WorldWideScience
1

Use of Microelectrode Arrays to Directly Measure Diffusion of ...  

Science.gov (United States)

... F.; Murray, R. W. J. Am. Chem. ... 14. Thackeray, J. W.; White, H. S.; Wrighton, M. SJ Phys. ... Dr. James S. Murday (1) Dr. Harold H. Singerman (i) ...

1990-05-16

2

Earth and Environment: murray_dobbie_morris  

Wastenet

... In recent years workers in this field have focused on nucleation by nano-porous materials . This was in part motivated by a theoretical study by Page and Sear (2006) who proposed a two step model for nucleation in pores which suggest that there is ...

3

Historical Indigenous use of aquatic resources in Australia's Murray-Darling Basin, and its implications for river management  

British Library Electronic Table of Contents (United Kingdom)

Summary Indigenous people demonstrably lived along rivers and around lakes and wetlands of Australia's Murray-Darling Basin in pre-European times. Waterways were, and continue to be, of major significance to the society and culture of Aboriginal peoples throughout Australia. Historically, they exploited most of the fauna - from mussels and crayfish, to fish and birds - and either ate, or used for other purposes, many species of aquatic plants. Such practices placed them in the role of environmental modifiers, a role played by all human groups from both past and present. They built sophisticated fish traps, cut gaps in river banks to allow fish to move on to floodplains, and there is evidence that they practised a form of fish culture by creating small impoundments in which small fish could...

2007-01-01

4

Effects of sediment quality on macroinvertebrates in the Sunraysia region of the Murray-Darling Rivers, Australia  

International Nuclear Information System (INIS)

A field-based microcosm approach was tested to identify deterioration of sediment quality in waterways using freshwater macroinvertebrates. The method can potentially identify the nature of contaminants based on species-specific responses. Sediments were collected from the Murray and Darling Rivers and irrigation drains within the Sunraysia region of south-eastern Australia and compared to non-polluted reference sediment. Clean sediments were also spiked with fertiliser to test whether nutrients affected the aquatic fauna. Seven of the eight sediments from the Sunraysia region had a negative impact on the macroinvertebrates, in particular sediment from the Darling River, which supported an impoverished fauna. Three species of chironomid showed varied responses to sediment quality and, although it was hypothesised that nutrients may have impacted on the macroinvertebrate fauna, the results suggest that other pollutants are also involved. The field-based microcosm ...

2008-12-01

5

NIK Stabilization in Osteoclasts Results in Osteoporosis and Enhanced Inflammatory Osteolysis  

UK PubMed Central (United Kingdom)

BackgroundMaintenance of healthy bone requires the balanced activities of osteoclasts (OCs), which resorb bone, and osteoblasts, which build bone. Disproportionate action of OCs...Full Text Available

6

JSpOC Cognitive Task Analysis  

Science.gov (United States)

... The goal is to understand and describe the work actors do, their information behavior, the context in which they work, and the reasons for their ...

2009-09-01

7

5Cc+ HyQZ HeTZ HaTZ 5C6= HRWZ %EH} H>ZZ 5CWD H*]Z %EH{ 5CyK %ELy ...  

Science.gov (United States)

C CCNA DPoPC @"y( mPC~ lPC; CCP0u# WSC# D kPC D`hPCs gOC0 D@dOC @Rq) bOCh DpaOC% @`0) ?u<9 D@]OC] DxZOC WOCR D@VOC D ROCG @vN% D`OOC LOC< D0KOC WPL` HOCs ...

8

Bulk amorphous and nanocrystalline Al83Fe17 alloys prepared by consolidation of mechanically alloyed amorphous powder  

British Library Electronic Table of Contents (United Kingdom)

In the present work, bulk amorphous and nanocrystalline Al83Fe17 alloys were obtained by consolidation of mechanically alloyed powders. Mechanical alloying of Al-17% Fe powder mixture yielded powder with an amorphous structure. Thermal behaviour of the milling product was examined using differential scanning calorimetry. This investigation revealed that the amorphous phase crystallised above 380^oC. The amorphous powder was compacted under a pressure of 7.7GPa in different conditions: at 380^oC for 600s and at 1000^oC for 180s. Structural investigations of the bulk material revealed that the amorphous structure was retained after consolidation process applied at 380^oC. Compaction under high pressure at 1000^oC caused crystallisation of the amorphous phase and appearance of metastable nano...

2010-01-01

9

Air quality monitoring report for Alberta, 1991  

Energy Technology Data Exchange (ETDEWEB)

In 1991, the air quality monitoring program in Alberta consisted of continuous, intermittent, static, portable, mobile, and acid precipitation monitoring networks. The air quality monitoring networks are described and results from the continuous, intermittent, static, and acid precipitation networks are summarized. Regulations and guidelines for individual pollutants are discussed in detail. Pollutants monitored continuously (1-h average basis) include ammonia, CO, coefficient of haze, H{sub 2}S, nitrogen oxides, ozone, SO{sub 2}, and total hydrocarbons. Good air quality was observed most of the time at all continuous monitoring stations in 1991. The frequency of good air quality ratings ranged from 81% at the Edmonton northwest station to 98% at the Fort McMurray station. Intermittent monitoring (every 6th day) was conducted for total suspended particulates and for vinyl chloride monomers in the Fort Saskatchewan area. Chemical analyses of benzo(a)pyrene and lead ...

1993-08-01

10

GaInP[sub 2]/GaAs tandem cells: Problems and solutions  

Energy Technology Data Exchange (ETDEWEB)

The various factors that affect the open-circuit voltage ([ital V][sub oc]) of a two-terminal GaInP[sub 2]/GaAs tandem cell are examined. These include a) an anomalous problem associated with the GaAs bottom cell and b) back surface passivation of the thin GaInP[sub 2] top cell. Solutions to these problems are presented and yield tandem [ital V][sub oc]s close to the practical theoretical limits.

1992-12-01

11

Synthesis and some properties of Ti{sub 3}SiC{sub 2} by hot pressing of Ti, Si and C powders. Part 2: Mechanical and other properties of Ti{sub 3}SiC{sub 2}  

Energy Technology Data Exchange (ETDEWEB)

Some properties of the remarkable Ti{sub 3}SiC{sub 2} based ceramic synthesised by hot pressing of elemental Ti, Si, and C powders have been investigated. Its flexural strength by using three point bending tests and fracture toughness by using single edge notched beam tests were measured at room temperature to be in the range 310-427 MPa and about 7.MPa m{sup 1/2}, respectively. This material is a relative 'soft' ceramic with a low hardness of 4 GPa. Ti{sub 3}SiC{sub 2} is similar to the soft metals and is a damage tolerant material that is able to contain the extent of microdamage. An oxidation test has been performed in the temperature range 1000-1400{sup o}C in air for 20 h. The oxidation resistance below 1100{sup o}C was good. Two oxidized layers were formed, the outer layer consisting of pure rutile-type TiO{sub 2}, and the inner layer a mixture of SiO{sub 2} and TiO{sub 2}. The average coefficient of thermal expansion ...

2005-09-15

12

Carbon dioxide absorption mechanisms of sodium added to calcium oxide at high temperatures  

Energy Technology Data Exchange (ETDEWEB)

To apply the CO{sub 2} absorber at about 1000{sup o}C for integrated coal gasification combined cycle (IGCC) furnace, the reactions of calcium oxide and CO{sub 2} at high temperatures was examined. Calcium carbonate reacts with sodium hydrogen carbonate below 200{sup o}C and forms sodium-calcium complex carbonate. The sodium-calcium complex carbonate melts at 813{sup o}C, and the carbon dioxide absorption and discharge reversible reactions of calcium-oxide takes place via liquid at around 1000{sup o}C. Sintering of calcium oxide at high temperature has been successfully avoided by the addition of sodium.

2004-07-01

13

New molten salt systems for high temperature molten salt batteries: Ternary and quaternary molten salt systems based on LiF-LiCl, LiF-LiBr, and LiCl-LiBr  

British Library Electronic Table of Contents (United Kingdom)

Using a new simulative technique developed by us, we systematically investigated new ternary or quaternary molten salt systems, which are based on LiF-LiCl, LiF-LiBr, and LiCl-LiBr binary systems, for use as electrolytes in thermal batteries, and evaluated their ionic conductivities and melting points experimentally. It was confirmed experimentally that LiF-LiBr-KF (melting point: 425^oC, ionic conductivity at 500^oC: 2.52Scm^-^1), LiCl-LiBr-KF (405^oC, 2.56Scm^-^1), LiCl-LiBr-NaF-KF (425^oC, 3.11Scm^-^1), LiCl-LiBr-NaCl-KCl (420^oC, 2.73Scm^-^1), and LiCl-LiBr-NaBr-KBr (420^oC, 2.76Scm^-^1) meet our targets for both melting point (350-430^oC) and ionic conductivity (2.0Scm^-^1 and higher at 500^oC). A single cell using the newly developed LiCl-LiBr-NaCl-KCl molten salt as an electrolyte w...

2011-01-01

14

Synthesis of nanocrystalline YSZ (ZrO_2-8Y_2O_3) powder by polymerized complex method  

International Nuclear Information System (INIS)

In this study nanocrystalline powders of yttria-stabilized zirconia (ZrO_2-8Y_2O_3) have been synthesized through 'polymerized complex method'. Zirconium chloride, yttrium nitrate, citric acid and ethylene glycol were polymerized at 80 "oC to produce a gel-like mass in which metallic ions were uniformly distributed. During the thermal treatment of dried gel, nanocrystalline powder was formed at 450 "oC and 650 "oC for 2 h. Thermal reactions and crystalline phase formation of the dried gel were investigated through thermal analysis and X-ray diffraction analysis, respectively. The results of thermal analysis and XRD showed the formation of nanocrystalline powder at less than 600 "oC. Chemical bonding of the dried gel was investigated by Fourier transform infrared spectroscopy analysis. Morphology of powder calcined at 650 "oC was analyzed by scanning electron microscope. ...

2010-02-18

15

Experimental evaluation of a non-azeotropic working fluid for geothermal heat pump system  

Energy Technology Data Exchange (ETDEWEB)

Geothermal energy resources are found in many countries. A reasonable and efficient utilization of these resources has been a worldwide concern. The application of geothermal heat pump systems (GHPS) can help increase the efficiency of using geothermal energy and reduce the thermal pollution to the earth surface. However, this is only possible with a proper working fluid. In this paper, a non-azeotropic working fluid (R290/R600a/R123) is presented for a GHPS where geothermal water at 40-45{sup o}C and heating network water at 70-80{sup o}C serve as the low and high temperature heat sources. Experimental results show that the coefficient of performance (COP) of a GHPS using the working fluid is above 3.5 with the condensation temperature above 80{sup o}C and the condensation pressure below 18 bar, while the temperature of the geothermal water is reduced from 40-46{sup o}C to 31-36{sup ...

2004-06-01

16

Detecting exposure to environmental organic toxins in individual cells: towards development of a micro-fabricated device  

Energy Technology Data Exchange (ETDEWEB)

A new method is being developed to quickly screen for the human exposure potential to polycyclic aromatic hydrocarbons (PAHs) and organochlorines (OCs). The development involves two key elements: identifying suitable signals that represent intracellular changes that are specific to PAH and OC exposure, and constructing a device to guide the biological cell growth so that signals from individual cells are consistent and reproducible. We are completing the identification of suitable signals by using synchrotron radiation-based (SR) Fourier-transform infrared (FTIR) spectromicroscopy in the mid-infrared region (4000-400 cm-1). Distinct changes have been observed in the IR spectra after treatment of human cells in culture medium with PAHs and OCs. The potential use of this method for detecting exposure to PAHs and OCs has been tested and compared to a reverse transcription polymerase chain reaction (RT-PCR) ...

1999-01-10

17

NETWORK : Practical sustainable processing management  

Environmental Research Database

Objectives1) To develop and test a simple yet effective management tool which the Chemical Process Industry can~%~ incorporate into its Environmental Management Systems linking Life Cycle Assessment with Sustainable~%~ Development and through Risk Assessment produce a Methodology which will allow companies to~%~ prioritize their moves towards a more sustainable business practice.~%~~%~ 2) Through this network on sustainable processing practice establish an inter-disciplinary li [continued...]Description~%~'Sustainable Development is a network of Sustainable Processing Routes, or ways of doing things' (Boron, Murray,2000)~%~~%~We should like to explore this concept, through the network of academic colleagues listed, supported by key companies who have already established EMAS /ISO accreditation portfolios (letters attached), and through collaboration with other like-minded practitioners in the field (SIGMA), attempt to develop the ...

2005-01-31

18

NAME=\\  

Wastenet

...Martin 1 1231 October 06, 2009, 08:56:25 PMby Joanna Saady Oxford meeting 30th September 2009 Joanna Saady 5 2403 October 09, 2009, 11:58:55 AMby Kjartan Bollason Oxford reginal group meeting - Weds 11th November - 6pm - 8pm Darren Aspinall 3 1433 November 05, 2009, 02:17:14 PMby Kjartan Bollason Nottingham Local Group 24th Sept Joanna Saady 6 2830 November 09, 2009, 07:45:44 PMby Peter Ashford SW Group Meeting, Weds 28th October at DCRS Paul jennings 2 1475 November 23, 2009, 10:02:58 AMby Adam Dadeby Cornwall Sustainable Building Guide Nigel Murray 2 668 December 03, 2009, 12:15:04 PMby Joanna Saady Brighton Regional Group Meeting - 25th November 2009 Joanna Saady 4 980 December ...

19

Methanogens and sulfate-reducing bacteria in oil sands fine tailings waste.  

Science.gov (United States)

In the past decade, the large tailings pond (Mildred Lake Settling Basin) on the Syncrude Canada Ltd. lease near Fort McMurray, Alta., has gone methanogenic. Currently, about 60%-80% of the flux of gas across the surface of the tailings pond is methane. As well as adding to greenhouse gas emissions, the production of methane in the fine tailings zone of this and other settling basins may affect the performance of these settling basins and impact reclamation options. Enumeration studies found methanogens (10(5)-10(6) MPN/g) within the fine tailings zone of various oil sands waste settling basins. SRB were also present (10(4)-10(5) MPN/g) with elevated numbers when sulfate was available. The methanogenic population was robust, and sample storage up to 9 months at 4 degrees C did not cause the MPN values to change. Nor was the ability of the consortium to produce methane delayed or less efficient after storage. Under laboratory conditions, fine tailings samples ...

2000-10-01

20

AGN Outflows in Emission and Absorption: The SDSS Perspective  

CERN Document Server

A variety of investigations have demonstrated commonalities between the Baldwin (1977) Effect, the blueshifting of CIV emission lines (e.g., Gaskell 1982; Richards et al. 2002), and the L_UV-L_X relationship (e.g., Avni & Tananbaum 1982; Strateva et al. 2005; Steffen et al. 2006); indeed all three of these observational effects may be manifestations of the same underlying (but still uncertain) physics. This commonality is of interest to investigations of accretion disk winds (e.g., Murray et al. 1995; Proga et al. 2000) from active galactic nuclei (AGN) as there is evidence that broad absorption line quasars (BALQSOs) are drawn from a parent sample of quasars that exhibit larger than average CIV blueshifts, weaker than average CIV emission line strengths, and bluer than average (intrinsic) colors. The properties of the absorption troughs appear to be dependent upon these parameters. Thus, it is suggested that not all quasars will host bona-fide BAL troughs, but ...

2006-01-01

21

Layered GdBa_0_._5Sr_0_._5Co_2O_5_+_#delta# as a cathode for proton-conducting solid oxide fuel cells with stable BaCe_0_._5Zr_0_._3Y_0_._1_6Zn_0_._0_4O_3_-_#delta# electrolyte  

International Nuclear Information System (INIS)

The layered GdBa_0_._5Sr_0_._5Co_2O_5_+_#delta# (GBSC) perovskite oxides are synthesized by modified Pechini method and investigated as a novel cathode material for solid oxide fuel cells (SOFCs) based on a stable perovskite oxide BaCe_0_._5Zr_0_._3Y_0_._1_6Zn_0_._0_4O_3_-_#delta# (BCZYZ) as electrolyte. The fabricated single cells of NiO-BCZYZ/BCZYZ (#approx#20 #mu#m)/GBSC (#approx#20 #mu#m) were operated from 550 to 700 "oC with humidified hydrogen (#approx#5% H_2O) as fuel. The BCZYZ perovskite electrolyte was completely dense after sintered at 1250 "oC for 5 h, lower than that without zinc dopant about 150 "oC. An open circuit voltage of 1.009 V and a maximal power density of 0.35 W cm"-"2 were achieved at 700 "oC. The interfacial polarization resistance was as low as 1.46, 0.45, 0.25 and 0.15 #OMEGA# cm"2 at 550, 600, 650 and 700 "oC, respectively. The ratio of polarization ...

2010-04-30

22

Structure and Optical Properties of Silicon Layers with GaSb Nanocrystals Created by Ion-Beam Synthesis  

International Nuclear Information System (INIS)

We have studied the ion-beam synthesis of GaSb nanocrystals in Si by high-fluence '' hot '' implantation of Sb and Ga ions followed by thermal annealing. The Rutherford backscattering, transmission electron microscopy/transmission electron diffraction, Raman spectroscopy and photoluminescence were used to characterize the implanted layers. It was found that the nanocrystal size increases from 5 to 60 nm in the samples annealed at 900"oC up to 20-90 nm in those annealed at 1100"oC. For the samples annealed at 900"oC a broad band in the region of 0.75-1.05 eV is registered in the photoluminescence spectra. The nature of this photoluminescence band is discussed. (author)

2011-07-01

23

Quantifying the thermal flowering rates of eighteen species of annual bedding plants  

British Library Electronic Table of Contents (United Kingdom)

The effect of mean daily air temperature (MDT) on flowering rate (the reciprocal of days to flower) was quantified for 18 species of annual bedding plants. Plants were grown in environmental growth chambers at constant air temperature set points of 5, 7.5, 10, 15, 25, or 30^oC and under an irradiance of 160-180mmolm^-^2s^-^1, with a 16-h photoperiod. Nonlinear mathematical equations were developed to predict the effect of MDT on flowering rate and to estimate the base, optimum, and maximum temperatures (Tmin, Topt, and Tmax), which are the temperatures at which flowering rates are zero (low temperature), maximal, and zero once again (high temperature), respectively. The estimated Tmin varied among species and ranged from 1.1^oC in French marigold (Tagetes patula L.) to 9.9^oC in angelonia ...

2011-01-01

24

Particulate composites in the TiC-TiYTZP system  

International Nuclear Information System (INIS)

Twelve powders of TiO_2-Y_2O_3-ZrO_2 solid solution of the methodically changed composition were prepared by a coprecipitation-calcination technique. After mixing with phenol-formaldehyde resin, the powders were calcinated for 2 hours at 1200"oC in vacuum. The resultant composite powders contained TiC and non-reacted carbon. Green compacts were sintered in vacuum at 1500"oC for 2 hours. A temperature increase was stopped at 1200"oC to react remains of carbon. There were two carbides in the composites TiC and ZrC. TiC non-stoichiometry depended on carbon content in the system. Phase composition of the depended on of titania and yttria in zirconia solid solution. The majority of the samples showed two tetragonal zirconia phases differing in lattice parameter and tetragonality. (author)

2004-09-12

25

Triethanolamine as an additive of high water content electrolyte to enhance the capacitor's performance  

Energy Technology Data Exchange (ETDEWEB)

Triethanolamine (TEA) has been evaluated as an additive to a commercial electrolyte to enhance the properties of aluminum electrolytic capacitors. The results showed 1-3wt.% TEA additive can prevent the pH and conductivity of the electrolytes from decreasing for 5000h at 60{sup o}C. The anodic restoration ability of an anode aluminum film in the electrolyte with TEA additive showed more efficient than the electrolyte without TEA additive. Low temperature electric characteristics of capacitors showed that TEA additive can prevent the electrolyte inside capacitors from freezing and losing electric characteristics even at -40{sup o}C. Load life test of capacitors impregnated with electrolytes with or without TEA additive showed remarkable differences. The TEA additive promoted 105{sup o}C load life time from 3019h up to 5624h and form 2144h up to 3621h for 125{sup o}C load life time test. (author)

2006-11-22

26

The effect of temperature on the passive film properties and pitting behaviour of a Fe-Cr-Ni alloy  

Energy Technology Data Exchange (ETDEWEB)

The effect of temperature (60-280{sup o}C) on the properties of the oxide films formed on Alloy 800 in 0.1 M NaCl and 0.1 M Na{sub 2}SO{sub 4} aqueous solutions was studied by in situ AC impedance spectroscopy and polarization in the Fe(CN{sub 6}){sup -3}/Fe(CN){sub 6}{sup -4} redox system. The anodic behavior under the same experimental conditions was examined by potentiodynamic polarization techniques. In both solutions the passive film was found to become more porous, and hence less protective, with increasing temperature. However, at temperatures above 150{sup o}C, the loss of film protectiveness is more pronounced in chloride solutions, in which pitting occurs. Pitting morphology was found to be strongly temperature dependent: isolated and deep pits were found up to 200{sup o}C whereas at higher temperatures a broad, shallow and more generalized type of attack was detected. No effect of temperature on the defect ...

1996-06-01

27

Rapid cold hardening increases cold and chilling tolerances more than acclimation in the adults of the sycamore lace bug, Corythucha ciliata (Say) (Hemiptera: Tingidae)  

British Library Electronic Table of Contents (United Kingdom)

The sycamore lace bug, Corythucha ciliata is a new, invasive pest of Platanus trees in China. Although C. ciliata is often subjected to acute low temperatures in early winter and spring in northern and eastern China, the cold tolerance of C. ciliata has not been well studied. The objectives of this study were to determine whether adults of C. ciliata are capable of rapid cold hardening (RCH), and to compare the benefits of RCH vs. cold acclimation (ACC) in the laboratory. When the adult females incubated at 26^oC were transferred directly to the discriminating temperature (-12^oC) for 2h, survival was only 22%. However, exposure to 0^oC for 4h before transfer to -12^oC for 2h induced RCH, i.e., increased survival to 68%. RCH could also be induced by gradual cooling of the insects at rates ...

2011-01-01

28

Proposed Gulf of Mexico OCS Oil and Gas Lease Sale 206  

Science.gov (United States)

... 2 km (0-1.2 mi) of new onshore pipelines projected as a result of proposed Lease Sale ... 2 km (0-1.2 mi) of new onshore pipelines projected as a result of proposed Lease Sale ... ...

29

Nanocrystallization of soft magnetic Fe-Co-Zr-Cu-B alloys  

International Nuclear Information System (INIS)

In the present study, Fe_4_1Co_4_1 B_1_0Zr_7Cu_1 alloy has been investigated in order to evaluate its thermal stability and structure after heat treatment, as well as the impact of heat treatment on magnetic properties. X-ray diffractometry, differential scanning calorimetry, chemical composition microanalysis, transmission electron microscopy, and magnetic hysteresis loop measurement techniques were employed. The crystallization temperature of the as-quenched alloy is 490"oC (continuous heating at 5 "oC/min). The melt spun ribbon having 27 #mu#m in thickness was annealed for 1 hour at temperatures from 400 to 700 "oC. The alloy after treatment at about 550"oC underwent primary crystallization, with the average size of crystals under 20 nm. This specimen shows the coercive field of 38 A/m, as compared to about 160 A/m reported for a similar alloy (Fe_4_4Co_4_4B_4Zr_7Cu_1) with a similar structure, annealed at ...

2001-09-23

30

Nanocrystallization of the amorphous Fe_1_4Ni_4_0Zr_7B_1_2 alloys studied by the Moessbauer spectroscopy  

International Nuclear Information System (INIS)

Formation of the soft magnetic nanostructure in amorphous Fe_1_4Ni_4_0Zr_7B_1_2 alloy due to heat treatment is studied by the Moessbauer, differential scanning calorimetry, and X-ray diffraction techniques. Annealing at temperatures 520-580 "oC leads to the formation of extremely soft nanocrystalline alloy as revealed by the rf-Moessbauer measurements. The superparamagnetic behaviour was observed for the alloy annealed at 620-640 "oC. At higher annealing temperatures good soft magnetic properties deteriorate. (author)

2001-09-23

31

Study of nanocrystallization in FINEMET alloy by active screen plasma nitriding  

International Nuclear Information System (INIS)

The nanocrystallization process of amorphous Fe_7_3_._5Si_1_3_._5B_9Nb_3Cu_1 was investigated by active screen plasma nitriding (ASPN) treatment at temperatures ranging from 410 "oC to 560 "oC for 3 h in two gas mixtures of 75% N_2-25% H_2 and 25% N_2-75% H_2 at 5 mbar atmosphere. The amorphous ribbons were then annealed under vacuum at the same time and temperatures mentioned above. The structure of the samples was analyzed using various techniques such as X-ray diffraction (XRD), atomic force microscopy (AFM) and differential scanning calorimetry (DSC). Microhardness measurements, electrical resistivity and Vibrating Sample Magnetometer (VSM) were used to study mechanical, electrical and magnetic properties of the samples, respectively. It was observed that the ASPN treatment leads to finer grain size and higher crystalline volume fraction and modifies the structural features of Fe(Si) phase. The Fe(Si) lattice parameter for the nitrided ...

2010-02-18

32

Oleoresin Capsicum toxicology evaluation and hazard review  

Energy Technology Data Exchange (ETDEWEB)

Oleoresin Capsicum (OC) is an extract of the pepper plant used for centuries as a culinary spice (hot peppers). This material has been identified as a safe and effective Less-Than- Lethal weapon for use by Law enforcement and security professionals against assault. The National Institute of Justice (NIJ) is currently also evaluating its use in conjunction with other Less-Than-Lethal agents such as aqueous foam for use in corrections applications. Therefore, a comprehensive toxicological review of the literature was performed for the National Institute of Justice Less-Than-Lethal Force program to review and update the information available on the toxicity and adverse health effects associated with OC exposure. The results of this evaluation indicate that exposure to OC can result in dermatitis, as well as adverse nasal, pulmonary, and gastrointestinal effects in humans. The primary effects of OC exposure ...

1995-10-01

33

Layered PrBaCo_2O_5_+_#delta# perovskite as a cathode for proton-conducting solid oxide fuel cells  

International Nuclear Information System (INIS)

The layered PrBaCo_2O_5_+_#delta# (PBCO) perovskite oxides were synthesized by modified Pechini method and investigated as a cathode material for solid oxide fuel cells (SOFCs) based on a stable and easily sintered perovskite oxide BaCe_0_._5Zr_0_._3Y_0_._1_6Zn_0_._0_4O_3_-_#delta# (BCZYZ) as electrolyte. The fabricated single cell of NiO-BCZYZ/BCZYZ (#approx#20 #mu#m)/PBCO was operated from 550 to 700 "oC with humidified hydrogen (#approx#5% H_2O) as fuel and the static air as oxidant. The BCZYZ perovskite electrolyte was completely dense after sintered at 1250 "oC for 5 h, lower than that without zinc dopant about 150 "oC. A high open-circuit potential of 1.007 V, a peak power density of 361 mW cm"-"2, and a low polarization resistance of the electrodes of 0.12 #OMEGA# cm"2 was achieved at 700 "oC. The ratio of polarization resistance to total cell resistance decreased with the increase of operating ...

2010-04-02

34

Evaluation of BaZr0.1Ce0.7Y0.2O3-?-based proton-conducting solid oxide fuel cells fabricated by a one-step co-firing process  

International Nuclear Information System (INIS)

Proton-conducting solid oxide fuel cells, incorporating BaZr0.1Ce0.7Y0.2O3-? (BZCY) electrolyte, NiO-BZCY anode, and Sm0.5Sr0.5CoO3-?-Ce0.8Sm0.2O2-? (SSC-SDC) cathode, were successfully fabricated by a combined co-pressing and printing technique after a one-step co-firing process at 1100, 1150, or 1200 oC. Scanning electron microscope (SEM) results revealed that the co-firing temperature significantly affected not only the density of the electrolyte membrane but the grain size and porosity of the electrodes. Influences of the co-firing temperature on the electrochemical performances of the single cells were also studied in detail. Using wet hydrogen (2% H2O) as the fuel and static air as the oxidant, the cell co-fired at 1150 oC showed the highest maximum power density (PDmax) of 552 and 370 mW cm-2 at 700 and 650 oC, respectively, while the one co-fired at 1100 oC showed the highest PDmax of 276 and ...

2011-01-01

35

Assessment of generation temperatures of crude oils  

Energy Technology Data Exchange (ETDEWEB)

Biological marker maturity parameters were used to estimate the minimum HC generation temperatures of crude oils from Eastern Hungary. More than 50 oils and oil shows were analysed. Molecular- and homologous-ratios of biological marker compounds (triterpanes, steranes, mono- and triaromatic steroid hydrocarbons) were used as maturation parameters. The oils have at least five maturity stages, i.e. they have been generated under different thermal conditions. The highest reservoir temperature in each group was chosen as the best estimate of the groups' temperature just below the generation temperature, i.e. reservoirs of the group might be expected to be at shallower depths (lower temperatures) than those of the generation zone due to vertical migration into pools. For each maturation level, a threshold temperature range for genesis was inferred from reservoir temperatures; they are from 130-135{sup o}C for the least mature oils to 210-215{sup ...

2000-07-01

36

lightsources.org: An Internet Site for Light SourceCommunication  

Energy Technology Data Exchange (ETDEWEB)

Research at the world's accelerator- (storage-ring and linac) based light sources is one of the most dynamic and rapidly growing fields of science. It frequently results in direct benefits to society, thereby demonstrating the value of the research with very concrete examples, but this is not widely understood or appreciated outside of the immediate user community. Our growing group of light source communicators from facilities in Europe, Asia, and the Americas, inspired by the Interactions.org Web site created by high-energy (elementary-particle)physics communicators, concluded that a light source community Web site (lightsources.org) would be the best tool for establishing effective collaboration between the communications offices of the world's light sources and to maximize the impact of our efforts. We envision lightsources.org to serve as a one-stop-shopping site for information about all aspects of light sources and the research they make possible. Audiences to ...

2004-10-04

37

Study on Sm"1"."8Ce"0"."2CuO"4-Ce"0"."9Gd"0"."1O"1"."9"5 composite cathode materials for intermediate temperature solid oxide fuel cell  

British Library Electronic Table of Contents (United Kingdom)

Sm"1"."8Ce"0"."2CuO"4-xCe"0"."9Gd"0"."1O"1"."9"5 (SCC-xCGO, x=0-12vol.%) composite cathodes supported on Ce"0"."9Gd"0"."1O"1"."9"5 (CGO) electrolyte are studied for applications in IT-SOFCs. Results show that Sm"1"."8Ce"0"."2CuO"4 material is chemically compatible with Ce"0"."9Gd"0"."1O"1"."9"5 at 1000^oC. The composite electrode exhibits optimum microstructure and forms good contact with the electrolyte after sintering at 1000^oC for 4h. The polarization resistance (R"p) reduces to the minimum value of 0.17@Wcm^2 at 750^oC in air for SCC-CGO06 composite cathode. The relationship between R"p and oxygen partial pressure indicates that the reaction rate-limiting step is the surface diffusion of the dissociative adsorbed oxygen on the composite cathode.

2011-01-01

38

Serum Osteocalcin/Bone-Specific Alkaline Phosphatase Ratio Is a Predictor for the Presence of Vertebral Fractures in Men with Type 2 Diabetes  

British Library Electronic Table of Contents (United Kingdom)

We examined whether or not BMD or bone markers were useful for assessing the risk of vertebral fractures in 248 Japanese men with type 2 diabetes. We analyzed the relationships between bone markers (osteocalcin [OC], bone-specific alkaline phosphatase [BAP], urinary N-terminal cross-linked telopeptide of type-I collagen) or BMD and HbA1c, urinary C-peptide, insulin-like growth factor-I (IGF-I), parathyroid hormone, 1,25(OH)2 vitamin D, and the presence of prevalent vertebral fractures. Multiple regression analysis adjusted for age, body height, weight, duration of diabetes, and serum creatinine showed that serum OC and OC/BAP ratio were correlated negatively with HbA1c (P?P?P?

2009-01-01

39

Olive bagasse (Olea europa L.) pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Olive bagasse (Olea europea L.) was pyrolysed in a fixed-bed reactor. The effects of pyrolysis temperature, heating rate, particle size and sweep gas flow rates on the yields of the products were investigated. Pyrolysis runs were performed using pyrolysis temperatures between 350 and 550 {sup o}C with heating rates of 10 and 50 {sup o}C min{sup -} {sup 1}. The particle size and sweep gas flow rate varied in the ranges 0.224-1.8 mm and 50-200 cm{sup 3} min {sup -1}, respectively. The bio-oil obtained at 500 {sup o}C was analysed and at this temperature the liquid product yield was the maximum. The various characteristics of bio-oil obtained under these conditions were identified on the basis of standard test methods. The empirical formula of the bio-oil with heating value of 31.8 MJ kg{sup -1} was established as CH{sub 1.65}O{sub 0.25}N{sub 0.03}. The chemical characterization showed that the bio-oil obtained from olive ...

2006-02-15

40

Effects of microwaves on cell survival at elevated temperatures  

Energy Technology Data Exchange (ETDEWEB)

Since microwaves are used in human cancer therapy, information on specific biological effects of microwaves at elevated temperatures is important. To help supply this information, we exposed mammalian cells (CHO) and bacteria (Serratia marcescens) to hyperthermal temperatures (43, 44, and 45/sup o/C for CHO and 48, 49, and 50/sup o/C for the bacteria) with and without microwave irradiation. Temperature control was maintained by a refrigeration-reheat system and high-velocity water recirculation. The 2450-MHz microwave source was operated in a pulsed mode with power density up to 500 mW/cm/sup 2/. As expected, the survival curve slopes for both cell types increased rapidly with temperature, doubling for each degree Celsius. Microwave irradiation produced no significant change in extrapolation number for either cell type. However, survival curves of CHO cells which received microwaves were steeper by a factor of 1.25 than their sham-irradiated ...

1981-12-01

41

Abnormal phase transition in BiNbO4 powders prepared by a citrate method  

British Library Electronic Table of Contents (United Kingdom)

Triclinic b-BiNbO4 prepared below 750^oC and above 1040^oC (denoted as Low-b and High-b, respectively) and pure orthorhombic a-BiNbO4 at 900^oC were successfully derived from a citrate method and the phase transition from b-BiNbO4 to a-BiNbO4 was first observed in BiNbO4 powders. This phenomenon proves that the abnormal phase transition from b-BiNbO4 to a-BiNbO4 exists in BiNbO4 powder system. The synthesis of Low-b powders can be attributed to the formation of the intermediate phase of Bi5Nb3O15 by the citrate method. With increasing temperature, the Low-b phase gradually turns into a-BiNbO4 due to the thermodynamically metastable state of Low-b. We also identified that the stress in pellet format can accelerate the phase transition from Low-b to a phase of BiNbO4 in comparison with powde...

2011-01-01

42

The capric-lauric acid and pentadecane combination as phase change material for cooling applications  

Energy Technology Data Exchange (ETDEWEB)

The mixture of 65 mol% capric acid and 35 mol% lauric acid (C-L acid) is a potential latent heat storage material. However, its melting temperature of 18.0 {sup o}C is quite high for low-temperature thermal energy storage. Addition of pentadecane, with a melting point of 9.9 {sup o}C, is proposed. The thermal characteristics of the combination of the C-L acid with pentadecane (CL:P) in different volume ratio are investigated employing the DSC analysis. The actual thermal performance of each CL:P combination is further determined from their radial and axial temperature distribution employing a fabricated thermal storage capsule. The 90:10 CL:P combination manifests an improvement in the melting characteristic of the C-L acid.(author)

2002-03-01

43

Synergistic effect of different phase on the photocatalytic activity of visible light sensitive silver antimonates  

British Library Electronic Table of Contents (United Kingdom)

We investigated phase transition of ilmenite-type AgSbO3 to pyrochlore by post-heat treatment and the synergy effect of the mixed phases of AgSbO3 on the photocatalytic activities to enhance the activities. The AgSbO3 with an ilmenite structure was prepared by a cation-exchange method. Phase transition from the ilmenite to pyrochlore occurred by proper control of post-heat treatment. The sample that was obtained by post-heat treatment of ilmenite-type AgSbO3 at 660^oC for 3h consisted of both of the ilmenite and pyrochlore phases, and the sample at 685^oC for 4h mainly consisted of the pyrochlore phase. Together with an increase in the ratio of the pyrochlore phase, the optical absorption spectra blue-shifted. The band gaps of single phases of the ilmenite and the pyrochlore were 2.4 and 2...

2010-01-01

44

Optimization of alkaline hydrolysis of paddy straw for ferulic acid extraction  

British Library Electronic Table of Contents (United Kingdom)

Response Surface Methodology (RSM) via Central Composite Design (CCD) was used to optimize the alkaline hydrolysis of paddy straw to improve ferulic acid extraction. The parameters involved, namely temperature (^oC), concentration of NaOH (M) and duration of extraction (h) are screened by Full Factorial Studies (FFD). The result obtained from FFD was 0.518% (5.18mg/g). The interactions between each parameters involved were studied using Central Composite Design (CCD). Upon optimization, the percentage of ferulic acid improved from 0.518% to 0.817% (8.17mg/g). The optimum conditions obtained from this study are 125^oC, 3.90M, 2.30h for temperature, concentration of NaOH and extraction time, respectively. This result shows a significant improvement than the previous published work. Details o...

2011-01-01

45

Mass transfer in horizontal flow channels with thermal gradients  

Energy Technology Data Exchange (ETDEWEB)

Mass transfer to a wall of a horizontal rectangular channel reactor was investigated by the limiting current technique for Reynolds numbers ranging from 200 to 32000. Overall mass transfer coefficients at various mass transfer surface angles were obtained while the reactor was operated under isothermal and non-isothermal conditions. Dimensionless correlations were developed for isothermal flows from 25 to 55{sup o}C and for non-isothermal flows with applied temperature differences up to 30{sup o}C. In the laminar flow range natural convection dominated, but under turbulent conditions combined natural and forced convection prevailed. Mass transfer was approximately doubled under optimum selection of channel surface rotation, temperature gradient and flow rate. (author)

1997-12-15

46

Mass transfer in horizontal flow channels with thermal gradients  

International Nuclear Information System (INIS)

Mass transfer to a wall of a horizontal rectangular channel reactor was investigated by the limiting current technique for Reynolds numbers ranging from 200 to 32000. Overall mass transfer coefficients at various mass transfer surface angles were obtained while the reactor was operated under isothermal and non-isothermal conditions. Dimensionless correlations were developed for isothermal flows from 25 to 55"oC and for non-isothermal flows with applied temperature differences up to 30"oC. In the laminar flow range natural convection dominated, but under turbulent conditions combined natural and forced convection prevailed. Mass transfer was approximately doubled under optimum selection of channel surface rotation, temperature gradient and flow rate. (author)

1997-12-01

47

Influence of sintering conditions on the #beta#-sialon ceramics properties from power station fly ashes  

International Nuclear Information System (INIS)

Fly ash from Lagisza power station with addition of kaolin and calculated amount of carbon was reacted in flowing nitrogen at 1520"oC in order to obtain #beta#-sialon. The resulted powder was sintered with and without Y_2O_3 addition. Examinations show that it is possible to sinter that material without any sintering additives, however additive of Y_2O_3 decreases sintering temperature of about 100"oC. Sintering temperature influences the final mechanical properties like: flexural strength, microhardness, Young elastic modulus (E) and fracture toughness (K_I_c). (author)

2004-09-12

48

Industrial application of green chromatography-I. Separation and analysis of niacinamide in skincare creams using pure water as the mobile phase  

British Library Electronic Table of Contents (United Kingdom)

In this work, chromatographic separation of niacin and niacinamide using pure water as the sole component in the mobile phase has been investigated. The separation and analysis of niacinamide have been optimized using three columns at different temperatures and various flow rates. Our results clearly demonstrate that separation and analysis of niacinamide from skincare products can be achieved using pure water as the eluent at 60^oC on a Waters XTerra MS C18 column, a Waters XBridge C18 column, or at 80^oC on a Hamilton PRP-1 column. The separation efficiency, quantification quality, and analysis time of this new method are at least comparable with those of the traditional HPLC methods. Compared with traditional HPLC, the major advantage of this newly developed green chromatography techniq...

2011-01-01

49

Evaluation and optimization of organosolv pretreatment using combined severity factors and response surface methodology  

British Library Electronic Table of Contents (United Kingdom)

In this study, ethanol organosolv pretreatment was investigated and optimized for the pretreatment of empty palm fruit bunch using (1) response surface methodology based on three-variable central composite design and (2) the combined severity parameters. The reaction parameters studied were sulfuric acid concentration (0.5-2.0%), reaction temperature (160-200^oC) and residence time (45-90min). Both models provide valuable and complementary informations: using combined severity parameters, very good predictions were obtained concerning xylan and lignin extraction whereas central composite design is the best model for glucose production. The optimal values of the variables were as the followings: sulfuric acid 2.0% w/w, 160^oC, 78min and the experimental values (96.0%) concerning glucose and...

2011-01-01

50

CO2 maritime transportation  

British Library Electronic Table of Contents (United Kingdom)

The objective of this study is to describe the complete transport chain of CO2 between capture and storage including a ship transport. This last one is composed by the following steps:Shore terminal including the liquefaction, temporary storage and CO2 loading. Ship with a capacity of 30,000m^3. On or off shore terminal including an unloading system, temporary storage and export towards the final storage. Between all the possible thermodynamic states, the liquid one is most relevant two options are compared in the study (-50^oC, 7bar) and (-30^oC, 15bar). The ship has an autonomy of 6 days, is able to cover 1000km with a cargo of 2.5Mt/year. Several scenarios are studied varying the geographical position of the CO2 source, the number of harbours and the way the CO2 is finally stored. Depen...

2010-01-01

51

Biosorption of reactive dye by waste biomass of Nostoc linckia  

British Library Electronic Table of Contents (United Kingdom)

Potential of spent biomass of a cyanobacterium, Nostoc linckia HA 46, from a hydrogen bioreactor was studied for biosorption of a textile dye, reactive red 198. The waste biomass was immobilized in calcium alginate and used for biosorption of the dye from aqueous solution using response surface methodology (RSM). Kinetics of the dye in aqueous solution was studied in batch mode. Interactive effects of initial dye concentration (100-500mg/L), pH (2-6) and temperature (25-45^oC) on dye removal were examined using Box-Behnken design. Maximum adsorption capacity of the immobilized biomass was 93.5mg/g at pH 2.0, initial concentration of 100mg/L and 35^oC temperature, when 94% of the dye was removed. Fourier transform infrared (FT-IR) studies revealed that biosorption was mainly mediated by fun...

2011-01-01

52

A field study of thermal comfort in outdoor and semi-outdoor environments in subtropical Sydney Australia  

Energy Technology Data Exchange (ETDEWEB)

In the absence of empirical outdoor thermal comfort studies it has been widely assumed that indoor thermal comfort theory generalises to outdoor settings without modification. Many indoor models were developed to describe thermal discomfort, not stress, therefore their relevance to conditions that vary greatly from neutrality, as many outdoor climatic conditions do, has not been critically validated in the field to date. The thermal comfort of 1018 subjects in outdoor and semi-outdoor locations in subtropical Sydney was investigated by a questionnaire and a comprehensive package of micro-meteorological instruments. The thermal neutrality in terms of the thermal comfort index OUT{sub S}ET* of 26.2 {sup o}C was significantly higher than the indoor SET* counterpart of 24{sup o}C (ASHRAE Trans. 92 (1986) 709). (author)

2003-05-01

53

(Ti,Cr,Nb)CN coatings deposited on nitrided high-speed steel by cathodic arc method  

British Library Electronic Table of Contents (United Kingdom)

The combined processes of plasma nitriding and cathodic arc deposition of (Ti,Cr,Nb)CN coatings were applied to HSS substrates. The nitrided layers, obtained in a mixture of H2 (70%) and N2 (30%) at two different temperatures (480^oC and 510^oC), were examined for the microhardness depth profiles. Characterization of the duplex coatings was performed by investigating elemental and phase composition, texture, hardness, friction and wear. XRD and XPS analyses revealed the formation of a mixture of a carbonitride fcc solid solution, in a dominant proportion, and metallic chromium. The film hardness was measured to be ~34GPa. The duplex (Ti,Cr,Nb)CN coatings exhibited superior tribological behavior as compared to both nitrided layers and non-duplex coatings.

2011-01-01

54

The deep borehole heat exchanger in Weggis - Performance monitoring after increasing the heat output power; Tiefe Erdwaermesonde Weggis. Messkampagne zur Dokumentierung der neuen Einfluesse beim Ausbau der Abnehmerleistung  

Energy Technology Data Exchange (ETDEWEB)

The deep borehole heat exchanger (BHE) of Weggis is operational since 1994. During the years 1995 to 2000 the BHE has produced for both, direct heating and as a source for the heat pumps, a yearly amount of heat of 220 MWh. The share of direct heating has been more than 60%. The global average power delivered to all consumers has been about 100 kW. This has yielded to a mean source temperature out of the deep BHE of 40.5 {sup o}C and to a mean return temperature of 33.3 {sup o}C. During the years 2000 and 2001 three additional multi-family dwellings have been connected as heat consumers to the BHE. The amount of delivered heat has nearly been doubled (from 220 to 440 MWh per year) as well as the nominal load. This has induced a small reduction of the delivery temperature and a significant reduction of the return temperature to the BHE (37.2 {sup o}C and 29.9 {sup o}C respectively). As a result, the ...

2003-07-01

55

Revolutionary news on superconductivity  

Energy Technology Data Exchange (ETDEWEB)

A brief article gives an update on the commercial exploitation of superconductivity by the American Superconductor Corporation. Potential applications include transmission and distribution, motors, magnetic storage systems, current limiters and transport. The company have produced a kilometre long, ''wrappable'' cable capable of carrying thousands of amps when operating at a temperature of below -140[sup o]C. (UK)

1994-09-01

56

Radiation-annealing hardening of vanadium  

International Nuclear Information System (INIS)

A study is made of the mechanical properties of vanadium irradiated with fast neutrons up to dose 8.6.10"-"4 dpa, as a function of the temperature of post-radiation annealing. The radiation-annealing hardening (RAH) effect is observed at 300"oC, in agreement with previous studies. It is established for the first time that RAH is accompanied by fall in ductility. A phenomenological model is described which explains the dependence of RAH on radiation dose and temperature, as well as on the content of chemically active alloying impurities. (author).

57

Prime Contract Awards Alphabetically by Contractor, State or ...  

Science.gov (United States)

... Iv mc.4N0 Kt afl qtl- 04n4 ( (Y 4 3.4 0.NO K0 00 0. 04 N oC 0 000 000 04 K1 0 a -# 0.N K) 0 0 0 00 00 a 0 0 0 00 0 C0 K ...

2011-05-14

58

Photophysical properties of new psoralen derivatives: psoralens linked to adenine through polymethylene chains  

International Nuclear Information System (INIS)

The model compounds, 8-methoxypsoralen-CH_2O(CH_2)_n-adenine (MOPCH_2OC_nAd, n=2,3,5,6,8, and 10) in which 5 position of 8-methoxypsoralen (8-MOP) is linked by various lengths of polymethylene bridge to N"9 of adenine. UV absorption spectra are identical with the sum of MOPCH_2OC3 and adenine absorption spectra. Solvent effect on the UV absorption and fluorescence emission spectra indicate that the lowest excited singlet state is the (#pi##->##pi#"*) state. The spectral characteristics of the fluorescence of MOPCH_2OC_nAd are strongly dependent upon the nature of the solvents. The fluorescence emission spectra in aprotic solvents are broad and structrueless due to the excimer formation through the folded conformation accelerated by hydrophobic #pi#-#pi# stacking interaction. Increasing polarity of the protic solvents leads to higher population of unfolded conformation stabilized through favorable solvation and H-bonding, ...

2002-10-01

59

Integrated Risk Framework for Gigawatt-Scale Deployments of Renewable Energy: The U.S. Wind Energy Case; October 2009  

Energy Technology Data Exchange (ETDEWEB)

Assessing the potential environmental and human effects of deploying renewable energy on private and public lands, along our coasts, on the Outer Continental Shelf (OCS), and in the Great Lakes requires a new way of evaluating potential environmental and human impacts. The author argues that deployment of renewables requires a framework risk paradigm that underpins effective future siting decisions and public policies.

2010-04-01

60

Formation of nano-sized particles of a solid electrolyte by laser ablation  

Energy Technology Data Exchange (ETDEWEB)

Nano-sized particles of a lithium ion conductive solid electrolyte, LiTi{sub 2}(PO{sub 4}){sub 3}, were prepared by laser ablation. The obtained particles were ca. 10nm in diameter. X-ray powder diffraction and Raman spectroscopy showed that they were amorphous with local structure similar to the crystalline counterpart. They were crystallized by the heating at ca. 630{sup o}C. (author)

2005-08-26

61

Corrosion Behavior of Titanium Grade 7 in Fluoride-Containing NaCl Brines.  

Science.gov (United States)

The effects of fluoride on the corrosion behavior of Titanium Grade 7 (0.12-0.25% Pd) have been investigated. Up to 0.1 mol/L fluoride was added to the NaCl brines at 95oC, and three pH values of 4, 8, and 11 were selected for studying pH dependence of fl...

2004-01-01

62

Alkane degradation under anoxic conditions by a nitrate-reducing bacterium with possible involvement of the electron acceptor in substrate activation  

UK PubMed Central (United Kingdom)

Microorganisms can degrade saturated hydrocarbons (alkanes) not only under oxic but also under anoxic conditions. Three denitrifying isolates (strains HxN1, OcN1, HdN1) able to grow under anoxic conditions...Full Text Available

2011-02-01

63

Waste heat utilization in the thermal spa of Lavey-les-Bains; Etude de la valorisation des rejets thermiques des Bains de Lavey  

Energy Technology Data Exchange (ETDEWEB)

This final report for the Swiss Federal Office of Energy looks at the possibilities for improved waste water utilization in the Lavey-les-Bains thermal spa, Switzerland. According to the regulations in force, the temperature of the waste water rejected into the Rhone river shall not exceed 30 {sup o}C, what is currently not the case. Also the operational cost shall be reduced and the waste water quality improved. The installations are presented. From the two geothermal wells, mineral water comes out at an average flow rate of 940 l/min and a temperature of 63 {sup o}C. Actual waste water data are reported. The measured thermal water consumption data, including seasonal variations, are analysed by computerized simulation and measures to reduce the consumed volume by the optimization of internal procedures are evaluated. Measures to reduce the quantity of the rejected free chlorine are discussed. Several possible adaptations of the existing space ...

2004-07-01

64

Waste heat utilization in the thermal spa of Lavey-les-Bains  

International Nuclear Information System (INIS)

This final report for the Swiss Federal Office of Energy looks at the possibilities for improved waste water utilization in the Lavey-les-Bains thermal spa, Switzerland. According to the regulations in force, the temperature of the waste water rejected into the Rhone river shall not exceed 30 "oC, what is currently not the case. Also the operational cost shall be reduced and the waste water quality improved. The installations are presented. From the two geothermal wells, mineral water comes out at an average flow rate of 940 l/min and a temperature of 63 "oC. Actual waste water data are reported. The measured thermal water consumption data, including seasonal variations, are analysed by computerized simulation and measures to reduce the consumed volume by the optimization of internal procedures are evaluated. Measures to reduce the quantity of the rejected free chlorine are discussed. Several possible adaptations of the existing space heating, ...

65

Synthesis of (Bi0.5Na0.5)TiO3 (BNT) and Pr doped BNT using the soft combustion technique and its properties  

British Library Electronic Table of Contents (United Kingdom)

In this work, bismuth sodium titanate (Bi0.5Na0.5)TiO3 (BNT) and praseodymium (Pr)-doped BNT were successfully produced using the soft combustion technique. The effects of Pr doping on stoichiometry, microstructure, density and dielectric properties were studied. Pure Pr-doped BNT was obtained in all samples containing 5, 10 and 20mol% Pr after calcination at 800^oC for 3h. The produced powders were then pressed into pellets and sintered at 1100^oC for 3h. The very similar ionic radii of Pr^3^+ with Bi^3^+ and Na^+ made it possible to substitute both Bi and Na. The crystallite size and grain size decreased with increasing Pr amount because Pr acted as grain growth inhibitor, both for calcined powders and for sintered pellets. Maximum density was obtained in 5mol% Pr-doped BNT, beyond which...

2011-01-01

66

Stearic acid gel derived MgTiO{sub 3} nanoparticles: A low temperature intermediate phase of Mg{sub 2}TiO{sub 4}  

Energy Technology Data Exchange (ETDEWEB)

Stearic acid gel is employed to study the phase evolution of MgTiO{sub 3} nanoparticles by thermal gravimetric analysis, X-ray diffraction, and Fourier transform infrared. During the preparation of stearic acid gel, tetrabutyl titanate easily absorbed moisture to hydrolyze into Ti(OH){sub 4} firstly, and then reacts with stearic acid and magnesium stearate to form magnesium-titanium oxide network polymer gel, meanwhile n-butanol is generated. When stearic acid gel is calcined in air, a series of oxidation and combustion reactions occur, meanwhile apparent heat is given off. The results show that a metastable intermediate phase Mg{sub 2}TiO{sub 4} is generated at 450 {sup o}C and nearly disappeared at 550 {sup o}C. Simultaneously, a new solid phase of MgTiO{sub 3} appears. The metastable intermediate phase Mg{sub 2}TiO{sub 4} is successfully identified in the current work.

2010-03-04

67

Spark plasma sintered tantalum carbide: Effect of pressure and nano-boron carbide addition on microstructure and mechanical properties  

British Library Electronic Table of Contents (United Kingdom)

TaC and TaC-1wt.% B4C powders were consolidated using spark plasma sintering (SPS) at 1850^oC and varying pressure of 100, 255 and 363MPa. The effect of pressure on the densification and grain size is evaluated. The role of nano-sized B4C as sintering aid and grain growth inhibitor is studied by means of XRD, SEM and high resolution TEM. Fully dense TaC samples were produced at a pressure of 255MPa and higher at 1850^oC. The increasing pressure also resulted in an increase in TaC grain size. Addition of B4C leads to an increase in the density of 100MPa sample from 89% to 97%. B4C nano-powder resists grain growth even at high pressure of 363MPa. The formation of TaB2/Carbon at TaC grain boundaries helps in pinning the grain boundary and inhibiting grain growth. The effect of B4C addition on...

2011-01-01

68

Preparation, characterization and properties of thermochromic tungsten-doped vanadium dioxide by thermal reduction and annealing  

International Nuclear Information System (INIS)

Thermochromic tungsten-doped vanadium dioxide (VO2) powders were successfully synthesized by thermal reduction using V2O5 as a vanadium precursor. The products were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The results indicated that W was successfully doped into the crystal lattice of VO2 matrix, and prepared tungsten-doped VO2 had a rod-like morphology. The effects of reducing temperature and annealing temperature on the crystallographic structures were also discussed. The phase transition temperature (Tt) of VO2 could be simply tuned by changing the doping concentration of tungsten. When the doping concentration was 1.58 mol%, the Tt could be reduced to 37.8 oC from initial 69.5 oC, suggesting that tungsten-doped VO2 possesses prominent thermochromic properties and optical switching characters. It has shown that this ...

2010-08-20

69

Phase diagram of the ternary system lauric acid-capric acid-naphthalene  

Energy Technology Data Exchange (ETDEWEB)

The mixture of lauric acid and capric acid is a potential latent heat storage material. However, its eutectic melting temperature is quite high for low-temperature thermal energy storage. Addition of naphthalene is proposed. The ternary system lauric acid-capric acid-naphthalene has been investigated by differential scanning calorimetry (DSC), visual polythermal and chromatography of gases. The phase diagram is of an incongruent eutectic type. The eutectic mixture contains 18.4mol% lauric acid, 63.1mol% capric acid and 18.5mol% naphthalene and melts at 13.3{sup o}C. The peritectic mixture contains 32.4mol% lauric acid, 48.2mol% capric acid and 19.4mol% naphthalene and peritectic temperature of 16.2{sup o}C. The incongruent compound was analysed to be CH{sub 3}(CH{sub 2}){sub 10}COOH.CH{sub 3}(CH{sub 2}){sub 8}COOH. The melting temperature of the lauric acid-capric acid-naphthalene eutectic mixture makes it suitable for cooling applications.

2004-12-15

70

Oxygen carriers for chemical looping combustion of solid fuels  

Energy Technology Data Exchange (ETDEWEB)

A thermal analyzer-differential scanning calorimeter-mass spectrometer (TG-DSC-MS) was used to study oxygen carriers (OC) for their potential use for the application of chemical looping combustion (CLC) to solid fuels. Reaction rates, changes in reaction rates with repeated oxidation-reductions, exothermic heats during oxidation, and the effect of changing reduction gas compositions were studied. Oxidation rates were greater than reduction rates and reaction rates were reproducible through multiple oxidation-reduction cycles except where agglomeration occurred with powders. Iron oxide (Fe{sub 2}O{sub 3} powder) and iron-based catalysts were found suitable for CLC of solid fuels having rapid reduction rates which increased with higher reducing gas concentrations. Fe{sub 2}O{sub 3} powder was used to oxidize a high carbon coal char in an inert gas removing 88% of the carbon from the char. Other properties such as cost and durability indicated iron oxide ...

2009-05-15

71

Modeling the suppression of boron transient enhanced diffusion in silicon by substitutional carbon incorporation  

Energy Technology Data Exchange (ETDEWEB)

Recent work has indicated that the suppression of boron transient enhanced diffusion (TED) in carbon-rich Si is caused by nonequilibrium Si point defect concentrations, specifically the undersaturation of Si self-interstitials, that result from the coupled out-diffusion of carbon interstitials via the kick-out and Frank--Turnbull reactions. This study of boron TED reduction in Si{sub 1-x-y}Ge{sub x}C{sub y} during 750{sup o}C inert anneals has revealed that the use of an additional reaction that further reduces the Si self-interstitial concentration is necessary to describe accurately the time evolved diffusion behavior of boron. In this article, we present a comprehensive model which includes {l_brace}311{r_brace} defects, boron-interstitial clusters, a carbon kick-out reaction, a carbon Frank--Turnbull reaction, and a carbon interstitial-carbon substitutional (C{sub i}C{sub s}) pairing reaction that successfully simulates carbon suppression of boron TED at ...

2001-08-15

72

Modeling the suppression of boron transient enhanced diffusion in silicon by substitutional carbon incorporation  

International Nuclear Information System (INIS)

Recent work has indicated that the suppression of boron transient enhanced diffusion (TED) in carbon-rich Si is caused by nonequilibrium Si point defect concentrations, specifically the undersaturation of Si self-interstitials, that result from the coupled out-diffusion of carbon interstitials via the kick-out and Frank--Turnbull reactions. This study of boron TED reduction in Si_1_-_x_-_yGe_xC_y during 750"oC inert anneals has revealed that the use of an additional reaction that further reduces the Si self-interstitial concentration is necessary to describe accurately the time evolved diffusion behavior of boron. In this article, we present a comprehensive model which includes #left brace#311#right brace# defects, boron-interstitial clusters, a carbon kick-out reaction, a carbon Frank--Turnbull reaction, and a carbon interstitial-carbon substitutional (C_iC_s) pairing reaction that successfully simulates carbon suppression of boron TED at ...

2001-08-15

73

Influence of bias voltage on the formation and properties of iron-based nitrides produced by plasma nitriding  

Energy Technology Data Exchange (ETDEWEB)

A series of experiments have been conducted on AISI 5140 low alloy steel using a hollow cathode discharge-assisted plasma nitriding apparatus with the aim of elucidating the role of substrate bias voltages in plasma nitriding process. For comparison, some samples were nitrided with applied substrate bias (-50 V) while other samples were nitrided at floating potential. Treatments were carried out in NH{sub 3} atmosphere of 150 Pa at temperatures ranging from 450 {sup o}C to 550 {sup o}C for 2 h, 4 h, and 6 h. The nitrided samples were characterized by optical microscopy, X-ray diffraction and micro-hardness measurement. The corrosion behaviors were evaluated using anodic polarization tests in 3.5% NaCl solution. The results showed that the microstructure and phase constituents of the nitride layers were strongly influenced by the bias voltages. It was also demonstrated that the better corrosion resistance with a thicker nitrided layer was ...

2010-05-14

74

Influence of bias voltage on the formation and properties of iron-based nitrides produced by plasma nitriding  

International Nuclear Information System (INIS)

A series of experiments have been conducted on AISI 5140 low alloy steel using a hollow cathode discharge-assisted plasma nitriding apparatus with the aim of elucidating the role of substrate bias voltages in plasma nitriding process. For comparison, some samples were nitrided with applied substrate bias (-50 V) while other samples were nitrided at floating potential. Treatments were carried out in NH_3 atmosphere of 150 Pa at temperatures ranging from 450 "oC to 550 "oC for 2 h, 4 h, and 6 h. The nitrided samples were characterized by optical microscopy, X-ray diffraction and micro-hardness measurement. The corrosion behaviors were evaluated using anodic polarization tests in 3.5% NaCl solution. The results showed that the microstructure and phase constituents of the nitride layers were strongly influenced by the bias voltages. It was also demonstrated that the better corrosion resistance with a thicker nitrided layer was obtained on the ...

2010-05-14

75

Improvement of MOM4 by including surface wave-induced vertical mixing  

British Library Electronic Table of Contents (United Kingdom)

A parameterized surface wave-induced vertical mixing (B"v) is incorporated into the Modular Ocean Model version 4 (MOM4). A comparison of the two numerical experiments with and without B"v shows that B"v can significantly improve the upper-ocean (20-100m) simulation in summer. The simulated upper-ocean temperature errors are reduced in summer due to the surface wave-induced vertical diffusive heat flux. The non-breaking-wave-induced vertical mixing can increase the probability of the simulated SST biases between -1^oC and 1^oC from 64% to 76% in the Southern Hemisphere (60^oS-10^oS) in January, and from 66% to 75% in the Northern Hemisphere (10^oN-60^oN) in July. The averaged mixed layer depth (MLD) simulated by the MOM4 without B"v is 14.4m shallower than the observations in 10^oS-60^oS i...

2011-01-01

76

Heat shock factor binds to heat shock elements upstream of heat shock protein 70a and Samui genes to confer transcriptional activity in Bombyx mori diapause eggs exposed to 5^oC  

British Library Electronic Table of Contents (United Kingdom)

To understand the molecular mechanisms of how 5^oC-incubation activates mRNA expression of Hsp70a and Samui genes in Bombyx mori diapause eggs, we first searched the 5'-upstream regions of the Hsp70a and Samui genes for heat shock elements (HSEs) and found two regions [Hsp70aHSE-1 (-95 to -58) and -2 (-145 to -121), and SamuiHSE-1 (-84 to -55) and -2 (-304 to -290)] corresponding to HSEs (repeats of nGAAn and/or nTTCn). We cloned four cDNAs encoding heat shock factor (HSF)-a2 (627 amino acids), -b (685 aa), -c (682 aa) and -d (705 aa), which were produced by alternative splicing. When we exposed diapause eggs to 5^oC beginning at 2 day post-oviposition to break diapause, HSFd mRNA only increased after chilling for 6-8 days, a pattern very similar to those of Hsp70a and Samui mRNAs. To exam...

2011-01-01

77

Generic assessment of air quality impacts associated with oil and gas development offshore California  

Energy Technology Data Exchange (ETDEWEB)

Oil and gas resources in the offshore areas of the US constitute a significant portion of US recoverable hydrocarbon resources. The exploration, development and production of these offshore resources in California, however, could have significant air quality implications for coastal air basins. This study was developed to address a problem that frequently arises with offshore air quality assessments. Typically, such assessments are performed for a specific activity scenario (e.g., a Federal OCS Lease Sale involving a projected number of drilling rigs, platforms, pipelines, etc.) and assume a projected (but uncertain) level of recoverable oil and gas resources. This study enables interested parties to estimate air emissions and impacts for a wide range of OCS-related development scenarios. The modular emission calculation procedure and the generic impact assessment provide for maximum flexibility in reassessing the emissions and impacts should ...

1984-01-01

78

Effect of substrate temperature on structural properties and corrosion resistance of carbon thin films used as bipolar plates in polymer electrolyte membrane fuel cells  

International Nuclear Information System (INIS)

In this work, the effects of substrate temperature that was changed from 100 to 500 "oC on the structural, chemical and electrical properties of carbon films, prepared by direct current magnetron sputtering technique, on 316L stainless steel as bipolar plate had been investigated. Raman spectroscopy and scanning electron microscopy (SEM) were performed to study the structure and the morphology of the deposited films, respectively. The corrosion resistance and the electrical resistivity were carried out by using corrosion tests and four point-probe technique. The results show that the carbon films change the structure from amorphous to graphite-like by increasing temperatures. At the temperatures higher than 300 "oC, the holes and porosities are formed on the film indicating a decrease of film quality. According to our results, corrosion resistance and electrical properties are depended strongly on the substrate temperature.

2010-07-23

79

Diffusion research between Ni3Al coating and titanium alloy produced by plasma spraying process  

British Library Electronic Table of Contents (United Kingdom)

A Ni3Al coating was prepared by plasma spraying technique on the surface of titanium alloy. Ni-Al mixed powders, coatings and reaction products were investigated by scanning electron microscope, EDS, DSC and XRD. A tight bonding between the coating and the substrate was formed. The X-ray diffraction analysis of the patterns showed that the coating not only had Ni3Al phase, but also had NiO and Al2O3 phase microcontent. Comparing Ni coated Al to Ni3Al at 900^oC, the diffusion was stronger and the diffusion layer was thicker. A minute pore structure was formed at 1200^oC in the front edge of solid-state reaction layer. So Ni3Al restrained the solid-state reaction of the coating with the substrate, and as a whole weakened the entry of oxygen atoms into the substrate and quenched the out-diffu...

2010-01-01

80

Densification of ashes from a thermal power plant  

Energy Technology Data Exchange (ETDEWEB)

Power plants generate a great amount of ash during coal combustion. From this process two different kinds of ashes are extracted: fly ash (FA) and bottom ash (BA). In this work possible use of both fly and bottom ash as raw material for the ceramic industry is analyzed. The samples were formed by mechanical mixing of both kinds of ashes, and density evolution during conformation as structural ceramic (packing, pressing and sintering) was studied. It was verified that powders with larger fly ash content exhibited higher packing density resulting in compacts with improved green and sintered densities. Preheating treatments at temperatures above 600{sup o}C also increased the green and sintered densities. Dilatometric curves on compacts formed from FA and BA powders were run at constant heating rate and at isothermal cycles. From the analysis of these data it can be established that liquid-phase sintering is the densification mechanism present at 1180{sup ...

2003-07-01

81

Co-precipitated ZnAl2O4 spinel precursor as potential sintering aid for pure alumina system  

British Library Electronic Table of Contents (United Kingdom)

Ultra-fine ZnAl2O4 spinel hydrogel precursor synthesized from mixed salt solutions of Zn^2^+ and Al^3^+ ions using ammonium hydroxide-hexamethylenetetramine as basic media for co-precipitation was used as bonding material and sintering aid for pure alumina system. The hydrogel powder exhibited some well-defined ZnAl2O4 spinel phases at 800^oC. Alumina compacts were fabricated by incorporating small proportions of the precursor in alumina powder and firing at different temperatures (1350-1500^oC). The degree of densification was studied by measurement of fired shrinkage, apparent porosity, bulk density and cold crushing strength. Phase compositions and microstructural features of sintered samples were evaluated by XRD and SEM respectively. Addition of 0.2% hydrogel powder to alumina exhibit...

2010-01-01

82

Chemical synthesis and characterization of Ca-substituted YAlO_3 as electrolyte for solid oxide fuel cells  

International Nuclear Information System (INIS)

In this study, perovskite type oxide YAlO_3 has been doped with different amounts of the divalent cation Ca to synthesize Y_1_-_xCa_xAlO_3_-_#delta# (x = 0-0.21) compositions. The effect of dopant concentration on the crystal structure and electrical properties of YAlO_3 synthesized by citrate gel route has been investigated. The phase purity of the samples has been carried out using X-ray diffraction. The microstructural evaluation of the samples has been conducted by scanning electron microscopy and energy dispersive spectrum analysis. Thermal analysis has been conducted to monitor the decomposition of the intermediate products. The electrical conductivity studies have been performed using a.c. impedance spectroscopy as a function of temperature in the range 200-800 "oC in air. The Y_0_._9_4Ca_0_._0_6AlO_3_-_#delta# composition exhibits a total conductivity of 2.5 mS/cm at 800 "oC.

2010-04-30

83

Analysis of the relationship between the coal properties and their liquefaction characteristics by using the coal data base; Tanshu data base ni yoru tanshitsu to ekika tokusei no kaiseki  

Energy Technology Data Exchange (ETDEWEB)

The relationship between coal properties and liquefaction or gasification characteristics was analyzed by using the analysis and test results and liquefaction characteristics in the coal data base. On liquefaction reaction, the close relation between an oil yield and coal constituent composition or a coal rank is well-known. Various multivariable regression analyses were conducted by using 6 factors as variables such as calorific value, volatile component, O/C and H/C atomic ratios, exinite+vitrinite content and vitrinite reflectance, and liquefaction characteristics as variate. On liquefaction characteristics, the oil yield of dehydrated and deashed coals, asphaltene yield, hydrogen consumption, produced water and gas quantities, and oil+asphaltene yield were predicted. The theoretical gasification efficiency of each specimen was calculated to evaluate the liquefaction reaction obtained. As a result, the oil yield increased with H/C atomic ratio, while the ...

1996-10-28

84

An implicit curve-fitting method for fast calculation of thermal properties of pure and mixed refrigerants  

Energy Technology Data Exchange (ETDEWEB)

Calculations of refrigerant thermal properties are desired to be very fast and stable in cases of simulation of refrigeration system, etc. The traditional method based on equation of state cannot meet such requirement because of unavoidable iterations in calculation. In this paper, a new calculation method for refrigerant thermal properties is presented. Low order implicit polynomial equations are got by using curve-fitting method at first, and then explicit formulae for calculating refrigerant thermal properties quickly are obtained by getting the analytical solution of these implicit equations. Explicit fast calculation formulae for thermal properties of R22 and R407C, covering the saturated temperature of -60{approx}80 {sup o}C and superheat of 0-65 {sup o}C, are presented as examples. The calculation speeds of the formulae of R22 are about 140 times faster than those of REFPROP 6.01 while the formulae of R407C are about 1000 times faster. ...

2005-09-01

85

Aluminum-containing intergranular phases in hot-pressed silicon carbide  

Energy Technology Data Exchange (ETDEWEB)

Aluminum-containing intergranular phases, forming intergranular films and secondary phase particles at triple-junctions in SiC hot-pressed with aluminum, boron, and carbon additions, were studied by transmission electron microscopy. Statistical high-resolution electron microscopy study of intergranular films indicated that a large fraction of the vitreous intergranular films in the s-hot-pressed SiC crystallized during postannealing in argon above 1000 C. However, brief heating to 1900 C indeed re-melted 25 percent of the crystallized intergranular films. The structural transitions were reflected in the statistical width distributions of the amorphous grain boundary layers. At triple-junctions, Al2O3, Al2OC-SiC solid solution, and mullite phases were newly identified. These phases,together with others reported before are represented in a quaternary phase diagram for 1900 C. It is proposed that a SiC-Al2OC liquid domain is to be included in this ...

2003-01-12

86

A facile one-pot hydrothermal method to prepare europium-doped titania hollow phosphors and their sensitized luminescence properties  

British Library Electronic Table of Contents (United Kingdom)

Monodisperse europium-activated titania hollow phosphors had been synthesized by a facile one-pot hydrothermal method using carbon spheres as hard templates. Samples were characterized by X-ray powder diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, energy dispersive spectrometer and photoluminescence spectrum. The strongest emission intensity was observed with TiO2:Eu0.2 hollow spheres and TiO2:Eu0.2 hollow spheres calcining at 550^oC. Moreover, the strongest excitation of TiO2:Eu0.2 hollow spheres transferred from 400 to 500^oC and the effective nonradiative energy transfer from the TiO2 hollow spheres host matrix to Eu^3^+ ions crystal field states was realized due to changes of crystalline field in the environment around Eu^3^+ ions occupying Ti^4^+ site...

2010-01-01

87

Simple integral screenprinting process for selective emitter polycrystalline silicon solar cells  

Energy Technology Data Exchange (ETDEWEB)

This letter describes a new simple fabrication process, developed recently for blue response'' improvement in low-cost polycrystalline silicon solar cells. A selective emitter is created by heavily doping the emitter, followed by a wet etching-back of the cell area between the fingers. An improvement up to 17 mV in {ital V}{sub oc}, 1.5 mA/cm{sup 2} in {ital J}{sub sc}, and 1% (absolute value) in {eta} is obtained. Effective phosphorus gettering, self-alignment, and application in a low-cost full screenprinting technology are the main advantages of the proposed process.

1991-09-23

88

Preparation of PbTiO3 nanoceramics based on hydrothermal nanopowders and characterization of their electrical properties  

British Library Electronic Table of Contents (United Kingdom)

In this work, we report the preparation of lead titanate (PT) nanoceramics (with an average grain size of ~200nm in diameter) by using hydrothermal PT nanoparticles as start materials and characterized the dielectric and ferroelectric properties. The dielectric constant of the ceramic was found to be ~180 (at 1kHz) at room temperature and reached a maximum value of 8330 at ~490^oC, suggesting that the Curie temperature of the nanoceramics is consistent with the known value of PT crystals. Ferroelectric domains and hysteresis loops were obtained through piezoelectric force microscopy measurements, which provide direct and clear evidence for the ferroelectricity in the nanoceramic samples.

2010-01-01

89

Preparation of NiZn-ferrite nanofibers by electrospinning for DNA separation  

Energy Technology Data Exchange (ETDEWEB)

We present the synthesis, magnetic and UV spectrometry of NiZn-ferrite nanofiber. The single phase of spinel ferrite was obtained at 600 {sup o}C. The NiZn-ferrite fibers fabricated by an electrospinning process were formed as a polygonal grain growth with firing temperature in fiber matrix. It appeared that the saturation magnetization (M{sub S}) of NiZn-ferrite nanofiber was dependent on Ni/Zn molar ratio which is similar to that of the inverse spinel ferrites. The NiZn-ferrite fibers showed good DNA adsorption efficiency that can be modified and utilized for DNA separation with magnetic nanofiber as a novel material in clinical applications.

2009-05-15

90

Freezing phenomena in ice-water systems  

Energy Technology Data Exchange (ETDEWEB)

The characteristics of solidification and melting are reviewed. The properties of water and ice and the phase diagram of water are discussed with special emphasis on ice density. A concise account of the freezing process and the Stefan problem is presented. To this end, the four stages of freezing are identified, supercooling, nucleation and the formation of dendritic ice, the growth of concentric rings of solid ice at 0{sup o}C and the final cooling of the solid ice are treated in some detail. The subject of bursting of pipes is given particular emphasis. Attention is drawn to a common misconception on pipe bursting and to misleading relationships for the computation of freezing time for ice blockage. Several current applications of melting and freezing systems are outlined. (author)

2002-09-01

91

Daya Bay gets underway  

International Nuclear Information System (INIS)

Unit one of Daya Bay, China's first nuclear power plant was officially opened in February 1994. The nuclear island has been built by Framatome and is an improved version of the Gravelines 5 and 6, 900MWe Pressurized Water Reactors. Extra seismic protection has been included because of greater earthquake risk. The heat exchanger capacity has also been increased as the sea cooling water can be at 30"oC. The technical specifications and details of the fuel loading are given. The technical assistance, management and training of Chinese personnel are discussed. Two further units may be built if Daya Bay 1 is successful. (UK).

92

Boric acid effect in phenolic composites on tribological properties in brake linings  

International Nuclear Information System (INIS)

In the present work, using a pad-on-disc-type wear tester, the tribological properties of the pad next to the disk made of cast iron were investigated with changing the substance of the components. As well, micro-structural characterisation of braking pads was performed using scanning electron microscopy and also temperature outcome of the pads was examined at the temperatures of 50-400 "oC in the pressure of 1050 and 3000 kPa. Finally, the effect of environment to the pads was studied in water, salty water, oil and braking liquid media.

93

Activated charcoal from coconut shell using ZnCl{sub 2} activation  

Energy Technology Data Exchange (ETDEWEB)

In this study attempts have been made to utilize biomass residues in a proper and efficient way. As a part of these attempts activated charcoal has been produced from coconut shell. The effects of temperature, time and impregnation ratio on activation and yield have also been studied. Experimental results show that higher temperature produces better activation but lower yield. The optimum values for activation time and impregnation ratio in producing activated charcoal were 50 min and 40%, respectively, at 600{sup o}C. (Author)

2002-05-01

94

Synthesis, structure and characterisation of the n=4 Aurivillius phase Bi5Ti3CrO15  

International Nuclear Information System (INIS)

The n=4 Aurivillius phase, Bi5Ti3CrO15, was synthesised by solid state reaction. Rietveld analysis of high resolution neutron diffraction data demonstrated this material to adopt the polar space group A21am at room temperature, transforming to the aristotype I4/mmm structure above 650 oC. This phase transition is coincident with an anomaly in DSC signal and relative permittivity, which are characteristic of a ferroelectric-paraelectric phase transition. Bi5Ti3CrO15 exhibits paramagnetic behaviour at low temperature, with short range antiferromagnetic interactions, but no evidence for long range magnetic ordering. This is considered a consequence of significant disorder of Ti and Cr over the available octahedral sites, as demonstrated by analysis of neutron diffraction data. -- Graphical abstract: We report here the synthesis, structure and characterisation of the n=4 Aurivillius phase Bi5Ti3CrO15. Analysis of neutron powder diffraction and XANES data, supported by ...

2011-02-01

95

Phase equilibria of the Ba-Sm-Y-Cu-O system for coated conductor applications  

International Nuclear Information System (INIS)

The complex phase relationships near the BaO-poor region of the quaternary Ba-Sm-Y-Cu-O oxide system prepared in pure air (pO2=22 kPa, 950 oC) and in 0.1% O2 (pO2=100 Pa, 810 oC) have been determined. This investigation also included the subsolidus compatibilities in ten subsystems (Ba-Sm-Y-O, Ba-Sm-Cu-O, Ba-Y-Cu-O, Sm-Y-Cu-O, Ba-Sm-O, Ba-Y-O, Ba-Cu-O, Sm-Y-O, Sm-Cu-O, and Y-Cu-O), and the homogeneity range of five solid solutions (Ba(SmxY2-x)CuO5, (Sm,Y)2O3, (Sm,Y)2CuO4, (Y,Sm)2Cu2O5, and Ba(Sm,Y)2O4). The single phase range of the superconductor solid solution, (Ba2-xSmx)(Sm1-yYy)Cu3O6+z, and the phase compatibilities in its vicinity, which are particularly important for processing, are described in detail. The phase equilibrium data of the Ba-Sm-Y-Cu-O system will enable the improvement of the intrinsic superconducting properties of second-generation wires, and facilitate the flux-pinning process. -- Graphical Abstract: Phase diagram ...

2010-12-01

96

Lithium ion conductive polymer electrolyte by side group rotation  

Energy Technology Data Exchange (ETDEWEB)

Ionic conductive materials are of much interest as an electrolyte for solid-state lithium batteries. Poly(alkylene oxide) and lithium salt complex exhibits high ionic conductivity in terms of its high solubility for lithium salts. However, the temperature dependency of its ionic conductivity is quite large and non-linear, the ionic conductivity drops down at low temperature, especially below glass transition temperature of the polymer. Because its ionic conductive mechanism is derived from its segmental motion of polymer main chain. A novel ionic conductive material, poly[2,6-dimethoxy-N-(4-vinylphenyl)benzamide] is synthesized and confirm ionic conductivity even below glass transition temperature. Ionic conductivity of the polymer with lithium ditrifluoromethylsulfonate imide complex shows 10{sup -5}Scm{sup -1} from 0 to 60{sup o}C. Its temperature dependency is linear, namely Arrehnius type dependency. Evaluating from these data, activation energy of ionic ...

2005-08-26

97

Lauric and palmitic acids eutectic mixture as latent heat storage material for low temperature heating applications  

Energy Technology Data Exchange (ETDEWEB)

Palmitic acid (PA, 59.8 {sup o}C) and lauric acid (LA, 42.6 {sup o}C) are phase change materials (PCM) having quite high melting temperatures which can limit their use in low temperature solar applications such as solar space heating and greenhouse heating. However, their melting temperatures can be tailored to appropriate value by preparing a eutectic mixture of the lauric and the palmitic acids. In the present study, the thermal analysis based on differential scanning calorimetry (DSC) technique shows that the mixture of 69.0 wt% LA and 31 wt% PA forms a eutectic mixture having melting temperature of 35.2 {sup o}C and the latent heat of fusion of 166.3 J g{sup -1}. This study also considers the experimental determination of the thermal characteristics of the eutectic mixture during the heat charging and discharging processes. Radial and axial temperature distribution, heat transfer coefficient between the heat transfer ...

2005-04-01

98

Fatigue behavior of Alloy 690 and Alloy 800 SG tubing at temperatures up to 330{sup o}C in very high cycle fatigue regime  

Energy Technology Data Exchange (ETDEWEB)

During the service in nuclear power plants, steam generator (SG) tubing will suffer from a vibration with a frequency from 30-40 Hz. This means that SG tubing will undergo a very high cycle fatigue process during the design life time (25 years=about 3x10{sup 10}cycles). The material degradation and the very high cycle fatigue life of SG tubing materials due to the vibration are therefore of concern. In this investigation, the fatigue properties of Alloy 690 and Alloy 800 SG tubing in the very high cycle fatigue regime (higher than 10{sup 7} cycles) and strain controlled fatigue at temperatures up to 330{sup o}C have been investigated. The fatigue properties of SG tubing of Alloy 690 are comparable to that of wrought material. The strain controlled fatigue properties of Alloy 690 and Alloy 800 are slightly better at 288{sup o}C than at room temperature (RT). At the stress near the fatigue endurance, the influence of temperature on the high cycle ...

2007-07-01

99

Fatigue behavior of Alloy 690 and Alloy 800 SG tubing at temperatures up to 330"oC in very high cycle fatigue regime  

International Nuclear Information System (INIS)

During the service in nuclear power plants, steam generator (SG) tubing will suffer from a vibration with a frequency from 30-40 Hz. This means that SG tubing will undergo a very high cycle fatigue process during the design life time (25 years=about 3x10"1"0cycles). The material degradation and the very high cycle fatigue life of SG tubing materials due to the vibration are therefore of concern. In this investigation, the fatigue properties of Alloy 690 and Alloy 800 SG tubing in the very high cycle fatigue regime (higher than 10"7 cycles) and strain controlled fatigue at temperatures up to 330"oC have been investigated. The fatigue properties of SG tubing of Alloy 690 are comparable to that of wrought material. The strain controlled fatigue properties of Alloy 690 and Alloy 800 are slightly better at 288"oC than at room temperature (RT). At the stress near the fatigue endurance, the influence of temperature on the high cycle fatigue properties ...

2007-08-19

100

Effects of combined electron-beam irradiation and sous-vide treatments on microbiological and other qualities of chicken breast meat  

Energy Technology Data Exchange (ETDEWEB)

The microbiological safety, refrigeration shelf-life, and nutritional quality of chicken breast meat were investigated following combined electron-beam irradiation and cooking under vacuum (sous-vide). Chicken breast meat inoculated with 10{sup 6} CFU/g of Listeria monocytogenes was irradiated with an electron beam at doses up to 3.1 kGy under vacuum in barrier bags, cooked in a boiling water bath for 3 min 45 s (previously determined to achieve an internal temperature of 71.1{sup o}C), and stored at 8{sup o}C for up to 5 weeks. Listeria was undetectable in samples treated with combined sous-vide and irradiation at 3.1 kGy, but the organism survived the sous-vide treatment without irradiation and multiplied during storage. A similar study, conducted with uninoculated chicken breast meat, revealed that the product which received both irradiation (3 kGy) and sous-vide treatment had a shelf-life of at least 8 weeks at 8{sup ...

1994-07-01

101

Effect of secondary fuels and combustor temperature on mercury speciation in pulverized fuel co-combustion: part 1  

Energy Technology Data Exchange (ETDEWEB)

The present work mainly involves bench scale studies to investigate partitioning of mercury in pulverized fuel co-combustion at 1000 and 1300{sup o}C. High volatile bituminous coal is used as a reference case and chicken manure, olive residue, and B quality (demolition) wood are used as secondary fuels with 10 and 20% thermal shares. The combustion experiments are carried out in an entrained flow reactor with a fuel input of 7-8 kWth. Elemental and total gaseous mercury concentrations in the flue gas of the reactor are measured on-line, and ash is analyzed for particulate mercury along with other elemental and surface properties. Animal waste like chicken manure behaves very differently from plant waste. The higher chlorine contents of chicken manure cause higher ionic mercury concentrations whereas even with high unburnt carbon, particulate mercury reduces with increase in the chicken manure share. This might be a problem due to coarse fuel particles, low surface ...

2007-08-15

102

Degradation of materials under conditions of the sulfur-iodine thermochemical cycle  

Energy Technology Data Exchange (ETDEWEB)

The sulfur-iodine (SI) thermochemical cycle is one of the main candidate methods to produce hydrogen from non-fossil sources like nuclear (GEN IV reactor) or solar thermal power. A major issue for the successful implementation of the SI cycle is the selection of technically viable and economic materials for construction of process components, particularly heat exchangers. Challenging conditions are encountered in each of the three sections of the SI cycle due to the corrosive chemicals present, including sulfuric acid, iodine, hydroiodic acid, sulfur dioxide, hydrogen, oxygen, and others. In Section I, aqueous, non-aqueous (liquid iodine), and gaseous multi-component phases are present at about 120 {sup o}C and 0.7 MPa. Section II involves gaseous and aqueous phases of sulfuric acid, sulfur dioxide, and oxygen at up to about 830 {sup o}C and 3.6 MPa. In Section III , aqueous, non-aqueous, and gaseous phases, at up to 310 {sup ...

2009-07-01

103

VVER technology: Czechs check out and choose bitumenisation  

International Nuclear Information System (INIS)

Bituminization has to be selected as the process for conditioning radioactive liquid wastes arising from the two VVER V-230 reactors being built at Temelin in the Czech Republic. In the process, a thin-film evaporator, operating at a waste-product temperature of 160"oC, evaporates all free water from the waste effluents. Remaining solids are homogeneously dispersed in a bitumen matrix which solidifies through natural cooling of the binder. The relative simplicity of the process reduces construction costs for on-line waste facilities and operating costs are less given the cheap basic material and simple maintenance. The reliability of the process has been demonstrated at Western reactors and reprocessing plants though adaptations have had to be made to accept VVER effluents. (UK).

1994-01-01

104

Utilisation of the binders prepared from coal tar pitch and phenolic resins for the production metallurgical quality briquettes from coke breeze and the study of their high temperature carbonization behaviour  

British Library Electronic Table of Contents (United Kingdom)

To reduce the cost of the formed coke briquettes which can be used as a substitute fuel to the metallurgical coke for the blast furnace from the coke breeze alternative binders and their blends were used. The high temperature behavior was investigated. The binders tested were: the nitrogen blown, air blown coal tar pitch and the blend of air blown coal tar pitch with the phenolic resins blends. The phenolic resin blends were prepared by mixing equal amount of resole and novalac. From the results, nitrogen blowing resulted in the weakest briquettes. The air blowing procedure should be preferred in place of nitrogen blowing for this purpose. When the air blown coal tar pitch was used alone as a binder, the briquettes must be cured at 200^oC for 2h, then carbonized at a temperature above 670^...

2010-01-01

105

The influence of heating rate on the response and trapping parameters of #alpha#-Al_2O_3:C  

International Nuclear Information System (INIS)

The effects of the heating rate from 0.6 up to 50"oC.s"-"1 on the thermoluminescence of #alpha#-Al_2O_3:C are very intensive. The material rapidly loses its high sensitivity as the heating rate increases. The peak shape characteristics, peak maximum and full width at half maximum agree only qualitatively with those theoretically predicted. The trapping parameters calculated by the curve fitting method, the peak shape method, the variable heating rate method and the initial rise method, were found to decrease as the heating rate increases. The validity of the results are discussed in the framework of the kinetic models. (author).

106

The influence of chlorine on the fate and activity of alkali metals during the gasification of wood  

Energy Technology Data Exchange (ETDEWEB)

Chlorine clearly inhibits the CO{sub 2}-gasification reaction of charcoal at 800{sup o}C. From this and other observations the picture emerges that the reduction in the gasification reactivity of the charcoal is intimately related to the deactivation of the catalytically active alkali metals residing in the wood due to the formation of the chloride salt. It is argued that the heavy metal chlorides will likely transfer the chlorine to the indigenous alkali metals during the pyrolysis stage of the wood. The fate of the thus formed alkali metal chlorides can then be either their removal from the sample (evaporation), or, when present at the gasification stage, re-activation (i.e., de-chlorination) under our gasification conditions. (author) 3 figs., 4 refs.

1999-08-01

107

The competition of neutrino energy loss due to the pair, photo-, plasma process at the late stages of stellar evolution  

International Nuclear Information System (INIS)

Based on the Weinberg-Salam theory, the competition of the Neutrino Energy Loss (NEL) rates due to the pair, photo- and plasma process are canvassed. The ratio factor C1, C2 and C3 which correspond the different contributions of the pair, photo- and plasma neutrino process to those of the total NEL rates are accurately taken into account. The ratio factors are very sensitive to the temperature and density. The ratio factor C2 always is lower than the ratio factor C1 and C3. The pair NEL process is the dominant contribution before the crossed point O(C1=C3=0.45) and the plasma NEL process will be the main dominant contribution after the crossed point O. With increasing temperature, the crossed point O will move to the direction of higher density. (authors)

2009-01-01

108

Technical evaluation of Solar Cells, Inc., CdTe module and array at NREL  

Energy Technology Data Exchange (ETDEWEB)

The Engineering and Technology Validation Team at the National Renewable Energy Laboratory (NREL) conducts in-situ technical evaluations of polycrystalline thin-film photovoltaic (PV) modules and arrays. This paper focuses on the technical evaluation of Solar Cells, Inc., (SCI) cadmium telluride (CdTe) module and array performance by attempting to correlate individual module and array performance. This is done by examining the performance and stability of the modules and array over a period of more than one year. Temperature coefficients for module and array parameters (P{sub max}, V{sub oc}, V{sub max}, I{sub sc}, I{sub max}) are also calculated.

1996-05-01

109

Systematic evaluation of pre-HPLC sample processing methods on total and individual isoflavones in soybeans and soy products  

British Library Electronic Table of Contents (United Kingdom)

There are mainly two protocols in isoflavone analysis, one that involves hydrolysis prior to HPLC analysis and the other direct HPLC analysis. In this study, three different hydrolysis methods were systematically re-evaluated, and compared with direct HPLC analysis. Acidic hydrolysis (1.2-3M HCl in ethanol at 80^oC) showed a maximum conversion of ca. 92% from glucosides to aglycones in 2h; however, longer reaction caused degradation of genistein. Alkaline hydrolysis using 2M NaOH converted acetylglucosides and malonylglucosides to their respective glucosides within 10min. Glucuronidase from H. pomatia effectively converted isoflavone glucosides and acetylglucosides to aglycones. Quantification of the total isoflavones in various soy food products showed no significant difference among dire...

2011-01-01

110

Synthesis and characterization of Fe3O4Gg nanocomposites and their antibacterial performance  

British Library Electronic Table of Contents (United Kingdom)

We synthesized Fe3O4Gg nanocomposites through a combination of solvothermal, hydrothermal, and chemical redox reactions. Characterization of the resulting samples by X-ray diffraction, Fourier-transform infrared spectroscopy, field-emission scanning and transmission electron microscopy, and magnetic measurement is reported. Compared to Fe3O4g nanocomposites, the Fe3O4Gg nanocomposites showed enhanced antibacterial activity. The Fe3O4Gg nanocomposites were able to almost entirely prevent growth of Escherichia coli when the concentration of Ag nanoparticles was 10mg/mL. Antibacterial activity of the Fe3O4Gg nanocomposites was maintained for more than 40h at 37^oC. The intermediate carbon layer not only protects magnetic core, but also improves the dispersion and antibacterial activity of the...

2011-01-01

111

Structural characterization of liposomes made of diether archaeal lipids and dipalmitoyl-L-a-phosphatidylcholine  

British Library Electronic Table of Contents (United Kingdom)

The physicochemical properties of binary lipid mixtures of diether C25,25 lipids and dipalmitoyl-L-a-phosphatidylcholine (DPPC) were studied using photon correlation, fluorescence and electron paramagnetic resonance spectroscopy, and transmission electron microscopy. These two types of lipids can be mixed at all molar ratios to form unilamellar and multilamellar liposomes. Fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatrien in mixed liposomes indicates that the abrupt changes in order parameter in the hydrophobic part of bilayer membranes made of DPPC lipids disappears with increasing mol%C25,25 lipids. Electron paramagnetic resonance spectroscopy shows that at temperatures below 50^oC, the interfacial regions of membrane bilayer of mixed liposomes is more fluid than for pure DPPC lipo...

2011-01-01

112

Raney-platinum film electrodes for potentially implantable glucose fuel cells. Part 2: Glucose-tolerant oxygen reduction cathodes  

British Library Electronic Table of Contents (United Kingdom)

We report the fabrication and characterization of glucose-tolerant Raney-platinum cathodes for oxygen reduction in potentially implantable glucose fuel. Fabricated by extraction of aluminum from 1mm thin platinum-aluminum bi-layers annealed at 300^oC, the novel cathodes show excellent resistance against hydrolytic and oxidative attack. This renders them superior over previous cathodes fabricated from hydrogel-bound catalyst particles. Annealing times of 60, 120, and 240min result in approximately 400-550nm thin porous films (roughness factors ~100-150), which contain platinum and aluminum in a ratio of ~9:1. Aluminum release during electrode operation can be expected to have no significant effect on physiological normal levels, which promises good biocompatibility. Annealing time has a dis...

2010-01-01

113

Raney-platinum film electrodes for potentially implantable glucose fuel cells. Part 1: Nickel-free glucose oxidation anodes  

British Library Electronic Table of Contents (United Kingdom)

We present a novel fabrication route yielding Raney-platinum film electrodes intended as glucose oxidation anodes for potentially implantable fuel cells. Fabrication roots on thermal alloying of an extractable metal with bulk platinum at 200^oC for 48h. In contrast to earlier works using carcinogenic nickel, we employ zinc as potentially biocompatible alloying partner. Microstructure analysis indicates that after removal of extractable zinc the porous Raney-platinum film (roughness factor ~2700) consists predominantly of the Pt3Zn phase. Release of zinc during electrode operation can be expected to have no significant effect on physiological normal levels in blood and serum, which promises good biocompatibility. In contrast to previous anodes based on hydrogel-bound catalyst particles the ...

2010-01-01

114

Pesticide residue level in tea ecosystems of Hill and Dooars regions of West Bengal, India  

British Library Electronic Table of Contents (United Kingdom)

In the present study we quantified the residues of organophosphorus (e.g. ethion and chlorpyrifos), organochlorine (e.g. heptachlor, dicofol, ?-endosulfan, ?-endosulfan, endosulfan sulfate) and synthetic pyrethroid (e.g. cypermethrin and deltamethrin) pesticides in made tea, fresh tea leaves, soils and water bodies from selected tea gardens in the Dooars and Hill regions of West Bengal, India during April and November, 2006. The organophosphorus (OP) pesticide residues were detected in 100% substrate samples of made tea, fresh tea leaves and soil in the Dooars region. In the Hill region, 20% to 40% of the substrate samples contained residues of organophosphorus (OP) pesticides. The organochlorine (OC) pesticide residues were detected in 33% to 100% of the substrate samples, excluding the w...

2009-01-01

115

Performance of a low cost solar paraboloidal dish steam generating system  

Energy Technology Data Exchange (ETDEWEB)

This paper presents the design, development and performance characteristics of a low cost solar steam generating system which incorporates recent design and materials innovations of parabolic dish technology. The concentrator is a deep dish of rather imperfect optics, made of silvered polymer reflectors fitted in the aluminum frame of a satellite communication dish. Conventional cavity receivers tend to be inadequate for this concentrator. Semi-cavity and modified cavity receivers, thermally optimised, with the fuzzy focal image have, therefore, been investigated. Preliminary field measurements and cost, as well as performance analyses of the system, indicate a solar to steam conversion efficiency of 70-80% at 450{sup o}C and a collector system cost of Rs 8000-9000/m{sup 2} (1 US dollar = Rs, 40.0). (author)

2000-05-01

116

Nanostructured Nb2O5-natural hydroxyapatite formed by the mechanical alloying method: A bulk composite  

British Library Electronic Table of Contents (United Kingdom)

The aim of this study was to develop a nanostructured Nb2O5-natural hydroxyapatite bulk composite to serve as an alternative biocompatible bulk material for implants. A set of samples of hydroxyapatite from fish bones with different concentrations of Nb2O5 were designed. They were prepared through a milling process, compacted under different pressures (350, 450, 550 and 650MPa) and sintered in air atmosphere at 1000^oC for 1h. The results revealed that the prepared composites presented strong interactions between the two elements and showed improvement in the sinterability with significant densification and microstructure changes, suggesting that they are promising for implants meant to replace bone tissues.

2011-01-01

117

Morphology evolution of Ir-Nb-X (X = Hf, Ta, or Ti) ternary alloys  

Energy Technology Data Exchange (ETDEWEB)

The microstructure evolution of nine samples from three Ir-base ternary systems, Ir-Nb-Hf, Ir-Nb-Ta, and Ir-Nb-Ti, was investigated by microstructure observation using scanning electron microscopy (SEM), composition map-analysis using electron probe microscopy analysis (EPMA), and phase determination using X-ray diffraction (XRD) patterns. The fcc/L1{sub 2} two-phase structure was detected in all the samples. Lattice misfits between fcc and L1{sub 2} phases were calculated. Ir-Nb-Ta and Ir-Nb-Ti alloys exhibited a microstructure quite similar to that of Ni-base superalloys, and the cuboidal L1{sub 2} precipitates in Ir-Nb-Ta and Ir-Nb-Ti alloys could maintain up to 1900 {sup o}C.

2007-01-31

118

Model for simulation of freezing and thawing processes in building materials  

Energy Technology Data Exchange (ETDEWEB)

This paper presents a mathematical model for simultaneous heat and moisture transfer under freezing-thawing in porous hygroscopic material. Even below O{sup o}C, unfrozen liquid water exists in the material which plays an important role in the processes. The model takes into account the existence of unfrozen liquid water. The system is treated as a three-(gas, liquid and solid) phase system of water. Moisture chemical potential is used as a moisture potential. Under freezing, moisture chemical potential is a unique function of local temperature. So, during freezing, two unknown variables to be solved are solid water content and moisture potential or temperature. A simple example of simulation for freezing processes is shown. (author)

2001-07-01

119

Magnetic layer formation on plasma nitrided CoCrMo alloy  

British Library Electronic Table of Contents (United Kingdom)

In this study structural and magnetic character of the expanded austenite phase (gN) layer formed on a medical grade CoCrMo alloy by a low-pressure Radio-Frequency plasma nitriding process was investigated. The formation of the expanded austenite phase is facilitated at a substrate temperature near 400^oC for 1, 2, 4, 6 and 20h under a gas mixture of 60% N2-40% H2. The magnetic state of the gN layers was determined by a surface sensitive technique, magneto-optic Kerr effect (MOKE), and with a scanning probe microscope in magnetic force mode (MFM). Strong evidence for the ferromagnetic nature of the gN-(Co,Cr,Mo) phase is provided by the observation of stripe domain structures and the hysteresis loops. The ferromagnetic state for the gN phase observed here is mainly linked to large lattice ...

2011-01-01

120

LiF enhanced nucleation of the low temperature microcrystalline silicon prepared by plasma enhanced chemical vapour deposition  

Energy Technology Data Exchange (ETDEWEB)

A 15-nm lithium fluoride (LiF) thin film evaporated on glass substrate is shown to enhance the nucleation of microcrystalline Si grown by plasma enhanced chemical vapour deposition at the amorphous/microcrystalline boundary conditions. The effect is more pronounced at low substrate temperatures, nucleation density being 10 times higher at {approx} 80 {sup o}C. The effect is ascribed to the ionic chemical nature of LiF, the low work function material used in organic electronic devices, and we propose its use for micro patterning crystalline Si regions in otherwise amorphous Si film.

2009-10-30

121

Infrared bleaching of the thermoluminescence of four feldspars  

International Nuclear Information System (INIS)

This paper studies the effect upon the thermoluminescence (TL) signal of four feldspar samples of exposing them to infrared stimulation, as occurs during infrared-stimulated luminescence (IRSL) measurement. Together with pulse annealing measurements these results are used to show which part of the TL signal is removed by exposure to IR and which part is directly related to the IRSL signal that is observed. When the samples are preheated prior to measurement in order to remove any low-temperature (< 200"oC) TL signals, a linear relationship is observed between the amount of TL that is lost and the IRSL light sum that is produced. The IRSL light sum is consistently four times larger than the amount of TL that is lost. Three possible explanations are proposed for this, but no conclusive evidence could be obtained to support any of them. A close similarity is observed in the pulse annealing results and the loss of TL due to IR exposure of the four samples. (author).

1995-06-01

122

Influence of SiC addition on tribological properties of SiAlON  

British Library Electronic Table of Contents (United Kingdom)

The tribological properties of gas pressure sintered SiAlON and its composite with 18wt% silicon carbide (SiC) against two different mating materials, i.e., alumina and SiAlON are evaluated. SiAlON and SiAlON-18%SiC composite ceramics were prepared by pressure less sintering and gas pressure sintering. Fretting wear tests were carried out under dry unlubricated ambient conditions (room temperature 23-25^oC; relative humidity 50-55%) with a load of 8N for 45,000 cycles. Friction and wear properties of SiAlON-SiC proved better than the monolithic SiAlON. The formation of silica roll like structure on the composite worn surface was observed.

2011-01-01

123

In vitro effects of medium tonicity, nutrient concentration, and free chlorine content on Acanthamoeba  

British Library Electronic Table of Contents (United Kingdom)

Background: The environment preferred by Acanthamoeba trophozoites and the mechanism by which the amebae enters the cornea are not yet fully understood. A better understanding of the pathogenesis of this disease may help with prevention and treatment. Purpose: To define the preferred environments for Acanthamoeba survival and proliferation in vitro by examining the effect of tonicity, nutrient concentration, and free chlorine content on Acanthamoeba. Materials and methods: Human corneal isolates of Acanthamoeba castellanii and Acanthamoeba polyphaga trophozoites were cultured at 22^oC (room temperature) in PYG (peptone-yeast extract-glucose) medium. The effect of tonicity on amebae was determined by incubating trophozoites in sodium chloride solutions in concentrations ranging from 0% to 1...

2011-01-01

124

Global suppression of mitogen-activated ovine peripheral blood mononuclear cells by surface protein activity from Mycoplasma ovipneumoniae  

British Library Electronic Table of Contents (United Kingdom)

Mycoplasma ovipneumoniae is associated with chronic non-progressive pneumonia of sheep and goats. As with many other mycoplasmas involved in animal diseases, protective immune responses have not been achieved with vaccines, even though antibody responses can be obtained. This study focuses on characterizing the interaction of M. ovipneumoniae with ovine PBMC using carboxy-fluorescein-succinimidyl-ester (CFSE) loading and flow cytometry to measure lymphoid cell division. M. ovipneumoniae induced a strong in vitro polyclonal suppression of CD4^+, CD8^+, and B blood lymphocyte subsets. The suppressive activity could be destroyed by heating to 60^oC, and partially impaired by formalin and binary ethyleneimine treatment that abolished its viability. The activity resided on the surface-exposed m...

2010-01-01

125

Ferrihydrite phase transformation in the presence of aqueous sulfide and supercritical CO2  

British Library Electronic Table of Contents (United Kingdom)

The transformation of ferrihydrite to siderite (FeCO3) in the presence of supercritical CO2 (scCO2) and aqueous sulfide has been investigated by in situ attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and ex situ X-ray diffraction (XRD). The chemical transformation of iron-bearing minerals to form iron carbonates may play a role in the chemistry related to the geological sequestration of carbon dioxide in the Earth's (sub)surface. The iron oxyhydroxide ferrihydrite in an aqueous solution containing sodium sulfide in contact with scCO2 at 100^oC reacts within 24h to form siderite and elemental sulfur. In situ studies of this reaction with ATR-FTIR show that ferrihydrite exists with an adsorbed layer of carbonate. However, the presence of the carbonate adsorbat...

2010-01-01

126

Effects of manganese doping on properties of sol-gel derived biphasic calcium phosphate ceramics  

British Library Electronic Table of Contents (United Kingdom)

We have investigated the effect of manganese (Mn) doping on properties of nanosized biphasic calcium phosphate powders and their dense bodies. Manganese levels of 0.6, 1.3, 1.9, 4.3, 7.0 and 11.9at.% were successfully incorporated into biphasic calcium phosphate via a sol-gel route. The prepared powders were calcined at temperatures of 500-1200^oC. The X-ray diffraction analysis revealed that a mix phase comprising of hydroxyapatite and @b-tricalcium phosphate were present, however the content of each phases in the structure was affected by the Mn content. The studies found that the largest portion of @b-tricalcium phosphate was detected at 4.3at.% Mn doping. The incorporation of Mn has also greatly increased the crystallinity of the biphasic calcium phosphate powder due to progressive den...

2011-01-01

127

Development of Point Arguello field, offshore California  

Energy Technology Data Exchange (ETDEWEB)

Development drilling from Chevron-operated Platform Hermosa, located on OCS-P 0316 of the Point Arguello field, began on January 30, 1987. To date, seven development wells have been drilled in to the northwest-southeast-trending, doubly plunging anticlinal structure. The results from drilling have confirmed the presence of intense folding and fracturing in the targeted Monterey Formation. Over 700 ft of conventional core were recovered from the B-2 well in the lower Sisquoc and Monterey Formations. Analysis of the core material has yielded important information on lithologic variations and fracture patterns in the productive Monterey Formation. Initial results of core studies, DST data, and wireline studies indicate a correlation between rock type and fracturing. Fracture trends and directional permeability suggested by drill-stem testing may affect future drilling patterns in the field.

1988-03-01

128

Conductivity studies on commercially available proton-conducting membranes with different equivalent weight  

Energy Technology Data Exchange (ETDEWEB)

Two perfluorosulfonic acid membranes, Nafion{sup R} 105 and Nafion{sup R} 115 with the same thickness but different equivalent weights (EW = 1000 g/eq. resp. 1100 g/eq.) were characterised by conductivity measurements at different water vapour activities in the temperature range of 25-70{sup o}C. The results demonstrate that a lower membrane equivalent weight opens the possibility to obtain the needed proton conductivity at lower water vapour activity. This is especially important for those fuel cell applications, in which the cell is operated without external humidification of the fuel gases. (author) 5 figs., 5 refs.

1999-08-01

129

Comparison on the growth of oxide films formed in alloy 800 and alloy 600 in an aqueous medium at high temperature  

International Nuclear Information System (INIS)

Alloy 800 and Alloy 600 are well known for their resistance to corrosion in an aqueous medium at high pressure and temperature, for which they have been widely used for more than 3 decades in different structural components of water refrigerated nuclear reactors, especially as material for the steam generator tubes (SG) in these nuclear plants. The SG tubes in the Atucha I and Embalse Nuclear Plants are made with Alloy 800. The speed of corrosion of these materials in a reactor's refrigerant medium, while very small is perfectly measurable and can be described by parabolic or logarithmic type kinetics. In other words this speed is high in the first states of growth during the formation of a protective oxide film but then drops to almost stationary values. One characteristic of these films is the formation of a double layer (or duplex): i) an internal adhering layer, of approximately constant thickness, formed by small microcrystals (#<=#0.05 mm), ii) a less adhering external one, ...

2006-12-01

130

Comparison of sodium zirconium phosphate and Synroc matrices for immobilization of high-level waste  

Energy Technology Data Exchange (ETDEWEB)

The aims of the present work were to investigate possible compatibility between sodium zirconium phosphate (NZP) and Synroc titanate phases, to prepare NZP-based waste forms by hot-pressing rather than sintering, and to investigate the incorporation in NZP of (a) Cs/Sr as simulated heat-generating nuclides; (b) simulated actinides; and (c) simulated Purex waste. The NZP samples were prepared by methods similar to those used for Synroc. The precursor NZP phase was formed from tetrabutyl zirconate Zr(OC{sub 4}H{sub 9}){sub 4}, sodium nitrate, and 85% orthophosphoric acid. Simulated waste nitrate solutions were then mixed with the liquid precursor. After stir drying of the precursor, calcination was carried out at 700{degree}C to remove nitrates and organics.

1996-12-31

131

Comparative study of functional properties of commercial and membrane processed yellow pea protein isolates  

British Library Electronic Table of Contents (United Kingdom)

Functional properties of commercial and membrane processed pea protein isolates (PPI) prepared from yellow peas were investigated. Four protein isolates were prepared from yellow pea flour using water and KCl extractions at 25^oC followed by ultrafiltration and diafiltration (UF and DF) at pHs of 7.5 and 7.5 or 6 respectively. Following assessment of compositional attributes; solubility, foaming, flow and dynamic rheology, emulsification ability and heat-induced textural and rheological properties of prepared PPIs and a commercially available PPI were tested and compared. Membrane purification of proteins resulted in 28% to 68% reduction in phytic acid and enhanced, comparatively, the tested functional properties. Solubility of membrane processed PPIs, at all tested pHs, was superior and t...

2011-01-01

132

Colour contrast in ballistic gelatine  

British Library Electronic Table of Contents (United Kingdom)

Gelatine is a reliable tissue simulant in wound ballistic experiments. The projectile penetrating the gelatine transfers energy and causes radial cracks according to the temporary cavity. Thus the crack length is a function of the energy spent in the medium. In practice the fissures are poorly contrasted for which reason an enhancement of contrast was searched. A series of six shoots with expanding bullets (9mmx19 Action-5, 9mmx19 Quick Defense 1, 5.56mmx45 Styx Action) was realized on 10% gelatine blocks at 4^oC temperature. Three blocks were marked with acryl paint on the front, three blocks were shot native. The blocks were cut in slices of 1cm thickness and optically scanned. The evaluation was performed according to Fackler's wound profile, the total crack length method and the polygo...

2010-01-01

133

CO and CO2 emissions from spontaneous heating of coal under different ventilation rates  

British Library Electronic Table of Contents (United Kingdom)

Carbon monoxide (CO) and carbon dioxide (CO2) emissions during a spontaneous heating event in a coal mine are important gases to monitor for detecting the spontaneous heating at an early stage. However, in underground coal mines, the CO and CO2 concentrations and their related fire ratios may be affected by mine ventilation. In this study, CO and CO2 emissions from spontaneous heating of a U.S. coal sample were evaluated in an isothermal oven under different airflow ventilation rates ranging from 100 to 500cm^3/min. Laboratory experiments were conducted at oven temperatures of 70, 90, and 100^oC. The temperature at the center of the coal sample was continually monitored, while the CO, CO2, and oxygen (O2) concentrations of the exit gas were continually measured. The results indicate that C...

2011-01-01

134

Biosorption of Acid Blue 25 by unmodified and CPC-modified biomass of Penicillium YW01: Kinetic study, equilibrium isotherm and FTIR analysis  

British Library Electronic Table of Contents (United Kingdom)

The main objective of this work was to investigate the biosorption performance of unmodified and Cetylpyridinium chloride (CPC)-modified biomass of Penicillium YW 01 for Acid Blue 25 (AB 25). Maximum biosorption capacity of AB 25 onto CPC-modified biosorbent was 118.48mgg^-^1 under phosphoric-phosphate buffer with initial dye concentration of 200mgL^-^1 at 30^oC. The biosorption pattern of AB 25 onto unmodified biosorbent in aqueous solution and phosphoric-phosphate buffer was well fitted with both Langmuir and Freundlich isotherm models. While the equilibrium data of CPC-modified biosorbent in aqueous solution and phosphoric-phosphate buffer failed to fit the Freundlich isotherm model, indicating the monolayer biosorption formed onto CPC-modified biosorbent. The values of initial biosorpt...

2011-01-01

135

Biomass tar recycling and destruction in a CFB gasifier  

Energy Technology Data Exchange (ETDEWEB)

Conversion of biomass into producer gas by thermal gasification broadens the scope of biomass applications. Usually, tar has to be removed from the producer gas. Tar recycling within the gasification process may solve the associated waste problem and increase the system efficiency, provided tar is broken down under gasification conditions. We present results of tar recycling experiments at a Circulating Fluidised Bed gasifier. At 830{sup o}C, from each of 15 main tar compounds 70-80% are broken down. Continuous recycling of tar would increase the tar content in raw producer gas by 50% at most and save about 3% fuel input. 10 refs., 3 figs., 3 tabs.

2005-03-01

136

Application of photoelectrochemistry and impedance measurements to the study of passive films on AISI 304 stainless steel  

International Nuclear Information System (INIS)

In this work passive films formed in AISI 304 stainless steel were envisaged as semiconductors and studied by means of photoelectrochemistry and Mott-Schottky plots. The passive films were potentiostatically formed at different potentials (0.2-0.8V) in a basic borate/boric acid solution without and with addition of NaCl (0.5 and 1g/l) and at various temperatures in the range 8-60"oC. The influence of these parameters on the photocurrent, quantum efficiency, bandgap energy and density of charge carriers was determined. The results show that the experimental conditions at which the films are formed influence the semiconductive properties of the film, which seem to be related to the higher or lower stability of the film. An Arrhenius type of relationship was also found between the density of charge carriers and temperature, leading to the determination of an activation energy. (author) 13 refs., 7 figs.

1988-07-01

137

Application of 14C analyses to source apportionment of carbonaceous PM2.5 in the UK  

British Library Electronic Table of Contents (United Kingdom)

Determination of the radiocarbon (14C) content of airborne particulate matter yields insight into the proportion of the carbonaceous material derived from fossil and contemporary carbon sources. Daily samples of PM2.5 were collected by high-volume sampler at an urban background site in Birmingham, UK, and the fraction of 14C in both the total carbon, and in the organic and elemental carbon fractions, determined by two-stage combustion to CO2, graphitisation and quantification by accelerator mass spectrometry. OC and EC content was also determined by Sunset Analyzer. The mean fraction contemporary TC in the PM2.5 samples was 0.50 (range 0.27-0.66, n=26). There was no seasonality to the data, but there was a positive trend between fraction contemporary TC and magnitude of SOC/TC ratio and fo...

2011-01-01

138

Analysis of the operating conditions influence on PEM fuel cell performances by means of a novel semi-empirical model  

British Library Electronic Table of Contents (United Kingdom)

The present paper concerns the development of a polymer electrolyte membrane (PEM) fuel cells model in order to analyse the behaviour of the cell varying its operating parameters such as temperature (70-120 ^oC), pressure (1-3 atm), relative humidity (35-100%) and CO content (0-200 ppm) in the feeding gas. The voltage output and the relative current of a generic PEM fuel cell has been predicted through a mathematical method based on semi-empirical correlations derived from the experimental data available in literature. The model has been implemented in a commercial process simulator (AspenPlus) and it has been validated by comparing the obtained results with further experimental data (not utilized for the model development). The comparison has underlined a good agreement with the experimen...

2011-01-01

139

Abces du muscle iliopsoas : complication rare de la sacro-iliite a pyogene chez lenfant  

British Library Electronic Table of Contents (United Kingdom)

Pyogenic sacroiliitis is a rare entity in children. Diagnosis is often delayed because of its variable clinical presentation, low suspicion by the examining physician, and rare findings on radiographs. Delayed diagnosis, however, results in complications such as iliopsoas abscess. We report the case of a 12-year-old girl hospitalized with a 21-day history of fever, pain in the left iliac fossa, and flexion contracture of the hip. On examination, she had fever (38.9 ^oC), psoitis, localized tenderness at the left sacroiliac joint, and pain elicited by lateral compression of the pelvis. The abdominal examination was normal. The erythrocyte sedimentation rate was 130mm in the first hour, C-reactive protein was 186mg/l, and the white blood cell count was 18,400/mm^3, with 79% neutrophils. Urin...

2010-01-01

140

A simple one-step fabrication of micrometer-scale hierarchical TiO2 hollow spheres  

British Library Electronic Table of Contents (United Kingdom)

Hierarchical TiO2 hollow spheres had been prepared based on bubble templates by a simple one-step hydrothermal method. The diameter of hollow spheres was about 700nm and the shell thickness of them was 69nm. They were composed of similar spindle- or needle-like building units. Furthermore, hydrothermal time had an important influence on the morphology and crystallinity of hollow spheres. Moreover, the UV-Vis diffuse reflectance spectra of TiO2 hollow spheres heated at 150^oC for 10h showed the strongest absorption in the UV-Vis region and the Raman spectrum demonstrated the anatase sample. Additionally, a possible formation mechanism of TiO2 hollow spheres was proposed. So this novel and simple method would provide a development direction to fabricate all kinds of inorganic hollow spheres ...

2010-01-01

141

A parametric study on the exergoeconomic assessment of a vertical ground-coupled (geothermal) heat pump system  

Energy Technology Data Exchange (ETDEWEB)

An exergoeconomic model of a vertical ground-source heat pump residential heating system presented in this study uses exergy and cost energy mass (EXCEM) methods. The data obtained from a ground-source heat pump (GSHP) residential heating system installed at the Solar Energy Institute, Ege University, Turkey, are utilized for calculations at different reference temperature values in the range 0-25{sup o}C. The performance of the geothermal heat pump residential heating system is evaluated to indicate how exergoeconomic parameter values change with system. We also undertake a parametric study to investigate how varying reference temperatures will affect the exergoeconomic analysis of the GSHP system. A correlation between the ratio of thermodynamic loss rate to capital cost and reference state temperature is developed. (author)

2007-03-15

142

A novel single-step synthesis of N-doped TiO"2 via a sonochemical method  

British Library Electronic Table of Contents (United Kingdom)

A novel single-step synthetic method for the preparation of anatase N-doped TiO"2 nanocrystalline at low temperature has been devoleped. The N-doped anatase TiO"2 nanoparticles were synthesized by sonication of the solution of tetraisopropyl titanium and urea in water and isopropyl alcohol at 80^oC for 150min. The as-prepared sample was characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and UV-vis absorption spectrum. The product structure depends on the reaction temperature and reaction time. The photocatalytic activity of the as-prepared photocatalyst was evaluated via the photodegradation of an azo dye direct sky blue 5B. The results show that the N-doped TiO"2 nanocrystalline prepared via sonication exhibit an excellent photocatalytic...

2011-01-01

143

Thermal energy storage performance of fatty acids as a phase change material  

Energy Technology Data Exchange (ETDEWEB)

Thermal energy storage performance of fatty acids and a eutectic mixture as phase change materials (PCMs) has been investigated experimentally. The selected PCMs for this study were palmitic acid, myristic acid, stearic acid, and a mixture of stearic and myristic acids in eutectic combination ratio of 65.7 wt% myristic acid and 34.3 wt% stearic acid. The PCMs have a melting temperature range of 50.0{sup o}C to 61.20{sup o}C and a latent heat range of 162.0 J/g to 204.5 J/g. The inlet temperature and the mass flow rate of heat transfer fluid (HTF) were selected as experimental parameters to test the thermal energy storage performance of the PCMs. The transition times, temperature range, propagation of the solid-liquid interface, as well as heat flow rate characteristics of the employed cylindrical tube storage system were studied at varied experimental parameters. The experimental results show that the melting front moves to inward in the radial ...

2006-01-21

144

Scope and construction of a gas and oil atlas series of the Gulf of Mexico: Examples from Texas offshore lower Miocene plays  

Energy Technology Data Exchange (ETDEWEB)

An atlas series about the offshore northern Gulf of Mexico will group gas and oil reservoirs into subregional plays and will display reservoir data on a computerized geographical information system. The atlas series will provide critically compiled reservoir engineering data to help the private sector explore and develop hydrocarbons and to help the public sector analyze the hydrocarbon endowment in this basin. In this report, we cover aspects of the play-analysis procedure and provide specific examples of lower Miocene plays from the upper Texas coast and Federal Outer Continental Shelf (OCS). Play analysis emphasizes using broad classes of structural style, depositional style and environments, and defining attributes to group reservoirs into plays. To date, we have identified 4 Oligocene and 25 Miocene plays in Texas State offshore waters and 115 plays in the Federal OCS. Texas State offshore plays are gas prone (cumulative production 3.7 ...

1994-12-31

145

Preparation and characteristics of rice-straw-based porous carbons with high adsorption capacity  

Energy Technology Data Exchange (ETDEWEB)

To prepare porous carbons with high adsorption capacity from rice straws, two different kinds of precursors, i.e. one as the raw rice straws (one-stage process) and the other as pre-carbonized rice straws (two-stage process), were active with KOH of various impregnation ratios. The two-stage process was found very effective for manufacturing porous carbons with high surface area and adsorption capacities for MB and I{sub 2}. For example, the porous carbon that was carbonized at 700{sup o}C and subsequently activated at 900{sup o}C exhibited the surface area of 2410 m{sup 2}/g, the adsorption capacities of 800 and 1720 mg/g for MB and I{sub 2}, respectively, and the total pore volume of 1.4 ml/g. In the two-stage method, there was a preferential optimum impregnation ratio of KOH to a precursor carbon, i.e. 4:1, with which high surface area of porous carbons could be achieved. The formation of uni- and bidentate carboxylic salt structure, induced ...

2002-02-01

146

Novel pseudo-morphotactic synthesis and characterization of tungsten nitride nanoplates  

International Nuclear Information System (INIS)

A novel pseudo-morphotactic transformation route was developed to synthesize polycrystalline ?-W2N nanoplates by thermally treating tungstate-based inorganic-organic hybrid nanobelts with a lamellar microstructure in an NH3 flow. The tungstate-based hybrid nanobelts were formed in a water-in-oil-microemulsion-like 'commercial H2WO4 powders/n-octylamine/heptane' reaction system. The as-obtained hybrid nanobelts were thermally treated in an NH3 atmosphere at 650-800 oC for 2 h to form cubic ?-W2N nanoplates. XRD, SEM, TEM, FT-IR and TG-DTA were used to characterize the precursors and their final products. The polycrystalline ?-W2N nanoplates derived from hybrid nanobelts, with side lengths of several hundred nanometers, consist of small nanocrystals with an average grain size of 3.2 nm. The formation of ?-W2N nanoplates involved two steps: decomposing tungstate-based hybrid nanobelts into WOy and W species and then nitridizing the active W-containing species to ?-W2N ...

2011-02-01

147

Investigation of amine amino acid salts for carbon dioxide absorption  

Energy Technology Data Exchange (ETDEWEB)

The carbon dioxide capture potential of amine amino acid salts (AAAS), formed by mixing equinormal amounts of amino acids; e.g. glycine. B-alanine and sarcosine, with an organic base; 3-(methylamino)propylamine (MAPA), was assessed by comparison with monoethanolamine (MEA), and with amino acid salt (AAS) from amino acid neutralized with an inorganic base; potassium hydroxide (KOH). Carbon dioxide absorption and desorption experiments were carried out on the solvent systems at 40{sup o}C and 80{sup o}C respectively. Experimental results showed that amine amino acid salts have similar CO{sub 2} absorption properties to MEA of the same concentration. They also showed good signs of stability during the experiments. Amino acid salt from an inorganic base, KOH, showed lower performance in CO{sub 2} absorption than the amine amino acid salts (AAAS) mainly due to a lower equilibrium temperature sensitivity. AAAS showed better performance than MEA of ...

2010-09-15

148

Investigation of (CeO_2)_x(Sc_2O_3)_(_0_._1_1_-_x_)(ZrO_2)_0_._8_9 (x = 0.01-0.10) electrolyte materials for intermediate-temperature solid oxide fuel cell  

International Nuclear Information System (INIS)

Oxide ionic conductivities of (CeO_2)_x(Sc_2O_3)_(_0_._1_1_-_x_)(ZrO_2)_0_._8_9 (x = 0.01-0.10) electrolytes were optimized for the application in intermediate-temperature solid oxide fuel cell (IT-SOFC). Powders with different contents of CeO_2 and Sc_2O_3 were prepared via a co-precipitation method. The obtained powders and pellets were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and impedance spectroscopy. Among all the compositions, (CeO_2)_0_._0_4(Sc_2O_3)_0_._0_7(ZrO_2)_0_._8_9(4Ce7ScZr) gives the highest ionic conductivity of 0.065 S cm"-"1 at 800 "oC. The effects on densification and electrical properties of different sintering additives, such as SiO_2, MgO, Co_3O_4, MoO_3 and Bi_2O_3, were studied and different conducting behavior with these additives were observed. The densification temperatures of CeO_2 and Sc_2O_3 co-doped electrolytes can be reduced by around 280 ...

2010-07-23

149

Characterization of activated carbon prepared from chicken waste and coal  

Energy Technology Data Exchange (ETDEWEB)

Activated carbons (ACs) were prepared from chicken waste (CW) and coal (E-coal) blended at the ratios of 100:0, 80:20, 50:50, 20:80, and 0:100. The process included carbonization in flowing gaseous nitrogen (300 mL min{sup -1}) at ca. 430{sup o}C for 60 min and successive steam activation (0.1 mL min{sup -1} water injection with a flow of N{sub 2} at 100 mL min{sup -1}) at 650{sup o}C for 30 min. Chicken waste is low in sulfur content but is high in volatile matter (about 55 wt %), and ACs with higher specific surface area were more successfully obtained by mixing with coal. The specific surface area of the CW/Coal blend AC can be estimated by SSA{sub BET} = -65.8x{sup 2} + 158x + 168, where SSA{sub BET} is the specific surface area in m{sup 2} g{sup -1} as determined by the BET method using CO{sub 2} as the adsorbent, where x is the coal fraction by weight in the CW/coal blend ranging from 0.0 to 1.0 (e.g., x = 0.0 signifies the blend contains ...

2007-12-15

150

Cement-clay pastes for stabilization/solidification of 2-chloroaniline  

International Nuclear Information System (INIS)

Immobilization of a model liquid organic pollutant, i.e. the 2-chloroaniline (2-CA), into a cement matrix using organoclays as pre-sorbent agents was investigated. Five cement-clay pastes were prepared with different nominal water-to-cement ratios (w/c=0.40, 0.25 and 0.15 wt/wt) and various amounts of waste (waste-to-cement o/c=0.20, 0.60 and 1.00 wt/wt); for comparison, a neat cement paste was also prepared. Dynamic leach tests were performed on solidified monoliths in order to assess the successful immobilization of the 2-CA. In monoliths at constant w/c ratio (0.40) the total amount of pollutant released increases with its initial content, and ranges from 15 to 35% with respect to it. By lowering w/c from 0.40 to 0.15 at constant o/c, the performances improved (<25% released). The microstructure of the hardened cement-clay pastes was characterized by quantitative X-ray diffraction (QXRD) and electronic microscopy (SEM-EDS) techniques; ...

2004-01-01

151

Catalytic wet air oxidation of phenol over CeO{sub 2}-TiO{sub 2} catalyst in the batch reactor and the packed-bed reactor  

Energy Technology Data Exchange (ETDEWEB)

CeO{sub 2}-TiO{sub 2} catalysts are prepared by coprecipitation method, and the activity and stability in the catalytic wet air oxidation (CWAO) of phenol are investigated in a batch reactor and packed-bed reactor. CeO{sub 2}-TiO{sub 2} mixed oxides show the higher activity than pure CeO{sub 2} and TiO{sub 2}, and CeO{sub 2}-TiO{sub 2} 1/1 catalyst displays the highest activity in the CWAO of phenol. In a batch reactor, COD and TOC removals are about 100% and 77% after 120 min in the CWAO of phenol over CeO{sub 2}-TiO{sub 2} 1/1 catalyst at reaction temperature of 150 {sup o}C, the total pressure of 3 MPa, phenol concentration of 1000 mg/L, and catalyst dosage of 4 g/L. In a packed-bed reactor using CeO{sub 2}-TiO{sub 2} 1/1 particle catalyst, over 91% COD and 80% TOC removals are obtained at the reaction temperature of 140 {sup o}C, the air total pressure of 3.5 MPa, the phenol concentration of 1000 mg/L for 100 h continue reaction. Leaching ...

2008-05-30

152

Catalytic effect of niobium oxide on hydrogen storage properties of mechanically ball milled MgH{sub 2}  

Energy Technology Data Exchange (ETDEWEB)

We examined a catalytic effect of niobium oxide (Nb{sub 2}O{sub 5}) on the hydrogen storage properties of MgH{sub 2} prepared by mechanical ball milling method. The MgH{sub 2} composite doped with 1 mol% Nb{sub 2}O{sub 5} by ball milling for 20 h desorbed hydrogen up to {approx}6 mass% in the temperature range from 200 to 250 {sup o}C at the heating rate of 5 {sup o}C/min under a purified helium flow. After dehydrogenation at 200 {sup o}C, the product showed remarkable hydrogen absorption kinetics. A large amount of gaseous hydrogen up to {approx}4.5 mass% was absorbed even at room temperature under 1 MPa hydrogen pressure within 15 s and finally its capacity reached up to 5 mass%. Furthermore, the valence state of Nb{sub 2}O{sub 5} doped in MgH{sub 2} was examined by X-ray absorption near edge structure (XANES) measurement. The results indicated that additive Nb{sub 2}O{sub 5} was reduced by MgH{sub 2} during mechanical milling. This suggests ...

2006-08-15

153

Carbon dioxide absorption with aqueous potassium carbonate promoted by piperazine  

Energy Technology Data Exchange (ETDEWEB)

Many commercial processes for the removal of carbon dioxide from high-pressure gases use aqueous potassium carbonate systems promoted by secondary amines. This paper presents thermodynamic and kinetic data for aqueous potassium carbonate promoted by piperazine. Research has been performed at typical absorber conditions for the removal of CO{sub 2} from flue gas. Piperazine, used as an additive in 20-30 wt% potassium carbonate, was investigated in a wetted-wall column using a concentration of 0.6 m at 40-80{sup o}C. The addition of 0.6 m piperazine to a 20 wt% potassium carbonate system decreases the CO{sub 2} equilibrium partial pressure by approximately 85% at intermediate CO{sub 2} loading. The distribution of piperazine species in the solution was determined by proton NMR. Using the speciation data and relevant equilibrium constants, a model was developed to predict system speciation and equilibrium. The addition of 0.6 m piperazine to 20 wt% potassium carbonate ...

2004-09-01

154

Carbon dioxide absorption with aqueous potassium carbonate promoted by piperazine  

Energy Technology Data Exchange (ETDEWEB)

This paper presents thermodynamic and kinetic data collected for aqueous blends of piperazine (PZ), an ethylamine, and potassium carbonate (K{sub 2}CO{sub 3}). Mixtures of K{sup +} and PZ have been investigated in a wetted-wall column at 40 to 80{sup o}C, typical conditions for an industrial absorber. The addition of 0.6 m PZ to 20 wt% (3.6 m) K{sub 2}CO{sub 3} increases the rate of CO{sub 2} absorption by a factor of ten from the value in unpromoted solutions at 60{sup o}C. The addition of PZ increases the heat of absorption from 4 kcal/mol in 3.6 m K{sup +} to 10 kcal/mol when 0.6 m PZ is added. The capacity, ranging from 0.4 to 0.7 mol-CO{sub 2}/kg-H{sub 2}O, approaches that of monoethanolamine (MEA) solutions and seems to be a strong function of K{sup +} concentration. Speciation of the solution was obtained using proton nuclear magnetic reasonance (NMR), verifying and quantifying the presence of three PZ species. An equilibrium model and a ...

2003-07-01

155

Caldicellulosiruptor obsidiansis sp. nov., an anaerobic, extremely thermophilic, cellulolytic bacterium isolated from Obsidian Pool, Yellowstone National Park  

Energy Technology Data Exchange (ETDEWEB)

A novel, obligately anaerobic, extremely thermophilic, cellulolytic bacterium, designated OB47T, was isolated from Obsidian Pool, Yellowstone National Park, WY, USA. The isolate was a non-motile, non-spore forming, Gram-positive rod approximately 2 m long by 0.2 m wide and grew at temperatures between 55-85oC with the optimum at 78oC. The pH range for growth was 6.0-8.0 with values of near 7.0 being optimal. Growth on cellobiose produced the fastest specific growth rates at 0.75 hr-1. The organism also displayed fermentative growth on glucose, maltose, arabinose, fructose, starch, lactose, mannose, sucrose, galactose, xylose, arabinogalactan, Avicel, xylan, filter paper, processed cardboard, pectin, dilute acid-pretreated switchgrass and Populus. OB47T was unable to grow on mannitol, fucose, lignin, Gelrite, acetate, glycerol, ribose, sorbital, carboxymethylcellulose and casein. Yeast extract stimulated growth and thiosulfate, sulfate, nitrate, ...

2010-02-01

156

An example of alkalization of SiO{sub 2} in a blast furnace coke  

Science.gov (United States)

Scanning electron microscopy and an electron-microprobe analysis of a sample of blast furnace (BF) coke have revealed alkalization (5.64 wt % Na{sub 2}O + K{sub 2}O) and Al saturation (17.28 wt % Al{sub 2}O{sub 3}) of SiO{sub 2} by BF gases. The K/Na{sub at} value of 1.15 in the new phase (alteration zone) reflects close atomic proportions of the elements and suggests that the abilities to incorporate K and Na during the process are almost equal. This Al saturation and alkalization of SiO{sub 2} indicates an active role for Al along with alkali metals in BF gases. The average width of the altered area in the SiO{sub 2} grain is about 10 m, which suggests that SiO{sub 2} particles of that size can be transformed fully to the new phase, provided that at least one of their faces is open to an external pore (surface of the coke) or internal pore with circulating BF gases. The grains that exceed 10 {mu}m can only be partly altered, which means that smaller SiO{sub 2} grains can incorporate ...

2007-09-15

157

XPS/AES Study of Electrical and Chemical Properties of Pd/SiC Interface  

Science.gov (United States)

Silicon carbide (SiC) based electronic devices are of great importance for applications under the condition of high temperature, high power and high radiation. Schottky diodes of Palladium/SiC are good candidates for hydrogen and hydrocarbon gas sensors at elevated temperature. The detection sensibility of the diodes has been found heavily temperature dependent. In this work, the electrical and chemical properties of Pd/SiC Schottky contacts were studied by XPS and AES at different annealing temperatures. Schottky diodes were made by depositing ultra-thin palladium films onto a silicon carbide substrate. No significant change in the Schottky barrier height of the Pd/SiC contact was found in the temperature range of 300-673K. Palladium diffusion into SiC and the formation of palladium silicides were observed at room temperature and became significant at 300^oC and higher temperature. The mechanism of diffusion and reaction at the Pd/SiC interface will be discussed. ...

1997-11-01

158

Water-soluble cis-[(NHC)PdBr2(TPPTS)] catalysts and their applications in Suzuki-Miyaura coupling of aryl chlorides  

British Library Electronic Table of Contents (United Kingdom)

New palladium(II) complexes (2), bearing NHC/TPPTS ligands, (NHC=benzimidazol-2-ylidene; TPPTS=triphenylphosphine-3,3',3''-trisulfonic acid trisodium salt) have been prepared and characterized by elemental analyses and spectroscopic methods. Their ability to catalyze the Suzuki-Miyaura reaction in neat water has been studied at 100^oC. Very high activities have been observed in the coupling of phenylboronic acid with aryl chlorides in the presence of 1% of the catalyst. We have compared the electronic properties of cis-[PdBr2(NHC)(TPPTS)] with the related complexes, [PdX2(NHC)]2 and [trans-PdBr2(NHC)(pdca)] (pdca=pyridine-2,6-dicarboxyic acid) (3) via three different techniques: cyclic voltammetry, thermogravimetric analysis and ^1^3C NMR spectroscopy.

2011-01-01

159

Use of boron waste as a fluxing agent in production of red mud brick  

Energy Technology Data Exchange (ETDEWEB)

The study was directed towards determining the usability of clay and fine wastes (CW and FW) of boron from the concentrator plant in Kirka (Turkey) as a fluxing agent in production of red mud (RM) brick. Both laboratory studies on the characterization of materials and industrial-scale tests for production of bricks were carried out. CW and FW, which have similar chemical composition but include different types and amounts of oxides, were added in amounts of 5, 10 and 15wt% to RM, which consists of high amounts of Fe{sub 2}O{sub 3}, Al{sub 2}O{sub 3}, SiO{sub 2} and alkalies. Six different sets of samples have been produced and fired at 700, 800 and 900{sup o}C. Dry shrinkage of green body, bending and compressive strength, firing shrinkage, water absorption, frost resistance and harmful magnesia and lime tests on heat-treated bodies have been performed. The mineralogical and mechanical tests showed that usability of boron wastes as a fluxing agent in the production ...

2006-12-15

160

Uplink Capacity and Interference Avoidance for Two-Tier Cellular Networks  

CERN Document Server

This paper presents an uplink capacity analysis and interference avoidance technique for a femtocell based two-tier DS-CDMA network using shared spectrum. Assuming randomly distributed macrocell users and femtocell base stations (BS), we evaluate a network-wide area spectral efficiency metric called the operating contour (OC) defined as the feasible combinations of the average macrocell users and femtocell BS per cell-site that meet a target outage constraint $\\epsilon$. A contribution of this work is an accurate characterization of the uplink outage probability taking cross-tier power control, path-loss and shadowing effects into account. We show that a time-hopped CDMA physical layer coupled with sectorized receive antennas shows dramatic performance improvements in both light and heavily loaded two-tier networks, relative to a split spectrum two-tier network with omnidirectional femtocell antennas. These results provide insights into design of robust shared ...

2007-01-01

161

Type of brown coal from North-Bohemian basin effect to quality of pyrolysis products  

Energy Technology Data Exchange (ETDEWEB)

By increasing the price of crude oil and natural gas and the decline in their stock a possibility of more intense use of coal reserves as a feedstock not only for energy purposes but also as a feedstock source for other industries, mainly chemical and steel industry, is opening up. At present brown coal exploited in the Czech Republic is explicitly burned in the power sources of various outputs. Coal pyrolysis under the defined conditions may be an outstanding way of non-energetic brown coal processing. The target of our work was to determine the behaviour of various types of brown coal from the North Bohemian Basin under the pyrolysis up to the temperature 750{sup o}C. At the same time, qualitative parameters of the pyrolysis products in dependence on the features of the input brown coal were observed. Various types of brown coal were used for the pyrolysis tests differing mainly in the content of ash, sulphur and tar. Within the work mass balances of the incurred ...

2005-07-01

162

Tribological and corrosion testing of surface engineered surgical grade CoCrMo alloy  

British Library Electronic Table of Contents (United Kingdom)

One of the main causes of hip prostheses failure is the premature wear of its components. Wear of metal-on-metal joints is a concern due to the toxicity and biological reaction of wear debris and metallic corrosion. The main aim of the present study was to investigate the tribological and corrosion behavior of surface engineering CoCrMo alloy. Different surface conditions were obtained on surgical grade wrought CoCrMo alloy: plasma nitrided (520^oC by 7h at gas mixture of 10% N2+90% H2), PVD coated (monolayer CrN and multilayer (TiN/CrN)x3) and modified using duplex surface engineering technology (a combination of the two previous approaches: plasma nitriding followed by plasma assisted PVD). Surfaces were characterized using scanning electron microscopy, nanoindentation, AFM and scratch t...

2011-01-01

163

Thermal reliability test of some fatty acids as PCMs used for solar thermal latent heat storage applications  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this study is to determine the thermal reliability of stearic acid, palmitic acid, myristic acid and lauric acid as latent heat energy storage materials with respect to various numbers of thermal cycles. The fatty acids, as phase change materials (PCMs), of industrial grade (purity between 90% and 97%) were subjected to accelerated thermal cycle tests. The differential scanning calorimetry (DSC) analysis technique was applied to the PCMs after 0, 120, 560, 850 and 1200 melt/freeze cycles in order to measure the melting temperatures and the latent heats of fusion of the PCMs. The DSC results indicated that the change in melting temperature for the PCMs was in the range of 0.07-7.87 {sup o}C, and the change in latent heat of fusion was -1.0% to -27.7%, except for stearic acid between 560 and 1200 melt/freeze cycles. However, the decrease in the latent heats of fusion for all the PCMs was not regular with increasing thermal cycles. The experimental ...

2003-08-01

164

The preparation of neem oil microemulsion (Azadirachta indica) and the comparison of acaricidal time between neem oil microemulsion and other formulations in vitro  

British Library Electronic Table of Contents (United Kingdom)

The preparation of neem oil microemulsion and its acaricidal activity in vitro was developed in this study. In these systems, the mixture of Tween-80 and the sodium dodecyl benzene sulfonate (SDBS) (4:1, by weight) was used as compound surfactant; the mixture of compound surfactant and hexyl alcohol (4:1, by weight) was used as emulsifier system; the mixture of neem oil, emulsifier system and water (1:3.5:5.5, by weight) was used as neem oil microemulsion. All the mixtures were stired in 800rpm for 15min at 40^oC. The acaricidal activity was measured by the speed of kill. The whole lethal time value of 10% neem oil microemulsion was 192.50min against Sarcoptes scabiei var. cuniculi larvae in vitro. The median lethal time value was 81.7463min with the toxicity regression equations of Y=-6.0...

2010-01-01

165

The CO{sub 2} gasification kinetics of olive residue  

Energy Technology Data Exchange (ETDEWEB)

Orujillo, sometimes called wood matter from pressed oil-stone (WPOS) is a residue from the olive oil mill industry. The generation of this biomass residue is concentrated in small areas allowing its use as fuel for medium size gasification and combustion plants. Rates of gasification of WPOS char were measured in a TGA at various temperatures (800-850-875-900-950{sup o}C), CO{sub 2} partial pressures (0.20-0.35-0.50 bar) and CO partial pressures (0.0-0.20 bar). The experiments were carried out with a monolayer bed of very fine particles well exposed to the gas so as to minimise mass and heat transfer resistances. Two kinetic models, the nth order model and Langmuir-Hinshelwood model, have been used to fit with the reactivity data. For pure CO{sub 2} experiments the kinetic parameters of nth order model were E=133 kJ/mol and n=0.43. The Langmuir-Hinshelwood kinetic model clearly describes the observed CO inhibition effect on the CO{sub 2} gasification.(author)

2003-02-01

166

Tantalum capping on platinum thin heater for selective area heating  

Energy Technology Data Exchange (ETDEWEB)

The thermal radiation which generated from the patterned Ta/Pt/Ta thin heater achieved a high temperature up to 1010 {sup o}C under applied current of 2.4 A. In order to reduce an electromigration at high current of 2 A, a Ta capping layer was placed on the Pt layer instead of conventional capping layer, such as SiNx and CoWP. Under the thermal radiation at the applied current of 2 A in the Ta/Pt/Ta thin heater, the Ta capping layer enhanced the lifetime of the Pt thin heater up to 5 h. A stamping process for the crystallization of a-Si was performed for 40 samples using the Ta/Pt/Ta thin heater. For all samples, a-Si has been selectively crystallized and Raman peaks were located near 519 cm{sup -} {sup 1}. These results indicated that the thermal radiation of the Ta/Pt/Ta thin heater was maintained constantly due to the Ta capping.

2009-05-29

167

Synthesis and electrochemical performance of carbon nanofiber-cobalt oxide composites  

Energy Technology Data Exchange (ETDEWEB)

Carbon nanofiber (CNF) supported cobalt oxide composites as high-capacity anode materials were prepared through a facile, effective method for potential use in rechargeable lithium-ion batteries. The effects of the calcining temperature on the crystallinity, grain size, specific surface area of Co{sub 3}O{sub 4} and phase transformation from Co{sub 3}O{sub 4} to CoO were studied in detail. Both the specific surface area and CNF content in CNF-cobalt oxide composites strongly affect the electrochemical performance of these series composites. The CNF-Co{sub 3}O{sub 4} composite with 24.3% CNF pyrolyzed at 500{sup o}C in Ar shows an excellent cycling performance, retaining a specific capacity of 881 mAh g{sup -1} beyond 100 cycles. Homogeneous deposition and distribution of nanosized Co{sub 3}O{sub 4} particles on the surface of CNF can stabilize the electronic and ionic conductivity as well as the morphology of Co{sub 3}O{sub 4} phase, which may be the main reason ...

2008-10-15

168

Supercritical fluid extraction from dried banana peel (Musa spp., genomic group AAB): Extraction yield, mathematical modeling, economical analysis and phase equilibria  

British Library Electronic Table of Contents (United Kingdom)

Supercritical fluid extraction from dried banana peel (Musa spp., subgroup Prata, genomic group AAB, popularly known in Brazil as Enxerto) was studied. The aspects investigated were: overall extraction curve (OEC), mass transfer modeling of the yield curves, economical analysis of the process and phase equilibrium data for the pseudo-ternary system of banana peel extract, carbon dioxide and ethanol. The extraction operating conditions evaluated were: pressure ranging from 100bar to 300bar, temperature from 40 to 50^oC and constant solvent flow rate of 5.0gCO2/min. Experimental extraction data were correlated using three kinetic models based on mass transfer equations (logistic, diffusion and Esquivel models). Phase equilibrium measurements were performed using pressure from 64.9bar to 239....

2010-01-01

169

Studies on thermal degradation and termite resistant properties of chemically modified wood  

Energy Technology Data Exchange (ETDEWEB)

A series of experiments were carried out to examine the resistant capacity of a chemically treated hard wood, Anthocephalus cadamba (Roxb) Miq. to thermal and termite degradation. The treatment with thermosetting resins viz. urea formaldehyde (UF), melamine formaldehyde (MF) and phenol formaldehyde (PF) at 31-33 levels of weight percent gain (WPG) increased the strength property i.e. modulus of rupture (MOR) by 7.50-21.02% and stiffness i.e. modulus of elasticity (MOE) by 9.50-12.18% over the untreated one with no remarkable effect on specific gravity. The treated samples were found resistant to termite attack, while the untreated one was badly damaged by termites on 12 months' exposure to a termite colony. The thermal degradations of untreated and treated wood samples were studied using thermogravimetric (TGA) and differential thermogravimetric (DTG) techniques at heating rates 20 and 30 {sup o}Cmin{sup -1} in temperature range 30-650{sup o}C. The treated ...

2002-09-01

170

Stimulation of reactive dye removal by cyanobacteria in media containing triacontanol hormone  

British Library Electronic Table of Contents (United Kingdom)

In this study, Reactive Red, Remazol Blue, and Reactive Black B removal capacities of Synechocystis sp. and Phormidium sp. were investigated. The microorganisms were cultivated in 100ml BG 11 medium and incubated at 30^oC under continuous illumination (12.5wm^-^2 (2400lx)) for 20 days in plant growth chamber. Trials were carried out at pH 9.5 for Reactive Red, pH 8.5 for Remazol Blue and Reactive Black B removal in media without and with triacontanol (TRIA). Removal capacities of Synechocystis sp. and Phormidium sp. were found higher in media containing TRIA. So that, Synechocystis sp. and Phormidium sp. removed Reactive Red with 25.7% and 35.4%, Remazol Blue with 37.5% and 25.5%, and Reactive Black B with 29.2% and 28.3% yield at 25mgl^-^1 dye concentrations, respectively. There is no rep...

2009-01-01

171

Spark plasma sintered tantalum carbide-carbon nanotube composite: Effect of pressure, carbon nanotube length and dispersion technique on microstructure and mechanical properties  

British Library Electronic Table of Contents (United Kingdom)

TaC-4wt.% CNT composites were synthesized using spark plasma sintering. Two kinds of CNTs, having long (10-20mm) and short (1-3mm) length, were dispersed by wet chemistry and spray drying techniques respectively. Spark plasma sintering was carried out at 1850^oC at pressures of 100, 255 and 363MPa. Addition of CNTs leads to an increase in the density of 100MPa sample from 89% to 95%. Short CNTs are more effective in increasing the density of the composites whereas long CNTs are more effective grain growth inhibitors. The longer CNTs are more effective in increasing the fracture toughness and an increase up to 60% was observed for 363MPa sample. Hardness and elastic modulus are found to increase by 22% and 18% respectively for 100MPa samples by addition of long CNTs. Raman spectroscopy, SEM...

2011-01-01

172

Sorption of atrazine and phenanthrene by organic matter fractions in soil and sediment  

International Nuclear Information System (INIS)

Atrazine and phenanthrene (Phen) sorption by nonhydrolyzable carbon (NHC), black carbon (BC), humic acid (HA) and whole sediment and soil samples was examined. Atrazine sorption isotherms were nearly linear. The single-point organic carbon (OC)-normalized distribution coefficients (K_O_C) of atrazine for the isolated HA1, NHC1 and BC1 from sediment 1 (ST1) were 36, 550, and 1470 times greater than that of ST1, respectively, indicating the importance of sediment organic matter, particularly the condensed fractions (NHC and BC). Similar sorption capacity of atrazine and Phen by NHC but different isotherm nonlinearity indicated different sorption domains due to their different structure and hydrophobicity. The positive relationship between (O + N)/C ratios of NHC and atrazine log K_O_C at low concentration suggests H-bonding interactions. This study shows that sediment is probably a less effective sorbent for atrazine than Phen, implying that atrazine applied in ...

2010-12-01

173

Solid fuels in chemical-looping combustion using a NiO-based oxygen carrier  

Energy Technology Data Exchange (ETDEWEB)

The feasibility of using three different solid fuels in chemical-looping combustion (CLC) has been investigated using NiO as oxygen carrier. A laboratory fluidized-bed reactor system for solid fuel was used, simulating a chemical-looping combustion system by exposing the sample to alternating reducing and oxidizing conditions. In each reducing phase 0.2g of fuel was added to the reactor containing 20g oxygen carrier. The experiments were performed at 970{sup o}C. Compared to previously published results with other oxygen carriers the reactivity of the used Ni-particles was considerably lower for the high-sulphur fuel and higher for the low-sulphur fuel. Much more unconverted CO was released and the fuel conversion was much slower for high-sulphur fuel such as petroleum coke, suggesting that the nickel-based oxygen carrier was deactivated by the presence of sulphur. The NiO particles also showed good reactivity with methane and a syngas mixture of 50% H{sub 2} and ...

2009-11-15

174

SnO{sub 2} thin films morphological and optical properties in terms of the Boubaker Polynomials Expansion Scheme BPES-related Opto-Thermal Expansivity {psi}{sub AB}  

Energy Technology Data Exchange (ETDEWEB)

In this study, SnO{sub 2} thin films have been grown using spray pyrolysis technique on glass substrates under a substrate temperature (T{sub s} = 440 {sup o}C). The precursors were methanol CH{sub 4}O and anhydrous tin tetrachloride. XRD analyses yielded strong (1 1 0)-(1 0 1)-(2 0 0) X-ray diffraction peaks which are characteristics to tetragonal crystals. Atomic Force Microscopy (AFM) analyses showed the existence of clusters with particular pyramidal shapes. The main part of this study concerns the optical measurements of transmittance T({lambda}) and reflectance R({lambda}) spectra inside 250-1800 nm domain. Conjoint optical and thermal properties were deduced using the Amlouk-Boubaker Opto-Thermal Expansivity {psi}{sub AB}. The obtained value: {psi}{sub AB} {approx} 23.4 m{sup 3} s{sup -1} helped situating the performance of the as-grown SnO{sub 2} compound among most known PV-T oxides like ZnO and TiO{sub 2}.

2010-02-04

175

SnO2 thin films morphological and optical properties in terms of the Boubaker Polynomials Expansion Scheme BPES-related Opto-Thermal Expansivity ?AB  

International Nuclear Information System (INIS)

In this study, SnO2 thin films have been grown using spray pyrolysis technique on glass substrates under a substrate temperature (Ts = 440 oC). The precursors were methanol CH4O and anhydrous tin tetrachloride. XRD analyses yielded strong (1 1 0)-(1 0 1)-(2 0 0) X-ray diffraction peaks which are characteristics to tetragonal crystals. Atomic Force Microscopy (AFM) analyses showed the existence of clusters with particular pyramidal shapes. The main part of this study concerns the optical measurements of transmittance T(?) and reflectance R(?) spectra inside 250-1800 nm domain. Conjoint optical and thermal properties were deduced using the Amlouk-Boubaker Opto-Thermal Expansivity ?AB. The obtained value: ?AB ? 23.4 m3 s-1 helped situating the performance of the as-grown SnO2 compound among most known PV-T oxides like ZnO and TiO2.

2010-02-04

176

Reaction of solid sorbents with hydrogen chloride gas at high temperature in a fixed-bed reactor  

Energy Technology Data Exchange (ETDEWEB)

The gas-solid reaction and breakthrough curves in the fixed-bed reactor are of great importance, and being influenced by a number of factors makes the prediction of these factors a difficult problem. In this study, the reaction rate between solid sorbents and hydrogen chloride gas at high temperature was first investigated. On the basis of a fixed-bed reactor, the experimental results were analyzed by the shrinking core model of diffusion and surface chemical reaction control. The results showed that reaction rates of two sorbents with hydrogen chloride gas were controlled by the combination of the surface chemical reaction and diffusion of product layers, and the reaction rates nearly keep constant within 15 h of the initial reaction period and then decrease gradually. The results of the breakthrough curves show that solid sorbents in the fixed-bed reactor are capable of reducing the HCl level to near-zero levels at 550{sup o}C. The experimental results and ...

2005-12-01

177

Production of a cellulolytic enzyme system in mixed-culture solid-state fermentation of soybean hulls supplemented with wheat bran  

British Library Electronic Table of Contents (United Kingdom)

Solid-state fermentation of soybean hulls supplemented with wheat bran using a co-culture of Trichoderma reesei and Aspergillus oryzae was performed. Three parameters - initial moisture content, incubation temperature, and initial pH - were optimized in culture flasks using response surface methodology. Parameter optimization was carried out with respect to filter paper activity and b-glucosidase activity in the culture. Temperature of 30^oC, pH of 5, and moisture content of 70% were found to be optimum. Optimized parameters were used for laboratory scale-up in static tray fermenters. The maximum filter paper activity of 10.7FPU/g-ds and b-glucosidase of 10.7IU/g-ds were obtained after 96-h incubation period in static tray fermenters in agreement with optimized activities at shake flask le...

2010-01-01

178

Process model for carbothermic production of silicon metal  

Energy Technology Data Exchange (ETDEWEB)

This thesis discusses an advanced dynamical two-dimensional cylinder symmetric model for the high temperature part of the carbothermic silicon metal process, and its computer encoding. The situation close to that which is believed to exist around one of three electrodes in full-scale industrial furnaces is modelled. This area comprises a gas filled cavity surrounding the lower tip of the electrode, the metal pool underneath and the lower parts of the materials above. The most important phenomena included are: Heterogeneous chemical reactions taking place in the high-temperature zone (above 1860 {sup o}C), Evaporation and condensation of silicon, Transport of materials by dripping, Turbulent or laminar fluid flow, DC electric arcs, Heat transport by convection, conduction and radiation. The results from the calculations, such as production rates, gas- and temperature distributions, furnace- and particle geometries, fluid flow fields etc, are presented graphically. ...

1995-09-12

179

Preparation of CaWO{sub 4}:Ln{sup 3+} SiO{sub 2} (Ln=Tb, Dy and Ho) nanoparticles by a combustion reaction and their optical properties  

Energy Technology Data Exchange (ETDEWEB)

The CaWO{sub 4}:Ln{sup 3+} SiO{sub 2} (Ln=Tb, Dy and Ho) nanoparticles were synthesized via a combustion process at 800 {sup o}C, using citric acid as chelating agent and fuel, ammonium nitrate as fuel, boric acid as flux material and silica as supports. The persistent phosphor nanoparticles were characterized by X-ray diffraction (XRD), reflectance UV-vis and fluorescence spectroscopy (PL) and transmission electron microscopy (TEM) techniques. XRD patterns indicated that crystalline calcium tungstate with scheelite structure was produced. The reflectance UV-vis spectra showed the broad absorption band of WO{sub 4}{sup 2-} groups and the PL spectra showed the WO{sub 4}{sup 2-} wide excitation band, broad emission band of WO{sub 4}{sup 2-} and characteristic emissions of Ln{sup 3+} ions. The average particle sizes were determined by TEM, which are about 50 nm.

2010-11-15

180

Preparation of CaWO_4:Ln"3"+ SiO_2 (Ln=Tb, Dy and Ho) nanoparticles by a combustion reaction and their optical properties  

International Nuclear Information System (INIS)

The CaWO_4:Ln"3"+ SiO_2 (Ln=Tb, Dy and Ho) nanoparticles were synthesized via a combustion process at 800 "oC, using citric acid as chelating agent and fuel, ammonium nitrate as fuel, boric acid as flux material and silica as supports. The persistent phosphor nanoparticles were characterized by X-ray diffraction (XRD), reflectance UV-vis and fluorescence spectroscopy (PL) and transmission electron microscopy (TEM) techniques. XRD patterns indicated that crystalline calcium tungstate with scheelite structure was produced. The reflectance UV-vis spectra showed the broad absorption band of WO_4"2"- groups and the PL spectra showed the WO_4"2"- wide excitation band, broad emission band of WO_4"2"- and characteristic emissions of Ln"3"+ ions. The average particle sizes were determined by TEM, which are about 50 nm.

2010-11-01

181

Potential for geothermal development in Southern Poland  

Energy Technology Data Exchange (ETDEWEB)

This paper discusses the potential for geothermal energy use in the central part of Southern Poland, such as the availability of thermal aquifers and the techniques for putting the latter to practical use. The geological and geothermal features of the region are presented within the context of the existence of aquifers containing geothermal resources that could be used in space heating. Also discussed are the three main geological units where thermal waters are known to exist: the Carpathians, the Miechow Trough, and the Silesian-Cracow Monocline. Particularly favourable hydrogeological conditions exist in the Inner Carpathians, in the Podhale Trough, where there is already one geothermal company using geothermal energy, Geotermia Podhalanska S.A. Equally interesting from the geothermal point of view are the areas north of the Cracow-Tarnow line, where, in Mesozoic aquifers, water temperatures range from 20 to 60 {sup o}C. In this paper we propose technological ...

2004-06-01

182

Poncirin promotes osteoblast differentiation but inhibits adipocyte differentiation in mesenchymal stem cells.  

Science.gov (United States)

Poncirin, flavanone glycoside, isolated from the fruit of Poncirus trifoliata, has anti-bacterial and anti-inflammatory activities. In this study, the effects of poncirin on the differentiation of mesenchymal stem cells were investigated. The C3H10T1/2 mesenchymal stem cells and primary bone marrow mesenchymal stem cells were studied. In the C3H10T1/2 cells, poncirin prevented adipocyte differentiation, as demonstrated by inhibition of cytoplasm lipid droplet accumulation and peroxisome proliferator-activating receptor-? (PPAR-?) and CCAAT-enhancer-binding protein-? (C/EBP-?) mRNA expression. By contrast, poncirin enhanced the expression of the key osteogenic transcription factors, runt-related transcription factor 2 (Runx2) and transcriptional coactivator with PDZ-binding motif (TAZ). Poncirin also enhanced expression of the osteogenic marker genes including alkaline phosphatase (ALP) and osteocalcin (OC). Poncirin increased mineral nodule formation in primary ...

2011-05-01

183

Performance analysis on a hybrid air-conditioning system of a green building  

Energy Technology Data Exchange (ETDEWEB)

This paper presents the performance analysis on a hybrid air-conditioning system according to the hybrid building energy system of the green building demonstration project in Shanghai, in which a 150 m{sup 2} solar collector is used to power two 10 kW adsorption chillers, a vapor compression heat pump is used to cool air in the evaporating end while the condensing heating at about 80{sup o}C is fully used to regenerate a liquid desiccant dehumidification system. In the hybrid system, the sensible cooling to the air is treated mainly by solar adsorption cooling and vapor compression cooling, whereas the latent heat is treated by the liquid desiccant dehumidification system with regeneration from the condensing heat of the heat pump. The results show that the performance of this system is 44.5% higher than conventional vapor compression system at a latent load of 30% and this improving can be achieved by 73.8% at a 42% latent load. The optimal ratio of adsorption ...

2006-05-15

184

Novel alloys to improve the electrochemical behavior of zinc anodes for zinc/air battery  

Energy Technology Data Exchange (ETDEWEB)

In our continued efforts for improving the performance of zinc anodes for a Zn/air battery, we now report the preparation of three alloys and improved performances of anodes made up with these alloys. The alloys contained zinc, nickel, and indium with different weight percentages and were calcined at two different temperatures. Out of the six alloys, the alloy which has a composition of zinc 90%, nickel 7.5% and Indium 2.5% and fired at 500{sup o}C is found to be the best. In the case of the hydrogen evolution reaction, this alloy had its potential shifted to a more negative potential. As far as the cyclic voltammograms were concerned, the difference between the anodic and cathodic part was minimal when compared with other alloys. Surprisingly, this alloy had reversibility even after 100 cycles of the cyclic voltammogram. This is a clear indication that dendrite formation was reduced to a considerable extent. Images taken with a scanning electron microscope also ...

2006-10-06

185

Nomographs for H[sub 2]O-LiBr absorption-panel cooling systems  

Energy Technology Data Exchange (ETDEWEB)

Panel cooling of buildings offers energy savings over conventional space-cooling systems. We present a procedure for calculating the performance of H[sub 2]O-LiBr absorption-panel cooling systems, in which the evaporator is the panel itself. Nomographs have been developed for this approach. Under the conditions examined, the H[sub 2]O-LiBr absorption unit operates with a theoretical performance coefficient of about 90% and with a practically constant specific cooling capacity of 2394 kJ/kg H[sub 2]O. For common values of the parameters involved, the panel cooling power varies from 25 to 175 W/m[sup 2] and the cooling water mass-flow through the panel is 40-260 g/m[sup 2]h. The thermal power needed to drive the system varies from 27 to 200 W/m[sup 2] and the associated temperatures from 70 to 100[sup o]C; thus, the system may be operated on solar energy. (Author).

1992-11-01

186

Nant-De-Chatillon: electric power generation by ORC (organic Rankine cycle) using waste heat from the Chatillon biogas plant; Nant-de-Chatillon: Production d'electricite par ORC a partir des rejets de chaleur du site de methanisation de Chatillon. Resume  

Energy Technology Data Exchange (ETDEWEB)

This report prepared for the Swiss Federal Office of Energy (SFOE) describes the practical realisation and testing of a heat recovery system based on a one-stage organic Rankine cycle with R134a as the working fluid. The waste heat has a temperature of 95 {sup o}C and originates from a gas engine that powers a small co-generation plant fuelled with biogas produced on-site. Two similar cycles have been built, ORC1 with one and ORC2 with two turbines. Only ORC1 has been tested so far. The maximum efficiency measured in these tests was 6.64% (theoretical Carnot-efficiency: 17 %) and the electric power output was 5.0 kW. The problems encountered during commissioning are described and recommendations for further improvements are given.

2005-07-01

187

Nanostructured p-CuIn3Se5/n-CdS heterojunction engineered using simple wet chemical approach at room temperature for photovoltaic application  

British Library Electronic Table of Contents (United Kingdom)

Herein, we report engineering of nanostructured p-CuIn3Se5/n-CdS heterojunction thin film on a glass substrate, which is prepared at room temperature using simple wet chemical approach involving ion exchange reactions between CdS and Cu^+, In^3^+ and Se^2^- ions in alkaline medium. The uniform deposition of heterojunction thin films is achieved by optimizing the pH, temperature and molarity of the reactant bath. The as-deposited thin-films were annealed at 200^oC in air for 1h and further characterized for structural, optical and electrical properties using UV-Vis spectrophotometer, X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), Hall effect for type of conductivity, and I-V measurement to investigate the char...

2011-01-01

188

NMR studies of Borrelia burgdorferi OspA, a 28 kDa protein containing a single-layer #beta#-sheet  

International Nuclear Information System (INIS)

The crystal structure of outer surface protein A (OspA) from Borrelia burgdorferi contains a single-layer #beta#-sheet connecting the N- and C-terminal globular domains. The central #beta#-sheet consists largely of polar amino acids and it is solvent-exposed on both faces, which so far appears to be unique among known protein structures. We have accomplished nearly complete backbone H, C and N and C";/H"#beta# assignments of OspA (28 kDa) using standard triple resonance techniques without perdeuteration. This was made possible by recording spectra at a high temperature (45 "oC ). The chemical shift index and "1"5N T_1/T_2 ratios show that both the secondary structure and the global conformation of OspA in solution are similar to the crystal structure, suggesting that the unique central #beta#-sheet is fairly rigid.

1998-05-01

189

Mullite long fibres prepared by sol-gel method using water solvent systems  

Energy Technology Data Exchange (ETDEWEB)

Mullite long fibres, which are a candidate for high temperature applications were prepared by sol-gel method from water solvent systems. They were synthesized from three different combinations of raw materials as follows: (1):Al(O{sub 1}C{sub 3}H{sub 7}){sub 3}, Al-nitrate and Si(OC{sub 2}H{sub 5}){sub 4} (TEOS), (2):Al metal, Al-chloride and TEOS, (3):Al metal, Al-nitrate and TEOS. In the methods (1) and (2), very fine SiO{sub 2} aerosol particles were also used partially replacing TEOS. The prepared solutions were condensed and examined the spinability by a hand drawing method. Dense and crack free mullite fibres were prepared from the methods (1) and (3) by firing up to 1100 C. Whereas the fibres prepared from the method (2) were less SiO{sub 2} than mullite composition and were porous by the firing due to evaporation of residual Cl ions at high temperature. (orig.) 10 refs.

1997-12-31

190

Lanthanum gallate and ceria composite as electrolyte for solid oxide fuel cells  

International Nuclear Information System (INIS)

The composite of doped lanthanum gallate (La_0_._9Sr_0_._1Ga_0_._8Mg_0_._2O_2_._8_5, LSGM) and doped ceria (Ce_0_._8Sm_0_._2O_1_._9, CSO) was investigated as an electrolyte for solid oxide fuel cell (SOFC). The LSGM-CSO composite was examined by X-ray diffraction (XRD) and impedance spectroscopy. It was found that the sintered LSGM-CSO composite contains mainly fluorite CeO_2 phase and a minority impurity phase, Sm_3Ga_5O_1_2. The LSGM-CSO composite electrolyte shows a small grain boundary response in the impedance spectroscopy as compared to LSGM and CSO pellets. The composite electrolyte exhibits the highest conductivity in the temperature range of 250-600 "oC, compared to LSGM and CSO. The LSGM-CSO composite can be expected to be an attractive intermediate temperature electrolyte material for solid oxide fuel cells.

2010-03-04

191

Kinetic investigations of graft copolymerization of sodium styrene sulfonate onto electron beam irradiated poly(vinylidene fluoride) films  

Energy Technology Data Exchange (ETDEWEB)

Graft copolymerization of sodium styrene sulfonate (SSS) onto electron beam (EB) irradiated poly(vinylidene fluoride) (PVDF) films was investigated to find out a simple preparation process for sulfonic acid proton exchange membranes with respect to monomer concentration, absorbed dose, temperature, film thickness and storage time. The reaction order of the monomer concentration and absorbed dose of grafting was found to be 2.84 and 1.20, respectively. The overall activation energy for graft copolymerization reaction was calculated to be 11.36 kJ/mol. The initial rate of grafting was found to decrease with an increase in the film thickness. The trapped radicals in the irradiated PVDF films remained effective in initiating the reaction without considerable loss in grafting level up to 180 days, when stored under -60 {sup o}C. The presence and distribution of polystyrene sulfonate grafts in the obtained membranes were observed by Fourier transform infrared (FTIR) ...

2011-01-15

192

Influence of anisotropic bending stiffness of gas diffusion layers on the degradation behavior of polymer electrolyte membrane fuel cells under freezing conditions  

British Library Electronic Table of Contents (United Kingdom)

The effects of gas diffusion layer's (GDL's) anisotropic bending stiffness on the degradation behavior of polymer electrolyte membrane fuel cells have been investigated under freezing conditions. We have prepared GDL sheet samples such that the higher stiffness direction of GDL roll is aligned with the major flow field direction of a metallic bipolar plate at angles of 0^o (parallel: '0^o GDL') and 90^o (perpendicular: '90^o GDL'). The I-V performances before and after 1000 temperature cycles between -10 and 1 ^oC of 90^o GDL stack are higher than those of 0^o GDL stack, and the voltages of 90^o GDL stack are decreased slower than those of 0^o GDL stack, indicating a higher durability of 90^o GDL stack. Furthermore, the values and increasing rates of high-frequency resistance of 90^o GDL s...

2011-01-01

193

Influence of Ce0.9Gd0.1O2-d particles on microstructure and oxygen permeability of Ba0.5Sr0.5Co0.8Fe0.2O3-d composite membrane  

British Library Electronic Table of Contents (United Kingdom)

This study examined the oxygen permeation behavior of Ce0.9Gd0.1O2-d (Gadolinium-Doped Ceria, GDC)/Ba0.5Sr0.5Co0.8Fe0.2O3-d (BSCF) composite membranes fabricated using a conventional sintering technique. GDC/BSCF composite membranes with a relative density >95% could be obtained when a green compact of BSCF and GDC was sintered at 1150^oC for 5h. It appears that GDC serves as a grain growth inhibitor because the average grain size of the composite decreased with increasing GDC content. The oxygen permeability of the BSCF and GDC/BSCF composite membranes strongly depends on the grain size and membrane thickness. The addition of GDC to BSCF resulted in a small grain size, low thermal expansion coefficient and high hardness. However, it is believed that oxygen permeation was blocked by GDC, a...

2010-01-01

194

High-efficiency GaAs solar cells on mm and sub-mm grain-size polycrystalline Ge substrates  

Energy Technology Data Exchange (ETDEWEB)

GaAs material and device structure optimization studies on optical-grade, millimeter-and-less grain-size polycrystalline Ge substrates are presented. We discuss the growth of high-quality epitaxial layers across various crystalline orientations of a polycrystalline substrate; this is important for obtaining high-performance solar cells. The GaAs solar cell on n-type poly-Ge substrate is a p-on-n type, with an undoped spacer between the p-emitter and the n-base. An experimental study of dark currents in these junctions, with and without the spacer, as a function of temperature (77K to 288K) is presented; this study suggests that the spacer reduces the tunneling contribution to dark current. In addition, we describe device-structure optimization studies that have led us to achieve an open-circuit voltage (V{sub oc}) exceeding 1 Volt and an AM1.5 efficiency of {approximately}19{percent} for a 4-cm{sup 2}-area GaAs cell on sub-mm grain-size poly-Ge. We have also ...

1997-02-01

195

High temperature friction and wear characteristics of superalloys X-750 and 188 for use in low heat rejection engines  

Energy Technology Data Exchange (ETDEWEB)

Engineering materials for use in low heat rejection engines are required to function under stringent tribological conditions. Severe wear damage and high friction between the components of the tribosystem limit the number of potential materials suitable for such application conditions. The superalloys X-750 and 188 are composed of alloying elements that not only promote a high mechanical and chemical stability but may also result in a reduced wear rate and friction coefficient at elevated temperatures. As a part of the DOE-ECUT Tribology program at Argonne, the present study was undertaken to evaluate the tribological characteristics of these alloys that will also be utilized as the substrates for ion beam deposited lubricous coatings. A wear test rig that crudely simulated the sliding conditions between a piston ring and a cylinder liner in an operating engine was utilized for friction and wear studies. The test results indicated that the wear and friction properties of these alloys ...

1988-01-01

196

High performance protonic ceramic membrane fuel cells (PCMFCs) with Sm_0_._5Sr_0_._5CoO_3_-_#delta# perovskite cathode  

International Nuclear Information System (INIS)

Protonic ceramic membrane fuel cells (PCMFCs) based on proton-conducting electrolytes have attracted much attention because of many advantages, such as low activation energy and high energy efficiency. A stable, easily sintered perovskite oxide BaCe_0_._5Zr_0_._3Y_0_._1_6Zn_0_._0_4O_3_-_#delta# (BCZYZ) as electrolyte for proton-conducting solid oxide fuel cells (SOFCs) with Sm_0_._5Sr_0_._5CoO_3_-_#delta# (SSC) composite cathode is investigated. By fabricating thin membrane BCZYZ electrolyte (#approx#20 #mu#m) synthesized by a modified Pechini method on NiO-BCZYZ anode support, PCMFCs are assembled and tested by selecting SSC perovskite cathode with high mixed ionic and electronic conductivities. An open-circuit potential of 1.015 V, a maximal power density of 528 mW cm"-"2, and a low polarization resistance of the electrodes of 0.15 #OMEGA# cm"2 is achieved at 700 "oC. The results indicate that BCZYZ proton-conducting electrolyte with SSC cathode is a promising ...

2010-04-02

197

Formation of nanostructures in UO_2 fuel at high burn-ups  

International Nuclear Information System (INIS)

In the present paper it is assumed that above a limiting value of fission fluency (burn-up) a more intensive process of irradiation introduced chemical interaction occurs. A significant part of fission gas product is thus expected to be chemically bounded in the matrix of UO_2 fuel. The fission gas atoms substituting, for example, uranium atoms in the crystallographic lattice can form weak facets. At a certain saturation condition, division of the grains can occur at the weak facets and the increase in fission-gas products release may be expected. The fact that the process of grain division for high burn-ups (70-80 MWd/kgU) forms an extremely fine structure up to the temperature as high as 1100 "oC and simultaneously the observed decreases in fission gas concentration in the fuel supports this concept. The analysis of fission gas concentration change due to the formation of nanostructures in UO_2 fuel at high burn-ups in terms of total surface area change in a ...

2001-09-23

198

Fatigue and creep crack growth of Alloy 800 and Alloy 617 at high temperatures  

Energy Technology Data Exchange (ETDEWEB)

A common evaluation is given for creep crack growth and fatigue crack growth experiments which have been performed at the companies ABB, Siemens-KWU and KFA. The materials under investigation were X10NiCrAlTi32 20 (Alloy 800) and NiCr22Col2Mo (Alloy 617). Several production lots and semi-finished materials as well as welded materials have been tested. Testing techniques differed at the different labs. In order to eliminate the influence of individual testing techniques, material from some production lots was investigated at different labs. The given data cover fatigue crack growth (the materials were tested between room temperature and 1050[sup o]C; the influence of temperature, R-ratio, and frequency was investigated) and creep crack growth (Alloy 800 was tested between 550sup(o)C and 900sup(o)C, Inconel 617 between 800sup(o)C and 1000sup(o)C; the evaluation was done on the basis of the fracture mechanics parameters Ksub(1) and Csup(*)). (Author).

1992-01-01

199

Fatigue and creep crack growth of Alloy 800 and Alloy 617 at high temperatures  

International Nuclear Information System (INIS)

A common evaluation is given for creep crack growth and fatigue crack growth experiments which have been performed at the companies ABB, Siemens-KWU and KFA. The materials under investigation were X10NiCrAlTi32 20 (Alloy 800) and NiCr22Col2Mo (Alloy 617). Several production lots and semi-finished materials as well as welded materials have been tested. Testing techniques differed at the different labs. In order to eliminate the influence of individual testing techniques, material from some production lots was investigated at different labs. The given data cover fatigue crack growth (the materials were tested between room temperature and 1050"oC; the influence of temperature, R-ratio, and frequency was investigated) and creep crack growth (Alloy 800 was tested between 550sup(o)C and 900sup(o)C, Inconel 617 between 800sup(o)C and 1000sup(o)C; the evaluation was done on the basis of the fracture mechanics parameters Ksub(1) and Csup(*)). (Author).

200

Effect of natural rubber processing sludge on the degradation of crude oil hydrocarbons in soil  

Energy Technology Data Exchange (ETDEWEB)

Crude oil-polluted soil (five parts of weathered crude oil per 100 parts of soil; equivalent to 50,000 mg oil kg{sup -}1 soil) samples were slurried in deionised water (300% of the water retention capacity of the soil) and treated with various amounts of natural-rubber processing sludge (nitrogen content 62.15 mgkg{sup -1} and phosphorus contents 8.75 mgkg{sup -1}) in a well-stirred, continuously-aerated tank at 29{sup o}C. Changes in the total hydrocarbon content of the soil sample were determined, using a spectrophotometric technique, as a function of time. The extent of crude oil degradation was markedly higher (by up to 100%) in the sludge-treated soil than in the untreated soil sample. The efficiency of biodegradation of the crude oil hydrocarbons using the slurry-phase technique was compared with that of solid-phase technique. (author)

2002-03-01

201

EPR investigation of some traditional oriental irradiated spices  

International Nuclear Information System (INIS)

The 9.50 GHz electron paramagnetic resonance (EPR) spectra of unirradiated and "6"0Co #gamma#-ray irradiated cardamom (Elettaria cardamomum L. Maton, Zingiberaceae), ginger ((Zingiber officinale Rosc., Zingiberaceae), and saffron (Crocus sativus L., Iridaceae) have been investigated at room temperature. All unirradiated spices presented a weak resonance line with g-factors around free-electron ones. After #gamma#-ray irradiation at an absorbed dose of up to 11.3 kGy, the presence of EPR spectra whose amplitude increase monotonously with the absorbed dose has been noticed with all spices. A 100 "oC isothermal annealing of 11.3 kGy irradiated samples has shown a differential reduction of amplitude of various components that compose initial spectra, but even after 3.6 h of thermal treatment, the remaining amplitude represents no less then 30% of the initial ones. The same peculiarities have been noticed after 83 days storage at room temperature but after 340 days ...

2007-06-01

202

EDF waste packages transport and compliance with regulations: prediction of retention of radionuclides by cementitious materials  

International Nuclear Information System (INIS)

Different concrete waste packages have been designed by Electricite de France (EDF) for the long-term storage of radioactive Low Level Waste (LLW). Their main function is to confine radionuclides from the biosphere for three hundred years in a near-surface disposal. According to the transport regulations, a Type-B package is needed for some waste like water filters. The water filters from EDF nuclear power plants are encapsulated in mortar and placed in a concrete container. Transport regulations for these containers have required the development of a methodology for safety assessment. The reference scenario of container degradation during transport considers a 9 m drop and a 800"oC fire for 30 min. First, the different chemical and physical processes involved in the containment of radionuclides are analysed. In particular, the radionuclide transport mechanisms in cement-based materials have been reviewed. Secondly, the effects of a container drop on the mortar and ...

203

Dynamic behaviors of sulfur evolved in the gas phase from pyrolysis of six Chinese coals  

Energy Technology Data Exchange (ETDEWEB)

Dynamic behaviors of gaseous sulfur-containing compounds evolved from pyrolysis of six Chinese coals were studied in the temperature range of up to 800{sup o}C under N{sub 2} and H{sub 2}. The released amount of total sulfur-containing gases was traced by an online flame photometric detector (FPD). Simultaneously, the changes of different sulfur forms, including H{sub 2}S, SO{sub 2}, COS and CS{sub 2}, also were investigated using an online mass spectrometer (MS). FPD results show that the effect of H{sub 2} on gaseous sulfur evolved is complex, which promoted certain peak and suppresses other peaks. Based on the data from MS, it is suggested that a series of competitive reactions between active sulfur and other active matters during pyrolysis may impact on the sulfur form in gas phase. Interactions between active sulfur-containing intermediates and the coal matrix are attributed to be the main factor determining the dynamic behavior.

2006-07-01

204

Design of experiment approach applied to reducing and oxidizing tolerance of anode supported solid oxide fuel cell. Part II: Electrical, electrochemical and microstructural characterization of tape-cast cells  

British Library Electronic Table of Contents (United Kingdom)

One of the major limitations of the nickel (Ni) - yttria-stabilized zirconia (YSZ) anode support for solid oxide fuel cells (SOFC) is its low capability to withstand transients between reducing and oxidizing atmospheres (''RedOx'' cycle), owing to the Ni-to-NiO volume expansion. This work presents results on different anode supports fabricated by tape casting. Three compositions are prepared, as the outcome of a preceding design of experiment approach. The NiO proportion is 40, 50 and 60wt% of the anode composite. The anode support characteristics like shrinkage during sintering, in-situ conductivity at high temperature, electrochemical performance and tolerance against RedOx cycles have been measured. Performance up to 0.72Wcm^-^2 (0.62V, 800^oC) is recorded for the 60wt% NiO sample on sm...

2011-01-01

205

Deep Heat Mining Project - Technical report on the Otterbach 2 geothermal test borehole in Basel; Technischer Bericht Geothermie-Sondierbohrung Otterbach 2, Basel  

Energy Technology Data Exchange (ETDEWEB)

This report for the Swiss Federal Office of Energy (SFOE) describes the borehole that has been driven into the underlying crystalline rock of the Rhine valley near Basle. This work has been carried out within the framework of the 'Deep Heat Mining' project. The 2,755 metre deep borehole provides geological information essential for the realisation of a proposed geothermal power station using the 'Hot Dry Rock' process. The boring of the test borehole is described. The results obtained from samples taken from the test borehole and the measurements made in it are presented, including details on geological formations, temperature, gas measurements and rock strain values. The author is of the opinion that the chances of finding temperatures of at least 200 {sup o}C in a depth of 5 km - as foreseen in the 'Deep Heat Mining' project - can be considered as being quite high.

2001-07-01

206

Construction and Calibration of the Laser Alignment System for the CMS Tracker  

CERN Document Server

The CMS detector (Compact Muon Solenoid) is under construction at one of the four proton-proton interaction points of the LHC (Large Hadron Collider) at CERN, the European Organization for Nuclear Research (Geneva, Switzerland). The inner tracking system of the CMS experiment consisting of silicon detectors will have a diameter of 2.4 m and a length of 5.4 m representing the largest silicon tracker ever. About 15000 silicon strip modules create an active silicon area of 200 m2 to detect charged particles from proton collisions. They are placed on a rigid carbon fibre structure, providing stability within the working conditions of a 4 T solenoid magnetic field at ?10oC. Knowledge of the position of the silicon detectors at the level of 100 ?m is needed for an efficient pattern recognition of charged particle tracks. Metrology methods are used to survey tracker subdetectors and the integrated Laser Alignment System (LAS) provides absolute positioning of support ...

2006-01-01

207

An experimental study for a combined system of tar sand, oil shale, and olive cake as a potential energy source in Jordan  

Energy Technology Data Exchange (ETDEWEB)

Jordan is an example of a third world country that is non-oil producing but contains huge reserves of other energy sources such as tar sand, oil shale, and olive cake. Some limited research is available about how to utilize these energy sources in pure form. However, available research does not deal with combinations of these energy sources. This experimental study investigates combinations of these energy forms as potential energy sources in Jordan. The experimental procedure involves characterization of samples by proximate analysis, calorific value determination of different combinations, and a compacting process of the different particles. The best combination, with respect to calorific value, is found to be 20% tar sand, 20% olive cake, and 60% oil shale. Compacting materials either with starch or with heated tar sand up to 110{sup o}C for 1 h indicates a feasible process for handling, packaging, and transporting. (author)

1999-07-01

208

A model of coal particle drying in fluidized bed combustion reactor  

Energy Technology Data Exchange (ETDEWEB)

Experimental and theoretical investigation on drying of a single coal particle in fluidized bed combustor is presented. Coal particle drying was considered via the moist shrinking core mechanism. The results of the drying test runs of low-rank Serbian coals were used for experimental verification of the model. The temperature of the coal particle center was measured, assuming that drying was completed when the temperature equalled 100{sup o}C. The influence of different parameters (thermal conductivity and specific heat capacity of coal, fluidized bed temperature, moisture content and superheating of steam) on drying time and temperature profile within the coal particle was analyzed by a parametric analysis. The experimentally obtained results confirmed that the moist shrinking core mechanism can be applied for the mathematical description of a coal particle drying, while dependence between drying time and coal particle radius, a square law relationship, implicates ...

2007-02-15

209

Phase diagram of SrO-InO1.5-CoOx and a new compound Sr3In0.9Co1.1O6  

International Nuclear Information System (INIS)

Sr3In0.9Co1.1O6, isostructural to Ca3Co2O6, is revealed by the study of the phase relations in the system SrO-InO1.5-CoOx (1000 oC). The structure of Sr3In0.9Co1.1O6 is refined by the combination of powder X-ray and neutron diffraction. Sr3In0.9Co1.1O6 crystallizes in a trigonal lattice with the cell parameters a=b=9.59438(3) A, c=11.02172(4) A with the space group R-3c. Its structure possesses 1D (In/Co)O3 chains running along the c-axis constructed by alternating face-sharing CoO6 octahedra and (In0.9Co0.1)O6 trigonal prisms. The co-occupation of In3+ and Co3+ at the trigonal prismatic site is evidenced by elementary analysis and determined by the structure refinement. Sr3In0.9Co1.1O6 is paramagnetic, and the susceptibility is consistent with the occupation of Co3+ at 10% of the trigonal prismatic positions in a high spin state (HS, S=2). The HS Co3+ is well separated by diamagnetic CoO6 octahedra and InO6 trigonal prisms and shows a g factor of 2.0 in the ...

2011-04-01

210

Perovskite-type SrTi1-xNbx(O,N)3 compounds: Synthesis, crystal structure and optical properties  

International Nuclear Information System (INIS)

The synthesis, crystal structure, thermal stability and absorbance spectra of perovskite-type oxynitrides with the general formula SrTi1-xNbx(O,N)3 (x=0.05, 0.10, 0.20, 0.50, 0.80, 0.90, 0.95) have been investigated. Oxide samples were prepared by a polymerized complex synthesis route and post-treated under ammonia at 850 oC for 24 h to substitute nitrogen for oxygen. Synchrotron X-ray powder diffraction (XRD) evidenced that the mixed oxide phases were all transformed into oxynitrides with perovskite-type structure during a thermal ammonolysis. SrTi1-xNbx(O,N)3 with compositions x?0.80 crystallized in a cubic and samples with x?0.90 in a tetragonal structure. The Rietveld refinement indicated a continuous enlargement of the lattice parameters towards higher niobium content of the samples. Thermogravimetric analysis (TGA) and hotgas extraction revealed the dependence of the nitrogen incorporation upon the degree of niobium substitution. It showed that more nitrogen ...

2011-04-01

211

High Temperature Capacitor Development  

Energy Technology Data Exchange (ETDEWEB)

The absence of high-temperature electronics is an obstacle to the development of untapped energy resources (deep oil, gas and geothermal). US natural gas consumption is projected to grow from 22 trillion cubic feet per year (tcf) in 1999 to 34 tcf in 2020. Cumulatively this is 607 tcf of consumption by 2020, while recoverable reserves using current technology are 177 tcf. A significant portion of this shortfall may be met by tapping deep gas reservoirs. Tapping these reservoirs represents a significant technical challenge. At these depths, temperatures and pressures are very high and may require penetrating very hard rock. Logistics of supporting 6.1 km (20,000 ft) drill strings and the drilling processes are complex and expensive. At these depths up to 50% of the total drilling cost may be in the last 10% of the well depth. Thus, as wells go deeper it is increasingly important that drillers are able to monitor conditions down-hole such as temperature, pressure, heading, etc. ...

2009-06-30

212

Carbon fibers and composites modified by intercalation  

International Nuclear Information System (INIS)

The aim of this paper was to describe ability to intercalation of laboratory prepared carbon composites and their constituents. In work the following materials were tested; pinch-based fibres of P-120 and K-1100 manufacturer's designations, carbon matrix and resulting composites. To prepare a matrix of composites, phenol-formaldehyde resin (Z) and pinch-based precursor (PAK) were used. After initial carbonization, the carbon matrix was heated to 2150 "oC i to improve ability to the future intercalation. Three kinds of composites (P/Z, K/Z and K/PAK), with two directional reinforcement (2D), were prepared. All carbon samples were intercalated with copper chloride(II). To study the structure of all materials, before and after intercalation, X-ray diffraction method was used. It enabled to measure microstructure parameters (L_c and L_a), interplanar distance (d_0_0_2) thickness of an intercalation layer (d_i). Before intercalation, graphite fibers are characterized by ...

213

Titania-supported iron oxide as oxygen carrier for chemical-looping combustion of methane  

Energy Technology Data Exchange (ETDEWEB)

Chemical-looping combustion is a two-stage process proposed as an alternative for the combustion of carbonaceous materials, such as natural gas or coal gas, for almost complete CO{sub 2} capture. In the reduction stage, the structural oxygen contained in the lattice of a reducible inorganic oxide, is used for combustion of the carbonaceous material. In the regeneration stage the oxygen carrier, found in a reduced state after the reduction stage, is regenerated with pure air to recover the physical and chemical properties of the carrier, ready to reinitiate a new cycle reduction-regeneration. In a typical multicycle reactor test, the carriers are subjected to accumulative chemical and thermal stresses and the performance will, probably, decay progressively with the number of cycles. The occurrence of some side reactions may limit the efficiency of the overall process in CO{sub 2} capture. In this paper, titania-supported iron oxides with different iron loadings have been tested in ...

2007-01-15

214

Thermal properties and thermal reliability of eutectic mixtures of some fatty acids as latent heat storage materials  

Energy Technology Data Exchange (ETDEWEB)

The present study deals with two subjects. The first one is to determine the thermal properties of lauric acid (LA)-stearic acid (SA), myristic acid (MA)-palmitic acid (PA) and palmitic acid (PA)-stearic acid (SA) eutectic mixtures as latent heat storage material. The properties were measured by the differential scanning calorimetry (DSC) analysis technique. The second one is to study the thermal reliability of these materials in view of the change in their melting temperatures and latent heats of fusion with respect to repeated thermal cycles. For this aim, the eutectic mixtures were subjected to 360 repeated melt/freeze cycles, and their thermal properties were measured after 0, 90,1 80 and 360 thermal cycles by the technique of DSC analysis. The DSC thermal analysis results show that the binary systems of LA-SA in the ratio of 75.5:24.5 wt.%, MA-PA in the ratio of 58:42 wt.% and PA-SA in the ratio of 64.2:35.8 wt.% form eutectic mixtures with melting temperatures of 37.0, 42.60 and ...

2004-02-01

215

The ternary silicide ZrPd{sub 3}Si{sub 3}, a stacking variant of the {alpha}-FeSi{sub 2} and Re{sub 3}B structure types  

Energy Technology Data Exchange (ETDEWEB)

The ternary zirconium palladium silicide ZrPd{sub 3}Si{sub 3} has been synthesized by arc-melting of the elemental components. It adopts a new structure type and crystallizes in the orthorhombic space group Cmcm with a = 3.8127(4){angstrom}, b = 15.551(1){angstrom}, c = 7.0390(5){angstrom}, and Z = 4 (Pearson symbol oC28). The structure can be regarded as being built up of Re{sub 3}B-type slabs of composition Pd{sub 3}Si alternating with {alpha}-FeSi{sub 2} slabs of composition ZrSi{sub 2}. Notable features include the presence of Si{sub 2} pairs, square pyramidal and tetrahedral coordination of Pd centers by Si atoms, an unusual distorted cubic coordination of the Zr atoms by the Si{sub 2} pairs, and an extensive network of Zr-Zr, Zr-Pd, and Pd-Pd metal-metal bonds. ZrPd{sub 3}Si{sub 3} is weakly metallic with a room-temperature resistivity of 1.7 x 10{sup {minus}3} {Omega} cm. Extended Hueckel band structure calculations confirm the metallic behavior; support the ...

1999-11-01

216

The role of condensed carbonaceous materials on the sorption of hydrophobic organic contaminants in subsurface sediments.  

Science.gov (United States)

The identification and characterization of carbonaceous materials (CMs) that control hydrophobic organic chemical (HOC) sorption is essential to predict the fate and transport of HOCs in soils and sediments. The objectives of this paper are to determine the types of CMs that control HOC sorption in the oxidized and reduced zones of a glacially deposited groundwater sediment in central Illinois, with a special emphasis on the roles of kerogen and black carbon. After collection, the sediments were treated to obtain fractions of the sediment samples enriched in different types of CMs (e.g., humic acid, kerogen, black carbon), and selected fractions were subject to quantitative petrographic analysis. The original sediments and their enrichment fractions were evaluated for their ability to sorb trichloroethene (TCE), a common groundwater pollutant. Isotherm results and mass fractions of CM enrichments were used to calculate sorption contributions of different CMs. The results indicate that ...

2008-03-01

217

The greenhouse gases N{sub 2}O, CH{sub 4} and CO{sub 2} in coniferous forest soils as influenced by nitrogen input, acidity, moisture and temperature; Drivhusgassene N{sub 2}O, CH{sub 4} og CO{sub 2} i barskogsjord under paavirking av N-tilfoersel, surhet, fuktighet og temperatur  

Energy Technology Data Exchange (ETDEWEB)

The thesis relates to an investigation done on greenhouse gases in coniferous forest soils. The production of nitrous oxide (N{sub 2}O) and carbon dioxide (CO{sub 2}), and the consumption of methane (CH{sub 4}) in a temperate forest soil were studied by a rapid and sensitive gas chromatographic (GC) method for analysing all three greenhouse gases at or below ambient levels. Gas fluxes were measured in soil incubation and lysimeter experiments. 15 soil samples were taken at random within a 100 m{sup 2} area in a Norway spruce forest stand (Picea abies). The fluxes of N{sub 2}O, CH{sub 4} and CO{sub 2} were measured under standardized laboratory incubation conditions to investigate spatial variability in relation to other factors such as nitrogen (N) mineralization rate, nitrification rate, organic carbon (OC), total N and pH. The effects of temperature, soil moisture content, and ammonium addition were also studied in an incubation experiment. A more detailed study ...

1994-07-01

218

Synthesis, crystal structure and photoluminescence of Eu-#alpha#-SiAlON  

International Nuclear Information System (INIS)

Eu-#alpha#-SiAlON (Eu_m_/_2Si_1_2_-_m_-_nAl_m_+_nO_nN_1_6_-_n) was synthesized with nominal compositions having small m and n values, by firing the powder mixture of Eu_2Si_5N_8, #alpha#-Si_3N_4, AlN, and Al_2O_3 at 1900 "oC for 6 h under 1 MPa nitrogen atmosphere. The ratio of the oxidation state of Eu"2"+/Eu"3"+ was estimated from the X-ray absorption fine structure (XAFS) measurement. The observed X-ray absorption near edge spectrum (XANES) showed that the Eu ion in Eu-#alpha#-SiAlON was mainly in divalent state but also coexisted with a small amount of Eu in the trivalent state. The crystal structure of Eu-#alpha#-SiAlON was refined by the Rietveld analysis of the X-ray powder diffraction patterns. The lattice constants of the samples increased with increasing m and n values. The excitation band of Eu-#alpha#-SiAlON ranged from the ultraviolet to the visible light region and a broad emission band centered at about 590 nm were observed. The emission intensity ...

2010-08-20

219

Spatial distributions of {sup 137}Cs and {sup 239+240}Pu in surface seawater within the Exclusive Economic Zone of East Coast Peninsular Malaysia  

Energy Technology Data Exchange (ETDEWEB)

The studies of {sup 137}Cs and {sup 239+240}Pu distributions in surface seawater at South China Sea within the Exclusive Economic Zone (EEZ) of Peninsular Malaysia were carried out in June 2008. The analysis results will serve as additional information to the expanded baseline data for Malaysia's marine environment. Thirty locations from extended study area were identified in the EEZ from which large volumes of surface seawater samples were collected. Different co-precipitation techniques were employed to concentrate cesium and plutonium separately. A known amount of {sup 134}Cs and {sup 242}Pu tracers were used as yield determinant. The precipitate slurry was collected and oven dried at 60 {sup o}C for 1-2 days. Cesium precipitate was fine-ground and counted using gamma-ray spectrometry system at 661.62 keV, while plutonium was separated from other radionuclides using anion exchange, electrodeposited and counted using alpha spectrometry. The activity ...

2010-09-15

220

Some fatty acids used for latent heat storage: thermal stability and corrosion of metals with respect to thermal cycling  

Energy Technology Data Exchange (ETDEWEB)

The present study includes thermal stability of some fatty acids as phase change materials (PCMs). The selected fatty acids were stearic, palmitic, myristic and lauric acid with melting temperatures between 40-63{sup o}C and industrial-grade with 90-95% purity. Latent heat storage capacity and phase transition temperature of the PCMs were determined by Differential Scanning Calorimetry (DSC) technique as a function of after repeated thermal cycles such as 40, 410, 700 and 910. The present work also comprises the investigation of corrosion resistance of some construction materials to the fatty acids over a long period. The containment materials tested were stainless steel (SS 304 L), carbon steel (steel C20), aluminium (Al) and copper (Cu). Gravimetric analysis as mass loss (mg/cm{sup 2}), corrosion rate (mg/day) and a microscopic or metallographic investigation were performed for corrosion tests after 910 thermal cycles. DSC measurements showed that all fatty acids ...

2003-05-01

221

Properties of dust particles sampled from windboxes of an iron ore sintering plant: Surface structures of unburned carbon  

Energy Technology Data Exchange (ETDEWEB)

Aiming to understand the formation mechanism of dioxins in the iron ore sintering process, dust samples obtained from some windboxes of a commercial iron ore sintering plant have been characterized with a powder X-ray diffraction (XRD), by the transmission electron microscope (TEM) equipped with an electron energy loss spectroscopy (EELS), and by the temperature-programmed desorption (TPD) and temperature-programmed oxidation (TPO) techniques. The elemental and XRD analyses reveal that the content of the Cl present in the samples ranges from 0.075 mass%-dry to 5.1 mass%-dry and tends to be higher at smaller dust particles, and that some of the Cl exists as KCl with the average crystalline size between 40 nm and 50 nm. Dust samples also contain a significant amount of unburned carbon, and the smallest dust particles, < 500 {mu}m, show the highest C contents in many cases and consist partly of C, K, and Cl elements. The TPD and TPO experiments exhibit that the dust samples have ...

2006-07-01

222

Probing anodic reaction kinetics and interfacial mass transport of a direct formic acid fuel cell using a nanostructured palladium-gold alloy microelectrode  

International Nuclear Information System (INIS)

The anodic reaction kinetics and interfacial mass transport of a direct polymer electrolyte membrane formic acid fuel cell have been investigated in an all solid-state electrochemical cell using a highly active nanostructured palladium-gold alloy microelectrode as an in situ probe. Well-defined 'S-shaped' steady-state cyclic voltammograms exhibiting current-rising region at lower overpotentials and limiting current region at higher overpotentials have been first obtained for the electrochemical oxidation of formic acid at varying temperature. The 'S-shaped' steady state polarization curves and chronoamperometric curves enable convenient measurements of the anodic reaction kinetics and interfacial mass transport of formic acid under real polymer electrolyte membrane conditions. It is encouragingly found that formic acid can be directly oxidized to CO2 with the first electron transfer being the likely rate-determining step and the formation of surface poison can be neglected. The ...

2009-07-30

223

New microwave assisted radiolabelling method and rat brain biodistribution study of two new "9"9"mTc-tricarbonyl complexes as potential brain imaging agents  

International Nuclear Information System (INIS)

Two new cyclopentadienyl piperidine derivatives, namely ferrocene carboxylic acid 1-ethyl-3-hydroxypiperidinyl ester and ferrocene carboxylic acid 4-hydroxypiperidinyl ester, were synthesized. The ligands were then radiolabelled with "9"9"mTc using two different approaches. The first method consisted of reacting the ligand precursor with Mn(CO)_5Br in pertechnetate "9"9"mTcO_4 - in normal saline and dimethyl formamide (DMF) at 150 "oC for 1 h. The yields were 70% and 90%, respectively. For the second method, the reactions mixtures were placed in a microwave oven for 2 min at 650 watt. The yields were higher than 90% for both "9"9"mTc complexes. Biodistribution studies showed that tricarbonyl[#eta#"5-[carboxy-3-hydroxy(N-ethyl)piperidine]cyclopentadienyl] technetium(I) had the highest brain uptake. The regional distribution in the brain also demonstrated relatively higher uptake of tricarbonyl [#eta#"5-[carboxy-3-hydroxy(N-ethyl) piperidine]cyclopentadienyl] ...

224

NGNP Composites R&D Technical Issues Study  

Energy Technology Data Exchange (ETDEWEB)

This study identifies potential applications and design requirements for ceramic materials (CMs) and ceramic composite materials (CCMs) in the NGNP hightemperature gas-cooled reactor (HTGR) primary circuit. Components anticipated for fabrication from non-graphite CMs and CCMs are identified along with recommended normal and off-normal operating conditions. The evaluation defines required dimensions and material properties of the candidate materials for normal operating conditions (NOC), anticipated transients, abnormal events, and design basis events. The report also identifies additional activities required for codifying the selected materials. The activities include ASTM Standard and ASME Code development and other work to support NRC licensing of the plant. Evaluation of the NGNP baseline design indicates components requiring either CMs or CCMs depend upon the reactor operating temperatures. For a reactor outlet temperature of 900 oC, four of the five evaluated ...

2008-09-01

225

Micro Gas Turbine Operation with Biomass Producer Gas and Mixtures of Biomass Producer Gas and Natural Gas  

Energy Technology Data Exchange (ETDEWEB)

We report the performance of a commercial recuperated micro gas turbine on biomass producer gas and mixtures of biomass producer gas with natural gas. The biomass producer gas, obtained by gasification at 850{sup o}C with air at atmospheric pressure, contains about 7% H2, 17% CO, 15% CO2, 4% CH4, 2% other hydrocarbons, 2% H2O, and a balance of N2 and Ar from air. It has a net heating value of about 6 MJ/(Nm{sup 3}). The micro gas turbine delivers full power (30 kW{sub e}) on gas mixtures with a net heating value of at least 15 MJ/(Nm{sup 3}). For gas of lower heating value, the maximum fuel gas flow allowed by the fuel control unit limits the attainable power. At reduced power, the lower limit for stable operation is a net heating value of about 8 MJ/(Nm{sup 3}). The gross efficiency of the micro gas turbine depends on the output power but not on the gas heating value, within our estimated measurement accuracy of about 2%. Above 70% of full power, NO emission is 5 ...

2007-08-15

226

Luminous HC3N line emission in NGC4418 - buried AGN or nascent starburst?  

CERN Document Server

IRAM 30m observations reveal that the deeply obscured IR-luminous galaxy NGC4418 has a rich molecular chemistry - including unusually luminous HC3N line emission. We furthermore detect: ortho-H2CO 2-1, 3-2; CN 1-0, 2-1; HCO+, 1-0. 3-2, HCN 3-2, HNC 1-0, 3-2 (and tentatively OCS 12-11). The HCN, HCO+, H2CO and CN line emission can be fitted to densities of n=5 x 10E4 - 10E5 cm-3 and gas temperatures Tk=80-150 K. Both HNC and HC3N are, however, significantly more excited than the other species which requires higher gas densities - or radiative excitation through e.g. mid-IR pumping. The HCN line intensity is fainter than that of HCO+ and HNC for the 3-2 transition, in contrast to previous findings for the 1-0 lines where the HCN emission is the most luminous. We tentatively suggest that the observed molecular line emission is consistent with a young starburst, where the emission can be understood as emerging from dense, warm gas with an additional PDR component. We ...

2007-01-01

227

Luminescent properties of Eu3+-activated Sr3B2SiO8: A red-emitting phosphor for white light-emitting diodes  

International Nuclear Information System (INIS)

Single-phased Sr3B2SiO8:Eu3+ phosphor was prepared by a solid-state method at 1020 oC. The luminescence spectra showed that Sr3B2SiO8:Eu3+ phosphor can be effectively excited by near ultraviolet light (393 nm) and blue light (464 nm). When excited at 393 or 464 nm Sr3B2SiO8:Eu3+ exhibited the main emission peaks at 611 and 620 nm, which resulted from the supersensitive 5D0#->#7F2 transition of Eu3+. The luminescence intensity of Sr3B2SiO8:Eu3+ at 611 and 620 nm reached the maximum when the doping content of Eu3+ was 4.5 mol%. Its chromaticity coordinates (0.646, 0.354) were very close to the NTSC standard values (0.67, 0.33). Thus, Sr3B2SiO8:Eu3+ is considered to be an efficient red-emitting phosphor for long-UV InGaN-based light-emitting diodes. - Highlights: ? Sr3B2SiO8:Eu3+ was synthesized using solid-state reaction method for the first time. ? The phosphor can be efficiently excited by the near-UV chips and gives strong red emission. ? The phosphor is a ...

2011-07-01

228

Kinetic and thermodynamic studies of the biosorption of Cr(VI) by Pinus sylvestris Linn  

Energy Technology Data Exchange (ETDEWEB)

Biosorption equilibrium, kinetics and thermodynamics of chromium(VI) ions onto cone biomass were studied in a batch system with respect to temperature and initial metal ion concentration. The biosorption efficiency of chromium ions to the cone biomass decreased as the initial concentration of metal ions was increased. But cone biomass of Pinus sylvestris Linn. exhibited the highest Cr(VI) uptake capacity at 45 {sup o}C. The biosorption efficiency increased from 67% to 84% with an increase in temperature from 25 to 45 deg. C at an initial Cr(VI) concentration of 300 mg/L. The Langmuir isotherm model was applied to experimental equilibrium data of Cr(VI) biosorption depending on temperature. According to Langmuir isotherm, the monolayer saturation capacity (Q{sub max}) is 238.10 mg/g. The pseudo-first-order and pseudo-second-order kinetic models were applied to test the experimental data for initial Cr(VI). The pseudo-second-order kinetic model provided the best ...

2008-05-01

229

Isolation and characterization of a novel lectin from the mushroom Armillaria luteo-virens  

Science.gov (United States)

From the dried fruiting bodies of the mushroom Armillaria luteo-virens, a dimeric lectin with a molecular mass of 29.4 kDa has been isolated. The purification procedure involved (NH{sub 4}){sub 2}SO{sub 4} precipitation, ion exchange chromatography on DEAE-cellulose, CM-cellulose, and Q-Sepharose, and gel filtration by fast protein liquid chromatography on Superdex 75. The hemagglutinating activity of the lectin could not be inhibited by simple sugars but was inhibited by the polysaccharide inulin. The activity was stable up to 70 {sup o}C but was acid- and alkali-labile. Salts including FeCl{sub 3}, AlCl{sub 3}, and ZnCl{sub 2} inhibited the activity whereas MgCl{sub 2}, MnCl{sub 2}, and CaCl{sub 2} did not. The lectin stimulated mitogenic response of mouse splenocytes with the maximal response achieved by 1 {mu}M lectin. Proliferation of tumor cells including MBL2 cells, HeLa cells, and L1210 cells was inhibited by the lectin with an IC{sub 5} of 2.5, 5, and 10 ...

2006-07-14

230

Isobutane/2-butene alkylation over potential heterogeneous catalysts in a slurry reactor  

Energy Technology Data Exchange (ETDEWEB)

The trend towards more effective use of fossil fuels and reduced environmental pollution represents a major task of improvement within the refinery processes. The highly isomerized and high octane paraffins produced from isobutane and light olefins by alkylation fulfill all the requirements for reformulated gasoline. This doctoral thesis discusses new catalyst systems because of their potential in alkylation. A slurry reactor apparatus for solid-acid catalysed isobutane/butene alkylation was developed and used to investigate the performance of various heterogeneous catalysts. The selected materials were mainly zeolite types with faujasite structures. The samples were characterized by various methods before alkylation. In general, the order of decreasing catalyst activity after 3 h of reaction at 80{sup o}C was found to be: H-EMT >> H-FAU, dealuminated H-FAU >> NS.500, TA-Y, CeY-98 > Nafion-H. The order of decreasing alkylate selectivity of the ...

1996-12-31

231

Ionizing radiation target groups of band 3 inserted into egg lecithin liposomes as determined by Raman spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

The purified integral membrane protein, band 3, from human erythrocytes was inserted into egg lecithin liposomes. The insertion of band 3 was determined from thermal transition data from the analysis of the C-H stretching region bands recorded at temperatures from 25 to -22[sup o]C. Raman spectra show that band 3 considerably broadens and lowers the thermal transition of egg lecithin liposomes, suggesting the insertion of band 3. The band 3-inserted liposomes were irradiated with gamma-rays (40 Gy) and the radiation target groups were determined by the analysis of the structural sensitive Raman bands in the 1600-1700 cm[sup -1] (amide I), 1200-1300 cm[sup -1] (amide III) and 550-1030 cm[sup -1] (side chain amino groups) regions. The radiation-sensitive groups as identified from Raman spectra in the region 550-1030 cm[sup -1] are tyrosines and cysteines. The radiation-induced changes in the secondary structure were determined from amide I and III bands. Quantitative ...

1993-03-01

232

Ionizing radiation target groups of band 3 inserted into egg lecithin liposomes as determined by Raman spectroscopy  

International Nuclear Information System (INIS)

The purified integral membrane protein, band 3, from human erythrocytes was inserted into egg lecithin liposomes. The insertion of band 3 was determined from thermal transition data from the analysis of the C-H stretching region bands recorded at temperatures from 25 to -22"oC. Raman spectra show that band 3 considerably broadens and lowers the thermal transition of egg lecithin liposomes, suggesting the insertion of band 3. The band 3-inserted liposomes were irradiated with gamma-rays (40 Gy) and the radiation target groups were determined by the analysis of the structural sensitive Raman bands in the 1600-1700 cm"-"1 (amide I), 1200-1300 cm"-"1 (amide III) and 550-1030 cm"-"1 (side chain amino groups) regions. The radiation-sensitive groups as identified from Raman spectra in the region 550-1030 cm"-"1 are tyrosines and cysteines. The radiation-induced changes in the secondary structure were determined from amide I and III bands. Quantitative estimation using the ...

233

Growth and characterization of new semi-organic L-proline strontium chloride monohydrate single crystals  

International Nuclear Information System (INIS)

The present communication deals with the synthesis, single crystal growth and characterization of a new nonlinear optical material L-proline strontium chloride monohydrate (L-PSCM). Single crystals have been grown using the slow solvent evaporation technique. Single crystal XRD analysis confirmed that the crystal belongs to the orthorhombic structure with lattice parameter a=6.6966(3) A, b=12.4530(5) A, c=15.2432(5) A and space group P2_12_12_1. Presence of various functional groups in L-PSCM and protonation of the ions were confirmed by Fourier transform infrared spectroscopy (FT-IR) analysis. The melting point of the single crystal was found to be 126 "oC using DSC. Ultraviolet-visible spectral analyses showed that the crystal has low UV cut-off at 226 nm combined with very good transparency of 90% in a wide range. The optical band gap was estimated to be 5.82 eV. Capacitance and dielectric-loss measurements were carried out at different temperatures in the ...

2011-01-01

234

GdBa_0_._5Sr_0_._5Co_2O_5_+_#delta# layered perovskite as promising cathode for proton conducting solid oxide fuel cells  

International Nuclear Information System (INIS)

BaZr_0_._1Ce_0_._7Y_0_._2O_3_-_#delta# (BZCY7) exhibits adequate proton conductivity as well as sufficient chemical and thermal stability over a wide range of SOFC operating conditions, while layered GdBa_0_._5Sr_0_._5Co_2O_5_+_#delta# (GBSC) perovskite deposited on a doped ceria electrolyte demonstrates advanced electrochemical properties. This research fully takes advantage of these advanced properties and develops novel protonic ceramic membrane fuel cells (PCMFCs) of Ni-BZCY7|BZCY7|GBSC. The results show that the open-circuit potential of 1.003 V, maximum power density of 430 mW cm"-"2, and a low polarization resistance of the electrodes of 0.08 #OMEGA# cm"2 are achieved at 700 "oC. With temperature increases, the total cell resistance decreases, among which electrolyte resistance becomes increasingly dominant over polarization resistance. The results also indicate that GBSC perovskite cathode is a good candidate for intermediate temperature PCMFC development, ...

2010-04-30

235

Gasification reactivity and kinetics of typical Chinese anthracite chars with steam and CO{sub 2}  

Energy Technology Data Exchange (ETDEWEB)

The gasification reactivities of six typical Chinese anthracite chars with steam and CO{sub 2} at 0.02-0.1 MPa and 920-1050{sup o}C were investigated by using thermogravimetric analysis (TGA). The reactivities of anthracite chars during steam gasification were found to have a good correlation to the coal volatile matter contents. The higher the coal volatile matter content, the higher the reactivity. The difference in reactivities of anthracite chars during CO{sub 2} gasification seems to be more dependent on the catalytic effect of inherent minerals in anthracite. The results show that the greater the alkali index, the higher the reactivity. The reactivities of demineralized anthracite chars vary very little compared with those the undemineralized chars at higher temperatures, whereas the reactivities of demineralized chars from Jincheng and Rujigou are lower than those of undemineralized ones and the reactivities of demineralized chars from Yangquan, Hunan, ...

2006-05-15

236

Effect of hydraulic retention time on the biodegradation of complex phenolic mixture from simulated coal wastewater in hybrid UASB reactors  

International Nuclear Information System (INIS)

This study describes the feasibility of anaerobic treatment of complex phenolics mixture from a simulated synthetic coal wastewater using four identical 13.5 L (effective volume) bench scale hybrid up-flow anaerobic sludge blanket (HUASB) (combining UASB + anaerobic filter) reactors at four different hydraulic retention times (HRT) under mesophilic (27 #+-# 5 "oC) conditions. Synthetic coal wastewater with an average chemical oxygen demand (COD) of 2240 mg/L and phenolics concentration of 752 mg/L was used as substrate. The phenolics contained phenol (490 mg/L); m-, o-, p-cresols (123.0, 58.6, 42 mg/L); 2,4-, 2,5-, 3,4- and 3,5-dimethyl phenols (6.3, 6.3, 4.4 and 21.3 mg/L) as major phenolic compounds. The study demonstrated that at optimum HRT, 24 h, and phenolic loading rate of 0.75 g COD/(m"3-d), the phenolics and COD removal efficiency of the reactors were 96% and 86%, respectively. Bio-kinetic models were applied to data obtained from experimental studies in ...

2008-05-01

237

Change of unit skeletons during an artificial coalification; Jinko sekitanka katei ni okeru tan`i kokkaku kozo no henka  

Energy Technology Data Exchange (ETDEWEB)

In order to obtain knowledge about formation and growth of condensed ring structure in a coalification process, discussions were given on product skeleton structure by using hydrogenation and hydrocracking of heated cellulose. In underwater heating of cellulose, reaction of dehydration has occurred at 200{degree}C or lower, that of decarbonation at 250{degree}C or higher, and that of demethanizing at 300{degree}C, resulting in production of a dark-brown coal-like substance. The substance has lower H/C value and higher O/C value than coal. As the underwater heating temperature rises, the hydrogenation reactivity of the heated substance decreases, and so does the ratio of conversion into toluene solubles. These phenomena are related to strength of cross-linking bond between unit skeleton structures. A substance heated at an underwater heating temperature of 200{degree}C turns toluene-soluble almost completely even during the hydrogenation reaction (350{degree}C for 2 ...

1996-10-28

238

Biodiesel development from high acid value polanga seed oil and performance evaluation in a CI engine  

Energy Technology Data Exchange (ETDEWEB)

Non-edible filtered high viscous (72 cSt at 40{sup o}C) and high acid value (44 mg KOH/gm) polanga (Calophyllum inophyllum L.) oil based mono esters (biodiesel) produced by triple stage transesterification process and blended with high speed diesel (HSD) were tested for their use as a substitute fuel of diesel in a single cylinder diesel engine. HSD and polanga oil methyl ester (POME) fuel blends (20%, 40%, 60%, 80%, and 100%) were used for conducting the short-term engine performance tests at varying loads (0%, 20%, 40%, 60%, 80%, and 100%). Tests were carried out over entire range of engine operation at varying conditions of speed and load. The brake specific fuel consumption (BSFC) and brake thermal efficiency (BTE) were calculated from the recorded data. The engine performance parameters such as fuel consumption, thermal efficiency, exhaust gas temperature and exhaust emissions (CO, CO{sub 2}, HC, NOx, and O{sub 2}) were recorded. The optimum engine operating ...

2007-02-15

239

A newly synthesized glycine derivative to control uniform and pitting corrosion processes of Al induced by SCN"- anions - Chemical, electrochemical and morphological studies  

International Nuclear Information System (INIS)

A newly synthesized glycine derivative (termed GlyD), 2-(4-(dimethylamino)benzylamino)acetic acid hydrochloride, was used to inhibit uniform and pitting corrosion processes of Al in 0.50 M KSCN solutions (pH 6.8) at 25 "oC. For uniform corrosion inhibition study, Tafel extrapolation, linear polarization resistance and impedance methods were used, complemented with SEM examinations. An independent method of chemical analysis, namely ICP-AES (inductively coupled plasma atomic emission spectrometry) was also used to test validity of corrosion rate measured by Tafel extrapolation method. GlyD inhibited uniform corrosion, even at low concentrations, reaching a value of inhibition efficiency up to 97% at a concentration of 5 x 10"-"3 M. Results obtained from the different corrosion evaluation techniques were in good agreement. This new synthesized glycine derivative was also used to control pit nucleation and growth on the pitted Al surface based on cyclic polarization, ...

2010-10-01

240

A Wheat Homolog of MOTHER OF FT AND TFL1 Acts in the Regulation of Germination.  

Science.gov (United States)

Seed dormancy is an adaptive mechanism and an important agronomic trait. Temperature during seed development strongly affects seed dormancy in wheat (Triticum aestivum) with lower temperatures producing higher levels of seed dormancy. To identify genes important for seed dormancy, we used a wheat microarray to analyze gene expression in embryos from mature seeds grown at lower and higher temperatures. We found that a wheat homolog of MOTHER OF FT AND TFL1 (MFT) was upregulated after physiological maturity in dormant seeds grown at the lower temperature. In situ hybridization analysis indicated that MFT was exclusively expressed in the scutellum and coleorhiza. Mapping analysis showed that MFT on chromosome 3A (MFT-3A) colocalized with the seed dormancy quantitative trait locus (QTL) QPhs.ocs-3A.1. MFT-3A expression levels in a dormant cultivar used for the detection of the QTL were higher after physiological maturity; this increased expression correlated with a ...

2011-09-01

241

A SURVEY OF MOLECULAR LINES TOWARD MASSIVE CLUMPS IN EARLY EVOLUTIONARY STAGES OF HIGH-MASS STAR FORMATION  

International Nuclear Information System (INIS)

We have observed the CH_3OH J = 2-1, SiO J = 2-1, C"3"4S J = 2-1, H"1"3CO"+ J = 1-0, HN"1"3C J = 1-0, CCH N = 1-0, OCS J = 8-7, and SO J_N = 2_2-1_1 lines toward 20 massive clumps, including Midcourse Space Experiment (MSX) 8 #mu#m dark sources (infrared dark clouds) and MSX 8 #mu#m sources, by using the Nobeyama Radio Observatory 45 m telescope. We have found that the velocity widths of the CH_3OH and C"3"4S lines are broader than those of the H"1"3CO"+ line in the MSX dark sources. On the other hand, they are comparable to the velocity width of the H"1"3CO"+ line in the MSX sources. In addition, the [SiO]/[H"1"3CO"+] abundance ratio is found to be enhanced in the MSX dark sources in comparison with the MSX sources. These results suggest that shocks caused by interaction between an outflow and an ambient dense gas would have substantial impact on the chemical composition of the MSX dark sources. The velocity widths of the CH_3OH and C"3"4S lines relative to that ...

2010-05-10

242

A REAL-TIME COAL CONTENT/ORE GRADE (C2OC) SENSOR  

Energy Technology Data Exchange (ETDEWEB)

This is the final report of a three year DOE funded project titled ''A real-time coal content/ore grade (C{sub 2}OG) sensor''. The sensor, which is based on hyperspectral imaging technology, was designed to give a machine vision assay of ore or coal. Sensors were designed and built at Resonon, Inc., and then deployed at the Stillwater Mining Company core room in southcentral Montana for analyzing platinum/palladium ore and at the Montana Tech Spectroscopy Lab for analyzing coal and other materials. The Stillwater sensor imaged 91' of core and analyzed this data for surface sulfides which are considered to be pathfinder minerals for platinum/palladium at this mine. Our results indicate that the sensor could deliver a relative ore grade provided tool markings and iron oxidation were kept to a minimum. Coal, talc, and titanium sponge samples were also imaged and analyzed for content and grade with promising results. This research has led ...

2005-04-01

243

Monitoring of DNA and cytogenetic damage in lymphocytes from persons with skin cancer diseases  

International Nuclear Information System (INIS)

There is a lot of interest in the studies that would help to understand whether there is a casual association between cancer and various types of molecular or cytogenetic damage detected in human cells. One major oncogenesis process is activation of proto-oncogenes by point mutations or chromosomal translocation. There are substantial evidence that indicates that the loss of heterozygosity of certain chromosomes is involved in human cancerogenesis. Our study aimed to elicit the possible association between cancer and DNA and cytogenetic abnormalities induced in lymphocytes of people bearing various categories of skin cancer cells. Fresh blood was collected by venipuncture from 25 individuals (including nine prior to cancer treatment). All patients were nonsmoking males, however 42.3 % of them were former smokers. Blood samples were divided into two parts and in the first part of samples cytogenetic studies were performed immediately, while from the second part lymphocytes were isolated ...

2004-11-01

244

Effect of the diameter and depth of pinholes on surface characteristics in the DC pulse plasma nitriding process  

International Nuclear Information System (INIS)

The ion nitriding treatment is a process widely used in steel alloys to improve the material's properties; such as surface hardness, resistance to wear, fatigue life and resistance to corrosion. But geometric changes in the components can produce during the nitriding process different effects on the behavior of the plasma, such as local variations in the electric field, an empty cathode effect, etc. These in turn can affect among other factors the local temperature and therefore the kinetics of the process, generating variations in the compound layer thicknesses and zone of diffusion, and micro-hardness profile. These heterogeneities limit the effectiveness of the plasma nitriding process, where control and duplication of the surface modification are most important. This work aims to study the effect of the geometry of the pieces treated with ionic nitriding, especially the effect of the orifices. An understanding of the operating mechanisms is sought in order to predict the ...

2006-12-01

245

Apparent slip at the surface of a small rotating sphere in a dilute quiescent suspension  

Energy Technology Data Exchange (ETDEWEB)

We consider the case of a test sphere (ball) of radius a{sub 1} rotating at constant angular velocity {omega} in an otherwise quiescent unbounded suspension of uniformly sized spheres of radii a{sub 2} dispersed in a Newtonian fluid of viscosity {mu}. To the first order in the volume fraction c of suspended spheres it is shown that when the ball is small compared with the suspended spheres the suspension does not behave as regards the hydrodynamic torque L exerted on the ball like a homogeneous Newtonian fluid characterized by the usual Einstein viscosity coefficient {mu}{sub s}={mu}(1+5/2c). Explicitly, the torque on the rotating sphere does not obey Kirchoff{close_quote}s law, L=8{pi}{mu}{sub s}a{sub 1}{sup 3}{omega} for no slip. Rather, a modified form of Kirchoff{close_quote}s law is obtained in which the Einstein coefficient of 5/2 is multiplied by a coefficient which is less than unity in magnitude and is functionally dependent only upon the suspended-sphere/test-sphere size ...

1998-03-01

246

A thermographic method as an alternative for gravimetric determination of the particulate diesel emissions; Ein thermographisches Messverfahren als Alternative zur Gravimetrie bei der Ermittlung von Dieselpartikel-Emissionen  

Energy Technology Data Exchange (ETDEWEB)

The basis of assessment for particulate exhaust emissions is the gravimetric analysis of the particle concentration of diluted exhaust gases at temperatures below 52 C. This is very time consuming and takes sufficient sensitivity at low particulate emission rates like downstream of particle filters. For this reason the C/S-method, based on the thermographic analysis of carbon and sulfur, has been developed as an alternative to the gravimetric anallysis. This method yields particle mass as well as the main particle compounds. Comparisons between both methods have been carried out for heavy duty and automobile diesel engines as well as road vehicles and large diesel engines. The tests were conducted with commercial diesel fuel and also with other fuels, such as heavy oils. It could be shown that the C/S-procedure yields the same results as the gravimetric procedure independent of engine, engine mode and kind of fuel. The analysis of all important particulate compounds - elemental carbon ...

1995-09-01

247

Investigations on solar grade silicon and process engineering of advanced silicon solar cells  

Energy Technology Data Exchange (ETDEWEB)

This thesis deals with the evaluation of Solar Grade Silicon (SoG-Si) purified by different techniques, and also the fabrication and characterization of high efficiency and advanced bifacial solar cells. In the beginning of Chapter 1, various SoG-Si production methods relevant for this work are qualitatively described. The three feedstock materials used in this work are from the Fluidized Bed Reactor (FBR) process, metallurgical feedstock-I and feedstock-II process. In metallurgical feedstock-I, the lifetime of the minority charge carriers in multicrystalline silicon (mc-Si) samples at the grain boundaries are found to be higher than the grains themselves possibly due to lower resistivities in the grain boundaries. The efficiency of the best solar cell obtained using the mc-Si metallurgical feedstock-I is 16.1%. It has been identified that the fast light induced degradation, whose magnitude is lower than that of a reference cell suggests the formation of a B-metal complex in the SoG-Si ...

2007-07-01

248

A study of flow boiling phenomena using real time neutron radiography  

International Nuclear Information System (INIS)

The operation and safety of both fossil-fuel and nuclear power stations depend on adequate cooling of the thermal source involved. This is usually accomplished using liquid coolants that are forced through the high temperature regions by a pumping system; this fluid then transports the thermal energy to another section of the power station. However, fluids that undergo boiling during this process create vapor that can be detrimental, and influence safe operation of other system components. The behavior of this vapor, or void, as it is generated and transported through the system is critical in predicting the operational and safety performance. This study uses two advanced penetrating radiation techniques, Real Time Neutron Radiography (RTNR), and High Speed X-Ray Tomography (HS-XCT), to examine void generation and transport behavior in a flow boiling system. The geometries studied were tube side flow boiling in a cylindrical configuration, and a similar flow channel with an internal ...

1346-01-01

249

A model for the devolatilization of a coal particle sufficiently large to be controlled by heat transfer  

Energy Technology Data Exchange (ETDEWEB)

This study follows previous experimental work showing that the shrinking-core model applies to the pyrolysis (i.e., heating in the absence of oxygen) of particles (diam.{approx}14 mm) of a bituminous coal or a lignite in a fluidized bed at 700-950 {sup o}C. These experimental facts are in accord with the production of volatile matter being endothermic and not thermoneutral, as often assumed. Also, the rate at which volatile matter is produced in the presence of oxygen (i.e., devolatilization) or in its absence (pyrolysis) is demonstrated here to be controlled not at all by mass transfer, but by heat conduction to a moving reaction front inside a coal particle, provided its diameter exceeds {approx}3 mm. The resulting steady-state model of devolatilization indicates that six dimensionless groups are required to describe the rate of(I)coal->char+volatile matter for a nonfragmenting and nonswelling coal. This reaction occurs for a total time of c{sub 1}r{sub ...

2006-08-15