Experimental determination of hydrogen content of oil extract from jatropha seeds

International Nuclear Information System (INIS)

Okunade, I.O.; Jonah, S.A.; Omede, M.O.

2010-01-01

The thermal neutron technique was used for the determination of hydrogen content of oil extract from Jatropha seeds. The experimental arrangement consists of a source holder, Am-Be neutron source embedded in paraffin wax and 3 He detector was used to measure reflection coefficient as a function of hydrogen content of various hydrocarbon materials used as calibration standards. The hydrogen content which is an important property of fuel oils was determined for jatropha oil and jatropha-synthetic diesel using their measured values of neutron reflection coefficients and calibration data. The result obtained showed that the hydrogen content of Jatropha oil exceeds that of the synthetic diesel, thus indicating its suitability as a fuel oil for powering diesel engines. The results obtained also indicated that hydrogen content of jatropha-synthetic diesel mixture increases as the volumetric concentration of jatropha oil in the mixture increases, indicating that jatropha oil can serve as a suitable additive to synthetic diesel oil.

Removal of heavy metal from industrial wastewater using hydrogen ...

African Journals Online (AJOL)

The batch removal of heavy metals lead (Pb), zinc (Zn) and copper (Cu) from industrial wastewater effluent under different experimental conditions using hydrogen peroxide was investigated. Experimental results indicated that at pH 6.5, pre-treatment analysis gave the following values: Pb 57.63 mg/l, Zn 18.9 mg/l and Cu ...

Dependence of hydrogen-induced lattice defects and hydrogen embrittlement of cold-drawn pearlitic steels on hydrogen trap state, temperature, strain rate and hydrogen content

International Nuclear Information System (INIS)

Doshida, Tomoki; Takai, Kenichi

2014-01-01

The effects of the hydrogen state, temperature, strain rate and hydrogen content on hydrogen embrittlement susceptibility and hydrogen-induced lattice defects were evaluated for cold-drawn pearlitic steel that absorbed hydrogen in two trapping states. Firstly, tensile tests were carried out under various conditions to evaluate hydrogen embrittlement susceptibility. The results showed that peak 2 hydrogen, desorbed at temperatures above 200 °C as determined by thermal desorption analysis (TDA), had no significant effect on hydrogen embrittlement susceptibility. In contrast, hydrogen embrittlement susceptibility increased in the presence of peak 1 hydrogen, desorbed from room temperature to 200 °C as determined by TDA, at temperatures higher than −30 °C, at lower strain rates and with higher hydrogen content. Next, the same effects on hydrogen-induced lattice defects were also evaluated by TDA using hydrogen as a probe. Peak 2 hydrogen showed no significant effect on either hydrogen-induced lattice defects or hydrogen embrittlement susceptibility. It was found that hydrogen-induced lattice defects formed under the conditions where hydrogen embrittlement susceptibility increased. This relationship indicates that hydrogen embrittlement susceptibility was higher under the conditions where the formation of hydrogen-induced lattice defects tended to be enhanced. Since hydrogen-induced lattice defects formed by the interaction between hydrogen and strain were annihilated by annealing at a temperature of 200 °C, they were presumably vacancies or vacancy clusters. One of the common atomic-level changes that occur in cold-drawn pearlitic steel showing higher hydrogen embrittlement susceptibility is the formation of vacancies and vacancy clusters

Problems of hydrogen - water vapor - inert gas mixture use in heavy liquid metal coolant technology

International Nuclear Information System (INIS)

Ul'yanov, V.V.; Martynov, P.N.; Gulevskij, V.A.; Teplyakov, Yu.A.; Fomin, A.S.

2014-01-01

The reasons of slag deposit formation in circulation circuits with heavy liquid metal coolants, which can cause reactor core blockage, are considered. To prevent formation of deposits hydrogen purification of coolant and surfaces of circulation circuit is used. It consists in introduction of gaseous mixtures hydrogen - water vapor - rare gas (argon or helium) directly into coolant flow. The principle scheme of hydrogen purification and the processes occurring during it are under consideration. Measures which make it completely impossible to overlap of the flow cross section of reactor core, steam generators, pumps and other equipment by lead oxides in reactor facilities with heavy liquid metal coolants are listed [ru

Heavy metals content in plant-growing products as the results of agroecological monitoring

International Nuclear Information System (INIS)

Kuznetsov, A.V.; Lunev, M.I.; Pavlikhina, A.V.; Lobas, N.V.

2008-01-01

The generalised data on the heavy metals and arsenic contents in grain and vegetable cultures, green mass and hay of various grasses are presented. The dependence of heavy metal accumulation factors in plant-growing products on soil properties is shown. The estimation of levels of the heavy metals contents in accordance with the admissible content standards is given.

Hydrogen in oxygen-free, phosphorus-doped copper-Charging techniques, hydrogen contents and modelling of hydrogen diffusion and depth profile

International Nuclear Information System (INIS)

Martinsson, Aasa; Sandstroem, Rolf; Lilja, Christina

2013-01-01

In Sweden spent nuclear fuel is planned to be disposed of by encapsulating in cast iron inserts protected by a copper shell. The copper can be exposed to hydrogen released during corrosion processes in the inserts. If the hydrogen is taken up by the copper, it could lead to hydrogen embrittlement. Specimens from oxygen-free copper have been hydrogen charged using two different methods. The purpose was to investigate how hydrogen could be introduced into copper in a controlled way. The thermal charging method resulted in a reduction of the initial hydrogen content. After electrochemical charging of cylindrical specimens, the measured hydrogen content was 2.6 wt. ppm which should compared with 0.6 wt. ppm before charging. The retained hydrogen after two weeks was reduced by nearly 40%. Recently the paper 'Hydrogen depth profile in phosphorus-doped, oxygen-free copper after cathodic charging' (Martinsson and Sandstrom, 2012) has been published. The paper describes experimental results for bulk specimens as well as presenting a model. Almost all the hydrogen is found to be located less than 100 μm from the surface. This model is used to interpret the experimental results on foils in the present report. Since the model is fully based on fundamental equations, it can be used to analyse what happens in new situations. In this report the effect of the charging intensity, the grain size, the critical nucleus size for hydrogen bubble formation as well as the charging time are analysed

Hydrogen in oxygen-free, phosphorus-doped copper - Charging techniques, hydrogen contents and modelling of hydrogen diffusion and depth profile

Energy Technology Data Exchange (ETDEWEB)

Martinsson, Aasa [Swerea KIMAB, Kista (Sweden); Sandstroem, Rolf [Swerea KIMAB, Kista (Sweden); Div. of Materials Science and Engineering, KTH Royal Institute of Technology, Stockholm (Sweden); Lilja, Christina [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

2013-01-15

In Sweden spent nuclear fuel is planned to be disposed of by encapsulating in cast iron inserts protected by a copper shell. The copper can be exposed to hydrogen released during corrosion processes in the inserts. If the hydrogen is taken up by the copper, it could lead to hydrogen embrittlement. Specimens from oxygen-free copper have been hydrogen charged using two different methods. The purpose was to investigate how hydrogen could be introduced into copper in a controlled way. The thermal charging method resulted in a reduction of the initial hydrogen content. After electrochemical charging of cylindrical specimens, the measured hydrogen content was 2.6 wt. ppm which should compared with 0.6 wt. ppm before charging. The retained hydrogen after two weeks was reduced by nearly 40%. Recently the paper 'Hydrogen depth profile in phosphorus-doped, oxygen-free copper after cathodic charging' (Martinsson and Sandstrom, 2012) has been published. The paper describes experimental results for bulk specimens as well as presenting a model. Almost all the hydrogen is found to be located less than 100 {mu}m from the surface. This model is used to interpret the experimental results on foils in the present report. Since the model is fully based on fundamental equations, it can be used to analyse what happens in new situations. In this report the effect of the charging intensity, the grain size, the critical nucleus size for hydrogen bubble formation as well as the charging time are analysed.

Improved correlations of hydrogen content versus combustion performance related properties of aviation turbine fuels

Energy Technology Data Exchange (ETDEWEB)

Nagpal, J.M.; Sharma, R.L.; Sagu, M.L.; Tiwari, G.B. (Indian Institute of Petroleum, Dehradun (India))

1994-01-01

In recent years the hydrogen content of Aviation Fuels has generated considerable interest. Various investigators have suggested correlation of hydrogen content with combustion related properties of aviation turbine fuel (ATF). A suitable threshold value of hydrogen content 13.8 wt% is being considered as a waiver of specifications such as specific energy, aniline gravity product, smoke point, aromatic content, naphthalenes and luminometer number. In the present paper relationship between the hydrogen content and combustion related properties has been examined and improved correlations of hydrogen content with several combustion related properties have been developed by incorporating a characterization factor in the equations. The supporting threshold value of a hydrogen content of 13.8wt% is verified with 25 data points for waiving of combustion properties such as specific energy, aniline gravity product, smoke point and aromatic content from aviation turbine fuel. 6 refs., 12 figs., 2 tabs.

Charge transfer to the continuum by heavy ions in atomic hydrogen

International Nuclear Information System (INIS)

Sellin, I.A.

1981-01-01

Design and installation of an atomic hydrogen target for measurements of charge transfer to the continuum by heavy ions are discussed. The design consists of a tungsten gas cell operated at temperatures of 2500 to 2600 0 K. Initial testing is underway

Determination of Hydrogen Density by Swift Heavy Ions.

Science.gov (United States)

Xu, Ge; Barriga-Carrasco, M D; Blazevic, A; Borovkov, B; Casas, D; Cistakov, K; Gavrilin, R; Iberler, M; Jacoby, J; Loisch, G; Morales, R; Mäder, R; Qin, S-X; Rienecker, T; Rosmej, O; Savin, S; Schönlein, A; Weyrich, K; Wiechula, J; Wieser, J; Xiao, G Q; Zhao, Y T

2017-11-17

A novel method to determine the total hydrogen density and, accordingly, a precise plasma temperature in a lowly ionized hydrogen plasma is described. The key to the method is to analyze the energy loss of swift heavy ions interacting with the respective bound and free electrons of the plasma. A slowly developing and lowly ionized hydrogen theta-pinch plasma is prepared. A Boltzmann plot of the hydrogen Balmer series and the Stark broadening of the H_{β} line preliminarily defines the plasma with a free electron density of (1.9±0.1)×10^{16}  cm^{-3} and a free electron temperature of 0.8-1.3 eV. The temperature uncertainty results in a wide hydrogen density, ranging from 2.3×10^{16} to 7.8×10^{18}  cm^{-3}. A 108 MHz pulsed beam of ^{48}Ca^{10+} with a velocity of 3.652  MeV/u is used as a probe to measure the total energy loss of the beam ions. Subtracting the calculated energy loss due to free electrons, the energy loss due to bound electrons is obtained, which linearly depends on the bound electron density. The total hydrogen density is thus determined as (1.9±0.7)×10^{17}  cm^{-3}, and the free electron temperature can be precisely derived as 1.01±0.04  eV. This method should prove useful in many studies, e.g., inertial confinement fusion or warm dense matter.

Heavy metal content of tinned soup as a function of storage time

Energy Technology Data Exchange (ETDEWEB)

Stelte, W.

1983-01-01

Samples were taken from soups prior to their preservation in tins. None of the samples showed an increased content of the investigated heavy metals lead and mercury exceeding the amounts normally found in food. Thus it may be considered as certain that the heavy metal content of soups is not adversely affected by technical processes during their preparation. Increase in heavy metal content by metallic residues from tin manufacture is slight and mainly due to tin, whose content is on average increased in the soup by 0.4 mg/kg. For lead the influence is smaller and for mercury it is not significantly demonstrable. The metallic residues from tin manufacture are an irrelevant quantity in terms of nutrition physiology. Within the investigated 4-year storage-period the lead content shows a tendency to increase towards saturation. Cadmium remains essentially constant, the content of mercury has a downward tendency and reaches zero after 2 to 4 years. Consumers' exposure is in a range known for the consumption of other foodstuffs as well. The use of varnished tins to package industrial soups involves no exposure of consumers to heavy metals justifying any apprehension even after prolonged storage.

Study of the behaviour of some heavy elements in solvents containing hydrogen fluoride

International Nuclear Information System (INIS)

Tarnero, M.

1967-01-01

The anhydrous liquid mixtures: dinitrogen tetroxide-hydrogen fluoride and antimony pentafluoride-hydrogen fluoride were studied as solvents for heavy elements interesting nuclear energy: uranium, thorium, zirconium and for some of their compounds. For N 2 O 4 -HF mixtures, electric conductivity measurements and liquid phase infrared spectra were also obtained. Uranium and zirconium tetrafluoride are much more soluble in N 2 O 4 -HF mixtures than in pure hydrogen fluoride. Uranium dissolved in these mixtures is pentavalent. In SbF 5 -HF mixtures, uranium dissolves with hydrogen evolution and becomes trivalent. The solid compound resulting from the dissolution is a fluoro-antimonate: U(SbF 6 ) 3 . (author) [fr

Hydrogen content, interfacial exchange and hydrogen diffusion in high-temperature protonic conductors based on strontium and barium cerates

International Nuclear Information System (INIS)

Vdovin, G.K.; Kurumchin, Eh.Kh.

2004-01-01

The hydrogen content and kinetics of the hydrogen exchange in the barium and strontium doped cerates are studied in the reduction atmosphere through the methods of isotope counterbalancing and isotope exchange. The measurements are carried out at 500-840 Deg C and hydrogen pressure of 2.7-16 gPa. It is established, that the hydrogen interfacial exchange proceeds at high velocities through the dissociative-type mechanisms. The effective activation energy of the hydrogen heteroexchange is determined. The coefficient of the hydrogen diffusion in BaCe 0.95 Nd 0.5 O 3-δ is calculated. The hydrogen content per formula unit constituted (0.48±0.05) in the SrCe 0.95 Y 0.05 O 3-δ and (0.60±0.05) in the BaCe 0.95 Nd 0.5 O 3-δ at 550 and 720 Deg C correspondingly and hydrogen pressure of 6.7 gPa [ru

Determination of hydrogen content of Jatropha biodiesel oil using neutron reflection technique

International Nuclear Information System (INIS)

Okunade, I. O.; Jonah, S. A.; Omede, M.

2014-01-01

Biofuel is an environmental-friendly alternative to fossil fuel and holds immense potential for the future energy needs of the country. Non-edible jatropha biodiesel oil has been identified as one of the suitable bio-fuel options. In this work, experimental measurements were performed to determine the total hydrogen content of jatropha oil and jatropha-synthetic diesel oil mixture. The work was carried out using a neutron reflection facility at the Centre for Energy Research and Training, Ahmadu Bello University, Zaria. Jatropha oil and jatropha-synthetic diesel mixture were subjected to experimental measurements for the purpose of determining bulk hydrogen content using neutron reflection facility that had been previously calibrated using various hydrocarbon materials of known hydrogen content. The hydrogen content of the sample were subsequently determined using their measured neutron reflection coefficient values and calibration data. In general, results obtained indicate high hydrogen content range of 10.68-12.16wt% for jatropha oil and the various jatropha-synthetic diesel mixtures. The implication of this is that jatropha oil or jatrophal-synthetic diesel mixture can be used as alternative fuel to mitigate high carbon monoxide emission.

Change of deuterium volume content in heavy water during carbon dioxide dissolution in it

International Nuclear Information System (INIS)

Efimova, T.I.; Kapitanov, V.F.; Levchenko, G.V.

1985-01-01

Carbon dioxide solution density in heavy water at increased temperature and pressure is measured and the influence of carbon dioxide solubility in heavy water on volumetric content of deuterium in it is determined. Investigations were conducted in the temperature range of 303-473 K and pressure range of 3-20 MPa by the autoclave method. Volumetric content of deuterium in heavy water decreases sufficiently with CO 2 dissolved in it in comparison with pure D 2 O under the similar conditions, and this decrease becomes more sufficient with the pressure increase. With the temperature increase the volumetric content of deuterium both for heavy water and for saturated carbon solution in heavy water decreases

Prototype CIRCE plant - industrial demonstration of heavy water production from reformed hydrogen source

International Nuclear Information System (INIS)

Spagnolo, D.A.; Boniface, H.A.; Sadhankar, R.R.; Everatt, A.E.; Miller, A.I.; Blouin, J.

2002-01-01

Heavy water (D 2 0) production has been dominated by the Girdler-Sulphide (G-S) process, which suffers several intrinsic disadvantages that lead to high production costs. Processes based on hydrogen/water exchange have become more attractive with the development of proprietary wetproofed catalysts by AECL. One process that is synergistic with industrial hydrogen production by steam methane reforming (SMR), the Combined Industrial Reforming and Catalytic Exchange (CIRCE) process, offers the best prospect for commercialization. SMRs are common globally in the oil-upgrading and ammonia industries. To study the CIRCE process in detail, AECL, in collaboration with Air Liquide Canada, constructed a prototype CIRCE plant (PCP) in Hamilton, Ontario. The plant became fully operational in 2000 July and is expected to operate to at least late fall of 2002. To-date, plant operation has confirmed the adequacy of the design and the capability of enriching deuterium to produce heavy water without compromising hydrogen production. The proprietary wetproofed catalyst has performed as expected, both in activity and in robustness. (author)

Impact of heavy metals on hydrogen production from organic fraction of municipal solid waste using co-culture of Enterobacter aerogenes and E. Coli.

Science.gov (United States)

Sharma, Preeti; Melkania, Uma

2018-05-01

In the present study, the effect of heavy metals (lead, mercury, copper, and chromium) on the hydrogen production from the organic fraction of municipal solid waste (OFMSW) was investigated using co-culture of facultative anaerobes Enterobacter aerogenes and E. coli. Heavy metals were applied at concentration range of 0.5, 1, 2, 5, 10, 20, 50 and 100 mg/L. The results revealed that lead, mercury, and chromium negatively affected hydrogen production for the range of concentrations applied. Application of copper slightly enhanced hydrogen production at low concentration and resulted in the hydrogen yield of 36.0 mLH 2 /gCarbo initial with 10 mg/L copper supplementation as compared to 24.2 mLH 2 /gCarbo initial in control. However, the higher concentration of copper (>10 mg/L) declined hydrogen production. Hydrogen production inhibition potential of heavy metals can be arranged in the following increasing order: Cu 2+  metal addition. Thus, the present study reveals that the presence of heavy metals in the feedstock is detrimental for the hydrogen production. Therefore, it is essential to remove the toxic heavy metals prior to anaerobic digestion. Copyright © 2018 Elsevier Ltd. All rights reserved.

Method for enriching and separating heavy hydrogen isotopes from substance streams containing such isotopes by means of isotope exchange

International Nuclear Information System (INIS)

Knochel, A.; Eggers, I.; Klatte, B.; Wilken, R. D.

1985-01-01

A process for enriching and separating heavy hydrogen isotopes having a heavy hydrogen cation (deuterium and/or tritium) from substance streams containing them, wherein the respectively present hydrogen isotopes are exchanged in chemical equilibria. A protic, acid solution containing deuterium and/or tritium is brought into contact with a value material from the group of open-chained polyethers or aminopolyethers, macro-monocyclic or macro-polycyclic polyethers, macro-monocyclic or macro-polycyclic amino polyethers, and mixtures of these values, in their free or proton salt form to form a reaction product of the heavy hydrogen cation with the value or value salt and bring about enrichment of deuterium and/or tritium in the reaction product. The reaction product containing the value or value salt is separated from the solution. The separated reaction product is treated to release the hydrogen isotope(s) to be enriched in the form of deuterium oxide (HDO) and/or tritium oxide (HTO) by regenerating the value or its salt, respectively. The regenerated value is returned for reuse

Hydrogen Solubility in Heavy Undefined Petroleum Fractions Using Group Contributions Methods

Directory of Open Access Journals (Sweden)

Aguilar-Cisneros Humberto

2017-01-01

Full Text Available Hydrogen solubility in heavy undefined petroleum fractions is estimated by taking as starting point a method of characterization based on functional groups [ Carreón-Calderón et al. (2012 Ind. Eng. Chem. Res. 51, 14188-14198 ]. Such method provides properties entering into equations of states and molecular pseudostructures formed by non-integer numbers of functional groups. Using Vapor-Liquid Equilibria (VLE data from binary mixtures of known compounds, interaction parameters between hydrogen and the calculated functional groups were estimated. Besides, the incorporation of the hydrogen-carbon ratio of the undefined petroleum fractions into the method allows the corresponding hydrogen solubility to be properly estimated. This procedure was tested with seven undefined petroleum fractions from 27 to 6 API over wide ranges of pressure and temperature (323.15 to 623.15 K. The results seem to be in good agreement with experimental data (overall Relative Average Deviation, RAD < 15%.

Heavy Metal Content in Terraced Rice Fields at Sruwen Tengaran Semarang - Indonesia

Science.gov (United States)

Hindarwati, Yulis; Soeprobowati, Tri Retnaningsih; Sudarno

2018-02-01

The presence of heavy metal on agricultural soils can be caused not only natural factors but also due to human intervention. Differences in management and lack of understanding of farmers in the production input of fertilizers and pesticides ensued in land ravaged. Periodic testing of paddy fields is necessary to minimize the contaminants from being absorbed by plants that will have an impact on health decline. The purpose of the assessment was to identify the heavy metal content in the terraced rice field in Sruwen Village, Tengaran District, Semarang Regency. Survey was conducted in February 2017. Sampling on terraced rice fields of different heights consisted of upper, middle, and upper down. Taken as many as eight single points and composed at a depth of 0-20 cm and 20-40 cm. The identification results showed that heavy metal content of Pb, Cd, and Cu were present at all altitudes. Heavy Metals Pb and Cd at a depth of 0-20 cm were higher from 20-40 cm in the upper and lower rice fields but lower in the middle rice field. Cu heavy metal at a depth of 0-20 cm was higher than 20-40 cm in all altitude land. The heavy metal content of Pb, Cd, and Cu was still below the heavy metal standard set by the European Union and India.

Heavy Metal Contents in Some Commonly Consumed Vegetables

African Journals Online (AJOL)

dell

This work reports on the levels of cadmium, lead, copper, manganese and ... source of both heavy metals and essential trace elements due to their ... content, clay mineral and other soil chemical ... addition, the interactions of soil-plant root-.

[Determination of deuterium concentration in foods and influence of water with modified isotopic composition on oxidation parameters and heavy hydrogen isotopes content in experimental animals].

Science.gov (United States)

Basov, A A; Bykov, I M; Baryshev, M G; Dzhimak, S S; Bykov, M I

2014-01-01

The article presents the results of the study of the deuterium (D) content in food products as well as the influence of deuterium depleted water (DDW) on the concentration of heavy hydrogen isotopes in the blood and lyophilized tissues of rats. The most significant difference in the content of D was found between potato and pork fat, which indexes the standard delta notation (δ) D in promille, related to the international standard SMOW (Standard Mean Ocean of Water) amounted to -83,2 per thousand and -250,7 per thousand, respectively (phydrogen atoms in the body. The data obtained in the experimental modeling of the diet of male Wistar rats in the age of 5-6 mo (weight 235 ± 16 g) using DDW (δD = -743,2 per thousand) instead of drinking water (δD = -37,0 per thousand) with identical mineral composition showed that after 2 weeks significant (p tissue") is due to different rates ofisotopic exchange reactions in plasma and tissues (liver, kidney, heart), which can be explained by entering into the composition of a modified diet of organic substrates with more than DDW concentration D, which are involved in the construction of cellular structures and eventually lead to a redistribution of D and change direction of D/H gradient "plasmaheavy non-radioactive atoms will allow the targeted nutritional correction of prooxidant-antioxidant status of the population in areas with adverse environmental conditions, stimulating by created isotopic D/H gradient cytoprotective mechanisms influencing the various components of nonspecific protection, including free radical oxidation processes. And then again, periodic assessment of the isotopic composition of nutrients will monitor the quality of food consumed by the population, and if

Recent search for quarks and very heavy hydrogen isotopes using an (almost) all-electrostatic system

International Nuclear Information System (INIS)

Schiffer, J.P.; Ernst, H.; Henning, W.; Kutschera, W.

1981-01-01

In order to search for +1/3e particles in metals we adapted the Argonne Dynamitron to accelerate particles from a metal filament. The particles, after being accelerated, were bent by an electrostatic deflector, passed through a foil which dissociated any molecules, and bent by a second electrostatic deflector to eliminate molecular fragments, through a slit system into a Si surface-barrier detector. Only charged particles that originated at the terminal of the accelerator and did not change their mass or charge state throughout, could reach the detector. The energy deposited in the detector was then a direct measure of the particle's charge: a +1/3e particle would have one third the energy of a single charged one. But all particles were accepted, independent of their mass. These experiments were performed with negative results. Recently we adapted this technique to a search for anomalously heavy isotopes of hydrogen. A limit on such particles would be useful on quite general grounds. In order to do the measurement, however, the technique had to be modified in several ways. 1) To eliminate the known isotopes of hydrogen a small magnetic field was introduced, sufficient to deflect the light isotopes onto a beam stop, but leaving very heavy isotopes essentially undeflected. 2) The solid state detector was replaced by a ΔE-E telescope, that provided charge identification, and 3) The two elements in the telescope were separated sufficiently to allow the time-of-flight measurements to be carried out, in order to search for heavy particles. 4) In addition, a nickel foil was placed in front of the detector of sufficient thickness to stop any normal ions (with Z greater than or equal to 2) but thin enough to readily transmit hydrogen-like particles of any mass. From preliminary tests we anticipate no problems in observing a heavy hydrogen isotope which is 10 -15 of the primary hydrogenic beam, and with minor improvements we might be able to reach 10 -17

Technical and economical feasibility studies and preliminary plan of a heavy water plant by the criogenic distillation method of hydrogen

International Nuclear Information System (INIS)

Dias Vargas, F.

1983-01-01

This paper presents the pre-feasibility study of a heavy water production plant, both from the technical and economical point of view. Criogenic distillation of hydrogen is used as the final enrichment stage. The deuterium source is water treated previously by a process of enrichment based on the water-hydrogen isotopic exchange. The economical analysis is aimed at the study of the feasibility of the installation of a heavy water moderated reaction in Chile. General properties of heavy water are presented and also the various materials of its enrichment at the industrial scale. The plant itself has a first stage based on the water-hydrogen isotopic exchange procesS, where deuterium is extracted from the water by the hydrogen which is subsequently treated in a criogenic distillation stage. An important fact of the plant analysis is the calculation of heat exchangers mainly in relation to the problem posed by tHe hydrogen's low point of liquifaction. The distillation units are also treated and designed. The economic evaluation produces project diScount rates of 15.71% and 21.97%, for 25 tons/year and 40 tons/year of production capacity. The heavy water price used for these evaluation was 600 $/Kg

Effect of hydrogen and oxygen content on the embrittlement of Zr alloys

International Nuclear Information System (INIS)

Griger, A.; Hozer, Z.; Matus, L.; Vasaros, L.; Horvath, M.

2001-01-01

An experimental study is carried out in the KFKI Atomic Energy Research Institute in order to clear up the role of oxidation and hydrogen uptake in the embrittlement process. Russian E110 type Zr1%Nb and Zircaloy-4 claddings are used as test materials. The differences between the properties of two alloys are examined. The sample preparation covered the following cases: oxidation in Ar+O 2 atmosphere; hydrogen uptake of as received and pre-oxidised samples (in Ar+O 2 atmosphere); oxidation in steam. The oxidation in Ar+O 2 and the subsequent hydrogen uptake procedure make possible the production of samples with well-characterized hydrogen and oxygen content. Corrosion treated ring samples of 8 mm height are examined in ring compression tests. The force-deformation curves are recorded and the crushing force and deformation are determined. The relative deformation is used for the characterisation of embrittlement level. The results of experiments provide detailed information about the effect of hydrogen and oxygen content on the embrittlement of zirconium alloys. The conclusions are: 1) hydrogen seems to play a more important role in the embrittlement of zirconium alloys than oxygen; 2) the Zircaloy-4 alloy becomes brittle at lower hydrogen content than the Zr1%Nb; 3) under steam oxidation conditions the Zr1%Nb alloy takes up much more hydrogen and becomes more brittle than the Zircaloy-4

HEAVY METAL CONTENT OF AYURVEDIC HERBAL MEDICINE PRODUCTS

Science.gov (United States)

Case reports of individuals taking Ayurvedic herbal medicine products (HMPs) suggest that they may contain lead, mercury, and/or arsenic. We analyzed the heavy metal content of Ayurvedic HMPs manufactured in India and Pakistan, available in South Asian grocery stores in the Bost...

The creation of strongly coupled plasmas using an intense heavy ion beam: low-entropy compression of hydrogen and the problem of hydrogen metallization

CERN Document Server

Tahir, N A; Shutov, A; Varentsov, D; Udrea, S; Hoffmann, Dieter H H; Juranek, H; Redmer, R; Portugues, R F; Lomonosov, I V; Fortov, V E

2003-01-01

Intense heavy ion beams deposit energy very efficiently over extended volumes of solid density targets, thereby creating large samples of strongly coupled plasmas. Intense beams of energetic heavy ions are therefore an ideal tool to research this interesting field. It is also possible to design experiments using special beam-target geometries to achieve low-entropy compression of samples of matter. This type of experiments is of particular interest for studying the problem of hydrogen metallization. In this paper we present a design study of such a proposed experiment that will be carried out at the future heavy ion synchrotron facility SIS100, at the Gesellschaft fuer Schwerionenforschung, Darmstadt. This study has been done using a two-dimensional hydrodynamic computer code. The target consists of a solid hydrogen cylinder that is enclosed in a thick shell of lead whose one face is irradiated with an ion beam which has an annular (ring shaped) focal spot. The beam intensity and other parameters are consider...

Hot vacuum outgassing to ensure low hydrogen content in MOX fuel pellets for thermal reactors

International Nuclear Information System (INIS)

Majumdar, S.; Nair, M.R.; Kumar, Arun

1983-01-01

Hot vacuum outgassing treatment to ensure low hydrogen content in Mixed Oxide Fuel (MOX) pellets for thermal reactors has been described. Hypostoichiometric sintered MOX pellets retain more hydrogen than UO 2 pellets. The hydrogen content further increases with the addition of admixed lubricant and pore formers. However, low hydrogen content in the MOX pellets can be ensured by a hot vacuum outgassing treatment at a temperature between 773K to 823K for 2 hrs. (author)

Hydrogen formation under gamma and heavy ions irradiation of geopolymers

International Nuclear Information System (INIS)

Chupin, F.; Dannoux-Papin, A.; D'Espinose de Lacaillerie, J.B.; Ngono Ravache, Y.

2015-01-01

This study examines the behavior under irradiation of geo-polymer which is not yet well known and attempts to highlight the importance of water radiolysis. For their use as embedding matrices, stability under ionizing radiation as well as low hydrogen gas released must be demonstrated. Different formulations of geo-polymers have been irradiated either with γ-rays ( 60 Co sources) or 75 MeV 36 Ar ions beams and the production of hydrogen released has been quantified. This paper presents the results of gas analysis in order to identify important structural parameters that influence confined water radiolysis. Indeed, a correlation between pore size, water content on one side, and the hydrogen production radiolytic yield (G(H 2 )) on the other side, has been demonstrated. For the 75 MeV 36 Ar ions irradiation, the effect of porosity has not been well emphasized. For both, the results have revealed the water content influence. (authors)

Prototype CIRCE plant-industrial demonstration of heavy-water production from a reformed hydrogen source

Energy Technology Data Exchange (ETDEWEB)

Spagnolo, D.A.; Boniface, H.A.; Sadhankar, R.R.; Everatt, A.E.; Miller, A.I. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Blouin, J. [Air Liquide Canada, Hamilton, Ontario (Canada)

2002-09-01

Heavy-water (D{sub 2}0) production has been dominated by the Girdler-Sulphide (G-S) process, which suffers several intrinsic disadvantages that lead to high production costs. Processes based on hydrogen/water exchange have become more attractive with the development of proprietary wetproofed catalysts by AECL. One process that is synergistic with industrial hydrogen production by steam methane reforming (SMR), the combined industrial reforming and catalytic exchange (CIRCE) process, offers the best prospect for commercialization. SMRs are common globally in the oil upgrading and ammonia industries. To study the CIRCE process in detail, AECL, in collaboration with Air Liquide Canada, constructed a prototype CIRCE plant (PCP) in Hamilton, ON. The plant became fully operational in 2000 July and is expected to operate to at least the late fall of 2002. To date, plant operation has confirmed the adequacy of the design and the capability of enriching deuterium to produce heavy water without compromising hydrogen production. The proprietary wetproofed catalyst has performed as expected, both in activity and in robustness. (author)

Prototype CIRCE plant-industrial demonstration of heavy-water production from a reformed hydrogen source

International Nuclear Information System (INIS)

Spagnolo, D.A.; Boniface, H.A.; Sadhankar, R.R.; Everatt, A.E.; Miller, A.I.; Blouin, J.

2002-09-01

Heavy-water (D 2 0) production has been dominated by the Girdler-Sulphide (G-S) process, which suffers several intrinsic disadvantages that lead to high production costs. Processes based on hydrogen/water exchange have become more attractive with the development of proprietary wetproofed catalysts by AECL. One process that is synergistic with industrial hydrogen production by steam methane reforming (SMR), the combined industrial reforming and catalytic exchange (CIRCE) process, offers the best prospect for commercialization. SMRs are common globally in the oil upgrading and ammonia industries. To study the CIRCE process in detail, AECL, in collaboration with Air Liquide Canada, constructed a prototype CIRCE plant (PCP) in Hamilton, ON. The plant became fully operational in 2000 July and is expected to operate to at least the late fall of 2002. To date, plant operation has confirmed the adequacy of the design and the capability of enriching deuterium to produce heavy water without compromising hydrogen production. The proprietary wetproofed catalyst has performed as expected, both in activity and in robustness. (author)

A REVIEW ON HEAVY METALS CONTENTS IN HIDE, SKIN AND PROCESSED LEATHERS

Directory of Open Access Journals (Sweden)

KOIZHAIGANOVA Meruyert

2016-05-01

Full Text Available Heavy metals are metals with high atomic weight which can be deposited in soil, water, plants and animals. It is generally known that mammal tissues are good bioindicators of trace elements, including heavy metals. Heavy metal analysis serves to identify and quantify the elements that are a potential hazard to the consumer after varying levels of contact. Usage area of leather is increasingly expanding in these days and it has also become a material requested and demanded by effect of fashion. Leather must protect its appearance and physical stability and also be problem-free in ecological terms and harmless to human health. There is a lack of data concerning the content of toxic elements in raw hide and skin of animals. Mainly information concerning metals content, including toxic ones, in processed leathers may be found in the literature. The aim of the present study was to review and compare the content of some heavy metals in raw hide, skin and the processed leathers in order to evaluate their accumulation and transition to the end-up product.

The creation of strongly coupled plasmas using an intense heavy ion beam: low-entropy compression of hydrogen and the problem of hydrogen metallization

Energy Technology Data Exchange (ETDEWEB)

Tahir, N A [Institut fuer Theoretische Physik, Universitaet Frankfurt, Postfach 11 19 32, 60054 Frankfurt (Germany); Piriz, A R [ETSI Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain); Shutov, A [Institute for Problems in Chemical Physics Research, Chernogolovka, Russia (Russian Federation); Varentsov, D [Institut fuer Kernphysik, Technische Universitaet Darmstadt, Schlossgarten Str. 9, 64289 Darmstadt (Germany); Udrea, S [Institut fuer Kernphysik, Technische Universitaet Darmstadt, Schlossgarten Str. 9, 64289 Darmstadt (Germany); Hoffmann, D H H [Institut fuer Kernphysik, Technische Universitaet Darmstadt, Schlossgarten Str. 9, 64289 Darmstadt (Germany); Juranek, H [Fachbereich Physik, Universitaet Rostock, 18051 Rostock (Germany); Redmer, R [Fachbereich Physik, Universitaet Rostock, 18051 Rostock (Germany); Portugues, R F [ETSI Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain); Lomonosov, I [Institute for Problems in Chemical Physics Research, Chernogolovka, Russia (Russian Federation); Fortov, V E [Institute for Problems in Chemical Physics Research, Chernogolovka, Russia (Russian Federation)

2003-06-06

Intense heavy ion beams deposit energy very efficiently over extended volumes of solid density targets, thereby creating large samples of strongly coupled plasmas. Intense beams of energetic heavy ions are therefore an ideal tool to research this interesting field. It is also possible to design experiments using special beam-target geometries to achieve low-entropy compression of samples of matter. This type of experiments is of particular interest for studying the problem of hydrogen metallization. In this paper we present a design study of such a proposed experiment that will be carried out at the future heavy ion synchrotron facility SIS100, at the Gesellschaft fuer Schwerionenforschung, Darmstadt. This study has been done using a two-dimensional hydrodynamic computer code. The target consists of a solid hydrogen cylinder that is enclosed in a thick shell of lead whose one face is irradiated with an ion beam which has an annular (ring shaped) focal spot. The beam intensity and other parameters are considered to be the same as expected at the future SIS100 facility. The simulations show that due to multiple shock reflection between the cylinder axis and the lead-hydrogen boundary, one can achieve up to 20 times solid density in hydrogen while keeping the temperature as low as a few thousand K. The corresponding pressure is of the order of 10 Mbar. These values of the physical parameters lie within the range of theoretically predicted values for hydrogen metallization. We have also carried out a parameter study of this problem by varying the target and beam parameters over a wide range. It has been found that the results are very insensitive to such changes in the input parameters.

The creation of strongly coupled plasmas using an intense heavy ion beam: low-entropy compression of hydrogen and the problem of hydrogen metallization

International Nuclear Information System (INIS)

Tahir, N A; Piriz, A R; Shutov, A; Varentsov, D; Udrea, S; Hoffmann, D H H; Juranek, H; Redmer, R; Portugues, R F; Lomonosov, I; Fortov, V E

2003-01-01

Intense heavy ion beams deposit energy very efficiently over extended volumes of solid density targets, thereby creating large samples of strongly coupled plasmas. Intense beams of energetic heavy ions are therefore an ideal tool to research this interesting field. It is also possible to design experiments using special beam-target geometries to achieve low-entropy compression of samples of matter. This type of experiments is of particular interest for studying the problem of hydrogen metallization. In this paper we present a design study of such a proposed experiment that will be carried out at the future heavy ion synchrotron facility SIS100, at the Gesellschaft fuer Schwerionenforschung, Darmstadt. This study has been done using a two-dimensional hydrodynamic computer code. The target consists of a solid hydrogen cylinder that is enclosed in a thick shell of lead whose one face is irradiated with an ion beam which has an annular (ring shaped) focal spot. The beam intensity and other parameters are considered to be the same as expected at the future SIS100 facility. The simulations show that due to multiple shock reflection between the cylinder axis and the lead-hydrogen boundary, one can achieve up to 20 times solid density in hydrogen while keeping the temperature as low as a few thousand K. The corresponding pressure is of the order of 10 Mbar. These values of the physical parameters lie within the range of theoretically predicted values for hydrogen metallization. We have also carried out a parameter study of this problem by varying the target and beam parameters over a wide range. It has been found that the results are very insensitive to such changes in the input parameters

Hydrogenation active sites of unsupported molybdenum sulfide catalysts for hydroprocessing heavy oils

Energy Technology Data Exchange (ETDEWEB)

Iwata, Y.; Araki, Y.; Honna, K. [Tsukuba-branch, Advanced Catalyst Research Laboratory, Petroleum Energy Center, 1-1 Higashi, Tsukuba, 305-8565 Ibaraki (Japan); Miki, Y.; Sato, K.; Shimada, H. [National Institute of Materials and Chemical Research, 1-1 Higashi, Tsukuba, 305-8565 Ibaraki (Japan)

2001-02-20

The purpose of the present study was to elucidate the nature of the hydrogenation active sites on unsupported molybdenum sulfide catalysts, aimed at the improvement of the catalysts for the slurry processes. The number of hydrogenation active sites was found to relate to the 'inflection' on the basal plane of the catalyst particles. The comparison of the catalytic activity to that of an oil-soluble catalyst in the hydroprocessing of heavy oils suggests that the performance of the oil-soluble catalyst was near the maximum, unless another component such as Ni or Co was incorporated.

Analysis of hydrogen sulfide releases in heavy water production facilities

International Nuclear Information System (INIS)

Croitoru, Cornelia; Dumitrescu, Maria; Preda, Irina; Lazar, Roxana

1996-01-01

Safety analyses conducted at ICIS concern primarily the heavy water production installations. The quantitative risk assessment needs the frequency calculation of accident sequences and consequences. In heavy water plants which obtain primary isotopic concentration of water by H 2 O - H 2 S exchange, large amounts of hydrogen sulfide which is a toxic, inflammable and explosive gas, are circulated. The first stage in calculating the consequences consists in potential analysis of H 2 S release. This work presents a study of this types of releases for pilot installations of the heavy water production at ICIS (Plant 'G' at Rm. Valcea). The installations which contain and maneuver large quantities of H 2 S and the mathematical models for different types of releases are presented. The accidents analyzed are: catastrophic column, container, spy-hole failures or gas-duct rupture and wall cracks in the installation. The main results are given as tables while the time variations of the flow rate and quantities of H 2 O released by stack disposal are plotted

Determination of hydrogen content by neutron techniques

International Nuclear Information System (INIS)

Santisteban, J.R.; Granada, J.R.; Mayer, R.E.

1997-01-01

The commonly available techniques for the determination of hydrogen dissolved in solids are usually destructive from the point of view of the sample. A new, nondestructive method for this kind of measurements has been developed at our laboratory, with the requirement of improved sensitivity for massive samples. This scattering method is based on the use of epithermal neutrons, and has been implemented through the design and construction of a spectrometer dedicated to that task. In addition, the traditional transmission method has been employed to determine hydrogen content in metals, using the full sub thermal and thermal neutron energy ranges. A pulsed neutron source based on an electron LINAC is employed, together with time-of-flight techniques. In this work we will present some results illustrative of the sensitivity achieved by these neutron techniques in different systems and for a wide range of hydrogen concentrations. (author) [es

Heavy metal content of combustible municipal solid waste in Denmark.

Science.gov (United States)

Riber, Christian; Fredriksen, Gry S; Christensen, Thomas H

2005-04-01

Data on the heavy metal composition of outlets from Danish incinerators was used to estimate the concentration of Zn, Cu, Pb, Cr, Ni, Cd, As and Hg in combustible waste (wet as received) at 14 Danish incinerators, representing about 80% of the waste incinerated in Denmark. Zn (1020 mg kg(-1)), Cu (620 mg kg(-1)) and Pb (370 mg kg(-1)) showed the highest concentration, whereas Hg (0.6 mg kg(-1)) showed the lowest concentration. The variation among the incinerators was in most cases within a factor of two to three, except for Cr that in two cases showed unexplained high concentrations. The fact that the data represent many incinerators and, in several cases, observations from a period of 4 to 5 years provides a good statistical basis for evaluating the content of heavy metals in combustible Danish waste. Such data may be used for identifying incinerators receiving waste with high concentrations of heavy metals suggesting the introduction of source control, or, if repeated in time, the data must also be used for monitoring the impacts of national regulation controlling heavy metals. It is recommended that future investigations consider the use of sample digestion methods that ensure complete digestion in order to use the data for determining the total heavy metal content of waste.

Effects of residues from municipal solid waste landfill on corn yield and heavy metal content

International Nuclear Information System (INIS)

Prabpai, S.; Charerntanyarak, L.; Siri, B.; Moore, M.R.; Noller, Barry N.

2009-01-01

The effects of residues from municipal solid waste landfill, Khon Kaen Municipality, Thailand, on corn (Zea mays L.) yield and heavy metal content were studied. Field experiments with randomized complete block design with five treatments (0, 20, 40, 60 and 80% v/v of residues and soil) and four replications were carried out. Corn yield and heavy metal contents in corn grain were analyzed. Corn yield increased by 50, 72, 85 and 71% at 20, 40, 60 and 80% treatments as compared to the control, respectively. All heavy metals content, except cadmium, nickel and zinc, in corn grain were not significantly different from the control. Arsenic, cadmium and zinc in corn grain were strongly positively correlated with concentrations in soil. The heavy metal content in corn grain was within regulated limits for human consumption.

Changes in Hydrogen Content During Steelmaking

OpenAIRE

Vrbek K.; Lamut J.; Marolt M.; Knap M.

2015-01-01

Štore Steel produces steel grades for spring, forging and engineering industry applications. Steelmaking technology consists of scrap melting in Electric Arc Furnace (EAF), secondary metallurgy in Ladle Furnace (LF) and continuous casting of billets (CC). Hydrogen content during steelmaking of various steel grades and steelmaking technologies was measured. Samples of steel melt from EAF, LF and CC were collected and investigated. Sampling from Electric Arc Furnace and Ladle Furnace was carrie...

The heavy metals content in wild growing mushrooms from burdened Spiš area

Directory of Open Access Journals (Sweden)

Marek Slávik

2016-05-01

Full Text Available In this work, we evaluated the rate of entry of heavy metals into the edible parts of wild mushrooms, from central Spiš area. The area is characterized by extremely high content of heavy metals particularly mercury in abiotic and biotic components of ecosystems. The toxicity of heavy metals is well known and described. Known is also the ability of fungi to accumulate contaminants from substrates in which mushrooms grow. We have collected commonly consumed species of mushrooms (Russula vesca., Macrolepiota procera, Lycoperdon pyriforme, Lecinum piceinum, Boletus reticulatus. Sampling was conducted for two years 2012 and 2013. The samples taken mushrooms and substrates on which to grow, we determined heavy metal content (Cd, Pb, Cu, including total mercury content modified by atomic absorption spectrometry (AMA - 254. In the substrate, we determined the humus content and pH value. The heavy metal content in soils were evaluated according to Law no. 220/2004 Z.z The exceedance limit values of Cd, Pb, Cu and Hg was recorded. Most significantly the respective limit was recorded in soil samples in the case of mercury. The determined concentration Hg was 39.01 mg.kg-1. From the results, we evaluated the degree of ability to bioaccumulate heavy metals different kinds of fungi. We also evaluated the health safety of the consumption of these fungi on the comparison with the limit values provided in the food code of SR. We recorded a high rate of accumulation of mercury in the species Boletus reticulatus and Macrolepiota procera. For these types we recorded the most significant than allowed concentrations of mercury in mushrooms. The highest recorded concentration reached 17.64 mg.kg-1 Hg in fresh matter. The limit value was exceeded also in the case of copper. We do not recommend to increased consumption of wild mushrooms in the reference area.

Recent progress of hydrogen isotope behavior studies for neutron or heavy ion damaged W

International Nuclear Information System (INIS)

Oya, Yasuhisa; Hatano, Yuji; Shimada, Masashi; Buchenauer, Dean; Kolasinski, Robert; Merrill, Brad; Kondo, Sosuke; Hinoki, Tatsuya; Alimov, Vladimir Kh.

2016-01-01

Highlights: • This paper reviews recent results pertaining to hydrogen isotope behavior in neutron and heavy ion damaged W. • Accumulation of damage in W creates stable trapping sites for hydrogen isotopes, thereby changing the observed desorption behavior. • The distribution of defects throughout the sample also changes the shape of TDS spectrum. • Experimental results show that production of Re by nuclear reaction of W with neutrons reduces the density of trapping sites, though no remarkable retention enhancement is observed. - Abstract: This paper reviews recent results pertaining to hydrogen isotope behavior in neutron and heavy ion damaged W. Accumulation of damage in W creates stable trapping sites for hydrogen isotopes, thereby changing the observed desorption behavior. In particular, the desorption temperature shifts higher as the defect concentration increases. In addition, the distribution of defects throughout the sample also changes the shape of TDS spectrum. Even if low energy traps were distributed in the bulk region, the D diffusion toward the surface requires additional time for trapping/detrapping during surface-to-bulk transport, contributing to a shift of desorption peaks toward higher temperatures. It can be said that both of distribution of damage (e.g. hydrogen isotope trapping sites) and their stabilities would have a large impact on desorption. In addition, transmutation effects should be also considered for an actual fusion environment. Experimental results show that production of Re by nuclear reaction of W with neutrons reduces the density of trapping sites, though no remarkable retention enhancement is observed.

Recent progress of hydrogen isotope behavior studies for neutron or heavy ion damaged W

Energy Technology Data Exchange (ETDEWEB)

Oya, Yasuhisa, E-mail: syoya@ipc.shizuoka.ac.jp [Shizuoka University, 836 Ohya, Suruga-ku Shizuoka 422-8529 (Japan); Hatano, Yuji [University of Toyama, 3190 Gofuku, Toyama 939-8555 (Japan); Shimada, Masashi [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Buchenauer, Dean; Kolasinski, Robert [Sandia National Laboratories, Livermore, CA 94551 (United States); Merrill, Brad [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Kondo, Sosuke; Hinoki, Tatsuya [Kyoto University, Gokasho, Uji 611-0011 (Japan); Alimov, Vladimir Kh. [University of Toyama, 3190 Gofuku, Toyama 939-8555 (Japan)

2016-12-15

Highlights: • This paper reviews recent results pertaining to hydrogen isotope behavior in neutron and heavy ion damaged W. • Accumulation of damage in W creates stable trapping sites for hydrogen isotopes, thereby changing the observed desorption behavior. • The distribution of defects throughout the sample also changes the shape of TDS spectrum. • Experimental results show that production of Re by nuclear reaction of W with neutrons reduces the density of trapping sites, though no remarkable retention enhancement is observed. - Abstract: This paper reviews recent results pertaining to hydrogen isotope behavior in neutron and heavy ion damaged W. Accumulation of damage in W creates stable trapping sites for hydrogen isotopes, thereby changing the observed desorption behavior. In particular, the desorption temperature shifts higher as the defect concentration increases. In addition, the distribution of defects throughout the sample also changes the shape of TDS spectrum. Even if low energy traps were distributed in the bulk region, the D diffusion toward the surface requires additional time for trapping/detrapping during surface-to-bulk transport, contributing to a shift of desorption peaks toward higher temperatures. It can be said that both of distribution of damage (e.g. hydrogen isotope trapping sites) and their stabilities would have a large impact on desorption. In addition, transmutation effects should be also considered for an actual fusion environment. Experimental results show that production of Re by nuclear reaction of W with neutrons reduces the density of trapping sites, though no remarkable retention enhancement is observed.

Heavy metal content in compost and earthworms from home composters

Directory of Open Access Journals (Sweden)

Bożym Marta

2017-12-01

Full Text Available The paper presents the results of compost tests from home composters and earthworms living there, that treating waste into compost. The samples were taken from home composters and allotment gardens from Opole Region. The composting material was green waste. The total content of heavy metals (Cd, Pb, Cu, Zn, Ni Cr in compost and compost earthworms’ samples were determined. It was found that the compost samples were not contaminated with heavy metals. According to the Polish classification of composts from municipal wastes, the composts met the requirements for first class of quality. The composts did not exceed the limits of heavy metals specified in the Polish law for solid organic fertilizers. The degree of metal accumulation by compost earthworms depended on the type of metal. The high value of the bioaccumulation factor (BAF was obtained for Cd, Pb and Zn. No accumulation of other metals (Ni, Cr, Cu in earthworm bodies was found. It has been found that earthworm species, naturally occurring in Poland, can also be used as potential bioindicators of metals in the environment, such as the species Eisenia fetida. The aim of the study was to evaluate the heavy metal content in composts from home composters and ability to accumulate metals by compost earthworms.

Evaluation of Trichoptera as an indicator organism for environmental pollution by heavy metals

International Nuclear Information System (INIS)

Aizawa, Shoichi; Tsunoda, Kin-ichi; Akatsuka, Masayoshi; Inoue, Sadao; Akaiwa, Hideo

1994-01-01

A method of analysis for heavy metals in trichopteran larvae by AAS was established to evaluate this aquatic insect as an indicator organism for environmental pollution by heavy metals. A wet digestion method with nitric acid and hydrogen peroxide was found to be suitable for the decomposition of trichopteran larva samples. No serious variation in heavy metal contents was found in individual samples collected from one sampling point. A weak negative correlation was observed between the body length and the heavy metal contents of trichopteran larvae. In addition, the heavy metal content of trichopteran larvae seems to show a seasonal fluctuation. Trichopteran larvae in the Watarase River, which has abandoned copper and manganese mines along its upper stream, show an enriched heavy metal content as compared with those in other non-polluted rivers. Moreover, this aquatic insect in the Kiryu River also shows enrichment of manganese due to abandoned manganese mines situated upstream. These facts suggest that the trichopteran larva in a useful indicator organism for environmental pollution by heavy metals. (author)

Determination of hydrogen content of petroleum products from Tema Oil Refinery using neutron backscatter technique

International Nuclear Information System (INIS)

Salifu, A. S.

2015-01-01

The hydrogen content of hydrocarbon materials is very important in several areas of industrial process such as mining, vegetable oil extraction and crude oil exploration and refining. A fast and more universal technique based on thermal neutron reflection was employed to determine the total hydrogen contents of petroleum samples from Tema Oil Refinery (TOR) and Crude oil samples from Jubilee field and Nigeria. The experimental set-up consisted of a source-holder housing a 1Ci Am-Be neutron source and a He-3 neutron detector. Two geometrical arrangements were considered and their sensitivities were compared. The set-up was used to measure the excess neutron count in both geometrical considerations and their reflection parameters were calculated as a function of hydrogen content of the samples. Calibration lines were deduced using liquid hydrocarbons containing well-known hydrogen and carbon contents as standards. Two linear equations were generated from the calibration lines and were used to further determine the hydrogen content of thirteen (13) petroleum samples obtained from Quality Control Department of TOR. The total hydrogen contents were found to be in the range of 7.211(hw %) - 15.069 (hw %) for vertical geometry and 7.206 (hw %) - 14.948 (hw %) for horizontal geometry respectively. The results obtained agreed constructively with other results obtained using different methodologies by other studies. The percentage error of the hydrogen contents denoted by (% E) for the various petroleum samples were also obtained and noticed to be within an acceptable range. The neutron backscatter technique was observed as an alternative and more generalized method for quality assurance and standardization in the petroleum industries

Determination of the Content of Heavy Metals in Pyrite Contaminated Soil and Plants

Directory of Open Access Journals (Sweden)

Miroslava Marić

2008-09-01

Full Text Available Determination of a pyrite contaminated soil texture, content of heavy metals in the soil and soil pH, was the aim in the investigation. Acidification of damaged soil was corrected by calcium carbonate. Mineral nutrients and organic matter (NPK, dung, earthworm cast, straw and coal dust were added to damaged soil. Afterwards, the soil was used for oat production. Determination of total heavy metal contents (Cu, Pb, Zn, Fe in soil was performed by atomic absorption spectrofotometry. Plant material (stems, seeds was analysed, too. Total concentration of the heavy metals in the plant material were greater than in crop obtained in unaffected soil.

Physico-chemical parameters and heavy metal contents of Ibuya ...

African Journals Online (AJOL)

The physico-chemical parameters and heavy metal contents of Ibuya River were investigated between September 2012 and August 2013 from four stations using standard methods to etermine acceptable water quality standards and evaluate possible sustainability of a thriving fisheries cum tourist sport fishing venture.

The study of microplasticity mechanism in Ti-50 wt.%Nb alloy with high hydrogen content

International Nuclear Information System (INIS)

Golovin, I.S.; Kollerov, M.U.; Schinaeva, E.V.

1996-01-01

The upper yield point (∼ 700 MPa) appears at the compression test curves (ε=0.024 sec -1 ) of b.c.c. Nb-50 wt.%Ti due to the increase of hydrogen content from 0 to 0.2 wt.% and more and leads to the non monotonous increase in compressive lower yield stress from 400 to 550 MPa. Taking into account close connection between macro- and microplasticity of metallic materials the low frequency (∼ 2 Hz) amplitude dependent internal friction (ADIF) spectrum (γ = 1. 60.10 -5 ) in hydrogenized Nb-50 wt.% Ti and Nb samples are studied. The ADIF investigation of the closed hysteresis loop ''loading-unloading'' shows the dependence of its width from the hydrogen content which evidences the fact of dislocation unpinning from hydrogen atmospheres in the 1/2 cycle of loading. The study of ADIF spectrum for samples with different hydrogen content before and after torsion deformation (γ ∼ 2%) shows the sharp increase of IF level at γ = 1. 10.10 -5 after ∼1 hour of natural ageing. At that time the ADIF curves change its shape from Γ-shape to U-shape. The amplitude range of the IF increase depends on the hydrogen content. It is the interaction of hydrogen atoms with dislocations that caused the above mentioned effect which has not been observed in hydrogen free samples. The time estimation for the formation of thermodynamically stable hydrogen atmospheres on dislocations shows that hydrogen atmospheres could not follow the dislocation during compressive tests and that leads to the upper yield point appearance. (orig.)

Heavy metal content of selected African leafy vegetables planted in ...

African Journals Online (AJOL)

Heavy metal content of selected African leafy vegetables planted in urban and peri-urban Nairobi, Kenya. ... African Journal of Environmental Science and Technology ... Government clean-up activities and monitoring of waste disposal is ...

Studies of heavy metal contents and microbial composition of ...

African Journals Online (AJOL)

This study investigated the heavy metal content and microbial composition of rhizosphere of Panicum maximum obtained from some auto mechanic workshops in Benin City, Nigeria. The grass was uprooted and soil sample was taken from its rhizosphere. The sample were labeled appropriately and immediately transported ...

Selected Heavy Metals Content in Soil and Arundina graminifolia from Pelepah Kanan Mine, Kota Tinggi, Johor, Malaysia

International Nuclear Information System (INIS)

Sahibin Abdul Rahim; Zulfahmi Ali Rahman; Wan Mohd Razi Idris; Azman Hashim; Tukimat Lihan; Muhd Barzani Gasim; Jumaat Adam; Lim, F.N.

2009-01-01

Heavy metals composition of Cd, Co, Cr, Ni, Pb and Zn in Arundina graminifolia collected from mining area at Lombong Pelepah Kanan, Kota Tinggi, Johor were determined. The heavy metal content was also analysed in their soil substrates. The plants were separated into different portions for example root, stem and leaf and extracted for their heavy metal content by digestion method whereas the soils heavy metal content was extracted by sequential extraction. Heavy metal content in soil and plant extract was determined using the Flame Atomic Absorption Spectrophotometer. Heavy metal contents of Cd, Cr, Ni and Pb in plants were compared with their content in the control plant, whereas the Co and Zn contents were three to five folds higher. As for heavy metal content in different plant parts, it was found that Cd concentration was high in roots (2.03 mg/ kg) followed by leaf (1.67 mg/ kg) and stem (1.49 mg/ kg). Co concentration was high in leaf (9.26 mg/ kg) followed by root (9.18 mg/ kg) and stem (6.94 mg/ kg). For Cr, the concentration in decreasing sequence was root (0.46 mg/ kg) > leaf (0.19 mg/ kg) > stem (0.08 mg/ kg). Ni concentration was higher in leaf (2.78 mg/ kg) followed by root (2.71 mg/ kg) and stem (1.66 mg/ kg). Concentration in decreasing order was root (10.34 mg/ kg) > leaf (4.18 mg/ kg) > stem (3.75 mg/ kg). Zn concentration was higher in leaf (44.03 mg/ kg) followed by root (32.30 mg/ kg) and stem (13.21 mg/ kg). Total heavy metal content in soil was 2.07 - 5.59 mg/ kg, 8.72 - 39.93 mg/ kg, 1.81 - 2.14 mg/ kg, 2.66 - 6.87 mg/ kg, 23.02 - 51.56 mg/ kg and 0.64 - 2.61 mg/ kg for Ni, Zn, Cd, Pb, Co and Cr, respectively. The available fraction of heavy metals in soil was 21.9 % for Ni, 15.3 % for Zn, 49.9 % for Cd, 19.3 % for Pb, 45.7 % for Co and nil percent for Cr. Biological adsorption coefficient for the heavy metals studied was very low except for Zn where BAC value slightly higher than 1. This plant was not suitable to be used as a phyto

Determination of Hydrogen and Carbon contents in crude oil and Petroleum fractions by NMR Spectroscopy

International Nuclear Information System (INIS)

Khadim, Mohammad A.; Wolny, R.A.; Al-Dhuwaihi, Abdullah S.; Al-Hajri, E.A.; Al-Ghamdi, M.A.

2003-01-01

Proton and carbon-13 NMR spectroscopic methods were developed for determining hydrogen and carbon contents in petroleum products. These methods are applicable to a wide of petroleum streams. A new reference standard, bis (trimethylsilyl) methane, BTMSM, is introduced fro both proton and carbon-13 NMR for the first time, which offers several advantages over those customarily employed. These methods are important for the calculation of the mass balance and hydrogen consumption in pilot plant studies. Unlike the ASTM D-5291 combustion method, the NMR methods also allow for the measurement of hydrogen and carbon content in low boiling fractions and those containing hydrogen as low as 1%. The NMR methods can also determine aromatic and aliphatic hydrogens carbons in a given sample without additional experimentation. The precision and accuracy of the newly developed NMR methods are compared with those of currently employed ASTM D-5291 combustion method. Using the proton NMR method, hydrogen content was determined in fifteen model compounds and sixty-eight petroleum fractions. The NMR and ASTM methods show an agreement within +5%for 48 out of a total number of 68 oil fractions. Using carbon-13 NMR, the carbon content was determined for four representative compounds and three fractions of crude oil. Both carbon-13 NMR and ASTM methods give comparable carbon content in model compounds and crude oil fractions. (author)

Effect of heavy metals on growth and heavy metal content of Allium porrum L. and Pisum sativum L

Energy Technology Data Exchange (ETDEWEB)

Gruenhage, L.; Jaeger, H.J.

1985-01-01

The effects of cadmium, lead, zinc and copper, singly and in combination, on yield, heavy metal content and the mineral composition of Allium porrum L. and Pisum sativum L. have been investigated. The Cd, Pb, Zn and Cu concentrations of shoots and roots of Allium porrum increased with increasing heavy metal contamination of soil. However, no visible symptoms of heavy metal toxicity were recognized. The dry matter production was reduced as a function of heavy metal concentration and combination. The mechanisms of combinations were mostly synergistic. The correlation between pollutant contents (nmol/shoot) and yield was higher than the correlation between heavy metal concentrations of soil or shoots (ppm) and yield. Results of regression analyses showed that the inhibition of copper translocation caused by Cd, Pb and Zn was responsible for the yield depressions. The antagonism between Cd and N-deficiency showed that the level of N-supply was without negative effects on yield depressions of Pisum sativum caused by Cd. In contrast to this, the N-form played an important role in Cd-toxicity as the synergism between Cd and NH4 illustrated. K-deficiency as well as acidic nutrient solution (pH=4) diminished the root/shoot-barrier for Cd and therefore Cd-translocation from roots to shoots increased. Concerning calcium, magnesium and iron the decrease of ion uptake caused by Cd was statistically significant higher than yield depression.

Analysis of hydrogen-deuterium mixtures and of mixtures of heavy-water and light-water by means of a mass spectrometer

International Nuclear Information System (INIS)

Chenouard, J.; Gueron, J.; Roth, E.

1951-07-01

The differences between hydrogen and deuterium with respect to the capture of thermal neutrons (hydrogen = 0.31 barn; deuterium 0.00065 barn) explains the interest of detecting small variations of the isotopic composition of the heavy waters used in the Chatillon nuclear pile. The aim of this report is to describe and discuss the method used since more than a year for the dosimetry of heavy waters. After a recall of the principle of mass spectroscopy analysis of deuterium-hydrogen mixtures, the preciseness of the results is presented and the balancing method used for the determination of the isotopic composition of hydrogen-deuterium mixtures is explained in detail. Finally, a brief comparison of the preciseness of mass spectroscopy measurements with the analyses made with other methods is performed. Some calculations and the tables of results are presented in appendixes. (J.S.)

The study of heavy metals and microbial content in beef bowel and red meat

International Nuclear Information System (INIS)

Harsojo; Darsono

2013-01-01

Indonesia's population has increased every year so the need for food increased, especially the availability of nutritious foods such as red meat. Red meat is one of the foods that contain sufficient elements of protein, but it was likely to contain heavy metals and bacterial contamination that has met the threshold standards. On the otherhand, beef bowels are very popular among Indonesian consumers, but many heavy metlas could accumulated into the bowels. The purpose of this research are to study the content of heavy metals and bacterial contamination on beef bowel from some places of slaughtering houses and some red meats from the market in Jakarta. The beef bowels are lung, tripe, intestine and liver while the red meats were veal and tender loin. Parameter of heavy metals measured are As, Cd and Hg, while for the initial bacterial contamination are total number of aerobic bacteria, total amount of coliform, Escherichia coli, Staphylococcus sp and Salmonella contamination. The heavy metals were analyzed using Neutron Activation Analysis, and for the total number of bacteria is using Total Plate Count. Result of research shows the As content in lung and tripe as well as the mercuric content in bowel has exceeded in the normal level such as 1.0 and 0.03 ppm, respectively. On the other hand, no heavy metals were detected in all red meats. The total microbes in beef bowel have exceeded allowable limit (1.0 x 10 6 cfu/g). No Salmonella was detected in all beef bowels and red meats observed. Nuclear technique are very helpful analysis of the heavy metas content in bowel dan red meats beef. The cleanliness slaughtering house of animals are remarkably ascertaining the quality of the beef bowel and red meats who will be sent. (author)

Simulations of Multi Combustion Modes Hydrogen Engines for Heavy Duty Trucks

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Alberto A. Boretti

2012-01-01

Full Text Available The paper presents the numerical study of a diesel direct injection heavy duty truck engine converted to hydrogen. The engine has a power turbine connected through a clutch and a continuously variable transmission to the crankshaft. The power turbine may be disconnected and by-passed when it is inefficient or inconvenient to use. The conversion is obtained by replacing the Diesel injector with a hydrogen injector and the glow plug with a jet ignition device. The hydrogen engine operates different modes of combustion depending on the relative phasing of the main injection and the jet ignition. The engine generally operates mostly in Diesel-like mode, with the most part of the main injection following the suitable creation in cylinder conditions by jet ignition. For medium-low loads, better efficienciy is obtained with the gasoline-like mode jet igniting the premixed homogeneous mixture at top dead centre. It’s permitted at higher loads or at very low loads for the excessive peak pressure or the mixture too lean to burn rapidly. The hydrogen engine has better efficiency than Diesel outputs and fuel conversion. Thanks to the larger rate of heat release, it has the opportunity to run closer to stoichiometry and the multi mode capabilities. The critical area for this engine development is found in the design of a hydrogen injector delivering the amount of fuel needed to the large volume cylinder within a Diesel-like injection time.

The effects of heavy metal ions on the chlorophyll content and cell membrane permeability of charophytes

International Nuclear Information System (INIS)

Fu Hualong; Chen Hao; Dong Bin; Qing Renwei

2001-01-01

The authors studied the effects of several heavy metal ions in different concentrations (Cd 2+ , Hg 2+ , Pb 2+ , Cr 6+ ) on the chlorophyll content and cell membrane permeability of Chara vulgaris L. It was discovered that the effects of heavy metal ions on the chlorophyll content and cell membrane permeability of Chara vulgaris L. changed with their different concentration. The trend was that the chlorophyll content and cell membrane permeability were decreased with the increase of the heavy metal ions. The degree of chlorophyll content affected was Cr 6+ , Cd 2+ , Hg 2+ , Pb 2+ , and that of cell membrane permeability affected was Cd 2+ , Cr 6+ , Hg 2+ , Pb 2+

Confident methods for the evaluation of the hydrogen content in nanoporous carbon microfibers

Science.gov (United States)

Culebras, Mario; Madroñero, Antonio; Cantarero, Andres; Amo, José Maria; Domingo, Concepción; López, Antonio

2012-10-01

Nanoporous carbon microfibers were grown by chemical vapor deposition in the vapor-liquid solid mode using different fluid hydrocarbons as precursors in different proportions. The as-grown samples were further treated in argon and hydrogen atmospheres at different pressure conditions and annealed at several temperatures in order to deduce the best conditions for the incorporation and re-incorporation of hydrogen into the microfibers through the nanopores. Since there are some discrepancies in the results on the hydrogen content obtained under vacuum conditions, in this work, we have measured the hydrogen content in the microfibers using several analytical methods in ambient conditions: surface tension, mass density, and Raman measurements. A discussion on the validity of the results obtained through the correlation between them is the purpose of the present work.

The relationship of heavy metals contents in soils to their content in legume seeds used in famous traditional food in kurdistan region-iraq

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Dalaram Sullaiman Ismael

2016-11-01

Full Text Available In this work the level of risk heavy metals contents in Cowpea seeds comparison with heavy metal content in soil was studied. For the experiment three cowpea cultivars (brown, red, white were used. Cowpeas were harvested at full ripeness in Kalak location in Erbil city. The flame AAS (AAS Varian AA Spectr. DUO 240 FS/240Z/UltrAA was used for the determination of heavy metal contents in soil and plant materials. The soil which cultivated Cowpea, characterized neutral to slit alkali, with a typical content of cations K, Mg and P. Beans and the seeds of faba bean, cowpea and chickpeas boiled with salt eaten in the form of Lablabe, traditionly used heavy sweets such as knafa. Ful, which is fava beans cooked with chickpeas (garbanzo beans or make soup from fresh cowpea, fresh faba bean, fresh fasoulia, as well as lentil soup (shorbat adas and different kinds of salad after boiled. Cowpea grain legumes occupy an important place in human nutrition, especially in the dietary pattern of low income groups of people in developing countries. The level risk heavy metal contents in the soil determined was only Cd content was on the level of limit value given for the soil extract by aqua regia as well as Co content was higher than the limit value given for the relationship between soil and plant. All of determined values were lower than critical value extracted by NH4NO3 only the maximal available soil content of mobile Pb forms was exceeded but cowpea accumulated seeds in amounts the risky elements contents, with the exception of Ni, did not exceed limit for the maximum levels of chosen risk elements in studied legume. The content of the metals studied with the exception of cadmium, not exceed the maximum permissible value in legumes, as defined in the Codex Alimentarius. The aim of this research, to study or determine the content of risky heavy metals (Cu, Ni, Cr, Pb, and Cd in the soil and their relationship in selected varieties cowpea seeds cultivar. Faba

[Fractionation of hydrogen stable isotopes in the human body].

Science.gov (United States)

Siniak, Iu E; Grigor'ev, A I; Skuratov, V M; Ivanova, S M; Pokrovskiĭ, B G

2006-01-01

Fractionation of hydrogen stable isotopes was studied in 9 human subjects in a chamber with normal air pressure imitating a space cabin. Mass-spectrometry of isotopes in blood, urine, saliva, and potable water evidenced increases in the contents of heavy H isotope (deuterium) in the body liquids as compared with water. These results support one of the theories according to which the human organism eliminates heavy stable isotopes of biogenous chemical elements.

Liquid alternative diesel fuels with high hydrogen content

Energy Technology Data Exchange (ETDEWEB)

Hancsok, Jenoe; Varga, Zoltan; Eller, Zoltan; Poelczmann, Gyoergy [Pannonia Univ., Veszprem (Hungary). MOL Dept. of Hydrocarbon Processing; Kasza, Tamas [MOL Hungarian Oil and Gas Plc., Szazhalombatta (Hungary)

2013-06-01

Mobility is a keystone of the sustainable development. In the operation of the vehicles as the tools of mobility internal combustion engines, so thus Diesel engines will play a remarkable role in the next decades. Beside fossil fuels - used for power these engines - liquid alternative fuels have higher and higher importance, because of their known advantages. During the presentation the categorization possibilities based on the chronology of their development and application will be presented. The importance of fuels with high hydrogen content will be reviewed. Research and development activity in the field of such kind of fuels will be presented. During this developed catalytic systems and main performance properties of the product will be presented which were obtained in case of biogasoils produced by special hydrocracking of natural triglycerides and in case of necessity followed by isomerization; furthermore in case of synthetic biogasoils obtained by the isomerization hydrocracking of Fischer-Tropsch paraffins produced from biomass based synthesis gas. Excellent combustion properties (cetane number > 65-75), good cold flow properties and reduced harmful material emission due to the high hydrogen content (C{sub n}H{sub 2n+2}) are highlighted. Finally production possibilities of linear and branched paraffins based on lignocelluloses are briefly reviewed. Summarizing it was concluded that liquid hydrocarbons with high isoparaffin content are the most suitable fuels regarding availability, economical and environmental aspects, namely the sustainable development. (orig.)

Hydrogen content and density in nanocrystalline carbon films of a predominant diamond character

International Nuclear Information System (INIS)

Hoffman, A.; Heiman, A.; Akhvlediani, R.; Lakin, E.; Zolotoyabko, E.; Cyterman, C.

2003-01-01

Nanocrystalline carbon films possessing a prevailing diamond or graphite character, depending on substrate temperature, can be deposited from a methane hydrogen mixture by the direct current glow discharge plasma chemical vapor deposition method. While at a temperature of ∼880 deg. C, following the formation of a thin precursor graphitic film, diamond nucleation occurs and a nanodiamond film grows, at higher and lower deposition temperatures the films maintain their graphitic character. In this study the hydrogen content, density and nanocrystalline phase composition of films deposited at various temperatures are investigated. We aim to elucidate the role of hydrogen in nanocrystalline films with a predominant diamond character. Secondary ion mass spectroscopy revealed a considerable increase of the hydrogen concentration in the films that accompanies the growth of nanodiamond. It correlates with near edge x-ray adsorption spectroscopy measurements, that showed an appearance of spectroscopic features associated with the diamond structure, and with a substantial increase of the film density detected by x-ray reflectivity. Electron energy loss spectroscopy showed that nanocrystalline diamond films can be deposited from a CH 4 /H 2 mixture with hydrogen concentration in the 80%-95% range. For a deposition temperature of 880 deg. C, the highest diamond character of the films was found for a hydrogen concentration of 91% of H 2 . The deposition temperature plays an important role in diamond formation, strongly influencing the content of adsorbed hydrogen with an optimum at 880 deg. C. It is suggested that diamond nucleation and growth of the nanodiamond phase is driven by densification of the deposited graphitic films which results in high local compressive stresses. Nanodiamond formation is accompanied by an increase of hydrogen concentration in the films. It is suggested that hydrogen retention is critical for stabilization of nanodiamond crystallites. At lower

Content of heavy metals in gleyic chernozem of Srem loess terrace under alfalfa

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Jakšić Snežana

2012-01-01

Full Text Available Production of high-quality forage from alfalfa is influenced not only by the presence of nutrients, but also by the absence of harmful elements, such as heavy metals. The examination of the total heavy metals content (Ni, Cr, Pb and As in gleyic chernozem soil of Srem loess terrace in Hrtkovci, under alfalfa (Medicago sativa L. were carried out in 2011 in order to determine suitability for the production of safe forage. It total content of Pb, As and Crwas below the maximum permitted concentrations. The content of As, Cr and Ni was higher in the surface layer, unlike Pb, whose content was higher in the deeper layers of soil. A significant positive correlation was found between the total content of Ni, Cr and As. An increased concentration of Ni was found, which was above the maximum permitted concentration. It is necessary to further control its content and accessibility examination and extraction from plants, to prevent its entry into the food chain and provide safe food.

Content Heavy Metal Pb, Cd In Perna viridis And Sediments In Semarang Bay

Science.gov (United States)

Suprapto, D.; Suryanti, S.; Latifah, N.

2018-02-01

Waste disposal from human activities, generally contain heavy metals such as Pb and Cd which derived from industrial activities. The aims of the study were to know the concentration of Pb and Cd heavy metals contained in Perna viridis tissue, sediment and water at Semarang Bay. This study was conducted in May 2017 at Semarang Bay. - Samples were collected using purposive sampling method. The heavy metal content in the water and clam was observed using- APHA method and was analyzed using AAS (Atomic Absorption Spectrophotometer). The results showed that concentration of heavy metal of Pb in the water was 0.00-50.5mg/L and the Cd content was of 26.9-51.7 mg/L, whereas the concentration of Pb in the sediment is 445.5-2.053.0mg/L and Cd 963.3-2,150.0 mg/L. Pb content in soft tissue of Perna viridis - is 67.1-1.933.9 mg/L and the concentration of Cd was 203.5-5.787.3 mg/L. The analysis of Pb and Cd in seawater, sediment and soft tissue of Perna viridis according to Enviroment Ministerial decree (KepMenLH ) number 51 of 2004 and applied by NOAA 1999 does not exceed the quality standard, that meant that the Perna viridis has been contaminated by metal Pb it is controversial with the above sentence and Cd. It concluded that the metal content of Pb and Cd in Perna viridis tissue exceeds the quality standard, so it is not suitable to be consumed, especially in high quantity

Evaluation of site-specific factors influencing heavy metal contents in the topsoil of vegetated infiltration swales

International Nuclear Information System (INIS)

Horstmeyer, Nils; Huber, Maximilian; Drewes, Jörg E.; Helmreich, Brigitte

2016-01-01

Stormwater runoff of traffic areas is usually polluted by organic and inorganic substances and must be treated prior to discharge into groundwater. One widely used treatment method is infiltrating the runoff over the topsoil of vegetated swales. The aim of this study was to evaluate the factors influencing the heavy metal contents in such topsoil layers of vegetated infiltration swales near highways, roads, and parking lots. In total, 262 topsoil samples were taken from 35 sampling sites, which varied in age, traffic volume, road design, driving style, and site-specific conditions. In the evaluation of all soil samples, the median heavy metal values of cadmium, chromium, copper, lead, and zinc were yielding 0.36 (mean: 1.21) mg/kg DM, 37.0 (mean: 44.5) mg/kg DM, 28.0 (mean: 61.5) mg/kg DM, 27.0 (mean: 71.9) mg/kg DM, and 120 (mean: 257) mg/kg DM, respectively. The main purpose was to evaluate the site-specific data (i.e., surrounding land use characteristics, traffic area site data, and operational characteristics). In general, heavy metal contents increased with increasing traffic volumes. However, other factors also had a notable impact. Factors such as road design (e.g., curves, crossings, and roundabouts) and grade of congestion significantly influenced the heavy metal contents. High heavy metal contents were detected for stop-and-go areas, roundabouts, crossings, and sites with traffic lights, signs, and guardrails. Findings of this study can be used to identify highly polluted traffic areas and to verify or improve standards regarding the treatment of runoff from traffic areas. - Highlights: • Correlation of contents with traffic volume, road design, and stop-and-go traffic • Increased heavy metal contents at stop-and-go sites, roundabouts, and crossings • Different soil contents and behavior of cadmium, chromium, copper, lead, and zinc • Identification of factors influencing the variability of zinc in topsoil samples

Evaluation of site-specific factors influencing heavy metal contents in the topsoil of vegetated infiltration swales

Energy Technology Data Exchange (ETDEWEB)

Horstmeyer, Nils; Huber, Maximilian; Drewes, Jörg E.; Helmreich, Brigitte, E-mail: b.helmreich@tum.de

2016-08-01

Stormwater runoff of traffic areas is usually polluted by organic and inorganic substances and must be treated prior to discharge into groundwater. One widely used treatment method is infiltrating the runoff over the topsoil of vegetated swales. The aim of this study was to evaluate the factors influencing the heavy metal contents in such topsoil layers of vegetated infiltration swales near highways, roads, and parking lots. In total, 262 topsoil samples were taken from 35 sampling sites, which varied in age, traffic volume, road design, driving style, and site-specific conditions. In the evaluation of all soil samples, the median heavy metal values of cadmium, chromium, copper, lead, and zinc were yielding 0.36 (mean: 1.21) mg/kg DM, 37.0 (mean: 44.5) mg/kg DM, 28.0 (mean: 61.5) mg/kg DM, 27.0 (mean: 71.9) mg/kg DM, and 120 (mean: 257) mg/kg DM, respectively. The main purpose was to evaluate the site-specific data (i.e., surrounding land use characteristics, traffic area site data, and operational characteristics). In general, heavy metal contents increased with increasing traffic volumes. However, other factors also had a notable impact. Factors such as road design (e.g., curves, crossings, and roundabouts) and grade of congestion significantly influenced the heavy metal contents. High heavy metal contents were detected for stop-and-go areas, roundabouts, crossings, and sites with traffic lights, signs, and guardrails. Findings of this study can be used to identify highly polluted traffic areas and to verify or improve standards regarding the treatment of runoff from traffic areas. - Highlights: • Correlation of contents with traffic volume, road design, and stop-and-go traffic • Increased heavy metal contents at stop-and-go sites, roundabouts, and crossings • Different soil contents and behavior of cadmium, chromium, copper, lead, and zinc • Identification of factors influencing the variability of zinc in topsoil samples.

Investigate of analysis for hydrogen contents in carbon films

International Nuclear Information System (INIS)

Yasui, Haruyuki; Hirose, Yukio; Sasaki, Toshihiko; Awazu, Kaoru; Naramoto, Hiroshi

2001-01-01

Hydrogen is a very common contaminant in carbon films. It can strongly influences on mechanical, physical and chemical properties of the films. The analysis of hydrogen is therefore a crucial problem to prepare the films with the reproducible property. We were measured two kinds of methods. Ion beam techniques using nuclear reactions are established methods for the quantitative determination of hydrogen concentration. A spectrometer has been constructed for the determination of hydrogen concentrations by detecting 4.43 MeV γ-rays from the resonant nuclear reactions 1 H( 15 N, α γ) 12 C at the 6.385 MeV. And the other measurement of hydrogen is GDOES (Glow Discharge Optical Emission Spectroscopy), with its high sputtering rates, had been used previously for depth profiling analysis of thin films. The depth profiling analysis was carried out at an argon atmosphere by applying an RF of 13.56 MHz. The sampling time interval was 0.1 sec. The detailed hydrogen analysis was made on BCN (Boron Carbonitride) and DLC (Diamond-like Carbon) thin films. The BCN films were prepared by ion beam assisted deposition, in which boron and carbon were deposited by electron beam heating of B 4 C solid and nitrogen was supplied by implantation simultaneously. The DLC films were prepared by HPPC (Hybrid-pulse plasma coating) system. It was a new coating system that we developed which consists fundamentally of plasma CVD (chemical vapor deposition) and ion-mixing. In this paper, we reported the comparison of analysis for hydrogen contents between RNRA and GDOES. (author)

Investigate of analysis for hydrogen contents in carbon films

Energy Technology Data Exchange (ETDEWEB)

Yasui, Haruyuki; Hirose, Yukio; Sasaki, Toshihiko [Kanazawa Univ., Kanazawa, Ishikawa (Japan); Awazu, Kaoru [Industrial Research Institute of Ishikawa, Kanazawa, Ishikawa (Japan); Naramoto, Hiroshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

2001-07-01

Hydrogen is a very common contaminant in carbon films. It can strongly influences on mechanical, physical and chemical properties of the films. The analysis of hydrogen is therefore a crucial problem to prepare the films with the reproducible property. We were measured two kinds of methods. Ion beam techniques using nuclear reactions are established methods for the quantitative determination of hydrogen concentration. A spectrometer has been constructed for the determination of hydrogen concentrations by detecting 4.43 MeV {gamma}-rays from the resonant nuclear reactions {sup 1}H({sup 15}N, {alpha} {gamma}){sup 12}C at the 6.385 MeV. And the other measurement of hydrogen is GDOES (Glow Discharge Optical Emission Spectroscopy), with its high sputtering rates, had been used previously for depth profiling analysis of thin films. The depth profiling analysis was carried out at an argon atmosphere by applying an RF of 13.56 MHz. The sampling time interval was 0.1 sec. The detailed hydrogen analysis was made on BCN (Boron Carbonitride) and DLC (Diamond-like Carbon) thin films. The BCN films were prepared by ion beam assisted deposition, in which boron and carbon were deposited by electron beam heating of B{sub 4}C solid and nitrogen was supplied by implantation simultaneously. The DLC films were prepared by HPPC (Hybrid-pulse plasma coating) system. It was a new coating system that we developed which consists fundamentally of plasma CVD (chemical vapor deposition) and ion-mixing. In this paper, we reported the comparison of analysis for hydrogen contents between RNRA and GDOES. (author)

Assessment of arsenic and heavy metal contents in cockles (Anadara granosa) using multivariate statistical techniques

International Nuclear Information System (INIS)

Abbas Alkarkhi, F.M.; Ismail, Norli; Easa, Azhar Mat

2008-01-01

Cockles (Anadara granosa) sample obtained from two rivers in the Penang State of Malaysia were analyzed for the content of arsenic (As) and heavy metals (Cr, Cd, Zn, Cu, Pb, and Hg) using a graphite flame atomic absorption spectrometer (GF-AAS) for Cr, Cd, Zn, Cu, Pb, As and cold vapor atomic absorption spectrometer (CV-AAS) for Hg. The two locations of interest with 20 sampling points of each location were Kuala Juru (Juru River) and Bukit Tambun (Jejawi River). Multivariate statistical techniques such as multivariate analysis of variance (MANOVA) and discriminant analysis (DA) were applied for analyzing the data. MANOVA showed a strong significant difference between the two rivers in term of As and heavy metals contents in cockles. DA gave the best result to identify the relative contribution for all parameters in discriminating (distinguishing) the two rivers. It provided an important data reduction as it used only two parameters (Zn and Cd) affording more than 72% correct assignations. Results indicated that the two rivers were different in terms of As and heavy metal contents in cockle, and the major difference was due to the contribution of Zn and Cd. A positive correlation was found between discriminate functions (DF) and Zn, Cd and Cr, whereas negative correlation was exhibited with other heavy metals. Therefore, DA allowed a reduction in the dimensionality of the data set, delineating a few indicator parameters responsible for large variations in heavy metals and arsenic content. Taking into account of these results, it can be suggested that a continuous monitoring of As and heavy metals in cockles be performed in these two rivers

Hydrogen content in Zircaloy-IV by neutron emissions

International Nuclear Information System (INIS)

Granada, J.R.

1991-01-01

The feasibility of using thermal neutron transmission techniques to determine the initial hydrogen content in Zry-IV is discussed in this work. The usual conditions of very low H concentration (∼ 10-20 ppm in weight) in the alloy, require a high degree of accuracy in the relevant cross sections in order to obtain reliable values of that concentration from the measured transmission spectra. Total cross sections corresponding to the metallic alloy and to hydrogen in that matrix were evaluated using interaction models developed in this Laboratory, for neutrons covering the range from subthermal up to epithermal energies. The sensitivity of this method as a function of neutron energy is discussed, and an optimized and self consistent procedure for data analysis after a transmission experiment is proposed. (Author) [es

Achievement report for fiscal 1997 on research under New Sunshine Program. Research on heavy oil hydrogenation and heavy oil/coal coprocessing; 1997 nendo jushitsuyu no suisoka shori narabi ni jushitsuyu/sekitan no coprocessing ni kansuru kenkyu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-02-01

The achievements of the Hokkaido National Industrial Research Institute relating to the titled research are reported. In the study relating to the structural properties of heavy oils, the structures of products of Green River shale oil carbonization is analyzed, heterofunctional groups contained in the oil are subjected to FT-IR (Fourier transform infrared) spectroscopic analysis, and their forms of existence are investigated. In the study relating to the hydrogenation process of heavy oils, findings obtained from experiments are reported, which involve the processing of shale oil by hydrogenation and changes brought about in its chemical structure, hydrogenation of oil sand bitumen, kinetics of hydrocracking of bitumen at a high conversion rate, and a lumping model for bitumen hydrocracking reaction. In the study relating to the coprocessing of heavy oil/coal, coprocessing is experimented for coal and shale oil, coal and oil sand bitumen, and other combinations, and the results are reported. Also, a review is made of the transfer of hydrogen in coprocessing. (NEDO)

Strain aging in tungsten heavy alloys

International Nuclear Information System (INIS)

Dowding, R.J.; Tauer, K.J.

1991-01-01

This paper reports on tungsten heavy alloys which are two-phase mixtures of body center cubic (BCC) tungsten surrounded by a face center cubic (FCC) matrix. The matrix is most often composed of nickel and iron in a ratio of 70:30 but, occasionally, the matrix may also contain cobalt or copper. Nickel, however, is always the primary matrix component. The tungsten heavy alloy is fabricated through powder metallurgy techniques. Elemental powders are blended, pressed to shape, and sintered. Depending upon the tungsten content, the sintering temperatures are usually in the range of 1450 degrees C to 1525 degrees C. These temperatures are high enough that, as a result, the matrix is at the liquid phase and the process is known as liquid phase sintering. At the liquid phase temperature, the matrix becomes saturated with tungsten, but this does not change the FCC character of the matrix. The sintering is usually done in a hydrogen atmosphere furnace in order to reduce the oxides on the tungsten powder surfaces and create clean, active surfaces which will enhance the adherence between the tungsten and the matrix. The hydrogen atmosphere also creates the presence of excess dissolved hydrogen in the alloy. It has been shown that the hydrogen degrades the toughness and ductility of the heavy alloy. A post-sintering vacuum heat treatment is generally required to insure that there is no residual hydrogen present. The as-sintered tensile strength of a 90% tungsten, 7% nickel, 3% iron alloy (90W) is in the range of 800 to 940 MPa and can be increased significantly by cold working, usually rolling or swaging. Swaging to reductions in area of 20% can result in tensile strengths of 1250 MPa or more. As the strength increases, the elongation, which may have been 30% or more, decreases to less than 5%

Correlation between heavy metal contents and antioxidants in medicinal plants grown in mining areas

International Nuclear Information System (INIS)

Maharia, R.; Dutta, R.K.; Acharya, R.; Reddy, A.V.R.

2010-01-01

Full texts: Medicinal plants are widely used as alternate therapeutic agents for various diseases. Three medicinal plants grown in copper mining regions of Khetri in Rajasthan was analyzed for heavy metal contents by instrumental neutron activation analysis. The copper levels were found to be two to three folds higher in these plant leaves as compared to the reported copper levels in the medicinal plants grown in environmentally friendly regions. In our previous study on heavy metals in soil and medicinal plant of Khetri region we have shown bioaccumulation of Cu in the medicinal plants. In addition, the levels of Cr, Fe and Zn were also higher. Antioxidant properties of medicinal plants are one of their major therapeutic functionalities. The role of elevated levels of heavy metals in the medicinal plants was studied with respect to their antioxidant properties. Standard procedures were used for measuring total phenols, flavanoids and DPPH assay of these medicinal plants which were correlated with the heavy metals contents of these plants

Downhole Upgrading of Orinoco Basin Extra-Heavy Crude Oil Using Hydrogen Donors under Steam Injection Conditions. Effect of the Presence of Iron Nanocatalysts

Directory of Open Access Journals (Sweden)

Cesar Ovalles

2015-03-01

Full Text Available An extra-heavy crude oil underground upgrading concept and laboratory experiments are presented which involve the addition of a hydrogen donor (tetralin to an Orinoco Basin extra-heavy crude oil under steam injection conditions (280–315 °C and residence times of at least 24-h. Three iron-containing nanocatalysts (20 nm, 60 nm and 90 nm were used and the results showed increases of up to 8° in API gravity, 26% desulfurization and 27% reduction in the asphaltene content of the upgraded product in comparison to the control reaction using inert sand. The iron nanocatalysts were characterized by SEM, XPS, EDAX, and Mössbauer spectroscopy before and after the upgrading reactions. The results indicated the presence of hematite (Fe2O3 as the predominant iron phase. The data showed that the catalysts were deactivating by particle sintering (~20% increase in particle size and also by carbon deposition. Probable mechanisms of reactions are proposed.

Topical and working papers on heavy water requirements and availability

International Nuclear Information System (INIS)

The documents included in this report are: Heavy water requirements and availability; technological infrastructure for heavy water plants; heavy water plant siting; hydrogen and methane availability; economics of heavy water production; monothermal, water fed heavy water process based on the ammonia/hydrogen isotopic exchange; production strategies to meet demand projections; hydrogen availability; deuterium sources; the independent UHDE heavy water process

Selection of the process for the heavy water production using isotopic exchange amonia-hydrogen

International Nuclear Information System (INIS)

Guzman R, G.H.

1980-01-01

The utilization of the Petroleos Mexicanos ammonia plants for heavy water production by the isotopic exchange NH 3 -H 2 process is presented, in addition a description of the other heavy water production processes was presented. In the ammonia hydrogen process exist two possible alternatives for the operation of the system, one of them is to carry out the enrichment to the same temperature, the second consists in making the enrichment at two different temperatures (dual temperature process), an analysis was made to select the best alternative. The conclusion was that the best operation is the dual temperature process, which presents higher advantages according to the thermodynamics and engineering of the process. (author)

THE EFFECT OF SEDIMENT GRAIN SIZE ON HEAVY METAL CONTENT

Directory of Open Access Journals (Sweden)

Svetlana Maslennikova

2012-06-01

Full Text Available In the natural surroundings tectonical, climatological, dynamic and physico-chemical conditions of sedimentation are the crucial factors in the process of sediment composition formation. Grain size is one of the most investigated reasons of space and temporary variability in heavy metal concentration. In general, the data on grain size measurement afford to appreciate sorption capacity of sediments and arrange them. The dependence heavy metal content on grain size of sediments has been examined in the enormous amount of research works. The main conclusion is that if grain size decreases, metal content increases.We have carried out sediment grain size measurement of two lakes (Chebachje Lake, Piketnoye Lake located in the South of Western Siberia, Russia. To define grain size of these sediments the sorting of samples collected layer-by-layer has been conducted by nest of sieves (from 43 to 1000 µm. Accomplished examinations allow to state that layer-by-layer grain size measurement of sediments has significant importance in reconstruction of paleoecologic peculiarities and also influences organic and inorganic matter concentrating in the sediments in dynamics

Study on the prediction of soil heavy metal elements content based on visible near-infrared spectroscopy

Science.gov (United States)

Liu, Jinbao; Zhang, Yang; Wang, Huanyuan; Du, Yichun

2018-06-01

The estimation of soils heavy metal content can reflect the impending surroundings of surface, which lays theoretical foundation for using covered vegetation to monitor environment and investigate resource. In this study, the contents of Cr, Mn, Ni, Cu, Zn, As, Cd, Hg and Pb in 44 soil samples were collected from Fufeng County, Yangling County and Wugong County, Shaanxi Province and were used as data sources. ASD FieldSpec HR (350-2500 nm), and then the NOR, MSC and SNV of the reflectance were pretreated, the first deviation, second deviation and reflectance reciprocal logarithmic transformation were carried out. The optimal spectroscopy estimation model of nine heavy metal elements of Cr, Mn, Ni, Cu, Zn, As, Cd, Hg and Pb was established by regression method. Comparing the diffuse reflectance characteristics of different heavy metal contents and the effect of different pretreatment methods on the establishment of soil heavy metal spectral inversion model. The results of chemical analysis show that there was a serious Hg pollution in the study area, and the Cd content was close to the critical value. The results show that: (1) NOR, MSC and SNV were adopted for the acquisition of visible near-infrared. Combining differential transformation can improve the information of heavy metal elements in the soil, and use the correlation band energy Significantly improve the stability and predictability of the model. (2) The modeling accuracy of the optimal model of nine heavy metal spectra of Cr, Mn, Ni, Cu, Zn, As, Cd, Hg and Pb by PLSR method were 0.70, 0.79, 0.69, 0.81, 0.86, 0.58, 0.55, 0.99, 0.62. (3) The optimal estimation model of different elements using different treatment methods has better stability and higher precision, and can realize the rapid prediction of nine kinds of heavy metal elements in this region.

Analysis of total hydrogen content in palm oil and palm kernel oil using thermal neutron moderation method

International Nuclear Information System (INIS)

Akaho, E.H.K.; Dagadu, C.P.K.; Maaku, B.T.; Anim-Sampong, S.; Kyere, A.W.K.; Jonah, S.A.

2001-01-01

A fast and non-destructive technique based on thermal neutron moderation has been used for determining the total hydrogen content in two types of red palm oil (dzomi and amidze) and palm kernel oil produced by traditional methods in Ghana. An equipment consisting of an 241 Am-Be neutron source and 3 He neutron detector was used in the investigation. The equipment was originally designed for detection of liquid levels in petrochemical and other process industries. Standards in the form of liquid hydrocarbons were used to obtain calibration lines for thermal neutron reflection parameter as a function of hydrogen content. Measured reflection parameters with respective hydrogen content with or without heat treatment of the three edible palm oils available on the market were compared with a brand cooking oil (frytol). The average total hydrogen content in the local oil samples prior to heating was measured to be 11.62 w% which compared well with acceptable value of 12 w% for palm oils in the sub-region. After heat treatment, the frytol oil (produced through bleaching process) had the least loss of hydrogen content of 0.26% in comparison with palm kernel oil of 0.44% followed by dzomi of 1.96% and by amidze of 3.22%. (author)

Influence of the P content on the transport parameters of hydrogen in Fe alloys

Energy Technology Data Exchange (ETDEWEB)

Peñalva, I., E-mail: igor.penalva@ehu.es [University of the Basque Country (UPV/EHU), Department of Nuclear Engineering & Fluid Mechanics, Faculty of Engineering, Alda. Urquijo s/n, 48013 Bilbao (Spain); Alberro, G.; Legarda, F. [University of the Basque Country (UPV/EHU), Department of Nuclear Engineering & Fluid Mechanics, Faculty of Engineering, Alda. Urquijo s/n, 48013 Bilbao (Spain); Ortiz, C.J.; Vila, R. [CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain)

2015-10-15

Highlights: • Gas permeation technique was used to study hydrogen diffusive transport parameters. • Four Fe alloys were analyzed to study the influence of the P content. • Increase in the P content leads to smaller values of permeability and diffusivity. • Trapping effects were observed at temperatures below 473 K for alloys containing P. - Abstract: In this work, the hydrogen transport parameters of permeability (ϕ), diffusivity (D) and Sieverts’ constant (K{sub S}) were experimentally measured in four Fe alloys supplied by the European Fusion Development Agreement (EFDA), by means of the gas evolution permeation technique. The samples had controlled chemical alloying element contents and microstructure. The experimental temperature range explored was from 423 K to 823 K and the high purity hydrogen loading pressures from 10{sup 3} Pa to 1.5·10{sup 5} Pa. The main objective of this work was to determine the influence of the P content of the alloy in the transport parameters of hydrogen. Two of the samples, pure Fe and FeC, contained negligible quantities of P (less than 5 ppm in weight), whereas the other two, FeP and FeCP, had the same metallurgical composition as their corresponding pair, with the only difference in the phosphorus content (89 ppm in weight and 88 ppm in weight, respectively). The experimental permeation results were analyzed using a non-linear least square fitting. The final resulting values of the aforementioned transport parameters were paired off in order to determine the effect of the P content: pure Fe versus FeP and FeC versus FeCP. We observed that the permeability obtained for all the samples follows an Arrhenius law in each case. In general terms, the increase of the P content in the alloy leads to smaller values of the permeability showing a decrease in the permeation activation energy. Regarding diffusivity and Sieverts’ constant, trapping effects have been observed for the alloys containing P. This phenomenon was

The influence of pH and organic matter content in paddy soil on heavy metal availability and their uptake by rice plants

Energy Technology Data Exchange (ETDEWEB)

Zeng Fanrong; Ali Shafaqat; Zhang Haitao [Department of Agronomy, College of Agriculture and Biotechnology, Huajiachi Campus, Zhejiang University, Hangzhou 310029 (China); Ouyang Younan [China National Rice Research Institute, Fuyang 310041 (China); Qiu Boyin; Wu Feibo [Department of Agronomy, College of Agriculture and Biotechnology, Huajiachi Campus, Zhejiang University, Hangzhou 310029 (China); Zhang Guoping, E-mail: zhanggp@zju.edu.c [China National Rice Research Institute, Fuyang 310041 (China)

2011-01-15

The experiments were done to investigate the effect of soil pH and organic matter content on EDTA-extractable heavy metal contents in soils and heavy metal concentrations in rice straw and grains. EDTA-extractable Cr contents in soils and concentrations in rice tissues were negatively correlated with soil pH, but positively correlated with organic matter content. The combination of soil pH and organic matter content would produce the more precise regression models for estimation of EDTA-Cu, Pb and Zn contents in soils, demonstrating the distinct effect of the two factors on the availability of these heavy metals in soils. Soil pH greatly affected heavy metal concentrations in rice plants. Furthermore, inclusion of other soil properties in the stepwise regression analysis improved the regression models for predicting straw Fe and grain Zn concentrations, indicating that other soil properties should be taken into consideration for precise predicting of heavy metal concentrations in rice plants. - Soil pH and organic matter content significantly affect heavy metal availability and accumulation in rice plants.

Effects of nitrogen enrichment on heavy metals content of cattle ...

African Journals Online (AJOL)

The research was carried out at John Ker Nigeria Organo-Mineral Company site at Ikot Ekpene, Akwa Ibom State, Nigeria, to investigate the effect of nitrogen enrichment on contents of heavy metals in cattle dung/poultry manure compost and the growth of maize. Cattle dung was mixed with poultry manure in the ratio of 3:1 ...

Chemometric approach to evaluate heavy metals’ content in Daucus Carota from different localities in Serbia

Directory of Open Access Journals (Sweden)

Mitic Violeta D.

2015-01-01

Full Text Available The aim of this study was to evaluate heavy metal content in carrots (Daucus carota from the different localities in Serbia and assess by the cluster analysis (CA and principal components analysis (PCA the heavy metal contamination of carrots from these areas. Carrot was collected at 13 locations in five districts. Chemometric methods (CA and PCA were applied to classify localities according to heavy metal content in carrots. CA separated localities into two statistical significant clusters. PCA permitted the reduction of 12 variables to four principal components explaining 79.94% of the total variance. The first most important principal component was strongly associated with the value of Cu, Sb, Pb and Tl. This study revealed that CA and PCA appear useful tools for differentiation of localities in different districts using the profile of heavy metal in carrot samples. [Projekat Ministarstva nauke Republike Srbije, br. 172051

Dependence of RF power on the content and configuration of hydrogen in amorphous hydrogenated silicon by reactive sputtering

Energy Technology Data Exchange (ETDEWEB)

Imura, T; Ushita, K; Mogi, K; Hiraki, A [Osaka Univ., Suita (Japan). Faculty of Engineering

1981-06-01

Infrared absorption spectra at stretching bands of Si-H were investigated in hydrogenated amorphous silicon fabricated by reactive sputtering in the atmosphere of Ar and H/sub 2/ (10 mole%) at various input rf powers in the range from 0.8 to 3.8 W/cm/sup 2/. Hydrogen content mainly due to the configuration of Si=H/sub 2/ in the film increased with the decreasing rf power, as the deposition rate was decreased. On the other hand, the quantity of the monohydride (Si-H) configuration depended less on the power. Attachment of hydrogen molecules onto the fresh and reactive surface of silicon deposited successively was proposed for possible process of hydrogen incusion into amorphous silicon resulting in Si=H/sub 2/ configuration. The photoconductivity increased as the input power became higher, when the deposition rate also increased linearly with the power.

Hydration effect on ion exchange resin irradiated by swift heavy ions and gamma rays

Science.gov (United States)

Boughattas, I.; Labed, V.; Gerenton, A.; Ngono-Ravache, Y.; Dannoux-Papin, A.

2018-06-01

Gamma radiolysis of ion exchange resins (IER) is widely studied since the sixties, as a function of different parameters (resin type, dose, atmosphere, water content …). However, to our knowledge, there are very few data concerning hydrogen emission from anionic and cationic resins irradiated at high Linear Energy Transfers (LET). In the present work, we focus on the influence of hydration on hydrogen emission, in anionic and cationic resins irradiated under inert atmosphere using Swift Heavy Ions (SHI) and gamma irradiations. The radiation chemical yield of molecular hydrogen is nonlinear with water content for both resins. The molecular hydrogen production depends first on the water form in IER (free or linked) and second on the solubility of degradation products. Three steps have been observed: at lower water content where G(H2) is stable, at 50%, G(H2) increases due to reactions between water radiolytic species and the resin functional groups and at high water content, G(H2) decreases probably due to its accumulation in water and its consumption by hydroxyl radicals in the supernatant.

The influence of Fe content on spreading ability of tungsten heavy alloys matrix on tungsten surface

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A. Krzyńska

2011-07-01

Full Text Available The results of experimental study of tungsten spreading ability with W-Ni-Co-Fe matrix are presented. The aim of these investigations was to see how Fe concentration in W – Ni – Co matrix influences the wettability of tungsten grains during liquid phase sintering. Four green compact specimens containing 50%W, 10%Co and Ni + Fe = 40% but with different Ni to Fe ratio were prepared. The cylindrical specimen 5mm diameter and 5mm height were put on clean pure tungsten substrate and then 20 minutes heated at 1520oC in hydrogen atmosphere. After heating the specimens were carefully measured and then the specimens for structure observations were prepared. It was concluded, that increase of Fe content decrease the melting temperature of W – Ni – Co alloy. The melting point decrease caused by Fe content increase substantially the spreading ability of tungsten substrate with W – Ni – Co alloy. Metallography investigations showed some microstructure changes in “reaction zone” identified in tungsten substrate – (WNi40-xCo10Fex interface. The results of the study confirmed our earlier observations that even relative small Fe addition promotes Weight Heavy Alloys (WHA liquid phase sintering.

Assessment and genetic analysis of heavy metal content in rice grain using an Oryza sativa × O. rufipogon backcross inbred line population.

Science.gov (United States)

Huang, De-Run; Fan, Ye-Yang; Hu, Biao-Lin; Xiao, Ye-Qing; Chen, Da-Zhou; Zhuang, Jie-Yun

2018-03-01

Heavy metal accumulation in rice is a growing concern for public health. Backcross inbred lines derived from an interspecific cross of Oryza sativa × O. rufipogon were grown in two distinct ecological locations (Hangzhou and Lingshui, China). The objective of this study was to characterise the contents of heavy metal in rice grains, and to identify quantitative trait loci (QTLs) for heavy metal contents. The contents of Ni, As, Pb, Cr and Hg in milled rice showed a significant decline as compared with those in brown rice, whereas the content of Cd showed little change. The concentration of heavy metal in rice grain varied greatly between the two environments. A total of 24 QTLs responsible for heavy metal contents were detected, including two for both the brown and milled rice, 13 for brown rice only, and nine for milled rice only. All the QTLs except two had the enhancing alleles derived from O. rufipogon. Sixteen QTLs were clustered in six chromosomal regions. Environmental variation plays an important role in the heavy metal contents in rice grain. QTLs detected in this study might be useful for breeding rice varieties with low heavy metal content. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Probabilistic consequence assessment of hydrogen sulphide releases from a heavy water plant

International Nuclear Information System (INIS)

Baynes, C.J.

1986-05-01

This report provides a summary of work carried out on behalf of the Atomic Energy Control Board, concerned with the consequences of accidental releases to the atmosphere of hydrogen sulphide (H 2 S) at a heavy water plant. In this study, assessments of consequences are made in terms of the probabilities of a range of possible outcomes, i.e., numbers of fatalities, given a certain release scenario. The report describes the major features of a computer model which was developed to calculate the consequences and their associated probabilities, and the major input data used in applying the model to a consequence assessment of the Bruce heavy water plant (HWP) in Ontario. The results of the sensitivity analyses of the model are summarized. Finally, the results of the consequence assessments of 43 accidental release scenarios at the Bruce HWP are summarized, together with a number of conclusions which were drawn from these results regarding the predicted consequences and the factors which influence them

Estimation of deuterium content in organic compounds by mass spectrometric methods

International Nuclear Information System (INIS)

Dave, S.M.; Goomer, N.C.

1979-01-01

Many organic sompounds are finding increasing importance in heavy water enrichment programme. New methods based on quantitative chemical conversion have been developed and standardized in for estimating deuterium contents of the exchanging organic molecules by mass spectrometry. The methods have been selected in such a way that the deuterium contents of both exchangeable as well as total hydrogens in the molecule can be conveniently estimated. (auth.)

Study on the prediction of soil heavy metal elements content based on visible near-infrared spectroscopy.

Science.gov (United States)

Liu, Jinbao; Zhang, Yang; Wang, Huanyuan; Du, Yichun

2018-06-15

The estimation of soils heavy metal content can reflect the impending surroundings of surface, which lays theoretical foundation for using covered vegetation to monitor environment and investigate resource. In this study, the contents of Cr, Mn, Ni, Cu, Zn, As, Cd, Hg and Pb in 44 soil samples were collected from Fufeng County, Yangling County and Wugong County, Shaanxi Province and were used as data sources. ASD FieldSpec HR (350-2500nm), and then the NOR, MSC and SNV of the reflectance were pretreated, the first deviation, second deviation and reflectance reciprocal logarithmic transformation were carried out. The optimal spectroscopy estimation model of nine heavy metal elements of Cr, Mn, Ni, Cu, Zn, As, Cd, Hg and Pb was established by regression method. Comparing the diffuse reflectance characteristics of different heavy metal contents and the effect of different pretreatment methods on the establishment of soil heavy metal spectral inversion model. The results of chemical analysis show that there was a serious Hg pollution in the study area, and the Cd content was close to the critical value. The results show that: (1) NOR, MSC and SNV were adopted for the acquisition of visible near-infrared. Combining differential transformation can improve the information of heavy metal elements in the soil, and use the correlation band energy Significantly improve the stability and predictability of the model. (2) The modeling accuracy of the optimal model of nine heavy metal spectra of Cr, Mn, Ni, Cu, Zn, As, Cd, Hg and Pb by PLSR method were 0.70, 0.79, 0.69, 0.81, 0.86, 0.58, 0.55, 0.99, 0.62. (3) The optimal estimation model of different elements using different treatment methods has better stability and higher precision, and can realize the rapid prediction of nine kinds of heavy metal elements in this region. Copyright © 2018 Elsevier B.V. All rights reserved.

Technical status study of heavy water enrichment

International Nuclear Information System (INIS)

Sukarsono; Imam Dahroni; Didik Herhady

2007-01-01

Technical status study of heavy water enrichment in Indonesia and also in the world has been done. Heavy water enrichment processes have been investigated were water distillation, hydrogen distillation, laser enrichment, electrolysis and isotop exchange. For the isotop exchange, the chemical pair can be used were water-hydrogen sulphite, ammonium-hydrogen, aminomethane-hydrogen, and water-hydrogen. For the isotope exchange, there was carried out by mono thermal or bi thermal. The highest producer of heavy water is Canada, and the other producer is USA, Norwegian and India. The processes be used in the world are isotope exchange Girdler Sulphide (GS), distillation and electrolysis. Research of heavy water carried out in Batan Yogyakarta, has a purpose to know the characteristic of heavy water purification. Several apparatus which has erected were 3 distillation column: Pyrex glass of 2 m tall, stainless steel column of 3 m tall and steel of 6 m tall. Electrolysis apparatus is 50 cell electrolysis and an isotope exchange unit which has catalyst: Ni- Cr 2 O 3 and Pt-Carbon. These apparatus were not ready to operate. (author)

Production of JET fuel containing molecules of high hydrogen content

Directory of Open Access Journals (Sweden)

Tomasek Sz.

2017-12-01

Full Text Available The harmful effects of aviation can only be reduced by using alternative fuels with excellent burning properties and a high hydrogen content in the constituent molecules. Due to increasing plastic consumption the amount of the plastic waste is also higher. Despite the fact that landfill plastic waste has been steadily reduced, the present scenario is not satisfactory. Therefore, the aim of this study is to produce JET fuel containing an alternative component made from straight-run kerosene and the waste polyethylene cracking fraction. We carried out our experiments on a commercial NiMo/Al2O3/P catalyst at the following process parameters: T=200-300°C, P=40 bar, LHSV=1.0-3.0 h-1, hydrogen/hydrocarbon ratio= 400 Nm3/m3. We investigated the effects of the feedstocks and the process parameters on the product yields, the hydrodesulfurization and hydrodearomatization efficiencies, and the main product properties. The liquid product yields varied between 99.7-99.8%. As a result of the hydrogenation the sulfur (1-1780 mg/kg and the aromatic contents (9.0-20.5% of the obtained products and the values of their smoke points (26.0-34.7 mm fulfilled the requirements of JET fuel standard. Additionally, the concentration of paraffins increased in the products and the burning properties were also improved. The freezing points of the products were higher than -47°C, therefore product blending is needed.

Heavy metal contents in the sediments of astatic ponds: Influence of geomorphology, hydroperiod, water chemistry and vegetation.

Science.gov (United States)

Gołdyn, Bartłomiej; Chudzińska, Maria; Barałkiewicz, Danuta; Celewicz-Gołdyn, Sofia

2015-08-01

The contents of heavy metals (Cd, Cr, Cu, Ni, Pb, Zn) were analysed in the bottom sediments of 30 small, astatic ponds located in the agricultural landscape of Western Poland. The samples were collected from 118 stations located in patches of four vegetation types. Relationships between the contents of particular elements and four groups of factors (geomorphology, hydroperiod, water quality and vegetation) were tested using Redundancy Analysis (RDA). The most important factors influencing the heavy metal contents were the maximum depth and area of the pond, its hydroperiod, water pH and conductivity values. In general, low quantities of heavy metals were recorded in the sediments of kettle-like ponds (small but located in deep depressions) and high in water bodies of the shore-bursting type (large but shallow). Moreover, quantities of particular elements were influenced by the structure of the vegetation covering the pond. Based on the results, we show which types of astatic ponds are most exposed to contamination and suggest some conservation practices that may reduce the influx of heavy metals. Copyright © 2015 Elsevier Inc. All rights reserved.

The effect of bottom sediment supplement on heavy metals content in plants (Zea mays and soil

Directory of Open Access Journals (Sweden)

Baran A.

2013-04-01

Full Text Available Important aspect of bottom sediments is the problem of their management or disposal after their extraction from the bottom of rivers, dam reservoirs, ports, channels or ponds. The research aimed at an assessment of potential environmental management of bottom sediment used as an admixture to light soil basing on its effect on contents of heavy metals in plants and soil. The research was conducted on light soil with granulometric structure of weakly loamy sand. The bottom sediment was added to light soil in the amount of 0 (control 5, 10, 30 i 50%. The test plant was maize (Zea mays, “Bora” c.v. The sediment applied in the presented research revealed high share of silt and clay fractions, alkaline pH and low contents of heavy metals, therefore it may be used as an admixture to the above mentioned soils to improve their productivity. The applied bottom sediment to the soil affected a decreased in Zn, Cd and Pb content in maize in comparison with the treatment without the deposit whereas increased content of Cu, Cr and Ni. No exceeded permissible content of heavy metals concerning plant assessment in view of their forage usability were registered in maize biomass.

Selected Heavy Metal Content in Ultra basic Soil and Mengkudu (Morinda citrifolia) from Kuala Pilah, Negeri Sembilan, Malaysia

International Nuclear Information System (INIS)

Sahibin Abdul Rahim; Wan Mohd Razi Idris; Zulfahmi Ali Rahman; Kadderi Mohd Desa; Tukimat Lihan; Azman Hashim; Sharilnizam Yusof; Kuan, L.H.

2009-01-01

This study was carried out at an ultra basic area, Selaru (S1 and S2) dan Felda Rokan Barat (S3), Kuala Pilah, Negeri Sembilan. Eighteen samples of plant and their substrates were collected from study area. The purpose of this study was to determine heavy metal such as Ni, Cr, Mn, Co, Fe and Zn contents in soils and different parts of the plant, such as leaf, stem, root and fruit. Biologal Absorption Coefficient (BAC) of the plant was obtained by calculation. Heavy metals content in the plant were extracted by digestion method whereas in soil the heavy metals were extracted by sequential extraction. Heavy metals content in soil and plant extract was determined using Flame Atomic Absorption Spectrophotometer. It was found that heavy metal concentrations in soil substrate for mengkudu (Morinda citrifolia) were high for Fe followed by Cr, Ni, Mn, Zn and Co with average concentration of 1208.5, 583.4, 352.4, 352.4, 70.7 and 53.6 mg.kg -1 , respectively. Available Mn and Zn concentrations were higher than the other heavy metals in term of percentage. Fe and Mn were dominant in all parts of plants however in terms of BAC average, Co showed the highest enrichment value in all parts of the plants. (author)

A city scale study on the effects of intensive groundwater heat pump systems on heavy metal contents in groundwater.

Science.gov (United States)

García-Gil, Alejandro; Epting, Jannis; Garrido, Eduardo; Vázquez-Suñé, Enric; Lázaro, Jesús Mateo; Sánchez Navarro, José Ángel; Huggenberger, P; Calvo, Miguel Ángel Marazuela

2016-12-01

As a result of the increasing use of shallow geothermal resources, hydraulic, thermal and chemical impacts affecting groundwater quality can be observed with ever increasing frequency (Possemiers et al., 2014). To overcome the uncertainty associated with chemical impacts, a city scale study on the effects of intensive geothermal resource use by groundwater heat pump systems on groundwater quality, with special emphasis on heavy metal contents was performed. Statistical analysis of geochemical data obtained from several field campaigns has allowed studying the spatiotemporal relationship between temperature anomalies in the aquifer and trace element composition of groundwater. The relationship between temperature and the concentrations of trace elements resulted in weak correlations, indicating that temperature changes are not the driving factor in enhancing heavy metal contaminations. Regression models established for these correlations showed a very low reactivity or response of heavy metal contents to temperature changes. The change rates of heavy metal contents with respect to temperature changes obtained indicate a low risk of exceeding quality threshold values by means of the exploitation regimes used, neither producing nor enhancing contamination significantly. However, modification of pH, redox potential, electrical conductivity, dissolved oxygen and alkalinity correlated with the concentrations of heavy metals. In this case, the change rates of heavy metal contents are higher, with a greater risk of exceeding threshold values. Copyright © 2016 Elsevier B.V. All rights reserved.

Heavy water: a distinctive and essential component of CANDU

International Nuclear Information System (INIS)

Miller, A.I.; van Alstyne, H.M.

1994-06-01

The exceptional properties of heavy water as a neutron moderator provide one of the distinctive features of CANDU reactors. Although most of the chemical and physical properties of deuterium and protium (mass 1 hydrogen) are appreciably different, the low terrestrial abundance of deuterium makes the separation of heavy water a relatively costly process, and so of considerable importance to the CANDU system. World heavy-water supplies are currently provided by the Girdler-Sulphide process or processes based on ammonia-hydrogen exchange. Due to cost and hazard considerations, new processes will be required for the production of heavy water in and beyond the next decade. Through AECL's development and refinement of wetproofed catalysts for the exchange of hydrogen isotopes between water and hydrogen, a family of new processes is expected to be deployed. Two monothermal processes, CECE (Combined Electrolysis and Catalytic Exchange, using water-to-hydrogen conversion by electrolysis) and CIRCE (Combined Industrially Reformed hydrogen and Catalytic Exchange, based on steam reforming of hydrocarbons), are furthest advanced. Besides its use for heavy-water production, the CECE process is a highly effective technology for heavy-water upgrading and for tritium separation from heavy (or light) water. (author). 10 refs., 1 tab., 7 figs

Production of heavy water in India

International Nuclear Information System (INIS)

Deshpande, P.G.; Bimbhat, K.S.; Bhargava, R.K.

India's first heavy water plant, using electrolysis of water followed by liquid hydrogen distillation, has been operating in association with a fertilizer plant at Nangal since 1962. A dual-temperature process plant at Kota uses heat from the Rajasthan Atomic Power Station. The heavy water plants at Baroda and Tuticorin use ammonia-hydrogen exchange and are integrated with fertilizer ammonia plants. Choice of a particular process for heavy water production depends upon local conditions as well as the extent of the heavy water requirement

Investigation of the energy loss and the charge state of high energy heavy ions in a hydrogen plasma

International Nuclear Information System (INIS)

Dietrich, K.G.

1991-07-01

For heavy ions with energy of 1.4 to 5.9 MeV/u the energy loss and charge state after transmission through a totally ionized hydrogen plasma are investigated. Plasma target was a Z-pinch device incorporated in the beam optics of the accelerator by a pumping system. In the 20 cm long pinch hydrogen plasmas with densities up to 1.5x10 19 cm -3 and temperatures above 5 eV are produced, with ionization efficiency higher than 99%. The ions pass the plasma on the symmetry axis of the plasma column through small apertures in the electrodes. The energy loss was measured by time-of-flight method, the plasma density by interferometry along the pinch axis. For the first time the ion charge after transmission through the plasma has been determined by a charge spectrometer being a combination of a dipole magnet and a position sensitive detector with high time resolution. A growth of the average charge of heavy ions in plasma higher than the equilibrium charge in cold gas was discovered, caused by a reduction of electron capture by fast heavy ions in ionized matter. The electron loss rates in plasma and cold gas are equal. (orig./AH) [de

Catalytic hydroprocessing of heavy oil feedstocks

International Nuclear Information System (INIS)

Okunev, A G; Parkhomchuk, E V; Lysikov, A I; Parunin, P D; Semeikina, V S; Parmon, V N

2015-01-01

A grave problem of modern oil refining industry is continuous deterioration of the produced oil quality, on the one hand, and increase in the demand for motor fuels, on the other hand. This necessitates processing of heavy oil feedstock with high contents of sulfur, nitrogen and metals and the atmospheric residue. This feedstock is converted to light oil products via hydrogenation processes catalyzed by transition metal compounds, first of all, cobalt- or nickel-promoted molybdenum and tungsten compounds. The processing involves desulfurization, denitrogenation and demetallization reactions as well as reactions converting heavy hydrocarbons to lighter fuel components. The review discusses the mechanisms of reactions involved in the heavy feedstock hydroprocessing, the presumed structure and state of the catalytically active components and methods for the formation of supports with the desired texture. Practically used and prospective approaches to catalytic upgrading of heavy oil feedstock as well as examples of industrial processing of bitumen and vacuum residues in the presence of catalysts are briefly discussed. The bibliography includes 140 references

Catalytic hydroprocessing of heavy oil feedstocks

Science.gov (United States)

Okunev, A. G.; Parkhomchuk, E. V.; Lysikov, A. I.; Parunin, P. D.; Semeikina, V. S.; Parmon, V. N.

2015-09-01

A grave problem of modern oil refining industry is continuous deterioration of the produced oil quality, on the one hand, and increase in the demand for motor fuels, on the other hand. This necessitates processing of heavy oil feedstock with high contents of sulfur, nitrogen and metals and the atmospheric residue. This feedstock is converted to light oil products via hydrogenation processes catalyzed by transition metal compounds, first of all, cobalt- or nickel-promoted molybdenum and tungsten compounds. The processing involves desulfurization, denitrogenation and demetallization reactions as well as reactions converting heavy hydrocarbons to lighter fuel components. The review discusses the mechanisms of reactions involved in the heavy feedstock hydroprocessing, the presumed structure and state of the catalytically active components and methods for the formation of supports with the desired texture. Practically used and prospective approaches to catalytic upgrading of heavy oil feedstock as well as examples of industrial processing of bitumen and vacuum residues in the presence of catalysts are briefly discussed. The bibliography includes 140 references.

Ammonia-water exchange front end process for ammonia-hydrogen heavy water plants (Preprint No. PD-1)

International Nuclear Information System (INIS)

Sadhukhan, H.K.; Varadarajan, T.G.; Nair, N.K.; Das, S.K.; Nath, G.K.

1989-04-01

The ammonia-hydrogen exchange process, which utilizes the deutrium exchange between liquid ammonia and gaseous hydrogen is a parasitic process and the heavy water plants (HWP) based on this process has to be linked with the fertilizer plant (FP) for its enormous requirements of hydrogen (synthesis gas, N 2 +3H 2 ). This dependence of HWP on FP gives rise to certain constraints which are listed. These deficiencies of the ammonia-hydrogen process can be overcome to a great extent by delinking the HWP from FP by incorporating NH 3 -H 2 O exchange as the front end step. In addition to the elimination of the above limitations, by employing water as the ultimate feed for the HWP, the plant capacity can be increased substantially and this would go a long way in achieving economies of the large capacity plants. A schematic diagram of this integrated plant is given. Some of the results of developmental efforts and feasibility studies of this NH 3 -H 2 O exchange are briefly reviewed. (author). 4 figs

Content of heavy metals and naturally occurring radioactive material in Leucaena leucocaphala (Lam.) de wit

International Nuclear Information System (INIS)

Nurul Sareeza Azidin

2012-01-01

This research was done to determine the content of heavy metals in Leucaena leucocaphala (Lam.) de Wit (Petai Belalang) at 5 different areas. Those areas were in the middle of city, former mining area, industrial area, domestic waste disposal area, and on expressway roadside. Heavy metal poisoning can happen if the concentration is too high and will cause severe damage to human health. For instance, it may cause gene mutation, cancer and damage to the human body systems. This plant was selected for the study of heavy metals and radionuclide content in the soil. The reason of selecting this plant is because this plant can live in extreme conditions, and perhaps able to absorb those elements better than other legumes. The aim of this study was to determine the content of toxic heavy metals in leaves, stems and roots of Leucaena leucocaphala including the soil where it is grown. The second objective was determine NORM in the soil where the plant grew and the last objective was to determine the transfer factor of heavy metals by the plant. The content analysis of toxic heavy metals for example Cu, Zn, Cd, Hg and Pb were determined by using the Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Gamma ray spectrometry on the other hand, was used to determine K-40, Ra-226, U-238 and Th-232 in the soil where the plant was sampled. The activity concentration of Ra-226, K-40, U-238 and Th-232 determined were 7.47 ± 3.03 Bq/ kg - 256.92 ± 164.36 Bq/ kg, 95.55 ± 72.62 Bq/ kg - 435.60 ± 88.32 Bq/ kg, 21.83 ± 8.83 Bq/ kg - 165.28 ± 109.61 Bq/ kg dan 43.41 ± 7.06 Bq/ kg - 91.19 ± 11.13 Bq/ kg respectively. In general, the former mining area recorded the highest heavy metal concentration for Cu (28.20 ± 32.54 mg/ kg), Zn (114.67 ± 75,61 mg/ kg), Cd (0.31 ± 0.11 mg/ kg) and Pb (48.08 ± 33.60 mg/ kg). Whereas the highest concentration of As recorded was on the roadside (261.92 ± 132.64) and Hg (0.44 ± 0.36 mg/kg) in the middle of the city. (author)

Absolute determination of the deuterium content of heavy water, measurement of absolute density

International Nuclear Information System (INIS)

Ceccaldi, M.; Riedinger, M.; Menache, M.

1975-01-01

The absolute density of two heavy water samples rich in deuterium (with a grade higher than 99.9%) was determined with the hydrostatic method. The exact isotopic composition of this water (hydrogen and oxygen isotopes) was very carefully studied. A theoretical estimate enabled us to get the absolute density value of isotopically pure D 2 16 O. This value was found to be 1104.750 kg.m -3 at t 68 =22.3 0 C and under the pressure of one atmosphere. (orig.) [de

Examinations of content of heavy metals in municipal solid waste and produced compost

International Nuclear Information System (INIS)

Golimowski, J.; Tykarska, A.; Orzechowska, K.

1993-01-01

The basic methods of utilization of municipal solid waste are biothermic and aerobic methods to compost. The content of heavy metals in composts depends on the initial their content in wastes as well as on the compost process. The voltammetric method has been applied for measurement of concentration of Zn, Cd, Pb, Cu, Cr, Ni and Hg in the waste and composts samples. (author). 24 refs, 2 figs, 3 tabs

The impact of multiphase behaviour on coke deposition in heavy oil hydroprocessing catalysts

Science.gov (United States)

Zhang, Xiaohui

Coke deposition in heavy oil catalytic hydroprocessing remains a serious problem. The influence of multiphase behaviour on coke deposition is an important but unresolved question. A model heavy oil system (Athabasca vacuum bottoms (ABVB) + decane) and a commercial heavy oil hydrotreating catalyst (NiMo/gamma-Al 2O3) were employed to study the impact of multiphase behaviour on coke deposition. The model heavy oil mixture exhibits low-density liquid + vapour (L1V), high-density liquid + vapour (L2V), as well as low-density liquid + high-density liquid + vapour (L1L2V) phase behaviour at a typical hydroprocessing temperature (380°C). The L2 phase only arises for the ABVB composition range from 10 to 50 wt %. The phase behaviour undergoes transitions from V to L2V, to L1L2V, to L1V with increasing ABVB compositions at the pressure examined. The addition of hydrogen into the model heavy oil mixtures at a fixed mass ratio (0.0057:1) does not change the phase behaviour significantly, but shifts the phase regions and boundaries vertically from low pressure to high pressure. In the absence of hydrogen, the carbon content, surface area and pore volume losses for catalyst exposed to the L1 phase are greater than for the corresponding L2 phase despite a higher coke precursor concentration in L2 than in L1. By contrast, in the presence of hydrogen, the carbon content, surface area and pore volume losses for the catalyst exposed to the L2 phase are greater than for the corresponding L1 phase. The higher hydrogen concentration in L1 appears to reverse the observed results. In the presence of hydrogen, L2 was most closely associated with coke deposition, L1 less associated with coke deposition, and V least associated with coke deposition. Coke deposition is maximized in the phase regions where the L2 phase arises. This key result is inconsistent with expectation and coke deposition models where the extent of coke deposition, at otherwise fixed reaction conditions, is asserted to

Finishing and upgrading of heavy water

International Nuclear Information System (INIS)

Butler, J.P.; Hammerli, M.

1981-01-01

This invention provides a process and apparatus for deuterium enrichment as a final stage in a heavy water plant, for continuous on-line enrichment of the heavy water in moderator and heat transfer systems in heavy water nuclear reactors, and for enrichment of hevy water that has been downgraded with natural water during the course of operating a heavy water nuclear reactor. The method comprises contacting partially-enriched heavy water feed in a catalyst column with hydrogen gas (essentially D 2 ) orginating in an electrolysis cell so as to enrich the feed water with deuterium extracted from the electrolytic hydrogen gas and passing the deuterium-enriched water to the electrolysis cell. The apparatus comprises a catalyst isotope exchange column with hydrogen gas and liquid water passing through in countercurrent isotope exchange, an electrolysis cell, a dehumidifer-scrubber; and means for passing the liquid water enriched in deuterium from the catalyst column through the dehumidifer-scrubber to the electrolysis cell, for passing the hydrogen gas evolved in the cathode side of the cell through the dehumidifier-scrubber to the catalyst column, for passing the hydrogen gas from the catalyst column to an output, for introducing an input water feed to the upper portion of the catalyst column, and for taking a product enriched in deuterium from the system. (LL)

Species variation of Aegilops genus and heavy metal content in plant habitat soil at southern Adriatic localities

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Dimitrijević Miodrag

2014-01-01

Full Text Available The Aegilops genus is a wild relative to the bread wheat, having chromosomes homologous to wheat chromosomes. That genus could be the source of many usefull abiotic stress tolerance genes. Facing a global climate changes, as well as, environmental erosion, it is important to create a desirable genetic variability that could correspond to environmental challenges. Heavy metals in soil could cause soil pollution, could lead to different phenotypic changes in plants, and could enter food chain. Assessment of Aegilops sp. population variation, as well as, heavy metal content in their habitat was the main goal in this research. Aegilops population composition was examined and samples were taken from 55 localities of South Adriatic coastal and littoral areas. Topsoil samples from all the localities were taken and heavy metal content, namely Cr, Pb, Zn, Ni, Cd and Cu, was analyzed,. Manganese content was measured, as well. Value of pH was established.

RESEARCH ON THE QUAIL EGGS ALBUMEN CONTENT IN SOME HEAVY METALS

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I. VIZITIU

2015-12-01

Full Text Available Out of a sample batch of 20 Japanese quails, Pharaoh race, with an age of 100 days and weighing 245 g, approximately 200 eggs were collected at the peak phase of the laying period. The eggs were measured, weighed and broken, separating the albumen from the other components. The data obtained served to calculate the physical and morphological indices. Primary chemical composition, caloricity, heavy metals content were first determined, the following data being obtained: quail eggs albumen has an average weight of 7.1025±0.061g, an average volume of 7.158±0.09cm3, an average density of 1.0168±0.0139 g/cm3 and an index (of freshness of 0.0797±0.0015. The albumen contains: 86.76% water, 13.24% dry matter, 0.835% mineral matter, 11.37% protein, 1.03% non-nitrogenous extractive substances and a caloricity of 289.498 kJ for 100 g product. The average content of heavy metals in albumen was: 1.33*10-3 ppm, for cadmium; 8.83*10-2 ppm, for zinc; 1.005 ppm, for cooper and 0.0 ppm, respectively, for lead.

Analysis of hydrogen-deuterium mixtures and of mixtures of heavy-water and light-water by means of a mass spectrometer; Analyse des melanges hydrogene-deuterium et des melanges d'eau lourde et d'eau legere au moyen du spectrometre de masse

Energy Technology Data Exchange (ETDEWEB)

Chenouard, J; Gueron, J; Roth, E

1951-07-01

The differences between hydrogen and deuterium with respect to the capture of thermal neutrons (hydrogen = 0.31 barn; deuterium 0.00065 barn) explains the interest of detecting small variations of the isotopic composition of the heavy waters used in the Chatillon nuclear pile. The aim of this report is to describe and discuss the method used since more than a year for the dosimetry of heavy waters. After a recall of the principle of mass spectroscopy analysis of deuterium-hydrogen mixtures, the preciseness of the results is presented and the balancing method used for the determination of the isotopic composition of hydrogen-deuterium mixtures is explained in detail. Finally, a brief comparison of the preciseness of mass spectroscopy measurements with the analyses made with other methods is performed. Some calculations and the tables of results are presented in appendixes. (J.S.)

Determination of heavy metal content and physico-chemical properties of soils in the vicinity of Tasik Chini, Pahang

International Nuclear Information System (INIS)

Sahibin Abdul Rahim; Muhd Barzani Gasim; Mohd Nizam Mohd Said; Wan Mohd Razi Idris; Azman Hashim; Sharilnizam Yusof; Masniyana Jamil

2008-01-01

This study was carried out to determine heavy metal content and physico-chemical properties of soils influencing heavy metal accumulation in some series surrounding the Chini Lakes. A total of 15 topsoil sample were collected randomly from 6 stations. The physical properties that were analyzed include particle size distribution and soil organic matter. Meanwhile, the chemical characteristics determined were pH, electrical conductivity and cation exchange capacity. It was found that heavy metal content of Cd, Cr, Cu, Co, Pb, Zn and Mn were low whereas Fe content was high. The textures of soil studied were clay, loamy sand, sandy loam, clay loam and silty clay loam. The mean of organic matter ranged from 2.68 to 11.46 %. The soil pH showed that the soil studied was acidic with values ranged between 3.36 to 3.72. The range of electrical conductivity mean was between 2150 μScm -1 to 2403 μScm -1 . Cation exchange capacity mean ranged from 2.85 until 8.59 cmol/ kg. Correlation analysis showed that there were positive and negative significant correlations between soils parameters heavy metal concentration. Analysis of variance (ANOVA) showed that there were significant differences in organic matter percentage, pH, cation exchange capacity and heavy metals except cadmium between sampling station. (author)

Evaluation of heavy metal content in irradiated sludge, chicken manure and fertilized soil in Indonesia

International Nuclear Information System (INIS)

Hilmy, N.; Suwirma, S.; Surtipanti, S.; Harsojo

1997-01-01

The contents of heavy metals, Hg, Cd, Cr, Cu, Ni, Pb, Zn and Co, were determined in two irradiated sludges, chicken manure and fertilized soil. Sludge I was collected from a treatment plant in Jakarta city, Sludge II from a sludge reservoir in a Jakarta suburb, chicken manure was obtained from a farm south of Jakarta, and the soil had been treated with phosphate fertilizer since 1967. The sludges and chicken manure were collected during the rainy and dry seasons, and the heavy-metal contents were determined by atomic-absorption spectrometry and neutron-activation analysis. The results obtained are compared with data from Canada, and are discussed in terms of permissible limits in the environment. (author)

Gas stripping and recirculation process in heavy water separation plant

International Nuclear Information System (INIS)

Nazzer, D.B.; Thayer, V.R.

1976-01-01

Hydrogen sulfide is stripped from hot effluent, in a heavy water separation plant of the dual temperature isotope separation type, by taking liquid effluent from the hot tower before passage through the humidifier, passing the liquid through one or more throttle devices to flash-off the H 2 S gas content, and feeding the gas into an absorption tower containing incoming feed water, for recycling of the gas through the process

Heavy metal content of lichens in relation to distance from a nickel smelter in Sudbury, Ontario

Energy Technology Data Exchange (ETDEWEB)

Nieboer, E; Ahmed, H M; Puckett, K J; Richardson, D H.S.

1972-01-01

The Sudbury region of Ontario has large deposits of nickel, iron, and copper, and thus a number of smelting plants which produce sulfur dioxide and heavy metal pollution. Since lichens are good indicators of SO/sub 2/ pollution levels, the pattern of heavy metal content in lichen species in the area of a copper smelter in Sudbury was correlated with distance from the smelter to ascertain whether lichens might also be good indicators of the amount of heavy metal fallout. The lichens were analyzed qualitatively and quantitatively. All seven species of lichens contained copper, iron, zinc, nickel, manganese, and lead. Cadmium and cobalt were detected in two species. Neither gold nor silver could be identified in lichen material with the tests used. A pollution model was developed and compared to field results. The simple dilution of the stack effluent was consistent with the fact that the lichen metal content was related to the reciprocal of the distance from the pollution source. The lichens from the area could tolerate simultaneously high concentrations of several heavy metals that are known to be toxic to other plants. The mechanism of metal uptake was not clearly established. The study showed that lichens and other epiphytes are potentially the most useful indicators of heavy metal fallout around industrial plants.

Selected bibliography on heavy water, tritiated water and hydrogen isotopes (1981-1992)

International Nuclear Information System (INIS)

Gopalakrishnan, V.T.; Sutawane, U.B.; Rathi, B.N.

1994-01-01

A selected bibliography on heavy water, tritiated water and hydrogen isotopes is presented. This bibliography covers the period 1981-1992 and is in continuation to Division's earlier report BARC-1192 (1983). The sources of information for this compilation are Chemical Abstracts, INIS Atom Index and also some scattered search through journals and reports available in our library. No claim is made towards exhaustiveness of this bibliography even though sincere attempts have been made for a wide coverage. The bibliography is arranged under the headings: (1) production, purification, recovery, reprocessing and storage, (2) isotope exchange, 3) isotope analysis, (4) properties and (5) miscellaneous. Total number of references in the bibliography are 1762. (author)

Chromatographic hydrogen isotope separation

International Nuclear Information System (INIS)

Aldridge, F.T.

1983-01-01

Intermetallic compounds with the CaCu5 type of crystal structure, particularly LaNiCo and CaNi5, exhibit high separation factors and fast equilibrium times and therefore are useful for packing a chromatographic hydrogen isotope separation column. The addition of an inert metal to dilute the hydride improves performance of the column. A large scale multi-stage chromatographic separation process run as a secondary process off a hydrogen feedstream from an industrial plant which uses large volumes of hydrogen can produce large quantities of heavy water at an effective cost for use in heavy water reactors

Chromatographic hydrogen isotope separation

International Nuclear Information System (INIS)

Aldridge, F.T.

1981-01-01

Intermetallic compounds with the CaCu5 type of crystal structure , particularly LaNiCo and CaNi5, exhibit high separation factors and fast equilibrium times and therefore are useful for packing a chromatographic hydrogen isotope separation colum. The addition of an inert metal to dilute the hydride improves performance of the column. A large scale mutli-stage chromatographic separation process run as a secondary process off a hydrogen feedstream from an industrial plant which uses large volumes of hydrogen can produce large quantities of heavy water at an effective cost for use in heavy water reactors

Probabilistic consequence assessment of hydrogen sulphide releases from a heavy water plant

International Nuclear Information System (INIS)

1983-01-01

This report is concerned with the evaluation of the consequences to the public of an accidental release of hydrogen sulphide (H 2 S) to the atmosphere following a pipe or pressure envelope failure, or some other process upset, at a heavy water plant. It covers the first stage of a programme in which the nature of the problem was analyzed and recommendations made for the implementation of a computer model. The concepts of risk assessment and consequence assessment are discussed and a methodology proposed for combining the various elements of the problem into an overall consequence model. These elements are identified as the 'Initiating Events', 'Route to Receptor' and 'Receptor Response' and each is studied in detail in the report. Such phenomena as the blowdown of H 2 S from a rupture, the initial gas cloud behaviour, atmospheric dispersion and the toxicity of H 2 S and sulphur dioxide (SO 2 ) are addressed. Critical factors are identified and modelling requirements specified, with special reference to the Bruce heavy water plant. Finally, an overall model is recommended for implementation at the next stage of the programme, together with detailed terms of reference for the remaining work

Removal and recovery of tritium from light and heavy water

International Nuclear Information System (INIS)

Butler, J.P.; Hammerli, M.

1979-01-01

A method and apparatus for removing tritium from light water are described, comprising contacting tritiated feed water in a catalyst column in countercurrent flow with hydrogen gas originating from an electrolysis cell so as to enrich this feed water with tritium from the electrolytic hydrogen gas and passing the tritium enriched water to an electrolysis cell wherein the electrolytic hydrogen gas is generated and then fed upwards through the catalyst column or recovered as product. The tritium content of the hydrogen gas leaving the top of the enricher catalyst column is further reduced in a stripper column containing catalyst which transfers the tritium to a countercurrent flow of liquid water. Anodic oxygen and water vapour from the anode compartment may be fed to a drier and condensed electrolyte recycled with a slip stream or recovered as a further tritium product stream. A similar method involving heavy water is also described. (author)

Operating experiences of Heavy Water Plant at Talcher using bithermal ammonia-hydrogen exchange process (Paper No. 1.9)

International Nuclear Information System (INIS)

Haldar, T.K.; Manoj Kumar; Ramamurty, C.B.

1992-01-01

A heavy water plant employing bithermal ammonia-hydrogen exchange process was set up at Talcher (India). The energy consumption in the process is lower as compared to monothermal process. The plant performance was affected by various problems and has resulted in low heavy water production. The problems are: (i)formation of solid deposits, (ii)inability of exchange towers to process design gas flow rates, (iii)inadequate exchange efficiency of the sieve trays provided as exchange trays, and (iv)differential amide concentration in different plant sections. These problems and their effect on the overall plant performance are discussed in detail and modifications to improve the performance are suggested. (author). 4 figs

Fe(CO)5-catalyzed coprocessing of coal and heavy oil vacuum residue using syngas-water as a hydrogen source; Fe(CO)5 shokubai ni yoru gosei gas-mizu wo suisogen to suru sekitan-jushitsuyu no coprocessing

Energy Technology Data Exchange (ETDEWEB)

Hata, K.; Wada, K.; Mitsudo, T. [Kyoto University, Kyoto (Japan)

1996-10-28

Improvement in efficiency and profitability of hydrogenation reaction of heavy hydrocarbon resources is the most important matter to be done. In this study, coprocessing of coal and heavy oil vacuum residue was conducted using syngas-water as a hydrogen source. For the investigation of effect of the reaction temperature during the coprocessing of Wandoan coal and Arabian heavy vacuum residue using Fe(CO)5 as a catalyst, the conversion, 66.0% was obtained at 425{degree}C. For the investigation of effect of reaction time, the yield of light fractions further increased during the two stage reaction at 400{degree}C for 60 minutes and at 425{degree}C for 60 minutes. Finally, almost 100% of THF-soluble matter was obtained through the reaction using 2 mmol of Fe(CO)5 catalyst at 400{degree}C for 60 minutes, and hydrogenation of heavy oil was proceeded simultaneously. When comparing coprocessing reactions using three kinds of hydrogen sources, i.e., hydrogen, CO-water, and syngas-water, the conversion yield and oil yield obtained by using syngas-water were similar to those obtained by using hydrogen, which demonstrated the effectiveness of syngas-water. 2 refs., 2 figs., 2 tabs.

[Heavy metals contents and Hg adsorption characteristics of mosses in virgin forest of Gongga Mountain].

Science.gov (United States)

Liang, Peng; Yang, Yong-Kui; He, Lei; Wang, Ding-Yong

2008-06-01

Seven main moss species in the Hailuogou virgin forest of Gongga Mountain were sampled to determine their heavy metals (Hg, Cr, Cd, Ni, Pb, Cu, Mn, Zn and Fe) content, and two widely distributed species, Pleurozium schreberi (Brid.) Mitt. and Racomitrium laetum Besch., were selected to study their Hg adsorption characteristics. The results showed that the heavy metals contents in the mosses were lower than the background values in Europe and America, except that the Cd had a comparable value, which indicated that the atmosphere in study area was not polluted by heavy metals and good in quality. The Hg adsorption by P. schreberi and R. laetum was an initiative and rapid process, with the equilibrium reached in about two hours, and could be well fitted by Freundlich and Langmuir equations. Based on Langmuir equation, the maximum Hg adsorption capacities of P. schreberi and R. laetum were 15.24 and 8.19 mg x g(-1), respectively, suggesting that the two mosses had a good capacity of Hg adsorption, and could be used as the bio-monitors of atmospheric Hg pollution.

Analysis of hydrogen content and distribution in hydrogen storage alloys using neutron radiography

International Nuclear Information System (INIS)

Sakaguchi, Hiroki; Hatakeyama, Keisuke; Satake, Yuichi; Esaka, Takao; Fujine, Shigenori; Yoneda, Kenji; Kanda, Keiji

2000-01-01

Small amounts of hydrogen in hydrogen storage alloys, such as Mg 2 Ni, were detected using neutron radiography (NRG). Hydrogen concentrations in a hydrogenated solid solution were determined by this technique. Furthermore, we were able to obtain NRG images for an initial stage of hydrogen absorption in the hydrogen storage alloys. NRG would be a new measurement method to clarify the behavior of hydrogen in hydrogen storage alloys. (author)

The Investigation of Heavy Metal Content (Cu, Cd, Pb in Sapu-Sapu Fish (Hypostomus plecostomus in Bengawan Solo River

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Ristiyana Eko Setyarini

2016-12-01

Full Text Available A study had been carried out to investigate heavy metal (Cu, Cd, Pb content in sapu-sapu fish (hypostomus plecostomus in Bengawan Solo river. The type of this research was observational research, with sapu-sapu fish inhabit Bengawan Solo River as the population. The samples were taken with purposive random sampling. Nine sapu-sapu fishes taken from 3 places, i.e.: Nguter Sukoharjo area, Premulung river outlet and Anyar river, 3 fishes from each palce, and then take examined the content of heavy metal. The result of study showed that the average content of Cu: 0.027 mg/100gr, Cd: 0.005 mg/100gr and Pb: 0.042 mg/100gr. Hence, sapu-sapu fish in Be3ngawan Solo had been contaminated with heavy metal (Cu, Cd, and Pb and should not be consumed.

HEAVY METALS (Ni, Cu, Zn AND Cd CONTENT IN SERUM OF RAT FED GREEN MUSSELS

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Muhammad Yudhistira Azis

2015-11-01

Full Text Available Green mussel (Perna viridis can playing role as bio-indicator or biomonitoring agent for heavy-metalcontaminations in the sea. In this research, the concentrations of four elements Ni, Cu, Zn and Cd in P. viridis and in the serum of rat which orally feed by P. viridis were determined by Atomic Absorption Spectrometry (AAS following dry acid digestion. Parameter analysis was evaluated by determining confidence limit for the obtained results. The result showed that there was a sequence of heavy-metal content in green mussels sample and laboratory rats serum, such as Ni < Cd < Cu < Zn. Keywords: heavy metals, green mussels, laboratory rats serum, AAS

Robust, Reliable Low Emission Gas Turbine Combustion of High Hydrogen Content Fuels

Energy Technology Data Exchange (ETDEWEB)

Wooldridge, Margaret Stacy [Univ. of Michigan, Ann Arbor, MI (United States); Im, Hong Geum [Univ. of Michigan, Ann Arbor, MI (United States)

2016-12-16

The effects of high hydrogen content fuels were studied using experimental, computational and theoretical approaches to understand the effects of mixture and state conditions on the ignition behavior of the fuels. A rapid compression facility (RCF) was used to measure the ignition delay time of hydrogen and carbon monoxide mixtures. The data were combined with results of previous studies to develop ignition regime criteria. Analytical theory and direct numerical simulation were used to validate and interpret the RCF ignition data. Based on the integrated information the ignition regime criteria were extended to non-dimensional metrics which enable application of the results to practical gas turbine combustion systems.

Effect of vermicomposting on calcium, sulphur and some heavy metal content of different biodegradable organic wastes under liming and microbial inoculation.

Science.gov (United States)

Das, Debabrata; Bhattacharyya, Pradip; Ghosh, B C; Banik, Pabitra

2012-01-01

A study was conducted to evaluate the changes in total calcium and sulphur and some heavy metal (Zn, Cu, and Pb) concentration of different organic wastes affected by liming and microorganism inoculation. Vermicomposting was an effective technology for disposal of organic substrates like municipal solid wastes (MSW), possessing comparatively higher concentration of heavy metals. The addition of lime in initial organic substrates significantly (P ≤ 0.05) increased total calcium and total sulphur content of vermicomposts. Inoculation of microorganisms significantly (P ≤ 0.05) reduced the heavy metal content of final products as compared to control. Fungal strains were comparatively more effective in detoxification of heavy metals than B. polymyxa.

Effect of high hydrogen content on metallurgical and mechanical properties of zirconium alloy claddings after heat-treatment at high temperature

International Nuclear Information System (INIS)

Turque, Isabelle

2016-01-01

Under hypothetical loss-of-coolant accident conditions, fuel cladding tubes made of zirconium alloys can be exposed to steam at high temperature (HT, up 1200 C) before being cooled and then quenched in water. In some conditions, after burst occurrence the cladding can rapidly absorb a significant amount of hydrogen (secondary hydriding), up to 3000 wt.ppm locally, during steam exposition at HT. The study deals with the effect, poorly studied up to date, of high contents of hydrogen on the metallurgical and mechanical properties of two zirconium alloys, Zircaloy-4 and M5, during and after cooling from high temperatures, at which zirconium is in its β phase. A specific facility was developed to homogeneously charge in hydrogen up to ∼ 3000 wt.ppm cladding tube samples of several centimeters in length. Phase transformations, chemical element partitioning and hydrogen precipitation during cooling from the β temperature domain of zirconium were studied by using several techniques, for the materials containing up to ∼ 3000 wt.ppm of hydrogen in average: in-situ neutron diffraction upon cooling from 700 C, X-ray diffraction, μ-ERDA, EPMA and electron microscopy in particular. The results were compared to thermodynamic predictions. In order to study the effect of high hydrogen contents on the mechanical behavior of the (prior-)μ phase of zirconium, axial tensile tests were performed at various temperatures between 20 and 700 C upon cooling from the β temperature domain, on samples with mean hydrogen contents up to ∼ 3000 wt.ppm. The results show that metallurgical and mechanical properties of the (prior-)β phase of zirconium alloys strongly depend on temperature and hydrogen content. (author) [fr

Performance and emission comparison of a supercharged dual-fuel engine fueled by producer gases with varying hydrogen content

Energy Technology Data Exchange (ETDEWEB)

Mohon Roy, Murari [Rajshahi University of Engineering and Technology (JSPS Research Fellow, Okayama University), Tsushima-Naka 3, Okayama 700-8530 (Japan); Department of Mechanical Engineering, Okayama University, Tsushima-Naka 3, Okayama 700-8530 (Japan); Tomita, Eiji; Kawahara, Nobuyuki; Harada, Yuji [Department of Mechanical Engineering, Okayama University, Tsushima-Naka 3, Okayama 700-8530 (Japan); Sakane, Atsushi (Mitsui Engineering and Shipbuilding Co. Ltd., 6-4 Tsukiji 5-chome, Chuo-ku, Tokyo)

2009-09-15

This study investigated the effect of hydrogen content in producer gas on the performance and exhaust emissions of a supercharged producer gas-diesel dual-fuel engine. Two types of producer gases were used in this study, one with low hydrogen content (H{sub 2} = 13.7%) and the other with high hydrogen content (H{sub 2} = 20%). The engine was tested for use as a co-generation engine, so power output while maintaining a reasonable thermal efficiency was important. Experiments were carried out at a constant injection pressure and injection quantity for different fuel-air equivalence ratios and at various injection timings. The experimental strategy was to optimize the injection timing to maximize engine power at different fuel-air equivalence ratios without knocking and within the limit of the maximum cylinder pressure. Two-stage combustion was obtained; this is an indicator of maximum power output conditions and a precursor of knocking combustion. Better combustion, engine performance, and exhaust emissions (except NO{sub x}) were obtained with the high H{sub 2}-content producer gas than with the low H{sub 2}-content producer gas, especially under leaner conditions. Moreover, a broader window of fuel-air equivalence ratio was found with highest thermal efficiencies for the high H{sub 2}-content producer gas. (author)

Content of heavy metals and chemical composition of the hydraulic cement marketed in Costa Rica

International Nuclear Information System (INIS)

Venegas Padilla, Jimmy; Calderon Jimenez, Bryan; Sibaja Brenes, Jose Pablo; Salazar Delgado, Jorge; Rodriguez Castro, Ellen

2017-01-01

The concentration of heavy metals, specifically lead (Pb), chromium (Cr), and mercury (Hg), and also the chemical composition (CaO, SiO 2 , Al 2 O 3 , Fe 2 O 3 among others) were quantified of the hydraulic cement marketed in Costa Rica. The physical parameters of density and fineness confirmed the homogeneity of the samples to determinate accurately the content of the major components and heavy metals in the cements. The mineralogical constitution was determined by X-ray Fluorescence (XRF). Specifically, the cements showed a mass fraction in the range of (61.22 - 63.12) % of CaO, (18.10 - 26.14) % of SiO 2 , (3.70 - 6.05) % of Al 2 O 3 , (2.57 - 3.36) % Fe 2 O 3 and (0.60 - 4.09) % de MgO. Other components such as MgO, TiO 2 , K 2 O, P 2 O 5 , Na 2 O and Mn 2 O 3 were found on an average mass fraction lower than 1%. Moreover, using the ignition test results and assuming a complete decomposition of the limestone, it was possible to estimate (indirectly) the content of CaCO 3 and CaO given by the raw materials. The metal content of the heavy metals was determined using Flame Atomic Absorption Spectroscopy (FAAS), Electrothermal Atomic Absorption Spectroscopy (ETAAS), and Cold Vapor Atomic Absorption Spectroscopy (CVAAS). The analysis demonstrated that the Pb in cements is present in different concentrations ranging the (2.45 ± 0.72) mg kg -1 to the (8.95 ± 1.34) mg kg -1 . Chromium (Cr) was presented in higher concentrations of (10.69 ± 0.92) mg kg-1. The Hg concentration was below 0.141 ± 0.021 mg kg -1 . In general terms, the hydraulic cements marketed and used in Costa Rica have a suitable chemical composition compared with some cements marketed in Germany. The results of the content of heavy metals presented in this study provide significant information for future studies in the area of toxicology, ecotoxicology, standardization and national regulation. (author) [es

NUTRITIONAL VALUE AND HEAVY METALS CONTENTS OF THE DRIED SEA CUCUMBER Stichopus vastus FROM SALEMO ISLAND, INDONESIA

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Abdullah Rasyid

2018-01-01

Full Text Available The dried sea cucumber Stichopus vastus is one of the commercially species harvested in Indonesian waters. This study aims to highlight the nutritional value and heavy metals content of dried sea cucumber S. vastus. Proximate (moisture, ash, protein, fat and carbohydrate, mineral (sodium, calcium, potassium and iron and heavy metal (mercury, cadmium, arsenic and lead were determined by standard method of AOAC, while phosphorous was determined by spectrophotometric method. Chondroitin sulphate was determined by UPLC method, glucosamine sulphate and vitamin (A, B1, B2 and E by HPLC method. Results show that protein was the major component in proximate analysis of dried sea cucumber S. vastus in the present study. The protein content was 38.70%. Moisture, ash, fat and carbohydrate content were 19.46%, 34.04%, 0.38% and 7.42% respectively. All vitamins and heavy metals examined in this study were not detected. The sodium content was 8054.36 mg/100 g higher than other minerals. Calcium, potassium, phosphorus and iron content were 2449.9 mg/100 g, 159.77 mg/100 g, 5085.2 mg/100 g and 520.8 mg/100 g respectively. Glucosamine sulphate content was found to be 2.429 g/100 g, whereas chondroitin sulphate was found to be 1.115 g/100 g. It can therefore, be concluded that the dried sea cucumber S. vastus from Salemo Island is safe for human consumption and hence can be used as a source of food supplement in the future. Keywords: food supplement, Salemo island, Stichopus vastus

Contents of heavy metals in urban parks and university campuses

Science.gov (United States)

Zhang, Yong; Chen, Qian

2018-01-01

Because the city park has become an important place for people's daily leisure, and the university campus is one of the most densely populated areas of the city, their environmental pollution is critical for the health and safety of the residents. In this paper, two kinds of evaluation methods were used to evaluate the content of Cu, Zn, As and Pb in soils of city parks and university campus in Xiangtan. The results showed that only Juhuatang Park was a non-polluted area, and the other 7 sampling sites were lightly polluted; Analysis shows the heavy metal contents of soil in city parks are closely related to vehicle emissions, agriculture and irrigation, combustion of household waste, living area and commercial shops, the use of fossil fuels, industrial waste gas and waste residue and other human activities.

THE STUDY OF HEAVY METALS CONTENT IN THE CATCHMENT AREA OF THE BIEBRZA RIVER AND THREE TRIBUTARIES

Directory of Open Access Journals (Sweden)

Zuzanna Kazimierowicz

2014-11-01

Full Text Available Sediment samples were taken in 11 measuring points of the Biebrza River and determined the contents of six metals (Cu, Cr, Co, Ni, Cd and Zn. Arithmetic mean, median and standard deviation were calculated. The sources of heavy metals in bottom sediments are: pollutants of fieldsand meadows (admixtures of plant protection products and fertilizers, discharges of domestic sewage and municipal from local wastewater treatment plants, wastewater di-scharges from rural buildings and pollutions of anthropogenic origin. Research of pollution of bottom sediments with heavy metals are needed tool for monitoring the aquatic environ-ment. Continuous monitoring metal content of the sediments will counteract the effects of the threat of biological life in the water reservoir, which may occur in the case of notorious exceeded permissible content of harmful substances.

Changes in fatty acid content and composition between wild type and CsHMA3 overexpressing Camelina sativa under heavy-metal stress.

Science.gov (United States)

Park, Won; Feng, Yufeng; Kim, Hyojin; Suh, Mi Chung; Ahn, Sung-Ju

2015-09-01

Under heavy-metal stress, CsHMA3 overexpressing transgenic Camelina plants displayed not only a better quality, but also a higher quantity of unsaturated fatty acids in their seeds compared with wild type. Camelina sativa L. belongs to the Brassicaceae family and is frequently used as a natural vegetable oil source, as its seeds contain a high content of fatty acids. In this study, we observed that, when subjected to heavy metals (Cd, Co, Zn and Pb), the seeds of CsHMA3 (Heavy-Metal P1B-ATPase 3) transgenic lines retained their original golden yellow color and smooth outline, unlike wild-type seeds. Furthermore, we investigated the fatty acids content and composition of wild type and CsHMA3 transgenic lines after heavy metal treatments compared to the control. The results showed higher total fatty acid amounts in seeds of CsHMA3 transgenic lines compared with those in wild-type seeds under heavy-metal stresses. In addition, the compositions of unsaturated fatty acids-especially 18:1 (oleic acid), 18:2 (linoleic acid; only in case of Co treatment), 18:3 (linolenic acid) and 20:1 (eicosenoic acid)-in CsHMA3 overexpressing transgenic lines treated with heavy metals were higher than those of wild-type seeds under the same conditions. Furthermore, reactive oxygen species (ROS) contents in wild-type leaves and roots when treated with heavy metal were higher than in CsHMA3 overexpressing transgenic lines. These results indicate that overexpression of CsHMA3 affects fatty acid composition and content-factors that are responsible for the fuel properties of biodiesel-and can alleviate ROS accumulation caused by heavy-metal stresses in Camelina. Due to these factors, we propose that CsHMA3 transgenic Camelina can be used for phytoremediation of metal-contaminated soil as well as for oil production.

Heavy metal content (Cd, Ni, Cr and Pb) in soil amendment with a low polluted biosolid

Science.gov (United States)

Gomez Lucas, Ignacio; Lag Brotons, Alfonso; Navarro-Pedreño, Jose; Belén Almendro-Candel, Maria; Jordán, Manuel M.; Bech, Jaume; Roca, Nuria

2016-04-01

The progressively higher water quality standards in Europe has led to the generation of large quantities of sewage sludge derived from wastewater treatment (Fytili and Zabaniotou 2008). Composting is an effective method to minimize these risks, as pathogens are biodegraded and heavy metals are stabilized as a result of organic matter transformations (Barker and Bryson 2002; Noble and Roberts 2004). Most of the studies about sewage sludge pollution are centred in medium and high polluted wastes. However, the aim of this study was to assess the effects on soil heavy metal content of a low polluted sewage sludge compost in order to identify an optimal application rate based in heavy metal concentration under a period of cultivation of a Mediterranean horticultural plant (Cynara carducnculus). The experiment was done between January to June: rainfall was 71 mm, the volume of water supplied every week was 10.5 mm, mean air temperatures was 14.2, 20.4 (maximum), and 9.2◦C (minimum). The soil was a clay-loam anthrosol (WRB 2006). The experimental plot (60 m2) was divided into five subplots with five treatments corresponding to 0, 2, 4, 6, and 8 kg compost/m2. Three top-soil (first 20 cm) samples from each treatment were taken (January, April and June) and these parameters were analysed: pH, electrical conductivity, organic matter and total content of heavy metals (microwave acid digestion followed by AAS-spectrometry determination). The results show that sewage sludge compost treatments increase the organic matter content and salinity (electrical conductivity of the soils) and diminish the pH. Cd and Ni total content in top-soil was affected and both slightly reduce their concentration. Pb and Cr show minor changes. In general, the application of this low polluted compost may affect the mobility of Cd and Ni due to the pH modification and the water added by irrigation along time but Pb and Cr remain their content in the top-soil. References Barker, A.V., and G.M. Bryson

Wide-scale utilization of MSWI fly ashes in cement production and its impact on average heavy metal contents in cements: The case of Austria.

Science.gov (United States)

Lederer, Jakob; Trinkel, Verena; Fellner, Johann

2017-02-01

A number of studies present the utilization of fly ashes from municipal solid waste incineration (MSWI) in cement production as a recycling alternative to landfilling. While there is a lot of research on the impact of MSWI fly ashes utilization in cement production on the quality of concrete or the leaching of heavy metals, only a few studies have determined the resulting heavy metal content in cements caused by this MSWI fly ashes utilization. Making use of the case of Austria, this study (1) determines the total content of selected heavy metals in cements currently produced in the country, (2) designs a scenario and calculates the resulting heavy metal contents in cements assuming that all MSWI fly ashes from Austrian grate incinerators were used as secondary raw materials for Portland cement clinker production and (3) evaluates the legal recyclability of demolished concretes produced from MSWI fly ash amended cements based on their total heavy metal contents. To do so, data from literature and statistics are combined in a material flow analysis model to calculate the average total contents of heavy metals in cements and in the resulting concretes according to the above scenario. The resulting heavy metal contents are then compared (i) to their respective limit values for cements as defined in a new technical guideline in Austria (BMLFUW, 2016), and (ii) to their respective limit values for recycling materials from demolished concrete. Results show that MSWI fly ashes utilization increases the raw material input in cement production by only +0.9%, but the total contents of Cd by +310%, and Hg, Pb, and Zn by +70% to +170%. However these and other heavy metal contents are still below their respective limit values for Austrian cements. The same legal conformity counts for recycling material derived from concretes produced from the MSWI fly ash cements. However, if the MSWI fly ash ratio in all raw materials used for cement production were increased from 0.9% to 22

Analysis of total hydrogen content in palm oil and palm kernel oil ...

African Journals Online (AJOL)

A fast and non-destructive technique based on thermal neutron moderation has been used for determining the total hydrogen content in two types of red palm oil (dzomi and amidze) and palm kernel oil produced by traditio-nal methods in Ghana. An equipment consisting of an 241Am-Be neutron source and 3He neutron ...

Determination of the hydrogen content of oil samples from Nigeria using an Am-Be neutron source

International Nuclear Information System (INIS)

Jonah, S.A.; Elegba, S.B.; Zakari, I.I.

1998-01-01

A 5 Ci Am-Be neutron source-based facility, which utilises the principles of thermal neutron reflection technique in combination with foil activation method, has been used to determine the total hydrogen content of commercial oil samples from Nigeria. With an established detection limit of 0.25 H w% for oil matrix of volume 600-ml, the total hydrogen contents of the samples were found to be in the range of 11.11-14.22 H w%. The facility is economical and suitable for the determination of moisture in solid samples. A brief description of the ongoing projects and future plans concerning the CRP are enumerated. (author)

The production of He-3 and heavy ion enrichment in He-3-rich flares by electromagnetic hydrogen cyclotron waves

Science.gov (United States)

Temerin, M.; Roth, I.

1992-01-01

A new model is presented for the production of He-3 and heavy ion enrichments in He-3-rich flares using a direct single-stage mechanism. In analogy with the production of electromagnetic hydrogen cyclotron waves in earth's aurora by electron beams, it is suggested that such waves should exist in the electron acceleration region of impulsive solar flares. Both analytic and test-particle models of the effect of such waves in a nonuniform magnetic field show that these waves can selectively accelerate He-3 and heavy ions to MeV energies in a single-stage process, in contrast to other models which require a two-stage mechanism.

In situ upgrading of heavy oil under steam injection with tetralin and catalyst

Energy Technology Data Exchange (ETDEWEB)

Mohammad, A.A. [Texas A and M Univ., College Station, TX (United States); Mamora, D.D. [Society of Petroleum Engineers, Richardson, TX (United States)]|[Texas A and M Univ., College Station, TX (United States)

2008-10-15

Steam injection has become the most successful thermal recovery method for heavy oil production. Heavy oil refineries use upgrading processes to improve oil quality. They generally involve the use of catalysts that are used to remove heavy metals, sulfur and nitrogen, or used in hydro-treating and hydro-cracking. In-situ upgrading is thought to have advantages over conventional surface upgrading technology. Experiments were performed to verify the feasibility of in-situ upgrading of heavy crude oil. A hydrogen donor called tetralin was used along with an organometallic catalyst, at steam injection temperatures and pressures normally encountered in the field. Crude oil from the Jobo Oil Field, located in Venezuela was used. The paper described the experimental methodology with reference to the injection cell; fluid injection system; fluid production system; data measurement and recording system; and experimental procedure. It also discussed the extent of upgrading by comparing the properties of the original and produced oil. Oil properties that were measured and compared included hydrogen-to-carbon ratio; heavy metal content; viscosity; and API gravity. The paper also presented a comparison of oil recovery and fluid production between all cases. It was concluded that in the field, the reaction time was significantly longer than encountered in the experiments and may lead to further upgrading, assuming the catalyst could be dispersed in the formation. 10 refs., 1 tab., 9 figs.

Red cabbage yield, heavy metal content, water use and soil chemical characteristics under wastewater irrigation.

Science.gov (United States)

Tunc, Talip; Sahin, Ustun

2016-04-01

The objective of this 2-year field study was to evaluate the effects of drip irrigation with urban wastewaters reclaimed using primary (filtration) and secondary (filtration and aeration) processes on red cabbage growth and fresh yield, heavy metal content, water use and efficiency and soil chemical properties. Filtered wastewater (WW1), filtered and aerated wastewater (WW2), freshwater and filtered wastewater mix (1:1 by volume) (WW3) and freshwater (FW) were investigated as irrigation water treatments. Crop evapotranspiration decreased significantly, while water use efficiency increased under wastewater treatments compared to FW. WW1 treatment had the lowest value (474.2 mm), while FW treatments had the highest value (556.7 mm). The highest water use efficiency was found in the WW1 treatment as 8.41 kg m(-3), and there was a twofold increase with regard to the FW. Wastewater irrigation increased soil fertility and therefore red cabbage yield. WW2 treatment produced the highest total fresh yield (40.02 Mg ha(-1)). However, wastewater irrigation increased the heavy metal content in crops and soil. Cd content in red cabbage heads was above the safe limit, and WW1 treatment had the highest value (0.168 mg kg(-1)). WW3 treatment among wastewater treatments is less risky in terms of soil and crop heavy metal pollution and faecal coliform contamination. Therefore, WW3 wastewater irrigation for red cabbage could be recommended for higher yield and water efficiency with regard to freshwater irrigation.

Mineral and heavy metal contents of the outer and inner tissues of commonly used fruits.

Science.gov (United States)

Özcan, Mehmet Musa; Harmankaya, Mustafa; Gezgin, Sait

2012-01-01

The rate of heavy metal pollution in some minor fruit samples growing at roadsides in Turkey were determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The mineral contents of samples were found to be different depending on the several parts Citrus fruits. The highest minor and heavy metal levels for Citrus fruits were determined between 17.24 and 45.30 mg/kg boron, 2.08 and 15.05 mg/kg copper, 1.01 and 16.00 mg/kg iron and 2.35 and 9.87 mg/kg zinc. Boron content ranged from 16.54 mg/kg (Deveci pear inner pulp) to 89.89 mg/kg (Arjantin apple outer skin). The level of Fe ranged from 1.49 mg/kg (quince pulp) to 25.05 mg/kg (Ankara pear pulp). Cu content of fruits ranged between 2.52 mg/kg (Fuji apple skin) and 25.93 mg/kg quince skin). Zn content was found between 0.46 mg/kg (Golden apple pulp) and 14.34 mg/kg (quince skin). P contents ranged from 651 mg/kg (Golden apple pulp) to 1269 mg/kg (quince skin). Na was found between 500 mg/kg (Fuji apple skin) and 907 mg/kg (Arjantin apple skin).

Determination of contents of carbonate and hydrogen carbonate in solutions for alkaline leading of uranium ores

International Nuclear Information System (INIS)

Radil, V.

1988-01-01

The new analytical method is based on the determination of the molar ratio carbonate - hydrogen carbonate using the measured concentration of hydrogen ions, the determination of the dissociation constant of carbonic acid for different values of ionic strength. The concentration of hydrogen ions was measured with a Metrohm 632 pH meter with the use of a combined glass electrode. The content of total carbonate carbon was determined coulometrically and the uranium content was determined by extraction with tributyl phosphate and by spectrometry of the complex of uranyl ions with Arsenazo III. Model solutions were used for the experiments which contained a high concentration of sulfate ions, thiosulfate ions, uranium and various proportions of carbonate and hydrogen carbonate. The composition of the individual samples of the extraction solutions are tabulated. The calibration was made of the glass combined electrode at different ionic strength, the values determined of dissociation constants of carbonic acid for different ionic strength. The mathematical procedure is described for the calculation of molar concentrations of carbonate and hudrogen carbonate and the results are presented of the analysis of model solutions. (E.S.). 5 tabs., 1 fig., 5 refs

Heavy metals content in degraded agricultural soils of a mountain region related to soil properties

Science.gov (United States)

Navarro-Pedreño, José; Belén Almendro-Candel, María; Gómez, Ignacio; Jordán, Manuel M.; Bech, Jaume; Zorpas, Antonis

2017-04-01

Agriculture has been practiced for long time in Mediterranean regions. Intensive agriculture and irrigation have developed mainly in the valleys and coastal areas. In the mountainous areas, dry farming has been practiced for centuries. Soils have been fertilized using mainly organic amendments. Plants extracted nutrients and other elements like heavy metals presented in soils and agricultural practices modified soil properties that could favor the presence of heavy metals. In this work, it has been checked the content of heavy metals in 100 agricultural soils samples of the NorthWest area of the province of Alicante (Spain) which has been long cultivated with cereals and olive trees, and now soils are abandoned and degraded because of the low agricultural yields. European policy has the aim to improve the sustainable agriculture and recover landscapes of mountain regions. So that, it is important to check the state of the soils (Marques et al. 2007). Soils samples (arable layer) were analyzed determining: pH (1:5, w/v, water extract), equivalent calcium carbonate content, organic matter by Walkley-Black method (Nelson and Sommers 1996), micronutrients (Cu, Fe, Mn, Zn) extracted with DTPA (Lindsay and Norvell, 1978) and measured by atomic absorption spectrometry, and total content of metals (Cd, Cr, Ni, Pb) measured in soil samples after microwave acid digestion (Moral et al. 1996), quantifying the content of metals by ICP analysis. The correlation between soil properties and metals. The results indicated that pH and carbonates are the most important properties of these soils correlated with the metals (both micronutrients and heavy metals). The available micronutrients (all of them) are close correlated with the pH and carbonates in soils. Moreover, heavy metals like Pb and Ni are related to available Mn and Zn. Keywords: pH, carbonates, heavy metals, abandoned soils. References: Lindsay,W.L., andW.A. Norvell. 1978. "Development of a DTPA Soil Test for Zinc, Iron

Radiostratigraphy and heavy mineral content of the Weches Formation (Eocene), Nacogdoches County, Texas

International Nuclear Information System (INIS)

Jobe, K.; Ledger, E.B.; Sharp, P.; Crocker, M.C.

1993-01-01

The Weches Formation of eastern Texas is a mudstone containing green sand-size clay aggregates. A vertical sequence of 43 samples was analyzed along an excavated cliff to determine radionuclide content. Samples average 5 ppm uranium and range from 2 to about 7 ppm. Thorium averages 20 ppm and ranges from 13 to almost 36 ppm. the gamma-ray spectrometer employed exhibits a certainty of about ±10% (one standard deviation) at the levels measured. Heavy mineral studies of mudstones are few, so one sample of the Weches mudstone was selected for heavy mineral separation and point counting of grain mounts. A total of 2606 grains were counted giving mineral percentages of zircon (28.8%), garnet (17.9%), tourmaline (10.5%), titanite (8.7%), apatite (7.6%), staurolite (6.4%), green hornblende (5.2%), epidote (5.1%), sillimanite (2.8%), monatite (2.2%), kyanite (1.9%), basaltic hornblende (1.5%), and biotite (1.3%). In addition, actinolite, spinel, rutile, and collophane were observed but not counted. Previous studies found a similar heavy mineral suite in the underlying Queen City Formation, but in different proportions. Differences in heavy mineral percentages probably reflect different water-flow regimes at the time of deposition. Heavy minerals in the Weches and Queen City formations are from the same general source area Measured radionuclide ratios are similar to granitic ratios and suggest that detrital heavy minerals, particularly zircon and monazite, are the main site of uranium and thorium and their decay products in the Weches Formation

Analysis of caffeine and heavy metal contents in branded and unbranded tea available in Pakistan

International Nuclear Information System (INIS)

Khan, S.R.; Inayat, A.; Chowdhry, M.N.; Waheed, A.

2010-01-01

In the investigation of caffeine and heavy metal contents in four branded and six unbranded tea samples collected from local markets of Lahore, Faisalabad and Peshawar, the amount of caffeine and heavy metals in all the branded tea samples were in agreement with the international standards. In unbranded tea samples, though the amount of caffeine was within standard limits but two of the samples collected from Peshawar had high concentrations of lead being, 13.69 and 15.78 mg/kg, consumption of which can lead to serious problems. (author)

Fracture resistance of the VNC-2USh steel with different content of diffusion-mobile hydrogen at low temperature

International Nuclear Information System (INIS)

Yablonskij, I.S.; Sankho, K.

1979-01-01

Presented are the investigation results for the diffusible hydrogen (DH) content effect on cracking resistance and mechanical properties of the VNC-2USh steel in the temperature range from -75-100 deg C. In this range σsub(B), σsub(0.2) and σ are not practically sensitive to the DH content change from 0.27 to 3 cm 3 /100g. At room temperature the increase of DH content in the above concentration range results in 45 % decrease of cracking resistance under static loading. At -75 deg C the cracking resistance does not depend on DH content. Within the temperature range from -40-75 deg C placed is a temperature boundary, separating the regions of predominant effects of hydrogen and low temperature embrittlement on repture strength of the VNC-2 steel at moderated rates of deformation

Production of jet fuel using heavy crude oil; Producao de combustiveis de aviacao a partir de petroleos pesados

Energy Technology Data Exchange (ETDEWEB)

Om, Neyda [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica; Cavado, Alberto; Reyes, Yordanka [Centro de Pesquisas do Petroleo, Cidade de Havana (Cuba); Dominguez, Zulema [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE)

2004-07-01

The production of heavy crude oils increased in the last years in the world. Crude oils with high density, viscosity, acidity and sulfur, nitrogen, metals and asphaltenes contents, by the others hand, low stability and low product quality. The challenger of many refiners is find solutions to refine the heavy crude oils, and produce fuels with certify quality, such as Jet Fuel. The principal aviation technique on the world work with gas turbines engines feted for jet fuel (JET A1). The quality specifications of this fuel are establish by International Norms: ASTM-1655, DEF STAN 91-91-3 (DERD 2494) and joint Fuelling System Check List. The world technologies to obtain jet fuel from mixtures of heavy crude oil with middle crude oils are: Atmospheric distillation, with a posterior hydrogenation and finally the additivation. Studies carried out have demonstrates that the Cubans heavy crude oils is characterized for having API less than 10, raised viscosity, high sulfur content (>6%) and asphaltenes content (more than 15%). These properties provide to its derivatives of low quality. This paper define the characteristic of Cuban heavy crude oil, the technology and operational conditions to produce jet fuel (Jet A1) and the quality of fuel produced. (author)

Heavy Metal Content in Selected Flavouring Plants and in Ultra-Basic Soil of Felda Rokan Barat, Negeri Sembilan, Malaysia

International Nuclear Information System (INIS)

Sahibin Abdul Rahim; Wan Mohd Razi Idris; Zulfahmi Ali Rahman; Tukimat Lihan; Ramlan Omar; Yan, L.K.

2012-01-01

A study was carried out at an ultra basic soil area in Felda Rokan Barat (FRB), Negeri Sembilan. Twenty plants of samples namely chili, turmeric, pandan and lemon grass were collected randomly for the determination of heavy metal contents such as Fe, Cd, Co, Cu, Mn, Ni, Pb, Cr and Zn. Heavy metals in plants were extracted by wet digestion method, whereas available and resistant heavy metals in soil were extracted by sequential extraction. Total heavy metals content in the soil were obtained by summation of resistant and available heavy metals. Heavy metals content in soil and plant extract were determined by using the Flame Atomic Absorption Spectrophotometer (FAAS). Results showed that Fe was the dominant composition in soil in the study area while Cd concentration was very low with values of < 10 mg/ kg. The range of heavy metals concentration in soils were Fe (2618.4 to 4248 mg/ kg), Mn (240.9 to 741.9 mg/ kg), Zn (81.9 to 324.8 mg/ kg), Cr (46.8 to 438.7 mg/ kg), Cu (15.7 to 81.7 mg/ kg), Pb (14.9 to 116.8 mg/ kg), Ni (10.1 to 545.6 mg/ kg), Cd (5.6 to 10.6 mg/ kg) dan Co (0.8 to 126.1 mg/ kg). Available Fe recorded the highest value in all of the plant substrates followed by Mn, Zn, Pb, Ni, Cr, Cu, Co and Cd. Based on percentage of availability Mn, Pb and Zn are considered most available by plant with availability percentage of 8 to 10 %. Concentration of Fe, Mn, Ni and Zn were high in all parts of plants compared to the other metals. The value of biological absorption coefficient (BAC) in chili, turmeric, pandan and lemon grass were in the range of 0.02-0.36, 0.03-0.41, 0.03-0.63 and 0.03-1.15, respectively. It can be concluded that the uptake of heavy metals by plants were normal even though the heavy metals concentration in the ultra basic soil was high. (author)

Safety and environmental aspects of heavy water production (Paper No. 4.1)

International Nuclear Information System (INIS)

Singh, Mohinder

1992-01-01

Different processes are utilised for heavy water production in the heavy water plants in India. H 2 S is used in large quantities as carrier gas to extract deuterium content from water. The safe handling of such large quantities of H 2 S gas poses a major problem because of its toxicity, high corrosive nature and high flammability. Handling of large quantities of synthesis gas in ammonia based plants at high pressure and temperature poses a major problem because it is a mixture of hydrogen and nitrogen. H 2 is highly inflammable and explosive when mixed with air or oxygen. All the safety aspects considered while designing, fabricating, constructing and operating the plants are described. (author). 5 tabs

Process for the preparation of ammonia and heavy water

International Nuclear Information System (INIS)

Mandrin, C.

1980-01-01

A process for the production of ammonia and heavy water comprises the steps of enriching a flow of water with deuterium in a monothermal isotropic process; supplying a first portion of the deuterium-enriched water to a heavy water preparation plant to produce heavy water and hydrogen; storing a second portion of the deuterium-enriched water substantially without interruption during the colder half of a year; electrolytically dissociating the stored deuterium-enriched water substantially without interruption during the wamer half of a year to form hydrogen; storing a portion of the electrolytically-produced hydrogen during said warmer half of a year while supplying the remainder to a synthesis circuit of a synthesizing plant and subsequently supplying the stored hydrogen to the synthesis circuit during said colder half of a year; removing some of the synthesis gas mixture from the synthesis circuit of the synthesizing plant; burning the removed synthesis gas mixture with air to produce a mixture consisting mainly of water and nitrogen; thereafter condensing and separating the water from the mixture of water and nitrogen; supplying the nitrogen of the mixture of water and nitrogen, the hydrogen from the heavy water preparation plant and the electrolytically-produced hydrogen to the synthesis circuit of the synthesizing plant to produce ammonia; and collecting deuterium-depleted water resulting from said burning step and feeding the collected deuterium-depleted water into the monothermal process

Effects of nitrogen and hydrogen in argon shielding gas on bead profile, delta-ferrite and nitrogen contents of the pulsed GTAW welds of AISI 316L stainless steel

Energy Technology Data Exchange (ETDEWEB)

Viyanit, Ekkarut [National Metal and Materials Technology Center (MTEC), Pathaumthani (Thailand). Failure Analysis and Surface Technology Lab; Hartung, Fritz; Lothongkum, Gobboon [Chulalongkom University, Bangkok (Thailand). Dept. of Metallurgical Engineering,; Phakpeetinan, Panyasak; Chianpairot, Amnuysak

2016-08-01

The general effects of 1, 2, 3 and 4 vol.-% nitrogen and 1, 5 and 10 vol.-% hydrogen in argon shielding gas on weld bead profile (depth/width ratio: D/W) and the δ-ferrite content of AISI 316L pulsed GTAW welds were investigated. The limits for imperfections for the quality levels of welds were based on ISO 5817 B. The plates with a thickness of 6 mm were welded at the flat position and the bead on plate. Increasing hydrogen content in argon shielding gas increases the D/W ratio. Excessive hydrogen addition to argon shielding gas will result in incompletely filled groove and excessive penetration of weld. Increasing welding speed decreases the weld-metal volume and the D/W ratios. Nitrogen addition to argon shielding gas has no effect on the D/W ratio. The addition of a mixture of nitrogen and hydrogen to argon shielding gas on the D/W ratio does not show any interaction between them. An effect on the D/W ratio can be exclusively observed as a function of hydrogen content. Increasing hydrogen content in argon shielding gas increases the δ-ferrite content of weld metal. Increasing either nitrogen content in shielding gas or welding speed decreases the δ-ferrite content of weld metal. The nitrogen addition increases the weld metal nitrogen content, however, the hydrogen addition leads to a decrease of weld metal nitrogen content.

Hydrogen safety

International Nuclear Information System (INIS)

Frazier, W.R.

1991-01-01

The NASA experience with hydrogen began in the 1950s when the National Advisory Committee on Aeronautics (NACA) research on rocket fuels was inherited by the newly formed National Aeronautics and Space Administration (NASA). Initial emphasis on the use of hydrogen as a fuel for high-altitude probes, satellites, and aircraft limited the available data on hydrogen hazards to small quantities of hydrogen. NASA began to use hydrogen as the principal liquid propellant for launch vehicles and quickly determined the need for hydrogen safety documentation to support design and operational requirements. The resulting NASA approach to hydrogen safety requires a joint effort by design and safety engineering to address hydrogen hazards and develop procedures for safe operation of equipment and facilities. NASA also determined the need for rigorous training and certification programs for personnel involved with hydrogen use. NASA's current use of hydrogen is mainly for large heavy-lift vehicle propulsion, which necessitates storage of large quantities for fueling space shots and for testing. Future use will involve new applications such as thermal imaging

Heavy metals content in acid mine drainage at abandoned and active mining area

Science.gov (United States)

Hatar, Hazirah; Rahim, Sahibin Abd; Razi, Wan Mohd; Sahrani, Fathul Karim

2013-11-01

This study was conducted at former Barite Mine, Tasik Chini and former iron mine Sungai Lembing in Pahang, and also active gold mine at Lubuk Mandi, Terengganu. This study was conducted to determine heavy metals content in acid mine drainage (AMD) at the study areas. Fourteen water sampling stations within the study area were chosen for this purpose. In situ water characteristic determinations were carried out for pH, electrical conductivity (EC), redox potential (ORP) and total dissolved solid (TDS) using multi parameter YSI 556. Water samples were collected and analysed in the laboratory for sulfate, total acidity and heavy metals which follow the standard methods of APHA (1999) and HACH (2003). Heavy metals in the water samples were determined directly using Inductive Coupled Plasma Mass Spectrometry (ICP-MS). Data obtained showed a highly acidic mean of pH values with pH ranged from 2.6 ± 0.3 to 3.2 ± 0.2. Mean of electrical conductivity ranged from 0.57 ± 0.25 to 1.01 ± 0.70 mS/cm. Redox potential mean ranged from 487.40 ± 13.68 to 579.9 ± 80.46 mV. Mean of total dissolved solids (TDS) in AMD ranged from 306.50 ± 125.16 to 608.14 ± 411.64 mg/L. Mean of sulfate concentration in AMD ranged from 32.33 ± 1.41 to 207.08 ± 85.06 mg/L, whereas the mean of total acidity ranged from 69.17 ± 5.89 to 205.12 ± 170.83 mgCaCO3/L. Heavy metals content in AMD is dominated by Fe, Cu, Mn and Zn with mean concentrations range from 2.16 ± 1.61 to 36.31 ± 41.02 mg/L, 0.17 ± 0.13 to 11.06 ± 2.85 mg/L, 1.12 ± 0.65 to 7.17 ± 6.05 mg/L and 0.62 ± 0.21 to 6.56 ± 4.11 mg/L, respectively. Mean concentrations of Ni, Co, As, Cd and Pb were less than 0.21, 0.51, 0.24, 0.05 and 0.45 mg/L, respectively. Significant correlation occurred between Fe and Mn, Cu, Zn, Co and Cd. Water pH correlated negatively with all the heavy metals, whereas total acidity, sulfate, total dissolved solid, and redox potential correlated positively. The concentration of heavy metals in the AMD

Heavy Metal Contents and Physical Parameters of Aegiceras corniculatum, Brassica juncea, and Litchi chinensis Honeys from Bangladesh

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Nandita Sarker

2015-01-01

Full Text Available The present study was undertaken to determine the heavy metal levels and the physicochemical parameters (pH, electrical conductivity (EC, and ash, moisture, and total sugar content of honeys from Bangladesh. Three different floral honeys were investigated, namely, khalsi (Aegiceras corniculatum, mustard (Brassica juncea, and litchi (Litchi chinensis honeys. The heavy metals in the honeys were determined by using a High Temperature Dry Oxidation method followed by Atomic Absorption Spectroscopy. The mean pH, EC, and ash, moisture, and total sugar contents of the investigated honeys were 3.6, 0.51 mS/cm, 0.18%, 18.83%, and 68.30%, respectively. Iron was the most abundant among all the investigated heavy metals, ranging from 13.51 to 15.44 mg/kg. The mean concentrations of Mn and Zn in the investigated honeys were 0.28 mg/kg and 2.99 mg/kg, respectively. Cd was below the detection limit, and lead was found in some honey samples, but their contents were below the recommended Maximum Acceptable Level. Cr was also found in all of the samples, but its concentration was within the limit. The physicochemical analysis of the honey samples yielded levels within the limits set by the international honey legislation, indicating that the honey samples were of good quality and had acceptable values for maturity, purity, and freshness.

The hydrogen and oxygen content of self-supporting carbon foils prepared by dc glow discharge in ethylene

International Nuclear Information System (INIS)

Tait, N.R.S.; Tolfree, D.W.L.; John, P.; Odeh, I.M.; Thomas, M.J.K.; Tricker, M.J.; Wilson, J.J.B.; England, J.B.A.; Newton, D.

1980-01-01

The hydrogen and oxygen content of self-supporting carbon films produced by dc glow discharge have been determined using a precise method involving the elastic scattering of 25 MeV α-particles. The number of carbon-hydrogen bonds has been determined for similar samples using infrared spectroscopy. The results are compared with those for samples made by the carbon arc process. Assuming that the glow discharge carbon contains graphitic regions surrounded by amorphous tetrahedrally bonded material to which hydrogen can attach, a simple estimate is made of the relative numbers of carbon atoms in the two forms. (orig.)

Content of Heavy Metal in the Dust of Leisure Squares and Its Health Risk Assessment-A Case Study of Yanta District in Xi'an.

Science.gov (United States)

Shao, Tianjie; Pan, Lihuan; Chen, Zhiqing; Wang, Ruiyuan; Li, Wenjing; Qin, Qing; He, Yuran

2018-02-25

Taking Yanta District in Xi'an as the research object, the present study measures the contents of Cadmium (Cd), Lead (Pb), Copper (Cu), Nickel (Ni), and Chromium (Cr) in dust samples and further assesses the health risk of heavy metals intake through dust based on the assessment method of human exposure risk proposed by U.S. EPA, with an aim to investigate the content of heavy metal in the dust of leisure squares and its exposure risk. As the results indicate, the average contents of five heavy metals are obviously higher than the soil background value in Shaanxi Province. Therefore, Cd, Ni, Cu, Pb, and Cr are obviously enriched in urban surface dust in Shaanxi Province, due to the influence of human activities. In addition, it can also be found that the non-carcinogen exposure risk in children is significantly higher than that in adults with the risk values of these five heavy metals all one order of magnitude higher than those of adults. Irrespective of whether addressing the results for children or adults, the non-carcinogen exposure doses of five heavy metals are sorted as Cr > Pb > Cu > Ni > Cd. According to the present situation, for a child, the total non-carcinogenic risk values of five heavy metals have exceeded the safety limit in 11 of the 20 leisure squares in Yanta District of Xi'an. That means the leisure squares are no longer suitable for physical and recreational activities. For the five heavy metals, the average non-carcinogenic risk value of Cr is largest, and causes the largest threat to health in Yanta District, Xi'an. The carcinogenic exposure doses of the heavy metals Cr, Cd, and Ni are very low in respiratory pathways and there is no carcinogenic health risk. In general, the Cr content in dust in domestic cities is higher than that of foreign cities; however, the Pb content is much lower.

Content of Heavy Metal in the Dust of Leisure Squares and Its Health Risk Assessment—A Case Study of Yanta District in Xi’an

Directory of Open Access Journals (Sweden)

Tianjie Shao

2018-02-01

Full Text Available Taking Yanta District in Xi’an as the research object, the present study measures the contents of Cadmium (Cd, Lead (Pb, Copper (Cu, Nickel (Ni, and Chromium (Cr in dust samples and further assesses the health risk of heavy metals intake through dust based on the assessment method of human exposure risk proposed by U.S. EPA, with an aim to investigate the content of heavy metal in the dust of leisure squares and its exposure risk. As the results indicate, the average contents of five heavy metals are obviously higher than the soil background value in Shaanxi Province. Therefore, Cd, Ni, Cu, Pb, and Cr are obviously enriched in urban surface dust in Shaanxi Province, due to the influence of human activities. In addition, it can also be found that the non-carcinogen exposure risk in children is significantly higher than that in adults with the risk values of these five heavy metals all one order of magnitude higher than those of adults. Irrespective of whether addressing the results for children or adults, the non-carcinogen exposure doses of five heavy metals are sorted as Cr > Pb > Cu > Ni > Cd. According to the present situation, for a child, the total non-carcinogenic risk values of five heavy metals have exceeded the safety limit in 11 of the 20 leisure squares in Yanta District of Xi’an. That means the leisure squares are no longer suitable for physical and recreational activities. For the five heavy metals, the average non-carcinogenic risk value of Cr is largest, and causes the largest threat to health in Yanta District, Xi’an. The carcinogenic exposure doses of the heavy metals Cr, Cd, and Ni are very low in respiratory pathways and there is no carcinogenic health risk. In general, the Cr content in dust in domestic cities is higher than that of foreign cities; however, the Pb content is much lower.

Content of Heavy Metal in the Dust of Leisure Squares and Its Health Risk Assessment—A Case Study of Yanta District in Xi’an

Science.gov (United States)

Shao, Tianjie; Pan, Lihuan; Chen, Zhiqing; Wang, Ruiyuan; Li, Wenjing; Qin, Qing; He, Yuran

2018-01-01

Taking Yanta District in Xi’an as the research object, the present study measures the contents of Cadmium (Cd), Lead (Pb), Copper (Cu), Nickel (Ni), and Chromium (Cr) in dust samples and further assesses the health risk of heavy metals intake through dust based on the assessment method of human exposure risk proposed by U.S. EPA, with an aim to investigate the content of heavy metal in the dust of leisure squares and its exposure risk. As the results indicate, the average contents of five heavy metals are obviously higher than the soil background value in Shaanxi Province. Therefore, Cd, Ni, Cu, Pb, and Cr are obviously enriched in urban surface dust in Shaanxi Province, due to the influence of human activities. In addition, it can also be found that the non-carcinogen exposure risk in children is significantly higher than that in adults with the risk values of these five heavy metals all one order of magnitude higher than those of adults. Irrespective of whether addressing the results for children or adults, the non-carcinogen exposure doses of five heavy metals are sorted as Cr > Pb > Cu > Ni > Cd. According to the present situation, for a child, the total non-carcinogenic risk values of five heavy metals have exceeded the safety limit in 11 of the 20 leisure squares in Yanta District of Xi’an. That means the leisure squares are no longer suitable for physical and recreational activities. For the five heavy metals, the average non-carcinogenic risk value of Cr is largest, and causes the largest threat to health in Yanta District, Xi’an. The carcinogenic exposure doses of the heavy metals Cr, Cd, and Ni are very low in respiratory pathways and there is no carcinogenic health risk. In general, the Cr content in dust in domestic cities is higher than that of foreign cities; however, the Pb content is much lower. PMID:29495319

Effect of Harvesting Frequency, Variety and Leaf Maturity on Nutrient Composition, Hydrogen Cyanide Content and Cassava Foliage Yield

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Khuc Thi Hue

2012-12-01

Full Text Available The experiment studied the effect of harvesting frequencies and varieties on yield, chemical composition and hydrogen cyanide content in cassava foliage. Foliage from three cassava varieties, K94 (very bitter, K98-7 (medium bitter and a local (sweet, were harvested in three different cutting cycles, at 3, 6 and 9 months; 6 and 9 months and 9 months after planting, in a 2-yr experiment carried out in Hanoi, Vietnam. Increasing the harvesting frequency increased dry matter (DM and crude protein (CP production in cassava foliage. The K94 variety produced higher foliage yields than the other two varieties. Dry matter, neutral detergent fibre (NDF, acid detergent fibre (ADF and total tannin content increased with months to the first harvest, whereas CP content decreased. Hydrogen cyanide (HCN content was lower at the first harvest than at later harvests for all cutting cycles. At subsequent harvests the content of total tannins tended to decline, while HCN content increased (p<0.05. Chemical composition differed somewhat across varieties except for total tannins and ash. Dry matter, NDF, ADF and total tannins were higher in fully matured leaves, while CP and HCN were lower in developing leaves.

High-energy elastic recoil detection heavy ions for light element analysis

International Nuclear Information System (INIS)

Goppelt-Langer, P.; Yamamoto, S.; Takeshita, H.; Aoki, Y.; Naramoto, H.

1994-01-01

The detection of light and medium heavy elements in not homogeneous solids is a severe problem in ion beam analysis. Heavy elements can be detected by the well established Rutherford backscattering technique (RBS). In a homogeneous host material most impurities can be easily analyzed by secondary ion mass spectroscopy (SIMS). Some isotopes ( 3 He, 6 Li, 10 B) can be measured by nuclear reaction analysis (NRA) using thermal neutrons inducing (n, p) or (n, α) reactions. Others can be detected by energetic ion beams by nuclear reactions (e.g. 15 N( 1 H, αγ) 12 C for analysis of hydrogen). A high content of H, D or T can be also determined by elastic recoil detection using an energetic He beam. The latter technique has been developed to a universal method for detection of light and heavy elements in any target, using a high energetic heavy ion beam and a detector system, which is able to identify the recoils and delivers energy and position of the particles. (author)

Hydrogen storage performance of Ti-V-based BCC phase alloys with various Fe content

International Nuclear Information System (INIS)

Yu, X.B.; Feng, S.L.; Wu, Z.; Xia, B.J.; Xu, N.X.

2005-01-01

The effect of Fe content on hydrogen storage characteristics of Ti-10Cr-18Mn-(32-x)V-xFe (x = 0, 2, 3, 4, 5) alloys has been investigated at 353 K. The X-ray diffraction (XRD) patterns and scanning electron microscopy (SEM) images of the alloys present BCC and C14 two-phase structures for all of the Fe-containing alloys. With the increasing Fe content, the lattice parameters of the BCC phase decrease, which results in an increase of the hydrogen desorption plateau pressure of the alloys. Among the studied alloys, Ti-10Cr-18Mn-27V-5Fe alloy exhibits the smallest PCT plateau slope and a more suitable plateau pressure (0.1 MPa equ <1 MPa). The maximum and effective capacities of the alloy are 3.32 wt.% and 2.26 wt.%, respectively, which are higher than other reported Fe-containing BCC phase alloys. In addition, the V/Fe ratio in this alloy is close to that of (VFe) alloy, whose cost is much lower than that of pure V

Heavy water. A production alternative for Venezuela

International Nuclear Information System (INIS)

A survey of heavy water production methods is made. Main facts about isotopic and distillation methods, reforming and coupling to a Hydrogen distillation plant are presented. A feasibility study on heavy water production in Venezuela is suggested

Air-stable magnesium nanocomposites provide rapid and high-capacity hydrogen storage without using heavy-metal catalysts

Science.gov (United States)

Jeon, Ki-Joon; Moon, Hoi Ri; Ruminski, Anne M.; Jiang, Bin; Kisielowski, Christian; Bardhan, Rizia; Urban, Jeffrey J.

2011-04-01

Hydrogen is a promising alternative energy carrier that can potentially facilitate the transition from fossil fuels to sources of clean energy because of its prominent advantages such as high energy density (142 MJ kg-1 ref. 1), great variety of potential sources (for example water, biomass, organic matter), light weight, and low environmental impact (water is the sole combustion product). However, there remains a challenge to produce a material capable of simultaneously optimizing two conflicting criteria—absorbing hydrogen strongly enough to form a stable thermodynamic state, but weakly enough to release it on-demand with a small temperature rise. Many materials under development, including metal-organic frameworks, nanoporous polymers, and other carbon-based materials, physisorb only a small amount of hydrogen (typically 1-2 wt%) at room temperature. Metal hydrides were traditionally thought to be unsuitable materials because of their high bond formation enthalpies (for example MgH2 has a ΔHf˜75 kJ mol-1), thus requiring unacceptably high release temperatures resulting in low energy efficiency. However, recent theoretical calculations and metal-catalysed thin-film studies have shown that microstructuring of these materials can enhance the kinetics by decreasing diffusion path lengths for hydrogen and decreasing the required thickness of the poorly permeable hydride layer that forms during absorption. Here, we report the synthesis of an air-stable composite material that consists of metallic Mg nanocrystals (NCs) in a gas-barrier polymer matrix that enables both the storage of a high density of hydrogen (up to 6 wt% of Mg, 4 wt% for the composite) and rapid kinetics (loading in <30 min at 200 °C). Moreover, nanostructuring of the Mg provides rapid storage kinetics without using expensive heavy-metal catalysts.

Influence of the C content on the permeation of hydrogen in Fe alloys with low contents of C

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I. Peñalva

2016-12-01

The experimental permeation results were analyzed using a non-linear least square fitting. The final resulting values of the permeability were paired off in order to determine the effect of the C content: pure Fe versus FeC, FeP versus FePC and Fe10%Cr versus Fe10%CrC. According to the results, the influence of the metallurgical composition of C in Fe alloys on the permeability of hydrogen is discussed together with the synergistic effects caused by the presence of P and Cr.

Total Contents and Sequential Extraction of Heavy Metals in Soils Irrigated with Wastewater, Akaki, Ethiopia

Science.gov (United States)

Fitamo, Daniel; Itana, Fisseha; Olsson, Mats

2007-02-01

The Akaki River, laden with untreated wastes from domestic, industrial, and commercial sources, serves as a source of water for irrigating vegetable farms. The purpose of this study is to identify the impact of waste-water irrigation on the level of heavy metals and to predict their potential mobility and bioavailability. Zn and V had the highest, whereas Hg the lowest, concentrations observed in the soils. The average contents of As, Co, Cr, Cu, Ni, Zn, V, and Hg of both soils; and Pb and Se from Fluvisol surpassed the mean + 2 SD of the corresponding levels reported for their uncontaminated counterparts. Apparently, irrigation with waste water for the last few decades has contributed to the observed higher concentrations of the above elements in the study soils (Vertisol and Fluvisol) when compared to uncontaminated Vertisol and Fluvisol. On the other hand, Vertisol accommodated comparatively higher average levels of Cr, Cu, Ni, Zn, etc V, and Cd, whereas high contents of Pb and Se were observed in Fluvisol. Alternatively, comparable levels of Co and Hg were found in either soil. Except for Ni, Cr, and Cd in contaminated Vertisol, heavy metals in the soils were not significantly affected by the depth (0-20 and 30-50 cm). When the same element from the two soils was compared, the levels of Cr, Cu, Ni, Pb, Se, Zn, V, Cd at 0-20 cm; and Cr, Ni, Cu, Cd, and Zn at 30-50 cm were significantly different. Organic carbon (in both soils), CEC (Fluvisol), and clay (Vertisol) exhibited significant positive correspondences with the total heavy metal levels. Conversely, Se and Hg contents revealed perceptible associations with carbonate and pH. The exchangeable fraction was dominated by Hg and Cd, whereas the carbonate fraction was abounded with Cd, Pb, and Co. conversely, V and Pb displayed strong affinity to reducible fraction, where as Cr, Cu, Zn, and Ni dominated the oxidizable fraction. Cr, Hg, Se, and Zn (in both soils) showed preference to the residual fraction

Method and apparatus for enrichment or upgrading heavy water

International Nuclear Information System (INIS)

Butler, J.P.; Hammerli, M.

1979-01-01

A method and apparatus for upgrading and final enrichment of heavy water are described, comprising means for contacting partially enriched heavy water feed in a catalyst column with hydrogen gas (essentially D 2 ) originating in an electrolysis cell so as to enrich the feed water with deuterium extracted from the electrolytic hydrogen gas and means for passing the deuterium enriched water to the electrolysis cell. (author)

The impact of sewage sludge treatment on the content of selected heavy metals and their fractions.

Science.gov (United States)

Ignatowicz, Katarzyna

2017-07-01

The aim of the study was to assess the physicochemical properties of compost made of municipal sewage sludge from selected Municipal Sewage Treatment Plant. Content of basic macroelements and heavy metals (Zn, Cu, Cr, Cd, Ni, Pb, Hg, Mg, Ca, N, P, K, Na) and their fractions was determined by means of BCR method. Based on the analyzes, it was found that the content of heavy metals in compost did not exceed the limits set by natural land management of sewage sludge; the compost is very abundant in biogenic elements - nitrogen and phosphorus - and it can be also considered a significant source of calcium and magnesium. The analysis of results obtained from the three-stage chemical extraction revealed that deposits subjected to aerobic stabilization and composting accumulate metals (in descending sequence) in fractions III and II, i.e. fractions virtually inaccessible to the ecosystem in optimal conditions of use. Copyright © 2017 Elsevier Inc. All rights reserved.

Comparing heavy metal contents in crops receiving mineral fertilisers and animal manure

DEFF Research Database (Denmark)

Christensen, Bent Tolstrup; Elsgaard, Lars

2014-01-01

Spring barley (grain, straw), grass-clover (two cuts), winter wheat (grain, straw) and silage maize grown in the Askov long-term experiment with different levels (0, ½, 1, 1½, 2) of mineral fertiliser (NPK) and animal manure (AM) had concentrations of As, Pb, Cd and Hg below the EC maximum permis...... of NPK and AM does not pose a threat in terms of feed quality. However, the long-term accumulation of heavy metals added with mineral fertilisers and animal manure is essentially irreversible and may threaten soil quality....... in the analysed metal contents between crops grown with NPK and AM. Crop contents of uranium and thallium were below the analytical detection limits regardless of nutrient source and addition rate. Thus in a farming context similar to that of the Askov experiment, the long-term application of standard rates...

Enhancing the use of waste activated sludge as bio-fuel through selectively reducing its heavy metal content.

Science.gov (United States)

Dewil, Raf; Baeyens, Jan; Appels, Lise

2007-06-18

Power plant or cement kiln co-incineration are important disposal routes for the large amounts of waste activated sludge (WAS) which are generated annually. The presence of significant amounts of heavy metals in the sludge however poses serious problems since they are partly emitted with the flue gases (and collected in the flue gas dedusting) and partly incorporated in the ashes of the incinerator: in both cases, the disposal or reuse of the fly ash and bottom ashes can be jeopardized since subsequent leaching in landfill disposal can occur, or their "pozzolanic" incorporation in cement cannot be applied. The present paper studies some physicochemical methods for reducing the heavy metal content of WAS. The used techniques include acid and alkaline thermal hydrolysis and Fenton's peroxidation. By degrading the extracellular polymeric substances, binding sites for a large amount of heavy metals, the latter are released into the sludge water. The behaviour of several heavy metals (Cd, Cr, Cu, Hg, Pb, Ni, Zn) was assessed in laboratory tests. Results of these show a significant reduction of most heavy metals.

Suspended matter and heavy metal content of the Elbe Estuary

International Nuclear Information System (INIS)

Vollbrecht, K.

1980-01-01

(1) In the River Elbe estuary there is a turbidity zone which is closely bound to the region of brackish waters. Its suspended matter content changes strongly with the tidal rhythm. Suspended matter and river bed sediments influence each other by exchanging their particles. Owing to that mechanism, the heavy metal ions bound or taken up by the suspended matter (sorption) enter the sediments. To obtain an estimation of the estuary's ability to cope with ( self purify ) a strong burden of industrial wastes, it is neccessary to take into consideration the absorbing capacity of both the mean suspension load and the sediments. (2) The concentration of nearly all heavy metal ions investigated in the suspension load decreases remarkably at the very beginning of the turbid zone already, in the Hamburg region. It indicates that the binding process are going on very rapidly and that the metal ion absorbing capacity of the Elbe estuary still requires only the first few miles of this self purification system. The results gained indicate that the suspended matter in Hamburg waters could bind or take up more heavy metal ions than are discharged into this area. (3) The concentration of most ions bound to the suspension material correlates very well with the grain size distribution of the (anorganic) particles. The concentration values decrease along the estuary and lead to a continuous transition to the values of the open sea. Cu, Ni and Cd appear to be captured preferably by organic suspended matter. This behaviour, however, is solely restricted to the turbid zone. In the open sea, after oxidation of the binding organic material, Cu and Ni correspond to the anorganic grain size distribution. (orig./HP) [de

The heavy water production plant at Arroyito, Argentina

International Nuclear Information System (INIS)

Ecabert, R.

1984-01-01

The author describes the construction of an industrial heavy water production plant (Planta Industrial de Agua Pesada, PIAP) in Argentina. The heavy water enrichment is based on a hydrogen/ammonia isotope exchange. (Auth.)

Influence of growing conditions on heavy metals content in cultivated mushrooms

International Nuclear Information System (INIS)

Kmitene, L.

1997-01-01

The aim of the research was to investigate the influence of growing terms, microclimate conditions and growing medium on the mushroom harvest and quality. Champignons were grown according to the Polish technology. Pleurotus ostreatus was grown in perforate sacks using chopped wheat straw. Mycelium was sowed in different terms. It was established that the harvest of mushrooms, especially their quality, depends not only on growing conditions, but also on the kind of mushrooms, composte quality, mushroom size (diameter of cap), picking of mushrooms, storage time and other conditions. The technology of mushroom growing will be developed after studying all the factors determining the content of heavy metals and radiation in mushrooms

Gasification of coal as efficient means of environment protection and hydrogenation of heavy oils residues

Energy Technology Data Exchange (ETDEWEB)

Krichko, A.A.; Maloletnev, A.S. [Fossil Fuel Institute, Moscow (Russian Federation)

1995-12-31

The Russia`s more then 50% of coals produced in its European part contain over 2,5% of sulphur, and the coals containing less than 1.5% of sulphurs comprise ca.20%. Thus, utilisation of the sulphide coals is inevitable, and there a problem arises concerning the technology of their sensible use and considering the requirements on the environment protection. Russia`s specialists have developed a design and construction for a steam-gas installation with a closed cycle gasification of the solid fuel. The gasification process will proceed in the fluidized bed under forced pressure of the steam-air blast. Characteristic features of this process are the following: a higher efficiency (the capacity of one gas generator is 3-3,5 times larger than that attained in the present gas generators of the Lurgy`s type): 2-2,5 times decreased fuel losses as compared to the Winkler`s generators; retention of the sensible heat, resulting in an increased total energy efficiency. The main task for petroleum refining industry at the present stage is the increase of depth of oil processing with the aim to intensify motor fuel production. One of the ways to solve the problem is to involve heavy oil residues into the processing. But the high metal and asphaltenes contents in the latter make the application of traditional methods and processes more difficult. Up to now there is no simple and effective technology which could give the opportunity to use oil residues for distillate fractions production. In Fossil fuel institute a process for hydrogenation of high boiling oil products, including with high sulphur, vanadium and nickel contents ones, into distillates and metals concentrates. The main point of the new process is as follows: the water solution of catalytic additive, for which purpose water soluble metal salts of VI-VIII groups are used, is mixed with tar, dispersed and then subjected to additional supercavitation in a special apparatus.

Improvement of lean combustion characteristics of heavy-hydrocarbon fuels with hydrogen addition; Suiso tenka ni yoru kokyu tanka suisokei nenryo no kihaku nensho no kaizen

Energy Technology Data Exchange (ETDEWEB)

Sakai, Y. [Saitama Institute of Technology, Saitama (Japan); Ishizuka, S. [Hiroshima University, Hiroshima (Japan). Faculty of Engineering

1999-09-25

The Lewis numbers of lean heavy-hydrocarbon fuels are larger than unity, and hence, their flames are prone to extinction in a shear flow, which occurs in a turbulent combustion. Here, propane is used as a representative fuel of heavy-hydrocarbon fuels because the Lewis number of lean propane/air mixtures is larger than unity, and an attempt to improve its combustion characteristics by hydrogen addition has been made. A tubular flame burner is used to evaluate its improvement, since a rotating, stretched vortex flow is established in the burner. The results show that with' hydrogen addition, the fuel concentration, the flame diameter and the flame temperature at extinction are reduced and its combustion characteristics are improved. However, it is found that the effective equivalence ration at extinction cannot become so small as that of lean methane/air mixture, which has a Lewis number less than unity. (author)

Influence of redox condition in iron, silicon and hydrogen contents of leached glass surface

International Nuclear Information System (INIS)

Manara, A.; Lanza, F.; Della Mea, G.; Rossi, C.; Salvagno, G.

1984-01-01

Surface analysis has been conducted on samples leached in a Sochlet apparatus at 100 0 C in the presence and in the absence of air. The XPS technique was applied to analyze the content of iron and silicon while the nuclear reaction method was utilized to analyze the content of hydrogen. Samples leached in argon atmosphere have shown a smaller content of iron and silicon with respect to the samples leached in air atmosphere. The H concentration has shown the same behavior. The results are discussed in terms of possible formation of iron compounds in the different redox condition and of their different stabilities and in terms of their efficiency in reducing exchange between Na + and H + ions. 11 references, 3 figures, 1 table

INFLUENCE OF ILLEGAL WASTE DUMPING SITES OF NORTH-WEST PART OF BARLINEK COMMUNITY ON HEAVY METALS CONTENT IN SOILS

Directory of Open Access Journals (Sweden)

Kamil Szydłowski

2017-02-01

Full Text Available The in-depth analysis of the soil samples study included 6 from 17 catalogued illegal waste dumps localized in the Barlinek Commune (Gmina Barlinek area. The samples were taken from the middle part of each waste dump and at 5 meter distance toward north and south directions. In the collected material the pH values and concentration of lead, zinc, cadmium, cobalt, manganese, nickel, chromium, iron, copper and mercury were determined. The results of laboratory analysis were compared with current standards (Regulation of the Minister of Environment from 9th September 2002 on soil quality standards and quality standards of soil - Journal of Laws 2002 No 165, item 1359 and with the soils classification by the content of trace elements, according to Kabata-Pendias et al. The reason of diversified content of heavy metals in the collected soils samples from different waste dumps is various morphological composition of deposited waste. Nonetheless, waste landfilled on illegal dumps were not significantly influencing the levels of soil contamination with heavy metals. The concentration of Hg, Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn, Fe qualifies those soils to geochemical natural levels of heavy metals content. Nevertheless, cadmium was the element, which concentration were most often (21 times exceeded.

Absorption of hydrogen by vanadium-palladium alloys

International Nuclear Information System (INIS)

Artman, D.; Lynch, J.F.; Flanagan, T.B.

1976-01-01

Pressure composition isotherms (273-373 K) have been determined for the absorption of hydrogen by a series of six palladium alloys (f.c.c) in the composition range from 1 to 8 at.% vanadium. At a given hydrogen content, the equilibrium hydrogen pressure progressively increases with vanadium content. Thermodynamic parameters for the absorption of hydrogen are reported at infinite dilution of hydrogen and for the formation of the nonstoichiometric hydride from the hydrogen-saturated alloy. The relative, partial molar enthalpy of solution of hydrogen at infinite dilution increases slightly with vanadium content. The presence of vanadium, which absorbs hydrogen itself in its normal b.c.c. structure, greatly inhibits the ability of palladium to absorb hydrogen. For example, the isobaric solubility of hydrogen (1 atm, 298K) decreases from H/Pd=0.7 (palladium) to 0.024 (V(6%)-Pd). The lattice expansion due to the presence of interstitial hydrogen has been determined by X-ray diffraction. From these data it can be concluded that the formation of two non-stoichiometric hydride phases does not occur at vanadium contents greater that 5 at.% (298 K). Electrical resistance has been measured as a function of the hydrogen content of the alloys. The electrical resistance increases more markedly with hydrogen content for these alloys than for any of the palladium alloys previously examined. (Auth.)

EVALUATION OF THE CONTENT OF HEAVY METALS IN FLUVISOLS OF FLOODPLAIN AREA DEPENDING ON THE TYPE OF LAND USE

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Mirosław Kobierski

2014-12-01

Full Text Available The aim of the research was the evaluation of the potential contamination with heavy metals in Fluvisols, used as grasslands and arable soils of Vistula River floodplain in the area of the Chełmiński and Nadwiślański Complex of Landscape Parks. The indicators proposed by Håkanson allow to evaluate the potential ecological risk of the contamination with heavy metals associated with the accumulation of one metal or a combination of multiple metals. The mean total content of Cd, Pb, Ni Cu, Zn, Mn, as well as Fe in Fluvisols at the depth of 120–150 cm was assumed as the content of the local geochemical background and it was: 1.0 mg·kg-1, 22.8 mg·kg-1, 26.9 mg·kg-1, 1.4 mg·kg-1, 60.8 mg·kg-1, 591 mg·kg-1, and 17.6 g·kg-1, respectively. The values of the indicators such as contamination factor (CF, enrichment factor (EF revealed higher levels of the accumulation of heavy metals in the soils of grasslands, which shows that the method of their use has a significant effect on the total metal content. Contamination with heavy metals in the surface layer of the investigated Fluvisols was found, and in terms of the content with cadmium there a moderate and considerable potential ecological risk was reported. Due to the fact that no unfavourable effect of trace elements on the riverside environment was proved and that the floodplain areas are under agricultural use, to evaluate the contamination with metals, the limit values for the soils of agricultural land were assumed as stipulated in the Regulation of Minister of the Environment of September 9, 2002. According to that criterion, the soils studied do not qualify as contaminated with metals. Only in one of the soil sampling points the total content of zinc was higher than the one determined as the maximum for agricultural land soils, namely 350 mg·kg-1. A significantly positive correlation was noted between the content of C org and the total content of metals as well as very numerous

Optimization of process parameter and reformer configuration for hydrogen production from steam reforming of heavy hydrocarbons. Paper no. IGEC-1-079

International Nuclear Information System (INIS)

Chen, Z.; Elnashaie, S.E.H.

2005-01-01

The present optimization investigation is classified into reforming configuration optimization in one hand and parameter optimization of each configuration on the other hand. Heptane is used as a model component for heavy hydrocarbons. The proposed novel reforming process is basically a Circulating Fluidized-Bed Membrane Reformer (CFBMR) with continuous catalyst regeneration and gas-solid separation. Composite hydrogen selective membranes are used for removing the product hydrogen from the reacting gas mixture and therefore driving the reversible reactions beyond their thermodynamic equilibriums. Dense perovskite oxygen selective membranes are also used to introduce oxygen for the exothermic oxidation of hydrocarbons and carbon. Four configurations are investigated, two of them are with the catalyst regeneration before the gas-solid separation and the other two are with the catalyst regeneration after the gas-solid separation. The optimization of the performance of each configuration is carried out for a number of design and operating parameters as optimization parameters and under both non-autothermal and autothermal reforming conditions. Results show that the autothermal operation with direct contact between cold feeds (water and heptane) and hot circulating catalyst can be the best configuration for efficient hydrogen production with minimum energy consumption. The maximum net hydrogen yield is 16.732 moles of hydrogen per mole of heptane fed, which is 76.05% of the maximum theoretical hydrogen yield of 22. (author)

Heavy metal contents and other physical quality indices of sewerage, canal and drinking water

International Nuclear Information System (INIS)

Mahmood, S.; Sattar, A.; Ihsanullash; Atta, S.; Arif, S. University of Engineering and Technology, Peshawar

2001-01-01

Analysis of Cd, Pb and Cu in canal, sewerage and drinking water by potentiometric stripping analysis (PSA) is described. Other quality indices of water such as temperature, pH, EC and total solid were also determined. The levels of heavy metal contents of sewerage, canal and drinking water revealed marked differences and wide coefficient of variability (CV). Generally Cd and Pb contents were higher in sewerage than canal and drinking water. However, Cu content of drinking waters was higher than other water tested. The total solids were found to be generally higher in sewerage and canal water than drinking water tested. The total solids were found to be generally higher in sewerage and canal water than drinking water The variations in temperature, pH and EC were marginal to marked depending upon the source and the location. (author)

CONTENT OF SELECTED HEAVY METALS IN NI-CONTAMINATED SOIL FOLLOWING THE APPLICATION OF HALLOYSITE AND ZEOLITE

Directory of Open Access Journals (Sweden)

Maja Radziemska

2016-07-01

Full Text Available Nickel has been listed as a priory control pollutant by the United States Environmental Protection Agency (US EPA. Compared with other methods, the combination of vegetation and the addition of mineral sorbents to heavy metal-contaminated soils can be readily applied on a large scale because of the simplicity of technology and low cost. Halloysite and zeolite, among others, can be used for this purpose. A greenhouse study was performed to evaluate the feasibility of using natural zeolite, as well as raw and modified halloysite for the remediation of simulated Ni-contaminated soil. The soil was spiked with five doses of nickel, i.e. 0 (control, 80, 160, 240 and 320 mg Ni kg-1 soil. The average accumulation of heavy metals in nickel-contaminated soil was found to follow the decreasing order of Ni>Zn>Cr>Cu>Pb. The highest reduction of Pb content was observed in soil samples taken from pots containing 80 and 160 mg.kg-1 of Ni along with the addition of modified halloysite. The strongest effects were caused by natural zeolite, which significantly reduced the average content of chromium. Contamination at 320 mg Ni.kg-1 of soil led to the highest increases in the Ni, Pb and Cr contents of soil.

Hydrogen isotope separation in hydrophobic catalysts between hydrogen and liquid water

Energy Technology Data Exchange (ETDEWEB)

Ye, Linsen, E-mail: yls2005@mail.ustc.edu.cn [China Academy of Engineering Physics, Mianyang 621900 (China); Luo, Deli [Science and Technology on Surface Physics and Chemistry Laboratory, Jiangyou 621907 (China); Tang, Tao; Yang, Wan; Yang, Yong [China Academy of Engineering Physics, Mianyang 621900 (China)

2015-11-15

Hydrogen isotope catalytic exchange between hydrogen and liquid water is a very effective process for deuterium-depleted potable water production and heavy water detritiation. To improve the characteristics of hydrophobic catalysts for this type of reaction, foamed and cellular structures of hydrophobic carbon-supported platinum catalysts were successfully prepared. Separation of deuterium or tritium from liquid water was carried out by liquid-phase catalytic exchange. At a gas–liquid ratio of 1.53 and exchange temperature of 70 °C, the theoretical plate height of the hydrophobic catalyst (HETP = 34.2 cm) was slightly lower than previously reported values. Changing the concentration of the exchange column outlet water yielded nonlinear changes in the height of the packing layer. Configurations of deuterium-depleted potable water and detritiation of heavy water provide references for practical applications.

HYDROGENATION OF TOLUENE ON Ni-Co-Mo SUPPORTED ...

African Journals Online (AJOL)

HOD

Keywords: Hydro treating catalysts; Hydrogenation; Toluene conversion; Surface area; Pore diameter. 1. ... decades in refineries to upgrade heavy oil fractions and residue. Metals often ...... "Hydroprocessing of heavy petroleum feeds: Tutorial ...

The prospects for hydrogen as an energy carrier: an overview of hydrogen energy and hydrogen energy systems

International Nuclear Information System (INIS)

Rosen, Marc A.; Koohi-Fayegh, Seama

2016-01-01

Hydrogen is expected to play a key role as an energy carrier in future energy systems of the world. As fossil-fuel supplies become scarcer and environmental concerns increase, hydrogen is likely to become an increasingly important chemical energy carrier and eventually may become the principal chemical energy carrier. When most of the world's energy sources become non-fossil based, hydrogen and electricity are expected to be the two dominant energy carriers for the provision of end-use services. In such a ''hydrogen economy,'' the two complementary energy carriers, hydrogen and electricity, are used to satisfy most of the requirements of energy consumers. A transition era will bridge the gap between today's fossil-fuel economy and a hydrogen economy, in which non-fossil-derived hydrogen will be used to extend the lifetime of the world's fossil fuels - by upgrading heavy oils, for instance - and the infrastructure needed to support a hydrogen economy is gradually developed. In this paper, the role of hydrogen as an energy carrier and hydrogen energy systems' technologies and their economics are described. Also, the social and political implications of hydrogen energy are examined, and the questions of when and where hydrogen is likely to become important are addressed. Examples are provided to illustrate key points. (orig.)

Canadian heavy water production

International Nuclear Information System (INIS)

Dahlinger, A.; Lockerby, W.E.; Rae, H.K.

1977-01-01

The paper reviews Canadian experience in the production of heavy water, presents a long-term supply projection, relates this projection to the anticipated long-term electrical energy demand, and highlights principal areas for further improvement that form the bulk of the Canadian R and D programme on heavy water processes. Six Canadian heavy water plants with a total design capacity of 4000Mg/a are in operation or under construction. All use the Girdler-Sulphide (GS) process, which is based on deuterium exchange between water and hydrogen sulphide. Early operating problems have been overcome and the plants have demonstrated annual capacity factors in excess of 70%, with short-term production rates equal to design rates. Areas for further improvement are: to increase production rates by optimizing the control of foaming to give both higher sieve tray efficiency and higher flow rates, to reduce the incapacity due to deposition of pyrite (FeS 2 ) and sulphur (between 5% and 10%), and to improve process control and optimization of operating conditions by the application of mathematical simulations of the detailed deuterium profile throughout each plant. Other processes being studied, which look potentially attractive are the hydrogen-water exchange and the hydrogen-amine exchange. Even if they become successful competitors to the GS process, the latter is likely to remain the dominant production method for the next 10-20 years. This programme, when related to the long-term electricity demand, indicates that heavy water supply and demand are in reasonable balance and that the Candu programme will not be inhibited because of shortages of this commodity. (author)

Influence of fillers on hydrogen penetration properties and blister fracture of rubber composites for O-ring exposed to high-pressure hydrogen gas

Energy Technology Data Exchange (ETDEWEB)

Yamabe, Junichiro; Nishimura, Shin [Department of Mechanical Science Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Research Center for Hydrogen Industrial Use and Storage (HYDROGENIUS), National Institute of Advanced Industrial Science and Technology (AIST), 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan)

2009-02-15

Ethylene-propylene rubber (EPDM) and nitrile-butadiene rubber (NBR) composites having carbon black, silica, and no fillers were exposed to hydrogen gas at a maximum pressure of 10 MPa; then, blister tests and the measurement of hydrogen content were conducted. The hydrogen contents of the composites were proportional to the hydrogen pressure, i.e., the behavior of their hydrogen contents follows Henry's law. This implies that hydrogen penetrates into the composite as a hydrogen molecule. The addition of carbon black raised the hydrogen content of the composite, while the addition of silica did not. Based on observations, the blister damages of composites with silica were less pronounced, irrespective of the hydrogen pressures. This may be attributed to their lower hydrogen content and relatively better tensile properties than the others. (author)

Recovering heavy rare earth metals from magnet scrap

Science.gov (United States)

Ott, Ryan T.; McCallum, Ralph W.; Jones, Lawrence L.

2017-08-08

A method of treating rare earth metal-bearing permanent magnet scrap, waste or other material in a manner to recover the heavy rare earth metal content separately from the light rare earth metal content. The heavy rare earth metal content can be recovered either as a heavy rare earth metal-enriched iron based alloy or as a heavy rare earth metal based alloy.

Effect Of Heavy Metals Stress On Enzyme Activities And Chlorophyll Content Of Pea (Pisum Sativum) And Tomato Plants

International Nuclear Information System (INIS)

Ahmed, B.M.; El Maghrabi, G.; Hashem, M.F.

2013-01-01

The effects of heavy metal stress on the chlorophyll in addition to catalase and peroxidase activities were studied in the leaves and roots of tomato and pea plants. Four groups were studied; the control group and other three groups treated with heavy metals. Group 1HM was treated with 1.0 mg CuSO 4 /l + 0.2 mg CdSO 4 /l + 0.1 mg ZnNO 3 /l every 10 days while in group 5 HM and group 10 HM, the doses were 5 and 10 folds the 1 HM, respectively. Leaves and roots of control and heavy metal-stressed plants were harvested after 10 weeks for chlorophyll determination. The chlorophyll content, especially chlo. b, was significantly decreased with the increase in heavy metals stress in both plants. In leaves of heavy metal-stressed plants, the peroxidase level in different stress levels was increased with increasing stress levels in tomato and pea while catalase was unchanged in leaves of tomato in comparison with the control. The activities of catalase and peroxidase in roots of heavy metal-stressed plants were increased in group 5 HM then decreased in case of group 10 HM. The increase in enzyme activities demonstrated that tomato is more tolerant to heavy metals than pea

Purification of hydrogen sulfide

International Nuclear Information System (INIS)

Tsao, U.

1978-01-01

A process is described for purifying a hydrogen sulfide gas stream containing carbon dioxide, comprising (a) passing the gas stream through a bed of solid hydrated lime to form calcium hydrosulfide and calcium carbonate and (b) regenerating hydrogen sulfide from said calcium hydrosulfide by reacting the calcium hydrosulfide with additional carbon dioxide. The process is especially applicable for use in a heavy water recovery process wherein deuterium is concentrated from a feed water containing carbon dioxide by absorption and stripping using hydrogen sulfide as a circulating medium, and the hydrogen sulfide absorbs a small quantity of carbon dioxide along with deuterium in each circulation

Cascade Processes in Muonic Hydrogen Atoms

International Nuclear Information System (INIS)

Faifman, M. P.; Men'Shikov, L. I.

2001-01-01

The QCMC scheme created earlier for cascade calculations in heavy hadronic atoms of hydrogen isotopes has been modified and applied to the study of cascade processes in the μp muonic hydrogen atoms. The distribution of μp atoms over kinetic energies has been obtained and the yields of K-series X-rays per one stopped muon have been calculated.Comparison with experimental data indicated directly that for muonic and pionic atoms new types of non-radiative transitions are essential, while they are negligible for heavy (kaonic, antiprotonic, etc.) atoms. These processes have been considered and their probabilities have been estimated.

Heavy metal (Pb, Cu, Zn and Cd content in wine produced from grape cultivar Mavrud, grown in an industrially polluted region

Directory of Open Access Journals (Sweden)

Violina Angelova

1999-09-01

Full Text Available The investigation was carried out in the period 1991-1993 with cv. Mavrud, grown in the region with a major industrial pollutant the Non-Ferrous-Metal Works (NFMW and a region with no industrial pollutants (as a control. The heavy metal content in soil, grapes and wine was determined. Most of the heavy metals in the grapes precipitate during fermentation into the sediments, which is the reason for their significantly lower content in the wine. Water washing of grape before processing leads to about 2 time decrease in the Pb, Cu, Zn and Cd contents of wine. The pre-washing of grapes does not lead to any quality deterioration in the wine produced. The amounts of Cu, Zn and Cd in the wine from cv. Mavrud, grown in the region of the NFMW-Plovdiv, are lower than the maximum admissible levels, while the Pb content exceeds them about two times.

Direction of Heavy Water Projects

International Nuclear Information System (INIS)

1984-07-01

Summary of the activities performed by the Heavy Water Projects Direction of the Argentine Atomic Energy Commission from 1950 to 1983. It covers: historical data; industrial plant (based on ammonia-hydrogen isotopic exchange); experimental plant (utilizing hydrogen sulfides-water process); Module-80 plant (2-3 tons per year experimental plant with national technology) and other related tasks on research and development (E.A.C.) [es

Heavy Metal Contents in Spices from Markets in Sarajevo, Bosnia and Herzegovina

Directory of Open Access Journals (Sweden)

Huremović, J.

2014-05-01

Full Text Available Spices are some of the most common foods in the human diet around the world. Spices are dried parts of plants used often as diet components to improve aroma and acceptability of food. The aim of this work was to determine the contents of seven heavy metals (Cr, Cu, Fe, Mn, Ni, Pb and Zn in spices available at local markets in Sarajevo. Metal concentrations in six spice samples (black pepper (Piper nigrum, basil (Ocimum basilicum, oregano (Oreganum vulgaris, paprika (Capsicum annuum, parsley (Petroselinum crispum and rosemary (Rosmarinus officinalis were determined by flame atomic absorption spectrometry. The content of chromium and nickel in all samples was below 5 mg kg-1 . Copper levels were in the range of 2.36-19.47 mg kg-1 , iron 6.80-785.56 mg kg-1 , manganese 6.14-59.36 mg kg-1 , lead 0.74-20.35 and zinc 6.93-85.44 mg kg-1 . These results were in agreement with other published data except in the case of Pb which content was slightly higher. Daily intake of different metals was calculated and compared with the MRL values given by ATSDR (2013. The content of lead in most of the samples was above the maximum permitted concentrations recommended by WHO and national regulations of Bosnia and Herzegovina.  

Mecanical Properties Degradation by Hydrogen Embrittlement

International Nuclear Information System (INIS)

Bertolino, G; Meyer, G; Perez Ipina J

2001-01-01

The presence of hydrogen-rich media during nuclear plant operation motivates the study of the zirconium alloys degradation of their mechanical properties influenced by hydrogen content and temperature.In this work we study samples with a microstructure of equiaxial grains resulted from hot-rolled, and with different homogeneous hydrogen content obtained by electrochemical charge and a thermal treatment.The influence of hydrogen content and temperature was analyzed from the results of fracture-mechanical tests on CT (compact test) probes using the J-criteria

The prospects for hydrogen as an energy carrier: an overview of hydrogen energy and hydrogen energy systems

Energy Technology Data Exchange (ETDEWEB)

Rosen, Marc A.; Koohi-Fayegh, Seama [Ontario Univ., Oshawa, ON (Canada). Inst. of Technology

2016-02-15

Hydrogen is expected to play a key role as an energy carrier in future energy systems of the world. As fossil-fuel supplies become scarcer and environmental concerns increase, hydrogen is likely to become an increasingly important chemical energy carrier and eventually may become the principal chemical energy carrier. When most of the world's energy sources become non-fossil based, hydrogen and electricity are expected to be the two dominant energy carriers for the provision of end-use services. In such a ''hydrogen economy,'' the two complementary energy carriers, hydrogen and electricity, are used to satisfy most of the requirements of energy consumers. A transition era will bridge the gap between today's fossil-fuel economy and a hydrogen economy, in which non-fossil-derived hydrogen will be used to extend the lifetime of the world's fossil fuels - by upgrading heavy oils, for instance - and the infrastructure needed to support a hydrogen economy is gradually developed. In this paper, the role of hydrogen as an energy carrier and hydrogen energy systems' technologies and their economics are described. Also, the social and political implications of hydrogen energy are examined, and the questions of when and where hydrogen is likely to become important are addressed. Examples are provided to illustrate key points. (orig.)

Production of light hydrocarbons, etc. [from heavy hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

1937-10-07

A process is given for the production of light hydrocarbons of the gasoline type and, if desired, of the middle-oil type, from liquid or fusible heavy or medium heavy hydrocarbon materials. The process comprises subjecting the said initial materials in the first stage to catalytic hydrofining, separating the lower boiling constituents and the hydrogenating gas from the resulting products and then subjecting the higher boiling constituents in a second stage to a splitting destructive hydrogenation and then recycling substantially the entire reaction mixture obtained in the second stage to the frst stage.

Determination of water, hydrogen, and carbon content of Korean main farm produces for the calculation of H-3 and C-14 ingestion dose

International Nuclear Information System (INIS)

Chung, Yang Geun; Lee, Gab Bock; Kim, Mi Ja; Eum, Hee Moon

2003-01-01

Water, hydrogen, and carbon content of grains, leafy vegetable, root vegetable, and fruits in Korea were determined to be used in the calculation of HTO, OBT, C-14 offsite ingestion dose. The individual items and the weighting factors of the 4 groups were based on the results of nationwide dietary intake survey in Korea. Items produced in an island or imported were excluded for the reason that they would not be affected directly by the nuclear power plants in the nation. On the same assumption, cooked and instant foods also were excluded. Items within 95% of the cumulative percentage of intake in each category were selected as the main farm produces, and then each intake percentage was taken as the weighting factor. Water, Hydrogen, and carbon content were determined using the data in Food Composition TABLE of Korea. H and C content were calculated from protein, fat, and carbohydrate content in the TABLE, and multiplied by each weighting factor to make the group-representative value. Grains, lefty and root vegetable, and fruits of Korea had 11.0%, 93.6%, 87.9%, 86.2% of water, 5.6%, 0.4%. 0.7%, 0.9% of hydrogen, and 39.6%, 2.5%, 5.2%, 6.0% of carbon, respectively. This is different from those in the ODCM from AECL data. Over ODCM, water content of grains and vegetable were 0.92-0.98 times ODCM, and fruits 1.03 times ODCM, which would result in the change of HTO ingestion dose as much. Hydrogen content of grains and vegetables are 1.02-2.33 times ODCM, but fruits 0.9 times ODCM. Carbon content of grains, leafy vegetables, and fruits are 0.7-0.98 times ODCM, but root vegetables 1.49 times ODCM. This would result in the change of ingestion dose as much

Future trends in heavy water production

International Nuclear Information System (INIS)

Galley, M.R.

1983-10-01

World heavy water production has spanned nearly fifty years and, for much of that period, the commodity was often in short supply, but that situation has changed, at least in Canada. There are now adequate reserves of heavy water and sufficient installed production capacity to service Canadian domestic and export demands for the next ten years or beyond. More than 90 percent of the world's inventory of heavy water has been produced by the GS process but this may not be the method that is chosen when the time comes to expand heavy water production again. Other countries, such as India and Argentina, have already chosen ammonia-hydrogen exchange as an alternative technology for part of their domestic production programs. Despite the present surplus of heavy water, research and development of new technologies is very active, particularly in Canada and Japan, because it is recognized that there are still attractive opportunities for future production by processes that are both less expensive and environmentally more acceptable, than either the demonstrated GS process or ammonia-hydrogen alternative. This paper describes the prospects for some of these new processes, contrasts them with the present established methods and assesses the probable impact on the future supply situation

Heavy metal contents and transfer capacities of Phragmites australis and Suaeda salsa in the Yellow River Delta, China

Science.gov (United States)

Zhang, Shuai; Bai, Junhong; Wang, Wei; Huang, Laibing; Zhang, Guangliang; Wang, Dawei

2018-04-01

Plant samples including roots, stems and leaves of Phragmites australis and Suaeda salsa were collected in the short-term flooding and tidal flooding wetlands of the Yellow River Delta of China. Six heavy metals (e.g., As, Cd, Cr, Cu, Pb, and Zn) were measured in roots, stems and leaves of each plant species using inductively coupled plasma atomic absorption spectrometry (ICP-AAS) to investigate the levels, and transfer capabilities of heavy metals in these two plant species. Our results showed that in the tidal flooding wetlands, the contents of As, Cr and Cd in roots of Phragmites australis and Suaeda salsa were higher than those in their stems and leaves. Suaeda salsa showed higher contents of Pb and Zn in leaves than those in roots and stems, whereas lower levels of Pb and Zn were observed in Phragmites australis. In the short-term flooding wetlands, heavy metal contents exhibited a big difference between different tissues of Phragmites australis and Suaeda salsa, and both plant species showed higher levels of Pb and Zn in leaves. Suaeda salsa roots enriched more As and Cd, whereas higher enrichment levels were observed in Phragmites australis leaves, which indicated different transfer capacities of these two wetland plants. The transfer factors for stems and leaves of Phragmites australis in the tidal flooding wetlands significantly differed from those in the short-term flooding wetlands, however, no significant differences in transfer factors for stems and leaves of Suaeda salsa were observed between these two types of wetlands.

Back-echo method for determining the content of C, CH, CH/sub 2/ and CH/sub 3/ fragments

Energy Technology Data Exchange (ETDEWEB)

Polonov, V.M.; Kalabin, G.A.; Kushnarev, D.F.; Latyshev, V.P.

1984-07-01

Possibility was investigated of determining the content of quaternary, tertiary, secondary and primary carbon atoms in soluble products from coal. Cubed residues of medium resin oil from semicoking Cheremkhovskii coals, hydrogenation products from mixtures of medium oil and light dephenolized oil, and asphaltenes separated from the hydrogenation products of Berezovsk coals were used as samples. A new method of quantitative analysis based on the pulse sequence of the back echo from the nuclear magnetic resonance of /sup 13/C was used. The method can be applied in the analysis of light and heavy products from coal, petroleum, shales and complex mixtures of organic substances. The method is limited by a decrease in accuracy when the heteroatom content in the samples increases, causing deterioration in the quality of spectra separation. 13 references.

Monitoring Heavy Metal Contents with Sphagnum Junghuhnianum Moss Bags in Relation to Traffic Volume in Wuxi, China.

Science.gov (United States)

Hu, Rong; Yan, Yun; Zhou, Xiaoli; Wang, Yanan; Fang, Yanming

2018-02-22

Despite its small size, a moss bag can reveal the different temporal and spatial deposition patterns of pollutants at a particular site; therefore, researchers can use moss bags to determine pollution sources and to put forward strategies for pollution control. Although the use of moss bags to monitor atmospheric pollution has been widely reported in Europe, there are few such empirical studies in China. Thus, in this study, bags containing the moss Sphagnum junghuhnianum were used to assess the concentrations of heavy metals (chromium (Cr), copper (Cu), lead (Pb), vanadium (V), and zinc (Zn)) at five sampling sites (four roads and a forest park) during the summer and winter of 2012. According to the relative accumulation factor (RAF) and contamination factor (CF) results, pollution in winter was heavier than that in summer, and Cr was found to be the most contaminating, having the highest mean CF. There was a significant positive correlation ( p heavy metals (Cr, Cu, and V) in winter, whereas a significant positive correlation ( p heavy metal elements (Cr, Pb, V, and Zn) in summer, indicating a close relationship between heavy metal contents and traffic volume. Although there was substantial variation in the concentrations of the five heavy metals in the moss bags, significant correlations between heavy metals suggested that the contaminants originated from a common source, namely vehicle emissions. The results demonstrated that the four roads were subject to different degrees of pollution depending on the volume of traffic using each road. Therefore, the results of this study suggest that traffic volume is a major reason for heavy metal pollution.

Integrated waste hydrogen utilization project

International Nuclear Information System (INIS)

Armstrong, C.

2004-01-01

'Full text:' The BC Hydrogen Highway's, Integrated Waste Hydrogen Utilization Project (IWHUP) is a multi-faceted, synergistic collaboration that will capture waste hydrogen and promote its use through the demonstration of 'Hydrogen Economy' enabling technologies developed by Canadian companies. IWHUP involves capturing and purifying a small portion of the 600 kg/hr of by-product hydrogen vented to the atmosphere at the ERCO's electrochemical sodium chlorate plant in North Vancouver, BC. The captured hydrogen will then be compressed so it is suitable for transportation on roadways and can be used as a fuel in transportation and stationary fuel cell demonstrations. In summary, IWHUP invests in the following; Facilities to produce up to 20kg/hr of 99.999% pure 6250psig hydrogen using QuestAir's leading edge Pressure Swing Absorption technology; Ultra high-pressure transportable hydrogen storage systems developed by Dynetek Industries, Powertech Labs and Sacre-Davey Engineering; A Mobile Hydrogen Fuelling Station to create Instant Hydrogen Infrastructure for light-duty vehicles; Natural gas and hydrogen (H-CNG) blending and compression facilities by Clean Energy for fueling heavy-duty vehicles; Ten hydrogen, internal combustion engine (H-ICE), powered light duty pick-up vehicles and a specialized vehicle training, maintenance, and emissions monitoring program with BC Hydro, GVRD and the District of North Vancouver; The demonstration of Westport's H-CNG technology for heavy-duty vehicles in conjunction with local transit properties and a specialized vehicle training, maintenance, and emissions monitoring program; The demonstration of stationary fuel cell systems that will provide clean power for reducing peak-load power demands (peak shaving), grid independence and water heating; A comprehensive communications and outreach program designed to educate stakeholders, the public, regulatory bodies and emergency response teams in the local community, Supported by industry

Comparative study of two methods for determining the diffusible hydrogen content in welds

International Nuclear Information System (INIS)

Celio de Abreu, L.; Modenesi, P.J.; Villani-Marques, P.

1994-01-01

This work presents a comparative study of the methods for measurement of the amount of diffusible hydrogen in welds: glycerin, mercury and gaseous chromatography. The effect of the variables collecting temperatures and times were analyzed. Basic electrodes type AWS E 9018-M were humidified and dried at different times and temperatures in order to obtain a large variation in the diffusible hydrogen contents. The results showed that the collecting time can be reduced when the collecting temperature is raised, the mercury and chromatography methods present similar results, higher than those obtained by the glycerin method, the use of liquid nitrogen in the preparation of the specimens for test is unessential. The chromatography method presents the lower dispersion and is the method that can have the collecting time more reduced by the raising of the collecting temperature. The use of equations for comparison between results obtained by the various methods encountered in the literature is also discussed. (Author) 16 refs

Process for exchanging tritium between gaseous hydrogen and water

International Nuclear Information System (INIS)

Hindin, S.G.; Roberts, G.W.

1981-01-01

An improved method of exchanging and concentrating the radioactive isotope of hydrogen from water or hydrogen gas is described. This heavy water enrichment system involves a low pressure, dual temperature process. (U.K.)

ASSESSMENT OF HEAVY METALS CONTENTS IN BOTTOM SEDIMENTS OF BUG RIVER

Directory of Open Access Journals (Sweden)

Elżbieta Skorbiłowicz

2014-07-01

Full Text Available The development of industry, agriculture, and transport contributes to an increased environmental pollution by heavy metals. The aim of the study was preliminary assessment of the contents of selected metals (lead, cobalt, copper, chromium, cadmium and nickel in the sediments of Bug river. The study comprised part of the river flowing through Poland. It was found that the Bug river sediments are not contaminated in respect to the content of tested metals. Based on the analysis of the study results, these metals can be lined up in the following order: Cr > Pb > Cu > Ni > Co > Cd. Statistical analysis showed that copper and chromium occur in Bug river sediments in forms bindings with organic matter in majority of cases. The granulometric analysis of sediments from Bug river revealed the largest percentage of two fractions: 1.0–0.2 mm with average of 47.7 ± 19.77% and 0.2–0.1 mm with average of 20.6 ± 7.7%. These are the dominant fractions with the accumulation of metals in river sediments, which has been confirmed by statistical analysis.

Assessment of heavy metal contents of green leafy vegetables

Directory of Open Access Journals (Sweden)

V. Jena

2013-01-01

Full Text Available Vegetables are rich sources of vitamins, minerals, and fibers, and have beneficial antioxidative effects. Ingestion of vegetables containing heavy metals is one of the main routes through which these elements enter the human body. Slowly released into the body, however, heavy metals can cause an array of diseases. In this study we investigated the concentrations of copper, chromium, zinc, and lead in the most frequently consumed vegetables including Pimpinella anisum, Spinacia oleracea, Amaranthus viridis, Coriandrum sativum, and Trigonella foenum graecum in various sites in Raipur city, India. Atomic absorption spectrophotometry was used to estimate the levels of these metals in vegetables. The mean concentration for each heavy metal in the samples was calculated and compared with the permissible levels set by the Food and Agriculture Organization and World Health Organization. The intake of heavy metals in the human diet was also calculated to estimate the risk to human health. Our findings indicated the presence of heavy metals in vegetables in the order of Cr > Zn > Cu > Pb. Based on these findings, we conclude that the vegetables grown in this region are a health hazard for human consumption.

Studies of heavy metal contents and microbial composition of ...

African Journals Online (AJOL)

FLEXI-DONEST

the use of private electricity generating sets, in recent times, have ... soil and evaluate the impact of heavy metal on soil degradable ..... a reasonable length of time by herbivores may .... Heavy Metals in Root, Stem and Leaves of Acalypha.

Hydrogen embrittlement due to hydrogen-inclusion interactions

International Nuclear Information System (INIS)

Yu, H.Y.; Li, J.C.M.

1976-01-01

Plastic flow around inclusions creates elastic misfit which attracts hydrogen towards the regions of positive dilatation. Upon decohesion of the inclusion-matrix interface, the excess hydrogen escapes into the void and can produce sufficient pressure to cause void growth by plastic deformation. This mechanism of hydrogen embrittlement can be used to understand the increase of ductility with temperature, the decrease of ductility with hydrogen content, and the increase of ductility with the ultimate strength of the matrix. An examination of the effect of the shape of spheroid inclusion reveals that rods are more susceptible to hydrogen embrittlement than disks. The size of the inclusion is unimportant while the volume fraction of inclusions plays the usual role

Heavy metals content in the stem bark of Detarium microcarpum ...

African Journals Online (AJOL)

The heavy metal analysis was carried out on the stem bark of D. microcarpum using an atomic absorption spectrophotometer (AAS). The heavy metals screened for include: lead, chromium, manganese, zinc and iron. The levels of manganese, zinc and iron were 13.91, 4.89 and 21.89 mg/L respectively. These heavy metals ...

Experimental Search for a Heavy Electron

Science.gov (United States)

Boley, C. D.; Elias, J. E.; Friedman, J. I.; Hartmann, G. C.; Kendall, H. W.; Kirk, P.N.; Sogard, M. R.; Van Speybroeck, L. P.; de Pagter, J. K.

1967-09-01

A search for a heavy electron of the type considered by Low and Blackmon has been made by studying the inelastic scattering of 5 BeV electrons from hydrogen. The search was made over a range of values of the mass of the heavy electron from 100 t0 1300 MeV. No evidence for such a particle was observed. Upper limits on the production cross sections were determined and employed to deducelimits on the values of the electron-photon-heavy electron coupling constant in Low and Blackmon=s theory.

Human health and ecological toxicity potentials due to heavy metal content in waste electronic devices with flat panel displays

International Nuclear Information System (INIS)

Lim, Seong-Rin; Schoenung, Julie M.

2010-01-01

Display devices such as cathode-ray tube (CRT) televisions and computer monitors are known to contain toxic substances and have consequently been banned from disposal in landfills in the State of California and elsewhere. New types of flat panel display (FPD) devices, millions of which are now purchased each year, also contain toxic substances, but have not previously been systematically studied and compared to assess the potential impact that could result from their ultimate disposal. In the current work, the focus is on the evaluation of end-of-life toxicity potential from the heavy metal content in select FPD devices with the intent to inform material selection and design-for-environment (DfE) decisions. Specifically, the metals antimony, arsenic, barium, beryllium, cadmium, chromium, cobalt, copper, lead, mercury, molybdenum, nickel, selenium, silver, vanadium, and zinc in plasma TVs, LCD (liquid crystal display) TVs, LCD computer monitors and laptop computers are considered. The human health and ecotoxicity potentials are evaluated through a life cycle assessment perspective by combining data on the respective heavy metal contents, the characterization factors in the U.S. EPA Tool for the Reduction and Assessment of Chemical and other environmental Impacts (TRACI), and a pathway and impact model. Principal contributors to the toxicity potentials are lead, arsenic, copper, and mercury. Although the heavy metal content in newer flat panel display devices creates less human health toxicity potential than that in CRTs, for ecological toxicity, the new devices are worse, especially because of the mercury in LCD TVs and the copper in plasma TVs.

Canadian hydrogen safety program

International Nuclear Information System (INIS)

MacIntyre, I.; Tchouvelev, A.V.; Hay, D.R.; Wong, J.; Grant, J.; Benard, P.

2007-01-01

The Canadian hydrogen safety program (CHSP) is a project initiative of the Codes and Standards Working Group of the Canadian transportation fuel cell alliance (CTFCA) that represents industry, academia, government, and regulators. The Program rationale, structure and contents contribute to acceptance of the products, services and systems of the Canadian Hydrogen Industry into the Canadian hydrogen stakeholder community. It facilitates trade through fair insurance policies and rates, effective and efficient regulatory approval procedures and accommodation of the interests of the general public. The Program integrates a consistent quantitative risk assessment methodology with experimental (destructive and non-destructive) failure rates and consequence-of-release data for key hydrogen components and systems into risk assessment of commercial application scenarios. Its current and past six projects include Intelligent Virtual Hydrogen Filling Station (IVHFS), Hydrogen clearance distances, comparative quantitative risk comparison of hydrogen and compressed natural gas (CNG) refuelling options; computational fluid dynamics (CFD) modeling validation, calibration and enhancement; enhancement of frequency and probability analysis, and Consequence analysis of key component failures of hydrogen systems; and fuel cell oxidant outlet hydrogen sensor project. The Program projects are tightly linked with the content of the International Energy Agency (IEA) Task 19 Hydrogen Safety. (author)

Studies of Radioactive Contaminations and heavy metal contents in vegetables and fruit from Lublin, Poland

International Nuclear Information System (INIS)

Chibowski, S.

2000-01-01

This paper presents studies of the level of some gamma radioactive elements and heavy metals in fruits, vegetables and plants from Lublin. Potassium 40 K isotope was most prevalent element in the examined samples. It concentrated mainly in aboveground parts of some vegetables, for example in parsley and carrots haulm and in leaves of red beet and leek (from 1135 to 1940 Bq/kg). considerably lower concentrations of this element were noticed in the roots of the vegetables, running from 210 to 448 Bq/kg of dry matter. In examined fruit, the 40 K contents ranged from 490 to 510 Bq/kg. Transfer factors of 40 K, from the soil to the vegetables and fruit, ranged from 0.3 to 2.9. The natural isotopes of uranium series account for 17% of total activity, whereas thorium series was 19-20% of its activity. In fact, in examined fruit (raspberry, red and black currants) and roots of vegetables caesium 137 Cs was not detected, whereas some amounts of it were noticed in green parts of vegetables, from 4.0 to 8.4 Bq/kg of dry matter. The transfer factor of 137 Cs from the soil to examined samples ranged from 0.03 to 0.4. in all studied samples examined on heavy metal contents no valid safety standards for these elements were exceeded. (author)

Magntic susceptibility as a proxy to heavy metal content in the sediments of Anzali wetland, Iran

Directory of Open Access Journals (Sweden)

Naseh Mohammad Reza Vesali

2012-12-01

Full Text Available Abstract Heavy metal concentrations and magnetic susceptibility of sediment samples were analyzed as indicators of urban and industrial contamination in Anzali wetland in Gilan, Iran. The aim was to investigate the suitability of magnetic properties measurements for indicating heavy metal pollution. The concentration of six heavy metals (Ni, Cr, Cd, Zn, Fe, and Pb was determined in different depths of four sediment core samples within four different regions of the wetland (Abkenar, Hendekhaleh, Shijan and Siakeshim. Average concentration of heavy metals in the sediment cores was higher than the severe effect level (SEL for Ni, Cr and Fe (77.26, 113.63 ppm and 5.2%, respectively and lower than SEL for Cd, Zn and Pb (0.84, 137.7, 29.77 ppm, respectively. It was found that the trend of metal concentrations with the depth is different in each core and is related to the pollution discharges into the rivers entering the wetland. Core magnetic susceptibility measurements also showed different magnetic properties in each core. Cluster analysis was applied using Pearson correlation coefficient between heavy metal concentrations and magnetic properties across each core. Significant relationship was found to exist between magnetic susceptibility and the concentration of Ni in Abkenar and the concentration of Fe in other regions. Whereas Abkenar is almost the isolated and uncontaminated region of the wetland, it revealed a difference in magnetic properties between contaminated and uncontaminated sediments. It was concluded that magnetic properties of samples from contaminated zone were mostly related to Fe content. The result of this study demonstrated that magnetic susceptibility measurements could be applied as a proxy method for heavy metal pollution determination in marine environments in Iran especially as a rapid and cost-effective introductory site assessments.

Monitoring Heavy Metal Contents with Sphagnum Junghuhnianum Moss Bags in Relation to Traffic Volume in Wuxi, China

Directory of Open Access Journals (Sweden)

Rong Hu

2018-02-01

Full Text Available Despite its small size, a moss bag can reveal the different temporal and spatial deposition patterns of pollutants at a particular site; therefore, researchers can use moss bags to determine pollution sources and to put forward strategies for pollution control. Although the use of moss bags to monitor atmospheric pollution has been widely reported in Europe, there are few such empirical studies in China. Thus, in this study, bags containing the moss Sphagnum junghuhnianum were used to assess the concentrations of heavy metals (chromium (Cr, copper (Cu, lead (Pb, vanadium (V, and zinc (Zn at five sampling sites (four roads and a forest park during the summer and winter of 2012. According to the relative accumulation factor (RAF and contamination factor (CF results, pollution in winter was heavier than that in summer, and Cr was found to be the most contaminating, having the highest mean CF. There was a significant positive correlation (p < 0.05 between traffic volume and concentration for three heavy metals (Cr, Cu, and V in winter, whereas a significant positive correlation (p < 0.05 was observed between traffic volume and concentrations for four heavy metal elements (Cr, Pb, V, and Zn in summer, indicating a close relationship between heavy metal contents and traffic volume. Although there was substantial variation in the concentrations of the five heavy metals in the moss bags, significant correlations between heavy metals suggested that the contaminants originated from a common source, namely vehicle emissions. The results demonstrated that the four roads were subject to different degrees of pollution depending on the volume of traffic using each road. Therefore, the results of this study suggest that traffic volume is a major reason for heavy metal pollution.

Influence of temperature and hydrogen content on stress-induced radial hydride precipitation in Zircaloy-4 cladding

Energy Technology Data Exchange (ETDEWEB)

Desquines, J., E-mail: jean.desquines@irsn.fr; Drouan, D.; Billone, M.; Puls, M.P.; March, P.; Fourgeaud, S.; Getrey, C.; Elbaz, V.; Philippe, M.

2014-10-15

Radial hydride precipitation in stress relieved Zircaloy-4 fuel claddings is studied using a new thermal–mechanical test. Two maximum temperatures for radial hydride precipitation heat treatment are studied, 350 and 450 °C with hydrogen contents ranging between 50 and 600 wppm. The new test provides two main results of interest: the minimum hoop stress required to precipitate radial hydrides and a maximum stress above which, all hydrides precipitate in the radial direction. Based on these two extreme stress conditions, a model is derived to determine the stress level required to obtain a given fraction of radial hydrides after high temperature thermal–mechanical heat treatment. The proposed model is validated using metallographic observation data on pressurized tubes cooled down under constant pressure. Most of the samples with reoriented hydrides are further subjected to a ductility test. Using finite element modeling, the test results are analyzed in terms of crack nucleation within radial hydrides at the outer diameter and crack growth through the thickness of the tubular samples. The combination of test results shows that samples with hydrogen contents of about 100 wppm had the lowest ductility.

Heavy metal contamination, microbiological spoilage and biogenic amine content in sushi available on the Polish market.

Science.gov (United States)

Kulawik, Piotr; Dordevic, Dani; Gambuś, Florian; Szczurowska, Katarzyna; Zając, Marzena

2018-05-01

The present study determined the heavy metal contamination (mercury, cadmium, lead, arsenic and nickel) of nori, restaurant-served sushi and ready-to-eat sushi meals available via retail chains. Moreover, both microbiological load and biogenic amine content in ready-to-eat sushi meals were analysed. All of the nori samples contained high levels of Cd (2.122 mg kg -1 ), Ni (0.715 mg kg -1 ), As (34.56 mg kg -1 ) and Pb (0.659 mg kg -1 ). The studied sushi samples contained high levels of Ni and Pb, reaching 0.194 and 0.142 mg kg -1 wet weight, respectively, being potentially hazardous to women during pregnancy and lactation and small children. None of the studied samples contained high levels of Hg. Overall, 37% of ready-to-eat sushi meals exceeded a microbiological load of 10 6  cfu g -1 . However, biogenic amine content in all of the samples was low, with a highest histamine content of 2.05 mg kg -1 . Sushi is not the source of high levels of biogenic amines even with high microbiological loads. Nevertheless, the high microbiological loads at the end of the shelf-life indicate that some processors might have problems with the distribution chain or implement a poor hygienic regime. Moreover as a result of possible risk associated with heavy metal contamination, the present study highlights the need to establish new regulations regarding the contamination of nori and sushi. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Phytotoxicity of thallium (Tl) in culture solution. Pt. 1. Effects of Tl(I) on the growth and heavy metal contents of pea and field bean plants

Energy Technology Data Exchange (ETDEWEB)

Poetsch, U; Austenfeld, F A

1985-01-01

The effects of TlNO/sub 3/ and Tl(I)EDTA on growth and heavy metal contents of pea plants and field bean plants were compared in hydroponic culture experiments. In the presence of TlNO/sub 3/, the essential heavy metals were available to the plants in their ionic forms. When Tl(I)EDTA was present the essential heavy metals were available as chelated complexes. With increasing concentration of TlNO/sub 3/ dry matter production of pea plants was lowered and the Tl content of each organ was increased. The highest Tl content was found within the stems. The increased Tl contents were accompanied by depressed Mn, Zn, and Cu contents of the roots and depressed Mn contents of the stems, but increased Fe contents of the stems. Substitution of TlNO/sub 3/ by Tl(I)EDTA resulted in a stronger growth inhibition of the pea plants, and higher Tl contents of each organ. The highest Tl content was found within the stems. Tl(I)EDTA depressed Mn in the roots, but increased Fe and Mn in the stems, and Fe, Zn and Cu in the leaves. The increases may due to concentration by growth inhibition. The growth of the field bean was not effected by TlNO/sub 3/ nor by Tl(I)EDTA. The field bean contained most of the Tl within the roots and translocated only relatively small amounts to the shoots. This pattern was independent of the Tl compound. Increasing concentrations of TlNO/sub 3/ resulted in depressed Mn and Zn contents of the roots, and Mn contents of the stems. Chelation of Tl(I) resulted in a decrease of the Tl content of each organ. Tl(I)EDTA depressed only the Mn content of the roots.

Deuterium exchange between liquid water and gaseous hydrogen

International Nuclear Information System (INIS)

Dave, S.M.; Ghosh, S.K.; Sadhukhan, H.K.

1982-01-01

The overall separation factors for the deuterium exchange between liquid water and gaseous hydrogen have been calculated over a wide range of temperature, pressure and deuterium concentrations. These data would be useful in the design and other considerations for heavy water production, based on hydrogen-water exchange. (author)

Degradation of the ethyl glucuronide content in hair by hydrogen peroxide and a non-destructive assay for oxidative hair treatment using infra-red spectroscopy.

Science.gov (United States)

Ammann, Dominic; Becker, Roland; Kohl, Anka; Hänisch, Jessica; Nehls, Irene

2014-11-01

The assessment of quantification results of the alcohol abuse marker ethyl glucuronide (EtG) in hair in comparison to the cut-off values for the drinking behavior may be complicated by cosmetic hair bleaching. Thus, the impact of increasing exposure to hydrogen peroxide on the EtG content of hair was investigated. Simultaneously, the change of absorbance in the range of 1000-1100 cm(-1) indicative for the oxidation of cystine was investigated non-destructively by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) using pulverized portions of the respective hair samples. Hair samples treated with hydrogen peroxide consistently displayed a significantly increased absorbance at 1040 cm(-1) associated with the formation of cysteic acid. The EtG content decreased significantly if the hair was treated with alkaline hydrogen peroxide as during cosmetic bleaching. It could be shown that ATR-FTIR is capable of detecting an exposure to hydrogen peroxide when still no brightening was visible and already before the EtG content deteriorated significantly. Thus, hair samples suspected of having been exposed to oxidative treatment may be checked non-destructively by a readily available technique. This assay is also possible retrospectively after EtG extraction and using archived samples. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Modification of hydrogen determinator for total hydrogen analysis in irradiated zircaloy cladding tube

International Nuclear Information System (INIS)

Park, Soon Dal; Choi, Kwnag Soon; Kim, Jong Goo; Joe, Kih Soo; Kim, Won Ho

1999-01-01

A hydrogen determinator was modified and installed in the glove box to analyse total hydrogen content in irradiated zircaloy tube. The analysis method of hydrogen is Inert Gas Fusion(IGF)-Thermal Conductivity Detection(TCD). The hydrogen recoveries of no tin method using Ti and Zr matrix standards, respectively, were available within 3 μg of hydrogen. Also the smaller size of sample showed the better hydrogen recovery. It was found that the hydrogen standard of Ti matrix is available to hydrogen analysis in zircaloy sample. The mean radioactivity of irradiated zircaloy sample was 10 mR/hr and hydrogen concentration was 130 ppm

Internal hydrogen embrittlement of gamma-stabilized uranium alloys

International Nuclear Information System (INIS)

Powell, G.L.; Koger, J.W.; Bennett, R.K.; Williamson, A.L.; Hemperly, V.C.

1976-01-01

Relationships between the tensile ductility and fracture characteristics of as-quenched, gamma-stabilized uranium alloys (uranium--10 wt percent molybdenum, uranium--8.5 wt percent niobium, uranium--10 wt percent niobium, and uranium--7.5 wt percent niobium--2.5 wt percent zirconium), the hydrogen content of the tensile specimens, and the hydrogen gas pressure during the annealing at 850 0 C of the tensile test blanks prior to quenching were established. For these alloys, the tensile ductility decreases only slightly with increasing hydrogen content up to a critical hydrogen concentration above which the tensile ductility drops to nearly zero. The only alloy not displaying this sharp drop in tensile ductility was U--7.5 Nb--2.5 Zr, probably because sufficiently high hydrogen contents could not be achieved under our experimental arrangements. The critical hydrogen content for ductility loss increased with increasing hydrogen solubility in the alloy. Fracture surfaces produced by internal hydrogen embrittlement do not resemble those produced by stress corrosion cracking (SCC) in aqueous environments containing chloride ions. 8 figs

Effect of Hydrogen Peroxide Content on the Preparation of Peroxotitanate Materials for the Treatment of Radioactive Wastewater

Directory of Open Access Journals (Sweden)

Wein-Duo Yang

2016-01-01

Full Text Available The modification of peroxotitanate using hydrogen peroxide significantly improved the ion-exchange capacity of titanate materials as sorbents for metal ions contained in a radioactive waste simulant solution. The effects of hydrogen peroxide content (hydrogen peroxide/titanium isopropoxide molar ratios, hereafter expressed as H/T on the properties of as-prepared titanate synthesized at 130°C and at pH of 6-7, followed by freeze-drying, were investigated. The peroxotitanate materials thus obtained were characterized by XRD, BET, SEM, TEM, EDX, ICP, and Raman spectroscopy. At an H/T ratio of 2, peroxotitanate predominantly exhibited an amorphous structure, with a clearly observed tubular or fibrous structure. Furthermore, peroxotitanate modified at an H/T ratio of 2 exhibited the best ion-exchange capacity of 191 mg g−1 for metal ions contained in a radioactive waste simulant solution. Hence, these peroxotitanate materials are suitable for removing metal ions from wastewater, especially lanthanide ions (Ln3+ and Sr2+.

Distribution of Heavy Metal Content Hg and Cr of Environmental Samples at Surabaya Area

International Nuclear Information System (INIS)

Agus Taftazani

2007-01-01

Determination of Hg and Cr content of Surabaya river and coastal environmental samples using Instrumental Neutron Activation Analysis (INAA) have been done. The environmental samples were water, sediment, Eichhornia crassipes (Mart) Solmms, Rhizophora stylosa, Johnius (Johnieops) borneensis fish, and Moolgarda delicate fish at 12 locations selected of Surabaya area. Dry powder of sediment and biotic samples and concentrate water samples was irradiated by neutron flux 1.05 x 10 11 n.cm -2 .det -1 during 12 hours. The analytical result showed that the concentration of the heavy metals of river water are smaller than Perda Surabaya City No. 02/2004 for the 4 th level water which are Hg (0.005 ppm) and Cr (1.000 ppm). All locations coastal water samples have Hg and Cr concentrations are higher than Kepmen LH No.51/2004 Hg (0.001 ppm) and Cr (0.005 ppm). The Hg concentration of fish samples have exceeded the threshold according to Kep. Dirjen POM No.03725/B/SK/VII/89 about the maximum concentration of metal pollution in food. The concentration of heavy metals in sediment, Eichhornia crassipes (Mart) Solmms and Rhizophora stylosa are not regulated, so then heavy metals pollution can not be referred to. The concentration of Hg and Cr elements of water samples are smaller than that of biotic and sediment samples. The distribution factor (F d ) is bigger than bioaccumulation factor (F b ). (author)

Heavy oils clean up

International Nuclear Information System (INIS)

Collitt, R.

1997-01-01

High production, transport and refining costs have long led oil companies to shun heavy crude oils. Advances in the technology of upgrading heavy oils, however, are likely to reduce transport costs and improve the refinery output. Research and development by Venezuela's state oil company, Petroleos de Venezuela (PDVSA), has resulted in a process called Aquaconversion which permits the upgrading of heavy crude oils using a catalyst and the hydrogen from steam. This may be carried out at the wellhead in small low-pressure and relatively inexpensive units. In addition, higher distillate yields of higher value could be produced by revamping the thermal cracking units of refineries to incorporate the new technology. This has generated considerable interest in Venezuela's large extra-heavy crude oil reserves and has led multinational oil companies along with PDVSA to pledge $17 billion to their development. Even at a $2 to $3 per barrel upgrading cost, Venezuela's extra heavy crudes are competitive with lighter oils from other countries. Other major markets for the new technology are likely to be China and Russia, given their own large heavy crude reserves. (UK)

Pyrolysis of de-oiled seed cake of Jatropha Curcas and catalytic steam reforming of pyrolytic bio-oil to hydrogen.

Science.gov (United States)

Renny, Andrew; Santhosh, Viswanathan; Somkuwar, Nitin; Gokak, D T; Sharma, Pankaj; Bhargava, Sanjay

2016-11-01

The aim of this work was to study the pyrolysis of de-oiled seed cake of Jatropha Curcas and catalytic steam reforming of pyrolytic bio-oil to hydrogen. As per literature, presence of heavy nitrogenous and oxygenated compounds leads to catalyst deactivation. Here, an attempt has been made to tune pyrolytic reactions to optimize the N and O content of the pyrolytic bio-oil. Bio-oil conversion and hydrogen yield decreased as reaction progressed, which attributes to temporary loss of catalytic activity by blockage of catalyst pores by carbon deposition. Further, retention of steam reforming activity after repetitive steam activation suggests long-term catalyst usage. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hydrogen manufacturing using plasma reformers

Energy Technology Data Exchange (ETDEWEB)

Bromberg, L.; Cohn, D.R.; Rabinovich, A.; Hochgreb, S.; O`Brien, C. [Massachusetts Institute of Technology, Cambridge, MA (United States)

1996-10-01

Manufacturing of hydrogen from hydrocarbon fuels is needed for a variety of applications. These applications include fuel cells used in stationary electric power production and in vehicular propulsion. Hydrogen can also be used for various combustion engine systems. There is a wide range of requirements on the capacity of the hydrogen manufacturing system, the purity of the hydrogen fuel, and capability for rapid response. The overall objectives of a hydrogen manufacturing facility are to operate with high availability at the lowest possible cost and to have minimal adverse environmental impact. Plasma technology has potential to significantly alleviate shortcomings of conventional means of manufacturing hydrogen. These shortcomings include cost and deterioration of catalysts; limitations on hydrogen production from heavy hydrocarbons; limitations on rapid response; and size and weight requirements. In addition, use of plasma technology could provide for a greater variety of operating modes; in particular the possibility of virtual elimination of CO{sub 2} production by pyrolytic operation. This mode of hydrogen production may be of increasing importance due to recent additional evidence of global warming.

classification of plants according to their heavy metal content around

African Journals Online (AJOL)

Mgina

accumulated heavy metals around North Mara Gold Mine were not known. To study such ... heavy metal hyperaccumulator plants for possible future remediation of the study area. ... mine is about 100 kilometers east of Lake. Victoria and 20 ...

Evaluation of the plasma hydrogen isotope content by residual gas analysis at JET and AUG

Science.gov (United States)

Drenik, A.; Alegre, D.; Brezinsek, S.; De Castro, A.; Kruezi, U.; Oberkofler, M.; Panjan, M.; Primc, G.; Reichbauer, T.; Resnik, M.; Rohde, V.; Seibt, M.; Schneider, P. A.; Wauters, T.; Zaplotnik, R.; ASDEX-Upgrade, the; EUROfusion MST1 Teams; contributors, JET

2017-12-01

The isotope content of the plasma reflects on the dynamics of isotope changeover experiments, efficiency of wall conditioning and the performance of a fusion device in the active phase of operation. The assessment of the isotope ratio of hydrogen and methane molecules is used as a novel method of assessing the plasma isotope ratios at JET and ASDEX-Upgrade (AUG). The isotope ratios of both molecules in general shows similar trends as the isotope ratio detected by other diagnostics. At JET, the absolute values of RGA signals are in relatively good agreement with each other and with spectroscopy data, while at AUG the deviation from neutral particle analyser data are larger, and the results show a consistent spatial distribution of the isotope ratio. It is further shown that the isotope ratio of the hydrogen molecule can be used to study the degree of dissociation of the injected gas during changeover experiments.

The potential role of electrolytic hydrogen in Canada

International Nuclear Information System (INIS)

Hammerli, M.

1982-03-01

The potential role of electrolytic hydrogen in Canada is assessed for the period 1980 to 2025 for large-scale uses only. Present uses of hydrogen, and specifically electrolytic hydrogen, are discussed briefly and hydrogen production processes are summarized. Only hydrogen derived from natural gas, coal, or electrolysis of sater are considered. Cost estimates of electrolytic hydrogen are obtained from a parametric equation, comparing values for unipolar water elecctrklyser technologies with those for bipolar electrolysers. Both by-products of electrolytic hydrogen production, namely heavy water and oxygen, are evaluated. Electrolytic hydrogen, based on non-fossil primary energy sources, is also considered as ankther 'liquid fuel option' for Canada along with the alcohols. The market potential for hydrogen in general and electrolytic hydrogen is assessed. Results show that the market potential for electrolytic hydrogen is large by the year 2025

Investigation of heavy metals content in medicinal plant, eclipta alba L

International Nuclear Information System (INIS)

Hussain, I.; Khan, H.

2010-01-01

Heavy metal such as Cr, Fe, Zn, Mn, Ni, Pb, Cu and Cd were investigated in a= medicinally important plant, Eclipta alba L. as well as in the soil it was grown using atomic absorption spectrophotometer. The plant samples were collected from their natural habitat at three different locations of Peshawar Pakistan. The whole plant materials (roots, stems and leaves) were found to contain all heavy metals except Cd, which corresponds to their concentration in the soil it was grown. Among all the heavy metals, Fe was found to be at the highest level (8.95 to 27.7 mg/kg) followed by Mn (0.44 to 14.0 mg/kg) and Zn (1.04 to 4.50 mg/kg), while the rest of metals were at low concentration. The present study showed that E. alba L. is suitable for the control of environmental pollutants such as heavy metals, however, for medicinal purposes; it should be collected from those areas which are not contaminated with heavy metals. The purpose of the current study was to standardize various indigenous medicinal plants for heavy metals contamination and to make awareness among the public regarding its safer use and collection areas, containing high level of heavy metals and their adverse health affects. (author)

Liquid-phase chemical hydrogen storage: catalytic hydrogen generation under ambient conditions.

Science.gov (United States)

Jiang, Hai-Long; Singh, Sanjay Kumar; Yan, Jun-Min; Zhang, Xin-Bo; Xu, Qiang

2010-05-25

There is a demand for a sufficient and sustainable energy supply. Hence, the search for applicable hydrogen storage materials is extremely important owing to the diversified merits of hydrogen energy. Lithium and sodium borohydride, ammonia borane, hydrazine, and formic acid have been extensively investigated as promising hydrogen storage materials based on their relatively high hydrogen content. Significant advances, such as hydrogen generation temperatures and reaction kinetics, have been made in the catalytic hydrolysis of aqueous lithium and sodium borohydride and ammonia borane as well as in the catalytic decomposition of hydrous hydrazine and formic acid. In this Minireview we briefly survey the research progresses in catalytic hydrogen generation from these liquid-phase chemical hydrogen storage materials.

Compacted sewage sludge as a barrier for tailings: the heavy metal speciation and total organic carbon content in the compacted sludge specimen.

Directory of Open Access Journals (Sweden)

Huyuan Zhang

Full Text Available Acid mine drainage (AMD was the main environmental problem facing the mining industry. For AMD had high heavy metals content and low pH, the compacted sewage sludge might be a barrier for tailings whose oxidation and weathering produced AMD, with its own carbon source, microorganism reduction ability and impermeability. To study the heavy metals environmental risk, under the simulate AMD, the deionized water (DW, and the pH 2.1 sulfuric acid water (SA seepage conditions, respectively, the changes of the chemical speciation of heavy metals Cd, Cu, Fe, Ni, Zn and total organic carbon (TOC content in the compacted sewage sludge were assessed in the different periods. The results indicated according to the distribution of heavy metals, the potential mobility was for Cd: 6.08 under AMD, 7.48 under SA, ∞ under DW; for Cu: 0.08 under AMD, 0.17 under SA, 0.59 under DW; for Fe: 0.15 under AMD, 0.22 under SA, 0.22 under DW; for Ni: 2.60 under AMD, 1.69 under SA, 1.67 under DW; and for Zn: 0.15 under AMD, 0.23 under SA and 0.21 under DW at the second checking time. TOC content firstly decreased from 67.62±0% to 66.29±0.35%, then increased to 67.74±0.65% under the AMD seepage while TOC decreased to 63.30±0.53%, then to 61.33±0.37% under the DW seepage, decreased to 63.86±0.41%, then to 63.28±0.49% under SA seepage. That indicated under the AMD seepage, the suitable microorganisms communities in the compacted sewage sludge were activated. And the heavy metals environmental risk of compacted sewage sludge was lower with AMD condition than with other two. So the compacted sewage sludge as a barrier for tailings was feasible as the aspect of environmental risk assessment.

Hydrogen application dynamics and networks

Energy Technology Data Exchange (ETDEWEB)

Schmidt, E. [Air Liquide Large Industries, Champigny-sur-Marne (France)

2010-12-30

The Chemical Industry consumes large volumes of hydrogen as raw material for the manufacture of numerous products (e.g. polyamides and polyurethanes account for 60% of hydrogen demand). The hydrogen demand was in the recent past and will continue to be driven by the polyurethane family. China will host about 60% of new hydrogen needs over the period 2010-2015 becoming the first hydrogen market next year and reaching 25% of market share by 2015 (vs. only 4% in 2001). Air Liquide supplies large volumes of Hydrogen (and other Industrial Gases) to customers by on-site plants and through pipeline networks which offer significant benefits such as higher safety, reliability and flexibility of supply. Thanks to its long term strategy and heavy investment in large units and pipeline networks, Air Liquide is the Industrial Gas leader in most of the world class Petrochemical basins (Rotterdam, Antwerp, US Gulf Coast, Yosu, Caojing,..) (orig.)

Features of hydrotreating catalytic cracking feed and heavy slow coking gas oils

Energy Technology Data Exchange (ETDEWEB)

Yefremov, N.I.; Kushnarev, D.F.; Frolov, P.A.; Chagovets, A.N.; Kalabin, G.A.

1993-12-31

A possible means of more extensive processing of crude oil is the use, in catalytic cracking, of heavy coking gas oils (HCGOs), a feature of which is a higher content of polycyclic aromatic compounds and resins by comparison with straight-run vacuum distillates. The presence of these compounds in catalytic cracking feed causes a reduction in the product yield and increased coke formation. Therefore, one of the problems of hydrotreating feedstock of this kind is the hydrogenation of polycyclic arenes. Processes of extensive desulphurization and denitration occur in parallel, since the sulphur and nitrogen compounds of HCGO are chiefly condensed benzoderivatives of thiophene, pyridine and carbazole, and largely concentrated in heavy aromatic and resinous fractions. The composition of the saturated part of the cracking feed plays a large role in achieving the optimum yields of gaseous and gasoline fractions. Thus an increase in the proportion of cyclanes in the feed raises the gasoline yield. In this way, an investigation of the hydrocarbon conversions during the hydrotreatment of cracking feed is of great importance. The present paper sets out the results for studying the change in the group-structural characteristics of the hydrogenation products of a mixture containing 30% HCGOs according to data of {sup 1}H and {sup 13}C NMR spectroscopy. 7 refs., 7 figs., 1 tab.

Hydrogenation and high temperature oxidation of Zirconium claddings

International Nuclear Information System (INIS)

Novotny, T.; Perez-Feró, E.; Horváth, M.

2015-01-01

In the last few years a new series of experiments started for supporting the new LOCA criteria, considering the proposals of US NRC. The effects which can cause the embrittlement of VVER fuel claddings were reviewed and evaluated in the framework of the project. The purpose of the work was to determine how the fuel cladding’s hydrogen uptake under normal operating conditions, effect the behavior of the cladding under LOCA conditions. As a first step a gas system equipment with gas valves and pressure gauge was built, in which the zirconium alloy can absorb hydrogen under controlled conditions. In this apparatus E110 (produced by electrolytic method, currently used at Paks NPP) and E110G (produced by a new technology) alloys were hydrogenated to predetermined hydrogen contents. According the results of ring compression tests the E110G alloys lose their ductility above 3200 ppm hydrogen content. This limit can be applied to determine the ductile-brittle transition of the nuclear fuel claddings. After the hydrogenation, high temperature oxidation experiments were carried out on the E110G and E110 samples at 1000 °C and 1200 °C. 16 pieces of E110G and 8 samples of E110 with 300 ppm and 600 ppm hydrogen content were tested. The oxidation of the specimens was performed in steam, under isothermal conditions. Based on the ring compression tests load-displacement curves were recorded. The main objective of the compression tests was to determine the ductile-brittle transition. These results were compared to the results of our previous experiments where the samples did not contain hydrogen. The original claddings showed more ductile behavior than the samples with hydrogen content. The higher hydrogen content resulted in a more brittle mechanical behavior. However no significant difference was observed in the oxidation kinetics of the same cladding types with different hydrogen content. The experiments showed that the normal operating hydrogen uptake of the fuel claddings

Neutronographic measurements of the motion of hydrogen and hydrogeneous substances in liquids and solids

International Nuclear Information System (INIS)

Zeilinger, A.; Pochman, W.A.; Rauch, H.; Suleiman, M.

1976-01-01

Earlier measurements of hydrogen motion in liquids by neutron radiography have been extended to obtain additional parameters of governing the mixing behavior of light and heavy water. Furthermore motion of water in concrete was measured leading to a determination of (1) the vapor diffusion coefficient of water in concrete, (2) the porosity of the concrete, and (3) the mass transfer coefficient of vapor from the concrete to the environment. Recently the ability of neutron radiography to measure the hydrogen motion in metals was demonstrated and the diffusion coefficients of hydrogen in V, Ta, Nb and beta-Ti was determined. In addition, some work on resolution measurements of neutron radiography will be reported. (author)

Hydrogenation properties of Zr films under various conditions of hydrogen plasma

CERN Document Server

Yan Guo Qiang; Zhou Zhu Ying; Zhao Guo Qing; Hu Pei Gang; Luo Shun Zhong; Peng Shu Ming; Ding Wei; Long Xing Gui

2002-01-01

The hydrogenation properties of Zr samples with and without an Ni overlayer under various plasma conditions were investigated by means of non-Rutherford backscattering and elastic recoil detection analysis. The theoretical maximum hydrogen capacity, 66.7 at%, could be achieved at a hydrogen absolute pressure of approx 2 Pa and a substrate temperature of approx 393K for a plasma irradiation of only 10 min; this was significantly greater than that for gas hydrogenation under the same hydrogen pressure and substrate temperature. It was also found that the C and O contamination on the sample surface strongly influences the hydrogenation, and that the maximum equilibrium hydrogen content drops dramatically with the increasing total contamination. In addition, the influence of the Ni overlayer on the plasma hydrogenation is discussed

76 FR 52994 - Application for a License To Export Heavy Water

Science.gov (United States)

2011-08-24

... NUCLEAR REGULATORY COMMISSION Application for a License To Export Heavy Water Pursuant to 10 CFR... (liters). producing an active water). pharmaceutical ingredient known as CTP-499, which incorporates heavy water as the source of deuterium to achieve the hydrogen-deuterium exchange. November 30, 2010 December...

Carbon: Hydrogen carrier or disappearing skeleton?

International Nuclear Information System (INIS)

De Jong, K.P.; Van Wechem, H.M.H.

1994-01-01

The use of liquid hydrocarbons as energy carriers implies the use of carbon as a carrier for hydrogen to facilitate hydrogen transport and storage. The current trend for liquid energy carriers used in the transport sector is to maximize the load of hydrogen on the carbon carrier. The recently developed Shell Middle Distillate Hydrogenation process for the manufacture of high quality diesel from aromatic refinery streams fits this picture. In the future, the hydrogen required to raise the product H/C ratio will be increasingly produced via gasification of large amounts of heavy residues. In the light of the strong preference towards using liquid fuels in the transport sector, the Shell Middle Distillate Synthesis process to convert natural gas into diesel of very high quality is discussed. Finally, a few comments on the use of hydrogen without a carbon carrier are made. Long lead times and the likelihood of producing the 'first' hydrogen from fossil fuel are highlighted. 13 figs., 6 tabs., 5 refs

Dynamics of the content of lipoproteins in blood serum of carp under the influence of ions of heavy metals

International Nuclear Information System (INIS)

Kurant, V.Z.; Sinyuk, Yu.V.; Arsan, V.O.; Grubyinko, V.V.

2005-01-01

A change of the content of lipoproteins in the blood serum of carp under the influence of ions of manganese, zinc, copper, and lead is studied. The important role of lipoproteins in the blood serum of fish in the processes of detoxication of ions of heavy metals that come to their organism from the water environment is shown

Hydrogen management in the MiRO refinery

Energy Technology Data Exchange (ETDEWEB)

Neumann, G. [Mineraloelraffinerie Oberrhein GmbH und Co. KG, Karlsruhe (Germany)

2010-12-30

The importance of hydrogen in refineries has increased over the last 20 years as new regulations affecting gasoline and diesel composition have been implemented throughout Europe and in an environment of increasingly stringent clean fuel regulations, decreasing heavy fuel oil demand and increasing heavy more sour crude supply. In Germany, the introduction of sulphur free gasoline and diesel with less than 10ppm sulphur(Auto Oil Program) and light home fuel oil with less than 50ppm this year were the last link in a long chain of environmental regulations, which had a considerable effect on the hydrogen demand in refineries. In the complex MiRO-refinery with a large FCC- and Coker-Unit for atmospheric residue conversion and a total throughput of more than 15 Mio.T/ a and more than 14 Mio.T/a crude oils of different origin from high sulphur, bituminous crudes to medium, low sulphur crudes for calcinate-production from green coke the only source of hydrogen for a long time was catalytic reforming. The only chance of balancing the hydrogen production and consumption was to improve the existing catalytic reforming and the optimisation of hydrogen recovery from waste or purge streams and the hydrogen network of the refinery. In 2007 a new hydrogen plant via steam reforming of natural gas went on stream. The main reason for this step was the shrinking market for gasoline in the last ten years and the blending of bio-ethanol into the gasoline pool, which released reforming capacities and the demand for octane. Another important issue is the production planning taking into account the potentials of hydrogen production via catalytic and steam reforming and the hydrogen consumption via desulphurisation and the saturation of olefins and (poly-)aromatics of the main product streams, gasoline, diesel and light home fuel oil. (orig.)

Atomic hydrogen reactor

International Nuclear Information System (INIS)

Massip de Turville, C.M.D.

1982-01-01

Methods are discussed of generating heat in an atomic hydrogen reactor which involve; the production of atomic hydrogen by an electrical discharge, the capture of nascent neutrons from atomic hydrogen in a number of surrounding steel alloy tubes having a high manganese content to produce 56 Mn, the irradiation of atomic hydrogen by the high energy antineutrinos from the beta decay of 56 Mn to yield nascent neutrons, and the removal of the heat generated by the capture of nascent neutrons by 55 Mn and the beta decay of 56 Mn. (U.K.)

Phytotoxicity of thallium (Tl) in culture solution. Pt. 2. Effects of Tl(III) on the growth and heavy metal contents of pea and field bean plants

Energy Technology Data Exchange (ETDEWEB)

Pieper, B; Austenfeld, F A

1985-01-01

The effects of Tl(NO/sub 3/)/sub 3/ and Tl(III)EDTA on growth and heavy metal contents of pea plants and field bean plants were compared in hydroponic culture experiments. In the presence of Tl(NO/sub 3/)/sub 3/, the essential heavy metals were available to the plants in their ionic forms. When Tl(III)EDTA was present the essential heavy metals were available as chelated complexes. Dry matter production of the pea plants was inhibited to a greater extent by Tl(III)EDTA than by Tl(NO/sub 3/)/sub 3/. The distribution of Tl within the plant was unaffected by the accompanying anion, however an increase of the Tl content of the stems and the leaves was observed in the presence of Tl(III)EDTA. The micronutrients exhibited different interactions with Tl(III). In the presence of increasing concentrations of Tl(NO/sub 3/)/sub 3/ the Mn content of each organ and the Zn content of the roots were lowered, but the Zn content of the stems was increased. Increasing concentrations of Tl(III)EDTA resulted only in a decrease of the Mn content of the roots, but in an increase of the contents of Fe and Mn within the stems, and Fe, Mn, Zn, and Cu within the leaves. The increases may be due to concentration by growth inhibition. In contrast to pea plants, growth of field bean plants was inhibited only by Tl(NO/sub 3/)/sub 3/. The field bean plants retained most of the Tl within the roots independent of the Tl compound in the solution. Chelation of Tl(III) resulted in higher Tl contents of both the roots and the stems, but equal or reduced Tl contents of the leaves. Whereas increasing concentrations of Tl(NO/sub 3/)/sub 3/ reduced the Mn content of each organ as well as the Zn content of the roots and the leaves, Tl(III)EDTA only reduced the Mn content of the roots.

Internal hydrogen-induced subcritical crack growth in austenitic stainless steels

Science.gov (United States)

Huang, J. H.; Altstetter, C. J.

1991-11-01

The effects of small amounts of dissolved hydrogen on crack propagation were determined for two austenitic stainless steel alloys, AISI 301 and 310S. In order to have a uniform distribution of hydrogen in the alloys, they were cathodically charged at high temperature in a molten salt electrolyte. Sustained load tests were performed on fatigue precracked specimens in air at 0 ‡C, 25 ‡C, and 50 ‡C with hydrogen contents up to 41 wt ppm. The electrical potential drop method with optical calibration was used to continuously monitor the crack position. Log crack velocity vs stress intensity curves had definite thresholds for subcritical crack growth (SCG), but stage II was not always clearly delineated. In the unstable austenitic steel, AISI 301, the threshold stress intensity decreased with increasing hydrogen content or increasing temperature, but beyond about 10 wt ppm, it became insensitive to hydrogen concentration. At higher concentrations, stage II became less distinct. In the stable stainless steel, subcritical crack growth was observed only for a specimen containing 41 wt ppm hydrogen. Fractographic features were correlated with stress intensity, hydrogen content, and temperature. The fracture mode changed with temperature and hydrogen content. For unstable austenitic steel, low temperature and high hydrogen content favored intergranular fracture while microvoid coalescence dominated at a low hydrogen content. The interpretation of these phenomena is based on the tendency for stress-induced phase transformation, the different hydrogen diffusivity and solubility in ferrite and austenite, and outgassing from the crack tip. After comparing the embrittlement due to internal hydrogen with that in external hydrogen, it is concluded that the critical hydrogen distribution for the onset of subcritical crack growth is reached at a location that is very near the crack tip.

Further investigation of the heavy metal content of the teeth of the bank vole as an exposure indicator of Environmental Pollution (1987)(1987)in Poland

Energy Technology Data Exchange (ETDEWEB)

Gdula-Argasinska, Joanna; Appleton, John; Sawicka-Kapusta, Katarzyna; Spence, Bill

2004-09-01

The content of heavy metals in mineralised dental tissues is an indicator of the exposure of their mineral phase to heavy metals during the time of tooth development and dental tissue formation. Therefore, teeth have been used as bio-indicators which accurately reflect the environmental or dietary exposure of animals and humans to heavy metals. This study follows from the earlier work in which it was demonstrated that the teeth from bank voles inhabiting various environmentally polluted and non-polluted forests in Southern Poland were reliable indicators of exposure to heavy metals. Using analytical techniques employed in the earlier study heavy metal concentrations were obtained in the teeth of bank voles trapped in 1998-2000 to determine if efforts to clean up the environment could be detected in changes in heavy metal concentrations in the teeth. The results show that these efforts are reflected in lower concentrations of heavy metals in the teeth but that cross border contamination remains a problem.

Heavy-Duty Diesel Fuel Analysis

Science.gov (United States)

EPA's heavy-duty diesel fuel analysis program sought to quantify the hydrocarbon, NOx, and PM emission effects of diesel fuel parameters (such as cetane number, aromatics content, and fuel density) on various nonroad and highway heavy-duty diesel engines.

Effect of irrigation on heavy metals content of wastewater irrigated ...

African Journals Online (AJOL)

There is an urgent need to educate farmers on the dangers of the presence of heavy metals in soils as well as the quality of irrigation water especially if it comes from tanning industries for increased crop production. Accordingly, soil and irrigation wastewater study was conducted to assess the concentrations of heavy ...

Summary of heavy ion theory

International Nuclear Information System (INIS)

Gavin, S.

1994-09-01

Can we study hot QCD using nuclear collisions? Can we learn about metallic hydrogen from the impact of comet Shoemaker-Levy 9 on Jupiter? The answer to both questions may surprise you exclamation point I summarize progress in relativistic heavy ion theory reported at DPF '94 in the parallel sessions

Behaviour of hydrogen in niobium

International Nuclear Information System (INIS)

Chuang, Y.C.; Tang, C.H.; Chuang, T.L.

1982-01-01

Polycrystalline niobium was charged electrolytically with hydrogen at room temperature. The behaviour of hydrogen in niobium has been investigated by optical microscopy, SEM, and ion microprobe analysis. It is shown that, when the hydrogen content in niobium is low, hydride tends to form at the grain boundary. As the hydrogen content is increased, precipitation of hydrides with domain structure takes place in the grain. The habit plane of the hydride formed in the vicinity of the grain boundary has been determined by Laue X-ray back reflection technique to be (130)c and (111)c. The structure of the hydride formed on the surface of niobium after 6 h hydrogen charging at room temperature (c.d. 0.2 A/cm 2 ) has been established to be identical to that of NbHsub(0.89). (orig.) [de

Experimental study of hydrogen isotopes storage on titanium bed

International Nuclear Information System (INIS)

Vasut, Felicia; Zamfirache, Marius; Bornea, Anisia; Pearsica, Claudia; Bidica, Nicolae

2002-01-01

As known, the Nuclear Power Plant Cernavoda equipped with a Canadian reactor, of CANDU type, is the most powerful tritium source from Europe. On long term, due to a 6·10 16 Bq/year, Cernavoda area will be contaminated due to the increasing tritium quantity. Also, the continuous contamination of heavy water from the reactor, induces a reduction of moderation's capacity. Therefore, one considers that it is improperly to use heavy water if its activity level is higher than 40 Ci/kg in the moderator and 2 Ci/kg in the cooling fluid. For these reasons, we have developed a detritiation technology, based on catalytic isotopic exchange and cryogenic distillation. Tritium will be removed from the tritiated heavy water, so it appears the necessity of storage of tritium in a special vessel that can provide a high level of protection and safety of environment and personal. There several metals were tested as storage beds for hydrogen isotopes. One of the reference materials used for storage of hydrogen isotopes is uranium, a material with a great storage capacity, but unfortunately it is a radioactive metal and also can react with the impurities from the stored gas. Other metals and alloys as ZrCo, Ti, FeTi are also adequate as storage beds at normal temperature. The paper presents studies about the reaction between hydrogen and titanium used as storage bed for the hydrogen isotopes resulted after the detritiation of tritiated heavy water. The experiments that were carried out used protium and mixture of deuterium and protium at different storage parameters as process gas. (authors)

Conceptual study of hydrogen donor solvent in the NEDOL coal liquefaction process

Energy Technology Data Exchange (ETDEWEB)

Kouzu, M.; Onozaki, M.; Oi, S. [Mitsui SRC Co Ltd, Tokyo (Japan)

2002-03-01

A 150 ton/day coal liquefaction pilot plant (PP) of the NEDOL process, supported by New Energy and Industrial Technology Development Organization (NEDO), was operated successfully for a total of 269 days at Kashima, Japan. With a great number of data obtained through the operation, the design procedure for the NEDOL process was studied. Middle and heavy oils from the coal employed were recycled as a hydrogen-donor solvent after hydrotreatment over Ni Mo/gamma-Al2O{sub 3} in a trickle bed reactor. The hydrogen donating ability of the solvent was high enough to obtain higher oil yield (50-58 wt%) at the aromaticity of ca. 0.45. Life expectancy of solvent hydrotreatment catalyst, requisite to the hydrotreater design, was estimated under PP operating conditions. In addition, physical properties of the solvent required for process design were determined, and hydrodynamics in the liquefaction bubble column reactors were examined. Taking the obtained hydrodynamics and thermal behavior into consideration, a design procedure of the liquefaction bubble column reactors was establsihed using a process simulator (CARD) validated by the product yields of PP. The simulation including distillation and solvent hydrotreatment showed that the content of heavy oil fraction (b.p. 350 - 538{degree} C) in the solvent was a determinant factor in the design of a large scale plant based on the NEDOL process.

ASSESSMENT OF HEAVY METALS AND CRUDE PROTEIN ...

African Journals Online (AJOL)

UNICORN

to quantify heavy metals (Cu, Zn, Pb and Cd) and crude protein content of these species that are sold in ... in protein, omega 3 and low fat content. Furthermore ... high levels of cadmium can cause kidney and liver damage in man [6]. Motivation .... analysis. Determination of heavy metals in the edible tissues of the organisms.

Mix for production of heavy concretes

International Nuclear Information System (INIS)

Skvara, F.; Halen, S.; Kolar, K.; Novotny, J.; Zadak, Z.; Zezulka, J.

1981-01-01

The mix consists of 76 to 99.79 wt.% of cement clay of a specific area of 150 to 3000 m 2 /kg, of heavy aggregate (in a ratio of 1 part of cement clay to more than 1 part of the heavy aggregate) and of 0.1 to 8 wt.% of lignosulphonic acid salt. The mix also contains 0.1 to 8 wt.% of boric acid, 0.01 to 8 wt.% of a carbonate or a hydrogen carbonate of an alkali metal. (H.S.)

Morphology, mechanical, cross-linking, thermal, and tribological properties of nitrile and hydrogenated nitrile rubber/multi-walled carbon nanotubes composites prepared by melt compounding: The effect of acrylonitrile content and hydrogenation

Energy Technology Data Exchange (ETDEWEB)

Likozar, Blaz, E-mail: blaz.likozar@fkkt.uni-lj.si [Polymer Competence Center Leoben GmbH, Montanuniversitaet Leoben, Roseggerstrasse 12, A-8700 Leoben (Austria); Major, Zoltan, E-mail: zoltan.major@jku.at [Polymer Competence Center Leoben GmbH, Montanuniversitaet Leoben, Roseggerstrasse 12, A-8700 Leoben (Austria)

2010-11-01

The purpose of this work was to prepare nanocomposites by mixing multi-walled carbon nanotubes (MWCNT) with nitrile and hydrogenated nitrile elastomers (NBR and HNBR). Utilization of transmission electronic microscopy (TEM), scanning electron microscopy (SEM), and small- and wide-angle X-ray scattering techniques (SAXS and WAXS) for advanced morphology observation of conducting filler-reinforced nitrile and hydrogenated nitrile rubber composites is reported. Principal results were increases in hardness (maximally 97 Shore, type A), elastic modulus (maximally 981 MPa), tensile strength (maximally 27.7 MPa), elongation at break (maximally 216%), cross-link density (maximally 7.94 x 10{sup 28} m{sup -3}), density (maximally 1.16 g cm{sup -3}), and tear strength (11.2 kN m{sup -1}), which were clearly visible at particular acrylonitrile contents both for unhydrogenated and hydrogenated polymers due to enhanced distribution of carbon nanotubes (CNT) and their aggregated particles in the applied rubber matrix. Conclusion was that multi-walled carbon nanotubes improved the performance of nitrile and hydrogenated nitrile rubber nanocomposites prepared by melt compounding.

Morphology, mechanical, cross-linking, thermal, and tribological properties of nitrile and hydrogenated nitrile rubber/multi-walled carbon nanotubes composites prepared by melt compounding: The effect of acrylonitrile content and hydrogenation

Science.gov (United States)

Likozar, Blaž; Major, Zoltan

2010-11-01

The purpose of this work was to prepare nanocomposites by mixing multi-walled carbon nanotubes (MWCNT) with nitrile and hydrogenated nitrile elastomers (NBR and HNBR). Utilization of transmission electronic microscopy (TEM), scanning electron microscopy (SEM), and small- and wide-angle X-ray scattering techniques (SAXS and WAXS) for advanced morphology observation of conducting filler-reinforced nitrile and hydrogenated nitrile rubber composites is reported. Principal results were increases in hardness (maximally 97 Shore, type A), elastic modulus (maximally 981 MPa), tensile strength (maximally 27.7 MPa), elongation at break (maximally 216%), cross-link density (maximally 7.94 × 1028 m-3), density (maximally 1.16 g cm-3), and tear strength (11.2 kN m-1), which were clearly visible at particular acrylonitrile contents both for unhydrogenated and hydrogenated polymers due to enhanced distribution of carbon nanotubes (CNT) and their aggregated particles in the applied rubber matrix. Conclusion was that multi-walled carbon nanotubes improved the performance of nitrile and hydrogenated nitrile rubber nanocomposites prepared by melt compounding.

Morphology, mechanical, cross-linking, thermal, and tribological properties of nitrile and hydrogenated nitrile rubber/multi-walled carbon nanotubes composites prepared by melt compounding: The effect of acrylonitrile content and hydrogenation

International Nuclear Information System (INIS)

Likozar, Blaz; Major, Zoltan

2010-01-01

The purpose of this work was to prepare nanocomposites by mixing multi-walled carbon nanotubes (MWCNT) with nitrile and hydrogenated nitrile elastomers (NBR and HNBR). Utilization of transmission electronic microscopy (TEM), scanning electron microscopy (SEM), and small- and wide-angle X-ray scattering techniques (SAXS and WAXS) for advanced morphology observation of conducting filler-reinforced nitrile and hydrogenated nitrile rubber composites is reported. Principal results were increases in hardness (maximally 97 Shore, type A), elastic modulus (maximally 981 MPa), tensile strength (maximally 27.7 MPa), elongation at break (maximally 216%), cross-link density (maximally 7.94 x 10 28 m -3 ), density (maximally 1.16 g cm -3 ), and tear strength (11.2 kN m -1 ), which were clearly visible at particular acrylonitrile contents both for unhydrogenated and hydrogenated polymers due to enhanced distribution of carbon nanotubes (CNT) and their aggregated particles in the applied rubber matrix. Conclusion was that multi-walled carbon nanotubes improved the performance of nitrile and hydrogenated nitrile rubber nanocomposites prepared by melt compounding.

Probabilistic consequence assessment of hydrogen sulphide releases from a heavy water plant

International Nuclear Information System (INIS)

1983-06-01

This report is the second in a series concerned with the evaluation of the consequences to the public of an accidental release of hydrogen sulphide (H 2 S) to the atmosphere following a pipe or pressure envelope failure, or some other process upset, at a heavy water plant. It consists of documentation of the code GASPROB, which has been developed to provide consequence probabilities for a range of postulated releases. The code includes mathematical simulations of initial gas behaviour upon release to the atmosphere, such as gravitational settling of a cold release and the rise of jets and flares, subsequent atmospheric dispersion under a range of weather conditions, and the toxic effects on the exposed population. The code makes use of the site-specific dispersion climatology, topography and population distribution, as well as the probabilistic lethal dose data for the released gas. Output for a given postulated release can be provided in terms of the concentration of the gas at ground level around the point of release, projected numbers of fatalities within specified areas and the projected total fatalities regardless of location. This report includes a general description of GASPROB, and specifics of the code structure, the function of each subroutine, input and output data, and the permanent data files established. Three appendices to the report contain a complete code listing, detailed subroutine descriptions and a sample output

Hydrogen analysis by elastic recoil spectrometry

International Nuclear Information System (INIS)

Tirira, J.; Trocellier, P.

1989-01-01

An absolute, quantitative procedure was developed to determine the hydrogen content and to describe its concentration profile in the near-surface region of solids. The experimental technique used was the elastic recoil detection analysis of protons induced by 4 He beam bombardment in the energy range <=1.8 MeV. The hydrogen content was calculated using a new recoil cross section expression. The analyses were performed in silicon crystals implanted with hydrogen at 10 keV. The implantation dose was evaluated with an accuracy of 10% and the hydrogen depth profile with that of +-10 nm around 200 nm. (author) 10 refs.; 3 figs

Effects of indium contents on photocatalytic performance of ZnIn_2S_4 for hydrogen evolution under visible light

International Nuclear Information System (INIS)

Song, Kelin; Zhu, Rongshu; Tian, Fei; Cao, Gang; Ouyang, Feng

2015-01-01

A series of ZnIn_xS_4_+_y (x=1.6, 2.0, 2.3, 2.6, 2.9, 3.1) photocatalysts were synthesized via a facile hydrothermal method and characterized by various analytical techniques, such as XRD, EDS, UV–vis DRS, SEM, TEM, BET and PL. The ZnIn_xS_4_+_y photocatalysts had a similar crystal structure. With the increase of indium content, the absorption edges of ZnIn_xS_4_+_y photocatalysts shifted to longer wavelength, their crystal sizes decreased firstly and then increased and the variation of the specific surface area and total pore volume was exactly opposite. Especially, when x=2.3, ZnIn_2_._3S_4_+_y catalyst had smallest crystal size, largest specific surface area and total pore volume. Additionally, the morphology of ZnIn_xS_4_+_y greatly depended on the contents of indium. The photocatalytic activity of ZnIn_xS_4_+_y was evaluated by photocatalytic hydrogen production from water under visible light. The ZnIn_2_._3S_4_+_y sample had the highest photocatalytic activity among these ZnIn_xS_4_+_y photocatalysts and its hydrogen production rate was 363 μmol/g h. - Graphical abstract: First, a series of catalysts were synthesized. And then those were characterized by various analytical techniques (such as SEM). finally, The photocatalytic activity of catalyst was evaluated by photocatalytic hydrogen production from water under visible light. - Highlights: • The photocatalytic property was studied upon visible-light irradiation. • ZnIn_xS_4_+_y photocatalysts show superior photocatalytic activity. • The catalyst of grain size, morphology and BET are related to indium content. • ZnIn_xS_4_+_y photocatalysts were synthesized via a facile hydrothermal method.

Evaluation of natural radioactivity and heavy metals content in Sudanese phosphate rocks used as low cost fertilizer

International Nuclear Information System (INIS)

Elkhangi, F.A.; Aamhed, M.M.O.; Abdalla, I.A.

1997-01-01

This study was carried out to determine the level of natural radioactivity and heavy metals content of Sudanese rock phosphate used as low cost fertilizer. Thirty samples collected from two types of local phosphate rocks from the Nuba mountains (Uro and Kurun) were used in this study and the activity concentrations of natural radioactivity determined using gamma spectroscopy were compared to those found in samples of imported phosphorous fertilizers Single Super phosphate (SSP) and Triple Super phosphate (TSP). The results showed that the ' Ra activity concentration was 0.6 - 0.8 Bq/g for Uro and 0.3 - 0.5 Bq/g for Kurun. As for the most commonly used imported fertilizer TSP, the result was found to be greater than that of Uro (around 1.0 Bq/g). The heavy metals content of Uro and Kurun rocks measured using X-ray Fluorescence Technique showed their levels were below the toxic levels reported by Christina (1991). It is evident that the environmental hazard is comparable in the local and imported fertilizers and is acceptable in both cases by international standards. The determine factor therefore in optioning for the use of a local or an imported brand should then be the fertilizing efficiency of the brand used against other economic consideration rather than the fertilizers environmental impact

Heavy metals in fish tissues/stomach contents in four marine wild commercially valuable fish species from the western continental shelf of South China Sea.

Science.gov (United States)

Gu, Yang-Guang; Lin, Qin; Huang, Hong-Hui; Wang, Liang-Gen; Ning, Jia-Jia; Du, Fei-Yan

2017-01-30

The concentrations of heavy metals (Cd, Pb, Cr, Ni, Cu and Zn) were determined in four commercially valuable fish species (Thunnus obesus, Decapterus lajang, Cubiceps squamiceps and Priacanthus macracanthus), collected in the western continental shelf of the South China Sea. Concentrations of Cd, Pb, Cr, Ni, Cu, and Zn in fish muscles were 0.006-0.050, 0.13-0.68, 0.18-0.85, 0.11-0.25, 0.12-0.77, and 2.41-4.73μg/g, wet weight, respectively. Concentrations of heavy metals in all species were below their acceptable daily upper limit, suggesting human consumption of these wild fish species may be safe, with health risk assessment based on the target hazard quotients (THQ) and total THQ, indicating no significant adverse health effects with consumption. The average concentrations of Zn were higher in gills than in stomach contents, backbones or muscle, while conversely, the other heavy metals had higher concentrations in stomach contents than in other tissues. Copyright © 2016 Elsevier Ltd. All rights reserved.

Proposal of guideline for bonding to prevention of hydrogen embrittlement at Ta/Zr bond interface. Hydrogen embrittlement in SUS304ULC/Ta/Zr explosive bonded joint

International Nuclear Information System (INIS)

Saida, Kazuyoshi; Fujimoto, Tetsuya; Nishimoto, Kazutoshi

2010-01-01

The occurrence condition of hydrogen embrittlement cracking at Ta/Zr bond interface was investigated with respect to the hydrogen content and applied stress in order to propose a guideline for the explosive bonding procedure to prevention of hydrogen embrittlement. Hydrogen charging test was conducted for SUS304ULC/Ta/Zr explosive bonded joints applied the different flexural strains. A hydrogen embrittlement crack occurred in the Zr substrate at Ta/Zr bond interface after hydrogen charging, and it was initiated at shorter charging times when the augmented strain was increased. The occurrence condition of hydrogen embrittlement cracking at Ta/Zr bond interface was shifted to lower stress and hydrogen content with an increase in the amount of explosive during bonding. It was suggested that hydrogen embrittlement in Ta/Zr explosive bonded joint could be inhibited by reducing the initial hydrogen content in Ta substrate less than approx. 5 ppm. (author)

Chemical aspects of hydrogen ingress in zirconium and zircaloy pressure tubes: ageing management of Indian PHWR coolant channels - determination of hydrogen and deuterium

International Nuclear Information System (INIS)

Sayi, Y.S.; Shankaran, P.S.; Yadav, C.S.; Ramanjaneyulu, P.S.; Venugopal, V.; Ramakumar, K.L.; Chhapru, G.C.; Prasad, R.; Jain, H.C.; Sood, D.D.

2009-02-01

Pressurized heavy water reactors (PHWRs) use zirconium and zirconium based alloys as clad and coolant tubes since its beginning. The first ever zircaloy-2 pressure tube failure occurred in 1983 at Ontario Hydro's Pickering Unit 2 in Canada which necessitated a thorough examination of causes of such failure. The failure was attributed to massive hydriding at the failed spot of pressure tube. Continuous usage of zirconium alloys could result in their hydrogen and deuterium pick-up leading to hydrogen/ deuterium embrittlement. The life of the zircaloy coolant channels is dictated by hydrogen/deuterium content and hence ageing management of the pressure tubes is essential for ensuring their trouble-free usage. It is desirable to have a sound knowledge on the chemical aspects of zirconium and zirconium based alloys metallurgy, the mechanistic principles of hydrogen ingress into the pressure tubes during in reactor service, and identifying suitable analytical methodologies for precise and accurate determination of hydrogen in wafer thin sliver samples carved out from insides of pressure tubes without causing any structural damage so that it can continue to remain in service. This is desirable so that the ageing management does not result in cost-escalation. This report is divided in to three main parts. The first part deals with the chemical aspects of zirconium and zirconium based alloy metallurgy, the mechanism of hydrogen pick-up and hydride formation in zirconium matrix. The second part describes various methodologies and their limitations, available for hydrogen/deuterium determination. The third part deals in detail, about the extensive investigations carried out at Radioanalytical Chemistry Division (RACD) in Radiochemistry and Isotope Group for establishing an indigenously developed hot vacuum extraction system in combination with quadrupole mass spectrometry for precise determination of hydrogen and deuterium in wafer thin sliver sample of zircaloy. The

Internal friction study of hydrides in zirconium at low hydrogen contents

International Nuclear Information System (INIS)

Peretti, H.A.; Corso, H.L.; Gonzalez, O.A.; Fernandez, L.; Ghilarducci, A.A.; Salva, H.R.

1999-01-01

Full text: Internal friction and shear modulus measurements were carried out on crystal bar zirconium in the as received and hydride conditions using an inverted forced pendulum. Hydriding was achieved in two ways: inside and out of the pendulum. The final hydrogen content determined by fusion analysis in the 'in situ' hydride sample was of 36 ppm. Another sample was hydride by the cathodic charge method with 25 ppm. The thermal solid solubility (TSS) phase boundary presents hysteresis between the precipitation (TSSP) and the dissolution (TSSD) temperatures for the zirconium hydrides. During the first thermal cycling the anelastic effects could be attributed to the δ, ε and metastable γ zirconium hydrides. After 'in situ' annealing at 490 K, these peaks completely disappear in the electrolytically charged sample, while in the 'in situ' hydride, the peaks remain with decreasing intensity. This effect can be understood in terms of the different surface conditions of the samples. (author)

Radiation Shielding Materials Containing Hydrogen, Boron, and Nitrogen: Systematic Computational and Experimental Study. Phase I

Science.gov (United States)

Thibeault, Sheila A.; Fay, Catharine C.; Lowther, Sharon E.; Earle, Kevin D.; Sauti, Godfrey; Kang, Jin Ho; Park, Cheol; McMullen, Amelia M.

2012-01-01

than possible with hydrogen storage; however, a systematic experimental hydrogenation study has not been reported. A combination of the two approaches may be explored to provide yet higher hydrogen content. The hydrogen containing BNNT produced in our study will be characterized for hydrogen content and thermal stability in simulated space service environments. These new materials systems will be tested for their radiation shielding effectiveness against high energy protons and high energy heavy ions at the HIMAC facility in Japan, or a comparable facility. These high energy particles simulate exposure to SEP and GCR environments. They will also be tested in the LaRC Neutron Exposure Laboratory for their neutron shielding effectiveness, an attribute that determines their capability to shield against the secondary neutrons found inside structures and on lunar and planetary surfaces. The potential significance is to produce a radiation protection enabling technology for future exploration missions. Crew on deep space human exploration missions greater than approximately 90 days cannot remain below current crew Permissible Exposure Limits without shielding and/or biological countermeasures. The intent of this research is to bring the Agency closer to extending space missions beyond the 90-day limit, with 1 year as a long-term goal. We are advocating a systems solution with a structural materials component. Our intent is to develop the best materials system for that materials component. In this Phase I study, we have shown, computationally, that hydrogen containing BNNT is effective for shielding against GCR, SEP, and neutrons over a wide range of energies. This is why we are focusing on hydrogen containing BNNT as an innovative advanced concept. In our future work, we plan to demonstrate, experimentally, that hydrogen, boron, and nitrogen based materials can provide mechanically strong, thermally stable, structural materials with effective radiation shielding against GCR

Electromagnetic radiation during electrolysis of heavy water

International Nuclear Information System (INIS)

Koval'chuk, E.P.; Yanchuk, O.M.; Reshetnyak, O.V.

1994-01-01

The radiation in the visible and ultraviolet spectral regions during electrolysis of heavy water on nickel and palladium cathodes was determined for the first time. A sharp jump of the intensity photon flow was observed at a current density of higher than 125 mA/cm 2 . A hypothesis about the relation of the electrochemiluminescence phenomenon during electrolysis of heavy water with the formation of fresh surfaces in consequence of the hydrogenous corrosion of the cathode material is formulated. ((orig.))

Insights into the Hydrogen-Atom Transfer of the Blue Aroxyl.

Science.gov (United States)

Bächle, Josua; Marković, Marijana; Kelterer, Anne-Marie; Grampp, Günter

2017-10-19

An experimental and theoretical study on hydrogen-atom transfer dynamics in the hydrogen-bonded substituted phenol/phenoxyl complex of the blue aroxyl (2,4,6-tri-tert-butylphenoxyl) is presented. The experimental exchange dynamics is determined in different organic solvents from the temperature-dependent alternating line-width effect in the continuous-wave ESR spectrum. From bent Arrhenius plots, effective tunnelling contributions with parallel heavy-atom motion are concluded. To clarify the transfer mechanism, reaction paths for different conformers of the substituted phenol/phenoxyl complex are modelled theoretically. Various DFT and post-Hartree-Fock methods including multireference methods are applied. From the comparison of experimental and theoretical data it is concluded that the system favours concerted hydrogen-atom transfer along a parabolic reaction path caused by heavy-atom motion. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electrolytic process for upgrading heavy water (Preprint No. PD-16)

International Nuclear Information System (INIS)

Rammohan, K.; Sadhukhan, H.K.

1989-04-01

In the reactor system the heavy water gets depleted in concentration due to leakages, intermixing and vapour collection in boiler vault system etc. Electrolysis of water was used as a secondary plant to enrich the dilute heavy water produced in the primery plant by hydrogen-sulfide-water exchange process. The studies made in the development of this process for the upgrading of downgra ded heavy water by setting up a full size Electrolyser Test Assembly are discussed a nd complete design of a heavy water upgrading plant based on electrolytic process for MAPS and NAPP is described. (author). 7 refs., 5 figs

Biosolids and heavy metals in soils

Directory of Open Access Journals (Sweden)

Silveira Maria Lucia Azevedo

2003-01-01

Full Text Available The application of sewage sludge or biosolids on soils has been widespread in agricultural areas. However, depending on their characteristics, they may cause increase in heavy metal concentration of treated soils. In general, domestic biosolids have lower heavy metal contents than industrial ones. Origin and treatment method of biosolids may markedly influence their characteristics. The legislation that controls the levels of heavy metal contents in biosolids and the maximum concentrations in soils is still controversial. In the long-term, heavy metal behavior after the and of biosolid application is still unknown. In soils, heavy metals may be adsorbed via specific or non-specific adsorption reactions. Iron oxides and organic matter are the most important soil constituents retaining heavy metals. The pH, CEC and the presence of competing ions also affect heavy metal adsorption and speciation in soils. In solution, heavy metals can be present either as free-ions or complexed with organic and inorganic ligands. Generally, free-ions are more relevant in environmental pollution studies since they are readily bioavailable. Some computer models can estimate heavy metal activity in solution and their ionic speciation. Thermodynamic data (thermodynamic stability constant, total metal and ligand concentrations are used by the GEOCHEM-PC program. This program allows studying heavy metal behavior in solution and the effect of changes in the conditions, such as pH and ionic strength and the application of organic and inorganic ligands caused by soil fertilization.

On line determination of deuterium in hydrogen water exchange reaction by mass spectrometry. IRP-10

International Nuclear Information System (INIS)

Sharma, J.D.; Alphonse, K.P.; Mishra, Sushama; Prabhu, S.A.; Mohan, Sadhana; Tangri, V.K.

2007-01-01

The Deuterium (D)/Hydrogen (H) analysis at low Concentration is generally carried out by Mass Spectrometry. Mass Spectrometer is specially designed for the measurement of Mass 2 and 3 ratio. The Deuterium analysis of water and hydrogen in concentration range of a few ppm to about 1% plays an important role in the Heavy Water Production Plants. For the enrichment of the Deuterium concentration in H 2 O by H 2 - H 2 O exchange a catalyst is essential as reaction is relatively slow. Heavy Water Division has developed in house Platinum based catalyst for the isotopic exchange of Hydrogen and Water

Analysis of oxidised heavy paraffininc products by high temperature comprehensive two-dimensional gas chromatography.

Science.gov (United States)

Potgieter, H; Bekker, R; Beigley, J; Rohwer, E

2017-08-04

Heavy petroleum fractions are produced during crude and synthetic crude oil refining processes and they need to be upgraded to useable products to increase their market value. Usually these fractions are upgraded to fuel products by hydrocracking, hydroisomerization and hydrogenation processes. These fractions are also upgraded to other high value commercial products like lubricant oils and waxes by distillation, hydrogenation, and oxidation and/or blending. Oxidation of hydrogenated heavy paraffinic fractions produces high value products that contain a variety of oxygenates and the characterization of these heavy oxygenates is very important for the control of oxidation processes. Traditionally titrimetric procedures are used to monitor oxygenate formation, however, these titrimetric procedures are tedious and lack selectivity toward specific oxygenate classes in complex matrices. Comprehensive two-dimensional gas chromatography (GC×GC) is a way of increasing peak capacity for the comprehensive analysis of complex samples. Other groups have used HT-GC×GC to extend the carbon number range attainable by GC×GC and have optimised HT-GC×GC parameters for the separation of aromatics, nitrogen-containing compounds as well as sulphur-containing compounds in heavy petroleum fractions. HT-GC×GC column combinations for the separation of oxygenates in oxidised heavy paraffinic fractions are optimised in this study. The advantages of the HT-GC×GC method in the monitoring of the oxidation reactions of heavy paraffinic fraction samples are illustrated. Copyright © 2017 Elsevier B.V. All rights reserved.

A painless approach to use distributed digital-control system for Heavy Water Plant- Tuticorin

International Nuclear Information System (INIS)

Potti, V.S.; Krishnan, S.; Rao, V.C.; Lamba, D.S.

1994-01-01

Heavy Water Plant (Tuticorin) production is based on mono thermal process of ammonia-hydrogen exchange and is connected with a 1100 tons per day capacity ammonia plant of M/s Southern Petrochemical Industries Limited for getting its feed. The deuterium concentration in the syngas (N 2 + 3H 2 ) is extracted through ammonia-hydrogen exchange process and finally burnt with air in the final product unit to get heavy water. The depleted syngas is sent back to M/s SPIC's synthesis unit. The purpose of this paper is to highlight the instrumentation requirements of heavy water production, problems encountered in use of DDCS along with remedial action taken for the back up facility. (author)

THE HEAVY METALS CONNTENT IN VEGETABLES FROM MIDDLE SPIŠ AREA

Directory of Open Access Journals (Sweden)

Marek Slávik,Tomáš Tóth

2014-02-01

Full Text Available In the middle area of Spiš, it is significantly burden by heavy metals what is documented by radical content of Hg in soil from Rudňany 58.583645 mg.kg -1. On the content of heavy metals in vegetables grown in this soil it has the same effect. 61.5% samples exceeded the limit value of heavy metals. The most dangerous vegetables were Lactuca sativa L. The limit value was exceed in all determine heavy metals - Hg, Cd, Pb and Cu in this vegetables. In the case of Hg, the limit value exceed 93.86 times. For relatively safety is growing of Pisum sativum L., where there was no exceed any limits values. The root vegetables are dangerous, where the sample of Raphanus sativus L. exceed 6.71978 times the limit values for Pb although the content of lead in the soil was under hygienic limits. Transfer of heavy metals into consume parts of vegetables was no limited by high content of humus into soil. Transfer of heavy metals into consume parts of vegetables was no limited by weakly alkaline soil reaction. These factors are considered for factors limited mobility and input heavy metals into plants. We determined heavy metals by AAS method on a Varian 240 FS and method AMA 254.

Fabrication of Metal Nanoparticle-Modified Screen Printed Carbon Electrodes for the Evaluation of Hydrogen Peroxide Content in Teeth Whitening Strips

Science.gov (United States)

Popa, Adriana; Abenojar, Eric C.; Vianna, Adam; Buenviaje, Czarina Y. A.; Yang, Jiahua; Pascual, Cherrie B.; Samia, Anna Cristina S.

2015-01-01

A laboratory experiment in which students synthesize Ag, Au, and Pt nanoparticles (NPs) and use them to modify screen printed carbon electrodes for the electroanalysis of the hydrogen peroxide content in commercially available teeth whitening strips is described. This experiment is designed for two 3-h laboratory periods and can be adapted for…

Hydrogen Sulfide Alleviates Aluminum Toxicity via Decreasing Apoplast and Symplast Al Contents in Rice

Directory of Open Access Journals (Sweden)

Chun Q. Zhu

2018-03-01

Full Text Available Hydrogen sulfide (H2S plays a vital role in Al3+ stress resistance in plants, but the underlying mechanism is unclear. In the present study, pretreatment with 2 μM of the H2S donor NaHS significantly alleviated the inhibition of root elongation caused by Al toxicity in rice roots, which was accompanied by a decrease in Al contents in root tips under 50 μM Al3+ treatment. NaHS pretreatment decreased the negative charge in cell walls by reducing the activity of pectin methylesterase and decreasing the pectin and hemicellulose contents in rice roots. This treatment also masked Al-binding sites in the cell wall by upregulating the expression of OsSATR1 and OsSTAR2 in roots and reduced Al binding in the cell wall by stimulating the expression of the citrate acid exudation gene OsFRDL4 and increasing the secretion of citrate acid. In addition, NaHS pretreatment decreased the symplasmic Al content by downregulating the expression of OsNRAT1, and increasing the translocation of cytoplasmic Al to the vacuole via upregulating the expression of OsALS1. The increment of antioxidant enzyme [superoxide dismutase (SOD, ascorbate peroxidase (APX, catalase (CAT, and peroxidase (POD] activity with NaHS pretreatment significantly decreased the MDA and H2O2 content in rice roots, thereby reducing the damage of Al3+ toxicity on membrane integrity in rice. H2S exhibits crosstalk with nitric oxide (NO in response to Al toxicity, and through reducing NO content in root tips to alleviate Al toxicity. Together, this study establishes that H2S alleviates Al toxicity by decreasing the Al content in the apoplast and symplast of rice roots.

Evaluation of mineral content and heavy metals of dromedary camel milk in Iran

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Mahdieh MOSTAFIDI

Full Text Available Abstract The aim of this study was to determine the amount of major mineral compounds and heavy metals of camel milk in Iran. For this purpose camel milk samples were collected from seven regions of Iran include Qazvin, Golestan, Semnan, Sistan-Baluchestan, Khuzestan, Bushehr and Tehran. The samples were analyzed using Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES method. The results showed that among the mineral contents, iron and zinc of camel milk were greater than bovine milk. Based on the codex standard 193-2007 standards, the maximum acceptable limit for lead and cadmium is 20 µg/kg and 10 µg/kg, respectively. The results of this study showed that the measured amounts of lead, cadmium and nickel in all samples were less than the acceptable limit for bovine milk. Bovine milk and dairy products are a poor source of iron, while the obtained data revealed that camel milk is a major source of minerals, especially iron. The camel milk’s iron was 10 times more than bovine milk. However, variations in mineral content in camel milk could be due to feed, stage of lactation, milk collection time, drought conditions, environmental conditions and associated analytical methods. Camel milk recommended as a valuable source of food for the human.

Hydrogen charging/discharging system with liquid organic compounds: a lacunar oxide catalyst to hydrogenate the unsaturated organic compound

International Nuclear Information System (INIS)

Jalowiecki-Duhamel, L.; Carpentier, J.; Payen, E.; Heurtaux, F.

2006-01-01

Lacunar mixed oxides based on cerium nickel and aluminium or zirconium CeM 0.5 Ni x O y s (M = Zr or Al), able to store high quantities of hydrogen, have been analysed in the hydrogenation of toluene into methyl-cyclohexane (MCH). When these solids present very good toluene hydrogenation activity and selectivity towards MCH in presence of H 2 , in absence of gaseous hydrogen, the reactive hydrogen species stored in the solid can hydrogenate toluene into MCH. The hydrogenation activity under helium + toluene flow decreases as a function of time and becomes nil. The integration of the curve obtained allows to determine the extractable hydrogen content of the solid used, and a value of 1.2 wt % is obtained at 80 C on a CeAl 0.5 Ni 3 O y compound pre-treated in H 2 at 300 C. To optimise the system, different parameters have been analysed, such as the catalyst formulation, the metal content, the pre-reducing conditions as well as the reaction conditions under helium + toluene. (authors)

Migration of heavy metals in soils in a uranium mining area

International Nuclear Information System (INIS)

Hu Ruixia; Gao Bai; Hu Baoqun; Feng Jiguang

2009-01-01

Contents of several heavy metals (Zn,Ni,Cu,Cd,Pb) in soil samples collected from different depths of the soil sections in a uranium mining area were analyzed, and vertical migration dis-ciplines of heavy metals were obtained. The results show that the concents of heavy metals in vertical direction decrease as the soil increases in thickness and there is a trend of facies-cumulation for the heavy metals. The accumulation status of each heavy metal in soils differs, which is dependent on the content and migration velocity of the heavy metal itself, the local natural environment about the soil, etc. (authors)

Effect of hydrogen addition on the microstructure of TC21 alloy

International Nuclear Information System (INIS)

Zhu Tangkui; Li Miaoquan

2010-01-01

Research highlights: → The aim of this paper is to study the effect of hydrogen content (0-0.887 wt.%H) on microstructure, phase composition, microhardness and β transus temperature of TC21 alloy. The results show that, with increasing hydrogen content, the β phase increases, the α/β interfaces of lamellar transformed β phase disappear, the lattice parameter of β phase increases and the β transus temperature decreases for the hydrogenated TC21 alloy. In comparison to the as-received TC21 alloy, the contrasts of primary α phase and transformed β phase under optical microscope in the TC21 alloy with high hydrogen content are reversed completely. Furthermore, the γ and δ hydrides are detected in the hydrogenated TC21 alloy. In addition, the variations of phase compositions for the hydrogenated TC21 alloy have influence on microhardness and β transus temperature. → In conclusion, this paper shows some significant rules about the influence of hydrogen on TC21 alloy. - Abstract: TC21 alloy was hydrogenated at 750 deg. C with different hydrogen contents ranging from 0 to 0.873 wt.%H, and its microstructural evolution and phase transformations were investigated by optical microscopy (OM) and X-ray diffraction (XRD). The microhardness and the β transus temperature for the hydrogenated TC21 alloy were determined by microhardness testing and metallographical approach, respectively. The results show that, hydrogen addition has a noticeable influence on microstructure, phase composition, microhardness and β transus temperature of TC21 alloy. With increasing hydrogen content, the β phase increases, the α/β interfaces of lamellar transformed β phase disappear, the lattice parameter of β phase increases and the β transus temperature decreases for the hydrogenated TC21 alloy. In comparison to the as-received TC21 alloy, the contrasts of primary α phase and transformed β phase under optical microscope in the hydrogenated TC21 alloy with high hydrogen

Determination of hydrogen solubility in Fe-Mn-C melts

Energy Technology Data Exchange (ETDEWEB)

Lob, Alexander; Senk, Dieter [Institute of Ferrous Metallurgy (IEHK), RWTH Aachen University (Germany); Hallstedt, Bengt [Materials Chemistry (MCh), RWTH Aachen University (Germany)

2011-02-15

High manganese steels are supposed to be sensitive to hydrogen embrittlement. This can be explained by increased hydrogen solubility in comparison to unalloyed steels. To minimise hydrogen pick up during melting operations, it is necessary to know accurately the hydrogen solubility as function of hydrogen partial pressure, temperature and Mn content. In this work in situ measurements of hydrogen content at 12, 18 and 23 wt.% Mn (and 0.6 wt.% C) using the Hydris {sup registered} system are compared to pin-tube measurements. Below about 7 ppm [H] both methods gave the same results and above 7 ppm [H] the in situ measurement showed slightly higher hydrogen contents because some hydrogen is lost during quenching with the pin-tube method. The measured solubilities were compared with thermodynamic calculations. Using dilute solution theory with data developed for alloyed Fe-based melts with up to 10 wt.% Mn gives reasonable results except that the hydrogen solubility is slightly underestimated for the presently investigated Mn contents. This could be compensated by using an interaction parameter of e{sup Mn}{sub H}=-0.004 instead of e{sup Mn}{sub H}=-0.0012. A Calphad type extrapolation from the binary Fe-H, Mn-H and Fe-Mn systems gave results very close to the experimental ones. This work is a contribution from the collaborative research centre SFB 761 ''Steel - ab initio''. (Copyright copyright 2011 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Heat, hydrogen peroxide, and UV resistance of Bacillus subtilis spores with increased core water content and with or without major DNA-binding proteins

International Nuclear Information System (INIS)

Popham, D.L.; Sengupta, S.; Setlow, P.

1995-01-01

Spores of a Bacillus subtilis strain with an insertion mutation in the dacB gene, which codes for an enzyme involved in spore cortex biosynthesis, have a higher core water content than wild-type spores. Spores lacking the two major α/β-type small, acid-soluble proteins (SASP) (termed a α - β - spores) have the same core water content as do wild-type spores, but α - β - dacB spores had more core water than did dacB spores. The resistance of α - β - , α - β - dacB, dacB, and wild-type spores to dry and moist heat, hydrogen peroxide, and UV radiation has been determined, as has the role of DNA damage in spore killing by moist heat and hydrogen peroxide. These data (1) suggest that core water content has little if any role in spore UV resistance and are consistent with binding of α/β-type SASP to DNA being the major mechanism providing protection to spores from UV radiation; (2) suggest that binding of αβ-type SASP to DNA is the major mechanism unique to spores providing protection from dry heat; (3) suggest that spore resistance to moist heat and hydrogen peroxide is affected to a large degree by the core water content, as increased core water resulted in large decreases in spore resistance to these agents; and (4) indicate that since this decreased resistance (i.e., in dacB spores) is not associated with increased spore killing by DNA damage, spore DNA must normally be extremely well protected against such damage, presumably by the saturation of spore DNA by α/β-type SASP. 19 refs., 2 figs., 5 tabs

Hydrogen alternatives for a regional upgrader

International Nuclear Information System (INIS)

Bailey, R.T.; Padamsey, R.

1991-01-01

For a proposed regional upgrader in Alberta, hydrogen will be needed to upgrade the bitumen and heavy oil to be processed by that facility. The upgrader will rely on high conversion hydrocracking which consumes 3.4 wt % hydrogen to produce a 106% volume yield of high quality synthetic crude. The costs of producing hydrogen via steam reforming of methane, partial oxidation of coal or upgrading residues, and electrolysis are compared, showing that steam reforming is the cheapest. However, an even cheaper source of hydrogen is available in the Edmonton and Fort Saskatchewan area as byproducts from petrochemical plants. An economic analysis is presented of a proposed scheme to capture, purify, compress, and transfer hydrogen from one or two such plants to a nearby regional upgrader. The two plants could supply a total of 126.6 million ft 3 /d of hydrogen at a total installed capital cost of about half of that of a steam reforming plant of equivalent size. When operating costs are added (including the cost of replacing the hydrogen, currently used as fuel at the two plants, with natural gas), the total cost of hydrogen is substantially less than the costs for a hydrogen plant within the upgrader. 3 refs., 5 figs., 4 tabs

Hydrogen damage in stainless steel

International Nuclear Information System (INIS)

Caskey, G.R. Jr.

1981-01-01

Hydrogen damage has been studied in a wide variety of stainless steels. Both internal and external hydrogen damage were evaluated by ductility or J-integral under rising tensile loads and by fractography. Analysis of the data has emphasized the potential effects of strain-induced martensite on hydrogen damage. Strain-induced martensite was neither necessary nor sufficient for hydrogen damage in the alloys studied. Neither ductility loss nor fracture-mode change correlated generally with martensite formation. Alloy composition, particularly nickel and nitrogen contents, was the primary factor in resistance to hydrogen damage. Thermomechanical processing, however, could alter the degree of hydrogen damage in an alloy and was critical for optimizing resistance to hydrogen damage. 10 figures, 10 tables

Production of hydrogen from hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Lohmueller, R

1984-03-01

Hydrocarbons are the preferred starting materials for the industrial production of hydrogen. Most hydrogen is produced by steam reforming of light hydrocarbons. Partial oxidation of heavy oil and residue is used for the production of H/sub 2/ and synthesis gas in large plants. In both cases gas purification was improved. Hydrogen-rich gases like coke oven gas, refinery-offgas, and offgases from the chemical and petrochemical industry have high potential for becoming a major source of hydrogen. Processes for recovering H/sub 2/ (and by-products) are condensation and rectification at low temperatures and, most attractive and versatile for the production of very pure H/sub 2/, adsorption (PSA). The environmental impact of H/sub 2/ production lies mainly in the emission of CO/sub 2/ and heat. Other forms of pollution can be considerably reduced by conventional methods. The economy of H/sub 2/ production depends essentially on price and availability of the raw materials.

A painless approach to use distributed digital-control system for Heavy Water Plant- Tuticorin

Energy Technology Data Exchange (ETDEWEB)

Potti, V S; Krishnan, S; Rao, V C; Lamba, D S [Heavy Water Project, Tuticorin (India)

1994-06-01

Heavy Water Plant (Tuticorin) production is based on mono thermal process of ammonia-hydrogen exchange and is connected with a 1100 tons per day capacity ammonia plant of M/s Southern Petrochemical Industries Limited for getting its feed. The deuterium concentration in the syngas (N{sub 2} + 3H{sub 2}) is extracted through ammonia-hydrogen exchange process and finally burnt with air in the final product unit to get heavy water. The depleted syngas is sent back to M/s SPIC`s synthesis unit. The purpose of this paper is to highlight the instrumentation requirements of heavy water production, problems encountered in use of DDCS along with remedial action taken for the back up facility. (author). 3 refs., 2 figs.

A study of heavy metal content and NORM in soil sample outside Lynas Malaysia Sdn. Bhd. Gebeng, Kuantan

International Nuclear Information System (INIS)

Nur Azera Izzati Mohammad

2012-01-01

Lynas Malaysia Sdn. Bhd. is established to build a processing plant of the rare earth lanthanides elements used to produce the starting material for manufacturing high-tech products analysed as cell phones, magnets, computer memory and many more. Analysis of soil samples was carried out outside the Lynas Malaysia Sdn. Bhd. The purpose of this study was to determine the contents of radionuclide activity concentration of natural elements in soil samples of 40 K, 232 Th and 238 U. A total of five heavy metals As, Cd, Cr, Cu and Pb were analysed for concentrations of heavy metals in soil samples. The analysis was performed and analysed using X-ray Fluorescence Spectrometer for the composition and concentration of heavy metals and Gamma Ray Spectrometer is to determine the radionuclide activity concentration of natural elements. Results showed that the concentrations of radionuclides activities for 40 K, 232 Th and 238 U are different at all stations. 40 K radionuclide has the highest radioactivity in the Station 3, which is 385 ± 4 Bq/ kg. For 232 Th and 238 U radionuclides have a high concentration of activity at Station 2 which are 102 ± 3 Bq/ kg and 105 ± 4 Bq/ kg, respectively. According to UNSCEAR 2000 average value, the value obtained exceeds the prescribed level. For heavy metal analysis showed there were only three heavy metals which could be found, namely As, Cr and Cu. For the highest concentration of As element has found at Station 5, which is 25.5 ± 2.1 ppm. For Cr and Cu element, high concentrations has found at Station 5 and Station 1, which are 225 ± 35 ppm and 95 ± ppm, respectively. (author)

Thermoanalytical investigation of the hydrogen absorption behaviour of Sm2Fe17-xGax at high hydrogen pressures

International Nuclear Information System (INIS)

Handstein, A.; Kubis, M.; Gebel, B.; Mueller, K.-H.; Schultz, L.; Gutfleisch, O.; Harris, I.R.; Birmingham Univ.

1998-01-01

The complete disproportionation of Sm 2 Fe 17-x Ga x during annealing in hydrogen is hindered due to an increased stability of the compounds with a higher Ga content (x ≥ 1). Therefore the HD process as the first step of HDDR (hydrogenation-disproportionation-desorption-recombination) has to be carried out at a high hydrogen pressure for x ≥ 1. The hydrogen absorption behaviour of Sm 2 Fe 17-x Ga x (x = 0, 0.5, 1 and 2) was investigated by means of hydrogen differential thermal analysis (HDTA) and high pressure differential scanning calorimetry (HPDSC) at hydrogen pressures up to 70 bar. A dependency of hydrogenation and disproportionation temperatures on hydrogen pressure and Ga content was found. The comparison with other substituents (M = Al and Si) instead of M = Ga showed an increased stability of Sm 2 Fe 17-x M x compounds against disproportionation by hydrogen in the sequence Al, Ga and Si. The Curie temperatures of the interstitially hydrogenated Th 2 Zn 17 -type materials increase with the hydrogen pressure. In order to produce coercive and thermally stable Sm 2 Fe 15 Ga 2 C y powder by means of the HDDR process, we recombined material disproportionated at different hydrogen pressures. Preliminary results of magnetic properties of this HDDR treated and gas-carburized Sm 2 Fe 15 Ga 2 C y are discussed. (orig.)

Method for the determination of lignin content of a sample by flash pyrolysis in an atmosphere of hydrogen or helium and method therefor

Science.gov (United States)

Shakkottai, Parthasarathy (Inventor); Kwack, Eug Y. (Inventor); Lawson, Daniel D. (Inventor)

1991-01-01

The lignin content of wood, paper pulp or other material containing lignin (such as filter paper soaked in black liquor) is more readily determined by flash pyrolysis of the sample at approximately 550.degree. C. in a reducing atmosphere of hydrogen or in an inert atmosphere of helium followed by a rapid analysis of the product gas by a mass spectrometer. The heated pyrolysis unit as fabricated comprises a small platinum cup welded to an electrically-heated stainless steel ribbon with control means for programmed short duration (1.5 sec, approximately) heating and means for continuous flow of hydrogen or helium. The pyrolysis products enter an electron-ionization mode mass spectrometer for spectral evaluation. Lignin content is obtained from certain ratios of integrated ion currents of many mass spectral lines, the ratios being linearly related to the Kappa number of Klason lignin.

Improved method of degassing of feed water at Heavy Water Plant, Kota

International Nuclear Information System (INIS)

Krishnan, G.K.; Agrawal, A.K.

1994-01-01

Heavy Water Plant (Kota) processes 450 MT/hr of feed water as the source of deuterium using water/hydrogen sulphide exchange process for the production of heavy water. Plant design has limited the ingress of dissolved oxygen in feed water to 0.2 ppm. However, even this low limit on dissolved oxygen has been found unacceptable during plant operation as over an operational period of 3-4 years accumulation of sulphur due to oxidation of hydrogen sulphide on exchange tower trays poses major operational problems. This paper discusses the results of nitrogen injection used for reducing the ingress of dissolved oxygen in the feed water system of the plant. (author)

Heavy metal content in the meat of common carp (Cyprinuscarpio L.and rainbow trout (Oncorhynchus mykiss W., cultivated under different technologies

Directory of Open Access Journals (Sweden)

St. Stoyanova

2016-03-01

Full Text Available Abstract. Water pollution from industrial production and developing agriculture is a serious problem in aquaculture. The aim of this study was to determine the content of heavy metals Zn (zink, Pb(lead, Ni (nickel and Cd (cadmium in the muscles of common carp (Cyprinus carpio L. and rainbow trout (Oncorhynchus mykiss W., grown under different technologies. In the current study were investigated common carp (Cyprinus carpio and rainbow trout (Oncorhynchus mykiss, cultivated in net cages, earthen ponds and raceways. The concentration of heavy metals in the muscles of fish was determined by the methods of AAS in the Scientific laboratory of the Faculty of Agriculture. The influence of different production technologies on the bioaccumulation of Zn, Pb, Ni and Cd (in the flesh of common carp and rainbow trout was found. The Ni content in muscles was 31.25% higher in common carp, cultured at earthen ponds, compared with its content in the flesh of the fish raised in net cages. The concentration of Pd and Ni in rainbow trout, raised in raceways was higher than that determinated for rainbow trout cultivated in net cages, by 25.0% and 7.14%, respectively. The concentration of Cd and Zn of these species, grown in raceways were lower by 33.33% and 2.14%, respectively, compared with their concentration in rainbow trout, cultivated in net cages.

Characteristics of tree bark as an indicator in high-immission areas : II. Contents of heavy metals.

Science.gov (United States)

Lötschert, W; Köhm, H -J

1978-01-01

1. Studies on indicator characteristics of bark of deciduous trees have been continued by measuring accumulation of Pb, Cd, Ni and Mn in the bark of Fraxinus excelsior at 34 sampling sites over an area of 150 km 2 in the immission area of Frankfurt am Main. 2. Iso-lines of equal Pb-contamination have been found. They include zones of graduated immissions. The pattern of these zones shows an eccentrical orientation and is the result of the distribution of the main traffic roads. A significant correlation of Pb in the bark and traffic congestion has been found. 3. The zones of Cd-contamination stretch from SW to NE. The orientation of these zones is determined by the distribution of the big emittenrs and the centers of heating power in the area and the predominating direction of wind. 4. A correlation between the accumulation of Pb and Cd has been detected. It is less significant than that between pH-value and sulfur content in the bark of trees in former investigations. 5. The distribution of Pb and Mn is antagonistic in the bark of Fraxinus excelsior and parallel in the needles of Taxus baccata. The content of Mn in the bark of Fraxinus is low. It must be accepted that this is partly an effect of elution by sulfur acid-aerosol formation. 6. The strongest accumulation of heavy metal immissions is found in mosses on the ground, mainly in Bryum argenteum. Nevertheless the bark of Fraxinus excelsior has shown consequently its accumulation characteristics as a good immission indicator for heavy metal contaminations by traffic and big emittents.

Support of a pathway to a hydrogen future

Energy Technology Data Exchange (ETDEWEB)

Hoffman, A.R. [Dept. of Energy, Washington, DC (United States). Office of Utility Technologies

1997-12-31

This paper consists of viewgraphs which outline the content of the presentation. Subjects addressed include: hydrogen research program vision; electricity industry restructuring -- opportunities and challenges for hydrogen; transportation sector -- opportunities for hydrogen; near-term and mid-term opportunities for hydrogen; and hydrogen production technologies from water. It is concluded that the global climate change challenge is the potential driver for the development of hydrogen systems.

[Investigation and analysis of heavy metal pollution related to soil-Panax notoginseng system].

Science.gov (United States)

Chen, Lu; Mi, Yan-Hua; Lin, Xin; Liu, Da-Hui; Zeng, Min; Chen, Xiao-Yan

2014-07-01

In this study, five heavy metals contamination of soil and different parts of Panax notoginseng in the plantation area was investigated. Analysis of heavy metals correlation between the planting soil and P. notoginseng; and the absorption and accumulation characteristics and translocation of soil heavy metals by P. notoginseng plants was revealed. Through field investigation and laboratory analytical methods, analysis of China's 30 different soil P. notoginseng origin and content of heavy metals in five different parts of the P. notoginseng plant content of heavy metals. The results revealed that the soil heavy metals should not be neglected in the plantation area Referring to the national soil quality standards (GB15608-1995), the excessive degree of soil heavy metals pollution showed Hg > As > Cd > Cr in the plantation area, and Pb content of soil was in the scope of the standard. Refer to 'Green Industry Standards for Import and Export of Medical Plants and Preparations', the excessive degree of heavy metals content of P. notoginseng plants showed As > Pb > Cr > Cd, and Hg content of plants was in the scope of the standard. Concentrations of five heavy metals of underground parts of P. notoginseng plants are higher than aboveground, and heavy metals elements are more concentrated in the root, followed by the rhizome of P. notoginseng plants. Heavy metal accumulation characteristics of the different parts of the P. notoginseng of the overall performance is the root > the rhizome > the root tuber > leaves > stems. From the point of view BCF value analysis of various parts of the P. notoginseng plants to absorb heavy metals in soil, BCF values of all samples were less than 1, description P. notoginseng not belong Hyperaccumulator. From the view of transportation and related analysis of the soil-P. notoginseng systems, the rhizome of P. notoginseng and the content of As and Cr in soil was significantly correlated, the root of P. notoginseng and the content of Cd in

High energy heavy ions: techniques and applications

International Nuclear Information System (INIS)

Alonso, J.R.

1985-04-01

Pioneering work at the Bevalac has given significant insight into the field of relativistic heavy ions, both in the development of techniques for acceleration and delivery of these beams as well as in many novel areas of applications. This paper will outline our experiences at the Bevalac; ion sources, low velocity acceleration, matching to the synchrotron booster, and beam delivery. Applications discussed will include the observation of new effects in central nuclear collisions, production of beams of exotic short-lived (down to 1 μsec) isotopes through peripheral nuclear collisions, atomic physics with hydrogen-like uranium ions, effects of heavy ''cosmic rays'' on satellite equipment, and an ongoing cancer radiotherapy program with heavy ions. 39 refs., 6 figs., 1 tab

Hydrogen, energy of the future?

International Nuclear Information System (INIS)

Alleau, Th.

2007-01-01

A cheap, non-polluting energy with no greenhouse gas emissions and unlimited resources? This is towards this fantastic future that this book brings us, analyzing the complex but promising question of hydrogen. The scientific and technical aspects of production, transport, storage and distribution raised by hydrogen are thoroughly reviewed. Content: I) Energy, which solutions?: 1 - hydrogen, a future; 2 - hydrogen, a foreseeable solution?; II) Hydrogen, an energy vector: 3 - characteristics of hydrogen (physical data, quality and drawbacks); 4 - hydrogen production (from fossil fuels, from water, from biomass, bio-hydrogen generation); 5 - transport, storage and distribution of hydrogen; 6 - hydrogen cost (production, storage, transport and distribution costs); III) Fuel cells and ITER, utopias?: 7 - molecular hydrogen uses (thermal engines and fuel cells); 8 - hydrogen and fusion (hydrogen isotopes, thermonuclear reaction, ITER project, fusion and wastes); IV) Hydrogen acceptability: 9 - risk acceptability; 10 - standards and regulations; 11 - national, European and international policies about hydrogen; 12 - big demonstration projects in France and in the rest of the world; conclusion. (J.S.)

On problems of hydrogen load of sponge palladium and determination of hydrogen content in it

International Nuclear Information System (INIS)

Mittag, E.; Pleis, U.; Roemer, J.

1977-01-01

In the process of catalytic dehalogenation applied as a method for preparation of organic compounds labelled with tritium a special importance pertains to the determination of hydrogen (or tritium) bound on the catalyst. Hydrogen contained in palladium black may be determined quantitatively by oxidation with Pd ++ ions and successive potentiometric titration of the released H + ions. The method permits to obtain data on the quality of the catalyst and on the gas losses on the catalyst. Moreover, in connection with the radioactivity measurement, this method may be used for specific activity determination of the tritium gas

Feasibility analysis of EDXRF method to detect heavy metal pollution in ecological environment

Science.gov (United States)

Hao, Zhixu; Qin, Xulei

2018-02-01

The change of heavy metal content in water environment, soil and plant can reflect the change of heavy metal pollution in ecological environment, and it is important to monitor the trend of heavy metal pollution in eco-environment by using water environment, soil and heavy metal content in plant. However, the content of heavy metals in nature is very low, the background elements of water environment, soil and plant samples are complex, and there are many interfering factors in the EDXRF system that will affect the spectral analysis results and reduce the detection accuracy. Through the contrastive analysis of several heavy metal elements detection methods, it is concluded that the EDXRF method is superior to other chemical methods in testing accuracy and method feasibility when the heavy metal pollution in soil is tested in ecological environment.

Behaviour of heavy metals in soils

NARCIS (Netherlands)

Harmsen, K.

1977-01-01

Fractions of Zn, Cd, Cu, Pb, Fe and Mn extractable with water, a salt solution and dilute acid, and residual fractions were determined in soils with raised contents of heavy metals, near zinc smelters, along a river formerly discharging heavy metals, and in a sewage farm. Special attention

Study on the effect of hydrogen addition on the variation of plasma parameters of argon-oxygen magnetron glow discharge for synthesis of TiO2 films

Directory of Open Access Journals (Sweden)

Partha Saikia

2016-04-01

Full Text Available We report the effect of hydrogen addition on plasma parameters of argon-oxygen magnetron glow discharge plasma in the synthesis of H-doped TiO2 films. The parameters of the hydrogen-added Ar/O2 plasma influence the properties and the structural phases of the deposited TiO2 film. Therefore, the variation of plasma parameters such as electron temperature (Te, electron density (ne, ion density (ni, degree of ionization of Ar and degree of dissociation of H2 as a function of hydrogen content in the discharge is studied. Langmuir probe and Optical emission spectroscopy are used to characterize the plasma. On the basis of the different reactions in the gas phase of the magnetron discharge, the variation of plasma parameters and sputtering rate are explained. It is observed that the electron and heavy ion density decline with gradual addition of hydrogen in the discharge. Hydrogen addition significantly changes the degree of ionization of Ar which influences the structural phases of the TiO2 film.

Chemically modified glasses for analysis of hydrogen isotopes by gas-chromatography

International Nuclear Information System (INIS)

Stanciu, Vasile; Stefanescu, Doina

1999-01-01

Hydrogen isotope separation process by such methods as cryogenic distillation or thermal diffusion method is one of the key technologies of the tritium separation from heavy water of CANDU reactors and in the tritium fuel cycle for a thermonuclear fusion reactor. In each process, the analytical techniques for measuring contents of hydrogen isotope mixture are necessary. An extensive experimental research has been carried out in order to produce the most suitable absorbent and define the best operating conditions for selective separation and analysis of hydrogen isotope by gas-chromatography. This paper describes the preparation of adsorbent materials utilised as stationary phase in the gas-chromatographic column for hydrogen isotope separation and treatment (activation) of stationary phase. Modified thermo-resisting glass with Fe(NH 4 ) 2 (SO 4 ) 2 6H 2 O and Cr 2 O 3 , respectively, have been experimentally investigated at 77 K for H 2 , HD and D 2 separation and the results of chromatographic runs are also reported and discussed. The gas-chromatographic apparatus used is composed of a Hewlett-Packard 7620A gas-chromatograph equipped with a gas carrier flow rate controller and a thermal conductivity detector (TCD). The apparatus comprises also a Dewar vessel containing the separation column. The hydrogen isotopes H 2 , HD, D 2 and their mixture have been obtained in our laboratories. The best operating conditions of the adsorbent column Fe (III)/glass and Cr 2 O 3 /glass, i.e. granulometry, column length, pressure-drop along the column, carrier gas flow rate, sample volume have been studied by means of the analysis of the retention times, separation factors and HETP. (authors)

Assessment of Heavy Metal Content of Branded Pakistani Herbal ...

African Journals Online (AJOL)

Erah

analyzed using a flame atomic absorption spectrometer. Results: Most of the products exceeded the permissible limits for lead (100 %), cadmium (68 %), .... absorption spectrometry. M e ta l n a m ..... Determination of Heavy Metals in Medicinal.

THE HEAVY METALS CONNTENT IN VEGETABLES FROM MIDDLE SPIŠ AREA

OpenAIRE

Marek Slávik,Tomáš Tóth; Július Árvay; Miriama Kopernická; Luboš Harangozo; Radovan Stanovič; Pavol Trebichalský; Petra Kavalcová

2014-01-01

In the middle area of Spiš, it is significantly burden by heavy metals what is documented by radical content of Hg in soil from Rudňany 58.583645 mg.kg -1. On the content of heavy metals in vegetables grown in this soil it has the same effect. 61.5% samples exceeded the limit value of heavy metals. The most dangerous vegetables were Lactuca sativa L. The limit value was exceed in all determine heavy metals - Hg, Cd, Pb and Cu in this vegetables. In the case of Hg, the limit value exceed 93.86...

Feasibility study of hydrogen determination in blended gas mixture by an indigenously developed hydrogen determinator

International Nuclear Information System (INIS)

Gaikwad, Revati; Sonar, V.R.; Pandey, R.K.; Karekar, C.D.; Raul, Seema; Mahanty, B.; Kelkar, A.; Bhatt, R.B.; Behere, P.G.

2017-01-01

It is required to determine accurately the percentage composition of hydrogen in the blended gas of N 2 and H 2 prior to deliver to the sintering furnace. A feasibility study has been carried out to determine the percentage composition of hydrogen in the blended gas by using an indigenously developed hydrogen determinator. The instrument uses gas chromatograph-thermal conductivity (GC-TCD) technique to determine hydrogen. The flow of carrier gas was kept at 100 mL min -1 during the analysis. A very close agreement between the determined value and the reported value of hydrogen content in the commercially available N 2 -H 2 mixed cylinder was found by using the indigenous hydrogen determinator. (author)

Nondestructive hydrogen analysis of steam-oxidized Zircaloy-4 by wide-angle neutron scattering

Science.gov (United States)

Yan, Yong; Qian, Shuo; Garrison, Ben; Smith, Tyler; Kim, Peter

2018-04-01

A nondestructive neutron scattering method to precisely measure the hydrogen content in high-temperature steam-oxidized Zircaloy-4 cladding was developed. Zircaloy-4 cladding was used to produce hydrided specimens with hydrogen content up to ≈500 wppm. Following hydrogen charging, the hydrogen content of the hydrided specimens was measured using the vacuum hot extraction method, by which the samples with desired hydrogen concentrations were selected for the neutron study. The hydrided samples were then oxidized in steam up to ≈6.0 wt. % at 1100 °C. Optical microscopy shows that our hydriding procedure results in uniform distribution of circumferential hydrides across the wall thickness, and uniform oxide layers were formed on the sample surfaces by the steam oxidation. Small- and wide-angle neutron scattering were simultaneously performed to provide a quick (less than an hour per sample) measurement of the hydrogen content in various types of hydrided and oxidized Zircaloy-4. Our study demonstrates that the hydrogen in pre-oxidized Zircaloy-4 cladding can be measured very accurately by both small- and wide-angle neutron scattering. For steam-oxidized samples, the small-angle neutron scattering is contaminated with coherent scattering from additional structural features induced by the steam oxidation. However, the scattering intensity of the wide-angle neutron scattering increases proportionally with the hydrogen charged in the samples. The hydrogen content and wide-angle neutron scattering intensity are highly linearly correlated for the oxidized cladding samples examined in this work, and can be used to precisely determine the hydrogen content in steam-oxidized Zircaloy-4 samples. Hydrogen contents determined by neutron scattering of oxidation samples were also found to be consistent with the results of chemical analysis within acceptable margins for error.

Hydrogen embrittlement of titanium tested with fracture mechanics specimens

International Nuclear Information System (INIS)

Aho-Mantila, I.; Rahko, P.

1990-11-01

Titanium is one of the possible canister materials for spent nuclear fuel. The aim of this study is to determine whether the hydrogen embrittlement of titanium could be a possible deterioration mechanism of titanium canisters. This experimental study was preceded by a literature review and an experimental study on crack nucleation. Tests in this study were carried out with hydrogen charged fracture mechanics specimens. The studied hydrogen contents were as received, 100 ppm, 200 ppm, 500 ppm and 700 ppm and the types of the studied titanium were ASTM Grades 2 and 12. Test methods were slow tensile test (0.027 mm/h) and fatigue test (stress ratio 0.7 or 0.8 and frequency 5 Hz). According to the literature titanium may be embrittled by hydrogen at slow strain rates and cracking may occur under sustained load. In this study no evidence of hydrogen embrittlement was noticed in slow strain rate tension with bulk hydrogen contents up to 700 ppm. The fatigue tests of titanium Grades 2 and 12 containing 700 ppm hydrogen showed even slower crack growth compared to the as received condition. Very high hydrogen contents well in eccess of 700 ppm on the surface of titanium can, however, facilitate surface crack nucleation and crack growth, as shown in the previous study

Heavy metals contents in agricultural topsoils in the Ebro basin (Spain). Application of the multivariate geoestatistical methods to study spatial variations

International Nuclear Information System (INIS)

Rodriguez Martin, Jose Antonio; Arias, Manuel Lopez; Grau Corbi, Jose Manuel

2006-01-01

In this work the content of seven heavy metals (Cd, Cr, Cu, Hg, Ni, Pb and Zn) and other parameters (the pH, organic matter, carbonates and granulometric fraction) in agricultural topsoil in the Ebro basin are quantified, based on 624 samples collected according to an 8 by 8 km square mesh. The average concentrations (mg/kg) obtained were: Cd 0.415 ± 0.163, Cr 20.27 ± 13.21, Cu 17.33 ± 14.97, Ni 20.50 ± 22.71, Pb 17.54 ± 10.41, Zn 17.53 ± 24.19 and Hg 35.6 ± 42.05 μg/kg. The concentration levels are relatively low in areas of high pH and low organic matter content concentration. The results of factor analysis group Cd, Cu, Hg, Pb and Zn in F1 and Cr y Ni in F2. The spatial heavy metals component maps based on geostatistical analysis, show definite association of these factors with the soil parent material. The local anomalies (found in Cu, Zn and Pb) are attributed to anthropogenic influence. - Geostatistical analyses showed definite association of metals with soil parent materials

Effect of distance from the roadway on heavy metal content and egg quality of village laying hen's egg along roadsides of tokat-turhal, turkey

International Nuclear Information System (INIS)

Sekeroglu, A.; Sari, H.; Sarica, M.; Duman, M.

2013-01-01

In this study, the heavy metal contents and egg quality characteristics of chicken eggs was studied. The eggs have been collected at distances of 0-100 (Distance A), 100-200 (Distance B) and 200-300 m (Distance C) away from the edge of Tokat-Turhal road.The distance from roadway had no significant effect on egg Cu and Mn contents (P>0.05), although a significant effect on egg Cd and Pb content (P 0.05). Eggs obtained from distance A and B had significantly higher weight than obtained from distance C (P<0.05). Egg obtained from distance B had significantly lower egg shell colour scales than those of the other distances (P<0.01). And, egg yolk colour was showed a significant variation among the distances away from the roadway, and the highest yolk colour value was detected in distance B (P<0.05). Depending on obtained results, it can be concluded that the egg heavy metal concentrations exceeded background levels for hen eggs. Therefore, consumers should be aware of the possible health risks related by the use of these eggs which has obtained from side of road.

Hydrogenated amorphous silicon coatings may modulate gingival cell response

Science.gov (United States)

Mussano, F.; Genova, T.; Laurenti, M.; Munaron, L.; Pirri, C. F.; Rivolo, P.; Carossa, S.; Mandracci, P.

2018-04-01

Silicon-based materials present a high potential for dental implant applications, since silicon has been proven necessary for the correct bone formation in animals and humans. Notably, the addition of silicon is effective to enhance the bioactivity of hydroxyapatite and other biomaterials. The present work aims to expand the knowledge of the role exerted by hydrogen in the biological interaction of silicon-based materials, comparing two hydrogenated amorphous silicon coatings, with different hydrogen content, as means to enhance soft tissue cell adhesion. To accomplish this task, the films were produced by plasma enhanced chemical vapor deposition (PECVD) on titanium substrates and their surface composition and hydrogen content were analyzed by means of X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectrophotometry (FTIR) respectively. The surface energy and roughness were measured through optical contact angle analysis (OCA) and high-resolution mechanical profilometry respectively. Coated surfaces showed a slightly lower roughness, compared to bare titanium samples, regardless of the hydrogen content. The early cell responses of human keratinocytes and fibroblasts were tested on the above mentioned surface modifications, in terms of cell adhesion, viability and morphometrical assessment. Films with lower hydrogen content were endowed with a surface energy comparable to the titanium surfaces. Films with higher hydrogen incorporation displayed a lower surface oxidation and a considerably lower surface energy, compared to the less hydrogenated samples. As regards mean cell area and focal adhesion density, both a-Si coatings influenced fibroblasts, but had no significant effects on keratinocytes. On the contrary, hydrogen-rich films increased manifolds the adhesion and viability of keratinocytes, but not of fibroblasts, suggesting a selective biological effect on these cells.

Improved method of degassing of feed water at Heavy Water Plant, Kota

Energy Technology Data Exchange (ETDEWEB)

Krishnan, G K; Agrawal, A K [Heavy Water Plant, Kota (India)

1994-06-01

Heavy Water Plant (Kota) processes 450 MT/hr of feed water as the source of deuterium using water/hydrogen sulphide exchange process for the production of heavy water. Plant design has limited the ingress of dissolved oxygen in feed water to 0.2 ppm. However, even this low limit on dissolved oxygen has been found unacceptable during plant operation as over an operational period of 3-4 years accumulation of sulphur due to oxidation of hydrogen sulphide on exchange tower trays poses major operational problems. This paper discusses the results of nitrogen injection used for reducing the ingress of dissolved oxygen in the feed water system of the plant. (author). 1 fig.

Heavy water isotopic rectification in the ''ORPHEE'' reactor. SACLAY studies Centre

International Nuclear Information System (INIS)

Lejeune, P.; Breant, P.

1993-01-01

ORPHEE reactor supplies neutron beams, which are got back in a heavy water reflector. The neutron beams intensity depends on the reflector quality which is determined by the isotopic content of the heavy water. The deuterium submitted to core irradiation changes in radioactive tritium which must be eliminated largely for reasons of safety. The column must keep the heavy water isotopic content of the reflector to a value higher than 99.8% by eliminating light water by fractional distillation or rectification. This column is also used for the tritium elimination of heavy water. 13 figs

Destructive hydrogenation. [British patent

Energy Technology Data Exchange (ETDEWEB)

1929-07-15

Liquid or readily liquefiable products are obtained from solid distillable carbonaceous materials such as coals, oil shales or other bituminous substances by subjecting the said initial materials to destructive hydrogenation under mild conditions so that the formation of benzine is substantially avoided, and then subjecting the treated material to extraction by solvents. By hydrogenating under mild conditions the heavy oils which prevent the asphaltic substances from being precipitated are preserved, and the separation of the liquid products from the solid residue is facilitated. Solid paraffins and high boiling point constituents suitable for the production of lubricating oils may be removed before or after the extraction process. The extraction is preferably carried out under pressure with solvents which do not precipitate asphaltic substances. Brown coal containing 11 per cent ash is passed at 450/sup 0/C, and 200 atmospheres pressure in counter current to hydrogen; 40 per cent of the coal is converted into liquid products which are condensed out of the hydrogen stream; the pasty residue, on extraction with benzene, yields 45 per cent of high molecular weight products suitable for the production of lubricating oil.

Heavy water cycle in the CANDU reactor

International Nuclear Information System (INIS)

Nanis, R.

2000-01-01

Hydrogen atom has two isotopes: deuterium 1 H 2 and tritium 1 H 3 . The deuterium oxide D 2 O is called heavy water due to its density of 1105.2 Kg/m 3 . Another important physical property of the heavy water is the low neutron capture section, suitable to moderate the neutrons into natural uranium fission reactor as CANDU. Due to the fact that into this reactor the fuel is cooled into the pressure tubes surrounded by a moderator, the usage of D 2 O as primary heat transport (PHT) agent is mandatory. Therefore a large amount of heavy water (approx. 500 tons) is used in a CANDU reactor. Being a costly resource - it represents 20% of the initial plant capital cost, D 2 O management is required to preserve it. (author)

Production of Hydrogen from Bio-ethanol

International Nuclear Information System (INIS)

Fabrice Giroudiere; Christophe Boyer; Stephane His; Robert Sanger; Kishore Doshi; Jijun Xu

2006-01-01

IFP and HyRadix are collaborating in the development of a new hydrogen production system from liquid feedstock such as bio-ethanol. Reducing greenhouse gas (GHG) emissions along with high hydrogen yield are the key objectives. Market application of the system will be hydrogen refueling stations as well as medium scale hydrogen consumers including the electronics, metals processing, and oils hydrogenation industries. The conversion of bio-ethanol to hydrogen will be performed within a co-developed process including an auto-thermal reformer working under pressure. The technology will produce high-purity hydrogen with ultralow CO content. The catalytic auto-thermal reforming technology combines the exothermic and endothermic reaction and leads to a highly efficient heat integration. The development strategy to reach a high hydrogen yield target with the bio-ethanol hydrogen generator is presented. (authors)

Heavy metal and trace element contents in edible muscle of three commercial fish species, and assessment of possible risks associated with their human consumption in Saudi Arabia

Directory of Open Access Journals (Sweden)

Sabry Mohamed El-Bahr

2015-09-01

Full Text Available Three different highly consumed fish species from Al-Ahsa market, Saudi Arabia namely Spangled emporer (Lethriuns nebulosus, Red striped seabream (Pagrus major and Black seabream (Spondyliosoma cantharus were evaluated for their muscle contents of heavy metals (e.g., Cd and Pb and trace elements (e.g., Cu, Zn, Fe and Mn. The possible risks associated with their human consumption were also studied. A total of 60 fresh fish samples comprising of 20 samples from each above mentioned fish were collected, and were subjected for determination of heavy metal and trace element contents by Atomic Absorption Spectrophotometry after Microwave Wet Digestion. The results showed that, accumulation patterns of the heavy metals and trace elements followed the order: Fe > Zn > Cu > Mn > Pb > Cd. There were variations among metal contents in the muscles of the three fish species; S. cantharus accumulated the highest levels of Cu, Zn and Mn, while the highest level of Fe could be detected in the muscles of P. major. The concentration of Cd and Pb remained comparable in the muscles of all three fish species. The calculated maximum daily intake (MDI values were found as 0.0003, 0.0009, 0.0035, 0.0001, 0.0000, 0.0000 mg/day/person for Cu, Zn, Fe, Mn, Cd and Pb, respectively. Conclusively, the present study indicated that, fish muscles contain relatively less burden of heavy metals and trace elements, and no health problem can be raised from human consumption of the examined commercial fishes at Al-Ahsa market, Saudi Arabia. [J Adv Vet Anim Res 2015; 2(3.000: 271-278

The hydrogen economy- A debate on the merits

CSIR Research Space (South Africa)

Van Vuuren, DS

2007-01-01

Full Text Available stream_source_info van Vuuren_2007.pdf.txt stream_content_type text/plain stream_size 5193 Content-Encoding UTF-8 stream_name van Vuuren_2007.pdf.txt Content-Type text/plain; charset=UTF-8 The Hydrogen Economy A Debate... cheapest alternative. • The Hydrogen Economy or its alternative will only really take off when cheap coal production begins to peak Slide 10 © CSIR 2006 www.csir.co.za Global Warming • The risk is real, but the debate...

Supercritical water treatment of heavy metal and arsenic metalloid-bioaccumulating-biomass.

Science.gov (United States)

Li, Jianxin; Chen, Jinbo; Chen, Shan

2018-08-15

Hyperaccumulator biomass, as a promising resource for renewable energy that can be converted into valuable fuel productions with high conversion efficiency, must be considered as hazardous materials and be carefully treated before further reuse due to the high contents of heavy metals. In this study, Pteris vittata L., an As-hyperaccumulator biomass was treated by an effective and environmental friendly method-supercritical water gasification (SCWG) using a bench-scale batch reactor. The contents of heavy metals (Cd, Pb and Zn) and arsenic metalloid in solid, liquid and gaseous products during SCWG process were thoroughly investigated. The speciation fractions including exchangeable, reducible, oxidizable and residual fractions of each heavy metal as the proportion of the total contents in solid residue were presented and the transformations trend of these heavy metals during the SCWG process was especially demonstrated. The significant operating parameters, including reaction temperature (395-445 °C), pressure (21-27 MPa) and residence time (0-40 min) were varied to explore their effects on the contents and forms. Moreover, the environmental risks of heavy metals in solid residues were evaluated based on risk assessment code, taking into consideration the speciation fractions and bioavailability. It was highlighted that although heavy metals particularly Pb and Zn tended to accumulate in solid residues with a maximum increment of about 50% in the total content, they were mostly converted to more stable oxidizable and residual fractions, and thus the ecotoxicity and bioavailability were greatly mitigated with no obvious increase in direct toxicity fractions. Each tested heavy metal presented no or low risk to the environments after SCWG treatments, meaning that the environmental pollution levels were markedly reduced with no or low risk to the environment. This study highlights the remarkable ability of SCWG for the heavy metal stabilization. Copyright �

Europe - the first hydrogen economy?

International Nuclear Information System (INIS)

Hart, D.

1999-01-01

An examination of the state of research relating to hydrogen production and utilization indicates that interest in hydrogen from major companies in Europe has increased by several orders of magnitude in recent years. Of the three major areas where a hydrogen economy could be expected to start, namely, Japan, the United States and Europe, the latter may have advantages in diversity of resources, attitudes towards environmental issues and specific fiscal and regulatory structures. Examples of ongoing research and development projects in Europe include Norway's hydrogen combustion turbine to run on hydrogen from decarbonised natural gas, a project in the Netherlands involving mixing hydrogen and methane in the natural gas grid and a variety of projects involving liquid hydrogen refuelling, hydrogen aircraft, hydrogen fuelling stations and fuel cell vehicle development. There are also ongoing projects in carbon sequestration and hydrogen production for power generation and vehicle use. The author's main contention is that the combination of natural surroundings, environmental problems and attitudes, and business and government frameworks strongly suggest that Europe may be the first to have a hydrogen-based economy. 8 refs

Hydrogen Contractors Meeting

Energy Technology Data Exchange (ETDEWEB)

Fitzsimmons, Tim [Dept. of Energy (DOE), Washington DC (United States). Office of Basic Energy Sciences. Division of Materials Sciences and Engineering

2006-05-16

This volume highlights the scientific content of the 2006 Hydrogen Contractors Meeting sponsored by the Division of Materials Sciences and Engineering (DMS&E) on behalf of the Office of Basic Energy Sciences (BES) of the U. S. Department of Energy (DOE). Hydrogen Contractors Meeting held from May 16-19, 2006 at the Crystal Gateway Marriott Hotel Arlington, Virginia. This meeting is the second in a series of research theme-based Contractors Meetings sponsored by DMS&E held in conjunction with our counterparts in the Office of Energy Efficiency and Renewable Energy (EERE) and the first with the Hydrogen, Fuel Cells and Infrastructure Technologies Program. The focus of this year’s meeting is BES funded fundamental research underpinning advancement of hydrogen storage. The major goals of these research efforts are the development of a fundamental scientific base in terms of new concepts, theories and computational tools; new characterization capabilities; and new materials that could be used or mimicked in advancing capabilities for hydrogen storage.

Hydrogen isotope separation by cryogenic distillation method

International Nuclear Information System (INIS)

Hayakawa, Nobuo; Mitsui, Jin

1987-01-01

Hydrogen isotope separation in fusion fuel cycle and tritium recovery from heavy water reactor are very important, and therefore the early establishment of these separation techniques are desired. The cryogenic distillation method in particular is promising for the separation of hydrogen isotope and the recovery of high concentrated tritium. The studies of hydrogen isotope separation by cryogenic distillation method have been carried out by using the experimental apparatus made for the first time in Japan. The separation of three components (H 2 -HD-D 2 ) under total reflux conditions was got by using the packing tower of 500 mm height. It was confirmed that the Height Equivalent Theoretical Plate (HETP) was 20 - 30 mm for the vapor's line velocity of 20 - 80 mm/s. (author)

Liquid hydrogen and deuterium targets; Cibles a hydrogene et deuterium liquides

Energy Technology Data Exchange (ETDEWEB)

Bougon, M; Marquet, M; Prugne, P [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1961-07-01

A description is given of 1) Atmospheric pressure target: liquid hydrogen, 400 mm thickness; thermal insulation: styrofoam; the hydrogen vapors are used to improve the target cooling; Mylar windows. 2) Vacuum target: 12 liter content: hydrogen or deuterium; liquid thickness 400 mm; thermal insulation is afforded by a vacuum vessel and a liquid nitrogen shield. Recovery and liquefaction of deuterium vapors are managed in the vacuum vessel which holds the target. The target emptying system is designed for operating in a few minutes. (author) [French] Description de: 1) Cible a pression atmospherique; hydrogene liquide, 400 mm d'epaisseur; l'isolement thermique: styrofoam; on utilise les vapeurs d'hydrogene pour ameliorer le refroidissement de la cible; hublots en Mylar. 2) Cible sous vide; contenance 12 litres; hydrogene ou deuterium; epaisseur du liquide 400 mm; l'isolement thermique est assure par une cuve a vide et un ecran d'azote liquide. Recuperation et liquefaction des vapeurs de deuterium sont effectuees dans la cuve a vide contenant la cible. Le systeme de vidange pour la cible est concu pour fonctionner en quelques minutes. (auteur)

Hydrogen embrittlement property of a 1700-MPa-class ultrahigh-strength tempered martensitic steel

Energy Technology Data Exchange (ETDEWEB)

Li Songjie; Zhang Boping [School of Materials Science and Engineering, University of Science and Technology Beijing, No. 30 Xueyuan Road, Hidian Zone, Beijing 100083 (China); Akiyama, Eiji; Yuuji, Kimura; Tsuzaki, Kaneaki [Structural Metals Center, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Uno, Nobuyoshi, E-mail: AKIYAMA.Eiji@nims.go.j [Nippon Steel and Sumikin Metal Products Co, Ltd, SA Bldg., 17-12 Kiba 2-chome, Koto-ku, Tokyo (Japan)

2010-04-15

The hydrogen embrittlement property of a prototype 1700-MPa-class ultrahigh-strength steel (NIMS17) containing hydrogen traps was evaluated using a slow strain rate test (SSRT) after cathodic hydrogen precharging, cyclic corrosion test (CCT) and atmospheric exposure. The hydrogen content in a fractured specimen was measured after SSRT by thermal desorption spectroscopy (TDS). The relationship between fracture stress and hydrogen content for the hydrogen-precharged specimens showed that the fracture stress of NIMS17 steel was higher, at a given hydrogen content, than that of conventional AISI 4135 steels with tensile strengths of 1300 and 1500 MPa. This suggests better resistance of NIMS17 steel to hydrogen embrittlement. However, hydrogen uptake to NIMS17 steel under CCT and atmospheric exposure decreased the fracture stress. This is because of the stronger hydrogen uptake to the steel containing hydrogen traps than to the AISI 4135 steels. Although NIMS17 steel has a higher strength level than AISI 4135 steel with a tensile strength of 1500 MPa, the decrease in fracture stress is similar between these steels.

Hydrogen embrittlement property of a 1700-MPa-class ultrahigh-strength tempered martensitic steel

Directory of Open Access Journals (Sweden)

Songjie Li, Eiji Akiyama, Kimura Yuuji, Kaneaki Tsuzaki, Nobuyoshi Uno and Boping Zhang

2010-01-01

Full Text Available The hydrogen embrittlement property of a prototype 1700-MPa-class ultrahigh-strength steel (NIMS17 containing hydrogen traps was evaluated using a slow strain rate test (SSRT after cathodic hydrogen precharging, cyclic corrosion test (CCT and atmospheric exposure. The hydrogen content in a fractured specimen was measured after SSRT by thermal desorption spectroscopy (TDS. The relationship between fracture stress and hydrogen content for the hydrogen-precharged specimens showed that the fracture stress of NIMS17 steel was higher, at a given hydrogen content, than that of conventional AISI 4135 steels with tensile strengths of 1300 and 1500 MPa. This suggests better resistance of NIMS17 steel to hydrogen embrittlement. However, hydrogen uptake to NIMS17 steel under CCT and atmospheric exposure decreased the fracture stress. This is because of the stronger hydrogen uptake to the steel containing hydrogen traps than to the AISI 4135 steels. Although NIMS17 steel has a higher strength level than AISI 4135 steel with a tensile strength of 1500 MPa, the decrease in fracture stress is similar between these steels.

Hydrogen embrittlement property of a 1700-MPa-class ultrahigh-strength tempered martensitic steel

International Nuclear Information System (INIS)

Li Songjie; Zhang Boping; Akiyama, Eiji; Yuuji, Kimura; Tsuzaki, Kaneaki; Uno, Nobuyoshi

2010-01-01

The hydrogen embrittlement property of a prototype 1700-MPa-class ultrahigh-strength steel (NIMS17) containing hydrogen traps was evaluated using a slow strain rate test (SSRT) after cathodic hydrogen precharging, cyclic corrosion test (CCT) and atmospheric exposure. The hydrogen content in a fractured specimen was measured after SSRT by thermal desorption spectroscopy (TDS). The relationship between fracture stress and hydrogen content for the hydrogen-precharged specimens showed that the fracture stress of NIMS17 steel was higher, at a given hydrogen content, than that of conventional AISI 4135 steels with tensile strengths of 1300 and 1500 MPa. This suggests better resistance of NIMS17 steel to hydrogen embrittlement. However, hydrogen uptake to NIMS17 steel under CCT and atmospheric exposure decreased the fracture stress. This is because of the stronger hydrogen uptake to the steel containing hydrogen traps than to the AISI 4135 steels. Although NIMS17 steel has a higher strength level than AISI 4135 steel with a tensile strength of 1500 MPa, the decrease in fracture stress is similar between these steels.

Lead-210 and heavy metal contents in dated ombrotrophic peat hummocks from Finland

International Nuclear Information System (INIS)

El-Daoushy, F.; Tolonen, K.

1984-01-01

Two Sphagnum fuscum hummock cores, core 1, Kaerpaensuo bog and core F9, Kunonniemensuo bog. from Finland were used in this study. The peats are ombrotrophic and were dated using the moss-increment method. The mosses in both cores were carefully examined for their botanical composition, degree of humification, ash percentage and bulk density. The total accumulated dry peat-matter in the Kunonniemensuo core was almost double that in the Kaerpaensuo core. The total 210 Pb and the supported 210 Pb were measured by isotope dilution and the radon emanation technique. Materials in the same peat samples were analysed for their 210 Pb content at the Institute of Physics, Uppsala, Sweden and the Technical Research Centre of Finland, Espoo, Finland. The annual content of unsupported 210 Pb in the dated peat-layers shows that peat materials are effective traps which could yield information on atmospheric-fluxes both chronologically and regionally. Lead, copper, zinc, iron and manganese were also measured by flame atomic absorption spectrometry (AAS). The total accumulated amounts over the past 150 y of the heavy metals investigated are almost identical for both cores apart from manganese which is considerably higher in the Kunonniemensuo core. However, the metal profiles studied exhibit discontinuity zones more pronounced in the Kunonniemensuo core. The 210 Pb data indicate that growth rate and bulk density variations in ombrotrophic peat bogs affects the accumulation of 210 Pb and similar trace metals. (orig.)

Hydrogen fuel injection - the bridge to fuel cells

International Nuclear Information System (INIS)

Gilchrist, J.S.

2004-01-01

'Full text:' For over a century, industry has embraced a wide variety of applications for hydrogen. Since the mid-1970's, the focus of the bulk of hydrogen research has been in the area of fuel cells. Unfortunately, there is limited awareness of more immediate applications for hydrogen as a catalyst designed to improve the performance of existing hydro-carbon fuelled internal combustion engines. Canadian Hydrogen Energy Company manufactures a patented Hydrogen Fuel Injection System (HFI) that produces hydrogen and oxygen from distilled water and injects them, in measured amounts, into the air intake system on any heavy-duty diesel or gasoline application including trucks, buses, stationary generators, etc. In use on over 30 fleets, research is supported by over 40 million miles of field data. The hydrogen acts as a catalyst to promote more complete combustion, with remarkable results. Dramatically reduce emissions, particularly Carbon Monoxide and Particulate Matter. Increase horsepower and torque. Improved fuel efficiency (a minimum 10% improvement is guaranteed). Reduced oil degradation The HFI system offers the first large-scale application of the use of hydrogen and an excellent bridge to the fuel-cell technologies of the future. (author)

Effect of hydrogen on transformation characteristics and deformation behavior in a Ti-Ni shape memory alloy

International Nuclear Information System (INIS)

Hoshiya, Taiji; Ando, Hiroei; Den, Shoji; Katsuta, Hiroshi.

1992-01-01

Transformation characteristics and deformation behavior of hydrogenated Ti-50.5 at% Ni alloys, which were occluded in a low pressure range of hydrogen between 1.1 and 78.5 kPa, have been studied by electrical resistivity measurement, tensile test, X-ray diffraction analysis and microstructural observation. M S temperature of the Ti-Ni alloys decreased with an increase in hydrogen content. This corresponds to the stabilization of the parent phase during cooling, which was confirmed by X-ray diffraction: The suppression effect of hydrogen takes place on the martensitic transformation. Critical stress for slip deformation of hydrogenated Ti-Ni alloys changed with hydrogen content and thus hydrogen had a major influence on deformation behavior of those alloys. With hydrogen contents above 0.032 mol%, hardening was distinguished from softening which was pronounced in the contents from 0 to 0.032 mol% H. Hydrides were formed in hydrogen contents over 1.9 mol%. The hydride formation results in the reorientation in variants of the R phase and increase in the lattice strains of the parent phase. (author)

Enhancing atom densities in solid hydrogen by isotopic substitution

International Nuclear Information System (INIS)

Collins, G.W.; Souers, P.C.; Mapoles, E.R.; Magnotta, F.

1991-01-01

Atomic hydrogen inside solid H 2 increases the energy density by 200 MegaJoules/m 3 , for each percent mole fraction stored. How many atoms can be stored in solid hydrogen? To answer this, we need to know: (1) how to produce and trap hydrogen atoms in solid hydrogen, (2) how to keep the atoms from recombining into the ground molecular state, and (3) how to measure the atom density in solid hydrogen. Each of these topics will be addressed in this paper. Hydrogen atoms can be trapped in solid hydrogen by co-condensing atoms and molecules, external irradiation of solid H 2 , or introducing a radioactive impurity inside the hydrogen lattice. Tritium, a heavy isotope of hydrogen, is easily condensed as a radioactive isotopic impurity in solid H 2 . Although tritium will probably not be used in future rockets, it provides a way of applying a large, homogenious dose to solid hydrogen. In all of the data presented here, the atoms are produced by the decay of tritium and thus knowing how many atoms are produced from the tritium decay in the solid phase is important. 6 refs., 6 figs

Heavy metal content of soil in urban parks of Belgrade

Directory of Open Access Journals (Sweden)

Kuzmanoski Maja M.

2014-01-01

Full Text Available This study focuses on soil pollution in four urban parks of Belgrade. The sampling locations within each park were chosen based on proximity to streets characterized by heavy traffic, and soil samples were taken at different depths down to 50 cm. Concentrations of six heavy metals (Cr, Cu, Fe, Mn, Ni and Zn were measured using Energy Dispersive X-Ray Fluorescence (EDXRF spectrometer. The following average abundance order of heavy metals was found: Fe >> Mn > Zn > Cr > Ni > Cu in topsoil samples. The highest enrichment in topsoil was observed for Zn. Copper and Zn, metals mainly related to traffic emissions, exhibited the highest concentrations at the sampling location close to a bus and trolleybus terminus. The highest Ni and Cr concentrations were observed in a park located in a city suburb, where a large number of individual heating units is present. The largest decrease in concentrations with soil dept was observed for Zn and Cu, followed by Ni and Cr, in the parks with the highest concentrations of these elements in topsoil. Generally high topsoil Cr and Ni concentrations were observed in comparison with average values reported in literature for other world cities. [Projekat Ministartsva nauke Republike Srbije, br. III43007

Decrease in Hydrogen Embrittlement Susceptibility of 10B21 Screws by Bake Aging

Directory of Open Access Journals (Sweden)

Kuan-Jen Chen

2016-08-01

Full Text Available The effects of baking on the mechanical properties and fracture characteristics of low-carbon boron (10B21 steel screws were investigated. Fracture torque tests and hydrogen content analysis were performed on baked screws to evaluate hydrogen embrittlement (HE susceptibility. The diffusible hydrogen content within 10B21 steel dominated the fracture behavior of the screws. The fracture torque of 10B21 screws baked for a long duration was affected by released hydrogen. Secondary ion mass spectroscopy (SIMS result showed that hydrogen content decreased with increasing baking duration, and thus the HE susceptibility of 10B21 screws improved. Diffusible hydrogen promoted crack propagation in high-stress region. The HE of 10B21 screws can be prevented by long-duration baking.

Surface studies: corrosion, hydrogen content and charge transport in materials and devices

International Nuclear Information System (INIS)

Jamieson, D.N.

1999-01-01

Presented here is a review of recent applications of the Melbourne nuclear microprobe applied to the study of surface phenomena in a variety of materials over the past two years. In addition to these applications, numerous improvements to the Melbourne system were initiated over the same period. These have been mainly directed at improvements in the spatial resolution through the installation of shielding to reduce stray magnetic fields and commissioning of a new event-by-event data acquisition system that can handle high count rates from up to four detectors with full dead time correction. In 1999 an ARC Research Infrastructure and Facilities Program grant has allowed us to perform a major upgrade of the Pelletron 5U accelerator. Major components of this upgrade include: a new ion source in the terminal, replacement of the column corona needles with resistors, replenishment of the SF6 gas supply and installation of a Danfysik analysing magnet power supply. In the near future we will also test some proposals to increase the ion source brightness based on reduction of the gas load on the column from the ion source. Many of the applications of the Melbourne nuclear microprobe over the past two years have employed the classic techniques of Ion Beam Analysis including PIXE and RBS. Pilot studies of involving the mapping of hydrogen in polysilicon solar cells has been done with the technique of elastic recoil detection analysis (ERDA). A number of different measurements such as depth distribution, stoichiometry, trace element distribution or hydrogen content were performed. Finally, we have also continued to study the visible light emitted from the specimen during ion irradiation. This can be collected to form images by ionoluminescense (IL). IL is an emerging technique for use with a nuclear microprobe that offers new insights into the presence of optically active defects in materials

Bio-oil Stabilization by Hydrogenation over Reduced Metal Catalysts at Low Temperatures

Energy Technology Data Exchange (ETDEWEB)

Wang, Huamin; Lee, Suh-Jane; Olarte, Mariefel V.; Zacher, Alan H.

2016-08-30

Biomass fast pyrolysis integrated with bio-oil upgrading represents a very attractive approach for converting biomass to hydrocarbon transportation fuels. However, the thermal and chemical instability of bio-oils presents significant problems when they are being upgraded, and development of effective approaches for stabilizing bio-oils is critical to the success of the technology. Catalytic hydrogenation to remove reactive species in bio-oil has been considered as one of the most efficient ways to stabilize bio-oil. This paper provides a fundamental understanding of hydrogenation of actual bio-oils over a Ru/TiO2 catalyst under conditions relevant to practical bio-oil hydrotreating processes. Bio-oil feed stocks, bio-oils hydrogenated to different extents, and catalysts have been characterized to provide insights into the chemical and physical properties of these samples and to understand the correlation of the properties with the composition of the bio-oil and catalysts. The results indicated hydrogenation of various components of the bio-oil, including sugars, aldehydes, ketones, alkenes, aromatics, and carboxylic acids, over the Ru/TiO2 catalyst and 120 to 160oC. Hydrogenation of these species significantly changed the chemical and physical properties of the bio-oil and overall improved its thermal stability, especially by reducing the carbonyl content, which represented the content of the most reactive species (i.e., sugar, aldehydes, and ketones). The change of content of each component in response to increasing hydrogen additions suggests the following bio-oil hydrogenation reaction sequence: sugar conversion to sugar alcohols, followed by ketone and aldehyde conversion to alcohols, followed by alkene and aromatic hydrogenation, and then followed by carboxylic acid hydrogenation to alcohols. Hydrogenation of bio-oil samples with different sulfur contents or inorganic material contents suggested that sulfur poisoning of the reduced Ru metal catalysts was

Alternate applications of heavy water in biological and technological fields

International Nuclear Information System (INIS)

Bhaskaran, M.; Prakash, R.

2005-01-01

Deuterium and its various compounds like heavy water exhibit distinctly different properties when compared to hydrogen and its compounds. The differences in properties are due to the primary and secondary isotopic effects. Though heavy water has been used solely for nuclear applications so far, its applications in life sciences and high technology areas are fast emerging. Heavy Water Board has taken up development of alternate applications of heavy water. The study taken up has indicated superior thermal stability for oral polio vaccine prepared in heavy water. This study has revealed various opportunities for application of heavy water or deuterium in life sciences and the paper dwells on these possibilities. The higher stability of compounds with deuterium has also brought in its applications in various high technology areas. These are mainly in micro electronics. Use of deuterium in manufacture of high quality optical fibres has already been established. These are also included in the paper. (author)

Low temperature heat capacity of lutetium and lutetium hydrogen alloys

International Nuclear Information System (INIS)

Thome, D.K.

1977-10-01

The heat capacity of high purity electrotransport refined lutetium was measured between 1 and 20 0 K. Results for theta/sub D/ were in excellent agreement with theta values determined from elastic constant measurements. The heat capacity of a series of lutetium-hydrogen solid solution alloys was determined and results showed an increase in γ from 8.2 to about 11.3 mJ/g-atom-K 2 for hydrogen content increasing from zero to about one atomic percent. Above one percent hydrogen γ decreased with increasing hydrogen contents. The C/T data showed an increase with temperature decreasing below about 2.5 0 K for samples with 0.1 to 1.5 atomic percent hydrogen. This accounts for a large amount of scatter in theta/sub D/ versus hydrogen content in this range. The heat capacity of a bulk sample of lutetium dihydride was measured between 1 and 20 0 K and showed a large increase in theta/sub D/ and a large decrease in γ compared to pure lutetium

Assessment of Heavy Metal Content of Branded Pakistani Herbal ...

African Journals Online (AJOL)

Purpose: To investigate the heavy metals present in branded Pakistani herbal medicines used in the management of various human ailments. Method: The herbal dosage forms assessed were tablets, capsules and syrups. The samples were prepared for analysis by wet digestion method using nitric acid and perchloric acid ...

Studies about interaction of hydrogen isotopes with metals and intermetallic compounds

International Nuclear Information System (INIS)

Vasut, F.; Anisoara, P.; Zamfirache, M.

2003-01-01

Hydrogen is a non-toxic but highly inflammable gas. Compared to other inflammable gases, its range of inflammability in air is much broader (4-74.5%) but it also vaporizes much more easily. Handling of hydrogen in form of hydrides enhances safety. The interaction of hydrogen with metals and intermetallic compounds is a major field within physical chemistry. Using hydride-forming metals and intermetallic compounds, for example, recovery, purification and storage of heavy isotopes in tritium containing system can solve many problems arising in the nuclear-fuel cycle. The paper presents the thermodynamics and the kinetics between hydrogen and metal or intermetallic compounds. (author)

Preparing interesting hydrocarbons by hydrogenation, etc

Energy Technology Data Exchange (ETDEWEB)

1938-02-15

Now, it has been found that gasoline and a combustible oil are produced by destructive hydrogenation of pastes prepared from solid carbonaceous materials and mixtures of middle oils and the mud in question, by regulating the composition of the products removed as vapors in a way that they contain at least the total new heavy oil formed in the course of the destructive hydrogenation and in using as mixing agent for the new raw material the mud proceeding from the operation and middle oil, having withdrawn from this mud all or part of the solid constituents. This destructive hydrogenation is carried out in a converter where a constant level of liquid is maintained, the vapors escaping at the top of the converter and the mud being drawn off at one or more places from the column of liquid undergoing reaction.

Heavy metals in vegetables and potential risk for human health

Directory of Open Access Journals (Sweden)

Fernando Guerra

2012-02-01

Full Text Available Ingestion of vegetables containing heavy metals is one of the main ways in which these elements enter the human body. Once entered, heavy metals are deposited in bone and fat tissues, overlapping noble minerals. Slowly released into the body, heavy metals can cause an array of diseases. This study aimed to investigate the concentrations of cadmium, nickel, lead, cobalt and chromium in the most frequently consumed foodstuff in the São Paulo State, Brazil and to compare the heavy metal contents with the permissible limits established by the Brazilian legislation. A value of intake of heavy metals in human diets was also calculated to estimate the risk to human health. Vegetable samples were collected at the São Paulo General Warehousing and Centers Company, and the heavy metal content was determined by atomic absorption spectrophotometry. All sampled vegetables presented average concentrations of Cd and Ni lower than the permissible limits established by the Brazilian legislation. Pb and Cr exceeded the limits in 44 % of the analyzed samples. The Brazilian legislation does not establish a permissible limit for Co contents. Regarding the consumption habit of the population in the São Paulo State, the daily ingestion of heavy metals was below the oral dose of reference, therefore, consumption of these vegetables can be considered safe and without risk to human health.

The impact of hydrogen enrichment and bluff-body lip thickness on characteristics of blended propane/hydrogen bluff-body stabilized turbulent diffusion flames

International Nuclear Information System (INIS)

Kashir, Babak; Tabejamaat, Sadegh; Jalalatian, Nafiseh

2015-01-01

Highlights: • Characteristics of C 3 H 8 –H 2 bluff-body stabilized flames are investigated. • Decreasing the bluff-body lip thickness led into enhanced flame length. • CO mass fraction is increased with reducing hydrogen content in the fuel stream. • Augmenting hydrogen content increased the maximum temperature. • Jet-like zone in propane–hydrogen bluff-body stabilized flames is very unstable. - Abstract: At the beginning of this study, the well-known turbulent bluff-body stabilized diffusion flame of HM1 is simulated by a coupled flamelet/radiation approach. The HM1 flame comprises a CH 4 :H 2 [50:50 Vol.] jet flame at a Reynolds number of 15,800. The results showed reasonable agreement for the flow field and species. Afterwards, the abovementioned approach is employed to investigate the effects of hydrogen addition on bluff-body stabilized flames of propane–hydrogen. Adding hydrogen to the blended fuel of propane/hydrogen shifts the recirculation zone outwards the bluff-body and thus culminates in increased flame length. Besides this, the flame length is predicted to be enhanced with decreasing the lip thickness of the bluff-body configuration. The CO emission level is found to be decreased with hydrogen addition in near-burner and far field regions which might be attributed to the decrease of inflow carbon atoms. The local radiative heat power reveals higher values for fuel blends with decreased contents of hydrogen at the recirculation and jet-like zones. This might be attributed to the increased local heat release rate due to breaking further carbon bonds

A kinetic study of the electrochemical hydrogenation of ethylene

International Nuclear Information System (INIS)

Sedighi, S.; Gardner, C.L.

2010-01-01

In this study, we have examined the kinetics of the electrochemical hydrogenation of ethylene in a PEM reactor. While in itself this reaction is of little industrial interest, this reaction can be looked upon as a model reaction for many of the important hydrogenation processes including the refining of heavy oils and the hydrogenation of vegetable oils. To study the electrochemical hydrogenation of ethylene, several experimental techniques have been used including polarization measurements, measurement of the composition of the exit gases and potential step, transient measurements. The results show that the hydrogenation reaction proceeds rapidly and essentially to completion. By fitting the experimental transient data to the results from a zero-dimensional mathematical model of the process, a set of kinetic parameters for the reactions has been obtained that give generally good agreement with the experimental results. It seems probable that similar experimental techniques could be used to study the electrochemical hydrogenation of other unsaturated organic molecules of more industrial significance.

Determination of Heavy Metals in Alpinia oxyphylla Miq. Collected from Different Cultivation Regions

OpenAIRE

Zhou, Dan; Fu, Yurong; Lai, Weiyong; Zhang, Junqing

2016-01-01

20 batches of Alpinia oxyphylla Miq. were collected from Yunnan, Guangdong, Guangxi, and Hainan province in China. The contents of heavy metals of As, Hg, Pb, Cd, and Cu were determined and compared. The results indicated that geographical source might be a major factor to influence the contents of heavy metals of arsenic (As), mercury (Hg), lead (Pb), cadmium (Cd), and copper (Cu) in Alpinia oxyphylla Miq. Compared to the criteria of heavy metals, the contents of As, Hg, Pb, and Cd in almost...

[MONITORING OF THE CONTENT OF HEAVY METALS AND ELEMENTS IN THE SNOW COVER IN AGRICULTURAL SOILS AT THE TERRITORY OF THE MOSCOW REGION].

Science.gov (United States)

Ermakov, A A; Karpova, E A; Malysheva, A G; Mikhaylova, R I; Ryzhova, I N

2015-01-01

The monitoring of snow cover pollution by heavy metals and elements (zinc, copper, lead, cadmium, arsenic, nickel, chromium, strontium, manganese, fluorine, lithium) was performed in 20 districts of the Moscow region in 2009, 2012 and 2013. The assessment of the levels of contamination by heavy metals and elements was given by means of comparison of them with the average values in the snow cover near Moscow in the end of the last century and in some areas of the world, that no exposed to technological environmental impact. 7 districts of Moscow region were characterized by a high content of lead and cadmium in the snow water. It requires the control of water, soil and agricultural products pollution.

Hydrogen and Nitrogen Control in Ladle and Casting Operations

Energy Technology Data Exchange (ETDEWEB)

Richard J. Fruehan; Siddhartha Misra

2005-01-15

In recent years there has been an increasing demand to reduce and control the amount of dissolved gases in steel. Hydrogen and nitrogen are two of the most important gases which when dissolved in liquid steel affect its properties significantly. Several steelmaking additions have been investigated in this research for their effect on the hydrogen and nitrogen content of steels. It has been established that calcium hydroxide (hydrated lime) acts as a source of hydrogen. Carburizers, such as metallurgical coke, were found to result in no hydrogen pickup when added to liquid steel. Addition of petroleum coke, on the other hand, increased the hydrogen content of liquid steel. Ferroalloy such as medium carbon ferromanganese when added to the liquid iron was found to increase its nitrogen content, the increase being proportional to the amount of ferroalloy added. Similarly, addition of pitch coke, which had a significant nitrogen impurity, increased the nitrogen content of liquid iron. A mathematical model was developed to quantify the absorption of nitrogen and hydrogen from the air bubbles entrained during tapping of liquid steel. During the bottom stirring of liquid metal in a ladle, the inert gas escaping from the top displaces the slag layer and often forms an open eye. The absorption of atmospheric nitrogen through the spout eye was estimated for different slag thickness and gas flow rate. The ultimate goal of this research was to develop a comprehensive set of equations which could predict the nitrogen and hydrogen pickup from their various sources. Estimates of hydrogen and nitrogen pickup during the steel transfer operations such as tapping and ladle stirring and the predicted pickup from steelmaking additions were integrated into empirical equations. The comprehensive model is designed to predict the gas pickup under varying operating conditions such as the metal oxygen and sulfur content, the total tapping or stirring time, the stirring gas flow rate and the

Modeling Emission of Heavy Energetic Neutral Atoms from the Heliosphere

International Nuclear Information System (INIS)

Swaczyna, Paweł; Bzowski, Maciej

2017-01-01

Observations of energetic neutral atoms (ENAs) are a fruitful tool for remote diagnosis of the plasma in the heliosphere and its vicinity. So far, instruments detecting ENAs from the heliosphere were configured for observations of hydrogen atoms. Here, we estimate emissions of ENAs of the heavy chemical elements helium, oxygen, nitrogen, and neon. A large portion of the heliospheric ENAs is created in the inner heliosheath from neutralized interstellar pick-up ions (PUIs). We modeled this process and calculated full-sky intensities of ENAs for energies 0.2–130 keV/nuc. We found that the largest fluxes among considered species are expected for helium, smaller for oxygen and nitrogen, and smallest for neon. The obtained intensities are 50–10 6 times smaller than the hydrogen ENA intensities observed by IBEX . The detection of heavy ENAs will be possible if a future ENA detector is equipped with the capability to measure the masses of observed atoms. Because of different reaction cross-sections among the different species, observations of heavy ENAs can allow for a better understanding of global structure of the heliosphere as well as the transport and energization of PUIs in the heliosphere.

Modeling Emission of Heavy Energetic Neutral Atoms from the Heliosphere

Energy Technology Data Exchange (ETDEWEB)

Swaczyna, Paweł; Bzowski, Maciej, E-mail: pswaczyna@cbk.waw.pl [Space Research Centre of the Polish Academy of Sciences (CBK PAN), Bartycka 18A, 00-716 Warsaw (Poland)

2017-09-10

Observations of energetic neutral atoms (ENAs) are a fruitful tool for remote diagnosis of the plasma in the heliosphere and its vicinity. So far, instruments detecting ENAs from the heliosphere were configured for observations of hydrogen atoms. Here, we estimate emissions of ENAs of the heavy chemical elements helium, oxygen, nitrogen, and neon. A large portion of the heliospheric ENAs is created in the inner heliosheath from neutralized interstellar pick-up ions (PUIs). We modeled this process and calculated full-sky intensities of ENAs for energies 0.2–130 keV/nuc. We found that the largest fluxes among considered species are expected for helium, smaller for oxygen and nitrogen, and smallest for neon. The obtained intensities are 50–10{sup 6} times smaller than the hydrogen ENA intensities observed by IBEX . The detection of heavy ENAs will be possible if a future ENA detector is equipped with the capability to measure the masses of observed atoms. Because of different reaction cross-sections among the different species, observations of heavy ENAs can allow for a better understanding of global structure of the heliosphere as well as the transport and energization of PUIs in the heliosphere.

Studies of effects on determination of trace hydrogen in U-Nb alloy

International Nuclear Information System (INIS)

Zou Lexi; Li Yingqiu; Liu Jun; Wu Lunqiang; Qi Lianzhu; Bian Min

2002-01-01

The affecting factors for determination of trace hydrogen in U-Nb alloy are studied. The status of samples affects greatly the measured hydrogen content, which has the higher value for scrap sample than cylinder sample. The hydrogen content in cylinder is closer to real value in U-Nb alloy. The hydrogen in U-Nb alloy is mainly from surface adsorption. The results of hydrogen determined by vacuum thermal evolved method, in which the relative standard uncertainty is less than 28%, are in agreement with those by inert-gas fusion method

Problems connected with the production of heavy water in France; Problemes relatifs a la production d'eau lourde en France

Energy Technology Data Exchange (ETDEWEB)

Roth, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1956-07-01

The decision to study the nuclear energy in France in 1945 has seen the construction of the first natural uranium reactor for research purpose only, Zoe reactor. The utilization of heavy water as moderator was motivated by permitting the economical utilization of natural uranium oxides as fuel and a good handling. The five tons of heavy water required by the Zoe reactor were initially obtained from Norway production. With nuclear development and the construction of the first power reactors for electricity production, the demand in heavy water increased. The heavy water production by French industry became of a great interest. The first production started in the southwest of France using a fertilizers production plant and the electrolytic process used in Norway. The electrolytic process of hydrogen was quickly limited by the limited number of large fertilizers plants in France. Thus, in 1953, French nuclear research concentrated on the distillation of liquid hydrogen and water distillation for the heavy water production. The liquid hydrogen distillation presents a better yield in heavy water extraction than the electrolytic process but it was still depending from large fertilizers production plants. Although the water distillation process is simple, the high purity required for nuclear uses induced a high cost. The advantages and disadvantages of these two processes are discussed as well as others heavy water production processes using concentration process of already enriched water and the prospect of the use of the natural gas from the Lacq deposit. Economical aspect and cost production for each of heavy water production processes will be also discussed. (M.P.)

Liquid hydrogen and deuterium targets

International Nuclear Information System (INIS)

Bougon, M.; Marquet, M.; Prugne, P.

1961-01-01

A description is given of 1) Atmospheric pressure target: liquid hydrogen, 400 mm thickness; thermal insulation: styrofoam; the hydrogen vapors are used to improve the target cooling; Mylar windows. 2) Vacuum target: 12 liter content: hydrogen or deuterium; liquid thickness 400 mm; thermal insulation is afforded by a vacuum vessel and a liquid nitrogen shield. Recovery and liquefaction of deuterium vapors are managed in the vacuum vessel which holds the target. The target emptying system is designed for operating in a few minutes. (author) [fr

Computer simulation of hydrogen diffusion and hydride precipitation at Ta/Zr bond interface. Hydrogen embrittlement in SUS304ULC/Ta/Zr explosive bonded joint

International Nuclear Information System (INIS)

Saida, Kazuyoshi; Fujimoto, Tetsuya; Nishimoto, Kazutoshi

2010-01-01

The concentration of hydrogen and precipitation of zirconium hydrides in Ta/Zr explosive bonded joint were analysed by computer simulation. Numerical model of hydride precipitation under hydrogen diffusion was simplified by the alternate model coupled the macroscopic hydrogen diffusion with the microscopic hydride precipitation. Effects of the initial hydrogen content in Ta, working degree of Zr and post-bond heat treatment on the hydrogen diffusion and hydride precipitation were investigated. Hydrogen was rapidly diffused from Ta substrate into Zr after explosive bonding and temporarily concentrated at Ta/Zr bond interface. Zirconium hydrides were precipitated and grew at Ta/Zr bond interface, and the precipitation zone of hydrides was enlarged with the lapse of time. The precipitation of zirconium hydrides was promoted when the initial hydrogen content in Ta and working degree of Zr were increased. The concentration of hydrogen and precipitation of hydrides at the bond interface were reduced and diminished by post-bond heat treatment at 373 K. It was deduced that hydrogen embrittlement in Ta/Zr explosive bonded joint was caused by the precipitation of zirconium hydrides and concentration of hydrogen at Ta/Zr bond interface during the diffusion of hydrogen containing in Ta substrate. (author)

A strategy for introducing hydrogen into transportation

International Nuclear Information System (INIS)

Farrell, A.E.; Keith, D.W.; Corbett, J.J.

2003-01-01

Considerable effort is being expended on research and demonstration projects aimed at introducing hydrogen into the transportation sector as a fuel, generally motivated by concerns about carbon dioxide emissions and petroleum imports (or scarcity). In this paper we focus on one aspect of strategy for introducing hydrogen--the choice of transportation mode. Our analysis suggests that cost of introducing hydrogen can be reduced by selecting a mode that uses a small number of relatively large vehicles that are operated by professional crews along a limited number of point-to-point routes or within a small geographic area. In addition, technological innovation in vehicle design will take place most quickly in modes where individual vehicles are produced to order and each receives significant engineering attention (not those manufactured in vast quantities on assembly lines). The immediate environmental benefits of introducing hydrogen fuel will occur in modes that have relatively less stringent pollution regulations applied to them. These insights, suggest that heavy-duty freight modes would be a less costly way to introduce hydrogen as a transportation fuel and a more effective way to advance hydrogen-related technologies so that they could subsequently be used more widely in light-duty vehicles

On the resonant coherent excitation of relativistic heavy ions

International Nuclear Information System (INIS)

Pivovarov, Y.L.; Geissel, H.; Filimonov, Yu.M.; Krivosheev, O.E.; Scheidenberger, C.

1995-07-01

New accelerator facilities open up an interesting new field of experiments on basic channeling as well as on atomic and nuclear resonant coherent exitation (RCE) of heavy ions penetrating through aligned crystals at relativistic energies. Results of computer simulations are presented to characterize the resonant coherent excitation of atomic levels of relativistic hydrogen-like heavy ions. Nuclear resonant coherent excitation reveals interesting different characteristics compared to the corresponding atomic excitation inside crystals. An important result of our model calculations is that poorly-channeled ions have a higher nuclear excitation probability than well-channeled ions. (orig.)

Effects of indium contents on photocatalytic performance of ZnIn{sub 2}S{sub 4} for hydrogen evolution under visible light

Energy Technology Data Exchange (ETDEWEB)

Song, Kelin [Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055 (China); Zhu, Rongshu, E-mail: rszhu@hitsz.edu.cn [Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055 (China); Public Platform for Technological Service in Urban Waste Reuse and Energy Regeneration, Shenzhen 518055 (China); Tian, Fei [Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055 (China); Cao, Gang, E-mail: caog@hotmail.com [Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055 (China); Public Platform for Technological Service in Urban Waste Reuse and Energy Regeneration, Shenzhen 518055 (China); Ouyang, Feng [Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055 (China); Public Platform for Technological Service in Urban Waste Reuse and Energy Regeneration, Shenzhen 518055 (China)

2015-12-15

A series of ZnIn{sub x}S{sub 4+y} (x=1.6, 2.0, 2.3, 2.6, 2.9, 3.1) photocatalysts were synthesized via a facile hydrothermal method and characterized by various analytical techniques, such as XRD, EDS, UV–vis DRS, SEM, TEM, BET and PL. The ZnIn{sub x}S{sub 4+y} photocatalysts had a similar crystal structure. With the increase of indium content, the absorption edges of ZnIn{sub x}S{sub 4+y} photocatalysts shifted to longer wavelength, their crystal sizes decreased firstly and then increased and the variation of the specific surface area and total pore volume was exactly opposite. Especially, when x=2.3, ZnIn{sub 2.3}S{sub 4+y} catalyst had smallest crystal size, largest specific surface area and total pore volume. Additionally, the morphology of ZnIn{sub x}S{sub 4+y} greatly depended on the contents of indium. The photocatalytic activity of ZnIn{sub x}S{sub 4+y} was evaluated by photocatalytic hydrogen production from water under visible light. The ZnIn{sub 2.3}S{sub 4+y} sample had the highest photocatalytic activity among these ZnIn{sub x}S{sub 4+y} photocatalysts and its hydrogen production rate was 363 μmol/g h. - Graphical abstract: First, a series of catalysts were synthesized. And then those were characterized by various analytical techniques (such as SEM). finally, The photocatalytic activity of catalyst was evaluated by photocatalytic hydrogen production from water under visible light. - Highlights: • The photocatalytic property was studied upon visible-light irradiation. • ZnIn{sub x}S{sub 4+y} photocatalysts show superior photocatalytic activity. • The catalyst of grain size, morphology and BET are related to indium content. • ZnIn{sub x}S{sub 4+y} photocatalysts were synthesized via a facile hydrothermal method.

Consequences of potential accidents in heavy water plants

International Nuclear Information System (INIS)

Croitoru, C.; Lazar, R.E.; Preda, I.A.; Dumitrescu, M.

2002-01-01

Heavy water plants achieve the primary isotopic concentration by H 2 O-H 2 S chemical exchange. In these plants are stored large quantities of hydrogen sulphide (high toxic, corrosive, flammable and explosive) maintained in process at relative high temperatures and pressures. It is required an assessment of risks associated with the potential accidents. The paper presents adopted model for quantitative consequences assessment in heavy water plants. Following five basic steps are used to identify the risks involved in plants operation: hazard identification, accident sequences development, H 2 S emissions calculus, dispersion analyses and consequences determination. A brief description of each step and some information from risk assessment for our heavy water pilot plant are provided. Accident magnitude, atmospheric conditions and population density in studied area were accounted for consequences calculus. (author)

Preparation of platinum-decorated porous graphite nanofibers, and their hydrogen storage behaviors.

Science.gov (United States)

Kim, Byung-Joo; Lee, Young-Seak; Park, Soo-Jin

2008-02-15

In this work, the hydrogen storage behaviors of porous graphite nanofibers (GNFs) decorated by Pt nanoparticles were investigated. The Pt nanoparticles were introduced onto the GNF surfaces using a well-known chemical reduction method. We investigated the hydrogen storage capacity of the Pt-doped GNFs for the platinum content range of 1.3-7.5 mass%. The microstructure of the Pt/porous GNFs was characterized by X-ray diffraction and transmission electron microscopy. The hydrogen storage behaviors of the Pt/GNFs were studied using a PCT apparatus at 298 K and 10 MPa. It was found that amount of hydrogen stored increased with increasing Pt content to 3.4 mass%, and then decreased. This result indicates that the hydrogen storage capacity of porous carbons is based on both their metal content and dispersion rate.

Survey of mercury, cadmium and lead content of household batteries

Energy Technology Data Exchange (ETDEWEB)

Recknagel, Sebastian, E-mail: sebastian.recknagel@bam.de [BAM Federal Institute for Materials Research and Testing, Department of Analytical Chemistry, Reference Materials, Richard-Willstätter-Straße 11, D-12489 Berlin (Germany); Radant, Hendrik [BAM Federal Institute for Materials Research and Testing, Department of Analytical Chemistry, Reference Materials, Richard-Willstätter-Straße 11, D-12489 Berlin (Germany); Kohlmeyer, Regina [German Federal Environment Agency (UBA), Section III 1.6 Extended Producer Responsibility, Wörlitzer Platz 1, D-06844 Dessau-Roßlau (Germany)

2014-01-15

Highlights: • A well selected sample of 146 batteries was analysed for its heavy metals content. • A comparison was made between heavy metals contents in batteries in 2006 and 2011. • No significant change after implementation of the new EU Batteries Directive. • Severe differences in heavy metal contents were found in different battery-types. - Abstract: The objective of this work was to provide updated information on the development of the potential impact of heavy metal containing batteries on municipal waste and battery recycling processes following transposition of the new EU Batteries Directive 2006/66/EC. A representative sample of 146 different types of commercially available dry and button cells as well as lithium-ion accumulators for mobile phones were analysed for their mercury (Hg)-, cadmium (Cd)- and lead (Pb)-contents. The methods used for preparing the cells and analysing the heavy metals Hg, Cd, and Pb were either developed during a former study or newly developed. Several batteries contained higher mass fractions of mercury or cadmium than the EU limits. Only half of the batteries with mercury and/or lead fractions above the marking thresholds were labelled. Alkaline–manganese mono-cells and Li-ion accumulators, on average, contained the lowest heavy metal concentrations, while zinc–carbon batteries, on average, contained the highest levels.

Survey of mercury, cadmium and lead content of household batteries

International Nuclear Information System (INIS)

Recknagel, Sebastian; Radant, Hendrik; Kohlmeyer, Regina

2014-01-01

Highlights: • A well selected sample of 146 batteries was analysed for its heavy metals content. • A comparison was made between heavy metals contents in batteries in 2006 and 2011. • No significant change after implementation of the new EU Batteries Directive. • Severe differences in heavy metal contents were found in different battery-types. - Abstract: The objective of this work was to provide updated information on the development of the potential impact of heavy metal containing batteries on municipal waste and battery recycling processes following transposition of the new EU Batteries Directive 2006/66/EC. A representative sample of 146 different types of commercially available dry and button cells as well as lithium-ion accumulators for mobile phones were analysed for their mercury (Hg)-, cadmium (Cd)- and lead (Pb)-contents. The methods used for preparing the cells and analysing the heavy metals Hg, Cd, and Pb were either developed during a former study or newly developed. Several batteries contained higher mass fractions of mercury or cadmium than the EU limits. Only half of the batteries with mercury and/or lead fractions above the marking thresholds were labelled. Alkaline–manganese mono-cells and Li-ion accumulators, on average, contained the lowest heavy metal concentrations, while zinc–carbon batteries, on average, contained the highest levels

Intercomparison of techniques for inspection and diagnostics of heavy water reactor pressure tubes. Determination of hydrogen concentration and blister characterization

International Nuclear Information System (INIS)

2009-03-01

Heavy water reactors (HWRs) comprise significant numbers of today's operating nuclear power plants, and more are under construction. Efficient and accurate inspection and diagnostic techniques for various reactor components and systems, especially pressure tubes, are an important factor in ensuring reliable and safe plant operation. To foster international collaboration in the efficient and safe use of nuclear power, the IAEA conducted a Coordinated Research Project (CRP) on Intercomparison of Techniques for HWR Pressure Tube Inspection and Diagnostics. This CRP was carried out within the framework of the IAEA's Technical Working Group on Advanced Technologies for HWRs (the TWG-HWR). The TWG-HWR is a group of experts nominated by their governments and designated by the IAEA to provide advice and to support implementation of IAEA's project on advanced technologies for HWRs. The objective of the CRP was to compare non-destructive inspection and diagnostic techniques, in use and being developed, for structural integrity assessment of HWR pressure tubes. During the first phase of this CRP participants investigated the capability of different techniques to detect and characterize flaws. During the second phase participants collaborated to detect and characterize hydride blisters and to determine the hydrogen concentration in zirconium alloys. The intention was to identify the most effective pressure tube inspection and diagnostic methods and to identify further development needs. The organizations which participated in phase 2 of this CRP are: - Comision Nacional de Energia Atomica (CNEA), Argentina; - Atomic Energy of Canada Ltd. (AECL), Chalk River Laboratories (CRL), Canada; - Bhabha Atomic Research Centre (BARC), India; - Korea Atomic Energy Research Institute (KAERI), Republic of Korea; - National Institute for Research and Development for Technical Physics (NIRDTP), Romania; - Nuclear Non-Destructive Testing Research and Services (NNDT), Romania. IAEA-TECDOC-1499

Assessment of heavy metals in loose deposits in drinking water distribution system.

Science.gov (United States)

Liu, Quanli; Han, Weiqiang; Han, Bingjun; Shu, Min; Shi, Baoyou

2018-06-09

Heavy metal accumulation and potential releases from loose deposits in drinking water distribution system (DWDS) can have critical impacts on drinking water safety, but the associated risks have not been sufficiently evaluated. In this work, the potential biological toxicity of heavy metals in loose deposits was calculated based on consensus-based sediment quality guidelines, and the effects of some of the main water quality parameters, such as the pH and bicarbonate and phosphate content, on the release behaviors of pre-accumulated heavy metals were investigated. The results showed that heavy metals (Cu, As, Cr, Pb, and Cd) significantly accumulated in all the samples, but the contents of the heavy metals were multiple magnitudes lower than the Fe and Mn contents. The potential biotoxicity of As and Cu was relatively high, but the biotoxicity of Cd was negligible. The water quality can significantly influence the release of heavy metals from loose deposits. As the pH increased from 7.0 to 9.0, the release of As and Cr obviously increased. The release of As, Cu, Pb, and Cr also accelerated with the addition of phosphate (from 1 to 5 mg/L). In contrast to the trends for the pH and phosphate, variations in the bicarbonate content did not have a significant influence on the release of As and Cr. The release ratios of heavy metals in the samples were very low, and there was not a correlation between the release rate of the heavy metals in the loose deposits and their potential biotoxicity.

Importance of using gamma rays to reduce microbial content in heavy cream

International Nuclear Information System (INIS)

Abed, H. A.; Aldurrah, O. A. A.; Aldarwash, A. K.

2012-12-01

The study aimed to investigate the effect of gamma rays on the pathogenic microorganisms that cause spoilage to the heavy cream and extend its storability period. The heavy cream samples were exposed to 0, 1 and 3 kGy and stored at 4 O C for 1, 10,20 and 30 days. The following microbial tests were carried out for evaluation (Total Bacterial Count, Presence Colonic Bacteria, Fungi and Yeast, Proteolytic Bacteria, and Lipolytic Bacteria). The result revealed that the dose 3 kGy was the best dose could used to control all type of the pathogenic microorganisms tested. Furthermore, the results of the sensory acceptability testes showed that all sensory characteristics of the heavy cream were not affected in comparison with that of the control after one day of storage. (Author)

Hydrogen production from high-moisture content biomass in supercritical water

Energy Technology Data Exchange (ETDEWEB)

Antal, M.J. Jr.; Adschiri, T.; Ekbom, T. [Univ. of Hawaii, Honolulu, HI (United States)] [and others

1996-10-01

Most hydrogen is produced by steam reforming methane at elevated pressures. The goal of this research is to develop commercial processes for the catalytic steam reforming of biomass and other organic wastes at high pressures. This approach avoids the high cost of gas compression and takes advantage of the unique properties of water at high pressures. Prior to this year the authors reported the ability of carbon to catalyze the decomposition of biomass and related model compounds in supercritical water. The product gas consists of hydrogen, carbon dioxide, carbon monoxide, methane, and traces of higher hydrocarbons. During the past year the authors have: (a) developed a method to extend the catalyst life, (b) begun studies of the role of the shift reaction, (c) completed studies of carbon dioxide absorption from the product effluent by high pressure water, (d) measured the rate of carbon catalyst gasification in supercritical water, (e) discovered the pumpability of oil-biomass slurries, and (f) completed the design and begun fabrication of a flow reactor that will steam reform whole biomass feedstocks (i.e. sewage sludge) and produce a hydrogen rich synthesis gas at very high pressure (>22 MPa).

High purity heavy water production: need for total organic carbon determination in process water streams

International Nuclear Information System (INIS)

Ayushi; Kumar, Sangita D.; Reddy, A.V.R.; Vithal, G.K.

2009-01-01

In recent times, demand for high purity heavy water (99.98% pure) in industries and laboratories has grown by manifold. Its application started in nuclear industry with the design of CANDU reactor, which uses natural uranium as fuel. In this reactor the purest grade of heavy water is used as the moderator and the primary coolant. Diverse industrial applications like fibre optics, medicine, semiconductors etc. use high purity heavy water extensively to achieve better performance of the specific material. In all these applications there is a stringent requirement that the total organic carbon content (TOC) of high purity heavy water should be very low. This is because the presence of TOC can lead to adverse interactions in different applications. To minimize the TOC content in the final product there is a need to monitor and control the TOC content at each and every stage of heavy water production. Hence a simple, rapid and accurate method was developed for the determination of TOC content in process water samples. The paper summarizes the results obtained for the TOC content in the water samples collected from process streams of heavy water production plant. (author)

AECB staff annual report of Bruce Heavy Water Plant operation for the year 1991

International Nuclear Information System (INIS)

1992-11-01

Bruce Heavy Water Plant operation was acceptably safe in 1991. There were no breaches of any of the regulations issued under the authority of the Atomic Energy Control Act. There was one violation of the operating licence. For one hour on October 30, 1991, water leaving the plant contained more hydrogen sulphide than Ontario regulations allow. There was no threat to public health or safety or harm to the environment as a result of this violation. One worker was overcome by hydrogen sulphide. The worker did not lose consciousness, but had the symptoms of H 2 S poisoning. Ontario Hydro took actions to increase awareness of the Operating Policy and Principles at Bruce Heavy Water Plant during 1991. All personnel attended a training course, and Ontario Hydro is reviewing all Bruce Heavy Water Plant documentation to ensure it is consistent with the Operating Policies and Principles. Ontario Hydro met 13 of 15 safety-related system availability targets. The AECB is satisfied appropriate action is being taken to improve the performance of the other two systems. Ontario Hydro continued to put heavy emphasis on safety training; however, they did not meet some of their other training targets. Ontario Hydro completed all of the planned emergency exercises at Bruce Heavy Water Plant in 1991. (Author)

Hydrogen atoms can be located accurately and precisely by x-ray crystallography.

Science.gov (United States)

Woińska, Magdalena; Grabowsky, Simon; Dominiak, Paulina M; Woźniak, Krzysztof; Jayatilaka, Dylan

2016-05-01

Precise and accurate structural information on hydrogen atoms is crucial to the study of energies of interactions important for crystal engineering, materials science, medicine, and pharmacy, and to the estimation of physical and chemical properties in solids. However, hydrogen atoms only scatter x-radiation weakly, so x-rays have not been used routinely to locate them accurately. Textbooks and teaching classes still emphasize that hydrogen atoms cannot be located with x-rays close to heavy elements; instead, neutron diffraction is needed. We show that, contrary to widespread expectation, hydrogen atoms can be located very accurately using x-ray diffraction, yielding bond lengths involving hydrogen atoms (A-H) that are in agreement with results from neutron diffraction mostly within a single standard deviation. The precision of the determination is also comparable between x-ray and neutron diffraction results. This has been achieved at resolutions as low as 0.8 Å using Hirshfeld atom refinement (HAR). We have applied HAR to 81 crystal structures of organic molecules and compared the A-H bond lengths with those from neutron measurements for A-H bonds sorted into bonds of the same class. We further show in a selection of inorganic compounds that hydrogen atoms can be located in bridging positions and close to heavy transition metals accurately and precisely. We anticipate that, in the future, conventional x-radiation sources at in-house diffractometers can be used routinely for locating hydrogen atoms in small molecules accurately instead of large-scale facilities such as spallation sources or nuclear reactors.

Assessment of heavy metal removal technologies for biowaste by physico-chemical fractionation

NARCIS (Netherlands)

Veeken, A.H.M.; Hamelers, H.V.M.

2003-01-01

In the Netherlands, the heavy metal content of biowaste-compost frequently exceeds the legal standards for heavy metals. In order to assess heavy metal removal technologies, a physico-chemical fractionation scheme was developed to gain insight into the distribution of heavy metals (Cd, Cu, Pb and

Production of dissociated hydrogen gas by electro-magnetically driven shock

International Nuclear Information System (INIS)

Kondo, Kotaro; Moriyama, Takao; Hasegawa, Jun; Horioka, Kazuhiko; Oguri, Yoshiyuki

2013-01-01

Evaluation of ion stopping power which has a dependence on target temperature and density is an essential issue for heavy-ion-driven high energy density experiment. We focus on experimentally unknown dissociated hydrogen atoms as target for stopping power measurement. The precise measurement of shock wave velocity is required because the dissociated gas is produced by electro-magnetically driven shock. For beam-dissociated hydrogen gas interaction experiment, shock velocity measurement using laser refraction is proposed. (author)

Study of the behaviour of some heavy elements in solvents containing hydrogen fluoride; Etude du comportement de quelques elements lourds dans des solvants a base d'acide fluorhydrique

Energy Technology Data Exchange (ETDEWEB)

Tarnero, M [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1967-01-01

The anhydrous liquid mixtures: dinitrogen tetroxide-hydrogen fluoride and antimony pentafluoride-hydrogen fluoride were studied as solvents for heavy elements interesting nuclear energy: uranium, thorium, zirconium and for some of their compounds. For N{sub 2}O{sub 4}-HF mixtures, electric conductivity measurements and liquid phase infrared spectra were also obtained. Uranium and zirconium tetrafluoride are much more soluble in N{sub 2}O{sub 4}-HF mixtures than in pure hydrogen fluoride. Uranium dissolved in these mixtures is pentavalent. In SbF{sub 5}-HF mixtures, uranium dissolves with hydrogen evolution and becomes trivalent. The solid compound resulting from the dissolution is a fluoro-antimonate: U(SbF{sub 6}){sub 3}. (author) [French] On a etudie les melanges liquides anhydres: peroxyde d'azote-acide fluorhydrique et pentafluorure d'antimoine-acide fluorhydrique comme solvants d'elements lourds interessant l'energie nucleaire: uranium, thorium, zirconium et de quelques uns de leurs composes. Pour les melanges N{sub 2}O{sub 4}-HF on a egalement effectue des mesures de conductivite electrique, ainsi que des spectres d'absorption infrarouge en phase liquide. Le tetrafluorure d'uranium et le tetrafluorure de zirconium sont beaucoup plus solubles dans les melanges N{sub 2}O{sub 4}-HF que dans l'acide fluorhydrique. L'uranium dissous dans ces melanges est a l'etat pentavalent. Dans les melanges SbF{sub 5}-HF l'uranium se dissout avec degagement d'hydrogene et passe a l'etat trivalent. Le compose solide resultant de la dissolution est un fluoantimoniate: U(SbF{sub 6}){sub 3}. (auteur)

The Content of Heavy Metals (Cu, Zn, Cr, Ni, Pb in The Soil Near The Arterial Roads in Wroclaw (Poland

Directory of Open Access Journals (Sweden)

Sobczyk Karolina

2017-01-01

Full Text Available The concentrations of heavy metals in soils along the motorway bypass of Wroclaw (AOW and the Eastern Ring Road of Wroclaw (WOW, Poland, have been determined. The soil samples were collected from the levels of 0-25 cm within 2 m from the edge of the road. The mineralizates were prepared in HNO3, 60%, using the Microwave Digestion System. The content of Cu, Zn, Cr, Ni and Pb in soils were determined using FAAS method. The physicochemical parameters, the conductivity and pH of the soil solutions were measured to evaluate the salinity of the soils and their active and exchangeable acidity. The pollution indexes (WN showing the enrichment of soils in metals have been determined. Excess of metal concentrations in soils compared to the geochemical background in uncontaminated soils of Poland has been observed. Permissible concentrations of heavy metals relative to the standard for soils, according to the Polish Ministry of Environment Regulation from September 1st, 2016, have not been exceeded.

Heavy water production by the method of ammonia rectification with heat pump. Experience of starting of industrial installation

International Nuclear Information System (INIS)

Rozen, A.M.

1995-01-01

Basic results of the start-up in 1955 of a facility for heavy water production by ammonia refining are presented to substantiate its economic profitability. The description of the facility is given, data on the materials corrosion resistance, efficiency of the operation of the trays and pumps are provided. It is shown that the mentioned method of heavy water production in terms of economic indices is similar to highly efficient methods, namely: refining of liquid hydrogen and water-hydrogen sulfide two-temperature isotopic exchange. 14 refs., 14 figs., 2 tabs

Hydrogen retorting of oil shales from Eastern Canada

Energy Technology Data Exchange (ETDEWEB)

Furimsky, E. (CANMET, Ottawa, Ontario (Canada)); Synnott, J.; Boorman, R.S.; Salter, R.S.

1984-04-01

The liquid production potential of thirty oil shale samples from Eastern Canada was determined by Fischer assay retort and pyrochem retort. For all shales, the presence of hydrogen during pyrochem retorting resulted in a significant increase in oil yields compared to Fischer assay yields. Ten oil shale samples were selected for detailed evaluation in the pyrochem retort in the presence of nitrogen and hydrogen. Besides increasing yields, the presence of hydrogen lowered the specific gravity of liquid products and the content of sulphur but increased the content of nitrogen. This was attributed to the stabilization of precursors to nitrogen compounds which prevented their polymerization. (J.H.K.)

Heavy metal hazards of Nigerian herbal remedies

International Nuclear Information System (INIS)

Obi, E.; Akunyili, Dora N.; Ekpo, B.; Orisakwe, Orish E.

2006-01-01

The uses of herbal products are not regulated in Nigeria and in many low-income countries and are freely available to everyone. The safety of these herbal medicines is poorly understood. This study characterizes the content of cadmium, copper, iron, nickel, selenium, zinc, lead and mercury in a random sample of Nigerian traditional products. Ready-to-use herbal products were purchased from the open market and digested using HNO 3 .The heavy metal content of the digested filtrate was determined by atomic absorption spectrometry Uni-cam Model 929. The result showed that 100% of the samples contained elevated amounts of heavy metals. These data alert us to the possibility of heavy metal toxicity from herbal products in Nigeria. The public health hazards from ingestion of herbal medicines should be identified and disclosed by in-depth risk assessment studies

Heavy metal hazards of Nigerian herbal remedies

Energy Technology Data Exchange (ETDEWEB)

Obi, E. [Toxicology Unit, Department of Pharmacology, College of Health Sciences, Nnamdi Azikiwe University, Nnewi (Nigeria); Akunyili, Dora N. [National Agency of Food and Drug Administration and Control (NAFDAC), Lagos (Nigeria); Ekpo, B. [Department of Biochemistry, College of Medical Sciences, Abia State University, Uturu (Nigeria); Orisakwe, Orish E. [Toxicology Unit, Department of Pharmacology, College of Health Sciences, Nnamdi Azikiwe University, Nnewi (Nigeria)]. E-mail: eorish@yahoo.com

2006-10-01

The uses of herbal products are not regulated in Nigeria and in many low-income countries and are freely available to everyone. The safety of these herbal medicines is poorly understood. This study characterizes the content of cadmium, copper, iron, nickel, selenium, zinc, lead and mercury in a random sample of Nigerian traditional products. Ready-to-use herbal products were purchased from the open market and digested using HNO{sub 3}.The heavy metal content of the digested filtrate was determined by atomic absorption spectrometry Uni-cam Model 929. The result showed that 100% of the samples contained elevated amounts of heavy metals. These data alert us to the possibility of heavy metal toxicity from herbal products in Nigeria. The public health hazards from ingestion of herbal medicines should be identified and disclosed by in-depth risk assessment studies.

Hydrogen production by Chlamydomonas reinhardtii under light driven sulfur deprived condition

Energy Technology Data Exchange (ETDEWEB)

Vijayaraghavan, Krishnan; Karthik, Rajendran [Biotechnology Research Division, Department of Biotechnology, Prathyusha Institute of Technology and Management, Aranvoyalkuppam, Thiruvallur District 602025, Tamil Nadu (India); Kamala Nalini, S.P. [Department of Biotechnology, Vel Group of Educational Institutions, Avadi, Alamadhi Road, Chennai 600062, Tamil Nadu (India)

2009-10-15

This article explores the possibility of demonstrating sustainable photohydrogen production using Chlamydomonas reinhardtii when grown in sulfur deprived photoautotrophic condition. The hydrogen evolving capability of the algal species was monitored based on alternating light and dark period. Investigation was carried out during the day time in order to exploit the solar energy for meeting the demand of the light period. The results showed that when the reactor was operated at varying photoperiod namely 2, 3 and 4 h of alternating light and dark period, the gas generation was found to be 32 {+-} 4, 63 {+-} 7 and 52 {+-} 5 mL/h, while the corresponding hydrogen content was 47, 86 and 87% respectively. Functional components of hydrogen generation reaction centers were also analyzed, which showed that the PS(I) reaction centers were involved in hydrogen production pathway, as the light absorption by PS(I) was prerequisite for hydrogen generation under sulfur deprived photoautotrophic condition. The findings showed a higher gas yield and hydrogen content under dark period, whereas under light period the gas content was below detectable level for hydrogen due to the reversible hydrogenase reaction. (author)

Effects of moisture content and initial pH in composting process on heavy metal removal characteristics of grass clipping compost used for stormwater filtration.

Science.gov (United States)

Khan, Eakalak; Khaodhir, Sutha; Ruangrote, Darin

2009-10-01

Heavy metals are common contaminants in stormwater runoff. One of the devices that can be used to effectively and economically remove heavy metals from runoff is a yard waste compost stormwater filter. The primary goal of composting is to reduce waste volume rather than to produce stormwater filter media. Moisture content (MC) and initial pH, the two important parameters in composting, were studied for their effects on yard waste volume reduction and heavy metal adsorption performances of the compost. The main objective of this investigation was to examine whether the conditions that provided high yard waste volume reduction would also result in compost with good heavy metal removal performances. Manila grass was composted at different initial pHs (5-9) and MCs (30-70%) and the composts were used to adsorb cadmium, copper, lead and zinc from water. Results indicated that MC is more critical than initial pH for both volume reduction and production of compost with high metal adsorption performances. The most optimal conditions for the two attributes were not exactly the same but lower MCs of 30-40% and pH 7 or higher tended to satisfy both high volume reduction and effective metal adsorption.

Investigation of Hydrogen and Nitrogen Content in Compacted Graphite Iron Production

OpenAIRE

Siafakas, Dimitrios

2013-01-01

The aim of this research, part of a wider program called SPOFIC, is to investigate how the casting procedure affects the concentration of hydrogen and nitrogen gases in Compacted Graphite Iron used for the production of truck cylinder blocks. Hydris equipment was used for the Hydrogen measurements and the Optical Emission Spectroscopy and combustion analysis methods were used for the nitrogen measurements. The experiment was performed in one of the cooperating foundries. It was found that Hyd...

Fractionation of oxygen and hydrogen isotopes at the hydrate gas forming in the sea sediments

International Nuclear Information System (INIS)

Pashkina, V.I.; Esikov, A.D.

1990-01-01

The paper gives data on isotope composition of interstitial and near-bottom waters sampled in a region of gas-hydrate formation in the Sea of Okhotsk. The studies show that heavy isotopes of oxygen and hydrogen is used in gas-hydrate formation, with the result that isotope composition of its constitution water constitutes δ 18 O=+1.99per mille, δD=+23per mille relatively to SMOW. Formation of autogenic carbonates leads to isotope exchange with interstitial water wich, in turn, changes its primary isotope composition in the direction of increasing of O-18 content. The near-bottom waters are isotope-light relatively to the SMOW standard and to the mean isotope composition of interstitial water in the studied region of gas-hydrate spreading. (orig.) [de

Chemical and biological effects of heavy distillate recycle in the SRC-II process

Energy Technology Data Exchange (ETDEWEB)

Wilson, B.W.; Pelroy, R.A.; Anderson, R.P.; Freel, J.

1983-12-01

Recent work from the Merriam Laboratory continuous coal liquefaction units shows that heavy distillate from the SRC-II process can be recycled to extinction, and hence a distillate product boiling entirely below 310/sup 0/C (590/sup 0/F) (or other selected boiling points) is feasible. In these runs distillate yield was not reduced; gas make was unaffected; and hydrogen consumption was increased only slightly, in keeping with the generally higher hydrogen content of lighter end products. Total distillate yield (C/sub 5/-590/sup 0/F) was 56 wt %, MAF coal in runs with subbituminous coal from the Amax Belle Ayr mine. Product endpoint is well below 371/sup 0/C (700/sup 0/F), the temperature above which coal distillates appear to become genotoxic; and the product was shown to be free of mutagenic activity in the Ames test. Chemical analyses showed both the < 270/sup 0/C (< 518/sup 0/F) and the < 310/sup 0/C (< 590/sup 0/F) distillates to be essentially devoid of several reference polycyclic compounds known to be carcinogenic in laboratory animals. Tests for tumorigenic or carcinogenic activity were not carried out on these materials. However, a comparison of chemical data from the Merriam heavy distillate samples with data on the other SRC-II distillates where carcinogenesis or tumorigenesis data is available leads to the expectation that < 371/sup 0/C (< 700/sup 0/F) materials from the Merriam Laboratory will have greatly reduced tumorigenic and carcinogenic activity in skin painting tests. Other studies suggest the product should be more readily upgraded than full-range (C/sub 5/-900/sup 0/F) distillate.

Experimental Study on Behavior of Bow-tie Tree Generation by Using Heavy Water

Science.gov (United States)

Kumazawa, Takao; Nakagawa, Wataru; Tsurumaru, Hidekazu

Bow-tie tree (BTT) generated from contaminant, e.g., metal, carbon, amber(over cured resin) or void in insulator is a significant deterioration factor of XLPE power cable. However, essential role of water in generation and progress of BTT is not yet sufficiently cleared. In order to investigate the role of water we paid attention to difference in chemical properties of light water (H2O) and heavy water (D2O), moreover we evaluated influence of isotopic effect due to hydrogen and deuterium on behavior of BTT generation. In accelerated aging test the number of BTT in XLPE sample, in which copper powder of 500ppm was contaminated as BTT cores, dipped in heavy water (D2O:100wt%) decreased to one third compared with light water(D2O:0wt%). Furthermore, the maximum length of BTT decreased with increase in concentration of heavy water. The experimental results show that heavy water exerted a depression effect on generation and progress of BTT. We considered that the depression effect due to hydrogen isotope appeared by inhibiting ionization and elution of BTT cores, because salt-solubility and ionic mobility of heavy water are about 15 to 20% smaller than those of light water. Therefore, the essential role of water seemed to be production and transport of ions in XLPE.

Method and equipment to extract and recover tritium from light and heavy water

International Nuclear Information System (INIS)

Butler, J.P.; Hammerli, M.M.

1979-01-01

A combined electrolysis-catalysis exchange process is proposed to extract tritium, with the aim of being able to reduce the tritium value in the heavy water moderation and cooling system of nuclear power plants. The tritium-contained water is brought into contact in a catalyst column in countercurrent with electrolytically produced hydrogen in this process, the hydrogen is then fed to a catalyst-containing separation column whilst the tritium-contained water flows to the electrolysis cell which produces the hydrogen gas. The process is described in detail. (UWI) [de

Distribution of heavy metals in peri-urban agricultural areas soils

International Nuclear Information System (INIS)

Iram, S.; Ahmad, I.; Akhtar, S.

2012-01-01

In industry oriented peri-urban areas, the heavy metals accumulation in soils caused by industrialization has become a potential threat. The top soil sample from 48 agricultural fields were collected from a typical industry based peri-urban areas (Lahore, Faisalabad, Multan, Kasur, Islamabad, Wah Cantt.) of Punjab, Pakistan to study the accumulation and distribution of heavy metals (Pb, Cd, Cr, Cu, Ni and Zn) by atomic absorption spectrophotometer. The aim of the study was to investigate influence of an industrialized environment on the accumulation of heavy metals in peri-urban agricultural soils. The results of the study showed that the Pb content in the soil ranged from 17.24 to 126.4 mg/kg and the highest Pb content was observed in Islamabad soil samples, and the lowest in that of Multan area. The Cd content ranged from 1.1 to 4.0 mg/kg in Lahore while the highest Cr concentration level was 210.2 mg/kg and it was observed in Kasur and lowest 30.60 in that of Multan. The Cu content ranged from 31.2 to 127.9 mg/kg (Kasur-Lahore). The highest Ni concentration (82.0 mg/kg) was observed in Lahore from the urban area and the lowest level of 12.15 mg/kg was observed in Multan. The Zn content ranged from 42.5 to 267.7 mg/kg (Faisalabad-Wah Cantt). The study concluded that the concentration level of the heavy metals (Pb, Cd, Cu, Ni, Cr, Zn) in the studied peri-urban areas was higher as compared to heavy metal content of normal Dutch soil. High automobile traffic and industrial waste both are the most likely sources of the contamination of the peri urban areas of Pakistan. (author)

Thermoanalytical investigation of the hydrogen absorption behaviour of Sm{sub 2}Fe{sub 17-x}Ga{sub x} at high hydrogen pressures

Energy Technology Data Exchange (ETDEWEB)

Handstein, A.; Kubis, M.; Gebel, B.; Mueller, K.-H.; Schultz, L. [Institut fuer Festkoerper- und Werkstofforschung Dresden e.V. (Germany). Inst. fuer Metallische Werkstoffe; Gutfleisch, O.; Harris, I.R. [Institut fuer Festkoerper- und Werkstofforschung Dresden e.V. (Germany). Inst. fuer Metallische Werkstoffe]|[Birmingham Univ. (United Kingdom). School of Metallurgy and Materials

1998-07-01

The complete disproportionation of Sm{sub 2}Fe{sub 17-x}Ga{sub x} during annealing in hydrogen is hindered due to an increased stability of the compounds with a higher Ga content (x {>=} 1). Therefore the HD process as the first step of HDDR (hydrogenation-disproportionation-desorption-recombination) has to be carried out at a high hydrogen pressure for x {>=} 1. The hydrogen absorption behaviour of Sm{sub 2}Fe{sub 17-x}Ga{sub x} (x = 0, 0.5, 1 and 2) was investigated by means of hydrogen differential thermal analysis (HDTA) and high pressure differential scanning calorimetry (HPDSC) at hydrogen pressures up to 70 bar. A dependency of hydrogenation and disproportionation temperatures on hydrogen pressure and Ga content was found. The comparison with other substituents (M = Al and Si) instead of M = Ga showed an increased stability of Sm{sub 2}Fe{sub 17-x}M{sub x} compounds against disproportionation by hydrogen in the sequence Al, Ga and Si. The Curie temperatures of the interstitially hydrogenated Th{sub 2}Zn{sub 17}-type materials increase with the hydrogen pressure. In order to produce coercive and thermally stable Sm{sub 2}Fe{sub 15}Ga{sub 2}C{sub y} powder by means of the HDDR process, we recombined material disproportionated at different hydrogen pressures. Preliminary results of magnetic properties of this HDDR treated and gas-carburized Sm{sub 2}Fe{sub 15}Ga{sub 2}C{sub y} are discussed. (orig.)