-01

    Full Text Available Summary. Statement of the problem. A disadvantage of the gypsum binder is the limited water resistance of products that historically led to the use of gypsum products mostly for internal construction and finishing works. To regulate the process of hydration and structure formation of the use of chemical additives that are introduced with the mixing water or in the production of the binder. As a rule, substances that increase the solubility of the gypsum binder referred to as the hardening accelerator, and substances which retard the solubility of the inhibitors of hardening of the mixture. Most accelerators and retarders hardening affect adversely on the final strength of the mixture. More effective impact on gypsum binder additives have plasticizers. The purpose of the article. Getting gypsum binder modified with the aim of improving its water resistance and improvement of some technological factors (the time of hardening, water gypsum ratio, etc. would reduce its shortcomings and expand the scope of application of the binder. Conclusion. The result of the research reviewed changes in the basic properties of the gypsum binder with the introduction of additives, plasticizers, and selected the most effective supplements to significantly reduce water gypsum ratio, to improve strength properties and to obtain gypsum binder more dense structure.

  16. Distinguishing modified gravity models

    Energy Technology Data Exchange (ETDEWEB)

    Brax, Philippe [Institut de Physique Théorique, Université Paris-Saclay, CEA, CNRS, F-91191 Gif/Yvette Cedex (France); Davis, Anne-Christine, E-mail: philippe.brax@cea.fr, E-mail: A.C.Davis@damtp.cam.ac.uk [DAMTP, Centre for Mathematical Sciences, University of Cambridge, Cambridge, CB3 0WA (United Kingdom)

    2015-10-01

    Modified gravity models with screening in local environments appear in three different guises: chameleon, K-mouflage and Vainshtein mechanisms. We propose to look for differences between these classes of models by considering cosmological observations at low redshift. In particular, we analyse the redshift dependence of the fine structure constant and the proton to electron mass ratio in each of these scenarios. When the absorption lines belong to unscreened regions of space such as dwarf galaxies, a time variation would be present for chameleons. For both K-mouflage and Vainshtein mechanisms, the cosmological time variation of the scalar field is not suppressed in both unscreened and screened environments, therefore enhancing the variation of constants and their detection prospect. We also consider the time variation of the redshift of distant objects using their spectrocopic velocities. We find that models of the K-mouflage and Vainshtein types have very different spectroscopic velocities as a function of redshift and that their differences with the Λ-CDM template should be within reach of the future ELT-HIRES observations.

  17. Shifted-modified Chebyshev filters

    OpenAIRE

    ŞENGÜL, Metin

    2013-01-01

    This paper introduces a new type of filter approximation method that utilizes shifted-modified Chebyshev filters. Construction of the new filters involves the use of shifted-modified Chebyshev polynomials that are formed using the roots of conventional Chebyshev polynomials. The study also includes 2 tables containing the shifted-modified Chebyshev polynomials and the normalized element values for the low-pass prototype filters up to degree 6. The transducer power gain, group dela...

  18. Genetically modified organisms (GMOs) and aquaculture.

    Science.gov (United States)

    Beardmore, J A; Porter, Joanne S

    2003-01-01

    This paper reviews the nature of genetically modified organisms (GMOs), the range of aquatic species in which GMOs have been produced, the methods and target genes employed, the benefits to aquaculture, the problems attached to use of GMOs in aquatic species and the regulatory and other social frameworks surrounding them. A set of recommendations aimed at best practice is appended. This states the potential value of GMOs in aquaculture but also calls for improved knowledge particularly of sites of integration, risk analysis, progress in achieving sterility in fish for production and better dissemination of relevant information.

  19. Provincialising Nature

    DEFF Research Database (Denmark)

    Provincialising Nature: Multidisciplinary Approaches to the Politics of the Environment in Latin America offers a timely analysis of some of the crucial challenges, contradictions and promises within current environmental discourses and practices in the region. This book shows both challenging...... scenarios and original perspectives that have emerged in Latin America in relation to the globally urgent issues of climate change and the environmental crisis. Two interconnected analytical frameworks guide the discussions in the book: the relationship between nature, knowledge and identity and their role...... in understanding recent and current practices of climate change and environmental policy. The different chapters in this volume contribute to this debate by offering multidisciplinary perspectives on particular aspects of these two frameworks and through a multidirectional outlook that links the local, national...

  20. Unbounded Naturalism

    Directory of Open Access Journals (Sweden)

    Andrew Taggart

    2008-10-01

    Full Text Available nbsp;font face="Times, serif"font size="3"In the Anglo-American reception of John McDowellrsquo;s /font/fontfont face="Times, serif"font size="3"emMind and World/em/font/fontfont face="Times, serif"font size="3", there has been little attention paid to the developmental aspect of his lsquo;partially re-enchantedrsquo; naturalism. In lsquo;Naturalism Unboundedrsquo;, I argue that McDowellrsquo;s story of our normal upbringing (/font/fontfont face="Times, serif"font size="3"emBildung/em/font/fontfont face="Times, serif"font size="3" presents problems for his claim that we have a lsquo;standing obligationrsquo; to reflect on our perceptual experiences. I follow this critique up with a Hegelian-inspired attempt to retain and revise the vital points he makes about experience./font/font

  1. Natural games

    International Nuclear Information System (INIS)

    Anttila, Jani; Annila, Arto

    2011-01-01

    A course of a game is formulated as a physical process that will consume free energy in the least time. Accordingly, the rate of entropy increase is the payoff function that will subsume all forms of free energy that motivate diverse decisions. Also other concepts of game theory are related to their profound physical counterparts. When the physical portrayal of behavior is mathematically analyzed, the course of a game is found to be inherently unpredictable because each move affects motives in the future. Despite the non-holonomic character of the natural process, the objective of consuming free energy in the least time will direct an extensive-form game toward a Lyapunov-stable point that satisfies the minimax theorem. -- Highlights: → Behavior in the context of game theory is described as a natural process. → The rate of entropy increase, derived from statistical physics of open systems, is identified as the payoff function. → Entropy as the payoff function also clarifies motives of collaboration and subjective nature of decision making. → Evolutionary equation of motion that accounts for the course of a game is inherently unpredictable.

  2. UNDERSTANDING OF GENETICALLY MODIFIED ORGANISMS

    Directory of Open Access Journals (Sweden)

    Željko Kaluđerović

    2012-09-01

    Full Text Available During the last sixteen years biotechnology, genetic engineering, transgenic organisms or genetically modified organisms (GMOs have been raising numerous controversies. In the scientific sphere, genetic engineering and GMOs represent a special challenge for geneticists, breeders and physicians, in philosophy it is a topic of interest for bioethicists and agricultural ethicists, environmentalists are interested in the interconnectictions between new technology and environment protection, for multinational companies this is a potential source of huge profits, and for certain governments they represent an instrument for strategic control of food production within their countries as well as internationally. By taking into account the views of both advocates and opponents of this "revolutionary" method, authors believe that we should not a priori reject new and insufficiently studied technologies, but that in this particular it is necessary to be extremely cautious, in other words that from (bioethical point of view only those GMO investigations limited to scientific purposes are justified, provided that all required precautions have been taken. Also, authors are of the opinion that in this region as well as in Europe as a whole, at this moment, transgenic organisms are not necessery, neither in agricultural production nor in the food chain. Arguments for such a statement are found primarily in the potential issues that intentional breeding of GMOs might inflict upon the human health and environment. Namely, if borders of individual species are not overstepped and if their endogenous traits are made stronger, the potential risk of causing irreparable damage for both present and future generations which may be brought by changed biological succession will be reduced, i.e. one of the four fundamental bioethical principles will be applied and that is the nonmaleficence. Further intentional decreasing of biodiversity should not be allowed, which means

  3. UNDERSTANDING OF GENETICALLY MODIFIED ORGANISMS

    Directory of Open Access Journals (Sweden)

    Željko Kaluđerović

    2012-09-01

    Full Text Available During the last sixteen years biotechnology, genetic engineering, transgenic organisms or genetically modified organisms (GMOs have been raising numerous controversies. In the scientific sphere, genetic engineering and GMOs represent a special challenge for geneticists, breeders and physicians, in philosophy it is a topic of interest for bioethicists and agricultural ethicists, environmentalists are interested in the interconnectictions between new technology and environment protection, for multinational companies this is a potential source of huge profits, and for certain governments they represent an instrument for strategic control of food production within their countries as well as internationally. By taking into account the views of both advocates and opponents of this "revolutionary" method, authors believe that we should not a priori reject new and insufficiently studied technologies, but that in this particular it is necessary to be extremely cautious, in other words that from (bioethical point of view only those GMO investigations limited to scientific purposes are justified, provided that all required precautions have been taken. Also, authors are of the opinion that in this region as well as in Europe as a whole, at this moment, transgenic organisms are not necessery, neither in agricultural production nor in the food chain. Arguments for such a statement are found primarily in the potential issues that intentional breeding of GMOs might inflict upon the human health and environment. Namely, if borders of individual species are not overstepped and if their endogenous traits are made stronger, the potential risk of causing irreparable damage for both present and future generations which may be brought by changed biological succession will be reduced, i.e. one of the four fundamental bioethical principles will be applied and that is the nonmaleficence. Further intentional decreasing of biodiversity should not be allowed, which means

  4. Structural simulation of natural zeolites

    International Nuclear Information System (INIS)

    Sanchez P, E.; Carrera G, L.M.

    1997-01-01

    The application of X-ray diffraction (XRD) in the study of crystalline structures of the natural and modified zeolites allows the identification, lattice parameter determination and the crystallinity grade of the sample of interest. Until two decades ago, simulation methods of X-ray diffraction patterns were developed with which was possible to do reliable determinations of their crystalline structure. In this work it is presented the first stage of the crystalline structure simulation of zeolitic material from Etla, Oaxaca which has been studied for using it in the steam production industry and purification of industrial water. So that the natural material was modified for increasing its sodium contents and this material in its turn was put in contact with aqueous solutions of Na, Mg and Ca carbonates. All the simulations were done with the Lazy-Pulverix method. The considered phase was clinoptilolite. It was done the comparison with three clinoptilolite reported in the literature. (Author)

  5. Horseshoes in modified Chen's attractors

    International Nuclear Information System (INIS)

    Huang Yan; Yang Xiaosong

    2005-01-01

    In this paper we study dynamics of a class of modified Chen's attractors, we show that these attractors are chaotic by giving a rigorous verification for existence of horseshoes in these systems. We prove that the Poincare maps derived from these modified Chen's attractors are semi-conjugate to the 2-shift map

  6. Surface-modified electrodes (SME)

    NARCIS (Netherlands)

    Schreurs, J.P.G.M.; Barendrecht, E.

    1984-01-01

    This review deals with the literature (covered up to August 1983), the characterization and the applications of Surface-Modified Electrodes (SME). As a special class of SME's, the Enzyme-Modified Electrode (EME) is introduced. Three types of modification procedures are distinguished; i.e. covalent

  7. Genetically modified foods and allergy.

    Science.gov (United States)

    Lee, T H; Ho, H K; Leung, T F

    2017-06-01

    2015 marked the 25th anniversary of the commercial use and availability of genetically modified crops. The area of planted biotech crops cultivated globally occupies a cumulative two billion hectares, equivalent to twice the land size of China or the United States. Foods derived from genetically modified plants are widely consumed in many countries and genetically modified soybean protein is extensively used in processed foods throughout the industrialised countries. Genetically modified food technology offers a possible solution to meet current and future challenges in food and medicine. Yet there is a strong undercurrent of anxiety that genetically modified foods are unsafe for human consumption, sometimes fuelled by criticisms based on little or no firm evidence. This has resulted in some countries turning away food destined for famine relief because of the perceived health risks of genetically modified foods. The major concerns include their possible allergenicity and toxicity despite the vigorous testing of genetically modified foods prior to marketing approval. It is imperative that scientists engage the public in a constructive evidence-based dialogue to address these concerns. At the same time, improved validated ways to test the safety of new foods should be developed. A post-launch strategy should be established routinely to allay concerns. Mandatory labelling of genetically modified ingredients should be adopted for the sake of transparency. Such ingredient listing and information facilitate tracing and recall if required.

  8. Modified General Relativity and Cosmology

    Science.gov (United States)

    Abdel-Rahman, A.-M. M.

    1997-10-01

    Aspects of the modified general relativity theory of Rastall, Al-Rawaf and Taha are discussed in both the radiation- and matter-dominated flat cosmological models. A nucleosynthesis constraint on the theory's free parameter is obtained and the implication for the age of the Universe is discussed. The consistency of the modified matter- dominated model with the neoclassical cosmological tests is demonstrated.

  9. Modified zirconium-eriochrome cyanine R determination of fluoride

    Science.gov (United States)

    Thatcher, L.L.

    1957-01-01

    The Eriochrome Cyanine R method for determining fluoride in natural water has been modified to provide a single, stable reagent solution, eliminate interference from oxidizing agents, extend the concentration range to 3 p.p.m., and extend the phosphate tolerance. Temperature effect was minimized; sulfate error was eliminated by precipitation. The procedure is sufficiently tolerant to interferences found in natural and polluted waters to permit the elimination of prior distillation for most samples. The method has been applied to 500 samples.

  10. Modified geodetic brane cosmology

    International Nuclear Information System (INIS)

    Cordero, Rubén; Cruz, Miguel; Molgado, Alberto; Rojas, Efraín

    2012-01-01

    We explore the cosmological implications provided by the geodetic brane gravity action corrected by an extrinsic curvature brane term, describing a codimension-1 brane embedded in a 5D fixed Minkowski spacetime. In the geodetic brane gravity action, we accommodate the correction term through a linear term in the extrinsic curvature swept out by the brane. We study the resulting geodetic-type equation of motion. Within a Friedmann–Robertson–Walker metric, we obtain a generalized Friedmann equation describing the associated cosmological evolution. We observe that, when the radiation-like energy contribution from the extra dimension is vanishing, this effective model leads to a self-(non-self)-accelerated expansion of the brane-like universe in dependence on the nature of the concomitant parameter β associated with the correction, which resembles an analogous behaviour in the DGP brane cosmology. Several possibilities in the description for the cosmic evolution of this model are embodied and characterized by the involved density parameters related in turn to the cosmological constant, the geometry characterizing the model, the introduced β parameter as well as the dark-like energy and the matter content on the brane. (paper)

  11. Natural games

    Science.gov (United States)

    Anttila, Jani; Annila, Arto

    2011-10-01

    A course of a game is formulated as a physical process that will consume free energy in the least time. Accordingly, the rate of entropy increase is the payoff function that will subsume all forms of free energy that motivate diverse decisions. Also other concepts of game theory are related to their profound physical counterparts. When the physical portrayal of behavior is mathematically analyzed, the course of a game is found to be inherently unpredictable because each move affects motives in the future. Despite the non-holonomic character of the natural process, the objective of consuming free energy in the least time will direct an extensive-form game toward a Lyapunov-stable point that satisfies the minimax theorem.

  12. Natural uranium

    International Nuclear Information System (INIS)

    Ammerich, Marc; Frot, Patricia; Gambini, Denis-Jean; Gauron, Christine; Moureaux, Patrick; Herbelet, Gilbert; Lahaye, Thierry; Pihet, Pascal; Rannou, Alain

    2014-08-01

    This sheet belongs to a collection which relates to the use of radionuclides essentially in unsealed sources. Its goal is to gather on a single document the most relevant information as well as the best prevention practices to be implemented. These sheets are made for the persons in charge of radiation protection: users, radioprotection-skill persons, labor physicians. Each sheet treats of: 1 - the radio-physical and biological properties; 2 - the main uses; 3 - the dosimetric parameters; 4 - the measurement; 5 - the protection means; 6 - the areas delimitation and monitoring; 7 - the personnel classification, training and monitoring; 8 - the effluents and wastes; 9 - the authorization and declaration administrative procedures; 10 - the transport; and 11 - the right conduct to adopt in case of incident or accident. This sheet deals specifically with natural uranium

  13. Uranium (Vi) sorption onto zirconium diphosphate chemically modified

    International Nuclear Information System (INIS)

    Garcia G, N.; Ordonez R, E.

    2010-10-01

    This work deals with the uranium (Vi) speciation after sorption onto zirconium diphosphate (ZrP 2 O 7 ) surface, hydrated and in a surface modified with organic acids. Oxalic and citric acids were chosen to modify the ZrP 2 O 7 surface because they have poly carboxylic groups and they mimic the organic matter in nature. Thus the interest of this work is to evaluate the uranium (Vi) sorption edge at different s ph values in natural and modified surfaces. The luminescence technique (fluorescence and phosphorescence, respectively) was used for the quantification and speciation of uranyl sorbed at the zirconium diphosphate interface. The fluorescence experiment, showed that adsorption of uranyl on surface of zirconium diphosphate tends to 100%. The speciation shows that there are different complexes in surface which were formed between zirconium diphosphate and uranyl, since it is produced a displacement of wavelength in fluorescence spectra of each system. (Author)

  14. Next nature : nature changes along with us

    NARCIS (Netherlands)

    Mensvoort, van K.M.; Grievink, H.J.

    2011-01-01

    We debate saving nature, we dream about escaping to nature, but rarely do we ask "What is nature?". The Next Nature book radically shifts your notion of nature. Where technology and nature are traditionally seen as opposed, they now appear to merge or even trade places. With our urge to design our

  15. Natural isotopes

    International Nuclear Information System (INIS)

    Vogel, J.C.

    1986-01-01

    14 C dates between 600 and 900 AD were obtained for early Iron Age sites in Natal, and from 1300 to 1450 AD for rock engraving sites in Bushmanland. Palaeoenvironmental data derived from the dating of samples related to sedimentary and geomorphic features in the central and northern Namib Desert enabled the production of a tentative graph for the changes in humidity in the region over the past 40000 years. These results suggest that relatively humid conditions came to an end in the Namib at ±25000 BP (before present). The increased precision of the SIRA mass spectrometer enabled the remeasurement of 13 C and 18 O in the Cango stalagmite. This data confirmed that the environmental temperatures in the Southern Cape remained constant to within ±1 o C during the past 5500 years. Techniques and applications for environmental isotopes in hydrology were developed to determine the origin and movement of ground water. Isotopic fractionation effects in light elements in nature were investigated. The 15 N/ 14 N ratio in bones of animals and humans increases in proportion to the aridity of the environment. This suggests that 15 N in bone from dated archaeological sites could be used to detect changes in past climatic conditions as naturally formed nitrate minerals are higly soluble and are only preserved in special, very dry environments. The sources and sinks of CO 2 on the South African subcontinent were also determined. The 13 C/ 12 C ratios of air CO 2 obtained suggest that the vegetation provides the major proportion of respired CO 2 . 9 refs., 1 fig

  16. The modified simple equation method for solving some fractional ...

    Indian Academy of Sciences (India)

    ... and processes in various areas of natural science. Thus, many effective and powerful methods have been established and improved. In this study, we establish exact solutions of the time fractional biological population model equation and nonlinearfractional Klein–Gordon equation by using the modified simple equation ...

  17. Influence of the measurement medium and matrix modifiers on the ...

    African Journals Online (AJOL)

    An electrothermal atomic absorption (ETAAS) method has been developed for the direct determination of Si in natural waters. Measurements were carried out on previously alkalinized samples and using a mixture of Pd and Mg(NO3)2 as matrix modifier, with an ashing temperature of 1400 oC and an atomization ...

  18. Anterior EEG Asymmetry and the Modifier Model of Autism

    Science.gov (United States)

    Burnette, Courtney P.; Henderson, Heather A.; Inge, Anne Pradella; Zahka, Nicole E.; Schwartz, Caley B.; Mundy, Peter C.

    2011-01-01

    Individual differences in the expression of autism complicate research on the nature and treatment of this disorder. In the Modifier Model of Autism (Mundy et al. 2007), we proposed that individual differences in autism may result not only from syndrome specific causal processes, but also from variability in generic, non-syndrome specific…

  19. TAILORING ACTIVATED CARBONS FOR ENHANCED REMOVAL OF NATURAL ORGANIC MATTER FROM NATURAL WATERS. (R828157)

    Science.gov (United States)

    Several pathways have been employed to systematically modify two granular activated carbons (GACs), F400 (coal-based) and Macro (wood-based), for examining adsorption of dissolved natural organic matter (DOM) from natural waters. A total of 24 activated carbons with different ...

  20. MS Disease-Modifying Medications

    Science.gov (United States)

    ... disease-modifying therapies Approval: 2014 US; 2014 CAN Pregnancy Category C (see footnote, page 11) Rash, headache, fever, nasal congestion, nausea, urinary tract infection, fatigue, insomnia, upper respiratory tract infection, herpes viral ...

  1. Value Modifier Public Use File

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Center for Medicare (CM) has created a standard analytical file intended to promote transparency. For each Value Modifier performance year, CM will publish a...

  2. Fungos micorrízicos nativos e Glomus clarun no rendimento de trevo vesiculoso cultivado em condições naturais e modificadas pela calagem e aplicação de fósforo Glomus clarun and native mycorrhizal fungi on yield of Trifolium spp. cultivated under natural and modified soil contitions with addition by phosphorus and liming

    Directory of Open Access Journals (Sweden)

    Antonio Carlos dos Santos Pessoa

    1997-03-01

    andcontrai which was without inocutation of AMF: twopH leveis: 4.4 and 5.4 and two phosphorus leveis by Mehlich I extractor: 6 and l5mg/kg of soil. It was noticed that when G. clarum was introduced isolately or with native AMF with pH of 4.4 and low P availability increased DM production and P accumulation. At medium P availability (15mg/kg of soil and pH 5.4 there were no diferences between inoculated treatments with AMF but from ones there was observed diferences on the contrai. These differences were due to the mycorrhizal dependence on Trifolium. Inoculated treatments with G. clarum showed higher DM production, Puptake, mycorrhizal colonization and number of spores. It can be concluded that the introduction of G. clariim can be viable when the nativo species are not efficient for the crop or become unefficient when the natural soilferlilily is modified by addition of phosphorus or liming.

  3. Radiation induced graft copolymerization of acrylonitrile on natural rubber

    International Nuclear Information System (INIS)

    Claramma, N.M.; Mathew, N.M.; Thomas, E.V.

    1989-01-01

    Acrylonitrile graft natural rubber was prepared by initiating the polymerization of acrylonitrile in natural rubber field latex using γ-rays. The reaction was carried out at different rubber-monomer concentrations and the properties of the modified rubbers were compared with those of natural rubber and nitrile rubber. (author)

  4. A MODIFIED GIFFLER AND THOMPSON ALGORITHM COMBINED WITH DYNAMIC SLACK TIME FOR SOLVING DYNAMIC SCHEDULE PROBLEMS

    Directory of Open Access Journals (Sweden)

    Tanti Octavia

    2003-01-01

    Full Text Available A Modified Giffler and Thompson algorithm combined with dynamic slack time is used to allocate machines resources in dynamic nature. It was compared with a Real Time Order Promising (RTP algorithm. The performance of modified Giffler and Thompson and RTP algorithms are measured by mean tardiness. The result shows that modified Giffler and Thompson algorithm combined with dynamic slack time provides significantly better result compared with RTP algorithm in terms of mean tardiness.

  5. Implant materials modified by colloids

    Directory of Open Access Journals (Sweden)

    Zboromirska-Wnukiewicz Beata

    2016-03-01

    Full Text Available Recent advances in general medicine led to the development of biomaterials. Implant material should be characterized by a high biocompatibility to the tissue and appropriate functionality, i.e. to have high mechanical and electrical strength and be stable in an electrolyte environment – these are the most important properties of bioceramic materials. Considerations of biomaterials design embrace also electrical properties occurring on the implant-body fluid interface and consequently the electrokinetic potential, which can be altered by modifying the surface of the implant. In this work, the surface of the implants was modified to decrease the risk of infection by using metal colloids. Nanocolloids were obtained using different chemical and electrical methods. It was found that the colloids obtained by physical and electrical methods are more stable than colloids obtained by chemical route. In this work the surface of modified corundum implants was investigated. The implant modified by nanosilver, obtained by electrical method was selected. The in vivo research on animals was carried out. Clinical observations showed that the implants with modified surface could be applied to wounds caused by atherosclerotic skeleton, for curing the chronic and bacterial inflammations as well as for skeletal reconstruction surgery.

  6. Associations between Potentially Modifiable Risk Factors and Alzheimer Disease : A Mendelian Randomization Study

    NARCIS (Netherlands)

    Ostergaard, Soren D.; Mukherjee, Shubhabrata; Sharp, Stephen J.; Proitsi, Petroula; Lotta, Luca A.; Day, Felix; Perry, John R. B.; Boehme, Kevin L.; Walter, Stefan; Kauwe, John S.; Gibbons, Laura E.; Larson, Eric B.; Powell, John F.; Langenberg, Claudia; Crane, Paul K.; Wareham, Nicholas J.; Scott, Robert A.; van der Schouw, YT

    Background Potentially modifiable risk factors including obesity, diabetes, hypertension, and smoking are associated with Alzheimer disease (AD) and represent promising targets for intervention. However, the causality of these associations is unclear. We sought to assess the causal nature of these

  7. A statistical assessment of differences and equivalences between genetically modified and reference plant varieties

    NARCIS (Netherlands)

    Voet, van der H.; Perry, J.N.; Amzal, B.; Paoletti, C.

    2011-01-01

    Background - Safety assessment of genetically modified organisms is currently often performed by comparative evaluation. However, natural variation of plant characteristics between commercial varieties is usually not considered explicitly in the statistical computations underlying the assessment.

  8. Nature and nature values in organic agriculture

    DEFF Research Database (Denmark)

    Hansen, Lene; Noe, Egon; Højring, Katrine

    2006-01-01

    The relationship between agriculture and nature is a centra issue in the current agricultural debate. Organic farming has ambitions and a special potential in relation to nature. Consideration for nature is part of the guiding principals of organic farming and many organic farmers are committed...... to protecting natural qualities. However, the issue of nature, landscape, and land use is not straightforward. Nature is an ambiguous concept that involves multiple interests and actors reaching far beyond farmers. The Danish research project ......

  9. A Systematic Approach to Modified BCJR MAP Algorithms for Convolutional Codes

    Directory of Open Access Journals (Sweden)

    Patenaude François

    2006-01-01

    Full Text Available Since Berrou, Glavieux and Thitimajshima published their landmark paper in 1993, different modified BCJR MAP algorithms have appeared in the literature. The existence of a relatively large number of similar but different modified BCJR MAP algorithms, derived using the Markov chain properties of convolutional codes, naturally leads to the following questions. What is the relationship among the different modified BCJR MAP algorithms? What are their relative performance, computational complexities, and memory requirements? In this paper, we answer these questions. We derive systematically four major modified BCJR MAP algorithms from the BCJR MAP algorithm using simple mathematical transformations. The connections between the original and the four modified BCJR MAP algorithms are established. A detailed analysis of the different modified BCJR MAP algorithms shows that they have identical computational complexities and memory requirements. Computer simulations demonstrate that the four modified BCJR MAP algorithms all have identical performance to the BCJR MAP algorithm.

  10. Modifying Knowledge, Emotions, and Attitudes Regarding Genetically Modified Foods

    Science.gov (United States)

    Heddy, Benjamin C.; Danielson, Robert W.; Sinatra, Gale M.; Graham, Jesse

    2017-01-01

    The purpose of this study was to explore whether conceptual change predicted emotional and attitudinal change while learning about genetically modified foods (GMFs). Participants were 322 college students; half read a refutation text designed to shift conceptual knowledge, emotions, and attitudes, while the other half served as a control group.…

  11. Modified crisis intervention for personality disorder.

    Science.gov (United States)

    Rudnick, A

    1998-01-01

    This study proposes that the goal of crisis intervention for persons with personality disorders should be to return them to their pre-crisis level of functioning, even though this is maladaptive. This is contrasted with standard crisis intervention, which aims to return normal or neurotic persons to their pre-crisis normal or neurotic functioning, usually by means of few and short-term therapeutic encounters. The modification proposed costs more time and resources in persons with personality disorders in crisis and fits the intervention to the personality type. This is illustrated by the case of Eve, a patient in crisis, whose pre-crisis functioning was maladaptive because of a dependent personality disorder. The goal of (modified) crisis intervention in this case was to return the patient to her dependent lifestyle, by means of pharmacotherapy combined with intensive supportive psychotherapy during 3-4 months of partial (day) hospitalization. The special nature of crisis in personality disorders is discussed.

  12. Organically modified clay removes oil from water

    International Nuclear Information System (INIS)

    Alther, G.R.

    1995-01-01

    When bentonite or other clays and zeolite are modified with quaternary amines, they become organophilic. Such modified bentonites are used to remove mechanically emulsified oil and grease, and other sparingly soluble organics. Types of oil found in water can include fats, lubricants, cutting fluids, heavy hydrocarbons such as tars, grease, crude oil, diesel oils; and light hydrocarbons such as kerosene, jet fuel, and gasoline. If the organoclay is granulated, it is placed into a liquid phase carbon filter vessel to remove FOGs (Free Oil and Grease) and chlorinated hydrocarbons. In this application the clay is mixed with anthrazite to prevent early plugging of the filter by oil or grease droplets. In batch systems a powdered organoclay is employed. Organoclay removes mechanically emulsified oil and grease at 5--7 times the rate of activated carbon, or 50% of its dry weight. Oil and grease and other large sparingly soluble chlorinated hydrocarbons and NOMs (Natural Organic Matter) blind the pores of activated carbon (and ion-exchange resins), reducing its effectiveness significantly. It is therefore economically advantageous for the end user to prepolish the water before it enters carbon vessels. Operating costs can often be reduced by 50% or more

  13. GENETICALLY MODIFIED FOOD CROPS AND PUBLIC HEALTH

    Directory of Open Access Journals (Sweden)

    Alejandro Chaparro Giraldo

    2008-09-01

    Full Text Available The progress made in plant biotechnology has provided an opportunity to new food crops being developed having desirable traits for improving crop yield, reducing the use of agrochemicals and adding nutritional properties to staple crops. However, genetically modified (GM crops have become a subject of intense debate in which opponents argue that GM crops represent a threat to individual freedom, the environment, public health and traditional economies. Despite the advances in food crop agriculture, the current world situation is still characterised by massive hunger and chronic malnutrition, representing a major public health problem. Biofortified GM crops have been considered an important and complementary strategy for delivering naturally-fortified staple foods to malnourished populations. Expert advice and public concern have led to designing strategies for assessing the potential risks involved in cultivating and consuming GM crops. The present critical review was aimed at expressing some conflicting points of view about the potential risks of GM crops for public health. It was concluded that GM food crops are no more risky than those genetically modified by conventional methods and that these GM crops might contribute towards reducing the amount of malnourished people around the world. However, all this needs to be complemented by effective political action aimed at increasing the income of people living below the poverty-line.

  14. Natural convection inside an irregular porous cavity

    International Nuclear Information System (INIS)

    Beltran, Jorge I. LLagostera; Trevisan, Osvair Vidal

    1990-01-01

    Natural convection flow induced by heating from below in a irregular porous cavity is investigated numerically. The influence of the modified Rayleigh number and geometric ratios on heat transfer and fluid flow is studied. Global and local Nusselt for Rayleigh numbers covering the range 0 - 1600 and for several geometric ratios. The fluid flow and the temperature field are illustrated by contour maps. (author)

  15. Modified Steiner functional string action

    International Nuclear Information System (INIS)

    Baillie, C.F.; Johnston, D.A.

    1992-01-01

    It has recently been suggested by Ambartzumian et al. that the modified Steiner functional has desirable properties as an action for random surfaces and hence string world sheets. We perform a simulation of this action on a dynamically triangulated random surface to investigate this claim and find that the surfaces are in a flat phase

  16. Modified gravity without dark matter

    NARCIS (Netherlands)

    Sanders, Robert; Papantonopoulos, L

    2007-01-01

    On an empirical level, the most successful alternative to dark matter in bound gravitational systems is the modified Newtonian dynamics, or MOND, proposed by Milgrom. Here I discuss the attempts to formulate MOND as a modification of General Relativity. I begin with a summary of the phenomenological

  17. MODIFIED TECHNIQUE OF TOTAL LARYNGECTOMY

    Directory of Open Access Journals (Sweden)

    Predrag Spirić

    2010-12-01

    Full Text Available Surgical technique of total laryngectomy is well presented in many surgical textbooks. Essentially, it has remained the same since Gluck an Soerensen in 1922 described all its details. Generally, it stresses the U shape skin incision with releasing laryngeal structures and removing larynx from up to down. Further, pharyngeal reconstruction is performed with different kinds of sutures in two or more layers and is finished with skin suture and suction drainage. One of worst complications following this surgery is pharyngocutaneous fistula (PF. Modifications proposed in this this article suggests vertical skin incision with larynx removal from below upwards. In pharyngeal reconstruction we used the running locked suture in submucosal plan with „tobacco sac“ at the end on the tongue base instead of traditional T shaped suture. Suction drains were not used.The aim of study was to present the modified surgical technique of total laryingectomy and its impact on hospital stay duration and pharyngocutanous fistula formation. In this randomized study we analyzed 49 patients operated with modified surgical technique compared to 49 patient operated with traditional surgical technique of total laryngectomy. The modified technique of total laryngectomy was presented. Using modified technique we managed to decrease the PF percentage from previous 20,41% to acceptable 8,16% (p=0,0334. Also, the average hospital stay was shortened from 14,96 to 10,63 days (t =-2.9850; p=0.0358.The modified technique of total laryngectomy is safe, short and efficient surgical intervention which decreases the number of pharyngocutaneos fistulas and shortens the hospital stay.

  18. Natural gas and crude oil

    International Nuclear Information System (INIS)

    Valais, M.R.

    1991-01-01

    Two main development could gradually modify these traditional features of natural gas markets and prices. First, environmental pressures and the tightening of emission standards and of the quality specifications for fuels should work in favor of natural gas. Second the increasing distance of resources in relation to the major consuming zones should bring about a considerable development of international natural gas trade. International expansion should mark the development of the gas industry in the coming decades. This evolution will give natural gas an importance and a role appreciably closer to those of oil on the world energy scene. But it is obvious that such a development can come about only at the cost of considerable investments for which the economic viability is and will remain dependent on the level of the prices of natural gas as the inlet to its consuming markets. This paper attempts to answer the questions: Will these markets accept a new scale of value for gas in relation to other fossil fuels, including oil, which will take into account new environmental constraints and which will be able to fulfill the formidable financial needs of the gas industry in the coming decades?

  19. Acidity characterization of a titanium and sulfate modified vermiculite

    International Nuclear Information System (INIS)

    Hernandez, W.Y.; Centeno, M.A.; Odriozola, J.A.; Moreno, S.; Molina, R.

    2008-01-01

    A natural vermiculite has been modified with titanium and sulfated by the intercalation and impregnation method in order to optimize the acidity of the clay mineral, and characterization of samples were analyzed by X-ray fluorescence (XRF), X-ray diffraction (XRD), nitrogen adsorption isotherms, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and temperature programmed desorption with ammonia (TPD-NH 3 ). All the modified solids have a significantly higher number of acidic sites with respect to the parent material and in all of these, Broensted as well as Lewis acidity are identified. The presence of sulfate appears not to increase the number of acidic centers in the modified clay. For the materials sulfated with the intercalation method, it is observed that the strength of the acidic sites found in the material increases with the nominal sulfate/metal ratio. Nevertheless, when elevated quantities of sulfur are deposited, diffusion problems in the heptane reaction appear

  20. Natural zeolite bitumen cracking

    Energy Technology Data Exchange (ETDEWEB)

    Kuznicki, S.M.; McCaffrey, W.C.; Bian, J.; Wangen, E.; Koenig, A. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering

    2006-07-01

    A study was conducted to demonstrate how low cost heavy oil upgrading in the field could reduce the need for diluents while lowering the cost for pipelining. Low cost field upgrading could also contribute to lowering contaminant levels. The performance of visbreaking processes could be improved by using disposable cracking agents. In turn, the economics of field upgrading of in-situ derived bitumen would be improved. However, in order to be viable, such agents would have to be far less expensive than current commercial cracking catalysts. A platy natural zeolite was selected for modification and testing due to its unique chemical and morphological properties. A catalyst-bearing oil sand was then heat-treated for 1 hour at 400 degrees C in a sealed microreactor. Under these mild cracking conditions, the catalyst-bearing oil sand produced extractable products of much lower viscosity. The products also contained considerably more gas oil and middle distillates than raw oil sand processed under the same conditions as thermal cracking alone. According to model cracking studies using hexadecane, these modified mineral zeolites may be more active cracking agents than undiluted premium commercial FCC catalyst. These materials hold promise for partial upgrading schemes to reduce solvent requirements in the field. tabs., figs.

  1. Acceptance of genetically modified foods: the relation between technology and evaluation.

    Science.gov (United States)

    Tenbült, Petra; De Vries, Nanne K; van Breukelen, Gerard; Dreezens, Ellen; Martijn, Carolien

    2008-07-01

    This study investigates why consumers accept different genetically modified food products to different extents. The study shows that whether food products are genetically modified or not and whether they are processed or not are the two important features that affect the acceptance of food products and their evaluation (in terms of perceived healthiness, naturalness, necessity and tastiness). The extent to which these evaluation attributes and acceptance of a product are affected by genetic modification or processing depends on whether the product is negatively affected by the other technology: Any technological change to a 'natural' product (when nonprocessed products are genetically modified or when non-genetically modified products are processed) affect evaluation and acceptance stronger than a change to an technologically adapted product (when processed products are also genetically modified or vice versa). Furthermore, evaluation attributes appear to mediate the effects of genetic modification and processing on acceptance.

  2. Naturally occurring methyl salicylate glycosides.

    Science.gov (United States)

    Mao, Ping; Liu, Zizhen; Xie, Meng; Jiang, Rui; Liu, Weirui; Wang, Xiaohong; Meng, Shen; She, Gaimei

    2014-01-01

    As an important part of non steroids anti-inflammation drug (NSAIDs), salicylate has developed from natural substance salicylic acid to natrium salicylicum, to aspirin. Now, methyl salicylate glycoside, a new derivative of salicylic acid, is modified with a -COOH group integrated one methyl radical into formic ether, and a -OH linked with a monosaccharide, a disaccharide or a trisaccharide unit by glycosidic linkage. It has the similar pharmacological activities, anti-inflammatory, analgesic, antipyretic and antithrombotic as the previous salicylates' without resulting in serious side effects, particularly the gastrointestinal toxicity. Owing to the superiority of those significant bioactivities, methyl salicylate glycosides have became a hot research area in NSAIDs for several years. This paper compiles all 9 naturally occurring methyl salicylate glycosides, their distribution of the resource and pharmacological mechanism, which could contribute to the new drug discovery.

  3. Thermal properties of hydrogenated liquid natural rubber

    Science.gov (United States)

    Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M.

    2015-09-01

    Natural rubber (NR) was modified to form liquid natural rubber (LNR) via photooxidative degradation. Hydrogenated liquid natural rubber (HLNR) was synthesized by using diimide as source of hydrogen which the diimide is produced by thermolysis of p-toluenesulfonyl hydrazide (TSH). The structure of HLNR was characterized by determining the changes of main peaks in Fourier Transform infrared and nuclear magnetic resonance spectra after hydrogenation. Thermogravimetric analysis showed that the HLNR had higher decomposition temperature compared to LNR and the decomposition temperature is directly proportional to the percentage of conversion.

  4. Thermal properties of hydrogenated liquid natural rubber

    International Nuclear Information System (INIS)

    Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M.

    2015-01-01

    Natural rubber (NR) was modified to form liquid natural rubber (LNR) via photooxidative degradation. Hydrogenated liquid natural rubber (HLNR) was synthesized by using diimide as source of hydrogen which the diimide is produced by thermolysis of p-toluenesulfonyl hydrazide (TSH). The structure of HLNR was characterized by determining the changes of main peaks in Fourier Transform infrared and nuclear magnetic resonance spectra after hydrogenation. Thermogravimetric analysis showed that the HLNR had higher decomposition temperature compared to LNR and the decomposition temperature is directly proportional to the percentage of conversion

  5. Thermal properties of hydrogenated liquid natural rubber

    Energy Technology Data Exchange (ETDEWEB)

    Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M. [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2015-09-25

    Natural rubber (NR) was modified to form liquid natural rubber (LNR) via photooxidative degradation. Hydrogenated liquid natural rubber (HLNR) was synthesized by using diimide as source of hydrogen which the diimide is produced by thermolysis of p-toluenesulfonyl hydrazide (TSH). The structure of HLNR was characterized by determining the changes of main peaks in Fourier Transform infrared and nuclear magnetic resonance spectra after hydrogenation. Thermogravimetric analysis showed that the HLNR had higher decomposition temperature compared to LNR and the decomposition temperature is directly proportional to the percentage of conversion.

  6. Surfactant modified clays’ consistency limits and contact angles

    Directory of Open Access Journals (Sweden)

    S Akbulut

    2012-07-01

    Full Text Available This study was aimed at preparing a surfactant modified clay (SMC and researching the effect of surfactants on clays' contact angles and consistency limits; clay was thus modified by surfactants formodifying their engineering properties. Seven surfactants (trimethylglycine, hydroxyethylcellulose  octyl phenol ethoxylate, linear alkylbenzene sulfonic acid, sodium lauryl ether sulfate, cetyl trimethylammonium chloride and quaternised ethoxylated fatty amine were used as surfactants in this study. The experimental results indicated that SMC consistency limits (liquid and plastic limits changedsignificantly compared to those of natural clay. Plasticity index and liquid limit (PI-LL values representing soil class approached the A-line when zwitterion, nonionic, and anionic surfactant percentageincreased. However, cationic SMC became transformed from CH (high plasticity clay to MH (high plasticity silt class soils, according to the unified soil classification system (USCS. Clay modifiedwith cationic and anionic surfactants gave higher and lower contact angles than natural clay, respectively.

  7. Complexation thermodynamics of modified cyclodextrins

    DEFF Research Database (Denmark)

    Schönbeck, Jens Christian Sidney; Westh, Peter; Holm, Rene

    2014-01-01

    Inclusion complexes between two bile salts and a range of differently methylated β-cyclodextrins were studied in an attempt to rationalize the complexation thermodynamics of modified cyclodextrins. Calorimetric titrations at a range of temperatures provided precise values of the enthalpies (ΔH......°), entropies (ΔS°), and heat capacities (ΔCp) of complexation, while molecular dynamics simulations assisted the interpretation of the obtained thermodynamic parameters. As previously observed for several types of modified cyclodextrins, the substituents at the rims of the cyclodextrin induced large changes......° and then a strong decrease when the degree of substitution exceeded some threshold. Exactly the same trend was observed for ΔCp. The dehydration of nonpolar surface, as quantified by the simulations, can to a large extent explain the variation in the thermodynamic parameters. The methyl substituents form additional...

  8. Generalized gravity from modified DFT

    International Nuclear Information System (INIS)

    Sakatani, Yuho; Uehara, Shozo; Yoshida, Kentaroh

    2017-01-01

    Recently, generalized equations of type IIB supergravity have been derived from the requirement of classical kappa-symmetry of type IIB superstring theory in the Green-Schwarz formulation. These equations are covariant under generalized T-duality transformations and hence one may expect a formulation similar to double field theory (DFT). In this paper, we consider a modification of the DFT equations of motion by relaxing a condition for the generalized covariant derivative with an extra generalized vector. In this modified double field theory (mDFT), we show that the flatness condition of the modified generalized Ricci tensor leads to the NS-NS part of the generalized equations of type IIB supergravity. In particular, the extra vector fields appearing in the generalized equations correspond to the extra generalized vector in mDFT. We also discuss duality symmetries and a modification of the string charge in mDFT.

  9. Generalized gravity from modified DFT

    Energy Technology Data Exchange (ETDEWEB)

    Sakatani, Yuho [Department of Physics, Kyoto Prefectural University of Medicine,Kyoto 606-0823 (Japan); Fields, Gravity and Strings, CTPU,Institute for Basic Sciences, Daejeon 34047 (Korea, Republic of); Uehara, Shozo [Department of Physics, Kyoto Prefectural University of Medicine,Kyoto 606-0823 (Japan); Yoshida, Kentaroh [Department of Physics, Kyoto University,Kitashirakawa Oiwake-cho, Kyoto 606-8502 (Japan)

    2017-04-20

    Recently, generalized equations of type IIB supergravity have been derived from the requirement of classical kappa-symmetry of type IIB superstring theory in the Green-Schwarz formulation. These equations are covariant under generalized T-duality transformations and hence one may expect a formulation similar to double field theory (DFT). In this paper, we consider a modification of the DFT equations of motion by relaxing a condition for the generalized covariant derivative with an extra generalized vector. In this modified double field theory (mDFT), we show that the flatness condition of the modified generalized Ricci tensor leads to the NS-NS part of the generalized equations of type IIB supergravity. In particular, the extra vector fields appearing in the generalized equations correspond to the extra generalized vector in mDFT. We also discuss duality symmetries and a modification of the string charge in mDFT.

  10. Disulfiram as a radiation modifier

    International Nuclear Information System (INIS)

    Taylor, R.D.; Maners, A.W.; Salari, H.; Baker, M.; Walker, E.M. Jr.

    1986-01-01

    The radiation modifying effect and toxicity of tetraethylthiuram disulfide (disulfiram) have been studied. Disulfiram (DSM) inhibits aldehyde dehydrogenase, dopamine-beta-oxygenase, microsomal mixed-function oxidases and cytochrome P-450 enzymes. It is widely used for aversion therapy in alcoholism. Disulfiram also inhibits tumor formation by several known carcinogens. A biphasic toxicity pattern of DSM is reported in the L-929 mouse fibroblast culture system. Disulfiram is 100 percent toxic at 2 X 10(-7) M (0.05 micrograms per ml), 23 percent toxic at 3 X 10(-7) M (0.1 microgram per ml), and 100 percent toxic again at 3.4 X 10(-6) M (1.0 microgram per ml). The pattern is similar to the biphasic toxicity pattern of DMS's major metabolite, sodium diethyldithiocarbamate (DTC). Reports of both radiation protection and radiation enhancement by DTC exist. Previously, a radioprotective effect by 2 X 10(-6) M DTC (dose modifying factor = 1.26) has been demonstrated in the L-929 cell system. To date, no radiation modifying properties of DSM have been reported. Our investigation of DSM as a radiation modifier at 3 X 10(-7) M (0.1 microgram per ml) did not show significant improvement in survival of irradiated cells treated with DSM relative to the irradiated control group, as determined by absence of a difference in the Do of the two groups. Considering DSM's close structural relationship to DTC, it is possible that DSM may exhibit a radioprotective effect when applied in a different concentration than what was used in our research

  11. QGP and Modified Jet Fragmentation

    International Nuclear Information System (INIS)

    Wang, Xin-Nian

    2005-01-01

    Recent progresses in the study of jet modification in hotmedium and their consequences in high-energy heavy-ion collisions are reviewed. In particular, I will discuss energy loss for propagating heavy quarks and the resulting modified fragmentation function. Medium modification of the parton fragmentation function due to quark recombination are formulated within finite temperature field theory and their implication on the search for deconfined quark-gluon plasma is also discussed

  12. Modified binders on the basis of flotation tailings

    Science.gov (United States)

    Shapovalov, N. A.; Zagorodnyuk, L. Kh; Shchekina, A. Yu; Gorodov, A. I.

    2018-03-01

    The article proposes compositions of efficient modified composite binders on the basis of portland cement and flotation tailings; the new binders attain the ultimate compressive stress that is twice as high as that of the cement stone. At that, use of annually growing volume of flotation tailings in the production of the composite binder is a rational way for recycling this type of waste and allows saving the planet's natural resources.

  13. Mechanizm of propylene oxidation on modified cobalt-molybdenum catalysts

    International Nuclear Information System (INIS)

    Kutyrev, M.Yu.; Rozentuller, B.V.; Isaev, O.V.; Margolis, L.Ya.; Krylov, O.V.

    1977-01-01

    Effect is studied of additions of iron, copper, nickel, and vanadium oxides, introduced into cobalt, molybdate, on oxidation reactions of propylene to acrolein and acrylicacid. The principal parameters determining the activity and selectivity of oxidation of propylene and acrolein on modified cobalt molibdate are the structure, the type of Mo-O bond, and the nature of the electron transitions in the solid under the effect of adsorption of the reaction components

  14. Piezotronically modified double Schottky barriers in ZnO varistors.

    Science.gov (United States)

    Raidl, Nadine; Supancic, Peter; Danzer, Robert; Hofstätter, Michael

    2015-03-25

    Double Schottky barriers in ZnO are modified piezotronically by the application of mechanical stresses. New effects such as the enhancement of the potential barrier height and the increase or decrease of the natural barrier asymmetry are presented. Also, an extended model for the piezotronic modification of double Schottky barriers is given. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Effect of ?-cyclodextrin on Rheological Properties of some Viscosity Modifiers

    OpenAIRE

    Rao, G. Chandra Sekhara; Ramadevi, K.; Sirisha, K.

    2014-01-01

    Cyclodextrins are a group of novel excipients, extensively used in the present pharmaceutical industry. Sometimes they show significant interactions with other conventional additives used in the formulation of dosage forms. The effect of β-cyclodextrin on the rheological properties of aqueous solutions of some selected viscosity modifiers was studied in the present work. β-cyclodextrin showed two different types of effects on the rheology of the selected polymers. In case of natural polymers ...

  16. Modified gravity in Arnowitt-Deser-Misner formalism

    International Nuclear Information System (INIS)

    Gao Changjun

    2010-01-01

    Motivated by Horava-Lifshitz gravity theory, we propose and investigate two kinds of modified gravity theories, the f(R) kind and the K-essence kind, in the Arnowitt-Deser-Misner (ADM) formalism. The f(R) kind includes one ultraviolet (UV) term and one infrared (IR) term together with the Einstein-Hilbert action. We find that these two terms naturally present the ultraviolet and infrared modifications to the Friedmann equation. The UV and IR modifications can avoid the past Big-Bang singularity and the future Big-Rip singularity, respectively. Furthermore, the IR modification can naturally account for the current acceleration of the Universe. The Lagrangian of K-essence kind modified gravity is made up of the three-dimensional Ricci scalar and an arbitrary function of the extrinsic curvature term. We find the cosmic acceleration can also be naturally interpreted without invoking any kind of dark energy. The static, spherically symmetry and vacuum solutions of both theories are Schwarzschild or Schwarzschild-de Sitter solution. Thus these modified gravity theories are viable for solar system tests.

  17. Modified gravity in Arnowitt-Deser-Misner formalism

    Science.gov (United States)

    Gao, Changjun

    2010-02-01

    Motivated by Hořava-Lifshitz gravity theory, we propose and investigate two kinds of modified gravity theories, the f(R) kind and the K-essence kind, in the Arnowitt-Deser-Misner (ADM) formalism. The f(R) kind includes one ultraviolet (UV) term and one infrared (IR) term together with the Einstein-Hilbert action. We find that these two terms naturally present the ultraviolet and infrared modifications to the Friedmann equation. The UV and IR modifications can avoid the past Big-Bang singularity and the future Big-Rip singularity, respectively. Furthermore, the IR modification can naturally account for the current acceleration of the Universe. The Lagrangian of K-essence kind modified gravity is made up of the three-dimensional Ricci scalar and an arbitrary function of the extrinsic curvature term. We find the cosmic acceleration can also be naturally interpreted without invoking any kind of dark energy. The static, spherically symmetry and vacuum solutions of both theories are Schwarzschild or Schwarzschild-de Sitter solution. Thus these modified gravity theories are viable for solar system tests.

  18. Ecology and Ethics: Some Relationships for Nature Conservation

    Science.gov (United States)

    Abedi-Sarvestani, Ahmad; Shahvali, Mansoor

    These days, the reality of environmental crises creates grave doubts about the future of the natural environment. Many believe that if present human behavior toward the natural environment continues, there will be no hope for a sustainable life. Therefore, it is vital that human behavior toward nature be modified and corrected. Although, ethic is traditionally concerned about relations between individuals, but it is getting more attention for modifying human behavior in order to correct human-nature interaction and establish a well-intentioned one. In this respect, we need science of ecology and ethics together. Ecology helps us to understand natural ecosystems and respective regulations and laws, whereas ethics teach us how to define right and wrong behaviors toward the natural environment. This research discusses some possible relationships that might exist between ecology and ethics toward nature conservation.

  19. Nature and nature values in organic agriculture

    DEFF Research Database (Denmark)

    Hansen, Lene; Noe, Egon; Højring, Katrine

    2006-01-01

    The relationship between agriculture and nature is a centra issue in the current agricultural debate. Organic farming has ambitions and a special potential in relation to nature. Consideration for nature is part of the guiding principals of organic farming and many organic farmers are committed...

  20. Fluorescent cellulose nanocrystals via supramolecular assembly of terpyridine-modified cellulose nanocrystals and terpyridine-modified perylene

    International Nuclear Information System (INIS)

    Hassan, Mohammad L.; Moorefield, Charles M.; Elbatal, Hany S.; Newkome, George R.; Modarelli, David A.; Romano, Natalie C.

    2012-01-01

    Highlights: ► Surfaces of cellulose nanocrystals were modified with terpyridine ligands. ► Fluorescent nanocrystals could be obtained via self-assembly of terpyridine-modified perylene dye onto the terpyridine-modified cellulose nanocrystals. ► Further self-assembly of azide-functionalized terpyridine onto the fluorescent cellulose nanocrystals was possible to obtain nanocellulosic material with expected use in bioimaging. - Abstract: Due to their natural origin, biocompatibility, and non-toxicity, cellulose nanocrystals are promising candidates for applications in nanomedicine. Highly fluorescent nanocellulosic material was prepared via surface modification of cellulose nanocrystals with 2,2′:6′,2″-terpyridine side chains followed by supramolecular assembly of terpyridine-modified perylene dye onto the terpyridine-modified cellulose nanocrystals (CTP) via Ru III /Ru II reduction. The prepared terpyridine-modified cellulose-Ru II -terpyridine-modified perylene (CTP-Ru II -PeryTP) fluorescent nanocrystals were characterized using cross-polarized/magic angle spin 13 C nuclear magnetic resonance (CP/MAS 13 C NMR), Fourier transform infrared (FTIR), UV–visible, and fluorescence spectroscopy. In addition, further self-assembly of terpyridine units with azide functional groups onto CTP-Ru II -PeryTP was possible via repeating the Ru III /Ru II reduction protocol to prepare supramolecular fluorescent nanocrystals with azide functionality (CTP-Ru II -PeryTP-Ru II -AZTP). The prepared derivative may have potential application in bio-imaging since the terminal azide groups can be easily reacted with antigens via “Click” chemistry reaction.

  1. Three Sorts of Naturalism

    DEFF Research Database (Denmark)

    Fink, Hans

    2006-01-01

    In "Two sorts of Naturalism" John McDowell is sketching his own sort of naturalism in ethics as an alternative to "bald naturalism". In this paper I distinguish materialist, idealist and absolute conceptions of nature and of naturalism in order to provide a framework for a clearer understanding...

  2. Natural gas trends

    International Nuclear Information System (INIS)

    Anderson, A.

    1991-01-01

    This book provides data on many facets of the natural gas industry. Topics include: Canadian, Mexican; US natural gas reserves and production; Mexican and US natural gas consumption; market conditions for natural gas in the US; and Canadian natural gas exports

  3. Cosmological tests of modified gravity.

    Science.gov (United States)

    Koyama, Kazuya

    2016-04-01

    We review recent progress in the construction of modified gravity models as alternatives to dark energy as well as the development of cosmological tests of gravity. Einstein's theory of general relativity (GR) has been tested accurately within the local universe i.e. the Solar System, but this leaves the possibility open that it is not a good description of gravity at the largest scales in the Universe. This being said, the standard model of cosmology assumes GR on all scales. In 1998, astronomers made the surprising discovery that the expansion of the Universe is accelerating, not slowing down. This late-time acceleration of the Universe has become the most challenging problem in theoretical physics. Within the framework of GR, the acceleration would originate from an unknown dark energy. Alternatively, it could be that there is no dark energy and GR itself is in error on cosmological scales. In this review, we first give an overview of recent developments in modified gravity theories including f(R) gravity, braneworld gravity, Horndeski theory and massive/bigravity theory. We then focus on common properties these models share, such as screening mechanisms they use to evade the stringent Solar System tests. Once armed with a theoretical knowledge of modified gravity models, we move on to discuss how we can test modifications of gravity on cosmological scales. We present tests of gravity using linear cosmological perturbations and review the latest constraints on deviations from the standard [Formula: see text]CDM model. Since screening mechanisms leave distinct signatures in the non-linear structure formation, we also review novel astrophysical tests of gravity using clusters, dwarf galaxies and stars. The last decade has seen a number of new constraints placed on gravity from astrophysical to cosmological scales. Thanks to on-going and future surveys, cosmological tests of gravity will enjoy another, possibly even more, exciting ten years.

  4. Observational tests of modified gravity

    International Nuclear Information System (INIS)

    Jain, Bhuvnesh; Zhang Pengjie

    2008-01-01

    Modifications of general relativity provide an alternative explanation to dark energy for the observed acceleration of the Universe. Modified gravity theories have richer observational consequences for large-scale structures than conventional dark energy models, in that different observables are not described by a single growth factor even in the linear regime. We examine the relationships between perturbations in the metric potentials, density and velocity fields, and discuss strategies for measuring them using gravitational lensing, galaxy cluster abundances, galaxy clustering/dynamics, and the integrated Sachs-Wolfe effect. We show how a broad class of gravity theories can be tested by combining these probes. A robust way to interpret observations is by constraining two key functions: the ratio of the two metric potentials, and the ratio of the gravitational 'constant' in the Poisson equation to Newton's constant. We also discuss quasilinear effects that carry signatures of gravity, such as through induced three-point correlations. Clustering of dark energy can mimic features of modified gravity theories and thus confuse the search for distinct signatures of such theories. It can produce pressure perturbations and anisotropic stresses, which break the equality between the two metric potentials even in general relativity. With these two extra degrees of freedom, can a clustered dark energy model mimic modified gravity models in all observational tests? We show with specific examples that observational constraints on both the metric potentials and density perturbations can in principle distinguish modifications of gravity from dark energy models. We compare our result with other recent studies that have slightly different assumptions (and apparently contradictory conclusions).

  5. Adhesives from modified soy protein

    Science.gov (United States)

    Sun, Susan [Manhattan, KS; Wang, Donghai [Manhattan, KS; Zhong, Zhikai [Manhattan, KS; Yang, Guang [Shanghai, CN

    2008-08-26

    The present invention provides useful adhesive compositions having similar adhesive properties to conventional UF and PPF resins. The compositions generally include a protein portion and modifying ingredient portion selected from the group consisting of carboxyl-containing compounds, aldehyde-containing compounds, epoxy group-containing compounds, and mixtures thereof. The composition is preferably prepared at a pH level at or near the isoelectric point of the protein. In other preferred forms, the adhesive composition includes a protein portion and a carboxyl-containing group portion.

  6. Metabolomics of Genetically Modified Crops

    Directory of Open Access Journals (Sweden)

    Carolina Simó

    2014-10-01

    Full Text Available Metabolomic-based approaches are increasingly applied to analyse genetically modified organisms (GMOs making it possible to obtain broader and deeper information on the composition of GMOs compared to that obtained from traditional analytical approaches. The combination in metabolomics of advanced analytical methods and bioinformatics tools provides wide chemical compositional data that contributes to corroborate (or not the substantial equivalence and occurrence of unintended changes resulting from genetic transformation. This review provides insight into recent progress in metabolomics studies on transgenic crops focusing mainly in papers published in the last decade.

  7. On the Modified Barkhausen Criterion

    DEFF Research Database (Denmark)

    Lindberg, Erik; Murali, K.

    2016-01-01

    Oscillators are normally designed according to the Modified Barkhausen Criterion i.e. the complex pole pair is moved out in RHP so that the linear circuit becomes unstable. By means of the Mancini Phaseshift Oscillator it is demonstrated that the distortion of the oscillator may be minimized by i...... by introducing a nonlinear ”Hewlett Resistor” so that the complex pole-pair is in the RHP for small signals and in the LHP for large signals i.e. the complex pole pair of the instant linearized small signal model is moving around the imaginary axis in the complex frequency plane....

  8. Metabolomics of Genetically Modified Crops

    Science.gov (United States)

    Simó, Carolina; Ibáñez, Clara; Valdés, Alberto; Cifuentes, Alejandro; García-Cañas, Virginia

    2014-01-01

    Metabolomic-based approaches are increasingly applied to analyse genetically modified organisms (GMOs) making it possible to obtain broader and deeper information on the composition of GMOs compared to that obtained from traditional analytical approaches. The combination in metabolomics of advanced analytical methods and bioinformatics tools provides wide chemical compositional data that contributes to corroborate (or not) the substantial equivalence and occurrence of unintended changes resulting from genetic transformation. This review provides insight into recent progress in metabolomics studies on transgenic crops focusing mainly in papers published in the last decade. PMID:25334064

  9. Particle acceleration in modified shocks

    International Nuclear Information System (INIS)

    Drury, L.O'C.; Axford, W.I.; Summers, D.

    1982-01-01

    Efficient particle acceleration in shocks must modify the shock structure with consequent changes in the particle acceleration. This effect is studied and analytic solutions are found describing the diffusive acceleration of particles with momentum independent diffusion coefficients in hyperbolic tangent type velocity transitions. If the input particle spectrum is a delta function, the shock smoothing replaces the truncated power-law downstream particle spectrum by a more complicated form, but one which has a power-law tail at high momenta. For a cold plasma this solution can be made completely self-consistent. Some problems associated with momentum dependent diffusion coefficients are discussed. (author)

  10. Particle acceleration in modified shocks

    Energy Technology Data Exchange (ETDEWEB)

    Drury, L.O' C. (Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany, F.R.)); Axford, W.I. (Max-Planck-Institut fuer Aeronomie, Katlenburg-Lindau (Germany, F.R.)); Summers, D. (Memorial Univ. of Newfoundland, St. John' s (Canada))

    1982-03-01

    Efficient particle acceleration in shocks must modify the shock structure with consequent changes in the particle acceleration. This effect is studied and analytic solutions are found describing the diffusive acceleration of particles with momentum independent diffusion coefficients in hyperbolic tangent type velocity transitions. If the input particle spectrum is a delta function, the shock smoothing replaces the truncated power-law downstream particle spectrum by a more complicated form, but one which has a power-law tail at high momenta. For a cold plasma this solution can be made completely self-consistent. Some problems associated with momentum dependent diffusion coefficients are discussed.

  11. Evaluation of a modified Cefsulodin-Irgasan-Novobiocin agar for isolation of Yersinia spp.

    Directory of Open Access Journals (Sweden)

    Lai Kuan Tan

    Full Text Available Y. enterocolitica and Y. pseudotuberculosis are important food borne pathogens. However, the presence of competitive microbiota makes the isolation of Y. enterocolitica and Y. pseudotuberculosis from naturally contaminated foods difficult. We attempted to evaluate the performance of a modified Cefsulodin-Irgasan-Novobiocin (CIN agar in the differentiation of Y. enterocolitica from non-Yersinia species, particularly the natural intestinal microbiota. The modified CIN enabled the growth of Y. enterocolitica colonies with the same efficiency as CIN and Luria-Bertani agar. The detection limits of the modified CIN for Y. enterocolitica in culture medium (10 cfu/ml and in artificially contaminated pork (10(4 cfu/ml were also comparable to those of CIN. However, the modified CIN provided a better discrimination of Yersinia colonies from other bacteria exhibiting Yersinia-like colonies on CIN (H2S-producing Citrobacter freundii, C. braakii, Enterobacter cloacae, Aeromonas hydrophila, Providencia rettgeri, and Morganella morganii. The modified CIN exhibited a higher recovery rate of Y. enterocolitica from artificially prepared bacterial cultures and naturally contaminated samples compared with CIN. Our results thus demonstrated that the use of modified CIN may be a valuable means to increase the recovery rate of food borne Yersinia from natural samples, which are usually contaminated by multiple types of bacteria.

  12. Evaluation of a Modified Cefsulodin-Irgasan-Novobiocin Agar for Isolation of Yersinia spp

    Science.gov (United States)

    Tan, Lai Kuan; Ooi, Peck Toung; Carniel, Elisabeth; Thong, Kwai Lin

    2014-01-01

    Y. enterocolitica and Y. pseudotuberculosis are important food borne pathogens. However, the presence of competitive microbiota makes the isolation of Y. enterocolitica and Y. pseudotuberculosis from naturally contaminated foods difficult. We attempted to evaluate the performance of a modified Cefsulodin-Irgasan-Novobiocin (CIN) agar in the differentiation of Y. enterocolitica from non-Yersinia species, particularly the natural intestinal microbiota. The modified CIN enabled the growth of Y. enterocolitica colonies with the same efficiency as CIN and Luria-Bertani agar. The detection limits of the modified CIN for Y. enterocolitica in culture medium (10 cfu/ml) and in artificially contaminated pork (104 cfu/ml) were also comparable to those of CIN. However, the modified CIN provided a better discrimination of Yersinia colonies from other bacteria exhibiting Yersinia-like colonies on CIN (H2S-producing Citrobacter freundii, C. braakii, Enterobacter cloacae, Aeromonas hydrophila, Providencia rettgeri, and Morganella morganii). The modified CIN exhibited a higher recovery rate of Y. enterocolitica from artificially prepared bacterial cultures and naturally contaminated samples compared with CIN. Our results thus demonstrated that the use of modified CIN may be a valuable means to increase the recovery rate of food borne Yersinia from natural samples, which are usually contaminated by multiple types of bacteria. PMID:25170941

  13. Modified Multi Prime RSA Cryptosystem

    Science.gov (United States)

    Ghazali Kamardan, M.; Aminudin, N.; Che-Him, Norziha; Sufahani, Suliadi; Khalid, Kamil; Roslan, Rozaini

    2018-04-01

    RSA [1] is one of the mostly used cryptosystem in securing data and information. Though, it has been recently discovered that RSA has some weaknesses and in advance technology, RSA is believed to be inefficient especially when it comes to decryption. Thus, a new algorithm called Multi prime RSA, an extended version of the standard RSA is studied. Then, a modification is made to the Multi prime RSA where another keys is shared secretly between the receiver and the sender to increase the securerity. As in RSA, the methodology used for modified Multi-prime RSA also consists of three phases; 1. Key Generation in which the secret and public keys are generated and published. In this phase, the secrecy is improved by adding more prime numbers and addition of secret keys. 2. Encryption of the message using the public and secret keys given. 3. Decryption of the secret message using the secret key generated. For the decryption phase, a method called Chinese Remainder Theorem is used which helps to fasten the computation. Since Multi prime RSA use more than two prime numbers, the algorithm is more efficient and secure when compared to the standard RSA. Furthermore, in modified Multi prime RSA another secret key is introduced to increase the obstacle to the attacker. Therefore, it is strongly believed that this new algorithm is better and can be an alternative to the RSA.

  14. Modified Synthesis of Erlotinib Hydrochloride

    Directory of Open Access Journals (Sweden)

    Leila Barghi

    2012-06-01

    Full Text Available Purpose: An improved and economical method has been described for the synthesis of erlotinib hydrochloride, as a useful drug in treatment of non-small-cell lung cancer. Methods: Erlotinib hydrochloride was synthesized in seven steps starting from 3, 4-dihydroxy benzoic acid. In this study, we were able to modify one of the key steps which involved the reduction of the 6-nitrobenzoic acid derivative to 6-aminobenzoic acid derivative. An inexpensive reagent such as ammonium formate was used as an in situ hydrogen donor in the presence of palladium/charcoal (Pd/C instead of hydrogen gas at high pressure. Results: This proposed method proceeded with 92% yield at room temperature. Synthesis of erlotinib was completed in 7 steps with overall yield of 44%.Conclusion: From the results obtained it can be concluded that the modified method eliminated the potential danger associated with the use of hydrogen gas in the presence of flammable catalysts. It should be mentioned that the catalyst was recovered after the reaction and could be used again.

  15. A Natural Language Architecture

    OpenAIRE

    Sodiya, Adesina Simon

    2007-01-01

    Natural languages are the latest generation of programming languages, which require processing real human natural expressions. Over the years, several groups or researchers have trying to develop widely accepted natural language languages based on artificial intelligence (AI). But no true natural language has been developed. The goal of this work is to design a natural language preprocessing architecture that identifies and accepts programming instructions or sentences in their natural forms ...

  16. Virginia Natural Heritage Program

    Science.gov (United States)

    Heritage About Natural Heritage Overview, Mission Natural Heritage Inventory Community Ecology Program ) | Strategic Plan (PDF) | Executive Progress Report (PDF) | Code of Ethics (PDF) Your browser does not support

  17. Natural Colorants: Food Colorants from Natural Sources.

    Science.gov (United States)

    Sigurdson, Gregory T; Tang, Peipei; Giusti, M Mónica

    2017-02-28

    The color of food is often associated with the flavor, safety, and nutritional value of the product. Synthetic food colorants have been used because of their high stability and low cost. However, consumer perception and demand have driven the replacement of synthetic colorants with naturally derived alternatives. Natural pigment applications can be limited by lower stability, weaker tinctorial strength, interactions with food ingredients, and inability to match desired hues. Therefore, no single naturally derived colorant can serve as a universal alternative for a specified synthetic colorant in all applications. This review summarizes major environmental and biological sources for natural colorants as well as nature-identical counterparts. Chemical characteristics of prevalent pigments, including anthocyanins, carotenoids, betalains, and chlorophylls, are described. The possible applications and hues (warm, cool, and achromatic) of currently used natural pigments, such as anthocyanins as red and blue colorants, and possible future alternatives, such as purple violacein and red pyranoanthocyanins, are also discussed.

  18. Regularities, Natural Patterns and Laws of Nature

    Directory of Open Access Journals (Sweden)

    Stathis Psillos

    2014-02-01

    Full Text Available  The goal of this paper is to sketch an empiricist metaphysics of laws of nature. The key idea is that there are regularities without regularity-enforcers. Differently put, there are natural laws without law-makers of a distinct metaphysical kind. This sketch will rely on the concept of a natural pattern and more significantly on the existence of a network of natural patterns in nature. The relation between a regularity and a pattern will be analysed in terms of mereology.  Here is the road map. In section 2, I will briefly discuss the relation between empiricism and metaphysics, aiming to show that an empiricist metaphysics is possible. In section 3, I will offer arguments against stronger metaphysical views of laws. Then, in section 4 I will motivate nomic objectivism. In section 5, I will address the question ‘what is a regularity?’ and will develop a novel answer to it, based on the notion of a natural pattern. In section 6, I will raise the question: ‘what is a law of nature?’, the answer to which will be: a law of nature is a regularity that is characterised by the unity of a natural pattern.

  19. Encoded libraries of chemically modified peptides.

    Science.gov (United States)

    Heinis, Christian; Winter, Greg

    2015-06-01

    The use of powerful technologies for generating and screening DNA-encoded protein libraries has helped drive the development of proteins as pharmaceutical ligands. However the development of peptides as pharmaceutical ligands has been more limited. Although encoded peptide libraries are typically several orders of magnitude larger than classical chemical libraries, can be more readily screened, and can give rise to higher affinity ligands, their use as pharmaceutical ligands is limited by their intrinsic properties. Two of the intrinsic limitations include the rotational flexibility of the peptide backbone and the limited number (20) of natural amino acids. However these limitations can be overcome by use of chemical modification. For example, the libraries can be modified to introduce topological constraints such as cyclization linkers, or to introduce new chemical entities such as small molecule ligands, fluorophores and photo-switchable compounds. This article reviews the chemistry involved, the properties of the peptide ligands, and the new opportunities offered by chemical modification of DNA-encoded peptide libraries. Copyright © 2015. Published by Elsevier Ltd.

  20. Fungal endophytes: modifiers of plant disease.

    Science.gov (United States)

    Busby, Posy E; Ridout, Mary; Newcombe, George

    2016-04-01

    Many recent studies have demonstrated that non-pathogenic fungi within plant microbiomes, i.e., endophytes ("endo" = within, "phyte" = plant), can significantly modify the expression of host plant disease. The rapid pace of advancement in endophyte ecology warrants a pause to synthesize our understanding of endophyte disease modification and to discuss future research directions. We reviewed recent literature on fungal endophyte disease modification, and here report on several emergent themes: (1) Fungal endophyte effects on plant disease span the full spectrum from pathogen antagonism to pathogen facilitation, with pathogen antagonism most commonly reported. (2) Agricultural plant pathosystems are the focus of research on endophyte disease modification. (3) A taxonomically diverse group of fungal endophytes can influence plant disease severity. And (4) Fungal endophyte effects on plant disease severity are context-dependent. Our review highlights the importance of fungal endophytes for plant disease across a broad range of plant pathosystems, yet simultaneously reveals that complexity within plant microbiomes presents a significant challenge to disentangling the biotic environmental factors affecting plant disease severity. Manipulative studies integrating eco-evolutionary approaches with emerging molecular tools will be poised to elucidate the functional importance of endophytes in natural plant pathosystems that are fundamental to biodiversity and conservation.

  1. Surface modified electrospun nanofibrous scaffolds for nerve tissue engineering

    International Nuclear Information System (INIS)

    Prabhakaran, Molamma P; Venugopal, J; Chan, Casey K; Ramakrishna, S

    2008-01-01

    The development of biodegradable polymeric scaffolds with surface properties that dominate interactions between the material and biological environment is of great interest in biomedical applications. In this regard, poly-ε-caprolactone (PCL) nanofibrous scaffolds were fabricated by an electrospinning process and surface modified by a simple plasma treatment process for enhancing the Schwann cell adhesion, proliferation and interactions with nanofibers necessary for nerve tissue formation. The hydrophilicity of surface modified PCL nanofibrous scaffolds (p-PCL) was evaluated by contact angle and x-ray photoelectron spectroscopy studies. Naturally derived polymers such as collagen are frequently used for the fabrication of biocomposite PCL/collagen scaffolds, though the feasibility of procuring large amounts of natural materials for clinical applications remains a concern, along with their cost and mechanical stability. The proliferation of Schwann cells on p-PCL nanofibrous scaffolds showed a 17% increase in cell proliferation compared to those on PCL/collagen nanofibrous scaffolds after 8 days of cell culture. Schwann cells were found to attach and proliferate on surface modified PCL nanofibrous scaffolds expressing bipolar elongations, retaining their normal morphology. The results of our study showed that plasma treated PCL nanofibrous scaffolds are a cost-effective material compared to PCL/collagen scaffolds, and can potentially serve as an ideal tissue engineered scaffold, especially for peripheral nerve regeneration.

  2. [A modified Onizuka cheiloplasty for repairing the unilateral cleft lip].

    Science.gov (United States)

    Zhang, Bin; Wang, Chao; Liu, Qiang; Li, Zengjian; Xu, Xianyi

    2011-08-01

    To explore the surgical technique of a modified Onizuka cheiloplasty for repairing the unilateral cleft lip. 24 patients with unilateral cleft lip were repaired by modified Onizuka cheiloplasty. The rotation flap ended at the midpoint of nasal columella crease. A small triangle skin flap was formed above the vermilion border of the advancement flap. The small triangle flap was inserted to the medial side after the Cupid's bow was built. The skin of the flap C was denuded along the nasal columella crease and the muscle was sutured to the alar base for augmentation of nostril floor on the cleft side. The tip of the advancement flap was sutured at the midpoint of nasal columella crease and the skin of nasal floor was trimmed to hide the incision line around the nasal columella base. It was found that the Cupid's bow was rebuilt in a natural form and the configuration of the upper lip was reconstructed symmetrically. The long term follow up studies showed that the philtrum column was not disturbed by the small triangle flap and the nasal floor was rebuilt without obvious scars. The modified Onizuka cheiloplasty is an easy learning technique and efficient for repairing the unilateral cleft lip. This technique can satisfy the patients by reducing the length of scar as well as rebuilding a natural form of upper lip and nostril floor.

  3. Chemically modified cellulose paper as a thin film microextraction phase.

    Science.gov (United States)

    Saraji, Mohammad; Farajmand, Bahman

    2013-11-01

    In this paper, chemically modified cellulose paper was introduced as a novel extracting phase for thin film microextraction (TFME). Different reagents (Octadecyltrichlorosilane, diphenyldichlorosilane, cyclohexyl isocyanate and phenyl isocyanate) were used to modify the cellulose papers. The modified papers were evaluated as a sorbent for the extraction of some synthetic and natural estrogenic hormones (17α-ethynylestradiol, estriol and estradiol) from aqueous samples. Liquid chromatography-fluorescence detection was used for the quantification of the extracted compounds. The cellulose paper modified with phenyl isocyanate showed the best affinity to the target compounds. TEME parameters such as desorption condition, shaking rate, sample ionic strength and extraction time were investigated and optimized. Limit of detections were between 0.05 and 0.23μgL(-1) and relative standard deviations were less than 11.1% under the optimized condition. The calibration curves were obtained in the range of 0.2-100μgL(-1) with a good linearity (r(2)>0.9935). Wastewater, human urine, pool and river water samples were studied as real samples for the evaluation of the method. Relative recoveries were found to be between 75% and 101%. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Multicriteria Personnel Selection by the Modified Fuzzy VIKOR Method

    Directory of Open Access Journals (Sweden)

    Rasim M. Alguliyev

    2015-01-01

    Full Text Available Personnel evaluation is an important process in human resource management. The multicriteria nature and the presence of both qualitative and quantitative factors make it considerably more complex. In this study, a fuzzy hybrid multicriteria decision-making (MCDM model is proposed to personnel evaluation. This model solves personnel evaluation problem in a fuzzy environment where both criteria and weights could be fuzzy sets. The triangular fuzzy numbers are used to evaluate the suitability of personnel and the approximate reasoning of linguistic values. For evaluation, we have selected five information culture criteria. The weights of the criteria were calculated using worst-case method. After that, modified fuzzy VIKOR is proposed to rank the alternatives. The outcome of this research is ranking and selecting best alternative with the help of fuzzy VIKOR and modified fuzzy VIKOR techniques. A comparative analysis of results by fuzzy VIKOR and modified fuzzy VIKOR methods is presented. Experiments showed that the proposed modified fuzzy VIKOR method has some advantages over fuzzy VIKOR method. Firstly, from a computational complexity point of view, the presented model is effective. Secondly, compared to fuzzy VIKOR method, it has high acceptable advantage compared to fuzzy VIKOR method.

  5. On mechanism of metals modifying

    International Nuclear Information System (INIS)

    Chernov, V.S.; Busol, F.I.

    1975-01-01

    Data from the literature are cited to show that in several cases, the mechanism of modification of metals and alloys by additives soluble in the melt cannot be explained by the adsorption hypothesis based on the surface activity of these additives. It is suggested that the mechanism of modification by soluble additives can be explained by the presence of a layer of liquid enriched (or depleted) in the additives preceding the crystallization front (densification by concentration), formed under actual conditions of crystallization as a result of the different solubilities of the additive in the solid and liquid phases of the base metal, regardless of its surface activity. This densification by concentration leads to the inhibition of crystal growth in the base metal (barrier action) and to concentration overcooling. On the basis of this theory it is suggested that the modifying action of additives can be predicted from some parameters of the phase diagrams. (author)

  6. Modified Aggressive Packet Combining Scheme

    International Nuclear Information System (INIS)

    Bhunia, C.T.

    2010-06-01

    In this letter, a few schemes are presented to improve the performance of aggressive packet combining scheme (APC). To combat error in computer/data communication networks, ARQ (Automatic Repeat Request) techniques are used. Several modifications to improve the performance of ARQ are suggested by recent research and are found in literature. The important modifications are majority packet combining scheme (MjPC proposed by Wicker), packet combining scheme (PC proposed by Chakraborty), modified packet combining scheme (MPC proposed by Bhunia), and packet reversed packet combining (PRPC proposed by Bhunia) scheme. These modifications are appropriate for improving throughput of conventional ARQ protocols. Leung proposed an idea of APC for error control in wireless networks with the basic objective of error control in uplink wireless data network. We suggest a few modifications of APC to improve its performance in terms of higher throughput, lower delay and higher error correction capability. (author)

  7. Genetically Modified Foods and Nutrition

    Directory of Open Access Journals (Sweden)

    Reci MESERI

    2008-10-01

    Full Text Available To consume a balanced diet may prevent many illnesses. After the Second World War the “Green Revolution” was conducted to increase efficiency in agriculture. After its harmful effects on environment were understood genetically modified foods (GMO were served to combat hunger in the world. Today insufficiency in food product is not the main problem; imbalanced food distribution is the problem. In addition, GMO’s might be harmful for health and environment. Moreover economical dependency to industrialized countries will carry on. If the community tends to use up all the sources and the population increases steadily hunger will not be the only scarcity that the human population would face. There will also be shortage in energy and clean water resources. In conclusion combating just with hunger using high technology will only postpone the problems for a short period of time. [TAF Prev Med Bull 2008; 7(5.000: 455-460

  8. The Modified Embedded Atom Method

    Energy Technology Data Exchange (ETDEWEB)

    Baskes, M.I.

    1994-08-01

    Recent modifications have been made to generalize the Embedded Atom Method (EAM) to describe bonding in diverse materials. By including angular dependence of the electron density in an empirical way, the Modified Embedded Atom Method (MEAM) has been able to reproduce the basic energetic and structural properties of 45 elements. This method is ideal for examining interfacial behavior of dissimilar materials. This paper explains in detail the derivation of the method, shows how parameters of MEAM are determined directly from experiment or first principles calculations, and examine the quality of the reproduction of the database. Materials with fcc, bcc, hcp, and diamond cubic crystal structure are discussed. A few simple examples of the application of the MEAM to surfaces and interfaces are presented. Calculations of pullout of a SiC fiber in a diamond matrix as a function of applied stress show nonuniform deformation of the fiber.

  9. Natural and near natural tropical forest values

    Science.gov (United States)

    Daniel H. Henning

    2011-01-01

    This paper identifies and describes some of the values associated with tropical rain forests in their natural and near-natural conditions. Tropical rain forests are moist forests in the humid tropics where temperature and rainfall are high and the dry season is short. These closed (non-logged) and broad-leaved forests are a global resource. Located almost entirely in...

  10. Natural gas in India

    International Nuclear Information System (INIS)

    Lefevre, Thierry; Todoc, Jessie L.

    1999-11-01

    Contains Executive Summary and Chapters on: Country background; Overview of the energy sector; Natural gas supply; Natural gas infrastructure; Natural gas infrastructure; Natural gas demand; Outlook-government policy reform and industry development, and Appendices on Global and regional energy and gas trends; Overview of India's investment policy, incentives and regulation; The ENRON Dabhol power project. (Author)

  11. Three Sorts of Naturalism

    OpenAIRE

    Fink, Hans

    2006-01-01

    In "Two sorts of Naturalism" John McDowell is sketching his own sort of naturalism in ethics as an alternative to "bald naturalism". In this paper I distinguish materialist, idealist and absolute conceptions of nature and of naturalism in order to provide a framework for a clearer understanding of what McDowell's own naturalism amounts to. I argue that nothing short of an absolute naturalism will do for a number of McDowell's own purposes, but that it is far from obvious that this is his posi...

  12. The chemistry of isoindole natural products

    OpenAIRE

    Speck, Klaus; Magauer, Thomas

    2013-01-01

    Summary This review highlights the chemical and biological aspects of natural products containing an oxidized or reduced isoindole skeleton. This motif is found in its intact or modified form in indolocarbazoles, macrocyclic polyketides (cytochalasan alkaloids), the aporhoeadane alkaloids, meroterpenoids from Stachybotrys species and anthraquinone-type alkaloids. Concerning their biological activity, molecular structure and synthesis, we have limited this review to the most inspiring examples...

  13. Natural gas monthly

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    The Natural Gas Monthly highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the Natural Gas Monthly features articles designed to assist readers in using and interpreting natural gas information.

  14. Polymeric materials and formulation technologies for modified-release tablet development.

    Science.gov (United States)

    Zarate, J; Igartua, M; Hernández, R M; Pedraz, J L

    2009-11-01

    Over the last years significant advances have been made in the area of drug delivery with the development of modified-release (MR) dosage forms. The present review is divided into two parts, one dealing with technologies for the design of modified-release drug delivery tablets and the other with the use of synthetic and natural polymers that are capable of controlling drug release.

  15. The Nature of Natural Hazards Communication (Invited)

    Science.gov (United States)

    Kontar, Y. Y.

    2013-12-01

    Some of the many issues of interest to natural hazards professionals include the analysis of proactive approaches to the governance of risk from natural hazards and approaches to broaden the scope of public policies related to the management of risks from natural hazards, as well as including emergency and environmental management, community development and spatial planning related to natural hazards. During the talk we will present results of scientific review, analysis and synthesis, which emphasize same new trends in communication of the natural hazards theories and practices within an up-to-the-minute context of new environmental and climate change issues, new technologies, and a new focus on resiliency. The presentation is divided into five sections that focus on natural hazards communication in terms of education, risk management, public discourse, engaging the public, theoretical perspectives, and new media. It includes results of case studies and best practices. It delves into natural hazards communication theories, including diffusion, argumentation, and constructivism, to name a few. The presentation will provide information about: (1) A manual of natural hazards communication for scientists, policymakers, and media; (2) An up-to-the-minute context of environmental hazards, new technologies & political landscape; (3) A work by natural hazards scientists for geoscientists working with social scientists and communication principles; (4) A work underpinned by key natural hazards communication theories and interspersed with pragmatic solutions; (5) A work that crosses traditional natural hazards boundaries: international, interdisciplinary, theoretical/applied. We will further explore how spatial planning can contribute to risk governance by influencing the occupation of natural hazard-prone areas, and review the central role of emergency management in risk policy. The goal of this presentation is to contribute to the augmentation of the conceptual framework

  16. Regulatory science requirements of labeling of genetically modified food.

    Science.gov (United States)

    Moghissi, A Alan; Jaeger, Lisa M; Shafei, Dania; Bloom, Lindsey L

    2018-05-01

    This paper provides an overview of the evolution of food labeling in the USA. It briefly describes the three phases of agricultural development consisting of naturally occurring, cross-bred, and genetically engineered, edited or modified crops, otherwise known as Genetically Modified Organisms (GMO). It uses the Best Available Regulatory Science (BARS) and Metrics for Evaluation of Regulatory Science Claims (MERSC) to evaluate the scientific validity of claims applicable to GMO and the Best Available Public Information (BAPI) to evaluate the pronouncements by public media and others. Subsequently claims on health risk, ecological risk, consumer choice, and corporate greed are evaluated based on BARS/MERSC and BAPI. The paper concludes by suggesting that labeling of food containing GMO should consider the consumer's choice, such as the food used by those who desire kosher and halal food. Furthermore, the consumer choice is already met by the exclusion of GMO in organic food.

  17. Strength of biodegradable polypropylene tapes filled with a modified starch

    Science.gov (United States)

    Vinidiktova, N. S.; Ermolovich, O. A.; Goldade, V. A.; Pinchuk, L. S.

    2006-05-01

    The possibility of creating composite materials with high deformation and strength characteristics based on polypropylene (PP) and a natural polysaccharide in the form of a modified starch (MS) has been studied. The modified starch is shown to interact chemically with functional groups of PP, thereby positively affecting the physicomechanical properties, structure, and water absorption properties of films and oriented flat fibers based on starch-filled PP. The strength characteristics of both oriented and unoriented composites are 1.5-2.0 times as high as those of the initial PP. The water absorption ability of the materials varies symbatically with content of MS, which points to the dominant contribution of interactions at the PP-MS interface. The introduction of MS into synthetic polymers offers a possibility of producing new ecologically safe materials with high strength characteristics.

  18. ZnS nanoflakes deposition by modified chemical method

    International Nuclear Information System (INIS)

    Desai, Mangesh A.; Sartale, S. D.

    2014-01-01

    We report deposition of zinc sulfide nanoflakes on glass substrates by modified chemical method. The modified chemical method involves adsorption of zinc–thiourea complex on the substrate and its dissociation in presence of hydroxide ions to release sulfur ions from thiourea which react with zinc ions present in the complex to form zinc sulfide nanoflakes at room temperature. Influence of zinc salt and thiourea concentrations ratios on the morphology of the films was investigated by scanning electron microscope (SEM). The ratio of zinc and thiourea in the zinc–thiourea complex significantly affect the size of the zinc sulfide nanoflakes, especially width and density of the nanoflakes. The X-ray diffraction analysis exhibits polycrystalline nature of the zinc sulfide nanoflakes with hexagonal phase

  19. Natural and synthetic polymers in fabric and home care applications

    Science.gov (United States)

    Paderes, Monissa; Ahirwal, Deepak; Fernández Prieto, Susana

    2017-07-01

    Polymers can be tailored to provide different benefits in Fabric & Home Care formulations depending on the monomers and modifications used, such as avoiding dye transfer inhibition in the wash, modifying the surface of tiles or increasing the viscosity and providing suspension properties to consumer products. Specifically, the rheology modification properties of synthetic and natural polymers are discussed in this chapter. The choice of a polymeric rheology modifier will depend on the formulation ingredients (charges, functional groups), the type and the amount of surfactants, the pH and the desired rheology modification. Natural polymeric rheology modifiers have been traditionally used in the food industry, being xanthan gum one of the most well-known ones. On the contrary, synthetic rheology modifiers are preferably used in paints & coats, textile printing and cleaning products.

  20. [Preparation of HDTMA-modified Zeolite and Its Performance in Nitro-phenol Adsorption from Wastewaters].

    Science.gov (United States)

    Guo, Jun-yuan; Wang, Bin

    2016-05-15

    In this study, natural zeolite was modified by HDTMA. Effects of the modified conditions, HDTMA-modified zeolite doses, solution pH values, and reaction time on nitro-phenol removal were investigated, and the adsorption kinetics and isotherms were discussed. Compared with natural zeolite, HDTMA-modified zeolite showed better performance in nitro-phenol removal. An adsorption capacity of 2.53 mg · g⁻¹ was achieved when the concentration of HDTMA solution (pH = 10) was 1.2% in preparation of modified zeolite. This adsorption capacity was higher than that obtained by natural zeolite (0.54 mg · g⁻¹). In adsorption tests, when HDTMA- modified zeolite dose was adjusted to 8 g · L⁻¹, the removal efficiency of nitro-phenol reached 93.9% after 90 min reaction, with wastewater pH of 6. Furthermore, the nitro-phenol adsorption process could be well fitted to the pseudo-first-order kinetics model (R² > 0.90), whereas the adsorption isotherm results indicated that Langmuir model provided the best fitting for the equilibrium data at different temperatures, with R² of higher than 0.90.

  1. Modifying Silicates for Better Dispersion in Nanocomposites

    Science.gov (United States)

    Campbell, Sandi

    2005-01-01

    An improved chemical modification has been developed to enhance the dispersion of layered silicate particles in the formulation of a polymer/silicate nanocomposite material. The modification involves, among other things, the co-exchange of an alkyl ammonium ion and a monoprotonated diamine with interlayer cations of the silicate. The net overall effects of the improved chemical modification are to improve processability of the nanocomposite and maximize the benefits of dispersing the silicate particles into the polymer. Some background discussion is necessary to give meaning to a description of this development. Polymer/silicate nanocomposites are also denoted polymer/clay composites because the silicate particles in them are typically derived from clay particles. Particles of clay comprise layers of silicate platelets separated by gaps called "galleries." The platelet thickness is 1 nm. The length varies from 30 nm to 1 m, depending on the silicate. In order to fully realize the benefits of polymer/silicate nanocomposites, it is necessary to ensure that the platelets become dispersed in the polymer matrices. Proper dispersion can impart physical and chemical properties that make nanocomposites attractive for a variety of applications. In order to achieve nanometer-level dispersion of a layered silicate into a polymer matrix, it is typically necessary to modify the interlayer silicate surfaces by attaching organic functional groups. This modification can be achieved easily by ion exchange between the interlayer metal cations found naturally in the silicate and protonated organic cations - typically protonated amines. Long-chain alkyl ammonium ions are commonly chosen as the ion-exchange materials because they effectively lower the surface energies of the silicates and ease the incorporation of organic monomers or polymers into the silicate galleries. This completes the background discussion. In the present improved modification of the interlayer silicate surfaces

  2. Modified paraffin wax for improvement of histological analysis efficiency.

    Science.gov (United States)

    Lim, Jin Ik; Lim, Kook-Jin; Choi, Jin-Young; Lee, Yong-Keun

    2010-08-01

    Paraffin wax is usually used as an embedding medium for histological analysis of natural tissue. However, it is not easy to obtain enough numbers of satisfactory sectioned slices because of the difference in mechanical properties between the paraffin and embedded tissue. We describe a modified paraffin wax that can improve the histological analysis efficiency of natural tissue, composed of paraffin and ethylene vinyl acetate (EVA) resin (0, 3, 5, and 10 wt %). Softening temperature of the paraffin/EVA media was similar to that of paraffin (50-60 degrees C). The paraffin/EVA media dissolved completely in xylene after 30 min at 50 degrees C. Physical properties such as the amount of load under the same compressive displacement, elastic recovery, and crystal intensity increased with increased EVA content. EVA medium (5 wt %) was regarded as an optimal composition, based on the sectioning efficiency measured by the numbers of unimpaired sectioned slices, amount of load under the same compressive displacement, and elastic recovery test. Based on the staining test of sectioned slices embedded in a 5 wt % EVA medium by hematoxylin and eosin (H&E), Masson trichrome (MT), and other staining tests, it was concluded that the modified paraffin wax can improve the histological analysis efficiency with various natural tissues. (c) 2010 Wiley-Liss, Inc.

  3. Seeing our self reflected in the world around us : The role of identity in making (natural) environments restorative

    NARCIS (Netherlands)

    Morton, Thomas A.; van der Bles, Anne Marthe; Haslam, S. Alexander

    Exposure to nature has been shown to restore cognitive capacities and activate intrinsic motivational states. The present research considered the role of salient identities in determining these effects. Three studies demonstrated that salient identities modify how people respond to natural

  4. Modified tubularized incised plate urethroplasty

    Directory of Open Access Journals (Sweden)

    Shivaji Mane

    2013-01-01

    Full Text Available Aim: To share our experience of doing tubularized incised plate urethroplasty with modifications. Materials and Methods: This is a single surgeon personal series from 2004 to 2009. One hundred patients of distal hypospadias were subjected for Snodgrass urethroplasty with preputioplasty. The age range was 1 to 5 year with mean age of 2.7 years. Selection criteria were good urethral plate, without chordee and torsion needing complete degloving. Main technical modification from original Snodgrass procedure was spongioplasty, preputioplasty, and dorsal slit when inability to retract prepuce during surgery. Results: Average follow-up period is 23 months. Seven (7% patients developed fistula and one patient had complete preputial dehiscence. Phimosis developed in three (3% patients and required circumcision. Dorsal slit was required in seven patients. One patient developed meatal stenosis in postoperative period. All other patients are passing single urinary stream and have cosmesis that is acceptable. Conclusions: Modified tubularized incised plate urethroplasty with preputioplasty effectively gives cosmetically normal looking penis with low complications.

  5. Nonderivative Modified Gravity: a Classification

    CERN Document Server

    Comelli, Denis; Pilo, Luigi

    2014-01-01

    We analyze the theories of gravity modified by a generic nonderivative potential built from the metric, under the minimal requirement of unbroken spatial rotations. Using the canonical analysis, we classify the potentials $V$ according to the number of degrees of freedom (DoF) that propagate at the nonperturbative level. We then compare the nonperturbative results with the perturbative DoF propagating around Minkowski and FRW backgrounds. A generic $V$ implies 6 propagating DoF at the non-perturbative level, with a ghost on Minkowski background. There exist potentials which propagate 5 DoF, as already studied in previous works. Here, no $V$ with unbroken rotational invariance admitting 4 DoF is found. Theories with 3 DoF turn out to be strongly coupled on Minkowski background. Finally, potentials with only the 2 DoF of a massive graviton exist. Their effect on cosmology is simply equivalent to a cosmological constant. Potentials with 2 or 5 DoF and explicit time dependence appear to be a further viable possib...

  6. Solution properties of hydrophobically modified

    Directory of Open Access Journals (Sweden)

    A.M. Al-Sabagh

    2016-12-01

    Full Text Available We tested nine hydrophobically modified polyacrylamides with molecular weights situated between 1.58 and 0.89 × 106 g/mol for enhanced oil recovery applications. Their solution properties were investigated in the distilled water, brine solution, formation water and sea water. Their critical association concentrations were determined from the relationship between their concentrations and the corresponding apparent viscosities (ηapp at 30 °C at shear rate 6 s−1. They were between 0.4 and 0.5 g/dl. The brine solutions of 0.5 g/dl of HM-PAMs were investigated at different conditions regarding their apparent viscosities. Such conditions were mono and divalent cations, temperature ranging from 30 to 90 °C, the shear rate ranging from 6 to 30 s−1 and the aging time for 45 days. The surface and interfacial tensions for the HM-PAMs were measured for concentration range from 0.01 to 1 g/dl brine solutions at 30 °C and their emulsification efficiencies were investigated for 7 days. The discrepancy in the properties and efficiencies of the tested copolymers was discussed in the light of their chemical structure.

  7. Rutting resistance of asphalt mixture with cup lumps modified binder

    Science.gov (United States)

    Shaffie, E.; Hanif, W. M. M. Wan; Arshad, A. K.; Hashim, W.

    2017-11-01

    Rutting is the most common pavement distress in pavement structures which occurs mainly due to several factors such as increasing of traffic volume, climatic conditions and also due to construction design errors. This failure reduced the service life of the pavement, reduced driver safety and increase cost of maintenance. Polymer Modified Binder has been observed for a long time in improving asphalt pavement performance. Research shows that the use of polymer in bituminous mix not only improve the resistance to rutting but also increase the life span of the pavement. This research evaluates the physical properties and rutting performance of dense graded Superpave-designed HMA mix. Two different types of dense graded Superpave HMA mix were developed consists of unmodified binder mix (UMB) and cup lumps rubber (liquid form) modified binder mix (CLMB). Natural rubber polymer modified binder was prepared from addition of 8 percent of cup lumps into binder. Results showed that all the mixes passed the Superpave volumetric properties criteria which indicate that these mixtures were good with respect to durability and flexibility. Furthermore, rutting results from APA rutting test was determined to evaluate the performance of these mixtures. The rutting result of CLMB demonstrates better resistance to rutting than those prepared using UMB mix. Addition of cup lumps rubber in asphalt mixture was found to be significant, where the cup lumps rubber has certainly improves the binder properties and enhanced its rutting resistance due to greater elasticity offered by the cup lumps rubber particles. It shows that the use of cup lumps rubber can significantly reduce the rut depth of asphalt mixture by 41% compared to the minimum rut depth obtained for the UMB mix. Therefore, it can be concluded that the cup lumps rubber is suitable to be used as a modifier to modified binder in order to enhance the properties of the binder and thus improves the performance of asphalt mixes.

  8. Modified teleparallel gravity: Inflation without an inflaton

    International Nuclear Information System (INIS)

    Ferraro, Rafael; Fiorini, Franco

    2007-01-01

    The Born-Infeld strategy to smooth theories having divergent solutions is applied to the teleparallel equivalent of general relativity. Differing from other theories of modified gravity, modified teleparallelism leads to second order equations, since the teleparallel Lagrangian only contains first derivatives of the vierbein. We show that the Born-Infeld-modified teleparallelism solves the particle horizon problem in a spatially flat Friedmann-Robertson-Walker (FRW) universe by providing an initial exponential expansion without resorting to an inflaton field

  9. Genetically Modified Products – Contradictions and Challenges

    OpenAIRE

    Rodica Pamfilie; Lavinia-Alexandra Cristescu

    2011-01-01

    This paper aims to identify the perception that consumers have about GM products, also taking into consideration the evolution of consumption and production of products based on genetically modified organisms. Therefore, the paper presents both aspects to clarify the concept of genetically modified organism (GMO issues such as typology, national or international regulations regarding this area) and global market development of genetically modified organisms, evolution which is presented by st...

  10. Disseminating genetically modified (GM) maize technology to ...

    African Journals Online (AJOL)

    Disseminating genetically modified (GM) maize technology to smallholder farmers in the Eastern Cape province of South Africa: extension personnel's awareness of stewardship requirements and dissemination practices.

  11. Breast reconstruction - natural tissue

    Science.gov (United States)

    ... flap; TRAM; Latissimus muscle flap with a breast implant; DIEP flap; DIEAP flap; Gluteal free flap; Transverse upper gracilis flap; TUG; Mastectomy - breast reconstruction with natural tissue; Breast cancer - breast reconstruction with natural tissue

  12. Natural short sleeper

    Science.gov (United States)

    Sleep - natural short sleeper ... 7 to 9 hours of sleep each night. Short sleepers sleep less than 75% of what is normal for their age. Natural short sleepers are different from people who chronically do ...

  13. Vermont Natural Resources Atlas

    Data.gov (United States)

    Vermont Center for Geographic Information — The purpose of the�Natural Resources Atlas�is to provide geographic information about environmental features and sites that the Vermont Agency of Natural Resources...

  14. Natural Weathering Exposure Station

    Data.gov (United States)

    Federal Laboratory Consortium — The Corps of Engineers' Treat Island Natural Weathering Exposure Station is a long-term natural weathering facility used to study concrete durability. Located on the...

  15. Accretion and evaporation of modified Hayward black hole

    International Nuclear Information System (INIS)

    Debnath, Ujjal

    2015-01-01

    We assume the most general static spherically symmetric black hole metric. The accretion of any general kind of fluid flow around the black hole is investigated. The accretion of the fluid flow around the modified Hayward black hole is analyzed, and we then calculate the critical point, the fluid's four-velocity, and the velocity of sound during the accretion process. Also the nature of the dynamical mass of the black hole during accretion of the fluid flow, taking into consideration Hawking radiation from the black hole, i.e., evaporation of the black hole, is analyzed. (orig.)

  16. Modified loss coefficients in the determination of optimum generation scheduling

    Energy Technology Data Exchange (ETDEWEB)

    Hazarika, D.; Bordoloi, P.K. (Assam Engineering Coll. (IN))

    1991-03-01

    A modified method has been evolved to form the loss coefficients of an electrical power system network by decoupling load and generation and thereby creating additional fictitious load buses. The system losses are then calculated and co-ordinated to arrive at an optimum scheduling of generation using the standard co-ordination equation. The method presented is superior to the ones currently available, in that it is applicable to a multimachine system with random variation of load and it accounts for limits in plant generations and line losses. The precise nature of results and the economy in the cost of energy production obtained by this method is quantified and presented. (author).

  17. Natural gas annual 1995

    International Nuclear Information System (INIS)

    1996-11-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1995 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1991 to 1995 for each Census Division and each State. Annual historical data are shown at the national level

  18. Natural gas annual 1993

    International Nuclear Information System (INIS)

    1994-01-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1993 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. Tables summarizing natural gas supply and disposition from 1989 to 1993 are given for each Census Division and each State. Annual historical data are shown at the national level

  19. Natural gas annual 1991

    International Nuclear Information System (INIS)

    1992-01-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1991 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. Tables summarizing natural gas supply and disposition form 1987 to 1991 are given for each Census Division and each State. Annual historical data are shown at the national level

  20. Assessment of future natural gas vehicle concepts

    Science.gov (United States)

    Groten, B.; Arrigotti, S.

    1992-10-01

    The development of Natural Gas Vehicles is progressing rapidly under the stimulus of recent vehicle emission regulations. The development is following what can be viewed as a three step progression. In the first step, contemporary gasoline or diesel fueled automobiles are retrofitted with equipment enabling the vehicle to operate on either natural gas or standard liquid fuels. The second step is the development of vehicles which utilize traditional internal combustion engines that have been modified to operate exclusively on natural gas. These dedicated natural gas vehicles operate more efficiently and have lower emissions than the dual fueled vehicles. The third step is the redesigning, from the ground up, of a vehicle aimed at exploiting the advantages of natural gas as an automotive fuel while minimizing its disadvantages. The current report is aimed at identifying the R&D needs in various fuel storage and engine combinations which have potential for providing increased efficiency, reduced emissions, and reductions in vehicle weight and size. Fuel suppliers, automobile and engine manufacturers, many segments of the natural gas and other industries, and regulatory authorities will influence or be affected by the development of such a third generation vehicle, and it is recommended that GRI act to bring these groups together in the near future to begin, developing the focus on a 'designed-for-natural-gas' vehicle.

  1. Restoring Environmental Flows by Modifying Dam Operations

    Directory of Open Access Journals (Sweden)

    Brian D. Richter

    2007-06-01

    Full Text Available The construction of new dams has become one of the most controversial issues in global efforts to alleviate poverty, improve human health, and strengthen regional economies. Unfortunately, this controversy has overshadowed the tremendous opportunity that exists for modifying the operations of existing dams to recover many of the environmental and social benefits of healthy ecosystems that have been compromised by present modes of dam operation. The potential benefits of dam "re-operation" include recovery of fish, shellfish, and other wildlife populations valued both commercially and recreationally, including estuarine species; reactivation of the flood storage and water purification benefits that occur when floods are allowed to flow into floodplain forests and wetlands; regaining some semblance of the naturally dynamic balance between river erosion and sedimentation that shapes physical habitat complexity, and arresting problems associated with geomorphic imbalances; cultural and spiritual uses of rivers; and many other socially valued products and services. This paper describes an assessment framework that can be used to evaluate the benefits that might be restored through dam re-operation. Assessing the potential benefits of dam re-operation begins by characterizing the dam's effects on the river flow regime, and formulating hypotheses about the ecological and social benefits that might be restored by releasing water from the dam in a manner that more closely resembles natural flow patterns. These hypotheses can be tested by implementing a re-operation plan, tracking the response of the ecosystem, and continually refining dam operations through adaptive management. The paper highlights a number of land and water management strategies useful in implementing a dam re-operation plan, with reference to a variety of management contexts ranging from individual dams to cascades of dams along a river to regional energy grids. Because many of the

  2. Natural gas for vehicles

    International Nuclear Information System (INIS)

    Prieur, A.

    2006-01-01

    Following a decade-long upsurge in the use of natural gas in the energy sector (heating and especially electricity), new outlets for natural gas are being developed in the transport sector. For countries endowed with substantial local resources, development in this sector can help reduce oil dependence. In addition, natural gas is often used to reduce pollution, particularly in cities

  3. Natural gas annual 1991

    International Nuclear Information System (INIS)

    1993-01-01

    The Natural Gas Annual 1991 provides information on the supply and disposition of natural gas to a wide audience including industry, consumers Federal and State agencies, and education institutions. This report, the Natural Gas Annual 1991 Supplement: Company Profiles, presents a detailed profile of selected companies

  4. Naturalisms and religion

    NARCIS (Netherlands)

    Drees, Willem

    1997-01-01

    Such terms as materialism, naturalism, and near synonyms evoke strong negative reactions among many believers. However, the notion of naturalism has various meanings; implications for religion differ for the several varieties of naturalism. In this paper I analyze epistemological and ontological

  5. NATURAL GAS TRANSPORTATION

    OpenAIRE

    Stanis³aw Brzeziñski

    2007-01-01

    In the paper, Author presents chosen aspects of natural gas transportation within global market. Natural gas transportation is a technicaly complicated and economicly expensive process; in infrastructure construction and activities costs. The paper also considers last and proposed initiatives in natural gas transportation.

  6. RESEARCH OF THE STRESS STATE OF A MODIFIED IN-SITU CONCRETE

    Directory of Open Access Journals (Sweden)

    D. V. Rudenko

    2016-12-01

    Full Text Available Purpose. The article focuses on investigation of the stress state of a modified in-situ concrete of natural hardening. Methodology. To achieve the aim, the research of the microstructure of the modified cement matrix of concrete, as well as the mechanism of structure formation of modified concrete with natural hardening was conducted; the methods for reliable evaluation of concrete strength were defined. Findings. The development of internal stresses affects the properties of concretedifferently. With an increase in temperature-shrinkage deformations in time and, thus, with increasing structural stresses in the cement sheath around the grains of the filler two opposite processes may develop: zone of plastic flow or cracking. Originality. It was established that the structural features complex of the modified concrete when the load transfer leads to the formation of extensive zones of prefracture which is able to absorb a significant amount of elastic strain energy that provides the design deformation properties of the concrete for special purposes. Ideas about the definition of the criteria of cracking modified concrete, hardening under natural conditions had further development. Practical value. The resulting equations allow to solve the problem about the minimum level of structural stress in monolithic concrete in a saturated large placeholder, as well as to assess the influence of structural stresses on the properties of concrete. In normal concrete with a relatively thin cement sheath at temperature-shrinkage deformations, high tangential and low radial tension occur. In vivo, this stress is higher as a result of higher values of Δε(τ, which is not observed in the modified concrete. In the modified concretes only tangential stresses are the greatest danger to structures. The change of shrinkage stress with time is straightforward. The total temperature-shrinkage deformations have a sawtooth graph. For modified concrete the amplitude is 48

  7. Natural gas marketing II

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    This book covers all aspects of gas marketing, from the basic regulatory structure to the latest developments in negotiating agreements and locating markets. Topics include: Federal regulation of the gas industry; Fundamentals of gas marketing contracts; FERC actions encouraging competitive markets; Marketing conditions from the pipelines' perspective; State non-utility regulation of natural gas production, transportation, and marketing; Natural gas wellhead agreements and tariffs; Natural gas processing agreements; Effective management of producer's natural gas contracts; Producer-pipeline litigation; Natural gas purchasing from the perspective of industrial gas users; Gas marketing by co-owners: problems of disproportionate sales, gas balancing, and accounting to royalty owners; Alternatives and new directions in marketing

  8. Nature in Preschool

    DEFF Research Database (Denmark)

    Husted, Mia; Frøkjær, Thorleif

    Nature and nature phenomena’ has formed a specific curriculum theme in Danish preschool since early childhood curriculum was prescribed by law in 2004. However, recent evaluations show that the implementation of an early childhood curriculum has not produced an increased pedagogical focus...... on ‘nature and nature phenomena’ in preschools (EVA 2012). This finding, along with an increased political interest in goals and measurable outcome of early childhood curriculum (Broström 2012), will be the starting point in our ambition to carry out a more thorough qualitative investigation into links...... between preschool teachers’ understanding and interest in teaching nature and the rather poor evaluation....

  9. Chromatin-modifying proteins in cancer

    DEFF Research Database (Denmark)

    Fog, Cathrine K; Jensen, Klaus T; Lund, Anders Henrik

    2007-01-01

    -despite the fact that all cells in the organism contain the same genetic information. A large amount of data gathered over the last decades has demonstrated that deregulation of chromatin-modifying proteins is etiologically involved in the development and progression of cancer. Here we discuss how epigenetic...... alterations influence cancer development and review known cancer-associated alterations in chromatin-modifying proteins....

  10. Public attitudes towards genetically-modified food

    NARCIS (Netherlands)

    Miles, S.; Ueland, O.; Frewer, L.J.

    2005-01-01

    Abstract: Purpose - This study aimed to investigate the impact of information about traceability and new detection methods for identifying genetically-modified organisms in food, on consumer attitudes towards genetically-modified food and consumer trust in regulators in Italy, Norway and England. It

  11. The Modified Enskog Equation for Mixtures

    NARCIS (Netherlands)

    Beijeren, H. van; Ernst, M.H.

    1973-01-01

    In a previous paper it was shown that a modified form of the Enskog equation, applied to mixtures of hard spheres, should be considered as the correct extension of the usual Enskog equation to the case of mixtures. The main argument was that the modified Enskog equation leads to linear transport

  12. Series expansion of the modified Einstein Procedure

    Science.gov (United States)

    Seema Chandrakant Shah-Fairbank

    2009-01-01

    This study examines calculating total sediment discharge based on the Modified Einstein Procedure (MEP). A new procedure based on the Series Expansion of the Modified Einstein Procedure (SEMEP) has been developed. This procedure contains four main modifications to MEP. First, SEMEP solves the Einstein integrals quickly and accurately based on a series expansion. Next,...

  13. Learning from nature: Nature-inspired algorithms

    DEFF Research Database (Denmark)

    Albeanu, Grigore; Madsen, Henrik; Popentiu-Vladicescu, Florin

    2016-01-01

    .), genetic and evolutionary strategies, artificial immune systems etc. Well-known examples of applications include: aircraft wing design, wind turbine design, bionic car, bullet train, optimal decisions related to traffic, appropriate strategies to survive under a well-adapted immune system etc. Based......During last decade, the nature has inspired researchers to develop new algorithms. The largest collection of nature-inspired algorithms is biology-inspired: swarm intelligence (particle swarm optimization, ant colony optimization, cuckoo search, bees' algorithm, bat algorithm, firefly algorithm etc...... on collective social behaviour of organisms, researchers have developed optimization strategies taking into account not only the individuals, but also groups and environment. However, learning from nature, new classes of approaches can be identified, tested and compared against already available algorithms...

  14. Biocontainment of genetically modified organisms by synthetic protein design

    Science.gov (United States)

    Mandell, Daniel J.; Lajoie, Marc J.; Mee, Michael T.; Takeuchi, Ryo; Kuznetsov, Gleb; Norville, Julie E.; Gregg, Christopher J.; Stoddard, Barry L.; Church, George M.

    2015-02-01

    Genetically modified organisms (GMOs) are increasingly deployed at large scales and in open environments. Genetic biocontainment strategies are needed to prevent unintended proliferation of GMOs in natural ecosystems. Existing biocontainment methods are insufficient because they impose evolutionary pressure on the organism to eject the safeguard by spontaneous mutagenesis or horizontal gene transfer, or because they can be circumvented by environmentally available compounds. Here we computationally redesign essential enzymes in the first organism possessing an altered genetic code (Escherichia coli strain C321.ΔA) to confer metabolic dependence on non-standard amino acids for survival. The resulting GMOs cannot metabolically bypass their biocontainment mechanisms using known environmental compounds, and they exhibit unprecedented resistance to evolutionary escape through mutagenesis and horizontal gene transfer. This work provides a foundation for safer GMOs that are isolated from natural ecosystems by a reliance on synthetic metabolites.

  15. Novel natural food antimicrobials.

    Science.gov (United States)

    Juneja, Vijay K; Dwivedi, Hari P; Yan, Xianghe

    2012-01-01

    Naturally occurring antimicrobial compounds could be applied as food preservatives to protect food quality and extend the shelf life of foods and beverages. These compounds are naturally produced and isolated from various sources, including plants, animals and microorganisms, in which they constitute part of host defense systems. Many naturally occurring compounds, such as nisin, plant essential oils, and natamycin, have been widely studied and are reported to be effective in their potential role as antimicrobial agents against spoilage and pathogenic microorganisms. Although some of these natural antimicrobials are commercially available and applied in food processing, their efficacy, consumer acceptance and regulation are not well defined. This manuscript reviews natural antimicrobial compounds with reference to their applications in food when applied individually or in combination with other hurdles. It also reviews the mechanism of action of selected natural antimicrobials, factors affecting their antimicrobial activities, and future prospects for use of natural antimicrobials in the food industry.

  16. On nature and bioethics.

    Science.gov (United States)

    Peterson, Paul Silas

    2010-01-01

    The account of nature and humanity's relationship to nature are of central importance for bioethics. The Scientific Revolution was a critical development in the history of this question and many contemporary accounts of nature find their beginnings here. While the innovative approach to nature going out of the seventeenth century was reliant upon accounts of nature from the early modern period, the Middle Ages, late-antiquity and antiquity, it also parted ways with some of the understandings of nature from these epochs. Here I analyze this development and suggests that some of the insights from older understandings of nature may be helpful for bioethics today, even if there can be no simple return to them.

  17. Phosphonium modified clay/polyimide nanocomposites

    International Nuclear Information System (INIS)

    Ceylan, Hatice; Çakmakçi, Emrah; Beyler-Çiǧil, Asli; Kahraman, Memet Vezir

    2014-01-01

    In this study, octyltriphenylphosphonium bromide [OTPP-Br] was prepared from the reaction of triphenylphosphine and 1 -bromooctane. The modification of clay was done by ion exchange reaction using OTPP-Br in water medium. Poly(amic acid) was prepared from the reaction of 3,3',4,4'-Benzophenonetetracarboxylic dianhydride (BTDA) and 4,4'-Oxydianiline (ODA). Polyimide(PI)/clay hybrids were prepared by blending of poly(amic acid) and organically modified clay as a type of layered clays. The morphology of the Polyimide/ phosphonium modified clay hybrids was characterized by scanning electron microscopy (SEM). Chemical structures of polyimide and Polyimide/ phosphonium modified clay hybrids were characterized by FTIR. SEM and FTIR results showed that the Polyimide/ phosphonium modified clay hybrids were successfully prepared. Thermal properties of the Polyimide/ phosphonium modified clay hybrids were characterized by thermogravimetric analysis (TGA)

  18. A Natural Love of Natural Products

    OpenAIRE

    Kingston, David G. I.

    2008-01-01

    Recent research on the chemistry of natural products from the author?s group that led to the receipt of the ACS Ernest Guenther Award in the Chemistry of Natural Products is reviewed. REDOR NMR and synthetic studies established the T-taxol conformation as the bioactive tubulin-binding conformation, and these results were confirmed by the synthesis of compounds which clearly owed their activity or lack of activity to whether or not they could adopt the T-taxol conformation. Similar studies wit...

  19. Harnessing natural product assembly lines: structure, promiscuity, and engineering.

    Science.gov (United States)

    Ladner, Christopher C; Williams, Gavin J

    2016-03-01

    Many therapeutically relevant natural products are biosynthesized by the action of giant mega-enzyme assembly lines. By leveraging the specificity, promiscuity, and modularity of assembly lines, a variety of strategies has been developed that enables the biosynthesis of modified natural products. This review briefly summarizes recent structural advances related to natural product assembly lines, discusses chemical approaches to probing assembly line structures in the absence of traditional biophysical data, and surveys efforts that harness the inherent or engineered promiscuity of assembly lines for the synthesis of non-natural polyketides and non-ribosomal peptide analogues.

  20. Natural fibers for hydrogels production and their applications in agriculture

    Directory of Open Access Journals (Sweden)

    Liliana Serna Cock

    2017-10-01

    Full Text Available This paper presents a review on hydrogels applied to agriculture emphasizing on the use of natural fibers. The objectives were to examine, trends in research addressed to identify natural fibers used in hydrogels development and methods for modifying natural fibers, understand factors which determine the water retention capacity of a hydrogel. Consequently, this paper shows some methodologies used to evaluate the hydrogels efficiency and to collect in tables, relevant information in relation to methods of natural fibers modification and hydrogel synthesis. It was found that previous research focused on hydrogels development processed with biodegradable polymers such as starch, chitosan and modified natural fibers, cross-linked with potassium acrylate and acrylamide, respectively. In addition, current researches aimed to obtaining hydrogels with improved properties, which have allowed a resistance to climatic variations and soil physicochemical changes, such as pH, presence of salts, temperature and composition. In fact, natural fibers such as sugarcane, agave fiber and kapok fiber, modified with maleic anhydride, are an alternative to obtain hydrogels due to an increasing of mechanical properties and chemically active sites. However, the use of natural nanofibers in hydrogels, has been a successful proposal to improve hydrogels mechanical and swelling properties, since they give to material an elasticity and rigidity properties. A hydrogel efficiency applied to soil, is measured throughout properties as swellability, mechanical strength, and soil water retention. It was concluded that hydrogels, are an alternative to the current needs for the agricultural sector.

  1. Detection of Genetically Modified Food: Has Your Food Been Genetically Modified?

    Science.gov (United States)

    Brandner, Diana L.

    2002-01-01

    Explains the benefits and risks of genetically-modified foods and describes methods for genetically modifying food. Presents a laboratory experiment using a polymerase chain reaction (PCR) test to detect foreign DNA in genetically-modified food. (Contains 18 references.) (YDS)

  2. Bifunctional avidin with covalently modifiable ligand binding site.

    Directory of Open Access Journals (Sweden)

    Jenni Leppiniemi

    Full Text Available The extensive use of avidin and streptavidin in life sciences originates from the extraordinary tight biotin-binding affinity of these tetrameric proteins. Numerous studies have been performed to modify the biotin-binding affinity of (streptavidin to improve the existing applications. Even so, (streptavidin greatly favours its natural ligand, biotin. Here we engineered the biotin-binding pocket of avidin with a single point mutation S16C and thus introduced a chemically active thiol group, which could be covalently coupled with thiol-reactive molecules. This approach was applied to the previously reported bivalent dual chain avidin by modifying one binding site while preserving the other one intact. Maleimide was then coupled to the modified binding site resulting in a decrease in biotin affinity. Furthermore, we showed that this thiol could be covalently coupled to other maleimide derivatives, for instance fluorescent labels, allowing intratetrameric FRET. The bifunctional avidins described here provide improved and novel tools for applications such as the biofunctionalization of surfaces.

  3. Document Categorization with Modified Statistical Language Models for Agglutinative Languages

    Directory of Open Access Journals (Sweden)

    Tantug

    2010-11-01

    Full Text Available In this paper, we investigate the document categorization task with statistical language models. Our study mainly focuses on categorization of documents in agglutinative languages. Due to the productive morphology of agglutinative languages, the number of word forms encountered in naturally occurring text is very large. From the language modeling perspective, a large vocabulary results in serious data sparseness problems. In order to cope with this drawback, previous studies in various application areas suggest modified language models based on different morphological units. It is reported that performance improvements can be achieved with these modified language models. In our document categorization experiments, we use standard word form based language models as well as other modified language models based on root words, root words and part-of-speech information, truncated word forms and character sequences. Additionally, to find an optimum parameter set, multiple tests are carried out with different language model orders and smoothing methods. Similar to previous studies on other tasks, our experimental results on categorization of Turkish documents reveal that applying linguistic preprocessing steps for language modeling provides improvements over standard language models to some extent. However, it is also observed that similar level of performance improvements can also be acquired by simpler character level or truncated word form models which are language independent.

  4. Enhanced fluoride adsorption using Al (III) modified calcium hydroxyapatite

    International Nuclear Information System (INIS)

    Nie, Yulun; Hu, Chun; Kong, Chuipeng

    2012-01-01

    Highlights: ► Al modified hydroxyapatite possessed a higher defluoridation capacity of 32.57 mg/g. ► Hydroxyl groups on the surface of Al-HAP was the adsorption sites for F − removal. ► Enhanced F − removal over Al-HAP was attributed to the modification with aluminum. - Abstract: Aluminum-modified hydroxyapatite (Al-HAP) was prepared and characterized using XRD and BET analyses. Al-HAP possessed higher defluoridation capacity (DC) of 32.57 mgF − /g than unmodified hydroxyapatite (HAP) which showed a DC of 16.38 mgF − /g. The effect of Al/Ca atomic ratio in Al-HAP, solution pH and co-existing anions was further studied. The results indicated that the adsorption data could be well described by the Langmuir isotherm model and the adsorption kinetic followed the pseudo-second-order model. The pH changes during the adsorption process suggested that the -OH on the surface of Al-HAP was the adsorption sites. The more adsorption sites were formed on Al modified HAP, which possessed abundant surface hydroxyl groups, resulting in higher efficiency of F − removal. Thermodynamic parameters such as ΔG°, ΔH° and ΔS° were calculated in order to understand the nature of adsorption process. The results revealed that the adsorption reaction was a spontaneous and endothermic process.

  5. Electrochemical determination of mesotrione at organoclay modified glassy carbon electrodes.

    Science.gov (United States)

    Kamga Wagheu, Josephine; Forano, Claude; Besse-Hoggan, Pascale; Tonle, Ignas K; Ngameni, Emmanuel; Mousty, Christine

    2013-01-15

    A natural Cameroonian smectite-type clay (SaNa) was exchanged with cationic surfactants, namely cetyltrimethylammonium (CTA) and didodecyldimethyl ammonium (DDA) modifying its physico-chemical properties. The resulting organoclays that have higher adsorption capacity for mesotrione than the pristine SaNa clay, have been used as modifiers of glassy carbon electrode for the electrochemical detection of this herbicide by square wave voltammetry. The stripping performances of SaNa, SaCTA and SaDDA modified electrodes were therefore evaluated and the experimental parameters were optimized. SaDDA gives the best results in deoxygenated acetate buffer solution (pH 6.0) after 2 min accumulation under open circuit conditions. Under optimal conditions, the reduction current is proportional to mesotrione concentration in the range from 0.25 to 2.5 μM with a detection limit of 0.26 μM. The fabricated electrode was also applied for the commercial formulation CALLISTO, used in European maize market. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Self-Consistent Sources Extensions of Modified Differential-Difference KP Equation

    Science.gov (United States)

    Gegenhasi; Li, Ya-Qian; Zhang, Duo-Duo

    2018-04-01

    In this paper, we investigate a modified differential-difference KP equation which is shown to have a continuum limit into the mKP equation. It is also shown that the solution of the modified differential-difference KP equation is related to the solution of the differential-difference KP equation through a Miura transformation. We first present the Grammian solution to the modified differential-difference KP equation, and then produce a coupled modified differential-difference KP system by applying the source generation procedure. The explicit N-soliton solution of the resulting coupled modified differential-difference system is expressed in compact forms by using the Grammian determinant and Casorati determinant. We also construct and solve another form of the self-consistent sources extension of the modified differential-difference KP equation, which constitutes a Bäcklund transformation for the differential-difference KP equation with self-consistent sources. Supported by the National Natural Science Foundation of China under Grant Nos. 11601247 and 11605096, the Natural Science Foundation of Inner Mongolia Autonomous Region under Grant Nos. 2016MS0115 and 2015MS0116 and the Innovation Fund Programme of Inner Mongolia University No. 20161115

  7. Application of acid-modified Imperata cylindrica powder for latent fingerprint development.

    Science.gov (United States)

    Low, Wei Zeng; Khoo, Bee Ee; Aziz, Zalina Binti Abdul; Low, Ling Wei; Teng, Tjoon Tow; bin Abdullah, Ahmad Fahmi Lim

    2015-09-01

    A novel powdering material that utilizes acid-modified Imperata cylindrica (IC) powder for the development of fingermarks was studied. Experiments were carried out to determine the suitability, adherence quality and sensitivity of the acid-modified IC powder. Fingermarks of different constituents (eccrine, sebaceous and natural fingermarks) on different types of surfaces were used. Acid-modified IC powder was also used to develop fingermarks of different ages as well as aged fingermarks recovered from the water. From the visual inspection, acid-modified IC powder was able to interact with different fingermark constituents and produced distinct ridge details on the examined surfaces. It was also able to develop aged fingermarks and fingermarks that were submerged in water. A statistical comparison was made against the Sirchie® Hi-Fi black powder in terms of the powders' sensitivity and quality of the developed natural fingermarks. The image quality was analyzed using MITRE's Image Quality of Fingerprint (IQF) software. From the experiments, acid-modified IC powder has the potential as a fingermark development powder, although natural fingermarks developed by Sirchie® black powder showed better quality and sensitivity based on the results of the statistical comparison. Copyright © 2015 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.

  8. Second DOE natural phenomena hazards mitigation conference

    International Nuclear Information System (INIS)

    1989-01-01

    This conference has been organized into ten presentation sessions which include an overview of the DOE Natural Phenomena Guidelines, Seismic Analysis, Seismic Design, Modifying Existing Facilities, DOE Orders, Codes, and Standards (2 sessions), Seismic Hazard (2 sessions), and Probabilistic Risk Assessment (2 sessions). Two poster sessions were also included in the program to provide a different forum for communication of ideas. Over the past fourteen years, Lawrence Livermore National Laboratory, Nuclear Systems Safety Program, has been working with the US Department of Energy, Office of Safety Appraisals and their predecessors in the area of natural phenomena hazards. During this time we have developed seismic, extreme wind/tornado, and flood hazard models for DOE sites in the United States. Guidelines for designing and evaluating DOE facilities for natural phenomena have been developed and are in interim use throughout the DOE community. A series of state-of-the practice manuals have also been developed to aid the designers. All of this material is listed in the Natural Phenomena Hazards Bibliography included in these proceedings. This conference provides a mechanism to disseminate current information on natural phenomena hazards and their mitigation. It provides an opportunity to bring together members of the DOE community to discuss current projects, to share information, and to hear practicing members of the structural engineering community discuss their experiences from past natural phenomena, future trends, and any changes to building codes. Each paper or poster presented is included in these proceedings. We have also included material related to the luncheon and dinner talks

  9. Natural Information Processing Systems

    OpenAIRE

    John Sweller; Susan Sweller

    2006-01-01

    Natural information processing systems such as biological evolution and human cognition organize information used to govern the activities of natural entities. When dealing with biologically secondary information, these systems can be specified by five common principles that we propose underlie natural information processing systems. The principles equate: (1) human long-term memory with a genome; (2) learning from other humans with biological reproduction; (3) problem solving through random ...

  10. Organically Modified Saponites: SAXS Study of Swelling and Application in Caffeine Removal.

    Science.gov (United States)

    Marçal, Liziane; de Faria, Emerson H; Nassar, Eduardo J; Trujillano, Raquel; Martín, Nuria; Vicente, Miguel A; Rives, Vicente; Gil, Antonio; Korili, Sophia A; Ciuffi, Katia J

    2015-05-27

    This study aimed to assess the capacity of saponite modified with n-hexadecyltrimethylammonium bromide (CTAB) and/or 3-aminopropyltriethoxysilane (APTS) to adsorb and remove caffeine from aqueous solutions. Powder X-ray diffraction (PXRD) revealed increased basal spacing in the modified saponites. Small-angle X-ray scattering (SAXS) confirmed the PXRD results; it also showed how the different clay layers were stacked and provided information on the swelling of natural saponite and of the saponites functionalized with CTAB and/or APTS. Thermal analyses, infrared spectroscopy, scanning electron microscopy, element chemical analysis, and textural analyses confirmed functionalization of the natural saponite. The maximum adsorption capacity at equilibrium was 80.54 mg/g, indicating that the saponite modified with 3-aminopropyltriethoxysilane constitutes an efficient and suitable caffeine adsorbent.

  11. Natural gas annual 1997

    International Nuclear Information System (INIS)

    1998-10-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1997 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1993 to 1997 for each Census Division and each State. Annual historical data are shown at the national level. 27 figs., 109 tabs

  12. Natural Ventilation in Atria

    DEFF Research Database (Denmark)

    Svidt, Kjeld; Heiselberg, Per; Hendriksen, Ole Juhl

    This case study comprises a monitoring programme as well as a Computational Fluid Dynamics (CFD) analysis of a natural ventilated atrium. The purpose has been to analyse the performance of a typical natural ventilation system in Denmark under both summer and winter conditions.......This case study comprises a monitoring programme as well as a Computational Fluid Dynamics (CFD) analysis of a natural ventilated atrium. The purpose has been to analyse the performance of a typical natural ventilation system in Denmark under both summer and winter conditions....

  13. Nature-based integration

    DEFF Research Database (Denmark)

    Pitkänen, Kati; Oratuomi, Joose; Hellgren, Daniela

    Increased attention to, and careful planning of the integration of migrants into Nordic societies is ever more important. Nature based integration is a new solution to respond to this need. This report presents the results of a Nordic survey and workshop and illustrates current practices of nature...... based integration by case study descriptions from Denmark, Sweden Norway and Finland. Across Nordic countries several practical projects and initiatives have been launched to promote the benefits of nature in integration and there is also growing academic interest in the topic. Nordic countries have...... the potential of becoming real forerunners in nature based integration even at the global scale....

  14. Natural gas annual 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-10-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1997 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1993 to 1997 for each Census Division and each State. Annual historical data are shown at the national level. 27 figs., 109 tabs.

  15. Natural gas outlook

    International Nuclear Information System (INIS)

    Molyneaux, M.P.

    1998-01-01

    An overview of natural gas markets in Canada and in the United States was provided. The major factors that determine the direction of natural gas prices were depicted graphically. Price volatility has decreased in recent months. As expected, April through November total energy consumption reached historically high levels. Demand for natural gas during the summer of 1997 was not as strong as anticipated. Nuclear energy appears to be on the slippery slope, with natural gas-driven electricity projects to fill the void. Hydroelectricity had a strong showing in 1997. Prospects are less bright for 1998 due to above average temperatures. Canadian natural gas export capacity has increased 5.5 times between 1986 and estimated 1999 levels. Despite this, in 1997, deliveries to the United States were marginally behind expectations. Natural gas consumption, comparative fuel prices, natural gas drilling activity, natural gas storage capacity, actual storage by region, and average weekly spot natural gas prices, for both the U. S. and Canada, were also provided. With regard to Canada, it was suggested that Canadian producers are well positioned for a significant increase in their price realization mostly because of the increase in Canada's export capacity in 1997 (+175 Mmcf/d), 1998 (1,060 Mmcf/d) and potentially in 1999 or 2000, via the Alliance Pipeline project. Nevertheless, with current production projections it appears next to impossible to fill the 10.9 Bcf/d of export capacity that will be potentially in place by the end of 1999. tabs., figs

  16. Nephrotoxicity of Natural Products.

    Science.gov (United States)

    Nauffal, Mary; Gabardi, Steven

    2016-01-01

    The manufacture and sale of natural products constitute a multi-billion dollar industry. Nearly a third of the American population admit to using some form of complementary or alternative medicine, with many using them in addition to prescription medications. Most patients fail to inform their healthcare providers of their natural product use and physicians rarely inquire. Annually, thousands of natural product-induced adverse events are reported to Poison Control Centers nationwide. Natural product manufacturers are not responsible for proving safety and efficacy, as the FDA does not regulate them. However, concerns exist surrounding the safety of natural products. This review provides details on natural products that have been associated with renal dysfunction. We have focused on products that have been associated with direct renal injury, immune-mediated nephrotoxicity, nephrolithiasis, rhabdomyolysis with acute renal injury, hepatorenal syndrome, and common adulterants or contaminants that are associated with renal dysfunction. The potential for natural products to cause renal dysfunction is justifiable. It is imperative that natural product use be monitored closely in all patients. Healthcare practitioners must play an active role in identifying patients using natural products and provide appropriate patient education. © 2016 S. Karger AG, Basel.

  17. Nature as Dissonant Heritage

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2014-01-01

    accepts that nature it not existing outside culture as something that be restored to its original state, but a contemporary product created and managed with certain objectives in mind, nature restoration like heritage production are prone to same kind of dissonance – our nature is not necessary...... their nature. According to Ashworth cultural dissonance can be managed in a number of different way depending on which type of plural society is preferred. Many of these management strategies consciously or unconsciously involve some form of denial, neglect, destruction, reinterpretation or marginalizing...

  18. Oklo natural reactor

    International Nuclear Information System (INIS)

    Fujii, Isao

    1985-01-01

    In 1954, Professor Kazuo, Kuroda of Arkansas University in USA published the possibility that spontaneously generated natural nuclear reactors existed in prehistoric age. In 1972, 18 years after that, Commissariat a l'Energie Atomique published that in the Oklo uranium deposit in Gabon, Africa, a natural nuclear reactor was found. This fact was immediately informed to the whole world, but in Japan, its details have not necessarily been well known. The chance of investigating into this fact and visiting the Oklo deposit by the favor of COMUF, the owner of the Oklo deposit, was given, therefore, the state of the natural reactors, which has been known so far, is reported. At present, 12 natural reactors have been found in the vicinity of the Oklo deposit. The natural reactors were generated spontaneously in uranium deposits about 1.7 billion years ago when the isotopic abundance of U-235 was 3 %, and the chain reaction started naturally. When the concentration of U-235 lowered, the reaction stopped naturally. The abnormality in the U-235 abundance in natural uranium was found, and the cause was pursued. The evidence of the existence of natural reactors was shown. (Kako, I.)

  19. A mathematical nature walk

    CERN Document Server

    Adam, John A

    2009-01-01

    How heavy is that cloud? Why can you see farther in rain than in fog? Why are the droplets on that spider web spaced apart so evenly? If you have ever asked questions like these while outdoors, and wondered how you might figure out the answers, this is a book for you. An entertaining and informative collection of fascinating puzzles from the natural world around us, A Mathematical Nature Walk will delight anyone who loves nature or math or both. John Adam presents ninety-six questions about many common natural phenomena--and a few uncommon ones--and then shows how to answer them using mostly b

  20. Allosteric regulation of epigenetic modifying enzymes.

    Science.gov (United States)

    Zucconi, Beth E; Cole, Philip A

    2017-08-01

    Epigenetic enzymes including histone modifying enzymes are key regulators of gene expression in normal and disease processes. Many drug development strategies to target histone modifying enzymes have focused on ligands that bind to enzyme active sites, but allosteric pockets offer potentially attractive opportunities for therapeutic development. Recent biochemical studies have revealed roles for small molecule and peptide ligands binding outside of the active sites in modulating the catalytic activities of histone modifying enzymes. Here we highlight several examples of allosteric regulation of epigenetic enzymes and discuss the biological significance of these findings. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Eigenvalue Decomposition-Based Modified Newton Algorithm

    Directory of Open Access Journals (Sweden)

    Wen-jun Wang

    2013-01-01

    Full Text Available When the Hessian matrix is not positive, the Newton direction may not be the descending direction. A new method named eigenvalue decomposition-based modified Newton algorithm is presented, which first takes the eigenvalue decomposition of the Hessian matrix, then replaces the negative eigenvalues with their absolute values, and finally reconstructs the Hessian matrix and modifies the searching direction. The new searching direction is always the descending direction. The convergence of the algorithm is proven and the conclusion on convergence rate is presented qualitatively. Finally, a numerical experiment is given for comparing the convergence domains of the modified algorithm and the classical algorithm.

  2. Pandora's picnic basket: the potential and hazards of genetically modified foods

    National Research Council Canada - National Science Library

    McHughen, Alan

    2000-01-01

    ... technologies in the them from with breeding whether examines and Picnic Basket subject, from potentially dangerous products. either use or about the regulatory processes established to protect us genetically other regulators modified "natural" the production. explains, in dear language, the technologies around the food, methods question of world of Researc...

  3. Modified rice cultivation in Tamil Nadu, India: Yield gains and farmers' (lack of) acceptance

    NARCIS (Netherlands)

    Senthilkumar, K.; Bindraban, P.S.; Thiyagarajan, T.M.; Ridder, de N.; Giller, K.E.

    2008-01-01

    The looming water crisis and water-intensive nature of rice cultivation are driving the search for alternative management methods to increase water productivity in rice cultivation. Experiments were conducted under on-station and on-farm conditions to compare rice production using modified methods

  4. Drought in a human-modified world : Reframing drought definitions, understanding, and analysis approaches

    NARCIS (Netherlands)

    Van Loon, Anne F.; Stahl, Kerstin; Di Baldassarre, Giuliano; Clark, Julian; Rangecroft, Sally; Wanders, Niko|info:eu-repo/dai/nl/364253940; Gleeson, Tom; Van Dijk, Albert I.J.M.|info:eu-repo/dai/nl/304847356; Tallaksen, Lena M.; Hannaford, Jamie; Uijlenhoet, Remko; Teuling, Adriaan J.; Hannah, David M.; Sheffield, Justin; Svoboda, Mark; Verbeiren, Boud; wagener, thorsten; van Lanen, Henny A.J.

    2016-01-01

    In the current human-modified world, or Anthropocene, the state of water stores and fluxes has become dependent on human as well as natural processes. Water deficits (or droughts) are the result of a complex interaction between meteorological anomalies, land surface processes, and human inflows,

  5. A density functional theory study of arsenic immobilization by the Al(III)-modified zeolite clinoptilolite

    NARCIS (Netherlands)

    Awuah, Joel B.; Dzade, N.Y.; Tia, Richard; Adei, Evans; Kwakye-Awuah, Bright; Catlow, C. Richard A.; de Leeuw, Nora H.

    2016-01-01

    We present density functional theory calculations of the adsorption of arsenic acid (AsO(OH)3) and arsenous acid (As(OH)3) on the Al(III)-modified natural zeolite clinoptilolite under anhydrous and hydrated conditions. From our calculated adsorption energies, we show that adsorption of both arsenic

  6. Polycarboxylate derivative of α-amino acid as growth modifier of ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 34; Issue 1 ... Construction of modified inorganic mineral with controlled mineralization analogues of those produced by nature is now of current interest for understanding the mechanism of the in vivo biomineralization processes, as well as looking for fresh industrial ...

  7. Sonochemical synthesis of (3-aminopropyl)triethoxysilane-modified monodispersed silica nanoparticles for protein immobilization

    International Nuclear Information System (INIS)

    Shen, Shou-Cang; Ng, Wai Kiong; Chia, Leonard; Dong, Yuan-Cai; Tan, Reginald B.H.

    2011-01-01

    Graphical abstract: 3-Aminopropyltriethoxysilane modified monodispersed silica nanoparticles were synthesized by rapid sonochemical co-condensation to achieve high capability for protein immobilization. Highlights: → Amino-modified monodispersed silica nanoparticles were synthesized by rapid co-condensation. → Strong positive charge was created by aminopropyl-modification. → Capability for immobilization of negatively charged protein was enhanced. → Electrostatic interaction between proteins and surface contributed to the enhanced adsorption. -- Abstract: 3-Aminopropyltriethoxysilane modified monodispersed silica nanoparticles were synthesized by a rapid sonochemical co-condensation synthesis procedure. The chemical nature of surface organic modifier on the obtained modified silica nanoparticle was characterized by 13 C and 29 Si MAS Nuclear Magnetic Resonance (NMR) spectroscopies, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA)- differential scanning calorimetry (DSC). Due to the strengthened positive surface charge of the silica nanoparticles by the modification with aminopropyl groups, the capability for bovine serum albumin (BSA) adsorption was significantly increased as compared with bare silica nanoparticles. 80 mg/g BSA was adsorbed on modified silica nanoparticles, whereas only 20 mg/g BSA could be loaded on pure silica nanoparticles. The enhanced positive surface charge repelled proteins with net positive charge and the modified silica nanoparticles exhibited negligible adsorption of lysozyme, thus a selective adsorption of proteins could be achieved.

  8. Sonochemical synthesis of (3-aminopropyl)triethoxysilane-modified monodispersed silica nanoparticles for protein immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Shou-Cang, E-mail: shen_shoucang@ices.a-star.edu.sg [Institute of Chemical and Engineering Sciences, A-STAR (Agency for Science, Technology and Research), 1 Pesek Road, Jurong Island, Singapore 627833 (Singapore); Ng, Wai Kiong; Chia, Leonard; Dong, Yuan-Cai [Institute of Chemical and Engineering Sciences, A-STAR (Agency for Science, Technology and Research), 1 Pesek Road, Jurong Island, Singapore 627833 (Singapore); Tan, Reginald B.H., E-mail: reginald_tan@ices.a-star.edu.sg [Institute of Chemical and Engineering Sciences, A-STAR (Agency for Science, Technology and Research), 1 Pesek Road, Jurong Island, Singapore 627833 (Singapore); Department of Chemical and Biomolecular Engineering, The National University of Singapore, 4 Engineering Drive 4, Singapore 117576 (Singapore)

    2011-10-15

    Graphical abstract: 3-Aminopropyltriethoxysilane modified monodispersed silica nanoparticles were synthesized by rapid sonochemical co-condensation to achieve high capability for protein immobilization. Highlights: {yields} Amino-modified monodispersed silica nanoparticles were synthesized by rapid co-condensation. {yields} Strong positive charge was created by aminopropyl-modification. {yields} Capability for immobilization of negatively charged protein was enhanced. {yields} Electrostatic interaction between proteins and surface contributed to the enhanced adsorption. -- Abstract: 3-Aminopropyltriethoxysilane modified monodispersed silica nanoparticles were synthesized by a rapid sonochemical co-condensation synthesis procedure. The chemical nature of surface organic modifier on the obtained modified silica nanoparticle was characterized by {sup 13}C and {sup 29}Si MAS Nuclear Magnetic Resonance (NMR) spectroscopies, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA)- differential scanning calorimetry (DSC). Due to the strengthened positive surface charge of the silica nanoparticles by the modification with aminopropyl groups, the capability for bovine serum albumin (BSA) adsorption was significantly increased as compared with bare silica nanoparticles. 80 mg/g BSA was adsorbed on modified silica nanoparticles, whereas only 20 mg/g BSA could be loaded on pure silica nanoparticles. The enhanced positive surface charge repelled proteins with net positive charge and the modified silica nanoparticles exhibited negligible adsorption of lysozyme, thus a selective adsorption of proteins could be achieved.

  9. Cyclic Sulfamidate Enabled Syntheses of Amino Acids, Peptides, Carbohydrates, and Natural Products

    Science.gov (United States)

    This article reviews the emergence of cyclic sulfamidates as versatile intermediatesfor the synthesis of unnatural amino acids, chalcogen peptides, modified sugars, drugs and drug candidates, and important natural products.

  10. The modified Gauss diagonalization of polynomial matrices

    International Nuclear Information System (INIS)

    Saeed, K.

    1982-10-01

    The Gauss algorithm for diagonalization of constant matrices is modified for application to polynomial matrices. Due to this modification the diagonal elements become pure polynomials rather than rational functions. (author)

  11. Cadmium Adsorption on HDTMA Modified Montmorillionite

    Directory of Open Access Journals (Sweden)

    Mohd. Elmuntasir I. Ahmed

    2009-06-01

    Full Text Available In this paper the possibility of cadmium removal from aqueous solutions by adsorption onto modified montmorillonite clay is investigated. Batch adsorption experiments performed revealed an enhanced removal of cadmium using HDTMA modified montmorillonite to 100% of its exchange capacity. Modified montmorillonite adsorption capacity increases at higher pHs suggesting adsorption occurs as a result of surface precipitation and HDTMA complex formation due to the fact that the original negatively charged montmorillonite is now covered by a cationic layer of HDTMA. Adsorption isotherms generated followed a Langmuir isotherm equation possibly indicating a monolayer coverage. Adsorption capacities of up to 49 mg/g and removals greater than 90% were achieved. Anionic selectivity of the HDTMA modified monmorillonite is particularly advantageous in water treatment applications where high concentrations of less adsorbable species are present, and the lack of organoclay affinity for these species may allow the available capacity to be utilized selectively by the targeted species.

  12. Active containment systems incorporating modified pillared clays

    International Nuclear Information System (INIS)

    Lundie, P.; McLeod, N.

    1997-01-01

    The application of treatment technologies in active containment systems provides a more advanced and effective method for the remediation of contaminated sites. These treatment technologies can be applied in permeable reactive walls and/or funnel and gate systems. The application of modified pillared clays in active containment systems provides a mechanism for producing permeable reactive walls with versatile properties. These pillared clays are suitably modified to incorporate reactive intercalatants capable of reacting with both a broad range of organic pollutants of varying molecular size, polarity and reactivity. Heavy metals can be removed from contaminated water by conventional ion-exchange and other reactive processes within the clay structure. Complex contamination problems can be addressed by the application of more than one modified clay on a site specific basis. This paper briefly describes the active containment system and the structure/chemistry of the modified pillared clay technology, illustrating potential applications of the in-situ treatment process for contaminated site remediation

  13. Modified Protein Improves Vitiligo Symptoms in Mice

    Science.gov (United States)

    ... Vitiligo Symptoms in Mice Spotlight on Research Modified Protein Improves Vitiligo Symptoms in Mice By Colleen Labbe, ... D., Ph.D., Rush University. Altering a key protein involved in the development of vitiligo may protect ...

  14. preconditioning the modified conjugate gradient method

    African Journals Online (AJOL)

    Admin

    steepest descent method, the number of matrix-vector products per iteration .... modified CGM algorithm is used for large class of problems that is not ..... New Trends in the Mathematical and Computer Sciences with Applications to Real World.

  15. Risks and benefits of genetically modified foods

    African Journals Online (AJOL)

    Jane

    2011-09-30

    Sep 30, 2011 ... education on the subject to the public. Modern ... published were on the progress of GMF technology followed by attitude studies (such as perceptions ..... Genetically Modified Corn: Environmental Benefits and. Risks.

  16. AquAdvantage Salmon Genetically modified organism

    OpenAIRE

    Núñez Saurí, Ester; Universitat Autònoma de Barcelona. Facultat de Veterinària

    2014-01-01

    Póster AquAdvantage Salmon is a genetically modified organism developed by AquBounty Technologies. The objective of this transgenic organism is to increase the growth rate to obtain the same of conventional salmon faster.

  17. Genetically Modified Organisms : Public Knowledge, Attitudes and ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... that genetically modified crops can contribute to food security in developing ... opponents maintain that their social and economic impacts are unknown and ... its 2017 call for proposals to establish Cyber Policy Centres in the Global South.

  18. Some Effects of a Modified Workweek

    Science.gov (United States)

    Wood, Jack M.

    1977-01-01

    Reports on a study that included examination of the degree of change in selected aspects of job satisfaction and organizational performance after the organization adopted a form of modified workweek. (Author/IRT)

  19. Modified and reverse radiometric flow injection analysis

    Energy Technology Data Exchange (ETDEWEB)

    Myint, U; Ba, H; Khin, M M; Aung, K; Thida, [Yangon Univ. (Myanmar). Dept. of Chemistry; Toelgyessy, J [Slovak Technical Univ., Bratislava (Slovakia). Dept. of Environmental Science

    1994-06-01

    Determination of [sup 137]Cs and [sup 60]Co by using modified and reverse radiometric flow injection analysis is described. Two component RFIA was also realized using [sup 60]Co and [sup 137]Cs radionuclides. (author) 2 refs.; 5 figs.

  20. Nature as Measure

    DEFF Research Database (Denmark)

    Peters, Terri

    2011-01-01

    The potential for biomimicry lies far beyond the direct imitation of natural forms. Guest-editor Terri Peters describes how Janine Benyus, the biologist and innovation consultant, is using biomimicry to create performance metrics from natural technologies and processes for assessing aspects...

  1. Greenland and Natural Resources

    DEFF Research Database (Denmark)

    Lyck, Lise

    Greenland policy can delay and maybe change the future of the forecasted development of the use of natural resources. This book is relevant for anyone interested in Greenland in general and the development of Greenland both politically and economically and in relation natural resources....

  2. Natural - synthetic - artificial!

    DEFF Research Database (Denmark)

    Nielsen, Peter E

    2010-01-01

    The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life.......The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life....

  3. European natural gas

    International Nuclear Information System (INIS)

    Thackeray, Fred

    1999-11-01

    Contains Executive Summary and Chapters on: Main issues; Natural gas consumption and supply: statistics and key features of individual countries; Sectoral natural gas consumption; Indigenous production; Imports; Prices and taxes; The spot market: The interconnector; Forecasts of production and consumption and contracted imports; Progress of markets liberalisation; Effects of environmentalist developments; Transmission networks and storage; Some principal players. (Author)

  4. Nature Foil Reliefs

    Science.gov (United States)

    Lane, Shaw J.

    2012-01-01

    Nature has always been a source of inspiration for artists across the centuries. Artists such as Leonardo da Vinci, Georgia O'Keeffe, Ansel Adams, and Andy Goldsworthy all drew inspiration for their work from nature. Seeds come from the dried pods, which when planted and cared for, bear fruit. In this article, the author describes how her…

  5. Plutonium in nature

    International Nuclear Information System (INIS)

    Madic, C.

    1994-01-01

    Plutonium in nature comes from natural sources and anthropogenic ones. Plutonium at the earth surface comes principally from anthropogenic sources. It is easily detectable in environment. The plutonium behaviour in environment is complex. It seems necessary for the future to reduce releases in environment, to improve predictive models of plutonium behaviour in geosphere, to precise biological impact of anthropogenic plutonium releases

  6. Exposure to natural radiation

    International Nuclear Information System (INIS)

    Green, B.M.R.

    1985-01-01

    A brief report is given of a seminar on the exposure to enhanced natural radiation and its regulatory implications held in 1985 at Maastricht, the Netherlands. The themes of the working sessions included sources of enhanced natural radiation, parameters influencing human exposure, measurement and survey programmes, technical countermeasures, risk and assessment studies, philosophies of dose limitations and national and international policies. (U.K.)

  7. Nature and landscape protection

    International Nuclear Information System (INIS)

    Klinda, J.; Lieskovska, Z.

    1998-01-01

    In accordance with National Council of the Slovak Republic Act N. 287/1994 Coll. on Nature and Landscape Protection, the system of complex nature landscape protection has been designed based on five levels of protection. Categories of protected areas as well as cultural monuments in the Slovak Republic are reviewed.Slovak contribution to the world heritage is included

  8. Penumbra modifier for optimal electron fields combination

    International Nuclear Information System (INIS)

    ElSherbini, N.; Hejazy, M.A.; Khalil, W.

    2003-01-01

    Abutment of two or more electron fields to irradiate extended areas may lead to significant dose inhomogeneities in the junction region. This study describes the geometric and dosimetric characteristics of a device developed to modify the penumbra of an electron beam and therapy improve of dose uniformity in the over lap region when fields are abutted. The device is lipowitz metal block placed on top of the insertion plate of the electron applicator and positioned to stop part of he electron beam on side of field abutment. The air-scattered electrons beyond the block increase the penumbra width from about 1,4 to 2-7-43.4 cm at SSD 100 cm, the modified penumbra is broad and almost linear at all depths for the 6.8, and 15 MeV electron beams used. Film dosimetry was used to obtain profiles, iso-dose distributions, single modified beams and matched fields of 6, 10, and 15 MeV. Wellhofer dosimetry system was used to obtain beam profiles and iso-dose distributions of single modified beams needed for CADPLAN treatment planning system, which used to optimize and compare the skin gap to be used and to quantify the dose uniformity in a junction of the field separation for both modified and non-modified beams. Results are presented for various field configurations without the penumbra modifier; lateral setup error of 2-3 mm may introduce dose variations of 20% or more in the junction region. Similar setup error cause less than 5% dose variations when the penumbra modifier is used to match the field

  9. Automatic bounding estimation in modified NLMS algorithm

    International Nuclear Information System (INIS)

    Shahtalebi, K.; Doost-Hoseini, A.M.

    2002-01-01

    Modified Normalized Least Mean Square algorithm, which is a sign form of Nlm based on set-membership (S M) theory in the class of optimal bounding ellipsoid (OBE) algorithms, requires a priori knowledge of error bounds that is unknown in most applications. In a special but popular case of measurement noise, a simple algorithm has been proposed. With some simulation examples the performance of algorithm is compared with Modified Normalized Least Mean Square

  10. Mechanical properties of chemically modified portuguese pinewood

    OpenAIRE

    Lopes, Duarte B; Mai, Carsten; Militz, Holger

    2014-01-01

    To turn wood into a construction material with enhanced properties, many methods of chemical modification have been developed in the last few decades. In this work, mechanical properties of pine wood were chemically modified, compared and evaluated. Maritime pine wood (Pinus pinaster) was modified with four chemical processes: 1,3-dimethylol-4,5- dihydroxyethyleneurea, N-methylol melamine formaldehyde, tetra-alkoxysilane and wax. The following mechanical properties were assessed experiment...

  11. Global Convergence of a Modified LS Method

    Directory of Open Access Journals (Sweden)

    Liu JinKui

    2012-01-01

    Full Text Available The LS method is one of the effective conjugate gradient methods in solving the unconstrained optimization problems. The paper presents a modified LS method on the basis of the famous LS method and proves the strong global convergence for the uniformly convex functions and the global convergence for general functions under the strong Wolfe line search. The numerical experiments show that the modified LS method is very effective in practice.

  12. Growing natural gas usage

    International Nuclear Information System (INIS)

    Saarni, T.

    1996-01-01

    Finnish natural gas usage topped the 3.3 billion cubic metre mark last year, up 3.6 % on the 1994 figure. Growth has increased now for 12 years in a row. Thanks to offtake by large individual users, the pipeline network has been expanded from South-East Finland to the Greater Helsinki area and central southern Finland. Natural gas plays a much larger role in this region than the 10 % accounted for by natural gas nationally would indicate. The growth in the share of Finland's energy use accounted for by natural gas has served to broaden the country's energy supply base. Natural gas has replaced coal and oil, which has considerably reduced the level of emissions resulting form energy generation

  13. Unnaturalised racial naturalism.

    Science.gov (United States)

    Hochman, Adam

    2014-06-01

    Quayshawn Spencer (2014) misunderstands my treatment of racial naturalism. I argued that racial naturalism must entail a strong claim, such as "races are subspecies", if it is to be a substantive position that contrasts with anti-realism about biological race. My recognition that not all race naturalists make such a strong claim is evident throughout the article Spencer reviews (Hochman, 2013a). Spencer seems to agree with me that there are no human subspecies, and he endorses a weaker form of racial naturalism. However, he supports his preferred version of 'racial naturalism' with arguments that are not well described as 'naturalistic'. I argue that Spencer offers us an unnaturalised racial naturalism. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Weak lensing probes of modified gravity

    International Nuclear Information System (INIS)

    Schmidt, Fabian

    2008-01-01

    We study the effect of modifications to general relativity on large-scale weak lensing observables. In particular, we consider three modified gravity scenarios: f(R) gravity, the Dvali-Gabadadze-Porrati model, and tensor-vector-scalar theory. Weak lensing is sensitive to the growth of structure and the relation between matter and gravitational potentials, both of which will in general be affected by modified gravity. Restricting ourselves to linear scales, we compare the predictions for galaxy-shear and shear-shear correlations of each modified gravity cosmology to those of an effective dark energy cosmology with the same expansion history. In this way, the effects of modified gravity on the growth of perturbations are separated from the expansion history. We also propose a test which isolates the matter-potential relation from the growth factor and matter power spectrum. For all three modified gravity models, the predictions for galaxy and shear correlations will be discernible from those of dark energy with very high significance in future weak lensing surveys. Furthermore, each model predicts a measurably distinct scale dependence and redshift evolution of galaxy and shear correlations, which can be traced back to the physical foundations of each model. We show that the signal-to-noise for detecting signatures of modified gravity is much higher for weak lensing observables as compared to the integrated Sachs-Wolfe effect, measured via the galaxy-cosmic microwave background cross-correlation.

  15. Macroeconomic Stabilization When the Natural Real Interest Rate Is Falling

    Science.gov (United States)

    Buttet, Sebastien; Roy, Udayan

    2015-01-01

    The authors modify the Dynamic Aggregate Demand-Dynamic Aggregate Supply model in Mankiw's widely used intermediate macroeconomics textbook to discuss monetary policy when the natural real interest rate is falling over time. Their results highlight a new role for the central bank's inflation target as a tool of macroeconomic stabilization. They…

  16. Natural zeolite reactivity towards ozone: The role of compensating cations

    International Nuclear Information System (INIS)

    Valdés, Héctor; Alejandro, Serguei; Zaror, Claudio A.

    2012-01-01

    Highlights: ► Chemical and thermal treatment enhances catalytic activity of natural zeolite. ► Modified natural zeolite exhibits high stability after thermal treatment. ► Reducing the compensating cation content leads to an increase on ozone abatement. ► Surface active atomic oxygen was detected using the DRIFT technique. ► The highest reactivity toward ozone was performed by NH4Z3 zeolite sample. - Abstract: Among indoor pollutants, ozone is recognised to pose a threat to human health. Recently, low cost natural zeolites have been applied as alternative materials for ozone abatement. In this work, the effect of compensating cation content of natural zeolite on ozone removal is studied. A Chilean natural zeolite is used here as starting material. The amount of compensating cations in the zeolite framework was modified by ion exchange using an ammonium sulphate solution (0.1 mol L −1 ). Characterisation of natural and modified zeolites were performed by X-ray powder diffraction (XRD), nitrogen adsorption at 77 K, elemental analysis, X-ray fluorescence (XRF), thermogravimetric analysis coupled with mass spectroscopy (TGA-MS), and temperature-programmed desorption of ammonia (NH 3 -TPD). Ozone adsorption and/or decomposition on natural and modified zeolites were studied by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Results show that the zeolite compensating cation content affects ozone interaction with zeolite active sites. Ammonium ion-exchange treatments followed by thermal out-gassing at 823 K, reduces ozone diffusion resistance inside the zeolite framework, increasing ozone abatement on zeolite surface active sites. Weak and strong Lewis acid sites of zeolite surface are identified here as the main active sites responsible of ozone removal.

  17. Natural zeolite reactivity towards ozone: The role of compensating cations

    Energy Technology Data Exchange (ETDEWEB)

    Valdes, Hector, E-mail: hvaldes@ucsc.cl [Laboratorio de Tecnologias Limpias (F. Ingenieria), Universidad Catolica de la Santisima Concepcion, Alonso de Ribera 2850, Concepcion (Chile); Alejandro, Serguei; Zaror, Claudio A. [Departamento de Ingenieria Quimica (F. Ingenieria), Universidad de Concepcion, Concepcion (Chile)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer Chemical and thermal treatment enhances catalytic activity of natural zeolite. Black-Right-Pointing-Pointer Modified natural zeolite exhibits high stability after thermal treatment. Black-Right-Pointing-Pointer Reducing the compensating cation content leads to an increase on ozone abatement. Black-Right-Pointing-Pointer Surface active atomic oxygen was detected using the DRIFT technique. Black-Right-Pointing-Pointer The highest reactivity toward ozone was performed by NH4Z3 zeolite sample. - Abstract: Among indoor pollutants, ozone is recognised to pose a threat to human health. Recently, low cost natural zeolites have been applied as alternative materials for ozone abatement. In this work, the effect of compensating cation content of natural zeolite on ozone removal is studied. A Chilean natural zeolite is used here as starting material. The amount of compensating cations in the zeolite framework was modified by ion exchange using an ammonium sulphate solution (0.1 mol L{sup -1}). Characterisation of natural and modified zeolites were performed by X-ray powder diffraction (XRD), nitrogen adsorption at 77 K, elemental analysis, X-ray fluorescence (XRF), thermogravimetric analysis coupled with mass spectroscopy (TGA-MS), and temperature-programmed desorption of ammonia (NH{sub 3}-TPD). Ozone adsorption and/or decomposition on natural and modified zeolites were studied by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Results show that the zeolite compensating cation content affects ozone interaction with zeolite active sites. Ammonium ion-exchange treatments followed by thermal out-gassing at 823 K, reduces ozone diffusion resistance inside the zeolite framework, increasing ozone abatement on zeolite surface active sites. Weak and strong Lewis acid sites of zeolite surface are identified here as the main active sites responsible of ozone removal.

  18. "Diseases and natural kinds".

    Science.gov (United States)

    Sulmasy, Daniel P

    2005-01-01

    David Thomasma called for the development of a medical ethics based squarely on the philosophy of medicine. He recognized, however, that widespread anti-essentialism presented a significant barrier to such an approach. The aim of this article is to introduce a theory that challenges these anti-essentialist objections. The notion of natural kinds presents a modest form of essentialism that can serve as the basis for a foundationalist philosophy of medicine. The notion of a natural kind is neither static nor reductionistic. Disease can be understood as making necessary reference to living natural kinds without invoking the claim that diseases themselves are natural kinds. The idea that natural kinds have a natural disposition to flourish as the kinds of things that they are provides a telos to which to tether the notion of disease - an objective telos that is broader than mere survival and narrower than subjective choice. It is argued that while nosology is descriptive and may have therapeutic implications, disease classification is fundamentally explanatory. Sickness and illness, while referring to the same state of affairs, can be distinguished from disease phenomenologically. Scientific and diagnostic fallibility in making judgments about diseases do not diminish the objectivity of this notion of disease. Diseases are things, not kinds. Injury is a concept parallel to disease that also makes necessary reference to living natural kinds. These ideas provide a new possibility for the development of a philosophy of medicine with implications for medical ethics.

  19. Almacenamiento de gas natural

    Directory of Open Access Journals (Sweden)

    Tomás Correa

    2008-12-01

    Full Text Available The largest reserves of natural gas worldwide are found in regions far of main cities, being necessary different alternatives to transport the fluid to the consumption cities, such as pipelines, CNG or ships, LNG, depending on distances between producing regions and demanding regions and the producing volumes. Consumption regions have three different markets to naturalgas; residential and commercial, industrial and power generation sector. The residential and commercial is highly seasonal and power generation sector is quite variable depending on increases of temperature during summer time. There are also external issuesthat affect the normal gas flow such as fails on the national system or unexpected interruptions on it, what imply that companies which distribute natural gas should design plans that allow supplying the requirements above mentioned. One plan is using underground natural gas storage with capacities and deliverability rates enough to supply demands. In Colombia there are no laws in this sense but it could be an exploration to discuss different ways to store gas either way as underground natural gas storage or above superficies. Existing basically three different types of underground natural gas storage; depleted reservoirs, salt caverns and aquifers. All ofthem are adequate according to geological characteristics and the needs of the distributors companies of natural gas. This paper is anexploration of technical and economical characteristics of different kind of storages used to store natural gas worldwide.

  20. What Is "Natural"? Consumer Responses to Selected Ingredients.

    Science.gov (United States)

    Chambers, Edgar; Chambers, Edgar; Castro, Mauricio

    2018-04-23

    Interest in “natural” food has grown enormously over the last decade. Because the United States government has not set a legal definition for the term “natural”, customers have formed their own sensory perceptions and opinions on what constitutes natural. In this study, we examined 20 ingredients to determine what consumers consider to be natural. Using a national database, 630 consumers were sampled (50% male and 50% female) online, and the results were analyzed using percentages and chi-square tests. No ingredient was considered natural by more than 69% of respondents. We found evidence that familiarity may play a major role in consumers’ determination of naturalness. We also found evidence that chemical sounding names and the age of the consumer have an effect on whether an ingredient and potentially a food is considered natural. Interestingly, a preference towards selecting GMO (genetically modified organisms) foods had no significant impact on perceptions of natural.

  1. Natural gas in Mexico

    International Nuclear Information System (INIS)

    Ramirez, M.

    1999-01-01

    A series of overhead viewgraphs accompanied this presentation which focused on various aspects of the natural gas industry in Mexico. Some of the viewgraphs depicted statistics from 1998 regarding natural gas throughput from various companies in North America, natural gas reserves around the world, and natural gas reserves in Mexico. Other viewgraphs depicted associated and non-associated natural gas production from 1988 to 1998 in million cubic feet per day. The Burgos Basin and the Cantarell Basin gas production from 1997 to 2004 was also depicted. Other viewgraphs were entitled: (1) gas processing infrastructure for 1999, (2) cryogenic plant at Cd. PEMEX, (3) average annual growth of dry natural gas production for 1997-2004 is estimated at 5.2 per cent, (4) gas flows for December 1998, (5) PGPB- interconnect points, (6) U.S. Mexico gas trade for 1994-1998, (7) PGPB's interconnect projects with U.S., and (8) natural gas storage areas. Technological innovations in the industry include more efficient gas turbines which allow for cogeneration, heat recovery steam generators which reduce pollutant emissions by 21 per cent, cold boxes which increase heat transfer efficiency, and lateral reboilers which reduce energy consumption and total costs. A pie chart depicting natural gas demand by sector shows that natural gas for power generation will increase from 16 per cent in 1997 to 31 per cent in 2004. The opportunities for cogeneration projects were also reviewed. The Comision Federal de Electricidad and independent power producers represent the largest opportunity. The 1997-2001 investment program proposes an 85 per cent sulphur dioxide emission reduction compared to 1997 levels. This presentation also noted that during the 1998-2001 period, total ethane production will grow by 58 tbd. 31 figs

  2. Magnetically-modified natural biogenic iron oxides for organic xenobiotics removal

    Czech Academy of Sciences Publication Activity Database

    Šafařík, Ivo; Filip, J.; Horská, Kateřina; Nowakova, M.; Tuček, J.; Šafaříková, Miroslava; Hashimoto, H.; Takada, J.; Zbořil, R.

    2015-01-01

    Roč. 12, č. 2 (2015), s. 673-682 ISSN 1735-1472 R&D Projects: GA MŠk(CZ) LH11111; GA MŠk LH12190 Institutional support: RVO:67179843 Keywords : Biogenic iron oxides * Leptothrix ochracea * Magnetic fluid * Magnetic adsorbents * Xenobiotics Subject RIV: EI - Biotechnology ; Bionics Impact factor: 2.344, year: 2015

  3. Influence of natural polymer derived from starch as a sensory modifier in sunscreen formulations

    OpenAIRE

    Rigon, Roberta B. [UNESP; Piffer, Adrielle R.; Lima, Aline A. S.; Bighetti, Aparecida E.; Chorilli, Marlus [UNESP

    2013-01-01

    Background: Nowadays, there has been increased incidence of skin cancer, which is mainly related to increased sun exposure. Although sunscreen products may prevent the appearing of this disease, consumers may not use them due to some factors, including the sensory properties. The Aluminum Starch Octenylsuccinate (Dry-Flo® Pure, Akzo Nobel), an aluminum salt produced by the reaction of anhydride octenylsuccinic with starch, is able to improve the spreadability on the skin and reduce the oiline...

  4. Perinatal outcome in singletons after modified natural cycle IVF and standard IVF with ovarian stimulation

    NARCIS (Netherlands)

    Pelinck, Marie-Jose; Keizer, Marjan H.; Hoek, Annemieke; Simons, Arnold H. M.; Schelling, Karin; Middelburg, Karin; Heineman, Maas Jan

    Objective: Singletons born after IVF treatment are at risk for adverse pregnancy outcome, the cause of which is unknown. The aim of the present study was to investigate the influence of ovarian stimulation on perinatal outcome. Study design: In this single-centre retrospective study, perinatal

  5. Perinatal outcome in singletons after modified natural cycle IVF and standard IVF with ovarian stimulation

    NARCIS (Netherlands)

    Pelinck, Marie-José; Keizer, Marjan H.; Hoek, Annemieke; Simons, Arnold H. M.; Schelling, Karin; Middelburg, Karin; Heineman, Maas Jan

    2010-01-01

    Objective: Singletons born after IVF treatment are at risk for adverse pregnancy outcome, the cause of which is unknown. The aim of the present study was to investigate the influence of ovarian stimulation on perinatal outcome. Study design: In this single-centre retrospective study, perinatal

  6. Natural and modified promoters for tailored metabolic engineering of the yeast Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Hubmann, Georg; Thevelein, Johan M; Nevoigt, Elke

    2014-01-01

    The ease of highly sophisticated genetic manipulations in the yeast Saccharomyces cerevisiae has initiated numerous initiatives towards development of metabolically engineered strains for novel applications beyond its traditional use in brewing, baking, and wine making. In fact, baker's yeast has

  7. Symbionts modify interactions between insects and natural enemies in the field

    Czech Academy of Sciences Publication Activity Database

    Hrček, Jan; McLean, A. H. C.; Godfray, H. C. J.

    2016-01-01

    Roč. 85, č. 6 (2016), s. 1605-1612 ISSN 0021-8790 Institutional support: RVO:60077344 Keywords : aphid * field experiment * host-parasite Subject RIV: EH - Ecology, Behaviour Impact factor: 4.474, year: 2016 http://onlinelibrary.wiley.com/doi/10.1111/1365-2656.12586/pdf

  8. A Modified Constant-Stress Coupon for Enhanced Natural Crack Start during Fatigue Testing

    Science.gov (United States)

    2016-05-01

    research positions in the University of Sydney and the University of NSW, and was also attached to Pacific Engineering Systems International as a CRC-ACS...Linux–based computer system . A distinct characteristic of shape-optimal designs is the presence of one or more large regions of uniform stress along the...is present (Cetin, Härkegård and Naess 2013). In addition, Molent, Barter and Wanhill (2011) and Barter , Molent and Wanhill (2012) have noted that

  9. 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.

  10. Closer to Nature?

    DEFF Research Database (Denmark)

    Borkfelt, Sune; Kondrup, Sara; Röcklinsberg, Helena

    2015-01-01

    discourses in order to sell one image of animal welfare in intensive animal production while the actual production at the same time presupposes a quite different paradigm of animal welfare. Specifically, product advertising utilizes representations tied to concepts of naturalness in depictions of both animal...... lives and product processes as “natural”. Product marketing suggests a coherence between nature, production process (farm, animal), and end product, thereby creating associations that the lives of production animals are lived in nature and that their products bring a wholesome and sustainable...

  11. Natural radiation environment

    International Nuclear Information System (INIS)

    Vohra, K.G.; Mishra, U.C.; Pillai, K.C.; Sadasivan, S.

    1982-01-01

    The volume presented contains papers presented at the Second Special Symposium on Natural Radiation Environment held at Bombay, India, during January 1981. The papers deal with such topics as : 1)high natural radiation background areas; 2)environmental natural radioactivity; 3)measurement techniques; 4)technologically enhanced radioactivity; 5)indoor radiation environment; 6)radon and daughters in ambient air, and 7)applications in Geosciences. Each of the 87 papers presented has been abstracted and indexed for the U.S. Department of Energy Technical Information Center's Energy Data Base

  12. EEC's: natural uramium supplies

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The demand for nuclear fuel to supply the nuclear plants within the ECC (31,200 MW at the end of last year) totalled nearly 9,600 tons of natural uranium and 4,900 of separation work units (SWU). Once reactors currently under construction come into service, the demand for natural uranium will reach 13,200 tons by 1985 and that for SWUs to 8,600. If one takes the years 1981 to 1985, total natural uranium needs during this period will be 56,300 tons and those for SWUs 35.100 [fr

  13. Living in cities, naturally.

    Science.gov (United States)

    Hartig, Terry; Kahn, Peter H

    2016-05-20

    Natural features, settings, and processes in urban areas can help to reduce stress associated with urban life. In this and other ways, public health benefits from, street trees, green roofs, community gardens, parks and open spaces, and extensive connective pathways for walking and biking. Such urban design provisions can also yield ecological benefits, not only directly but also through the role they play in shaping attitudes toward the environment and environmental protection. Knowledge of the psychological benefits of nature experience supports efforts to better integrate nature into the architecture, infrastructure, and public spaces of urban areas. Copyright © 2016, American Association for the Advancement of Science.

  14. The unnatural racial naturalism.

    Science.gov (United States)

    Spencer, Quayshawn

    2014-06-01

    In the recent article, "Against the New Racial Naturalism", Adam Hochman (2013, p. 332) argues that new racial naturalists have been too hasty in their racial interpretation of genetic clustering results of human populations. While Hochman makes a number of good points, the purpose of this paper is to show that Hochman's attack on new racial naturalists is misguided due to his definition of 'racial naturalism'. Thus, I will show that Hochman's critique is merely a consequence of an unnatural interpretation of racial naturalism. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Diagrams of natural deductions

    Energy Technology Data Exchange (ETDEWEB)

    Popov, S V

    1982-01-01

    The concept of natural deductions was investigated by the author in his analysis of the complexity of deductions in propositional computations (1975). Here some natural deduction systems are considered, and an analytical procedure proposed which results in a deduction diagram for each system. Each diagram takes the form of an orientated, charge graph, features of which can be used to establish the equivalence of classes of deductions. For each of the natural deduction systems considered, a system of equivalent transformation schemes is derived, which is complete with respect to the given definition of equivalence. 2 references.

  16. Gout: a review of non-modifiable and modifiable risk factors

    Science.gov (United States)

    MacFarlane, Lindsey A.; Kim, Seoyoung C.

    2014-01-01

    Gout is a common inflammatory arthritis triggered by the crystallization of uric acid within the joints. Gout affects millions worldwide and has an increasing prevalence. Recent research has been carried out to better qualify and quantify the risk factors predisposing individuals to gout. These can largely be broken into non-modifiable risk factors such as sex, age, race, and genetics, and modifiable risk factors such as diet and lifestyle. Increasing knowledge of factors predisposing certain individuals to gout could potentially lead to improved preventive practices. This review summarizes the non-modifiable and modifiable risk factors associated with development of gout. PMID:25437279

  17. Characterization of lime mortar additivated with crystallization modifiers

    NARCIS (Netherlands)

    Granneman, S.J.C.; Lubelli, B.; van Hees, R.P.J.

    2018-01-01

    Additivating mortars with crystallization modifiers is a novel approach to mitigate salt crystallization damage in historic masonry. Once verified the effectiveness of crystallization modifiers in bulk solution, the next step consists in verifying whether: (i) modifiers are still effective when

  18. Searching for reciclability of modified clays for an environmental application

    Science.gov (United States)

    Del Hoyo Martínez, Carmen; Solange Lozano García, Marina; Sánchez Escribano, Vicente; Antequera, Jorge

    2014-05-01

    Thanks to the development of the science and the technology of the nourishment in the last 50 years, there have revealed itself several new substances that can fulfill beneficial functions in the food, and these substances, named food additives, are today within reach of all. The food additives recover a very important role in the complex nourishing supply. The additives fulfill several useful functions in the food, which often we give for sat. Nevertheless the widespread use of food additives in the food production also influences the public health. The food industries, which are very important for the economy, spill residues proved from its activity that they have to be controlled to evaluate the environmental impact and to offer the necessary information about the quantitative evaluation of the chemical risk of the use of food additives for the public health. The clay materials have led to numerous applications in the field of public health (del Hoyo, 2007; Volzone, 2007) having been demonstrated its effectiveness as adsorbents of all contaminants. Some biodegradable materials are used for for adsorption of chemical contaminants: lignins (Valderrabano et al., 2008) and also clays and clay minerals, whose colloidal properties, ease of generating structural changes, abundance in nature, and low cost make them very suitable for this kind of applications. Among the strategies used at present to preserve the quality of the water and this way to diminish the environmental risk that supposes the chemical pollution, stands out the use of adsorbents of under cost, already they are natural or modified, to immobilize these compounds and to avoid the pollution of the water with the consequent reduction of environmental and economic costs. We have studied the adsorption of several contaminants related to the food industry by natural or modified clays, searching their interaction mechanisms and the possible recycling of these materials for environmental purposes and

  19. Artificial specific binders directly recovered from chemically modified nucleic acid libraries.

    Science.gov (United States)

    Kasahara, Yuuya; Kuwahara, Masayasu

    2012-01-01

    Specific binders comprised of nucleic acids, that is, RNA/DNA aptamers, are attractive functional biopolymers owing to their potential broad application in medicine, food hygiene, environmental analysis, and biological research. Despite the large number of reports on selection of natural DNA/RNA aptamers, there are not many examples of direct screening of chemically modified nucleic acid aptamers. This is because of (i) the inferior efficiency and accuracy of polymerase reactions involving transcription/reverse-transcription of modified nucleotides compared with those of natural nucleotides, (ii) technical difficulties and additional time and effort required when using modified nucleic acid libraries, and (iii) ambiguous efficacies of chemical modifications in binding properties until recently; in contrast, the effects of chemical modifications on biostability are well studied using various nucleotide analogs. Although reports on the direct screening of a modified nucleic acid library remain in the minority, chemical modifications would be essential when further functional expansion of nucleic acid aptamers, in particular for medical and biological uses, is considered. This paper focuses on enzymatic production of chemically modified nucleic acids and their application to random screenings. In addition, recent advances and possible future research are also described.

  20. Artificial Specific Binders Directly Recovered from Chemically Modified Nucleic Acid Libraries

    Directory of Open Access Journals (Sweden)

    Yuuya Kasahara

    2012-01-01

    Full Text Available Specific binders comprised of nucleic acids, that is, RNA/DNA aptamers, are attractive functional biopolymers owing to their potential broad application in medicine, food hygiene, environmental analysis, and biological research. Despite the large number of reports on selection of natural DNA/RNA aptamers, there are not many examples of direct screening of chemically modified nucleic acid aptamers. This is because of (i the inferior efficiency and accuracy of polymerase reactions involving transcription/reverse-transcription of modified nucleotides compared with those of natural nucleotides, (ii technical difficulties and additional time and effort required when using modified nucleic acid libraries, and (iii ambiguous efficacies of chemical modifications in binding properties until recently; in contrast, the effects of chemical modifications on biostability are well studied using various nucleotide analogs. Although reports on the direct screening of a modified nucleic acid library remain in the minority, chemical modifications would be essential when further functional expansion of nucleic acid aptamers, in particular for medical and biological uses, is considered. This paper focuses on enzymatic production of chemically modified nucleic acids and their application to random screenings. In addition, recent advances and possible future research are also described.

  1. Web life: Ask Nature

    Science.gov (United States)

    2012-11-01

    Ask Nature is a site devoted to biomimicry, an interdisciplinary field in which practitioners study how animals and plants solve problems, and then use those solutions to develop better human technologies.

  2. Natural Gas Acquisition Program

    Data.gov (United States)

    General Services Administration — The "NGAP" system is a web based application which serves NGAP GSA users for tracking information details for various natural gas supply chain elements like Agency,...

  3. Sciences & Nature: Submissions

    African Journals Online (AJOL)

    Sciences & nature publish original works in French or in English that have not been ... This page should provide a summary (200 words maximum) in French and English .... one copy of the journal where his article is published, and 10 offprints.

  4. Natural Hazards Image Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Photographs and other visual media provide valuable pre- and post-event data for natural hazards. Research, mitigation, and forecasting rely on visual data for...

  5. The Nature of Grammar

    Institute of Scientific and Technical Information of China (English)

    王楠

    2012-01-01

    This paper describes the nature of grammar as "universalness". The universal grammar indicates that all the languages in the world have identical grammar. This is discussed from three aspects, which gives insight into grammar acquisition.

  6. Art, Technology and Nature

    DEFF Research Database (Denmark)

    Camilla Skovbjerg Paldam and Jacob Wamberg trace the Kantian heritage of radically separating art and technology, and inserting both at a distance to nature, suggesting this was a transient chapter in history. Thus, they argue, the present renegotiation between art, technology and nature is reminiscent......Since 1900, the connections between art and technology with nature have become increasingly inextricable. Through a selection of innovative readings by international scholars, this book presents the first investigation of the intersections between art, technology and nature in post-medieval times....... Transdisciplinary in approach, this volume’s 14 essays explore art, technology and nature’s shifting constellations that are discernible at the micro level and as part of a larger chronological pattern. Included are subjects ranging from Renaissance wooden dolls, science in the Italian art academies, and artisanal...

  7. Historic Natural Vegetation

    Data.gov (United States)

    California Natural Resource Agency — In 2001, the US Fish and Wildlife Service (USFWS) and the U.S. Bureau of Reclamation (BOR) contracted with the California State University, Chico Research Foundation...

  8. Vermont Designated Natural Areas

    Data.gov (United States)

    Vermont Center for Geographic Information — Under Natural Areas Law (10 Vermont Statutes Annotated, Chapter 83 � 2607) the FPR commissioner, with the approval of the governor, may designate and set aside areas...

  9. Radon - natural health threat

    International Nuclear Information System (INIS)

    Wrixon, Anthony

    1985-01-01

    Natural sources of radiation attract little attention, yet a survey has found radon gas in buildings at levels which put the occupants at some risk. The author wants safety standards set without undue delay. (author)

  10. Natural gas pricing

    International Nuclear Information System (INIS)

    Freedenthal, C.

    1993-01-01

    Natural gas pricing is the heart and soul of the gas business. Price specifically affects every phase of the industry. Too low a price will result in short supplies as seen in the mid-1970s when natural gas was scarce and in tight supply. To fully understand the pricing of this energy commodity, it is important to understand the total energy picture. In addition, the effect and impact of world and US economies, and economics in general are crucial to understanding natural gas pricing. The purpose of this presentation will be to show the parameters going into US natural gas pricing including the influence of the many outside industry factors like crude oil and coal pricing, market drivers pushing the gas industry, supply/demand parameters, risk management for buyers and sellers, and other elements involved in pricing analysis

  11. Natural Gas STAR Program

    Science.gov (United States)

    EPA’s Voluntary Methane Programs encourage oil and natural gas companies to adopt cost-effective technologies and practices that improve operational efficiency and reduce emissions of methane, a potent greenhouse gas.

  12. Natural gas for vehicles

    International Nuclear Information System (INIS)

    Chauveron, S. de

    1996-01-01

    This article presents compressed natural gas for vehicles (CNG), which can provide considerable advantages both as an alternative fuel and as a clean fuel. These assets are not only economic but also technical. The first part deals with what is at stake in developing natural gas as a motor fuel. The first countries to use CNG were those with natural gas resources in their subsoil. Today, with a large number of countries having to cope with growing concern about increasing urban pollution, natural gas is also seen as a clean fuel that can help cut vehicle pollutant emissions dramatically. In the second part a brief technical descriptions is given of CNG stations and vehicles, with the aim of acquainting the reader with some of CNG's specific technical features as compared to gasoline and diesel oil. Here CNG technologies are seen to be very close to the more conventional ones. (author)

  13. Natural polymers: an overview

    CSIR Research Space (South Africa)

    John, MJ

    2012-08-01

    Full Text Available The scarcity of natural polymers during the world war years led to the development of synthetic polymers like nylon, acrylic, neoprene, styrene-butadiene rubber (SBR) and polyethylene. The increasing popularity of synthetic polymers is partly due...

  14. Solitonic natural orbitals

    Science.gov (United States)

    Cioslowski, Jerzy

    2018-04-01

    The dependence of the natural amplitudes of the harmonium atom in its ground state on the confinement strength ω is thoroughly investigated. A combination of rigorous analysis and extensive, highly accurate numerical calculations reveals the presence of only one positive-valued natural amplitude ("the normal sign pattern") for all ω ≥1/2 . More importantly, it is shown that unusual, weakly occupied natural orbitals (NOs) corresponding to additional positive-valued natural amplitudes emerge upon sufficient weakening of the confinement. These solitonic NOs, whose shapes remain almost invariant as their radial positions drift toward infinity upon the critical values of ω being approached from below, exhibit strong radial localization. Their asymptotic properties are extracted from the numerical data and their relevance to calculations on fully Coulombic systems is discussed.

  15. Biomimetics: nature based innovation

    National Research Council Canada - National Science Library

    Bar-Cohen, Yoseph

    2012-01-01

    "Based on the concept that nature offers numerous sources of inspiration for inventions related to mechanisms, materials, processes, and algorithms, this book covers the topic of biomimetics and the inspired innovation...

  16. Natural gas benefits

    International Nuclear Information System (INIS)

    1999-01-01

    The General Auditor in the Netherlands studied the natural gas policy in the Netherlands, as has been executed in the past decades, in the period 1997-1999. The purpose of the study is to inform the Dutch parliament on the planning and the backgrounds of the natural gas policy and on the policy risks with respect to the benefits for the Dutch State, taking into account the developments in the policy environment. The final conclusion is that the proposed liberalization of the national natural gas market will result in a considerable deprivation of income for the State in case the benefit policy is not adjusted. This report includes a reaction of the Dutch Minister of Economic Affairs and an afterword of the General Auditor. In the appendix an outline is given of the natural gas policy

  17. Natural Gas Market Hubs

    Data.gov (United States)

    Department of Homeland Security — A hub is a physical transfer point for natural gas where several pipelines are connected. A market center is a hub where the operator offers services that facilitate...

  18. Managing soil natural capital

    DEFF Research Database (Denmark)

    Cong, Ronggang; Termansen, Mette; Brady, Mark

    2017-01-01

    Farmers are exposed to substantial weather and market related risks. Rational farmers seek to avoid large losses. Future climate change and energy price fluctuations therefore make adaptating to increased risks particularly important for them. Managing soil natural capital—the capacity of the soil...... to generate ecosystem services of benefit to farmers—has been proven to generate the double dividend: increasing farm profit and reducing associated risk. In this paper we explore whether managing soil natural capital has a third dividend: reducing the downside risk (increasing the positive skewness of profit......). This we refer to as the prudence effect which can be viewed as an adaptation strategy for dealing with future uncertainties through more prudent management of soil natural capital. We do this by developing a dynamic stochastic portfolio model to optimize the stock of soil natural capital—as indicated...

  19. Lesson "Balance in Nature

    Science.gov (United States)

    Chapanova, V.

    2012-04-01

    Lesson "Balance in Nature" This simulation game-lesson (Balance in Nature) gives an opportunity for the students to show creativity, work independently, and to create models and ideas. It creates future-oriented thought connected to their experience, allowing them to propose solutions for global problems and personal responsibility for their activities. The class is divided in two teams. Each team chooses questions. 1. Question: Pollution in the environment. 2. Question: Care for nature and climate. The teams work on the chosen tasks. They make drafts, notes and formulate their solutions on small pieces of paper, explaining the impact on nature and society. They express their points of view using many different opinions. This generates alternative thoughts and results in creative solutions. With the new knowledge and positive behaviour defined, everybody realizes that they can do something positive towards nature and climate problems and the importance of individuals for solving global problems is evident. Our main goal is to recover the ecological balance, and everybody explains his or her own well-grounded opinions. In this work process the students obtain knowledge, skills and more responsible behaviour. This process, based on his or her own experience, dialogue and teamwork, helps the participant's self-development. Making the model "human↔ nature" expresses how human activities impact the natural Earth and how these impacts in turn affect society. Taking personal responsibility, we can reduce global warming and help the Earth. By helping nature we help ourselves. Teacher: Veselina Boycheva-Chapanova " Saint Patriarch Evtimii" Scholl Str. "Ivan Vazov"-19 Plovdiv Bulgaria

  20. More natural gas

    International Nuclear Information System (INIS)

    Leprince, P.; Valais, M.

    1993-01-01

    This paper reports that large resources and growing markets are the salient prospects of natural gas for the coming decades. The greater impact of natural gas on the worldwide energy market can become a reality if several scientific disciplines can be mobilized in order to succeed in cutting production costs. Modeling, mechanics of complex fluids, and physical chemistry of interfaces are basic disciplines for understanding and mastering the gas processing technologies