Control of cast iron and casts manufacturing by Inmold method

Directory of Open Access Journals (Sweden)

S. Pietrowski

2009-07-01

Full Text Available In this paper the usability of cast iron spheroidizing process in mould control by ATD method as well as by ultrasonic method were presented. Structure of instrumentation needed for control form performance of cast iron spheroidizing by Inmold method was illustrated. Author, pointed out that amount of magnesium master alloy should obtain 0,8 ÷ 1,0% of mass in form at all. Such quantity of preliminary alloy assure of obtain of nodular graphite in cast iron. In consequence of this, is reduce the cast iron liquidus temperature and decrease of recalescence temperature of graphite-eutectic crystallization in compare with initial cast iron. Control of casts can be carried out by ultrasonic method. In plain cast iron, ferritic-pearlitic microstructure is obtaining. Additives of 1,5% Cu ensure pearlitic structure.

Borax as flux on sintering of iron Ancor Steel 1000® under glow discharge

Science.gov (United States)

Ariza Suarez, H. G.; Sarmiento Santos, A.; Ortiz Otálora, C. A.

2016-02-01

This work studies the flux effect of borax (di sodium tetraborate decahydrate) on sintering of iron Ancor Steel 1000® in abnormal glow discharge. The incidence of the percentage by weight of borax and the sintering temperature in the process were observed. Samples of powder metallurgical iron were prepared with proportions of 0.50%, 2.0%, 4.0% and 6.0% by weight of borax using the procedures of powder metallurgy. The samples were sintered at 800 and 1100°C for 30min, by glow discharge at low pressure in a reducing atmosphere composed of 20% H2+80% Ar. The samples in compact green-state were analyzed by TGA-DSC to determine the fusion process and mass loss during sintering. The analysis of microhardness and density, shows that at a sintering temperature of 800°C the sample density decreases and the sample microhardness increases with respect to sintered samples without borax. Sintered samples were analysed by DRX showing the absence of precipitates.

Diffusion of iron in β-iron telluride (Fe1.12Te) by Moessbauer spectroscopy and tracer method

International Nuclear Information System (INIS)

Magara, Masaaki; Tsuji, Toshihide; Naito, Keiji

1993-01-01

The diffusion coefficient of iron in a β-iron telluride (Fe 1.12 Te) polycrystalline sample was measured by Moessbauer diffusional line broadening method which relates to the collapse of coherence in gamma-ray photon by the atomic jump at local sites. The diffusion coefficient of iron along the c-axis in nearly single crystal of β-iron telluride was also measured by tracer technique which shows the results of an atom transport in long distance. The activation energies for the diffusion of iron in Fe 1.12 Te obtained by the Moessbauer spectroscopy and the tracer method were 91.5±5.4 and 106±23 kJ/mol, respectively. The diffusion coefficients of iron in β-iron telluride obtained by Moessbauer line broadening are in fair agreement with the values averaged from that along c-axis obtained by tracer method and that along a- and b-axes obtained from reaction rate constant between iron and tellurium by the previous study of the present authors. (orig.)

Method for producing dysprosium-iron-boron alloy powder

International Nuclear Information System (INIS)

Camp, F.E.; Wooden, S.A.

1989-01-01

A method for producing a dysprosium-iron alloy adapted for use in the manufacture of rare-earth element containing, iron-boron permanent magnets, the method including providing a particle mixture comprising dysprosium oxide, iron and calcium, compacting the particle mixture to produce a consolidated article, heating the article for a time at temperature to form a metallic compound comprising dysprosium and iron and to form calcium oxide, producing a particle mass of -35 mesh from the compact, washing the particle mass with water at a temperature no greater than 10 0 C to react to the calcium and to the calcium oxide therewith to form a calcium hydroxide, while preventing oxidation of the particle mass, and removing the calcium hydroxide from the particle mass

Method of coating an iron-based article

Science.gov (United States)

Magdefrau, Neal; Beals, James T.; Sun, Ellen Y.; Yamanis, Jean

2016-11-29

A method of coating an iron-based article includes a first heating step of heating a substrate that includes an iron-based material in the presence of an aluminum source material and halide diffusion activator. The heating is conducted in a substantially non-oxidizing environment, to cause the formation of an aluminum-rich layer in the iron-based material. In a second heating step, the substrate that has the aluminum-rich layer is heated in an oxidizing environment to oxidize the aluminum in the aluminum-rich layer.

Advances in the Surface Renewal Flux Measurement Method

Science.gov (United States)

Shapland, T. M.; McElrone, A.; Paw U, K. T.; Snyder, R. L.

2011-12-01

The measurement of ecosystem-scale energy and mass fluxes between the planetary surface and the atmosphere is crucial for understanding geophysical processes. Surface renewal is a flux measurement technique based on analyzing the turbulent coherent structures that interact with the surface. It is a less expensive technique because it does not require fast-response velocity measurements, but only a fast-response scalar measurement. It is therefore also a useful tool for the study of the global cycling of trace gases. Currently, surface renewal requires calibration against another flux measurement technique, such as eddy covariance, to account for the linear bias of its measurements. We present two advances in the surface renewal theory and methodology that bring the technique closer to becoming a fully independent flux measurement method. The first advance develops the theory of turbulent coherent structure transport associated with the different scales of coherent structures. A novel method was developed for identifying the scalar change rate within structures at different scales. Our results suggest that for canopies less than one meter in height, the second smallest coherent structure scale dominates the energy and mass flux process. Using the method for resolving the scalar exchange rate of the second smallest coherent structure scale, calibration is unnecessary for surface renewal measurements over short canopies. This study forms the foundation for analysis over more complex surfaces. The second advance is a sensor frequency response correction for measuring the sensible heat flux via surface renewal. Inexpensive fine-wire thermocouples are frequently used to record high frequency temperature data in the surface renewal technique. The sensible heat flux is used in conjunction with net radiation and ground heat flux measurements to determine the latent heat flux as the energy balance residual. The robust thermocouples commonly used in field experiments

System and method for producing metallic iron

Science.gov (United States)

Englund, David J.; Schlichting, Mark; Meehan, John; Crouch, Jeremiah; Wilson, Logan

2014-07-29

A method of production of metallic iron nodules comprises assembling a hearth furnace having a moveable hearth comprising refractory material and having a conversion zone and a fusion zone, providing a hearth material layer comprising carbonaceous material on the refractory material, providing a layer of reducible material comprising and iron bearing material arranged in discrete portions over at least a portion of the hearth material layer, delivering oxygen gas into the hearth furnace to a ratio of at least 0.8:1 ponds of oxygen to pounds of iron in the reducible material to heat the conversion zone to a temperature sufficient to at least partially reduce the reducible material and to heat the fusion zone to a temperature sufficient to at least partially reduce the reducible material, and heating the reducible material to form one or more metallic iron nodules and slag.

Variations of iron flux and organic carbon remineralization in a subterranean estuary caused by interannual variations in recharge

Science.gov (United States)

Roy, Moutusi; Martin, Jonathan B.; Cable, Jaye E.; Smith, Christopher G.

2013-01-01

We determine the inter-annual variations in diagenetic reaction rates of sedimentary iron (Fe ) in an east Florida subterranean estuary and evaluate the connection between metal fluxes and recharge to the coastal aquifer. Over the three-year study period (from 2004 to 2007), the amount of Fe-oxides reduced at the study site decreased from 192 g/yr to 153 g/yr and associated organic carbon (OC) remineralization decreased from 48 g/yr to 38 g/yr. These reductions occurred although the Fe-oxide reduction rates remained constant around 1 mg/cm2/yr. These results suggest that changes in flow rates of submarine groundwater discharge (SGD) related to changes in precipitation may be important to fluxes of the diagenetic reaction products. Rainfall at a weather station approximately 5 km from the field area decreased from 12.6 cm/month to 8.4 cm/month from 2004 to 2007. Monthly potential evapotranspiration (PET) calculated from Thornthwaite’s method indicated potential evapotranspiration cycled from about 3 cm/month in the winter to about 15 cm/month in the summer so that net annual recharge to the aquifer decreased from 40 cm in 2004 to -10 cm in 2007. Simultaneously, with the decrease in recharge of groundwater, freshwater SGD decreased by around 20% and caused the originally 25 m wide freshwater seepage face to decrease in width by about 5 m. The smaller seepage face reduced the area under which Fe-oxides were undergoing reductive dissolution. Consequently, the observed decrease in Fe flux is controlled by hydrology of the subterranean estuary. These results point out the need to better understand linkages between temporal variations in diagenetic reactions and changes in flow within subterranean estuaries in order to accurately constrain their contribution to oceanic fluxes of solutes from subterranean estuaries.

Atmospheric iron supply and enhanced vertical carbon flux in the NE subarctic Pacific: Is there a connection?

Science.gov (United States)

Boyd, P. W.; Wong, C. S.; Merrill, J.; Whitney, F.; Snow, J.; Harrison, P. J.; Gower, J.

1998-09-01

Recent studies have confirmed the relationship between iron supply and phytoplankton growth rates in all three high-nitrate low-chlorophyll (HNLC) oceanic provinces. However, there is little evidence, so far, of the role of iron in altering the efficiency of the biological pump via increased downward export of particulate organic carbon (POC). The NE subarctic Pacific is unique among HNLC regions in that long time series pelagic observations and deep-moored sediment trap records exist which may provide the best opportunity thus far to test aspects of the iron hypothesis. Episodic elevated levels of chlorophyll a (> 2.0 μg L-1) were observed 6 times between 1964 and 1976 at the former site of Ocean Station Papa (OSP). In addition, between 1984 and 1990 on at least three occasions, concurrent pulses of POC and biogenic silica were recorded in deep-moored traps at OSP. Possible explanations for these events, such as lateral advection of more productive waters, iron-mediated blooms, or grazing by salp swarms are discussed and tested using an existing downward POC flux model. Owing to the episodic nature of such events, no available data are sufficiently comprehensive to unequivocally rule out any of these explanations. Nevertheless, from the data available, the occurrence of pelagic or deep water pulses, approximately once every 3 years, are most consistent with iron-mediated diatom blooms, and of the sinking of POC and biogenic silica (from such a bloom) to depth, respectively. A comparison of the timing of these iron-mediated pulses with that of the transport probabilities of atmospheric dust supply from Asia and Alaska provides an opportunity to assess the likelihood of a coupling between the atmosphere and the ocean.

Synthetic flux as a whitening agent for ceramic tiles

Energy Technology Data Exchange (ETDEWEB)

Rodrigues dos Santos, Geocris, E-mail: geocris.rodrigues@gmail.com [INNOVARE Inteligência Em Cerâmica, 13566-420 São Carlos, SP (Brazil); Departamento De Engenharia Dos Materiais, Universidade Federal De São Carlos, 13565-905 São Carlos, SP (Brazil); Salvetti, Alfredo Roque [Departamento De Física, Universidade Federal De Mato Grosso Do Sul (Brazil); Cabrelon, Marcelo Dezena [INNOVARE Inteligência Em Cerâmica, 13566-420 São Carlos, SP (Brazil); Departamento De Engenharia Dos Materiais, Universidade Federal De São Carlos, 13565-905 São Carlos, SP (Brazil); Morelli, Márcio Raymundo [Departamento De Engenharia Dos Materiais, Universidade Federal De São Carlos, 13565-905 São Carlos, SP (Brazil)

2014-12-05

Highlights: • The synthetic flux acts as a whitening agent of firing color in raw material ceramics. • The raw material ceramics have high levels of the iron oxides and red color. • The different process obtained red color clays with hematite and illite phases. • The whiteness ceramic obtained herein can be used in a porcelain tile industry. - Abstract: A synthetic flux is proposed as a whitening agent of firing color in tile ceramic paste during the sinterization process, thus turning the red firing color into whiteness. By using this mechanism in the ceramic substrates, the stoneware tiles can be manufactured using low cost clays with high levels of iron oxides. This method proved to be an economical as well as commercial strategy for the ceramic tile industries because, in Brazil, the deposits have iron compounds as mineral component (Fe{sub 2}O{sub 3}) in most of the raw materials. Therefore, several compositions of tile ceramic paste make use of natural raw materials, and a synthetic flux in order to understand how the interaction of the iron element, in the mechanism of firing color ceramic, occurs in this system. The bodies obtained were fired at 1100 °C for 5 min in air atmosphere to promote the color change. After the heating, the samples were submitted to X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) analyses. The results showed that the change of firing color occurs because the iron element, which is initially in the crystal structure of the hematite phase, is transformed into a new crystal (clinopyroxenes phase) formed during the firing, so as to make the final firing color lighter.

Effects of resuspension on benthic fluxes of oxygen, nutrients, dissolved inorganic carbon, iron and manganese in the Gulf of Finland, Baltic Sea

NARCIS (Netherlands)

Almroth, E.; Tengberg, A.; Andersson, J.H.; Pakhomova, S.; Hall, P.O.J.

2009-01-01

The effect of resuspension on benthic fluxes of oxygen (O2), ammonium (NH4+), nitrate (NO3-), phosphate (PO43-), silicate (Si(OH)4), dissolved inorganic carbon (DIC), total dissolved iron (Fe) and total dissolved manganese (Mn) was studied at three different stations in the Gulf of Finland (GoF),

Evaluating the Effectiveness of Various Methods of Iron Deficiency Prevention in Infants

Directory of Open Access Journals (Sweden)

N.А. Bielykh

2015-02-01

Full Text Available Objective: to evaluate the effectiveness of various methods of iron deficiency prevention in infants. Materials and Methods. Within 30-cluster regional epidemiological study on the prevalence of iodine and iron deficiency in children, we have analyzed the results of screening for anemia in 948 children, carried out questioning of mothers, determined the concentration of iron in breast milk. The effectiveness of preventive measures was assessed by indicators of iron supplementation of the body in 96 children depending on the existing method of iron prophylaxis. Results of the Study. It was found that the use by mother during lactation of iron-containing vitamin-mineral complexes had no effect on the iron content in breast milk. It is proved that administration of iron (III hydroxide polymaltose complex 1 mg/kg/day for 2 months is the most effective way to prevent iron deficiency in children who are exclusively breastfed.

How to choose methods for lake greenhouse gas flux measurements?

Science.gov (United States)

Bastviken, David

2017-04-01

Lake greenhouse gas (GHG) fluxes are increasingly recognized as important for lake ecosystems as well as for large scale carbon and GHG budgets. However, many of our flux estimates are uncertain and it can be discussed if the presently available data is representative for the systems studied or not. Data are also very limited for some important flux pathways. Hence, many ongoing efforts try to better constrain fluxes and understand flux regulation. A fundamental challenge towards improved knowledge and when starting new studies is what methods to choose. A variety of approaches to measure aquatic GHG exchange is used and data from different methods and methodological approaches have often been treated as equally valid to create large datasets for extrapolations and syntheses. However, data from different approaches may cover different flux pathways or spatio-temporal domains and are thus not always comparable. Method inter-comparisons and critical method evaluations addressing these issues are rare. Emerging efforts to organize systematic multi-lake monitoring networks for GHG fluxes leads to method choices that may set the foundation for decades of data generation and therefore require fundamental evaluation of different approaches. The method choices do not only regard the equipment but also for example consideration of overall measurement design and field approaches, relevant spatial and temporal resolution for different flux components, and accessory variables to measure. In addition, consideration of how to design monitoring approaches being affordable, suitable for widespread (global) use, and comparable across regions is needed. Inspired by discussions with Prof. Dr. Cristian Blodau during the EGU General Assembly 2016, this presentation aims to (1) illustrate fundamental pros and cons for a number of common methods, (2) show how common methodological approaches originally adapted for other environments can be improved for lake flux measurements, (3) suggest

Magnetic flux reconstruction methods for shaped tokamaks

International Nuclear Information System (INIS)

Tsui, Chi-Wa.

1993-12-01

The use of a variational method permits the Grad-Shafranov (GS) equation to be solved by reducing the problem of solving the 2D non-linear partial differential equation to the problem of minimizing a function of several variables. This high speed algorithm approximately solves the GS equation given a parameterization of the plasma boundary and the current profile (p' and FF' functions). The author treats the current profile parameters as unknowns. The goal is to reconstruct the internal magnetic flux surfaces of a tokamak plasma and the toroidal current density profile from the external magnetic measurements. This is a classic problem of inverse equilibrium determination. The current profile parameters can be evaluated by several different matching procedures. Matching of magnetic flux and field at the probe locations using the Biot-Savart law and magnetic Green's function provides a robust method of magnetic reconstruction. The matching of poloidal magnetic field on the plasma surface provides a unique method of identifying the plasma current profile. However, the power of this method is greatly compromised by the experimental errors of the magnetic signals. The Casing Principle provides a very fast way to evaluate the plasma contribution to the magnetic signals. It has the potential of being a fast matching method. The performance of this method is hindered by the accuracy of the poloidal magnetic field computed from the equilibrium solver. A flux reconstruction package has been implemented which integrates a vacuum field solver using a filament model for the plasma, a multi-layer perception neural network as an interface, and the volume integration of plasma current density using Green's functions as a matching method for the current profile parameters. The flux reconstruction package is applied to compare with the ASEQ and EFIT data. The results are promising

Mathematical model of the reformer sponge iron cycle

Energy Technology Data Exchange (ETDEWEB)

Fraser, S.; Hacker, V.; Evers, B.; Hierzer, J.; Besenhard, J.O. [Graz University of Technology, Graz (Austria). Inst. for Chemical Technology of Inorganic Materials Christian Doppler Pilot-Lab. for Fuel Cell Systems

2003-07-01

An innovative hydrogen production process called the Reformer Sponge Iron Cycle (RESC), based on redox reactions of iron ore pellets, was mathematically modeled. The hydrogen is produced by blowing steam over hot iron pellets in the oxidation stage, resulting in the oxidation of the iron. Synthesis gas coming from a reformer mixed with a fraction of recycled off-gas was used to reduce the iron oxide pellets (wuestite and-or magnetite) in the reduction stage, leading once more to iron . Once the mathematical model was developed, it was verified utilizing experimental data. Based on calculations of the equilibrium gas concentrations for reformer and sponge iron reactor (SIR), the model computes mass fluxes, molar fluxes, partial pressures, and variations of them throughout the complete cycle. The recycle rate, which determines the fraction of SIR off-gas recycled and added to the input gas stream, was optimized to maximize the amount of iron oxide reduced for a certain input gas flow. 5 refs., 4 figs.

Variations of iron flux and organic carbon remineralization in a subterranean estuary caused by inter-annual variations in recharge

Science.gov (United States)

Roy, Moutusi; Martin, Jonathan B.; Cable, Jaye E.; Smith, Christopher G.

2013-02-01

We determine the inter-annual variations in diagenetic reaction rates of sedimentary iron (Fe) in an east Florida subterranean estuary and evaluate the connection between metal fluxes and recharge to the coastal aquifer. Over the three years study period (from 2004 to 2007), the amount of Fe-oxides reduced at the study site decreased from 192 to 153 g/yr and associated organic carbon (OC) remineralization decreased from 48 to 38 g/yr. These reductions occurred although the Fe-oxide reduction rates remained constant around 1 mg/cm2/yr. These results suggest that changes in flow rates of submarine groundwater discharge (SGD) related to changes in precipitation may be important to fluxes of the diagenetic reaction products. Rainfall at a weather station approximately 5 km from the field area decreased from 12.6 to 8.4 cm/month from 2004 to 2007. Monthly potential evapotranspiration (PET) calculated from Thornthwaite's method indicated potential evapotranspiration cycled from about 3 cm/month in the winter to about 15 cm/month in the summer so that net annual recharge to the aquifer decreased from 40 cm in 2004 to -10 cm in 2007. Simultaneously with the decrease in recharge of groundwater, freshwater SGD decreased by around 20% and caused the originally 25 m wide freshwater seepage face to decrease in width by about 5 m. The smaller seepage face reduced the area under which Fe-oxides were undergoing reductive dissolution. Consequently, the observed decrease in Fe flux is controlled by hydrology of the subterranean estuary. These results point out the need to better understand linkages between temporal variations in diagenetic reactions and changes in flow within subterranean estuaries in order to accurately constrain their contribution to oceanic fluxes of solutes from subterranean estuaries.

The Effect Of Local Coal And Smelting Sponge Iron On Iron Content Of Pig Iron

Science.gov (United States)

Oediyani, Soesaptri; Juwita Sari, Pramita; Hadi P, Djoko

2018-03-01

The new regulation on mineral resources was announced by Ministry of Energy and Mineral resources (ESDM) of Indonesia at 2014 which it called Permen ESDM No 1/2014. Therefore, this research was conducted to add the value of local iron ores by using smelting technology. The objective of the research is to produce pig iron that meet the requirement of the new regulation of mineral resources such as 90% Fe. First, iron ores and coal mixed together with lime as a flux, then smelted in a Electric Arc Furnace at 1800°C. The process variables are (1; 1.25; 1.5; 1.75; 2.0) and the composition of coal (0.8%, 1.6%, 3.0%). The type of coal that used in this research was bituminous coal from Kalimantan and also the iron ores from Kalimantan. The products of the smelting technology are Pig iron and slag. Both pig iron and slag then analyzed by SEM-EDS to measure the iron content. The result shows that the maximum iron content on pig iron is about 95.04% meanwhile the minimum iron content on slag is about 3.66%. This result achieved at 1.6% coal and 2.0.

A Novel Method for the Filterless Preconcentration of Iron

DEFF Research Database (Denmark)

Andersen, Jens Enevold Thaulov

2005-01-01

A novel method of analysis of iron by filterless preconcentration is presented. This is the first example of efficient preconcentration of a refractory transition metal where coprecipitation and columns were omitted. The method applies a manifold of flow injection analysis (FIA) to iron species...... that are preconcentrated on the inner walls of a tubular reactor. It was found that the adsorption of iron species to the walls was particularly pronounced in reactors of nylon material and enrichment factors of 30-35 could be attained, as dependent on the length of the reactor and on the time of preconcentration....... In the preconcentration step of the FIA accessory, the optimum efficacy was obtained when the acidity of the samples were adjusted by HCl to pH = 2.5 whereas the ammonia preconcentration buffer should be kept alkaline at pH = 9.8. After being preconcentrated on the tubular reactor, the iron species were eluted...

Ice sheets as a significant source of highly reactive nanoparticulate iron to the oceans.

Science.gov (United States)

Hawkings, Jon R; Wadham, Jemma L; Tranter, Martyn; Raiswell, Rob; Benning, Liane G; Statham, Peter J; Tedstone, Andrew; Nienow, Peter; Lee, Katherine; Telling, Jon

2014-05-21

The Greenland and Antarctic Ice Sheets cover ~ 10% of global land surface, but are rarely considered as active components of the global iron cycle. The ocean waters around both ice sheets harbour highly productive coastal ecosystems, many of which are iron limited. Measurements of iron concentrations in subglacial runoff from a large Greenland Ice Sheet catchment reveal the potential for globally significant export of labile iron fractions to the near-coastal euphotic zone. We estimate that the flux of bioavailable iron associated with glacial runoff is 0.40-2.54 Tg per year in Greenland and 0.06-0.17 Tg per year in Antarctica. Iron fluxes are dominated by a highly reactive and potentially bioavailable nanoparticulate suspended sediment fraction, similar to that identified in Antarctic icebergs. Estimates of labile iron fluxes in meltwater are comparable with aeolian dust fluxes to the oceans surrounding Greenland and Antarctica, and are similarly expected to increase in a warming climate with enhanced melting.

The effect on the multipolar electromagnet for the levitation of thin iron plate

Energy Technology Data Exchange (ETDEWEB)

Osabe, H [Dept. of Electrical and Electronic Engineering, Musashi Inst. of Technology, Tokyo (Japan); Watada, M [Dept. of Electrical and Electronic Engineering, Musashi Inst. of Technology, Tokyo (Japan); Torii, S [Dept. of Electrical and Electronic Engineering, Musashi Inst. of Technology, Tokyo (Japan); Ebihara, D [Dept. of Electrical and Electronic Engineering, Musashi Inst. of Technology, Tokyo (Japan)

1996-12-31

The thin iron plate is needed to be transported without the degradation of the quality of surface, and magnetic levitation technology is one of the solutions to satisfy these requirements. Magnetic saturation in the objective, however, is a severe problem for the levitation of the thin iron plate. Design and evaluation method of the electromagnet is studied to avoid the saturation. In this paper, the shape of the electromagnet is studied to obtain the maximum attractive force without the saturation in the thin iron plate. The magnetic saturation position is investigated first, and it is proved that the saturation occurs in the iron plate especially when it is very thin. Therefore, the preferable shape of electromagnet should be investigated to secure the large cross sectional area of flux path in the plate. The authors propose the Multipolar electromagnet to solve this problem. The relationship between the electromagnet shape and the cross sectional area of flux path in the plate is studied. (orig.)

Cellular iron transport.

Science.gov (United States)

Garrick, Michael D; Garrick, Laura M

2009-05-01

Iron has a split personality as an essential nutrient that also has the potential to generate reactive oxygen species. We discuss how different cell types within specific tissues manage this schizophrenia. The emphasis in enterocytes is on regulating the body's supply of iron by regulating transport into the blood stream. In developing red blood cells, adaptations in transport manage the body's highest flux of iron. Hepatocytes buffer the body's stock of iron. Macrophage recycle the iron from effete red cells among other iron management tasks. Pneumocytes provide a barrier to prevent illicit entry that, when at risk of breaching, leads to a need to handle the dangers in a fashion essentially shared with macrophage. We also discuss or introduce cell types including renal cells, neurons, other brain cells, and more where our ignorance, currently still vast, needs to be removed by future research.

An alternative method for the measurement of neutron flux

Indian Academy of Sciences (India)

A simple and easy method for measuring the neutron flux is presented. This paper deals with the experimental verification of neutron dose rate–flux relationship for a non-dissipative medium. Though the neutron flux cannot be obtained from the dose rate in a dissipative medium, experimental result shows that for ...

Particle fluxes above forests: Observations, methodological considerations and method comparisons

International Nuclear Information System (INIS)

Pryor, S.C.; Larsen, S.E.; Sorensen, L.L.; Barthelmie, R.J.

2008-01-01

This paper reports a study designed to test, evaluate and compare micro-meteorological methods for determining the particle number flux above forest canopies. Half-hour average particle number fluxes above a representative broad-leaved forest in Denmark derived using eddy covariance range from -7 x 10 7 m -2 s -1 (1st percentile) to 5 x 10 7 m -2 s -1 (99th percentile), and have a median value of -1.6 x 10 6 m -2 s -1 . The statistical uncertainties associated with the particle number flux estimates are larger than those for momentum fluxes and imply that in this data set approximately half of the particle number fluxes are not statistically different to zero. Particle number fluxes from relaxed eddy accumulation (REA) and eddy covariance are highly correlated and of almost identical magnitude. Flux estimates from the co-spectral and dissipation methods are also correlated with those from eddy covariance but exhibit higher absolute magnitude of fluxes. - Number fluxes of ultra-fine particles over a forest computed using four micro-meteorological techniques are highly correlated but vary in magnitude

Dynamic performance analysis of permanent magnet contactor with a flux-weakening control strategy

Science.gov (United States)

Wang, Xianbing; Lin, Heyun; Fang, Shuhua; Jin, Ping; Wang, Junhua; Ho, S. L.

2011-04-01

A new flux-weakening control strategy for permanent magnet contactors is proposed. By matching the dynamic attraction force and the antiforce, the terminal velocity and collision energy of the movable iron in the closing process are significantly reduced. The movable iron displacement is estimated by detecting the closing voltage and current with the proposed control. A dynamic mathematical model is also established under four kinds of excitation scenarios. The attraction force and flux linkage are predicted by finite element method and the dynamics of the closing process is simulated using the 4th-order Runge-Kutta algorithm. Experiments are carried out on a 250A prototype with an intelligent control unit to verify the proposed control strategy.

Mathematical model of the reformer sponge iron cycle

International Nuclear Information System (INIS)

Fraser, S.; Hacker, V.; Evers, B.; Hierzer, J.; Besenhard, J.O.

2003-01-01

A mathematical model of the Reformer Sponge Iron Cycle (RESC), an innovative hydrogen production process based on redox reactions of iron ore pellets is presented. In the oxidation stage of the RESC, hydrogen is produced by blowing steam over hot iron pellets, hence oxidizing the iron. In the reduction stage, synthesis gas coming from a reformer mixed with a fraction of recycled off-gas is used to reduce the iron oxide pellets (wuestite and/or magnetite) back into iron again. A mathematical model of the complete RESC was developed and verified with experimental data. The model is based on calculations of the equilibrium gas concentrations for reformer and Sponge Iron Reactor (SIR). The current model computes mass fluxes, molar fluxes, partial pressures and variations of the respective throughout the complete cycle. The recycle rate, determining the fraction of SIR off-gas recycled and added to the input gas stream was subsequently optimized in order to maximize the amount of iron oxide reduced for a certain input gas flow. (author)

Iron microencapsulation in gum tragacanth using solvent evaporation method.

Science.gov (United States)

Asghari-Varzaneh, Elham; Shahedi, Mohammad; Shekarchizadeh, Hajar

2017-10-01

In this study iron salt (FeSO 4 ·7H 2 O) was microencapsulated in gum tragacanth hydrogel using solvent evaporation method. Three significant parameters (ferrous sulfate content, content of gum tragacanth, and alcohol to mixture ratio) were optimized by response surface methodology to obtain maximum encapsulation efficiency. Ferrous sulfate content, 5%, content of gum tragacanth, 22%, and alcohol to mixture ratio, 11:1 was determined to be the optimum condition to reach maximum encapsulation efficiency. Microstructure of iron microcapsules was thoroughly monitored using scanning electron microscopy (SEM). The microphotographs indicated two distinct crystalline and amorphous structures in the microcapsules. This structure was confirmed by X-ray diffraction (XRD) pattern of microcapsules. Fourier transform infrared (FTIR) spectra of iron microcapsules identified the presence of iron in the tragacanth microcapsules. The average size of microcapsules was determined by particle size analyzer. Release assessment of iron in simulated gastric fluid showed its complete release in stomach which is necessary for its absorption in duodenum. However, the use of encapsulated iron in gum tragacanth in watery foods is rather recommended due to the fast release of iron in water. Copyright © 2017 Elsevier B.V. All rights reserved.

Spatial distribution of bremsstrahlung in water and water-iron by 22-MeV electron bombardment measured with activation detectors

International Nuclear Information System (INIS)

Nakamura, Takashi; Nishimoto, Takanao; Hirayama, Hideo.

1977-01-01

The spatial distributions of bremsstrahlung in water (1 m thick) and water (60 cm thick)-iron (6.3 cm thick) bombarded by 22-MeV electrons were measured by using a new activation method which we developed. These informations are useful for studying shielding, residual activity and radiation damage of accelerator and target materials. From the measured activities, the bremsstrahlung spectra in water were evaluated with the LYRA and the SAND-II unfolding codes. The evaluated spectra were in good agreement with the analytical calculation by the DIBRE code, except for the higher energy ends. The longitudinal and the lateral distributions of bremsstrahlung flux in water were obtained by integrating the evaluated spectra above 8 MeV. The agreement of the experimental and the calculated flux distributions was very good except for a large angle to beam direction. The total photon number crossing a plane normal to the beam axis attenuates exponentially along the axial depth. The iso-flux contour of bremsstrahlung flux was given by interpolating the flux distribution curves. Only the saturated activities of gold detectors were obtained for water-iron in good experimental accuracy. The spatial distribution of gold saturated activities in water-iron clearly shows the attenuating effect due to strong absorption in iron. (auth.)

Preservation of iron(II) by carbon-rich matrices in a hydrothermal plume

Energy Technology Data Exchange (ETDEWEB)

Toner, Brandy M.; Fakra, Sirine C.; Manganini, Steven J.; Santelli, Cara M.; Marcus, Matthew A.; Moffett, James W.; Rouxel, Olivier; German, Christopher R.; Edwards, Katrina J.

2008-09-20

Hydrothermal venting associated with mid-ocean ridge volcanism is globally widespread. This venting is responsible for a dissolved iron flux to the ocean that is approximately equal to that associated with continental riverine runoff. For hydrothermal fluxes, it has long been assumed that most of the iron entering the oceans is precipitated in inorganic forms. However, the possibility of globally significant fluxes of iron escaping these mass precipitation events and entering open-ocean cycles is now being debated, and two recent studies suggest that dissolved organic ligands might influence the fate of hydrothermally vented metals. Here we present spectromicroscopic measurements of iron and carbon in hydrothermal plume particles at the East Pacific Rise mid-ocean ridge. We show that organic carbon-rich matrices, containing evenly dispersed iron(II)-rich materials, are pervasive in hydrothermal plume particles. The absence of discrete iron(II) particles suggests that the carbon and iron associate through sorption or complexation. We suggest that these carbon matrices stabilize iron(II) released from hydrothermal vents in the region, preventing its oxidation and/or precipitation as insoluble minerals. Our findings have implications for deep-sea biogeochemical cycling of iron, a widely recognized limiting nutrient in the oceans.

Insignificant enhancement of export flux in the highly productive subtropical front, east of New Zealand: a high resolution study of particle export fluxes based on 234Th: 238U disequilibria

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J. A. Hall

2012-03-01

Full Text Available We evaluated the export fluxes of Particulate Organic Carbon (POC in the Subtropical Frontal zone (STF of the SW Pacific sector of the Southern Ocean. The site is characterized by enhanced primary productivity, which has been suggested to be stimulated through so-called natural iron fertilization processes where iron-depleted subantarctic water (SAW mixes with mesotrophic, iron-replete subtropical water (STW. We adopted the small-volume 234Th method to achieve the highest possible spatial sampling resolution in austral late autumn-early winter, May–June, 2008. Inventories of chlorophyll-a, particulate 234Th and POC observed in the upper 100 m were all elevated in the mid-salinity water type (34.5 34.8 salinity waters which were of STW origin with low macronutrients. However, Steady-State 234Th fluxes were similar across the salinity gradient being, 25 ± 0.78 ((1.5 ± 0.047 × 103 in the mid-salinity, and 29 ± 0.53 ((1.8 ± 0.032 × 103 and 22 ± 1.1 Bq m−2 d−1 ((1.3 ± 0.066 × 103 dpm m−2 d–1 in the high and low salinity waters respectively. Bottle POC/Th ratios at the depth of 100 m were used to convert 234Th fluxes into POC export fluxes. The derived POC flux did not appear to be enhanced in mid-salinity waters where the primary productivity was inferred to be the highest at the time of sampling, with a flux of 11 ± 0.45 mmol C m−2 d−1, compared to 14 ± 0.39 mmol C m−2 d−1 in high salinity waters and 8.5 ± 0.66 mmol C m−2 d−1 in low salinity waters. This study thus implied that natural iron fertilization does not necessarily lead to an enhancement of POC export in STF regions.

A multiscale mortar multipoint flux mixed finite element method

KAUST Repository

Wheeler, Mary Fanett

2012-02-03

In this paper, we develop a multiscale mortar multipoint flux mixed finite element method for second order elliptic problems. The equations in the coarse elements (or subdomains) are discretized on a fine grid scale by a multipoint flux mixed finite element method that reduces to cell-centered finite differences on irregular grids. The subdomain grids do not have to match across the interfaces. Continuity of flux between coarse elements is imposed via a mortar finite element space on a coarse grid scale. With an appropriate choice of polynomial degree of the mortar space, we derive optimal order convergence on the fine scale for both the multiscale pressure and velocity, as well as the coarse scale mortar pressure. Some superconvergence results are also derived. The algebraic system is reduced via a non-overlapping domain decomposition to a coarse scale mortar interface problem that is solved using a multiscale flux basis. Numerical experiments are presented to confirm the theory and illustrate the efficiency and flexibility of the method. © EDP Sciences, SMAI, 2012.

A multiscale mortar multipoint flux mixed finite element method

KAUST Repository

Wheeler, Mary Fanett; Xue, Guangri; Yotov, Ivan

2012-01-01

In this paper, we develop a multiscale mortar multipoint flux mixed finite element method for second order elliptic problems. The equations in the coarse elements (or subdomains) are discretized on a fine grid scale by a multipoint flux mixed finite

Methods of preparing deposits containing iron oxides for recycling

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T. Lis

2013-04-01

Full Text Available The metallurgical industry is one of the largest sources of wastes. Some of them, however, owing to their content of metals such as zinc or iron, may become valuable secondary raw materials. In order to achieve that purpose, they require appropriate preparation. This article provides a discussion on the methods of preparation of scrap from steelworks, namely deposits containing iron oxides, enabling their recycling.

Magnetic flux concentration methods for magnetic energy harvesting module

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Wakiwaka Hiroyuki

2013-01-01

Full Text Available This paper presents magnetic flux concentration methods for magnetic energy harvesting module. The purpose of this study is to harvest 1 mW energy with a Brooks coil 2 cm in diameter from environmental magnetic field at 60 Hz. Because the harvesting power is proportional to the square of the magnetic flux density, we consider the use of a magnetic flux concentration coil and a magnetic core. The magnetic flux concentration coil consists of an air­core Brooks coil and a resonant capacitor. When a uniform magnetic field crossed the coil, the magnetic flux distribution around the coil was changed. It is found that the magnetic field in an area is concentrated larger than 20 times compared with the uniform magnetic field. Compared with the air­core coil, our designed magnetic core makes the harvested energy ten­fold. According to ICNIRP2010 guideline, the acceptable level of magnetic field is 0.2 mT in the frequency range between 25 Hz and 400 Hz. Without the two magnetic flux concentration methods, the corresponding energy is limited to 1 µW. In contrast, our experimental results successfully demonstrate energy harvesting of 1 mW from a magnetic field of 0.03 mT at 60 Hz.

An evaluation of multigroup flux predictions in the EBR-II core

International Nuclear Information System (INIS)

Hill, R.N.; Fanning, T.H.; Finck, P.J.

1991-01-01

The unique physics characteristics of EBR-II which are difficult to model with conventional neutronic methodologies are identified; the high neutron leakage fraction and importance of neutron reflection cause errors when conventional calculational approximations are utilized. In this paper, various conventional and higher-order group constant evaluations and flux computation methods are compared for a simplified R-Z model of the EBR-II system. Although conventional methods do provide adequate predictions of the flux in the core region, significant mispredictions are observed in the reflector and radial blanket regions. Calculational comparisons indicate that a fine energy group structure is required for accurate predictions of the eigenvalue and flux distribution; greater detail is needed in the iron resonance scattering treatment. Calculational comparisons also indicate that transport theory with detailed anisotropic scattering treatment is required

An evaluation of multigroup flux predictions in the EBR-II core

Energy Technology Data Exchange (ETDEWEB)

Hill, R.N.; Fanning, T.H.; Finck, P.J.

1991-12-31

The unique physics characteristics of EBR-II which are difficult to model with conventional neutronic methodologies are identified; the high neutron leakage fraction and importance of neutron reflection cause errors when conventional calculational approximations are utilized. In this paper, various conventional and higher-order group constant evaluations and flux computation methods are compared for a simplified R-Z model of the EBR-II system. Although conventional methods do provide adequate predictions of the flux in the core region, significant mispredictions are observed in the reflector and radial blanket regions. Calculational comparisons indicate that a fine energy group structure is required for accurate predictions of the eigenvalue and flux distribution; greater detail is needed in the iron resonance scattering treatment. Calculational comparisons also indicate that transport theory with detailed anisotropic scattering treatment is required.

An evaluation of multigroup flux predictions in the EBR-II core

Energy Technology Data Exchange (ETDEWEB)

Hill, R.N.; Fanning, T.H.; Finck, P.J.

1991-01-01

The unique physics characteristics of EBR-II which are difficult to model with conventional neutronic methodologies are identified; the high neutron leakage fraction and importance of neutron reflection cause errors when conventional calculational approximations are utilized. In this paper, various conventional and higher-order group constant evaluations and flux computation methods are compared for a simplified R-Z model of the EBR-II system. Although conventional methods do provide adequate predictions of the flux in the core region, significant mispredictions are observed in the reflector and radial blanket regions. Calculational comparisons indicate that a fine energy group structure is required for accurate predictions of the eigenvalue and flux distribution; greater detail is needed in the iron resonance scattering treatment. Calculational comparisons also indicate that transport theory with detailed anisotropic scattering treatment is required.

Two dimensional analysis for magnetic flux distribution in electromagnet used for MHD applications

International Nuclear Information System (INIS)

Desai, S.V.; Venkatramani, N.; Rohatgi, V.K.

1984-01-01

Magnetic flux densities in air and iron region of iron core MHD electromagnet, are calculated based on concept of magnetic vector potential. Numerical solution to the problem is obtained by converting partial differential equations into finite difference form with simplifying assumptions. A computer progrm is developed, giving solution by finite difference method. Over-relaxation technique based on Stoke's theorem is applied. Magnetic induction along the transverse axis of the magnet and plot for magnetic induction lines for current = 2420 A is presented. (author)

Comparison between Evapotranspiration Fluxes Assessment Methods

Science.gov (United States)

Casola, A.; Longobardi, A.; Villani, P.

2009-11-01

Knowledge of hydrological processes acting in the water balance is determinant for a rational water resources management plan. Among these, the water losses as vapour, in the form of evapotranspiration, play an important role in the water balance and the heat transfers between the land surface and the atmosphere. Mass and energy interactions between soil, atmosphere and vegetation, in fact, influence all hydrological processes modificating rainfall interception, infiltration, evapotraspiration, surface runoff and groundwater recharge.A numbers of methods have been developed in scientific literature for modelling evapotranspiration. They can be divided in three main groups: i) traditional meteorological models, ii) energy fluxes balance models, considering interaction between vegetation and the atmosphere, and iii) remote sensing based models. The present analysis preliminary performs a study of fluxes directions and an evaluation of energy balance closure in a typical Mediterranean short vegetation area, using data series recorded from an eddy covariance station, located in the Campania region, Southern Italy. The analysis was performed on different seasons of the year with the aim to assess climatic forcing features impact on fluxes balance, to evaluate the smaller imbalance and to highlight influencing factors and sampling errors on balance closure. The present study also concerns evapotranspiration fluxes assessment at the point scale. Evapotranspiration is evaluated both from empirical relationships (Penmann-Montheit, Penmann F AO, Prestley&Taylor) calibrated with measured energy fluxes at mentioned experimental site, and from measured latent heat data scaled by the latent heat of vaporization. These results are compared with traditional and reliable well known models at the plot scale (Coutagne, Turc, Thorthwaite).

Detailed comparative study regarding different formulae of predicting the iron losses in a machine excited by non-sinusoidal supply

International Nuclear Information System (INIS)

El-Kharashi, Eyhab

2014-01-01

Variable-speed drives in any machine provide an accurate control and high-energy efficiency. More and more often machines are excited by non-sinusoidal voltages. Predicting the amount of iron losses in non-sinusoidal excitation is important. The paper aims to achieve accurate efficiency estimation by presenting a new modified calculation method to predict the iron losses. In a switched reluctance motor, the iron losses can't be ignored, it has considered value. This paper presents conventional and modified Steinmetz formulae for the estimation of the iron losses. The conventional Steinmetz formula consists of three terms: hysteresis, eddy current and anomalous losses. The equations of hysteresis and eddy current losses depend mainly on the value of the peak flux density. The reason to modify the Steinmetz formula is to avoid the need of knowing the peak flux density and the anomalous losses in accurate figures. The paper also explains and clarifies the methods of using both the conventional as well as the modified Steinmetz formulae in accurate calculation of the iron losses in different sections of the magnetic circuit. For both formulae, a comparison is made between the distributions of the iron losses in different parts of the magnetic circuit and the efficiencies. - Highlights: • The paper aims to achieve accurate efficiency estimation. • The predicted iron loss by the conventional Steinmetz formula is inaccurate. • The modified Steinmetz formula is more accurate because it includes the minor loops losses caused by each flux density. • The paper compared the predicted losses obtained by the two different formals to stand on the degree of accuracy

PCBP1 and NCOA4 regulate erythroid iron storage and heme biosynthesis.

Science.gov (United States)

Ryu, Moon-Suhn; Zhang, Deliang; Protchenko, Olga; Shakoury-Elizeh, Minoo; Philpott, Caroline C

2017-05-01

Developing erythrocytes take up exceptionally large amounts of iron, which must be transferred to mitochondria for incorporation into heme. This massive iron flux must be precisely controlled to permit the coordinated synthesis of heme and hemoglobin while avoiding the toxic effects of chemically reactive iron. In cultured animal cells, iron chaperones poly rC-binding protein 1 (PCBP1) and PCBP2 deliver iron to ferritin, the sole cytosolic iron storage protein, and nuclear receptor coactivator 4 (NCOA4) mediates the autophagic turnover of ferritin. The roles of PCBP, ferritin, and NCOA4 in erythroid development remain unclear. Here, we show that PCBP1, NCOA4, and ferritin are critical for murine red cell development. Using a cultured cell model of erythroid differentiation, depletion of PCBP1 or NCOA4 impaired iron trafficking through ferritin, which resulted in reduced heme synthesis, reduced hemoglobin formation, and perturbation of erythroid regulatory systems. Mice lacking Pcbp1 exhibited microcytic anemia and activation of compensatory erythropoiesis via the regulators erythropoietin and erythroferrone. Ex vivo differentiation of erythroid precursors from Pcbp1-deficient mice confirmed defects in ferritin iron flux and heme synthesis. These studies demonstrate the importance of ferritin for the vectorial transfer of imported iron to mitochondria in developing red cells and of PCBP1 and NCOA4 in mediating iron flux through ferritin.

An optimizing design method for a compact iron shielded superconducting magnet for use in MRI

International Nuclear Information System (INIS)

Tang Xin; Zu Donglin; Wang Tao; Han Baohui

2010-01-01

A method is developed for designing a special iron shielded superconducting magnet for MRI in this paper. The shield is designed as an integral part of the cryostat and high permeability and high saturated magnetization iron material is adopted. This scheme will result in a compact iron shielded magnet. In the presented design, the finite element (FE) method is adopted to calculate the magnetic field produced by superconducting coils and nonlinear iron material. The FE method is incorporated into the simulated annealing method which is employed for corresponding optimization. Therefore, geometrical configurations of both coils and iron shield can be optimized together. This method can deal with discrete design variables which are defined to describe the cable arrangements of coil cross sections. A detailed algorithm of the present design is described and an example for designing a 1.5 T clinical iron shielded magnet for MRI is shown.

Effect of flux discontinuity on spatial approximations for discrete ordinates methods

International Nuclear Information System (INIS)

Duo, J.I.; Azmy, Y.Y.

2005-01-01

This work presents advances on error analysis of the spatial approximation of the discrete ordinates method for solving the neutron transport equation. Error norms for different non-collided flux problems over a two dimensional pure absorber medium are evaluated using three numerical methods. The problems are characterized by the incoming flux boundary conditions to obtain solutions with different level of differentiability. The three methods considered are the Diamond Difference (DD) method, the Arbitrarily High Order Transport method of the Nodal type (AHOT-N), and of the Characteristic type (AHOT-C). The last two methods are employed in constant, linear and quadratic orders of spatial approximation. The cell-wise error is computed as the difference between the cell-averaged flux computed by each method and the exact value, then the L 1 , L 2 , and L ∞ error norms are calculated. The results of this study demonstrate that the level of differentiability of the exact solution profoundly affects the rate of convergence of the numerical methods' solutions. Furthermore, in the case of discontinuous exact flux the methods fail to converge in the maximum error norm, or in the pointwise sense, in accordance with previous local error analysis. (authors)

Comparison between different methods of measurement of momentum and sensible heat fluxes over canopies

Directory of Open Access Journals (Sweden)

Marc Aubinet

1997-01-01

Full Text Available Différent methods of measurement of momentum and sensible heat flux densifies are presented and compared above a gras covered fallow. The aerodynamic (AD and eddy covariance (EC methods are presented and compared for both momentum and sensible heat measurements. In addition, the temperature fluctuation (TF method is compared to the HEC method for the sensible heat flux measurement. The AD and EC methods are in good agreement for the momentum flux measurements. For the sensible heat flux, the AD method is very sensible to temperature errors. So it is unusable during night and gives biased estimations during the day. The TF method gives only estimations of the sensible heat flux. It is in good agreement with the EC method during the day but diverges completely during night, being unable to disceming positive from négative fluxes. From the three methods, the EC method is the sole that allows to measure continuously both momentum and sensible heat flux but it requires a loud data treatment. We présent in this paper the algorithm used for this treatment.

A punctual flux estimator and reactions rates optimization in neutral particles transport calculus by the Monte Carlo method

International Nuclear Information System (INIS)

Authier, N.

1998-12-01

One of the questions asked in radiation shielding problems is the estimation of the radiation level in particular to determine accessibility of working persons in controlled area (nuclear power plants, nuclear fuel reprocessing plants) or to study the dose gradients encountered in material (iron nuclear vessel, medical therapy, electronics in satellite). The flux and reaction rate estimators used in Monte Carlo codes give average values in volumes or on surfaces of the geometrical description of the system. But in certain configurations, the knowledge of punctual deposited energy and dose estimates are necessary. The Monte Carlo estimate of the flux at a point of interest is a calculus which presents an unbounded variance. The central limit theorem cannot be applied thus no easy confidence level may be calculated. The convergence rate is then very poor. We propose in this study a new solution for the photon flux at a point estimator. The method is based on the 'once more collided flux estimator' developed earlier for neutron calculations. It solves the problem of the unbounded variance and do not add any bias to the estimation. We show however that our new sampling schemes specially developed to treat the anisotropy of the photon coherent scattering is necessary for a good and regular behavior of the estimator. This developments integrated in the TRIPOLI-4 Monte Carlo code add the possibility of an unbiased punctual estimate on media interfaces. (author)

Quantitative comparison of in situ soil CO2 flux measurement methods

Science.gov (United States)

Jennifer D. Knoepp; James M. Vose

2002-01-01

Development of reliable regional or global carbon budgets requires accurate measurement of soil CO2 flux. We conducted laboratory and field studies to determine the accuracy and comparability of methods commonly used to measure in situ soil CO2 fluxes. Methods compared included CO2...

The higher order flux mapping method in large size PHWRs

International Nuclear Information System (INIS)

Kulkarni, A.K.; Balaraman, V.; Purandare, H.D.

1997-01-01

A new higher order method is proposed for obtaining flux map using single set of expansion mode. In this procedure, one can make use of the difference between predicted value of detector reading and their actual values for determining the strength of local fluxes around detector site. The local fluxes are arising due to constant perturbation changes (both extrinsic and intrinsic) taking place in the reactor. (author)

An analytical transport theory method for calculating flux distribution in slab cells

International Nuclear Information System (INIS)

Abdel Krim, M.S.

2001-01-01

A transport theory method for calculating flux distributions in slab fuel cell is described. Two coupled integral equations for flux in fuel and moderator are obtained; assuming partial reflection at moderator external boundaries. Galerkin technique is used to solve these equations. Numerical results for average fluxes in fuel and moderator and the disadvantage factor are given. Comparison with exact numerical methods, that is for total reflection moderator outer boundaries, show that the Galerkin technique gives accurate results for the disadvantage factor and average fluxes. (orig.)

Theoretical simulation of the dual-heat-flux method in deep body temperature measurements.

Science.gov (United States)

Huang, Ming; Chen, Wenxi

2010-01-01

Deep body temperature reveals individual physiological states, and is important in patient monitoring and chronobiological studies. An innovative dual-heat-flux method has been shown experimentally to be competitive with the conventional zero-heat-flow method in its performance, in terms of measurement accuracy and step response to changes in the deep temperature. We have utilized a finite element method to model and simulate the dynamic process of a dual-heat-flux probe in deep body temperature measurements to validate the fundamental principles of the dual-heat-flux method theoretically, and to acquire a detailed quantitative description of the thermal profile of the dual-heat-flux probe. The simulation results show that the estimated deep body temperature is influenced by the ambient temperature (linearly, at a maximum rate of 0.03 °C/°C) and the blood perfusion rate. The corresponding depth of the estimated temperature in the skin and subcutaneous tissue layer is consistent when using the dual-heat-flux probe. Insights in improving the performance of the dual-heat-flux method were discussed for further studies of dual-heat-flux probes, taking into account structural and geometric considerations.

Analysis method of intracellular iron accumulated in phytoplankton

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Jorge Falcão Paredes

1977-01-01

Full Text Available A colorimetric method for the assessment of iron accumulated in the cells of phytoplankton utilizing potassium ferrocyanide was developed. Two experiences with Phaeodactylum tricornutum and Chlorella sp. were carried out: the first one, on uptake of the iron relatively to the age of the culture: the second one, on the iron uptake by the cells, relatively to different concentrations of the chelator EDTA.Foi desenvolvido um método para análise do ferro acumulado em células de fitoplâncton, usando ferrocianeto de potássio como agente complexante. Com esse objetivo montaram-se duas experiências: uma em que se mostra o acúmulo de ferro em relação à idade das células e uma segunda experiência onde a assimilação é plotada em função da concentração de EDTA no meio de cultura.

A Spatial-Temporal Comparison of Lake Mendota CO2 Fluxes and Collection Methods

Science.gov (United States)

Baldocchi, A. K.; Reed, D. E.; Desai, A. R.; Loken, L. C.; Schramm, P.; Stanley, E. H.

2017-12-01

Monitoring of carbon fluxes at the lake/atmosphere interface can help us determine baselines from which to understand responses in both space and time that may result from our warming climate or increasing nutrient inputs. Since recent research has shown lakes to be hotspots of global carbon cycling, it is important to quantify carbon sink and source dynamics as well as to verify observations between multiple methods in the context of long-term data collection efforts. Here we evaluate a new method for measuring space and time variation in CO2 fluxes based on novel speedboat-based collection method of aquatic greenhouse gas concentrations and a flux computation and interpolation algorithm. Two-hundred and forty-nine consecutive days of spatial flux maps over the 2016 open ice period were compared to ongoing eddy covariance tower flux measurements on the shore of Lake Mendota, Wisconsin US using a flux footprint analysis. Spatial and temporal alignments of the fluxes from these two observational datasets revealed both similar trends from daily to seasonal timescales as well as biases between methods. For example, throughout the Spring carbon fluxes showed strong correlation although off by an order of magnitude. Isolating physical patterns of agreement between the two methods of the lake/atmosphere CO2 fluxes allows us to pinpoint where biology and physical drivers contribute to the global carbon cycle and help improve modelling of lakes and utilize lakes as leading indicators of climate change.

Comparisons of Measured and Calculated Neutron Fluxes in Laminated iron and Heavy Water

Energy Technology Data Exchange (ETDEWEB)

Aalto, E

1964-10-15

Measurements of neutron fluxes have been performed in configurations depicting the regions extending radially and axially outwards from the core of a PHWR reactor in order to test the accuracy of the available methods in shield design on thin alternating laminae of Fe and D{sub 2}O. A 'dry' experimental set-up was constructed, i.e. the D{sub 2}O was contained in flat tanks made of Al. The first set of measurements was performed through solid Fe and D{sub 2}O layers, and only the results of these experiments are described in this report. The set-up allowed measurements also in a mock-up of a reactor top penetrated by D{sub 2}O or air-filled channels (to be reported later). The results are compared to fluxes calculated by the British 18-group removal-diffusion method and by the NRN method developed at AE. The results show that the values predicted may be expected to be within a factor of 2 from the true values in most cases. The predicted relative flux distributions follow the observed ones with a very good accuracy in spite of the apparent misuse of diffusion theory for the thin regions in question. Finally, it is shown that the predicted change in the fast spectrum while penetrating these set-ups should be confirmable with certain threshold detectors.

A method for recovery of iron, titanium, and vanadium from vanadium-bearing titanomagnetite

Science.gov (United States)

Zhang, Yi-min; Wang, Li-na; Chen, De-sheng; Wang, Wei-jing; Liu, Ya-hui; Zhao, Hong-xin; Qi, Tao

2018-02-01

An innovative method for recovering valuable elements from vanadium-bearing titanomagnetite is proposed. This method involves two procedures: low-temperature roasting of vanadium-bearing titanomagnetite and water leaching of roasting slag. During the roasting process, the reduction of iron oxides to metallic iron, the sodium oxidation of vanadium oxides to water-soluble sodium vanadate, and the smelting separation of metallic iron and slag were accomplished simultaneously. Optimal roasting conditions for iron/slag separation were achieved with a mixture thickness of 42.5 mm, a roasting temperature of 1200°C, a residence time of 2 h, a molar ratio of C/O of 1.7, and a sodium carbonate addition of 70wt%, as well as with the use of anthracite as a reductant. Under the optimal conditions, 93.67% iron from the raw ore was recovered in the form of iron nugget with 95.44% iron grade. After a water leaching process, 85.61% of the vanadium from the roasting slag was leached, confirming the sodium oxidation of most of the vanadium oxides to water-soluble sodium vanadate during the roasting process. The total recoveries of iron, vanadium, and titanium were 93.67%, 72.68%, and 99.72%, respectively.

Multiobjective flux balancing using the NISE method for metabolic network analysis.

Science.gov (United States)

Oh, Young-Gyun; Lee, Dong-Yup; Lee, Sang Yup; Park, Sunwon

2009-01-01

Flux balance analysis (FBA) is well acknowledged as an analysis tool of metabolic networks in the framework of metabolic engineering. However, FBA has a limitation for solving a multiobjective optimization problem which considers multiple conflicting objectives. In this study, we propose a novel multiobjective flux balance analysis method, which adapts the noninferior set estimation (NISE) method (Solanki et al., 1993) for multiobjective linear programming (MOLP) problems. NISE method can generate an approximation of the Pareto curve for conflicting objectives without redundant iterations of single objective optimization. Furthermore, the flux distributions at each Pareto optimal solution can be obtained for understanding the internal flux changes in the metabolic network. The functionality of this approach is shown by applying it to a genome-scale in silico model of E. coli. Multiple objectives for the poly(3-hydroxybutyrate) [P(3HB)] production are considered simultaneously, and relationships among them are identified. The Pareto curve for maximizing succinic acid production vs. maximizing biomass production is used for the in silico analysis of various combinatorial knockout strains. This proposed method accelerates the strain improvement in the metabolic engineering by reducing computation time of obtaining the Pareto curve and analysis time of flux distribution at each Pareto optimal solution. (c) 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009.

Effect of chamber enclosure time on soil respiration flux: A comparison of linear and non-linear flux calculation methods

DEFF Research Database (Denmark)

Kandel, Tanka P; Lærke, Poul Erik; Elsgaard, Lars

2016-01-01

One of the shortcomings of closed chamber methods for soil respiration (SR) measurements is the decreased CO2 diffusion rate from soil to chamber headspace that may occur due to increased chamber CO2 concentrations. This feedback on diffusion rate may lead to underestimation of pre-deployment flu......One of the shortcomings of closed chamber methods for soil respiration (SR) measurements is the decreased CO2 diffusion rate from soil to chamber headspace that may occur due to increased chamber CO2 concentrations. This feedback on diffusion rate may lead to underestimation of pre...... was placed on fixed collars, and CO2 concentration in the chamber headspace were recorded at 1-s intervals for 45 min. Fluxes were measured in different soil types (sandy, sandy loam and organic soils), and for various manipulations (tillage, rain and drought) and soil conditions (temperature and moisture......) to obtain a range of fluxes with different shapes of flux curves. The linear method provided more stable flux results during short enclosure times (few min) but underestimated initial fluxes by 15–300% after 45 min deployment time. Non-linear models reduced the underestimation as average underestimation...

Absorption of medicamental iron and iron from food

International Nuclear Information System (INIS)

Reizenstein, P.; Carlmark, B.; Ehn, L.; Forsberg, K.; Hoeglund, S.; Terpstra, T.

1976-01-01

Methods are reviewed for the measurement of iron absorption. The chemical balance method has been almost entirely supplanted by radioisotope methods, which include notably whole-body counting and measurement of incorporation of radioiron into red cells. A survey is also given of the various conditions that influence iron absorption, including chemical form of iron, amount of iron, accompanying diet. Absorption tests must be conducted under relevant conditions. (author)

Application of sorption method on hydroxides for purification of some reactive from iron(III) markings

International Nuclear Information System (INIS)

Rakhmonberdiev, A.D.; Khamidov, B.O.

1986-01-01

The method of purification of solutions of citric acid, tartaric acid and their salts, potassium hydroxide, potassium nitrate and chloride, sodium perchlorate from iron (III) impurities by means of sorption method on zirconium hydroxide is elaborated. The control of iron(III) content in solutions is conducted by inversion voltammetry method with mercury-graphite electrode. It is defined that complete sorption of iron (III) ions achieves at ph =4÷14.

Improved vertical streambed flux estimation using multiple diurnal temperature methods in series

Science.gov (United States)

Irvine, Dylan J.; Briggs, Martin A.; Cartwright, Ian; Scruggs, Courtney; Lautz, Laura K.

2017-01-01

Analytical solutions that use diurnal temperature signals to estimate vertical fluxes between groundwater and surface water based on either amplitude ratios (Ar) or phase shifts (Δϕ) produce results that rarely agree. Analytical solutions that simultaneously utilize Ar and Δϕ within a single solution have more recently been derived, decreasing uncertainty in flux estimates in some applications. Benefits of combined (ArΔϕ) methods also include that thermal diffusivity and sensor spacing can be calculated. However, poor identification of either Ar or Δϕ from raw temperature signals can lead to erratic parameter estimates from ArΔϕ methods. An add-on program for VFLUX 2 is presented to address this issue. Using thermal diffusivity selected from an ArΔϕ method during a reliable time period, fluxes are recalculated using an Ar method. This approach maximizes the benefits of the Ar and ArΔϕ methods. Additionally, sensor spacing calculations can be used to identify periods with unreliable flux estimates, or to assess streambed scour. Using synthetic and field examples, the use of these solutions in series was particularly useful for gaining conditions where fluxes exceeded 1 m/d.

A new method to produce nanoscale iron for nitrate removal

International Nuclear Information System (INIS)

Chen, S.-S.; Hsu, H.-D.; Li, C.-W.

2004-01-01

This article proposes a novel technology combining electrochemical and ultrasonic methods to produce nanoscale zero valent iron (NZVI). With platinum placed in the cathode and the presence of the dispersion agent, 0.2g/l cetylpyridinium chloride (CPC), a cation surfactant, in the solution, the nanoscale iron particle was successfully produced with diameter of 1-20 nm and specific surface area of 25.4m 2 /g. The produced NZVI was tested in batch experiments for nitrate removal. The results showed that the nitrate reduction was affected by pH. Al low pH, nitrate was shown faster decline and more reduction in term of g NO 3 - -N/g NZVI. The reaction was first order and kinetic coefficients for the four pHs were directly related to pH with R 2 >0.95. Comparing with microscale zero-valent iron (45μm, 0.183m 2 /g), microscale zero-valent iron converted nitrate to ammonia completely, but NZVI converted nitrate to ammonia partially from 36.2 to 45.3% dependent on pH. For mass balance of iron species, since the dissolved iron in the solution was very low ( 2 O 3 was recognized. Thus the reaction mechanisms can be determined

Tabular method of critical heat flux description in square packing rod bundles

International Nuclear Information System (INIS)

Bobkov, V.P.; Smogalev, I.P.

2003-01-01

Elaborations of harnessing tabular method for the description and calculation of critical heat fluxes in square packing rod bundles are presented. The tabular method for fuel rod triangular assemblies derived from using basic table for critical heat fluxes in triangular fuel assemblies demonstrates good results. For the harnessing tabular method in square packing rod bundles correction functions reflecting specific geometry were found. Comparative evaluations of calculated values for the critical heat fluxes with experimental ones are presented. Good agreement of calculations with experiments is noted in all range of parameters [ru

Digital signal processing control of induction machine`s torque and stator flux utilizing the direct stator flux field orientation method

Energy Technology Data Exchange (ETDEWEB)

Seiz, Julie Burger [Union College, Schenectady, NY (United States)

1997-04-01

This paper presents a review of the Direct Stator Flux Field Orientation control method. This method can be used to control an induction motor`s torque and flux directly and is the application of interest for this thesis. This control method is implemented without the traditional feedback loops and associated hardware. Predictions are made, by mathematical calculations, of the stator voltage vector. The voltage vector is determined twice a switching period. The switching period is fixed throughout the analysis. The three phase inverter duty cycle necessary to control the torque and flux of the induction machine is determined by the voltage space vector Pulse Width Modulation (PWM) technique. Transient performance of either the flux or torque requires an alternate modulation scheme which is also addressed in this thesis. A block diagram of this closed loop system is provided. 22 figs., 7 tabs.

Composition of MBE-grown iron oxide films

NARCIS (Netherlands)

Voogt, F.C; Hibma, T; Smulders, P.J M; Niesen, L

A wide range of iron oxides have been grown epitaxially on MgO(100) substrates using a dual beam technique in which the deposited iron is oxidised by a beam of NO2 particles. At high fluxes magnetite (Fe3-deltaO4) phases with compositions between near-stoichiometric magnetite (Fe3O4, delta = 0) and

Measurement of absolute neutron flux in LWSCR based on the nuclear track method

International Nuclear Information System (INIS)

Sadeghzadeh, J.; Nassiri Mofakham, N.; Khajehmiri, Z.

2012-01-01

Highlights: ► Up to now the spectral parameters of thermal neutrons are measured with activation foils that are not always reliable in low flux systems. ► We applied a solid state nuclear track detector to measure the absolute neutron flux in the light water sub-critical reactor (LWSCR). ► Experiments concerning fission track detecting were performed and were investigated using the Monte Carlo code MCNP. ► The neutron fluxes obtained in experiment are in fairly good agreement with the results obtained by MCNP. - Abstract: In the present paper, a solid state nuclear track detector is applied to measure the absolute neutron flux in the light water sub-critical reactor (LWSCR) in Nuclear Science and Technology Research Institute (NSTRI). Up to now, the spectral parameters of thermal neutrons have been measured with activation foils that are not always reliable in low flux systems. The method investigated here is the irradiation method. Experiments concerning fission track detecting were performed. The experiment including neutron flux calculation method has also been investigated using the Monte Carlo code MCNP. The analysis shows that the values of neutron flux obtained by experiment are in fairly good agreement with the results obtained by MCNP. Thus, this method may be able to predict the absolute value of neutron flux at LWSCR and other similar reactors.

Review of unfolding methods for neutron flux dosimetry

International Nuclear Information System (INIS)

Stallmann, F.W.; Kam, F.B.K.

1975-01-01

The primary method in reactor dosimetry is the foil activation technique. To translate the activation measurements into neutron fluxes, a special data processing technique called unfolding is needed. Some general observations about the problems and the reliability of this approach to reactor dosimetry are presented. Current unfolding methods are reviewed. 12 references. (auth)

Two-wavelength Method Estimates Heat fluxes over Heterogeneous Surface in North-China

Science.gov (United States)

Zhang, G.; Zheng, N.; Zhang, J.

2017-12-01

Heat fluxes is a key process of hydrological and heat transfer of soil-plant-atmosphere continuum (SPAC), and now it is becoming an important topic in meteorology, hydrology, ecology and other related research areas. Because the temporal and spatial variation of fluxes at regional scale is very complicated, it is still difficult to measure fluxes at the kilometer scale over a heterogeneous surface. A technique called "two-wavelength method" which combines optical scintillometer with microwave scintillometer is able to measure both sensible and latent heat fluxes over large spatial scales at the same time. The main purpose of this study is to investigate the fluxes over non-uniform terrain in North-China. Estimation of heat fluxes was carried out with the optical-microwave scintillometer and an eddy covariance (EC) system over heterogeneous surface in Tai Hang Mountains, China. EC method was set as a benchmark in the study. Structure parameters obtained from scintillometer showed that the typical measurement values of Cn2 are around 10-13 m-2/3 for microwave scintillometer, and values of Cn2 were around 10-15 m-2/3 for optical scintillometer. The correlation of heat fluxes (H) derived from scintillometer and EC system showed as a ratio of 1.05,and with R2=0.75, while the correlation of latent heat fluxes (LE) showed as 1.29 with R2=0.67. It was also found that heat fluxes derived from the two system showed good agreement (R2=0.9 for LE, R2=0.97 for H) when the Bowen ratio (β) was 1.03, while discrepancies showed significantly when β=0.75, and RMSD in H was 139.22 W/m2, 230.85 W/m2 in LE respectively.Experiment results in our research shows that, the two-wavelength method gives a larger heat fluxes over the study area, and a deeper study should be conduct. We expect that our investigate and analysis can be promoted the application of scintillometry method in regional evapotranspiration measurements and relevant disciplines.

Variationally derived coarse mesh methods using an alternative flux representation

International Nuclear Information System (INIS)

Wojtowicz, G.; Holloway, J.P.

1995-01-01

Investigation of a previously reported variational technique for the solution of the 1-D, 1-group neutron transport equation in reactor lattices has inspired the development of a finite element formulation of the method. Compared to conventional homogenization methods in which node homogenized cross sections are used, the coefficients describing this system take on greater spatial dependence. However, the methods employ an alternative flux representation which allows the transport equation to be cast into a form whose solution has only a slow spatial variation and, hence, requires relatively few variables to describe. This alternative flux representation and the stationary property of a variational principle define a class of coarse mesh discretizations of transport theory capable of achieving order of magnitude reductions of eigenvalue and pointwise scalar flux errors as compared with diffusion theory while retaining diffusion theory's relatively low cost. Initial results of a 1-D spectral element approach are reviewed and used to motivate the finite element implementation which is more efficient and almost as accurate; one and two group results of this method are described

Heme iron content in lamb meat is differentially altered upon boiling, grilling, or frying as assessed by four distinct analytical methods.

Science.gov (United States)

Pourkhalili, Azin; Mirlohi, Maryam; Rahimi, Ebrahim

2013-01-01

Lamb meat is regarded as an important source of highly bioavailable iron (heme iron) in the Iranians diet. The main objective of this study is to evaluate the effect of traditional cooking methods on the iron changes in lamb meat. Four published experimental methods for the determination of heme iron were assessed analytically and statistically. Samples were selected from lambs' loin. Standard methods (AOAC) were used for proximate analysis. For measuring heme iron, the results of four experimental methods were compared regarding their compliance to Ferrozine method which was used for the determination of nonheme iron. Among three cooking methods, the lowest total iron and heme iron were found in boiling method. The heme iron proportions to the total iron in raw, boiled lamb meat and grilled, were counted as 65.70%, 67.75%, and 76.01%, receptively. Measuring the heme iron, the comparison of the methods in use showed that the method in which heme extraction solution was composed of 90% acetone, 18% water, and 2% hydrochloric acid was more appropriate and more correlated with the heme iron content calculated by the difference between total iron and nonheme iron.

Heme Iron Content in Lamb Meat Is Differentially Altered upon Boiling, Grilling, or Frying as Assessed by Four Distinct Analytical Methods

Directory of Open Access Journals (Sweden)

Azin Pourkhalili

2013-01-01

Full Text Available Lamb meat is regarded as an important source of highly bioavailable iron (heme iron in the Iranians diet. The main objective of this study is to evaluate the effect of traditional cooking methods on the iron changes in lamb meat. Four published experimental methods for the determination of heme iron were assessed analytically and statistically. Samples were selected from lambs' loin. Standard methods (AOAC were used for proximate analysis. For measuring heme iron, the results of four experimental methods were compared regarding their compliance to Ferrozine method which was used for the determination of nonheme iron. Among three cooking methods, the lowest total iron and heme iron were found in boiling method. The heme iron proportions to the total iron in raw, boiled lamb meat and grilled, were counted as 65.70%, 67.75%, and 76.01%, receptively. Measuring the heme iron, the comparison of the methods in use showed that the method in which heme extraction solution was composed of 90% acetone, 18% water, and 2% hydrochloric acid was more appropriate and more correlated with the heme iron content calculated by the difference between total iron and nonheme iron.

An optimal method of iron starvation of the obligate intracellular pathogen, Chlamydia trachomatis

Directory of Open Access Journals (Sweden)

Christopher C. Thompson

2011-02-01

Full Text Available Iron is an essential cofactor in a number of critical biochemical reactions, and as such, its acquisition, storage, and metabolism is highly regulated in most organisms. The obligate intracellular bacterium, Chlamydia trachomatis experiences a developmental arrest when iron within the host is depleted. The nature of the iron starvation response in Chlamydia is relatively uncharacterized because of the likely inefficient method of iron depletion, which currently relies on the compound deferoxamine mesylate (DFO. Inefficient induction of the iron starvation response precludes the identification of iron-regulated genes. This report evaluated DFO with another iron chelator, 2,2’-bipyridyl (Bpdl and presented a systematic comparison of the two across a range of criteria in a single-treatment time-of-infection regimen. We demonstrate that the membrane permeable Bpdl was superior to DFO in the inhibition of chlamydia development, the induction of aberrant morphology, and the induction of an iron starvation transcriptional response in both host and bacteria. Furthermore, iron starvation using Bpdl identified the periplasmic iron binding protein-encoding ytgA gene as iron- responsive. Overall, the data present a compelling argument for the use of Bpdl, rather than DFO, in future iron starvation studies of chlamydia and other intracellular bacteria.

Heat flux estimation in an infrared experimental furnace using an inverse method

International Nuclear Information System (INIS)

Le Bideau, P.; Ploteau, J.P.; Glouannec, P.

2009-01-01

Infrared emitters are widely used in industrial furnaces for thermal treatment. In these processes, the knowledge of the incident heat flux on the surface of the product is a primary step to optimise the command emitters and for maintenance shift. For these reasons, it is necessary to develop autonomous flux meters that could provide an answer to these requirements. These sensors must give an in-line distribution of infrared irradiation in the tunnel furnace and must be able to measure high heat flux in severe thermal environments. In this paper we present a method for in-line assessments solving an inverse heat conduction problem. A metallic mass is instrumented by thermocouples and an inverse method allows the incident heat flux to be estimated. In the first part, attention is focused on a new design tool, which is a numerical code, for the evaluation of potential options during captor conception. In the second part we present the realization and the test of this 'indirect' flux meter and its associated inverse problem. 'Direct' detectors based on thermoelectric devices are compared with this new flux meter in the same conditions in the same furnace. Results prove that this technique is a reliable method, appropriate for high temperature ambiances. This technique can be applied to furnaces where the heat flux is inaccessible to 'direct' measurements.

Preparation of Iron Nanoparticles by Selective Leaching Method

Czech Academy of Sciences Publication Activity Database

Michalcová, A.; Vojtěch, D.; Kubatík, Tomáš František; Stehlíková, K.; Brabec, F.; Marek, I.

2015-01-01

Roč. 128, č. 4 (2015), s. 640-642 ISSN 0587-4246. [International Symposium on Physics of Materials (ISPMA) /13./. Prague, 31.08.2014-04.09.2014] Institutional support: RVO:61389021 Keywords : Iron nanoparticles * selective leaching method Subject RIV: JK - Corrosion ; Surface Treatment of Materials Impact factor: 0.525, year: 2015

Comparison of eddy covariance and modified Bowen ratio methods for measuring gas fluxes and implications for measuring fluxes of persistent organic pollutants

Directory of Open Access Journals (Sweden)

D. J. Bolinius

2016-04-01

Full Text Available Semi-volatile persistent organic pollutants (POPs cycle between the atmosphere and terrestrial surfaces; however measuring fluxes of POPs between the atmosphere and other media is challenging. Sampling times of hours to days are required to accurately measure trace concentrations of POPs in the atmosphere, which rules out the use of eddy covariance techniques that are used to measure gas fluxes of major air pollutants. An alternative, the modified Bowen ratio (MBR method, has been used instead. In this study we used data from FLUXNET for CO2 and water vapor (H2O to compare fluxes measured by eddy covariance to fluxes measured with the MBR method using vertical concentration gradients in air derived from averaged data that simulate the long sampling times typically required to measure POPs. When concentration gradients are strong and fluxes are unidirectional, the MBR method and the eddy covariance method agree within a factor of 3 for CO2, and within a factor of 10 for H2O. To remain within the range of applicability of the MBR method, field studies should be carried out under conditions such that the direction of net flux does not change during the sampling period. If that condition is met, then the performance of the MBR method is neither strongly affected by the length of sample duration nor the use of a fixed value for the transfer coefficient.

Flocculated meltwater particles control Arctic land-sea fluxes of labile iron

DEFF Research Database (Denmark)

Markussen, Thor Nygaard; Elberling, Bo; Winter, Christian

2016-01-01

Glacial meltwater systems supply the Arctic coastal ocean with large volumes of sediment and potentially bioavailable forms of iron, nitrogen and carbon. The particulate fraction of this supply is significant but estuarine losses have been thought to limit the iron supply from land. Here, our...... the influence of terrestrial hotspots on the nutrient and solute cycles in Arctic coastal waters....

A scalar flux - oriented method for the transport equation in slab geometry

International Nuclear Information System (INIS)

Budd, C.

1981-01-01

A new method for solving the neutron transport equation is described. An unusual feature of this method is that it deals principally with scalar fluxes rather than angular fluxes. An alternative approach in slab geometry promises to be cheaper to run and does not suffer from many of the problems of the discrete ordinates method. It also appears possible to extend the method to several dimensions and this is discussed. (U.K.)

Development of methodics for the characterization of the composition of the ion-collision-induced secondary-particle flux by comparison of the yield contributions of photoinduced ion formation processes

International Nuclear Information System (INIS)

Vering, Guido

2008-01-01

The aim of this work was to develop a method to distinguish between different ion formation processes and to determine the influence of these processes on the total number of detected monatomic ions of a certain element. A vector/matrix-formalism was developed, which describes the physical processes of sputtering, ion formation, mass separation and detection in laser-SNMS. In the framework of the method developed, based on this theoretic formalism, changes in the secondary flux contribution of the respective element were observed by comparing the detected monatomic ion yield obtained in specifically aligned (SIMS and) laser-SNMS experiments. The yields resulting from these experiments were used to calculate characteristic numbers to compare the flux composition from different surfaces. The potential of the method was demonstrated for the elements boron, iron and gadolinium by investigating the changes in the flux composition of secondary particles sputtered from metallic surfaces, as a function of the oxygen concentration at the surface. Finally, combined laser-SNMS depth profiles and images, obtained with both laser systems, were presented to demonstrate how the parallel detection of the three differently originated ion signals of the same element can be used to get additional information about the composition of the flux of secondary particles synchronously during the analysis of elemental distributions. In this respect the presented method can be a very helpful tool to prevent misleading interpretations of SIMS or laser-SNMS data. (orig.)

A punctual flux estimator and reactions rates optimization in neutral particles transport calculus by the Monte Carlo method; Mise au point d'un estimateur ponctuel du flux et des taux de reactions dans les calculs de transport de particules neutres par la methode de monte carlo

Energy Technology Data Exchange (ETDEWEB)

Authier, N

1998-12-01

One of the questions asked in radiation shielding problems is the estimation of the radiation level in particular to determine accessibility of working persons in controlled area (nuclear power plants, nuclear fuel reprocessing plants) or to study the dose gradients encountered in material (iron nuclear vessel, medical therapy, electronics in satellite). The flux and reaction rate estimators used in Monte Carlo codes give average values in volumes or on surfaces of the geometrical description of the system. But in certain configurations, the knowledge of punctual deposited energy and dose estimates are necessary. The Monte Carlo estimate of the flux at a point of interest is a calculus which presents an unbounded variance. The central limit theorem cannot be applied thus no easy confidencelevel may be calculated. The convergence rate is then very poor. We propose in this study a new solution for the photon flux at a point estimator. The method is based on the 'once more collided flux estimator' developed earlier for neutron calculations. It solves the problem of the unbounded variance and do not add any bias to the estimation. We show however that our new sampling schemes specially developed to treat the anisotropy of the photon coherent scattering is necessary for a good and regular behavior of the estimator. This developments integrated in the TRIPOLI-4 Monte Carlo code add the possibility of an unbiased punctual estimate on media interfaces. (author)

A punctual flux estimator and reactions rates optimization in neutral particles transport calculus by the Monte Carlo method; Mise au point d'un estimateur ponctuel du flux et des taux de reactions dans les calculs de transport de particules neutres par la methode de monte carlo

Energy Technology Data Exchange (ETDEWEB)

Authier, N

1998-12-01

One of the questions asked in radiation shielding problems is the estimation of the radiation level in particular to determine accessibility of working persons in controlled area (nuclear power plants, nuclear fuel reprocessing plants) or to study the dose gradients encountered in material (iron nuclear vessel, medical therapy, electronics in satellite). The flux and reaction rate estimators used in Monte Carlo codes give average values in volumes or on surfaces of the geometrical description of the system. But in certain configurations, the knowledge of punctual deposited energy and dose estimates are necessary. The Monte Carlo estimate of the flux at a point of interest is a calculus which presents an unbounded variance. The central limit theorem cannot be applied thus no easy confidencelevel may be calculated. The convergence rate is then very poor. We propose in this study a new solution for the photon flux at a point estimator. The method is based on the 'once more collided flux estimator' developed earlier for neutron calculations. It solves the problem of the unbounded variance and do not add any bias to the estimation. We show however that our new sampling schemes specially developed to treat the anisotropy of the photon coherent scattering is necessary for a good and regular behavior of the estimator. This developments integrated in the TRIPOLI-4 Monte Carlo code add the possibility of an unbiased punctual estimate on media interfaces. (author)

Flux form Semi-Lagrangian methods for parabolic problems

Directory of Open Access Journals (Sweden)

Bonaventura Luca

2016-09-01

Full Text Available A semi-Lagrangian method for parabolic problems is proposed, that extends previous work by the authors to achieve a fully conservative, flux-form discretization of linear and nonlinear diffusion equations. A basic consistency and stability analysis is proposed. Numerical examples validate the proposed method and display its potential for consistent semi-Lagrangian discretization of advection diffusion and nonlinear parabolic problems.

Advantages of iron core in a tokamak

International Nuclear Information System (INIS)

Bettis, E.S.; Ballou, J.K.; Becraft, W.R.; Peng, Y.K.M.; Watts, H.L.

1977-01-01

A quantitative comparison of the iron core vs air core concepts was carried out on a preliminary basis by using a representative tokamak reactor design with the following self-consistent reference parameters. In the area of plasma engineering, poloidal field and MHD equilibrium considerations with an unsaturated iron core is discussed. The question of proper poloidal field coils to maintain D-shaped plasmas of relatively high anti β (7%) with a saturated iron core is also discussed. Estimates of the required iron core size, volt seconds, magnetic flux and its influence on force loading on the superconducting toroidal field coils are shown. Conceptual designs of the mechanical structure of an iron core device are presented. Favorable impacts on the OH power supply cost and complexity are indicated

Quantitative method for measuring heat flux emitted from a cryogenic object

Science.gov (United States)

Duncan, R.V.

1993-03-16

The present invention is a quantitative method for measuring the total heat flux, and of deriving the total power dissipation, of a heat-fluxing object which includes the steps of placing an electrical noise-emitting heat-fluxing object in a liquid helium bath and measuring the superfluid transition temperature of the bath. The temperature of the liquid helium bath is thereafter reduced until some measurable parameter, such as the electrical noise, exhibited by the heat-fluxing object or a temperature-dependent resistive thin film in intimate contact with the heat-fluxing object, becomes greatly reduced. The temperature of the liquid helum bath is measured at this point. The difference between the superfluid transition temperature of the liquid helium bath surrounding the heat-fluxing object, and the temperature of the liquid helium bath when the electrical noise emitted by the heat-fluxing object becomes greatly reduced, is determined. The total heat flux from the heat-fluxing object is determined as a function of this difference between these temperatures. In certain applications, the technique can be used to optimize thermal design parameters of cryogenic electronics, for example, Josephson junction and infrared sensing devices.

Quantitative method for measuring heat flux emitted from a cryogenic object

International Nuclear Information System (INIS)

Duncan, R.V.

1993-01-01

The present invention is a quantitative method for measuring the total heat flux, and of deriving the total power dissipation, of a heat-fluxing object which includes the steps of placing an electrical noise-emitting heat-fluxing object in a liquid helium bath and measuring the superfluid transition temperature of the bath. The temperature of the liquid helium bath is thereafter reduced until some measurable parameter, such as the electrical noise, exhibited by the heat-fluxing object or a temperature-dependent resistive thin film in intimate contact with the heat-fluxing object, becomes greatly reduced. The temperature of the liquid helum bath is measured at this point. The difference between the superfluid transition temperature of the liquid helium bath surrounding the heat-fluxing object, and the temperature of the liquid helium bath when the electrical noise emitted by the heat-fluxing object becomes greatly reduced, is determined. The total heat flux from the heat-fluxing object is determined as a function of this difference between these temperatures. In certain applications, the technique can be used to optimize thermal design parameters of cryogenic electronics, for example, Josephson junction and infrared sensing devices

Flux-weakening control methods for hybrid excitation synchronous motor

Directory of Open Access Journals (Sweden)

Mingming Huang

2015-09-01

Full Text Available The hybrid excitation synchronous motor (HESM, which aim at combining the advantages of permanent magnet motor and wound excitation motor, have the characteristics of low-speed high-torque hill climbing and wide speed range. Firstly, a new kind of HESM is presented in the paper, and its structure and mathematical model are illustrated. Then, based on a space voltage vector control, a novel flux-weakening method for speed adjustment in the high speed region is presented. The unique feature of the proposed control method is that the HESM driving system keeps the q-axis back-EMF components invariable during the flux-weakening operation process. Moreover, a copper loss minimization algorithm is adopted to reduce the copper loss of the HESM in the high speed region. Lastly, the proposed method is validated by the simulation and the experimental results.

A Method for Monitoring Iron and Steel Factory Economic Activity Based on Satellites

Directory of Open Access Journals (Sweden)

Yi Zhou

2018-06-01

Full Text Available The Chinese government has promulgated a de-capacity policy for economic growth and environmental sustainability, especially for the iron and steel industry. With these policies, this study aimed to monitor the economic activities and evaluate the production conditions of an iron and steel factory based on satellites via Landsat-8 Thermal Infrared Sensor (TIRS data and high-resolution images from January 2013 to October 2017, and propel next economic adjustment and environmental protection. Our methods included the construction of a heat island intensity index for an iron and steel factory (ISHII, a heat island radio index for an iron and steel factory (ISHRI and a dense classifying approach to monitor the spatiotemporal changes of the internal heat field of an iron and steel factory. Additionally, we used GF-2 and Google Earth images to identify the main production area, detect facility changes to a factory that alters its heat field and verify the accuracy of thermal analysis in a specific time span. Finally, these methods were used together to evaluate economic activity. Based on five iron and steel factories in the Beijing-Tianjin-Hebei region, when the ISHII curve is higher than the seasonal changes in a time series, production is normal; otherwise, there is a shut-down or cut-back. In the spatial pattern analyses, the ISHRI is large in normal production and decreases when cut-back or shut-down occurs. The density classifying images and high-resolution images give powerful evidence to the above-mentioned results. Finally, three types of economic activities of normal production, shut-down or cut-back were monitored for these samples. The study provides a new perspective and method for monitoring the economic activity of an iron and steel factory and provides supports for sustainable development in China.

Modern Cored Wire Injection 2PE-9 Method in the Production of Ductile Iron

Directory of Open Access Journals (Sweden)

E. Guzik

2012-04-01

Full Text Available The results of studies on the use of modern two cored wires injection method for production of nodular graphite cast iron with use of unique implementation of drum ladle as a treatment/ transport and casting ladle instead vertical treatment ladle was described. The injection of length of Ø 9mm wires, cored: in FeSi + Mg nodulariser mixture and inoculant master alloy is a treatment method which can be used to produce iron melted in coreless induction furnace. This paper describes the results of using this method for possibility production of ductile iron under specific industrial conditions. In this case was taken ductile iron with material designation: EN-GJS-450- 10 Grade according PN-EN 1563:2000. Microstructure of 28 trials was controlled on internally used sample which has been correlated with standard sample before. The paper presents typical metallic matrix and graphite characteristic. Additionally, mechanical properties were checked in one experiment. Because of further possibility treatment temperature reduction only the rough magnesium recovery and cost of this new method are given.

Measurement of iron absorption from meals contaminated with iron

International Nuclear Information System (INIS)

Hallberg, L.; Bjoern-Rasmussen, E.

1981-01-01

A method is described to measure in vitro the extent of isotopic exchange between the native nonheme food iron and added inorganic reduction to radioiron tracer. The food is digested with pepsin and trypsin in the presence of radioiron. The exchangeability of food iron is calculated from the specific activity in the food and in an extract of bathophenantroline in isoamyl alcohol obtained after digesting this food. The precision and accuracy of the method is illustrated by two kinds of studies, those in which different amounts of contamination iron are added to a meal and those evaluating contamination iron in natural meals. The present method will make it possible to measure validly iron absorption from meals contaminated with unknown amounts of iron of unknown exchangeability with the extrinsic radioiron tracer

Comparison of ecosystem water flux measured with the Eddy covariance- and the direct xylem sap flux method in a mountainous forest

Energy Technology Data Exchange (ETDEWEB)

Stefanicki, G; Geissbuehler, P; Siegwolf, R [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1999-08-01

The Eddy covariance technique allows to measure different components of turbulent air fluxes, including the flow of water vapour. Sap flux measurements determine directly the water flow in tree stems. We compared the water flux just above the crowns of trees in a forest by the technique of Eddy covariance and the water flux by the xylem sap flux method. These two completely different approaches showed a good qualitative correspondence. The correlation coefficient is 0.8. With an estimation of the crown diameter of the measured tree we also find a very good quantitative agreement. (author) 3 figs., 5 refs.

Theoretical analysis of integral neutron transport equation using collision probability method with quadratic flux approach

International Nuclear Information System (INIS)

Shafii, Mohammad Ali; Meidianti, Rahma; Wildian,; Fitriyani, Dian; Tongkukut, Seni H. J.; Arkundato, Artoto

2014-01-01

Theoretical analysis of integral neutron transport equation using collision probability (CP) method with quadratic flux approach has been carried out. In general, the solution of the neutron transport using the CP method is performed with the flat flux approach. In this research, the CP method is implemented in the cylindrical nuclear fuel cell with the spatial of mesh being conducted into non flat flux approach. It means that the neutron flux at any point in the nuclear fuel cell are considered different each other followed the distribution pattern of quadratic flux. The result is presented here in the form of quadratic flux that is better understanding of the real condition in the cell calculation and as a starting point to be applied in computational calculation

Theoretical analysis of integral neutron transport equation using collision probability method with quadratic flux approach

Energy Technology Data Exchange (ETDEWEB)

Shafii, Mohammad Ali, E-mail: mashafii@fmipa.unand.ac.id; Meidianti, Rahma, E-mail: mashafii@fmipa.unand.ac.id; Wildian,, E-mail: mashafii@fmipa.unand.ac.id; Fitriyani, Dian, E-mail: mashafii@fmipa.unand.ac.id [Department of Physics, Andalas University Padang West Sumatera Indonesia (Indonesia); Tongkukut, Seni H. J. [Department of Physics, Sam Ratulangi University Manado North Sulawesi Indonesia (Indonesia); Arkundato, Artoto [Department of Physics, Jember University Jember East Java Indonesia (Indonesia)

2014-09-30

Theoretical analysis of integral neutron transport equation using collision probability (CP) method with quadratic flux approach has been carried out. In general, the solution of the neutron transport using the CP method is performed with the flat flux approach. In this research, the CP method is implemented in the cylindrical nuclear fuel cell with the spatial of mesh being conducted into non flat flux approach. It means that the neutron flux at any point in the nuclear fuel cell are considered different each other followed the distribution pattern of quadratic flux. The result is presented here in the form of quadratic flux that is better understanding of the real condition in the cell calculation and as a starting point to be applied in computational calculation.

Calculations of the spectra of fast neutrons in iron spheres using the vitamin-C file

International Nuclear Information System (INIS)

Ahmed, F.; Aizawa, O.; Kadotani, H.

1984-01-01

Steady-state space-dependent fast neutron angular and scalar spectra and total flux in various iron spheres have been calculated using the one-dimensional discrete ordinate transport code ANISN and Vitamin-C nuclear data file. The results have been used to study the question of establishment of equilibrium and of an associated fast neutron diffusion length in iron. The authors find that true equilibrium conditions are not established even inside a 3-m-radius iron sphere. However, from the study of spatial decay of total flux, one can obtain the value of the fast neutron diffusion length in iron, which in the present case is found to be 24.4 cm

TORT/MCNP coupling method for the calculation of neutron flux around a core of BWR

International Nuclear Information System (INIS)

Kurosawa, M.

2005-01-01

For the analysis of BWR neutronics performance, accurate data are required for neutron flux distribution over the In-Reactor Pressure Vessel equipments taking into account the detailed geometrical arrangement. The TORT code can calculate neutron flux around a core of BWR in a three-dimensional geometry model, but has difficulties in fine geometrical modelling and lacks huge computer resource. On the other hand, the MCNP code enables the calculation of the neutron flux with a detailed geometry model, but requires very long sampling time to give enough number of particles. Therefore, a TORT/MCNP coupling method has been developed to eliminate the two problems mentioned above in each code. In this method, the TORT code calculates angular flux distribution on the core surface and the MCNP code calculates neutron spectrum at the points of interest using the flux distribution. The coupling method will be used as the DOT-DOMINO-MORSE code system. This TORT/MCNP coupling method was applied to calculate the neutron flux at points where induced radioactivity data were measured for 54 Mn and 60 Co and the radioactivity calculations based on the neutron flux obtained from the above method were compared with the measured data. (authors)

TORT/MCNP coupling method for the calculation of neutron flux around a core of BWR.

Science.gov (United States)

Kurosawa, Masahiko

2005-01-01

For the analysis of BWR neutronics performance, accurate data are required for neutron flux distribution over the In-Reactor Pressure Vessel equipments taking into account the detailed geometrical arrangement. The TORT code can calculate neutron flux around a core of BWR in a three-dimensional geometry model, but has difficulties in fine geometrical modelling and lacks huge computer resource. On the other hand, the MCNP code enables the calculation of the neutron flux with a detailed geometry model, but requires very long sampling time to give enough number of particles. Therefore, a TORT/MCNP coupling method has been developed to eliminate the two problems mentioned above in each code. In this method, the TORT code calculates angular flux distribution on the core surface and the MCNP code calculates neutron spectrum at the points of interest using the flux distribution. The coupling method will be used as the DOT-DOMINO-MORSE code system. This TORT/MCNP coupling method was applied to calculate the neutron flux at points where induced radioactivity data were measured for 54Mn and 60Co and the radioactivity calculations based on the neutron flux obtained from the above method were compared with the measured data.

Study of granitic biotites by X-ray fluorescence analysis: determination of iron, manganese, titanium, calcium, potassium, silicon and aluminium

International Nuclear Information System (INIS)

Toubes, R. O.; Bermudez Polonio, J.

1968-01-01

A method for the quantitative determination of iron, manganese, titanium, calcium potassium, silicon, and aluminium, is reported, Sample preparation is carried out by the miniature flux technique, and rubidium is used as internal standard for silicon and aluminium. (Author) 5 refs

A Hybrid Excited Machine with Flux Barriers and Magnetic Bridges

Directory of Open Access Journals (Sweden)

Marcin Wardach

2018-03-01

Full Text Available In this paper, an U-shape flux barrier rotor concept for a hybrid excited synchronous machine with flux magnetic bridges fixed on the rotor is presented. Using 3D finite element analysis, the influence of axial flux bridges on the field-weakening and -strengthening characteristics, electromagnetic torque, no-load magnetic flux linkage, rotor iron losses and back electromotive force is shown. Three different rotor designs are analyzed. Furthermore, the field control characteristics depending on additional DC control coil currents are shown.

A diffusion-theoretical method to calculate the neutron flux distribution in multisphere configurations

International Nuclear Information System (INIS)

Schuerrer, F.

1980-01-01

For characterizing heterogene configurations of pebble-bed reactors the fine structure of the flux distribution as well as the determination of the macroscopic neutronphysical quantities are of interest. When calculating system parameters of Wigner-Seitz-cells the usual codes for neutron spectra calculation always neglect the modulation of the neutron flux by the influence of neighbouring spheres. To judge the error arising from that procedure it is necessary to determinate the flux distribution in the surrounding of a spherical fuel element. In the present paper an approximation method to calculate the flux distribution in the two-sphere model is developed. This method is based on the exactly solvable problem of the flux determination of a point source of neutrons in an infinite medium, which contains a spherical perturbation zone eccentric to the point source. An iteration method allows by superposing secondary fields and alternately satisfying the conditions of continuity on the surface of each of the two fuel elements to advance to continually improving approximations. (orig.) 891 RW/orig. 892 CKA [de

Pelagic Iron Recycling in the Southern Ocean: Exploring the Contribution of Marine Animals

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Lavenia Ratnarajah

2018-03-01

fecal iron. The flux of dissolved iron from pelagic recycling is comparable to other sources in the region such as atmospheric dust, vertical diffusivity, vertical flux, lateral flux and upwelling, but lower than sea ice, icebergs, sediment resuspension, and deep winter mixing. The temporal and seasonal importance of these various factors requires further examination.

Diffusion of hydrogen in iron oxides

International Nuclear Information System (INIS)

Bruzzoni, P.

1993-01-01

The diffusion of hydrogen in transitions metals oxides has been recently studied at room temperature through the permeability electrochemical technique. This work studies thin oxide layers grown in air or in presence of oxidizing atmospheres at temperatures up to 200 deg C. The substrate was pure iron with different superficial treatments. It was observed that these oxides reduce up to three magnitudes orders, the hydrogen stationary flux through membranes of usual thickness in comparison with iron membranes free of oxide. (Author)

A comparison of in vivo and in vitro methods for determining availability of iron from meals

International Nuclear Information System (INIS)

Schricker, B.R.; Miller, D.D.; Rasmussen, R.R.; Van Campen, D.

1981-01-01

A comparison is made between in vitro and human and rat in vivo methods for estimating food iron availability. Complex meals formulated to replicate meals used by Cook and Monsen (Am J Clin Nutr 1976;29:859) in human iron availability trials were used in the comparison. The meals were prepared by substituting pork, fish, cheese, egg, liver, or chicken for beef in two basic test meals and were evaluated for iron availability using in vitro and rat in vivo methods. When the criterion for comparison was the ability to show statistically significant differences between iron availability in the various meals, there was substantial agreement between the in vitro and human in vivo methods. There was less agreement between the human in vivo and the rat in vivo and between the in vivo and the rat in vivo and between the in vitro and the rat in vivo methods. Correlation analysis indicated significant agreement between in vitro and human in vivo methods. Correlation between the rat in vivo and human in vivo methods were also significant but correlations between the in vitro and rat in vivo methods were less significant and, in some cases, not significant. The comparison supports the contention that the in vitro method allows a rapid, inexpensive, and accurate estimation of nonheme iron availability in complex meals

Description of heat flux measurement methods used in hydrocarbon and propellant fuel fires at Sandia.

Energy Technology Data Exchange (ETDEWEB)

Nakos, James Thomas

2010-12-01

The purpose of this report is to describe the methods commonly used to measure heat flux in fire applications at Sandia National Laboratories in both hydrocarbon (JP-8 jet fuel, diesel fuel, etc.) and propellant fires. Because these environments are very severe, many commercially available heat flux gauges do not survive the test, so alternative methods had to be developed. Specially built sensors include 'calorimeters' that use a temperature measurement to infer heat flux by use of a model (heat balance on the sensing surface) or by using an inverse heat conduction method. These specialty-built sensors are made rugged so they will survive the environment, so are not optimally designed for ease of use or accuracy. Other methods include radiometers, co-axial thermocouples, directional flame thermometers (DFTs), Sandia 'heat flux gauges', transpiration radiometers, and transverse Seebeck coefficient heat flux gauges. Typical applications are described and pros and cons of each method are listed.

Evaluation of Application Methods Efficiency of Zinc and Iron for Canola(Brassica napus L.

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Ahmad BYBORDI

2010-03-01

Full Text Available In order to evaluation of application method efficiency of zinc and iron microelements in canola, an experiment was conducted in the Agricultural Research Station of Eastern Azerbaijan province in 2008. The experimental design was a RCBD with eight treatments (F1: control, F2: iron, F3: zinc, F4: iron + zinc in the form of soil utility, F5: iron, F6: zinc, F7: iron+ zinc in the form of solution foliar application, and F8: iron + zinc in the form of soil utility and foliar application. Analysis of variance showed that there were significant differences among treatments on given traits, antioxidant enzymes activity, fatty acids percentage, plant height, seed weight to capitulum weight ratio, protein percentage, oil percentage, oil yield, 1000 seed weight, seed yield, nitrogen, phosphorous and potassium percentage of leaves, zinc and iron content of leaves and capitulum diameters. The highest seed yield, oil yield, oil percentage, 1000 seed weight, seed weight to capitulum weight ratio and protein percentage were obtained from the soil and foliar application of iron + zinc treatments (F8. Also, the highest amounts of nitrogen, phosphorous and potassium concentration in leaves were achieved from control treatment which was an indication of non-efficiency of iron and zinc on the absorption rate of these substances in the leaves. The correlation between effective traits on the seed yield, such as, capitalism diameter, number of seed rows in capitulum, seed weight to capitulum weight ratio and 1000 seed weight were positively significant. In general, foliar and soil application of zinc and iron had the highest efficiency in aspect of seed production. The comparison of the various methods of fertilization showed that foliar application was more effective than soil application. Also, micronutrient foliar application increased concentration of elements, especially zinc and iron. Antioxidant enzymes activity was different in response to treatments also the

Self-powered neutron flux detector assembly

International Nuclear Information System (INIS)

Allan, C.J.; McIntyre, I.L.

1980-01-01

A self-powered neutron flux detector has both the central emitter electrode and its surrounding collector electrode made of inconel 600. The lead cables may also be made of inconel. Other nickel alloys, or iron, nickel, titamium, chromium, zirconium or their alloys may also be used for the electrodes

Pellet by pellet neutron flux calculations coupled with nodal expansion method

International Nuclear Information System (INIS)

Aldo, Dall'Osso

2003-01-01

We present a technique whose aim is to replace 2-dimensional pin by pin de-homogenization, currently done in core reactor calculations with the nodal expansion method (NEM), by a 3-dimensional finite difference diffusion calculation. This fine calculation is performed as a zoom in each node taking as boundary conditions the results of the NEM calculations. The size of fine mesh is of the order of a fuel pellet. The coupling between fine and NEM calculations is realised by an albedo like boundary condition. Some examples are presented showing fine neutron flux shape near control rods or assembly grids. Other fine flux behaviour as the thermal flux rise in the fuel near the reflector is emphasised. In general the results show the interest of the method in conditions where the separability of radial and axial directions is not granted. (author)

Flux schemes based finite volume method for internal transonic flow with condensation

Czech Academy of Sciences Publication Activity Database

Halama, Jan; Benkhaldoun, F.; Fořt, J.

2011-01-01

Roč. 65, č. 8 (2011), s. 953-968 ISSN 0271-2091 Institutional research plan: CEZ:AV0Z20760514 Keywords : VFFC flux * SRNH flux * two-phase homogeneous flow * fractional step method * condensation Subject RIV: BK - Fluid Dynamics Impact factor: 1.176, year: 2011

Determination of iron and titanium in kaolins by the method of non-dispersive X-ray fluorescence

International Nuclear Information System (INIS)

Bialy, N.; Kierzek, J.; Parus, J.

1976-01-01

The possibility of application of the radioactive source excited X-ray fluorescence analysis for titanium and iron determination in kaolins to the routine test of the refinement process has been studied. The iron content can be determined with a simple counting system using a single-channel pulse height analyser, argon filled proportional counter and 109 Cd source of 3 mCi for the excitation of K Fe rays. The samples were analyzed both as pellets and powders. The iron content ranged from 0.2-2.5% and titanium from 0.1-0.64%. The best values of precision and determination limit have been achieved for iron with 238 Pu and for titanium with 55 Fe. The precision and accuracy of the X-ray fluorescence method of iron and titanium determination in kaolins are comparable to those of the chemical method. For the simultaneous iron and titanium determination in the discussed region of concentration it is the most advantageous to use the plutonium source with the activity of several tens of mCi and Si(Li) detector with a moderate resolution (250-300 eV for 5.9 keV). The time of the analysis carried out by the described method is several times shorter than the chemical method. The apparatus used in this method is relatively simple, the sample preparation does not require any chemical treatment and the cost of labour of the sample preparation is minimal. (T.G.)

Methods for the shipboard determination of dissolved iron and manganese in samples of sediment interstitial water

International Nuclear Information System (INIS)

Hydes, D.J.; Chapman, E.

1986-01-01

Iron is extremely unstable in the presence of oxygen. A working atmosphere containing less than 0.2% oxygen is required if iron losses are not to be significant. Iron can be determined with a single addition of reagent, either manually or by a continuous flow procedure using ferrozine. Using a continuous flow procedure with a 5 cm colorimeter cell the method is linear up to 40 μM Fe and the precision is 2%. Manganese can similarly be determined with a single reagent addition using formaldoxime. For the continuous flow procedure with a 5 cm colorimeter cell the method is linear up to 60 μM Mn and the precision is 1%; however, under these conditions a solution containing 100 μm of iron produces an interference equivalent to 4.7 μM of manganese. A two-reagent procedure was developed using EDTA to suppress the iron interference. Using a 5% EDTA solution interference from a solution containing 100 μM of iron was undetectable. (author)

Gas-Kinetic Theory Based Flux Splitting Method for Ideal Magnetohydrodynamics

Science.gov (United States)

Xu, Kun

1998-01-01

A gas-kinetic solver is developed for the ideal magnetohydrodynamics (MHD) equations. The new scheme is based on the direct splitting of the flux function of the MHD equations with the inclusion of "particle" collisions in the transport process. Consequently, the artificial dissipation in the new scheme is much reduced in comparison with the MHD Flux Vector Splitting Scheme. At the same time, the new scheme is compared with the well-developed Roe-type MHD solver. It is concluded that the kinetic MHD scheme is more robust and efficient than the Roe- type method, and the accuracy is competitive. In this paper the general principle of splitting the macroscopic flux function based on the gas-kinetic theory is presented. The flux construction strategy may shed some light on the possible modification of AUSM- and CUSP-type schemes for the compressible Euler equations, as well as to the development of new schemes for a non-strictly hyperbolic system.

Comparison of sap flux, moisture flux tower and MODIS enhanced vegetation index methods for estimating riparian evapotranspiration

Science.gov (United States)

Nagler, Pamela L.; Glenn, Edward P.; Morino, Kiyomi; Neale, Christopher M.U; Cosh, Michael H.

2010-01-01

Riparian evapotranspiration (ET) was measured on a salt cedar (Tamarix spp.) dominated river terrace on the Lower Colorado River from 2007 to 2009 using tissue-heat-balance sap flux sensors at six sites representing very dense, medium dense, and sparse stands of plants. Salt cedar ET varied markedly across sites, and sap flux sensors showed that plants were subject to various degrees of stress, detected as mid-day depression of transpiration and stomatal conductance. Sap flux results were scaled from the leaf level of measurement to the stand level by measuring plant-specific leaf area index and fractional ground cover at each site. Results were compared to Bowen ratio moisture tower data available for three of the sites. Sap flux sensors and flux tower results ranked the sites the same and had similar estimates of ET. A regression equation, relating measured ET of salt cedar and other riparian plants and crops on the Lower Colorado River to the Enhanced Vegetation Index from the MODIS sensor on the Terra satellite and reference crop ET measured at meteorological stations, was able to predict actual ET with an accuracy or uncertainty of about 20%, despite between-site differences for salt cedar. Peak summer salt cedar ET averaged about 6 mm d-1 across sites and methods of measurement.

Anthropogenic combustion iron as a complex climate forcer.

Science.gov (United States)

Matsui, Hitoshi; Mahowald, Natalie M; Moteki, Nobuhiro; Hamilton, Douglas S; Ohata, Sho; Yoshida, Atsushi; Koike, Makoto; Scanza, Rachel A; Flanner, Mark G

2018-04-23

Atmospheric iron affects the global carbon cycle by modulating ocean biogeochemistry through the deposition of soluble iron to the ocean. Iron emitted by anthropogenic (fossil fuel) combustion is a source of soluble iron that is currently considered less important than other soluble iron sources, such as mineral dust and biomass burning. Here we show that the atmospheric burden of anthropogenic combustion iron is 8 times greater than previous estimates by incorporating recent measurements of anthropogenic magnetite into a global aerosol model. This new estimation increases the total deposition flux of soluble iron to southern oceans (30-90 °S) by 52%, with a larger contribution of anthropogenic combustion iron than dust and biomass burning sources. The direct radiative forcing of anthropogenic magnetite is estimated to be 0.021 W m -2 globally and 0.22 W m -2 over East Asia. Our results demonstrate that anthropogenic combustion iron is a larger and more complex climate forcer than previously thought, and therefore plays a key role in the Earth system.

Testing an inversion method for estimating electron energy fluxes from all-sky camera images

Directory of Open Access Journals (Sweden)

N. Partamies

2004-06-01

Full Text Available An inversion method for reconstructing the precipitating electron energy flux from a set of multi-wavelength digital all-sky camera (ASC images has recently been developed by tomografia. Preliminary tests suggested that the inversion is able to reconstruct the position and energy characteristics of the aurora with reasonable accuracy. This study carries out a thorough testing of the method and a few improvements for its emission physics equations. We compared the precipitating electron energy fluxes as estimated by the inversion method to the energy flux data recorded by the Defense Meteorological Satellite Program (DMSP satellites during four passes over auroral structures. When the aurorae appear very close to the local zenith, the fluxes inverted from the blue (427.8nm filtered ASC images or blue and green line (557.7nm images together give the best agreement with the measured flux values. The fluxes inverted from green line images alone are clearly larger than the measured ones. Closer to the horizon the quality of the inversion results from blue images deteriorate to the level of the ones from green images. In addition to the satellite data, the precipitating electron energy fluxes were estimated from the electron density measurements by the EISCAT Svalbard Radar (ESR. These energy flux values were compared to the ones of the inversion method applied to over 100 ASC images recorded at the nearby ASC station in Longyearbyen. The energy fluxes deduced from these two types of data are in general of the same order of magnitude. In 35% of all of the blue and green image inversions the relative errors were less than 50% and in 90% of the blue and green image inversions less than 100%. This kind of systematic testing of the inversion method is the first step toward using all-sky camera images in the way in which global UV images have recently been used to estimate the energy fluxes. The advantages of ASCs, compared to the space-born imagers, are

Analysis of the neutron flux in an annular pulsed reactor by using finite volume method

Energy Technology Data Exchange (ETDEWEB)

Silva, Mário A.B. da; Narain, Rajendra; Bezerra, Jair de L., E-mail: mabs500@gmail.com, E-mail: narain@ufpe.br, E-mail: jairbezerra@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Centro de Tecnologia e Geociências. Departamento de Energia Nuclear

2017-07-01

Production of very intense neutron sources is important for basic nuclear physics and for material testing and isotope production. Nuclear reactors have been used as sources of intense neutron fluxes, although the achievement of such levels is limited by the inability to remove fission heat. Periodic pulsed reactors provide very intense fluxes by a rotating modulator near a subcritical core. A concept for the production of very intense neutron fluxes that combines features of periodic pulsed reactors and steady state reactors was proposed by Narain (1997). Such a concept is known as Very Intense Continuous High Flux Pulsed Reactor (VICHFPR) and was analyzed by using diffusion equation with moving boundary conditions and Finite Difference Method with Crank-Nicolson formalism. This research aims to analyze the flux distribution in the Very Intense Continuous Flux High Pulsed Reactor (VICHFPR) by using the Finite Volume Method and compares its results with those obtained by the previous computational method. (author)

Analysis of the neutron flux in an annular pulsed reactor by using finite volume method

International Nuclear Information System (INIS)

Silva, Mário A.B. da; Narain, Rajendra; Bezerra, Jair de L.

2017-01-01

Production of very intense neutron sources is important for basic nuclear physics and for material testing and isotope production. Nuclear reactors have been used as sources of intense neutron fluxes, although the achievement of such levels is limited by the inability to remove fission heat. Periodic pulsed reactors provide very intense fluxes by a rotating modulator near a subcritical core. A concept for the production of very intense neutron fluxes that combines features of periodic pulsed reactors and steady state reactors was proposed by Narain (1997). Such a concept is known as Very Intense Continuous High Flux Pulsed Reactor (VICHFPR) and was analyzed by using diffusion equation with moving boundary conditions and Finite Difference Method with Crank-Nicolson formalism. This research aims to analyze the flux distribution in the Very Intense Continuous Flux High Pulsed Reactor (VICHFPR) by using the Finite Volume Method and compares its results with those obtained by the previous computational method. (author)

Impact of the natural Fe-fertilization on the magnitude, stoichiometry and efficiency of particulate biogenic silica, nitrogen and iron export fluxes

Science.gov (United States)

Lemaitre, N.; Planquette, H.; Dehairs, F.; van der Merwe, P.; Bowie, A. R.; Trull, T. W.; Laurenceau-Cornec, E. C.; Davies, D.; Bollinger, C.; Le Goff, M.; Grossteffan, E.; Planchon, F.

2016-11-01

The Kerguelen Plateau is characterized by a naturally Fe-fertilized phytoplankton bloom that extends more than 1000 km downstream in the Antarctic Circumpolar Current. During the KEOPS2 study, in austral spring, we measured particulate nitrogen (PN), biogenic silica (BSi) and particulate iron (PFe) export fluxes in order to investigate how the natural fertilization impacts the stoichiometry and the magnitude of export fluxes and therefore the efficiency of the biological carbon pump. At 9 stations, we estimated elemental export fluxes based on element concentration to 234Th activity ratios for particulate material collected with in-situ pumps and 234Th export fluxes (Planchon et al., 2015). This study revealed that the natural Fe-fertilization increased export fluxes but to variable degrees. Export fluxes for the bloom impacted area were compared with those of a high-nutrient, low-chlorophyll (HNLC), low-productive reference site located to the south-west of Kerguelen and which had the lowest BSi and PFe export fluxes (2.55 mmol BSi m-2 d-1 and 1.92 μmol PFem-2 d-1) and amongst the lowest PN export flux (0.73 mmol PN m-2 d-1). The impact of the Fe fertilization was the greatest within a meander of the polar front (PF), to the east of Kerguelen, with fluxes reaching 1.26 mmol PN m-2 d-1; 20.4 mmol BSi m-2 d-1 and 22.4 μmol PFe m-2 d-1. A highly productive site above the Kerguelen Plateau, on the contrary, was less impacted by the fertilization with export fluxes reaching 0.72 mmol PN m-2 d-1; 4.50 mmol BSi m-2 d-1 and 21.4 μmol PFe m-2 d-1. Our results suggest that ecosystem features (i.e. type of diatom community) could play an important role in setting the magnitude of export fluxes of these elements. Indeed, for the PF meander, the moderate productivity was sustained by the presence of large and strongly silicified diatom species while at the higher productivity sites, smaller and slightly silicified diatoms dominated. Interestingly, our results suggest that

Elemental analysis of two Egyptian iron ores and produced industrial iron samples by neutron activation analysis

International Nuclear Information System (INIS)

Sroor, A.; Abdel-Basset, N.; Abdel-Haleem, A.S.; Hassan, A.M.

2001-01-01

Elemental analysis of two iron ores and initial industrial iron production prepared by the Egyptian Iron and Steel Company of Helwan near Cairo were performed by the instrumental neutron activation analysis technique. Five samples of each type were irradiated for 48 h in a thermal neutron flux of 4x10 12 n/cm 2 s in the first Egyptian research reactor ET-RR-1. Also, the Pneumatic Irradiation Rabbit System (PIRS), attached to the reactor ET-RR-1 in Inshass, was used to measure short-life elements. The γ-ray spectra were obtained with a hyper pure germanium detection system. The concentration percentage values of major, minor and trace elements are presented. Implications of the elemental concentration values obtained are presented

Determining Accuracy of Thermal Dissipation Methods-based Sap Flux in Japanese Cedar Trees

Science.gov (United States)

Su, Man-Ping; Shinohara, Yoshinori; Laplace, Sophie; Lin, Song-Jin; Kume, Tomonori

2017-04-01

Thermal dissipation method, one kind of sap flux measurement method that can estimate individual tree transpiration, have been widely used because of its low cost and uncomplicated operation. Although thermal dissipation method is widespread, the accuracy of this method is doubted recently because some tree species materials in previous studies were not suitable for its empirical formula from Granier due to difference of wood characteristics. In Taiwan, Cryptomeria japonica (Japanese cedar) is one of the dominant species in mountainous area, quantifying the transpiration of Japanese cedar trees is indispensable to understand water cycling there. However, no one have tested the accuracy of thermal dissipation methods-based sap flux for Japanese cedar trees in Taiwan. Thus, in this study we conducted calibration experiment using twelve Japanese cedar stem segments from six trees to investigate the accuracy of thermal dissipation methods-based sap flux in Japanese cedar trees in Taiwan. By pumping water from segment bottom to top and inserting probes into segments to collect data simultaneously, we compared sap flux densities calculated from real water uptakes (Fd_actual) and empirical formula (Fd_Granier). Exact sapwood area and sapwood depth of each sample were obtained from dying segment with safranin stain solution. Our results showed that Fd_Granier underestimated 39 % of Fd_actual across sap flux densities ranging from 10 to 150 (cm3m-2s-1); while applying sapwood depth corrected formula from Clearwater, Fd_Granier became accurately that only underestimated 0.01 % of Fd_actual. However, when sap flux densities ranging from 10 to 50 (cm3m-2s-1)which is similar with the field data of Japanese cedar trees in a mountainous area of Taiwan, Fd_Granier underestimated 51 % of Fd_actual, and underestimated 26 % with applying Clearwater sapwood depth corrected formula. These results suggested sapwood depth significantly impacted on the accuracy of thermal dissipation

Minnealloy: a new magnetic material with high saturation flux density and low magnetic anisotropy

Science.gov (United States)

Mehedi, Md; Jiang, Yanfeng; Suri, Pranav Kumar; Flannigan, David J.; Wang, Jian-Ping

2017-09-01

We are reporting a new soft magnetic material with high saturation magnetic flux density, and low magnetic anisotropy. The new material is a compound of iron, nitrogen and carbon, α‧-Fe8(NC), which has saturation flux density of 2.8  ±  0.15 T and magnetic anisotropy of 46 kJ m-3. The saturation flux density is 27% higher than pure iron, a widely used soft magnetic material. Soft magnetic materials are very important building blocks of motors, generators, inductors, transformers, sensors and write heads of hard disk. The new material will help in the miniaturization and efficiency increment of the next generation of electronic devices.

A method to calculate flux distribution in reactor systems containing materials with grain structure

International Nuclear Information System (INIS)

Stepanek, J.

1980-01-01

A method is proposed to compute the neutron flux spatial distribution in slab, spherical or cylindrical systems containing zones with close grain structure of material. Several different types of equally distributed particles embedded in the matrix material are allowed in one or more zones. The multi-energy group structure of the flux is considered. The collision probability method is used to compute the fluxes in the grains and in an ''effective'' part of the matrix material. Then the overall structure of the flux distribution in the zones with homogenized materials is determined using the DPN ''surface flux'' method. Both computations are connected using the balance equation during the outer iterations. The proposed method is written in the code SURCU-DH. Two testcases are computed and discussed. One testcase is the computation of the eigenvalue in simplified slab geometry of an LWR container of one zone with boral grains equally distributed in an aluminium matrix. The second is the computation of the eigenvalue in spherical geometry of the HTR pebble-bed cell with spherical particles embedded in a graphite matrix. The results are compared to those obtained by repeated use of the WIMS Code. (author)

Pure-iron/iron-based-alloy hybrid soft magnetic powder cores compacted at ultra-high pressure

Science.gov (United States)

Saito, Tatsuya; Tsuruta, Hijiri; Watanabe, Asako; Ishimine, Tomoyuki; Ueno, Tomoyuki

2018-04-01

We developed Fe/FeSiAl soft magnetic powder cores (SMCs) for realizing the miniaturization and high efficiency of an electromagnetic conversion coil in the high-frequency range (˜20 kHz). We found that Fe/FeSiAl SMCs can be formed with a higher density under higher compaction pressure than pure-iron SMCs. These SMCs delivered a saturation magnetic flux density of 1.7 T and iron loss (W1/20k) of 158 kW/m3. The proposed SMCs exhibited similar excellent characteristics even in block shapes, which are closer to the product shapes.

Pure-iron/iron-based-alloy hybrid soft magnetic powder cores compacted at ultra-high pressure

Directory of Open Access Journals (Sweden)

Tatsuya Saito

2018-04-01

Full Text Available We developed Fe/FeSiAl soft magnetic powder cores (SMCs for realizing the miniaturization and high efficiency of an electromagnetic conversion coil in the high-frequency range (∼20 kHz. We found that Fe/FeSiAl SMCs can be formed with a higher density under higher compaction pressure than pure-iron SMCs. These SMCs delivered a saturation magnetic flux density of 1.7 T and iron loss (W1/20k of 158 kW/m3. The proposed SMCs exhibited similar excellent characteristics even in block shapes, which are closer to the product shapes.

Advances on geometric flux optical design method

Science.gov (United States)

García-Botella, Ángel; Fernández-Balbuena, Antonio Álvarez; Vázquez, Daniel

2017-09-01

Nonimaging optics is focused on the study of methods to design concentrators or illuminators systems. It can be included in the area of photometry and radiometry and it is governed by the laws of geometrical optics. The field vector method, which starts with the definition of the irradiance vector E, is one of the techniques used in nonimaging optics. Called "Geometrical flux vector" it has provide ideal designs. The main property of this model is, its ability to estimate how radiant energy is transferred by the optical system, from the concepts of field line, flux tube and pseudopotential surface, overcoming traditional raytrace methods. Nevertheless this model has been developed only at an academic level, where characteristic optical parameters are ideal not real and the studied geometries are simple. The main objective of the present paper is the application of the vector field method to the analysis and design of real concentration and illumination systems. We propose the development of a calculation tool for optical simulations by vector field, using algorithms based on Fermat`s principle, as an alternative to traditional tools for optical simulations by raytrace, based on reflection and refraction law. This new tool provides, first, traditional simulations results: efficiency, illuminance/irradiance calculations, angular distribution of light- with lower computation time, photometrical information needs about a few tens of field lines, in comparison with million rays needed nowadays. On the other hand the tool will provides new information as vector field maps produced by the system, composed by field lines and quasipotential surfaces. We show our first results with the vector field simulation tool.

Photon and proton activation analysis of iron and steel standards using the internal standard method coupled with the standard addition method

International Nuclear Information System (INIS)

Masumoto, K.; Hara, M.; Hasegawa, D.; Iino, E.; Yagi, M.

1997-01-01

The internal standard method coupled with the standard addition method has been applied to photon activation analysis and proton activation analysis of minor elements and trace impurities in various types of iron and steel samples issued by the Iron and Steel Institute of Japan (ISIJ). Samples and standard addition samples were once dissolved to mix homogeneously, an internal standard and elements to be determined and solidified as a silica-gel to make a similar matrix composition and geometry. Cerium and yttrium were used as an internal standard in photon and proton activation, respectively. In photon activation, 20 MeV electron beam was used for bremsstrahlung irradiation to reduce matrix activity and nuclear interference reactions, and the results were compared with those of 30 MeV irradiation. In proton activation, iron was removed by the MIBK extraction method after dissolving samples to reduce the radioactivity of 56 Co from iron via 56 Fe(p, n) 56 Co reaction. The results of proton and photon activation analysis were in good agreement with the standard values of ISIJ. (author)

Iron fertilization of the Subantarctic Ocean during the last ice age

Science.gov (United States)

Martinez-Garcia, A.

2015-12-01

Dust has the potential to modify global climate by influencing the radiative balance of the atmosphere and by supplying iron and other essential limiting micronutrients to the ocean. The scarcity of iron limits marine productivity and carbon uptake in one-quarter of the world ocean where the concentration of major nutrients (phosphorus and nitrogen) is perennially high. The Southern Ocean is the region where variations in iron availability can have the largest effect on Earth's carbon cycle through its fertilizing effect on marine ecosystems. Paleoceanographic records from the Subantarctic Atlantic have revealed a remarkable correlation between phytoplankton productivity and aeolian iron flux during glacial periods supporting the iron fertilization hypothesis. In addition, a recent study has shown that peak glacial times and millennial cold events were nearly universally associated not only with increases in dust flux and export production, but also with an increase in nutrient consumption (the last indicated by higher foraminifera-bound δ15N) (Martinez-Garcia et al. 2014). This combination of changes is uniquely consistent with ice age iron fertilization of the Subantarctic Atlantic. The strengthening of the biological pump associated with the observed increase in Subantarctic nutrient consumption during the high-dust intervals of the last two ice ages can explain up to ~40 ppm of the CO2 decrease that characterizes the transitions from mid-climate states to full ice age conditions. However, the impact of iron fertilization in other sectors of the Southern Ocean characterized by lower ice age dust fluxes than the Atlantic remains unclear. A series of recently published records from the Subantarctic Pacific indicate that dust deposition and marine export production were three times higher during glacial periods than during interglacials (Lamy et al. 2014). Here we present new measurements of foraminifera-bound nitrogen isotopes in a sediment core located in the

Estimation of aerosol plutonium transport by the dust-flux method: a perspective on application of detailed data

International Nuclear Information System (INIS)

Shinn, J.H.

1976-01-01

Two methods of dust-flux measurements are discussed which have been utilized to estimate aerosol plutonium deposition and resuspension. In previous studies the methods were found to be sufficiently detailed to permit parameterization of dust-flux to the erodibility of the soil, and a seventh-power dependency of dust-flux (or plutonium flux) to wind speed was observed in worst case conditions. The eddy-correlation method is technically more difficult, requires high-speed data acquisition, and requires an instrument response time better than one second, but the eddy-correlation method has been shown feasible with new fast-response sensors, and it is more useful in limited areas because it can be used as a probe. The flux-gradient method is limited by critical assumptions and is more bulky, but the method is more commonly used and accepted. The best approach is to use both methods simultaneously. It is suggested that several questions should be investigated by the methods, such as saltation stimulation of dust-flux, simultaneous suspension and deposition, foliar deposition and trapping, erodibility of crusted surfaces, and horizontally heterogeneous erodibility

Therapeutic iron : Evaluation of methods to assess intravenous iron safety profiles and the development of a novel formulation for oral iron delivery

NARCIS (Netherlands)

Span, K.|info:eu-repo/dai/nl/357800842

2018-01-01

Iron treatment is necessary to replenish iron deficit due to several clinical conditions such as chronic diseases. However, as an excess of iron can result in redox imbalance resulting in oxidative stress and thus severe damage to tissue and organs, it is of utmost importance to develop iron

A Family of Multipoint Flux Mixed Finite Element Methods for Elliptic Problems on General Grids

KAUST Repository

Wheeler, Mary F.; Xue, Guangri; Yotov, Ivan

2011-01-01

In this paper, we discuss a family of multipoint flux mixed finite element (MFMFE) methods on simplicial, quadrilateral, hexahedral, and triangular-prismatic grids. The MFMFE methods are locally conservative with continuous normal fluxes, since

Neutron spectrum in small iron pile surrounded by lead reflector

International Nuclear Information System (INIS)

Kimura, Itsuro; Hayashi, S.A.; Kobayashi, Katsuhei; Matsumura, Tetsuo; Nishihara, Hiroshi.

1978-01-01

In order to save the quantity of sample material, a possibility to assess group constants of a reactor material through measurement and analysis of neutron spectrum in a small sample pile surrounded by a reflector of heavy moderator, was investigated. As the sample and the reflector, we chose iron and lead, respectively. Although the time dispersion in moderation of neutrons was considerably prolonged by the lead reflector, this hardly interferes with the assessment of group constants. Theoretical calculation revealed that both the neutron flux spectrum and the sensitivity coefficient of group constants in an iron sphere, 35 cm in diameter surrounded by the lead reflector, 25 cm thick, were close to those of the bare iron sphere, 108 cm in diameter. The neutron spectra in a small iron pile surrounded by a lead reflector were experimentally obtained by the time-of-flight method with an electron linear accelerator and the result was compared with the predicted values. It could be confirmed that a small sample pile surrounded by a reflector, such as lead, was as useful as a much larger bulk pile for the assessment of group constants of a reactor material. (auth.)

Heme Iron Content in Lamb Meat Is Differentially Altered upon Boiling, Grilling, or Frying as Assessed by Four Distinct Analytical Methods

OpenAIRE

Pourkhalili, Azin; Mirlohi, Maryam; Rahimi, Ebrahim

2013-01-01

Lamb meat is regarded as an important source of highly bioavailable iron (heme iron) in the Iranians diet. The main objective of this study is to evaluate the effect of traditional cooking methods on the iron changes in lamb meat. Four published experimental methods for the determination of heme iron were assessed analytically and statistically. Samples were selected from lambs' loin. Standard methods (AOAC) were used for proximate analysis. For measuring heme iron, the results of four experi...

New sulphiding method for steel and cast iron parts

Science.gov (United States)

Tarelnyk, V.; Martsynkovskyy, V.; Gaponova, O.; Konoplianchenko, Ie; Dovzyk, M.; Tarelnyk, N.; Gorovoy, S.

2017-08-01

A new method for sulphiding steel and cast iron part surfaces by electroerosion alloying (EEA) with the use of a special electrode is proposed, which method is characterized in that while manufacturing the electrode, on its surface, in any known manner (punching, threading, pulling, etc.), there is formed at least a recess to be filled with sulfur as a consistent material, and then there is produced EEA by the obtained electrode without waiting for the consistent material to become dried.

Measurement of Critical Heat Flux Using the Transient Inverse Heat Conduction Method in Spray cooling

Energy Technology Data Exchange (ETDEWEB)

Kim, Yeung Chan [Andong Nat’l Univ., Andong (Korea, Republic of)

2016-10-15

A study on the measurement of critical heat flux using the transient inverse heat conduction method in spray cooling was performed. The inverse heat conduction method estimates the surface heat flux or temperature using a measured interior temperature history. The effects of the measuring time interval and location of temperature measurement on the measurement of critical heat flux were primarily investigated. The following results were obtained. The estimated critical heat flux decreased as the time interval of temperature measurement increased. Meanwhile, the effect of measurement location on critical heat flux was not significant. It was also found, from the experimental results, that the critical superheat increased as the measurement location of thermocouple neared the heat transfer surface.

Measurement of Critical Heat Flux Using the Transient Inverse Heat Conduction Method in Spray cooling

International Nuclear Information System (INIS)

Kim, Yeung Chan

2016-01-01

A study on the measurement of critical heat flux using the transient inverse heat conduction method in spray cooling was performed. The inverse heat conduction method estimates the surface heat flux or temperature using a measured interior temperature history. The effects of the measuring time interval and location of temperature measurement on the measurement of critical heat flux were primarily investigated. The following results were obtained. The estimated critical heat flux decreased as the time interval of temperature measurement increased. Meanwhile, the effect of measurement location on critical heat flux was not significant. It was also found, from the experimental results, that the critical superheat increased as the measurement location of thermocouple neared the heat transfer surface.

System and method for making metallic iron with reduced CO.sub.2 emissions

Science.gov (United States)

Kiesel, Richard F; Englund, David J; Schlichting, Mark; Meehan, John; Crouch, Jeremiah; Wilson, Logan

2014-10-14

A method and system for making metallic iron nodules with reduced CO.sub.2 emissions is disclosed. The method includes: assembling a linear hearth furnace having entry and exit portions, at least a conversion zone and a fusion zone, and a moving hearth adapted to move reducible iron bearing material through the furnace on contiguous hearth sections; assembling a shrouded return substantially free of air ingress extending adjacent at least the conversion and fusion zones of the furnace through which hearth sections can move from adjacent the exit portion to adjacent the entry portion of the furnace; transferring the hearth sections from the furnace to the shrouded return adjacent the exit portion; reducing reducible material in the linear hearth furnace to metallic iron nodules; and transporting gases from at least the fusion zone to the shrouded return to heat the hearth sections while in the shrouded return.

A path flux analysis method for the reduction of detailed chemical kinetic mechanisms

Energy Technology Data Exchange (ETDEWEB)

Sun, Wenting; Ju, Yiguang [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States); Chen, Zheng [State Key Laboratory for Turbulence and Complex Systems, College of Engineering, Peking University, Beijing 100871 (China); Gou, Xiaolong [School of Power Engineering, Chongqing University, Chongqing 400044 (China)

2010-07-15

A direct path flux analysis (PFA) method for kinetic mechanism reduction is proposed and validated by using high temperature ignition, perfect stirred reactors, and steady and unsteady flame propagations of n-heptane and n-decane/air mixtures. The formation and consumption fluxes of each species at multiple reaction path generations are analyzed and used to identify the important reaction pathways and the associated species. The formation and consumption path fluxes used in this method retain flux conservation information and are used to define the path indexes for the first and the second generation reaction paths related to a targeted species. Based on the indexes of each reaction path for the first and second generations, different sized reduced chemical mechanisms which contain different number of species are generated. The reduced mechanisms of n-heptane and n-decane obtained by using the present method are compared to those generated by the direct relation graph (DRG) method. The reaction path analysis for n-decane is conducted to demonstrate the validity of the present method. The comparisons of the ignition delay times, flame propagation speeds, flame structures, and unsteady spherical flame propagation processes showed that with either the same or significantly less number of species, the reduced mechanisms generated by the present PFA are more accurate than that of DRG in a broad range of initial pressures and temperatures. The method is also integrated with the dynamic multi-timescale method and a further increase of computation efficiency is achieved. (author)

Growth and characterization of CaFe1-xCoxAsF single crystals by CaAs flux method

Science.gov (United States)

Ma, Yonghui; Hu, Kangkang; Ji, Qiucheng; Gao, Bo; Zhang, Hui; Mu, Gang; Huang, Fuqiang; Xie, Xiaoming

2016-10-01

Millimeter sized single crystals of CaFe1-x Cox AsF were grown using a self-flux method. It is found that high-quality single crystals can be grown from three approaches with different initial raw materials. The chemical compositions and crystal structure were characterized carefully. Compared with the undoped parent phase CaFeAsF, the crystal lattice along the c-axis is suppressed by the Co substitution while that along the a-axis expands slightly. Superconductivity with the critical transition Tc as high as 21 K was confirmed by both the resistivity and magnetic susceptibility measurements in the sample with x=0.118. Moreover, it is found that Tc can be enhanced for about 1 K under the very small hydrostatic pressure of 0.22 GPa, which is more quick than that reported in the polycrystalline samples. Our results are a promotion for the physical investigations of 1111 phase iron-pnictide superconductors.

Inter-comparison of Flux-Gradient and Relaxed Eddy Accumulation Methods for Measuring Ammonia Flux Above a Corn Canopy in Central Illinois, USA

Science.gov (United States)

Nelson, A. J.; Koloutsou-Vakakis, S.; Rood, M. J.; Lichiheb, N.; Heuer, M.; Myles, L.

2017-12-01

Ammonia (NH3) is a precursor to fine particulate matter (PM) in the ambient atmosphere. Agricultural activities represent over 80% of anthropogenic emissions of NH3 in the United States. The use of nitrogen-based fertilizers contribute > 50% of total NH3 emissions in central Illinois. The U.S. EPA Science Advisory Board has called for improved methods to measure, model, and report atmospheric NH3 concentrations and emissions from agriculture. High uncertainties in the temporal and spatial distribution of NH3 emissions contribute to poor performance of air quality models in predicting ambient PM concentrations. This study reports and compares NH­3 flux measurements of differing temporal resolution obtained with two methods: relaxed eddy accumulation (REA) and flux-gradient (FG). REA and FG systems were operated concurrently above a corn canopy at the University of Illinois at Urbana-Champaign (UIUC) Energy Biosciences Institute (EBI) Energy Farm during the 2014 corn-growing season. The REA system operated during daytime, providing average fluxes over four-hour sampling intervals, where time resolution was limited by detection limit of denuders. The FG system employed a cavity ring-down spectrometer, and was operated continuously, reporting 30 min flux averages. A flux-footprint evaluation was used for quality control, resulting in 1,178 qualified FG measurements, 82 of which were coincident with REA measurements. Similar emission trends were observed with both systems, with peak NH3 emission observed one week after fertilization. For all coincident samples, mean NH3 flux was 205 ± 300 ng-N-m2s-1 and 110 ± 256 ng-N-m2s-1 as measured with REA and FG, respectively, where positive flux indicates emission. This is the first reported inter-comparison of REA and FG methods as used for quantifying NH3 fluxes from cropland. Preliminary analysis indicates the improved temporal resolution and continuous sampling enabled by FG allow for the identification of emission pulses

Critical flux determination by flux-stepping

DEFF Research Database (Denmark)

Beier, Søren; Jonsson, Gunnar Eigil

2010-01-01

In membrane filtration related scientific literature, often step-by-step determined critical fluxes are reported. Using a dynamic microfiltration device, it is shown that critical fluxes determined from two different flux-stepping methods are dependent upon operational parameters such as step...... length, step height, and.flux start level. Filtrating 8 kg/m(3) yeast cell suspensions by a vibrating 0.45 x 10(-6) m pore size microfiltration hollow fiber module, critical fluxes from 5.6 x 10(-6) to 1.2 x 10(-5) m/s have been measured using various step lengths from 300 to 1200 seconds. Thus......, such values are more or less useless in itself as critical flux predictors, and constant flux verification experiments have to be conducted to check if the determined critical fluxes call predict sustainable flux regimes. However, it is shown that using the step-by-step predicted critical fluxes as start...

Extension of the heat flux method to subatmospheric pressures

NARCIS (Netherlands)

Bosschaart, K.J.; Goey, de L.P.H.

2004-01-01

The heat flux method for measuring laminar burning velocities has been extended to subatmospheric pressures, down to 80mbar. The new setup is described and adaptations necessary for the new conditions are analyzed. This includes a new burner plate to compensate for the decrease of sensitivity of the

Inter-comparison of different direct and indirect methods to determine radon flux from soil

International Nuclear Information System (INIS)

Grossi, C.; Vargas, A.; Camacho, A.; Lopez-Coto, I.; Bolivar, J.P.; Xia Yu; Conen, F.

2011-01-01

The physical and chemical characteristics of radon gas make it a good tracer for use in the application of atmospheric transport models. For this purpose the radon source needs to be known on a global scale and this is difficult to achieve by only direct experimental methods. However, indirect methods can provide radon flux maps on larger scales, but their reliability has to be carefully checked. It is the aim of this work to compare radon flux values obtained by direct and indirect methods in a measurement campaign performed in the summer of 2008. Different systems to directly measure radon flux from the soil surface and to measure the related parameters terrestrial γ dose and 226 Ra activity in soil, for indirect estimation of radon flux, were tested. Four eastern Spanish sites with different geological and soil characteristics were selected: Teruel, Los Pedrones, Quintanar de la Orden and Madrid. The study shows the usefulness of both direct and indirect methods for obtaining radon flux data. Direct radon flux measurements by continuous and integrated monitors showed a coefficient of variation between 10% and 23%. At the same time, indirect methods based on correlations between 222 Rn and terrestrial γ dose rate, or 226 Ra activity in soil, provided results similar to the direct measurements, when these proxies were directly measured at the site. Larger discrepancies were found when proxy values were extracted from existing data bases. The participating members involved in the campaign study were the Institute of Energy Technology (INTE) of the Technical University of Catalonia (UPC), Huelva University (UHU), and Basel University (BASEL).

Detecting the position of the moving-iron solenoid by non-displacement sensor based on parameter identification of flux linkage characteristics

Science.gov (United States)

Wang, Xuping; Quan, Long; Xiong, Guangyu

2013-11-01

Currently, most researches use signals, such as the coil current or voltage of solenoid, to identify parameters; typically, parameter identification method based on variation rate of coil current is applied for position estimation. The problem exists in these researches that the detected signals are prone to interference and difficult to obtain. This paper proposes a new method for detecting the core position by using flux characteristic quantity, which adds a new group of secondary winding to the coil of the ordinary switching electromagnet. On the basis of electromagnetic coupling theory analysis and simulation research of the magnetic field regarding the primary and secondary winding coils, and in accordance with the fact that under PWM control mode varying core position and operating current of windings produce different characteristic of flux increment of the secondary winding. The flux increment of the electromagnet winding can be obtained by conducting time domain integration for the induced voltage signal of the extracted secondary winding, and the core position from the two-dimensional fitting curve of the operating winding current and flux-linkage characteristic quantity of solenoid are calculated. The detecting and testing system of solenoid core position is developed based on the theoretical research. The testing results show that the flux characteristic quantity of switching electromagnet magnetic circuit is able to effectively show the core position and thus to accomplish the non-displacement transducer detection of the said core position of the switching electromagnet. This paper proposes a new method for detecting the core position by using flux characteristic quantity, which provides a new theory and method for switch solenoid to control the proportional valve.

Simple time-saving method for iron determination based on fluorescence quenching of an azaflavanon-3-ol compound.

Science.gov (United States)

Başoğlu, Aysel; Tosun, Gonca; Ocak, Miraç; Alp, Hakan; Yaylı, Nurettin; Ocak, Ümmühan

2015-03-18

A simple and time-saving spectrofluorometric method developed using an azaflavanon-3-ol compound was used for the determination of iron in various food samples. Nitric acid and hydrogen peroxide were used for digestion of samples in a closed microwave system. The method was validated by analyzing two certified reference materials (CRM-SA-C Sandy Soil C and Mixed Polish Herbs INCT-MPH-2). Measurements were carried out using a modified standard addition method. The standard addition graph was linear until 21.6 mg/L in the determination of iron(III). Detection and quantification limits were 0.81 and 2.4 mg/L, respectively. Satisfactory accuracy was obtained for spinach, dill, mint, purslane, rocket, red lentils, dry beans, and two iron medicinal tablets. High recoveries were found for streamwater samples fortified at three different concentrations. The method is simple, time-saving, cost-effective, and suitable for the determination of the iron content of foods.

Iron deficiency or anemia of inflammation? : Differential diagnosis and mechanisms of anemia of inflammation.

Science.gov (United States)

Nairz, Manfred; Theurl, Igor; Wolf, Dominik; Weiss, Günter

2016-10-01

Iron deficiency and immune activation are the two most frequent causes of anemia, both of which are based on disturbances of iron homeostasis. Iron deficiency anemia results from a reduction of the body's iron content due to blood loss, inadequate dietary iron intake, its malabsorption, or increased iron demand. Immune activation drives a diversion of iron fluxes from the erythropoietic bone marrow, where hemoglobinization takes place, to storage sites, particularly the mononuclear phagocytes system in liver and spleen. This results in iron-limited erythropoiesis and anemia. This review summarizes current diagnostic and pathophysiological concepts of iron deficiency anemia and anemia of inflammation, as well as combined conditions, and provides a brief outlook on novel therapeutic options.

Examination of Cast Iron Material Properties by Means of the Nanoindentation Method

Directory of Open Access Journals (Sweden)

Trytek A.

2012-12-01

Full Text Available The paper presents results of examination of material parameters of cast iron with structure obtained under rapid resolidification conditions carried out by means of the nanoindentation method.

Methods and applications in high flux neutron imaging

International Nuclear Information System (INIS)

Ballhausen, H.

2007-01-01

This treatise develops new methods for high flux neutron radiography and high flux neutron tomography and describes some of their applications in actual experiments. Instead of single images, time series can be acquired with short exposure times due to the available high intensity. To best use the increased amount of information, new estimators are proposed, which extract accurate results from the recorded ensembles, even if the individual piece of data is very noisy and in addition severely affected by systematic errors such as an influence of gamma background radiation. The spatial resolution of neutron radiographies, usually limited by beam divergence and inherent resolution of the scintillator, can be significantly increased by scanning the sample with a pinhole-micro-collimator. This technique circumvents any limitations in present detector design and, due to the available high intensity, could be successfully tested. Imaging with scattered neutrons as opposed to conventional total attenuation based imaging determines separately the absorption and scattering cross sections within the sample. For the first time even coherent angle dependent scattering could be visualized space-resolved. New applications of high flux neutron imaging are presented, such as materials engineering experiments on innovative metal joints, time-resolved tomography on multilayer stacks of fuel cells under operation, and others. A new implementation of an algorithm for the algebraic reconstruction of tomography data executes even in case of missing information, such as limited angle tomography, and returns quantitative reconstructions. The setup of the world-leading high flux radiography and tomography facility at the Institut Laue-Langevin is presented. A comprehensive appendix covers the physical and technical foundations of neutron imaging. (orig.)

Four-year measurement of methane flux over a temperate forest with a relaxed eddy accumulation method

Science.gov (United States)

Sakabe, A.; Kosugi, Y.; Ueyama, M.; Hamotani, K.; Takahashi, K.; Iwata, H.; Itoh, M.

2013-12-01

Forests are generally assumed to be an atmospheric methane (CH4) sink (Le Mer and Roger, 2001). However, under Asian monsoon climate, forests are subject to wide spatiotemporal range in soil water status, where forest soils often became water-saturated condition heterogeneously. In such warm and humid conditions, forests may act as a CH4 source and/or sink with considerable spatiotemporal variations. Micrometeorological methods such as eddy covariance (EC) method continuously measure spatially-representative flux at a canopy scale without artificial disturbance. In this study, we measured CH4 fluxes over a temperate forest during four-year period using a CH4 analyzer based on tunable diode laser spectroscopy detection with a relaxed eddy accumulation (REA) method (Hamotani et al., 1996, 2001). We revealed the amplitude and seasonal variations of canopy-scale CH4 fluxes. The REA method is the attractive alternative to the EC method to measure trace-gas flux because it allows the use of analyzers with an optimal integration time. We also conducted continuous chamber measurements on forest floor to reveal spatial variations in soil CH4 fluxes and its controlling processes. The observations were made in an evergreen coniferous forest in central Japan. The site has a warm temperate monsoon climate with wet summer. Some wetlands were located in riparian zones along streams within the flux footprint area. For the REA method, the sonic anemometer (SAT-550, Kaijo) was mounted on top of the 29-m-tall tower and air was sampled from just below the sonic anemometer to reservoirs according to the direction of vertical wind velocity (w). After accumulating air for 30 minutes, the air in the reservoirs was pulled into a CO2/H2O gas analyzer (LI-840, Li-Cor) and a CH4 analyzer (FMA-200, Los Gatos Research). Before entering the analyzers, the sampled air was dried using a gas dryer (PD-50 T-48; Perma Pure Inc.). The REA flux is obtained from the difference in the mean concentrations

Analysis of the plasma magnetohydrodynamic equilibrium in iron core transformer Tokamak HL-1M

International Nuclear Information System (INIS)

Chen Xiaoguang; Yuan Baoshan

1992-01-01

The physical and mathematical model are presented on the problem of MHD equilibrium with the self consistent in iron core transformer HL-1M. Calculation and analysis for the plasma equilibrium of the stable boundary and free boundary are shown respectively, in an axisymmetric equilibrium model of two dimensions. First, a variation formulation of the problem is written and the equations of the poloided flux ψ are solved by a finite element method; the Picard and Newton algorithms are tested for the non-linearities. The plasma boundary and the magnetic surfaces are being simulated, with the currents in the coils, the total plasma current, its current density function and the magnetic permeability of the iron being the data for the problem; a certain number of the characteristic parameter of the equilibrium configuration is calculated. Secondly, a simple method of calculation is adopted in the determination of equilibrium fields and currents in iron core HL-1M tokamak device. In the plasma equilibrium, the magnetic effect of the air gaps in the iron core and the iron magnetic shielded plate are considered in HL-1M device. Reliable data are provided for designing and constructing the poloidal field system of HL-1M device. A good computer code is constructed, which may be useful in operating on analysis for the future device

Iron Pole Shape Optimization of IPM Motors Using an Integrated Method

Directory of Open Access Journals (Sweden)

JABBARI, A.

2010-02-01

Full Text Available An iron pole shape optimization method to reduce cogging torque in Interior Permanent Magnet (IPM motors is developed by using the reduced basis technique coupled by finite element and design of experiments methods. Objective function is defined as the minimum cogging torque. The experimental design of Taguchi method is used to build the approximation model and to perform optimization. This method is demonstrated on the rotor pole shape optimization of a 4-poles/24-slots IPM motor.

Determination of Iron Content in Iron Deficiency Drugs by UV-Visible Spectrophotometer

Directory of Open Access Journals (Sweden)

Isam Eldin Hussein Elgailani

2017-07-01

Full Text Available The objective of this work was to validate a simple, precise and accurate spectrophotometric method for the determination of iron in the iron deficiency drugs, namely are Feroglobin B12, Ferose-F and Ferose. The proposed method is based on the reaction of iron with ammonium thiocyanate after the wet digestion of the drugs under study with HNO3 and H2O2.  Effects of pH, temperature, standing time and thiocyanate concentration on the determination of iron in drugs containing iron have been investigated. The λmax was 430 nm and the molar absorptivity of 0.0399 L mol-1 cm-1. The linear regression was in the range 0.5 - 60 μg/mL for iron content in hemoglobin. The detection limit and the limit of quantification were found to be 0.040 and 0.122 µg mL-1 for the iron respectively, and with a linear regression correlation coefficient of 0.998. Recovery measurements ranged from 99.63-100.20%. This method is simple and fast can be used for the determination of iron in the iron deficiency drugs in pharmaceutical laboratories. DOI: http://dx.doi.org/10.17807/orbital.v9i3.953

Measured and Predicted Neutron Flux Distributions in a Material Surrounding a Cylindrical Duct

Energy Technology Data Exchange (ETDEWEB)

Nilsson, J; Sandlin, R

1966-03-15

The radial fast neutron flux attenuations in the material (iron) surrounding ducts of diameters 7, 9, and 15 cm and total duct length of about 1.5 m have been investigated with and without neutron scattering cans filled with D{sub 2}O in the duct. Experimentally the problem was solved by the use of foil activation techniques. Theoretically it was attacked by, in the first place, a Monte Carlo program specially written for this purpose and utilizing an importance sampling technique. In the second place non- and single-scattering removal flux codes were tried, and also simple hand calculations. The Monte Carlo results accounted well for the fast flux attenuation, while the non- and single-scattering methods overestimated the attenuation generally by a factor of 10 or less. Simple hand calculations using three empirical parameters could be fitted to the measured data within a factor of 1.2 - 1.3 at penetration depths greater than 3 - 4 cm. The distribution of the D{sub 2}O-scattered flux could well be described in terms of single scattering.

Nuclear-physical methods of technical iron analysis

International Nuclear Information System (INIS)

Mukhamedshina, N.M.; Mirsagatova, A.A.; Usmanova, M.M.; Zinov'ev, V.G.

1998-01-01

The instrumental neutron-activation (INAA) techniques for detecting of regulated (Al, Si, P, S, Mn) and some metallic (Sc, V, Cr, Co, Ni, Cu, Zn, As, Mo, Sb, W) impurities in iron with 10 -3 - 10 -5 % discovering limits while using heat and resonance neutrons of nuclear reactor have been carried out. Elaborated INAA techniques have been used on all stages of obtaining of compact material. According to the results the efficient purification of iron is done almost from all mentioned impurities (impurities content in initial iron is 0,01 - 0,5 %), besides Si, Co, Ni, Cu, thus its content in final compact metal is not more than 0,001%. X-ray radiometrical technique of obtaining of Fe in Fe-containing materials with error not more than 1 - 3% has been carried out. (author)

Online In-Core Thermal Neutron Flux Measurement for the Validation of Computational Methods

International Nuclear Information System (INIS)

Mohamad Hairie Rabir; Muhammad Rawi Mohamed Zin; Yahya Ismail

2016-01-01

In order to verify and validate the computational methods for neutron flux calculation in RTP calculations, a series of thermal neutron flux measurement has been performed. The Self Powered Neutron Detector (SPND) was used to measure thermal neutron flux to verify the calculated neutron flux distribution in the TRIGA reactor. Measurements results obtained online for different power level of the reactor. The experimental results were compared to the calculations performed with Monte Carlo code MCNP using detailed geometrical model of the reactor. The calculated and measured thermal neutron flux in the core are in very good agreement indicating that the material and geometrical properties of the reactor core are modelled well. In conclusion one can state that our computational model describes very well the neutron flux distribution in the reactor core. Since the computational model properly describes the reactor core it can be used for calculations of reactor core parameters and for optimization of RTP utilization. (author)

Large flux change due to the intervening cold absorbers in NGC 3516

International Nuclear Information System (INIS)

Nogami, K.; Negoro, H.; Hong, S.; Mihara, T.

2004-01-01

NGC3516 in the low flux state shows a flat energy spectrum (photon index ∼1) and an intense narrow iron line. Such spectra are also observed in other Seyfert galaxies, and a broad bump structure around 6 keV above the 'flat' power-law spectrum has been interpreted as the gravitationally red-shifted iron line, disk reflection, or cold and/or warm absorbers. However, six years if BeppoSAX observations, including our latest three ones in 2001, clearly demonstrate that energy spectra above 20 keV always exhibit steep power-laws with photon indices ∼2, and the flux changes only by a factor of 2, while the soft X-ray flux by a factor of ∼10. From this fact, using BeppoSAX and ASCA data, we have concluded that the flat spectrum results from reprocessed, and partially covered power-laws with Γ∼1.8 by warm matter nearby the central source and a cold absorber moved in the line of sight, respectively, and that the broad iron line and disk reflection components are less significant than one ever thought. Thus, the long-term spectral variations can be considered by intervening absorbers rather than changes in the accretion rate

Growth of yttrium iron garnet single crystals in Na2O-B2O3 flux system in air

International Nuclear Information System (INIS)

Bandyopadhyay, Tarun; Saha, Prasenjit

1977-01-01

Detailed studies of growth of yttrium iron garnet (YIG) in the flux system Na 2 O-B 2 O 3 were made to delineate the phase stability regions of YIG and the neighbouring crystalline phases, and a tentative working diagram of Na 2 O-B 2 O 3 -YIG in air was drawn from the results of small batch crystal growth runs and solubility studies. The occurrence of a rather narrow field of YIG crystallization in this system was explained on the basis of relative solubilities of different oxides constituting YIG. Several long-time growth runs with some typical compositions were carried out in this system to evaluate its suitability for bulk growth of YIG crystals. The system, although possessing some inherent advantages, was found to suffer from limitations because the maximum size of the self-nucleated crystals grown hardly exceeded 2.00 mm. (author)

Genomic insights into microbial iron oxidation and iron uptake strategies in extremely acidic environments.

Science.gov (United States)

Bonnefoy, Violaine; Holmes, David S

2012-07-01

This minireview presents recent advances in our understanding of iron oxidation and homeostasis in acidophilic Bacteria and Archaea. These processes influence the flux of metals and nutrients in pristine and man-made acidic environments such as acid mine drainage and industrial bioleaching operations. Acidophiles are also being studied to understand life in extreme conditions and their role in the generation of biomarkers used in the search for evidence of existing or past extra-terrestrial life. Iron oxidation in acidophiles is best understood in the model organism Acidithiobacillus ferrooxidans. However, recent functional genomic analysis of acidophiles is leading to a deeper appreciation of the diversity of acidophilic iron-oxidizing pathways. Although it is too early to paint a detailed picture of the role played by lateral gene transfer in the evolution of iron oxidation, emerging evidence tends to support the view that iron oxidation arose independently more than once in evolution. Acidic environments are generally rich in soluble iron and extreme acidophiles (e.g. the Leptospirillum genus) have considerably fewer iron uptake systems compared with neutrophiles. However, some acidophiles have been shown to grow as high as pH 6 and, in the case of the Acidithiobacillus genus, to have multiple iron uptake systems. This could be an adaption allowing them to respond to different iron concentrations via the use of a multiplicity of different siderophores. Both Leptospirillum spp. and Acidithiobacillus spp. are predicted to synthesize the acid stable citrate siderophore for Fe(III) uptake. In addition, both groups have predicted receptors for siderophores produced by other microorganisms, suggesting that competition for iron occurs influencing the ecophysiology of acidic environments. Little is known about the genetic regulation of iron oxidation and iron uptake in acidophiles, especially how the use of iron as an energy source is balanced with its need to take up

A Family of Multipoint Flux Mixed Finite Element Methods for Elliptic Problems on General Grids

KAUST Repository

Wheeler, Mary F.

2011-01-01

In this paper, we discuss a family of multipoint flux mixed finite element (MFMFE) methods on simplicial, quadrilateral, hexahedral, and triangular-prismatic grids. The MFMFE methods are locally conservative with continuous normal fluxes, since they are developed within a variational framework as mixed finite element methods with special approximating spaces and quadrature rules. The latter allows for local flux elimination giving a cell-centered system for the scalar variable. We study two versions of the method: with a symmetric quadrature rule on smooth grids and a non-symmetric quadrature rule on rough grids. Theoretical and numerical results demonstrate first order convergence for problems with full-tensor coefficients. Second order superconvergence is observed on smooth grids. © 2011 Published by Elsevier Ltd.

Standard Test Method for Measuring Heat Flux Using Flush-Mounted Insert Temperature-Gradient Gages

CERN Document Server

American Society for Testing and Materials. Philadelphia

2009-01-01

1.1 This test method describes the measurement of the net heat flux normal to a surface using gages inserted flush with the surface. The geometry is the same as heat-flux gages covered by Test Method E 511, but the measurement principle is different. The gages covered by this standard all use a measurement of the temperature gradient normal to the surface to determine the heat that is exchanged to or from the surface. Although in a majority of cases the net heat flux is to the surface, the gages operate by the same principles for heat transfer in either direction. 1.2 This general test method is quite broad in its field of application, size and construction. Two different gage types that are commercially available are described in detail in later sections as examples. A summary of common heat-flux gages is given by Diller (1). Applications include both radiation and convection heat transfer. The gages used for aerospace applications are generally small (0.155 to 1.27 cm diameter), have a fast time response ...

Comparison of methods for measuring flux gradients in type II superconductors

International Nuclear Information System (INIS)

Kroeger, D.M.; Koch, C.C.; Charlesworth, J.P.

1975-01-01

A comparison has been made of four methods of measuring the critical current density J/sub c/ in hysteretic type II superconductors, having a wide range of K and J/sub c/ values, in magnetic fields up to 70 kOe. Two of the methods, (a) resistive measurements and (b) magnetization measurements, were carried out in static magnetic fields. The other two methods involved analysis of the response of the sample to a small alternating field superimposed on the static field. The response was analyzed either (c) by measuring the third-harmonic content or (d) by integration of the waveform to obtain measure of flux penetration. The results are discussed with reference to the agreement between the different techniques and the consistency of the critical state hypothesis on which all these techniques are based. It is concluded that flux-penetration measurements by method (d) provide the most detailed information about J/sub c/ but that one must be wary of minor failures of the critical state hypothesis. Best results are likely to be obtained by using more than one method. (U.S.)

A Method for the neutron flux determination during the activation process

International Nuclear Information System (INIS)

Maayouf, R.M.A.; Khalil, M.I.

2000-01-01

The present work deals with an accurate method for determining the neutron flux coming out from a neutron source during the experimental measurements. Accordingly, a suitable detector, followed by preamplifier and amplifier, is connected to a data acquisition system designed specially for this purpose; and the number of neutrons detected during every sampling period is stored in the PC. The historical file can be used to compute the average or the integral flux during any time period; considering the detector efficiency, geometrical arrangement and the amplification gain

Neutron Flux Interpolation with Finite Element Method in the Nuclear Fuel Cell Calculation using Collision Probability Method

International Nuclear Information System (INIS)

Shafii, M. Ali; Su'ud, Zaki; Waris, Abdul; Kurniasih, Neny; Ariani, Menik; Yulianti, Yanti

2010-01-01

Nuclear reactor design and analysis of next-generation reactors require a comprehensive computing which is better to be executed in a high performance computing. Flat flux (FF) approach is a common approach in solving an integral transport equation with collision probability (CP) method. In fact, the neutron flux distribution is not flat, even though the neutron cross section is assumed to be equal in all regions and the neutron source is uniform throughout the nuclear fuel cell. In non-flat flux (NFF) approach, the distribution of neutrons in each region will be different depending on the desired interpolation model selection. In this study, the linear interpolation using Finite Element Method (FEM) has been carried out to be treated the neutron distribution. The CP method is compatible to solve the neutron transport equation for cylindrical geometry, because the angle integration can be done analytically. Distribution of neutrons in each region of can be explained by the NFF approach with FEM and the calculation results are in a good agreement with the result from the SRAC code. In this study, the effects of the mesh on the k eff and other parameters are investigated.

Method to eliminate flux linkage DC component in load transformer for static transfer switch.

Science.gov (United States)

He, Yu; Mao, Chengxiong; Lu, Jiming; Wang, Dan; Tian, Bing

2014-01-01

Many industrial and commercial sensitive loads are subject to the voltage sags and interruptions. The static transfer switch (STS) based on the thyristors is applied to improve the power quality and reliability. However, the transfer will result in severe inrush current in the load transformer, because of the DC component in the magnetic flux generated in the transfer process. The inrush current which is always 2 ~ 30 p.u. can cause the disoperation of relay protective devices and bring potential damage to the transformer. The way to eliminate the DC component is to transfer the related phases when the residual flux linkage of the load transformer and the prospective flux linkage of the alternate source are equal. This paper analyzes how the flux linkage of each winding in the load transformer changes in the transfer process. Based on the residual flux linkage when the preferred source is completely disconnected, the method to calculate the proper time point to close each phase of the alternate source is developed. Simulation and laboratory experiments results are presented to show the effectiveness of the transfer method.

Reconciling PM10 analyses by different sampling methods for Iron King Mine tailings dust.

Science.gov (United States)

Li, Xu; Félix, Omar I; Gonzales, Patricia; Sáez, Avelino Eduardo; Ela, Wendell P

2016-03-01

The overall project objective at the Iron King Mine Superfund site is to determine the level and potential risk associated with heavy metal exposure of the proximate population emanating from the site's tailings pile. To provide sufficient size-fractioned dust for multi-discipline research studies, a dust generator was built and is now being used to generate size-fractioned dust samples for toxicity investigations using in vitro cell culture and animal exposure experiments as well as studies on geochemical characterization and bioassay solubilization with simulated lung and gastric fluid extractants. The objective of this study is to provide a robust method for source identification by comparing the tailing sample produced by dust generator and that collected by MOUDI sampler. As and Pb concentrations of the PM10 fraction in the MOUDI sample were much lower than in tailing samples produced by the dust generator, indicating a dilution of Iron King tailing dust by dust from other sources. For source apportionment purposes, single element concentration method was used based on the assumption that the PM10 fraction comes from a background source plus the Iron King tailing source. The method's conclusion that nearly all arsenic and lead in the PM10 dust fraction originated from the tailings substantiates our previous Pb and Sr isotope study conclusion. As and Pb showed a similar mass fraction from Iron King for all sites suggesting that As and Pb have the same major emission source. Further validation of this simple source apportionment method is needed based on other elements and sites.

Development of Coincidence Method for Determination Thermal Neutron Flux on RSG-GAS

International Nuclear Information System (INIS)

Bakhri, Syaiful; Hamzah, Amir

2004-01-01

The research to develop detection radiation system using coincidence method has been done to determine thermal neutron flux in RS1 and RS2 irradiation facilities RSG-GAS. At this research has arranged beta-gamma coincidence equipment system and parameter of measurement according to Au-198 beta-gamma spectrum. Gold foils that have irradiated for period of time, counted, and the activities of radiation is analyzed to get neutron flux. Result of research indicate that systems measurement of absolute activity with gamma beta coincidence method functioning well and can be applied at activity measurement of gold foil for irradiation facility characterization. The results show that thermal neutron flux in RS1 and RS2, respectively is 2.007E+12 n/cm 2 s and 2.147E+12 n/cm 2 s. To examine the system performance, the result was compared to measure activity using high resolution of Hp Ge detector and achieved discrepancy is about 1.26% and 6.70%. (author)

Ductile cast iron obtaining by Inmold method with use of LOST FOAM process

Directory of Open Access Journals (Sweden)

T. Pacyniak

2010-01-01

Full Text Available The possibility of manufacturing of ductile cast iron castings by Inmold method with use of LOST FOAM process was presented in this work. The spheroidization was carried out by magnesium master alloy in amounts of 1% casting mass. Nodulizer was located in the reactive chamber in the gating system made of foamed polystyrene. Pretests showed, that there are technical possibilities of manufacturing of casts from ductile cast iron in the LOST FOAM process with use of spheroidization in mould.

A multigrid Newton-Krylov method for flux-limited radiation diffusion

International Nuclear Information System (INIS)

Rider, W.J.; Knoll, D.A.; Olson, G.L.

1998-01-01

The authors focus on the integration of radiation diffusion including flux-limited diffusion coefficients. The nonlinear integration is accomplished with a Newton-Krylov method preconditioned with a multigrid Picard linearization of the governing equations. They investigate the efficiency of the linear and nonlinear iterative techniques

A simplified method for determination of radioactive iron in whole-blood samples

DEFF Research Database (Denmark)

Bukhave, Klaus; Sørensen, Anne Dorthe; Hansen, M.

2001-01-01

in humans. The overall recovery of radioiron from blood is more than 90%, and the coefficient of variation, as judged by the variation in the ratio Fe-55/Fe-59 is in the order of 4%. Combined with whole-body counting of 59Fe and direct gamma -counting of Fe-59 on blood samples, this method represents......For studies on iron absorption in man radioisotopes represent an easy and simple tool. However, measurement of the orbital electron emitting radioiron, Fe-55, in blood is difficult and insufficiently described in the literature. The present study describes a relatively simple method...... for simultaneous determination of Fe-55 and Fe-59 in blood, using a dry-ashing procedure and recrystallization of the remaining iron. The detection Limit of the method permits measurements of 0.1 Bq/ml blood thus allowing detection of Less than 1% absorption from a 40 kBq dose, which is ethically acceptable...

Higher iron bioavailability of a human-like collagen iron complex.

Science.gov (United States)

Zhu, Chenhui; Yang, Fan; Fan, Daidi; Wang, Ya; Yu, Yuanyuan

2017-07-01

Iron deficiency remains a public health problem around the world due to low iron intake and/or bioavailability. FeSO 4 , ferrous succinate, and ferrous glycinate chelate are rich in iron but have poor bioavailability. To solve the problem of iron deficiency, following previous research studies, a thiolated human-like collagen-ironcomplex supplement with a high iron content was prepared in an anaerobic workstation. In addition, cell viability tests were evaluated after conducting an MTT assay, and a quantitative analysis of the thiolated human-like collagen-iron digesta samples was performed using the SDS-PAGE method coupled with gel filtration chromatography. The iron bioavailability was assessed using Caco-2 cell monolayers and iron-deficiency anemia mice models. The results showed that (1) one mole of thiolated human-like collagen-iron possessed approximately 35.34 moles of iron; (2) thiolated human-like collagen-iron did not exhibit cytotoxity and (3) thiolated human-like collagen- iron digesta samples had higher bioavailability than other iron supplements, including FeSO 4 , ferrous succinate, ferrous glycine chelate and thiolated human-like collagen-Fe iron. Finally, the iron bioavailability was significantly enhanced by vitamin C. These results indicated that thiolated human-like collagen-iron is a promising iron supplement for use in the future.

Carbonate counter pump stimulated by natural iron fertilization in the Polar Frontal Zone

Science.gov (United States)

Salter, Ian; Schiebel, Ralf; Ziveri, Patrizia; Movellan, Aurore; Lampitt, Richard; Wolff, George A.

2014-12-01

The production of organic carbon in the ocean's surface and its subsequent downward export transfers carbon dioxide to the deep ocean. This CO2 drawdown is countered by the biological precipitation of carbonate, followed by sinking of particulate inorganic carbon, which is a source of carbon dioxide to the surface ocean, and hence the atmosphere over 100-1,000 year timescales. The net transfer of CO2 to the deep ocean is therefore dependent on the relative amount of organic and inorganic carbon in sinking particles. In the Southern Ocean, iron fertilization has been shown to increase the export of organic carbon, but it is unclear to what degree this effect is compensated by the export of inorganic carbon. Here we assess the composition of sinking particles collected from sediment traps located in the Polar Frontal Zone of the Southern Ocean. We find that in high-nutrient, low-chlorophyll regions that are characterized by naturally high iron concentrations, fluxes of both organic and inorganic carbon are higher than in regions with no iron fertilization. However, the excess flux of inorganic carbon is greater than that of organic carbon. We estimate that the production and flux of carbonate in naturally iron-fertilized waters reduces the overall amount of CO2 transferred to the deep ocean by 6-32%, compared to 1-4% at the non-fertilized site. We suggest that an increased export of organic carbon, stimulated by iron availability in the glacial sub-Antarctic oceans, may have been accompanied by a strengthened carbonate counter pump.

Influencing factors and kinetics analysis on the leaching of iron from boron carbide waste-scrap with ultrasound-assisted method.

Science.gov (United States)

Li, Xin; Xing, Pengfei; Du, Xinghong; Gao, Shuaibo; Chen, Chen

2017-09-01

In this paper, the ultrasound-assisted leaching of iron from boron carbide waste-scrap was investigated and the optimization of different influencing factors had also been performed. The factors investigated were acid concentration, liquid-solid ratio, leaching temperature, ultrasonic power and frequency. The leaching of iron with conventional method at various temperatures was also performed. The results show the maximum iron leaching ratios are 87.4%, 94.5% for 80min-leaching with conventional method and 50min-leaching with ultrasound assistance, respectively. The leaching of waste-scrap with conventional method fits the chemical reaction-controlled model. The leaching with ultrasound assistance fits chemical reaction-controlled model, diffusion-controlled model for the first stage and second stage, respectively. The assistance of ultrasound can greatly improve the iron leaching ratio, accelerate the leaching rate, shorten leaching time and lower the residual iron, comparing with conventional method. The advantages of ultrasound-assisted leaching were also confirmed by the SEM-EDS analysis and elemental analysis of the raw material and leached solid samples. Copyright © 2017 Elsevier B.V. All rights reserved.

The obtaining of iron acetate from processed iron comprising catalyst of ammonia synthesis

International Nuclear Information System (INIS)

Mansurov, M.M.; Lugovenko, A.N.; Mirzoeva, M.M.

1993-01-01

Present article is devoted to obtaining of iron acetate from processed iron comprising catalyst of ammonia synthesis. The method of synthesis of iron acetate from processed iron comprising catalyst of ammonia synthesis was elaborated. The structure of complex was determined.

Cast iron repair method of stitching pin

International Nuclear Information System (INIS)

Yun, In Sik; Yu, Yeong Chul; Kim, Steve S.; Reed, Gary J.

2003-01-01

Many cast iron parts are welded and suffer from improper pre-heating and poor welding skills which destroy the castings due to new cracks, deformations etc. This is due mainly to the lack of understanding of the properties of cast iron. Welding, however impractical, was the only alternative for many years. Locks are used to add strength across a crack. Special drilling jigs are used to create a precise hole pattern that locks are driven into. Our locks have a unique ability to pull the sides of a crack together. Bottom locks are stacked or laminated to a depth of 80% of the casting thickness. Thicker surface locks finish off lock installation, allowing repairs in irregular shapes and contours. Installing products can be done quickly with pneumatic tools. Up to one inch of repair can be done in 5 minutes in 1/4 inch thick cast iron.

Improved collision probability method for thermal-neutron-flux calculation in a cylindrical reactor cell

International Nuclear Information System (INIS)

Bosevski, T.

1986-01-01

An improved collision probability method for thermal-neutron-flux calculation in a cylindrical reactor cell has been developed. Expanding the neutron flux and source into a series of even powers of the radius, one' gets a convenient method for integration of the one-energy group integral transport equation. It is shown that it is possible to perform an analytical integration in the x-y plane in one variable and to use the effective Gaussian integration over another one. Choosing a convenient distribution of space points in fuel and moderator the transport matrix calculation and cell reaction rate integration were condensed. On the basis of the proposed method, the computer program DISKRET for the ZUSE-Z 23 K computer has been written. The suitability of the proposed method for the calculation of the thermal-neutron-flux distribution in a reactor cell can be seen from the test results obtained. Compared with the other collision probability methods, the proposed treatment excels with a mathematical simplicity and a faster convergence. (author)

Formulation of the relationship between indices of neutron-gamma and gamma-gamma method and the percentrage of iron

International Nuclear Information System (INIS)

Majorowicz, J.

1973-01-01

In this article, the author presents the possibility of a complex utilization of radiometric logging methods, neutron-gamma profiling and gamma-gamma density logging for determining percentage of iron and establishing geophysical possibilities of identifying zones of economically profitable ores in borehole profiles. Figures present the correlations between indices of neutron-gamma and gamma-gamma logging methods and the percentage of iron, as well as the correlation of neutron-gamma and gamma-gamma indices for zones minerallized with iron ores. The article presents the correlational analyses of the results: the correlational coefficients are given as well as total error in determining iron content on the basis of each of the methods described. Next, a multidimensional statistical analysis is carried out on the results obtained. On the basis of the two-dimensional correlational coefficients calculated and the average standard deviation, an equation of linear regression was formulated, simultaneously involving three parameters - the indices of neutron-gamma and gamma-gamma logging and the percentage of iron. The multiple correlational coefficient obtained markedly exceeds the two-dimentional correlation coefficient (r=0.974>rsub(xz)>rsub(yz)>rsub(xy)). The given method of utilizing multidimensional statistics in borehole geophysics for identifying iron ores is an efficient one. On the basis of several relationships among independent variables which are less obvious (smaller values of correlational coefficient), it is possible to obtain a single distinct relationship involving all variables simultaneously. (author)

Effect of atmospheric organic complexation on iron-bearing dust solubility

OpenAIRE

Paris , R.; Desboeufs , K. V.

2013-01-01

International audience; Recent studies reported that the effect of organic complexation may be a potentially important process to be considered by models estimating atmospheric iron flux to the ocean. In this study, we investigated this process effect by a series of dissolution experiments on iron-bearing dust in the presence or the absence of various organic compounds (acetate, formate, oxalate, malonate, succinate, glutarate, glycolate, lactate, tartrate and humic acid as an analogue of hum...

Iron status in Danish women, 1984-1994: a cohort comparison of changes in iron stores and the prevalence of iron deficiency and iron overload

DEFF Research Database (Denmark)

Milman, N.; Byg, K.E.; Ovesen, Lars

2003-01-01

Background and objectives: From 1954 to 1986, flour in Denmark was fortified with 30 mg carbonyl iron per kilogram. This mandatory enrichment of cereal products was abolished in 1987. The aim was to evaluate iron status in the Danish female population before and after abolishment of iron...... fortification. Methods: Iron status, serum ferritin and haemoglobin, was assessed in population surveys in 1983-1984 comprising 1221 Caucasian women (1089 non-blood-donors, 130 donors) and in 1993-1994 comprising 1261 women (1155 non-blood-donors, 104 donors) equally distributed in age cohorts of 40, 50, 60......, postmenopausal women had median ferritin of 75 mug/L and in 1994 of 93 mug/L (P iron stores (ferritin iron stores (ferritin less...

Iron colloids reduce the bioavailability of phosphorus to the green alga Raphidocelis subcapitata.

Science.gov (United States)

Baken, Stijn; Nawara, Sophie; Van Moorleghem, Christoff; Smolders, Erik

2014-08-01

Phosphorus (P) is a limiting nutrient in many aquatic systems. The bioavailability of P in natural waters strongly depends on its speciation. In this study, structural properties of iron colloids were determined and related to their effect on P sorption and P bioavailability. The freshwater green alga Raphidocelis subcapitata was exposed to media spiked with radiolabelled (33)PO4, and the uptake of (33)P was monitored for 1 h. The media contained various concentrations of synthetic iron colloids with a size between 10 kDa and 0.45 μm. The iron colloids were stabilised by natural organic matter. EXAFS spectroscopy showed that these colloids predominantly consisted of ferrihydrite with small amounts of organically complexed Fe. In colloid-free treatments, the P uptake flux by the algae obeyed Michaelis-Menten kinetics. In the presence of iron colloids at 9 or 90 μM Fe, corresponding to molar P:Fe ratios between 0.02 and 0.17, the truly dissolved P (<10 kDa) was between 4 and 60% of the total dissolved P (<0.45 μm). These colloids reduced the P uptake flux by R. subcapitata compared to colloid-free treatments at the same total dissolved P concentration. However, the P uptake flux from colloid containing solutions equalled that from colloid-free ones when expressed as truly dissolved P. This demonstrates that colloidal P did not contribute to the P uptake flux. It is concluded that, on the short term, phosphate adsorbed to ferrihydrite colloids is not available to the green alga R. subcapitata. Copyright © 2014 Elsevier Ltd. All rights reserved.

A new method for simultaneous measurement of convective and radiative heat flux in car underhood applications

International Nuclear Information System (INIS)

Khaled, M; Garnier, B; Peerhossaini, H; Harambat, F

2010-01-01

A new experimental technique is presented that allows simultaneous measurement of convective and radiative heat flux in the underhood. The goal is to devise an easily implemented and accurate experimental method for application in the vehicle underhood compartment. The new method is based on a technique for heat-flux measurement developed by the authors (Heat flow (flux) sensors for measurement of convection, conduction and radiation heat flow 27036-2, © Rhopoint Components Ltd, Hurst Green, Oxted, RH8 9AX, UK) that uses several thermocouples in the thickness of a thermal resistive layer (foil heat-flux sensor). The method proposed here uses a pair of these thermocouples with different radiative properties. Measurements validating this novel technique are carried out on a flat plate with a prescribed constant temperature in both natural- and forced-convection flow regimes. The test flat plate is instrumented by this new technique, and also with a different technique that is intrusive but very accurate, used as reference here (Bardon J P and Jarny Y 1994 Procédé et dispositif de mesure transitoire de température et flux surfacique Brevet n°94.011996, 22 February). Discrepancies between the measurements by the two techniques are less than 10% for both convective and radiative heat flux. Error identification and sensitivity analysis of the new method are also presented

Proposal for a new method of reactor neutron flux distribution determination

Energy Technology Data Exchange (ETDEWEB)

Popic, V R [Institute of nuclear sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1964-01-15

A method, based on the measurements of the activity produced in a medium flowing with variable velocity through a reactor, for the determination of the neutron flux distribution inside a reactor is considered theoretically (author)

Methods to assess high-resolution subsurface gas concentrations and gas fluxes in wetland ecosystems

DEFF Research Database (Denmark)

Elberling, Bo; Kühl, Michael; Glud, Ronnie Nøhr

2013-01-01

The need for measurements of soil gas concentrations and surface fluxes of greenhouse gases at high temporal and spatial resolution in wetland ecosystem has lead to the introduction of several new analytical techniques and methods. In addition to the automated flux chamber methodology for high-re...

Method and Apparatus of Implementing a Magnetic Shield Flux Sweeper

Science.gov (United States)

Sadleir, John E. (Inventor)

2018-01-01

The present invention relates to a method and apparatus of protecting magnetically sensitive devices with a shield, including: a non-superconducting metal or lower transition temperature (T.sub.c) material compared to a higher transition temperature material, disposed in a magnetic field; means for creating a spatially varying order parameter's |.PSI.(r,T)|.sup.2 in a non-superconducting metal or a lower transition temperature material; wherein a spatially varying order parameter is created by a proximity effect, such that the non-superconducting metal or the lower transition temperature material becomes superconductive as a temperature is lowered, creating a flux-free Meissner state at a center thereof, in order to sweep magnetic flux lines to the periphery.

A study on the fabrication of superhydrophobic iron surfaces by chemical etching and galvanic replacement methods and their anti-icing properties

Energy Technology Data Exchange (ETDEWEB)

Li, Kunquan, E-mail: likunquan1987@gmail.com; Zeng, Xingrong, E-mail: psxrzeng@gmail.com; Li, Hongqiang, E-mail: hqli1979@gmail.com; Lai, Xuejun, E-mail: msxjlai@scut.edu.cn

2015-08-15

Graphical abstract: - Highlights: • Superhydrophobic iron surfaces were prepared by etching and replacement method. • The fabrication process was simple, time-saving and inexpensive. • Galvanic replacement method was more favorable to create roughness on iron surface. • The superhydrophobic iron surface showed excellent anti-icing properties. - Abstract: Hierarchical structures on iron surfaces were constructed by means of chemical etching by hydrochloric acid (HCl) solution or the galvanic replacement by silver nitrate (AgNO{sub 3}) solution. The superhydrophobic iron surfaces were successfully prepared by subsequent hydrophobic modification with stearic acid. The superhydrophobic iron surfaces were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and water contact angle (WCA). The effects of reactive concentration and time on the microstructure and the wetting behavior were investigated. In addition, the anti-icing properties of the superhydrophobic iron surfaces were also studied. The FTIR study showed that the stearic acid was chemically bonded onto the iron surface. With the HCl concentration increase from 4 mol/L to 8 mol/L, the iron surface became rougher with a WCA ranging from 127° to 152°. The AgNO{sub 3} concentration had little effect on the wetting behavior, but a high AgNO{sub 3} concentration caused Ag particle aggregates to transform from flower-like formations into dendritic crystals, owing to the preferential growth direction of the Ag particles. Compared with the etching method, the galvanic replacement method on the iron surface more favorably created roughness required for achieving superhydrophobicity. The superhydrophobic iron surface showed excellent anti-icing properties in comparison with the untreated iron. The icing time of water droplets on the superhydrophobic surface was delayed to 500 s, which was longer than that of 295 s for

Changes in serum iron, total iron binding capacity and transferrin ...

African Journals Online (AJOL)

Background: Iron is a vital constituent of cells but in excess may be harmful and is associated with a raised risk for some malignant diseases including breast cancer. We aimed to study changes in iron profile in Sudanese females newly diagnosed with breast cancer. Methods: A case- control study in which serum iron, Total ...

Neutron flux calculation by means of Monte Carlo methods

International Nuclear Information System (INIS)

Barz, H.U.; Eichhorn, M.

1988-01-01

In this report a survey of modern neutron flux calculation procedures by means of Monte Carlo methods is given. Due to the progress in the development of variance reduction techniques and the improvements of computational techniques this method is of increasing importance. The basic ideas in application of Monte Carlo methods are briefly outlined. In more detail various possibilities of non-analog games and estimation procedures are presented, problems in the field of optimizing the variance reduction techniques are discussed. In the last part some important international Monte Carlo codes and own codes of the authors are listed and special applications are described. (author)

Coal fly ash as a source of iron in atmospheric dust.

Science.gov (United States)

Chen, Haihan; Laskin, Alexander; Baltrusaitis, Jonas; Gorski, Christopher A; Scherer, Michelle M; Grassian, Vicki H

2012-02-21

Anthropogenic coal fly ash (FA) aerosol may represent a significant source of bioavailable iron in the open ocean. Few measurements have been made that compare the solubility of atmospheric iron from anthropogenic aerosols and other sources. We report here an investigation of iron dissolution for three FA samples in acidic aqueous solutions and compare the solubilities with that of Arizona test dust (AZTD), a reference material for mineral dust. The effects of pH, simulated cloud processing, and solar radiation on iron solubility have been explored. Similar to previously reported results on mineral dust, iron in aluminosilicate phases provides the predominant component of dissolved iron. Iron solubility of FA is substantially higher than of the crystalline minerals comprising AZTD. Simulated atmospheric processing elevates iron solubility due to significant changes in the morphology of aluminosilicate glass, a dominant material in FA particles. Iron is continuously released into the aqueous solution as FA particles break up into smaller fragments. These results suggest that the assessment of dissolved atmospheric iron deposition fluxes and their effect on the biogeochemistry at the ocean surface should be constrained by the source, environmental pH, iron speciation, and solar radiation.

Current superimposition variable flux reluctance motor with 8 salient poles

Science.gov (United States)

Takahara, Kazuaki; Hirata, Katsuhiro; Niguchi, Noboru; Kohara, Akira

2017-12-01

We propose a current superimposition variable flux reluctance motor for a traction motor of electric vehicles and hybrid electric vehicles, which consists of 10 salient poles in the rotor and 12 slots in the stator. However, iron losses of this motor in high rotation speed ranges is large because the number of salient poles is large. In this paper, we propose a current superimposition variable flux reluctance motor that consists of 8 salient poles and 12 slots. The characteristics of the 10-pole-12-slot and 8-pole-12-slot current superimposition variable flux reluctance motors are compared using finite element analysis under vector control.

Current superimposition variable flux reluctance motor with 8 salient poles

Directory of Open Access Journals (Sweden)

Takahara Kazuaki

2017-12-01

Full Text Available We propose a current superimposition variable flux reluctance motor for a traction motor of electric vehicles and hybrid electric vehicles, which consists of 10 salient poles in the rotor and 12 slots in the stator. However, iron losses of this motor in high rotation speed ranges is large because the number of salient poles is large. In this paper, we propose a current superimposition variable flux reluctance motor that consists of 8 salient poles and 12 slots. The characteristics of the 10-pole-12-slot and 8-pole-12-slot current superimposition variable flux reluctance motors are compared using finite element analysis under vector control.

One step paired electrochemical synthesis of iron and iron oxide nanoparticles

Directory of Open Access Journals (Sweden)

Ordoukhanian Juliet

2016-09-01

Full Text Available In this study, a new one step paired electrochemical method is developed for simultaneous synthesis of iron and iron oxide nanoparticles. iron and iron oxide are prepared as cathodic and anodic products from iron (ii sulfate aqueous solution in a membrane divided electrolytic cell by the pulsed current electrosynthesis. Because of organic solvent-free and electrochemical nature of the synthesis, the process could be considered as green and environmentally friendly. The reduction of energy consumption and low cost are the other significant advantages of this new method that would have a great application potential in the chemical industry. The nanostructure of prepared samples was characterized by Fourier transform infrared spectroscopy (FT-IR, X-ray diffraction (XRD, scanning electron microscopy (SEM and transmission electron microscopy (TEM. The magnetic properties were studied by vibrating sample magnetometer (VsM.

Transfer matrix method for four-flux radiative transfer.

Science.gov (United States)

Slovick, Brian; Flom, Zachary; Zipp, Lucas; Krishnamurthy, Srini

2017-07-20

We develop a transfer matrix method for four-flux radiative transfer, which is ideally suited for studying transport through multiple scattering layers. The model predicts the specular and diffuse reflection and transmission of multilayer composite films, including interface reflections, for diffuse or collimated incidence. For spherical particles in the diffusion approximation, we derive closed-form expressions for the matrix coefficients and show remarkable agreement with numerical Monte Carlo simulations for a range of absorption values and film thicknesses, and for an example multilayer slab.

A method for neutron dosimetry in ultrahigh flux environments

International Nuclear Information System (INIS)

Ougouag, A.M.; Wemple, C.A.; Rogers, J.W.

1996-01-01

A method for neutron dosimetry in ultrahigh flux environments is developed, and devices embodying it are proposed and simulated using a Monte Carlo code. The new approach no longer assumes a linear relationship between the fluence and the activity of the nuclides formed by irradiation. It accounts for depletion of the original ''foil'' material and for decay and depletion of the formed nuclides. In facilities where very high fluences are possible, the fluences inferred by activity measurements may be ambiguous. A method for resolving these ambiguities is also proposed and simulated. The new method and proposed devices should make possible the use of materials not traditionally considered desirable for neutron activation dosimetry

A method for the determination of ascorbic acid using the iron(II)-pyridine-dimethylglyoxime complex

International Nuclear Information System (INIS)

Arya, S. P.; Mahajan, M.

1998-01-01

A simple and rapid spectrophotometric method for the determination of ascorbic acid is proposed. Ascorbic acid reduces iron (III) to iron (II) which forms a red colored complex with dimethylglyoxime in the presence of pyridine. The absorbance of the resulting solution is measured at 514 nm and a linear relationship between absorbance and concentration of ascorbic acid is observed up to 14 μg ml -1 . Studies on the interference of substances usually associated with ascorbic acid have been carried out and the applicability of the method has been tested by analysing pharmaceutical preparations of vitamin C [it

Iron interference in arsenic absorption by different plant species, analysed by neutron activation, k0-method

International Nuclear Information System (INIS)

Uemura, George; Matos, Ludmila Vieira da Silva; Silva, Maria Aparecida da; Menezes, Maria Angela de Barros Correia

2009-01-01

Natural arsenic contamination is a cause for concern in many countries of the world including Argentina, Bangladesh, Chile, China, India, Mexico, Thailand, United States of America and also in Brazil, specially in the Iron Quadrangle area, where mining activities have been contributing to aggravate natural contamination. Among other elements, iron is capable to interfere with the arsenic absorption by plants; iron ore has been proposed to remediate areas contaminated by the mentioned metalloid. In order to verify if iron can interfere with arsenic absorption by different taxa of plants, specimens of Brassicacea and Equisetaceae were kept in a 1/4 Murashige and Skoog basal salt solution (M and S), with 10 μgL -1 of arsenic acid. And varying concentrations of iron. The specimens were analysed by neutron activation analysis, k 0 -method, a routine technique in CDTN, and also very appropriate for arsenic studies. The preliminary results were quite surprising, showing that iron can interfere with arsenic absorption by plants, but in different ways, according to the species studied. (author)

Monte Carlo methods for flux expansion solutions of transport problems

International Nuclear Information System (INIS)

Spanier, J.

1999-01-01

Adaptive Monte Carlo methods, based on the use of either correlated sampling or importance sampling, to obtain global solutions to certain transport problems have recently been described. The resulting learning algorithms are capable of achieving geometric convergence when applied to the estimation of a finite number of coefficients in a flux expansion representation of the global solution. However, because of the nonphysical nature of the random walk simulations needed to perform importance sampling, conventional transport estimators and source sampling techniques require modification to be used successfully in conjunction with such flux expansion methods. It is shown how these problems can be overcome. First, the traditional path length estimators in wide use in particle transport simulations are generalized to include rather general detector functions (which, in this application, are the individual basis functions chosen for the flus expansion). Second, it is shown how to sample from the signed probabilities that arise as source density functions in these applications, without destroying the zero variance property needed to ensure geometric convergence to zero error

Corrosion behavior of austempered ductile iron (ADI) in iron ore slurry

African Journals Online (AJOL)

Corrosion behavior of austempered ductile iron (ADI) in iron ore slurry was studied as a function of the microstructure developed by austempering at 380 and 300°C for different exposure time in the slurry. The corrosion rates of the ADI balls immersed in the iron ore slurry was determined using weight loss method.

The Janus face of iron on anoxic worlds: iron oxides are both protective and destructive to life on the early Earth and present-day Mars.

Science.gov (United States)

Wadsworth, Jennifer; Cockell, Charles S

2017-05-01

The surface of the early Earth was probably subjected to a higher flux of ultraviolet (UV) radiation than today. UV radiation is known to severely damage DNA and other key molecules of life. Using a liquid culture and a rock analogue system, we investigated the interplay of protective and deleterious effects of iron oxides under UV radiation on the viability of the model organism, Bacillus subtilis. In the presence of hydrogen peroxide, there exists a fine balance between iron oxide's protective effects against this radiation and its deleterious effects caused by Photo-Fenton reactions. The maximum damage was caused by a concentration of hematite of ∼1 mg/mL. Concentrations above this confer increasing protection by physical blockage of the UV radiation, concentrations below this cause less effective UV radiation blockage, but also a correspondingly less effective Photo-Fenton reaction, providing an overall advantage. These results show that on anoxic worlds, surface habitability under a high UV flux leaves life precariously poised between the beneficial and deleterious effects of iron oxides. These results have relevance to the Archean Earth, but also the habitability of the Martian surface, where high levels of UV radiation in combination with iron oxides and hydrogen peroxide can be found. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A New Energy-Based Method for 3-D Finite-Element Nonlinear Flux Linkage computation of Electrical Machines

DEFF Research Database (Denmark)

Lu, Kaiyuan; Rasmussen, Peter Omand; Ritchie, Ewen

2011-01-01

This paper presents a new method for computation of the nonlinear flux linkage in 3-D finite-element models (FEMs) of electrical machines. Accurate computation of the nonlinear flux linkage in 3-D FEM is not an easy task. Compared to the existing energy-perturbation method, the new technique......-perturbation method. The new method proposed is validated using experimental results on two different permanent magnet machines....

Theoretical Investigation of Hydrogen Adsorption and Dissociation on Iron and Iron Carbide Surfaces Using the ReaxFF Reactive Force Field Method

Energy Technology Data Exchange (ETDEWEB)

Zou, Chenyu; van Duin, Adri C.T.; Sorescu, Dan C.

2012-06-01

We have developed a ReaxFF reactive force field to describe hydrogen adsorption and dissociation on iron and iron carbide surfaces relevant for simulation of Fischer–Tropsch (FT) synthesis on iron catalysts. This force field enables large system (>>1000 atoms) simulations of hydrogen related reactions with iron. The ReaxFF force field parameters are trained against a substantial amount of structural and energetic data including the equations of state and heats of formation of iron and iron carbide related materials, as well as hydrogen interaction with iron surfaces and different phases of bulk iron. We have validated the accuracy and applicability of ReaxFF force field by carrying out molecular dynamics simulations of hydrogen adsorption, dissociation and recombination on iron and iron carbide surfaces. The barriers and reaction energies for molecular dissociation on these two types of surfaces have been compared and the effect of subsurface carbon on hydrogen interaction with iron surface is evaluated. We found that existence of carbon atoms at subsurface iron sites tends to increase the hydrogen dissociation energy barrier on the surface, and also makes the corresponding hydrogen dissociative state relatively more stable compared to that on bare iron. These properties of iron carbide will affect the dissociation rate of H{sub 2} and will retain more surface hydride species, thus influencing the dynamics of the FT synthesis process.

Problems and perspectives of nuclear-physical methods for Kazakhstan iron-ore deposits

International Nuclear Information System (INIS)

Portnov, V.S.; Yurov, V.M.

2005-01-01

Thermal dynamical analysis of gamma-gamma-method (GGM) is carried out, and formula linking the measuring system respond function with required element concentration is obtained. In the work the dependence of scattered gamma-radiation from iron concentration is determined. The GGM sensitivity dependence on initial radiation energy

Oral iron administration in suckling piglets – a review

Directory of Open Access Journals (Sweden)

Martin Svoboda

2018-01-01

Full Text Available Iron deficiency is presently a serious problem in suckling piglets on pig farms. The most often used method of anaemia prevention in piglets is parenteral administration of iron dextran. Oral iron represents an alternative to this method. The goal of this article is to review current knowledge on oral iron administration in suckling piglets. The substances that can be used for this purpose include iron dextran, iron salts, iron chelates, carbonyl iron, an iron polymaltose complex and iron microparticles. The different methods of oral iron administration in piglets are discussed.

Analysis of iron state in some Argentinian soils by dissolution methods and Moessbauer spectroscopy

International Nuclear Information System (INIS)

Venegas, R.; Labenski de Kanter, F.; Acebal, S.; Grassi, R.; Rueda, E.H.; Aguirre, M.E.; Saragovi, C.

1994-01-01

Bahia Blanca (Argentina) soils, in particular entisols, are studied by Moessbauer spectroscopy. X-ray diffraction and scanning electron microscopy are used to characterize the samples. Samples were treated with different chemical iron extraction methods, in order to determine relative Fe o and Fe d fractions. The Fe o /Fe d ratios are obtained and the relative effect of iron extraction treatment on spectra components are determined. In addition, the effect of extraction procedures, dithionite-citrate-bicarbonate and oxalate, in the residual soil fraction are analyzed. (orig.)

A Method to Assess Flux Hazards at CSP Plants to Reduce Avian Mortality

Energy Technology Data Exchange (ETDEWEB)

Ho, Clifford K.; Wendelin, Timothy; Horstman, Luke; Yellowhair, Julius

2017-06-27

A method to evaluate avian flux hazards at concentrating solar power plants (CSP) has been developed. A heat-transfer model has been coupled to simulations of the irradiance in the airspace above a CSP plant to determine the feather temperature along prescribed bird flight paths. Probabilistic modeling results show that the irradiance and assumed feather properties (thickness, absorptance, heat capacity) have the most significant impact on the simulated feather temperature, which can increase rapidly (hundreds of degrees Celsius in seconds) depending on the parameter values. The avian flux hazard model is being combined with a plant performance model to identify alternative heliostat standby aiming strategies that minimize both avian flux hazards and negative impacts on plant performance.

Serum Iron and Haemoglobin Estimation in Oral Submucous Fibrosis and Iron Deficiency Anaemia: A Diagnostic Approach.

Science.gov (United States)

Bhardwaj, Divya; Dinkar, Ajit D; Satoskar, Sujata K; Desai, Sapna Raut

2016-12-01

Oral Submucous Fibrosis (OSMF) is a premalignant condition with potential malignant behaviour characterized by juxta-epithelial fibrosis of the oral cavity. In the process of collagen synthesis, iron gets utilized, by the hydroxylation of proline and lysine, leading to decreased serum iron levels. The trace element like iron is receiving much attention in the detection of oral cancer and precancerous condition like OSMF as it was found to be significantly altered in these conditions. The aim of this study was to compare the haemoglobin and serum iron values of OSMF subjects with that of iron deficiency anaemia subjects. Total of 120 subjects were included, 40 subjects with the OSMF, 40 with the iron deficiency anemia without tobacco chewing habit, 40 healthy control subjects without OSMF and iron deficiency anaemia. A total of 5ml of venous blood was withdrawn from all the subjects and serum iron and haemoglobin levels were estimated for all the subjects. Estimation of iron was done using Ferrozine method and haemoglobin by Sahli's method. The statistical method applied were Kruskal Wallis, Mann Whitney and Pearson correlation coefficient test. There was a statistically significant difference in serum iron and haemoglobin level in all three groups (pauxillary test in assessment of prognosis of the disease.

Methods of preparation and modification of advanced zero-valent iron nanoparticles, their properties and application in water treatment technologies

Science.gov (United States)

Filip, Jan; Kašlík, Josef; Medřík, Ivo; Petala, Eleni; Zbořil, Radek; Slunský, Jan; Černík, Miroslav; Stavělová, Monika

2014-05-01

Zero-valent iron nanoparticles are commonly used in modern water treatment technologies. Compared to conventionally-used macroscopic iron or iron microparticles, the using of nanoparticles has the advantages given mainly by their generally large specific surface area (it drives their high reactivity and/or sorption capacity), small dimensions (it allows their migration e.g. in ground water), and particular physical and chemical properties. Following the applications of zero-valent iron particles in various pilot tests, there arose several critical suggestions for improvements of used nanomaterials and for development of new generation of reactive nanomaterials. In the presentation, the methods of zero-valent iron nanoparticles synthesis will be summarized with a special attention paid to the thermally-induced solid-state reaction allowing preparation of zero-valent iron nanoparticles in an industrial scale. Moreover, the method of thermal reduction of iron-oxide precursors enables to finely tune the critical parameters (mainly particle size and morphology, specific surface area, surface chemistry of nanoparticles etc.) of resulting zero-valet iron nanoparticles. The most important trends of advanced nanoparticles development will be discussed: (i) surface modification of nanomaterilas, (ii) development of nanocomposites and (iii) development of materials for combined reductive-sorption technologies. Laboratory testing of zero-valent iron nanoparticles reactivity and migration will be presented and compared with the field observations: the advanced zero-valent iron nanoparticles were used for groundwater treatment at the locality contaminated by chlorinated hydrocarbons (VC, DCE, TCE and PCE) and reacted nanoparticles were extracted from the sediments for their fate assessment. The authors gratefully acknowledge the support by the Technology Agency of the Czech Republic "Competence Centres" (project No. TE01020218) and the EU FP7 (project NANOREM).

A method for prompt calculation of neutron flux from measured SPND [self-powered neutron detectors] currents

International Nuclear Information System (INIS)

Kulacsy, K.; Lux, I.

1997-01-01

A new, approximate method is given to calculate the in-core flux from the current of SPNDs, with a delay of only a few seconds. The stability of this stepwise algorithm is proven to be satisfactory, and the results of tests performed both on synthetic and on real data are presented. The reconstructed flux is found to follow both steady state and transient fluxes well. (author)

Sulphide fluxes and concentrations in the spent nuclear fuel repository at Olkiluoto

International Nuclear Information System (INIS)

Wersin, P.; Alt-Epping, P.; Pitkaenen, P.

2014-01-01

Sulphide may act as corrodant for the copper canister in the KBS-3 disposal concept. Sulphide fluxes at repository level are affected by various sources in the host rock, the backfill and the buffer. Hydrogen sulphide is effectively immobilised by Fe to form insoluble iron sulphide minerals. Thus, dissolved sulphide levels in reducing environment and also in Olkiluoto groundwaters are generally low. In zones favourable for sulphate reducing bacteria (SRB), however, temporarily more elevated sulphide concentrations are possible. The sulphate reduction and subsequent iron sulphide precipitation process depends on geochemical conditions, microbial activity and mass transfer of the reactants and is thus highly system-specific. The overall objective of the work presented in this report is to provide a thorough background for the sulphide concentrations and sulphide fluxes in the near field and the far field used in the performance assessment 2012

Single-dose intravenous iron infusion or oral iron for treatment of fatigue after postpartum haemorrhage

DEFF Research Database (Denmark)

Holm, C; Thomsen, L L; Norgaard, A

2017-01-01

BACKGROUND AND OBJECTIVES: To evaluate the clinical efficacy of a single-dose intravenous infusion of iron isomaltoside compared with current treatment practice with oral iron measured by physical fatigue in women after postpartum haemorrhage. MATERIALS AND METHODS: Single-centre, open-label, ran......BACKGROUND AND OBJECTIVES: To evaluate the clinical efficacy of a single-dose intravenous infusion of iron isomaltoside compared with current treatment practice with oral iron measured by physical fatigue in women after postpartum haemorrhage. MATERIALS AND METHODS: Single-centre, open...

Methane and carbon dioxide fluxes over a lake: comparison between eddy covariance, floating chambers and boundary layer method

Directory of Open Access Journals (Sweden)

K.-M. Erkkilä

2018-01-01

Full Text Available Freshwaters bring a notable contribution to the global carbon budget by emitting both carbon dioxide (CO2 and methane (CH4 to the atmosphere. Global estimates of freshwater emissions traditionally use a wind-speed-based gas transfer velocity, kCC (introduced by Cole and Caraco, 1998, for calculating diffusive flux with the boundary layer method (BLM. We compared CH4 and CO2 fluxes from BLM with kCC and two other gas transfer velocities (kTE and kHE, which include the effects of water-side cooling to the gas transfer besides shear-induced turbulence, with simultaneous eddy covariance (EC and floating chamber (FC fluxes during a 16-day measurement campaign in September 2014 at Lake Kuivajärvi in Finland. The measurements included both lake stratification and water column mixing periods. Results show that BLM fluxes were mainly lower than EC, with the more recent model kTE giving the best fit with EC fluxes, whereas FC measurements resulted in higher fluxes than simultaneous EC measurements. We highly recommend using up-to-date gas transfer models, instead of kCC, for better flux estimates. BLM CO2 flux measurements had clear differences between daytime and night-time fluxes with all gas transfer models during both stratified and mixing periods, whereas EC measurements did not show a diurnal behaviour in CO2 flux. CH4 flux had higher values in daytime than night-time during lake mixing period according to EC measurements, with highest fluxes detected just before sunset. In addition, we found clear differences in daytime and night-time concentration difference between the air and surface water for both CH4 and CO2. This might lead to biased flux estimates, if only daytime values are used in BLM upscaling and flux measurements in general. FC measurements did not detect spatial variation in either CH4 or CO2 flux over Lake Kuivajärvi. EC measurements, on the other hand, did not show any spatial variation in CH4 fluxes but did show a clear difference

Magnetic properties and phase transformations of iron sulfides synthesized under the hydrothermal method

Science.gov (United States)

Li, S. H.; Chen, Y. H.

2016-12-01

The iron sulfide nano-minerals possess advantages of high abundance, low cost, and low toxicity. These advantages make them be competitive in the magnetic, electronic, and photoelectric applications. Mackinawite can be used in soil or water remediations. Greigite is very important for paleomagnetic and geochemical environment studies and the anode materials for lithium ion batteries. Besides, greigite is also utilized for hyperthermia and biomedicine. Pyrrhotite can be applied as geothermometry. Due to the above-mentioned reasons, iron sulfide minerals have specific significances and they must be further investigated, like their phase transformations, magnetic properties, and etc. In this study, the iron sulfide minerals were synthesized by using a hydrothermal method. The ex-situ and in-situ X-ray diffraction (XRD) was used to examine the crystal structure and phase transformation of iron sulfide minerals. The Transmission electron microscopy (TEM) and superconducting quantum interference device (SQUID) were carried out to investigate their morphology and magnetic properties, respectively. The results suggested that the phase transformation sequence was followed the order: mackinawite → greigite → (smythite) → pyrrhotite. Two pure mineral phases of greigite and pyrrhotite were obtained under the hydrothermal conditions. The morphology of the pure greigite is granular aggregates with a particle size of approximately 30 nm and pyrrhotite presented a hexagonal sheet stacking with a particle size of thousands nanometers. The greigite had a ferri-magnetic behavior and pyrrhotite was weak ferro-magnetic. Both of them had a pseudo-single magnetic domain (PSD) based on the Day's plot from SQUID data. The complete phase-transformation pathways and high magnetization of iron sulfide minerals are observed in this study and these kind of iron sulfide minerals are worthy to further study.

Evaluation of different methods to model near-surface turbulent fluxes for a mountain glacier in the Cariboo Mountains, BC, Canada

Science.gov (United States)

Radić, Valentina; Menounos, Brian; Shea, Joseph; Fitzpatrick, Noel; Tessema, Mekdes A.; Déry, Stephen J.

2017-12-01

As part of surface energy balance models used to simulate glacier melting, choosing parameterizations to adequately estimate turbulent heat fluxes is extremely challenging. This study aims to evaluate a set of four aerodynamic bulk methods (labeled as C methods), commonly used to estimate turbulent heat fluxes for a sloped glacier surface, and two less commonly used bulk methods developed from katabatic flow models. The C methods differ in their parameterizations of the bulk exchange coefficient that relates the fluxes to the near-surface measurements of mean wind speed, air temperature, and humidity. The methods' performance in simulating 30 min sensible- and latent-heat fluxes is evaluated against the measured fluxes from an open-path eddy-covariance (OPEC) method. The evaluation is performed at a point scale of a mountain glacier, using one-level meteorological and OPEC observations from multi-day periods in the 2010 and 2012 summer seasons. The analysis of the two independent seasons yielded the same key findings, which include the following: first, the bulk method, with or without the commonly used Monin-Obukhov (M-O) stability functions, overestimates the turbulent heat fluxes over the observational period, mainly due to a substantial overestimation of the friction velocity. This overestimation is most pronounced during the katabatic flow conditions, corroborating the previous findings that the M-O theory works poorly in the presence of a low wind speed maximum. Second, the method based on a katabatic flow model (labeled as the KInt method) outperforms any C method in simulating the friction velocity; however, the C methods outperform the KInt method in simulating the sensible-heat fluxes. Third, the best overall performance is given by a hybrid method, which combines the KInt approach with the C method; i.e., it parameterizes eddy viscosity differently than eddy diffusivity. An error analysis reveals that the uncertainties in the measured meteorological

Evaluation of different methods to model near-surface turbulent fluxes for a mountain glacier in the Cariboo Mountains, BC, Canada

Directory of Open Access Journals (Sweden)

V. Radić

2017-12-01

Full Text Available As part of surface energy balance models used to simulate glacier melting, choosing parameterizations to adequately estimate turbulent heat fluxes is extremely challenging. This study aims to evaluate a set of four aerodynamic bulk methods (labeled as C methods, commonly used to estimate turbulent heat fluxes for a sloped glacier surface, and two less commonly used bulk methods developed from katabatic flow models. The C methods differ in their parameterizations of the bulk exchange coefficient that relates the fluxes to the near-surface measurements of mean wind speed, air temperature, and humidity. The methods' performance in simulating 30 min sensible- and latent-heat fluxes is evaluated against the measured fluxes from an open-path eddy-covariance (OPEC method. The evaluation is performed at a point scale of a mountain glacier, using one-level meteorological and OPEC observations from multi-day periods in the 2010 and 2012 summer seasons. The analysis of the two independent seasons yielded the same key findings, which include the following: first, the bulk method, with or without the commonly used Monin–Obukhov (M–O stability functions, overestimates the turbulent heat fluxes over the observational period, mainly due to a substantial overestimation of the friction velocity. This overestimation is most pronounced during the katabatic flow conditions, corroborating the previous findings that the M–O theory works poorly in the presence of a low wind speed maximum. Second, the method based on a katabatic flow model (labeled as the KInt method outperforms any C method in simulating the friction velocity; however, the C methods outperform the KInt method in simulating the sensible-heat fluxes. Third, the best overall performance is given by a hybrid method, which combines the KInt approach with the C method; i.e., it parameterizes eddy viscosity differently than eddy diffusivity. An error analysis reveals that the uncertainties in

Coupling multipoint flux mixed finite element methodswith continuous Galerkin methods for poroelasticity

KAUST Repository

Wheeler, Mary; Xue, Guangri; Yotov, Ivan

2013-01-01

We study the numerical approximation on irregular domains with general grids of the system of poroelasticity, which describes fluid flow in deformable porous media. The flow equation is discretized by a multipoint flux mixed finite element method

A method for determination of [Fe3+]/[Fe2+] ratio in superparamagnetic iron oxide

Science.gov (United States)

Jiang, Changzhao; Yang, Siyu; Gan, Neng; Pan, Hongchun; Liu, Hong

2017-10-01

Superparamagnetic iron oxide nanoparticles (SPION), as a kind of nanophase materials, are widely used in biomedical application, such as magnetic resonance imaging (MRI), drug delivery, and magnetic field assisted therapy. The magnetic property of SPION has close connection with its crystal structure, namely it is related to the ratio of Fe3+ and Fe2+ which form the SPION. So a simple way to determine the content of the Fe3+ and Fe2+ is important for researching the property of SPION. This review covers a method for determination of the Fe3+ and Fe2+ ratio in SPION by UV-vis spectrophotometry based the reaction of Fe2+ and 1,10-phenanthroline. The standard curve of Fe with R2 = 0.9999 is used for determination the content of Fe2+ and total iron with 2.5 mL 0.01% (w/v) SPION digested by HCl, pH = 4.30 HOAc-NaAc buffer 10 mL, 0.01% (w/v) 1,10-phenanthroline 5 mL and 10% (w/v) ascorbic acid 1 mL for total iron determine independently. But the presence of Fe3+ interfere with obtaining the actual value of Fe2+ (the error close to 9%). We designed a calibration curve to eliminate the error by devising a series of solution of different ratio of [Fe3+]/[Fe2+], and obtain the calibration curve. Through the calibration curve, the error between the measured value and the actual value can be reduced to 0.4%. The R2 of linearity of the method is 0.99441 and 0.99929 for Fe2+ and total iron respectively. The error of accuracy of recovery and precision of inter-day and intra-day are both lower than 2%, which can prove the reliability of the determination method.

TRANSHEX, 2-D Thermal Neutron Flux Distribution from Epithermal Flux in Hexagonal Geometry

International Nuclear Information System (INIS)

Patrakka, E.

1994-01-01

1 - Description of program or function: TRANSHEX is a multigroup integral transport program that determines the thermal scalar flux distribution arising from a known epithermal flux in two- dimensional hexagonal geometry. 2 - Method of solution: The program solves the isotropic collision probability equations for a region-averaged scalar flux by an iterative method. Either a successive over-relaxation or an inner-outer iteration technique is applied. Flat flux collision probabilities between trigonal space regions with white boundary condition are utilized. The effect of epithermal flux is taken into consideration as a slowing-down source that is calculated for a given spatial distribution and 1/E energy dependence of the epithermal flux

Standard test method for determining nodularity and nodule count in ductile iron using image analysis

CERN Document Server

American Society for Testing and Materials. Philadelphia

2011-01-01

1.1 This test method is used to determine the percent nodularity and the nodule count per unit area (that is, number of nodules per mm2) using a light microscopical image of graphite in nodular cast iron. Images generated by other devices, such as a scanning electron microscope, are not specifically addressed, but can be utilized if the system is calibrated in both x and y directions. 1.2 Measurement of secondary or temper carbon in other types of cast iron, for example, malleable cast iron or in graphitic tool steels, is not specifically included in this standard because of the different graphite shapes and sizes inherent to such grades 1.3 This standard deals only with the recommended test method and nothing in it should be construed as defining or establishing limits of acceptability or fitness for purpose of the material tested. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.5 This standard does not purport to address al...

The analysis of RPV fast neutron flux calculation for PWR with three-dimensional SN method

International Nuclear Information System (INIS)

Yang Shouhai; Chen Yixue; Wang Weijin; Shi Shengchun; Lu Daogang

2011-01-01

Discrete ordinates (S N ) method is one of the most widely used method for reactor pressure vessel (RPV) design. As the fast development of computer CPU speed and memory capacity and consummation of three-dimensional discrete-ordinates method, it is mature for 3-D S N method to be used to engineering design for nuclear facilities. This work was done specifically for PWR model, with the results of 3-D core neutron transport calculation by 3-D core calculation, 3-D RPV fast neutron flux distribution obtain by 3-D S N method were compared with gained by 1-D and 2-D S N method and the 3-D Monte Carlo (MC) method. In this paper, the application of three-dimensional S N method in calculating RPV fast neutron flux distribution for pressurized water reactor (PWR) is presented and discussed. (authors)

a Borehole-Dilution Method for Quantifying Vertical Darcy Fluxes in the Hyporheic Zone

Science.gov (United States)

Augustine, S. D.; Annable, M. D.; Cho, J.

2017-12-01

The borehole dilution method has consistently and successfully been used for estimating local water fluxes, however, this method can be relatively labor intensive and expensive. The focus of this research is aimed at developing a low-cost, borehole dilution method for quantifying vertical water fluxes in the hyporheic zone at the surface-groundwater interface. This would allow for the deployment of multiple units within a targeted surface water body and thus produce high-resolution, spatially distributed data on the infiltration rates over a short period of time with minimal set-up requirements. The device consists of a 2-inch, inner diameter PVC pipe containing short, screened sections in its upper and lower segments. The working unit is driven into the sediment and acts as a continuous flow reactor creating a pathway between the subsurface pore-water and the overlying surface water where the presence of a hydraulic gradient facilitates vertical movement. We developed a simple electrode and tracer-injection system housed within the unit to inject and measure salt tracer concentrations at the desired intervals while monitoring and storing those measurements using open-source Arduino technology. Preliminary lab and field scale trials provided data that was fit to both zero and first order reaction rate functions for analysis. The field test was conducted over approximately one day within a wet retention basin. The initial results estimated a vertical Darcy flux of 113.5 cm/d. Additional testing over a range of expected Darcy fluxes will be presented along with an evaluation considering enhanced water flow due to the high hydraulic conductivity of the device.

Accuracy of various iron parameters in the prediction of iron deficiency in an acute care hospital

NARCIS (Netherlands)

Ong, K. H.; Tan, H. L.; Lai, H. C.; Kuperan, P.

2005-01-01

INTRODUCTION: Iron parameters like serum ferritin and iron saturation are routinely used in diagnosing iron deficiency. However, these tests are influenced by many factors. We aimed to review the accuracy of iron parameters among inpatients in an acute care hospital. MATERIALS AND METHODS: From

Iron persistence in a distal hydrothermal plume supported by dissolved-particulate exchange

Science.gov (United States)

Fitzsimmons, Jessica N.; John, Seth G.; Marsay, Christopher M.; Hoffman, Colleen L.; Nicholas, Sarah L.; Toner, Brandy M.; German, Christopher R.; Sherrell, Robert M.

2017-02-01

Hydrothermally sourced dissolved metals have been recorded in all ocean basins. In the oceans' largest known hydrothermal plume, extending westwards across the Pacific from the Southern East Pacific Rise, dissolved iron and manganese were shown by the GEOTRACES program to be transported halfway across the Pacific. Here, we report that particulate iron and manganese in the same plume also exceed background concentrations, even 4,000 km from the vent source. Both dissolved and particulate iron deepen by more than 350 m relative to 3He--a non-reactive tracer of hydrothermal input--crossing isopycnals. Manganese shows no similar descent. Individual plume particle analyses indicate that particulate iron occurs within low-density organic matrices, consistent with its slow sinking rate of 5-10 m yr-1. Chemical speciation and isotopic composition analyses reveal that particulate iron consists of Fe(III) oxyhydroxides, whereas dissolved iron consists of nanoparticulate Fe(III) oxyhydroxides and an organically complexed iron phase. The descent of plume-dissolved iron is best explained by reversible exchange onto slowly sinking particles, probably mediated by organic compounds binding iron. We suggest that in ocean regimes with high particulate iron loadings, dissolved iron fluxes may depend on the balance between stabilization in the dissolved phase and the reversibility of exchange onto sinking particles.

Determination of metallic iron in sponge-iron

International Nuclear Information System (INIS)

Mueller, C.S.

1974-01-01

The amount of metallic iron in sponge-iron is a parameter of major interest in the evaluation of the performance of the ore-reduction process and in the determination of the composition of the load of the electric furnace used to produce the steel. Moessbauer effect offers the promise of a simple and elegant analysis method, capable of competing directly with the usually time-consuming chemical procedures. The applicability of the method is considered and the possible sources of error are analyzed, resulting in the design of an instrument that is reasonably accurate and simple to use. Detailed electronic circuity required to produce a direct-reading digital instrument is shown [pt

Significance of bioleaching method in dissolution of iron and in the quality improvement of non-metallics

Directory of Open Access Journals (Sweden)

Iveta Štyriaková

2006-12-01

Full Text Available Simple laboratory bioleaching experiments for the iron removal with heterotrophic bacteria on natural raw materials were conducted to explore a simple cyclic operation for a potential use at the industrial scale. Heterotrophic bacteria of Bacillus spp. growing in the presence of feldspar raw materials are able to dissolve iron. Anaerobic conditions Quickly formed by bacteria enable a simple manipulation with the sample solution. Insoluble Fe(III in the feldspars sample could be enzymatically dissolved as Fe3+ and also reduced to soluble Fe2+ by silicate bacteria of Bacillus spp. This metal was efficiently removed from the feldspars sample as documented by a Fe2O3 decrease (from 0.29 % to 0.12 % after bioleaching in the conical flask and by a Fe2O3 decrease (from 0.29 % to 0.19 % after bioleaching in the percolate column. Bioleaching of Fe was more effective in the conical flask. Iron-bearing minerals can be easily removed by magnetic separation, but ultra fine iron particles are difficult to treat by conventional mineral processing methods. Thus bioleaching is an attractive alternative for effective removal of iron minerals. The removal of iron with the whiteness increase should give a product, which is fit for industrial ceramic applications.

Efficacy of iron-fortified whole maize flour on iron status of schoolchildren in Kenya: a randomised controlled trial

NARCIS (Netherlands)

Andang'o, P.E.A.; Osendarp, S.J.M.; Ayah, R.; West, C.E.; Mwaniki, D.; Wolf, de C.A.; Kraaijenhagen, R.; Kok, F.J.; Verhoef, H.

2007-01-01

Background Sodium iron edetic acid (NaFeEDTA) might be a more bioavailable source of iron than electrolytic iron, when added to maize flour. We aimed to assess the effect, on children's iron status, of consumption of whole maize flour fortified with iron as NaFeEDTA or electrolytic iron. Methods 516

Methods of synthesis and performance improvement of lithium iron phosphate for high rate Li-ion batteries: A review

Directory of Open Access Journals (Sweden)

T.V.S.L. Satyavani

2016-03-01

Full Text Available Lithium ion battery technology has the potential to meet the requirements of high energy density and high power density applications. A continuous search for novel materials is pursued continually to exploit the latent potential of this technology. In this review paper, methods for preparation of Lithium Iron Phosphate are discussed which include solid state and solution based synthesis routes. The methods to improve the electrochemical performance of lithium iron phosphate are presented in detail.

A study on the fabrication of superhydrophobic iron surfaces by chemical etching and galvanic replacement methods and their anti-icing properties

Science.gov (United States)

Li, Kunquan; Zeng, Xingrong; Li, Hongqiang; Lai, Xuejun

2015-08-01

Hierarchical structures on iron surfaces were constructed by means of chemical etching by hydrochloric acid (HCl) solution or the galvanic replacement by silver nitrate (AgNO3) solution. The superhydrophobic iron surfaces were successfully prepared by subsequent hydrophobic modification with stearic acid. The superhydrophobic iron surfaces were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and water contact angle (WCA). The effects of reactive concentration and time on the microstructure and the wetting behavior were investigated. In addition, the anti-icing properties of the superhydrophobic iron surfaces were also studied. The FTIR study showed that the stearic acid was chemically bonded onto the iron surface. With the HCl concentration increase from 4 mol/L to 8 mol/L, the iron surface became rougher with a WCA ranging from 127° to 152°. The AgNO3 concentration had little effect on the wetting behavior, but a high AgNO3 concentration caused Ag particle aggregates to transform from flower-like formations into dendritic crystals, owing to the preferential growth direction of the Ag particles. Compared with the etching method, the galvanic replacement method on the iron surface more favorably created roughness required for achieving superhydrophobicity. The superhydrophobic iron surface showed excellent anti-icing properties in comparison with the untreated iron. The icing time of water droplets on the superhydrophobic surface was delayed to 500 s, which was longer than that of 295 s for untreated iron. Meanwhile, the superhydrophobic iron surface maintained superhydrophobicity after 10 icing and de-icing cycles in cold conditions.

HNO3 fluxes to a deciduous forest derived using gradient and REA methods

DEFF Research Database (Denmark)

Pryor, S.C.; Barthelmie, R.J.; Jensen, B.

2002-01-01

Summertime nitric acid concentrations over a deciduous forest in the midwestern United States are reported, which range between 0.36 and 3.3 mug m(-3). Fluxes to the forest are computed using the relaxed eddy accumulation technique and gradient methods. In accord with previous studies, the results...... indicate substantial uncertainties in the gradient-based calculations. The relaxed eddy accumulation (REA) derived fluxes are physically reasonable and are shown to be of similar magnitude to dry deposition estimates from gradient sampling. The REA derived mean deposition velocity is approximately 3 cm s......(-1), which is also comparable to growing season estimates derived by Meyers et al. for a similar deciduous forest. Occasional inverted concentration gradients and fluxes are observed but most are not statistically significant. Data are also presented that indicate substantial through canopy...

Neutron flux measurement with 6Li and 7Li dual glass scintillators by γ compensation method

International Nuclear Information System (INIS)

Ji Changsong; Zhang Shulan; Zhang Shuheng

1996-01-01

Based on the characteristics of 6 Li glass scintillator which is sensitive to both neutron and gamma rays, and 7 Li glass scintillator which is sensitive to gamma rays only, a new method of detecting weak neutron flux under interference of strong gamma radiation has been investigated by means of 6 Li- 7 Li pair glass scintillator gamma compensation method. The result of neutron flux measurement by above-mentioned method with an error of about 1% when the gamma ray interference is up to 18.7% has been obtained

Neutron flux measurement with 6Li and 7Li dual glass scintillators by γ compensation method

International Nuclear Information System (INIS)

Ji Changsong; Zhang Shulan; Zhang Shuheng

1998-01-01

Based on the characteristics of 6 Li glass scintillator which is sensitive to both neutron and gamma rays, and 7 Li glass scintillator which is sensitive to gamma rays only, a new method of detecting weak neutron flux under interference of strong gamma radiation has been investigated by mans of 6 Li- 7 Li dual glass scintillator gamma compensation method. The result of neutron flux measurement by above-mentioned method with an error of about 1% when the gamma ray interference is up to 18.7% has been obtained

Studying Irony Detection Beyond Ironic Criticism: Let's Include Ironic Praise

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Richard Bruntsch

2017-04-01

Full Text Available Studies of irony detection have commonly used ironic criticisms (i.e., mock positive evaluation of negative circumstances as stimulus materials. Another basic type of verbal irony, ironic praise (i.e., mock negative evaluation of positive circumstances is largely absent from studies on individuals' aptitude to detect verbal irony. However, it can be argued that ironic praise needs to be considered in order to investigate the detection of irony in the variety of its facets. To explore whether the detection ironic praise has a benefit beyond ironic criticism, three studies were conducted. In Study 1, an instrument (Test of Verbal Irony Detection Aptitude; TOVIDA was constructed and its factorial structure was tested using N = 311 subjects. The TOVIDA contains 26 scenario-based items and contains two scales for the detection of ironic criticism vs. ironic praise. To validate the measurement method, the two scales of the TOVIDA were experimentally evaluated with N = 154 subjects in Study 2. In Study 3, N = 183 subjects were tested to explore personality and ability correlates of the two TOVIDA scales. Results indicate that the co-variance between the ironic TOVIDA items was organized by two inter-correlated but distinct factors: one representing ironic praise detection aptitude and one representing ironic criticism detection aptitude. Experimental validation showed that the TOVIDA items truly contain irony and that item scores reflect irony detection. Trait bad mood and benevolent humor (as a facet of the sense of humor were found as joint correlates for both ironic criticism and ironic praise detection scores. In contrast, intelligence, trait cheerfulness, and corrective humor were found as unique correlates of ironic praise detection scores, even when statistically controlling for the aptitude to detect ironic criticism. Our results indicate that the aptitude to detect ironic praise can be seen as distinct from the aptitude to detect ironic

Formation cross section of iron-60 with reactor neutrons in 59Fe(n, γ)60Fe reaction

International Nuclear Information System (INIS)

Sato, T.; Suzuki, T.

1993-01-01

Ingrowth of 60 Co radioactivity in an iron sample irradiated in a nuclear reactor has been measured for determination of formation cross section of 60 Fe in the 59 Fe(n, γ) 60 Fe reaction with reactor neutrons. After 5 years cooling, the irradiated iron was purified from 60 Co and other radioactive nuclides by an anion exchange separation method and isopropyl ether extraction in hydrochloric acid. The amount of 60 Co ingrowth was measured by γ-spectrometry using a Ge-detector coupled to a multichannel pulse height analyzer 4 years after the purification of iron. Neutron flux of the irradiation position was calculated from the amount of 55 Fe produced. The observed value of 12.5 ± 2.8 barn is slightly greater than reported value for burnup cross section of 59 Fe(n, x)X, where x refers γ, α, d, p and 2n, and X is any nuclide produced by the above reactions. (author) 8 refs.; 2 tabs

Iron excess in recreational marathon runners

NARCIS (Netherlands)

Mettler, S.; Zimmermann, M.B.

2010-01-01

Background/Objectives: Iron deficiency and anemia may impair athletic performance, and iron supplements are commonly consumed by athletes. However, iron overload should be avoided because of the possible long-term adverse health effects. Methods: We investigated the iron status of 170 male and

Neutron transmission benchmark problems for iron and concrete shields in low, intermediate and high energy proton accelerator facilities

Energy Technology Data Exchange (ETDEWEB)

Nakane, Yoshihiro; Sakamoto, Yukio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Hayashi, Katsumi [and others

1996-09-01

Benchmark problems were prepared for evaluating the calculation codes and the nuclear data for accelerator shielding design by the Accelerator Shielding Working Group of the Research Committee on Reactor Physics in JAERI. Four benchmark problems: transmission of quasi-monoenergetic neutrons generated by 43 MeV and 68 MeV protons through iron and concrete shields at TIARA of JAERI, neutron fluxes in and around an iron beam stop irradiated by 500 MeV protons at KEK, reaction rate distributions inside a thick concrete shield irradiated by 6.2 GeV protons at LBL, and neutron and hadron fluxes inside an iron beam stop irradiated by 24 GeV protons at CERN are compiled in this document. Calculational configurations and neutron reaction cross section data up to 500 MeV are provided. (author)

Comparison of response between food supplemented with powdered iron and iron in syrup form for iron deficiency anemia

International Nuclear Information System (INIS)

Ahmed, P.

2003-01-01

Objective: To evaluate and compare the response between food supplemented with iron in powdered and iron in syrup forms for the treatment of iron deficiency anemia in children aged 1-5 years. Results: Over half (51 %) of the patients were between 1-2 years of age. One hundred thirty-two were males and 68 females. Most of the patients belonged to poor socioeconomic class. The iron in powder form was better tolerated than iron syrup as this group witnessed fewer episodes of gastrointestinal disturbances. The rise in mean Hb level after 6 weeks of treatment in group A and B was 1.6 g/dl and 1.9 g/dl respectively. Hemoglobin rise in group B was more than group A but this was statistically non-significant (p>0.05). There was small but significant (p<0.05) rise in serum ferritin in both the groups. There was no significant difference between the two groups for response to the two forms of iron administration. Conclusion: The powdered form of iron is a cost-effective and better tolerated method of iron administration in children and can be considered as an alternate option for the treatment of iron deficiency anemia in children. (author)

Bioavailable iron in typical Thai meals: Comparative studies between radioactive in vitro and in vivo food iron absorption measurements

International Nuclear Information System (INIS)

Sritongkul, N.

1989-03-01

Presently available in vivo methods for assessing iron absorption in human subjects, although physiologically acceptable and accurate, are not practical for screening large numbers of food and diet samples. A simple in vitro method for determining the amount of iron available for absorption was therefore investigated. It is based on the common pool concept of food iron absorption using radioactive Fe-59 as a marker of the iron present in the bioavailable iron pool. The ionizable iron was measured after an initial peptic digestion by using pepsin/HCl at pH 1.35 followed by an increase of the pH to 6.0 to simulate duodenal alkalinity. The method was proved to be simple, reproducible and applicable either to single food items or whole meals of varying composition. It is able to detect known enhancers or inhibitors of food iron absorption. The percent ionizable iron among 5 different meals with the inclusion of inhibitor or enhancer was shown to correlate closely with the percentage of iron absorbed in human subjects (r=0.9197, p<0.001). A high correlation between the in vivo and in vitro methods was also observed when the results were expressed as absorption ratios and ionizable ratios (r=0.9192, p<0.001). The method is expected to be useful for improving diet composition to increase the iron availability of some typical meals in developing countries, including those which are known to contain considerable amounts of inhibitors of iron absorption. 39 refs, 1 fig., 13 tabs

Iron absorption studies

International Nuclear Information System (INIS)

Ekenved, G.

1976-01-01

The main objective of the present work was to study iron absorption from different iron preparations in different types of subjects and under varying therapeutic conditions. The studies were performed with different radioiron isotope techniques and with a serum iron technique. The preparations used were solutions of ferrous sulphate and rapidly-disintegrating tablets containing ferrous sulphate, ferrous fumarate and ferrous carbonate and a slow-release ferrous sulphate tablet of an insoluble matrix type (Duroferon Durules). The serum iron method was evaluated and good correlation was found between the serum iron response and the total amount of iron absorbed after an oral dose of iron given in solution or in tablet form. New technique for studying the in-vivo release properties of tablets was presented. Iron tablets labelled with a radio-isotope were given to healthy subjects. The decline of the radioactivity in the tablets was followed by a profile scanning technique applied to different types of iron tablets. The release of iron from the two types of tablets was shown to be slower in vivo than in vitro. It was found that co-administration of antacids and iron tablets led to a marked reduction in the iron absorption and that these drugs should not be administered sumultaneously. A standardized meal markedly decreased the absorbability of iron from iron tablets. The influence of the meal was more marked with rapidly-disintegrating than with slow-release ferrous sulphate tablets. The absorption from rapidly-disintegrating and slow-release ferrous sulphate tablets was compared under practical clinical conditions during an extended treatment period. The studies were performed in healthy subjects, blood donors and patients with iron deficiency anaemia and it was found that the absorption of iron from the slow-release tablets was significantly better than from the rapidly-disintegrating tablets in all three groups of subjects. (author)

Study of Ascorbic Acid as Iron(III Reducing Agent for Spectrophotometric Iron Speciation

Directory of Open Access Journals (Sweden)

Antesar Elmagirbi

2012-10-01

Full Text Available The study of ascorbic acid as a reducing agent for iron(III has been investigated in order to obtain an alternative carcinogenic reducing agent, hydroxylamine, used in spectrophotometric standard method based on the formation of a red-orange complex of Fe(II-o-phenanthroline. The study was optimised with regards to ascorbic acid concentration as well as pH solution. The results showed that ascorbic acid showed maximum capacity as reducing agent of iron(III under concentration of 4.46.10-4 M and pH solution of 1-4.Under these conditions, ascorbic acid reduced iron(III proportionally and performed similarly to that of hydroxylamine.  The method gave result to linear calibration over the range of 0.2-2 mg/L withhigh accuracy of 97 % and relative standard deviation of less than 2 %. This method was successfully applied to assay iron speciation in water samples.

A transmission probability method for calculation of neutron flux distributions in hexagonal geometry

International Nuclear Information System (INIS)

Wasastjerna, F.; Lux, I.

1980-03-01

A transmission probability method implemented in the program TPHEX is described. This program was developed for the calculation of neutron flux distributions in hexagonal light water reactor fuel assemblies. The accuracy appears to be superior to diffusion theory, and the computation time is shorter than that of the collision probability method. (author)

COMPARISON OF THE NEW IRON DOSAGE METHODS FOR DRINKING WATER PRODUCTION

DEFF Research Database (Denmark)

Kowalski, Krysztof; Søgaard, Erik Gydesen

Arsenic is considered as one of the most concerned pollutants in the world due to its adverse health effects. Therefore, its content in drinking water has been recommended to be limited to 10 μg/L (WHO 2006). On of the conventional methods for arsenic removal is based on the addition of ferrous......, it can be controlled, which brings main advantage in large scale water processing. However, both techniques have limitations, which results in different area of implementation. The aim of this work is to compare and evaluate new iron dosage methods by comparing the water treatment plants where ZVI...

Effect of atmospheric organic complexation on iron-bearing dust solubility

Directory of Open Access Journals (Sweden)

R. Paris

2013-05-01

Full Text Available Recent studies reported that the effect of organic complexation may be a potentially important process to be considered by models estimating atmospheric iron flux to the ocean. In this study, we investigated this process effect by a series of dissolution experiments on iron-bearing dust in the presence or the absence of various organic compounds (acetate, formate, oxalate, malonate, succinate, glutarate, glycolate, lactate, tartrate and humic acid as an analogue of humic like substances, HULIS typically found in atmospheric waters. Only 4 of tested organic ligands (oxalate, malonate, tartrate and humic acid caused an enhancement of iron solubility which was associated with an increase of dissolved Fe(II concentrations. For all of these organic ligands, a positive linear dependence of iron solubility to organic concentrations was observed and showed that the extent of organic complexation on iron solubility decreased in the following order: oxalate >malonate = tartrate > humic acid. This was attributed to the ability of electron donors of organic ligands and implies a reductive ligand-promoted dissolution. This study confirms that among the known atmospheric organic binding ligands of Fe, oxalate is the most effective ligand promoting dust iron solubility and showed, for the first time, the potential effect of HULIS on iron dissolution under atmospheric conditions.

Calculations of Neutron Flux Distributions by Means of Integral Transport Methods

Energy Technology Data Exchange (ETDEWEB)

Carlvik, I

1967-05-15

Flux distributions have been calculated mainly in one energy group, for a number of systems representing geometries interesting for reactor calculations. Integral transport methods of two kinds were utilised, collision probabilities (CP) and the discrete method (DIT). The geometries considered comprise the three one-dimensional geometries, planes, sphericals and annular, and further a square cell with a circular fuel rod and a rod cluster cell with a circular outer boundary. For the annular cells both methods (CP and DIT) were used and the results were compared. The purpose of the work is twofold, firstly to demonstrate the versatility and efficacy of integral transport methods and secondly to serve as a guide for anybody who wants to use the methods.

Trapped field properties of a Y–Ba–Cu–O bulk by pulsed field magnetization using a split coil inserted by iron yokes with various geometries and electromagnetic properties

Energy Technology Data Exchange (ETDEWEB)

Takahashi, K., E-mail: t2216017@iwate-u.ac.jp [Department of Physical Science and Materials Engineering, Faculty of Science and Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Ainslie, M.D. [Bulk Superconductivity Group, Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ (United Kingdom); Fujishiro, H.; Naito, T. [Department of Physical Science and Materials Engineering, Faculty of Science and Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Shi, Y-H.; Cardwell, D.A. [Bulk Superconductivity Group, Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ (United Kingdom)

2017-05-15

Highlights: • The trapped field characteristics of a standard Y–Ba–Cu–O bulk magnetized by PFM was investigated using a split coil with three kinds of iron yokes inserted in the bores of coil,both experimentally and numerically. • Numerical results encourage better understanding of the role of yoke, including the typical behavior of the magnetic flux, such as a flux jump during PFM. • A higher saturation magnetic flux density of the yoke material was effective to reduce flux flow in the descending stage of the pulsed field. • A conductivity of the yoke material also acts to reduce the velocity of the flux intruding the bulk because of eddy currents that flow in the yoke that oppose the magnetization, which reduces the temperature rise in the bulk. - Abstract: We have investigated, both experimentally and numerically, the trapped field characteristics of a standard Y–Ba–Cu–O bulk of 30 mm in diameter and 14 mm in thickness magnetized by pulsed field magnetization (PFM) using a split coil, in which three kinds of iron yoke are inserted in the bore of the coil: soft iron with a flat surface, soft iron with a taper, and permendur (50Fe + 50Co alloy) with a flat surface. The highest trapped field, B{sub Tmax}, of 2.93 T was achieved at 40 K in the case of the permendur yoke, which was slightly higher than that obtained for the flat soft iron or the tapered soft iron yokes, and was much higher than 2.20 T in the case without the yoke. The insertion effect of the yoke on the trapped field characteristics was also investigated using numerical simulations. The results suggest that the saturation magnetic flux density, B{sub sat}, of the yoke acts to reduce the flux flow due to its hysteretic magnetization curve and the higher electrical conductivity, σ, of the yoke material also acts to suppress the flux increase rate. A flux jump (or flux leap) can be reproduced in the ascending stage of PFM using numerical simulation, using an assumption of relatively

Synthesis of iron oxide nanoparticles via sonochemical method and their characterization

Institute of Scientific and Technical Information of China (English)

Amir Hassanjani-Roshan; Mohammad Reza Vaezi; Ali Shokuhfar; Zohreh Rajabali

2011-01-01

Preparation of iron oxide (α-Fe2O3) nanoparticles was carried out via a sonochemical process. The process parameters such as temperature,sonication time and power of ultrasonication play important roles in the size and morphology of the final products. The iron oxide nanoparticles were characterized by transmission electron microscopy,X-ray powder diffraction,and thermogravimetric and differential thermal analyses. From transmission electron microscopy observations,the size of the iron oxide nanoparticles is estimated to be significantly smaller than 19 nm. X-ray diffraction data of the powder after annealing provide direct evidence that the iron oxide was formed during the sonochemical process.

Intravenous Iron Therapy in Patients with Iron Deficiency Anemia: Dosing Considerations

Directory of Open Access Journals (Sweden)

Todd A. Koch

2015-01-01

Full Text Available Objective. To provide clinicians with evidence-based guidance for iron therapy dosing in patients with iron deficiency anemia (IDA, we conducted a study examining the benefits of a higher cumulative dose of intravenous (IV iron than what is typically administered. Methods. We first individually analyzed 5 clinical studies, averaging the total iron deficit across all patients utilizing a modified Ganzoni formula; we then similarly analyzed 2 larger clinical studies. For the second of the larger studies (Study 7, we also compared the efficacy and retreatment requirements of a cumulative dose of 1500 mg ferric carboxymaltose (FCM to 1000 mg iron sucrose (IS. Results. The average iron deficit was calculated to be 1531 mg for patients in Studies 1–5 and 1392 mg for patients in Studies 6-7. The percentage of patients who were retreated with IV iron between Days 56 and 90 was significantly (p<0.001 lower (5.6% in the 1500 mg group, compared to the 1000 mg group (11.1%. Conclusions. Our data suggests that a total cumulative dose of 1000 mg of IV iron may be insufficient for iron repletion in a majority of patients with IDA and a dose of 1500 mg is closer to the actual iron deficit in these patients.

An accelerated test method of luminous flux depreciation for LED luminaires and lamps

International Nuclear Information System (INIS)

Qian, C.; Fan, X.J.; Fan, J.J.; Yuan, C.A.; Zhang, G.Q.

2016-01-01

Light Emitting Diode (LED) luminaires and lamps are energy-saving and environmental friendly alternatives to traditional lighting products. However, current luminous flux depreciation test at luminaire and lamp level requires a minimum of 6000 h testing, which is even longer than the product development cycle time. This paper develops an accelerated test method for luminous flux depreciation to reduce the test time within 2000 h at an elevated temperature. The method is based on lumen maintenance boundary curve, obtained from a collection of LED source lumen depreciation data, known as LM-80 data. The exponential decay model and Arrhenius acceleration relationship are used to determine the new threshold of lumen maintenance and acceleration factor. The proposed method has been verified by a number of simulation studies and experimental data for a wide range of LED luminaire and lamp types from both internal and external experiments. The qualification results obtained by the accelerated test method agree well with traditional 6000 h tests. - Highlights: • We develop an accelerated test method for LED luminaires and lamps. • The method is proposed based on a “Boundary Curve” concept. • The parameters of the boundary curve are extracted from LM-80 test reports. • Qualification results from the proposed method agree with ES requirements.

Determination of Non-Transferrin Bound Iron, Transferrin Bound Iron, Drug Bound Iron and Total Iron in Serum in a Rats after IV Administration of Sodium Ferric Gluconate Complex by Simple Ultrafiltration Inductively Coupled Plasma Mass Spectrometric Detection

Directory of Open Access Journals (Sweden)

Murali K. Matta

2018-02-01

Full Text Available A rapid, sensitive and specific ultrafiltration inductively-coupled plasma mass spectrometry method was developed and validated for the quantification of non-transferrin bound iron (NTBI, transferrin bound iron (TBI, drug bound iron (DI and total iron (TI in the same rat serum sample after intravenous (IV administration of iron gluconate nanoparticles in sucrose solution (Ferrlecit®. Ultrafiltration with a 30 kDa molecular cut-off filter was used for sample cleanup. Different elution solvents were used to separate each form of iron from sample serum. Isolated fractions were subjected to inductively-coupled mass spectrometric analysis after microwave digestion in 4% nitric acid. The reproducibility of the method was evaluated by precision and accuracy. The calibration curve demonstrated linearity from 5–500 ng/mL with a regression (r2 of more than 0.998. This method was effectively implemented to quantify rat pharmacokinetic study samples after intravenous administration of Ferrlecit®. The method was successfully applied to a pharmacokinetic (PK study of Ferrlecit in rats. The colloidal iron followed first order kinetics with half-life of 2.2 h and reached background or pre-dose levels after 12 h post-dosing. The drug shown a clearance of 0.31 mL/min/kg and volume of distribution of 0.05 L/kg. 19.4 ± 2.4 mL/h/kg.

Iron traps terrestrially derived dissolved organic matter at redox interfaces

Science.gov (United States)

Riedel, Thomas; Zak, Dominik; Biester, Harald; Dittmar, Thorsten

2013-01-01

Reactive iron and organic carbon are intimately associated in soils and sediments. However, to date, the organic compounds involved are uncharacterized on the molecular level. At redox interfaces in peatlands, where the biogeochemical cycles of iron and dissolved organic matter (DOM) are coupled, this issue can readily be studied. We found that precipitation of iron hydroxides at the oxic surface layer of two rewetted fens removed a large fraction of DOM via coagulation. On aeration of anoxic fen pore waters, >90% of dissolved iron and 27 ± 7% (mean ± SD) of dissolved organic carbon were rapidly (within 24 h) removed. Using ultra-high-resolution MS, we show that vascular plant-derived aromatic and pyrogenic compounds were preferentially retained, whereas the majority of carboxyl-rich aliphatic acids remained in solution. We propose that redox interfaces, which are ubiquitous in marine and terrestrial settings, are selective yet intermediate barriers that limit the flux of land-derived DOM to oceanic waters. PMID:23733946

No iron fertilization in the equatorial Pacific Ocean during the last ice age.

Science.gov (United States)

Costa, K M; McManus, J F; Anderson, R F; Ren, H; Sigman, D M; Winckler, G; Fleisher, M Q; Marcantonio, F; Ravelo, A C

2016-01-28

The equatorial Pacific Ocean is one of the major high-nutrient, low-chlorophyll regions in the global ocean. In such regions, the consumption of the available macro-nutrients such as nitrate and phosphate is thought to be limited in part by the low abundance of the critical micro-nutrient iron. Greater atmospheric dust deposition could have fertilized the equatorial Pacific with iron during the last ice age--the Last Glacial Period (LGP)--but the effect of increased ice-age dust fluxes on primary productivity in the equatorial Pacific remains uncertain. Here we present meridional transects of dust (derived from the (232)Th proxy), phytoplankton productivity (using opal, (231)Pa/(230)Th and excess Ba), and the degree of nitrate consumption (using foraminifera-bound δ(15)N) from six cores in the central equatorial Pacific for the Holocene (0-10,000 years ago) and the LGP (17,000-27,000 years ago). We find that, although dust deposition in the central equatorial Pacific was two to three times greater in the LGP than in the Holocene, productivity was the same or lower, and the degree of nitrate consumption was the same. These biogeochemical findings suggest that the relatively greater ice-age dust fluxes were not large enough to provide substantial iron fertilization to the central equatorial Pacific. This may have been because the absolute rate of dust deposition in the LGP (although greater than the Holocene rate) was very low. The lower productivity coupled with unchanged nitrate consumption suggests that the subsurface major nutrient concentrations were lower in the central equatorial Pacific during the LGP. As these nutrients are today dominantly sourced from the Subantarctic Zone of the Southern Ocean, we propose that the central equatorial Pacific data are consistent with more nutrient consumption in the Subantarctic Zone, possibly owing to iron fertilization as a result of higher absolute dust fluxes in this region. Thus, ice-age iron fertilization in the

The impact of different stator and rotor slot number combinations on iron losses of a three-phase induction motor at no-load

International Nuclear Information System (INIS)

Marcic, T.; Stumberger, B.; Stumberger, G.; Hadziselimovic, M.; Zagradisnik, I.

2008-01-01

The electromechanical characteristics of induction motors depend on the used stator and rotor slot combination. The correlation between the usage of different stator and rotor slot number combinations, magnetic flux density distributions, no-load iron losses and rated load winding over-temperatures for a specific induction motor is presented. The motor's magnetic field was analyzed by traces of the magnetic flux density vector, obtained by FEM. Post-processing of FE magnetic field solution was used for posterior iron loss calculation of the motor iron loss at no-load. The examined motor stator lamination had 36 semi-closed slots and the rotor laminations had 28, 33, 34, 44 and 46 semi-closed slots

Regional contributions of ocean iron fertilization to atmospheric CO2 changes during the last glacial termination

Science.gov (United States)

Opazo, N. E.; Lambert, F.

2017-12-01

Mineral dust aerosols affect climate directly by changing the radiative balance of the Earth, and indirectly by acting as cloud condensation nuclei and by affecting biogeochemical cycles. The impact on marine biogeochemical cycles is primarily through the supply of micronutrients such as iron to nutrient-limited regions of the oceans. Iron fertilization of High Nutrient Low Chlorophyll (HNLC) regions of the oceans is thought to have significantly affected the carbon cycle on glacial-interglacial scales and contributed about one fourth of the 80-100 ppm lowering of glacial atmospheric CO2 concentrations.In this study, we quantify the effect of global dust fluxes on atmospheric CO2 using the cGENIE model, an Earth System Model of Intermediate Complexity with emphasis on the carbon cycle. Global Holocene and Last Glacial Maximum (LGM) dust flux fields were obtained from both dust model simulations and reconstructions based on observational data. The analysis was performed in two stages. In the first instance, we produced 8 global intermediate dust flux fields between Holocene and LGM and simulated the atmospheric CO2 drawdown due to these 10 dust levels. In the second stage, we only changed dust flux levels in specific HNLC regions to isolate the effect of these ocean basins. We thus quantify the contribution of the South Atlantic, the South Pacific, the North Pacific, and the Central Pacific HNLC regions to the total atmospheric CO2 difference due to iron fertilization of the Earth's oceans.

Iron and stony-iron meteorites

DEFF Research Database (Denmark)

Ruzicka, Alex M.; Haack, Henning; Chabot, Nancy L.

2017-01-01

By far most of the melted and differentiated planetesimals that have been sampled as meteorites are metal-rich iron meteorites or stony iron meteorites. The parent asteroids of these meteorites accreted early and differentiated shortly after the solar system formed, producing some of the oldest...... and interpretations for iron and stony iron meteorites (Plate 13.1). Such meteorites provide important constraints on the nature of metal-silicate separation and mixing in planetesimals undergoing partial to complete differentiation. They include iron meteorites that formed by the solidification of cores...... (fractionally crystallized irons), irons in which partly molten metal and silicates of diverse types were mixed together (silicate-bearing irons), stony irons in which partly molten metal and olivine from cores and mantles were mixed together (pallasites), and stony irons in which partly molten metal...

Direct Iron Coating onto Nd-Fe-B Powder by Thermal Decomposition of Iron Pentacarbonyl

International Nuclear Information System (INIS)

Yamamuro, S; Okano, M; Tanaka, T; Sumiyama, K; Nozawa, N; Nishiuchi, T; Hirosawa, S; Ohkubo, T

2011-01-01

Iron-coated Nd-Fe-B composite powder was prepared by thermal decomposition of iron pentacarbonyl in an inert organic solvent in the presence of alkylamine. Though this method is based on a modified solution-phase process to synthesize highly size-controlled iron nanoparticles, it is in turn featured by a suppressed formation of iron nanoparticles to achieve an efficient iron coating solely onto the surfaces of rare-earth magnet powder. The Nd-Fe-B magnetic powder was successfully coated by iron shells whose thicknesses were of the order of submicrometer to micrometer, being tuneable by the amount of initially loaded iron pentacarbonyl in a reaction flask. The amount of the coated iron reached to more than 10 wt.% of the initial Nd-Fe-B magnetic powder, which is practically sufficient to fabricate Nd-Fe-B/α-Fe nanocomposite permanent magnets.

Uncertainty analysis of scintillometers methods in measuring sensible heat fluxes of forest ecosystem

Science.gov (United States)

Zheng, N.

2017-12-01

degree of uncertainty with quantitative analysis. The study can provide theoretical basis and technical support for accurately measuring sensible heat fluxes of forest ecosystem with scintillometer method, and can also provide work foundation for further study on role of forest ecosystem in energy balance and climate change.

Coupling multipoint flux mixed finite element methodswith continuous Galerkin methods for poroelasticity

KAUST Repository

Wheeler, Mary

2013-11-16

We study the numerical approximation on irregular domains with general grids of the system of poroelasticity, which describes fluid flow in deformable porous media. The flow equation is discretized by a multipoint flux mixed finite element method and the displacements are approximated by a continuous Galerkin finite element method. First-order convergence in space and time is established in appropriate norms for the pressure, velocity, and displacement. Numerical results are presented that illustrate the behavior of the method. © Springer Science+Business Media Dordrecht 2013.

Sedimentary and mineral dust sources of dissolved iron to the world ocean

Directory of Open Access Journals (Sweden)

J. K. Moore

2008-05-01

Full Text Available Analysis of a global compilation of dissolved-iron observations provides insights into the processes controlling iron distributions and some constraints for ocean biogeochemical models. The distribution of dissolved iron appears consistent with the conceptual model developed for Th isotopes, whereby particle scavenging is a two-step process of scavenging mainly by colloidal and small particulates, followed by aggregation and removal on larger sinking particles. Much of the dissolved iron (<0.4 μm is present as small colloids (>~0.02 μm and, thus, is subject to aggregation and scavenging removal. This implies distinct scavenging regimes for dissolved iron consistent with the observations: 1 a high scavenging regime – where dissolved-iron concentrations exceed the concentrations of strongly binding organic ligands; and 2 a moderate scavenging regime – where dissolved iron is bound to both colloidal and soluble ligands. Within the moderate scavenging regime, biological uptake and particle scavenging decrease surface iron concentrations to low levels (<0.2 nM over a wide range of low to moderate iron input levels. Removal rates are also highly nonlinear in areas with higher iron inputs. Thus, observed surface-iron concentrations exhibit a bi-modal distribution and are a poor proxy for iron input rates. Our results suggest that there is substantial removal of dissolved iron from subsurface waters (where iron concentrations are often well below 0.6 nM, most likely due to aggregation and removal on sinking particles of Fe bound to organic colloids.

We use the observational database to improve simulation of the iron cycle within a global-scale, Biogeochemical Elemental Cycling (BEC ocean model. Modifications to the model include: 1 an improved particle scavenging parameterization, based on the sinking mass flux of particulate organic material, biogenic silica, calcium carbonate, and mineral dust particles; 2 desorption of dissolved iron

Development of methodics for the characterization of the composition of the ion-collision-induced secondary-particle flux by comparison of the yield contributions of photoinduced ion formation processes; Entwicklung einer Methodik zur Charakterisierung der Zusammensetzung des ionenbeschussinduzierten Sekundaerteilchenflusses durch Vergleich der Ausbeuteanteile photoinduzierter Ionenbildungsprozesse

Energy Technology Data Exchange (ETDEWEB)

Vering, Guido

2008-10-13

The aim of this work was to develop a method to distinguish between different ion formation processes and to determine the influence of these processes on the total number of detected monatomic ions of a certain element. A vector/matrix-formalism was developed, which describes the physical processes of sputtering, ion formation, mass separation and detection in laser-SNMS. In the framework of the method developed, based on this theoretic formalism, changes in the secondary flux contribution of the respective element were observed by comparing the detected monatomic ion yield obtained in specifically aligned (SIMS and) laser-SNMS experiments. The yields resulting from these experiments were used to calculate characteristic numbers to compare the flux composition from different surfaces. The potential of the method was demonstrated for the elements boron, iron and gadolinium by investigating the changes in the flux composition of secondary particles sputtered from metallic surfaces, as a function of the oxygen concentration at the surface. Finally, combined laser-SNMS depth profiles and images, obtained with both laser systems, were presented to demonstrate how the parallel detection of the three differently originated ion signals of the same element can be used to get additional information about the composition of the flux of secondary particles synchronously during the analysis of elemental distributions. In this respect the presented method can be a very helpful tool to prevent misleading interpretations of SIMS or laser-SNMS data. (orig.)

IRON CONTENT OF FOOD COOKED IN IRON UTENSILS: A TRADITIONAL INDIAN WAY

Directory of Open Access Journals (Sweden)

Bibifatima Bawakhan

2016-08-01

Full Text Available BACKGROUND Since most of the Indian population depends on vegetarian diet, prevalence of iron deficiency status is higher in India compared to other developing countries. In spite of many national programs and treatment options available in correcting this, the incidence is increasing due to poor patient compliance and intolerance to treatment. This study was an effort to show how iron content of Indian food can be increased just by following the traditional way of cooking. OBJECTIVE To compare the iron levels in the Jowar roti cooked in iron and non-iron utensils. METHODOLOGY A cross-sectional study was conducted at KIMS, Hubli. Jowar rotis were prepared from equal quantity of jowar flour in iron and non-iron tawa. Another sample of roti was prepared in iron tawa after treating with lemon juice. Six samples were homogenised and filtered. The filtrates were replicated and analysed for iron levels by FerroZine method. RESULTS In the present study, we found no change in iron levels in the roti prepared in non-iron utensil, 1.45 and 1.94 fold increase in the roti prepared in new iron tawa without water boiled in it and with water boiled in it for dough preparation respectively when compared with iron levels of plain jowar flour. There was 5.77 fold rise in iron levels in lemon juice treated roti which signifies the bioavailability of iron in food. The study showed statistical significance at ‘p’- value < 0.05. CONCLUSION Several studies have shown the similar results and this was done to strengthen the findings in our staple food. Hence, the daily iron requirement can be met easily and effectively by taking the food cooked with lemon juice in iron utensils.

Retrospective comparison of gradient recalled echo R2* and spin-echo R2 magnetic resonance analysis methods for estimating liver iron content in children and adolescents

Energy Technology Data Exchange (ETDEWEB)

Serai, Suraj D.; Fleck, Robert J. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, MLC 5031, Cincinnati, OH (United States); Quinn, Charles T. [Cincinnati Children' s Hospital Medical Center, Division of Hematology, Cincinnati, OH (United States); Zhang, Bin [Cincinnati Children' s Hospital Medical Center, Division of Biostatistics and Epidemiology, Cincinnati, OH (United States); Podberesky, Daniel J. [Nemours Children' s Health System Nemours Children' s Hospital, Department of Radiology, Orlando, FL (United States)

2015-10-15

Serial surveillance of liver iron concentration (LIC) provides guidance for chelation therapy in patients with iron overload. The diagnosis of iron overload traditionally relies on core liver biopsy, which is limited by invasiveness, sampling error, cost and general poor acceptance by pediatric patients and parents. Thus noninvasive diagnostic methods such as MRI are highly attractive for quantification of liver iron concentration. To compare two MRI-based methods for liver iron quantification in children. 64 studies on 48 children and young adults (age range 4-21 years) were examined by gradient recalled echo (GRE) R2* and spin-echo R2 MRI at 1.5T to evaluate liver iron concentration. Scatter plots and Bland-Altman difference plots were generated to display and assess the relationship between the methods. With the protocols used in this investigation, Bland-Altman agreement between the methods is best when LIC is <20 mg/g dry tissue. Scatter plots show that all values with LIC <20 mg/g dry tissue fall within the 95% prediction limits. Liver iron concentration as determined by the R2* and R2 MR methods is statistically comparable, with no statistical difference between these methods for LIC <20 mg/g. (orig.)

Radon flux measurement methodologies

International Nuclear Information System (INIS)

Nielson, K.K.; Rogers, V.C.

1984-01-01

Five methods for measuring radon fluxes are evaluated: the accumulator can, a small charcoal sampler, a large-area charcoal sampler, the ''Big Louie'' charcoal sampler, and the charcoal tent sampler. An experimental comparison of the five flux measurement techniques was also conducted. Excellent agreement was obtained between the measured radon fluxes and fluxes predicted from radium and emanation measurements

A novel method of synthesizing cyclodextrin grafted multiwall carbon nanotubes/iron oxides and its adsorption of organic pollutant

Energy Technology Data Exchange (ETDEWEB)

Liu, Wei; Jiang, Xinyu [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Chen, Xiaoqing, E-mail: xqchen@csu.edu.cn [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Collaborative Innovation Center of Resource-conserving and Environment-friendly Society and Ecological Civilization (China)

2014-11-30

Highlights: • A cost-effective and one-step method for grafting cyclodextrin onto magnetic material. • Relatively good separation and regeneration properties as adsorbent. • The adsorption capacities are comparable with other adsorbents reported previously. - Abstract: A novel methodology for the synthesis of the multiwalled carbon nanotubes/iron oxides modified by β-cyclodextrin (denoted as MWCNTs/iron oxides/β-CD) was proposed using 1,6-diisocyanatohexane as cross-linker in N,N-dimethyl formamide, which avoided complex steps in the link of β-cyclodextrin and MWCNTs/iron oxides via conventional synthetic methods. The characteristic results of Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), powder X-ray diffraction (XRD), and thermogravimetric analysis (TGA) showed that β-CD was grafted onto the MWCNTs/iron oxides successfully. In addition, vibrating sample magnetometer (VSM) and magnetic separation experiment suggested that the prepared composite exhibited preferable magnetic property and good dispersion property in aqueous solution. The effects of contact time, initial adsorbent content, solution pH and temperature on the adsorption of p-nitrophenol (PNP) were studied systematically. The adsorption kinetics and equilibrium isotherms data fitted well with pseudo-second-order kinetic equation and Langmuir isotherm model, respectively. Furthermore, the adsorption-desorption experiment of PNP demonstrated that MWCNTs/iron oxides/β-CD is a cost-effective material with high regeneration efficiency.

Flux weighted method for solution of stiff neutron dynamic equations and its application

International Nuclear Information System (INIS)

Li Huiyun; Jiao Huixian

1987-12-01

To analyze reactivity event for nuclear power plants, it is necessary to solve the neutron dynamic equations, which is a group of typical stiff constant differential equations. Very small time steps could only be adopted when the group of equations is solved by common methods. However, a large time steps might be selected if the Flux Weighted Medthod introduced in this paper is used. Generally, weighted factor θ i1 is set as a constant. Naturally, this treatment method can decrease the accuracy of calculation for the increase of the steadiness of solving the equations. An accurate theoretical formula of 4 x 4 matrix of θ i1 is rigorously derived so that the accuracy of calculation is ensured, as well as the steadiness of solved equations is increased. This method have the advantage over classical Runge-kutta Method and other methods. The time steps could be increased by a factor of 1 ∼ 3 orders of magnitude so as to save a lot of computating time. The programe solving neutron dynamic equation, which is prepared by using Flux Weighted Method, could be sued for real time analog of training simulator, as well as for analysis and computation of reactivity event (including rod jumping out event)

Experience in studying of the iron mineralogy in the oxidation zone of uranium deposits by physical methods

International Nuclear Information System (INIS)

Kochenov, A.V.; Dobrovol'skaya, N.V.; Zajtseva, G.M.; Korovushkin, V.V.; Moiseev, V.M.; Yakubovskaya, N.Yu.

1977-01-01

Possibilities are considered of increasing the reliability of the diagnostics and the resolving power of the procedure for the determination of the minaral forms and percentage of iron oxides and hydroxides in the oxidized zone of uranium deposits using a combination of methods of nuclear gamma resonance, thermomagnetic analysis and the Faraday method. The apparatus used included a YaGRS-4 spectrometer in combination with an AI-236 analyzer and a vibration magnetometer. The essence of the methods and of the procedure of analyses is presented. Parameters of reference samples of goethite, maghemite, etc. which emerged from their analysis by the above combination of methods are given. The established diagnostic features have been used in the study of iron mineralogy of oxidized zones, uranium deposits of sedimantarycoal and sandstone types, as well as crusts of weathering of sedimentary rocks. It has been found that in zone of epigenetically altered rocks iron minerals are of mixed multicomponent composition reflecting the fact that the processes of formation of oxidized zones are multistage and not unidirectional in character. The procedure proposed allows one to diagnose finely dispersed, roentgenoamorphous or poorly crystallized minerals, to discover ferruginous minerals in complex multiphase systems and determine their percentages

Iron losses evaluation in soft magnetic materials with a sinusoidal voltage supply

DEFF Research Database (Denmark)

Nedelcu, Steluţa; Ritchie, Ewen; Leban, Krisztina Monika

2013-01-01

This paper presents an evaluation method of for specific iron losses in non-oriented laminated steel suitable for electric motors and transformers in the case of a sinusoidal excitation. The model is based on the separation of loss contribution due to hysteresis, eddy currents and excess losses...... (between 0.35 mm and 0.65 mm) and alloy compositions. Hysteresis and eddy currents loss coefficients have been considered as dependent on the frequency. For curve fitting of these coefficients third and fourth polynomials were employed, with good result for all the frequencies and magnetic flux density...... and it is proposing an identification procedure for the model coefficients from multi-frequency single sheet tests. The frequencies used are in the range 10 Hz and 150 Hz and with the values of magnetic flux density in the range 0.1 T and 1.4 T. The model was applied on six magnetic materials of different thicknesses...

An analysis of pavement heat flux to optimize the water efficiency of a pavement-watering method

International Nuclear Information System (INIS)

Hendel, Martin; Colombert, Morgane; Diab, Youssef; Royon, Laurent

2015-01-01

Pavement-watering as a technique of cooling dense urban areas and reducing the urban heat island effect has been studied since the 1990's. The method is currently considered as a potential tool for and climate change adaptation against increasing heat wave intensity and frequency. However, although water consumption necessary to implement this technique is an important aspect for decision makers, optimization of possible watering methods has only rarely been conducted. An analysis of pavement heat flux at a depth of 5 cm and solar irradiance measurements is proposed to attempt to optimize the watering period, cycle frequency and water consumption rate of a pavement-watering method applied in Paris over the summer of 2013. While fine-tuning of the frequency can be conducted on the basis of pavement heat flux observations, the watering rate requires a heat transfer analysis based on a relation established between pavement heat flux and solar irradiance during pavement insolation. From this, it was found that watering conducted during pavement insolation could be optimized to 30-min cycles and water consumption could be reduced by more than 80% while reducing the cooling effect by less than 13%. - Highlights: • The thermal effects of pavement-watering were investigated in Paris, France. • Pavement-watering was found to significantly affect pavement heat flux 5 cm deep. • When insolated, a linear relation was found between heat flux and solar radiation. • Pavement-watering did not alter its slope, but introduced a negative intercept. • Subsequent improvements of the watering period, frequency and rate are proposed

Iron oxide nanoparticles: the Influence of synthesis method and size on composition and magnetic properties

International Nuclear Information System (INIS)

Carvalho, M.D.; Henriques, F.; Ferreira, L.P.; Godinho, M.; Cruz, M.M.

2013-01-01

Iron oxide nanoparticles with mean diameter ranging from 7 to 20 nm were synthesized using two routes: the precipitation method in controlled atmosphere and a reduction–precipitation method under air, in some cases followed by a hydrothermal treatment. The smallest nanoparticles were obtained by the reduction–precipitation method. In order to establish the composition of the iron oxide nanoparticles and its relation with size, the morphological, structural and magnetic properties of the prepared samples were investigated using X-ray diffraction, transmission electron microscopy, Mössbauer spectroscopy and SQUID magnetometry. The results allow to conclude that the nanoparticles can be essentially described as Fe 3−x O 4 , x decreasing with the particle size increase. The composition and magnetic behavior of the synthesized iron oxide nanoparticles are directly related with their size. The overall results are compatible with a core@shell structure model, where a magnetite core is surrounded by an oxidized magnetite layer (labeled as maghemite), the magnetite core dimension depending on the average particle size. - Graphical abstract: TEM images and Mössbauer spectroscopy spectra of Fe 3−x O 4 samples with different sizes. Highlights: ► Fe 3−x O 4 nanoparticles with a mean size between 7 and 20 nm were synthesized. ► The smallest nanoparticles were obtained by a reduction precipitation method, under air. ► The increase of particles size was succeeded using a hydrothermal treatment at 150 °C. ► The magnetic properties of the nanoparticles are directly related with their size

Method for preparing high cure temperature rare earth iron compound magnetic material

Science.gov (United States)

Huang, Yuhong; Wei, Qiang; Zheng, Haixing

2002-01-01

Insertion of light elements such as H,C, or N in the R.sub.2 Fe.sub.17 (R=rare earth metal) series has been found to modify the magnetic properties of these compounds, which thus become prospective candidates for high performance permanent magnets. The most spectacular changes are increases of the Curie temperature, T.sub.c, of the magnetization, M.sub.s, and of coercivity, H.sub.c, upon interstitial insertion. A preliminary product having a component R--Fe--C,N phase is produced by a chemical route. Rare earth metal and iron amides are synthesized followed by pyrolysis and sintering in an inert or reduced atmosphere, as a result of which, the R--Fe--C,N phases are formed. Fabrication of sintered rare earth iron nitride and carbonitride bulk magnet is impossible via conventional process due to the limitation of nitridation method.

Study of granitic biotites by X-ray fluorescence analysis: determination of iron, manganese, titanium, calcium, potassium, silicon and aluminium; Estudio de biotitas graniticas por fluorescencia de rayos X: Determinacion de hierro, manganeso, titanio, calcio, potasio, silicio y aluminio

Energy Technology Data Exchange (ETDEWEB)

Toubes, R. O.; Bermudez Polonio, J.

1968-07-01

A method for the quantitative determination of iron, manganese, titanium, calcium potassium, silicon, and aluminium, is reported, Sample preparation is carried out by the miniature flux technique, and rubidium is used as internal standard for silicon and aluminium. (Author) 5 refs.

Dechlorination of TCE with palladized iron

Science.gov (United States)

Fernando, Quintus; Muftikian, Rosy; Korte, Nic

1997-01-01

The present invention relates to various methods, such as an above-ground method and an in-ground method, of using a palladized iron bimetallic system for the dechlorination of chlorinated organic compounds from effluents containing the same. The use of palladized iron bimetallic system results in the dechlorination of the chlorinated organic compound into environmentally safe reaction products. The present invention also provides kits, devices, and other instruments that use the above-mentioned palladized iron bimetallic system for the dechlorination of chlorinated organic compounds.

Optoelectronic iron detectors for pharmaceutical flow analysis.

Science.gov (United States)

Rybkowska, Natalia; Koncki, Robert; Strzelak, Kamil

2017-10-25

Compact flow-through optoelectronic detectors fabricated by pairing of light emitting diodes have been applied for development of economic flow analysis systems dedicated for iron ions determination. Three analytical methods with different chromogens selectively recognizing iron ions have been compared. Ferrozine and ferene S based methods offer higher sensitivity and slightly lower detection limits than method with 1,10-phenantroline, but narrower ranges of linear response. Each system allows detection of iron in micromolar range of concentration with comparable sample throughput (20 injections per hour). The developed flow analysis systems have been successfully applied for determination of iron in diet supplements. The utility of developed analytical systems for iron release studies from drug formulations has also been demonstrated. Copyright © 2017 Elsevier B.V. All rights reserved.

Hydrogen permeation through sol-gel-coated iron during galvanostatic charging

International Nuclear Information System (INIS)

Zakorchemna, I.; Carmona, N.; Zakroczymski, T.

2008-01-01

One-layer sol-gel silica-zirconia and two-layer silica-zirconia and zirconia coatings were deposited on one side of iron membranes by spin-coating, densified in air and annealed up to 800 deg. C in vacuum. Hydrogen permeation through the membranes, coated and uncoated, polarised cathodically under galvanostatic control in 0.1 M NaOH solution was studied using the electrochemical permeation technique. During the initial period, the effect of the sol-gel coatings was insignificant. However, the coatings quite efficiently prevented the iron surface become more active to hydrogen entry during a long-lasting cathodic polarisation. In addition, the electrochemical-corrosion behaviour of the coated iron and the effect of the sol-gel coatings on the effective diffusivity of hydrogen in the coated membranes were studied. On the basis of the polarisation curves and the hydrogen permeation data it was proved that the sol-gel coatings blocked the iron surface for the hydrogen evolution reaction and, consequently, for the hydrogen entry into iron. The effective coating coverage was determined by comparison of the hydrogen fluxes permeating the coated and uncoated membranes. Finally the real concentration of hydrogen beneath the uncoated iron sites and the amount of hydrogen stored in a membrane were evaluated

Quantitating Iron in Serum Ferritin by Use of ICP-MS

Science.gov (United States)

Smith, Scott M.; Gillman, Patricia L.

2003-01-01

A laboratory method has been devised to enable measurement of the concentration of iron bound in ferritin from small samples of blood (serum). Derived partly from a prior method that depends on large samples of blood, this method involves the use of an inductively-coupled-plasma mass spectrometer (ICP-MS). Ferritin is a complex of iron with the protein apoferritin. Heretofore, measurements of the concentration of serum ferritin (as distinguished from direct measurements of the concentration of iron in serum ferritin) have been used to assess iron stores in humans. Low levels of serum ferritin could indicate the first stage of iron depletion. High levels of serum ferritin could indicate high levels of iron (for example, in connection with hereditary hemochromatosis an iron-overload illness that is characterized by progressive organ damage and can be fatal). However, the picture is complicated: A high level of serum ferritin could also indicate stress and/or inflammation instead of (or in addition to) iron overload, and low serum iron concentration could indicate inflammation rather than iron deficiency. Only when concentrations of both serum iron and serum ferritin increase and decrease together can the patient s iron status be assessed accurately. Hence, in enabling accurate measurement of the iron content of serum ferritin, the present method can improve the diagnosis of the patient s iron status. The prior method of measuring the concentration of iron involves the use of an atomic-absorption spectrophotometer with a graphite furnace. The present method incorporates a modified version of the sample- preparation process of the prior method. First, ferritin is isolated; more specifically, it is immobilized by immunoprecipitation with rabbit antihuman polyclonal antibody bound to agarose beads. The ferritin is then separated from other iron-containing proteins and free iron by a series of centrifugation and wash steps. Next, the ferritin is digested with nitric acid

Can sediments at hydrocarbon seep sites represent a source for marine bioavailable iron? — A case study from the South China Sea

Science.gov (United States)

Li, N.; Feng, D.; Chen, D.

2017-12-01

Niu Li1, Dong Feng1,2, and Duofu Chen2,31CAS Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China. 2Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266061, China. 3Hadal Science and Technology Research Center, College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China. Iron is an essential micronutrient and commonly considered to be one of the key-limiting factors for biological productivity in many ocean regions. Seafloor Fe supply should be most efficient in suboxic conditions. Recent studies shown that widely spread anoxic environments can develop in hydrocarbon seep sediment and local bottom water, owing to the occurrence of aerobic and/or anaerobic methane oxidation. Under this condition, the iron in sediment can be reduced to dissolved Fe2+ in the ocean. However, questions remain about whether the hydrocarbon seep sediment can represent a source for bioavailable iron to the ocean, and the control factor for the transformation of iron in the sediment remains largely unexplored. For a number of hydrocarbon seeps from the northern and southern South China Sea, the iron speciation, pyrite sulfur isotope, and iron isotope, as well as the major and trace elements are used to constrain the intensity of cold seep, and its impact on transformation of iron in sediment. Samples from both areas show sediment iron lost during the high methane flux conditions, owing to the suboxic conditions cause by aerobic methane oxidation. On the other hand, high sediment iron content accompanied by high sulfur content can be seen during the conditions of high methane flux without the occurrence of aerobic methane oxidation, which is possible ascribed to the anaerobic methane oxidation and the release of iron through seep activity. This study reveals the transformation of iron in the sediment is closely related to the

Measurement of Total Free Iron in Soils by H2S Chemisorption and Comparison with the Citrate Bicarbonate Dithionite Method

Directory of Open Access Journals (Sweden)

Shui-Sheng Fan

2016-01-01

Full Text Available Free iron is one of the major analytical items for soil basic properties. It is also an important indicator for understanding the genesis of soil, soil classification, and soil distribution behavior. In this study, an alternative analytical method (chemisorption based on thermodynamic knowledge was proposed for measurement of total free iron oxides in soils. Several representative soil samples belonging to alfisols, ultisols, inceptisols, and entisols were collected from Taiwan and tested by the chemisorption, and the estimated total free iron oxides were compared with those measured from the traditional citrate bicarbonate dithionite (CBD method. Experimental results showed that the optimal operating temperature was found to be at 773 K and the carbon monoxide (CO is the best gaseous reagent to promote the formation of FeS. The estimated total free iron oxides for soil samples determined from the chemisorption in the presence of CO were very close to those from the CBD technique. The result of regression indicates that the estimated total free iron is strongly correlated with the CBD-Fe content (R2=0.999 in the presence of CO.

Temperature effect correction for muon flux at the Earth surface: estimation of the accuracy of different methods

International Nuclear Information System (INIS)

Dmitrieva, A N; Astapov, I I; Kovylyaeva, A A; Pankova, D V

2013-01-01

Correction of the muon flux at the Earth surface for temperature effect with the help of two simple methods is considered. In the first method, it is assumed that major part of muons are generated at some effective generation level, which altitude depends on the temperature profile of the atmosphere. In the second method, dependence of muon flux on the mass-averaged atmosphere temperature is considered. The methods were tested with the data of muon hodoscope URAGAN (Moscow, Russia). Difference between data corrected with the help of differential in altitude temperature coefficients and simplified methods does not exceed 1-1.5%, so the latter ones may be used for introduction of a fast preliminary correction.

WATSFAR: numerical simulation of soil WATer and Solute fluxes using a FAst and Robust method

Science.gov (United States)

Crevoisier, David; Voltz, Marc

2013-04-01

To simulate the evolution of hydro- and agro-systems, numerous spatialised models are based on a multi-local approach and improvement of simulation accuracy by data-assimilation techniques are now used in many application field. The latest acquisition techniques provide a large amount of experimental data, which increase the efficiency of parameters estimation and inverse modelling approaches. In turn simulations are often run on large temporal and spatial domains which requires a large number of model runs. Eventually, despite the regular increase in computing capacities, the development of fast and robust methods describing the evolution of saturated-unsaturated soil water and solute fluxes is still a challenge. Ross (2003, Agron J; 95:1352-1361) proposed a method, solving 1D Richards' and convection-diffusion equation, that fulfil these characteristics. The method is based on a non iterative approach which reduces the numerical divergence risks and allows the use of coarser spatial and temporal discretisations, while assuring a satisfying accuracy of the results. Crevoisier et al. (2009, Adv Wat Res; 32:936-947) proposed some technical improvements and validated this method on a wider range of agro- pedo- climatic situations. In this poster, we present the simulation code WATSFAR which generalises the Ross method to other mathematical representations of soil water retention curve (i.e. standard and modified van Genuchten model) and includes a dual permeability context (preferential fluxes) for both water and solute transfers. The situations tested are those known to be the less favourable when using standard numerical methods: fine textured and extremely dry soils, intense rainfall and solute fluxes, soils near saturation, ... The results of WATSFAR have been compared with the standard finite element model Hydrus. The analysis of these comparisons highlights two main advantages for WATSFAR, i) robustness: even on fine textured soil or high water and solute

Solidification of cast iron - A study on the effect of microalloy elements on cast iron

DEFF Research Database (Denmark)

Moumeni, Elham

The present thesis deals with the heat transfer and solidification of ductile and microalloyed grey cast iron. Heterogeneous nucleation of nodular graphite at inclusions in ductile iron during eutectic solidification has been investigated. A series of ductile iron samples with two different...... of the austenite, in the last region to solidify. The superfine graphite which forms in this type of irons is short (10-20µm) and stubby. The microstructure of this kind of graphite flakes in titanium alloyed cast iron is studied using electron microscopy techniques. The methods to prepare samples of cast iron...... for comprehensive transmission electron microscopy of graphite and the surrounding iron matrix have been developed and explained. Dual beam microscopes are used for sample preparation. A TEM study has been carried out on graphite flakes in grey cast iron using selected area electron diffraction (SAED). Based...

Preparation of yttrium iron garnet (YIG) by modified domestic iron oxide

International Nuclear Information System (INIS)

Mozaffari, M.; Amighian

2002-01-01

Iron oxide by product of a local steel complex was modified to use for preparation of Yttrium iron garnet (YIG). The improvement was necessary to reduce impurities, especially the Si0 2 and Cl contents, which have deteriorative effects on magnetic properties and equipment used for preparation of the samples. The modified iron oxide was then mixed with Yttrium oxide of Merck Company in appropriate proportion to obtain a stoichiometric single phase YIG, using the conventional ceramic technique. XRD and SEM equipments were used to identify the resulting phases and microstructure respectively. Magnetic parameters were measured by VSM. Curie temperature of the samples was obtained by DTG (M) method. The results were compared with those obtained from samples that made by Merck iron oxide. There are small differences between the results. This was discussed according to extra pores and minute secondary phase in the samples made by domestic iron oxide. (Author)

Gradient heat flux measurement as monitoring method for the diesel engine

Science.gov (United States)

Sapozhnikov, S. Z.; Mityakov, V. Yu; Mityakov, A. V.; Vintsarevich, A. V.; Pavlov, A. V.; Nalyotov, I. D.

2017-11-01

The usage of gradient heat flux measurement for monitoring of heat flux on combustion chamber surface and optimization of diesel work process is proposed. Heterogeneous gradient heat flux sensors can be used at various regimes for an appreciable length of time. Fuel injection timing is set by the position of the maximum point on the angular heat flux diagram however, the value itself of the heat flux may not be considered. The development of such an approach can be productive for remote monitoring of work process in the cylinders of high-power marine engines.

Ocean fertilization with iron: effects on climate and air quality

International Nuclear Information System (INIS)

Liss, Peter; Chuck, Adele; Bakker, Dorothee; Turner, Suzanne

2005-01-01

It is well known that iron fertilization can increase primary production and hence CO 2 drawdown over a significant fraction of the oceans. What is less well established is the extent to which this leads to long-term sequestration of carbon to the deep oceans, and to feedbacks to the atmosphere arising from increased biological activity. In this note results for changes in trace gas concentrations during an iron addition experiment in the Southern Ocean are presented. They demonstrate that a complex situation exists; some gases (DMS, CH 3 I, CHBr 2 Cl) show increases in concentration following fertilization with iron while others show no change (CH 3 ONO 2 , CH 2 ClI) or even a decrease (CHBr 3 ). The concomitant effects on air/sea fluxes of these gases are potentially important for climate and atmospheric composition

A method for measuring element fluxes in an undisturbed soil: nitrogen and carbon from earthworms

International Nuclear Information System (INIS)

Bouche, M.B.

1984-01-01

Data on chemical cycles, as nitrogen or carbon cycles, are extrapolated to the fields or ecosystems without the possibility for checking conclusions; i.e. from scientific knowledge (para-ecology). A new method, by natural introduction of an earthworm compartment into an undisturbed soil, with earthworms labelled both by isotopes ( 15 N, 14 C) and by staining is described. This method allows us to measure fluxes of chemicals. The first results, gathered during the improvement of the method in partly artificial conditions, are cross-checked with other data given by direct observation in the field. Measured flux (2.2 mg N/g fresh mass empty gut/day/15 0 C) is far more important than para-ecological estimations; animal metabolism plays directly an important role in nitrogen and carbon cycles. (author)

Detailed non-LTE calculations of the iron emission from NGC 1068

Science.gov (United States)

Band, David L.; Klein, Richard I.; Castor, John I.; Nash, J. K.

1989-01-01

The X-ray iron line emission from NGC 1068 observed by the Ginga satellite is modeled using the new multiline, multilevel, non-LTE radiative transport code ALTAIR and a detailed atomic model for Ne-like through stripped iron. The parameter space of the obscured type 1 Seyfert nucleus model for this object is studied. The equivalent width is greater than previously predicted. It is found that detailed radiative transfer can have a significant effect on the observed line flux both for the K alpha line and for the L-shell emission. The ionization of the iron increases with temperature. Therefore the K alpha equivalent width and energy is a function not only of the ionization parameter, but also of the column depth and temperature. For a likely model of NGC 1068 it is found that the iron abundance is about twice solar, but that modifications of this model may permit a smaller abundance.

Assessment of iron deficiency in pregnant women by determining iron status

International Nuclear Information System (INIS)

Raza, N.; Munazza, B.; Ayub, M.; Sarwar, I

2011-01-01

Background: Pregnant women constitute a high risk group for iron deficiency. Maternal iron deficiency and particularly iron deficiency anaemia may be associated with detrimental effects on maternal and infant function and particularly with a higher risk of preterm delivery and delivery of low birth weight neonates. Objective of this study was to assess and compare the iron status of normal healthy non-pregnant women with that of pregnant women of Hazara Division. Methods: This study was conducted at Faculty of Health Sciences, Hazara University, and Ayub Medical College, Abbottabad from first March to /31 August 2006. Altogether 120 women, 90 pregnant at various stages of pregnancy and 30 non-pregnant women as control group were included in this study by convenience sampling. Their iron status was assessed by determination of haemoglobin (Hb), Serum ferritin, Serum-iron, Total Iron Binding Capacity (TIBC), Unsaturated Iron Binding Capacity (UIBC), and Percentage saturation of transferrin. Data generated on these variables were subjected to ANOVA and correlation analysis. Results: The salient finding of this study is a significant decrease in Hb, Serum ferritin, Serum iron, percentage saturation of transferrin and a significant increase in values of TIBC and a pronounced increase in UIBC in second and third trimester compared to first trimester in iron deficient pregnant women. The mean values of Hb, SF, and Fe/TIBC% were significantly lower in the cases than in the control and significantly higher values of TIBC and UIBC were observed in the cases compared to controls. Significant correlations were observed for TIBC, UIBC and Fe/TIBC% against serum iron in different trimesters of pregnancy. Conclusion: A high percentage of the pregnant women are iron deficient due to factors such as high parity, poor dietary habits and socioeconomic status. (author)

Investigation of Flux-Linkage Profile Measurement Methods for Switched-Reluctance Motors and Permanent-Magnet Motors

DEFF Research Database (Denmark)

Lu, Kaiyuan; Rasmussen, Peter Omand; Ritchie, Ewen

2009-01-01

Knowledge of actual flux linkage versus current profiles plays an important role in design verification and performance prediction for switched reluctance motors (SRM's) and permanent magnet motors (PMM's). Various measurement methods have been proposed and discussed so far but each method has its...

An inverse hyperbolic heat conduction problem in estimating surface heat flux by the conjugate gradient method

International Nuclear Information System (INIS)

Huang, C.-H.; Wu, H.-H.

2006-01-01

In the present study an inverse hyperbolic heat conduction problem is solved by the conjugate gradient method (CGM) in estimating the unknown boundary heat flux based on the boundary temperature measurements. Results obtained in this inverse problem will be justified based on the numerical experiments where three different heat flux distributions are to be determined. Results show that the inverse solutions can always be obtained with any arbitrary initial guesses of the boundary heat flux. Moreover, the drawbacks of the previous study for this similar inverse problem, such as (1) the inverse solution has phase error and (2) the inverse solution is sensitive to measurement error, can be avoided in the present algorithm. Finally, it is concluded that accurate boundary heat flux can be estimated in this study

Bioavailable iron in the Southern Ocean: the significance of the iceberg conveyor belt.

Science.gov (United States)

Raiswell, Rob; Benning, Liane G; Tranter, Martyn; Tulaczyk, Slawek

2008-05-30

Productivity in the Southern Oceans is iron-limited, and the supply of iron dissolved from aeolian dust is believed to be the main source from outside the marine reservoir. Glacial sediment sources of iron have rarely been considered, as the iron has been assumed to be inert and non-bioavailable. This study demonstrates the presence of potentially bioavailable Fe as ferrihydrite and goethite in nanoparticulate clusters, in sediments collected from icebergs in the Southern Ocean and glaciers on the Antarctic landmass. Nanoparticles in ice can be transported by icebergs away from coastal regions in the Southern Ocean, enabling melting to release bioavailable Fe to the open ocean. The abundance of nanoparticulate iron has been measured by an ascorbate extraction. This data indicates that the fluxes of bioavailable iron supplied to the Southern Ocean from aeolian dust (0.01-0.13 Tg yr(-1)) and icebergs (0.06-0.12 Tg yr(-1)) are comparable. Increases in iceberg production thus have the capacity to increase productivity and this newly identified negative feedback may help to mitigate fossil fuel emissions.

Chambers versus Relaxed Eddy Accumulation: an intercomparison study of two methods for short-term measurements of biogenic CO2 fluxes

Science.gov (United States)

Jasek, Alina; Zimnoch, Miroslaw; Gorczyca, Zbigniew; Chmura, Lukasz; Necki, Jaroslaw

2014-05-01

The presented work is a part of comprehensive study aimed at thorough characterization of carbon cycle in the urban environment of Krakow, southern Poland. In the framework of this study two independent methods were employed to quantify biogenic CO2 flux in the city: (i) closed chambers, and (ii) Relaxed Eddy Accumulation (REA). The results of a three-day intensive intercomparison campaign performed in July 2013 and utilizing both measurement methods are reported here. The chamber method is a widely used approach for measurements of gas exchange between the soil and the atmosphere. The system implemented in this study consisted of a single chamber operating in a closed-dynamic mode, combined with Vaisala CarboCAP infrared CO2 sensor in a mobile setup. An alternative flux measurement method, covering larger area is represented by REA, which is a modification of the eddy covariance method. It consists of a 3D anemometer (Gill Windmaster Pro) and the system collecting updraft and downdraft samples to 5-litre Tedlar bags. The CO2 mixing ratios in the collected samples are measured by Picarro G2101i analyzer. The setup consists of two sets of bags so that the sampling can be performed continuously with 15-min temporal resolution. A 48-hectares open meadow located close the city center was chosen as a test site for comparison of the two methods of CO2 flux measurements outlined above. In the middle of the meadow a 3-metre high tripod was installed with the anemometer and REA inlet system. For a period of 46 hours the system was measuring net CO2 flux from the surrounding area. A meteorological conditions and intensity of photosynthetically active radiation (PAR) were also recorded. In the same time, CO2 flux from several points around the REA inlet was measured with the chamber system, resulting in 93 values for both respiration and net CO2 flux. Chamber results show rather homogenous distribution of the soil CO2 flux (the mean value equal to 40.9 ± 2.2 mmol/m2h), with

An Optimal Estimation Method to Obtain Surface Layer Turbulent Fluxes from Profile Measurements

Science.gov (United States)

Kang, D.

2015-12-01

In the absence of direct turbulence measurements, the turbulence characteristics of the atmospheric surface layer are often derived from measurements of the surface layer mean properties based on Monin-Obukhov Similarity Theory (MOST). This approach requires two levels of the ensemble mean wind, temperature, and water vapor, from which the fluxes of momentum, sensible heat, and water vapor can be obtained. When only one measurement level is available, the roughness heights and the assumed properties of the corresponding variables at the respective roughness heights are used. In practice, the temporal mean with large number of samples are used in place of the ensemble mean. However, in many situations the samples of data are taken from multiple levels. It is thus desirable to derive the boundary layer flux properties using all measurements. In this study, we used an optimal estimation approach to derive surface layer properties based on all available measurements. This approach assumes that the samples are taken from a population whose ensemble mean profile follows the MOST. An optimized estimate is obtained when the results yield a minimum cost function defined as a weighted summation of all error variance at each sample altitude. The weights are based one sample data variance and the altitude of the measurements. This method was applied to measurements in the marine atmospheric surface layer from a small boat using radiosonde on a tethered balloon where temperature and relative humidity profiles in the lowest 50 m were made repeatedly in about 30 minutes. We will present the resultant fluxes and the derived MOST mean profiles using different sets of measurements. The advantage of this method over the 'traditional' methods will be illustrated. Some limitations of this optimization method will also be discussed. Its application to quantify the effects of marine surface layer environment on radar and communication signal propagation will be shown as well.

Measurement of the epithermal neutron flux of the Argonauta reactor by the Sandwich method

International Nuclear Information System (INIS)

Nascimento, H.M.

1973-01-01

A common method of obtaining information about the neutron spectrum in the energy range of 1 eV to a few keV is by using resonance sandwich detectors. A sandwich detector is usually made up of three foils placed one on top of the other, each having the same thickness and being made of the same material which has a pronounced absorption resonance. To make an adequate evaluation, the sandwich method was compared with one using an isolated detector. The results obtained from approximate theoretical calculations were checked experimentally, using In, Au and Mn foils, in an isotropic 1/E flux in the Argonaut Reactor at I.E.N. As practical application of this method, the deviation from a 1/E spectrum of the epithermal neutron flux in the core and external graphite reflector of the Argonaut Reactor has been measured with the sandwich foils previously calibrated in a 1/E spectrum. (author)

The Marine Geochemistry of Iron and Iron Isotopes

Science.gov (United States)

2004-09-01

Analytical Chemistry 76(2), 322-327. Barbeau K. and Moffett J. W. (1998) Dissolution of iron oxides by phagotropic protists : using a novel method to...oxides by phagotropic protists : using a novel method to quantify reaction rates. Environmental Science and Technology 32, 2969-2975. Barbeau K. and

Extension of the heat flux method to liquid (bio-)fuels

Energy Technology Data Exchange (ETDEWEB)

Meuwissen, R.

2009-01-15

The adiabatic burning velocity S{sub L} of a fuel/oxidizer mixture is a key parameter governing many properties of combustion, such as the shape and stabilization of the flame. It can be applied as an input parameter for many combustion models. Furthermore, kinetic schemes can be validated by the use of this parameter. A great extend of research has been performed on determining the adiabatic burning velocities of gaseous fuels. Liquid fuels however, have been examined far less extensive. Literature available shows eminent scatter amongst the data of independent groups and distinctive techniques. The methods used for measuring burning velocities need certain corrections for flame properties which cause additional uncertainties and make the scattering of data not completely unexpected. The heat flux burner used in this work, previously developed at the TU/e, creates a flat flame coherently no corrections for stretch are necessary. Instead, the heat exchange with the burner is considered; by measuring the temperature distribution over the burner plate, the net heat flux of the flame to the burner can be determined. By tuning the unburnt gas velocity until there is no net heat flux, the adiabatic burning velocity is found by interpolation. An extension to the original design, using a vaporized fluid in a carrier gas flow, enables to measure burning velocities of liquid fuels. In the present research, burning velocity measurements have been performed on vaporized ethanol/air flames in order to validate the setup. Similarities with the latest experimental research have been evaluated and good agreement has been found. Furthermore, temperature dependencies have been elucidated and compared to power law correlations stated by this external research. Again, good resemblance can be claimed, although the expanding of certain input parameters on mixture composition could give more solid confirmation. Subsequently, comparison with numerically performed calculations has been

Maximum stellar iron core mass

Indian Academy of Sciences (India)

An analytical method of estimating the mass of a stellar iron core, just prior to core collapse, is described in this paper. The method employed depends, in part, upon an estimate of the true relativistic mass increase experienced by electrons within a highly compressed iron core, just prior to core collapse, and is significantly ...

Studies on the removal of interference of iron in the determination of uranium by direct titration with ammonium meta vanadate method

International Nuclear Information System (INIS)

Chavan, A.A.; Charyulu, M.M.

2009-01-01

To determine the uranium content in metal powder and alloys, routinely used method in NUMAC control Lab is dissolution of sample in 10 M phosphoric acid under heating and determination of uranium by ammonium meta vanadate method-visual indicator end point. If iron is present, it interferes quantitatively. The method is modified for removing the interference of iron by dissolving the samples in conc. phosphoric acid and Fe 2+ is quantitatively oxidized to Fe 3+ by nitric acid prior to analysis. (author)

Determination of calcium and iron in limestone by X-ray fluorescence method

International Nuclear Information System (INIS)

Sovtsova, M.K.

1977-01-01

The results of determining calcium and iron content in limestone by X-ray fluorescence method are described. The 109 Cd isotape was chosen as a source for excitation, as it permited to reduce the concentration degeneration in the range of large Ca contents due to the larger energy of the primary radiation. The root-mean-square deviation from the data of chemical analysis was +-0.02%FeO and +-0.22%CaO

Females Are Protected From Iron?Overload Cardiomyopathy Independent of Iron Metabolism: Key Role of Oxidative Stress

OpenAIRE

Das, Subhash K.; Patel, Vaibhav B.; Basu, Ratnadeep; Wang, Wang; DesAulniers, Jessica; Kassiri, Zamaneh; Oudit, Gavin Y.

2017-01-01

Background Sex?related differences in cardiac function and iron metabolism exist in humans and experimental animals. Male patients and preclinical animal models are more susceptible to cardiomyopathies and heart failure. However, whether similar differences are seen in iron?overload cardiomyopathy is poorly understood. Methods and Results Male and female wild?type and hemojuvelin?null mice were injected and fed with a high?iron diet, respectively, to develop secondary iron overload and geneti...

A prediction method of the effect of radial heat flux distribution on critical heat flux in CANDU fuel bundles

International Nuclear Information System (INIS)

Yuan, Lan Qin; Yang, Jun; Harrison, Noel

2014-01-01

Fuel irradiation experiments to study fuel behaviors have been performed in the experimental loops of the National Research Universal (NRU) Reactor at Atomic Energy of Canada Limited (AECL) Chalk River Laboratories (CRL) in support of the development of new fuel technologies. Before initiating a fuel irradiation experiment, the experimental proposal must be approved to ensure that the test fuel strings put into the NRU loops meet safety margin requirements in critical heat flux (CHF). The fuel strings in irradiation experiments can have varying degrees of fuel enrichment and burnup, resulting in large variations in radial heat flux distribution (RFD). CHF experiments performed in Freon flow at CRL for full-scale bundle strings with a number of RFDs showed a strong effect of RFD on CHF. A prediction method was derived based on experimental CHF data to account for the RFD effect on CHF. It provides good CHF predictions for various RFDs as compared to the data. However, the range of the tested RFDs in the CHF experiments is not as wide as that required in the fuel irradiation experiments. The applicability of the prediction method needs to be examined for the RFDs beyond the range tested by the CHF experiments. The Canadian subchannel code ASSERT-PV was employed to simulate the CHF behavior for RFDs that would be encountered in fuel irradiation experiments. The CHF predictions using the derived method were compared with the ASSERT simulations. It was observed that the CHF predictions agree well with the ASSERT simulations in terms of CHF, confirming the applicability of the prediction method in fuel irradiation experiments. (author)

Effect of different home-cooking methods on the bioaccessibility of zinc and iron in conventionally bred cowpea (Vigna unguiculata L. Walp consumed in Brazil

Directory of Open Access Journals (Sweden)

Elenilda J. Pereira

2016-03-01

Full Text Available Background: The cowpea (Vigna unguiculata L. Wap. is an excellent source of iron and zinc. However, iron from plant sources is poorly absorbed compared with iron from animal sources. Objectives: The objective of this study was to evaluate iron and zinc bioaccessibility in cowpea cultivars after processing. Methods: Zinc and iron bioaccessibilities in cowpea samples were determined based on an in vitro method involving simulated gastrointestinal digestion with suitable modifications. Results: When water-soaked beans were cooked in a regular pan, the highest percentage of bioaccessible iron obtained was 8.92%, whereas when they were cooked in a pressure cooker without previous soaking, the highest percentage was 44.33%. Also, the percentage of bioaccessible zinc was 52.78% when they were cooked in a regular pan without prior soaking. Higher percentages of bioaccessible iron were found when cooking was done in a pressure cooker compared with regular pan cooking. In all cultivars, cooking of cowpea beans in both pressure cooker and in a regular pan yielded higher percentages of bioaccessible zinc compared with availability of bioaccessible iron. Conclusions: Iron bioaccessibility values suggest that cooking in a regular pan did not have a good effect on iron availability, since the percentage of bioaccessible iron was lower than that of zinc. The determination of iron and zinc bioaccessibility makes it possible to find out the actual percentage of absorption of such minerals and allows the development of efficient strategies for low-income groups to access foods with high levels of these micronutrients.

Analytical applications of condensed phosphoric acid-I Determination of ferrous and total iron in iron ores after decomposition with condensed phosphoric acid.

Science.gov (United States)

Mizoguchi, T; Ishii, H

1978-06-01

A simple method is described for the determination of ferrous and total iron in iron ores. Iron ores are dissolved by condensed phosphoric acid (CPA) very rapidly without any tedious and time-consuming manipulations such as elimination of silica and filtration. Under the proposed conditions (amount of sample 100 mg, amount of CPA added 10 g, heating temperature 290 degrees , heating time 30 min), magnetite, limonite and hematite are completely dissolved. The iron content can be determined in the presence of condensed phosphoric acid by titration with dichromate solution, if a slight modification is made. The total iron in iron ores, determined by the present method, is in agreement with that found by the JIS method. The ferrous iron in iron ores can be determined by dissolving the samples with CPA in a nitrogen atmosphere and titrating with dichromate solution. Chelatometric titration of iron after solvent extraction with MIBK from solutions prepared by use of CPA is found to be accurate for samples such as pyrite cinder. The ability of CPA to dissolve various materials has been investigated.

Harmonic Fluxes and Electromagnetic Forces of Concentric Winding Brushless Permanent Magnet Motor

Science.gov (United States)

Ishibashi, Fuminori; Takemasa, Ryo; Matsushita, Makoto; Nishizawa, Takashi; Noda, Shinichi

Brushless permanent magnet motors have been widely used in home applications and industrial fields. These days, high efficiency and low noise motors are demanded from the view point of environment. Electromagnetic noise and iron loss of the motor are produced by the harmonic fluxes and electromagnetic forces. However, order and space pattern of these have not been discussed in detail. In this paper, fluxes, electromagnetic forces and magneto-motive forces of brushless permanent magnet motors with concentric winding were analyzed analytically, experimentally and numerically. Time harmonic fluxes and time electromagnetic forces in the air gap were measured by search coils on the inner surface of the stator teeth and analyzed by FEM. Space pattern of time harmonic fluxes and time electromagnetic forces were worked out with experiments and FEM. Magneto motive forces due to concentric winding were analyzed with equations and checked by FEM.

Iron and stony-iron meteorites

DEFF Research Database (Denmark)

Benedix, Gretchen K.; Haack, Henning; McCoy, T. J.

2014-01-01

Without iron and stony-iron meteorites, our chances of ever sampling the deep interior of a differentiated planetary object would be next to nil. Although we live on a planet with a very substantial core, we will never be able to sample it. Fortunately, asteroid collisions provide us with a rich...... sampling of the deep interiors of differentiated asteroids. Iron and stony-iron meteorites are fragments of a large number of asteroids that underwent significant geological processing in the early solar system. Parent bodies of iron and some stony-iron meteorites completed a geological evolution similar...... to that continuing on Earth – although on much smaller length- and timescales – with melting of the metal and silicates; differentiation into core, mantle, and crust; and probably extensive volcanism. Iron and stony-iron meteorites are our only available analogues to materials found in the deep interiors of Earth...

Study on electrolytic reduction with controlled oxygen flow for iron from molten oxide slag containing FeO

Directory of Open Access Journals (Sweden)

Gao Y.M.

2013-01-01

Full Text Available A ZrO2-based solid membrane electrolytic cell with controlled oxygen flow was constructed: graphite rod /[O]Fe+C saturated / ZrO2(MgO/(FeO slag/iron crucible. The feasibility of extraction of iron from molten oxide slag containing FeO at an applied voltage was investigated by means of the electrolytic cell. The effects of some important process factors on the FeO electrolytic reduction with the controlled oxygen flow were discussed. The results show that: solid iron can be extracted from molten oxide slag containing FeO at 1450ºC and an applied potential of 4V. These factors, such as precipitation and growth of solid iron dendrites, change of the cathode active area on the inner wall of the iron crucible and ion diffusion flux in the molten slag may affect the electrochemical reaction rate. The reduction for Fe2+ ions mainly appears on new iron dendrites of the iron crucible cathode, and a very small amount of iron are also formed on the MSZ (2.18% MgO partially stabilized zirconia tube/slag interface due to electronic conductance of MSZ tube. Internal electronic current through MSZ tube may change direction at earlier and later electrolytic reduction stage. It has a role of promoting electrolytic reduction for FeO in the molten slag at the earlier stage, but will lower the current efficiency at the later stage. The final reduction ratio of FeO in the molten slag can achieve 99%. A novel electrolytic method with controlled oxygen flow for iron from the molten oxide slag containing FeO was proposed. The theory of electrolytic reduction with the controlled oxygen flow was developed.

Iron-based soft magnetic composites with Mn-Zn ferrite nanoparticles coating obtained by sol-gel method

Science.gov (United States)

Wu, Shen; Sun, Aizhi; Xu, Wenhuan; Zhang, Qian; Zhai, Fuqiang; Logan, Philip; Volinsky, Alex A.

2012-11-01

This paper focuses on iron-based soft magnetic composites which were synthesized by utilizing Mn-Zn ferrite nanoparticles to coat iron powder. The nanocrystalline iron powders, with an average particle diameter of 20 nm, were obtained via the sol-gel method. Scanning electron microscopy, energy dispersive X-ray spectroscopy and distribution maps show that the iron particle surface is covered with a thin layer of Mn-Zn ferrites. Mn-Zn ferrite uniformly coated the surface of the powder particles, resulting in a reduced imaginary permeability, increased electrical resistivity and a higher operating frequency of the synthesized magnets. Mn-Zn ferrite coated samples have higher permeability and lower magnetic loss when compared with the non-magnetic epoxy resin coated compacts. The real part of permeability increases by 33.5% when compared with the epoxy resin coated samples at 10 kHz. The effects of heat treatment temperature on crystalline phase formation and on the magnetic properties of the Mn-Zn ferrite were investigated via X-ray diffraction and a vibrating sample magnetometer. Ferrites decomposed to FeO and MnO after annealing above 400 °C in nitrogen; thus it is the optimum annealing temperature to attain the desired permeability.

Method of forming magnetostrictive rods from rare earth-iron alloys

Science.gov (United States)

McMasters, O. Dale

1986-09-02

Rods of magnetrostructive alloys of iron with rare earth elements are formed by flowing a body of rare earth-iron alloy in a crucible enclosed in a chamber maintained under an inert gas atmosphere, forcing such molten rare-earth-iron alloy into a hollow mold tube of refractory material positioned with its lower end portion within the molten body by means of a pressure differential between the chamber and mold tube and maintaining a portion of the molten alloy in the crucible extending to a level above the lower end of the mold tube so that solid particles of higher melting impurities present in the alloy collect at the surface of the molten body and remain within the crucible as the rod is formed in the mold tube.

The assessment of water vapour and carbon dioxide fluxes above arable crops - a comparison of methods

Energy Technology Data Exchange (ETDEWEB)

Schaaf, S.; Daemmgen, U.; Burkart, S. [Federal Agricultural Research Centre, Inst. of Agroecology, Braunschweig (Germany); Gruenhage, L. [Justus-Liebig-Univ., Inst. for Plant Ecology, Giessen (Germany)

2005-04-01

Vertical fluxes of water vapour and carbon dioxide obtained from gradient, eddy covariance (closed and open path systems) and chamber measurements above arable crops were compared with the directly measured energy balance and the harvested net biomass carbon. The gradient and chamber measurements were in the correct order of magnitude, whereas the closed path eddy covariance system showed unacceptably small fluxes. Correction methods based on power spectra analysis yielded increased fluxes. However, the energy balance could not be closed satisfactorily. The application of the open path system proved to be successful. The SVAT model PLATIN which had been adapted to various arable crops was able to depict the components of the energy balance adequately. Net carbon fluxes determined with the corrected closed path data sets, chamber, and SVAT model equal those of the harvested carbon. (orig.)

Ultrafine ferromagnetic iron oxide nanoparticles: Facile synthesis by low temperature decomposition of iron glycerolate

Energy Technology Data Exchange (ETDEWEB)

Bartůněk, Vilém, E-mail: vilem.bartunek@vscht.cz [Department of Inorganic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology, Technická 5, 166 28 Prague 6 (Czech Republic); Průcha, David [Department of Inorganic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology, Technická 5, 166 28 Prague 6 (Czech Republic); Švecová, Marie [Department of Analytical Chemistry, Faculty of Chemical Engineering, University of Chemistry and Technology, Technická 5, 166 28 Prague 6 (Czech Republic); Ulbrich, Pavel [Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology, Technická 3, 166 28 Prague 6 (Czech Republic); Huber, Štěpán; Sedmidubský, David; Jankovský, Ondřej [Department of Inorganic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology, Technická 5, 166 28 Prague 6 (Czech Republic)

2016-09-01

We synthesized dark colored ultrafine – sub 10 nm iron oxide nanoparticles by a facile and low temperature process based on thermal decomposition of an affordable precursor – iron glycerolate. Simultaneous thermal analysis (STA) was used to study the thermal behaviour during the decomposition. The iron glycerolate was thoroughly analysed by various methods. The size of the iron nanoparticles was determined from XRD patterns and by transmission electron microscopy (TEM) and their composition has been confirmed by XPS. Magnetic properties of the nanoparticles were studied by vibrating sample magnetometry. The prepared single phase material exhibiting ferromagnetic properties is usable in a wide range of applications and may be suitable even for large scale industrial applications. - Highlights: • Iron glycerolate prepared and characterised. • Iron oxide nanoparticles prepared by thermal decomposition of iron glycerolate. • STA used to study the decomposition. • Products characterised by XRD, XPS, FT-IR, SEM and TEM. • Magnetic behaviour of monophasic samples determined.

Method of fabricating thin-walled articles of tungsten-nickel-iron alloy

Science.gov (United States)

Hovis, Jr., Victor M.; Northcutt, Jr., Walter G.

1982-01-01

The present invention relates to a method for fabricating thin-walled high-density structures oftungsten-nickel-iron alloys. A powdered blend of the selected alloy constituents is plasma sprayed onto a mandrel having the desired article configuration. The sprayed deposit is removed from the mandrel and subjected to liquid phase sintering to provide the alloyed structure. The formation of the thin-walled structure by plasma spraying significantly reduces shrinkage, and cracking while increasing physical properties of the structure over that obtainable by employing previously known powder metallurgical procedures.

Method of manufacturing iron aluminide by thermomechanical processing of elemental powders

Science.gov (United States)

Deevi, Seetharama C.; Lilly, Jr., A. Clifton; Sikka, Vinod K.; Hajaligol, Mohammed R.

2000-01-01

A powder metallurgical process of preparing iron aluminide useful as electrical resistance heating elements having improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The iron aluminide has an entirely ferritic microstructure which is free of austenite and can include, in weight %, 20 to 32% Al, and optional additions such as .ltoreq.1% Cr, .gtoreq.05% Zr or ZrO.sub.2 stringers extending perpendicular to an exposed surface of the heating element, .ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Zr, .ltoreq.1% C, .ltoreq.0.1% B, .ltoreq.30% oxide dispersoid and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1 % rare earth metal, .ltoreq.1% oxygen, and/or .ltoreq.3% Cu. The process includes forming a mixture of aluminum powder and iron powder, shaping the mixture into an article such as by cold rolling the mixture into a sheet, and sintering the article at a temperature sufficient to react the iron and aluminum powders and form iron aluminide. The sintering can be followed by hot or cold rolling to reduce porosity created during the sintering step and optional annealing steps in a vacuum or inert atmosphere.

Serum-ferritin and iron absorption for the study of body iron stored in the Thai population

International Nuclear Information System (INIS)

Plehachinda, R.

1984-05-01

Measurements of serum ferritin by an ''in-house'' immunoradiometric assay (IRMA) method were used in conjunction with estimations of gastro-intestinal iron absorption from a standard test dose of ferrous ascorbate, measurements of blood haemoglobin and measurements of other haematological parameters to study body iron status in various population groups and to assess changes in body iron status after food-iron fortification. The IRMA method particularly covered the lower range of serum ferritin levels from 0.5 to 10 μg/litre, corresponding to iron deficiency. Quality control indicated satisfactory assay performance. In preliminary studies, serum ferritin level was found to be well correlated with gastro-intestinal iron absorption as an indicator of body iron status. Normal adult male subjects in Bangkok showed levels of 21-314 μg/litre and normal adult female levels of 13-173 μg/litre, in general agreement with values reported by other authors. Measurements were then extended to subjects in an area of north-eastern Thailand where iron-deficiency was common, to assess the effectiveness of food-iron fortification programmes. Measurements were also made on male blood donors in Bangkok, pregnant female subjects in Bangkok and north-eastern Thailand, school children in an area of southern Thailand where hookworm infestation was common and schoolchildren and adult female subjects in an area of northern Thailand where goitre was endemic. The results of all these studies are presented

Surface renewal: an advanced micrometeorological method for measuring and processing field-scale energy flux density data.

Science.gov (United States)

McElrone, Andrew J; Shapland, Thomas M; Calderon, Arturo; Fitzmaurice, Li; Paw U, Kyaw Tha; Snyder, Richard L

2013-12-12

Advanced micrometeorological methods have become increasingly important in soil, crop, and environmental sciences. For many scientists without formal training in atmospheric science, these techniques are relatively inaccessible. Surface renewal and other flux measurement methods require an understanding of boundary layer meteorology and extensive training in instrumentation and multiple data management programs. To improve accessibility of these techniques, we describe the underlying theory of surface renewal measurements, demonstrate how to set up a field station for surface renewal with eddy covariance calibration, and utilize our open-source turnkey data logger program to perform flux data acquisition and processing. The new turnkey program returns to the user a simple data table with the corrected fluxes and quality control parameters, and eliminates the need for researchers to shuttle between multiple processing programs to obtain the final flux data. An example of data generated from these measurements demonstrates how crop water use is measured with this technique. The output information is useful to growers for making irrigation decisions in a variety of agricultural ecosystems. These stations are currently deployed in numerous field experiments by researchers in our group and the California Department of Water Resources in the following crops: rice, wine and raisin grape vineyards, alfalfa, almond, walnut, peach, lemon, avocado, and corn.

Numerical studies of the flux-to-current ratio method in the KIPT neutron source facility

International Nuclear Information System (INIS)

Cao, Y.; Gohar, Y.; Zhong, Z.

2013-01-01

The reactivity of a subcritical assembly has to be monitored continuously in order to assure its safe operation. In this paper, the flux-to-current ratio method has been studied as an approach to provide the on-line reactivity measurement of the subcritical system. Monte Carlo numerical simulations have been performed using the KIPT neutron source facility model. It is found that the reactivity obtained from the flux-to-current ratio method is sensitive to the detector position in the subcritical assembly. However, if multiple detectors are located about 12 cm above the graphite reflector and 54 cm radially, the technique is shown to be very accurate in determining the k eff this facility in the range of 0.75 to 0.975. (authors)

Reactive oxygen species and associated reactivity of peroxymonosulfate activated by soluble iron species

Science.gov (United States)

Watts, Richard J.; Yu, Miao; Teel, Amy L.

2017-10-01

The activation of peroxymonosulfate by iron (II), iron (III), and iron (III)-EDTA for in situ chemical oxidation (ISCO) was compared using nitrobenzene as a hydroxyl radical probe, anisole as a hydroxyl radical + sulfate radical probe, and hexachloroethane as a reductant + nucleophile probe. In addition, activated peroxymonosulfate was investigated for the treatment of the model groundwater contaminants perchloroethylene (PCE) and trichloroethylene (TCE). The relative activities of hydroxyl radical and sulfate radical in the degradation of the probe compounds and PCE and TCE were isolated using the radical scavengers tert-butanol and isopropanol. Iron (II), iron (III), and iron (III)-EDTA effectively activated peroxymonosulfate to generate hydroxyl radical and sulfate radical, but only a minimal flux of reductants or nucleophiles. Iron (III)-EDTA was a more effective activator than iron (II) and iron (III), and also provided a non-hydroxyl radical, non-sulfate radical degradation pathway. The contribution of sulfate radical relative to hydroxyl radical followed the order of anisole > > TCE > PCE > > nitrobenzene; i.e., sulfate radical was less dominant in the oxidation of more oxidized target compounds. Sulfate radical is often assumed to be the primary oxidant in activated peroxymonosulfate and persulfate systems, but the results of this research demonstrate that the reactivity of sulfate radical with the target compound must be considered before drawing such a conclusion.

Reactive oxygen species and associated reactivity of peroxymonosulfate activated by soluble iron species.

Science.gov (United States)

Watts, Richard J; Yu, Miao; Teel, Amy L

2017-10-01

The activation of peroxymonosulfate by iron (II), iron (III), and iron (III)-EDTA for in situ chemical oxidation (ISCO) was compared using nitrobenzene as a hydroxyl radical probe, anisole as a hydroxyl radical+sulfate radical probe, and hexachloroethane as a reductant+nucleophile probe. In addition, activated peroxymonosulfate was investigated for the treatment of the model groundwater contaminants perchloroethylene (PCE) and trichloroethylene (TCE). The relative activities of hydroxyl radical and sulfate radical in the degradation of the probe compounds and PCE and TCE were isolated using the radical scavengers tert-butanol and isopropanol. Iron (II), iron (III), and iron (III)-EDTA effectively activated peroxymonosulfate to generate hydroxyl radical and sulfate radical, but only a minimal flux of reductants or nucleophiles. Iron (III)-EDTA was a more effective activator than iron (II) and iron (III), and also provided a non-hydroxyl radical, non-sulfate radical degradation pathway. The contribution of sulfate radical relative to hydroxyl radical followed the order of anisole>TCE>PCE >nitrobenzene; i.e., sulfate radical was less dominant in the oxidation of more oxidized target compounds. Sulfate radical is often assumed to be the primary oxidant in activated peroxymonosulfate and persulfate systems, but the results of this research demonstrate that the reactivity of sulfate radical with the target compound must be considered before drawing such a conclusion. Published by Elsevier B.V.

From elementary flux modes to elementary flux vectors: Metabolic pathway analysis with arbitrary linear flux constraints

Science.gov (United States)

Klamt, Steffen; Gerstl, Matthias P.; Jungreuthmayer, Christian; Mahadevan, Radhakrishnan; Müller, Stefan

2017-01-01

Elementary flux modes (EFMs) emerged as a formal concept to describe metabolic pathways and have become an established tool for constraint-based modeling and metabolic network analysis. EFMs are characteristic (support-minimal) vectors of the flux cone that contains all feasible steady-state flux vectors of a given metabolic network. EFMs account for (homogeneous) linear constraints arising from reaction irreversibilities and the assumption of steady state; however, other (inhomogeneous) linear constraints, such as minimal and maximal reaction rates frequently used by other constraint-based techniques (such as flux balance analysis [FBA]), cannot be directly integrated. These additional constraints further restrict the space of feasible flux vectors and turn the flux cone into a general flux polyhedron in which the concept of EFMs is not directly applicable anymore. For this reason, there has been a conceptual gap between EFM-based (pathway) analysis methods and linear optimization (FBA) techniques, as they operate on different geometric objects. One approach to overcome these limitations was proposed ten years ago and is based on the concept of elementary flux vectors (EFVs). Only recently has the community started to recognize the potential of EFVs for metabolic network analysis. In fact, EFVs exactly represent the conceptual development required to generalize the idea of EFMs from flux cones to flux polyhedra. This work aims to present a concise theoretical and practical introduction to EFVs that is accessible to a broad audience. We highlight the close relationship between EFMs and EFVs and demonstrate that almost all applications of EFMs (in flux cones) are possible for EFVs (in flux polyhedra) as well. In fact, certain properties can only be studied with EFVs. Thus, we conclude that EFVs provide a powerful and unifying framework for constraint-based modeling of metabolic networks. PMID:28406903

Fission track dating method: I. Study of neutron flux uniformity in some irradiation positions of IEA-R1 reactor

International Nuclear Information System (INIS)

Osorio, A.M.; Hadler, J.C.; Iunes, P.J.; Paulo, S.R. de

1993-06-01

In order to use the fission track dating method the flux gradient was verified within the sample holder, in some irradiation positions of the IEA-R1 reactor at IPEN/CNEN, Sao Paulo. The fission track dating method considers only the thermal neutron fission tracks, to subtract the other contributions sample irradiations with a cadmium cover was performed. The neutron flux cadmium influence was studied. (author)

A multipoint flux mixed finite element method on distorted quadrilaterals and hexahedra

KAUST Repository

Wheeler, Mary

2011-11-06

In this paper, we develop a new mixed finite element method for elliptic problems on general quadrilateral and hexahedral grids that reduces to a cell-centered finite difference scheme. A special non-symmetric quadrature rule is employed that yields a positive definite cell-centered system for the pressure by eliminating local velocities. The method is shown to be accurate on highly distorted rough quadrilateral and hexahedral grids, including hexahedra with non-planar faces. Theoretical and numerical results indicate first-order convergence for the pressure and face fluxes. © 2011 Springer-Verlag.

SUMOFLUX: A Generalized Method for Targeted 13C Metabolic Flux Ratio Analysis

Science.gov (United States)

Kogadeeva, Maria

2016-01-01

Metabolic fluxes are a cornerstone of cellular physiology that emerge from a complex interplay of enzymes, carriers, and nutrients. The experimental assessment of in vivo intracellular fluxes using stable isotopic tracers is essential if we are to understand metabolic function and regulation. Flux estimation based on 13C or 2H labeling relies on complex simulation and iterative fitting; processes that necessitate a level of expertise that ordinarily preclude the non-expert user. To overcome this, we have developed SUMOFLUX, a methodology that is broadly applicable to the targeted analysis of 13C-metabolic fluxes. By combining surrogate modeling and machine learning, we trained a predictor to specialize in estimating flux ratios from measurable 13C-data. SUMOFLUX targets specific flux features individually, which makes it fast, user-friendly, applicable to experimental design and robust in terms of experimental noise and exchange flux magnitude. Collectively, we predict that SUMOFLUX's properties realistically pave the way to high-throughput flux analyses. PMID:27626798

Microsegregation in Nodular Cast Iron with Carbides

Directory of Open Access Journals (Sweden)

S. Pietrowski

2012-12-01

Full Text Available In this paper results of microsegregation in the newly developed nodular cast iron with carbides are presented. To investigate the pearlitic and bainitic cast iron with carbides obtained by Inmold method were chosen. The distribution of linear elements on the eutectic cell radius was examined. To investigate the microsegregation pearlitic and bainitic cast iron with carbides obtained by Inmold method were chosen.The linear distribution of elements on the eutectic cell radius was examined. Testing of the chemical composition of cast iron metal matrix components, including carbides were carried out. The change of graphitizing and anti-graphitizing element concentrations within eutectic cell was determined. It was found, that in cast iron containing Mo carbides crystallizing after austenite + graphite eutectic are Si enriched.

Microsegregation in Nodular Cast Iron with Carbides

Directory of Open Access Journals (Sweden)

Pietrowski S.

2012-12-01

Full Text Available In this paper results of microsegregation in the newly developed nodular cast iron with carbides are presented. To investigate the pearlitic and bainitic cast iron with carbides obtained by Inmold method were chosen. The distribution of linear elements on the eutectic cell radius was examined. To investigate the microsegregation pearlitic and bainitic cast iron with carbides obtained by Inmold method were chosen. The linear distribution of elements on the eutectic cell radius was examined. Testing of the chemical composition of cast iron metal matrix components, including carbides were carried out. The change of graphitizing and anti-graphitizing element concentrations within eutectic cell was determined. It was found, that in cast iron containing Mo carbides crystallizing after austenite + graphite eutectic are Si enriched.

The quantum flux in quasis one-dimensional conductors

International Nuclear Information System (INIS)

Ventura, J.

1989-01-01

A method is presented which quantizes electromagnetic fluxes directly in flux space. It is based on the commutation law [φ B , φ E ] = i, where φ B is the magnetic flux, and φ E the longitudinal electric flux of a quasi one-dimensional conductor. The relevance of such a method for the description of the quantized Hall plateaus is discussed. In a second step, the polarization electric flux is introduced, together with a method for quantization of hybrid variables formed with pure electromagnetic fluxes plus electronic variables. (author) [pt

The effects of metamorphism on iron mineralogy and the iron speciation redox proxy

Science.gov (United States)

Slotznick, Sarah P.; Eiler, John M.; Fischer, Woodward W.

2018-03-01

As the most abundant transition metal in the Earth's crust, iron is a key player in the planetary redox budget. Observations of iron minerals in the sedimentary record have been used to describe atmospheric and aqueous redox environments over the evolution of our planet; the most common method applied is iron speciation, a geochemical sequential extraction method in which proportions of different iron minerals are compared to calibrations from modern sediments to determine water-column redox state. Less is known about how this proxy records information through post-depositional processes, including diagenesis and metamorphism. To get insight into this, we examined how the iron mineral groups/pools (silicates, oxides, sulfides, etc.) and paleoredox proxy interpretations can be affected by known metamorphic processes. Well-known metamorphic reactions occurring in sub-chlorite to kyanite rocks are able to move iron between different iron pools along a range of proxy vectors, potentially affecting paleoredox results. To quantify the effect strength of these reactions, we examined mineralogical and geochemical data from two classic localities where Silurian-Devonian shales, sandstones, and carbonates deposited in a marine sedimentary basin with oxygenated seawater (based on global and local biological constraints) have been regionally metamorphosed from lower-greenschist facies to granulite facies: Waits River and Gile Mountain Formations, Vermont, USA and the Waterville and Sangerville-Vassalboro Formations, Maine, USA. Plotting iron speciation ratios determined for samples from these localities revealed apparent paleoredox conditions of the depositional water column spanning the entire range from oxic to ferruginous (anoxic) to euxinic (anoxic and sulfidic). Pyrrhotite formation in samples highlighted problems within the proxy as iron pool assignment required assumptions about metamorphic reactions and pyrrhotite's identification depended on the extraction techniques

Evaluation of Ferric and Ferrous Iron Therapies in Women with Iron Deficiency Anaemia

Science.gov (United States)

Berber, Ilhami; Erkurt, Mehmet Ali; Aydogdu, Ismet; Kuku, Irfan

2014-01-01

Introduction. Different ferric and ferrous iron preparations can be used as oral iron supplements. Our aim was to compare the effects of oral ferric and ferrous iron therapies in women with iron deficiency anaemia. Methods. The present study included 104 women diagnosed with iron deficiency anaemia after evaluation. In the evaluations performed to detect the aetiology underlying the iron deficiency anaemia, it was found and treated. After the detection of the iron deficiency anaemia aetiology and treatment of the underlying aetiology, the ferric group consisted of 30 patients treated with oral ferric protein succinylate tablets (2 × 40 mg elemental iron/day), and the second group consisted of 34 patients treated with oral ferrous glycine sulphate tablets (2 × 40 mg elemental iron/day) for three months. In all patients, the following laboratory evaluations were performed before beginning treatment and after treatment. Results. The mean haemoglobin and haematocrit increases were 0.95 g/dL and 2.62% in the ferric group, while they were 2.25 g/dL and 5.91% in the ferrous group, respectively. A significant difference was found between the groups regarding the increase in haemoglobin and haematocrit values (P < 0.05). Conclusion. Data are submitted on the good tolerability, higher efficacy, and lower cost of the ferrous preparation used in our study. PMID:25006339

Remote-sensing data processing with the multivariate regression analysis method for iron mineral resource potential mapping: a case study in the Sarvian area, central Iran

Science.gov (United States)

Mansouri, Edris; Feizi, Faranak; Jafari Rad, Alireza; Arian, Mehran

2018-03-01

This paper uses multivariate regression to create a mathematical model for iron skarn exploration in the Sarvian area, central Iran, using multivariate regression for mineral prospectivity mapping (MPM). The main target of this paper is to apply multivariate regression analysis (as an MPM method) to map iron outcrops in the northeastern part of the study area in order to discover new iron deposits in other parts of the study area. Two types of multivariate regression models using two linear equations were employed to discover new mineral deposits. This method is one of the reliable methods for processing satellite images. ASTER satellite images (14 bands) were used as unique independent variables (UIVs), and iron outcrops were mapped as dependent variables for MPM. According to the results of the probability value (p value), coefficient of determination value (R2) and adjusted determination coefficient (Radj2), the second regression model (which consistent of multiple UIVs) fitted better than other models. The accuracy of the model was confirmed by iron outcrops map and geological observation. Based on field observation, iron mineralization occurs at the contact of limestone and intrusive rocks (skarn type).

A successive over-relaxation for slab geometry Simplified SN method with interface flux iteration

International Nuclear Information System (INIS)

Yavuz, M.

1995-01-01

A Successive Over-Relaxation scheme is proposed for speeding up the solution of one-group slab geometry transport problems using a Simplified S N method. The solution of the Simplified S N method that is completely free from all spatial truncation errors is based on the expansion of the angular flux in spherical-harmonics solutions. One way to obtain the (numerical) solution of the Simplified S N method is to use Interface Flux Iteration, which can be considered as the Gauss-Seidel relaxation scheme; the new information is immediately used in the calculations. To accelerate the convergence, an over relaxation parameter is employed in the solution algorithm. The over relaxation parameters for a number of cases depending on scattering ratios and mesh sizes are determined by Fourier analyzing infinite-medium Simplified S 2 equations. Using such over relaxation parameters in the iterative scheme, a significant increase in the convergence of transport problems can be achieved for coarse spatial cells whose spatial widths are greater than one mean-free-path

Accuracy evaluation of the current data and method applied to shielding design of the Fusion Experimental Reactor (FER)

International Nuclear Information System (INIS)

Mori, Seiji; Kobayashi, Takeshi; Seki, Yasushi

1988-06-01

Shielding benchmarking study of the current data and method applied to the Fusion Experimental Reactor (FER) was performed. First, neutron and gamma ray fluxes were calculated by the one-dimensional S N code using various cross section libraries and the continuous energy Monte Carlo code. The results were compared in terms of the S N /MC ratio. The worst ratios are about 0.5 and 0.25 for neutron flux and gamma ray flux, respectively. Next, the analytical calculations of the iron sphere transmission experiment of 14 MeV neutrons were performed to examine the accuracy of cross section data of iron, which is the most important material of shield. The E/C ratio is larger than 2 even if the continuous energy Monte Carlo code was used. Thirdly, the influence of geometrical representation of the shield was investigated by comparing the homogeneous model and the heterogeneous model (alternating layers of SS316 and water). As a result, it was made clear that the homogeneous model underestimates neutron flux by a factor of 2. Finally, the necessity of benchmark experiment and improvement of cross section library was pointed out as the further R and D issues. (author)

Continuous Manual Exchange Transfusion for Patients with Sickle Cell Disease: An Efficient Method to Avoid Iron Overload.

Science.gov (United States)

Koehl, Bérengère; Missud, Florence; Holvoet, Laurent; Ithier, Ghislaine; Sakalian-Black, Oliver; Haouari, Zinedine; Lesprit, Emmanuelle; Baruchel, André; Benkerrou, Malika

2017-03-14

Children with sickle cell anemia (SCA) may be at risk of cerebral vasculopathy and strokes, which can be prevented by chronic transfusion programs. Repeated transfusions of packed red blood cells (PRBCs) is currently the simplest and most used technique for chronic transfusion programs. However, iron overload is one of the major side effects of this therapy. More developed methods exist, notably the apheresis of RBC (erythrapheresis), which is currently the safest and most efficient method. However, it is costly, complicated, and cannot be implemented everywhere, nor is it suitable for all patients. Manual exchange transfusions combine one or more manual phlebotomies with a PRBC transfusion. At the Reference Center of Sickle Cell Disease, we set up a continuous method of manual exchange transfusion that is feasible for all hospital settings, demands no specific equipment, and is widely applicable. In terms of HbS decrease, stroke prevention, and iron overload prevention, this method showed comparable efficiency to erythrapheresis. In cases where erythrapheresis is not available, this method can be a good alternative for patients and care centers.

Research on common methods for evaluating the operation effect of integrated wastewater treatment facilities of iron and steel enterprises

Science.gov (United States)

Bingsheng, Xu

2017-04-01

Considering the large quantities of wastewater generated from iron and steel enterprises in China, this paper is aimed to research the common methods applied for evaluating the integrated wastewater treatment effect of iron and steel enterprises. Based on survey results on environmental protection performance, technological economy, resource & energy consumption, services and management, an indicator system for evaluating the operation effect of integrated wastewater treatment facilities is set up. By discussing the standards and industrial policies in and out of China, 27 key secondary indicators are further defined on the basis of investigation on main equipment and key processes for wastewater treatment, so as to determine the method for setting key quantitative and qualitative indicators for evaluation indicator system. It is also expected to satisfy the basic requirements of reasonable resource allocation, environmental protection and sustainable economic development, further improve the integrated wastewater treatment effect of iron and steel enterprises, and reduce the emission of hazardous substances and environmental impact.

Window Material Daylighting Performance Assessment Algorithm: Comparing Radiosity and Split-Flux Methods

Directory of Open Access Journals (Sweden)

Yeo Beom Yoon

2014-04-01

Full Text Available Windows are the primary aperture to introduce solar radiation to the interior space of a building. This experiment explores the use of EnergyPlus software for analyzing the illuminance level on the floor of a room with reference to its distance from the window. For this experiment, a double clear glass window has been used. The preliminary modelling in EnergyPlus showed a consistent result with the experimentally monitored data in real time. EnergyPlus has two mainly used daylighting algorithms: DElight method employing radiosity technique and Detailed method employing split-flux technique. Further analysis for illuminance using DElight and Detailed methods showed significant difference in the results. Finally, we compared the algorithms of the two analysis methods in EnergyPlus.

Active superconducting DC fault current limiter based on flux compensation

International Nuclear Information System (INIS)

Shi Jing; Tang Yuejin; Wang, Chen; Zhou Yusheng; Li Jingdong; Ren Li; Chen Shijie

2006-01-01

With the extensive application of DC power systems, suppression of DC fault current is an important subject that guarantees system security. This paper presents an active superconducting DC fault current limiter (DC-SFCL) based on flux compensation. The DC-SFCL is composed of two superconducting windings wound on a single iron core, the primary winding is in series with DC power system, and the second winding is connected with AC power system through a PWM converter. In normal operating state, the flux in the iron core is compensated to zero, and the SFCL has no influence on DC power system. In the case of DC system accident, through regulating the active power exchange between the SFCL's second winding and the AC power system, the current on the DC side can be limited to different level complying with the system demand. Moreover, the PWM converter that interface the DC system and AC system can be controlled as a reactive power source to supply voltage support for the AC side, which has little influence on the performance of SFCL. Using MATLAB SIMULINK, the mathematic model of the DC-SFCL is created, simulation results validate the dynamics of system, and the performance of DC-SFCL is confirmed

On the Evolution of the Inner Disk Radius with Flux in the Neutron Star Low-mass X-Ray Binary Serpens X-1

Science.gov (United States)

Chiang, Chia - Ying; Morgan, Robert A.; Cackett, Edward M.; Miller, Jon M.; Bhattacharyya, Sudip; Strohmayer, Tod E.

2016-01-01

We analyze the latest Suzaku observation of the bright neutron star (NS) low-mass X-ray binary Serpens X-1 taken in 2013 October and 2014 April. The observation was taken using the burst mode and only suffered mild pile-up effects. A broad iron line is clearly detected in the X-ray spectrum. We test different models and find that the iron line is asymmetric and best interpreted by relativistic reflection. The relativistically broadened iron line is generally believed to originate from the innermost regions of the accretion disk, where strong gravity causes a series of special and general relativistic effects. The iron line profile indicates an inner radius of approx. 8 R(sub G), which gives an upper limit on the size of the NS. The asymmetric iron line has been observed in a number of previous observations, which gives several inner radius measurements at different flux states. We find that the inner radius of Serpens X-1 does not evolve significantly over the range of L/L(sub Edd) approx. 0.4-0.6, and the lack of flux dependence of the inner radius implies that the accretion disk may be truncated outside of the innermost stable circular orbit by the boundary layer, rather than the stellar magnetic field.

ON THE EVOLUTION OF THE INNER DISK RADIUS WITH FLUX IN THE NEUTRON STAR LOW-MASS X-RAY BINARY SERPENS X-1

Energy Technology Data Exchange (ETDEWEB)

Chiang, Chia-Ying; Morgan, Robert A.; Cackett, Edward M. [Department of Physics and Astronomy, Wayne State University, 666 W. Hancock, Detroit, MI 48202 (United States); Miller, Jon M. [Department of Astronomy, The University of Michigan, 500 Church Street, Ann Arbor, MI 48109-1046 (United States); Bhattacharyya, Sudip [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Mumbai 400005 (India); Strohmayer, Tod E., E-mail: ft8320@wayne.edu [X-Ray Astrophysics Lab, Astrophysics Science Division, NASA’s Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2016-11-01

We analyze the latest Suzaku observation of the bright neutron star (NS) low-mass X-ray binary Serpens X-1 taken in 2013 October and 2014 April. The observation was taken using the burst mode and only suffered mild pile-up effects. A broad iron line is clearly detected in the X-ray spectrum. We test different models and find that the iron line is asymmetric and best interpreted by relativistic reflection. The relativistically broadened iron line is generally believed to originate from the innermost regions of the accretion disk, where strong gravity causes a series of special and general relativistic effects. The iron line profile indicates an inner radius of ∼8 R {sub G}, which gives an upper limit on the size of the NS. The asymmetric iron line has been observed in a number of previous observations, which gives several inner radius measurements at different flux states. We find that the inner radius of Serpens X-1 does not evolve significantly over the range of L / L {sub Edd} ∼ 0.4–0.6, and the lack of flux dependence of the inner radius implies that the accretion disk may be truncated outside of the innermost stable circular orbit by the boundary layer, rather than the stellar magnetic field.

Spectrophotometric Determination of Iron(II and Cobalt(II by Direct, Derivative, and Simultaneous Methods Using 2-Hydroxy-1-Naphthaldehyde-p-Hydroxybenzoichydrazone

Directory of Open Access Journals (Sweden)

V. S. Anusuya Devi

2012-01-01

Full Text Available Optimized and validated spectrophotometric methods have been proposed for the determination of iron and cobalt individually and simultaneously. 2-hydroxy-1-naphthaldehyde-p-hydroxybenzoichydrazone (HNAHBH reacts with iron(II and cobalt(II to form reddish-brown and yellow-coloured [Fe(II-HNAHBH] and [Co(II-HNAHBH] complexes, respectively. The maximum absorbance of these complexes was found at 405 nm and 425 nm, respectively. For [Fe(II-HNAHBH], Beer’s law is obeyed over the concentration range of 0.055–1.373 μg mL−1 with a detection limit of 0.095 μg mL−1 and molar absorptivity ɛ, 5.6 × 104 L mol−1 cm−1. [Co(II-HNAHBH] complex obeys Beer’s law in 0.118–3.534 μg mL−1 range with a detection limit of 0.04 μg mL−1 and molar absorptivity, ɛ of 2.3 × 104 L mol−1 cm−1. Highly sensitive and selective first-, second- and third-order derivative methods are described for the determination of iron and cobalt. A simultaneous second-order derivative spectrophotometric method is proposed for the determination of these metals. All the proposed methods are successfully employed in the analysis of various biological, water, and alloy samples for the determination of iron and cobalt content.

Iron Refractory Iron Deficiency Anaemia: A Rare Cause of Iron Deficiency Anaemia

LENUS (Irish Health Repository)

McGrath, T

2018-01-01

We describe the case of a 17-month-old boy with a hypochromic microcytic anaemia, refractory to oral iron treatment. After exclusion of dietary and gastrointestinal causes of iron deficiency, a genetic cause for iron deficiency was confirmed by finding two mutations in the TMPRSS6 gene, consistent with a diagnosis of iron-refractory iron deficiency anaemia (IRIDA).

Integration of Flux-Based Methods and Triad Principles for DNAPL Site Management, Part II: Review of Flux Measurement Methods

Science.gov (United States)

Managing dense nonaqueous phase liquid (DNAPL) contaminated sites continues to be among the most pressing environmental problems currently faced. One approach that has recently been investigated for use in DNAPL site characterization and remediation is mass flux (mass per unit ar...

Transport methods: general. 6. A Flux-Limited Diffusion Theory Derived from the Maximum Entropy Eddington Factor

International Nuclear Information System (INIS)

Yin, Chukai; Su, Bingjing

2001-01-01

The Minerbo's maximum entropy Eddington factor (MEEF) method was proposed as a low-order approximation to transport theory, in which the first two moment equations are closed for the scalar flux f and the current F through a statistically derived nonlinear Eddington factor f. This closure has the ability to handle various degrees of anisotropy of angular flux and is well justified both numerically and theoretically. Thus, a lot of efforts have been made to use this approximation in transport computations, especially in the radiative transfer and astrophysics communities. However, the method suffers numerical instability and may lead to anomalous solutions if the equations are solved by certain commonly used (implicit) mesh schemes. Studies on numerical stability in one-dimensional cases show that the MEEF equations can be solved satisfactorily by an implicit scheme (of treating δΦ/δx) if the angular flux is not too anisotropic so that f 32 , the classic diffusion solution P 1 , the MEEF solution f M obtained by Riemann solvers, and the NFLD solution D M for the two problems, respectively. In Fig. 1, NFLD and MEEF quantitatively predict very close results. However, the NFLD solution is qualitatively better because it is continuous while MEEF predicts unphysical jumps near the middle of the slab. In Fig. 2, the NFLD and MEEF solutions are almost identical, except near the material interface. In summary, the flux-limited diffusion theory derived from the MEEF description is quantitatively as accurate as the MEEF method. However, it is more qualitatively correct and user-friendly than the MEEF method and can be applied efficiently to various steady-state problems. Numerical tests show that this method is widely valid and overall predicts better results than other low-order approximations for various kinds of problems, including eigenvalue problems. Thus, it is an appealing approximate solution technique that is fast computationally and yet is accurate enough for a

Steady-State Characteristics Analysis of Hybrid-Excited Flux-Switching Machines with Identical Iron Laminations

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Gan Zhang

2015-11-01

Full Text Available Since the air-gap field of flux-switching permanent magnet (FSPM machines is difficult to regulate as it is produced by the stator-magnets alone, a type of hybrid-excited flux-switching (HEFS machine is obtained by reducing the magnet length of an original FSPM machine and introducing a set of field windings into the saved space. In this paper, the steady-state characteristics, especially for the loaded performances of four prototyped HEFS machines, namely, PM-top, PM-middle-1, PM-middle-2, and PM-bottom, are comprehensively compared and evaluated based on both 2D and 3D finite element analysis. Also, the influences of PM materials including ferrite and NdFeB, respectively, on the characteristics of HEFS machines are covered. Particularly, the impacts of magnet movement in the corresponding slot on flux-regulating performances are studied in depth. The best overall performances employing NdFeB can be obtained when magnets are located near the air-gap. The FEA predictions are validated by experimental measurements on corresponding machine prototypes.

A note on the effective evaluation height for flux-gradient relationships and its application to herbicide fluxes

Science.gov (United States)

Volatilization represents a significant loss pathway for many pesticides, herbicides and other agrochemicals. One common method for measuring the volatilization of agrochemicals is the flux-gradient method. Using this method, the chemical flux is estimated as the product of the vertical concentratio...

Iron oxide nanoparticle-based magnetic resonance method to monitor release kinetics from polymeric particles with high resolution.

Science.gov (United States)

Chan, Minnie; Schopf, Eric; Sankaranarayanan, Jagadis; Almutairi, Adah

2012-09-18

A new method to precisely monitor rapid release kinetics from polymeric particles using super paramagnetic iron oxide nanoparticles, specifically by measuring spin-spin relaxation time (T(2)), is reported. Previously, we have published the formulation of logic gate particles from an acid-sensitive poly-β-aminoester ketal-2 polymer. Here, a series of poly-β-aminoester ketal-2 polymers with varying hydrophobicities were synthesized and used to formulate particles. We attempted to measure fluorescence of released Nile red to determine whether the structural adjustments could finely tune the release kinetics in the range of minutes to hours; however, this standard technique did not differentiate each release rate of our series. Thus, a new method based on encapsulation of iron oxide nanoparticles was developed, which enabled us to resolve the release kinetics of our particles. Moreover, the kinetics matched the relative hydrophobicity order determined by octanol-water partition coefficients. To the best of our knowledge, this method provides the highest resolution of release kinetics to date.

Production of iron from metallurgical waste

Science.gov (United States)

Hendrickson, David W; Iwasaki, Iwao

2013-09-17

A method of recovering metallic iron from iron-bearing metallurgical waste in steelmaking comprising steps of providing an iron-bearing metallurgical waste containing more than 55% by weight FeO and FeO equivalent and a particle size of at least 80% less than 10 mesh, mixing the iron-bearing metallurgical waste with a carbonaceous material to form a reducible mixture where the carbonaceous material is between 80 and 110% of the stoichiometric amount needed to reduce the iron-bearing waste to metallic iron, and as needed additions to provide a silica content between 0.8 and 8% by weight and a ratio of CaO/SiO.sub.2 between 1.4 and 1.8, forming agglomerates of the reducible mixture over a hearth material layer to protect the hearth, heating the agglomerates to a higher temperature above the melting point of iron to form nodules of metallic iron and slag material from the agglomerates by melting.

Neutron flux monitoring device

International Nuclear Information System (INIS)

Goto, Yasushi; Mitsubori, Minehisa; Ohashi, Kazunori.

1997-01-01

The present invention provides a neutron flux monitoring device for preventing occurrence of erroneous reactor scram caused by the elevation of the indication of a start region monitor (SRM) due to a factor different from actual increase of neutron fluxes. Namely, judgement based on measured values obtained by a pulse counting method and a judgment based on measured values obtained by a Cambel method are combined. A logic of switching neutron flux measuring method to be used for monitoring, namely, switching to an intermediate region when both of the judgements are valid is adopted. Then, even if the indication value is elevated based on the Cambel method with no increase of the counter rate in a neutron source region, the switching to the intermediate region is not conducted. As a result, erroneous reactor scram such as 'shorter reactor period' can be avoided. (I.S.)

Establishment of an easy Ic measurement method of HTS superconducting tapes using clipped voltage taps

International Nuclear Information System (INIS)

Shin, Hyung Seop; Nisay, Arman; Dedicatoria, Marlon; Sim, Ki Deok

2014-01-01

The critical current, I c of HTS superconducting tapes can be measured by transport or contactless method. Practically, the transport method using the four-probe method is the most common. In this study, a simple test procedure by clipping the voltage lead taps have been introduced instead of soldering which reduces time and effort and thereby achieving a much faster measurement of I c . When using a pair of iron clips, I c value decreased as compared with the measured one by standard method using soldered voltage taps and varies with the width of the clipped specimen part. However, when using a pure Cu clip, both by clipping and by soldering voltage taps give a comparable result and I c measured are equal and close to the samples specification. As a result, material to be used as voltage clip should be considered and should not influence the potential voltage between the leads during I c measurement. Furthermore, the simulation result of magnetic flux during I c measurement test showed that the decrease of I c observed in the experiment is due to the magnetic flux density, By produced at the clipped part of the sample by the operating current with iron clips attached to the sample.

KoFlux: Korean Regional Flux Network in AsiaFlux

Science.gov (United States)

Kim, J.

2002-12-01

AsiaFlux, the Asian arm of FLUXNET, held the Second International Workshop on Advanced Flux Network and Flux Evaluation in Jeju Island, Korea on 9-11 January 2002. In order to facilitate comprehensive Asia-wide studies of ecosystem fluxes, the meeting launched KoFlux, a new Korean regional network of long-term micrometeorological flux sites. For a successful assessment of carbon exchange between terrestrial ecosystems and the atmosphere, an accurate measurement of surface fluxes of energy and water is one of the prerequisites. During the 7th Global Energy and Water Cycle Experiment (GEWEX) Asian Monsoon Experiment (GAME) held in Nagoya, Japan on 1-2 October 2001, the Implementation Committee of the Coordinated Enhanced Observing Period (CEOP) was established. One of the immediate tasks of CEOP was and is to identify the reference sites to monitor energy and water fluxes over the Asian continent. Subsequently, to advance the regional and global network of these reference sites in the context of both FLUXNET and CEOP, the Korean flux community has re-organized the available resources to establish a new regional network, KoFlux. We have built up domestic network sites (equipped with wind profiler and radiosonde measurements) over deciduous and coniferous forests, urban and rural rice paddies and coastal farmland. As an outreach through collaborations with research groups in Japan, China and Thailand, we also proposed international flux sites at ecologically and climatologically important locations such as a prairie on the Tibetan plateau, tropical forest with mixed and rapid land use change in northern Thailand. Several sites in KoFlux already begun to accumulate interesting data and some highlights are presented at the meeting. The sciences generated by flux networks in other continents have proven the worthiness of a global array of micrometeorological flux towers. It is our intent that the launch of KoFlux would encourage other scientists to initiate and

Long-term measurement of terpenoid flux above a Larix kaempferi forest using a relaxed eddy accumulation method

Science.gov (United States)

Mochizuki, Tomoki; Tani, Akira; Takahashi, Yoshiyuki; Saigusa, Nobuko; Ueyama, Masahito

2014-02-01

Terpenoids emitted from forests contribute to the formation of secondary organic aerosols and affect the carbon budgets of forest ecosystems. To investigate seasonal variation in terpenoid flux involved in the aerosol formation and carbon budget, we measured the terpenoid flux of a Larix kaempferi forest between May 2011 and May 2012 by using a relaxed eddy accumulation method. Isoprene was emitted from a fern plant species Dryopteris crassirhizoma on the forest floor and monoterpenes from the L. kaempferi. α-Pinene was the dominant compound, but seasonal variation of the monoterpene composition was observed. High isoprene and monoterpene fluxes were observed in July and August. The total monoterpene flux was dependent on temperature, but several unusual high positive fluxes were observed after rain fall events. We found a good correlation between total monoterpene flux and volumetric soil water content (r = 0.88), and used this correlation to estimate monoterpene flux after rain events and calculate annual terpenoid emissions. Annual carbon emission in the form of total monoterpenes plus isoprene was determined to be 0.93% of the net ecosystem exchange. If we do not consider the effect of rain fall, carbon emissions may be underestimated by about 50%. Our results suggest that moisture conditions in the forest soil is a key factor controlling the monoterpene emissions from the forest ecosystem.

Method of Relative Magnitudes for Calculating Magnetic Fluxes in Electrical Machine

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Oleg A.

2018-03-01

Full Text Available Introduction: The article presents the study results of the model of an asynchronous electric motor carried out by the author within the framework of the Priorities Research Program “Research and development in the priority areas of development of Russia’s scientific and technical complex for 2014–2020”. Materials and Methods: A model of an idealized asynchronous machine (with sinusoidal distribution of magnetic induction in air gap is used in vector control systems. It is impossible to create windings for this machine. The basis of the new calculation approach was the Conductivity of Teeth Contours Method, developed at the Electrical Machines Chair of the Moscow Power Engineering Institute (MPEI. Unlike this method, the author used not absolute values, but relative magnitudes of magnetic fluxes. This solution fundamentally improved the method’s capabilities. The relative magnitudes of the magnetic fluxes of the teeth contours do not required the additional consideration for exact structure of magnetic field of tooth and adjacent slots. These structures are identical for all the teeth of the machine and differ only in magnitude. The purpose of the calculations was not traditional harmonic analysis of magnetic induction distribution in air gap of machine, but a refinement of the equations of electric machine model. The vector control researchers used only the cos(θ function as a value of mutual magnetic coupling coefficient between the windings. Results: The author has developed a way to take into account the design of the windings of a real machine by using imaginary measuring winding with the same winding design as a real phase winding. The imaginary winding can be placed in the position of any machine windings. The calculation of the relative magnetic fluxes of this winding helped to estimate the real values of the magnetic coupling coefficients between the windings, and find the correction functions for the model of an idealized

A straightforward method for Vacuum-Ultraviolet flux measurements: The case of the hydrogen discharge lamp and implications for solid-phase actinometry

International Nuclear Information System (INIS)

Fulvio, D.; Brieva, A. C.; Jäger, C.; Cuylle, S. H.; Linnartz, H.; Henning, T.

2014-01-01

Vacuum-Ultraviolet (VUV) radiation is responsible for the photo-processing of simple and complex molecules in several terrestrial and extraterrestrial environments. In the laboratory such radiation is commonly simulated by inexpensive and easy-to-use microwave-powered hydrogen discharge lamps. However, VUV flux measurements are not trivial and the methods/devices typically used for this purpose, mainly actinometry and calibrated VUV silicon photodiodes, are not very accurate or expensive and lack of general suitability to experimental setups. Here, we present a straightforward method for measuring the VUV photon flux based on the photoelectric effect and using a gold photodetector. This method is easily applicable to most experimental setups, bypasses the major problems of the other methods, and provides reliable flux measurements. As a case study, the method is applied to a microwave-powered hydrogen discharge lamp. In addition, the comparison of these flux measurements to those obtained by O 2 actinometry experiments allow us to estimate the quantum yield (QY) values QY 122  = 0.44 ± 0.16 and QY 160  = 0.87 ± 0.30 for solid-phase O 2 actinometry.

A straightforward method for Vacuum-Ultraviolet flux measurements: The case of the hydrogen discharge lamp and implications for solid-phase actinometry

Energy Technology Data Exchange (ETDEWEB)

Fulvio, D., E-mail: daniele.fulvio@uni-jena.de, E-mail: dfu@oact.inaf.it; Brieva, A. C.; Jäger, C. [Laboratory Astrophysics Group of the Max Planck Institute for Astronomy at the Friedrich Schiller University Jena, Institute of Solid State Physics, Helmholtzweg 3, D-07743 Jena (Germany); Cuylle, S. H.; Linnartz, H. [Raymond and Beverly Sackler Laboratory for Astrophysics, Leiden Observatory, Leiden University, P.O. box 9513, 2300 RA Leiden (Netherlands); Henning, T. [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany)

2014-07-07

Vacuum-Ultraviolet (VUV) radiation is responsible for the photo-processing of simple and complex molecules in several terrestrial and extraterrestrial environments. In the laboratory such radiation is commonly simulated by inexpensive and easy-to-use microwave-powered hydrogen discharge lamps. However, VUV flux measurements are not trivial and the methods/devices typically used for this purpose, mainly actinometry and calibrated VUV silicon photodiodes, are not very accurate or expensive and lack of general suitability to experimental setups. Here, we present a straightforward method for measuring the VUV photon flux based on the photoelectric effect and using a gold photodetector. This method is easily applicable to most experimental setups, bypasses the major problems of the other methods, and provides reliable flux measurements. As a case study, the method is applied to a microwave-powered hydrogen discharge lamp. In addition, the comparison of these flux measurements to those obtained by O{sub 2} actinometry experiments allow us to estimate the quantum yield (QY) values QY{sub 122} = 0.44 ± 0.16 and QY{sub 160} = 0.87 ± 0.30 for solid-phase O{sub 2} actinometry.

Pulsed magnetic flux leakage method for hairline crack detection and characterization

Science.gov (United States)

Okolo, Chukwunonso K.; Meydan, Turgut

2018-04-01

The Magnetic Flux leakage (MFL) method is a well-established branch of electromagnetic Non-Destructive Testing (NDT), extensively used for evaluating defects both on the surface and far-surface of pipeline structures. However the conventional techniques are not capable of estimating their approximate size, location and orientation, hence an additional transducer is required to provide the extra information needed. This research is aimed at solving the inevitable problem of granular bond separation which occurs during manufacturing, leaving pipeline structures with miniature cracks. It reports on a quantitative approach based on the Pulsed Magnetic Flux Leakage (PMFL) method, for the detection and characterization of the signals produced by tangentially oriented rectangular surface and far-surface hairline cracks. This was achieved through visualization and 3D imaging of the leakage field. The investigation compared finite element numerical simulation with experimental data. Experiments were carried out using a 10mm thick low carbon steel plate containing artificial hairline cracks with various depth sizes, and different features were extracted from the transient signal. The influence of sensor lift-off and pulse width variation on the magnetic field distribution which affects the detection capability of various hairline cracks located at different depths in the specimen is explored. The findings show that the proposed technique can be used to classify both surface and far-surface hairline cracks and can form the basis for an enhanced hairline crack detection and characterization for pipeline health monitoring.

Management of Iron Deficiency Anemia

Science.gov (United States)

Jimenez, Kristine; Kulnigg-Dabsch, Stefanie

2015-01-01

Anemia affects one-fourth of the world’s population, and iron deficiency is the predominant cause. Anemia is associated with chronic fatigue, impaired cognitive function, and diminished well-being. Patients with iron deficiency anemia of unknown etiology are frequently referred to a gastroenterologist because in the majority of cases the condition has a gastrointestinal origin. Proper management improves quality of life, alleviates the symptoms of iron deficiency, and reduces the need for blood transfusions. Treatment options include oral and intravenous iron therapy; however, the efficacy of oral iron is limited in certain gastrointestinal conditions, such as inflammatory bowel disease, celiac disease, and autoimmune gastritis. This article provides a critical summary of the diagnosis and treatment of iron deficiency anemia. In addition, it includes a management algorithm that can help the clinician determine which patients are in need of further gastrointestinal evaluation. This facilitates the identification and treatment of the underlying condition and avoids the unnecessary use of invasive methods and their associated risks. PMID:27099596

Iron transport in a confined high-temperature plasma

International Nuclear Information System (INIS)

Demokan, O.; Waelbroeck, F.

1981-06-01

The neo-classical flux, GAMMAsub(n.c), of Fe XXIII is calculated for the experimental conditions produced in PLT by using the data on the iron density profiles and the plasma parameters. The actual flux of Fe XXIII, GAMMAsub(c.e), is then evaluated from the continuity equation, by using the same data. GAMMAsub(c.e) is on the average two orders of magnitude larger than GAMMAsub(n.c), the neo-classical prediction. These results are further tested by introducing the neo-classical coefficients which are multiplied by various anomaly factors into the continuity equation and solving for the density profile of Fe XXIII, using the experimental profiles of Fe XXII and Fe XXIV as given. The results of this section indicate that the first and the second terms in the neo-classical flux expression, GAMMAsub(n.c) = -D 1 (dn/dr) + D 2 n, should be multiplied approximately by the factors (100) and (25), respectively in order to yield the experimentally observed profile of Fe XXIII. (orig./HT)

Nodular cast iron and casting monitoring

Directory of Open Access Journals (Sweden)

S. Pietrowski

2008-10-01

Full Text Available In this paper quality monitoring of nodular cast iron and casting made of it is presented. A control system of initial liquid cast iron to spheroidization, after spheroidization and inoculation with using of TDA method was shown. An application of an ultrasonic method to assessment of the graphite form and the metal matrix microstructure of castings was investigated.

Iron bioavailability of Lupinus rotundiflorus seeds and roots in low-iron-diet treated rats

Directory of Open Access Journals (Sweden)

Elia Herminia VALDÉS MIRAMONTES

Full Text Available ABSTRACT Objective To evaluate iron bioavailability of roots and cooked seeds of Lupinus rotundiflorus for human consumption using a low-iron-diet rat model. Methods A hemoglobin depletion–repletion test was performed using rats. A standard diet containing 8mg kg-1 of iron was used. Three experimental diets were prepared based on the standard diet: 2.3g of root flour added to D1, 21.5g cooked seed flour added to D2, and 0.03g of ferrous sulfate added to D3 (control diet, adjusting iron concentration of the diets to 24mg kg-1. Hemoglobin regeneration efficiency was used to measure iron bioavailability. Results Hemoglobin regeneration efficiency showed values of 13.80+2.49%, 13.70+1.60% and 18.38+1.56 in D1, D2 and D3 respectively, and biological relative values of 72.8, 75.08, and 100.00% (.<0.05. Conclusion Roots and cooked seeds of Lupinus rotundiflorus showed potential iron bioavailability, despite being a vegetal source, which could also encourage the study of other species of lupin as a source of iron.

Jendl-3.1 iron validation on the PCA-REPLICA (H2O/Fe) shielding benchmark experiment

International Nuclear Information System (INIS)

Pescarini, M.; Borgia, M. G.

1997-03-01

The PCA-REPLICA (H 2 O/Fe) neutron shielding benchmarks experiment is analysed using the SN 2-D DOT 3.5-E code and the 3-D-equivalent flux synthesis method. This engineering benchmark reproduces the ex-core radial geometry of a PWR, including a mild steel reactor pressure vessel (RPV) simulator, and is designed to test the accuracy of the calculation of the in-vessel neutron exposure parameters. This accuracy is strongly dependent on the quality of the iron neutron cross sections used to describe the nuclear reactions within the RPV simulator. In particular, in this report, the cross sections based on the JENDL-3.1 iron data files are tested, through a comparison of the calculated integral and spectral results with the corresponding experimental data. In addition, the present results are compared, on the same benchmark experiment, with those of a preceding ENEA-Bologna validation of the ENDF/B VI iron cross sections. The integral result comparison indicates that, for all the threshold detectors considered (Rh-103 (n, n') Rh-103m, In-115 (n, n') In-115m and S-32 (n, p) P-32), the JENDL-3.1 natural iron data produce satisfactory results similar to those obtained with the ENDF/B VI iron data. On the contrary, when the JENDL/3.1 Fe-56 data file is used, strongly underestimated results are obtained for the lower energy threshold detectors, Rh-103 and In-115. This fact, in particular, becomes more evident with increasing the neutron penetration depth in the RPV simulator

An easy-to-use method for measuring the flux of free atoms in a cluster beam

International Nuclear Information System (INIS)

Cuvellier, J.; Binet, A.

1988-01-01

A method is proposed to measure the flux of free atoms remaining in a beam of clusters. The time-of-flight (TOF) of an Ar beam containing clusters was analysed for this purpose using an electron impact + quadrupole mass spectrometer as detector. When considering TOF's with mass settings at Ar + , a double mode structure was observed. The slow component was interpreted as coming from Ar clusters that fragment as Ar + in the ionization chamber of the detector. The rapid mode in the TOF's was linked to the free atoms remaining in the Ar beam. Evaluating the area of this mode allowed one to measure the flux of free atoms in the Ar beam. The method is not restricted to measurements on Ar beams

Measurement of helium production cross sections of iron for d-T neutrons by helium accumulation method

Energy Technology Data Exchange (ETDEWEB)

Takao, Yoshiyuki; Kanda, Yukinori; Nagae, Koji; Fujimoto, Toshihiro [Kyushu Univ., Fukuoka (Japan); Ikeda, Yujiro

1997-03-01

Helium production cross sections of Iron were measured by helium accumulation method for neutron energies from 13.5 to 14.9 MeV. Iron samples were irradiated with FNS, an intense d-T neutron source of JAERI. As the neutron energy varies according to the emission angle at the neutron source, the samples were set around the neutron source and were irradiated by neutrons of different energy depending on each sample position. The amount of helium produced in a sample was measured by Helium Atoms Measurement System at Kyushu University. The results of this work are in good agreement with other experimental data in the literature and also compared with the evaluated values in JENDL-3. (author)

Nondestructive testing of hardness of grey iron casts by upper harmonics method

International Nuclear Information System (INIS)

Ershov, R.E.; Ivanenko, T.G.; Kuznetsky, S.S.; Mutovin, V.A.

1982-01-01

The relation between microstructure of grey iron and his surface hardness on the one hand and magnetic characteristics on the other hand has been investigated on toroidal samples. It is shown that surface hardness of grey iron and parameter a in Froelich formula are dependent linearly on the total surface of graphite inclusions. The conclusion was made that the testing of the grey iron hardness better to make by using the phase of the upper harmonics of the output signal of the overlain transducer. The coefficient of the linear correlation between readings corresponding device and the hardness is 0.86. (orig.)

Genetics Home Reference: iron-refractory iron deficiency anemia

Science.gov (United States)

... refractory iron deficiency anemia Iron-refractory iron deficiency anemia Printable PDF Open All Close All Enable Javascript ... expand/collapse boxes. Description Iron-refractory iron deficiency anemia is one of many types of anemia , which ...

Seasonal analyses of carbon dioxide and energy fluxes above an oil palm plantation using the eddy covariance method

Science.gov (United States)

Ibrahim, Anis; Haniff Harun, Mohd; Yusup, Yusri

2017-04-01

A study presents the measurements of carbon dioxide and latent and sensible heat fluxes above a mature oil palm plantation on mineral soil in Keratong, Pahang, Peninsular Malaysia. The sampling campaign was conducted over an 25-month period, from September 2013 to February 2015 and May 2016 to November 2016, using the eddy covariance method. The main aim of this work is to assess carbon dioxide and energy fluxes over this plantation at different time scales, seasonal and diurnal, and determine the effects of season and relevant meteorological parameters on the latter fluxes. Energy balance closure analyses gave a slope between latent and sensible heat fluxes and total incoming energy to be 0.69 with an R2 value of 0.86 and energy balance ratio of 0.80. The averaged net radiation was 108 W m-2. The results show that at the diurnal scale, carbon dioxide, latent and sensible heat fluxes exhibited a clear diurnal trend where carbon dioxide flux was at its minimum - 3.59 μmol m-2 s-1 in the mid-afternoon and maximum in the morning while latent and sensible behaved conversely to the carbon dioxide flux. The average carbon dioxide flux was - 0.37 μmol m-2 s-1. At the seasonal timescale, carbon dioxide fluxes did not show any apparent trend except during the Northeast Monsoon where the highest variability of the monthly means of carbon dioxide occurred.

Magnetic behavior of iron-modified MCM-41 correlated with clustering processes from the wet impregnation method

Energy Technology Data Exchange (ETDEWEB)

Cuello, Natalia I.; Elías, Verónica R. [Centro de Investigación y Tecnología Química (CITeQ) (UTN-CONICET), Facultad Regional Córdoba. Maestro López y Cruz Roja Argentina, Ciudad Universitaria, Córdoba 5016 (Argentina); Winkler, Elin [Centro Atómico Bariloche, Comisión Nacional de Energía Atómica – CONICET, Avenue Bustillo 9500, San Carlos de Bariloche 8400 (Argentina); Pozo-López, Gabriela; Oliva, Marcos I. [Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba – IFEG, CONICET, Ciudad Universitaria, Córdoba 5000 (Argentina); Eimer, Griselda A., E-mail: geimer@frc.utn.edu.ar [Centro de Investigación y Tecnología Química (CITeQ) (UTN-CONICET), Facultad Regional Córdoba. Maestro López y Cruz Roja Argentina, Ciudad Universitaria, Córdoba 5016 (Argentina)

2016-06-01

Magnetic MCM-41 type mesoporous silica materials were synthetized and modified with different iron loadings by the wet impregnation method. The evolution of iron speciation, depending on the metal loading and associated with a particular magnetic behavior was investigated by M vs. H curves, FC–ZFC curves, EPR spectroscopy and other complementary techniques such as SEM, TEM, and chemisorption of pyridine followed by FT-IR studies. A superparamagnetic contribution was larger for the lower loadings suggesting the high dispersion of very small sized iron nanospecies. However, this contribution decreased with increasing metal loading due to the growth of magnetically blocked nanoparticles (hematite) on the outer surface. Finally, a bimodal size distribution for the superparamagnetic nanospecies could be inferred; then the anisotropy constant for this phase and the corresponding nanospecies sizes were estimated. - Highlights: • All samples showed a main superparamagnetic contribution. • The oxide particles grow at expense of superparamagnetic nanospecies. • Bimodal distribution of nanospecies in superparamagnetic regime was determined. • The anisotropy constant for superparamagnetic nanospecies was calculated.

[Tolerability of iron preparation Actiferol Fe® in children treated for iron deficiency anemia].

Science.gov (United States)

Jackowska, Teresa; Sapała-Smoczyńska, Alicja; Kamińska, Ewa

2015-01-01

Iron de„ciency anemia is the most frequently occurring anemia during the childhood period. Supplementation with adequate doses of iron remains a basic method of prevention and treatment. The various available products containing iron are characterized by a different degree of patient tolerability. Actiferol Fe® is a micronized, dispersible ferric pyrophosphate which improves its water solubility, and therefore it has better absorption and bioavailability. The assessment of tolerability of Actiferol Fe® in children who were administered this product to treat or prevent of iron de„ciency anemia. The methods of administration and the incidence of adverse effects were analyzed. Eighty children (64 boys and 16 girls) aged from one month to 6 years who met the criteria of an indication to be treated with iron were included into the study. The assessment of selected parameters was based on the questionnaire which included questions about tolerability, method of administration, convenience of usage and adverse e#ects. The questionnaire was „lled in by parents (usually by the mother). The study indicated that Actiferol Fe® has very good or good tolerability in 87.5% (70/80) of patients - 46.3% (37/80) and 41.2% (33/80), respectively. The most frequent method of administration was in liquid form after dissolving: in water - 31,3% (25/80), in orange juice - 18.8% (15/80) or in milk formulas - in 17.5% (14/80) of patients. The method of administration was assessed as convenient or very convenient by 84% (67/80) of participants. Out of the adverse effects reported, the most frequent were change in the stool consistency into harder, abdominal pain and constipation - in 20% (16/80), 11.25% (9/80), 10% (8/80) cases, respectively. Diarrhea, pain during defecation occurred occasionally. A dark color of the stool was reported by 55% (44/80) of patients. In only one case (1.25%) the parents resigned from the product administration and replaced it with another iron product (no

Instant Noodles and Iron Nutrition

International Nuclear Information System (INIS)

Tuntawiroon, Malulee; Sritongkul, Nopamon; Sookpeng Witoo

2003-06-01

Instant noodles represent the biggest category of instant foods in the supermarket. This study was undertaken to determine dietary availability for iron from their varieties without and with an addition of pork and/or vitamin C rich-vegetables by in vitro radiometric ( 59 Fe) method. The results showed that 8 to 13 percent of iron in the noodles was available for absorption of which contributed to 0.79 mg absorbed iron per day. This amount was too low to meet certain requirements for children, adolescents and menstruating women. With added pork or vegetables, iron availability increased by 2 to 3 times, and by 4 times with added pork and collard or cabbage (p<0.001). The amounts as high as 1.5 to 3.4 mg absorbed iron per day can meet the FAO/WHO requirements for most of the high-risk groups

Iron-carbonate interaction at Earth's core-mantle boundary

Science.gov (United States)

Dorfman, S. M.; Badro, J.; Nabiei, F.; Prakapenka, V.; Gillet, P.

2015-12-01

Carbon storage and flux in the deep Earth are moderated by oxygen fugacity and interactions with iron-bearing phases. The amount of carbon stored in Earth's mantle versus the core depends on carbon-iron chemistry at the core-mantle boundary. Oxidized carbonates subducted from Earth's surface to the lowermost mantle may encounter reduced Fe0 metal from disproportionation of Fe2+ in lower mantle silicates or mixing with the core. To understand the fate of carbonates in the lowermost mantle, we have performed experiments on sandwiches of single-crystal (Ca0.6Mg0.4)CO3 dolomite and Fe foil in the laser-heated diamond anvil cell at lower mantle conditions of 49-110 GPa and 1800-2500 K. Syntheses were conducted with in situ synchrotron X-ray diffraction to identify phase assemblages. After quench to ambient conditions, samples were sectioned with a focused Ga+ ion beam for composition analysis with transmission electron microscopy. At the centers of the heated spots, iron melted and reacted completely with the carbonate to form magnesiowüstite, iron carbide, diamond, magnesium-rich carbonate and calcium carbonate. In samples heated at 49 and 64 GPa, the two carbonates exhibit a eutectoid texture. In the sample heated at 110 GPa, the carbonates form rounded ~150-nm-diameter grains with a higher modal proportion of interspersed diamonds. The presence of reduced iron in the deep lower mantle and core-mantle boundary region will promote the formation of diamonds in carbonate-bearing subducted slabs. The complete reaction of metallic iron to oxides and carbides in the presence of mantle carbonate supports the formation of these phases at the Earth's core-mantle boundary and in ultra-low velocity zones.

Effect of dietary iron source and iron status on iron bioavailability tests in the rat

International Nuclear Information System (INIS)

Zhang, D.; Hendricks, D.G.; Mahoney, A.W.

1986-01-01

Weanling male rats were made anemic in 7 days by feeding a low iron diet and bleeding. Healthy rats were fed the low iron diet supplemented with ferrous sulfate (29 ppm Fe). Each group was subdivided and fed for 10 days on test diets containing about 29 ppm iron that were formulated with meat:spinach mixtures or meat:soy mixtures to provided 100:0, 75:25, 50:50, 25:75, or 0:100% of the dietary iron from these sources or from a ferrous sulfate diet. After 3 days on the diets all rats were dosed orally with 2 or 5 micro curries of 59 Fe after a 18 hour fast and refeeding for 1.5 hours. Iron status influenced liver iron, carcass iron, liver radio activity and percent of radioactive dose retained. Diet influenced fecal iron and apparent absorption of iron. In iron bioavailability studies assessment methodology and iron status of the test subject greatly influences the estimates of the value of dietary sources of iron

Integrated passive flux measurement in groundwater: design and performance of iFLUX samplers

Science.gov (United States)

Verreydt, Goedele; Razaei, Meisam; Meire, Patrick; Van Keer, Ilse; Bronders, Jan; Seuntjens, Piet

2017-04-01

The monitoring and management of soil and groundwater is a challenge. Current methods for the determination of movement or flux of pollution in groundwater use no direct measurements but only simulations based on concentration measurements and Darcy velocity estimations. This entails large uncertainties which cause remediation failures and higher costs for contaminated site owners. On top of that, the lack of useful data makes it difficult to get approval for a risk-based management approach which completely avoids costly remedial actions. The iFLUX technology is a key development of Dr. Goedele Verreydt at the University of Antwerp and VITO. It is supported by the passive flux measurement technology as invented by Prof. Mike Annable and his team at the University of Florida. The iFLUX technology includes an in situ measurement device for capturing dynamic groundwater quality and quantity, the iFLUX sampler, and an associated interpretation and visualization method. The iFLUX sampler is a modular passive sampler that provides simultaneous in situ point determinations of a time-averaged target compound mass flux and water flux. The sampler is typically installed in a monitoring well where it intercepts the groundwater flow and captures the compounds of interest. The sampler consists of permeable cartridges which are each packed with a specific sorbent matrix. The sorbent matrix of the water flux cartridge is impregnated with known amounts of water soluble resident tracers. These tracers are leached from the matrix at rates proportional to the groundwater flux. The measurements of the contaminants and the remaining resident tracer are used to determine groundwater and target compound fluxes. Exposure times range from 1 week to 6 months, depending on the expected concentration and groundwater flow velocity. The iFLUX sampler technology has been validated and tested at several field projects. Currently, 4 cartridges are tested and available: 1 waterflux cartridge to

Compilation of neutron flux density spectra and reaction rates in different neutron fields

International Nuclear Information System (INIS)

Ertek, C.

1979-07-01

Upon the recommendation of International Working Group of Reactor Radiation Measurements (IWGRRM), the compilation of neutron flux density spectra and the reaction rates obtained by activation and fission foils in different neutron fields is presented. The neutron fields considered are as follows: 1/E; iron block; LWR core and pressure vessel; LMFBR core and blanket; CTR first wall and blanket; fission spectrum

Magnetic properties of iron-based soft magnetic composites with SiO{sub 2} coating obtained by reverse microemulsion method

Energy Technology Data Exchange (ETDEWEB)

Wu, Shen [School of Material Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); Sun, Aizhi, E-mail: sunaizhi@126.com [School of Material Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); Lu, Zhenwen; Cheng, Chuan [School of Material Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Gao, Xuexu [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China)

2015-05-01

In this work, iron-based soft magnetic composites coated with the amorphous SiO{sub 2} layer have been fabricated by utilizing tetraethoxysilane in the reverse microemulsion method, and then the effects of addition amount of SiO{sub 2} and annealing temperature on the magnetic properties were investigated. The results show that the surface of iron powders contains a thin amorphous SiO{sub 2} insulation layer, which effectively decreases the magnetic loss of synthesized magnets. The magnetic loss of coated samples decreased by 87.8% as compared with that of uncoated samples at 150 kHz. Magnetic measurements show that the sample with 1.25 wt% SiO{sub 2} has an acceptable real part and minimum imaginary part of permeability in comparison with other samples. Also, the annealing treatment increased the initial permeability, the maximum permeability and the magnetic induction and decreased the coercivity with increasing temperature in the range 300–600 °C. The results of the loss separation imply that the annealed SMCs have a higher hysteresis loss coefficient (k{sub 2}) and lower eddy current loss coefficient (k{sub 3}) as compared with the pure iron compacts after the same heat treatment due to the preservation of the SiO{sub 2} layer. - Highlights: • SiO{sub 2} coated the iron powder by reverse microemulsion method, decreased the magnetic loss of SMCs. • 25 wt% is the optimum coating amount to attain the desired permeability. • The influence of annealing temperature on the magnetic performance of the core was discussed. • Compare with the pure iron compacts, the annealed SMCs have lower value of eddy current coefficient.

The truth is out there: measured, calculated and modelled benthic fluxes.

Science.gov (United States)

Pakhomova, Svetlana; Protsenko, Elizaveta

2016-04-01

In a modern Earth science there is a great importance of understanding the processes, forming the benthic fluxes as one of element sources or sinks to or from the water body, which affects the elements balance in the water system. There are several ways to assess benthic fluxes and here we try to compare the results obtained by chamber experiments, calculated from porewater distributions and simulated with model. Benthic fluxes of dissolved elements (oxygen, nitrogen species, phosphate, silicate, alkalinity, iron and manganese species) were studied in the Baltic and Black Seas from 2000 to 2005. Fluxes were measured in situ using chamber incubations (Jch) and at the same time sediment cores were collected to assess the porewater distribution at different depths to calculate diffusive fluxes (Jpw). Model study was carried out with benthic-pelagic biogeochemical model BROM (O-N-P-Si-C-S-Mn-Fe redox model). It was applied to simulate biogeochemical structure of the water column and upper sediment and to assess the vertical fluxes (Jmd). By the behaviour at the water-sediment interface all studied elements can be divided into three groups: (1) elements which benthic fluxes are determined by the concentrations gradient only (Si, Mn), (2) elements which fluxes depend on redox conditions in the bottom water (Fe, PO4, NH4), and (3) elements which fluxes are strongly connected with organic matter fate (O2, Alk, NH4). For the first group it was found that measured fluxes are always higher than calculated diffusive fluxes (1.5disadvantages and the main facing us question is - which value should be taken for calculation the balance? This research is funded by VISTA - a basic research program and collaborative partnership between the Norwegian Academy of Science and Letters and Statoil.

Assessment of 12 CHF prediction methods, for an axially non-uniform heat flux distribution, with the RELAP5 computer code

Energy Technology Data Exchange (ETDEWEB)

Ferrouk, M. [Laboratoire du Genie Physique des Hydrocarbures, University of Boumerdes, Boumerdes 35000 (Algeria)], E-mail: m_ferrouk@yahoo.fr; Aissani, S. [Laboratoire du Genie Physique des Hydrocarbures, University of Boumerdes, Boumerdes 35000 (Algeria); D' Auria, F.; DelNevo, A.; Salah, A. Bousbia [Dipartimento di Ingegneria Meccanica, Nucleare e della Produzione, Universita di Pisa (Italy)

2008-10-15

The present article covers the evaluation of the performance of twelve critical heat flux methods/correlations published in the open literature. The study concerns the simulation of an axially non-uniform heat flux distribution with the RELAP5 computer code in a single boiling water reactor channel benchmark problem. The nodalization scheme employed for the considered particular geometry, as modelled in RELAP5 code, is described. For this purpose a review of critical heat flux models/correlations applicable to non-uniform axial heat profile is provided. Simulation results using the RELAP5 code and those obtained from our computer program, based on three type predictions methods such as local conditions, F-factor and boiling length average approaches were compared.

A budget impact analysis of parenteral iron treatments for iron deficiency anemia in the UK: reduced resource utilization with iron isomaltoside 1000

Directory of Open Access Journals (Sweden)

Pollock RF

2017-08-01

Full Text Available Richard F Pollock,1 Gorden Muduma2 1Ossian Health Economics and Communications GmbH, Basel, Switzerland; 2Pharmacosmos A/S, Holbaek, Denmark Background and aims: The reported prevalence of iron deficiency anemia (IDA varies widely but estimates suggest that 3% of men and 8% of women have IDA in the UK. Parenteral iron is indicated for patients intolerant or unresponsive to oral iron or requiring rapid iron replenishment. This study evaluated differences in the cost of treating these patients with iron isomaltoside (Monofer®, IIM relative to other intravenous iron formulations. Methods: A budget impact model was developed to evaluate the cost of using IIM relative to ferric carboxymaltose (Ferinject®, FCM, low molecular weight iron dextran (Cosmofer®, LMWID, and iron sucrose (Venofer®, IS in patients with IDA. To establish iron need, iron deficits were modeled using a simplified dosing table. The base case analysis was conducted over 1 year in patients with IDA with mean bodyweight of 82.4 kg (SD 22.5 kg and hemoglobin levels of 9.99 g/dL (SD 1.03 g/dL based on an analysis of patient characteristics in IDA trials. Costs were modeled using UK health care resource groups. Results: Using IIM required 1.3 infusions to correct the mean iron deficit, compared with 1.3, 1.8, and 7.7 with LMWID, FCM, and IS, respectively. Patients using IIM required multiple infusions in 35% of cases, compared with 35%, 77%, and 100% of patients with LMWID, FCM, and IS, respectively. Total costs were estimated to be GBP 451 per patient with IIM or LMWID, relative to GBP 594 with FCM (a GBP 143 or 24% saving with IIM or GBP 2,600 with IS (a GBP 2,149 or 83% saving with IIM. Conclusion: Using IIM or LMWID in place of FCM or IS resulted in a marked reduction in the number of infusions required to correct iron deficits in patients with IDA. The reduction in infusions was accompanied by substantial reductions in cost relative to FCM and IS over 1 year. Keywords: iron

Development of a primary method for the determination of iron in serum

International Nuclear Information System (INIS)

Palos, Marie; Del Castillo Busto, Maria Estela; Fisicaro, Paola; Vaslin-Reimann, Sophie; Hattchouel, Jean-Marc; Pannier, Florence

2015-01-01

This work presents the development of a reference method by ICP-MS for the determination of iron in serum. To ensure the metrological traceability of the results, isotope dilution associated with ICP-MS (ID-ICP-MS) has been applied, which has the potential to be a primary measurement procedure. Method validation has been demonstrated through the use of a certified reference material (SRM 1598a) and the participation in an international comparison between National Metrology Institutes (BIPM-CCQM K107). The validated method is now available to support clinical laboratories in the evaluation of their measurement capabilities and for quality assurance and quality control programs. In fact, this ID-ICP-MS method can be used to certify reference materials or to assign reference values to samples used in proficiency testing schemes. The feasibility has been tested on two unknown samples, i.e. BCR"R -637, IRMM sample and an ANSM B17 sample (a material distributed during a National Quality Control program). (authors)

Fast flux module detection using matroid theory.

Science.gov (United States)

Reimers, Arne C; Bruggeman, Frank J; Olivier, Brett G; Stougie, Leen

2015-05-01

Flux balance analysis (FBA) is one of the most often applied methods on genome-scale metabolic networks. Although FBA uniquely determines the optimal yield, the pathway that achieves this is usually not unique. The analysis of the optimal-yield flux space has been an open challenge. Flux variability analysis is only capturing some properties of the flux space, while elementary mode analysis is intractable due to the enormous number of elementary modes. However, it has been found by Kelk et al. (2012) that the space of optimal-yield fluxes decomposes into flux modules. These decompositions allow a much easier but still comprehensive analysis of the optimal-yield flux space. Using the mathematical definition of module introduced by Müller and Bockmayr (2013b), we discovered useful connections to matroid theory, through which efficient algorithms enable us to compute the decomposition into modules in a few seconds for genome-scale networks. Using that every module can be represented by one reaction that represents its function, in this article, we also present a method that uses this decomposition to visualize the interplay of modules. We expect the new method to replace flux variability analysis in the pipelines for metabolic networks.

Effect of treatment with single total-dose intravenous iron versus daily oral iron(III-hydroxide polymaltose on moderate puerperal iron-deficiency anemia

Directory of Open Access Journals (Sweden)

Iyoke CA

2017-05-01

Full Text Available Chukwuemeka Anthony Iyoke,1 Fausta Chioma Emegoakor,1 Euzebus Chinonye Ezugwu,1 Lucky Osaheni Lawani,2 Leonard Ogbonna Ajah,1 Jude Anazoeze Madu,3 Hyginus Uzo Ezegwui,1 Frank Okechukwu Ezugwu4 1Department of Obstetrics and Gynaecology, University of Nigeria, Enugu Campus, 2Department of Obstetrics and Gynaecology, Federal Teaching Hospital, Abakaliki, 3Department of Haematology, University of Nigeria, Nsukka, 4Department of Obstetrics and Gynaecology, College of Medicine, Enugu State University, Enugu, Nigeria Background: Iron-deficiency anemia is the most common nutritional cause of anemia in pregnancy and is often responsible for puerperal anemia. Puerperal anemia can impair postpartum maternal and neonatal well-being. Objective: To determine the effect of treatment of moderate puerperal iron-deficiency anemia using a single intravenous total-dose iron dextran versus daily single dose oral iron(III-hydroxide polymaltose. Methodology: A randomized controlled study in which postpartum women with moderate iron-deficiency anemia were randomized into treatment with either a single total-dose intravenous iron dextran or with daily single doses of oral iron(III-hydroxide polymaltose tablets for 6 weeks. Effects on hemoglobin concentration using either method were compared at 6 weeks postpartum. Analysis was per protocol using SPSS version 17 for windows. P-values ≤0.05 were considered significant. Results: Two hundred eighty-four women were recruited for the study: 142 women received single total dose intravenous infusion of iron dextran while 142 received daily oral iron(III-hydroxide polymaltose tablets. Approximately 84.0% (237/282 completed the study and were analyzed including 81% (115/142 of those randomized to injectable iron therapy compared to 85.9% (122/142 of those randomized to oral treatment. The proportions of women who had attained hemoglobin concentration of at least 10 g/dL by the 6 weeks postpartum visit did not differ

An analog computer method for solving flux distribution problems in multi region nuclear reactors

Energy Technology Data Exchange (ETDEWEB)

Radanovic, L; Bingulac, S; Lazarevic, B; Matausek, M [Boris Kidric Institute of Nuclear Sciences Vinca, Beograd (Yugoslavia)

1963-04-15

The paper describes a method developed for determining criticality conditions and plotting flux distribution curves in multi region nuclear reactors on a standard analog computer. The method, which is based on the one-dimensional two group treatment, avoids iterative procedures normally used for boundary value problems and is practically insensitive to errors in initial conditions. The amount of analog equipment required is reduced to a minimum and is independent of the number of core regions and reflectors. (author)

Hepatic iron overload: Quantitative MR imaging

International Nuclear Information System (INIS)

Gomori, J.M.; Horev, G.; Tamary, H.; Zandback, J.; Kornreich, L.; Zaizov, R.; Freud, E.; Krief, O.; Ben-Meir, J.; Rotem, H.

1991-01-01

Iron deposits demonstrate characteristically shortened T2 relaxation times. Several previously published studies reported poor correlation between the in vivo hepatic 1/T2 measurements made by means of midfield magnetic resonance (MR) units and the hepatic iron content of iron-overloaded patients. In this study, the authors assessed the use of in vivo 1/T2 measurements obtained by means of MR imaging at 0.5 T using short echo times (13.4 and 30 msec) and single-echo-sequences as well as computed tomographic (CT) attenuation as a measure of liver iron concentration in 10 severely iron-overloaded patients with beta-thalassemia major. The iron concentrations in surgical wedge biopsy samples of the liver, which varied between 3 and 9 mg/g of wet weight (normal, less than or equal to 0.5 mg/g), correlated well (r = .93, P less than or equal to .0001) with the preoperative in vivo hepatic 1/T2 measurements. The CT attenuation did not correlate with liver iron concentration. Quantitative MR imaging is a readily available noninvasive method for the assessment of hepatic iron concentration in iron-overloaded patients, reducing the need for needle biopsies of the liver

A simple method to extract information on anisotropy of particle fluxes from spin-modulated counting rates of cosmic ray telescopes

International Nuclear Information System (INIS)

Hsieh, K.C.; Lin, Y.C.; Sullivan, J.D.

1975-01-01

A simple method to extract information on anisotropy of particle fluxes from data collected by cosmic ray telescopes on spinning spacecraft but without sectored accumulators is presented. Application of this method to specific satellite data demonstrates that it requires no prior assumption on the form of angular distribution of the fluxes; furthermore, self-consistency ensures the validity of the results thus obtained. The examples show perfect agreement with the corresponding magnetic field directions

Ironing out the Details: Exploring the Role of Iron and Heme in Blood-Sucking Arthropods

Science.gov (United States)

Whiten, Shavonn R.; Eggleston, Heather; Adelman, Zach N.

2018-01-01

Heme and iron are essential molecules for many physiological processes and yet have the ability to cause oxidative damage such as lipid peroxidation, protein degradation, and ultimately cell death if not controlled. Blood-sucking arthropods have evolved diverse methods to protect themselves against iron/heme-related damage, as the act of bloodfeeding itself is high risk, high reward process. Protective mechanisms in medically important arthropods include the midgut peritrophic matrix in mosquitoes, heme aggregation into the crystalline structure hemozoin in kissing bugs and hemosomes in ticks. Once heme and iron pass these protective mechanisms they are presumed to enter the midgut epithelial cells via membrane-bound transporters, though relatively few iron or heme transporters have been identified in bloodsucking arthropods. Upon iron entry into midgut epithelial cells, ferritin serves as the universal storage protein and transport for dietary iron in many organisms including arthropods. In addition to its role as a nutrient, heme is also an important signaling molecule in the midgut epithelial cells for many physiological processes including vitellogenesis. This review article will summarize recent advancements in heme/iron uptake, detoxification and exportation in bloodfeeding arthropods. While initial strides have been made at ironing out the role of dietary iron and heme in arthropods, much still remains to be discovered as these molecules may serve as novel targets for the control of many arthropod pests. PMID:29387018

Iron absorption in relation to iron status

International Nuclear Information System (INIS)

Magnusson, B.; Bjoern-Rasmussen, E.; Hallberg, L.; Rossander, L.

1981-01-01

The absorption from a 3 mg dose of ferrous iron was measured in 250 male subjects. The absorption was related to the log concentration of serum ferritin in 186 subjects of whom 99 were regular blood donors (r= -0.76), and to bone marrow haemosiderin grading in 52 subjects with varying iron status. The purpose was to try and establish a percentage absorption from such a dose that is representative of subjects who are borderline iron deficient. This information is necessary for food iron absorption studies in order (1) to calculate the absorption of iron from the diet at a given iron status and (2) compare the absorption of iron from different meals studied in different groups of subjects by different investigarors. The results suggest that an absorption of about 40% of a 3 mg reference dose of ferrous iron is given in a fasting state, roughly corresponds to the absorption in borderline-iron-deficient subjects. The results indicate that this 40% absorption value corresponds to a serum ferritin level of 30 μg/l and that food iron absorption in a group of subjects should be expressed preferably as the absorption corresponding to a reference-dose absorption of 45%, or possibly a serum ferritin level of 30 μg/l. (author)

Application of Circuit Simulation Method for Differential Modeling of TIM-2 Iron Uptake and Metabolism in Mouse Kidney Cells

Directory of Open Access Journals (Sweden)

Zhijian eXie

2013-06-01

Full Text Available Circuit simulation is a powerful methodology to generate differential mathematical models. Due to its highly accurate modelling capability, circuit simulation can be used to investigate interactions between the parts and processes of a cellular system. Circuit simulation has become a core technology for the field of electrical engineering, but its application in biology has not yet been fully realized. As a case study for evaluating the more advanced features of a circuit simulation tool called Advanced Design System (ADS, we collected and modeled laboratory data for iron metabolism in mouse kidney cells for a H ferritin (HFt receptor, T cell immunoglobulin and mucin domain-2 (TIM-2. The internal controlling parameters of TIM-2 associated iron metabolism were extracted and the ratios of iron movement among cellular compartments were quantified by ADS. The differential model processed by circuit simulation demonstrated a capability to identify variables and predict outcomes that could not be readily measured by in vitro experiments. For example, an initial rate of uptake of iron-loaded HFt was 2.17 pmol per million cells. TIM-2 binding probability with iron-loaded HFt was 16.6%. An average of 8.5 minutes was required for the complex of TIM-2 and iron-loaded HFt to form an endosome. The endosome containing HFt lasted roughly 2 hours. At the end of endocytosis, about 28% HFt remained intact and the rest was degraded. Iron released from degraded HFt was in the labile iron pool (LIP and stimulated the generation of endogenous HFt for new storage. Both experimental data and the model showed that TIM-2 was not involved in the process of iron export. The extracted internal controlling parameters successfully captured the complexity of TIM-2 pathway and the use of circuit simulation-based modeling across a wider range of cellular systems is the next step for validating the significance and utility of this method.

Automated flux chamber for investigating gas flux at water-air interfaces.

Science.gov (United States)

Duc, Nguyen Thanh; Silverstein, Samuel; Lundmark, Lars; Reyier, Henrik; Crill, Patrick; Bastviken, David

2013-01-15

Aquatic ecosystems are major sources of greenhouse gases (GHG). Representative measurements of GHG fluxes from aquatic ecosystems to the atmosphere are vital for quantitative understanding of relationships between biogeochemistry and climate. Fluxes occur at high temporal variability at diel or longer scales, which are not captured by traditional short-term deployments (often in the order of 30 min) of floating flux chambers. High temporal frequency measurements are necessary but also extremely labor intensive if manual flux chamber based methods are used. Therefore, we designed an inexpensive and easily mobile automated flux chamber (AFC) for extended deployments. The AFC was designed to measure in situ accumulation of gas in the chamber and also to collect gas samples in an array of sample bottles for subsequent analysis in the laboratory, providing two independent ways of CH(4) concentration measurements. We here present the AFC design and function together with data from initial laboratory tests and from a field deployment.

Iron Absorption from Two Milk Formulas Fortified with Iron Sulfate Stabilized with Maltodextrin and Citric Acid

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Fernando Pizarro

2015-10-01

Full Text Available Background: Fortification of milk formulas with iron is a strategy widely used, but the absorption of non-heme iron is low. The purpose of this study was to measure the bioavailability of two iron fortified milk formulas designed to cover toddlers´ nutritional needs. These milks were fortified with iron sulfate stabilized with maltodextrin and citric acid. Methods: 15 women (33–47 years old participated in study. They received on different days, after an overnight fast, 200 mL of Formula A; 200 mL of Formula B; 30 mL of a solution of iron and ascorbic acid as reference dose and 200 mL of full fat cow’s milk fortified with iron as ferrous sulfate. Milk formulas and reference dose were labeled with radioisotopes 59Fe or 55Fe, and the absorption of iron measured by erythrocyte incorporation of radioactive Fe. Results: The geometric mean iron absorption corrected to 40% of the reference dose was 20.6% for Formula A and 20.7% for Formula B, versus 7.5% of iron fortified cow’s milk (p < 0.001. The post hoc Sheffé indeed differences between the milk formulas and the cow’s milk (p < 0.001. Conclusion: Formulas A and B contain highly bioavailable iron, which contributes to covering toddlers´ requirements of this micronutrient.

An iron-57 Moessbauer spectroscopic study of titania-supported iron- and iron-iridium catalysts

International Nuclear Information System (INIS)

Berry, F.J.; Jobson, S.

1992-01-01

57 Fe Moessbauer spectroscopy shows that titania-supported iron is reduced by treatment in hydrogen at significantly lower temperatures than corresponding silica- and alumina-supported catalysts. The metallic iron formed under hydrogen at 600deg C is partially converted to carbide by treatment in carbon monoxide and hydrogen. In contrast to its alumina- and silica-supported counterparts, the remainder of the titania-supported iron is unchanged by this gaseous mixture. The 57 Fe Moessbauer spectra of EXAFS show that iron and iridium in the titania-supported iron-iridium catalysts are reduced in hydrogen at even lower temperatures and, after treatment at 600deg C, are predominantly present as the iron-iridium alloy. The treatment of these reduced catalysts in carbon monoxide and hydrogen is shown by Moessbauer spectroscopy and EXAFS to induce the segregation of iron from the iron-iridium alloy and its conversion to iron oxide. (orig.)

Iron concentration in breast milk normalised within one week of a single high-dose infusion of iron isomaltoside in randomised controlled trial

DEFF Research Database (Denmark)

Holm, Charlotte; Thomsen, Lars Lykke; Nørgaard, Astrid

2017-01-01

AIM: We compared the iron concentration in breast milk after a single high-dose of intravenous iron isomaltoside or daily oral iron for postpartum haemorrhage. METHODS: In this randomised controlled trial, the women were allocated a single dose of intravenous 1,200mg iron isomaltoside or oral iron...... deviation) iron concentration in breast milk in the intravenous and oral groups were 0.72 ± 0.27 mg/L and 0.40 ± 0.18 mg/L at three days (p birth. CONCLUSION: A single high...

Jendl-3.1 iron validation on the PCA-REPLICA (H{sub 2}O/Fe) shielding benchmark experiment

Energy Technology Data Exchange (ETDEWEB)

Pescarini, M.; Borgia, M. G. [ENEA, Centro Ricerche ``Ezio Clementel``, Bologna (Italy). Dipt. Energia

1997-03-01

The PCA-REPLICA (H{sub 2}O/Fe) neutron shielding benchmarks experiment is analysed using the SN 2-D DOT 3.5-E code and the 3-D-equivalent flux synthesis method. This engineering benchmark reproduces the ex-core radial geometry of a PWR, including a mild steel reactor pressure vessel (RPV) simulator, and is designed to test the accuracy of the calculation of the in-vessel neutron exposure parameters. This accuracy is strongly dependent on the quality of the iron neutron cross sections used to describe the nuclear reactions within the RPV simulator. In particular, in this report, the cross sections based on the JENDL-3.1 iron data files are tested, through a comparison of the calculated integral and spectral results with the corresponding experimental data. In addition, the present results are compared, on the same benchmark experiment, with those of a preceding ENEA-Bologna validation of the ENDF/B VI iron cross sections. The integral result comparison indicates that, for all the threshold detectors considered (Rh-103 (n, n`) Rh-103m, In-115 (n, n`) In-115m and S-32 (n, p) P-32), the JENDL-3.1 natural iron data produce satisfactory results similar to those obtained with the ENDF/B VI iron data. On the contrary, when the JENDL/3.1 Fe-56 data file is used, strongly underestimated results are obtained for the lower energy threshold detectors, Rh-103 and In-115. This fact, in particular, becomes more evident with increasing the neutron penetration depth in the RPV simulator.

A Novel Method to Magnetic Flux Linkage Optimization of Direct-Driven Surface-Mounted Permanent Magnet Synchronous Generator Based on Nonlinear Dynamic Analysis

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Qian Xie

2016-07-01

Full Text Available This paper pays attention to magnetic flux linkage optimization of a direct-driven surface-mounted permanent magnet synchronous generator (D-SPMSG. A new compact representation of the D-SPMSG nonlinear dynamic differential equations to reduce system parameters is established. Furthermore, the nonlinear dynamic characteristics of new D-SPMSG equations in the process of varying magnetic flux linkage are considered, which are illustrated by Lyapunov exponent spectrums, phase orbits, Poincaré maps, time waveforms and bifurcation diagrams, and the magnetic flux linkage stable region of D-SPMSG is acquired concurrently. Based on the above modeling and analyses, a novel method of magnetic flux linkage optimization is presented. In addition, a 2 MW D-SPMSG 2D/3D model is designed by ANSYS software according to the practical design requirements. Finally, five cases of D-SPMSG models with different magnetic flux linkages are simulated by using the finite element analysis (FEA method. The nephograms of magnetic flux density are agreement with theoretical analysis, which both confirm the correctness and effectiveness of the proposed approach.

Spectroscopic Diagnostics of Solar Magnetic Flux Ropes Using Iron Forbidden Line

Science.gov (United States)

Cheng, X.; Ding, M. D.

2016-05-01

In this Letter, we present Interface Region Imaging Spectrograph Fe xxi 1354.08 Å forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of ≥1000 km s-1 and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The extreme-ultraviolet images at the 131 and 94 Å passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot channel-like structures. Interestingly, part of the MFRs is also visible in the Fe xxi 1354.08 forbidden line, even prior to the eruption, e.g., for the SOL2014-09-10 event. However, the line emission is very weak and that only appears at a few locations but not the whole structure of the MFRs. This implies that the MFRs could be comprised of different threads with different temperatures and densities, based on the fact that the formation of the Fe xxi forbidden line requires a critical temperature (˜11.5 MK) and density. Moreover, the line shows a non-thermal broadening and a blueshift in the early phase. It suggests that magnetic reconnection at that time has initiated; it not only heats the MFR and, at the same time, produces a non-thermal broadening of the Fe xxi line but also produces the poloidal flux, leading to the ascension of the MFRs.

SPECTROSCOPIC DIAGNOSTICS OF SOLAR MAGNETIC FLUX ROPES USING IRON FORBIDDEN LINE

International Nuclear Information System (INIS)

Cheng, X.; Ding, M. D.

2016-01-01

In this Letter, we present Interface Region Imaging Spectrograph Fe xxi 1354.08 Å forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of ≥1000 km s"−"1 and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The extreme-ultraviolet images at the 131 and 94 Å passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot channel-like structures. Interestingly, part of the MFRs is also visible in the Fe xxi 1354.08 forbidden line, even prior to the eruption, e.g., for the SOL2014-09-10 event. However, the line emission is very weak and that only appears at a few locations but not the whole structure of the MFRs. This implies that the MFRs could be comprised of different threads with different temperatures and densities, based on the fact that the formation of the Fe xxi forbidden line requires a critical temperature (∼11.5 MK) and density. Moreover, the line shows a non-thermal broadening and a blueshift in the early phase. It suggests that magnetic reconnection at that time has initiated; it not only heats the MFR and, at the same time, produces a non-thermal broadening of the Fe xxi line but also produces the poloidal flux, leading to the ascension of the MFRs.

SPECTROSCOPIC DIAGNOSTICS OF SOLAR MAGNETIC FLUX ROPES USING IRON FORBIDDEN LINE

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Cheng, X.; Ding, M. D., E-mail: xincheng@nju.edu.cn [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China)

2016-05-20

In this Letter, we present Interface Region Imaging Spectrograph Fe xxi 1354.08 Å forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of ≥1000 km s{sup −1} and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The extreme-ultraviolet images at the 131 and 94 Å passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot channel-like structures. Interestingly, part of the MFRs is also visible in the Fe xxi 1354.08 forbidden line, even prior to the eruption, e.g., for the SOL2014-09-10 event. However, the line emission is very weak and that only appears at a few locations but not the whole structure of the MFRs. This implies that the MFRs could be comprised of different threads with different temperatures and densities, based on the fact that the formation of the Fe xxi forbidden line requires a critical temperature (∼11.5 MK) and density. Moreover, the line shows a non-thermal broadening and a blueshift in the early phase. It suggests that magnetic reconnection at that time has initiated; it not only heats the MFR and, at the same time, produces a non-thermal broadening of the Fe xxi line but also produces the poloidal flux, leading to the ascension of the MFRs.

Instant Noodles and Iron Nutrition

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