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Sample records for equivalent oxide thickness

  1. Direct comparison of the electrical properties in metal/oxide/nitride/oxide/silicon and metal/aluminum oxide/nitride/oxide/silicon capacitors with equivalent oxide thicknesses

    Energy Technology Data Exchange (ETDEWEB)

    An, Ho-Myoung; Seo, Yu Jeong; Kim, Hee Dong; Kim, Kyoung Chan; Kim, Jong-Guk [School of Electrical Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Cho, Won-Ju; Koh, Jung-Hyuk [Department of Electronic Materials Engineering, Kwangwoon University, Seoul 139-701 (Korea, Republic of); Sung, Yun Mo [Department of Materials and Science Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Kim, Tae Geun, E-mail: tgkim1@korea.ac.k [School of Electrical Engineering, Korea University, Seoul 136-713 (Korea, Republic of)

    2009-07-31

    We examine the electrical properties of metal/oxide/nitride/oxide/silicon (MONOS) capacitors with two different blocking oxides, SiO{sub 2} and Al{sub 2}O{sub 3}, under the influence of the same electric field. The thickness of the Al{sub 2}O{sub 3} layer is set to 150 A, which is electrically equivalent to a thickness of the SiO{sub 2} layer of 65 A, in the MONOS structure for this purpose. The capacitor with the Al{sub 2}O{sub 3} blocking layer shows a larger capacitance-voltage memory window of 8.6 V, lower program voltage of 7 V, faster program/erase speeds of 10 ms/1 {mu}s, lower leakage current of 100 pA and longer data retention than the one with the SiO{sub 2} blocking layer does. These improvements are attributed to the suppression of the carrier transport to the gate electrode afforded by the use of an Al{sub 2}O{sub 3} blocking layer physically thicker than the SiO{sub 2} one, as well as the effective charge-trapping by Al{sub 2}O{sub 3} at the deep energy levels in the nitride layer.

  2. Use of water vapor for suppressing the growth of unstable low-{kappa} interlayer in HfTiO gate-dielectric Ge metal-oxide-semiconductor capacitors with sub-nanometer capacitance equivalent thickness

    Energy Technology Data Exchange (ETDEWEB)

    Xu, J.P. [Department of Electronic Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 (China); Zou, X. [School of Electromachine and Architecture Engineering, Jianghan University, Wuhan, 430056 (China); Lai, P.T. [Department of Electrical and Electronic Engineering, University of Hong Kong, Pokfulam Road (Hong Kong)], E-mail: laip@eee.hku.hk; Li, C.X.; Chan, C.L. [Department of Electrical and Electronic Engineering, University of Hong Kong, Pokfulam Road (Hong Kong)

    2009-03-02

    Annealing of high-permittivity HfTiO gate dielectric on Ge substrate in different gases (N{sub 2}, NH{sub 3}, NO and N{sub 2}O) with or without water vapor is investigated. Analysis by transmission electron microscopy indicates that the four wet anneals can greatly suppress the growth of a GeO{sub x} interlayer at the dielectric/Ge interface, and thus decrease interface states, oxide charges and gate leakage current. Moreover, compared with the wet N{sub 2} anneal, the wet NH{sub 3}, NO and N{sub 2}O anneals decrease the equivalent permittivity of the gate dielectric due to the growth of a GeO{sub x}N{sub y} interlayer. Among the eight anneals, the wet N{sub 2} anneal produces the best dielectric performance with an equivalent relative permittivity of 35, capacitance equivalent thickness of 0.81 nm, interface-state density of 6.4 x 10{sup 11} eV{sup -1} cm{sup -2} and gate leakage current of 2.7 x 10{sup -4} A/cm{sup 2} at V{sub g} = 1 V.

  3. Use of water vapor for suppressing the growth of unstable low-κ interlayer in HfTiO gate-dielectric Ge metal-oxide-semiconductor capacitors with sub-nanometer capacitance equivalent thickness

    International Nuclear Information System (INIS)

    Xu, J.P.; Zou, X.; Lai, P.T.; Li, C.X.; Chan, C.L.

    2009-01-01

    Annealing of high-permittivity HfTiO gate dielectric on Ge substrate in different gases (N 2 , NH 3 , NO and N 2 O) with or without water vapor is investigated. Analysis by transmission electron microscopy indicates that the four wet anneals can greatly suppress the growth of a GeO x interlayer at the dielectric/Ge interface, and thus decrease interface states, oxide charges and gate leakage current. Moreover, compared with the wet N 2 anneal, the wet NH 3 , NO and N 2 O anneals decrease the equivalent permittivity of the gate dielectric due to the growth of a GeO x N y interlayer. Among the eight anneals, the wet N 2 anneal produces the best dielectric performance with an equivalent relative permittivity of 35, capacitance equivalent thickness of 0.81 nm, interface-state density of 6.4 x 10 11 eV -1 cm -2 and gate leakage current of 2.7 x 10 -4 A/cm 2 at V g = 1 V

  4. Measurement Of Lead Equivalent Thickness For Irradiation Room: An Analysis

    International Nuclear Information System (INIS)

    Mohd Khalid Matori; Azuhar Ripin; Husaini Salleh; Mohd Khairusalih Mohd Zin; Muhammad Jamal Muhd Isa; Mohd Faizal Abdul Rahman

    2014-01-01

    The Malaysian Ministry of Health (MOH) has established that the irradiation room must have a sufficient thickness of shielding to ensure that requirements for the purpose of radiation protection of patients, employees and the public are met. This paper presents a technique using americium-241 source to test and verify the integrity of the shielding thickness in term of lead equivalent for irradiation room at health clinics own by MOH. Results of measurement of 8 irradiation rooms conducted in 2014 were analyzed for this presentation. Technical comparison of the attenuation of gamma rays from Am-241 source through the walls of the irradiation room and pieces of lead were used to assess the lead equivalent thickness of the walls. Results showed that almost all the irradiation rooms tested meet the requirements of the Ministry of Health and is suitable for the installation of the intended diagnostic X-ray apparatus. Some specific positions such as door knobs and locks, electrical plug sockets were identified with potential to not met the required lead equivalent thickness hence may contribute to higher radiation exposure to workers and the public. (author)

  5. Determination of equivalent copper thickness of patient equivalent phantoms in terms of attenuation, used in radiology

    International Nuclear Information System (INIS)

    Jansen, J.Th.M.; Suliman, I.I.; Zoetelief, J.

    2002-01-01

    Full text: In the radiation protection research programme of the European Union, as part of the DIMOND concerted action, constancy check protocols for fluoroscopic systems have been developed. For practical reasons copper filters are preferred to patients and tissue equivalent, water or PMMA, phantoms. The objectives are to derive patient entrance surface dose rates and the dose rate at the image intensifier input. The protocol states that copper sheets of either 1 mm or 1.5 mm thick may be used. The present study investigates the equivalent thickness of copper filters compared to PMMA phantoms in terms of attenuation for both geometries and different tube voltage and filter combinations. The geometry to determine the patient entrance surface dose is with the copper filter close to the image intensifier. The ionisation chamber is placed on the side of the copper sheet nearest to the X-ray tube. The inverse square law is used to correct for differences in position. Measurements are performed with different settings and with and without the use of an anti-scatter grid. The geometry to determine the air kerma rate at the image intensifier is with the copper filter attached to the X-ray tube diaphragm. The ionisation chamber is placed on the surface of the image intensifier housing. Again measurements are performed with different settings and with and without anti-scatter grid. If necessary, the inverse square law correction is applied. Two different radiation beam sizes are used, i.e., a small beam with a diameter of 0.10 m at a distance of 1.00 m from the focus and a large beam with a diameter of 0.23 m at a distance of 1.00 m from the focus. The applied tube voltages and PMMA phantom thickness combinations are 60 kV, 13 cm; 80 kV, 14 cm; 100 kV, 16 cm; 120 kV, 17 cm; 150 kV, 18 cm; 150 kV, 20 cm and 150 kV, 30 cm. The spectra for the different tube voltages are generated with the IPEM Report 78 software at an anode angle of 16 degree, 0% ripple and 2.5 mm added

  6. on THICKNESS OF COPPER (|) OXIDE

    African Journals Online (AJOL)

    2006-12-20

    Dec 20, 2006 ... known materials to be used as semiconductor devices. The oxide is. Observed to be an attractive starting material for the production of solar cells for low cost terrestrial conversion of solar energy to electricity. Copper (I) oxide is one Of the earliest known photovoltaic materials and the first in which the ...

  7. Behavior of the equivalent slab thickness over three European stations

    Czech Academy of Sciences Publication Activity Database

    Mosert, M.; Magdaleno, S.; Burešová, Dalia; Altadill, D.; Gende, M.; Gularte, E.; Scida, L.

    2013-01-01

    Roč. 51, č. 4 (2013), s. 677-682 ISSN 0273-1177 Institutional support: RVO:68378289 Keywords : Ionospheric slab thickness * F2-layer peak * TEC * European stations Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.238, year: 2013 http://www.sciencedirect.com/science/article/pii/S0273117712003754

  8. Lead Equivalent Thickness Measurement for Mixed Compositions of Barium Plaster Block

    International Nuclear Information System (INIS)

    Norriza Mohd Isa; Muhammad Jamal Muhammad Isa; Nur Shahriza Zainuddin; Mohd Khairusalih Md Zin; Shahrul Azlan Azizan

    2016-01-01

    Measurement of lead equivalent thickness for ionizing radiation exposure room wall shall be performed as stated in Malaysian Standard MS 838. A few numbers of sample blocks with different mixture of barium plaster compositions based and varies certain thickness as a shielding material for exposure room wall belong to a local company were tested by using Cs-137, Co-60 and Am-241 with different activities . Radiations passed through the samples were detected with calibrated survey meter. The distance between radiation source and the detector is about 40 cm. Lead uniformity test on the samples was also determined at three labeled points on the samples. Lead equivalent thicknesses for the samples were evaluated based on a calibration graph that was plotted with lead sheets and with the radiation sources. Results shown that lead equivalent thickness for the samples with same actual physical thickness represent different values for different sources. (author)

  9. Metallic oxide switches using thick film technology

    Science.gov (United States)

    Patel, D. N.; Williams, L., Jr.

    1974-01-01

    Metallic oxide thick film switches were processed on alumina substrates using thick film technology. Vanadium pentoxide in powder form was mixed with other oxides e.g., barium, strontium copper and glass frit, ground to a fine powder. Pastes and screen printable inks were made using commercial conductive vehicles and appropriate thinners. Some switching devices were processed by conventional screen printing and firing of the inks and commercial cermet conductor terminals on 96% alumina substrates while others were made by applying small beads or dots of the pastes between platinum wires. Static, and dynamic volt-ampere, and pulse tests indicate that the switching and self-oscillatory characteristics of these devices could make them useful in memory element, oscillator, and automatic control applications.

  10. Aluminum oxide film thickness and emittance

    International Nuclear Information System (INIS)

    Thomas, J.K.; Ondrejcin, R.S.

    1991-11-01

    Aluminum reactor components which are not actively cooled could be subjected to high temperatures due to gamma heating after the core coolant level dropped during the ECS phase of a hypothetical LOCA event. Radiative heat transfer is the dominant heat transfer process in this scenario and therefore the emittance of these components is of interest. Of particular interest are the safety rod thimbles and Mark 60B blanket assemblies; for the K Reactor, these components have been exposed to low temperature (< 55 degrees C) moderator for about a year. The average moderator temperature was assumed to be 30 degrees C. The Al oxide film thickness at this temperature, after one year of exposure, is predicted to be 6.4 μm ± 10%; insensitive to exposure time. Dehydration of the film during the gamma heating accident would result in a film thickness of 6.0 μm ± 11%. Total hemispherical emittance is predicted to be 0.69 at 96 degrees C, decreasing to 0.45 at 600 degrees C. Some phenomena which would tend to yield thicker oxide films in the reactor environment relative to those obtained under experimental conditions were neglected and the predicted film thickness values are therefore conservative. The emittance values predicted for a given film thickness are also conservative. The conservativisms inherent in the predicted emittance are particularly relevant for uncertainty analysis of temperatures generated using these values

  11. Americium-241 use of measurement lead equivalent thickness for medical x-ray room: A review

    International Nuclear Information System (INIS)

    Mohd Khalid Matori; Husaini Saleh; Abd Aziz Mhd Ramli; Muhammad Jamal Md Isa; Mohd Firdaus Abd Rahman; Zainal Jamaluddin

    2010-01-01

    Lead equivalent thickness measurement of a shielding material in diagnostic radiology is very important to ensure that requirements for the purpose of radiation protection of patients, employees and the public are met. The Malaysian Ministry of Health (MOH) has established that the irradiation room must have sufficient shielding thickness, for example for general radiography it must be at least equal to 2.0 mm of Pb, for panoramic dental radiography at least equal to 1.5 mm of Pb and for mammography should be a minimum of 1.0 mm of Pb. This paper presents a technique using americium-241 source to test and verify the integrity of the shielding thickness in term of lead equivalent for X-ray room at health centres. Results of measurement of 30 irradiation rooms conducted from 2009 to mid 2010 were analyzed for this presentation. Technical comparison of the attenuation of gamma rays from Am-241 source through the walls of the irradiation room and pieces of lead were used to assess the lead equivalent thickness of the walls. Results showed that 96.7 % of the irradiation rooms tested meet the requirements of the Ministry of Health and is suitable for the installation of the intended diagnostic X-ray apparatus. Some specific positions such as door knobs and locks, electrical plug sockets were identified with potential to not met the required lead equivalent thickness hence may contribute to higher radiation exposure to workers and the public. (author)

  12. Equivalent half-value thickness and mean energies of filtered X-ray bremsstrahlung spectra

    International Nuclear Information System (INIS)

    Seelentag, W.W.; Panzer, W.

    1980-01-01

    X-ray beam qualities are often conveniently described by half-value thicknesses (in connection with tube voltage and filtration). Aluminium and copper are commonly used as half-value thickness materials, and either material may be used in a large intermediate energy range. Data comparisons frequently require conversions from values in Al to values in Cu. Equivalent half-value thicknesses for polychromatic radiations depend on the shapes of the spectra, but spectrometry is too expensive for routine application. Half-value thicknesses in both Al and Cu have been determined for some 250 spectra (tube potentials 10 to 300 kV). The results are tabulated, and these results together with a nomogram enable conversion with an accuracy of better than +- 5% in most cases. (UK)

  13. Determination of lead equivalent thickness to building blocks used in shielding of diagnostic x-ray rooms in Syria

    International Nuclear Information System (INIS)

    Kawash, A.; Khedr, M.; Wannus, K.; Souliman, J.; Al-Oudat, M.

    1998-06-01

    Lead equivalent thicknesses of various kinds of blocks (Hollow core, solid, filled, roof) with different thicknesses were determined. These blocks are widely used for building the diagnostic X-rya departments in Syria. Different applied voltages at X-ray tube (65, 85, 100, 125, 150 KVp) were examined. The results showed that the highest lead equivalent thicknesses for hollow core blocks were at 100 KVp. These equivalent thicknesses were 0.4372, 0.7008 and 0.928 mm for block thicknesses of 10, 15 and 20 cm, respectively. it was also found that, the lead equivalent thicknesses for filled, solid and concrete block were 3.5 to 4 times higher than that of the hollow core block for the same thicknesses and the applied KVp. Values obtained for roof blocks were similar to that of hollow core for the same conditions and geometry. (Author)

  14. Transtendon, Double-Row, Transosseous-Equivalent Arthroscopic Repair of Partial-Thickness, Articular-Surface Rotator Cuff Tears

    OpenAIRE

    Dilisio, Matthew F.; Miller, Lindsay R.; Higgins, Laurence D.

    2014-01-01

    Arthroscopic transtendinous techniques for the arthroscopic repair of partial-thickness, articular-surface rotator cuff tears offer the advantage of minimizing the disruption of the patient's remaining rotator cuff tendon fibers. In addition, double-row fixation of full-thickness rotator cuff tears has shown biomechanical advantages. We present a novel method combining these 2 techniques for transtendon, double-row, transosseous-equivalent arthroscopic repair of partial-thickness, articular-s...

  15. Water equivalent thickness values of materials used in beams of protons, helium, carbon and iron ions.

    Science.gov (United States)

    Zhang, Rui; Taddei, Phillip J; Fitzek, Markus M; Newhauser, Wayne D

    2010-05-07

    Heavy charged particle beam radiotherapy for cancer is of increasing interest because it delivers a highly conformal radiation dose to the target volume. Accurate knowledge of the range of a heavy charged particle beam after it penetrates a patient's body or other materials in the beam line is very important and is usually stated in terms of the water equivalent thickness (WET). However, methods of calculating WET for heavy charged particle beams are lacking. Our objective was to test several simple analytical formulas previously developed for proton beams for their ability to calculate WET values for materials exposed to beams of protons, helium, carbon and iron ions. Experimentally measured heavy charged particle beam ranges and WET values from an iterative numerical method were compared with the WET values calculated by the analytical formulas. In most cases, the deviations were within 1 mm. We conclude that the analytical formulas originally developed for proton beams can also be used to calculate WET values for helium, carbon and iron ion beams with good accuracy.

  16. Rapid optical determination of topological insulator nanoplate thickness and oxidation

    Directory of Open Access Journals (Sweden)

    Fan Yang

    2017-01-01

    Full Text Available The stability of 2D antimony telluride (Sb2Te3 nanoplates in ambient conditions is elucidated. These materials exhibit an anisotropic oxidation mode, and CVD synthesized samples oxidize at a much faster rate than exfoliated samples investigated in previous studies. Optical measurement techniques are introduced to rapidly measure the oxidation modes and thickness of 2D materials. Auger characterization were conducted to confirm that oxygen replaces tellurium as opposed to antimony under ambient conditions. No surface morphology evolution was detected in AFM before and after exposure to air. These techniques were employed to determine the origin of the thickness dependent color change effect in Sb2Te3. It is concluded that this effect is a combination of refractive index change due to oxidation and Fresnel effects.

  17. Oxide thickness measurement for monitoring fuel performance at high burnup

    International Nuclear Information System (INIS)

    Jaeger, M.A.; Van Swam, L.F.P.; Brueck-Neufeld, K.

    1991-01-01

    For on-site monitoring of the fuel performance at high burnup, Advanced Nuclear Fuels uses the linear scan eddy current method to determine the oxide thickness of irradiated Zircaloy fuel cans. Direct digital data acquisition methods are employed to collect the data on magnetic storage media. This field-proven methodology allows oxide thickness measurements and rapid interpretation of the data during the reactor outages and makes it possible to immediately reinsert the assemblies for the next operating cycle. The accuracy of the poolside measurements and data acquisition/interpretation techniques have been verified through hot cell metallographic measurements of rods previously measured in the fuel pool. The accumulated data provide a valuable database against which oxide growth models have been benchmarked and allow for effective monitoring of fuel performance. (orig.) [de

  18. About a global model of the equivalent slab thickness of the ionosphere

    Science.gov (United States)

    Maltseva, Olga; Mozhaeva, Natalya

    2016-07-01

    Use of a median of an equivalent slab thickness of the ionosphere τ(med) is the simplest case of assimilation of the total electron content TEC. To use τ(med) on a global scale it is necessary to have its model. Some variants are possible: (1) construction of superficial function of kriging type using values of τ(med) in several points, (2) the NGM model which can be constructed on the basis of two empirical Neustrelitz models for TEC and NmF2, (3) the IRI-Plas model. Construction of a model with use of τ(med) values is difficult because of the large variability of values (in particular, a strong pre-sunrise peak at some latitudes). Testing of models NGM and IRI-Plas shows that they not always provide satisfactory results in that or another region of globe. Besides, they are not pure empirical models. In the present work, an attempt is done to use two-parameter model on a basis of hyperbolic dependence of τ(med) from NmF2 (τ(hyp) =b0+b1/NmF2) and approximation of coefficient K(τ) = τ(med)/τ(IRI) in a latitudinal course. On an example of March 2015 when there was a great number of ionosonde data, coefficients b0 and b1 were modeled. Results are presented for two regions Lat1 and Lat2. Area Lat1 contains 13 stations, basically, on the American continent of northern and southern hemispheres. Area Lat2 contains 20 stations of the European, Siberian and Southeast regions. Certain advantage of use of coefficients K(τ) can be that in its numerator there is a magnitude of τ(IRI), having a global character, and a small variation of K(τ) in zones with close longitudes. Difference is a model construction at each hour. Degree of coincidence is better to illustrate on circular diagrams. Models were tested by elimination of one of stations and definition of deviations of calculated foF2 from experimental values. Authors thank Southern Federal University for support by grant #213.01-11/2014-22.

  19. Development of examination technique for oxide layer thickness measurement of irradiated fuel rods

    International Nuclear Information System (INIS)

    Koo, D. S.; Park, S. W.; Kim, J. H.; Seo, H. S.; Min, D. K.; Kim, E. K.; Chun, Y. B.; Bang, K. S.

    1999-06-01

    Technique for oxide layer thickness measurement of irradiated fuel rods was developed to measure oxide layer thickness and study characteristic of fuel rods. Oxide layer thickness of irradiated fuels were measured, analyzed. Outer oxide layer thickness of 3 cycle-irradiated fuel rods were 20 - 30 μm, inner oxide layer thickness 0 - 10 μm and inner oxide layer thickness on cracked cladding about 30 μm. Oxide layer thickness of 4 cycle-irradiated fuel rods were about 2 times as thick as those of 1 cycle-irradiated fuel rods. Oxide layer on lower region of irradiated fuel rods was thin and oxide layer from lower region to upper region indicated gradual increase in thickness. Oxide layer thickness from 2500 to 3000 mm showed maximum and oxide layer thickness from 3000 to top region of irradiated fuel rods showed decreasing trend. Inner oxide layer thicknesses of 4 cycle-irradiated fuel rod were about 8 μm at 750 - 3500 mm from the bottom end of fuel rod. Outer oxide layer thickness were about 8 μm at 750 - 1000 mm from the bottom end of fuel rod. These indicated gradual increase up to upper region from the bottom end of fuel rod. These indicated gradual increase up to upper region from the bottom end of fuel. Oxide layer thickness technique will apply safety evaluation and study of reactor fuels. (author). 6 refs., 14 figs

  20. Formation of silicon Oxide nano thickness on Si (III) with the assistance of Cs

    International Nuclear Information System (INIS)

    Bahari, A.; Bagheri, M.

    2006-01-01

    : The possibility of controlling the growth of a uniform ultra thin oxide on silicon via oxygen dosing at low temperatures, would be a great interest for the projected further development of nano electronics. One way to achieve this is to be able to control the conversion of chemically adsorbed oxygen and retained at room temperature into oxide during subsequent heating. Oxygen is chemisorbed at room temperature on Si(111) surface to saturation ( >100 L O 2 ), and the experimental chamber is then evacuated. This leaves adsorbed oxygen as atomically inserted on Si surface which sits on the back bonds. This surface is then used as a base for further processing which in one case consists of annealing to 600- 700 d eg C and subsequent exposures equivalent to the first step. This is repeated again. As the focus of this work, a series of experiments are done with adsorbed Cs, which assists in retaining oxygen and in transforming the adsorbed oxygen into oxide upon heating. It was found that the oxide formed on the surface at low coverage clusters. Without any external influence, the clusters may be made to coalesce upon further oxygen adsorption at room temperature, and annealing terminates as a continuous monolayer of amorphous oxide on top of a well-ordered silicon substrate. This configuration is inert to further uptake of oxygen. A higher oxide thickness could be obtained with Cs. Also in this case, the oxide growth saturates in an inert oxide Iayer

  1. Transtendon, double-row, transosseous-equivalent arthroscopic repair of partial-thickness, articular-surface rotator cuff tears.

    Science.gov (United States)

    Dilisio, Matthew F; Miller, Lindsay R; Higgins, Laurence D

    2014-10-01

    Arthroscopic transtendinous techniques for the arthroscopic repair of partial-thickness, articular-surface rotator cuff tears offer the advantage of minimizing the disruption of the patient's remaining rotator cuff tendon fibers. In addition, double-row fixation of full-thickness rotator cuff tears has shown biomechanical advantages. We present a novel method combining these 2 techniques for transtendon, double-row, transosseous-equivalent arthroscopic repair of partial-thickness, articular-surface rotator cuff tears. Direct visualization of the reduction of the retracted articular tendon layer to its insertion on the greater tuberosity is the key to the procedure. Linking the medial-row anchors and using a double-row construct provide a stable repair that allows early shoulder motion to minimize the risk of postoperative stiffness.

  2. Usage of neural network to predict aluminium oxide layer thickness.

    Science.gov (United States)

    Michal, Peter; Vagaská, Alena; Gombár, Miroslav; Kmec, Ján; Spišák, Emil; Kučerka, Daniel

    2015-01-01

    This paper shows an influence of chemical composition of used electrolyte, such as amount of sulphuric acid in electrolyte, amount of aluminium cations in electrolyte and amount of oxalic acid in electrolyte, and operating parameters of process of anodic oxidation of aluminium such as the temperature of electrolyte, anodizing time, and voltage applied during anodizing process. The paper shows the influence of those parameters on the resulting thickness of aluminium oxide layer. The impact of these variables is shown by using central composite design of experiment for six factors (amount of sulphuric acid, amount of oxalic acid, amount of aluminium cations, electrolyte temperature, anodizing time, and applied voltage) and by usage of the cubic neural unit with Levenberg-Marquardt algorithm during the results evaluation. The paper also deals with current densities of 1 A · dm(-2) and 3 A · dm(-2) for creating aluminium oxide layer.

  3. Usage of Neural Network to Predict Aluminium Oxide Layer Thickness

    Directory of Open Access Journals (Sweden)

    Peter Michal

    2015-01-01

    Full Text Available This paper shows an influence of chemical composition of used electrolyte, such as amount of sulphuric acid in electrolyte, amount of aluminium cations in electrolyte and amount of oxalic acid in electrolyte, and operating parameters of process of anodic oxidation of aluminium such as the temperature of electrolyte, anodizing time, and voltage applied during anodizing process. The paper shows the influence of those parameters on the resulting thickness of aluminium oxide layer. The impact of these variables is shown by using central composite design of experiment for six factors (amount of sulphuric acid, amount of oxalic acid, amount of aluminium cations, electrolyte temperature, anodizing time, and applied voltage and by usage of the cubic neural unit with Levenberg-Marquardt algorithm during the results evaluation. The paper also deals with current densities of 1 A·dm−2 and 3 A·dm−2 for creating aluminium oxide layer.

  4. Environmental Controls on Snow Cover Thickness and Water Equivalent in Two Sub-Arctic Mountain Catchments

    OpenAIRE

    Cosgrove, Christopher

    2015-01-01

    The spatial variability of snow cover characteristics (depth, density, and snow water equivalent [SWE]) has paramount importance for the management of water resources in mountain environments. Passive microwave (PM) inference of SWE from space-borne instrumentation is increasingly used but the reliability of this technique remains limited in mountainous areas. Complex topography and the transition between forest and alpine tundra vegetation zones create large spatial heterogeneities in the sn...

  5. Total free radical species and oxidation equivalent in polluted air.

    Science.gov (United States)

    Wang, Guoying; Jia, Shiming; Niu, Xiuli; Tian, Haoqi; Liu, Yanrong; Chen, Xuefu; Li, Lan; Zhang, Yuanhang; Shi, Gaofeng

    2017-12-31

    Free radicals are the most important chemical intermediate or agent of the atmosphere and influenced by thousands of reactants. The free radicals determine the oxidizing power of the polluted air. Various gases present in smog or haze are oxidants and induce organ and cellular damage via generation of free radical species. At present, however, the high variability of total free radicals in polluted air has prevented the detection of possible trends or distributions in the concentration of those species. The total free radicals are a kind of contaminants with colorless, tasteless characteristics, and almost imperceptible by human body. Here we present total free radical detection and distribution characteristics, and analyze the effects of total free radicals in polluted air on human health. We find that the total free radical values can be described by not only a linear dependence on ozone at higher temperature period, but also a linear delay dependence on particulate matter at lower temperature period throughout the measurement period. The total free radical species distribution is decrease from west to east in Lanzhou, which closely related to the distribution of the air pollutants. The total free radical oxidation capacity in polluted air roughly matches the effects of tobacco smoke produced by the incomplete combustion of a controlled amount of tobacco in a smoke chamber. A relatively unsophisticated chromatographic fingerprint similarity is used for indicating preliminarily the effect of total free radicals in polluted air on human health. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. The critical oxide thickness for Pb-free reflow soldering on Cu substrate

    Energy Technology Data Exchange (ETDEWEB)

    Chung, C. Key [Department of Materials Science and Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan (China); Assembly Test Global Materials, Intel Microelectronics Asia Ltd, B1, No. 205, Tun-Hwa North Road, 10595 Taipei, Taiwan (China); Chen, Y.J.; Li, C.C. [Department of Materials Science and Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan (China); Kao, C.R., E-mail: crkao@ntu.edu.tw [Department of Materials Science and Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan (China)

    2012-06-01

    Oxidation is an undesirable effect of reflow soldering. Non-wetting occurs when the oxide layer grows above the critical thickness. Characterizing the critical oxide thickness for soldering is challenging due to oxide's nano-scale thickness and irregular topographic surface. In this paper, the critical copper oxide thickness was characterized by Time-of-Flight Secondary Ion Mass Spectrometry, Scanning Electron Microscopy, Energy-Dispersive X-ray spectroscopy, and Transmission Electron Microscopy. Copper substrates were coated with an Organic-Solderable-Preservative (OSP) layer and baked at 150 Degree-Sign C and 85% Relative Humidity for different amounts of time. The onset of the non-wetting phenomenon occurred when the oxide thickness reached 18 {+-} 5 nm. As the oxide grew beyond this critical thickness, the percentage of non-wetting solder joint increased exponentially. The growth of the oxide thickness followed a parabolic rate law. The rate constant of oxidation was 0.6 Multiplication-Sign 10{sup -15} cm{sup 2} min{sup -1}. Oxidation resulted from interdiffusion of copper and oxygen atoms through the OSP and oxide layers. The oxidation mechanism will be presented and discussed. - Highlights: Black-Right-Pointing-Pointer Critical oxide thickness for Pb free solder on Cu substrate is 18 {+-} 5 nm. Black-Right-Pointing-Pointer Above the critical oxide, non-wet solder joint increases exponentially. Black-Right-Pointing-Pointer A maximum 13-nm oxide thickness is suggested for good solder joint. Black-Right-Pointing-Pointer Initial growth of oxide thickness is logarithmic and then parabolic after 12 nm. Black-Right-Pointing-Pointer Thick oxide (360-560 nm) is formed as pores shorten the oxidation path.

  7. Analysis of zircaloy oxide thickness data from PWRs

    International Nuclear Information System (INIS)

    Sheppard, K.D.; Speyer, D.M.; Chan, Y.Y.; Frankl, I.; Strasser, A.A.

    1990-02-01

    Prior EPRI funded research (Project 1250-1) resulted in a set of Zircaloy waterside corrosion models. These models were based principally on KWU reactor data. The objective of this study was to evaluate the ability of the KWU corrosion models to predict available domestic USA data for all domestic PWR vendors in order to further validate the models and to provide a consistent basis to judge the corrosion data of the domestic plants. A methodology for analyzing the large amount of data was developed and implemented in a single channel model. This model includes the capability, by a method described herein, of accounting for open core related effects (crossflow) and the effect of the immediately adjacent fuel rods, guide tubes, etc., on the coolant conditions around the fuel rods that were measured for oxide thickness. Data from the Arkansas Unit number-sign 2 (ANO-2) Combustion Engineering (C-E), Oconee Units 1 and 2 built by Babcock ampersand Wilcox (B ampersand W), and the Trojan reactor built by Westinghouse (W) were used in this study. The corrosion models previously developed, and the present single channel model methodology, were able to predict the corrosion data quite well. The maximum corrosion thickness was on the order of 20 to 40 microns in all plants studied. 13 refs., 11 figs., 5 tabs

  8. Equivalent network for resistance and temperature coefficient of resistance versus temperature and composition of thick resistive films

    International Nuclear Information System (INIS)

    Kusy, A.

    1987-01-01

    Two types of elementary resistances in thick resistive films have been considered: (i) constriction resistance R/sub C/ determined by the bulk properties of conducting material and by the geometry of constriction, and (ii) barrier resistance R/sub B/ determined by the parameters of a thermally activated type of tunneling process and by the geometry of the metal-insulator-metal unit. On this basis a resistance network composed of a large number of the two types of resistances has been defined. The network has been considered as being equivalent to thick resistive film (TRF) from the point of view of the resistance and temperature coefficient of resistance (TCR). The parameters of this network have been evaluated by the computer-aided approximation of the experimental data found for RuO 2 -based TRFs. On the basis of the equations derived for the network as well as the results of the approximation process, it can be concluded that the small values of the network TCR result from the superposition of the TCR of the conducting component β/sub C/ and of the temperature coefficient of barrier resistance α/sub B/. In this superposition β/sub C/ is attenuated (by 1--2 orders of magnitude), while α/sub B/ is attenuated by only few percentages. The network has been found to be strongly barrier dominated

  9. Thickness-Dependent Bioelectrochemical and Energy Applications of Thickness-Controlled Meso-Macroporous Antimony-Doped Tin Oxide

    Directory of Open Access Journals (Sweden)

    Daniel Mieritz

    2018-04-01

    Full Text Available Coatings of hierarchically meso-macroporous antimony-doped tin oxide (ATO enable interfacing adsorbed species, such as biomacromolecules, with an electronic circuit. The coating thickness is a limiting factor for the surface coverage of adsorbates, that are electrochemically addressable. To overcome this challenge, a carbon black-based templating method was developed by studying the composition of the template system, and finding the right conditions for self-standing templates, preventing the reaction mixture from flowing out of the mask. The thicknesses of as-fabricated coatings were measured using stylus profilometry to establish a relationship between the mask thickness and the coating thickness. Cyclic voltammetry was performed on coatings with adsorbed cytochrome c to check whether the entire coating thickness was electrochemically addressable. Further, bacterial photosynthetic reaction centers were incorporated into the coatings, and photocurrent with respect to coating thickness was studied. The template mixture required enough of both carbon black and polymer, roughly 7% carbon black and 6% poly(ethylene glycol. Coatings were fabricated with thicknesses approaching 30 µm, and thickness was shown to be controllable up to at least 15 µm. Under the experimental conditions, photocurrent was found to increase linearly with the coating thickness, up to around 12 µm, above which were diminished gains.

  10. Research on the equivalent circuit model of a circular flexural-vibration-research on the equivalent circuit model of a circular flexural-vibration-mode piezoelectric transformer with moderate thickness.

    Science.gov (United States)

    Huang, Yihua; Huang, Wenjin; Wang, Qinglei; Su, Xujian

    2013-07-01

    The equivalent circuit model of a piezoelectric transformer is useful in designing and optimizing the related driving circuits. Based on previous work, an equivalent circuit model for a circular flexural-vibration-mode piezoelectric transformer with moderate thickness is proposed and validated by finite element analysis. The input impedance, voltage gain, and efficiency of the transformer are determined through computation. The basic behaviors of the transformer are shown by numerical results.

  11. Thick-film effects in the oxidation and hydriding of zirconium alloys

    International Nuclear Information System (INIS)

    Johnson, A.B. Jr.

    1989-08-01

    One of the fundamental discoveries involving radiation effects on the oxidation of Zircaloy in low-oxygen aqueous environments is the influence of thick oxide films. Zircaloy oxidation rates in low-oxygen (hydrogen-rich) coolants initially proceed at relatively low rates, often almost uninfluenced by radiation. Marked upturns in oxidation rate have signaled the onset of radiation effects. The radiation effects appear to correlate with a threshold oxide thickness. Results of the test reactor experiments lead to formulation of the Thick-Film Hypothesis: beyond a threshold oxide thickness, radiolysis of water that infiltrates oxide cracks and pores controls the oxidation rate; radiation creates microenvironments inside the oxide film, producing highly oxidizing conditions, that are no longer suppressed by the coolant-borne hydrogen. Upturns in oxidation rate on high-exposure Zircaloy pressure tubes add confirmatory evidence for the thick-film effect. This paper summarizes the early evidence for thick-film behavior, including oxidation and hydriding trends, updates confirmatory evidence from Zircaloy reactor and fuel assembly components, and highlights other observations from the test reactor series that have potential fundamental significance to explanations of radiation effects on Zircaloy. 23 refs., 10 figs

  12. Equivalent-circuit model for the thickness-shear mode resonator with a viscoelastic film near film resonance.

    Science.gov (United States)

    Martin, S J; Bandey, H L; Cernosek, R W; Hillman, A R; Brown, M J

    2000-01-01

    We derive a lumped-element, equivalent-circuit model for the thickness-shear mode (TSM) resonator with a viscoelastic film. This modified Butterworth-Van Dyke model includes in the motional branch a series LCR resonator, representing the quartz resonance, and a parallel LCR resonator, representing the film resonance. This model is valid in the vicinity of film resonance, which occurs when the acoustic phase shift across the film is an odd multiple of pi/2 rad. For low-loss films, this model accurately predicts the frequency changes and damping that arise at resonance and is a reasonable approximation away from resonance. Elements of the parallel LCR resonator are explicitly related to film properties and can be interpreted in terms of elastic energy storage and viscous power dissipation. The model leads to a simple graphical interpretation of the coupling between the quartz and film resonances and facilitates understanding of the resulting responses. These responses are compared with predictions from the transmission-line and Sauerbrey models.

  13. The use of Am-241 as Equivalence Thickness Measurement for Irradiation Room at National institute for Cancer and Malacca Hospital: A Review

    International Nuclear Information System (INIS)

    Mohd Khalid Matori; Azuhar Ripin; Husaini Salleh

    2013-01-01

    Lead equivalent thickness measurement of a shielding material in diagnostic radiology is very important to ensure that requirements for the purpose of radiation protection of patients, employees and the public are met. The Malaysian Ministry of Health (MOH) has established that the irradiation room must have sufficient shielding thickness, for example for general radiography it must be at least equal to 2.0 mm of Pb, for panoramic dental radiography at least equal to 1.5 mm of Pb and for mammography should be a minimum of 1.0 mm of Pb. This paper presents a technique using americium-241 source to test and verify the integrity of the shielding thickness in term of lead equivalent for irradiation room at National Institute for Cancer (IKN) and General Malacca Hospital. Results of measurement of 10 irradiation rooms conducted in 2012 were analyzed for this presentation. Technical comparison of the attenuation of gamma rays from Am-241 source through the walls of the irradiation room and pieces of lead were used to assess the lead equivalent thickness of the walls. Results showed that almost all the irradiation rooms tested meet the requirements of the Ministry of Health and is suitable for the installation of the intended diagnostic X-ray apparatus. Some specific positions such as door knobs and locks, electrical plug sockets were identified with potential to not met the required lead equivalent thickness hence may contribute to higher radiation exposure to workers and the public. (author)

  14. Impact of metal nano layer thickness on tunneling oxide and memory performance of core-shell iridium-oxide nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, W.; Maikap, S. [Thin Film Nano Tech. Lab., Department of Electronic Engineering, Chang Gung University, Tao-Yuan, Taiwan 333, Taiwan (China); Tien, T.-C. [Material Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan 310, Taiwan (China); Li, W.-C.; Yang, J.-R. [Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan (China)

    2011-10-01

    The impact of iridium-oxide (IrO{sub x}) nano layer thickness on the tunneling oxide and memory performance of IrO{sub x} metal nanocrystals in an n-Si/SiO{sub 2}/Al{sub 2}O{sub 3}/IrO{sub x}/Al{sub 2}O{sub 3}/IrO{sub x} structure has been investigated. A thinner (1.5 nm) IrO{sub x} nano layer has shown better memory performance than that of a thicker one (2.5 nm). Core-shell IrO{sub x} nanocrystals with a small average diameter of 2.4 nm and a high density of {approx}2 x 10{sup 12}/cm{sup 2} have been observed by scanning transmission electron microscopy. The IrO{sub x} nanocrystals are confirmed by x-ray photoelectron spectroscopy. A large memory window of 3.0 V at a sweeping gate voltage of {+-}5 V and 7.2 V at a sweeping gate voltage of {+-} 8 V has been observed for the 1.5 nm-thick IrO{sub x} nano layer memory capacitors with a small equivalent oxide thickness of 8 nm. The electrons and holes are trapped in the core and annular regions of the IrO{sub x} nanocrystals, respectively, which is explained by Gibbs free energy. High electron and hole-trapping densities are found to be 1.5 x 10{sup 13}/cm{sup 2} and 2 x 10{sup 13}/cm{sup 2}, respectively, due to the small size and high-density of IrO{sub x} nanocrystals. Excellent program/erase endurance of >10{sup 6} cycles and good retention of 10{sup 4} s with a good memory window of >1.2 V under a small operation voltage of {+-} 5 V are obtained. A large memory size of >10 Tbit/sq. in. can be designed by using the IrO{sub x} nanocrystals. This study is not only important for the IrO{sub x} nanocrystal charge-trapping memory investigation but it will also help to design future metal nanocrystal flash memory.

  15. Impact of metal nano layer thickness on tunneling oxide and memory performance of core-shell iridium-oxide nanocrystals

    International Nuclear Information System (INIS)

    Banerjee, W.; Maikap, S.; Tien, T.-C.; Li, W.-C.; Yang, J.-R.

    2011-01-01

    The impact of iridium-oxide (IrO x ) nano layer thickness on the tunneling oxide and memory performance of IrO x metal nanocrystals in an n-Si/SiO 2 /Al 2 O 3 /IrO x /Al 2 O 3 /IrO x structure has been investigated. A thinner (1.5 nm) IrO x nano layer has shown better memory performance than that of a thicker one (2.5 nm). Core-shell IrO x nanocrystals with a small average diameter of 2.4 nm and a high density of ∼2 x 10 12 /cm 2 have been observed by scanning transmission electron microscopy. The IrO x nanocrystals are confirmed by x-ray photoelectron spectroscopy. A large memory window of 3.0 V at a sweeping gate voltage of ±5 V and 7.2 V at a sweeping gate voltage of ± 8 V has been observed for the 1.5 nm-thick IrO x nano layer memory capacitors with a small equivalent oxide thickness of 8 nm. The electrons and holes are trapped in the core and annular regions of the IrO x nanocrystals, respectively, which is explained by Gibbs free energy. High electron and hole-trapping densities are found to be 1.5 x 10 13 /cm 2 and 2 x 10 13 /cm 2 , respectively, due to the small size and high-density of IrO x nanocrystals. Excellent program/erase endurance of >10 6 cycles and good retention of 10 4 s with a good memory window of >1.2 V under a small operation voltage of ± 5 V are obtained. A large memory size of >10 Tbit/sq. in. can be designed by using the IrO x nanocrystals. This study is not only important for the IrO x nanocrystal charge-trapping memory investigation but it will also help to design future metal nanocrystal flash memory.

  16. The influence of diabetes mellitus type 1 and 2 on the thickness, shape, and equivalent refractive index of the human crystalline lens

    NARCIS (Netherlands)

    Wiemer, N.G.M.; Dubbelman, M.; Kostense, P.J.; Ringens, P.J.; Polak, B.C.P.

    2008-01-01

    Purpose: To study the influence of diabetes mellitus (DM) types 1 and 2 on the thickness, radius of curvature, equivalent refractive index, and power of the lens. Design: Observational cross-sectional study. Participants and Controls: One hundred fourteen patients with DM type 1, 112 patients with

  17. Impact of oxide thickness on gate capacitance – Modelling and ...

    Indian Academy of Sciences (India)

    Department of Electronics and Communication Engineering, National ... conventional HEMT, Schottky barrier diode is formed at the gate electrode. .... term corresponds to the energy required for the electric field in the oxide layer and the.

  18. Changes in Nitric Oxide Level and Thickness Index of Synovial Fluid ...

    African Journals Online (AJOL)

    Changes in Nitric Oxide Level and Thickness Index of Synovial Fluid in Osteoarthritis Patients ... Tropical Journal of Pharmaceutical Research ... and moderate phase patients after intra-articular injection of sodium hyaluronate, while the effect ...

  19. The thickness of native oxides on aluminum alloys and single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Evertsson, J., E-mail: jonas.evertsson@sljus.lu.se [Division of Synchrotron Radiation Research, Lund University, Box 118, 221 00 Lund (Sweden); Bertram, F. [Division of Synchrotron Radiation Research, Lund University, Box 118, 221 00 Lund (Sweden); Zhang, F. [KTH Royal Institute of Technology, Department of Chemistry, Division of Surface and Corrosion Science, Drottning Kristinas Vg 51, 100 44 Stockholm (Sweden); Rullik, L.; Merte, L.R.; Shipilin, M. [Division of Synchrotron Radiation Research, Lund University, Box 118, 221 00 Lund (Sweden); Soldemo, M.; Ahmadi, S. [KTH Royal Institute of Technology, ICT, Material Physics, 16440 Kista (Sweden); Vinogradov, N.; Carlà, F. [ESRF, B.P. 220, 38043 Grenoble (France); Weissenrieder, J.; Göthelid, M. [KTH Royal Institute of Technology, ICT, Material Physics, 16440 Kista (Sweden); Pan, J. [KTH Royal Institute of Technology, Department of Chemistry, Division of Surface and Corrosion Science, Drottning Kristinas Vg 51, 100 44 Stockholm (Sweden); Mikkelsen, A. [Division of Synchrotron Radiation Research, Lund University, Box 118, 221 00 Lund (Sweden); Nilsson, J.-O. [Sapa Technology, Kanalgatan 1, 612 31 Finspång (Sweden); Lundgren, E. [Division of Synchrotron Radiation Research, Lund University, Box 118, 221 00 Lund (Sweden)

    2015-09-15

    Highlights: • We have determined the native oxide film thickness on several Al samples. • The results obtained from XRR and XPS show excellent agreement. • The results obtained from EIS show consistently thinner oxide films. • The oxides on the alloys are thicker than the oxides on the single crystals. - Abstract: We present results from measurements of the native oxide film thickness on four different industrial aluminum alloys and three different aluminum single crystals. The thicknesses were determined using X-ray reflectivity, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy. In addition, atomic force microscopy was used for micro-structural studies of the oxide surfaces. The reflectivity measurements were performed in ultra-high vacuum, vacuum, ambient, nitrogen and liquid water conditions. The results obtained using X-ray reflectivity and X-ray photoelectron spectroscopy demonstrate good agreement. However, the oxide thicknesses determined from the electrochemical impedance spectroscopy show a larger discrepancy from the above two methods. In the present contribution the reasons for this discrepancy are discussed. We also address the effect of the substrate type and the presence of water on the resultant oxide thickness.

  20. Expression of proliferative and inflammatory markers in a full-thickness human skin equivalent following exposure to the model sulfur mustard vesicant, 2-chloroethyl ethyl sulfide

    International Nuclear Information System (INIS)

    Black, Adrienne T.; Hayden, Patrick J.; Casillas, Robert P.; Heck, Diane E.; Gerecke, Donald R.; Sinko, Patrick J.; Laskin, Debra L.; Laskin, Jeffrey D.

    2010-01-01

    Sulfur mustard is a potent vesicant that induces inflammation, edema and blistering following dermal exposure. To assess molecular mechanisms mediating these responses, we analyzed the effects of the model sulfur mustard vesicant, 2-chloroethyl ethyl sulfide, on EpiDerm-FT TM , a commercially available full-thickness human skin equivalent. CEES (100-1000 μM) caused a concentration-dependent increase in pyknotic nuclei and vacuolization in basal keratinocytes; at high concentrations (300-1000 μM), CEES also disrupted keratin filament architecture in the stratum corneum. This was associated with time-dependent increases in expression of proliferating cell nuclear antigen, a marker of cell proliferation, and poly(ADP-ribose) polymerase (PARP) and phosphorylated histone H2AX, markers of DNA damage. Concentration- and time-dependent increases in mRNA and protein expression of eicosanoid biosynthetic enzymes including COX-2, 5-lipoxygenase, microsomal PGE 2 synthases, leukotriene (LT) A 4 hydrolase and LTC 4 synthase were observed in CEES-treated skin equivalents, as well as in antioxidant enzymes, glutathione S-transferases A1-2 (GSTA1-2), GSTA3 and GSTA4. These data demonstrate that CEES induces rapid cellular damage, cytotoxicity and inflammation in full-thickness skin equivalents. These effects are similar to human responses to vesicants in vivo and suggest that the full thickness skin equivalent is a useful in vitro model to characterize the biological effects of mustards and to develop potential therapeutics.

  1. A comparison of Zircaloy oxide thicknesses on Millstone-3 and North Anna-1 PWR fuel cladding

    International Nuclear Information System (INIS)

    Polley, M.V.; Evans, H.E.

    1993-08-01

    High concentrations of lithium in the coolant may enhance the corrosion rate of Zircaloy fuel cladding. In the present work, oxide thicknesses on fuel cladding from the Millstone 3 PWR were compared with those from the North Anna 1 PWR. The intention was to identify whether the higher lithium levels (up to 3.5 ppM) in the Millstone 3 primary coolant during cycles 2 and 3 led to significantly greater oxidation rates than in North Anna 1 which operated generally with lithium levels lower than 2.2 ppM. The comparisons were made by comparing the measurements with code predictions of Zircaloy oxidation in order to factor out the effect of operational variables on the oxide thicknesses achieved. Overall, Millstone 3 oxide thicknesses were found to be approximately 14% greater than North Anna 1 values. However, approximately 29% lower oxide thicknesses were found on reload Millstone 3 rods exposed to one cycle of elevated lithium chemistry than on Millstone 3 initial fuel exposed to one cycle of normal lithium chemistry during cycle 1. Furthermore, oxide thicknesses on Millstone 3 rods exposed to two cycles of elevated lithium chemistry were approximately 36% lower than on Millstone 3 rods exposed to one cycle of normal lithium chemistry plus one cycle of elevated lithium chemistry. Therefore, it cannot be concluded that elevated lithium operation in Millstone 3 led to enhanced Zircaloy fuel clad corrosion

  2. Thickness measurement of a thin hetero-oxide film with an interfacial oxide layer by X-ray photoelectron spectroscopy

    Science.gov (United States)

    Kim, Kyung Joong; Lee, Seung Mi; Jang, Jong Shik; Moret, Mona

    2012-02-01

    The general equation Tove = L cos θ ln(Rexp/R0 + 1) for the thickness measurement of thin oxide films by X-ray photoelectron spectroscopy (XPS) was applied to a HfO2/SiO2/Si(1 0 0) as a thin hetero-oxide film system with an interfacial oxide layer. The contribution of the thick interfacial SiO2 layer to the thickness of the HfO2 overlayer was counterbalanced by multiplying the ratio between the intensity of Si4+ from a thick SiO2 film and that of Si0 from a Si(1 0 0) substrate to the intensity of Si4+ from the HfO2/SiO2/Si(1 0 0) film. With this approximation, the thickness levels of the HfO2 overlayers showed a small standard deviation of 0.03 nm in a series of HfO2 (2 nm)/SiO2 (2-6 nm)/Si(1 0 0) films. Mutual calibration with XPS and transmission electron microscopy (TEM) was used to verify the thickness of HfO2 overlayers in a series of HfO2 (1-4 nm)/SiO2 (3 nm)/Si(1 0 0) films. From the linear relation between the thickness values derived from XPS and TEM, the effective attenuation length of the photoelectrons and the thickness of the HfO2 overlayer could be determined.

  3. Adjusting the Parameters of Metal Oxide Gapless Surge Arresters’ Equivalent Circuits Using the Harmony Search Method

    Directory of Open Access Journals (Sweden)

    Christos A. Christodoulou

    2017-12-01

    Full Text Available The appropriate circuit modeling of metal oxide gapless surge arresters is critical for insulation coordination studies. Metal oxide arresters present a dynamic behavior for fast front surges; namely, their residual voltage is dependent on the peak value, as well as the duration of the injected impulse current, and should therefore not only be represented by non-linear elements. The aim of the current work is to adjust the parameters of the most frequently used surge arresters’ circuit models by considering the magnitude of the residual voltage, as well as the dissipated energy for given pulses. In this aim, the harmony search method is implemented to adjust parameter values of the arrester equivalent circuit models. This functions by minimizing a defined objective function that compares the simulation outcomes with the manufacturer’s data and the results obtained from previous methodologies.

  4. Ellipsometry measurements of thickness of oxide and water layers on spherical and flat silicon surfaces

    International Nuclear Information System (INIS)

    Kenny, M.J.; Netterfield, R.; Wielunski, L.S.

    1998-01-01

    Full text: Ellipsometry has been used to measure the thickness of oxide layers on single crystal silicon surfaces, both flat and spherical and also to measure the extent of adsorption of moisture on the surface as a function of partial water vapour pressure. The measurements form part of an international collaborative project to make a precise determination of the Avogadro constant (ΔN A /N A -8 ) which will then be used to obtain an absolute definition of the kilogram, rather than one in terms of an artefact. Typically the native oxide layer on a cleaned silicon wafer is about 2 nm thick. On a polished sphere this oxide layer is typically 8 to 10 nm thick, the increased thickness being attributed to parameters related to the polishing process. Ellipsometry measurements on an 89 mm diameter polished silicon sphere at both VUW and CSIRO indicated a SiO 2 layer at 7 to 10 nm thick. It was observed that this thickness varied regularly. The crystal orientation of the sphere was determined using electron patterns generated from an electron microscope and the oxide layer was then measured through 180 arcs of great circles along (110) and (100) planes. It was observed that the thickness varied systematically with orientation. The minimum thickness was 7.4 nm at the axis (softest direction in silicon) and the greatest thickness was 9.5 nm at the axis (hardest direction in silicon). This is similar to an orientation dependent cubic pattern which has been observed to be superimposed on polished silicon spheres. At VUW, the sphere was placed in an evacuated bell jar and the ellipsometry signal was observed as the water vapour pressure was progressively increased up to saturation. The amount of water vapour adsorbed at saturation was one or two monolayers, indicating that the sphere does not wet

  5. A comparison of oxide thickness predictability from the perspective of codes

    Energy Technology Data Exchange (ETDEWEB)

    Park, Joo-Young; Shin, Hye-In; Kim, Kyung-Tae; Han, Hee-Tak; Kim, Hong-Jin; Kim, Yong-Hwan [KEPCO Nuclear Fuel Co. Ltd., Daejeon (Korea, Republic of)

    2016-10-15

    In Korea, OPR1000 and Westinghouse type nuclear power plant reactor fuel rods oxide thickness has been evaluated by imported code A. Because of this, there have been multiple constraints in operation and maintenance of fuel rod design system. For this reason, there has been a growing demand to establish an independent fuel rod design system. To meet this goal, KNF has recently developed its own code B for fuel rod design. The objective of this study is to compare oxide thickness prediction performance between code A and code B and to check the validity of predicting corrosion behaviors of newly developed code B. This study is based on Pool Side Examination (PSE) data for the performance confirmation. For the examination procedures, the oxide thickness measurement methods and equipment of PSE are described in detail. In this study, code B is confirmed conservatism and validity on evaluating cladding oxide thickness through the comparison with code A. Code prediction values show higher value than measured data from PSE. Throughout this study, the values by code B are evaluated and proved to be valid in a view point of the oxide thickness evaluation. However, the code B input for prediction has been made by designer's judgment with complex handwork that might be lead to excessive conservative result and ineffective design process with some possibility of errors.

  6. The application of the barrier-type anodic oxidation method to thickness testing of aluminum films

    Science.gov (United States)

    Chen, Jianwen; Yao, Manwen; Xiao, Ruihua; Yang, Pengfei; Hu, Baofu; Yao, Xi

    2014-09-01

    The thickness of the active metal oxide film formed from a barrier-type anodizing process is directly proportional to its formation voltage. The thickness of the consumed portion of the metal film is also corresponding to the formation voltage. This principle can be applied to the thickness test of the metal films. If the metal film is growing on a dielectric substrate, when the metal film is exhausted in an anodizing process, because of the high electrical resistance of the formed oxide film, a sudden increase of the recorded voltage during the anodizing process would occur. Then, the thickness of the metal film can be determined from this voltage. As an example, aluminum films are tested and discussed in this work. This method is quite simple and is easy to perform with high precision.

  7. Effect of Thickness on Oxidation Behavior of Cr coated Zircaloy-4 using Arc Ion Plating

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eui Jung; Kim, Sun Jin [Hanyang University, Seoul (Korea, Republic of); Park, Jung Hwan; Kim, Hyun Gil; Jung, Yang Il; Park, Dong Jun [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    Ever since the Fukushima accident, accident tolerant fuel (ATF) has been widely studied. To increase the life time and safety of nuclear claddings, there are increasing demands for protective coatings exhibiting excellent oxidation resistance. Many metal and oxide films are produced by using this method because of the high kinetic energy of the ions, ionization efficiency and deposition rate. Candidate materials for a protective layer have higher thermal neutron absorption cross sections than Zr. However, there is no systematic study of thickness effect on oxidation resistance of protective layer. In this study, Cr films with different thickness (from 1 μm to 50 μm) were deposited on the cladding surfaces by AIP. The high temperature oxidation resistance of Cr films with different thicknesses has been investigated. Uniform oxide layer with nanoporous structures have been fabricated on the surface of Zr-Nb-Sn alloy. Oxidation behavior of the pristine Zr-Nb-Sn alloy and the Zr-Nb-Sn alloy with nanostructured oxide layer evaluated by measuring weight gain (TGA).

  8. Effects of stress on the oxide layer thickness and post-oxidation creep strain of zircaloy-4

    International Nuclear Information System (INIS)

    Lim, Sang Ho; Yoon, Young Ku

    1986-01-01

    Effects of compressive stress generated in the oxide layer and its subsequent relief on oxidation rate and post-oxidation creep characteristics of zircaloy-4 were investigated by oxidation studies in steam with and without applied tensile stress and by creep testing at 700 deg C in high purity argon. The thickness of oxide layer increased with the magnitude of tensile stress applied during oxidation at 650 deg C in steam whereas similar phenomenon was not observed during oxidation at 800 deg C. Zircaloy-4 specimens oxidized at 600 deg C in steam without applied stress exhibited higher creep strain than that shown by unoxidized specimens when creep-tested in argon. Zircaloy-4 specimens oxidized at 600 deg C steam under the applied stress of 8.53MPa and oxidized at 800 deg C under the applied stress of 0 and 8.53MPa exhibited lower strain than that shown by unoxidized specimen. The above experimental results were accounted for on the basis of interactions among applied stress during oxidation, compressive stress generated in the oxide layer and elasticity of zircaloy-4 matrix. (Author)

  9. Measurement of oxide-layer thickness of internal granules in high-purity aluminium

    International Nuclear Information System (INIS)

    Takacs, S.; Ditroi, F.; Mahunka, I.

    1989-01-01

    Charged-particle activation analysis was used for the determination of bulk oxygen concentration in aluminium. High-purity aluminium samples and mixtures containing different amounts of alumina were irradiated by 13 MeV 3 He particles. The aim of the investigation was to determine the oxide-layer thickness on the surface of internal aluminium granules. The measurement was carried out by determining the bulk oxygen concentration in the samples, and calculating the oxide-layer thickness, by using model conditions about the microstructure of the aluminium samples. (author) 5 refs

  10. Angiotensin II stimulates superoxide production by nitric oxide synthase in thick ascending limbs.

    Science.gov (United States)

    Gonzalez-Vicente, Agustin; Saikumar, Jagannath H; Massey, Katherine J; Hong, Nancy J; Dominici, Fernando P; Carretero, Oscar A; Garvin, Jeffrey L

    2016-02-01

    Angiotensin II (Ang II) causes nitric oxide synthase (NOS) to become a source of superoxide (O2 (-)) via a protein kinase C (PKC)-dependent process in endothelial cells. Ang II stimulates both NO and O2 (-) production in thick ascending limbs. We hypothesized that Ang II causes O2 (-) production by NOS in thick ascending limbs via a PKC-dependent mechanism. NO production was measured in isolated rat thick ascending limbs using DAF-FM, whereas O2 (-) was measured in thick ascending limb suspensions using the lucigenin assay. Consistent stimulation of NO was observed with 1 nmol/L Ang II (P thick ascending limbs via a PKC- and NADPH oxidase-dependent process; and (2) the effect of Ang II is not due to limited substrate. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  11. Studies on Gas Sensing Performance of Pure and Surface Chrominated Indium Oxide Thick Film Resistors

    Directory of Open Access Journals (Sweden)

    D. N. CHAVAN

    2010-12-01

    Full Text Available The thick films of AR grade In2O3 were prepared by standard screen-printing technique. The gas sensing performance of thick film was tested for various gases. It showed maximum gas response to ethanol vapor at 350 oC for 80 ppm. To improve the gas response and selectivity of the film towards a particular gas, In2O3 thick films were modified by dipping them in an aqueous solution of 0.1 M CrO3 for different intervals of time. The surface chrominated (20 min In2O3 thick film showed maximum response to H2S gas (40 ppm than pure In2O3 thick film at 250 oC. Chromium oxide on the surface of the film shifts the gas response from ethanol vapor to H2S gas. A systematic study of sensing performance of the sensor indicates the key role played by chromium oxide on the surface of thick film. The selectivity, gas response and recovery time of the sensor were measured and presented.

  12. Studies on Gas Sensing Performance of Cr-doped Indium Oxide Thick Film Sensors

    Directory of Open Access Journals (Sweden)

    D. N. Chavan

    2011-02-01

    Full Text Available A series of In1-xCrxO3 composites, with x ranging from 0.01 to 0.5wt% were prepared by mechanochemically starting from InCl3 and CrO3. Structural and micro structural characteristics of the sample were investigated by XRD, SEM with EDAX. Thick films of pure Indium Oxide and composites were prepared by standard screen printing technique. The gas sensitivity of these thick films was tested for various gases. The pure Indium Oxide thick film (x=0 shows maximum sensitivity to ethanol vapour (80 ppm at 350 oC, but composite-A (x=0.01 thick film shows maximum sensitivity to H2S gas (40 ppm at 250 oC, composite-B (x=0.1 thick film shows higher sensitivity to NH3 gas (80 ppm at 250 oC and composite-C (x=0.5 thick film shows maximum sensitivity to Cl2 gas (80 ppm at 350 oC. A systematic study of gas sensing performance of the sensors indicates the key role played by concentration variation of Cr doped species. The sensitivity, selectivity and recovery time of the sensor were measured and presented.

  13. Oxide thickness measurement technique for duplex-layer Zircaloy-4 cladding

    International Nuclear Information System (INIS)

    McClelland, R.G.; O'Leary, P.M.

    1992-01-01

    Siemens Nuclear Power Corporation (SNP) is investigating the use of duplex-layer Zircaloy-4 tubing to improve the waterside corrosion resistance of cladding for high-burnup pressurized water reactor (PWR) fuel designs. Standard SNP PWR cladding is typically 0.762-mm (0.030-in.)-thick Zircaloy-4. The SNP duplex cladding is nominally 0.660-mm (0.026-in.)-thick Zircalloy-4 with an ∼0.102-mm (0.004-in.) outer layer of another, more corrosion-resistant, zirconium-based alloy. It is common industry practice to monitor the in-reactor corrosion behavior of Zircaloy cladding by using an eddy-current 'lift-off' technique to measure the oxide thickness on the outer surface of the fuel cladding. The test program evaluated three different cladding samples, all with the same outer diameter and wall thickness: Zircaloy-4 and duplex clad types D2 and D4

  14. Resveratrol increases nitric oxide production in the rat thick ascending limb via Ca2+/calmodulin.

    Science.gov (United States)

    Gonzalez-Vicente, Agustin; Cabral, Pablo D; Garvin, Jeffrey L

    2014-01-01

    The thick ascending limb of the loop of Henle reabsorbs 30% of the NaCl filtered through the glomerulus. Nitric oxide (NO) produced by NO synthase 3 (NOS3) inhibits NaCl absorption by this segment. Resveratrol, a polyphenol, has beneficial cardiovascular and renal effects, many of which are mediated by NO. Resveratrol increases intracellular Ca2+ (Cai) and AMP kinase (AMPK) and NAD-dependent deacetylase sirtuin1 (SIRT1) activities, all of which could activate NO production. We hypothesized that resveratrol stimulates NO production by thick ascending limbs via a Ca2+/calmodulin-dependent mechanism. To test this, the effect of resveratrol on NO bioavailability was measured in thick ascending limb suspensions. Cai was measured in single perfused thick ascending limbs. SIRT1 activity and expression were measured in thick ascending limb lysates. Resveratrol (100 µM) increased NO bioavailability in thick ascending limb suspensions by 1.3±0.2 AFU/mg/min (pthick ascending limbs via a Ca2+/calmodulin dependent mechanism, and SIRT1 and AMPK do not participate. Resveratrol-stimulated NO production in thick ascending limbs may account for part of its beneficial effects.

  15. Determination of oxide film thickness on aluminium using 14-MeV neutron activation and BET method

    International Nuclear Information System (INIS)

    Foerster, H.

    1983-01-01

    A new method is described for the determination of the mean film thickness of aluminium oxides by 14-MeV neutron activation analysis of the oxygen and by BET measurement of the surface area. The mean film thickness obtained is independent of the surface roughness. Stable oxide films consisting of only a few atomic layers of oxygen are detected on aluminium. (author)

  16. Thickness-dependent photocatalytic performance of graphite oxide for degrading organic pollutants under visible light.

    Science.gov (United States)

    Oh, Junghoon; Chang, Yun Hee; Kim, Yong-Hyun; Park, Sungjin

    2016-04-28

    Photocatalysts use sustainable solar light energy to trigger various catalytic reactions. Metal-free nanomaterials have been suggested as cost-effective and environmentally friendly photocatalysts. In this work, we propose thickness-controlled graphite oxide (GO) as a metal-free photocatalyst, which is produced by exfoliating thick GO particles via stirring and sonication. All GO samples exhibit photocatalytic activity for degrading an organic pollutant, rhodamine B under visible light, and the thickest sample shows the best catalytic performance. UV-vis-NIR diffuse reflectance absorption spectra indicate that thicker GO samples absorb more vis-NIR light than thinner ones. Density-functional theory calculations show that GO has a much smaller band gap than that of single-layer graphene oxide, and thus suggest that the largely-reduced band gap is responsible for this trend of light absorption.

  17. Chemical Vapor Identification by Plasma Treated Thick Film Tin Oxide Gas Sensor Array and Pattern Recognition

    Directory of Open Access Journals (Sweden)

    J. K. Srivastava

    2011-02-01

    Full Text Available Present study deals the class recognition potential of a four element plasma treated thick film tin oxide gas sensor array exposed with volatile organic compounds (VOCs. Methanol, Ethanol and Acetone are selected as target VOCs and exposed on sensor array at different concentration in range from 100-1000 ppm. Sensor array consist of four tin oxide sensors doped with 1-4 % PbO concentrations were fabricated by thick film technology and then treated with oxygen plasma for 5-10 minute durations. Sensor signal is analyzed by principal component analysis (PCA for visual classification of VOCs. Further output of PCA is used as input for classification of VOCs by four pattern classification techniques as: linear discriminant analysis (LDA, k-nearest neighbor (KNN, back propagation neural network (BPNN and support vector machine (SVM. All the four classifier results 100 % correct classification rate of VOCs by response analysis of sensor array treated with plasma for 5 minute.

  18. Room temperature synthesis of indium tin oxide nanotubes with high precision wall thickness by electroless deposition

    Directory of Open Access Journals (Sweden)

    Mario Boehme

    2011-02-01

    Full Text Available Conductive nanotubes consisting of indium tin oxide (ITO were fabricated by electroless deposition using ion track etched polycarbonate templates. To produce nanotubes (NTs with thin walls and small surface roughness, the tubes were generated by a multi-step procedure under aqueous conditions. The approach reported below yields open end nanotubes with well defined outer diameter and wall thickness. In the past, zinc oxide films were mostly preferred and were synthesized using electroless deposition based on aqueous solutions. All these methods previously developed, are not adaptable in the case of ITO nanotubes, even with modifications. In the present work, therefore, we investigated the necessary conditions for the growth of ITO-NTs to achieve a wall thickness of around 10 nm. In addition, the effects of pH and reductive concentrations for the formation of ITO-NTs are also discussed.

  19. Reaction products between Bi-Sr-Ca-Cu-oxide thick films and alumina substrates

    International Nuclear Information System (INIS)

    Alarco, J.A.; Ilushechkin, A.; Yamashita, T.; Bhargava, A.; Barry, J.; Mackinnon, I.D.R.

    1997-01-01

    The structure and composition of reaction products between Bi-Sr-Ca-Cu-oxide (BSCCO) thick films and alumina substrates have been characterized using a combination of electron diffraction, scanning electron microscopy and energy dispersive X-ray spectrometry (EDX). Sr and Ca are found to be the most reactive cations with alumina. Sr 4 Al 6 O 12 SO 4 is formed between the alumina substrates and BSCCO thick films prepared from paste with composition close to Bi-2212 (and Bi-2212+10 wt.% Ag). For paste with composition close to Bi(Pb)-2223 +20 wt.% Ag, a new phase with f.c.c. structure, lattice parameter about a=24.5 A and approximate composition Al 3 Sr 2 CaBi 2 CuO x has been identified in the interface region. Understanding and control of these reactions is essential for growth of high quality BSCCO thick films on alumina. (orig.)

  20. Effect of Processing Parameters on Pore Structure and Thickness of Anodic Aluminum Oxide (AAO) Tubular Membranes

    OpenAIRE

    Belwalkar, A.; Grasing, E.; Van Geertruyden, W.; Huang, Z.; Misiolek, W.Z.

    2008-01-01

    Nanoporous anodic aluminum oxide (AAO) tubular membranes were fabricated from aluminum alloy tubes in sulfuric and oxalic acid electrolytes using a two-step anodization process. The membranes were investigated for characteristics such as pore size, interpore distance and thickness by varying applied voltage and electrolyte concentration. Morphology of the membranes was examined using light optical and scanning electron microscopy and characterized using ImageJ software. Results showed that me...

  1. CANDU fuel sheath integrity and oxide layer thickness determination by Eddy current technique

    International Nuclear Information System (INIS)

    Gheorghe, Gabriela; Man, Ion; Parvan, Marcel; Valeca, Serban

    2010-01-01

    This paper presents results concerning the integrity assessment of the fuel elements cladding and measurements of the oxide layer on sheaths, using the eddy current technique. Flaw detection using eddy current provides information about the integrity of fuel element sheath or presence of defects in the sheath produced by irradiation. The control equipment consists of a flaw detector with eddy currents, operable in the frequency range 10 Hz to 10 MHz, and a differential probe. The calibration of the flaw detector is done using artificial defects (longitudinal, transversal, external and internal notches, bored and unbored holes) obtained on Zircaloy-4 tubes identical to those out of which the sheath of the CANDU fuel element is manufactured (having a diameter of 13.08 mm and a wall thickness of 0.4 mm). When analyzing the behavior of the fuel elements' cladding facing the corrosion is important to know the thickness of the zirconium oxide layer. The calibration of the device measuring the thickness of the oxide layer is done using a Zircaloy-4 tube identical to that which the cladding of the CANDU fuel element is manufactured of, and calibration foils, as well. (authors)

  2. The Effect of Thickness and Chemical Reduction of Graphene Oxide on Nanoscale Friction.

    Science.gov (United States)

    Kwon, Sangku; Lee, Kyung Eun; Lee, Hyunsoo; Koh, Sang Joon; Ko, Jae-Hyeon; Kim, Yong-Hyun; Kim, Sang Ouk; Park, Jeong Young

    2018-01-18

    The tribological properties of two-dimensional (2D) atomic layers are quite different from three-dimensional continuum materials because of the unique mechanical responses of 2D layers. It is known that friction on graphene shows a remarkable decreasing behavior as the number of layers increases, which is caused by the puckering effect. On other graphene derivatives, such as graphene oxide (GO) or reduced graphene oxide (rGO), the thickness dependence of friction is important because of the possibilities for technical applications. In this report, we demonstrate unexpected layer-dependent friction behavior on GO and rGO layers. Friction force microscopy measurements show that nanoscale friction on GO does not depend on the number of layers; however, after reduction, friction on rGO shows an inverse thickness dependence compared with pristine graphene. We show that the friction on rGO is higher than that on SiO 2 at low load, and that an interesting crossover behavior at higher load occurs because of the lower friction coefficient and higher adhesion of the rGO. We provide a relevant interpretation that explains the effect of thickness and chemical reduction on nanoscale friction.

  3. Preparation and spectroscopic analysis of zinc oxide nanorod thin films of different thicknesses

    Directory of Open Access Journals (Sweden)

    Mia Nasrul Haque

    2017-10-01

    Full Text Available Zinc oxide thin films with different thicknesses were prepared on microscopic glass slides by sol-gel spin coating method, then hydrothermal process was applied to produce zinc oxide nanorod arrays. The nanorod thin films were characterized by various spectroscopic methods of analysis. From the images of field emission scanning electron microscope (FESEM, it was observed that for the film thickness up to 200 nm the formed nanorods with wurtzite hexagonal structure were uniformly distributed over the entire surface substrate. From X-ray diffraction analysis it was revealed that the thin films had good polycrystalline nature with highly preferred c-axis orientation along (0 0 2 plane. The optical characterization done by UV-Vis spectrometer showed that all the films had high transparency of 83 % to 96 % in the visible region and sharp cut off at ultraviolet region of electromagnetic spectrum. The band gap of the films decreased as their thickness increased. Energy dispersive X-ray spectroscopy (EDS showed the presence of zinc and oxygen elements in the films and Fourier transform infrared spectroscopy (FT-IR revealed the chemical composition of ZnO in the film.

  4. Ion Diffusion-Directed Assembly Approach to Ultrafast Coating of Graphene Oxide Thick Multilayers.

    Science.gov (United States)

    Zhao, Xiaoli; Gao, Weiwei; Yao, Weiquan; Jiang, Yanqiu; Xu, Zhen; Gao, Chao

    2017-10-24

    The layer-by-layer (LbL) assembly approach has been widely used to fabricate multilayer coatings on substrates with multiple cycles, whereas it is hard to access thick films efficiently. Here, we developed an ion diffusion-directed assembly (IDDA) strategy to rapidly make multilayer thick coatings in one step on arbitrary substrates. To achieve multifunctional coatings, graphene oxide (GO) and metallic ions were selected as the typical building blocks and diffusion director in IDDA, respectively. With diffusion of metallic ions from substrate to negatively charged GO dispersion spontaneously (i.e., from high-concentration region to low-concentration region), GO was assembled onto the substrate sheet-by-sheet via sol-gel transformation. Because metallic ions with size of subnanometers can diffuse directionally and freely in the aqueous dispersion, GO was coated on the substrate efficiently, giving rise to films with desired thickness up to 10 μm per cycle. The IDDA approach shows three main merits: (1) high efficiency with a μm-scale coating rate; (2) controllability over thickness and evenness; and (3) generality for substrates of plastics, metals and ceramics with any shapes and morphologies. With these merits, IDDA strategy was utilized in the efficient fabrication of functional graphene coatings that exhibit outstanding performance as supercapacitors, electromagnetic interference shielding textiles, and anticorrosion coatings. This IDDA approach can be extended to other building blocks including polymers and colloidal nanoparticles, promising for the scalable production and application of multifunctional coatings.

  5. Impact of oxide thickness on SEGR failure in vertical power MOSFETs: Development of a semi-empirical expression

    International Nuclear Information System (INIS)

    Titus, J.L.; Wheatley, C.F.; Burton, D.I.; Mouret, I.; Allenspach, M.; Brews, J.; Schrimpf, R.; Galloway, K.; Pease, R.L.

    1995-01-01

    This paper investigates the role that the gate oxide thickness (T ox ) plays on the gate and drain failure threshold voltages required to induce the onset of single-event gate rupture (SEGR). The impact of gate oxide thickness on SEGR is experimentally determined from vertical power metal-oxide semiconductor field-effect transistors (MOSFETs) having identical process and design parameters, except for the gate oxide thickness. Power MOSFETs from five variants were specially fabricated with nominal gate oxide thicknesses of 30, 50, 70, 100, and 150 nm. Devices from each variant were characterized to mono-energetic ion beams of Nickel, Bromine, Iodine, and Gold, Employing different bias conditions, failure thresholds for the onset of SEGR were determined for each oxide thickness. Applying these experimental test results, the previously published empirical expression is extended to include the effects of gate oxide thickness. In addition, observations of ion angle, temperature, cell geometry, channel conductivity, and curvature at high drain voltages are briefly discussed

  6. Water equivalent thickness of immobilization devices in proton therapy planning - Modelling at treatment planning and validation by measurements with a multi-layer ionization chamber.

    Science.gov (United States)

    Fellin, Francesco; Righetto, Roberto; Fava, Giovanni; Trevisan, Diego; Amelio, Dante; Farace, Paolo

    2017-03-01

    To investigate the range errors made in treatment planning due to the presence of the immobilization devices along the proton beam path. The measured water equivalent thickness (WET) of selected devices was measured by a high-energy spot and a multi-layer ionization chamber and compared with that predicted by treatment planning system (TPS). Two treatment couches, two thermoplastic masks (both un-stretched and stretched) and one headrest were selected. At TPS, every immobilization device was modelled as being part of the patient. The following parameters were assessed: CT acquisition protocol, dose-calculation grid-sizes (1.5 and 3.0mm) and beam-entrance with respect to the devices (coplanar and non-coplanar). Finally, the potential errors produced by a wrong manual separation between treatment couch and the CT table (not present during treatment) were investigated. In the thermoplastic mask, there was a clear effect due to beam entrance, a moderate effect due to the CT protocols and almost no effect due to TPS grid-size, with 1mm errors observed only when thick un-stretched portions were crossed by non-coplanar beams. In the treatment couches the WET errors were negligible (0.5mm with a 3.0mm grid-size. In the headrest, WET errors were negligible (0.2mm). With only one exception (un-stretched mask, non-coplanar beams), the WET of all the immobilization devices was properly modelled by the TPS. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  7. Effects of Zinc Injection on the Cladding Oxide Thickness in the Domestic Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Hak Kyu; Kim, Hong Jin; Shin, Jung Cheol [KEPCO Nuclear Fuel Co. Ltd., Daejeon (Korea, Republic of)

    2013-10-15

    The first commercial plant for zinc injection demonstration was Farley-2 in 1994, and the effect of zinc injection was successfully demonstrated. Since then the PWR with zinc injection has been increased, there are about 80 PWR with zinc injection in the world in 2012. Zinc injection at the high duty plant has potential risk of increasing the cladding oxide thickness. Zinc injection doesn't affect the cladding corrosion directly but it may negatively affect crud deposit in the subcooled boiling region of the fuel. So the effect of zinc injection on fuel integrity has been evaluated. For low duty plant it is confirmed that zinc injection doesn't affect the fuel integrity. For high duty plant Callaway in U. S. and Vandellos II in Spain were successfully demonstrated but the experience with zinc injection of high duty plant was still lacking. Thus EPRI recommend the fuel surveillance programs for the high duty plant to apply zinc. The High Duty Core Index (HDCI) of most domestic nuclear power plant is above 150 Btu/ft{sup 2}-gal- .deg. F. Those plants with a HDCI of 150 Btu/ft{sup 2}-gal- .deg. F or greater may be considered as 'high duty'. As aforementioned, the experience with zinc injection of high duty plant was lacking. Thus to apply zinc injection in domestic plant with high duty, prudent approach is needed. In this study the effect of zinc injection in Hanul unit 1 with a HDCI of around 150 Btu/ft{sup 2}-gal- .deg. F was evaluated. And in the next study the effect of zinc injection in the plant of HDCI of around 200 Btu/ft{sup 2}-gal- .deg. F will be evaluated. Zinc injection had not caused any increase in oxide thickness in Hanul unit 1. Most of the oxide thickness measurement data with zinc injection are well within the non-zinc injection database. And the computer code which was developed based on non-zinc injection database well predicts oxide thickness for fuel rod with zinc injection. Thus, it can be concluded that zinc injection doesn

  8. Effects of Zinc Injection on the Cladding Oxide Thickness in the Domestic Nuclear Power Plant

    International Nuclear Information System (INIS)

    Yoon, Hak Kyu; Kim, Hong Jin; Shin, Jung Cheol

    2013-01-01

    The first commercial plant for zinc injection demonstration was Farley-2 in 1994, and the effect of zinc injection was successfully demonstrated. Since then the PWR with zinc injection has been increased, there are about 80 PWR with zinc injection in the world in 2012. Zinc injection at the high duty plant has potential risk of increasing the cladding oxide thickness. Zinc injection doesn't affect the cladding corrosion directly but it may negatively affect crud deposit in the subcooled boiling region of the fuel. So the effect of zinc injection on fuel integrity has been evaluated. For low duty plant it is confirmed that zinc injection doesn't affect the fuel integrity. For high duty plant Callaway in U. S. and Vandellos II in Spain were successfully demonstrated but the experience with zinc injection of high duty plant was still lacking. Thus EPRI recommend the fuel surveillance programs for the high duty plant to apply zinc. The High Duty Core Index (HDCI) of most domestic nuclear power plant is above 150 Btu/ft 2 -gal- .deg. F. Those plants with a HDCI of 150 Btu/ft 2 -gal- .deg. F or greater may be considered as 'high duty'. As aforementioned, the experience with zinc injection of high duty plant was lacking. Thus to apply zinc injection in domestic plant with high duty, prudent approach is needed. In this study the effect of zinc injection in Hanul unit 1 with a HDCI of around 150 Btu/ft 2 -gal- .deg. F was evaluated. And in the next study the effect of zinc injection in the plant of HDCI of around 200 Btu/ft 2 -gal- .deg. F will be evaluated. Zinc injection had not caused any increase in oxide thickness in Hanul unit 1. Most of the oxide thickness measurement data with zinc injection are well within the non-zinc injection database. And the computer code which was developed based on non-zinc injection database well predicts oxide thickness for fuel rod with zinc injection. Thus, it can be concluded that zinc injection doesn't accelerate clad corrosion. Based

  9. Effect of thermal processing on silver thin films of varying thickness deposited on zinc oxide and indium tin oxide

    International Nuclear Information System (INIS)

    Sivaramakrishnan, K.; Ngo, A. T.; Alford, T. L.; Iyer, S.

    2009-01-01

    Silver films of varying thicknesses (25, 45, and 60 nm) were deposited on indium tin oxide (ITO) on silicon and zinc oxide (ZnO) on silicon. The films were annealed in vacuum for 1 h at different temperatures (300-650 deg. C). Four-point-probe measurements were used to determine the resistivity of the films. All films showed an abrupt change in resistivity beyond an onset temperature that varied with thickness. Rutherford backscattering spectrometry measurements revealed agglomeration of the Ag films upon annealing as being responsible for the resistivity change. X-ray pole figure analysis determined that the annealed films took on a preferential texturing; however, the degree of texturing was significantly higher in Ag/ZnO/Si than in Ag/ITO/Si samples. This observation was accounted for by interface energy minimization. Atomic force microscopy (AFM) measurements revealed an increasing surface roughness of the annealed films with temperature. The resistivity behavior was explained by the counterbalancing effects of increasing crystallinity and surface roughness. Average surface roughness obtained from the AFM measurements were also used to model the agglomeration of Ag based on Ostwald ripening theory

  10. Nano-thick calcium oxide armed titanium: boosts bone cells against methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Cao, Huiliang; Qin, Hui; Zhao, Yaochao; Jin, Guodong; Lu, Tao; Meng, Fanhao; Zhang, Xianlong; Liu, Xuanyong

    2016-02-22

    Since the use of systemic antibiotics for preventing acute biomaterial-associated infections (BAIs) may build up bacterial resistance and result in huge medical costs and unpredictable mortality, new precaution strategies are required. Here, it demonstrated that titanium armed with a nano-thick calcium oxide layer was effective on averting methicillin-resistant Staphylococcus aureus (MRSA) infections in rabbits. The calcium oxide layer was constructed by, firstly, injecting of metallic calcium into titanium via a plasma immersion ion implantation process, and then transforming the outer most surface into oxide by exposing to the atmosphere. Although the calcium oxide armed titanium had a relative low reduction rate (~74%) in growth of MRSA in vitro, it could markedly promote the osteogenic differentiation of bone marrow stem cells (BMSCs), restore local bone integration against the challenge of MRSA, and decrease the incidence of MRSA infection with a rate of 100% (compared to the titanium control). This study demonstrated for the first time that calcium, as one of the major elements in a human body, could be engineered to avert MRSA infections, which is promising as a safe precaution of disinfection for implantable biomedical devices.

  11. Nano-thick calcium oxide armed titanium: boosts bone cells against methicillin-resistant Staphylococcus aureus

    Science.gov (United States)

    Cao, Huiliang; Qin, Hui; Zhao, Yaochao; Jin, Guodong; Lu, Tao; Meng, Fanhao; Zhang, Xianlong; Liu, Xuanyong

    2016-02-01

    Since the use of systemic antibiotics for preventing acute biomaterial-associated infections (BAIs) may build up bacterial resistance and result in huge medical costs and unpredictable mortality, new precaution strategies are required. Here, it demonstrated that titanium armed with a nano-thick calcium oxide layer was effective on averting methicillin-resistant Staphylococcus aureus (MRSA) infections in rabbits. The calcium oxide layer was constructed by, firstly, injecting of metallic calcium into titanium via a plasma immersion ion implantation process, and then transforming the outer most surface into oxide by exposing to the atmosphere. Although the calcium oxide armed titanium had a relative low reduction rate (~74%) in growth of MRSA in vitro, it could markedly promote the osteogenic differentiation of bone marrow stem cells (BMSCs), restore local bone integration against the challenge of MRSA, and decrease the incidence of MRSA infection with a rate of 100% (compared to the titanium control). This study demonstrated for the first time that calcium, as one of the major elements in a human body, could be engineered to avert MRSA infections, which is promising as a safe precaution of disinfection for implantable biomedical devices.

  12. Influence of thickness and coatings morphology in the antimicrobial performance of zinc oxide coatings

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, P. [Department of Physics, University of Minho, Campus de Azurém, 4800-058 Guimaraes (Portugal); Sampaio, P. [CBMA, University of Minho, Campus de Gualtar, 4700 Braga (Portugal); Azevedo, S. [Department of Physics, University of Minho, Campus de Azurém, 4800-058 Guimaraes (Portugal); Vaz, C. [CBMA, University of Minho, Campus de Gualtar, 4700 Braga (Portugal); Espinós, J.P. [Instituto de Ciencia de Materiales de Sevilla, CSIC-University of Sevilla, Avda. Américo Vespucio 49, 41092 Sevilla (Spain); Teixeira, V., E-mail: vasco@fisica.uminho.pt [Department of Physics, University of Minho, Campus de Azurém, 4800-058 Guimaraes (Portugal); Carneiro, J.O., E-mail: carneiro@fisica.uminho.pt [Department of Physics, University of Minho, Campus de Azurém, 4800-058 Guimaraes (Portugal)

    2014-07-01

    In this research work, the production of undoped and silver (Ag) doped zinc oxide (ZnO) thin films for food-packaging applications were developed. The main goal was to determine the influence of coatings morphology and thickness on the antimicrobial performance of the produced samples. The ZnO based thin films were deposited on PET (Polyethylene terephthalate) substrates by means of DC reactive magnetron sputtering. The thin films were characterized by optical spectroscopy, X-Ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Scanning Electron Microscopy (SEM). The antimicrobial performance of the undoped and Ag-doped ZnO thin films was also evaluated. The results attained have shown that all the deposited zinc oxide and Ag-doped ZnO coatings present columnar morphology with V-shaped columns. The increase of ZnO coatings thickness until 200 nm increases the active surface area of the columns. The thinner samples (50 and 100 nm) present a less pronounced antibacterial activity than the thickest ones (200–600 nm). Regarding Ag-doped ZnO thin films, it was verified that increasing the silver content decreases the growth rate of Escherichia coli and decreases the amount of bacteria cells present at the end of the experiment.

  13. Estimation of residual life of boiler tubes using steamside oxide scale thickness

    International Nuclear Information System (INIS)

    Vikrant, K.S.N.; Ramareddy, G.V.; Pavan, A.H.V.; Singh, Kulvir

    2013-01-01

    In thermal power plants, remaining-life-estimation of boiler tubes is required at regular intervals for a safer and a better functionality of boilers. In this paper, a new method is proposed for the residual life estimation of service exposed boiler tubes using Non-Destructive Ultrasonic Oxide scale thickness measurements, average metal temperature and creep master curve. While steady state conduction heat transfer equations are solved to calculate the average metal temperature, creep master curve is generated from short term stress rupture data of rupture life less than 5000 h on a virgin material. In the present study, the residual life of T22 (2.25Cr-1Mo) service exposed Platen Superheater tube is estimated using two master creep curves, i.e. Larson-Miller Parametric (LMP) method of standard ASME T22 creep data and Wilshire approach of short term stress rupture data of T22. As the residual life is calculated from fundamental conduction heat transfer theory and creep rupture data, the proposed method can be applied for different grades of boiler materials. -- Highlights: ► Residual life is calculated from non-destructive oxide scale thickness, creep master curve and average metal temperature. ► A new method is proposed for calculating residual life using above parameters and from conduction heat transfer principles. ► The method can be applied to different boiler grades for estimating residual life and hence the method is generic

  14. Effect of Processing Parameters on Pore Structure and Thickness of Anodic Aluminum Oxide (AAO) Tubular Membranes

    Science.gov (United States)

    Belwalkar, A.; Grasing, E.; Huang, Z.; Misiolek, W.Z.

    2008-01-01

    Nanoporous anodic aluminum oxide (AAO) tubular membranes were fabricated from aluminum alloy tubes in sulfuric and oxalic acid electrolytes using a two-step anodization process. The membranes were investigated for characteristics such as pore size, interpore distance and thickness by varying applied voltage and electrolyte concentration. Morphology of the membranes was examined using light optical and scanning electron microscopy and characterized using ImageJ software. Results showed that membranes having narrow pore size and uniform pore distribution with parallel channel arrays were obtained. The pore sizes were ranging from 14 to 24 nm and the wall thicknesses as high as 76 µm. It was found that the pore size increased in direct proportion with the applied voltage and inversely with the electrolyte concentration while the interpore distance increased linearly with the applied voltage. It was also observed that increase in acid concentration increased tubular membrane wall thickness that improved mechanical handling. By using anodic alumina technology, robust ceramic tubes with uniformly distributed pore-structure and parallel nano-channels of lengths and sizes practical for industrial applications were reliably produced in quantity. PMID:19578471

  15. Effect of Processing Parameters on Pore Structure and Thickness of Anodic Aluminum Oxide (AAO) Tubular Membranes.

    Science.gov (United States)

    Belwalkar, A; Grasing, E; Van Geertruyden, W; Huang, Z; Misiolek, W Z

    2008-07-01

    Nanoporous anodic aluminum oxide (AAO) tubular membranes were fabricated from aluminum alloy tubes in sulfuric and oxalic acid electrolytes using a two-step anodization process. The membranes were investigated for characteristics such as pore size, interpore distance and thickness by varying applied voltage and electrolyte concentration. Morphology of the membranes was examined using light optical and scanning electron microscopy and characterized using ImageJ software. Results showed that membranes having narrow pore size and uniform pore distribution with parallel channel arrays were obtained. The pore sizes were ranging from 14 to 24 nm and the wall thicknesses as high as 76 microm. It was found that the pore size increased in direct proportion with the applied voltage and inversely with the electrolyte concentration while the interpore distance increased linearly with the applied voltage. It was also observed that increase in acid concentration increased tubular membrane wall thickness that improved mechanical handling. By using anodic alumina technology, robust ceramic tubes with uniformly distributed pore-structure and parallel nano-channels of lengths and sizes practical for industrial applications were reliably produced in quantity.

  16. Thickness effects of yttria-doped ceria interlayers on solid oxide fuel cells

    Science.gov (United States)

    Fan, Zeng; An, Jihwan; Iancu, Andrei; Prinz, Fritz B.

    2012-11-01

    Determining the optimal thickness range of the interlayed yttria-doped ceria (YDC) films promises to further enhance the performance of solid oxide fuel cells (SOFCs) at low operating temperatures. The YDC interlayers are fabricated by the atomic layer deposition (ALD) method with one super cycle of the YDC deposition consisting of 6 ceria deposition cycles and one yttria deposition cycle. YDC films of various numbers of ALD super cycles, ranging from 2 to 35, are interlayered into bulk fuel cells with a 200 um thick yttria-stabilized zirconia (YSZ) electrolyte. Measurements and analysis of the linear sweep voltammetry of these fuel cells reveal that the performance of the given cells is maximized at 10 super cycles. Auger elemental mapping and X-ray photoelectron spectroscopy (XPS) techniques are employed to determine the film completeness, and they verify 10 super cycles of YDC to be the critical thickness point. This optimal YDC interlayer condition (6Ce1Y × 10 super cycles) is applied to the case of micro fuel cells as well, and the average performance enhancement factor is 1.4 at operating temperatures of 400 and 450 °C. A power density of 1.04 W cm-2 at 500 °C is also achieved with the optimal YDC recipe.

  17. Preperitoneal Fat Thicknesses, Lipid Profile, and Oxidative Status in Women With Uterine Fibroids.

    Science.gov (United States)

    Vignini, Arianna; Sabbatinelli, Jacopo; Clemente, Nicolò; Delli Carpini, Giovanni; Tassetti, Marta; Zagaglia, Giulia; Ciavattini, Andrea

    2017-10-01

    There is growing evidence supporting a possible role for metabolic syndrome and its determinants, such as dyslipidemia, in uterine fibroid (UF) pathogenesis. The present study aims to investigate the association between UFs and visceral and subcutaneous fat thickness (SFT), lipid profile, and oxidative and antioxidative status. In this cross-sectional study, 35 patients diagnosed with UFs and 15 women without UFs were enrolled. Clinical history and anthropometric parameters were collected for every woman. Characteristics of UFs, preperitoneal fat thickness (PFT), and SFT were assessed ultrasonically. Lipid profile, glucose, thiobarbituric acid reactive substances (TBARs), and superoxide dismutase (SOD) activity were evaluated on plasma from participants. Women with UFs showed a significantly increased PFT (11.63 ± 3.39 vs 7.01 ± 3.10 mm; P HDL-C; 45.4 ± 8.3 vs 57.2 ± 13.4 mg/dL; P = .017), higher levels of low-density lipoprotein cholesterol (LDL-C; 92.3 ± 21.5 vs 72.0 ± 14.6 mg/dL; P = .007), and oxidized LDL (65.2 ± 20.7 vs 43.0 ± 11.3 U/L; P = .002). In patients, TBARs concentration was significantly higher (9.41 ± 6.49 vs 2.92 ± 1.65 nmol malondialdehyde/100 μg prot; P body mass index, oxidized LDL, and TBARs. At multivariate analysis, PFT and HDL-C maintained a significant correlation with the diagnosis of UFs. Chronic inflammation triggered and sustained by visceral fat could play a determinant role in cell differentiation and proliferation processes, necessary for the development of UFs. Alterations in cholesterol fractions may be explained as a consequence of the increased visceral fat deposits and can reflect an increased risk of subclinical atherosclerosis in patients with UF.

  18. Investigation of the fabrication parameters of thick film metal oxide-polymer pH electrodes

    International Nuclear Information System (INIS)

    Gac, Arnaud

    2002-01-01

    This thesis describes a study into the development of an optimum material and fabrication process for the production of thick film pH electrodes. These devices consist of low cost, miniature and rugged pH sensors formed by screen printing a metal oxide bearing paste onto a high temperature (∼850 deg C) fired metal back contact supported on a standard alumina substrate. The pH sensitive metal oxide layer must be fabricated at relatively low temperatures (<300 deg C) in order to maintain the pH sensitivity of the layer and hence requires the use of a suitably stable low temperature curing binder. Bespoke fabricated inks are derived from a Taguchi style factorial experimental plans in which, different binder types, curing temperatures, hydration level and percentage mixtures of different metal oxides and layer thicknesses were investigated. The pH responses of 18 printed electrodes per batch were assessed in buffer solutions with respect to a commercial reference electrode forming a complete potentiometric circuit. The evaluation criteria used in the study included the device-to-device variation in sensitivity of the pH sensors and their sensitivity variation as a function of time. The results indicated the importance of the choice of binder type in particular on the performance characteristics. Reproducible device-to-device variation in sensitivity was determined for the best inks found, whatever the ink fabrication batch. A reduction in the sensitivity variation with time has been determined using the mathematical models derived from an experimental plan. The lack of reproducibility of the sensitivity magnitude, regardless of the ink manufacturing batch, seems to be a recurrent problem with prototype inks. Experimental sub-Nernstian responses are discussed in the light of possible pH mechanisms. (author)

  19. Effect of coating thickness of iron oxide nanoparticles on their relaxivity in the MRI

    Directory of Open Access Journals (Sweden)

    Farzaneh Hajesmaeelzadeh

    2016-02-01

    Full Text Available Objective(s:Iron oxide nanoparticles have found prevalent applications in various fields including drug delivery, cell separation and as contrast agents. Super paramagnetic iron oxide (SPIO nanoparticles allow researchers and clinicians to enhance the tissue contrast of an area of interest by increasing the relaxation rate of water. In this study, we evaluate the dependency of hydrodynamic size of iron oxide nanoparticles coated with Polyethylene  glycol (PEG on their relativities with 3 Tesla clinical MRI. Materials and Methods: We used three groups of nanoparticles with nominal sizes 20, 50 and 100 nm with a core size of 8.86 nm, 8.69 nm and 10.4 nm that they were covered with PEG 300 and 600 Da. A clinical magnetic resonance scanner determines the T1 and T2 relaxation times for various concentrations of PEG-coated nanoparticles. Results: The size measurement by photon correlation spectroscopy showed the hydrodynamic sizes of MNPs with nominal 20, 50 and 100 nm with 70, 82 and 116 nm for particles with PEG 600 coating and 74, 93 and 100 nm for  particles with PEG 300 coating, respectively. We foud that the relaxivity decreased with increasing overall particle size (via coating thickness. Magnetic resonance imaging showed that by increasing the size of the nanoparticles, r2/r1 increases linearly. Conclusion: According to the data obtained from this study it can be concluded that increments in coating thickness have more influence on relaxivities compared to the changes in core size of magnetic nanoparticles.

  20. A thermally robust and thickness independent ferroelectric phase in laminated hafnium zirconium oxide

    Directory of Open Access Journals (Sweden)

    S. Riedel

    2016-09-01

    Full Text Available Ferroelectric properties in hafnium oxide based thin films have recovered the scaling potential for ferroelectric memories due to their ultra-thin-film- and CMOS-compatibility. However, the variety of physical phenomena connected to ferroelectricity allows a wider range of applications for these materials than ferroelectric memory. Especially mixed HfxZr1-xO2 thin films exhibit a broad compositional range of ferroelectric phase stability and provide the possibility to tailor material properties for multiple applications. Here it is shown that the limited thermal stability and thick-film capability of HfxZr1-xO2 can be overcome by a laminated approach using alumina interlayers.

  1. The effects of gate oxide thickness on radiation damage in MOS system

    International Nuclear Information System (INIS)

    Zhu Hui; Yan Rongliang; Wang Yu; He Jinming

    1988-01-01

    The dependences of the flatband voltage shift (ΔV FB ) and the threshold voltage shift (ΔV TH ) in MOS system on the oxide thickness (T ox ) and on total irradiated dose (D) of electron-beam and 60 Co γ-ray have been studied. It has been found that ΔV FB ∝ T ox 3 , with +10V of gate bias during irradiation for n-Si substrate MOS capacitors; ΔV TH ∝ T ox 3 D 2/3 , with 'on' gate bias during irradiation for n- and P-channel MOS transistors; ΔV TP ∝ T ox 2 D 2/3 , with 'off' gate bias during irradiation for P-channel MOS transistors. These results are explained by Viswanathan model. According to ∼T ox 3 dependence, the optimization of radiation hardening process for MOS system is also simply discussed

  2. Thickness dependent growth of low temperature atomic layer deposited zinc oxide films

    International Nuclear Information System (INIS)

    Montiel-González, Z.; Castelo-González, O.A.; Aguilar-Gama, M.T.; Ramírez-Morales, E.; Hu, H.

    2017-01-01

    Highlights: • Polycrystalline columnar ZnO thin films deposited by ALD at low temperatures. • Higher deposition temperature leads to a greater surface roughness in the ALD ZnO films. • Higher temperature originates larger refractive index values of the ALD ZnO films. • ZnO thin films were denser as the numbers of ALD deposition cycles were larger. • XPS analysis revels mayor extent of the DEZ reaction during the ALD process. - Abstract: Zinc oxide films are promising to improve the performance of electronic devices, including those based on organic materials. However, the dependence of the ZnO properties on the preparation conditions represents a challenge to obtain homogeneous thin films that satisfy specific applications. Here, we prepared ZnO films of a wide range of thicknesses by atomic layer deposition (ALD) at relatively low temperatures, 150 and 175 °C. From the results of X-ray photoelectron spectroscopy, X-ray diffraction and Spectroscopic Ellipsometry it is concluded that the polycrystalline structure of the wurtzite is the main phase of the ALD samples, with OH groups on their surface. Ellipsometry revealed that the temperature and the deposition cycles have a strong effect on the films roughness. Scanning electron micrographs evidenced such effect, through the large pyramids developed at the surface of the films. It is concluded that crystalline ZnO thin films within a broad range of thickness and roughness can be obtained for optic or optoelectronic applications.

  3. CdO Doped Indium Oxide Thick Film as a Low Temperature H2S Gas Sensor

    Directory of Open Access Journals (Sweden)

    D. N. CHAVAN

    2011-06-01

    Full Text Available The thick films of AR grade In2O3 were prepared by standard screen-printing technique. The gas sensing performance of thick film was tested for various gases. It showed maximum gas response to ethanol vapor at 350 oC for 80 ppm. To improve the gas response and selectivity of the film towards a particular gas, In2O3 thick films were modified by dipping them in an aqueous solution of 0.1 M CdCl2 for different intervals of time. The surface modified (10 min In2O3 thick film showed maximum response to H2S gas (10 ppm than pure In2O3 thick film at 150 oC. Cadmium oxide on the surface of the film shifts the gas response from ethanol vapor to H2S gas. A systematic study of sensing performance of the thick films indicates the key role played by cadmium oxide on the surface of thick films. The selectivity, gas response and recovery time of the thick films were measured and presented.

  4. Equivalent distributed capacitance model of oxide traps on frequency dispersion of C-V curve for MOS capacitors

    Science.gov (United States)

    Lu, Han-Han; Xu, Jing-Ping; Liu, Lu; Lai, Pui-To; Tang, Wing-Man

    2016-11-01

    An equivalent distributed capacitance model is established by considering only the gate oxide-trap capacitance to explain the frequency dispersion in the C-V curve of MOS capacitors measured for a frequency range from 1 kHz to 1 MHz. The proposed model is based on the Fermi-Dirac statistics and the charging/discharging effects of the oxide traps induced by a small ac signal. The validity of the proposed model is confirmed by the good agreement between the simulated results and experimental data. Simulations indicate that the capacitance dispersion of an MOS capacitor under accumulation and near flatband is mainly caused by traps adjacent to the oxide/semiconductor interface, with negligible effects from the traps far from the interface, and the relevant distance from the interface at which the traps can still contribute to the gate capacitance is also discussed. In addition, by excluding the negligible effect of oxide-trap conductance, the model avoids the use of imaginary numbers and complex calculations, and thus is simple and intuitive. Project supported by the National Natural Science Foundation of China (Grant Nos. 61176100 and 61274112), the University Development Fund of the University of Hong Kong, China (Grant No. 00600009), and the Hong Kong Polytechnic University, China (Grant No. 1-ZVB1).

  5. Equivalent distributed capacitance model of oxide traps on frequency dispersion of C – V curve for MOS capacitors

    International Nuclear Information System (INIS)

    Lu Han-Han; Xu Jing-Ping; Liu Lu; Lai Pui-To; Tang Wing-Man

    2016-01-01

    An equivalent distributed capacitance model is established by considering only the gate oxide-trap capacitance to explain the frequency dispersion in the C – V curve of MOS capacitors measured for a frequency range from 1 kHz to 1 MHz. The proposed model is based on the Fermi–Dirac statistics and the charging/discharging effects of the oxide traps induced by a small ac signal. The validity of the proposed model is confirmed by the good agreement between the simulated results and experimental data. Simulations indicate that the capacitance dispersion of an MOS capacitor under accumulation and near flatband is mainly caused by traps adjacent to the oxide/semiconductor interface, with negligible effects from the traps far from the interface, and the relevant distance from the interface at which the traps can still contribute to the gate capacitance is also discussed. In addition, by excluding the negligible effect of oxide-trap conductance, the model avoids the use of imaginary numbers and complex calculations, and thus is simple and intuitive. (paper)

  6. The thiol oxidant dipyridyl disulfide can supply the PDI-Ero1p pathway with additional oxidative equivalents

    DEFF Research Database (Denmark)

    López-Mirabal, H Reynaldo; Winther, Jakob R

    2007-01-01

    Membrane-permeant oxidants have become a standard tool for studying eukaryotic organisms because they affect the redox state and the redox regulation of different compartments. The ero1-1 mutant is temperature sensitive (37 degrees C) and cannot grow under anaerobic conditions. Low micromolar con...

  7. Alcohol vapor sensing by cadmium-doped zinc oxide thick films based chemical sensor

    Science.gov (United States)

    Zargar, R. A.; Arora, M.; Chackrabarti, S.; Ahmad, S.; Kumar, J.; Hafiz, A. K.

    2016-04-01

    Cadmium-doped zinc oxide nanoparticles were derived by simple chemical co-precipitation route using zinc acetate dihydrate and cadmium acetate dihydrate as precursor materials. The thick films were casted from chemical co-precipitation route prepared nanoparticles by economic facile screen printing method. The structural, morphological, optical and electrical properties of the film were characterized relevant to alcohol vapor sensing application by powder XRD, SEM, UV-VIS and DC conductivity techniques. The response and sensitivity of alcohol (ethanol) vapor sensor are obtained from the recovery curves at optimum working temperature range from 20∘C to 50∘C. The result shows that maximum sensitivity of the sensor is observed at 25∘C operating temperature. On varying alcohol vapor concentration, minor variation in resistance has been observed. The sensing mechanism of sensor has been described in terms of physical adsorption and chemical absorption of alcohol vapors on cadmium-doped zinc oxide film surface and inside film lattice network through weak hydrogen bonding, respectively.

  8. Densification of ∼5 nm-thick SiO_2 layers by nitric acid oxidation

    International Nuclear Information System (INIS)

    Choi, Jaeyoung; Joo, Soyeong; Park, Tae Joo; Kim, Woo-Byoung

    2017-01-01

    Highlights: • Leakage current density of the commercial PECVD grown ∼5 nm SiO_2 layer has been decreased about three orders of magnitude by densification. • The densification of SiO_2 layer is achieved by high oxidation ability of O·. • Densities of suboxide, fixed charge (N_f) and defect state (N_d) in SiO_2/Si interface are decreased by NAOS and PMA. • Tunneling barrier height (Φ_t) is increased because of the increase of atomic density in SiO_2 layer. - Abstract: Low-temperature nitric acid (HNO_3) oxidation of Si (NAOS) has been used to improve the interface and electrical properties of ∼5 nm-thick SiO_2/Si layers produced by plasma-enhanced chemical vapor deposition (PECVD). Investigations of the physical properties and electrical characteristics of these thin films revealed that although their thickness is not changed by NAOS, the leakage current density at a gate bias voltage of −1 V decreases by about two orders of magnitude from 1.868 × 10"−"5 A/cm"2. This leakage current density was further reduced by post-metallization annealing (PMA) at 250 °C for 10 min in a 5 vol.% hydrogen atmosphere, eventually reaching a level (5.2 × 10"−"8 A/cm"2) approximately three orders of magnitude less than the as-grown SiO_2 layer. This improvement is attributed to a decrease in the concentration of suboxide species (Si"1"+, Si"2"+ and Si"3"+) in the SiO_2/Si interface, as well as a decrease in the equilibrium density of defect sites (N_d) and fixed charge density (N_f). The barrier height (Φ_t) generated by a Poole-Frenkel mechanism also increased from 0.205 to 0.371 eV after NAOS and PMA. The decrease in leakage current density is therefore attributed to a densification of the SiO_2 layer in combination with the removal of OH species and increase in interfacial properties at the SiO_2/Si interface.

  9. A direct current potential drop method for evaluating oxide film thickness formed in high-temperature water

    International Nuclear Information System (INIS)

    Anzai, Hideya; Ishibashi, Ryo; Saka, Masumi

    2016-01-01

    To establish an evaluation technique for oxide film thickness in-situ, the applicability of a four-point-probe direct current potential drop method is discussed in this study. Several samples of JIS SUS316L stainless steel with different oxide film thickness were prepared after immersing them in oxygenated pure water at 288°C for different periods. The oxide film thickness was measured by cross sectional observation using a transmission electron microscope. Potential drop on the oxide surface was measured every second during an acquisition period of about 20 s while a constant current was being injected into the sample simultaneously. This kind of measurement was repeatedly carried out at several arbitrary contact positions on the surface of the same sample. The measurement results showed that the potential drop slightly changed during the acquisition period and the tendency varied at the different contact positions. Multiple measurements at different contact positions revealed that the tendency could be categorized into two general types: the decreasing potential drop and the increasing potential drop, defined by the overall trend of the potential drop during the acquisition time. It was found that the ratio of contact positions with a decreasing potential drop tendency to all the contact positions of measurement tended to increase as applied current increased. This tendency depended on the oxide film thickness. The threshold value of applied current was found to correlate well with the oxide film thickness when the occurrence rate of decreasing potential drop ranged from 70 to 90% showing the best correlation at 70%. (author)

  10. Effect of different dextrose equivalents of maltodextrin on oxidation stability in encapsulated fish oil by spray drying.

    Science.gov (United States)

    Abd Ghani, Asmaliza; Adachi, Sae; Shiga, Hirokazu; Neoh, Tze Loon; Adachi, Shuji; Yoshii, Hidefumi

    2017-04-01

    Encapsulating fish oil by spray drying with an adequate wall material was investigated to determine if stable powders containing emulsified fish-oil-droplets can be formed. In particular, the dextrose equivalent (DE) of maltodextrin (MD) affects the powder structure, surface-oil ratio, and oxidative stability of fish oil. The carrier solution was prepared using MD with different DEs (DE = 11, 19, and 25) and sodium caseinate as the wall material and the emulsifier, respectively. The percentage of microcapsules having a vacuole was 73, 39, and 38% for MD with DE = 11, 19, and 25, respectively. Peroxide values (PVs) were measured for the microcapsules incubated at 60 °C. The microcapsules prepared with MD of DE = 25 and 19 had lower PVs than those prepared with MD of DE = 11. The difference in PV can be ascribed to the difference in the surface-oil ratio of the spray-dried microcapsules.

  11. Development of a novel gas sensor based on oxide thick films

    International Nuclear Information System (INIS)

    Arshak, K.; Gaidan, I.

    2005-01-01

    Zinc and iron oxide thick film gas sensors were fabricated using screen-printing technology on glass substrates that had silver interdigitated electrodes. The sensor was used to detect methanol, ethanol and propanol with a concentration range of 0-8000 ppm. Using the formula to calculate a change in resistance, ΔR = R gas - R air, resistance was seen to increase linearly alongside increasing concentrations of the gas vapours. The sensor showed the highest sensitivity to propanol followed by ethanol and methanol when the operating temperature was 25 deg. C. The sensitivities (slope of graphs) of methanol, ethanol and propanol changed from 0.07, 0.5, and 3.54 to 0.075, 0.115, and 0.5 Ω/ppm when the operating temperature was increased from 25 to 50 deg. C. The response/recovery times of the sensor for 4000 ppm at room temperature were, 10/10, 15/20 and 40/70 s for methanol, ethanol and propanol, respectively. X-ray diffraction (XRD) was used to examine the final composition of the film, while scanning electron microscopy (SEM) was used to examine the final composition of grain size. The final composition has two phases: ZnO and ZnFe 2 O 4

  12. Prediction model for oxide thickness on aluminum alloy cladding during irradiation

    International Nuclear Information System (INIS)

    Kim, Yeon Soo; Hofman, G.L.; Hanan, N.A.; Snelgrove, J.L.

    2003-01-01

    An empirical model predicting the oxide film thickness on aluminum alloy cladding during irradiation has been developed as a function of irradiation time, temperature, heat flux, pH, and coolant flow rate. The existing models in the literature are neither consistent among themselves nor fit the measured data very well. They also lack versatility for various reactor situations such as a pH other than 5, high coolant flow rates, and fuel life longer than ∼1200 hrs. Particularly, they were not intended for use in irradiation situations. The newly developed model is applicable to these in-reactor situations as well as ex-reactor tests, and has a more accurate prediction capability. The new model demonstrated with consistent predictions to the measured data of UMUS and SIMONE fuel tests performed in the HFR, Petten, tests results from the ORR, and IRIS tests from the OSIRIS and to the data from the out-of-pile tests available in the literature as well. (author)

  13. Characterization of 10 μm thick porous silicon dioxide obtained by complex oxidation process for RF application

    International Nuclear Information System (INIS)

    Park, Jeong-Yong; Lee, Jong-Hyun

    2003-01-01

    This paper proposes a 10 μm thick oxide layer structure, which can be used as a substrate for RF circuits. The structure has been fabricated by anodic reaction and complex oxidation, which is a combined process of low temperature thermal oxidation (500 deg. C, for 1 h at H 2 O/O 2 ) and a rapid thermal oxidation (RTO) process (1050 deg. C, for 1 min). The electrical characteristics of oxidized porous silicon layer (OPSL) were almost the same as those of standard thermal silicon dioxide. The leakage current through the OPSL of 10 μm was about 100-500 pA in the range of 0-50 V. The average value of breakdown field was about 3.9 MV cm -1 . From the X-ray photo-electron spectroscopy (XPS) analysis, surface and internal oxide films of OPSL, prepared by complex process were confirmed to be completely oxidized and also the role of RTO process was important for the densification of porous silicon layer (PSL) oxidized at a lower temperature. For the RF-test of Si substrate with thick silicon dioxide layer, we have fabricated high performance passive devices such as coplanar waveguide (CPW) on OPSL substrate. The insertion loss of CPW on OPSL prepared by complex oxidation process was -0.39 dB at 4 GHz and similar to that of CPW on OPSL prepared by a temperature of 1050 deg. C (1 h at H 2 O/O 2 ). Also the return loss of CPW on OPSL prepared by complex oxidation process was -23 dB at 10 GHz, which is similar to that of CPW on OPSL prepared by high temperature

  14. Improvement of the effective work function and transmittance of thick indium tin oxide/ultrathin ruthenium doped indium oxide bilayers as transparent conductive oxide

    International Nuclear Information System (INIS)

    Taweesup, Kattareeya; Yamamoto, Ippei; Chikyow, Toyohiro; Lothongkum, Gobboon; Tsukagoshi, Kazutoshi; Ohishi, Tomoji; Tungasmita, Sukkaneste; Visuttipitukul, Patama; Ito, Kazuhiro; Takahashi, Makoto; Nabatame, Toshihide

    2016-01-01

    Ruthenium doped indium oxide (In_1_−_xRu_xO_y) films fabricated using DC magnetron co-sputtering with In_2O_3 and Ru targets were investigated for use as transparent conductive oxides. The In_1_−_xRu_xO_y films had an amorphous structure in the wide compositional range of x = 0.3–0.8 and had an extremely smooth surface. The transmittance and resistivity of the In_1_−_xRu_xO_y films increased as the Ru content increased. The transmittance of the In_0_._3_8Ru_0_._6_2O_y film improved to over 80% when the film thickness was less than 5 nm, while the specific resistivity (ρ) was kept to a low value of 1.6 × 10"−"4 Ω cm. Based on these experimental data, we demonstrated that thick indium tin oxide (In_0_._9Sn_0_._1O_y, ITO) (150 nm)/ultrathin In_0_._3_8Ru_0_._6_2O_y (3 nm) bilayers have a high effective work function of 5.3 eV, transmittance of 86%, and low ρ of 9.2 × 10"−"5 Ω cm. This ITO/In_0_._3_8Ru_0_._6_2O_y bilayer is a candidate for use as an anode for organic electroluminescent devices. - Highlights: • We investigated characteristics of thick ITO/ultrathin Ru doped In_2O_3 bilayers. • Effect of Ru addition in In_2O_3 results in smooth surface because of an amorphous structure. • The In_0_._3_8Ru_0_._6_2O_y film with less than 5 nm improves to high transmittance over 80%. • ITO/In_0_._3_8Ru_0_._6_2O_y bilayer has a high effective work function of 5.3 eV. • We conclude that ITO/ultrathin In_0_._3_8Ru_0_._6_2O_y bilayer is a candidate as an anode of OEL.

  15. Adhesion-enhanced thick copper film deposition on aluminum oxide by an ion-beam-mixed Al seed layer

    International Nuclear Information System (INIS)

    Kim, Hyung-Jin; Park, Jae-Won

    2012-01-01

    We report a highly-adherent 30-μm Cu conductive-path coating on an aluminum-oxide layer anodized on an aluminum-alloy substrate for a metal-printed circuit-board application. A 50-nm Al layer was first coated with an e-beam evaporative deposition method on the anodized oxide, followed by ion bombardment to mix the interfacial region. Subsequently, a Cu coating was deposited onto the mixed seed layer to the designed thickness. Adhesions of the interface were tested by using tape adhesion test, and pull-off tests and showed commercially acceptable adhesions for such thick coating layers. The ion beam mixing (IBM) plays the role of fastening the thin seed coating layer to the substrate and enhancing the adhesion of the Cu conductive path on the anodized aluminum surface.

  16. Derivation of endogenous equivalent values to support risk assessment and risk management decisions for an endogenous carcinogen: Ethylene oxide.

    Science.gov (United States)

    Kirman, C R; Hays, S M

    2017-12-01

    An approach is presented for ethylene oxide (EO) to derive endogenous equivalent (EE) values, which are endogenous levels normally found within the body expressed in terms of exogenous exposures. EE values can be used to support risk assessment and risk management decisions for chemicals such as EO that have both endogenous and exogenous exposure pathways. EE values were derived using a meta-analysis of data from the published literature characterizing the distribution for an EO biomarker of exposure, hemoglobin N-(2-hydroxyethyl)-valine (HEV), in unexposed populations. These levels are compared to the those reported in exposed populations (smokers, workers). Correlation between the biomarker of exposure and external exposures of EO were applied to this distribution to determine corresponding EE values, which range from 0.13 to 6.9 ppb for EO in air. These values are orders of magnitude higher than risk-based concentration values derived for EO using default methods, and are provided as a pragmatic, data-driven alternative approach to managing the potential risks from exogenous exposures to EO. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Colloidal titania-silica-iron oxide nanocomposites and the effect from silica thickness on the photocatalytic and bactericidal activities

    Energy Technology Data Exchange (ETDEWEB)

    Chanhom, Padtaraporn [Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Charoenlap, Nisanart [Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210 (Thailand); Tomapatanaget, Boosayarat [Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Insin, Numpon, E-mail: Numpon.I@chula.ac.th [Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand)

    2017-04-01

    New types of colloidal multifunctional nanocomposites that combine superparamagnetic character and high photocatalytic activity were synthesized and investigated. The superparamagnetic nanocomposites composed of anatase titania, silica, and iron oxide nanoparticles (TSI) were synthesized using thermal decomposition method followed by microemulsion method, without calcination at high temperature. Different techniques including X-ray diffraction (XRD) and transmission electron microscope (TEM) were used to characterize and confirm the structure of the nanocomposites. These nanocomposites showed high photocatalytic activity when used in the photodegradation of methylene blue under irradiation with a black light lamp. Moreover, the nanocomposites exhibited high antibacterial properties. From our study, the nanocomposites can be useful in various applications such as removal of pollutants with readily separation from the environment using an external magnetic field. These composites could effectively photo-degrade the dye at least three cycles without regeneration. The effects of silica shell thickness on the photocatalytic activity was investigated, and the thickness of 6 nm of the silica interlayer is enough for the inhibition of electron translocation between titania and iron oxide nanoparticles and maintaining the efficiency of photocatalytic activity of titania nanoparticles. - Highlights: • New colloidal nanocomposites of iron oxide-silica-titania were prepared. • The nanocomposites exhibited high photocatalytic activity with magnetic response. • The effects of silica thickness on photocatalytic activity were investigated. • Bactericidal activity of the nanocomposites was demonstrated.

  18. TRPV4 activation mediates flow-induced nitric oxide production in the rat thick ascending limb

    Science.gov (United States)

    Garvin, Jeffrey L.

    2014-01-01

    Nitric oxide (NO) regulates renal function. Luminal flow stimulates NO production in the thick ascending limb (TAL). Transient receptor potential vanilloid 4 (TRPV4) is a mechano-sensitive channel activated by luminal flow in different types of cells. We hypothesized that TRPV4 mediates flow-induced NO production in the rat TAL. We measured NO production in isolated, perfused rat TALs using the fluorescent dye DAF FM. Increasing luminal flow from 0 to 20 nl/min stimulated NO from 8 ± 3 to 45 ± 12 arbitrary units (AU)/min (n = 5; P < 0.05). The TRPV4 antagonists, ruthenium red (15 μmol/l) and RN 1734 (10 μmol/l), blocked flow-induced NO production. Also, luminal flow did not increase NO production in the absence of extracellular calcium. We also studied the effect of luminal flow on NO production in TALs transduced with a TRPV4shRNA. In nontransduced TALs luminal flow increased NO production by 47 ± 17 AU/min (P < 0.05; n = 5). Similar to nontransduced TALs, luminal flow increased NO production by 39 ± 11 AU/min (P < 0.03; n = 5) in TALs transduced with a control negative sequence-shRNA while in TRPV4shRNA-transduced TALs, luminal flow did not increase NO production (Δ10 ± 15 AU/min; n = 5). We then tested the effect of two different TRPV4 agonists on NO production in the absence of luminal flow. 4α-Phorbol 12,13-didecanoate (1 μmol/l) enhanced NO production by 60 ± 11 AU/min (P < 0.002; n = 7) and GSK1016790A (10 ηmol/l) increased NO production by 52 ± 15 AU/min (P < 0.03; n = 5). GSK1016790A (10 ηmol/l) did not stimulate NO production in TRPV4shRNA-transduced TALs. We conclude that activation of TRPV4 channels mediates flow-induced NO production in the rat TAL. PMID:24966090

  19. Quantitative comparisons of genotoxic effects of atomic energy and fossil-fuelled energy. Rad-equivalences for ethylene, ethylene oxide and formaldehyde - consequences for decisions at Government level

    International Nuclear Information System (INIS)

    Latarjet, R.; Averbeck, D.; Levy, S.; Poirier, V.

    1982-01-01

    Rad-equivalences have been determined on the basis of data on the genotoxic effects of low linear energy transfer ionizing radiation and of three chemical pollutants - ethylene, ethylene oxide and formaldehyde - emitted from energy-producing power plants. In the case of ethylene and its metabolite, ethylene oxide, the conditions were particularly favourable because the equivalences could be based on the induction of total mutations in the mouse, which is the same genetic end-point used for the assessment of radiation risks. Once established, the rad-equivalences were used (a) to extrapolate the rules adopted for radiation to each of these two compounds and (b) to make recommendations for exposed workers at 'hot spots' and for the general population. Measurements of ethylene in power plants and in the atmosphere of Paris have indicated that in most cases the measured values fall within the recommended values. However, pollution by ethylene oxide in cold sterilization units should be reduced. Rad-equivalences obtained for lethal effects, and for the induction of chromosome aberrations by formaldehyde in human cells in vitro, suggest that the maximum admissible concentrations are far too high in most countries and must be reconsidered. In France, the Ministry of Health is taking the rad-equivalences into consideration for the preparation of a law regulating pollution by ethylene and ethylene oxide - as a first step. These results show that rad-equivalences can be used for risk assessments of genotoxic effects from power plants and that decisions can be made by extrapolating the rules adopted for radiation protection to some chemical mutagens, when certain strict conditions are fulfilled. (author)

  20. Equivalente esférico e valores da espessura da camada de fibras nervosas obtidas com o GDX TM Scanning Laser System® Spherical equivalent and nerve fiber layer thickness assessed with GDX TM Scanning Laser System®

    Directory of Open Access Journals (Sweden)

    Lênio Souza Alvarenga

    1999-12-01

    Full Text Available Objetivo: Estudar a influência do equivalente esférico nos valores obtidos pelo GDX TM Scanning Laser System®. Métodos: Foram avaliados 41 olhos de 41 voluntários sem doenças oculares e com campo visual sem alterações. Foi realizada a polarimetria de varredura a laser com o GDX TM Scanning Laser System® de acordo com as instruções contidas no manual do aparelho. Foram comparados os valores obtidos nesse exame em um grupo de pacientes com equivalente esférico positivo e em um outro com este valor nulo ou negativo, pelo teste de Mann-Whitney. Resultados: Não se verificou diferença estatística entre os valores obtidos nos olhos de pacientes do grupo I e os do grupo II. Não foi encontrada correlação entre o equivalente esférico e os valores obtidos com o GDX TM Scanning Laser System®. Conclusões: Na amostra estudada não houve diferença estatística entre os valores obtidos em um grupo de olhos com equivalente esférico positivo e outro com este valor negativo ou nulo, usando-se o GDX TM Scanning Laser System®.Purpose: To evaluate the effect of spherical equivalent on the acquisition of nerve fiber layer (NFL thickness with GDX TM Scanning Laser System®. Methods: Forty-one eyes of 41 volunteers were enrolled in this study. All of them presented with no ocular disease and no visual field defect. The NFL thickness was measured with GDX TM Scanning Laser System® as described in its manual. The values obtained in a group of volunteers with negative spherical equivalent (group I were compared to those from a group with a positive spherical equivalent (group II by the Mann-Whitney test. Results: There was no statistical difference between mea-surements in eyes of group I and those in group II. The NFL thickness measurements were not correlated with the sphe-rical equivalent. Conclusions: In the studied group there was no statistical difference in the GDX TM Scanning Laser System® parameters related to spherical equivalent.

  1. Numerical modelling of the impedance plane for simultaneous determining, by eddy currents, the oxide thickness and conductivity in Zircaloy

    International Nuclear Information System (INIS)

    Lois, Alejandro E.

    2001-01-01

    During service at high temperature or in aggressive media, metallic structures and components may suffer different types of changes or degradation. As an example, phase transformations may occur, second phases may precipitate, and in consequence the mechanical and chemical properties of the material may change. Their behavior will therefore differ from that considered for the design of the component. The knowledge of the amount of a precipitated second phase in a component should be an important tool in the hands of the maintenance engineer. And it would be very important to obtain this knowledge nondestructively and reliably. The objective of this project is to evaluate by eddy currents the amount of the hydrogen incorporated during service in structural zirconium base materials. For this purpose, a series of Zircaloy-4 specimens with oxide layers of different thickness and different concentration of hydrogen obtained by controlled autoclave treatments were used. These specimens were tested with eddy current equipment. The information produced by an eddy current test is the superposition of many variables, e.g.: thickness of oxide layers, conductance, thickness of specimen, etc. In order to sort out this information, an analytical model of the impedance plane was programmed in a PC, with which this information was processed, permitting, in this way, to evaluate the conductivity of materials, taking into account the effect of oxide layers thickness. A linear relationship between the conductivity and the hydrogen content in the range of hydrogen concentrations of technological interest was observed. Therefore, the calculated electrical conductivity may be transformed to the amount of hydrogen content, using a suitable calibration curve. This process will allow for the nondestructive assessment of the amount of hydrogen in reactor components, such as pressure and calandria tubes, a knowledge which will enable the experts to predict the degree of fragility of those

  2. The magnetic characteristics of perpendicular magnetic tunnel junction with MgO and Al-O oxidation layers in various thickness

    International Nuclear Information System (INIS)

    Chen, T.-J.; Canizo-Cabrera, A.; Chang, C.-H.; Liao, K.-A.; Li, Simon C.; Hou, C.-K.; Wu Teho

    2006-01-01

    In this work we show the magnetic characteristics of perpendicular magnetic tunnel junction (pMTJ) with different oxidation layers. The pMTJs structures were made by RF and DC magnetron sputtering. Individual depositions of magnesium oxide layers and of aluminum oxide films were prepared by plasma oxidation. The experimental results showed that the initial switching field was decreased as the magnesium oxide thickness was increased. Further work of the aluminum oxide surface roughness and hysteresis loop influenced by different oxidation layers on pMTJs structures will be discussed as well

  3. Ultrasound evaluation of arthroscopic full-thickness supraspinatus rotator cuff repair: single-row versus double-row suture bridge (transosseous equivalent) fixation. Results of a prospective, randomized study.

    Science.gov (United States)

    Gartsman, Gary M; Drake, Gregory; Edwards, T Bradley; Elkousy, Hussein A; Hammerman, Steven M; O'Connor, Daniel P; Press, Cyrus M

    2013-11-01

    The purpose of this study was to compare the structural outcomes of a single-row rotator cuff repair and double-row suture bridge fixation after arthroscopic repair of a full-thickness supraspinatus rotator cuff tear. We evaluated with diagnostic ultrasound a consecutive series of ninety shoulders in ninety patients with full-thickness supraspinatus tears at an average of 10 months (range, 6-12) after operation. A single surgeon at a single hospital performed the repairs. Inclusion criteria were full-thickness supraspinatus tears less than 25 mm in their anterior to posterior dimension. Exclusion criteria were prior operations on the shoulder, partial thickness tears, subscapularis tears, infraspinatus tears, combined supraspinatus and infraspinatus repairs and irreparable supraspinatus tears. Forty-three shoulders were repaired with single-row technique and 47 shoulders with double-row suture bridge technique. Postoperative rehabilitation was identical for both groups. Ultrasound criteria for healed repair included visualization of a tendon with normal thickness and length, and a negative compression test. Eighty-three patients were available for ultrasound examination (40 single-row and 43 suture-bridge). Thirty of 40 patients (75%) with single-row repair demonstrated a healed rotator cuff repair compared to 40/43 (93%) patients with suture-bridge repair (P = .024). Arthroscopic double-row suture bridge repair (transosseous equivalent) of an isolated supraspinatus rotator cuff tear resulted in a significantly higher tendon healing rate (as determined by ultrasound examination) when compared to arthroscopic single-row repair. Copyright © 2013 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  4. Effect of thickness on optoelectrical properties of Nb-doped indium tin oxide thin films deposited by RF magnetron sputtering

    Science.gov (United States)

    Li, Shi-na; Ma, Rui-xin; Ma, Chun-hong; Li, Dong-ran; Xiao, Yu-qin; He, Liang-wei; Zhu, Hong-min

    2013-05-01

    Niobium-doped indium tin oxide (ITO:Nb) thin films are prepared on glass substrates with various film thicknesses by radio frequency (RF) magnetron sputtering from one piece of ceramic target material. The effects of thickness (60-360 nm) on the structural, electrical and optical properties of ITO: Nb films are investigated by means of X-ray diffraction (XRD), ultraviolet (UV)-visible spectroscopy, and electrical measurements. XRD patterns show the highly oriented (400) direction. The lowest resistivity of the films without any heat treatment is 3.1×10-4Ω·cm-1, and the resistivity decreases with the increase of substrate temperature. The highest Hall mobility and carrier concentration are 17.6 N·S and 1.36×1021 cm-3, respectively. Band gap energy of the films depends on substrate temperature, which varies from 3.48 eV to 3.62 eV.

  5. Changes in Nitric Oxide Level and Thickness Index of Synovial Fluid ...

    African Journals Online (AJOL)

    patients after intra-articular injection of sodium hyaluronate, while the effect is insignificant in severe patients. Thus, sodium hyaluronate can effectively improve nitric oxide levels in synovial fluid, reduce ..... Modern Med Health, 2014; 1:.

  6. Structural, electrical, and electrochemical characterization of Ni--Pr oxide thick films

    Energy Technology Data Exchange (ETDEWEB)

    Mari, C; Scolari, V; Fiori, G; Pizzini, S

    1977-03-01

    Oxides with metallic conductivity could and have been used instead of noble metals as insert electrodes in aqueous solutions as well as electrodes for high temperature fuel cells and electrolyzers and as catalysts for the conversion of exhaust gases from internal combustion engines. The aim of this paper is to report the results of a physico-chemical characterization (structure, morphology, electrochemical behavior) of Ni--Pr oxides which have been proposed as electrode materials for high temperature fuel cells. The electrochemical characterization was carried out in aqueous solutions at room temperature and with solid electrolytes at high temperature. Evidence has been found in the former case for an oxide electrode type of behavior. In the high temperature case, very low overvoltage values have been observed during cathodic oxygen reduction, while the electrode undergoes a reaction with oxygen during anodic oxygen evolution.

  7. Reagent-Free Electrophoretic Synthesis of Few-Atom-Thick Metal Oxide Nanosheets

    DEFF Research Database (Denmark)

    Hou, Chengyi; Zhang, Minwei; Zhang, Lili

    2017-01-01

    Engineering traditional materials into the new form of atomic and free-standing two-dimensional structures is of both fundamental interest and practical significance, but it is in general facing challenges especially for metal oxide semiconductors. We herein report an ultragreen method for the cost......-effective and fast preparation of atomic metal oxide nanosheets that can be further transformed into nanofilms. The method combines top-down building block synthesis and bottom-up electrophoretic assembly in water under ambient conditions, using only bulk metal and Milli-Q water without involving any additional...

  8. Effect of annealing and oxide layer thickness on doping profiles shape of ''through-oxide'' implanted P+ ions in textured silicon

    International Nuclear Information System (INIS)

    El-Dessouki, M.S.; Galloni, R.

    1987-10-01

    Phosphorous ions at energies of 60+100 KeV, and doses (4+5)x10 15 atom/cm 2 have been implanted randomly through SiO 2 layers into textured silicon crystals. The penetration profiles of the P + ions have been determined by means of differential sheet resistivity and Hall-effect, together with the anodic oxidation stripping technique. The effect of the oxide layer thickness, annealing temperature on the junction properties has been studied. The damage produced by implantation, has also been investigated using transmission electron microscope (TEM). From the mobility measurements of the free carriers as a function of depth through the junction, two minima have been observed in through oxide implanted samples. The one nearer to the Si-SiO 2 interface (at about 200A from the interface) was related to the damage produced by the recoil oxygen atoms from the oxide layer into silicon. The deeper minimum is lying at ∼ 0.2μm from the interface and was attributed to the damage produced by the implanted P + ions, which caused clusters and defect loops after annealing. This damage was observed through TEM photographs. The optimum conditions for producing shallow junction without losing much of the implanted P + ions through the oxide layer were estimated. (author). 22 refs, 7 figs, 1 tab

  9. An equivalence study comparing nitrous oxide and oxygen with low-dose sevoflurane and oxygen as inhalation sedation agents in dentistry for adults.

    Science.gov (United States)

    Allen, M; Thompson, S

    2014-11-01

    The aim of this study was to examine whether sevoflurane in oxygen was equivalent to near equipotent concentrations of nitrous oxide in oxygen when used as an inhalation sedation agent in terms of patient and user acceptability. Forty anxious dental patients referred to the sedation suite at Cardiff University School of Dentistry received either nitrous oxide to a maximum concentration of 40% or sevoflurane to a maximum concentration of 0.3% for a routine maxillary plastic restoration with articaine infiltration local analgesia. The inhalation sedation agent to be administered was chosen by a random number allocator. Measurements of blood pressure, oxygen saturation, heart rate, respiratory rate and bispectral index were recorded every 5 minutes. At the end of the treatment episode the patient, the operator and an observer who was unaware of the agent used, recorded their impressions about the episode by completing questionnaires. In the doses used in this study, sevoflurane was found to be as effective as an inhalation sedation agent as the standard dose of nitrous oxide used in normal inhalation sedation in the treatment of adult anxious dental patients. Sevoflurane in low concentrations is equivalent in effect to near equipotent concentrations of nitrous oxide. This would suggest that further research, perhaps with slightly higher concentrations of sevoflurane, is needed. If sevoflurane was shown to be acceptable at slightly higher concentrations, there is scope to explore the development of equipment specifically designed to deliver sevoflurane as an inhalation sedation agent in future.

  10. Type-2 diabetes mellitus reduces cortical thickness and decreases oxidative metabolism in sensorimotor regions after stroke.

    Science.gov (United States)

    Ferris, Jennifer K; Peters, Sue; Brown, Katlyn E; Tourigny, Katherine; Boyd, Lara A

    2018-05-01

    Individuals with type-2 diabetes mellitus experience poor motor outcomes after ischemic stroke. Recent research suggests that type-2 diabetes adversely impacts neuronal integrity and function, yet little work has considered how these neuronal changes affect sensorimotor outcomes after stroke. Here, we considered how type-2 diabetes impacted the structural and metabolic function of the sensorimotor cortex after stroke using volumetric magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS). We hypothesized that the combination of chronic stroke and type-2 diabetes would negatively impact the integrity of sensorimotor cortex as compared to individuals with chronic stroke alone. Compared to stroke alone, individuals with stroke and diabetes had lower cortical thickness bilaterally in the primary somatosensory cortex, and primary and secondary motor cortices. Individuals with stroke and diabetes also showed reduced creatine levels bilaterally in the sensorimotor cortex. Contralesional primary and secondary motor cortex thicknesses were negatively related to sensorimotor outcomes in the paretic upper-limb in the stroke and diabetes group such that those with thinner primary and secondary motor cortices had better motor function. These data suggest that type-2 diabetes alters cerebral energy metabolism, and is associated with thinning of sensorimotor cortex after stroke. These factors may influence motor outcomes after stroke.

  11. Controlling the Performance of P-type Cu2O/SnO Bilayer Thin-Film Transistors by Adjusting the Thickness of the Copper Oxide Layer

    KAUST Repository

    Al-Jawhari, Hala A.

    2014-11-11

    The effect of copper oxide layer thickness on the performance of Cu2O/SnO bilayer thin-film transistors was investigated. By using sputtered Cu2O films produced at an oxygen partial pressure, Opp, of 10% as the upper layer and 3% Opp SnO films as the lower layer we built a matrix of bottom-gate Cu2O/SnO bilayer thin-film transistors of different thickness. We found that the thickness of the Cu2O layer is of major importance in oxidation of the SnO layer underneath. The thicker the Cu2O layer, the more the underlying SnO layer is oxidized, and, hence, the more transistor mobility is enhanced at a specific temperature. Both device performance and the annealing temperature required could be adjusted by controlling the thickness of each layer of Cu2O/SnO bilayer thin-film transistors.

  12. A theoretical analysis of the response of an air-cored eddy current coil for remote oxide thickness measurements on reactor components

    International Nuclear Information System (INIS)

    Wilson, R.

    1979-10-01

    It is shown how the impedance of an air-cored eddy current coil in close proximity to an oxidised steel component may be calculated. Representative values were selected for the oxide thickness, lift off, operating frequency, conductivities and permeabilities of the oxide coating and steel base. The values of these parameters in the calculations were allowed to vary between suitable limits to quantify the effect of each one on coil impedance. The results of the calculations are used to determine the most suitable conditions for the measurement of oxide thickness on steel components using an air-cored eddy current probe. (author)

  13. Equivalent Lagrangians

    International Nuclear Information System (INIS)

    Hojman, S.

    1982-01-01

    We present a review of the inverse problem of the Calculus of Variations, emphasizing the ambiguities which appear due to the existence of equivalent Lagrangians for a given classical system. In particular, we analyze the properties of equivalent Lagrangians in the multidimensional case, we study the conditions for the existence of a variational principle for (second as well as first order) equations of motion and their solutions, we consider the inverse problem of the Calculus of Variations for singular systems, we state the ambiguities which emerge in the relationship between symmetries and conserved quantities in the case of equivalent Lagrangians, we discuss the problems which appear in trying to quantize classical systems which have different equivalent Lagrangians, we describe the situation which arises in the study of equivalent Lagrangians in field theory and finally, we present some unsolved problems and discussion topics related to the content of this article. (author)

  14. Josephson junction in superconducting oxides thick films. Jonction Josephson en couche epaisse d'oxydes supraconducteurs

    Energy Technology Data Exchange (ETDEWEB)

    Gunther, C; Monfort, Y; Lam Chok Sing, M; Bloyet, D; Brousse, T; Provost, J; Raveau, B [Institut des Sciences de la Matiere du Rayonnement, 14 - Caen (FR)

    1992-02-01

    Constrictions engraved in YBaCuO thick films fabricated by screen printing on YSZ substrate (J{sub c} > 3 000 A/cm{sup 2} at 77 K) have been studied. Microwave irradiation of the devices at LN{sub 2} showed distinct Shapiro steps demonstrating the presence intrinsic Josephson junctions. The latter have an I{sub c}(T) dependence fitting (1 - T/T{sub c}){sup 2} characteristic of SNS junctions. Furthermore, dc SQUID effects have also been observed with a peak-to-peak response {approx equal} 0.2 {mu}V and with a magnetic field periodicity extending through several hundred of {phi}{sub o}. An energy resolution close to 3 x 10{sup -29} J/Hz is estimated for our constriction operating in the white noise frequency range (f > 50 Hz) at 77 K. This sensitivity is adequate to use this flux sensor in many applications: geomagnetism, magnetocardiology,... 19 refs; 7 figs.

  15. Magnetron sputtered zinc oxide nanorods as thickness-insensitive cathode interlayer for perovskite planar-heterojunction solar cells.

    Science.gov (United States)

    Liang, Lusheng; Huang, Zhifeng; Cai, Longhua; Chen, Weizhong; Wang, Baozeng; Chen, Kaiwu; Bai, Hua; Tian, Qingyong; Fan, Bin

    2014-12-10

    Suitable electrode interfacial layers are essential to the high performance of perovskite planar heterojunction solar cells. In this letter, we report magnetron sputtered zinc oxide (ZnO) film as the cathode interlayer for methylammonium lead iodide (CH3NH3PbI3) perovskite solar cell. Scanning electron microscopy and X-ray diffraction analysis demonstrate that the sputtered ZnO films consist of c-axis aligned nanorods. The solar cells based on this ZnO cathode interlayer showed high short circuit current and power conversion efficiency. Besides, the performance of the device is insensitive to the thickness of ZnO cathode interlayer. Considering the high reliability and maturity of sputtering technique both in lab and industry, we believe that the sputtered ZnO films are promising cathode interlayers for perovskite solar cells, especially in large-scale production.

  16. Excimer laser sintering of indium tin oxide nanoparticles for fabricating thin films of variable thickness on flexible substrates

    International Nuclear Information System (INIS)

    Park, Taesoon; Kim, Dongsik

    2015-01-01

    Technology to fabricate electrically-conducting, transparent thin-film patterns on flexible substrates has possible applications in flexible electronics. In this work, a pulsed-laser sintering process applicable to indium tin oxide (ITO) thin-film fabrication on a substrate without thermal damage to the substrate was developed. A nanosecond pulsed laser was used to minimize thermal penetration into the substrate and to control the thickness of the sintered layer. ITO nanoparticles (NPs) of ~ 20 nm diameter were used to lower the process temperature by exploiting their low melting point. ITO thin film patterns were fabricated by first spin coating the NPs onto a surface, then sintering them using a KrF excimer laser. The sintered films were characterized using field emission scanning electron microscopy. The electrical resistivity and transparency of the film were measured by varying the process parameters. A single laser pulse could generate the polycrystalline structure (average grain size ~ 200 nm), reducing the electrical resistivity of the film by a factor of ~ 1000. The sintering process led to a minimum resistivity of 1.1 × 10 −4 Ω·m without losing the transparency of the film. The thickness of the sintered layer could be varied up to 150 nm by adjusting the laser fluence. Because the estimated thermal penetration depth in the ITO film was less than 200 nm, no thermal damage was observed in the substrate. This work suggests that the proposed process, combined with various particle deposition methods, can be an effective tool to form thin-film ITO patterns on flexible substrates. - Highlights: • Excimer laser sintering can fabricate ITO thin films on flexible substrates. • The laser pulse can form a polycrystalline structure without thermal damage. • The laser sintering process can reduce the electrical resistivity substantially. • The thickness of the sintered layer can be varied effectively

  17. Excimer laser sintering of indium tin oxide nanoparticles for fabricating thin films of variable thickness on flexible substrates

    Energy Technology Data Exchange (ETDEWEB)

    Park, Taesoon; Kim, Dongsik, E-mail: dskim87@postech.ac.kr

    2015-03-02

    Technology to fabricate electrically-conducting, transparent thin-film patterns on flexible substrates has possible applications in flexible electronics. In this work, a pulsed-laser sintering process applicable to indium tin oxide (ITO) thin-film fabrication on a substrate without thermal damage to the substrate was developed. A nanosecond pulsed laser was used to minimize thermal penetration into the substrate and to control the thickness of the sintered layer. ITO nanoparticles (NPs) of ~ 20 nm diameter were used to lower the process temperature by exploiting their low melting point. ITO thin film patterns were fabricated by first spin coating the NPs onto a surface, then sintering them using a KrF excimer laser. The sintered films were characterized using field emission scanning electron microscopy. The electrical resistivity and transparency of the film were measured by varying the process parameters. A single laser pulse could generate the polycrystalline structure (average grain size ~ 200 nm), reducing the electrical resistivity of the film by a factor of ~ 1000. The sintering process led to a minimum resistivity of 1.1 × 10{sup −4} Ω·m without losing the transparency of the film. The thickness of the sintered layer could be varied up to 150 nm by adjusting the laser fluence. Because the estimated thermal penetration depth in the ITO film was less than 200 nm, no thermal damage was observed in the substrate. This work suggests that the proposed process, combined with various particle deposition methods, can be an effective tool to form thin-film ITO patterns on flexible substrates. - Highlights: • Excimer laser sintering can fabricate ITO thin films on flexible substrates. • The laser pulse can form a polycrystalline structure without thermal damage. • The laser sintering process can reduce the electrical resistivity substantially. • The thickness of the sintered layer can be varied effectively.

  18. Microstructure and thermoelectric properties of screen-printed thick-films of misfit-layered cobalt oxides with Ag addition

    DEFF Research Database (Denmark)

    Van Nong, Ngo; Samson, Alfred Junio; Pryds, Nini

    2012-01-01

    Thermoelectric properties of thick (~60 μm) films prepared by a screen-printing technique using p-type misfit-layered cobalt oxide Ca3Co4O9+δ with Ag addition have been studied. The screen-printed films were sintered in air at various temperatures ranging from 973 K to 1223 K. After each sintering...... process, crystal and microstructure analyses were carried out to determine the optimal sintering condition. The results show that the thermoelectric properties of pure Ca3Co4O9+δ thick film are comparable to those of cold isostatic pressing (CIP) samples. We found that the maximum power factor...... was improved by about 67% (to 0.3 mW/m K2) for film with proper silver (Ag) metallic inclusions as compared with 0.18 mW/m K2 for pure Ca3Co4O9+δ film under the same sintering condition of 1223 K for 2 h in air....

  19. The nanostructure of microbially-reduced graphene oxide fosters thick and highly-performing electrochemically-active biofilms

    Science.gov (United States)

    Virdis, Bernardino; Dennis, Paul G.

    2017-07-01

    Biofilms of electrochemically-active organisms are used in microbial electrochemical technologies (METs) to catalyze bioreactions otherwise not possible at bare electrodes. At present, however, achievable current outputs are still below levels considered sufficient for economic viability of large-scale METs implementations. Here, we report three-dimensional, self-aggregating biofilm composites comprising of microbial cells embedded with microbially-reduced graphene oxide (rGO) nanoparticles to form a thick macro-porous network with superior electrochemical properties. In the presence of metabolic substrate, these hybrid biofilms are capable of producing up to five times more catalytic current than the control biofilms. Cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy, show that in spite of the increased thickness, the biofilms amended with GO display lower polarization/charge transfer resistance compared to the controls, which we ascribe to the incorporation of rGO into the biofilms, which (1) promotes fast electron transfer, yet conserving a macroporous structure that allows free diffusion of reactants and products, and (2) enhances the interfacial dynamics by allowing a higher load of microbial cells per electrode surface area. These results suggest an easy-to-apply and cost-effective method to produce high-performing electrochemically-active biofilms in situ.

  20. Characterization of Series Resistance and Mobility Degradation Parameter and Optimizing Choice of Oxide Thickness in Thin Oxide N-Channel MOSFET

    Directory of Open Access Journals (Sweden)

    Noureddine Maouhoub

    2011-01-01

    Full Text Available We present two methods to extract the series resistance and the mobility degradation parameter in short-channel MOSFETs. The principle of the first method is based on the comparison between the exponential model and the classical model of effective mobility and for the second method is based on directly calculating the two parameters by solving a system of two equations obtained by using two different points in strong inversion at small drain bias from the characteristic (. The results obtained by these techniques have shown a better agreement with data measurements and allowed in the same time to determine the surface roughness amplitude and its influence on the maximum drain current and give the optimal oxide thickness.

  1. Dependence of the optical constants and the performance in the SPREE gas measurement on the thickness of doped tin oxide over coatings

    Science.gov (United States)

    Fischer, D.; Hertwig, A.; Beck, U.; Negendank, D.; Lohse, V.; Kormunda, M.; Esser, N.

    2017-11-01

    In this study, thickness related changes of the optical properties of doped tin oxide were studied. Two different sets of samples were prepared. The first set was doped with iron or nickel on silicon substrate with thicknesses of 29-56 nm, the second was iron doped on gold/glass substrate with 1.6-6.3 nm. The optical constants were determined by using spectral ellipsometry (SE) followed by modelling of the dielectric function with an oscillator model using Gaussian peaks. The analysis of the optical constants shows a dependence of the refraction and the absorption on the thickness of the doped tin oxide coating. In addition to the tin oxide absorption in the UV, one additional absorption peak was found in the near-IR/red which is related to plasmonic effects due to the doping. This peak shifts from the near-IR to the red part of the visible spectrum and becomes stronger by reducing the thickness, probably due to the formation of metal nanoparticles in this layer. These results were found for two different sets of samples by using the same optical model. Afterwards the second sample set was tested in the Surface Plasmon Resonance Enhanced Ellipsometric (SPREE) gas measurement with CO gas. It was found that the thickness has significant influence on the sensitivity and thus the adsorption of the CO gas. By increasing the thickness from 1.6 nm to 5.1 nm, the sensing ability is enhanced due to a higher coverage of the surface with the over coating. This is explained by the high affinity of CO molecules to the incorporated Fe-nanoparticles in the tin oxide coating. By increasing the thickness further to 6.3 nm, the sensing ability drops because the layer disturbs the SPR sensing effect too much.

  2. Densification of ∼5 nm-thick SiO{sub 2} layers by nitric acid oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jaeyoung [Department of Energy Engineering, Dankook University, Cheonan 311-16 (Korea, Republic of); Joo, Soyeong [Institute for Advanced Engineering (IAE), Advanced Materials & Processing Center, Youngin 449-863 (Korea, Republic of); Park, Tae Joo [Department of Materials Science and Chemical Engineering, Hanyang University, Ansan 15588 (Korea, Republic of); Kim, Woo-Byoung, E-mail: woo7838@dankook.ac.kr [Department of Energy Engineering, Dankook University, Cheonan 311-16 (Korea, Republic of)

    2017-08-15

    Highlights: • Leakage current density of the commercial PECVD grown ∼5 nm SiO{sub 2} layer has been decreased about three orders of magnitude by densification. • The densification of SiO{sub 2} layer is achieved by high oxidation ability of O·. • Densities of suboxide, fixed charge (N{sub f}) and defect state (N{sub d}) in SiO{sub 2}/Si interface are decreased by NAOS and PMA. • Tunneling barrier height (Φ{sub t}) is increased because of the increase of atomic density in SiO{sub 2} layer. - Abstract: Low-temperature nitric acid (HNO{sub 3}) oxidation of Si (NAOS) has been used to improve the interface and electrical properties of ∼5 nm-thick SiO{sub 2}/Si layers produced by plasma-enhanced chemical vapor deposition (PECVD). Investigations of the physical properties and electrical characteristics of these thin films revealed that although their thickness is not changed by NAOS, the leakage current density at a gate bias voltage of −1 V decreases by about two orders of magnitude from 1.868 × 10{sup −5} A/cm{sup 2}. This leakage current density was further reduced by post-metallization annealing (PMA) at 250 °C for 10 min in a 5 vol.% hydrogen atmosphere, eventually reaching a level (5.2 × 10{sup −8} A/cm{sup 2}) approximately three orders of magnitude less than the as-grown SiO{sub 2} layer. This improvement is attributed to a decrease in the concentration of suboxide species (Si{sup 1+}, Si{sup 2+} and Si{sup 3+}) in the SiO{sub 2}/Si interface, as well as a decrease in the equilibrium density of defect sites (N{sub d}) and fixed charge density (N{sub f}). The barrier height (Φ{sub t}) generated by a Poole-Frenkel mechanism also increased from 0.205 to 0.371 eV after NAOS and PMA. The decrease in leakage current density is therefore attributed to a densification of the SiO{sub 2} layer in combination with the removal of OH species and increase in interfacial properties at the SiO{sub 2}/Si interface.

  3. Controlling the Performance of P-type Cu2O/SnO Bilayer Thin-Film Transistors by Adjusting the Thickness of the Copper Oxide Layer

    KAUST Repository

    Al-Jawhari, Hala A.; Caraveo-Frescas, Jesus Alfonso; Hedhili, Mohamed N.

    2014-01-01

    The effect of copper oxide layer thickness on the performance of Cu2O/SnO bilayer thin-film transistors was investigated. By using sputtered Cu2O films produced at an oxygen partial pressure, Opp, of 10% as the upper layer and 3% Opp SnO films

  4. A novel locus in the oxidative stress-related gene ALOX12 moderates the association between PTSD and thickness of the prefrontal cortex.

    Science.gov (United States)

    Miller, Mark W; Wolf, Erika J; Sadeh, Naomi; Logue, Mark; Spielberg, Jeffrey M; Hayes, Jasmeet P; Sperbeck, Emily; Schichman, Steven A; Stone, Angie; Carter, Weleetka C; Humphries, Donald E; Milberg, William; McGlinchey, Regina

    2015-12-01

    Oxidative stress has been implicated in many common age-related diseases and is hypothesized to play a role in posttraumatic stress disorder (PTSD)-related neurodegeneration (Miller and Sadeh, 2014). This study examined the influence of the oxidative stress-related genes ALOX 12 and ALOX 15 on the association between PTSD and cortical thickness. Factor analyses were used to identify and compare alternative models of the structure of cortical thickness in a sample of 218 veterans. The best-fitting model was then used for a genetic association analysis in White non-Hispanic participants (n=146) that examined relationships between 33 single nucleotide polymorphisms (SNPs) spanning the two genes, 8 cortical thickness factors, and each SNP×PTSD interaction. Results identified a novel ALOX12 locus (indicated by two SNPs in perfect linkage disequilibrium: rs1042357 and rs10852889) that moderated the association between PTSD and reduced thickness of the right prefrontal cortex. A whole-cortex vertex-wise analysis showed this effect to be localized to clusters spanning the rostral middle frontal gyrus, superior frontal gyrus, rostral anterior cingulate cortex, and medial orbitofrontal cortex. These findings illustrate a novel factor-analytic approach to neuroimaging-genetic analyses and provide new evidence for the possible involvement of oxidative stress in PTSD-related neurodegeneration. Published by Elsevier Ltd.

  5. Evaluation of flow accelerated corrosion by coupled analysis of corrosion and flow dynamics. Relationship of oxide film thickness, hematite/magnetite ratio, ECP and wall thinning rate

    International Nuclear Information System (INIS)

    Uchida, Shunsuke; Naitoh, Masanori; Okada, Hidetoshi; Uehara, Yasushi; Koshizuka, Seiichi

    2011-01-01

    Systematic approaches to evaluate flow accelerated corrosion (FAC) are desired before discussing application of countermeasures for FAC. First, future FAC occurrence should be evaluated to identify locations where a higher possibility of FAC occurrence exists, and then, wall thinning rate at the identified FAC occurrence zone is evaluated to obtain the preparation time for applying countermeasures. Wall thinning rates were calculated with two coupled models: 1.static electrochemical analysis and 2.dynamic oxide layer growth analysis. The anodic current density and the electrochemical corrosion potential (ECP) were calculated with the static electrochemistry model based on an Evans diagram. The ferrous ion release rate, determined by the anodic current density, was applied as input for the dynamic double oxide layer model. Some of the dissolved ferrous ion was removed to the bulk water and others precipitated on the surface as magnetite particles. The thickness of oxide layer was calculated with the dynamic oxide layer growth model and then its value was used as input in the electrochemistry model. It was confirmed that the calculated results (corrosion rate and ECP) based on the coupled models were in good agreement with the measured ones. Higher ECP was essential for preventing FAC rate. Moderated conditions due to lower mass transfer coefficients resulted in thicker oxide layer thickness and then higher ECP, while moderated corrosion conditions due to higher oxidant concentrations resulted in larger hematite/magnetite rate and then higher ECP.

  6. Evaluation of flow accelerated corrosion by coupled analysis of corrosion and flow dynamics (3), relationship of oxide film thickness, hematite/magnetite ratio, ECP and wall thinning rate

    International Nuclear Information System (INIS)

    Uchida, Shunsuke; Naitoh, Masanori; Okada, Hidetoshi; Uehara, Yasushi; Koshizuka, Seiichi

    2009-01-01

    Systematic approaches for evaluating flow accelerated corrosion (FAC) are desired before discussing application of countermeasures for FAC. Firstly, future FAC occurrence should be evaluated to identify locations where a higher possibility of FAC occurrence exists, and then, wall thinning rate at the identified FAC occurrence zone is evaluated to obtain the preparation time for applying countermeasures. Wall thinning rates were calculated with the coupled models of static electrochemical analysis and dynamic double oxide layer analysis. Anodic current density and electrochemical corrosion potential (ECP) were calculated with the static electrochemistry model based on an Evans diagram and ferrous ion release rate determined by the anodic current density was applied as input for the dynamic double oxide layer model. Some of the dissolved ferrous ion was removed to the bulk water and others precipitated on the surface as magnetite particles. The thickness of oxide layer was calculated with the dynamic double oxide layer model and then was applied as input for the electrochemistry model. It was confirmed that the calculated results based on the coupled models resulted good agreement with the measured ones. Higher ECP was essential for preventing FAC rate. Moderated conditions due to lower mass transfer coefficients resulted in thicker oxide layer thickness and then higher ECP, while moderated corrosion conditions due to higher oxidant concentrations resulted in larger hematite/magnetite rate and then higher ECP. (author)

  7. Gyrokinetic equivalence

    International Nuclear Information System (INIS)

    Parra, Felix I; Catto, Peter J

    2009-01-01

    We compare two different derivations of the gyrokinetic equation: the Hamiltonian approach in Dubin D H E et al (1983 Phys. Fluids 26 3524) and the recursive methodology in Parra F I and Catto P J (2008 Plasma Phys. Control. Fusion 50 065014). We prove that both approaches yield the same result at least to second order in a Larmor radius over macroscopic length expansion. There are subtle differences in the definitions of some of the functions that need to be taken into account to prove the equivalence.

  8. Indium-Nitrogen Codoped Zinc Oxide Thin Film Deposited by Ultrasonic Spray Pyrolysis on n-(111 Si Substrate: The Effect of Film Thickness

    Directory of Open Access Journals (Sweden)

    Cheng-Chang Yu

    2014-01-01

    Full Text Available Indium-nitrogen codoped zinc oxide (INZO thin films were fabricated by spray pyrolysis deposition technique on n-(111 Si substrate with different film thicknesses at 450°C using a precursor containing zinc acetate, ammonium acetate, and indium nitrate with 1 : 3 : 0.05 at.% concentration. The morphology and structure studies were carried out by scanning electron microscopy (SEM and X-ray diffraction (XRD. The grain size of the films increased when increasing the film thickness. From XRD spectra, polycrystalline ZnO structure can be observed and the preferred orientation behavior varied from (002 to (101 as the film thickness increased. The concentration and mobility were investigated by Hall effect measurement. the p-type films with a hole mobility around 3 cm2V−1s−1 and hole concentration around 3×1019 cm−3 can be achieved with film thickness less than 385 nm. The n-type conduction with concentration 1×1020 cm−3 is observed for film with thickness 1089 nm. The defect states were characterized by photoluminescence. With temperature-dependent conductivity analysis, acceptor state with activation energy 0.139 eV dominate the p type conduction for thin INZO film. And the Zn-related shallow donors with activation energy 0.029 eV dominate the n-type conduction for the thick INZO film.

  9. Determining the thickness of aliphatic alcohol monolayers covalently attached to silicon oxide surfaces using angle-resolved X-ray photoelectron spectroscopy

    Science.gov (United States)

    Lee, Austin W. H.; Kim, Dongho; Gates, Byron D.

    2018-04-01

    The thickness of alcohol based monolayers on silicon oxide surfaces were investigated using angle-resolved X-ray photoelectron spectroscopy (ARXPS). Advantages of using alcohols as building blocks for the formation of monolayers include their widespread availability, ease of handling, and stability against side reactions. Recent progress in microwave assisted reactions demonstrated the ease of forming uniform monolayers with alcohol based reagents. The studies shown herein provide a detailed investigation of the thickness of monolayers prepared from a series of aliphatic alcohols of different chain lengths. Monolayers of 1-butanol, 1-hexanol, 1-octanol, 1-decanol, and 1-dodecanol were each successfully formed through microwave assisted reactions and characterized by ARXPS techniques. The thickness of these monolayers consistently increased by ∼1.0 Å for every additional methylene (CH2) within the hydrocarbon chain of the reagents. Tilt angles of the molecules covalently attached to silicon oxide surfaces were estimated to be ∼35° for each type of reagent. These results were consistent with the observations reported for thiol based or silane based monolayers on either gold or silicon oxide surfaces, respectively. The results of this study also suggest that the alcohol based monolayers are uniform at a molecular level.

  10. Structure and corrosion behavior of sputter deposited cerium oxide based coatings with various thickness on Al 2024-T3 alloy substrates

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yuanyuan [College of Materials Science and Engineering, Chongqing University, Chongqing 400045 (China); Materials Research Center, Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Huang, Jiamu, E-mail: huangjiamu@cqu.edu.cn [College of Materials Science and Engineering, Chongqing University, Chongqing 400045 (China); Claypool, James B.; Castano, Carlos E. [Materials Research Center, Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); O’Keefe, Matthew J., E-mail: mjokeefe@mst.edu [Materials Research Center, Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States)

    2015-11-15

    Highlights: • Crystalline CeO{sub 2} coatings are deposited on Al 2024-T3 alloys by magnetron sputtering. • The crystal size and internal stress both increased with the thickness of CeO{sub 2} coating. • The ∼210 nm thick coating has the highest adhesion strength to the Al alloy substrate. • The ∼900 nm thick coating increased the corrosion resistance two orders of magnitude. • CeO{sub 2} coatings provide good cathodic inhibition for Al alloys by acting as physical barriers. - Abstract: Cerium oxide based coatings from ∼100 to ∼1400 nm in thickness were deposited onto Al 2024-T3 alloy substrates by magnetron sputtering of a 99.99% pure CeO{sub 2} target. The crystallite size of CeO{sub 2} coatings increased from 15 nm to 46 nm as the coating thickness increased from ∼100 nm to ∼1400 nm. The inhomogeneous lattice strain increased from 0.36% to 0.91% for the ∼100 nm to ∼900 nm thick coatings and slightly decreased to 0.89% for the ∼1400 nm thick coating. The highest adhesion strength to Al alloy substrates was for the ∼210 nm thick coating, due to a continuous film coverage and low internal stress. Electrochemical measurements indicated that sputter deposited crystalline CeO{sub 2} coatings acted as physical barriers that provide good cathodic inhibition for Al alloys in saline solution. The ∼900 nm thick CeO{sub 2} coated sample had the best corrosion performance that increased the corrosion resistance by two orders magnitude and lowered the cathodic current density 30 times compared to bare Al 2024-T3 substrates. The reduced defects and exposed surface, along with suppressed charge mobility, likely accounts for the improved corrosion performance as coating thickness increased from ∼100 nm to ∼900 nm. The corrosion performance decreased for ∼1400 nm thick coatings due in part to an increase in coating defects and porosity along with a decrease in adhesion strength.

  11. Carotid intima-media thickness and oxidative stress markers for assessment of atherosclerosis in children with β thalassemia major

    Directory of Open Access Journals (Sweden)

    Geetanjali Jindal

    2016-05-01

    Full Text Available The present study evaluates carotid intimamedia thickness (CIMT in children with β thalassemia major to assess atherosclerosis and its relation to the underlying proposed causative mechanisms via lipid peroxidation product malondialdehyde (MDA, oxidized lowdensity lipoproteins (LDL, total antioxidant level, and lipid profile. A cross sectional study was conducted on 62 children (31 cases and 31 controls. CIMT by high resolution ultrasound and biochemical parameters i.e., total cholesterol, triglycerides, high-density lipoproteins, LDL, Oxidized LDL, lipoprotein (a, lipid peroxidation product MDA and total antioxidant were measured in enrolled subjects and compared. In our study, CIMT was significantly increased in β thalassemia major patients’ as compared to healthy controls. Mean CIMT in cases was 0.69±0.11 mm and in controls 0.51±0.07 mm. Mean oxidized LDL (EU/mL in cases 39.3±34.4 (range 14.4 to 160 was significantly raised (P=0.02, t test as compared to controls 23.9±13.4 (range 12 to 70. In our study we found MDA levels (nmol/mL to be increased in β thalassemia patients as compared to controls. Mean MDA was 10.0±3.27 (4.41 to 17.48 in cases while in controls was 6.87±4.55 (1.5 to 17.9. Our study results show CIMT as an early marker of atherogenesis in β thalassemia major. Oxidative stress markers are also increased in β thalassemia major patients and lipoprotein (a shows a positive correlation with CIMT. The present study points towards various atherogenetic mechanisms in β thalassemia major. 本研究评价β重型地中海贫血患儿颈动脉内膜中层厚度(CIMT),以评估动脉粥样硬化,以及与潜在通过血脂过氧化反应产物丙二醛(MDA)、氧化低密度脂蛋白(LDL)、总抗氧化水平和血脂谱所提出致病机制之间的关系。 在62名儿童(31例病例和31例对照)中进行了一项横断面研究。 在入组受试者中通过高分辨率超声和生化指标(

  12. Solid-state dewetting of single- and bilayer Au-W thin films: Unraveling the role of individual layer thickness, stacking sequence and oxidation on morphology evolution

    Directory of Open Access Journals (Sweden)

    A. Herz

    2016-03-01

    Full Text Available Self-assembly of ultrathin Au, W, and Au-W bilayer thin films is investigated using a rapid thermal annealing technique in an inert ambient. The solid-state dewetting of Au films is briefly revisited in order to emphasize the role of initial film thickness. W films deposited onto SiO2 evolve into needle-like nanocrystals rather than forming particle-like agglomerates upon annealing at elevated temperatures. Transmission electron microscopy reveals that such nanocrystals actually consist of tungsten (VI oxide (WO3 which is related to an anisotropic oxide crystal growth out of the thin film. The evolution of W films is highly sensitive to the presence of any residual oxygen. Combination of both the dewetting of Au and the oxide crystal growth of WO3 is realized by using various bilayer film configurations of the immiscible Au and W. At low temperature, Au dewetting is initiated while oxide crystal growth is still suppressed. Depending on the stacking sequence of the Au-W bilayer thin film, W acts either as a substrate or as a passivation layer for the dewetting of Au. Being the ground layer, W changes the wettability of Au which clearly modifies its initial state for the dewetting. Being the top layer, W prevents Au from dewetting regardless of Au film thickness. Moreover, regular pattern formation of Au-WO3 nanoparticles is observed at high temperature demonstrating how bilayer thin film dewetting can create unique nanostructure arrangements.

  13. Solid-state dewetting of single- and bilayer Au-W thin films: Unraveling the role of individual layer thickness, stacking sequence and oxidation on morphology evolution

    Energy Technology Data Exchange (ETDEWEB)

    Herz, A., E-mail: andreas.herz@tu-ilmenau.de, E-mail: dong.wang@tu-ilmenau.de; Franz, A.; Theska, F.; Hentschel, M.; Kups, Th.; Wang, D., E-mail: andreas.herz@tu-ilmenau.de, E-mail: dong.wang@tu-ilmenau.de; Schaaf, P. [Department of Materials for Electronics and Electrical Engineering, Institute of Materials Science and Engineering and Institute of Micro- and Nanotechnologies MacroNano, TU Ilmenau, D-98693 Ilmenau (Germany)

    2016-03-15

    Self-assembly of ultrathin Au, W, and Au-W bilayer thin films is investigated using a rapid thermal annealing technique in an inert ambient. The solid-state dewetting of Au films is briefly revisited in order to emphasize the role of initial film thickness. W films deposited onto SiO{sub 2} evolve into needle-like nanocrystals rather than forming particle-like agglomerates upon annealing at elevated temperatures. Transmission electron microscopy reveals that such nanocrystals actually consist of tungsten (VI) oxide (WO{sub 3}) which is related to an anisotropic oxide crystal growth out of the thin film. The evolution of W films is highly sensitive to the presence of any residual oxygen. Combination of both the dewetting of Au and the oxide crystal growth of WO{sub 3} is realized by using various bilayer film configurations of the immiscible Au and W. At low temperature, Au dewetting is initiated while oxide crystal growth is still suppressed. Depending on the stacking sequence of the Au-W bilayer thin film, W acts either as a substrate or as a passivation layer for the dewetting of Au. Being the ground layer, W changes the wettability of Au which clearly modifies its initial state for the dewetting. Being the top layer, W prevents Au from dewetting regardless of Au film thickness. Moreover, regular pattern formation of Au-WO{sub 3} nanoparticles is observed at high temperature demonstrating how bilayer thin film dewetting can create unique nanostructure arrangements.

  14. Synchrotron X-ray irradiation effects on the device characteristics and the resistance to hot-carrier damage of MOSFETs with 4 nm thick gate oxides

    International Nuclear Information System (INIS)

    Tanaka, Yuusuke; Tanabe, Akira; Suzuki, Katsumi

    1998-01-01

    The effects of synchrotron x-ray irradiation on the device characteristics and hot-carrier resistance of n- and p-channel metal oxide semiconductor field effect transistors (MOSFETs) with 4 nm thick gate oxides are investigated. In p-channel MOSFETs, device characteristics were significantly affected by the x-ray irradiation but completely recovered after annealing, while the device characteristics in n-channel MOSFETs were not noticeably affected by the irradiation. This difference appears to be due to a difference in interface-state generation. In p-channel MOSFETs, defects caused by boron-ion penetration through the gate oxides may be sensitive to x-ray irradiation, causing the generation of many interface states. These interface states are completely eliminated after annealing in hydrogen gas. The effects of irradiation on the resistance to hot-carrier degradation in annealed 4 nm thick gate-oxide MOSFETs were negligible even at an x-ray dose of 6,000 mJ/cm 2

  15. TECHNICAL BASIS FOR DOE STANDARD 3013 EQUIVALENCY SUPPORTING REDUCED TEMPERATURE STABILIZATION OF OXALATE-DERIVED PLUTONIUM OXIDE PRODUCED BY THE HB-LINE FACILITY AT SAVANNAH RIVER SITE

    Energy Technology Data Exchange (ETDEWEB)

    Duffey, J.; Livingston, R.; Berg, J.; Veirs, D.

    2012-07-02

    The HB-Line (HBL) facility at the Savannah River Site (SRS) is designed to produce high-purity plutonium dioxide (PuO{sub 2}) which is suitable for future use in production of Mixed Oxide (MOX) fuel. The MOX Fuel Fabrication Facility (MFFF) requires PuO{sub 2} feed to be packaged per the U.S. Department of Energy (DOE) Standard 3013 (DOE-STD-3013) to comply with the facility's safety basis. The stabilization conditions imposed by DOE-STD-3013 for PuO{sub 2} (i.e., 950 C for 2 hours) preclude use of the HBL PuO{sub 2} in direct fuel fabrication and reduce the value of the HBL product as MFFF feedstock. Consequently, HBL initiated a technical evaluation to define acceptable operating conditions for production of high-purity PuO{sub 2} that fulfills the DOE-STD-3013 criteria for safe storage. The purpose of this document is to demonstrate that within the defined operating conditions, the HBL process will be equivalent for meeting the requirements of the DOE-STD-3013 stabilization process for plutonium-bearing materials from the DOE complex. The proposed 3013 equivalency reduces the prescribed stabilization temperature for high-purity PuO{sub 2} from oxalate precipitation processes from 950 C to 640 C and places a limit of 60% on the relative humidity (RH) at the lowest material temperature. The equivalency is limited to material produced using the HBL established flow sheet, for example, nitric acid anion exchange and Pu(IV) direct strike oxalate precipitation with stabilization at a minimum temperature of 640 C for four hours (h). The product purity must meet the MFFF acceptance criteria of 23,600 {micro}g/g Pu (i.e., 2.1 wt %) total impurities and chloride content less than 250 {micro}g/g of Pu. All other stabilization and packaging criteria identified by DOE-STD-3013-2012 or earlier revisions of the standard apply. Based on the evaluation of test data discussed in this document, the expert judgment of the authors supports packaging the HBL product under a 3013

  16. Gamma-ray irradiation and post-irradiation at room and elevated temperature response of pMOS dosimeters with thick gate oxides

    Directory of Open Access Journals (Sweden)

    Pejović Momčilo M.

    2011-01-01

    Full Text Available Gamma-ray irradiation and post-irradiation response at room and elevated temperature have been studied for radiation sensitive pMOS transistors with gate oxide thickness of 100 and 400 nm, respectively. Their response was followed based on the changes in the threshold voltage shift which was estimated on the basis of transfer characteristics in saturation. The presence of radiation-induced fixed oxide traps and switching traps - which lead to a change in the threshold voltage - was estimated from the sub-threshold I-V curves, using the midgap technique. It was shown that fixed oxide traps have a dominant influence on the change in the threshold voltage shift during gamma-ray irradiation and annealing.

  17. Effect of Al2O3 insulator thickness on the structural integrity of amorphous indium-gallium-zinc-oxide based thin film transistors.

    Science.gov (United States)

    Kim, Hak-Jun; Hwang, In-Ju; Kim, Youn-Jea

    2014-12-01

    The current transparent oxide semiconductors (TOSs) technology provides flexibility and high performance. In this study, multi-stack nano-layers of TOSs were designed for three-dimensional analysis of amorphous indium-gallium-zinc-oxide (a-IGZO) based thin film transistors (TFTs). In particular, the effects of torsional and compressive stresses on the nano-sized active layers such as the a-IGZO layer were investigated. Numerical simulations were carried out to investigate the structural integrity of a-IGZO based TFTs with three different thicknesses of the aluminum oxide (Al2O3) insulator (δ = 10, 20, and 30 nm), respectively, using a commercial code, COMSOL Multiphysics. The results are graphically depicted for operating conditions.

  18. Effects of thickness and geometric variations in the oxide gate stack on the nonvolatile memory behaviors of charge-trap memory thin-film transistors

    Science.gov (United States)

    Bak, Jun Yong; Kim, So-Jung; Byun, Chun-Won; Pi, Jae-Eun; Ryu, Min-Ki; Hwang, Chi Sun; Yoon, Sung-Min

    2015-09-01

    Device designs of charge-trap oxide memory thin-film transistors (CTM-TFTs) were investigated to enhance their nonvolatile memory performances. The first strategy was to optimize the film thicknesses of the tunneling and charge-trap (CT) layers in order to meet requirements of both higher operation speed and longer retention time. While the program speed and memory window were improved for the device with a thinner tunneling layer, a long retention time was obtained only for the device with a tunneling layer thicker than 5 nm. The carrier concentration and charge-trap densities were optimized in the 30-nm-thick CT layer. It was observed that 10-nm-thick tunneling, 30-nm-thick CT, and 50-nm-thick blocking layers were the best configuration for our proposed CTM-TFTs, where a memory on/off margin higher than 107 was obtained, and a memory margin of 6.6 × 103 was retained even after the lapse of 105 s. The second strategy was to examine the effects of the geometrical relations between the CT and active layers for the applications of memory elements embedded in circuitries. The CTM-TFTs fabricated without an overlap between the CT layer and the drain electrode showed an enhanced program speed by the reduced parasitic capacitance. The drain-bias disturbance for the memory off-state was effectively suppressed even when a higher read-out drain voltage was applied. Appropriate device design parameters, such as the film thicknesses of each component layer and the geometrical relations between them, can improve the memory performances and expand the application fields of the proposed CTM-TFTs.

  19. n-VO{sub 2}/p-GaN based nitride–oxide heterostructure with various thickness of VO{sub 2} layer grown by MBE

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Minhuan [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Bian, Jiming, E-mail: jmbian@dlut.edu.cn [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Key Laboratory of Inorganic Coating Materials, Chinese Academy of Sciences, Shanghai 200050, China (China); Sun, Hongjun; Liu, Weifeng [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Zhang, Yuzhi [Key Laboratory of Inorganic Coating Materials, Chinese Academy of Sciences, Shanghai 200050, China (China); Luo, Yingmin [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

    2016-12-15

    Graphical abstract: The significant influences of VO{sub 2} layer thickness on the structural, electrical and contact properties of the n-VO{sub 2}/p-GaN based nitride-oxide heterostructure were investigated systemically. - Highlights: • High quality VO{sub 2} films with precisely controlled thickness were grown on p-GaN/sapphire substrates by oxide molecular beam epitaxy (O-MBE). • A distinct reversible SMT phase transition was observed for the n-VO{sub 2}/p-GaN based nitride-oxide heterostructure. • The clear rectifying transport characteristics originated from the n-VO{sub 2}/p-GaN interface were demonstrated before and after SMT of the VO{sub 2} over layer. • The XPS analyses confirmed the valence state of V in VO{sub 2} films was principally composed of V{sup 4+} with trace amount of V{sup 5+}. • The design and modulation of the n-VO{sub 2}/p-GaN based heterostructure devices will benefit significantly from these achievements. - Abstract: High quality VO{sub 2} films with precisely controlled thickness were grown on p-GaN/sapphire substrates by oxide molecular beam epitaxy (O-MBE). Results indicated that a distinct reversible semiconductor-to-metal (SMT) phase transition was observed for all the samples in the temperature dependent electrical resistance measurement, and the influence of VO{sub 2} layer thickness on the SMT properties of the as-grown n-VO{sub 2}/p-GaN based nitride-oxide heterostructure was investigated. Meanwhile, the clear rectifying transport characteristics originated from the n-VO{sub 2}/p-GaN interface were demonstrated before and after SMT of the VO{sub 2} over layer, which were attributed to the p-n junction behavior and Schottky contact character, respectively. Moreover, the X-ray photoelectron spectroscopy (XPS) analyses confirmed the valence state of vanadium (V) in VO{sub 2} films was principally composed of V{sup 4+} with trace amount of V{sup 5+}. The design and modulation of the n-VO{sub 2}/p-GaN based heterostructure

  20. Prediction of overpotential and effective thickness of Ni/YSZ anode for solid oxide fuel cell by improved species territory adsorption model

    Science.gov (United States)

    Nagasawa, Tsuyoshi; Hanamura, Katsunori

    2017-06-01

    The reliability of analytical model for hydrogen oxidation at Ni/YSZ anode in solid oxide fuel cell named as species territory adsorption model has been improved by introducing referenced thermodynamic and kinetic parameters predicted by density function theory calculations. The model can explicitly predict anode overpotential using unknown values of quantities of state for oxygen migration process in YSZ near a triple phase boundary (TPB), frequency factor for hydrogen oxidation, and effective anode thickness. The former two are determined through careful fitting process between the predicted and experimental results of Ni/YSZ cermet and Ni-patterned anodes. This makes it possible to estimate effective anode thickness, which tends to increase with temperature in six kinds of Ni/YSZ anodes in references. In addition, the comparison between the proposed model and a published numerical simulation indicates that the model can predict more precise dependence of anode overpotential on steam partial pressure than that by Butler-Volmer equation with empirical exchange current density. The introduction of present model into numerical simulation instead of Butler-Volmer equation can give more accurate prediction of anode polarization.

  1. Formation of thick stratiform Fe-Ti oxide layers in layered intrusion and frequent replenishment of fractionated mafic magma: Evidence from the Panzhihua intrusion, SW China

    Science.gov (United States)

    Song, Xie-Yan; Qi, Hua-Wen; Hu, Rui-Zhong; Chen, Lie-Meng; Yu, Song-Yue; Zhang, Jia-Fei

    2013-03-01

    Panzhihua intrusion is one of the largest layered intrusions that hosts huge stratiform Fe-Ti oxide layers in the central part of the Emeishan large igneous province, SW China. Up to 60 m thick stratiform massive Fe-Ti oxide layers containing 85 modal% of magnetite and ilmenite and overlying magnetite gabbro compose cyclic units of the Lower Zone of the intrusion. The cyclic units of the Middle Zone consist of magnetite gabbro and overlying gabbro. In these cyclic units, contents of Fe2O3(t), TiO2 and Cr and Fe3+/Ti4+ ratio of the rocks decrease upward, Cr content of magnetite and forsterite percentage of olivine decrease as well. The Upper Zone consists of apatite gabbro characterized by enrichment of incompatible elements (e.g., 12-18 ppm La, 20-28 ppm Y) and increasing of Fe3+/Ti4+ ratio (from 1.3 to 2.3) upward. These features indicate that the Panzhihua intrusion was repeatedly recharged by more primitive magma and evolved magmas had been extracted. Calculations using MELTS indicate that extensive fractionation of olivine and clinopyroxene in deep level resulted in increasing Fe and Ti contents in the magma. When these Fe-Ti-enriched magmas were emplaced along the base of the Panzhihua intrusion, Fe-Ti oxides became an early crystallization phase, leading to a residual magma of lower density. We propose that the unusually thick stratiform Fe-Ti oxide layers resulted from coupling of gravity settling and sorting of the crystallized Fe-Ti oxides from Fe-Ti-enriched magmas and frequent magma replenishment along the floor of the magma chamber.

  2. Rhodamine B triggers ovarian toxicity through oxidative stress, decreases in the number of follicles, 17B-estradiol level, and thickness of endometrium

    Directory of Open Access Journals (Sweden)

    Syiska Atik Maryanti

    2014-06-01

    Full Text Available Objective: The purpose of this study was to analyze the effects of exposure to rhodamine B on ovarian oxidative stress, ovarian follicles, hormone 17beta-estradiol and thickness of endometrium. Methods: A total of 28 female rats were divided into four groups consisting of control; groups treated with rhodamine B at doses of 4.5; 9, and 18 milligram/200 gram body weight. Rhodamine B was administered orally for 36 days with the probe. Analysis of MDA level was done spectrophotometrically. Analysis of the number of ovarian follicles and thickness of endometrium was done histopathologically by hematoxylin eosin staining. Analysis of 17-estradiol level was done by ELISA. Results: Rhodamine B administered in different doses in female rats can increase ovarian MDA levels significantly than the control (P 0.05. Administration of rhodamine B of the second and third doses in female rats can reduce the number of primary, secondary, and De Graaf follicles significantly compared to the control (P 0.05. Administration of rhodamine B of the second and third doses in female rats can reduce 17-estradiol level significantly compared to the control (P 0.05. The administration of rhodamine B could reduce thickness of endometrium significantly compared to the control (P 0.05. Conclusion: It was concluded that administration of rhodamine B triggered ovarian toxicity through oxidative stress, a decrease in the number of follicles, and decreased level of 17-estradiol which ultimately lowered the thickness of endometrium. [Cukurova Med J 2014; 39(3.000: 451-457

  3. Enhanced energy storage and suppressed dielectric loss in oxide core-shell-polyolefin nanocomposites by moderating internal surface area and increasing shell thickness

    Energy Technology Data Exchange (ETDEWEB)

    Fredin, Lisa A.; Li, Zhong; Ratner, Mark A.; Marks, Tobin J. [Department of Chemistry Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States); Lanagan, Michael T. [Center for Dielectric Studies, Materials Research Institute, The Pennsylvania State University, University Park, PA 16802-4800 (United States)

    2012-11-20

    Dielectric loss in metal oxide core/Al{sub 2}O{sub 3} shell polypropylene nanocomposites scales with the particle surface area. By moderating the interfacial surface area between the phases and using increasing shell thicknesses, dielectric loss is significantly reduced, and thus the energy stored within, and recoverable from, capacitors fabricated from these materials is significantly increased, to as high as 2.05 J/cm{sup 3}. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Effect of interfacial oxide thickness on the photocatalytic activity of magnetron-sputtered TiO2coatings on aluminum substrate

    DEFF Research Database (Denmark)

    Daviðsdóttir, Svava; Petit, Jean-Pierre; Shabadi, Rajashekhara

    2015-01-01

    The influence of the coating/substrate interface on the photocatalytic behavior of Al-TiO2 coatings was investigated. The TiO2 coatings were prepared by magnetron sputtering. The nanoscale structure of the coating was analyzed using X-ray diffraction; atomic force microscopy; scanning electron...... transport between the coating and the metallic substrate. The highest photocurrents were indeed obtained when the thickness of interfacial aluminum oxide could be reduced by sputtering a thin Ti layer prior to TiO2 coating. Photocurrent plotted for different photon energy for a TiO2 coating on a Ti...

  5. Contact Selectivity Engineering in a 2 μm Thick Ultrathin c-Si Solar Cell Using Transition-Metal Oxides Achieving an Efficiency of 10.8.

    Science.gov (United States)

    Xue, Muyu; Islam, Raisul; Meng, Andrew C; Lyu, Zheng; Lu, Ching-Ying; Tae, Christian; Braun, Michael R; Zang, Kai; McIntyre, Paul C; Kamins, Theodore I; Saraswat, Krishna C; Harris, James S

    2017-12-06

    In this paper, the integration of metal oxides as carrier-selective contacts for ultrathin crystalline silicon (c-Si) solar cells is demonstrated which results in an ∼13% relative improvement in efficiency. The improvement in efficiency originates from the suppression of the contact recombination current due to the band offset asymmetry of these oxides with Si. First, an ultrathin c-Si solar cell having a total thickness of 2 μm is shown to have >10% efficiency without any light-trapping scheme. This is achieved by the integration of nickel oxide (NiO x ) as a hole-selective contact interlayer material, which has a low valence band offset and high conduction band offset with Si. Second, we show a champion cell efficiency of 10.8% with the additional integration of titanium oxide (TiO x ), a well-known material for an electron-selective contact interlayer. Key parameters including V oc and J sc also show different degrees of enhancement if single (NiO x only) or double (both NiO x and TiO x ) carrier-selective contacts are integrated. The fabrication process for TiO x and NiO x layer integration is scalable and shows good compatibility with the device.

  6. Influence of Nitinol wire surface treatment on oxide thickness and composition and its subsequent effect on corrosion resistance and nickel ion release.

    Science.gov (United States)

    Clarke, B; Carroll, W; Rochev, Y; Hynes, M; Bradley, D; Plumley, D

    2006-10-01

    Medical implants and devices are now used successfully in surgical procedures on a daily basis. Alloys of nickel and titanium, and in particular Nitinol are of special interest in the medical device industry, because of their shape memory and superelastic properties. The corrosion behavior of nitinol in the body is also of critical importance because of the known toxicological effects of nickel. The stability of a NiTi alloy in the physiological environment is dependant primarily on the properties of the mostly TiO(2) oxide layer that is present on the surface. For the present study, a range of nitinol wires have been prepared using different drawing processes and a range of surface preparation procedures. It is clear from the results obtained that the wire samples with very thick oxides also contain a high nickel content in the oxide layer. The untreated samples with the thicker oxides show the lowest pitting potential values and greater nickel release in both long and short-term experiments. It was also found that after long-term immersion tests breakdown potentials increased for samples that exhibited lower values initially. From these results it would appear that surface treatment is essential for the optimum bioperformance of nitinol. (c) 2006 Wiley Periodicals, Inc

  7. Oxidative damage markers are significantly associated with the carotid artery intima-media thickness after controlling for conventional risk factors of atherosclerosis in men.

    Directory of Open Access Journals (Sweden)

    Jin-Ha Yoon

    Full Text Available This study aimed to assess the association between oxidative damage markers and carotid artery intima-media thickness (CIMT after controlling for conventional risk factors of atherosclerosis in multiple logistic regression models.Fifty-one case male participants (CIMT ≥ 0.9 mm were enrolled during their visits to Korean Genomic Rural Cohort Study of Wonju centers between May 1 and August 31, 2011, along with 51 control participants (CIMT < 0.9 mm selected using frequency matching by age group. The levels of oxidative damage markers, 8-hydroxy-2'-deoxyquuanosine (8-OHdG, malondialdehyde (MDA, and 8-iso-prostaglandin F2α (Isoprostane, were measured. Conditional logistic regression models were used to evaluate relative relationships between the oxidative damage markers and the risk of high CIMT.The markers of oxidative lipid (Isoprostane and MDA and DNA (8-OHdG damage were associated with CIMT after controlling for the conventional risk factors, including age, low density lipoprotein, body mass index, smoking history, alcohol consumption, and metabolic syndrome (ORs [95% CI] for Isoprostane: 3rd tertile, 8.47 [2.59-27.67]; for MDA: 3rd tertile, 8.47 [2.59-27.67]; for 8-OHdG: 3rd tertile, 5.58 [1.79-17.33]. When all the oxidative damage markers were incorporated in the same logistic regression model, only Isoprostane was significantly related to CIMT (OR [95% CI]: 4.22 [1.31-13.53] in 2nd tertile and 14.21 [3.34-60.56] in 3rd tertile.In this nested case-control study, the oxidative damage markers of lipid and DNA were associated with CIMT even after controlling for the conventional risk factors of cardiovascular diseases.

  8. Thickness dependence of the switching voltage in all-oxide ferroelectric thin-film capacitors prepared by pulsed laser deposition

    NARCIS (Netherlands)

    Cillessen, J.F.M.; Prins, M.W.J.; Wolf, R.M.

    1997-01-01

    Thin-film ferroelectric capacitors consisting of PbZr0.53Ti0.47O3 sandwiched between La0.5Sr0.5CoO3 electrodes have been deposited using pulsed laser deposition. The combination of oxidic perovskite-type materials results in capacitors with a coercive field (Ec) which is comparable with values for

  9. Thickness-self-controlled synthesis of porous transparent polyaniline-reduced graphene oxide composites towards advanced bifacial dye-sensitized solar cells

    Science.gov (United States)

    Wang, Yu-Sheng; Li, Shin-Ming; Hsiao, Sheng-Tsung; Liao, Wei-Hao; Yang, Shin-Yi; Tien, Hsi-Wen; Ma, Chen-Chi M.; Hu, Chi-Chang

    2014-08-01

    A powerful synthesis strategy is proposed for fabricating porous polyaniline-reduced graphene oxide (PANI-RGO) composites with transparency up to 80% and thickness from 300 to 1000 nm for the counter electrode (CE) of bifacial dye-sensitizing solar cells (DSSCs). The first step is to combine the in-situ positive charge transformation of graphene oxide (GO) through aniline (ANI) prepolymerization and the electrostatic adsorption of ANI oligomer-GO to effectively control the thickness of ultrathin PANI-GO films by adjusting pH of the polymerization media. In the second step, PANI-GO films are reduced with hydroiodic acid to simultaneously enhance the apparent redox activity for the I3-/I- couple and their electronic conductivity. Incorporating the RGO increases the transparency of PANI and facilitates the light-harvesting from the rear side. A DSSC assembled with such a transparent PANI-RGO CE exhibits an excellent efficiency of 7.84%, comparable to 8.19% for a semi-transparent Pt-based DSSC. The high light-harvesting ability of PANI-RGO enhances the efficiency retention between rear- and front-illumination modes to 76.7%, compared with 69.1% for a PANI-based DSSC. The higher retention reduces the power-to-weight ratio and the total cost of bifacial DSSCs, which is also promising in other applications, such as windows, power generators, and panel screens.

  10. Study of thickness and uniformity of oxide passivation with DI-O3 on silicon substrate for electronic and photonic applications

    Science.gov (United States)

    Sharma, Mamta; Hazra, Purnima; Singh, Satyendra Kumar

    2018-05-01

    Since the beginning of semiconductor fabrication technology evolution, clean and passivated substrate surface is one of the prime requirements for fabrication of Electronic and optoelectronic device fabrication. However, as the scale of silicon circuits and device architectures are continuously decreased from micrometer to nanometer (from VLSI to ULSI technology), the cleaning methods to achieve better wafer surface qualities has raised research interests. The development of controlled and uniform silicon dioxide is the most effective and reliable way to achieve better wafer surface quality for fabrication of electronic devices. On the other hand, in order to meet the requirement of high environment safety/regulatory standards, the innovation of cleaning technology is also in demand. The controlled silicon dioxide layer formed by oxidant de-ionized ozonated water has better uniformity. As the uniformity of the controlled silicon dioxide layer is improved on the substrate, it enhances the performance of the devices. We can increase the thickness of oxide layer, by increasing the ozone time treatment. We reported first time to measurement of thickness of controlled silicon dioxide layer and obtained the uniform layer for same ozone time.

  11. Improvement in the Sensitivity of PbO Doped Tin Oxide Thick Film Gas Sensor by RF and Microwave Oxygen Plasma Treatment

    Directory of Open Access Journals (Sweden)

    J. K. SRIVASTAVA

    2010-07-01

    Full Text Available In the present work efforts have been made to analyze the effect of oxygen plasma and PbO doping on the sensitivity of SnO2-based thick film gas sensor for methanol, propanol and acetone. The effect of substrate temperature on the response of dual frequency (RF and microwave plasma treated thick film sensor array has also been studied. To achieve this, three sensor arrays (each with four tin oxide sensors doped with different (1 %, 2 %, 3 % and 4 % PbO concentrations were fabricated by thick film technology and then treated with oxygen plasma for various durations (5 min, 10 min. and 15 min.. The plasma treated sensors were found to possess appreciably high sensitivity at room temperature in comparison to untreated sensor. The sensitivity showed the increasing trend with plasma exposure time and 15 minutes exposure time was found to be most suitable as the sensitivity of the plasma treated sensors for this duration were high towards all the chosen vapors with maximum (97 % value for propanol. The sensitivity of the sensors were found to be increasing gradually as PbO concentration was varied from 1- 4%.

  12. STRUCTURAL, PHOTO-FUNCTIONAL AND SEMICONDUCTOR PROPERTIES OF COPPER OXIDE THIN FILMS PREPARED BY DC REACTIVE METHOD UNDER VARIOUS THICKNESSES Anmar H. Shukur

    Directory of Open Access Journals (Sweden)

    Anmar H. Shukur

    2018-01-01

    Full Text Available Cuprous oxide (Cu2O has been formed on glass substrates by dc reactive magnetron sputtering method, whereas pure target of the solid copper was sputtered with a mixture of plasma for argon gas and oxygen gas was used to form these films. Under vacuum chamber pressure of 1.2×10-5 Pa, thin film thickness was changed from 100 nm to 300 nm while other deposition parameters were fixed. The influence of changing the thickness of thin films on the electrical and the optical properties was investigated in this study. X-ray photoelectron spectroscopy (XPS, X-ray Diffractions system XRD, Atomic Force Microscopy (AFM, hall effect measurement system, UV–VIS spectrophotometer were employed to determine the characteristic of the deposited thin films. Thin film of 200 nm has observed low resistivity of 60.63 Ω cm and direct band gap of 2.5eV. This study has demonstrated that the thickness has direct influence on electrical and optical properties.

  13. Evolution of the thickness of the aluminum oxide film due to the pH of the cooling water and surface temperature of the fuel elements clad of a nuclear reactor

    International Nuclear Information System (INIS)

    Babiche, Ivan

    2013-01-01

    This paper describes the mechanism of growth of a film of aluminum oxide on an alloy of the same material, which serves as a protective surface being the constituent material of the RP-10 nuclear reactor fuel elements clads. The most influential parameters on the growth of this film are: the pH of the cooling water and the clad surface temperature of the fuel element. For this study, a mathematical model relating the evolution of the aluminum oxide layer thickness over the time, according to the same oxide film using a power law is used. It is concluded that the time of irradiation, the heat flux at the surface of the aluminum material, the speed of the coolant, the thermal conductivity of the oxide, the initial thickness of the oxide layer and the solubility of the protective oxide are parameters affecting in the rate and film formation. (author).

  14. Politico-economic equivalence

    DEFF Research Database (Denmark)

    Gonzalez Eiras, Martin; Niepelt, Dirk

    2015-01-01

    Traditional "economic equivalence'' results, like the Ricardian equivalence proposition, define equivalence classes over exogenous policies. We derive "politico-economic equivalence" conditions that apply in environments where policy is endogenous and chosen sequentially. A policy regime and a st......Traditional "economic equivalence'' results, like the Ricardian equivalence proposition, define equivalence classes over exogenous policies. We derive "politico-economic equivalence" conditions that apply in environments where policy is endogenous and chosen sequentially. A policy regime...... their use in the context of several applications, relating to social security reform, tax-smoothing policies and measures to correct externalities....

  15. Evaluation of Permacol as a cultured skin equivalent.

    Science.gov (United States)

    MacLeod, T M; Cambrey, A; Williams, G; Sanders, R; Green, C J

    2008-12-01

    Skin loss following severe burn requires prompt wound closure to avoid such complications as fluid and electrolyte imbalance, infection, immune suppression, and pain. In clinical situations in which insufficient donor skin is available, the development of cultured skin equivalents (dermal matrices seeded with keratinocytes and fibroblasts) may provide a useful alternative. The aim of this study was to assess the suitability of a porcine-derived dermal collagen matrix (Permacol) to function as a cultured skin equivalent in supporting the growth of keratinocytes in vitro and providing cover to full thickness wounds in the BALB C/nude mouse model. A histological comparison was against Glycerol treated-Ethylene Oxide Sterilised Porcine Dermis (Gly-EO Dermis) which has successfully been used as a cultured skin equivalent in previous studies. Both Gly-EO Dermis and to a lesser extent Permacol were able to support the growth of cultured keratinocytes following a 16-day period of cell culture, however, this study was only able to demonstrate the presence of an epidermal layer on Gly-EO dermis 2 weeks after grafting onto full-thickness wounds in the BALB C/nude mouse model.

  16. Role of the SiO2 buffer layer thickness in the formation of Si/SiO2/nc-Ge/SiO2 structures by dry oxidation

    International Nuclear Information System (INIS)

    Kling, A.; Ortiz, M.I.; Prieto, A.C.; Rodriguez, A.; Rodriguez, T.; Jimenez, J.; Ballesteros, C.; Soares, J.C.

    2006-01-01

    Nanomemories, containing Ge-nanoparticles in a SiO 2 matrix, can be produced by dry thermal oxidation of a SiGe layer deposited onto a Si-wafer with a barrier SiO 2 layer on its top. Rutherford backscattering spectrometry has been used to characterize the kinetics of the oxidation process, the composition profile of the growing oxide, the Ge-segregation and its diffusion into the barrier oxide in samples with thin and thick barrier oxide layers. The Ge segregated during the oxidation of the SiGe layer diffuses into the barrier oxide. In the first case the diffusion through the thin oxide is enhanced by the proximity of the substrate that acts as a sink for the Ge, resulting in the formation of a low Ge concentration SiGe layer in the surface of the Si-wafer. In the second case, the Ge-diffusion progresses as slowly as in bulk SiO 2 . Since barrier oxide layers as thin as possible are favoured for device fabrication, the structures should be oxidized at lower temperatures and the initial SiGe layer thickness reduced to minimize the Ge-diffusion

  17. Optical and structural properties of zinc oxide films with different thicknesses prepared by successive ionic layer adsorption and reaction method

    Energy Technology Data Exchange (ETDEWEB)

    Taner, Ahmet, E-mail: ataner@anadolu.edu.tr [Institute of Science and Technology, Anadolu University, Eskisehir 26470 (Turkey); Kul, Metin; Turan, Evren; Aybek, A. Senol; Zor, Muhsin [Department of Physics, Anadolu University, Eskisehir 26470 (Turkey); Taskoeprue, Turan [Department of Physics, Anadolu University, Eskisehir 26470 (Turkey); Department of Physics, Cank Latin-Small-Letter-Dotless-I r Latin-Small-Letter-Dotless-I Karatekin University, Cank Latin-Small-Letter-Dotless-I r Latin-Small-Letter-Dotless-I 18100 (Turkey)

    2011-12-01

    In this work, zinc oxide semiconducting films belonging to the II-VI group have been produced by successive ionic layer adsorption and reaction (SILAR) method on glass substrates with 10, 15, 20 and 25 cycles at room temperature. Following the deposition, the samples were dried in air at 400 Degree-Sign C for 1 h. The films were characterized by X-ray diffraction, field emission scanning electron microscopy and optical absorption measurement techniques. The X-ray diffractions of the films showed that they are hexagonal in structure. The crystallite size of ZnO films varied between 34 and 38 nm accordingly with the number of SILAR cycles. The material has exhibited direct band gap transition with the band gap values lying in the range between 3.13 and 3.18 eV. The red shift is observed in the absorption edge as the cycles increased. Transmission of the films decreased from 65 to 40% with increasing the number of cycles.

  18. Optical and structural properties of zinc oxide films with different thicknesses prepared by successive ionic layer adsorption and reaction method

    International Nuclear Information System (INIS)

    Taner, Ahmet; Kul, Metin; Turan, Evren; Aybek, A. Şenol; Zor, Muhsin; Taşköprü, Turan

    2011-01-01

    In this work, zinc oxide semiconducting films belonging to the II-VI group have been produced by successive ionic layer adsorption and reaction (SILAR) method on glass substrates with 10, 15, 20 and 25 cycles at room temperature. Following the deposition, the samples were dried in air at 400 °C for 1 h. The films were characterized by X-ray diffraction, field emission scanning electron microscopy and optical absorption measurement techniques. The X-ray diffractions of the films showed that they are hexagonal in structure. The crystallite size of ZnO films varied between 34 and 38 nm accordingly with the number of SILAR cycles. The material has exhibited direct band gap transition with the band gap values lying in the range between 3.13 and 3.18 eV. The red shift is observed in the absorption edge as the cycles increased. Transmission of the films decreased from 65 to 40% with increasing the number of cycles.

  19. Laboratory measurements of nitric oxide release from forest soil with a thick organic layer under different understory types

    Directory of Open Access Journals (Sweden)

    A. Bargsten

    2010-05-01

    Full Text Available Nitric oxide (NO plays an important role in the photochemistry of the troposphere. NO from soil contributes up to 40% to the global budget of atmospheric NO. Soil NO emissions are primarily caused by biological activity (nitrification and denitrification, that occurs in the uppermost centimeter of the soil, a soil region often characterized by high contents of organic material. Most studies of NO emission potentials to date have investigated mineral soil layers. In our study we sampled soil organic matter under different understories (moss, grass, spruce and blueberries in a humid mountainous Norway spruce forest plantation in the Fichtelgebirge (Germany. We performed laboratory incubation and flushing experiments using a customized chamber technique to determine the response of net potential NO flux to physical and chemical soil conditions (water content and temperature, bulk density, particle density, pH, C/N ratio, organic C, soil ammonium, soil nitrate. Net potential NO fluxes (in terms of mass of N from soil samples taken under different understories ranged from 1.7–9.8 ng m−2 s−1 (soil sampled under grass and moss cover, 55.4–59.3 ng m−2 s−1 (soil sampled under spruce cover, and 43.7–114.6 ng m−2 s−1 (soil sampled under blueberry cover at optimum water content and a soil temperature of 10 °C. The water content for optimum net potential NO flux ranged between 0.76 and 0.8 gravimetric soil moisture for moss covered soils, between 1.0 and 1.1 for grass covered soils, 1.1 and 1.2 for spruce covered soils, and 1.3 and 1.9 for blueberry covered soils. Effects of soil physical and chemical characteristics on net potential NO flux were statistically significant (0.01 probability level only for NH4+. Therefore, as an alternative explanation for the differences in soil biogenic NO emission we consider more biological factors like understory

  20. Thick Toenails

    Science.gov (United States)

    ... in individuals with nail fungus (onychomycosis), psoriasis and hypothyroidism. Those who have problems with the thickness of their toenails should consult a foot and ankle surgeon for proper diagnosis and treatment. Find an ACFAS Physician Search Search Tools Find ...

  1. Process-structure-property relationships of micron thick gadolinium oxide films deposited by reactive electron beam-physical vapor deposition (EB-PVD)

    Science.gov (United States)

    Grave, Daniel A.

    Gadolinium oxide (Gd2O3) is an attractive material for solid state neutron detection due to gadolinium's high thermal neutron capture cross section. Development of neutron detectors based on Gd2 O3 requires sufficiently thick films to ensure neutron absorption. In this dissertation work, the process-structure-property relationships of micron thick Gd2O3 films deposited by reactive electron-beam physical vapor deposition (EB-PVD) were studied. Through a systematic design of experiments, fundamental studies were conducted to determine the effects of processing conditions such as deposition temperature, oxygen flow rate, deposition rate, and substrate material on Gd2O3 film crystallographic phase, texture, morphology, grain size, density, and surface roughness. Films deposited at high rates (> 5 A/s) were examined via x-ray diffraction (XRD) and Raman spectroscopy. Quantitative phase volume calculations were performed via a Rietveld refinement technique. All films deposited at high rates were found to be fully monoclinic or mixed cubic/monoclinic phase. Generally, increased deposition temperature and increased oxygen flow resulted in increased cubic phase volume. As film thickness increased, monoclinic phase volume increased. Grazing incidence x-ray diffraction (GIXRD) depth profiling analysis showed that cubic phase was only present under large incidence angle (large penetration depth) measurements, and after a certain point, only monoclinic phase was grown. This was confirmed by transmission electron microscopy (TEM) analysis with selected area diffraction (SAD). Based on this information, a large compressive stress was hypothesized to cause the formation of the monoclinic phase and this hypothesis was confirmed by demonstrating the existence of a stress induced phase transition. An experiment was designed to introduce compressive stress into the Gd2O 3 films via ion beam assisted deposition (IBAD). This allowed for systematic increase in compressive stress while

  2. doped ZnO thick film resistors

    Indian Academy of Sciences (India)

    The characterization and ethanol gas sensing properties of pure and doped ZnO thick films were investigated. Thick films of pure zinc oxide were prepared by the screen printing technique. Pure zinc oxide was almost insensitive to ethanol. Thick films of Al2O3 (1 wt%) doped ZnO were observed to be highly sensitive to ...

  3. Electrical characteristics of AlO{sub x}N{sub y} prepared by oxidation of sub-10-nm-thick AlN films for MOS gate dielectric applications

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Sang Hun; Jang, Hyeon Woo; Kim, Hyun Soo; Noh, Do Young; Hwang, Hyun Sang [Kwangju Institute of Science and Technology, Kwangju (Korea, Republic of)

    2000-12-01

    In this research, the feasibility of ultrathin AlO{sub x}N{sub y} prepared by oxidation of sub 100-A-thick AlN thin films for metal-oxide-semiconductor (MOS) gate dielectric applications was investigated. Oxidation of 51-A-and 98-A-thick as-deposited AlN at 800 .deg. C was used to form 72-A-and 130-A-thick AlO{sub x}N{sub y}, respectively. Based on the capacitance-voltage (C-V) measurements of the MOS capacitor, the dielectric constants of 72 A-thick and 130 A-thick Al-oxynitride were 5.15 and 7, respectively. The leakage current of Al-oxynitride at low field was almost the same as that of thermal SiO{sub 2}. based on the CV data, the interface state density of Al-oxynitride was relatively higher than that of SiO{sub 2}. Although process optimization is still necessary, the Al-oxynitride exhibits some possibility for future MOS gate dielectric applications.

  4. Electrical characteristics of AlO sub x N sub y prepared by oxidation of sub-10-nm-thick AlN films for MOS gate dielectric applications

    CERN Document Server

    Jeon, S H; Kim, H S; Noh, D Y; Hwang, H S

    2000-01-01

    In this research, the feasibility of ultrathin AlO sub x N sub y prepared by oxidation of sub 100-A-thick AlN thin films for metal-oxide-semiconductor (MOS) gate dielectric applications was investigated. Oxidation of 51-A-and 98-A-thick as-deposited AlN at 800 .deg. C was used to form 72-A-and 130-A-thick AlO sub x N sub y , respectively. Based on the capacitance-voltage (C-V) measurements of the MOS capacitor, the dielectric constants of 72 A-thick and 130 A-thick Al-oxynitride were 5.15 and 7, respectively. The leakage current of Al-oxynitride at low field was almost the same as that of thermal SiO sub 2. based on the CV data, the interface state density of Al-oxynitride was relatively higher than that of SiO sub 2. Although process optimization is still necessary, the Al-oxynitride exhibits some possibility for future MOS gate dielectric applications.

  5. Body fat of stock-type horses predicted by rump fat thickness and deuterium oxide dilution and validated by near-infrared spectroscopy of dissected tissues.

    Science.gov (United States)

    Ferjak, E N; Cavinder, C A; Burnett, D D; Argo, C Mc; Dinh, T T N

    2017-10-01

    Body condition score and percent body fat (BF; %) of horses are positively correlated with reproductive efficiency and are indicative of metabolic issues. However, BF in horses may be poorly predicted because current procedures are either subjective or dependent on one anatomical location. Therefore, the objectives of the current study were to compare 2 methods of predicting BF using rump fat thickness (RFT) and deuterium oxide (DO) dilution with actual tissue fat analysis by near-infrared spectroscopy (NIRS) in stock-type horses and to identify the relationship between BF and BCS. Twenty-four stock-type horses were selected to be humanely euthanized based on 3 primary criteria: geriatric, crippled, and/or unsafe. Approximately 20 h before slaughter, horses were weighed and BCS assessed to be 1 ( = 1; 433 kg), 2 ( = 1; 415 kg), 3 ( = 1; 376 kg), 4 ( = 7; 468 ± 13 kg), 5 ( = 10; 455 ± 11 kg), and 6 ( = 4; 493 ± 12 kg) and RFT was measured using ultrasonography. Blood samples were collected immediately before and 4 h after DO infusion (0.12 g/kg BW). Deuterium oxide concentration of plasma was determined by gas isotope ratio mass spectrometry. Horses were housed in a dry lot overnight before being individually sedated (1.1 mg xylazine/kg BW) and anesthetized using a jugular venipuncture (2.2 mg ketamine/kg BW), and potassium chloride (KCl) solution was administered to cease cardiac function before exsanguination. After euthanasia, horse carcasses were processed and dissected and tissues were collected for NIRS analysis. Body fat predicted by DO dilution was correlated with BF measured by NIRS analysis on various weight bases ( = 0.76 to 0.81, horses.

  6. Equivalence principles and electromagnetism

    Science.gov (United States)

    Ni, W.-T.

    1977-01-01

    The implications of the weak equivalence principles are investigated in detail for electromagnetic systems in a general framework. In particular, it is shown that the universality of free-fall trajectories (Galileo weak equivalence principle) does not imply the validity of the Einstein equivalence principle. However, the Galileo principle plus the universality of free-fall rotation states does imply the Einstein principle.

  7. Electrochemical impedance spectroscopy of oxidized porous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Mula, Guido, E-mail: guido.mula@unica.it [Dipartimento di Fisica, Università degli Studi di Cagliari, Cittadella Universitaria di Monserrato, S.P. 8 km 0.700, 09042 Cagliari (Italy); Tiddia, Maria V. [Dipartimento di Fisica, Università degli Studi di Cagliari, Cittadella Universitaria di Monserrato, S.P. 8 km 0.700, 09042 Cagliari (Italy); Ruffilli, Roberta [Nanochemistry, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova (Italy); Falqui, Andrea [Nanochemistry, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova (Italy); Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, Cittadella Universitaria di Monserrato, S.P. 8 km 0.700, 09042 Cagliari (Italy); Palmas, Simonetta; Mascia, Michele [Dipartimento di Ingegneria Meccanica Chimica e dei Materiali, Università degli Studi di Cagliari, Piazza d' Armi, 09126 Cagliari (Italy)

    2014-04-01

    We present a study of the electrochemical oxidation process of porous silicon. We analyze the effect of the layer thickness (1.25–22 μm) and of the applied current density (1.1–11.1 mA/cm{sup 2}, values calculated with reference to the external samples surface) on the oxidation process by comparing the galvanostatic electrochemical impedance spectroscopy (EIS) measurements and the optical specular reflectivity of the samples. The results of EIS were interpreted using an equivalent circuit to separate the contribution of different sample parts. A different behavior of the electrochemical oxidation process has been found for thin and thick samples: whereas for thin samples the oxidation process is univocally related to current density and thickness, for thicker samples this is no more true. Measurements by Energy Dispersive Spectroscopy using a Scanning Electron Microscopy confirmed that the inhomogeneity of the electrochemical oxidation process is increased by higher thicknesses and higher currents. A possible explanation is proposed to justify the different behavior of thin and thick samples during the electrochemical process. - Highlights: • A multidisciplinary approach on porous Si electrochemical oxidation is proposed. • Electrochemical, optical, and structural characterizations are used. • Layer thickness and oxidation current effects are shown. • An explanation of the observed behavior is proposed.

  8. Neutrons production in thick targets of Be and {sup 238}U bombarded by 100 MeV/u deuterons and in a thick target of C bombarded by 95 MeV/u {sup 36}Ar. Attenuation in concrete and dose equivalent rate of the activated uranium; Neutrons produits dans des cibles epaisses de Be et {sup 238}U irradiees par des deutons de 100 MeV/u et dans une cible epaisse de C irradiee par des {sup 36}Ar de 95 MeV/u. Longueurs d'attenuation dans du beton et debit d'equivalent de dose resultant de l'activation de l'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Pauwels, N.; Proust, J.; Clapier, F.; Gara, P.; Obert, J. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire; Mirea, M. [Institute of Physics and Nuclear Engineering, Bucharest (Romania); Belier, G.; Ethvignot, T.; Granier, T. [CEA/DAM-Ile de France, 91 - Bruyeres-Le-Chatel (France). Service de Physique Nucleaire; Liang, C.F. [Paris-11 Univ., 91 - Orsay (France). Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse; Bajard, M.; Leroy, R.; Villari, A.C.C. [Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France)

    1999-09-01

    Neutrons production in thick targets of Be and {sup 238}U bombarded by 100 MeV/u deuterons and in a thick target of C bombarded by 95 MeV/u {sup 36}Ar. Attenuation in concrete and dose equivalent rate of the activated uranium. The yields of secondary neutrons produced by the interaction of a beam with thick target were determined with activation detectors. Three projectile-target couples have been studied: deuterons (100 MeV/u)+{sup 238}U, deuterons (100 MeV/u)+{sup 9}Be and {sup 36}Ar (95 MeV/u)+{sup 12}C. At 0 deg.. the yields were also measured after a piece of concrete and the corresponding attenuation length evaluated. The dose rate of the uranium target was monitored during several days after the end of the irradiation. (author)

  9. Equivalent nozzle in thermomechanical problems

    International Nuclear Information System (INIS)

    Cesari, F.

    1977-01-01

    When analyzing nuclear vessels, it is most important to study the behavior of the nozzle cylinder-cylinder intersection. For the elastic field, this analysis in three dimensions is quite easy using the method of finite elements. The same analysis in the non-linear field becomes difficult for designs in 3-D. It is therefore necessary to resolve a nozzle in two dimensions equivalent to a 3-D nozzle. The purpose of the present work is to find an equivalent nozzle both with a mechanical and thermal load. This has been achieved by the analysis in three dimensions of a nozzle and a nozzle cylinder-sphere intersection, of a different radius. The equivalent nozzle will be a nozzle with a sphere radius in a given ratio to the radius of a cylinder; thus, the maximum equivalent stress is the same in both 2-D and 3-D. The nozzle examined derived from the intersection of a cylindrical vessel of radius R=191.4 mm and thickness T=6.7 mm with a cylindrical nozzle of radius r=24.675 mm and thickness t=1.350 mm, for which the experimental results for an internal pressure load are known. The structure was subdivided into 96 finite, three-dimensional and isoparametric elements with 60 degrees of freedom and 661 total nodes. Both the analysis with a mechanical load as well as the analysis with a thermal load were carried out on this structure according to the Bersafe system. The thermal load consisted of a transient typical of an accident occurring in a sodium-cooled fast reactor, with a peak of the temperature (540 0 C) for the sodium inside the vessel with an insulating argon temperature constant at 525 0 C. The maximum value of the equivalent tension was found in the internal area at the union towards the vessel side. The analysis of the nozzle in 2-D consists in schematizing the structure as a cylinder-sphere intersection, where the sphere has a given relation to the

  10. The effect of oxide shell thickness on the structural, electronic, and optical properties of Si-SiO{sub 2} core-shell nano-crystals: A (time dependent)density functional theory study

    Energy Technology Data Exchange (ETDEWEB)

    Nazemi, Sanaz, E-mail: s.nazemi@ut.ac.ir, E-mail: pourfath@ut.ac.ir; Soleimani, Ebrahim Asl [School of Electrical and Computer Engineering, University of Tehran, Tehran 14395-515 (Iran, Islamic Republic of); Pourfath, Mahdi, E-mail: s.nazemi@ut.ac.ir, E-mail: pourfath@ut.ac.ir [School of Electrical and Computer Engineering, University of Tehran, Tehran 14395-515 (Iran, Islamic Republic of); Institute for Microelectronics, Technische Universität Wien, Wien A-1040 (Austria); Kosina, Hans [Institute for Microelectronics, Technische Universität Wien, Wien A-1040 (Austria)

    2016-04-14

    Due to their tunable properties, silicon nano-crystals (NC) are currently being investigated. Quantum confinement can generally be employed for size-dependent band-gap tuning at dimensions smaller than the Bohr radius (∼5 nm for silicon). At the nano-meter scale, however, increased surface-to-volume ratio makes the surface effects dominant. Specifically, in Si-SiO{sub 2} core-shell semiconductor NCs the interfacial transition layer causes peculiar electronic and optical properties, because of the co-existence of intermediate oxidation states of silicon (Si{sup n+}, n = 0–4). Due to the presence of the many factors involved, a comprehensive understanding of the optical properties of these NCs has not yet been achieved. In this work, Si-SiO{sub 2} NCs with a diameter of 1.1 nm and covered by amorphous oxide shells with thicknesses between 2.5 and 4.75 Å are comprehensively studied, employing density functional theory calculations. It is shown that with increased oxide shell thickness, the low-energy part of the optical transition spectrum of the NC is red shifted and attenuated. Moreover, the absorption coefficient is increased in the high-energy part of the spectrum which corresponds to SiO{sub 2} transitions. Structural examinations indicate a larger compressive stress on the central silicon cluster with a thicker oxide shell. Examination of the local density of states reveals the migration of frontier molecular orbitals from the oxide shell into the silicon core with the increase of silica shell thickness. The optical and electrical properties are explained through the analysis of the density of states and the spatial distribution of silicon sub-oxide species.

  11. Effective dose equivalent

    International Nuclear Information System (INIS)

    Huyskens, C.J.; Passchier, W.F.

    1988-01-01

    The effective dose equivalent is a quantity which is used in the daily practice of radiation protection as well as in the radiation hygienic rules as measure for the health risks. In this contribution it is worked out upon which assumptions this quantity is based and in which cases the effective dose equivalent can be used more or less well. (H.W.)

  12. Characterization of revenue equivalence

    NARCIS (Netherlands)

    Heydenreich, B.; Müller, R.; Uetz, Marc Jochen; Vohra, R.

    2009-01-01

    The property of an allocation rule to be implementable in dominant strategies by a unique payment scheme is called revenue equivalence. We give a characterization of revenue equivalence based on a graph theoretic interpretation of the incentive compatibility constraints. The characterization holds

  13. Characterization of Revenue Equivalence

    NARCIS (Netherlands)

    Heydenreich, Birgit; Müller, Rudolf; Uetz, Marc Jochen; Vohra, Rakesh

    2008-01-01

    The property of an allocation rule to be implementable in dominant strategies by a unique payment scheme is called \\emph{revenue equivalence}. In this paper we give a characterization of revenue equivalence based on a graph theoretic interpretation of the incentive compatibility constraints. The

  14. On the operator equivalents

    International Nuclear Information System (INIS)

    Grenet, G.; Kibler, M.

    1978-06-01

    A closed polynomial formula for the qth component of the diagonal operator equivalent of order k is derived in terms of angular momentum operators. The interest in various fields of molecular and solid state physics of using such a formula in connection with symmetry adapted operator equivalents is outlined

  15. Low-density lipoprotein subfraction, carotid artery intima-media thickness, nitric oxide, and tumor necrosis factor alpha are associated with newly diagnosed ischemic stroke

    Directory of Open Access Journals (Sweden)

    Medine Cumhur Cure

    2013-01-01

    Full Text Available Objectives: Small dense (sd low-density lipoprotein (LDL, tumor necrosis factor (TNF alpha (a, and nitric oxide (NO have recently emerged as important stroke risk factors. The aim of the study was to investigate the effects of increased levels of small LDL particle size, TNF-a and NO on the developed ischemic stroke and increased carotid artery intima-media thickness (CIMT. Materials and Methods: A total of 29 women and 25 men (a total of 54 ischemic stroke patients and a similar age group of 50 controls (29 females and 21 males were included in the study. CIMT, C-reactive protein (CRP, TNF-a, NO, and lipid subfraction test of the two groups were measured. Results: The mean LDL particle size was smaller in patients with stroke than in the controls (26.8 ± 0.31 nm vs. 27.0 ± 0.31 nm, P = 0.003. sd-LDL, TNF-a, NO, CRP, right CIMT, and left CIMT were higher in patients with stroke than in the controls (respectively; 8.2 ± 7.8 mg/dL vs. 3.3 ± 3.5 mg/dL, P < 0.001;75.6 ± 25.0 pg/mL vs. 65.4 ± 9.1 pg/mL, P = 0.009;76.4 ± 53.3 mmol/L vs. 41.5 ± 27.0 mmol/L, P < 0.001;1.9 ± 2.6 mm vs. 0.4 ± 0.3 mm P < 0.001;0.97 ± 0.38 mm vs. 0.83 ± 0.15 mm, P = 0.007;1.04 ± 0.44 mm vs. 0.87 ± 0.19 mm, P = 0.010. Conclusion: These results show that sd-LDL is independently associated with the incidence of stroke and may be a risk factor in the development of stroke. In addition, TNF-a, NO, right CIMT, and left CIMT may be a risk factor in the development of ischemic stroke.

  16. Contribution to the study of slab thickness

    International Nuclear Information System (INIS)

    Moraitis, G.A.; Rorris, G.P.

    1978-01-01

    A method is proposed for calculating the time-independent values of the equivalent slab thickness of the ionosphere, defined as the ratio of the total electron content to the corresponding maximum electron density of the F region. Periodic variations of slab thickness are studied and are correlated to relative changes in exospheric temperature, deduced from the OGO-6 model

  17. Equivalent Dynamic Models.

    Science.gov (United States)

    Molenaar, Peter C M

    2017-01-01

    Equivalences of two classes of dynamic models for weakly stationary multivariate time series are discussed: dynamic factor models and autoregressive models. It is shown that exploratory dynamic factor models can be rotated, yielding an infinite set of equivalent solutions for any observed series. It also is shown that dynamic factor models with lagged factor loadings are not equivalent to the currently popular state-space models, and that restriction of attention to the latter type of models may yield invalid results. The known equivalent vector autoregressive model types, standard and structural, are given a new interpretation in which they are conceived of as the extremes of an innovating type of hybrid vector autoregressive models. It is shown that consideration of hybrid models solves many problems, in particular with Granger causality testing.

  18. Establishing Substantial Equivalence: Transcriptomics

    Science.gov (United States)

    Baudo, María Marcela; Powers, Stephen J.; Mitchell, Rowan A. C.; Shewry, Peter R.

    Regulatory authorities in Western Europe require transgenic crops to be substantially equivalent to conventionally bred forms if they are to be approved for commercial production. One way to establish substantial equivalence is to compare the transcript profiles of developing grain and other tissues of transgenic and conventionally bred lines, in order to identify any unintended effects of the transformation process. We present detailed protocols for transcriptomic comparisons of developing wheat grain and leaf material, and illustrate their use by reference to our own studies of lines transformed to express additional gluten protein genes controlled by their own endosperm-specific promoters. The results show that the transgenes present in these lines (which included those encoding marker genes) did not have any significant unpredicted effects on the expression of endogenous genes and that the transgenic plants were therefore substantially equivalent to the corresponding parental lines.

  19. Study of the oxidation effects on isothermal solidification based high temperature stable Pt/In/Au and Pt/In/Ag thick film interconnections on LTCC substrate

    International Nuclear Information System (INIS)

    Kumar, Duguta Suresh; Khanna, P. K.; Suri, Nikhil; Sharma, R. P.

    2016-01-01

    The objective of the presented paper is to determine the oxidized phase compositions of indium lead-free solders during solidification at 190 ° C under room environment with the help of X-ray diffraction (XRD) and Energy dispersive spectroscopy (EDX). Many lead-free solders alloys available oxidizes and have poor wetting properties. The oxidation of pure indium solder foil, Au, Pt, and Ag alloys were identified and investigated, in the process of isothermal solidification based solder joints construction at room environment and humidity. Both EDX and XRD characterization techniques were performed to trace out the amount of oxide levels and variety of oxide formations at solder interface respectively. The paper also aims to report the isothermal solidification technique to provide interconnections to pads on Low temperature co-fired ceramic (LTCC) substrate. It also elaborates advantages of isothermal solidification over the other methods of interconnection. Scanning electron microscope (SEM) used to identify the oxidized spots on the surface of Pt, Ag substrates and In solder. The identified oxides were reported.

  20. The principle of equivalence

    International Nuclear Information System (INIS)

    Unnikrishnan, C.S.

    1994-01-01

    Principle of equivalence was the fundamental guiding principle in the formulation of the general theory of relativity. What are its key elements? What are the empirical observations which establish it? What is its relevance to some new experiments? These questions are discussed in this article. (author). 11 refs., 5 figs

  1. Radioactive waste equivalence

    International Nuclear Information System (INIS)

    Orlowski, S.; Schaller, K.H.

    1990-01-01

    The report reviews, for the Member States of the European Community, possible situations in which an equivalence concept for radioactive waste may be used, analyses the various factors involved, and suggests guidelines for the implementation of such a concept. Only safety and technical aspects are covered. Other aspects such as commercial ones are excluded. Situations where the need for an equivalence concept has been identified are processes where impurities are added as a consequence of the treatment and conditioning process, the substitution of wastes from similar waste streams due to the treatment process, and exchange of waste belonging to different waste categories. The analysis of factors involved and possible ways for equivalence evaluation, taking into account in particular the chemical, physical and radiological characteristics of the waste package, and the potential risks of the waste form, shows that no simple all-encompassing equivalence formula may be derived. Consequently, a step-by-step approach is suggested, which avoids complex evaluations in the case of simple exchanges

  2. Equivalent Colorings with "Maple"

    Science.gov (United States)

    Cecil, David R.; Wang, Rongdong

    2005-01-01

    Many counting problems can be modeled as "colorings" and solved by considering symmetries and Polya's cycle index polynomial. This paper presents a "Maple 7" program link http://users.tamuk.edu/kfdrc00/ that, given Polya's cycle index polynomial, determines all possible associated colorings and their partitioning into equivalence classes. These…

  3. Correspondences. Equivalence relations

    International Nuclear Information System (INIS)

    Bouligand, G.M.

    1978-03-01

    We comment on sections paragraph 3 'Correspondences' and paragraph 6 'Equivalence Relations' in chapter II of 'Elements de mathematique' by N. Bourbaki in order to simplify their comprehension. Paragraph 3 exposes the ideas of a graph, correspondence and map or of function, and their composition laws. We draw attention to the following points: 1) Adopting the convention of writting from left to right, the composition law for two correspondences (A,F,B), (U,G,V) of graphs F, G is written in full generality (A,F,B)o(U,G,V) = (A,FoG,V). It is not therefore assumed that the co-domain B of the first correspondence is identical to the domain U of the second (EII.13 D.7), (1970). 2) The axiom of choice consists of creating the Hilbert terms from the only relations admitting a graph. 3) The statement of the existence theorem of a function h such that f = goh, where f and g are two given maps having the same domain (of definition), is completed if h is more precisely an injection. Paragraph 6 considers the generalisation of equality: First, by 'the equivalence relation associated with a map f of a set E identical to (x is a member of the set E and y is a member of the set E and x:f = y:f). Consequently, every relation R(x,y) which is equivalent to this is an equivalence relation in E (symmetrical, transitive, reflexive); then R admits a graph included in E x E, etc. Secondly, by means of the Hilbert term of a relation R submitted to the equivalence. In this last case, if R(x,y) is separately collectivizing in x and y, theta(x) is not the class of objects equivalent to x for R (EII.47.9), (1970). The interest of bringing together these two subjects, apart from this logical order, resides also in the fact that the theorem mentioned in 3) can be expressed by means of the equivalence relations associated with the functions f and g. The solutions of the examples proposed reveal their simplicity [fr

  4. The equivalence theorem

    International Nuclear Information System (INIS)

    Veltman, H.

    1990-01-01

    The equivalence theorem states that, at an energy E much larger than the vector-boson mass M, the leading order of the amplitude with longitudinally polarized vector bosons on mass shell is given by the amplitude in which these vector bosons are replaced by the corresponding Higgs ghosts. We prove the equivalence theorem and show its validity in every order in perturbation theory. We first derive the renormalized Ward identities by using the diagrammatic method. Only the Feynman-- 't Hooft gauge is discussed. The last step of the proof includes the power-counting method evaluated in the large-Higgs-boson-mass limit, needed to estimate the leading energy behavior of the amplitudes involved. We derive expressions for the amplitudes involving longitudinally polarized vector bosons for all orders in perturbation theory. The fermion mass has not been neglected and everything is evaluated in the region m f ∼M much-lt E much-lt m Higgs

  5. Equivalence, commensurability, value

    DEFF Research Database (Denmark)

    Albertsen, Niels

    2017-01-01

    Deriving value in Capital Marx uses three commensurability arguments (CA1-3). CA1 establishes equivalence in exchange as exchangeability with the same third commodity. CA2 establishes value as common denominator in commodities: embodied abstract labour. CA3 establishes value substance...... as commonality of labour: physiological labour. Tensions between these logics have permeated Marxist interpretations of value. Some have supported value as embodied labour (CA2, 3), others a monetary theory of value and value as ‘pure’ societal abstraction (ultimately CA1). They all are grounded in Marx....

  6. Increased Levels of Oxidative Stress Markers, Soluble CD40 Ligand, and Carotid Intima-Media Thickness Reflect Acceleration of Atherosclerosis in Male Patients with Ankylosing Spondylitis in Active Phase and without the Classical Cardiovascular Risk Factors

    Directory of Open Access Journals (Sweden)

    Agata Stanek

    2017-01-01

    Full Text Available Objective. The primary aim of the study was to assess levels of oxidative stress markers, soluble CD40 ligand (sCD40L, serum pregnancy-associated plasma protein-A (PAPP-A, and placental growth factor (PlGF as well as carotid intima-media thickness (IMT in patients with ankylosing spondylitis (AS with active phase without concomitant classical cardiovascular risk factors. Material and methods. The observational study involved 96 male subjects: 48 AS patients and 48 healthy ones, who did not differ significantly regarding age, BMI, comorbid disorders, and distribution of classical cardiovascular risk factors. In both groups, we estimated levels of oxidative stress markers, lipid profile, and inflammation parameters as well as sCD40L, serum PAPP-A, and PlGF. In addition, we estimated carotid IMT in each subject. Results. The study showed that markers of oxidative stress, lipid profile, and inflammation, as well as sCD40L, PlGF, and IMT, were significantly higher in the AS group compared to the healthy group. Conclusion. Our results demonstrate that ankylosing spondylitis may be associated with increased risk for atherosclerosis.

  7. Waste Determination Equivalency - 12172

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, Rebecca D. [Savannah River Remediation (United States)

    2012-07-01

    by the Secretary of Energy in January of 2006 based on proposed processing techniques with the expectation that it could be revised as new processing capabilities became viable. Once signed, however, it became evident that any changes would require lengthy review and another determination signed by the Secretary of Energy. With the maturation of additional salt removal technologies and the extension of the SWPF start-up date, it becomes necessary to define 'equivalency' to the processes laid out in the original determination. For the purposes of SRS, any waste not processed through Interim Salt Processing must be processed through SWPF or an equivalent process, and therefore a clear statement of the requirements for a process to be equivalent to SWPF becomes necessary. (authors)

  8. Establishing Substantial Equivalence: Proteomics

    Science.gov (United States)

    Lovegrove, Alison; Salt, Louise; Shewry, Peter R.

    Wheat is a major crop in world agriculture and is consumed after processing into a range of food products. It is therefore of great importance to determine the consequences (intended and unintended) of transgenesis in wheat and whether genetically modified lines are substantially equivalent to those produced by conventional plant breeding. Proteomic analysis is one of several approaches which can be used to address these questions. Two-dimensional PAGE (2D PAGE) remains the most widely available method for proteomic analysis, but is notoriously difficult to reproduce between laboratories. We therefore describe methods which have been developed as standard operating procedures in our laboratory to ensure the reproducibility of proteomic analyses of wheat using 2D PAGE analysis of grain proteins.

  9. Quantification of the equivalence principle

    International Nuclear Information System (INIS)

    Epstein, K.J.

    1978-01-01

    Quantitative relationships illustrate Einstein's equivalence principle, relating it to Newton's ''fictitious'' forces arising from the use of noninertial frames, and to the form of the relativistic time dilatation in local Lorentz frames. The equivalence principle can be interpreted as the equivalence of general covariance to local Lorentz covariance, in a manner which is characteristic of Riemannian and pseudo-Riemannian geometries

  10. Efficient one-pot sonochemical synthesis of thickness-controlled silica-coated superparamagnetic iron oxide (Fe3O4/SiO2) nanospheres

    Science.gov (United States)

    Abbas, Mohamed; Abdel-Hamed, M. O.; Chen, Jiangang

    2017-12-01

    A facile and eco-friendly efficient sonochemical approach was designed for the synthesis of highly crystalline Fe3O4 and Fe3O4/SiO2 core/shell nanospheres in single reaction. The generated physical properties (shock waves, microjets, and turbulent flows) from ultrasonication as a consequence of the collapse of microbubbles and polyvinylpyrrolidone (PVP) as a chemical linker were found to play a crucial role in the successful formation of the core/shell NPs within short time than the previously reported methods. Transmission electron microscopy revealed that a uniform SiO2 shell is successfully coated over Fe3O4 nanospheres, and the thickness of the silica shell could be easily controlled in the range from 5 to 15 nm by adjusting the reaction parameters. X-ray diffraction data were employed to confirm the formation of highly crystalline and pure phase of a cubic inverse spinel structure for magnetite (Fe3O4) nanospheres. The magnetic properties of the as-synthesized Fe3O4 and Fe3O4/SiO2 core/shell nanospheres were measured at room temperature using vibrating sample magnetometer, and the results demonstrated a high magnetic moment values with superparamagnetic properties.

  11. New recommendations for dose equivalent

    International Nuclear Information System (INIS)

    Bengtsson, G.

    1985-01-01

    In its report 39, the International Commission on Radiation Units and Measurements (ICRU), has defined four new quantities for the determination of dose equivalents from external sources: the ambient dose equivalent, the directional dose equivalent, the individual dose equivalent, penetrating and the individual dose equivalent, superficial. The rationale behind these concepts and their practical application are discussed. Reference is made to numerical values of these quantities which will be the subject of a coming publication from the International Commission on Radiological Protection, ICRP. (Author)

  12. System equivalent model mixing

    Science.gov (United States)

    Klaassen, Steven W. B.; van der Seijs, Maarten V.; de Klerk, Dennis

    2018-05-01

    This paper introduces SEMM: a method based on Frequency Based Substructuring (FBS) techniques that enables the construction of hybrid dynamic models. With System Equivalent Model Mixing (SEMM) frequency based models, either of numerical or experimental nature, can be mixed to form a hybrid model. This model follows the dynamic behaviour of a predefined weighted master model. A large variety of applications can be thought of, such as the DoF-space expansion of relatively small experimental models using numerical models, or the blending of different models in the frequency spectrum. SEMM is outlined, both mathematically and conceptually, based on a notation commonly used in FBS. A critical physical interpretation of the theory is provided next, along with a comparison to similar techniques; namely DoF expansion techniques. SEMM's concept is further illustrated by means of a numerical example. It will become apparent that the basic method of SEMM has some shortcomings which warrant a few extensions to the method. One of the main applications is tested in a practical case, performed on a validated benchmark structure; it will emphasize the practicality of the method.

  13. Comparison of the Pulmonary Oxidative Stress Caused by Intratracheal Instillation and Inhalation of NiO Nanoparticles when Equivalent Amounts of NiO Are Retained in the Lung

    Directory of Open Access Journals (Sweden)

    Masanori Horie

    2016-01-01

    Full Text Available NiO nanoparticles were administered to rat lungs via intratracheal instillation or inhalation. During pulmonary toxicity caused by NiO nanoparticles, the induction of oxidative stress is a major factor. Both intratracheal instillation and inhalation of NiO nanoparticles induced pulmonary oxidative stress. The oxidative stress response protein, heme oxygenase-1 (HO-1, was induced by the administration of NiO nanoparticles at both the protein and gene expression level. Additionally, certain oxidative-stress markers in the lung, such as 8-iso-prostaglandin F2α, thioredoxin, and inducible nitric oxide synthase were increased. Furthermore, the concentration of myeloperoxidase (MPO in the lung was also increased by the administration of NiO nanoparticles. When the amount of NiO in the lung is similar, the responses against pulmonary oxidative stress of intratracheal instillation and inhalation are also similar. However, the state of pulmonary oxidative stress in the early phase was different between intratracheal instillation and inhalation, even if the amount of NiO in the lung was similar. Inhalation causes milder oxidative stress than that caused by intratracheal instillation. On evaluation of the nanoparticle-induced pulmonary oxidative stress in the early phase, we should understand the different states of oxidative stress induced by intratracheal instillation and inhalation.

  14. The equivalence principle

    International Nuclear Information System (INIS)

    Smorodinskij, Ya.A.

    1980-01-01

    The prerelativistic history of the equivalence principle (EP) is presented briefly. Its role in history of the general relativity theory (G.R.T.) discovery is elucidated. A modern idea states that the ratio of inert and gravitational masses does not differ from 1 at least up to the 12 sign after comma. Attention is paid to the difference of the gravitational field from electromagnetic one. The difference is as follows, the energy of the gravitational field distributed in space is the source of the field. These fields always interact at superposition. Electromagnetic fields from different sources are put together. On the basis of EP it is established the Sun field interact with the Earth gravitational energy in the same way as with any other one. The latter proves the existence of gravitation of the very gravitational field to a heavy body. A problem on gyroscope movement in the Earth gravitational field is presented as a paradox. The calculation has shown that gyroscope at satellite makes a positive precession, and its axis turns in an angle equal to α during a turn of the satellite round the Earth, but because of the space curvature - into the angle two times larger than α. A resulting turn is equal to 3α. It is shown on the EP basis that the polarization plane in any coordinate system does not turn when the ray of light passes in the gravitational field. Together with the historical value of EP noted is the necessity to take into account the requirements claimed by the EP at description of the physical world

  15. Logically automorphically equivalent knowledge bases

    OpenAIRE

    Aladova, Elena; Plotkin, Tatjana

    2017-01-01

    Knowledge bases theory provide an important example of the field where applications of universal algebra and algebraic logic look very natural, and their interaction with practical problems arising in computer science might be very productive. In this paper we study the equivalence problem for knowledge bases. Our interest is to find out how the informational equivalence is related to the logical description of knowledge. Studying various equivalences of knowledge bases allows us to compare d...

  16. Testing statistical hypotheses of equivalence

    CERN Document Server

    Wellek, Stefan

    2010-01-01

    Equivalence testing has grown significantly in importance over the last two decades, especially as its relevance to a variety of applications has become understood. Yet published work on the general methodology remains scattered in specialists' journals, and for the most part, it focuses on the relatively narrow topic of bioequivalence assessment.With a far broader perspective, Testing Statistical Hypotheses of Equivalence provides the first comprehensive treatment of statistical equivalence testing. The author addresses a spectrum of specific, two-sided equivalence testing problems, from the

  17. Equivalent Circuit Modeling of the Dielectric Loaded Microwave Biosensor

    Directory of Open Access Journals (Sweden)

    M. T. Jilani

    2014-12-01

    Full Text Available This article describes the modeling of biological tissues at microwave frequency using equivalent lumped elements. A microwave biosensor based on microstrip ring resonator (MRR, that has been utilized previously for meat quality evaluation is used for this purpose. For the first time, the ring-resonator loaded with the lossy and high permittivity dielectric material, such as; biological tissue, in a partial overlay configuration is analyzed. The equivalent circuit modeling of the structure is then performed to identify the effect of overlay thickness on the resonance frequency. Finally, the relationship of an overlay thickness with the corresponding RC values of the meat equivalent circuit is established. Simulated, calculated and measured results are then compared for validation. Results are well agreed while the observed discrepancy is in acceptable limit.

  18. SAPONIFICATION EQUIVALENT OF DASAMULA TAILA

    OpenAIRE

    Saxena, R. B.

    1994-01-01

    Saponification equivalent values of Dasamula taila are very useful for the technical and analytical work. It gives the mean molecular weight of the glycerides and acids present in Dasamula Taila. Saponification equivalent values of Dasamula taila are reported in different packings.

  19. Saponification equivalent of dasamula taila.

    Science.gov (United States)

    Saxena, R B

    1994-07-01

    Saponification equivalent values of Dasamula taila are very useful for the technical and analytical work. It gives the mean molecular weight of the glycerides and acids present in Dasamula Taila. Saponification equivalent values of Dasamula taila are reported in different packings.

  20. A study on lead equivalent

    International Nuclear Information System (INIS)

    Lin Guanxin

    1991-01-01

    A study on the rules in which the lead equivalent of lead glass changes with the energy of X rays or γ ray is described. The reason of this change is discussed and a new testing method of lead equivalent is suggested

  1. Modelling of oxidation and hydriding behaviour of Zircaloy-2 pressure tubes in PHWR

    International Nuclear Information System (INIS)

    Sah, D.N.; Sunil Kumar; Khan, K.B.

    2002-01-01

    A computer model named DOCTOR (Deuteriding of Coolant Tubes during Operation of Reactor) has been developed for predicting the axial profile of oxide thickness and hydrogen (Deuterium) concentration in PHWR pressure tubes. This model is applicable to single channel or full core analysis. The main source of hydrogen is considered to be oxidation of pressure tube on the i.d. surface by high temperature coolant water. Three stages of oxidation is considered namely, pre- transition, post transition and accelerated. Oxidation rate is considered to be dependent on channel power, axial power/flux distribution, coolant temperature and pre-existing oxide thickness at the location. The kinetics parameters for oxidation model are derived from the actual measurement of oxide thickness on a number of pressure tubes examined in PIE Division. The input data required for the model are: channel power, channel power factor, axial flux distribution, coolant inlet temperature, critical oxide thickness, hydrogen pick up fraction, initial hydrogen in the material and time of operation (efpy). The model calculates the oxide layer thickness on the inside surface of the pressure tube along the length. The amount of hydrogen picked up by the pressure tube is calculated from the oxide thickness using hydrogen pick up fraction determined from the PIE data. The pressure tube length is divided into a number of axial segments for calculation. The temperature and fast neutron flux assumed to be constant in a given segment. The axial temperature profile calculated from the axial power profile in the channel is used for calculating the oxidation rate at various locations in the pressure tube. The model has been validated with PIE data of hydrogen equivalent measurement on a number of irradiated Zircaloy-2 pressure tubes of various PHWRs. The performance of the model in predicting the axial profile of hydrogen in the pressure tubes has been found to be good. (author)

  2. Photoprotection by pistachio bioactives in a 3-dimensional human skin equivalent tissue model.

    Science.gov (United States)

    Chen, C-Y Oliver; Smith, Avi; Liu, Yuntao; Du, Peng; Blumberg, Jeffrey B; Garlick, Jonathan

    2017-09-01

    Reactive oxygen species (ROS) generated during ultraviolet (UV) light exposure can induce skin damage and aging. Antioxidants can provide protection against oxidative injury to skin via "quenching" ROS. Using a validated 3-dimensional (3D) human skin equivalent (HSE) tissue model that closely mimics human skin, we examined whether pistachio antioxidants could protect HSE against UVA-induced damage. Lutein and γ-tocopherol are the predominant lipophilic antioxidants in pistachios; treatment with these compounds prior to UVA exposure protected against morphological changes to the epithelial and connective tissue compartments of HSE. Pistachio antioxidants preserved overall skin thickness and organization, as well as fibroblast morphology, in HSE exposed to UVA irradiation. However, this protection was not substantiated by the analysis of the proliferation of keratinocytes and apoptosis of fibroblasts. Additional studies are warranted to elucidate the basis of these discordant results and extend research into the potential role of pistachio bioactives promoting skin health.

  3. Determination of dose equivalent with tissue-equivalent proportional counters

    International Nuclear Information System (INIS)

    Dietze, G.; Schuhmacher, H.; Menzel, H.G.

    1989-01-01

    Low pressure tissue-equivalent proportional counters (TEPC) are instruments based on the cavity chamber principle and provide spectral information on the energy loss of single charged particles crossing the cavity. Hence such detectors measure absorbed dose or kerma and are able to provide estimates on radiation quality. During recent years TEPC based instruments have been developed for radiation protection applications in photon and neutron fields. This was mainly based on the expectation that the energy dependence of their dose equivalent response is smaller than that of other instruments in use. Recently, such instruments have been investigated by intercomparison measurements in various neutron and photon fields. Although their principles of measurements are more closely related to the definition of dose equivalent quantities than those of other existing dosemeters, there are distinct differences and limitations with respect to the irradiation geometry and the determination of the quality factor. The application of such instruments for measuring ambient dose equivalent is discussed. (author)

  4. What is correct: equivalent dose or dose equivalent

    International Nuclear Information System (INIS)

    Franic, Z.

    1994-01-01

    In Croatian language some physical quantities in radiation protection dosimetry have not precise names. Consequently, in practice either terms in English or mathematical formulas are used. The situation is even worse since the Croatian language only a limited number of textbooks, reference books and other papers are available. This paper compares the concept of ''dose equivalent'' as outlined in International Commission on Radiological Protection (ICRP) recommendations No. 26 and newest, conceptually different concept of ''equivalent dose'' which is introduced in ICRP 60. It was found out that Croatian terminology is both not uniform and unprecise. For the term ''dose equivalent'' was, under influence of Russian and Serbian languages, often used as term ''equivalent dose'' even from the point of view of ICRP 26 recommendations, which was not justified. Unfortunately, even now, in Croatia the legal unit still ''dose equivalent'' defined as in ICRP 26, but the term used for it is ''equivalent dose''. Therefore, in Croatian legislation a modified set of quantities introduced in ICRP 60, should be incorporated as soon as possible

  5. Formation of corrosion-resistant oxide film on uranium

    International Nuclear Information System (INIS)

    Petit, G.S.

    1976-01-01

    A vacuum heat-treatment method was developed for coating metallic uranium with an adherent protective film of uranium oxide. The film is prepared by vacuum heat-treating the metallic uranium at 625 0 C for 1 h while controlling the amount of oxygen being metered into the furnace. Uranium coupons with the protective film were exposed for several hundred hours in a corrosion test bath at 95 0 C and 100 percent RH without corroding. Film thicknesses ranging from 5 to 25 μm (0.0002 to 0.001 in.) were prepared and corrosion tested; the film thickness can be controlled to less than +-2.5 μm (+-0.0001 in.). The oxide film is hard, nonwetting, and very adherent. The resulting surface finish of the metal is equivalent to that of the original finish. The advantages of the oxide films over other protective coatings are given. 12 fig

  6. Lead Thickness Measurements

    International Nuclear Information System (INIS)

    Rucinski, R.

    1998-01-01

    The preshower lead thickness applied to the outside of D-Zero's superconducting solenoid vacuum shell was measured at the time of application. This engineering documents those thickness measurements. The lead was ordered in sheets 0.09375-inch and 0.0625-inch thick. The tolerance on thickness was specified to be +/- 0.003-inch. The sheets all were within that thickness tolerance. The nomenclature for each sheet was designated 1T, 1B, 2T, 2B where the numeral designates it's location in the wrap and 'T' or 'B' is short for 'top' or 'bottom' half of the solenoid. Micrometer measurements were taken at six locations around the perimeter of each sheet. The width,length, and weight of each piece was then measured. Using an assumed pure lead density of 0.40974 lb/in 3 , an average sheet thickness was calculated and compared to the perimeter thickness measurements. In every case, the calculated average thickness was a few mils thinner than the perimeter measurements. The ratio was constant, 0.98. This discrepancy is likely due to the assumed pure lead density. It is not felt that the perimeter is thicker than the center regions. The data suggests that the physical thickness of the sheets is uniform to +/- 0.0015-inch.

  7. Education and "Thick" Epistemology

    Science.gov (United States)

    Kotzee, Ben

    2011-01-01

    In this essay Ben Kotzee addresses the implications of Bernard Williams's distinction between "thick" and "thin" concepts in ethics for epistemology and for education. Kotzee holds that, as in the case of ethics, one may distinguish between "thick" and "thin" concepts of epistemology and, further, that this distinction points to the importance of…

  8. Thick film hydrogen sensor

    Science.gov (United States)

    Hoffheins, Barbara S.; Lauf, Robert J.

    1995-01-01

    A thick film hydrogen sensor element includes an essentially inert, electrically-insulating substrate having deposited thereon a thick film metallization forming at least two resistors. The metallization is a sintered composition of Pd and a sinterable binder such as glass frit. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors.

  9. Kinetics and mechanism of the conversion of a coordinated thiol to a coordinated disulfide by the one-equivalent oxidants neptunium(VI) and cobalt(III) in aqueous perchloric acid

    International Nuclear Information System (INIS)

    Woods, M.; Karbwang, J.; Sullivan, J.C.; Deutsch, E.

    1976-01-01

    Reaction of excess (2-mercaptoethylamine-N,S)bis(ethylenediamine)cobalt(III), I, with the 1-equiv oxidant Np(VI) (or Co 3+ (aq)) in aqueous perchloric acid media is shown to lead to (2-aminoethyl-N 2-ammonioethyl disulfide-S 1 ) bis(ethylenediamine)cobalt(III), II, according to the stoichiometry 5H + + 2I + Np(VI) → II + Co 2+ (aq) + Np(V) + 2enH 2 2+ . This reaction follows the rate law -d[I]/dt = k'' [I] [oxidant]. For Np(VI) as oxidant k'' is independent of [H + ]; at 25 0 C, μ = 1.00 M (LiClO 4 ), k'' = k 0 = 2842 +- 15 M -1 s -1 , ΔH 0 * = 7.57 +- 0.08 kcal/mol, and ΔS 0 * = -17.4 +- 0.3 eu. For Co 3+ (aq) as oxidant, k'' = k 0 + k/sub -1/[H + ] -1 where the inverse acid path is taken to reflect oxidation by CoOH 2+ (aq); at 25 0 C, μ = 1.00 M (LiClO 4 ), k 0 = 933 +- 32 M -1 s -1 , k/sub -1/ = 1152 +- 22 s -1 , ΔH 0 * = 12.5 +- 0.7 kcal/mol, ΔH*/sub -1/ = 18.0 +- 0.4 kcal/mol, ΔS 0 *= -3.1 +- 2.4 eu, and ΔS*/sub -1/ = 15.8 +- 1.2 eu. It is proposed that the conversion of I to II proceeds by initial 1-equiv oxidation of the coordinated thiol, reaction of the resultant coordinated thiol radical (RS.) with additional I to form a relatively stable radical ion dimer (RSSR. - ), and then internal electron transfer within the dimer to yield Co 2+ (aq) and II which contains a coordinated disulfide. The possible generality of this mechanism and its relevance to biological metal-thiol-disulfide interactions are noted

  10. A Pilot Study Providing Evidence for a Relationship between a Composite Lifestyle Score and Risk of Higher Carotid Intima-Media Thickness: Is There a Link to Oxidative Stress?

    Directory of Open Access Journals (Sweden)

    Neda Seyedsadjadi

    2018-01-01

    Full Text Available Lifestyle behaviours have been closely linked to the progressive cell damage associated with oxidative stress (OS and the development of cardiovascular disease (CVD. Early detection of lifestyle-linked OS may therefore be useful in the early identification of prodromal disease. To test this hypothesis, this study assessed the relationship between a comprehensive redox balance lifestyle score (RBLS and carotid intima-media thickness (CIMT, a recognized marker for CVD, and plasma biomarkers of OS. In a cross-sectional study design, 100 apparently healthy middle-aged participants were asked to complete a comprehensive lifestyle questionnaire, followed by DXA scanning, CIMT ultrasonography, and blood collection. The RBLS was composed of lifestyle components with pro- and antioxidant properties with a higher score indicative of lower oxidative activity. Multiple linear regression and logistic regression analysis were performed for statistical analysis. The RBLS was significantly associated with the risk for increased CIMT that was independent of conventional CVD risk factors (χ29=35.60, P≤0.001. The adjusted model explained 42.4% of the variance in CIMT. Participants with RBLS below the median were at significantly increased risk of higher CIMT compared to participants with RBLS above the median (OR=3.60, 95% CI: 1.19–10.88, P=0.023. Significant associations were also observed between the RBLS, plasma total antioxidant capacity (TAC (r99=0.28, P=0.006, hydroperoxide (HPX (rs99=−0.28, P=0.005, TAC/HPX ratio (r98=0.41, P≤0.001, γ-glutamyltransferase (r97=−0.23, P=0.024, uric acid (r98=−0.20, P=0.045, and inflammatory C-reactive protein (rs97=−0.25, P=0.012 and interleukin-1β (r97=−0.21, P=0.040. These findings highlight the importance of identifying the collective influence of lifestyle behaviours on OS activity and its potential to remodel the vascular endothelium.

  11. Symmetries of dynamically equivalent theories

    Energy Technology Data Exchange (ETDEWEB)

    Gitman, D.M.; Tyutin, I.V. [Sao Paulo Univ., SP (Brazil). Inst. de Fisica; Lebedev Physics Institute, Moscow (Russian Federation)

    2006-03-15

    A natural and very important development of constrained system theory is a detail study of the relation between the constraint structure in the Hamiltonian formulation with specific features of the theory in the Lagrangian formulation, especially the relation between the constraint structure with the symmetries of the Lagrangian action. An important preliminary step in this direction is a strict demonstration, and this is the aim of the present article, that the symmetry structures of the Hamiltonian action and of the Lagrangian action are the same. This proved, it is sufficient to consider the symmetry structure of the Hamiltonian action. The latter problem is, in some sense, simpler because the Hamiltonian action is a first-order action. At the same time, the study of the symmetry of the Hamiltonian action naturally involves Hamiltonian constraints as basic objects. One can see that the Lagrangian and Hamiltonian actions are dynamically equivalent. This is why, in the present article, we consider from the very beginning a more general problem: how the symmetry structures of dynamically equivalent actions are related. First, we present some necessary notions and relations concerning infinitesimal symmetries in general, as well as a strict definition of dynamically equivalent actions. Finally, we demonstrate that there exists an isomorphism between classes of equivalent symmetries of dynamically equivalent actions. (author)

  12. Retinal sensitivity and choroidal thickness in high myopia.

    Science.gov (United States)

    Zaben, Ahmad; Zapata, Miguel Á; Garcia-Arumi, Jose

    2015-03-01

    To estimate the association between choroidal thickness in the macular area and retinal sensitivity in eyes with high myopia. This investigation was a transversal study of patients with high myopia, all of whom had their retinal sensitivity measured with macular integrity assessment microperimetry. The choroidal thicknesses in the macular area were then measured by optical coherence tomography, and statistical correlations between their functionality and the anatomical structuralism, as assessed by both types of measurements, were analyzed. Ninety-six eyes from 77 patients with high myopia were studied. The patients had a mean age ± standard deviation of 38.9 ± 13.2 years, with spherical equivalent values ranging from -6.00 diopter to -20.00 diopter (8.74 ± 2.73 diopter). The mean central choroidal thickness was 159.00 ± 50.57. The mean choroidal thickness was directly correlated with sensitivity (r = 0.306; P = 0.004) and visual acuity but indirectly correlated with the spherical equivalent values and patient age. The mean sensitivity was not significantly correlated with the macular foveal thickness (r = -0.174; P = 0.101) or with the overall macular thickness (r = 0.103; P = 0.334); furthermore, the mean sensitivity was significantly correlated with visual acuity (r = 0.431; P < 0.001) and the spherical equivalent values (r = -0.306; P = 0.003). Retinal sensitivity in highly myopic eyes is directly correlated with choroidal thickness and does not seem to be associated with retinal thickness. Thus, in patients with high myopia, accurate measurements of choroidal thickness may provide more accurate information about this pathologic condition because choroidal thickness correlates to a greater degree with the functional parameters, patient age, and spherical equivalent values.

  13. Matching of equivalent field regions

    DEFF Research Database (Denmark)

    Appel-Hansen, Jørgen; Rengarajan, S.B.

    2005-01-01

    In aperture problems, integral equations for equivalent currents are often found by enforcing matching of equivalent fields. The enforcement is made in the aperture surface region adjoining the two volumes on each side of the aperture. In the case of an aperture in a planar perfectly conducting...... screen, having the same homogeneous medium on both sides and an impressed current on one aide, an alternative procedure is relevant. We make use of the fact that in the aperture the tangential component of the magnetic field due to the induced currents in the screen is zero. The use of such a procedure...... shows that equivalent currents can be found by a consideration of only one of the two volumes into which the aperture plane divides the space. Furthermore, from a consideration of an automatic matching at the aperture, additional information about tangential as well as normal field components...

  14. Teleparallel equivalent of Lovelock gravity

    Science.gov (United States)

    González, P. A.; Vásquez, Yerko

    2015-12-01

    There is a growing interest in modified gravity theories based on torsion, as these theories exhibit interesting cosmological implications. In this work inspired by the teleparallel formulation of general relativity, we present its extension to Lovelock gravity known as the most natural extension of general relativity in higher-dimensional space-times. First, we review the teleparallel equivalent of general relativity and Gauss-Bonnet gravity, and then we construct the teleparallel equivalent of Lovelock gravity. In order to achieve this goal, we use the vielbein and the connection without imposing the Weitzenböck connection. Then, we extract the teleparallel formulation of the theory by setting the curvature to null.

  15. Attainment of radiation equivalency principle

    International Nuclear Information System (INIS)

    Shmelev, A.N.; Apseh, V.A.

    2004-01-01

    Problems connected with the prospects for long-term development of the nuclear energetics are discussed. Basic principles of the future large-scale nuclear energetics are listed, primary attention is the safety of radioactive waste management of nuclear energetics. The radiation equivalence principle means close of fuel cycle and management of nuclear materials transportation with low losses on spent fuel and waste processing. Two aspects are considered: radiation equivalence in global and local aspects. The necessity of looking for other strategies of fuel cycle management in full-scale nuclear energy on radioactive waste management is supported [ru

  16. Alkynes as Allylmetal Equivalents in Redox-Triggered C–C Couplings to Primary Alcohols: (Z)-Homoallylic Alcohols via Ruthenium-Catalyzed Propargyl C–H Oxidative Addition

    Science.gov (United States)

    2015-01-01

    The cationic ruthenium catalyst generated upon the acid–base reaction of H2Ru(CO)(PPh3)3 and 2,4,6-(2-Pr)3PhSO3H promotes the redox-triggered C–C coupling of 2-alkynes and primary alcohols to form (Z)-homoallylic alcohols with good to complete control of olefin geometry. Deuterium labeling studies, which reveal roughly equal isotopic compositions at the allylic and distal vinylic positions, along with other data, corroborate a catalytic mechanism involving ruthenium(0)-mediated allene–aldehyde oxidative coupling to form a transient oxaruthenacycle, an event that ultimately defines (Z)-olefin stereochemistry. PMID:25075434

  17. Ocean Sediment Thickness Contours

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ocean sediment thickness contours in 200 meter intervals for water depths ranging from 0 - 18,000 meters. These contours were derived from a global sediment...

  18. Comments on field equivalence principles

    DEFF Research Database (Denmark)

    Appel-Hansen, Jørgen

    1987-01-01

    It is pointed Out that often-used arguments based on a short-circuit concept in presentations of field equivalence principles are not correct. An alternative presentation based on the uniqueness theorem is given. It does not contradict the results obtained by using the short-circuit concept...

  19. EQUIVALENCE VERSUS NON-EQUIVALENCE IN ECONOMIC TRANSLATION

    Directory of Open Access Journals (Sweden)

    Cristina, Chifane

    2012-01-01

    Full Text Available This paper aims at highlighting the fact that “equivalence” represents a concept worth revisiting and detailing upon when tackling the translation process of economic texts both from English into Romanian and from Romanian into English. Far from being exhaustive, our analysis will focus upon the problems arising from the lack of equivalence at the word level. Consequently, relevant examples from the economic field will be provided to account for the following types of non-equivalence at word level: culturespecific concepts; the source language concept is not lexicalised in the target language; the source language word is semantically complex; differences in physical and interpersonal perspective; differences in expressive meaning; differences in form; differences in frequency and purpose of using specific forms and the use of loan words in the source text. Likewise, we shall illustrate a number of translation strategies necessary to deal with the afore-mentioned cases of non-equivalence: translation by a more general word (superordinate; translation by a more neutral/less expressive word; translation by cultural substitution; translation using a loan word or loan word plus explanation; translation by paraphrase using a related word; translation by paraphrase using unrelated words; translation by omission and translation by illustration.

  20. The Thickness Dependence of Optical Constants of Ultrathin Iron Films

    International Nuclear Information System (INIS)

    Gao Shang; Lian Jie; Wang Xiao; Li Ping; Sun Xiao-Fen; Li Qing-Hao

    2013-01-01

    Ultrathin iron films with different thicknesses from 7.1 to 51.7 nm are deposited by magnetron sputtering and covered by tantalum layers protecting them from being oxidized. These ultrathin iron films are studied by spectroscopic ellipsometry and transmittance measurement. An extra tantalum film is deposited under the same sputtering conditions and its optical constants and film thickness are obtained by a combination of ellipsometry and transmission measurement. After introducing these obtained optical constants and film thickness into the tantalum-iron film, the optical constants and film thicknesses of ultrathin iron films with different thicknesses are obtained. The results show that combining ellipsometry and transmission measurement improves the uniqueness of the obtained film thickness. The optical constants of ultrathin iron films depend strongly on film thicknesses. There is a broad absorption peak at about 370 nm and it shifts to 410 nm with film thickness decreasing

  1. Determination of equivalent breast phantoms for different age groups of Taiwanese women: An experimental approach

    International Nuclear Information System (INIS)

    Dong, Shang-Lung; Chu, Tieh-Chi; Lin, Yung-Chien; Lan, Gong-Yau; Yeh, Yu-Hsiu; Chen, Sharon; Chuang, Keh-Shih

    2011-01-01

    Purpose: Polymethylmethacrylate (PMMA) slab is one of the mostly used phantoms for studying breast dosimetry in mammography. The purpose of this study was to evaluate the equivalence between exposure factors acquired from PMMA slabs and patient cases of different age groups of Taiwanese women in mammography. Methods: This study included 3910 craniocaudal screen/film mammograms on Taiwanese women acquired on one mammographic unit. The tube loading, compressed breast thickness (CBT), compression force, tube voltage, and target/filter combination for each mammogram were collected for all patients. The glandularity and the equivalent thickness of PMMA were determined for each breast using the exposure factors of the breast in combination with experimental measurements from breast-tissue-equivalent attenuation slabs. Equivalent thicknesses of PMMA to the breasts of Taiwanese women were then estimated. Results: The average ± standard deviation CBT and breast glandularity in this study were 4.2 ± 1.0 cm and 54% ± 23%, respectively. The average equivalent PMMA thickness was 4.0 ± 0.7 cm. PMMA slabs producing equivalent exposure factors as in the breasts of Taiwanese women were determined for the age groups 30-49 yr and 50-69 yr. For the 4-cm PMMA slab, the CBT and glandularity values of the equivalent breast were 4.1 cm and 65%, respectively, for the age group 30-49 yr and 4.4 cm and 44%, respectively, for the age group 50-69 yr. Conclusions: The average thickness of PMMA slabs producing the same exposure factors as observed in a large group of Taiwanese women is less than that reported for American women. The results from this study can provide useful information for determining a suitable thickness of PMMA for mammographic dose survey in Taiwan. The equivalence of PMMA slabs and the breasts of Taiwanese women is provided to allow average glandular dose assessment in clinical practice.

  2. Determination of equivalent breast phantoms for different age groups of Taiwanese women: An experimental approach

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Shang-Lung; Chu, Tieh-Chi; Lin, Yung-Chien; Lan, Gong-Yau; Yeh, Yu-Hsiu; Chen, Sharon; Chuang, Keh-Shih [Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, 101 Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Department of Radiology, Cheng Hsin General Hospital, 45 Cheng Hsin Street, Pai-Tou District, Taipei 11220, Taiwan (China); Department of Medical Imaging and Radiological Sciences, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 80708, Taiwan (China); Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, 101 Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China)

    2011-07-15

    Purpose: Polymethylmethacrylate (PMMA) slab is one of the mostly used phantoms for studying breast dosimetry in mammography. The purpose of this study was to evaluate the equivalence between exposure factors acquired from PMMA slabs and patient cases of different age groups of Taiwanese women in mammography. Methods: This study included 3910 craniocaudal screen/film mammograms on Taiwanese women acquired on one mammographic unit. The tube loading, compressed breast thickness (CBT), compression force, tube voltage, and target/filter combination for each mammogram were collected for all patients. The glandularity and the equivalent thickness of PMMA were determined for each breast using the exposure factors of the breast in combination with experimental measurements from breast-tissue-equivalent attenuation slabs. Equivalent thicknesses of PMMA to the breasts of Taiwanese women were then estimated. Results: The average {+-} standard deviation CBT and breast glandularity in this study were 4.2 {+-} 1.0 cm and 54% {+-} 23%, respectively. The average equivalent PMMA thickness was 4.0 {+-} 0.7 cm. PMMA slabs producing equivalent exposure factors as in the breasts of Taiwanese women were determined for the age groups 30-49 yr and 50-69 yr. For the 4-cm PMMA slab, the CBT and glandularity values of the equivalent breast were 4.1 cm and 65%, respectively, for the age group 30-49 yr and 4.4 cm and 44%, respectively, for the age group 50-69 yr. Conclusions: The average thickness of PMMA slabs producing the same exposure factors as observed in a large group of Taiwanese women is less than that reported for American women. The results from this study can provide useful information for determining a suitable thickness of PMMA for mammographic dose survey in Taiwan. The equivalence of PMMA slabs and the breasts of Taiwanese women is provided to allow average glandular dose assessment in clinical practice.

  3. Validity of the Aluminum Equivalent Approximation in Space Radiation Shielding

    Science.gov (United States)

    Badavi, Francis F.; Adams, Daniel O.; Wilson, John W.

    2009-01-01

    The origin of the aluminum equivalent shield approximation in space radiation analysis can be traced back to its roots in the early years of the NASA space programs (Mercury, Gemini and Apollo) wherein the primary radiobiological concern was the intense sources of ionizing radiation causing short term effects which was thought to jeopardize the safety of the crew and hence the mission. Herein, it is shown that the aluminum equivalent shield approximation, although reasonably well suited for that time period and to the application for which it was developed, is of questionable usefulness to the radiobiological concerns of routine space operations of the 21 st century which will include long stays onboard the International Space Station (ISS) and perhaps the moon. This is especially true for a risk based protection system, as appears imminent for deep space exploration where the long-term effects of Galactic Cosmic Ray (GCR) exposure is of primary concern. The present analysis demonstrates that sufficiently large errors in the interior particle environment of a spacecraft result from the use of the aluminum equivalent approximation, and such approximations should be avoided in future astronaut risk estimates. In this study, the aluminum equivalent approximation is evaluated as a means for estimating the particle environment within a spacecraft structure induced by the GCR radiation field. For comparison, the two extremes of the GCR environment, the 1977 solar minimum and the 2001 solar maximum, are considered. These environments are coupled to the Langley Research Center (LaRC) deterministic ionized particle transport code High charge (Z) and Energy TRaNsport (HZETRN), which propagates the GCR spectra for elements with charges (Z) in the range I aluminum equivalent approximation for a good polymeric shield material such as genetic polyethylene (PE). The shield thickness is represented by a 25 g/cm spherical shell. Although one could imagine the progression to greater

  4. The Source Equivalence Acceleration Method

    International Nuclear Information System (INIS)

    Everson, Matthew S.; Forget, Benoit

    2015-01-01

    Highlights: • We present a new acceleration method, the Source Equivalence Acceleration Method. • SEAM forms an equivalent coarse group problem for any spatial method. • Equivalence is also formed across different spatial methods and angular quadratures. • Testing is conducted using OpenMOC and performance is compared with CMFD. • Results show that SEAM is preferable for very expensive transport calculations. - Abstract: Fine-group whole-core reactor analysis remains one of the long sought goals of the reactor physics community. Such a detailed analysis is typically too computationally expensive to be realized on anything except the largest of supercomputers. Recondensation using the Discrete Generalized Multigroup (DGM) method, though, offers a relatively cheap alternative to solving the fine group transport problem. DGM, however, suffered from inconsistencies when applied to high-order spatial methods. While an exact spatial recondensation method was developed and provided full spatial consistency with the fine group problem, this approach substantially increased memory requirements for realistic problems. The method described in this paper, called the Source Equivalence Acceleration Method (SEAM), forms a coarse-group problem which preserves the fine-group problem even when using higher order spatial methods. SEAM allows recondensation to converge to the fine-group solution with minimal memory requirements and little additional overhead. This method also provides for consistency when using different spatial methods and angular quadratures between the coarse group and fine group problems. SEAM was implemented in OpenMOC, a 2D MOC code developed at MIT, and its performance tested against Coarse Mesh Finite Difference (CMFD) acceleration on the C5G7 benchmark problem and on a 361 group version of the problem. For extremely expensive transport calculations, SEAM was able to outperform CMFD, resulting in speed-ups of 20–45 relative to the normal power

  5. Equivalent statistics and data interpretation.

    Science.gov (United States)

    Francis, Gregory

    2017-08-01

    Recent reform efforts in psychological science have led to a plethora of choices for scientists to analyze their data. A scientist making an inference about their data must now decide whether to report a p value, summarize the data with a standardized effect size and its confidence interval, report a Bayes Factor, or use other model comparison methods. To make good choices among these options, it is necessary for researchers to understand the characteristics of the various statistics used by the different analysis frameworks. Toward that end, this paper makes two contributions. First, it shows that for the case of a two-sample t test with known sample sizes, many different summary statistics are mathematically equivalent in the sense that they are based on the very same information in the data set. When the sample sizes are known, the p value provides as much information about a data set as the confidence interval of Cohen's d or a JZS Bayes factor. Second, this equivalence means that different analysis methods differ only in their interpretation of the empirical data. At first glance, it might seem that mathematical equivalence of the statistics suggests that it does not matter much which statistic is reported, but the opposite is true because the appropriateness of a reported statistic is relative to the inference it promotes. Accordingly, scientists should choose an analysis method appropriate for their scientific investigation. A direct comparison of the different inferential frameworks provides some guidance for scientists to make good choices and improve scientific practice.

  6. Monitoring production target thickness

    International Nuclear Information System (INIS)

    Oothoudt, M.A.

    1993-01-01

    Pion and muon production targets at the Clinton P. Anderson Meson Physics Facility consist of rotating graphite wheels. The previous target thickness monitoring Procedure scanned the target across a reduced intensity beam to determine beam center. The fractional loss in current across the centered target gave a measure of target thickness. This procedure, however, required interruption of beam delivery to experiments and frequently indicated a different fractional loss than at normal beam currents. The new monitoring Procedure compares integrated ups and downs toroid current monitor readings. The current monitors are read once per minute and the integral of readings are logged once per eight-hour shift. Changes in the upstream to downstream fractional difference provide a nonintrusive continuous measurement of target thickness under nominal operational conditions. Target scans are now done only when new targets are installed or when unexplained changes in the current monitor data are observed

  7. 21 CFR 26.9 - Equivalence determination.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Equivalence determination. 26.9 Section 26.9 Food... Specific Sector Provisions for Pharmaceutical Good Manufacturing Practices § 26.9 Equivalence determination... document insufficient evidence of equivalence, lack of opportunity to assess equivalence or a determination...

  8. Information Leakage from Logically Equivalent Frames

    Science.gov (United States)

    Sher, Shlomi; McKenzie, Craig R. M.

    2006-01-01

    Framing effects are said to occur when equivalent frames lead to different choices. However, the equivalence in question has been incompletely conceptualized. In a new normative analysis of framing effects, we complete the conceptualization by introducing the notion of information equivalence. Information equivalence obtains when no…

  9. Wijsman Orlicz Asymptotically Ideal -Statistical Equivalent Sequences

    Directory of Open Access Journals (Sweden)

    Bipan Hazarika

    2013-01-01

    in Wijsman sense and present some definitions which are the natural combination of the definition of asymptotic equivalence, statistical equivalent, -statistical equivalent sequences in Wijsman sense. Finally, we introduce the notion of Cesaro Orlicz asymptotically -equivalent sequences in Wijsman sense and establish their relationship with other classes.

  10. Equivalence relations of AF-algebra extensions

    Indian Academy of Sciences (India)

    In this paper, we consider equivalence relations of *-algebra extensions and describe the relationship between the isomorphism equivalence and the unitary equivalence. We also show that a certain group homomorphism is the obstruction for these equivalence relations to be the same.

  11. Mass thickness measurement of dual-sample by dual-energy X-rays

    International Nuclear Information System (INIS)

    Chen Mincong; Li Hongmei; Chen Ziyu; Shen Ji

    2008-01-01

    X-ray equivalent energy can be used to measure mass thicknesses of materials. Based on this, a method of mass thickness measurement of dual-sample was discussed. It was found that in the range of sample mass thickness under investigation, the equivalent mass attenuation coefficient of a component could be used to compute mass thicknesses of a dual-sample, with relative errors of less than 5%. Mass thickness measurement of a fish sample was performed, and the fish bone and flesh could be displayed separately and clearly by their own mass thicknesses. This indicates that the method is effective in mass thickness measurement of dual-sample of suitable thicknesses. (authors)

  12. Mixed field dose equivalent measuring instruments

    International Nuclear Information System (INIS)

    Brackenbush, L.W.; McDonald, J.C.; Endres, G.W.R.; Quam, W.

    1985-01-01

    In the past, separate instruments have been used to monitor dose equivalent from neutrons and gamma rays. It has been demonstrated that it is now possible to measure simultaneously neutron and gamma dose with a single instrument, the tissue equivalent proportional counter (TEPC). With appropriate algorithms dose equivalent can also be determined from the TEPC. A simple ''pocket rem meter'' for measuring neutron dose equivalent has already been developed. Improved algorithms for determining dose equivalent for mixed fields are presented. (author)

  13. Coating thickness measurement

    International Nuclear Information System (INIS)

    1976-12-01

    The standard specifies measurements of the coating thickness, which make use of beta backscattering and/or x-ray fluorescence. For commonly used combinations of coating material and base material the appropriate measuring ranges and radionuclides to be used are given for continuous as well as for discontinuous measurements

  14. A study on assessment of bone mass from aluminum-equivalent image by digital imaging system

    International Nuclear Information System (INIS)

    Kim, Jin Soo; Kim, Jae Duck; Choi, Eui Hwan

    1997-01-01

    The purpose of this study was to evaluated the method for quantitative assessment of bone mass from aluminum-equivalent value of hydroxyapatite by using digital imaging system consisted of Power Macintosh 7200/120, 15-inch color monitor, and GT-9000 scanner with transparency unit. After aluminum-equivalent image made from correlation between aluminum thickness and grey scale, the accuracy of conversion to mass from aluminum-equivalent value was evaluated. Measured bone mass was compared with converted bone mass from aluminum-equivalent value of hydroxyapatite block by correlation formula between aluminum-equivalent value of hydroxy apatite block and hydroxyapatite mass. The results of this study were as follows : 1. Correlation between aluminum thickness and grey level for obtaining aluminum-equivalent image was high positively associated (r2=0.99). Converted masses from aluminum-equivalent value were very similar to measured masses. There was, statistically, no significant difference (P<0.05) between them. 2. Correlation between hydroxyapatite aluminum-equivalent and hydroxyapatite mass was shown to linear relation (r2 =0.95). 3. Converted masses from aluminum-equivalent value of 3 dry mandible segments were similar to measured masses. The difference between the exposure directions was not significantly different (P<0.05).

  15. Derived equivalences for group rings

    CERN Document Server

    König, Steffen

    1998-01-01

    A self-contained introduction is given to J. Rickard's Morita theory for derived module categories and its recent applications in representation theory of finite groups. In particular, Broué's conjecture is discussed, giving a structural explanation for relations between the p-modular character table of a finite group and that of its "p-local structure". The book is addressed to researchers or graduate students and can serve as material for a seminar. It surveys the current state of the field, and it also provides a "user's guide" to derived equivalences and tilting complexes. Results and proofs are presented in the generality needed for group theoretic applications.

  16. Skin thickness effects on in vivo LXRF

    International Nuclear Information System (INIS)

    Preiss, I.L.; Washington, W. II

    1995-01-01

    The analysis of lead concentration in bone utilizing LXRF can be adversely effected by overlying issue. A quantitative measure of the attenuation of the 10.5 keV Pb L a x-ray signal by skin and skin equivalent plastic has been conducted. Concentration ranges in plaster of Paris and goat bone from 7 to 90 ppm with attenuators of Lucite reg-sign and pig skin were examined. It is concluded that no quantitative or semi quantitative analysis can be achieved if overlying sue thickness exceeds 3 mm for Ph concentrations of less than 30 porn Ph in bone

  17. Calculation methods for determining dose equivalent

    International Nuclear Information System (INIS)

    Endres, G.W.R.; Tanner, J.E.; Scherpelz, R.I.; Hadlock, D.E.

    1987-11-01

    A series of calculations of neutron fluence as a function of energy in an anthropomorphic phantom was performed to develop a system for determining effective dose equivalent for external radiation sources. Critical organ dose equivalents are calculated and effective dose equivalents are determined using ICRP-26 [1] methods. Quality factors based on both present definitions and ICRP-40 definitions are used in the analysis. The results of these calculations are presented and discussed. The effective dose equivalent determined using ICRP-26 methods is significantly smaller than the dose equivalent determined by traditional methods. No existing personnel dosimeter or health physics instrument can determine effective dose equivalent. At the present time, the conversion of dosimeter response to dose equivalent is based on calculations for maximal or ''cap'' values using homogeneous spherical or cylindrical phantoms. The evaluated dose equivalent is, therefore, a poor approximation of the effective dose equivalent as defined by ICRP Publication 26. 3 refs., 2 figs., 1 tab

  18. Synthesis of nanometre-thick MoO3 sheets

    Science.gov (United States)

    Kalantar-Zadeh, Kourosh; Tang, Jianshi; Wang, Minsheng; Wang, Kang L.; Shailos, Alexandros; Galatsis, Kosmas; Kojima, Robert; Strong, Veronica; Lech, Andrew; Wlodarski, Wojtek; Kaner, Richard B.

    2010-03-01

    The formation of MoO3 sheets of nanoscale thickness is described. They are made from several fundamental sheets of orthorhombic α-MoO3, which can be processed in large quantities via a low cost synthesis route that combines thermal evaporation and mechanical exfoliation. These fundamental sheets consist of double-layers of linked distorted MoO6 octahedra. Atomic force microscopy (AFM) measurements show that the minimum resolvable thickness of these sheets is 1.4 nm which is equivalent to the thickness of two double-layers within one unit cell of the α-MoO3 crystal.

  19. Coating thickness measuring device

    International Nuclear Information System (INIS)

    Joffe, B.B.; Sawyer, B.E.; Spongr, J.J.

    1984-01-01

    A device especially adapted for measuring the thickness of coatings on small, complexly-shaped parts, such as, for example, electronic connectors, electronic contacts, or the like. The device includes a source of beta radiation and a radiation detector whereby backscatter of the radiation from the coated part can be detected and the thickness of the coating ascertained. The radiation source and detector are positioned in overlying relationship to the coated part and a microscope is provided to accurately position the device with respect to the part. Means are provided to control the rate of descent of the radiation source and radiation detector from its suspended position to its operating position and the resulting impact it makes with the coated part to thereby promote uniformity of readings from operator to operator, and also to avoid excessive impact with the part, thereby improving accuracy of measurement and eliminating damage to the parts

  20. Editorial: New operational dose equivalent quantities

    International Nuclear Information System (INIS)

    Harvey, J.R.

    1985-01-01

    The ICRU Report 39 entitled ''Determination of Dose Equivalents Resulting from External Radiation Sources'' is briefly discussed. Four new operational dose equivalent quantities have been recommended in ICRU 39. The 'ambient dose equivalent' and the 'directional dose equivalent' are applicable to environmental monitoring and the 'individual dose equivalent, penetrating' and the 'individual dose equivalent, superficial' are applicable to individual monitoring. The quantities should meet the needs of day-to-day operational practice, while being acceptable to those concerned with metrological precision, and at the same time be used to give effective control consistent with current perceptions of the risks associated with exposure to ionizing radiations. (U.K.)

  1. Thick melanoma in Tuscany.

    Science.gov (United States)

    Chiarugi, Alessandra; Nardini, Paolo; Borgognoni, Lorenzo; Brandani, Paola; Gerlini, Gianni; Rubegni, Pietro; Lamberti, Arianna; Salvini, Camilla; Lo Scocco, Giovanni; Cecchi, Roberto; Sirna, Riccardo; Lorenzi, Stefano; Gattai, Riccardo; Battistini, Silvio; Crocetti, Emanuele

    2017-03-14

    The epidemiologic trends of cutaneous melanoma are similar in several countries with a Western-type life style, where there is a progressive increasing incidence and a low but not decreasing mor- tality, or somewhere an increase too, especially in the older age groups. Also in Tuscany there is a steady rise in incidence with prevalence of in situ and invasive thin melanomas, with also an increase of thick melanomas. It is necessary to reduce the frequency of thick melanomas to reduce specific mortality. The objective of the current survey has been to compare, in the Tuscany population, by a case- case study, thin and thick melanoma cases, trying to find out those personal and tumour characteristics which may help to customize preventive interventions. RESULTS The results confirmed the age and the lower edu- cation level are associated with a later detection. The habit to perform skin self-examination is resulted protec- tive forward thick melanoma and also the diagnosis by a doctor. The elements emerging from the survey allow to hypothesize a group of subjects resulting at higher risk for a late diagnosis, aged over 50 and carrier of a fewer constitutional and environmental risk factors: few total and few atypical nevi, and lower sun exposure and burning. It is assumable that a part of people did not be reached from messages of prevention because does not recognize oneself in the categories of people at risk for skin cancers described in educational cam- paigns. If we want to obtain better results on diagnosis of skin melanoma we have to think a new strategy. At least to think over the educational messages discriminating people more at risk of incidence of melanoma from people more at risk to die from melanoma, and to renewed active involvement of the Gen- eral Practitioners .

  2. Thick brane solutions

    International Nuclear Information System (INIS)

    Dzhunushaliev, Vladimir; Minamitsuji, Masato; Folomeev, Vladimir

    2010-01-01

    This paper gives a comprehensive review on thick brane solutions and related topics. Such models have attracted much attention from many aspects since the birth of the brane world scenario. In many works, it has been usually assumed that a brane is an infinitely thin object; however, in more general situations, one can no longer assume this. It is also widely considered that more fundamental theories such as string theory would have a minimal length scale. Many multidimensional field theories coupled to gravitation have exact solutions of gravitating topological defects, which can represent our brane world. The inclusion of brane thickness can realize a variety of possible brane world models. Given our understanding, the known solutions can be classified into topologically non-trivial solutions and trivial ones. The former class contains solutions of a single scalar (domain walls), multi-scalar, gauge-Higgs (vortices), Weyl gravity and so on. As an example of the latter class, we consider solutions of two interacting scalar fields. Approaches to obtain cosmological equations in the thick brane world are reviewed. Solutions with spatially extended branes (S-branes) and those with an extra time-like direction are also discussed.

  3. Nano lead oxide and epdm composite for development of polymer based radiation shielding material: Gamma irradiation and attenuation tests

    Science.gov (United States)

    Özdemir, T.; Güngör, A.; Akbay, I. K.; Uzun, H.; Babucçuoglu, Y.

    2018-03-01

    It is important to have a shielding material that is not easily breaking in order to have a robust product that guarantee the radiation protection of the patients and radiation workers especially during the medical exposure. In this study, nano sized lead oxide (PbO) particles were used, for the first time, to obtain an elastomeric composite material in which lead oxide nanoparticles, after the surface modification with silane binding agent, was used as functional material for radiation shielding. In addition, the composite material including 1%, 5%, 10%, 15% and 20% weight percent nano sized lead oxide was irradiated with doses of 81, 100 and 120 kGy up to an irradiation period of 248 days in a gamma ray source with an initial dose rate of 21.1 Gy/h. Mechanical, thermal properties of the irradiated materials were investigated using DSC, DMA, TGA and tensile testing and modifications in thermal and mechanical properties of the nano lead oxide containing composite material via gamma irradiation were reported. Moreover, effect of bismuth-III oxide addition on radiation attenuation of the composite material was investigated. Nano lead oxide and bismuth-III oxide particles were mixed with different weight ratios. Attenuation tests have been conducted to determine lead equivalent values for the developed composite material. Lead equivalent thickness values from 0.07 to 0.65 (2-6 mm sample thickness) were obtained.

  4. Foreword: Biomonitoring Equivalents special issue.

    Science.gov (United States)

    Meek, M E; Sonawane, B; Becker, R A

    2008-08-01

    The challenge of interpreting results of biomonitoring for environmental chemicals in humans is highlighted in this Foreword to the Biomonitoring Equivalents (BEs) special issue of Regulatory Toxicology and Pharmacology. There is a pressing need to develop risk-based tools in order to empower scientists and health professionals to interpret and communicate the significance of human biomonitoring data. The BE approach, which integrates dosimetry and risk assessment methods, represents an important advancement on the path toward achieving this objective. The articles in this issue, developed as a result of an expert panel meeting, present guidelines for derivation of BEs, guidelines for communication using BEs and several case studies illustrating application of the BE approach for specific substances.

  5. Radiological equivalent of chemical pollutants

    International Nuclear Information System (INIS)

    Medina, V.O.

    1982-01-01

    The development of the peaceful uses of nuclear energy has caused continued effort toward public safety through radiation health protection measures and nuclear management practices. However, concern has not been focused on the development specifically in the operation of chemical pestrochemical industries as well as other industrial processes brought about by technological advancements. This article presents the comparison of the risk of radiation and chemicals. The methods used for comparing the risks of late effects of radiation and chemicals are considered at three levels. (a) as a frame of reference to give an impression of resolving power of biological tests; (b) as methods to quantify risks; (c) as instruments for an epidemiological survey of human populations. There are marked dissimilarities between chemicals and radiation and efforts to interpret chemical activity may not be achieved. Applicability of the concept of rad equivalence has many restrictions and as pointed out this approach is not an established one. (RTD)

  6. Tissue equivalence in neutron dosimetry

    International Nuclear Information System (INIS)

    Nutton, D.H.; Harris, S.J.

    1980-01-01

    A brief review is presented of the essential features of neutron tissue equivalence for radiotherapy and gives the results of a computation of relative absorbed dose for 14 MeV neutrons, using various tissue models. It is concluded that for the Bragg-Gray equation for ionometric dosimetry it is not sufficient to define the value of W to high accuracy and that it is essential that, for dosimetric measurements to be applicable to real body tissue to an accuracy of better than several per cent, a correction to the total absorbed dose must be made according to the test and tissue atomic composition, although variations in patient anatomy and other radiotherapy parameters will often limit the benefits of such detailed dosimetry. (U.K.)

  7. Expanding the Interaction Equivalency Theorem

    Directory of Open Access Journals (Sweden)

    Brenda Cecilia Padilla Rodriguez

    2015-06-01

    Full Text Available Although interaction is recognised as a key element for learning, its incorporation in online courses can be challenging. The interaction equivalency theorem provides guidelines: Meaningful learning can be supported as long as one of three types of interactions (learner-content, learner-teacher and learner-learner is present at a high level. This study sought to apply this theorem to the corporate sector, and to expand it to include other indicators of course effectiveness: satisfaction, knowledge transfer, business results and return on expectations. A large Mexican organisation participated in this research, with 146 learners, 30 teachers and 3 academic assistants. Three versions of an online course were designed, each emphasising a different type of interaction. Data were collected through surveys, exams, observations, activity logs, think aloud protocols and sales records. All course versions yielded high levels of effectiveness, in terms of satisfaction, learning and return on expectations. Yet, course design did not dictate the types of interactions in which students engaged within the courses. Findings suggest that the interaction equivalency theorem can be reformulated as follows: In corporate settings, an online course can be effective in terms of satisfaction, learning, knowledge transfer, business results and return on expectations, as long as (a at least one of three types of interaction (learner-content, learner-teacher or learner-learner features prominently in the design of the course, and (b course delivery is consistent with the chosen type of interaction. Focusing on only one type of interaction carries a high risk of confusion, disengagement or missed learning opportunities, which can be managed by incorporating other forms of interactions.

  8. Equivalent damage of loads on pavements

    CSIR Research Space (South Africa)

    Prozzi, JA

    2009-05-26

    Full Text Available This report describes a new methodology for the determination of Equivalent Damage Factors (EDFs) of vehicles with multiple axle and wheel configurations on pavements. The basic premise of this new procedure is that "equivalent pavement response...

  9. Investigation of Equivalent Circuit for PEMFC Assessment

    International Nuclear Information System (INIS)

    Myong, Kwang Jae

    2011-01-01

    Chemical reactions occurring in a PEMFC are dominated by the physical conditions and interface properties, and the reactions are expressed in terms of impedance. The performance of a PEMFC can be simply diagnosed by examining the impedance because impedance characteristics can be expressed by an equivalent electrical circuit. In this study, the characteristics of a PEMFC are assessed using the AC impedance and various equivalent circuits such as a simple equivalent circuit, equivalent circuit with a CPE, equivalent circuit with two RCs, and equivalent circuit with two CPEs. It was found in this study that the characteristics of a PEMFC could be assessed using impedance and an equivalent circuit, and the accuracy was highest for an equivalent circuit with two CPEs

  10. 46 CFR 175.540 - Equivalents.

    Science.gov (United States)

    2010-10-01

    ... Safety Management (ISM) Code (IMO Resolution A.741(18)) for the purpose of determining that an equivalent... Organization (IMO) “Code of Safety for High Speed Craft” as an equivalent to compliance with applicable...

  11. Numerical Simulation on Open Wellbore Shrinkage and Casing Equivalent Stress in Bedded Salt Rock Stratum

    Directory of Open Access Journals (Sweden)

    Jianjun Liu

    2013-01-01

    Full Text Available Most salt rock has interbed of mudstone in China. Owing to the enormous difference of mechanical properties between the mudstone interbed and salt rock, the stress-strain and creep behaviors of salt rock are significantly influenced by neighboring mudstone interbed. In order to identify the rules of wellbore shrinkage and casings equivalent stress in bedded salt rock stratum, three-dimensional finite difference models were established. The effects of thickness and elasticity modulus of mudstone interbed on the open wellbore shrinkage and equivalent stress of casing after cementing operation were studied, respectively. The results indicate that the shrinkage of open wellbore and equivalent stress of casings decreases with the increase of mudstone interbed thickness. The increasing of elasticity modulus will reduce the shrinkage of open wellbore and casing equivalent stress. Research results can provide the scientific basis for the design of mud density and casing strength.

  12. Model for thickness dependence of radiation charging in MOS structures

    Science.gov (United States)

    Viswanathan, C. R.; Maserjian, J.

    1976-01-01

    The model considers charge buildup in MOS structures due to hole trapping in the oxide and the creation of sheet charge at the silicon interface. The contribution of hole trapping causes the flatband voltage to increase with thickness in a manner in which square and cube dependences are limiting cases. Experimental measurements on samples covering a 200 - 1000 A range of oxide thickness are consistent with the model, using independently obtained values of hole-trapping parameters. An important finding of our experimental results is that a negative interface charge contribution due to surface states created during irradiation compensates most of the positive charge in the oxide at flatband. The tendency of the surface states to 'track' the positive charge buildup in the oxide, for all thicknesses, applies both in creation during irradiation and in annihilation during annealing. An explanation is proposed based on the common defect origin of hole traps and potential surface states.

  13. Some spectral equivalences between Schroedinger operators

    International Nuclear Information System (INIS)

    Dunning, C; Hibberd, K E; Links, J

    2008-01-01

    Spectral equivalences of the quasi-exactly solvable sectors of two classes of Schroedinger operators are established, using Gaudin-type Bethe ansatz equations. In some instances the results can be extended leading to full isospectrality. In this manner we obtain equivalences between PT-symmetric problems and Hermitian problems. We also find equivalences between some classes of Hermitian operators

  14. The definition of the individual dose equivalent

    International Nuclear Information System (INIS)

    Ehrlich, Margarete

    1986-01-01

    A brief note examines the choice of the present definition of the individual dose equivalent, the new operational dosimetry quantity for external exposure. The consequences of the use of the individual dose equivalent and the danger facing the individual dose equivalent, as currently defined, are briefly discussed. (UK)

  15. Full reflector thickness and isolation thickness on neutron transport

    International Nuclear Information System (INIS)

    Sakai, Tomohiro; Naito, Yoshitaka; Komuro, Yuichi.

    1988-08-01

    A method to determine ''full reflector thickness'' and ''isolation thickness'', which is utilized for criticality safety evaluation on nuclear fuel facilities, was proposed in this paper. Firstly, a calculation was tryed to obtain the two kinds of thicknesses from the result of criticality calculations for a specific case. Then, two simple equations which calculates the two kinds of thicknesses were made from the relation between reflector (or isolator) thickness and k eff , and one-group diffusion theory. Finally, we proposed a new method to determine the thicknesses. From the method we proposed, ''full reflector thickness'' and ''isolation thickness'' can be obtain using the equations and migration length of the reflector (or isolator) and infinite and effective multiplication factor of the fuel. (author)

  16. The lead equivalence of plate glass for diagnostic x-rays

    International Nuclear Information System (INIS)

    Young, B.F.; Morris, N.D.

    1983-01-01

    The effectiveness of plate glass as a radiation protection barrier was determined. For x ray energies between 80 and 140 kVp, the lead equivalence of plate glass is energy independent, but below 80 kVp there is an apparent dependence. A thickness of plate glass of 25 mm for radiation energies between 80 and 140 kVp is equivalent to lead of .3mm thickness. There could be a limited application for the use of plate glass in viewing panels

  17. Interocular Symmetry in Macular Choroidal Thickness in Children

    Directory of Open Access Journals (Sweden)

    Christiane Al-Haddad

    2014-01-01

    Full Text Available Objective. To report interocular differences in choroidal thickness in children using spectral domain optical coherence tomography (SD-OCT and correlate findings with biometric data. Methods. This observational cross-sectional study included 91 (182 eyes healthy children aged 6 to 17 years with no ocular abnormality except refractive error. After a comprehensive eye exam and axial length measurement, high definition macular scans were performed using SD-OCT. Two observers manually measured the choroidal thickness at the foveal center and at 1500 µm nasally, temporally, inferiorly, and superiorly. Interocular differences were computed; correlations with age, gender, refractive error, and axial length were performed. Results. Mean age was 10.40 ± 3.17 years; mean axial length and refractive error values were similar between fellow eyes. There was excellent correlation between the two observers’ measurements. No significant interocular differences were observed at any location. There was only a trend for right eyes to have higher values in all thicknesses, except the superior thickness. Most of the choroidal thickness measurements correlated positively with spherical equivalent but not with axial length, age, or gender. Conclusion. Choroidal thickness measurements in children as performed using SD-OCT revealed a high level of interobserver agreement and consistent interocular symmetry. Values correlated positively with spherical equivalent refraction.

  18. Interocular symmetry in macular choroidal thickness in children.

    Science.gov (United States)

    Al-Haddad, Christiane; El Chaar, Lama; Antonios, Rafic; El-Dairi, Mays; Noureddin, Baha'

    2014-01-01

    Objective. To report interocular differences in choroidal thickness in children using spectral domain optical coherence tomography (SD-OCT) and correlate findings with biometric data. Methods. This observational cross-sectional study included 91 (182 eyes) healthy children aged 6 to 17 years with no ocular abnormality except refractive error. After a comprehensive eye exam and axial length measurement, high definition macular scans were performed using SD-OCT. Two observers manually measured the choroidal thickness at the foveal center and at 1500 µm nasally, temporally, inferiorly, and superiorly. Interocular differences were computed; correlations with age, gender, refractive error, and axial length were performed. Results. Mean age was 10.40 ± 3.17 years; mean axial length and refractive error values were similar between fellow eyes. There was excellent correlation between the two observers' measurements. No significant interocular differences were observed at any location. There was only a trend for right eyes to have higher values in all thicknesses, except the superior thickness. Most of the choroidal thickness measurements correlated positively with spherical equivalent but not with axial length, age, or gender. Conclusion. Choroidal thickness measurements in children as performed using SD-OCT revealed a high level of interobserver agreement and consistent interocular symmetry. Values correlated positively with spherical equivalent refraction.

  19. Examination of optimal radiation quality in the lead equivalent examination of x-ray protective clothing

    International Nuclear Information System (INIS)

    Inoue, Shinichi; Matsuzawa, Rie; Matsumoto, Mitsuhiro

    2004-01-01

    The objective of this study was to determine the effective lead thickness of the apron for radiation protective clothing, i.e., the lead equivalent, a method of performing the lead equivalent examination is provided in the Japanese Industrial Standards (JIS). We proposed a method of computation using an attenuation coefficient, and examined the measurement accuracy and optimal radiation quality using both. We were able to compute the lead equivalent with sufficient accuracy when using radiation quality of about 60 keV in the range of radiation quality examined. This technique was also examined in the measurement used for the marketing of radiation protective clothing. (author)

  20. Radioactive thickness gauge (1962)

    International Nuclear Information System (INIS)

    Guizerix, J.

    1962-01-01

    The author describes a thickness gauge in which the scintillating crystal detector alternately 'sees' a radioactive source through the material which is to be measured and then a control source of the same material; the radiations are separated in time by an absorbing valve whose sections are alternately full and hollow. The currents corresponding to the two sources are separated beyond the photomultiplier tube by a detector synchronized with the rotation of the valve. The quotient of these two currents is then obtained with a standard recording potentiometer. It is found that the average value of the response which is in the form G = f(I 1 /I 2 ) is not affected by decay of the radioactive sources, and that it is little influenced by variations of high tension, temperature, or properties of the air in the source detector interval. The performance of the gauge is given. (author) [fr

  1. Thick-Big Descriptions

    DEFF Research Database (Denmark)

    Lai, Signe Sophus

    The paper discusses the rewards and challenges of employing commercial audience measurements data – gathered by media industries for profitmaking purposes – in ethnographic research on the Internet in everyday life. It questions claims to the objectivity of big data (Anderson 2008), the assumption...... communication systems, language and behavior appear as texts, outputs, and discourses (data to be ‘found’) – big data then documents things that in earlier research required interviews and observations (data to be ‘made’) (Jensen 2014). However, web-measurement enterprises build audiences according...... to a commercial logic (boyd & Crawford 2011) and is as such directed by motives that call for specific types of sellable user data and specific segmentation strategies. In combining big data and ‘thick descriptions’ (Geertz 1973) scholars need to question how ethnographic fieldwork might map the ‘data not seen...

  2. Disentangling The Thick Concept Argument

    DEFF Research Database (Denmark)

    Blomberg, Olle

    2007-01-01

    Critics argue that non-cognitivism cannot adequately account for the existence and nature of some thick moral concepts. They use the existence of thick concepts as a lever in an argument against non-cognitivism, here called the Thick Concept Argument (TCA). While TCA is frequently invoked...

  3. Construction of a self-supporting tissue-equivalent dividing wall and operational characteristics of a coaxial double-cylindrical tissue-equivalent proportional counter

    International Nuclear Information System (INIS)

    Saion, E.B.; Watt, D.E.

    1994-01-01

    An additional feature incorporated in a coaxial double-cylindrical tissue-equivalent proportional counter, is the presence of a common tissue-equivalent dividing wall between the inner and outer counters of thickness equivalent to the corresponding maximum range of protons at the energy of interest. By appropriate use of an anti-coincidence arrangement with the outer counter, the inner counter could be used to discriminate microdosimetric spectra of neutrons at the desired low energy range from those of the faster neutrons. The construction of an A-150 self-supporting tissue-equivalent dividing wall and an anti-coincidence unit are described. Some operational characteristic tests have been performed to determine the operation of the new microdosimeter. (author)

  4. Improvement of the equivalent sphere model for better estimates of skin or eye dose in space radiation environments

    International Nuclear Information System (INIS)

    Lin, Z.W.

    2011-01-01

    It is often useful to get a quick estimate of the dose or dose equivalent of an organ, such as blood-forming organs, the eye or the skin, in a radiation field. Sometimes an equivalent sphere is used to represent the organ for this purpose. For space radiation environments, recently it has been shown that the equivalent sphere model does not work for the eye or the skin in solar particle event environments. In this study, we improve the representation of the eye and the skin using a two-component equivalent sphere model. Motivated by the two-peak structure of the body organ shielding distribution for the eye and the skin, we use an equivalent sphere with two radius parameters, for example a partial spherical shell of a smaller thickness over a proper fraction of the full solid angle combined with a concentric partial spherical shell of a larger thickness over the rest of the full solid angle, to represent the eye or the skin. We find that using an equivalent sphere with two radius parameters instead of one drastically improves the accuracy of the estimates of dose and dose equivalent in space radiation environments. For example, in solar particle event environments the average error in the estimate of the skin dose equivalent using an equivalent sphere with two radius parameters is about 8%, while the average error of the conventional equivalent sphere model using one radius parameter is around 100%.

  5. The Complexity of Identifying Large Equivalence Classes

    DEFF Research Database (Denmark)

    Skyum, Sven; Frandsen, Gudmund Skovbjerg; Miltersen, Peter Bro

    1999-01-01

    We prove that at least 3k−4/k(2k−3)(n/2) – O(k)equivalence tests and no more than 2/k (n/2) + O(n) equivalence tests are needed in the worst case to identify the equivalence classes with at least k members in set of n elements. The upper bound is an improvement by a factor 2 compared to known res...

  6. Equivalent Simplification Method of Micro-Grid

    OpenAIRE

    Cai Changchun; Cao Xiangqin

    2013-01-01

    The paper concentrates on the equivalent simplification method for the micro-grid system connection into distributed network. The equivalent simplification method proposed for interaction study between micro-grid and distributed network. Micro-grid network, composite load, gas turbine synchronous generation, wind generation are equivalent simplification and parallel connect into the point of common coupling. A micro-grid system is built and three phase and single phase grounded faults are per...

  7. Calculation methods for determining dose equivalent

    International Nuclear Information System (INIS)

    Endres, G.W.R.; Tanner, J.E.; Scherpelz, R.I.; Hadlock, D.E.

    1988-01-01

    A series of calculations of neutron fluence as a function of energy in an anthropomorphic phantom was performed to develop a system for determining effective dose equivalent for external radiation sources. critical organ dose equivalents are calculated and effective dose equivalents are determined using ICRP-26 methods. Quality factors based on both present definitions and ICRP-40 definitions are used in the analysis. The results of these calculations are presented and discussed

  8. Equivalences of real submanifolds in complex space.

    OpenAIRE

    ZAITSEV, DMITRI

    2001-01-01

    PUBLISHED We show that for any real-analytic submanifold M in CN there is a proper real-analytic subvariety V contained in M such that for any p ? M \\ V , any real-analytic submanifold M? in CN, and any p? ? M?, the germs of the submanifolds M and M? at p and p? respectively are formally equivalent if and only if they are biholomorphically equivalent. More general results for k-equivalences are also stated and proved.

  9. Relations of equivalence of conditioned radioactive waste

    International Nuclear Information System (INIS)

    Kumer, L.; Szeless, A.; Oszuszky, F.

    1982-01-01

    A compensation for the wastes remaining with the operator of a waste management center, to be given by the agent having caused the waste, may be assured by effecting a financial valuation (equivalence) of wastes. Technically and logically, this equivalence between wastes (or specifically between different waste categories) and financial valuation has been established as reasonable. In this paper, the possibility of establishing such equivalences are developed, and their suitability for waste management concepts is quantitatively expressed

  10. Behavioural equivalence for infinite systems - Partially decidable!

    DEFF Research Database (Denmark)

    Sunesen, Kim; Nielsen, Mogens

    1996-01-01

    languages with two generalizations based on traditional approaches capturing non-interleaving behaviour, pomsets representing global causal dependency, and locality representing spatial distribution of events. We first study equivalences on Basic Parallel Processes, BPP, a process calculus equivalent...... of processes between BPP and TCSP, not only are the two equivalences different, but one (locality) is decidable whereas the other (pomsets) is not. The decidability result for locality is proved by a reduction to the reachability problem for Petri nets....

  11. Equivalence in Bilingual Lexicography: Criticism and Suggestions*

    Directory of Open Access Journals (Sweden)

    Herbert Ernst Wiegand

    2011-10-01

    Full Text Available

    Abstract: A reminder of general problems in the formation of terminology, as illustrated by theGerman Äquivalence (Eng. equivalence and äquivalent (Eng. equivalent, is followed by a critical discussionof the concept of equivalence in contrastive lexicology. It is shown that especially the conceptof partial equivalence is contradictory in its different manifestations. Consequently attemptsare made to give a more precise indication of the concept of equivalence in the metalexicography,with regard to the domain of the nominal lexicon. The problems of especially the metalexicographicconcept of partial equivalence as well as that of divergence are fundamentally expounded.In conclusion the direction is indicated to find more appropriate metalexicographic versions of theconcept of equivalence.

    Keywords: EQUIVALENCE, LEXICOGRAPHIC EQUIVALENT, PARTIAL EQUIVALENCE,CONGRUENCE, DIVERGENCE, CONVERGENCE, POLYDIVERGENCE, SYNTAGM-EQUIVALENCE,ZERO EQUIVALENCE, CORRESPONDENCE

    Abstrakt: Äquivalenz in der zweisprachigen Lexikographie: Kritik und Vorschläge.Nachdem an allgemeine Probleme der Begriffsbildung am Beispiel von dt. Äquivalenzund dt. äquivalent erinnert wurde, wird zunächst auf Äquivalenzbegriffe in der kontrastiven Lexikologiekritisch eingegangen. Es wird gezeigt, dass insbesondere der Begriff der partiellen Äquivalenzin seinen verschiedenen Ausprägungen widersprüchlich ist. Sodann werden Präzisierungenzu den Äquivalenzbegriffen in der Metalexikographie versucht, die sich auf den Bereich der Nennlexikbeziehen. Insbesondere der metalexikographische Begriff der partiellen Äquivalenz sowie derder Divergenz werden grundsätzlich problematisiert. In welche Richtung man gehen kann, umangemessenere metalexikographische Fassungen des Äquivalenzbegriffs zu finden, wird abschließendangedeutet.

    Stichwörter: ÄQUIVALENZ, LEXIKOGRAPHISCHES ÄQUIVALENT, PARTIELLE ÄQUIVALENZ,KONGRUENZ, DIVERGENZ, KONVERGENZ, POLYDIVERGENZ

  12. Influence of implantation energy on the electrical properties of ultrathin gate oxides grown on nitrogen implanted Si substrates

    International Nuclear Information System (INIS)

    Kapetanakis, E.; Skarlatos, D.; Tsamis, C.; Normand, P.; Tsoukalas, D.

    2003-01-01

    Metal-oxide-semiconductor tunnel diodes with gate oxides, in the range of 2.5-3.5 nm, grown either on 25 or 3 keV nitrogen-implanted Si substrates at (0.3 or 1) x10 15 cm -2 dose, respectively, are investigated. The dependence of N 2 + ion implant energy on the electrical quality of the growing oxide layers is studied through capacitance, equivalent parallel conductance, and gate current measurements. Superior electrical characteristics in terms of interface state trap density, leakage current, and breakdown fields are found for oxides obtained through 3 keV nitrogen implants. These findings together with the full absence of any extended defect in the silicon substrate make the low-energy nitrogen implantation technique an attractive option for reproducible low-cost growth of nanometer-thick gate oxides

  13. Modelo predictivo del espesor de la capa de óxido y microdureza en aluminio Al3003-B14 y Al6063-T6 anodizado usando análisis multifactorial Oxide film thickness and microhardness prediction model of Al3003-B14 and Al6063-T6 anodized aluminum using multifactorial analysis

    Directory of Open Access Journals (Sweden)

    Leonardo Eladio Vergara Guillén

    2011-08-01

    Full Text Available En esta investigación se modela a partir de los parámetros del proceso el espesor de la capa de óxido y la microdureza de los aluminios Al3003 y Al6063 anodizados. Para ello se realizaron estudios de la microdureza y espesor de capa de la superficie anodizada, utilizando técnicas de análisis multifactorial y diseño robusto. Se establecieron los siguientes niveles de los parámetros del proceso: temperatura [15 °C, 25 °C], tiempo [30 min; 60 min], concentración de electrolito [1,2 M; 2 M], densidad de corriente [1 Amp/dm²; 3 Amp/dm²], aluminio [Al3003,Al6063] y como variable de ruido, la deformación plástica [0%, 10%, 20%, 30%]. Se propuso un diseño fraccionado 2(7-2 mixto, con el cual se efectuó un total de 48 pruebas usando soluciones electrolíticas de ácido sulfúrico. La medición de microdureza se realizó con un indentador Vickers con carga de 400 g; el espesor de la capa de óxido se captó mediante microscopia electrónica. A los resultados se les realizó un análisis de varianza (ANOVA, para determinar los factores significativos y la robustez de los efectos. Se encontraron resultados de microdureza [HV] [85,74-308,87]; y espesor de óxido [µm] [12,82- 94,69]. Finalmente, se muestran los modelos de predicción de cada una de las respuestas en función de los factores significativos estas ecuaciones permitirán seleccionar la microdureza y espesor de la capa de óxido para cumplir los requerimientos de un producto particular mediante una selección apropiada de los parámetros del proceso.In this research, the thickness of the oxide layer and the microhardness of anodized aluminum Al3003 and Al6063 are modeled based on process parameters. To this end, studies of the microhardness and the thickness layer of the anodized surface were made, via techniques of multifactorial analysis and robust design. The following levels of the process parameters were established: temperature [15°C, 25°C], time [30min; 60min

  14. Equivalent drawbead performance in deep drawing simulations

    NARCIS (Netherlands)

    Meinders, Vincent T.; Geijselaers, Hubertus J.M.; Huetink, Han

    1999-01-01

    Drawbeads are applied in the deep drawing process to improve the control of the material flow during the forming operation. In simulations of the deep drawing process these drawbeads can be replaced by an equivalent drawbead model. In this paper the usage of an equivalent drawbead model in the

  15. On uncertainties in definition of dose equivalent

    International Nuclear Information System (INIS)

    Oda, Keiji

    1995-01-01

    The author has entertained always the doubt that in a neutron field, if the measured value of the absorbed dose with a tissue equivalent ionization chamber is 1.02±0.01 mGy, may the dose equivalent be taken as 10.2±0.1 mSv. Should it be 10.2 or 11, but the author considers it is 10 or 20. Even if effort is exerted for the precision measurement of absorbed dose, if the coefficient being multiplied to it is not precise, it is meaningless. [Absorbed dose] x [Radiation quality fctor] = [Dose equivalent] seems peculiar. How accurately can dose equivalent be evaluated ? The descriptions related to uncertainties in the publications of ICRU and ICRP are introduced, which are related to radiation quality factor, the accuracy of measuring dose equivalent and so on. Dose equivalent shows the criterion for the degree of risk, or it is considered only as a controlling quantity. The description in the ICRU report 1973 related to dose equivalent and its unit is cited. It was concluded that dose equivalent can be considered only as the absorbed dose being multiplied by a dimensionless factor. The author presented the questions. (K.I.)

  16. Orientifold Planar Equivalence: The Chiral Condensate

    DEFF Research Database (Denmark)

    Armoni, Adi; Lucini, Biagio; Patella, Agostino

    2008-01-01

    The recently introduced orientifold planar equivalence is a promising tool for solving non-perturbative problems in QCD. One of the predictions of orientifold planar equivalence is that the chiral condensates of a theory with $N_f$ flavours of Dirac fermions in the symmetric (or antisymmetric...

  17. 7 CFR 1005.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1005.54 Section 1005.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1005.54 Equivalent price. See § 1000.54. Uniform Prices ...

  18. 7 CFR 1126.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1126.54 Section 1126.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1126.54 Equivalent price. See § 1000.54. Producer Price Differential ...

  19. 7 CFR 1001.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1001.54 Section 1001.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1001.54 Equivalent price. See § 1000.54. Producer Price Differential ...

  20. 7 CFR 1032.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1032.54 Section 1032.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1032.54 Equivalent price. See § 1000.54. Producer Price Differential ...

  1. 7 CFR 1124.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1124.54 Section 1124.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Class Prices § 1124.54 Equivalent price. See § 1000.54. Producer Price Differential ...

  2. 7 CFR 1030.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1030.54 Section 1030.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1030.54 Equivalent price. See § 1000.54. ...

  3. 7 CFR 1033.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1033.54 Section 1033.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1033.54 Equivalent price. See § 1000.54. Producer Price Differential ...

  4. 7 CFR 1131.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1131.54 Section 1131.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1131.54 Equivalent price. See § 1000.54. Uniform Prices ...

  5. 7 CFR 1006.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1006.54 Section 1006.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1006.54 Equivalent price. See § 1000.54. Uniform Prices ...

  6. 7 CFR 1007.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1007.54 Section 1007.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1007.54 Equivalent price. See § 1000.54. Uniform Prices ...

  7. 7 CFR 1000.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1000.54 Section 1000.54 Agriculture... Prices § 1000.54 Equivalent price. If for any reason a price or pricing constituent required for computing the prices described in § 1000.50 is not available, the market administrator shall use a price or...

  8. Finding small equivalent decision trees is hard

    NARCIS (Netherlands)

    Zantema, H.; Bodlaender, H.L.

    2000-01-01

    Two decision trees are called decision equivalent if they represent the same function, i.e., they yield the same result for every possible input. We prove that given a decision tree and a number, to decide if there is a decision equivalent decision tree of size at most that number is NPcomplete. As

  9. What is Metaphysical Equivalence? | Miller | Philosophical Papers

    African Journals Online (AJOL)

    Theories are metaphysically equivalent just if there is no fact of the matter that could render one theory true and the other false. In this paper I argue that if we are judiciously to resolve disputes about whether theories are equivalent or not, we need to develop testable criteria that will give us epistemic access to the obtaining ...

  10. EQUIVALENT MODELS IN COVARIANCE STRUCTURE-ANALYSIS

    NARCIS (Netherlands)

    LUIJBEN, TCW

    1991-01-01

    Defining equivalent models as those that reproduce the same set of covariance matrices, necessary and sufficient conditions are stated for the local equivalence of two expanded identified models M1 and M2 when fitting the more restricted model M0. Assuming several regularity conditions, the rank

  11. Pharmaceutical equivalence of gabapentin tablets with various extragranular binders Pharmaceutical equivalence of gabapentin tablets with various extragranular binders

    Directory of Open Access Journals (Sweden)

    SWATI C. JAGDALE

    2010-06-01

    Full Text Available Gabapentin is a high-dose drug widely used as an oral anti-epilepticagent. Due to high crystalline and has poor compaction properties it is difficult to form tablets by direct compression. The aim of this study was to develop gabapentin tablets, pharmaceutically equivalent to the reference product Neurontin (marketed in USA. Gabapentin 800mg tablets were produced by wet granulation by keeping intragranular binder as well as its concentration constant and by changing with various extragranular binders with its concentration (A = PVPK 30, B = HPMC 15 cps, C = Kollidon VA 64, D =Klucel EXF.The tablet having no weight, thickness and hardness variation and having appropriate, friability as well as disintegration profile were coated with a 3% film coating solution .Seven formulations F1 (A in lower concentration F2 (A in higher concentration, F3 (B in lower concentration and F4 (B in higher concentration, F5 (C in lower concentration, F6 (C in higher concentration, F7 (D in lower concentration were formulated. Among them F6 demonstrated adequate hardness, friability, disintegration, uniformity of content, and total drug dissolution after 45minutes. The dissimilarity factor (f1 is 5.93 and the similarity factor (f2 is 67.85. So F6 was found to be equivalent to Neurontin.Gabapentin is widely used as an oral anti-epileptic agent. However, owing to its high crystallinity and poor compaction properties, it is difficult to form tablets of this drug by direct compression. The aim of this study was to develop gabapentin tablets, pharmaceutically equivalent to the brand-name pioneer product Neurontin® (marketed in USA. Gabapentin 800mg tablets were produced by wet granulation with a constant concentration of intragranular binder and a varying concentration of extragranular binders (A = polyvinylpyrrolidone K30, B = hydroxypropylmethylcellulose 15 cps, C = Kollidon VA64, D =Klucel EXF. The tablets that did not vary in weight, thickness or hardness and had

  12. Equivalence in Ventilation and Indoor Air Quality

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max; Walker, Iain; Logue, Jennifer

    2011-08-01

    We ventilate buildings to provide acceptable indoor air quality (IAQ). Ventilation standards (such as American Society of Heating, Refrigerating, and Air-Conditioning Enginners [ASHRAE] Standard 62) specify minimum ventilation rates without taking into account the impact of those rates on IAQ. Innovative ventilation management is often a desirable element of reducing energy consumption or improving IAQ or comfort. Variable ventilation is one innovative strategy. To use variable ventilation in a way that meets standards, it is necessary to have a method for determining equivalence in terms of either ventilation or indoor air quality. This study develops methods to calculate either equivalent ventilation or equivalent IAQ. We demonstrate that equivalent ventilation can be used as the basis for dynamic ventilation control, reducing peak load and infiltration of outdoor contaminants. We also show that equivalent IAQ could allow some contaminants to exceed current standards if other contaminants are more stringently controlled.

  13. Beyond Language Equivalence on Visibly Pushdown Automata

    DEFF Research Database (Denmark)

    Srba, Jiri

    2009-01-01

    We study (bi)simulation-like preorder/equivalence checking on the class of visibly pushdown automata and its natural subclasses visibly BPA (Basic Process Algebra) and visibly one-counter automata. We describe generic methods for proving complexity upper and lower bounds for a number of studied...... preorders and equivalences like simulation, completed simulation, ready simulation, 2-nested simulation preorders/equivalences and bisimulation equivalence. Our main results are that all the mentioned equivalences and preorders are EXPTIME-complete on visibly pushdown automata, PSPACE-complete on visibly...... one-counter automata and P-complete on visibly BPA. Our PSPACE lower bound for visibly one-counter automata improves also the previously known DP-hardness results for ordinary one-counter automata and one-counter nets. Finally, we study regularity checking problems for visibly pushdown automata...

  14. Static and dynamic through thickness lamina properties of thick laminates

    NARCIS (Netherlands)

    Lahuerta, F.; Nijssen, R.P.L.; Van der Meer, F.P.; Sluys, L.J.

    2015-01-01

    Thick laminates are increasingly present in large composites structures such as wind turbine blades. Different factors are suspected to be involved in the decreased static and dynamic performance of thick laminates. These include the effect of self-heating, the scaling effect, and the manufacturing

  15. Stabilized chromium oxide film

    Science.gov (United States)

    Garwin, Edward L.; Nyaiesh, Ali R.

    1988-01-01

    Stabilized air-oxidized chromium films deposited on high-power klystron ceramic windows and sleeves having a thickness between 20 and 150.ANG. are useful in lowering secondary electron emission yield and in avoiding multipactoring and window failure due to overheating. The ceramic substrate for the film is chosen from alumina, sapphire or beryllium oxide.

  16. High-temperature oxidation of Zircaloy in hydrogen-steam mixtures

    International Nuclear Information System (INIS)

    Chung, H.M.; Thomas, G.R.

    1982-09-01

    Oxidation rates of Zircaloy-4 cladding tubes have been measured in hydrogen-steam mixtures at 1200 to 1700 0 C. For a given isothermal oxidation temperature, the oxide layer thicknesses have been measured as a function of time, steam supply rate, and hydrogen overpressure. The oxidation rates in the mixtures were compared with similar data obtained in pure steam and helium-steam environments under otherwise identical conditions. The rates in pure steam and helium-steam mixtures were equivalent and comparable to the parabolic rates obtained under steam-saturated conditions and reported in the literature. However, when the helium was replaced with hydrogen of equivalent partial pressure, a significantly smaller oxidation rate was observed. For high steam-supply rates, the oxidation kinetics in a hydrogen-steam mixture were parabolic, but the rate was smaller than for pure steam or helium-steam mixtures. Under otherwise identical conditions, the ratio of the parabolic rate for hydrogen-steam to that for pure steam decreased with increasing temperature and decreasing steam-supply rate

  17. 78 FR 67360 - Ambient Air Monitoring Reference and Equivalent Methods: Designation of Five New Equivalent Methods

    Science.gov (United States)

    2013-11-12

    ... Methods: Designation of Five New Equivalent Methods AGENCY: Office of Research and Development; Environmental Protection Agency (EPA). ACTION: Notice of the designation of five new equivalent methods for...) has designated, in accordance with 40 CFR Part 53, five new equivalent methods, one for measuring...

  18. 77 FR 60985 - Ambient Air Monitoring Reference and Equivalent Methods: Designation of Three New Equivalent Methods

    Science.gov (United States)

    2012-10-05

    ... Methods: Designation of Three New Equivalent Methods AGENCY: Environmental Protection Agency. ACTION: Notice of the designation of three new equivalent methods for monitoring ambient air quality. SUMMARY... equivalent methods, one for measuring concentrations of PM 2.5 , one for measuring concentrations of PM 10...

  19. Analytical and numerical construction of equivalent cables.

    Science.gov (United States)

    Lindsay, K A; Rosenberg, J R; Tucker, G

    2003-08-01

    The mathematical complexity experienced when applying cable theory to arbitrarily branched dendrites has lead to the development of a simple representation of any branched dendrite called the equivalent cable. The equivalent cable is an unbranched model of a dendrite and a one-to-one mapping of potentials and currents on the branched model to those on the unbranched model, and vice versa. The piecewise uniform cable, with a symmetrised tri-diagonal system matrix, is shown to represent the canonical form for an equivalent cable. Through a novel application of the Laplace transform it is demonstrated that an arbitrary branched model of a dendrite can be transformed to the canonical form of an equivalent cable. The characteristic properties of the equivalent cable are extracted from the matrix for the transformed branched model. The one-to-one mapping follows automatically from the construction of the equivalent cable. The equivalent cable is used to provide a new procedure for characterising the location of synaptic contacts on spinal interneurons.

  20. Optimum target thickness for polarimeters

    International Nuclear Information System (INIS)

    Sitnik, I.M.

    2003-01-01

    Polarimeters with thick targets are a tool to measure the proton polarization. But the question about the optimum target thickness is still the subject of discussion. An attempt to calculate the most common parameters concerning this problem, in a few GeV region, is made

  1. Geometry of the local equivalence of states

    Energy Technology Data Exchange (ETDEWEB)

    Sawicki, A; Kus, M, E-mail: assawi@cft.edu.pl, E-mail: marek.kus@cft.edu.pl [Center for Theoretical Physics, Polish Academy of Sciences, Al Lotnikow 32/46, 02-668 Warszawa (Poland)

    2011-12-09

    We present a description of locally equivalent states in terms of symplectic geometry. Using the moment map between local orbits in the space of states and coadjoint orbits of the local unitary group, we reduce the problem of local unitary equivalence to an easy part consisting of identifying the proper coadjoint orbit and a harder problem of the geometry of fibers of the moment map. We give a detailed analysis of the properties of orbits of 'equally entangled states'. In particular, we show connections between certain symplectic properties of orbits such as their isotropy and coisotropy with effective criteria of local unitary equivalence. (paper)

  2. On the variation in the electrical properties and ac conductivity of through-thickness nano-porous anodic alumina with temperature

    International Nuclear Information System (INIS)

    Tahir, Mahmood; Mehmood, Mazhar; Nadeem, Muhammad; Waheed, Abdul; Tanvir, Muhammad Tauseef

    2013-01-01

    The electrical response of self-organized through-thickness anodic alumina with hexagonal arrangement of cylindrical pores has been studied as a function of temperature. Mechanically stable thick porous anodic alumina was prepared, by through-thickness anodic oxidation of aluminum sheet in sulfuric acid, with extremely high aspect ratio pores exhibiting fairly uniform diameter and interpore distance. It was observed that the electrical properties of through-thickness anodic alumina are very sensitive to minute changes in temperature and the role of surface conductivity in governing its electrical response cannot be overlooked. At high frequencies, intrinsic dielectric response of anodic alumina was dominant. The frequency-dependent conductivity behavior at low and intermediate frequencies was explained on the basis of correlated barrier hopping (CBH) and quantum mechanical tunneling (QMT) models, respectively. Experimental data was modeled using an equivalent circuit consisting of Debye circuit, for bulk alumina, parallel to surface conduction path. The surface conduction was primarily based on two circuits in series, each with a parallel arrangement of a resistor and a constant phase element. This suggested heterogeneity in alumina pore surface, possibly related with islands of physisorbed water separated by the regions of chemisorbed water. Temperature dependence of some circuit elements has been analyzed to express different charge migration phenomena occurring in nano-porous anodic alumina

  3. Estimation of Oxidation Kinetics and Oxide Scale Void Position of Ferritic-Martensitic Steels in Supercritical Water

    Directory of Open Access Journals (Sweden)

    Li Sun

    2017-01-01

    Full Text Available Exfoliation of oxide scales from high-temperature heating surfaces of power boilers threatened the safety of supercritical power generating units. According to available space model, the oxidation kinetics of two ferritic-martensitic steels are developed to predict in supercritical water at 400°C, 500°C, and 600°C. The iron diffusion coefficients in magnetite and Fe-Cr spinel are extrapolated from studies of Backhaus and Töpfer. According to Fe-Cr-O ternary phase diagram, oxygen partial pressure at the steel/Fe-Cr spinel oxide interface is determined. The oxygen partial pressure at the magnetite/supercritical water interface meets the equivalent oxygen partial pressure when system equilibrium has been attained. The relative error between calculated values and experimental values is analyzed and the reasons of error are suggested. The research results show that the results of simulation at 600°C are approximately close to experimental results. The iron diffusion coefficient is discontinuous in the duplex scale of two ferritic-martensitic steels. The simulation results of thicknesses of the oxide scale on tubes (T91 of final superheater of a 600 MW supercritical boiler are compared with field measurement data and calculation results by Adrian’s method. The calculated void positions of oxide scales are in good agreement with a cross-sectional SEM image of the oxide layers.

  4. Quantum equivalence principle without mass superselection

    International Nuclear Information System (INIS)

    Hernandez-Coronado, H.; Okon, E.

    2013-01-01

    The standard argument for the validity of Einstein's equivalence principle in a non-relativistic quantum context involves the application of a mass superselection rule. The objective of this work is to show that, contrary to widespread opinion, the compatibility between the equivalence principle and quantum mechanics does not depend on the introduction of such a restriction. For this purpose, we develop a formalism based on the extended Galileo group, which allows for a consistent handling of superpositions of different masses, and show that, within such scheme, mass superpositions behave as they should in order to obey the equivalence principle. - Highlights: • We propose a formalism for consistently handling, within a non-relativistic quantum context, superpositions of states with different masses. • The formalism utilizes the extended Galileo group, in which mass is a generator. • The proposed formalism allows for the equivalence principle to be satisfied without the need of imposing a mass superselection rule

  5. On the equivalence of chaos control systems

    International Nuclear Information System (INIS)

    Wang Xiaofan

    2003-01-01

    For a given chaotic system, different control systems can be constructed depending on which parameter is tuned or where the external input is added. We prove that two different feedback control systems are qualitatively equivalent if they are feedback linearizable

  6. Equivalence relations and the reinforcement contingency.

    Science.gov (United States)

    Sidman, M

    2000-07-01

    Where do equivalence relations come from? One possible answer is that they arise directly from the reinforcement contingency. That is to say, a reinforcement contingency produces two types of outcome: (a) 2-, 3-, 4-, 5-, or n-term units of analysis that are known, respectively, as operant reinforcement, simple discrimination, conditional discrimination, second-order conditional discrimination, and so on; and (b) equivalence relations that consist of ordered pairs of all positive elements that participate in the contingency. This conception of the origin of equivalence relations leads to a number of new and verifiable ways of conceptualizing equivalence relations and, more generally, the stimulus control of operant behavior. The theory is also capable of experimental disproof.

  7. REFractions: The Representing Equivalent Fractions Game

    Science.gov (United States)

    Tucker, Stephen I.

    2014-01-01

    Stephen Tucker presents a fractions game that addresses a range of fraction concepts including equivalence and computation. The REFractions game also improves students' fluency with representing, comparing and adding fractions.

  8. ON THE EQUIVALENCE OF THE ABEL EQUATION

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This article uses the reflecting function of Mironenko to study some complicated differential equations which are equivalent to the Abel equation. The results are applied to discuss the behavior of solutions of these complicated differential equations.

  9. interpratation: of equivalences and cultural untranslatability

    African Journals Online (AJOL)

    jgmweri

    translatability in cultural diversity in terms equivalences such as –Vocabulary or lexical ..... A KSL interpreter who does not understand this English idiom may literally interpret it .... Nida, E.A. (1958) Analysis of meaning and dictionary making.

  10. Equivalence Principle, Higgs Boson and Cosmology

    Directory of Open Access Journals (Sweden)

    Mauro Francaviglia

    2013-05-01

    Full Text Available We discuss here possible tests for Palatini f(R-theories together with their implications for different formulations of the Equivalence Principle. We shall show that Palatini f(R-theories obey the Weak Equivalence Principle and violate the Strong Equivalence Principle. The violations of the Strong Equivalence Principle vanish in vacuum (and purely electromagnetic solutions as well as on short time scales with respect to the age of the universe. However, we suggest that a framework based on Palatini f(R-theories is more general than standard General Relativity (GR and it sheds light on the interpretation of data and results in a way which is more model independent than standard GR itself.

  11. The gauge principle vs. the equivalence principle

    International Nuclear Information System (INIS)

    Gates, S.J. Jr.

    1984-01-01

    Within the context of field theory, it is argued that the role of the equivalence principle may be replaced by the principle of gauge invariance to provide a logical framework for theories of gravitation

  12. Dark matter and the equivalence principle

    Science.gov (United States)

    Frieman, Joshua A.; Gradwohl, Ben-Ami

    1993-01-01

    A survey is presented of the current understanding of dark matter invoked by astrophysical theory and cosmology. Einstein's equivalence principle asserts that local measurements cannot distinguish a system at rest in a gravitational field from one that is in uniform acceleration in empty space. Recent test-methods for the equivalence principle are presently discussed as bases for testing of dark matter scenarios involving the long-range forces between either baryonic or nonbaryonic dark matter and ordinary matter.

  13. S-equivalents lagrangians in generalized mechanics

    International Nuclear Information System (INIS)

    Negri, L.J.; Silva, Edna G. da.

    1985-01-01

    The problem of s-equivalent lagrangians is considered in the realm of generalized mechanics. Some results corresponding to the ordinary (non-generalized) mechanics are extended to the generalized case. A theorem for the reduction of the higher order lagrangian description to the usual order is found to be useful for the analysis of generalized mechanical systems and leads to a new class of equivalence between lagrangian functions. Some new perspectives are pointed out. (Author) [pt

  14. Experimental Evaluation of Equivalent-Fluid Models for Melamine Foam

    Science.gov (United States)

    Allen, Albert R.; Schiller, Noah H.

    2016-01-01

    Melamine foam is a soft porous material commonly used in noise control applications. Many models exist to represent porous materials at various levels of fidelity. This work focuses on rigid frame equivalent fluid models, which represent the foam as a fluid with a complex speed of sound and density. There are several empirical models available to determine these frequency dependent parameters based on an estimate of the material flow resistivity. Alternatively, these properties can be experimentally educed using an impedance tube setup. Since vibroacoustic models are generally sensitive to these properties, this paper assesses the accuracy of several empirical models relative to impedance tube measurements collected with melamine foam samples. Diffuse field sound absorption measurements collected using large test articles in a laboratory are also compared with absorption predictions determined using model-based and measured foam properties. Melamine foam slabs of various thicknesses are considered.

  15. [Features associated with retinal thickness extension in diabetic macular oedema].

    Science.gov (United States)

    Razo Blanco-Hernández, Dulce Milagros; Lima-Gómez, Virgilio; García-Rubio, Yatzul Zuhaila

    2015-01-01

    Clinically significant macular edema has features that are associated with a major risk of visual loss, with thickening that involves the centre of the macula, field 7 or visual deficiency, although it is unknown if these features are related to retinal thickness extension. An observational, analytical, prospective, cross-sectional and open study was conducted. The sample was divided into initial visual acuity ≥0.5, central field thickness, center point thickness, field 7 and macular volume more than the reported 2 standard deviation mean value in eyes without retinopathy. The extension was determined by the number of the central field area equivalent thickening and these features were compared with by Student's t test for independent samples. A total of 199 eyes were included. In eyes with visual acuity of ≥0.5, the mean extension was 2.88±1.68 and 3.2±1.63 in area equivalent in eyes with visual acuity 0.5 (p=0.12). The mean extension in eyes with less than 2 standard deviation of central field thickness, center point thickness, field 7 and macular volume was significantly lower than in eyes with more than 2 standard deviations (1.9±0.93 vs. 4.07±1.49, 2.44±1.47 vs. 3.94±1.52, 1.79±1.07 vs. 3.61±1.57 and 1.6±0.9 vs. 3.9±1.4, respectively, p<0.001). The extension of retinal thickness is related with the anatomical features reported with a greater risk of visual loss, but is not related to initial visual deficiency. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

  16. Degradation modes of austenitic and ferritic–martensitic stainless steels in He–CO–CO2 and liquid sodium environments of equivalent oxygen and carbon chemical potentials

    International Nuclear Information System (INIS)

    Gulsoy, G.; Was, G.S.; Pawel, S.J.; Busby, J.T.

    2013-01-01

    The objective of this work is to explore possible thermodynamic correlations between the degradation modes of austenitic and ferritic–martensitic alloys observed in high temperature He–CO–CO 2 environments with oxygen and carbon chemical potentials equivalent to that in a liquid sodium environment containing 2–5 molppm oxygen and 0.02–0.2 molppm carbon at temperatures 500–700 °C. Two He–CO–CO 2 environments (Pco/Pco 2 = 1320, Pco = 1980 molppm, and Pco/Pco 2 = 9, Pco = 13.5 molppm) were selected to test alloys NF616 and 316L at 700 and 850 °C. Upon exposure to He environments at 850 °C, 316L samples exhibited thick surface Cr 2 O 3 scales and substantial internal oxidation; however at 700 °C no significant internal oxidation was observed. NF616 samples exhibited relatively thinner surface Cr 2 O 3 scales compared to 316L samples at both temperatures. NF616 samples exposed to liquid sodium at 700 °C and He–Pco/Pco 2 = 9 at 850 °C showed decarburization. No surface oxide formation was observed on the sample exposed to the Na environment. Results obtained from He exposure experiments provide insight into what may occur during long exposure times in a sodium environment

  17. Degradation modes of austenitic and ferritic–martensitic stainless steels in He–CO–CO{sub 2} and liquid sodium environments of equivalent oxygen and carbon chemical potentials

    Energy Technology Data Exchange (ETDEWEB)

    Gulsoy, G., E-mail: gulsoy@umich.edu [Department of Materials Science and Engineering, University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States); Was, G.S. [Department of Materials Science and Engineering, University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States); Pawel, S.J.; Busby, J.T. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

    2013-10-15

    The objective of this work is to explore possible thermodynamic correlations between the degradation modes of austenitic and ferritic–martensitic alloys observed in high temperature He–CO–CO{sub 2} environments with oxygen and carbon chemical potentials equivalent to that in a liquid sodium environment containing 2–5 molppm oxygen and 0.02–0.2 molppm carbon at temperatures 500–700 °C. Two He–CO–CO{sub 2} environments (Pco/Pco{sub 2} = 1320, Pco = 1980 molppm, and Pco/Pco{sub 2} = 9, Pco = 13.5 molppm) were selected to test alloys NF616 and 316L at 700 and 850 °C. Upon exposure to He environments at 850 °C, 316L samples exhibited thick surface Cr{sub 2}O{sub 3} scales and substantial internal oxidation; however at 700 °C no significant internal oxidation was observed. NF616 samples exhibited relatively thinner surface Cr{sub 2}O{sub 3} scales compared to 316L samples at both temperatures. NF616 samples exposed to liquid sodium at 700 °C and He–Pco/Pco{sub 2} = 9 at 850 °C showed decarburization. No surface oxide formation was observed on the sample exposed to the Na environment. Results obtained from He exposure experiments provide insight into what may occur during long exposure times in a sodium environment.

  18. Isotopes in oxidation reactions

    International Nuclear Information System (INIS)

    Stewart, R.

    1976-01-01

    The use of isotopes in the study of organic oxidation mechanisms is discussed. The help provided by tracer studies to demonstrate the two-equivalent path - hydride transfer, is illustrated by the examples of carbonium oxidants and the Wacker reaction. The role of kinetic isotope effects in the study of the scission of carbon-hydrogen bonds is illustrated by hydride abstraction, hydrogen atom abstraction, proton abstraction and quantum mechanical tunnelling. Isotopic studies on the oxidation of alcohols, carbonyl compounds, amines and hydrocarbons are discussed. The role of isotopes in the study of biochemical oxidation is illustrated with a discussion on nicotinamide and flavin coenzymes. (B.R.H.)

  19. Thermal behavior variations in coating thickness using pulse phase thermography

    Energy Technology Data Exchange (ETDEWEB)

    Ranjit, Shrestha; Chung, Yoonjae; Kim, Won Tae [Kongju National University, Cheonan (Korea, Republic of)

    2016-08-15

    This paper presents a study on the use of pulsed phase thermography in the measurement of thermal barrier coating thickness with a numerical simulation. A multilayer heat transfer model was used to analyze the surface temperature response acquired from one-sided pulsed thermal imaging. The test sample comprised four layers: the metal substrate, bond coat, thermally grown oxide and the top coat. The finite element software, ANSYS, was used to model and predict the temperature distribution in the test sample under an imposed heat flux on the exterior of the TBC. The phase image was computed with the use of the software MATLAB and Thermofit Pro using a Fourier transform. The relationship between the coating thickness and the corresponding phase angle was then established with the coating thickness being expressed as a function of the phase angle. The method is successfully applied to measure the coating thickness that varied from 0.25 mm to 1.5 mm.

  20. Corneal thickness: measurement and implications.

    Science.gov (United States)

    Ehlers, Niels; Hjortdal, Jesper

    2004-03-01

    The thickness of the cornea was reported in more than 100-year-old textbooks on physiological optics (Helmholtz, Gullstrand). Physiological interest was revived in the 1950s by David Maurice, and over the next 50 years, this 'simple' biological parameter has been studied extensively. Several techniques for its measurement have been described and physiological and clinical significance have been studied. In this review, the different methods and techniques of measurement are briefly presented (optical, ultrasound). While the corneal thickness of many animals are the same over a considerable part of the surface, in the human cornea anterior and posterior curvature are not concentric giving rise to a problem of definition. Based on this the precision and accuracy of determining the central corneal thickness are discussed. Changes in corneal thickness reflects changes in function of the boundary layers, in particular the endothelial barrier. The absolute value of thickness is of importance for the estimation of IOP but also in diagnosis of corneal and systemic disorders. Finally it is discussed to what extent the thickness is a biometric parameter of significance, e.g. in the progression of myopia or in the development of retinal detachment.

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

    Energy Technology Data Exchange (ETDEWEB)

    Huslage, J; Buechi, F N; Scherer, G G [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    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.

  2. The principle of equivalence reconsidered: assessing the relevance of the principle of equivalence in prison medicine.

    Science.gov (United States)

    Jotterand, Fabrice; Wangmo, Tenzin

    2014-01-01

    In this article we critically examine the principle of equivalence of care in prison medicine. First, we provide an overview of how the principle of equivalence is utilized in various national and international guidelines on health care provision to prisoners. Second, we outline some of the problems associated with its applications, and argue that the principle of equivalence should go beyond equivalence to access and include equivalence of outcomes. However, because of the particular context of the prison environment, third, we contend that the concept of "health" in equivalence of health outcomes needs conceptual clarity; otherwise, it fails to provide a threshold for healthy states among inmates. We accomplish this by examining common understandings of the concepts of health and disease. We conclude our article by showing why the conceptualization of diseases as clinical problems provides a helpful approach in the delivery of health care in prison.

  3. Equivalence of Szegedy's and coined quantum walks

    Science.gov (United States)

    Wong, Thomas G.

    2017-09-01

    Szegedy's quantum walk is a quantization of a classical random walk or Markov chain, where the walk occurs on the edges of the bipartite double cover of the original graph. To search, one can simply quantize a Markov chain with absorbing vertices. Recently, Santos proposed two alternative search algorithms that instead utilize the sign-flip oracle in Grover's algorithm rather than absorbing vertices. In this paper, we show that these two algorithms are exactly equivalent to two algorithms involving coined quantum walks, which are walks on the vertices of the original graph with an internal degree of freedom. The first scheme is equivalent to a coined quantum walk with one walk step per query of Grover's oracle, and the second is equivalent to a coined quantum walk with two walk steps per query of Grover's oracle. These equivalences lie outside the previously known equivalence of Szegedy's quantum walk with absorbing vertices and the coined quantum walk with the negative identity operator as the coin for marked vertices, whose precise relationships we also investigate.

  4. Lead oxide-decorated graphene oxide/epoxy composite towards X-Ray radiation shielding

    Science.gov (United States)

    Hashemi, Seyyed Alireza; Mousavi, Seyyed Mojtaba; Faghihi, Reza; Arjmand, Mohammad; Sina, Sedigheh; Amani, Ali Mohammad

    2018-05-01

    In this study, employing modified Hummers method coupled with a multi-stage manufacturing procedure, graphene oxide (GO) decorated with Pb3O4 (GO-Pb3O4) at different weight ratios was synthesized. Thereupon, via the vacuum shock technique, composites holding GO-Pb3O4 at different filler loadings (5 and 10 wt%) and thicknesses (4 and 6 mm) were fabricated. Successful decoration of GO with Pb3O4 was confirmed via FTIR analysis. Moreover, particle size distribution of the produced fillers was examined using particle size analyzer. X-ray attenuation examination revealed that reinforcement of epoxy-based composites with GO-Pb3O4 led to a significant improvement in the overall attenuation rate of X-ray beam. For instance, composites containing 10 wt% GO-Pb3O4 with 6 mm thickness showed 4.06, 4.83 and 3.91 mm equivalent aluminum thickness at 40, 60 and 80 kVp energies, denoting 124.3, 124.6 and 103.6% improvement in the X-ray attenuation rate compared to a sample holding neat epoxy resin, respectively. Simulation results revealed that the effect of GO-Pb3O4 loading on the X-ray shielding performance undermined with increase in the voltage of the applied X-ray beam.

  5. Quantum mechanics and the equivalence principle

    International Nuclear Information System (INIS)

    Davies, P C W

    2004-01-01

    A quantum particle moving in a gravitational field may penetrate the classically forbidden region of the gravitational potential. This raises the question of whether the time of flight of a quantum particle in a gravitational field might deviate systematically from that of a classical particle due to tunnelling delay, representing a violation of the weak equivalence principle. I investigate this using a model quantum clock to measure the time of flight of a quantum particle in a uniform gravitational field, and show that a violation of the equivalence principle does not occur when the measurement is made far from the turning point of the classical trajectory. The results are then confirmed using the so-called dwell time definition of quantum tunnelling. I conclude with some remarks about the strong equivalence principle in quantum mechanics

  6. Water equivalence of polymer gel dosimeters

    International Nuclear Information System (INIS)

    Sellakumar, P.; James Jebaseelan Samuel, E.; Supe, Sanjay S.

    2007-01-01

    To evaluate the water equivalence and radiation transport properties of polymer gel dosimeters over the wide range of photon and electron energies 14 different types of polymer gels were considered. Their water equivalence was evaluated in terms of effective atomic number (Z eff ), electron density (ρ e ), photon mass attenuation coefficient (μ/ρ), photon mass energy absorption coefficient (μ en /ρ) and total stopping power (S/ρ) tot of electrons using the XCOM and the ESTAR database. The study showed that the effective atomic number of polymer gels were very close ( en /ρ for all polymer gels were in close agreement ( tot of electrons in polymer gel dosimeters were within 1% agreement with that of water. From the study we conclude that at lower energy (<80keV) the polymer gel dosimeters cannot be considered water equivalent and study has to be carried out before using the polymer gel for clinical application

  7. Using frequency equivalency in stability calculations

    Energy Technology Data Exchange (ETDEWEB)

    Gruzdev, I.A.; Temirbulatov, R.A.; Tereshko, L.A.

    1981-01-01

    A methodology for calculating oscillatory instability that involves using frequency equivalency is employed in carrying out the following proceedures: dividing an electric power system into subgroups; determining the adjustments to the automatic excitation control in each subsystem; simplifying the mathematical definition of the separate subsystems by using frequency equivalency; gradually re-tuning the automatic excitation control in the separate subsystems to account for neighboring subsystems by using their equivalent frequency characteristics. The methodology is to be used with a computer program to determine the gain in the stabilization channels of the automatic excitation control unit in which static stability of the entire aggregate of normal and post-breakdown conditions acceptable damping of transient processes are provided. The possibility of reducing the equation series to apply to chosen regions of the existing range of frequencies is demonstrated. The use of the methodology is illustrated in a sample study on stability in a Siberian unified power system.

  8. Thin zirconium oxides

    International Nuclear Information System (INIS)

    Oviedo, Cristina

    2000-01-01

    Polycrystalline Zr and two pure Zr single-crystal samples, one oriented with the normal to the surface parallel to the c-axis of the hcp structure (Z1) and the other with the normal perpendicular to c (Z2), were oxidised at 10 -8 , 10 -7 and 10 -6 Torr and room temperature. Oxidation kinetics, composition and thicknesses of the oxide films formed in each case were analyzed using XPS (X-ray Photoelectron Spectroscopy) as the main technique. The oxidation kinetics followed logarithmic laws in all cases. The deconvolution of XPS Zr3d peaks indicated the formation of two Zr-O compounds before the formation of ZrO 2 . Varying the photoelectrons take-off angle, the compound distribution inside the oxide films could be established. Thus, it was confirmed that the most external oxide, in contact with the gas, was ZrO 2 . The thickness of the films grown at the different pressures was determined. In the polycrystalline samples, thicknesses between 15 and 19 ± 2Angstroem were obtained for pressures between 10 -8 and 10 -6 Torr, in close coincidence with the determined ones for Z2. The thicknesses measured in Z1 were smaller, reaching 13 ± 2Angstroem for the oxidations performed at 10 -6 Torr. (author)

  9. The equivalence problem for LL- and LR-regular grammars

    NARCIS (Netherlands)

    Nijholt, Antinus; Gecsec, F.

    It will be shown that the equivalence problem for LL-regular grammars is decidable. Apart from extending the known result for LL(k) grammar equivalence to LLregular grammar equivalence, we obtain an alternative proof of the decidability of LL(k) equivalence. The equivalence prob]em for LL-regular

  10. Fiscal adjustments in Europe and Ricardian equivalence

    Directory of Open Access Journals (Sweden)

    V. DE BONIS

    1998-09-01

    Full Text Available According to the ‘Ricardian’ equivalence hypothesis, consumption is dependent on permanent disposable income and current deficits are equivalent to future tax payments. This hypothesis is tested on 14 European countries in the 1990s. The relationships between private sector savings and general government deficit, and the GDP growth rate and the unemployment rate are determined. The results show the change in consumers' behaviour with respect to government deficit, and that expectations of an increase in future wealth are no longer associated with a decrease in deficit.

  11. Equivalent circuit analysis of terahertz metamaterial filters

    KAUST Repository

    Zhang, Xueqian

    2011-01-01

    An equivalent circuit model for the analysis and design of terahertz (THz) metamaterial filters is presented. The proposed model, derived based on LMC equivalent circuits, takes into account the detailed geometrical parameters and the presence of a dielectric substrate with the existing analytic expressions for self-inductance, mutual inductance, and capacitance. The model is in good agreement with the experimental measurements and full-wave simulations. Exploiting the circuit model has made it possible to predict accurately the resonance frequency of the proposed structures and thus, quick and accurate process of designing THz device from artificial metamaterials is offered. ©2011 Chinese Optics Letters.

  12. Topological equivalence of nonlinear autonomous dynamical systems

    International Nuclear Information System (INIS)

    Nguyen Huynh Phan; Tran Van Nhung

    1995-12-01

    We show in this paper that the autonomous nonlinear dynamical system Σ(A,B,F): x' = Ax+Bu+F(x) is topologically equivalent to the linear dynamical system Σ(A,B,O): x' = Ax+Bu if the projection of A on the complement in R n of the controllable vectorial subspace is hyperbolic and if lipschitz constant of F is sufficiently small ( * ) and F(x) = 0 when parallel x parallel is sufficiently large ( ** ). In particular, if Σ(A,B,O) is controllable, it is topologically equivalent to Σ(A,B,F) when it is only that F satisfy ( ** ). (author). 18 refs

  13. A neutron dose equivalent meter at CAEP

    International Nuclear Information System (INIS)

    Tian Shihai; Lu Yan; Wang Heyi; Yuan Yonggang; Chen Xu

    2012-01-01

    The measurement of neutron dose equivalent has been a widespread need in industry and research. In this paper, aimed at improving the accuracy of neutron dose equivalent meter: a neutron dose counter is simulated with MCNP5, and the energy response curve is optimized. The results show that the energy response factor is from 0.2 to 1.8 for neutrons in the energy range of 2.53×10 -8 MeV to 10 MeV Compared with other related meters, it turns that the design of this meter is right. (authors)

  14. Measurements of the personal dose equivalent

    International Nuclear Information System (INIS)

    Scarlat, F.; Scarisoreanu, A.; Badita, E.; Oane, M.; Mitru, E.

    2008-01-01

    Full text: The paper presents the results of measurements related to the personal dose equivalent in the rooms adjacent to NILPRP 7 MeV linear accelerator, by means of the secondary standard chamber T34035 Hp(10). The chamber was calibrated by PTB at S- 137 Cs (E av = 661.6 keV, T 1/2 11050 days) and has N H = 3.17x10 6 Sv/C calibration factor for the personal dose equivalent, Hp(10), at a depth of 10 mm in climatic reference conditions. The measurements were made for the two operation mode of the 7 MeV linac: electrons and bremsstrahlung

  15. Thickness independent reduced forming voltage in oxygen engineered HfO{sub 2} based resistive switching memories

    Energy Technology Data Exchange (ETDEWEB)

    Sharath, S. U., E-mail: sharath@oxide.tu-darmstadt.de; Kurian, J.; Komissinskiy, P.; Hildebrandt, E.; Alff, L. [Institute of Materials Science, Technische Universität Darmstadt, 64287 Darmstadt (Germany); Bertaud, T.; Walczyk, C.; Calka, P. [IHP, Im Technologiepark 25, 15236 Frankfurt Oder (Germany); Schroeder, T. [IHP, Im Technologiepark 25, 15236 Frankfurt Oder (Germany); Brandenburgische Technische Universität, Konrad-Zuse-Strasse 1, 03046 Cottbus (Germany)

    2014-08-18

    The conducting filament forming voltage of stoichiometric hafnium oxide based resistive switching layers increases linearly with layer thickness. Using strongly reduced oxygen deficient hafnium oxide thin films grown on polycrystalline TiN/Si(001) substrates, the thickness dependence of the forming voltage is strongly suppressed. Instead, an almost constant forming voltage of about 3 V is observed up to 200 nm layer thickness. This effect suggests that filament formation and switching occurs for all samples in an oxidized HfO{sub 2} surface layer of a few nanometer thickness while the highly oxygen deficient thin film itself merely serves as a oxygen vacancy reservoir.

  16. Effect of ultrathin GeOx interfacial layer formed by thermal oxidation on Al2O3 capped Ge

    International Nuclear Information System (INIS)

    Han Le; Zhang Xiong; Wang Sheng-Kai; Xue Bai-Qing; Liu Hong-Gang; Wu Wang-Ran; Zhao Yi

    2014-01-01

    We propose a modified thermal oxidation method in which an Al 2 O 3 capping layer is used as an oxygen blocking layer (OBL) to form an ultrathin GeO x interfacial layer, and obtain a superior Al 2 O 3 /GeO x /Ge gate stack. The GeO x interfacial layer is formed in oxidation reaction by oxygen passing through the Al 2 O 3 OBL, in which the Al 2 O 3 layer could restrain the oxygen diffusion and suppress the GeO desorption during thermal treatment. The thickness of the GeO x interfacial layer would dramatically decrease as the thickness of Al 2 O 3 OBL increases, which is beneficial to achieving an ultrathin GeO x interfacial layer to satisfy the demand for small equivalent oxide thickness (EOT). In addition, the thickness of the GeO x interfacial layer has little influence on the passivation effect of the Al 2 O 3 /Ge interface. Ge (100) p-channel metal–oxide–semiconductor field-effect transistors (pMOSFETs) using the Al 2 O 3 /GeO x /Ge gate stacks exhibit excellent electrical characteristics; that is, a drain current on-off (I on /I off ) ratio of above 1×10 4 , a subthreshold slope of ∼ 120 mV/dec, and a peak hole mobility of 265 cm 2 /V·s are achieved. (condensed matter: structural, mechanical, and thermal properties)

  17. 77 FR 32632 - Ambient Air Monitoring Reference and Equivalent Methods: Designation of Three New Equivalent Methods

    Science.gov (United States)

    2012-06-01

    ... Methods: Designation of Three New Equivalent Methods AGENCY: Environmental Protection Agency. ACTION... accordance with 40 CFR Part 53, three new equivalent methods: One for measuring concentrations of nitrogen... INFORMATION: In accordance with regulations at 40 CFR Part 53, the EPA evaluates various methods for...

  18. Confluence Modulo Equivalence in Constraint Handling Rules

    DEFF Research Database (Denmark)

    Christiansen, Henning; Kirkeby, Maja Hanne

    2015-01-01

    Previous results on confluence for Constraint Handling Rules, CHR, are generalized to take into account user-defined state equivalence relations. This allows a much larger class of programs to enjoy the advantages of confluence, which include various optimization techniques and simplified...

  19. Free Fall and the Equivalence Principle Revisited

    Science.gov (United States)

    Pendrill, Ann-Marie

    2017-01-01

    Free fall is commonly discussed as an example of the equivalence principle, in the context of a homogeneous gravitational field, which is a reasonable approximation for small test masses falling moderate distances. Newton's law of gravity provides a generalisation to larger distances, and also brings in an inhomogeneity in the gravitational field.…

  20. Estimation of Toxicity Equivalent Concentration (TEQ) of ...

    African Journals Online (AJOL)

    Estimation of Toxicity Equivalent Concentration (TEQ) of carcinogenic polycyclic aromatic hydrocarbons in soils from Idu Ekpeye playground and University of Port ... Effective soil remediation and detoxification method like Dispersion by chemical reaction technology should be deployed to clean-up sites to avoid soil toxicity ...

  1. Chemical equivalence assessment of three brands of ...

    African Journals Online (AJOL)

    Assay for content of active ingredients is a critical test of drug quality; failure to meet up the standard for content of active ingredients will result to sub therapeutic quantities. Three brands (A, B and C) of carbamazepine were assayed to determine their chemical equivalence as well as their anticonvulsant activities. This was ...

  2. On Behavioral Equivalence of Rational Representations

    NARCIS (Netherlands)

    Trentelman, Harry L.; Willems, JC; Hara, S; Ohta, Y; Fujioka, H

    2010-01-01

    This article deals with the equivalence of representations of behaviors of linear differential systems In general. the behavior of a given linear differential system has many different representations. In this paper we restrict ourselves to kernel representations and image representations Two kernel

  3. Visual Equivalence and Amodal Completion in Cuttlefish.

    Science.gov (United States)

    Lin, I-Rong; Chiao, Chuan-Chin

    2017-01-01

    Modern cephalopods are notably the most intelligent invertebrates and this is accompanied by keen vision. Despite extensive studies investigating the visual systems of cephalopods, little is known about their visual perception and object recognition. In the present study, we investigated the visual processing of the cuttlefish Sepia pharaonis , including visual equivalence and amodal completion. Cuttlefish were trained to discriminate images of shrimp and fish using the operant conditioning paradigm. After cuttlefish reached the learning criteria, a series of discrimination tasks were conducted. In the visual equivalence experiment, several transformed versions of the training images, such as images reduced in size, images reduced in contrast, sketches of the images, the contours of the images, and silhouettes of the images, were used. In the amodal completion experiment, partially occluded views of the original images were used. The results showed that cuttlefish were able to treat the training images of reduced size and sketches as the visual equivalence. Cuttlefish were also capable of recognizing partially occluded versions of the training image. Furthermore, individual differences in performance suggest that some cuttlefish may be able to recognize objects when visual information was partly removed. These findings support the hypothesis that the visual perception of cuttlefish involves both visual equivalence and amodal completion. The results from this research also provide insights into the visual processing mechanisms used by cephalopods.

  4. Possibility and necessity measures and integral equivalence

    Czech Academy of Sciences Publication Activity Database

    Chen, T.; Mesiar, Radko; Li, J.; Stupňanová, A.

    2017-01-01

    Roč. 86, č. 1 (2017), s. 62-72 ISSN 0888-613X Institutional support: RVO:67985556 Keywords : Integral equivalence * Necessity measure * Possibility measure * Survival function * Universal integral Subject RIV: BA - General Mathematics OBOR OECD: Statistics and probability Impact factor: 2.845, year: 2016 http://library.utia.cas.cz/separaty/2017/E/mesiar-0477092.pdf

  5. Fuel Cell Equivalent Electric Circuit Parameter Mapping

    DEFF Research Database (Denmark)

    Jeppesen, Christian; Zhou, Fan; Andreasen, Søren Juhl

    In this work a simple model for a fuel cell is investigated for diagnostic purpose. The fuel cell is characterized, with respect to the electrical impedance of the fuel cell at non-faulty conditions and under variations in load current. Based on this the equivalent electrical circuit parameters can...

  6. Weak equivalence classes of complex vector bundles

    Czech Academy of Sciences Publication Activity Database

    Le, Hong-Van

    LXXVII, č. 1 (2008), s. 23-30 ISSN 0862-9544 R&D Projects: GA AV ČR IAA100190701 Institutional research plan: CEZ:AV0Z10190503 Keywords : chern classes * complex Grassmannians weak equivalence Subject RIV: BA - General Mathematics

  7. Violation of Equivalence Principle and Solar Neutrinos

    International Nuclear Information System (INIS)

    Gago, A.M.; Nunokawa, H.; Zukanovich Funchal, R.

    2001-01-01

    We have updated the analysis for the solution to the solar neutrino problem by the long-wavelength neutrino oscillations induced by a tiny breakdown of the weak equivalence principle of general relativity, and obtained a very good fit to all the solar neutrino data

  8. Bilingual Dictionaries and Communicative Equivalence for a ...

    African Journals Online (AJOL)

    This implies that a bilingual dictionary becomes a poly functional instrument, presenting more information than just translation equivalents. ... With the emphasis on the user perspective, metalexicographical criteria are used to investigate problems regarding the access structure and the addressing procedures in Afrikaans ...

  9. Equivalent operator preconditioning for elliptic problems

    Czech Academy of Sciences Publication Activity Database

    Axelsson, Owe; Karátson, J.

    2009-01-01

    Roč. 50, č. 3 (2009), s. 297-380 ISSN 1017-1398 Institutional research plan: CEZ:AV0Z30860518 Keywords : Elliptic problem * Conjugate gradient method * preconditioning * equivalent operators * compact operators Subject RIV: BA - General Mathematics Impact factor: 0.716, year: 2009 http://en.scientificcommons.org/42514649

  10. Superstring field theory equivalence: Ramond sector

    International Nuclear Information System (INIS)

    Kroyter, Michael

    2009-01-01

    We prove that the finite gauge transformation of the Ramond sector of the modified cubic superstring field theory is ill-defined due to collisions of picture changing operators. Despite this problem we study to what extent could a bijective classical correspondence between this theory and the (presumably consistent) non-polynomial theory exist. We find that the classical equivalence between these two theories can almost be extended to the Ramond sector: We construct mappings between the string fields (NS and Ramond, including Chan-Paton factors and the various GSO sectors) of the two theories that send solutions to solutions in a way that respects the linearized gauge symmetries in both sides and keeps the action of the solutions invariant. The perturbative spectrum around equivalent solutions is also isomorphic. The problem with the cubic theory implies that the correspondence of the linearized gauge symmetries cannot be extended to a correspondence of the finite gauge symmetries. Hence, our equivalence is only formal, since it relates a consistent theory to an inconsistent one. Nonetheless, we believe that the fact that the equivalence formally works suggests that a consistent modification of the cubic theory exists. We construct a theory that can be considered as a first step towards a consistent RNS cubic theory.

  11. Equivalence Scales for the Former West Germany

    NARCIS (Netherlands)

    Charlier, E.

    1997-01-01

    Equivalence scales provide answers to questions like how much a household with four children needs to spend compared to a household with two children or how much a childless couple needs to spend compared to a single person household to attain the same welfare level. These are important questions

  12. Confluence Modulo Equivalence in Constraint Handling Rules

    DEFF Research Database (Denmark)

    Christiansen, Henning; Kirkeby, Maja Hanne

    2014-01-01

    Previous results on confluence for Constraint Handling Rules, CHR, are generalized to take into account user-defined state equivalence relations. This allows a much larger class of programs to enjoy the ad- vantages of confluence, which include various optimization techniques and simplified...

  13. Equivalence of rational representations of behaviors

    NARCIS (Netherlands)

    Gottimukkala, Sasanka; Fiaz, Shaik; Trentelman, H.L.

    This article deals with the equivalence of representations of behaviors of linear differential systems. In general, the behavior of a given linear differential system has many different representations. In this paper we restrict ourselves to kernel and image representations. Two kernel

  14. 24 h stability of thick multilayer silicene in air

    International Nuclear Information System (INIS)

    De Padova, Paola; Ottaviani, Carlo; Quaresima, Claudio; Generosi, Amanda; Paci, Barbara; Le Lay, Guy; Olivieri, Bruno; Imperatori, Patrizia; Salomon, Eric; Angot, Thierry; Quagliano, Lucia; Romano, Claudia; Vona, Alessandro; Muniz-Miranda, Maurizio

    2014-01-01

    Thick epitaxial multilayer silicene films with a √3 × √3R(30°) surface structure show only mild surface oxidation after 24 h in air, as measured by Auger electron spectroscopy. X-ray diffraction and Raman spectroscopy measurements performed in air without any protective capping, as well as, for comparison, with a thin Al 2 O 3 cap, showed the (002) reflection and the G, D and 2D Raman structures, which are unique fingerprints of thick multilayer silicene. (letter)

  15. Are galaxy discs optically thick?

    International Nuclear Information System (INIS)

    Disney, Michael; Davies, Jonathan; Phillipps, Steven

    1989-01-01

    We re-examine the classical optical evidence for the low optical depths traditionally assigned to spiral discs and argue that it is highly model-dependent and unconvincing. In particular, layered models with a physically thin but optically thick dust layer behave like optically thin discs. The opposite hypotheses, that such discs are optically thick is then examined in the light of modern evidence. We find it to be consistent with the near-infrared and IRAS observations, with the surface brightnesses, with the HI and CO column densities and with the Hα measurements. (author)

  16. Equivalent physical models and formulation of equivalent source layer in high-resolution EEG imaging

    International Nuclear Information System (INIS)

    Yao Dezhong; He Bin

    2003-01-01

    In high-resolution EEG imaging, both equivalent dipole layer (EDL) and equivalent charge layer (ECL) assumed to be located just above the cortical surface have been proposed as high-resolution imaging modalities or as intermediate steps to estimate the epicortical potential. Presented here are the equivalent physical models of these two equivalent source layers (ESL) which show that the strength of EDL is proportional to the surface potential of the layer when the outside of the layer is filled with an insulator, and that the strength of ECL is the normal current of the layer when the outside is filled with a perfect conductor. Based on these equivalent physical models, closed solutions of ECL and EDL corresponding to a dipole enclosed by a spherical layer are given. These results provide the theoretical basis of ESL applications in high-resolution EEG mapping

  17. Equivalent physical models and formulation of equivalent source layer in high-resolution EEG imaging

    Energy Technology Data Exchange (ETDEWEB)

    Yao Dezhong [School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu City, 610054, Sichuan Province (China); He Bin [The University of Illinois at Chicago, IL (United States)

    2003-11-07

    In high-resolution EEG imaging, both equivalent dipole layer (EDL) and equivalent charge layer (ECL) assumed to be located just above the cortical surface have been proposed as high-resolution imaging modalities or as intermediate steps to estimate the epicortical potential. Presented here are the equivalent physical models of these two equivalent source layers (ESL) which show that the strength of EDL is proportional to the surface potential of the layer when the outside of the layer is filled with an insulator, and that the strength of ECL is the normal current of the layer when the outside is filled with a perfect conductor. Based on these equivalent physical models, closed solutions of ECL and EDL corresponding to a dipole enclosed by a spherical layer are given. These results provide the theoretical basis of ESL applications in high-resolution EEG mapping.

  18. Eddy current measurement of the thickness of top Cu film of the multilayer interconnects in the integrated circuit (IC) manufacturing process

    Science.gov (United States)

    Qu, Zilian; Meng, Yonggang; Zhao, Qian

    2015-03-01

    This paper proposes a new eddy current method, named equivalent unit method (EUM), for the thickness measurement of the top copper film of multilayer interconnects in the chemical mechanical polishing (CMP) process, which is an important step in the integrated circuit (IC) manufacturing. The influence of the underneath circuit layers on the eddy current is modeled and treated as an equivalent film thickness. By subtracting this equivalent film component, the accuracy of the thickness measurement of the top copper layer with an eddy current sensor is improved and the absolute error is 3 nm for sampler measurement.

  19. [Endoscopic full-thickness resection].

    Science.gov (United States)

    Meier, B; Schmidt, A; Caca, K

    2016-08-01

    Conventional endoscopic resection techniques such as endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) are powerful tools for the treatment of gastrointestinal (GI) neoplasms. However, those techniques are limited to the superficial layers of the GI wall (mucosa and submucosa). Lesions without lifting sign (usually arising from deeper layers) or lesions in difficult anatomic positions (appendix, diverticulum) are difficult - if not impossible - to resect using conventional techniques, due to the increased risk of complications. For larger lesions (>2 cm), ESD appears to be superior to the conventional techniques because of the en bloc resection, but the procedure is technically challenging, time consuming, and associated with complications even in experienced hands. Since the development of the over-the-scope clips (OTSC), complications like bleeding or perforation can be endoscopically better managed. In recent years, different endoscopic full-thickness resection techniques came to the focus of interventional endoscopy. Since September 2014, the full-thickness resection device (FTRD) has the CE marking in Europe for full-thickness resection in the lower GI tract. Technically the device is based on the OTSC system and combines OTSC application and snare polypectomy in one step. This study shows all full-thickness resection techniques currently available, but clearly focuses on the experience with the FTRD in the lower GI tract.

  20. Gammatography of thick lead vessels

    International Nuclear Information System (INIS)

    Raghunath, V.M.; Bhatnagar, P.K.; Sundaram, V.M.

    1979-01-01

    Radiography, scintillation and GM counting and dose measurements using ionisation chamber equipment are commonly used for detecting flaws/voids in materials. The first method is mostly used for steel vessels and to a lesser extent thin lead vessels also and is essentially qualitative. Dose measuring techniques are used for very thick and large lead vessels for which high strength radioactive sources are required, with its inherent handling problems. For vessels of intermediate thicknesses, it is ideal to use a small strength source and a GM or scintillation counter assembly. At the Reactor Research Centre, Kalpakkam, such a system was used for checking three lead vessels of thicknesses varying from 38mm to 65mm. The tolerances specified were +- 4% variation in lead thickness. The measurements also revealed the non concentricity of one vessel which had a thickness varying from 38mm to 44mm. The second vessel was patently non-concentric and the dimensional variation was truly reproduced in the measurements. A third vessel was fabricated with careful control of dimensions and the measurements exhibited good concentricity. Small deviations were observed, attributable to imperfect bondings between steel and lead. This technique has the following advantages: (a) weaker sources used result in less handling problems reducing the personnel exposures considerably; (b) the sensitivity of the instrument is quite good because of better statistics; (c) the time required for scanning a small vessel is more, but a judicious use of a scintillometer for initial fast scan will help in reducing the total scanning time; (d) this method can take advantage of the dimensional variations themselves to get the calibration and to estimate the deviations from specified tolerances. (auth.)

  1. Thick resist for MEMS processing

    Science.gov (United States)

    Brown, Joe; Hamel, Clifford

    2001-11-01

    The need for technical innovation is always present in today's economy. Microfabrication methods have evolved in support of the demand for smaller and faster integrated circuits with price performance improvements always in the scope of the manufacturing design engineer. The dispersion of processing technology spans well beyond IC fabrication today with batch fabrication and wafer scale processing lending advantages to MEMES applications from biotechnology to consumer electronics from oil exploration to aerospace. Today the demand for innovative processing techniques that enable technology is apparent where only a few years ago appeared too costly or not reliable. In high volume applications where yield and cost improvements are measured in fractions of a percent it is imperative to have process technologies that produce consistent results. Only a few years ago thick resist coatings were limited to thickness less than 20 microns. Factors such as uniformity, edge bead and multiple coatings made high volume production impossible. New developments in photoresist formulation combined with advanced coating equipment techniques that closely controls process parameters have enable thick photoresist coatings of 70 microns with acceptable uniformity and edge bead in one pass. Packaging of microelectronic and micromechanical devices is often a significant cost factor and a reliability issue for high volume low cost production. Technologies such as flip- chip assembly provide a solution for cost and reliability improvements over wire bond techniques. The processing for such technology demands dimensional control and presents a significant cost savings if it were compatible with mainstream technologies. Thick photoresist layers, with good sidewall control would allow wafer-bumping technologies to penetrate the barriers to yield and production where costs for technology are the overriding issue. Single pass processing is paramount to the manufacturability of packaging

  2. Effect of carbon nano tube working electrode thickness on charge transport kinetics and photo-electrochemical characteristics of dye-sensitized solar cells

    Science.gov (United States)

    Gacemi, Yahia; Cheknane, Ali; Hilal, Hikmat S.

    2018-02-01

    Physiochemical processes at the photo-electrode and the counter electrode of dye sensitized solar cells (DSSCs) involving having carbon nanotubes (CNTs) instead of the TiO2 layer, within the working electrode, are simulated in this work. Attention is paid to find the effect of CNT layer thickness on photo-electrochemical (PEC) characteristics of the CNT-DSSCs. Comparison with other conventional TiO2-DSSC systems, taking into account the working electrode film thickness, is also described here. To achieve these goals, a model is presented to explain charge transport and electron recombination which involve electron photo-excitation in dye molecules, injection of electrons from the excited dye to CNT working electrode conduction band, diffusion of electrons inside the CNT electrode, charge transfer between oxidized dye and (I-) and recombination of electrons. The simulation is based on solving non-linear equations using the Newton-Raphson numerical method. This concept is proposed for modelling numerical Faradaic impedance at the photo-electrode and the platinum counter electrode. It then simulates the cell impedance spectrum describing the locus of the three semicircles in the Nyquist diagram. The transient equivalent circuit model is also presented based on optimizing current-voltage curves of CNT-DSSCs so as to optimize the fill factor (FF) and conversion efficiency (η). The results show that the simulated characteristics of CNT-DSSCs, with different active CNT layer thicknesses, are superior to conventional TiO2-DSSCs.

  3. Thermal Oxidation of Structured Silicon Dioxide

    DEFF Research Database (Denmark)

    Christiansen, Thomas Lehrmann; Hansen, Ole; Jensen, Jørgen Arendt

    2014-01-01

    The topography of thermally oxidized, structured silicon dioxide is investigated through simulations, atomic force microscopy, and a proposed analytical model. A 357 nm thick oxide is structured by removing regions of the oxide in a masked etch with either reactive ion etching or hydrofluoric acid....... Subsequent thermal oxidation is performed in both dry and wet ambients in the temperature range 950◦C to 1100◦C growing a 205 ± 12 nm thick oxide in the etched mask windows. Lifting of the original oxide near the edge of the mask in the range 6 nm to 37 nm is seen with increased lifting for increasing...

  4. On the equivalence of GPD representations

    International Nuclear Information System (INIS)

    Müller, Dieter; Semenov-Tian-Shansky, Kirill

    2016-01-01

    Phenomenological representations of generalized parton distributions (GPDs) implementing the non-trivial field theoretical requirements are employed in the present day strategies for extracting of hadron structure information encoded in GPDs from the observables of hard exclusive reactions. Showing out the equivalence of various GPD representations can help to get more insight into GPD properties and allow to build up flexible GPD models capable of satisfactory description of the whole set of available experimental data. Below we review the mathematical aspects of establishing equivalence between the the double partial wave expansion of GPDs in the conformal partial waves and in the t-channel SO(3) partial waves and the double distribution representation of GPDs

  5. Developing equivalent circuits for radial distribution networks

    Energy Technology Data Exchange (ETDEWEB)

    Prada, Ricardo; Coelho, Agnelo; Rodrigues, Anselmo [Catholic University of Rio de Janeiro (PUC-Rio), RJ (Brazil). Dept. of Electrical Engineering], Emails: prada@ele.puc-rio.br, agnelo@ele.puc-rio.br, nebulok_99@yahoo.com; Silva, Maria da Guia da [Federal University of Maranhao, Sao Luiz, MA (Brazil). Dept. of Electrical Engineering

    2009-07-01

    This paper presents a method for evaluating External Equivalent in Electric Distribution Networks (EDN).The proposed method has as its main objectives the reduction of the computational costs in distribution network reconfiguration, investigation of the optimal allocation of banks of capacitors, investigation of the allocation of distributed generation, etc. In these sorts of problems a large number of alternative projects must be assessed in order to identify the optimal solution. The optimal solution comes up with the voltage level in the load points within specified limits. Consequently, the EDN must retain the external network load points but without major increasing in the dimension of the equivalent circuit. The proposed method has been tested and validated in a substation of the Electricity Utility of Maranhao - CEMAR, in Brazil. (author)

  6. Thermoluminescence dosemeter for personal dose equivalent assessment

    International Nuclear Information System (INIS)

    Silva, T.A. da; Rosa, L.A.R. da; Campos, L.L.

    1995-01-01

    The possibility was investigated of utilising a Brazilian thermoluminescence individual dosemeter, usually calibrated in terms of photon dose equivalent, for the assessment of the personal dose equivalent, H p (d), at depths of 0.07 and 10 mm. The dosemeter uses four CaSO 4 :Dy thermoluminescent detectors, between different filters, as the sensitive materials. It was calibrated in gamma and X radiation fields in the energy range from 17 to 1250 keV. Linear combinations of the responses of three detectors, in this energy range, allow the evaluation of H p (0.07) and H p (10), for radiation incidence angles varying from 0 to 60 degrees, with an accuracy better than 35%. The method is not applicable to mixed photon-beta fields. (author)

  7. Thevenin Equivalent Method for Dynamic Contingency Assessment

    DEFF Research Database (Denmark)

    Møller, Jakob Glarbo; Jóhannsson, Hjörtur; Østergaard, Jacob

    2015-01-01

    A method that exploits Thevenin equivalent representation for obtaining post-contingency steady-state nodal voltages is integrated with a method of detecting post-contingency aperiodic small-signal instability. The task of integrating stability assessment with contingency assessment is challenged...... by the cases of unstable post-contingency conditions. For unstable postcontingency conditions there exists no credible steady-state which can be used for basis of a stability assessment. This paper demonstrates how Thevenin Equivalent methods can be applied in algebraic representation of such bifurcation...... points which may be used in assessment of post-contingency aperiodic small-signal stability. The assessment method is introduced with a numeric example....

  8. The Logic of Equivalence in Academic Discourse?

    DEFF Research Database (Denmark)

    Madsen, Dorte

    2017-01-01

    of discourse to distinguish between the scientific field, where interrelationships among academic disciplines are taken as an object of research, and the widespread uses of ‘interdisciplinary’ and ‘interdisciplinarity’ in academic discourse more generally, typically for legitimation purposes. The assumption......-discourses meet. It is suggested that the logics of signification, and the tension between difference and equivalence, may be important tools for theorizing this borderland. It is argued that whereas the logic of equivalence and the production of empty signifiers appears to be of marginal interest...... to the scientific field, the logic of difference as a more complex articulation of elements, seems to be more in line with the ideals of academic discourse....

  9. On equivalent resistance of electrical circuits

    Science.gov (United States)

    Kagan, Mikhail

    2015-01-01

    While the standard (introductory physics) way of computing the equivalent resistance of nontrivial electrical circuits is based on Kirchhoff's rules, there is a mathematically and conceptually simpler approach, called the method of nodal potentials, whose basic variables are the values of the electric potential at the circuit's nodes. In this paper, we review the method of nodal potentials and illustrate it using the Wheatstone bridge as an example. We then derive a closed-form expression for the equivalent resistance of a generic circuit, which we apply to a few sample circuits. The result unveils a curious interplay between electrical circuits, matrix algebra, and graph theory and its applications to computer science. The paper is written at a level accessible by undergraduate students who are familiar with matrix arithmetic. Additional proofs and technical details are provided in appendices.

  10. Symmetry adaptation, operator equivalents and magnetic resonance

    International Nuclear Information System (INIS)

    Kibler, M.; Chatterjee, R.

    1977-12-01

    Basic quantities for symmetry adaptation are discussed in connection with molecular and solid state physics. This gives rise to a formalism whose the central elements are operator equivalents adapted to a point group. Such symmetry adapted operator equivalents are defined in terms of Schwinger operators so that they cover the off-diagonal and diagonal cases. Special emphasis is put on the applications of the formalism to magnetic resonance. More specifically, it is shown how to apply the formalism to the construction, the study of the transformation properties, and the determination of the eigenstates of a generalized spin hamiltonian. Numerous examples are given as well as key tables relative to the chain SO(3) for making easy the application of the formalism to electron paramagnetic resonance [fr

  11. A Logical Characterisation of Static Equivalence

    DEFF Research Database (Denmark)

    Hüttel, Hans; Pedersen, Michael D.

    2007-01-01

    -order logic for frames with quantification over environment knowledge which, under certain general conditions, characterizes static equivalence and is amenable to construction of characteristic formulae. The logic can be used to reason about environment knowledge and can be adapted to a particular application...... by defining a suitable signature and associated equational theory. The logic can furthermore be extended with modalities to yield a modal logic for e.g. the Applied Pi calculus....

  12. Global equivalent magnetization of the oceanic lithosphere

    Science.gov (United States)

    Dyment, J.; Choi, Y.; Hamoudi, M.; Lesur, V.; Thebault, E.

    2015-11-01

    As a by-product of the construction of a new World Digital Magnetic Anomaly Map over oceanic areas, we use an original approach based on the global forward modeling of seafloor spreading magnetic anomalies and their comparison to the available marine magnetic data to derive the first map of the equivalent magnetization over the World's ocean. This map reveals consistent patterns related to the age of the oceanic lithosphere, the spreading rate at which it was formed, and the presence of mantle thermal anomalies which affects seafloor spreading and the resulting lithosphere. As for the age, the equivalent magnetization decreases significantly during the first 10-15 Myr after its formation, probably due to the alteration of crustal magnetic minerals under pervasive hydrothermal alteration, then increases regularly between 20 and 70 Ma, reflecting variations in the field strength or source effects such as the acquisition of a secondary magnetization. As for the spreading rate, the equivalent magnetization is twice as strong in areas formed at fast rate than in those formed at slow rate, with a threshold at ∼40 km/Myr, in agreement with an independent global analysis of the amplitude of Anomaly 25. This result, combined with those from the study of the anomalous skewness of marine magnetic anomalies, allows building a unified model for the magnetic structure of normal oceanic lithosphere as a function of spreading rate. Finally, specific areas affected by thermal mantle anomalies at the time of their formation exhibit peculiar equivalent magnetization signatures, such as the cold Australian-Antarctic Discordance, marked by a lower magnetization, and several hotspots, marked by a high magnetization.

  13. Visual Equivalence and Amodal Completion in Cuttlefish

    OpenAIRE

    Lin, I-Rong; Chiao, Chuan-Chin

    2017-01-01

    Modern cephalopods are notably the most intelligent invertebrates and this is accompanied by keen vision. Despite extensive studies investigating the visual systems of cephalopods, little is known about their visual perception and object recognition. In the present study, we investigated the visual processing of the cuttlefish Sepia pharaonis, including visual equivalence and amodal completion. Cuttlefish were trained to discriminate images of shrimp and fish using the operant conditioning pa...

  14. Canonizing certain Borel equivalences for Silver forcing

    Czech Academy of Sciences Publication Activity Database

    Doucha, Michal

    2012-01-01

    Roč. 159, č. 13 (2012), s. 2973-2979 ISSN 0166-8641. [Prague Symposium on General Topology and its Relations to Modern Analysis and Algebra /11./. Prague, 07.08.2011-12.08.2011] Institutional research plan: CEZ:AV0Z10190503 Keywords : Borel equivalence relations * silver ideal * canonical Ramsey theorem Subject RIV: BA - General Mathematics Impact factor: 0.562, year: 2012 http://www.sciencedirect.com/science/article/pii/S0166864112002180#

  15. Quantum mechanics from an equivalence principle

    International Nuclear Information System (INIS)

    Faraggi, A.E.

    1997-01-01

    The authors show that requiring diffeomorphic equivalence for one-dimensional stationary states implies that the reduced action S 0 satisfies the quantum Hamilton-Jacobi equation with the Planck constant playing the role of a covariantizing parameter. The construction shows the existence of a fundamental initial condition which is strictly related to the Moebius symmetry of the Legendre transform and to its involutive character. The universal nature of the initial condition implies the Schroedinger equation in any dimension

  16. Equivalency of two-dimensional algebras

    International Nuclear Information System (INIS)

    Santos, Gildemar Carneiro dos; Pomponet Filho, Balbino Jose S.

    2011-01-01

    Full text: Let us consider a vector z = xi + yj over the field of real numbers, whose basis (i,j) satisfy a given algebra. Any property of this algebra will be reflected in any function of z, so we can state that the knowledge of the properties of an algebra leads to more general conclusions than the knowledge of the properties of a function. However structural properties of an algebra do not change when this algebra suffers a linear transformation, though the structural constants defining this algebra do change. We say that two algebras are equivalent to each other whenever they are related by a linear transformation. In this case, we have found that some relations between the structural constants are sufficient to recognize whether or not an algebra is equivalent to another. In spite that the basis transform linearly, the structural constants change like a third order tensor, but some combinations of these tensors result in a linear transformation, allowing to write the entries of the transformation matrix as function of the structural constants. Eventually, a systematic way to find the transformation matrix between these equivalent algebras is obtained. In this sense, we have performed the thorough classification of associative commutative two-dimensional algebras, and find that even non-division algebra may be helpful in solving non-linear dynamic systems. The Mandelbrot set was used to have a pictorial view of each algebra, since equivalent algebras result in the same pattern. Presently we have succeeded in classifying some non-associative two-dimensional algebras, a task more difficult than for associative one. (author)

  17. Cryogenic test of the equivalence principle

    International Nuclear Information System (INIS)

    Worden, P.W. Jr.

    1976-01-01

    The weak equivalence principle is the hypothesis that the ratio of internal and passive gravitational mass is the same for all bodies. A greatly improved test of this principle is possible in an orbiting satellite. The most promising experiments for an orbital test are adaptations of the Galilean free-fall experiment and the Eotvos balance. Sensitivity to gravity gradient noise, both from the earth and from the spacecraft, defines a limit to the sensitivity in each case. This limit is generally much worse for an Eotvos balance than for a properly designed free-fall experiment. The difference is related to the difficulty of making a balance sufficiently isoinertial. Cryogenic technology is desirable to take full advantage of the potential sensitivity, but tides in the liquid helium refrigerant may produce a gravity gradient that seriously degrades the ultimate sensitivity. The Eotvos balance appears to have a limiting sensitivity to relative difference of rate of fall of about 2 x 10 -14 in orbit. The free-fall experiment is limited by helium tide to about 10 -15 ; if the tide can be controlled or eliminated the limit may approach 10 -18 . Other limitations to equivalence principle experiments are discussed. An experimental test of some of the concepts involved in the orbital free-fall experiment is continuing. The experiment consists in comparing the motions of test masses levitated in a superconducting magnetic bearing, and is itself a sensitive test of the equivalence principle. At present the levitation magnets, position monitors and control coils have been tested and major noise sources identified. A measurement of the equivalence principle is postponed pending development of a system for digitizing data. The experiment and preliminary results are described

  18. Extended equivalent dipole model for radiated emissions

    OpenAIRE

    Obiekezie, Chijioke S.

    2016-01-01

    This work is on the characterisation of radiated fields from electronic devices. An equivalent dipole approach is used. Previous work showed that this was an effective approach for single layer printed circuit boards where an infinite ground plane can be assumed. In this work, this approach is extended for the characterisation of more complex circuit boards or electronic systems.\\ud For complex electronic radiators with finite ground planes, the main challenge is characterising field diffract...

  19. Investigation of the Section Thickness Measurement in Tomosynthesis by Thin Metal Plate Edge Method.

    Science.gov (United States)

    Ikeno, Kaoru; Akita, Tsunemichi; Hanai, Kozo; Muramatsu, Yoshihisa

    When performing tomosynthesis, the section thickness needs to be set depending on a radiographic part and its diagnostic purpose. However, the section thickness in tomosynthesis has not been clearly defined and its measurement method has not been established yet. In this study, we devised the alternative measurement method to diagnose the section thickness using an edge of thin metal plate, and compared with the simulation results, the wire and bead method reported in the previous papers. The tomographic image of the thin metal plate positioned on the table top inclining 30 degrees, which showed the edge spread function (ESF) of each tomographic height, was taken, and then the line spread function (LSF) was obtained by differentiating the ESF image. For the next, a profile curve was plotted by maximum values of LSF of each tomographic height, and a section thickness was calculated using the full width at half maximum (FWHM) of the profile curve. The edge method derived the section thickness close to the simulation results than the other methods. Further, the section thickness depends on the thickness of the metal plate and not the material. The thickness of the metal plate suitable for the evaluation of section thickness is 0.3 mm that is equivalent to pixel size of the flat panel detector (FPD). We conducted quantitative verification to establish the measurement method of the section thickness. The edge method is a useful technique as well as the wire and bead method for grasping basic characteristics of an imaging system.

  20. Correlation between zirconium oxide impedance and corrosion behavior of Zr-Nb-Sn-Fe-Cu alloys

    International Nuclear Information System (INIS)

    Park, Sang Yoon; Lee, Myung Ho; Choi, Byoung Kwon; Jeong, Yong Hwan; Jung, Youn Ho

    2001-01-01

    To evaluate the correlation of Zr oxide impedance and corrosion behavior of Zr-Nb-Sn-Fe-Cu alloys, the corrosion behavior of the alloys was tested in the autoclave containing 70 ppm LiOH solution at 360 .deg. C. The characteristics of the oxide on the alloys were investigated by using the electrochemical impedance spectrosocpy (EIS) method. The corrosion resistance of the alloys was evaluated from the corrosion rate determined as a function of the concentration of Nb. The equivalent circuit of the oxide was composed on the base of the spectrum from EIS measurements on the oxide layers that had formed at pre-and post-transition regions on the curve of corrosion rate. By using the capacitance characteristics of the equivalent circuit, the thickness of impervious layer, it's electrical resistance and characteristics of space charge layer were evaluated. The corrosion characteristics of the Zr-Nb-Sn-Fe-Cu alloys were successfully explained by applying the EIS test results

  1. Equivalence of Lagrangian and Hamiltonian BRST quantizations

    International Nuclear Information System (INIS)

    Grigoryan, G.V.; Grigoryan, R.P.; Tyutin, I.V.

    1992-01-01

    Two approaches to the quantization of gauge theories using BRST symmetry are widely used nowadays: the Lagrangian quantization, developed in (BV-quantization) and Hamiltonian quantization, formulated in (BFV-quantization). For all known examples of field theory (Yang-Mills theory, gravitation etc.) both schemes give equivalent results. However the equivalence of these approaches in general wasn't proved. The main obstacle in comparing of these formulations consists in the fact, that in Hamiltonian approach the number of ghost fields is equal to the number of all first-class constraints, while in the Lagrangian approach the number of ghosts is equal to the number of independent gauge symmetries, which is equal to the number of primary first-class constraints only. This paper is devoted to the proof of the equivalence of Lagrangian and Hamiltonian quantizations for the systems with first-class constraints only. This is achieved by a choice of special gauge in the Hamiltonian approach. It's shown, that after integration over redundant variables on the functional integral we come to effective action which is constructed according to rules for construction of the effective action in Lagrangian quantization scheme

  2. Energy conservation and the principle of equivalence

    International Nuclear Information System (INIS)

    Haugan, M.P.

    1979-01-01

    If the equivalence principle is violated, then observers performing local experiments can detect effects due to their position in an external gravitational environment (preferred-location effects) or can detect effects due to their velocity through some preferred frame (preferred frame effects). We show that the principle of energy conservation implies a quantitative connection between such effects and structure-dependence of the gravitational acceleration of test bodies (violation of the Weak Equivalence Principle). We analyze this connection within a general theoretical framework that encompasses both non-gravitational local experiments and test bodies as well as gravitational experiments and test bodies, and we use it to discuss specific experimental tests of the equivalence principle, including non-gravitational tests such as gravitational redshift experiments, Eoetvoes experiments, the Hughes-Drever experiment, and the Turner-Hill experiment, and gravitational tests such as the lunar-laser-ranging ''Eoetvoes'' experiment, and measurements of anisotropies and variations in the gravitational constant. This framework is illustrated by analyses within two theoretical formalisms for studying gravitational theories: the PPN formalism, which deals with the motion of gravitating bodies within metric theories of gravity, and the THepsilonμ formalism that deals with the motion of charged particles within all metric theories and a broad class of non-metric theories of gravity

  3. Control of Alq3 wetting layer thickness via substrate surface functionalization.

    Science.gov (United States)

    Tsoi, Shufen; Szeto, Bryan; Fleischauer, Michael D; Veinot, Jonathan G C; Brett, Michael J

    2007-06-05

    The effects of substrate surface energy and vapor deposition rate on the initial growth of porous columnar tris(8-hydroxyquinoline)aluminum (Alq3) nanostructures were investigated. Alq3 nanostructures thermally evaporated onto as-supplied Si substrates bearing an oxide were observed to form a solid wetting layer, likely caused by an interfacial energy mismatch between the substrate and Alq3. Wetting layer thickness control is important for potential optoelectronic applications. A dramatic decrease in wetting layer thickness was achieved by depositing Alq3 onto alkyltrichlorosilane-derivatized Si/oxide substrates. Similar effects were noted with increasing deposition rates. These two effects enable tailoring of the wetting layer thickness.

  4. SWEAT: Snow Water Equivalent with AlTimetry

    Science.gov (United States)

    Agten, Dries; Benninga, Harm-Jan; Diaz Schümmer, Carlos; Donnerer, Julia; Fischer, Georg; Henriksen, Marie; Hippert Ferrer, Alexandre; Jamali, Maryam; Marinaci, Stefano; Mould, Toby JD; Phelan, Liam; Rosker, Stephanie; Schrenker, Caroline; Schulze, Kerstin; Emanuel Telo Bordalo Monteiro, Jorge

    2017-04-01

    To study how the water cycle changes over time, satellite and airborne remote sensing missions are typically employed. Over the last 40 years of satellite missions, the measurement of true water inventories stored in sea and land ice within the cryosphere have been significantly hindered by uncertainties introduced by snow cover. Being able to determine the thickness of this snow cover would act to reduce such error, improving current estimations of hydrological and climate models, Earth's energy balance (albedo) calculations and flood predictions. Therefore, the target of the SWEAT (Snow Water Equivalent with AlTimetry) mission is to directly measure the surface Snow Water Equivalent (SWE) on sea and land ice within the polar regions above 60°and below -60° latitude. There are no other satellite missions currently capable of directly measuring SWE. In order to achieve this, the proposed mission will implement a novel combination of Ka- and Ku-band radioaltimeters (active microwave sensors), capable of penetrating into the snow microstructure. The Ka-band altimeter (λ ≈ 0.8 cm) provides a low maximum snow pack penetration depth of up to 20 cm for dry snow at 37 GHz, since the volume scattering of snow dominates over the scattering caused by the underlying ice surface. In contrast, the Ku-band altimeter (λ ≈ 2 cm) provides a high maximum snowpack penetration depth of up to 15 m in high latitudes regions with dry snow, as volume scattering is decreased by a factor of 55. The combined difference in Ka- and Ku-band signal penetration results will provide more accurate and direct determination of SWE. Therefore, the SWEAT mission aims to improve estimations of global SWE interpreted from passive microwave products, and improve the reliability of numerical snow and climate models.

  5. Calculation of equivalent dose index for electrons from 5,0 to 22,0 MeV by the Monte Carlo method

    International Nuclear Information System (INIS)

    Peixoto, J.E.

    1979-01-01

    The index of equivalent dose in depth and in a sphere surface of a soft tissue equivalent material were determined by Monte Carlo method for electron irradiations from 5,0 to 22.00 MeV. The effect of different irradiation geometries which simulate the incidence of onedirectional opposite rotational and isotropic beams was studied. It is also shown that the detector of wall thickness with 0.5g/cm 2 and isotropic response com be used to measure index of equivalent dose for fast electrons. The alternative concept of average equivalent dose for radiation protection is discussed. (M.C.K.) [pt

  6. Interfacial and electrical properties of HfAlO/GaSb metal-oxide-semiconductor capacitors with sulfur passivation

    International Nuclear Information System (INIS)

    Tan Zhen; Zhao Lian-Feng; Wang Jing; Xu Jun

    2014-01-01

    Interfacial and electrical properties of HfAlO/GaSb metal-oxide-semiconductor capacitors (MOSCAPs) with sulfur passivation were investigated and the chemical mechanisms of the sulfur passivation process were carefully studied. It was shown that the sulfur passivation treatment could reduce the interface trap density D it of the HfAlO/GaSb interface by 35% and reduce the equivalent oxide thickness (EOT) from 8 nm to 4 nm. The improved properties are due to the removal of the native oxide layer, as was proven by x-ray photoelectron spectroscopy measurements and high-resolution cross-sectional transmission electron microscopy (HRXTEM) results. It was also found that GaSb-based MOSCAPs with HfAlO gate dielectrics have interfacial properties superior to those using HfO 2 or Al 2 O 3 dielectric layers. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  7. Gauge equivalence of the Gross Pitaevskii equation and the equivalent Heisenberg spin chain

    Science.gov (United States)

    Radha, R.; Kumar, V. Ramesh

    2007-11-01

    In this paper, we construct an equivalent spin chain for the Gross-Pitaevskii equation with quadratic potential and exponentially varying scattering lengths using gauge equivalence. We have then generated the soliton solutions for the spin components S3 and S-. We find that the spin solitons for S3 and S- can be compressed for exponentially growing eigenvalues while they broaden out for decaying eigenvalues.

  8. Equivalent models of wind farms by using aggregated wind turbines and equivalent winds

    International Nuclear Information System (INIS)

    Fernandez, L.M.; Garcia, C.A.; Saenz, J.R.; Jurado, F.

    2009-01-01

    As a result of the increasing wind farms penetration on power systems, the wind farms begin to influence power system, and therefore the modeling of wind farms has become an interesting research topic. In this paper, new equivalent models of wind farms equipped with wind turbines based on squirrel-cage induction generators and doubly-fed induction generators are proposed to represent the collective behavior on large power systems simulations, instead of using a complete model of wind farms where all the wind turbines are modeled. The models proposed here are based on aggregating wind turbines into an equivalent wind turbine which receives an equivalent wind of the ones incident on the aggregated wind turbines. The equivalent wind turbine presents re-scaled power capacity and the same complete model as the individual wind turbines, which supposes the main feature of the present equivalent models. Two equivalent winds are evaluated in this work: (1) the average wind from the ones incident on the aggregated wind turbines with similar winds, and (2) an equivalent incoming wind derived from the power curve and the wind incident on each wind turbine. The effectiveness of the equivalent models to represent the collective response of the wind farm at the point of common coupling to grid is demonstrated by comparison with the wind farm response obtained from the detailed model during power system dynamic simulations, such as wind fluctuations and a grid disturbance. The present models can be used for grid integration studies of large power system with an important reduction of the model order and the computation time

  9. Accurate thickness measurement of graphene

    International Nuclear Information System (INIS)

    Shearer, Cameron J; Slattery, Ashley D; Stapleton, Andrew J; Shapter, Joseph G; Gibson, Christopher T

    2016-01-01

    Graphene has emerged as a material with a vast variety of applications. The electronic, optical and mechanical properties of graphene are strongly influenced by the number of layers present in a sample. As a result, the dimensional characterization of graphene films is crucial, especially with the continued development of new synthesis methods and applications. A number of techniques exist to determine the thickness of graphene films including optical contrast, Raman scattering and scanning probe microscopy techniques. Atomic force microscopy (AFM), in particular, is used extensively since it provides three-dimensional images that enable the measurement of the lateral dimensions of graphene films as well as the thickness, and by extension the number of layers present. However, in the literature AFM has proven to be inaccurate with a wide range of measured values for single layer graphene thickness reported (between 0.4 and 1.7 nm). This discrepancy has been attributed to tip-surface interactions, image feedback settings and surface chemistry. In this work, we use standard and carbon nanotube modified AFM probes and a relatively new AFM imaging mode known as PeakForce tapping mode to establish a protocol that will allow users to accurately determine the thickness of graphene films. In particular, the error in measuring the first layer is reduced from 0.1–1.3 nm to 0.1–0.3 nm. Furthermore, in the process we establish that the graphene-substrate adsorbate layer and imaging force, in particular the pressure the tip exerts on the surface, are crucial components in the accurate measurement of graphene using AFM. These findings can be applied to other 2D materials. (paper)

  10. Soliton models for thick branes

    International Nuclear Information System (INIS)

    Peyravi, Marzieh; Riazi, Nematollah; Lobo, Francisco S.N.

    2016-01-01

    In this work, we present new soliton solutions for thick branes in 4+1 dimensions. In particular, we consider brane models based on the sine-Gordon (SG), φ 4 and φ 6 scalar fields, which have broken Z 2 symmetry in some cases and are responsible for supporting and stabilizing the thick branes. The origin of the symmetry breaking in these models resides in the fact that the modified scalar field potential may have non-degenerate vacua. These vacua determine the cosmological constant on both sides of the brane. We also study the geodesic equations along the fifth dimension, in order to explore the particle motion in the neighborhood of the brane. Furthermore, we examine the stability of the thick branes, by determining the sign of the w 2 term in the expansion of the potential for the resulting Schroedinger-like equation, where w is the five-dimensional coordinate. It turns out that the φ 4 brane is stable, while there are unstable modes for certain ranges of the model parameters in the SG and φ 6 branes. (orig.)

  11. Soliton models for thick branes

    Energy Technology Data Exchange (ETDEWEB)

    Peyravi, Marzieh [Ferdowsi University of Mashhad, Department of Physics, School of Sciences, Mashhad (Iran, Islamic Republic of); Riazi, Nematollah [Shahid Beheshti University, Physics Department, Tehran (Iran, Islamic Republic of); Lobo, Francisco S.N. [Faculdade de Ciencias da Universidade de Lisboa, Instituto de Astrofisica e Ciencias do Espaco, Lisbon (Portugal)

    2016-05-15

    In this work, we present new soliton solutions for thick branes in 4+1 dimensions. In particular, we consider brane models based on the sine-Gordon (SG), φ{sup 4} and φ{sup 6} scalar fields, which have broken Z{sub 2} symmetry in some cases and are responsible for supporting and stabilizing the thick branes. The origin of the symmetry breaking in these models resides in the fact that the modified scalar field potential may have non-degenerate vacua. These vacua determine the cosmological constant on both sides of the brane. We also study the geodesic equations along the fifth dimension, in order to explore the particle motion in the neighborhood of the brane. Furthermore, we examine the stability of the thick branes, by determining the sign of the w{sup 2} term in the expansion of the potential for the resulting Schroedinger-like equation, where w is the five-dimensional coordinate. It turns out that the φ{sup 4} brane is stable, while there are unstable modes for certain ranges of the model parameters in the SG and φ{sup 6} branes. (orig.)

  12. Electrical equivalent circuit of an ion-exchange membrane system

    Energy Technology Data Exchange (ETDEWEB)

    Nikonenko, Victor V., E-mail: v_nikonenko@mail.r [Membrane Institute, Kuban State University, Krasnodar (Russian Federation); Kozmai, Anton E. [Membrane Institute, Kuban State University, Krasnodar (Russian Federation)

    2011-01-01

    Usually, the current flowing through an electrochemical cell is divided into the faradaic current going to an electrochemical interface reaction, and the current charging electric double layer (EDL). This division leads to the Randles-Ershler equivalent circuit with an EDL capacitance in one branch, and the faradaic impedance in the other, specific for each particular system. However, the physics of the separation of the impedance into faradaic and capacitive components for different electrochemical systems is not sufficiently clear. The most of derivations resulting in the formal construction of the Randles-Ershler or similar equivalent circuits are based on the a priori separation of the electroneutral and the double-layer regions. In this paper, we derive an equation for the impedance of a three-layer system consisted of an ion-exchange membrane and two adjoining diffusion boundary layers (DBL) starting from the Poisson equation. The system is polarized by a constant electric current over which a small sinusoidal signal is applied. The equation shows that the impedance of the considered system can be formally interpreted via an equivalent circuit with a frequency dependent capacitance in one branch and a finite-length Warburg-type impedance in the other. To take into account this dependence, the impedance of the system may be presented as a series connection of five circuits. Three of them are consisted of a geometric capacitance connected in parallel with an ohmic resistance, respectively, for both diffusion layers and for the membrane bulk; the two others being the double-layer capacitance in parallel with the finite-length Warburg impedance for the left and the right interfaces, respectively. The comparison of the impedance spectra calculated within our analytical approach with those obtained by the full numerical solution of the Nernst-Planck-Poisson (NPP) equations shows a good agreement. Different possible situations, which might arise in real systems

  13. Frequency characteristics of the MIM thick film capacitors fabricated by laser micro-cladding electronic pastes

    International Nuclear Information System (INIS)

    Cao Yu; Li Xiangyou; Zeng Xiaoyan

    2008-01-01

    With rapid development of the electronic industry, how to respond the market requests quickly, shorten R and D prototyping fabrication period, and reduce the cost of the electronic devices have become a challenge work, which need flexible manufacturing methods. In this work, two direct write processing methods, direct material deposition by microPen and Nd:YAG laser micro-cladding, are integrated with CAD/CAM technology for the hybrid fabrication of passive electronic components. Especially, the metal-insulator-metal (MIM) type thick film capacitors are fabricated on ceramic substrates by this method. A basic two-step procedure of laser micro-cladding electronic pastes (LMCEPs) process for the thick film pattern preparation is presented. For a better understanding of the MIM thick film capacitor characterization, equivalent circuit models at low-frequency and high-frequency domains are introduced, respectively. The frequency characteristics tests up to 1.8 GHz of capacitance stability, equivalent series resistance (ESR), equivalent series inductance (ESL) and impendence are performed, and the results show good DC voltage stability (<2.48%), good frequency stability (<2.6%) and low dissipation factor (<0.6%) of the MIM thick film capacitors, which may get application to megahertz regions. The further developments of the LMCEP process for fabricating MIM thick film capacitors are also investigated

  14. Frequency characteristics of the MIM thick film capacitors fabricated by laser micro-cladding electronic pastes

    Energy Technology Data Exchange (ETDEWEB)

    Cao Yu; Li Xiangyou [Wuhan National Laboratory for Optoelectronics, Huazhong University of Sci and Tech, 430074 Wuhan, Hubei (China); Zeng Xiaoyan [Wuhan National Laboratory for Optoelectronics, Huazhong University of Sci and Tech, 430074 Wuhan, Hubei (China)], E-mail: xyzeng@mail.hust.edu.cn

    2008-05-25

    With rapid development of the electronic industry, how to respond the market requests quickly, shorten R and D prototyping fabrication period, and reduce the cost of the electronic devices have become a challenge work, which need flexible manufacturing methods. In this work, two direct write processing methods, direct material deposition by microPen and Nd:YAG laser micro-cladding, are integrated with CAD/CAM technology for the hybrid fabrication of passive electronic components. Especially, the metal-insulator-metal (MIM) type thick film capacitors are fabricated on ceramic substrates by this method. A basic two-step procedure of laser micro-cladding electronic pastes (LMCEPs) process for the thick film pattern preparation is presented. For a better understanding of the MIM thick film capacitor characterization, equivalent circuit models at low-frequency and high-frequency domains are introduced, respectively. The frequency characteristics tests up to 1.8 GHz of capacitance stability, equivalent series resistance (ESR), equivalent series inductance (ESL) and impendence are performed, and the results show good DC voltage stability (<2.48%), good frequency stability (<2.6%) and low dissipation factor (<0.6%) of the MIM thick film capacitors, which may get application to megahertz regions. The further developments of the LMCEP process for fabricating MIM thick film capacitors are also investigated.

  15. Generating carbyne equivalents with photoredox catalysis

    Science.gov (United States)

    Wang, Zhaofeng; Herraiz, Ana G.; Del Hoyo, Ana M.; Suero, Marcos G.

    2018-02-01

    Carbon has the unique ability to bind four atoms and form stable tetravalent structures that are prevalent in nature. The lack of one or two valences leads to a set of species—carbocations, carbanions, radicals and carbenes—that is fundamental to our understanding of chemical reactivity. In contrast, the carbyne—a monovalent carbon with three non-bonded electrons—is a relatively unexplored reactive intermediate; the design of reactions involving a carbyne is limited by challenges associated with controlling its extreme reactivity and the lack of efficient sources. Given the innate ability of carbynes to form three new covalent bonds sequentially, we anticipated that a catalytic method of generating carbynes or related stabilized species would allow what we term an ‘assembly point’ disconnection approach for the construction of chiral centres. Here we describe a catalytic strategy that generates diazomethyl radicals as direct equivalents of carbyne species using visible-light photoredox catalysis. The ability of these carbyne equivalents to induce site-selective carbon-hydrogen bond cleavage in aromatic rings enables a useful diazomethylation reaction, which underpins sequencing control for the late-stage assembly-point functionalization of medically relevant agents. Our strategy provides an efficient route to libraries of potentially bioactive molecules through the installation of tailored chiral centres at carbon-hydrogen bonds, while complementing current translational late-stage functionalization processes. Furthermore, we exploit the dual radical and carbene character of the generated carbyne equivalent in the direct transformation of abundant chemical feedstocks into valuable chiral molecules.

  16. Equivalent conserved currents and generalized Noether's theorem

    International Nuclear Information System (INIS)

    Gordon, T.J.

    1984-01-01

    A generalized Noether theorem is presented, relating symmetries and equivalence classes of local) conservation laws in classical field theories; this is contrasted with the standard theorem. The concept of a ''Noether'' field theory is introduced, being a theory for which the generalized theorem applies; not only does this include the cases of Lagrangian and Hamiltonian field theories, these structures are ''derived'' from the Noether property in a natural way. The generalized theorem applies to currents and symmetries that contain derivatives of the fields up to an arbitrarily high order

  17. Gravitational leptogenesis, C, CP and strong equivalence

    International Nuclear Information System (INIS)

    McDonald, Jamie I.; Shore, Graham M.

    2015-01-01

    The origin of matter-antimatter asymmetry is one of the most important outstanding problems at the interface of particle physics and cosmology. Gravitational leptogenesis (baryogenesis) provides a possible mechanism through explicit couplings of spacetime curvature to appropriate lepton (or baryon) currents. In this paper, the idea that these strong equivalence principle violating interactions could be generated automatically through quantum loop effects in curved spacetime is explored, focusing on the realisation of the discrete symmetries C, CP and CPT which must be broken to induce matter-antimatter asymmetry. The related issue of quantum corrections to the dispersion relation for neutrino propagation in curved spacetime is considered within a fully covariant framework.

  18. European Equivalencies in Legal Interpreting and Translation

    DEFF Research Database (Denmark)

    Corsellis, Ann; Hertog, Erik; Martinsen, Bodil

    2002-01-01

    Within Europe there is increasing freedom of movement between countries and increasing inward migration. As a result, equivalent standards of legl interpreting and translation are required to allow reliable communication for judicial cooperation between member states, for criminal and civil matters...... which cross national borders and for the needs of multilingual populations. The European Convention of Human Rights (article 6, paragrph 3) is one of the main planks of relevant legislation. This international, two year project has been funded by the EU Grotius programme to set out what is required...

  19. Testing efficiency transfer codes for equivalence

    International Nuclear Information System (INIS)

    Vidmar, T.; Celik, N.; Cornejo Diaz, N.; Dlabac, A.; Ewa, I.O.B.; Carrazana Gonzalez, J.A.; Hult, M.; Jovanovic, S.; Lepy, M.-C.; Mihaljevic, N.; Sima, O.; Tzika, F.; Jurado Vargas, M.; Vasilopoulou, T.; Vidmar, G.

    2010-01-01

    Four general Monte Carlo codes (GEANT3, PENELOPE, MCNP and EGS4) and five dedicated packages for efficiency determination in gamma-ray spectrometry (ANGLE, DETEFF, GESPECOR, ETNA and EFFTRAN) were checked for equivalence by applying them to the calculation of efficiency transfer (ET) factors for a set of well-defined sample parameters, detector parameters and energies typically encountered in environmental radioactivity measurements. The differences between the results of the different codes never exceeded a few percent and were lower than 2% in the majority of cases.

  20. The equivalence principle in a quantum world

    DEFF Research Database (Denmark)

    Bjerrum-Bohr, N. Emil J.; Donoghue, John F.; El-Menoufi, Basem Kamal

    2015-01-01

    the energy is small, we now have the tools to address this conflict explicitly. Despite the violation of some classical concepts, the EP continues to provide the core of the quantum gravity framework through the symmetry - general coordinate invariance - that is used to organize the effective field theory......We show how modern methods can be applied to quantum gravity at low energy. We test how quantum corrections challenge the classical framework behind the equivalence principle (EP), for instance through introduction of nonlocality from quantum physics, embodied in the uncertainty principle. When...

  1. Equivalent Circuit Modeling of Hysteresis Motors

    Energy Technology Data Exchange (ETDEWEB)

    Nitao, J J; Scharlemann, E T; Kirkendall, B A

    2009-08-31

    We performed a literature review and found that many equivalent circuit models of hysteresis motors in use today are incorrect. The model by Miyairi and Kataoka (1965) is the correct one. We extended the model by transforming it to quadrature coordinates, amenable to circuit or digital simulation. 'Hunting' is an oscillatory phenomenon often observed in hysteresis motors. While several works have attempted to model the phenomenon with some partial success, we present a new complete model that predicts hunting from first principles.

  2. Money and bonds: an equivalence theorem

    OpenAIRE

    Narayana R. Kocherlakota

    2007-01-01

    This paper considers four models in which immortal agents face idiosyncratic shocks and trade only a single risk-free asset over time. The four models specify this single asset to be private bonds, public bonds, public money, or private money respectively. I prove that, given an equilibrium in one of these economies, it is possible to pick the exogenous elements in the other three economies so that there is an outcome-equivalent equilibrium in each of them. (The term ?exogenous variables? ref...

  3. Gravitational leptogenesis, C, CP and strong equivalence

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, Jamie I.; Shore, Graham M. [Department of Physics, Swansea University,Swansea, SA2 8PP (United Kingdom)

    2015-02-12

    The origin of matter-antimatter asymmetry is one of the most important outstanding problems at the interface of particle physics and cosmology. Gravitational leptogenesis (baryogenesis) provides a possible mechanism through explicit couplings of spacetime curvature to appropriate lepton (or baryon) currents. In this paper, the idea that these strong equivalence principle violating interactions could be generated automatically through quantum loop effects in curved spacetime is explored, focusing on the realisation of the discrete symmetries C, CP and CPT which must be broken to induce matter-antimatter asymmetry. The related issue of quantum corrections to the dispersion relation for neutrino propagation in curved spacetime is considered within a fully covariant framework.

  4. Diffusion of hydrogen in iron oxides

    International Nuclear Information System (INIS)

    Bruzzoni, P.

    1993-01-01

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

  5. Dose determination algorithms for a nearly tissue equivalent multi-element thermoluminescent dosimeter

    International Nuclear Information System (INIS)

    Moscovitch, M.; Chamberlain, J.; Velbeck, K.J.

    1988-01-01

    In a continuing effort to develop dosimetric systems that will enable reliable interpretation of dosimeter readings in terms of the absorbed dose or dose-equivalent, a new multi-element TL dosimeter assembly for Beta and Gamma dose monitoring has been designed. The radiation-sensitive volumes are four LiF-TLD elements, each covered by its own unique filter. For media-matching, care has been taken to employ nearly tissue equivalent filters of thicknesses of 1000 mg/cm 2 and 300 mg/cm 2 for deep dose and dose to the lens-of-the-eye measurements respectively. Only one metal filter (Cu) is employed to provide low energy photon discrimination. A Thin TL element (0.09 mm thick) is located behind an open window designed to improve the energy under-response to low energy beta rays and to provide closer estimate of the shallow dose equivalent. The deep and shallow dose equivalents are derived from the correlation of the response of the various TL elements to the above quantities through computations based on previously defined relationships obtained from experimental results. The theoretical formalization for the dose calculation algorithms is described in detail, and provides a useful methodology which can be applied to different tissue-equivalent dosimeter assemblies. Experimental data has been obtained by performing irradiation according to the specifications established by DOELAP, using 27 types of pure and mixed radiation fields including Cs-137 gamma rays, low energy photons down to 20 keV, Sr/Y-90, Uranium, and Tl-204 beta particles

  6. Investigation on the dominant key to achieve superior Ge surface passivation by GeOx based on the ozone oxidation

    International Nuclear Information System (INIS)

    Wang, Xiaolei; Xiang, Jinjuan; Wang, Wenwu; Xiong, Yuhua; Zhang, Jing; Zhao, Chao

    2015-01-01

    Highlights: • The dominant key to achieve superior Ge passivation by GeO x is investigated. • The interface state density decreases with increasing the GeO x thickness. • The Ge 3+ oxide component is the dominant key to passivate the Ge surface. • The atomic structure at the GeO x /Ge interface is built by XPS. - Abstract: The dominant key to achieve superior Ge surface passivation by GeO x interfacial layer is investigated based on ozone oxidation. The interface state density (D it ) measured from low temperature conduction method is found to decrease with increasing the GeO x thickness (0.26–1.06 nm). The X-ray photoelectron spectroscopy (XPS) is employed to demonstrate the interfacial structure of GeO x /Ge with different GeO x thicknesses. And the XPS results show that Ge 3+ oxide component is responsible to the decrease of the D it due to the effective passivation of Ge dangling bonds. Therefore, the formation of Ge 3+ component is the dominant key to achieve low D it for Ge gate stacks. Our work confirms that the same physical mechanism determines the Ge surface passivation by the GeO x regardless of the oxidation methods to grow the GeO x interfacial layer. As a result, to explore a growth process that can realize sufficient Ge 3+ component in the GeO x interlayer as thin as possible is important to achieve both equivalent oxide thickness scaling and superior interfacial property simultaneously. This conclusion is helpful to engineer the optimization of the Ge gate stacks.

  7. The crustal thickness of Australia

    Science.gov (United States)

    Clitheroe, G.; Gudmundsson, O.; Kennett, B.L.N.

    2000-01-01

    We investigate the crustal structure of the Australian continent using the temporary broadband stations of the Skippy and Kimba projects and permanent broadband stations. We isolate near-receiver information, in the form of crustal P-to-S conversions, using the receiver function technique. Stacked receiver functions are inverted for S velocity structure using a Genetic Algorithm approach to Receiver Function Inversion (GARFI). From the resulting velocity models we are able to determine the Moho depth and to classify the width of the crust-mantle transition for 65 broadband stations. Using these results and 51 independent estimates of crustal thickness from refraction and reflection profiles, we present a new, improved, map of Moho depth for the Australian continent. The thinnest crust (25 km) occurs in the Archean Yilgarn Craton in Western Australia; the thickest crust (61 km) occurs in Proterozoic central Australia. The average crustal thickness is 38.8 km (standard deviation 6.2 km). Interpolation error estimates are made using kriging and fall into the range 2.5-7.0 km. We find generally good agreement between the depth to the seismologically defined Moho and xenolith-derived estimates of crustal thickness beneath northeastern Australia. However, beneath the Lachlan Fold Belt the estimates are not in agreement, and it is possible that the two techniques are mapping differing parts of a broad Moho transition zone. The Archean cratons of Western Australia appear to have remained largely stable since cratonization, reflected in only slight variation of Moho depth. The largely Proterozoic center of Australia shows relatively thicker crust overall as well as major Moho offsets. We see evidence of the margin of the contact between the Precambrian craton and the Tasman Orogen, referred to as the Tasman Line. Copyright 2000 by the American Geophysical Union.

  8. Semiconducting properties of oxide films formed onto an Nb electrode in NaOH solutions

    Directory of Open Access Journals (Sweden)

    VLADIMIR D. JOVIC

    2008-03-01

    Full Text Available In this paper, the results of the potentiostatic formation of homogeneous and heterogeneous, nano-crystalline passive films of Nb2O5 onto an Nb electrode in NaOH solutions of different concentrations at potentials lower than 3.0 V vs. SCE are presented. The semiconducting properties of such films were investigated by EIS measurements. After fitting the EIS results by appropriate equivalent circuits, the space charge capacitance (Csc and space charge resistance (Rsc of these films were determined. The donor density (Nsc, flat band potential (Efb and thickness of the space charge layer (dsc for such oxide films were determined from the corresponding Mott–Schottky (M–S plots. It is shown that all oxide films were n-type semiconductors in a certain potential range.

  9. Integrable topological billiards and equivalent dynamical systems

    Science.gov (United States)

    Vedyushkina, V. V.; Fomenko, A. T.

    2017-08-01

    We consider several topological integrable billiards and prove that they are Liouville equivalent to many systems of rigid body dynamics. The proof uses the Fomenko-Zieschang theory of invariants of integrable systems. We study billiards bounded by arcs of confocal quadrics and their generalizations, generalized billiards, where the motion occurs on a locally planar surface obtained by gluing several planar domains isometrically along their boundaries, which are arcs of confocal quadrics. We describe two new classes of integrable billiards bounded by arcs of confocal quadrics, namely, non-compact billiards and generalized billiards obtained by gluing planar billiards along non-convex parts of their boundaries. We completely classify non-compact billiards bounded by arcs of confocal quadrics and study their topology using the Fomenko invariants that describe the bifurcations of singular leaves of the additional integral. We study the topology of isoenergy surfaces for some non-convex generalized billiards. It turns out that they possess exotic Liouville foliations: the integral trajectories of the billiard that lie on some singular leaves admit no continuous extension. Such billiards appear to be leafwise equivalent to billiards bounded by arcs of confocal quadrics in the Minkowski metric.

  10. Twisted conformal field theories and Morita equivalence

    Energy Technology Data Exchange (ETDEWEB)

    Marotta, Vincenzo [Dipartimento di Scienze Fisiche, Universita di Napoli ' Federico II' and INFN, Sezione di Napoli, Compl. universitario M. Sant' Angelo, Via Cinthia, 80126 Napoli (Italy); Naddeo, Adele [CNISM, Unita di Ricerca di Salerno and Dipartimento di Fisica ' E.R. Caianiello' , Universita degli Studi di Salerno, Via Salvador Allende, 84081 Baronissi (Italy); Dipartimento di Scienze Fisiche, Universita di Napoli ' Federico II' , Compl. universitario M. Sant' Angelo, Via Cinthia, 80126 Napoli (Italy)], E-mail: adelenaddeo@yahoo.it

    2009-04-01

    The Morita equivalence for field theories on noncommutative two-tori is analysed in detail for rational values of the noncommutativity parameter {theta} (in appropriate units): an isomorphism is established between an Abelian noncommutative field theory (NCFT) and a non-Abelian theory of twisted fields on ordinary space. We focus on a particular conformal field theory (CFT), the one obtained by means of the m-reduction procedure [V. Marotta, J. Phys. A 26 (1993) 3481; V. Marotta, Mod. Phys. Lett. A 13 (1998) 853; V. Marotta, Nucl. Phys. B 527 (1998) 717; V. Marotta, A. Sciarrino, Mod. Phys. Lett. A 13 (1998) 2863], and show that it is the Morita equivalent of a NCFT. Finally, the whole m-reduction procedure is shown to be the image in the ordinary space of the Morita duality. An application to the physics of a quantum Hall fluid at Jain fillings {nu}=m/(2pm+1) is explicitly discussed in order to further elucidate such a correspondence and to clarify its role in the physics of strongly correlated systems. A new picture emerges, which is very different from the existing relationships between noncommutativity and many body systems [A.P. Polychronakos, arXiv: 0706.1095].

  11. Planck Constant Determination from Power Equivalence

    Science.gov (United States)

    Newell, David B.

    2000-04-01

    Equating mechanical to electrical power links the kilogram, the meter, and the second to the practical realizations of the ohm and the volt derived from the quantum Hall and the Josephson effects, yielding an SI determination of the Planck constant. The NIST watt balance uses this power equivalence principle, and in 1998 measured the Planck constant with a combined relative standard uncertainty of 8.7 x 10-8, the most accurate determination to date. The next generation of the NIST watt balance is now being assembled. Modification to the experimental facilities have been made to reduce the uncertainty components from vibrations and electromagnetic interference. A vacuum chamber has been installed to reduce the uncertainty components associated with performing the experiment in air. Most of the apparatus is in place and diagnostic testing of the balance should begin this year. Once a combined relative standard uncertainty of one part in 10-8 has been reached, the power equivalence principle can be used to monitor the possible drift in the artifact mass standard, the kilogram, and provide an accurate alternative definition of mass in terms of fundamental constants. *Electricity Division, Electronics and Electrical Engineering Laboratory, Technology Administration, U.S. Department of Commerce. Contribution of the National Institute of Standards and Technology, not subject to copyright in the U.S.

  12. Development of a tissue-engineered human oral mucosa equivalent based on an acellular allogeneic dermal matrix: a preliminary report of clinical application to burn wounds.

    Science.gov (United States)

    Iida, Takuya; Takami, Yoshihiro; Yamaguchi, Ryo; Shimazaki, Shuji; Harii, Kiyonori

    2005-01-01

    Tissue-engineered skin equivalents composed of epidermal and dermal components have been widely investigated for coverage of full-thickness skin defects. We developed a tissue-engineered oral mucosa equivalent based on an acellular allogeneic dermal matrix and investigated its characteristics. We also tried and assessed its preliminary clinical application. Human oral mucosal keratinocytes were separated from a piece of oral mucosa and cultured in a chemically-defined medium. The keratinocytes were seeded on to the acellular allogeneic dermal matrix and cultured. Histologically, the mucosa equivalent had a well-stratified epithelial layer. Immunohistochemical study showed that it was similar to normal oral mucosa. We applied this equivalent in one case with an extensive burn wound. The equivalent was transplanted three weeks after the harvest of the patient's oral mucosa and about 30% of the graft finally survived. We conclude that this new oral mucosa equivalent could become a therapeutic option for the treatment of extensive burns.

  13. Magnetic property zonation in a thick lava flow

    Science.gov (United States)

    Audunsson, Haraldur; Levi, Shaul; Hodges, Floyd

    1992-04-01

    Intraflow structures and magmatic evolution in an extensive and thick (30-60 m) basaltic lava flow are examined on the basis of grain size and composition-dependent magnetic properties of titanomagnetite materials. Microprobe data indicate that the intraflow oxidation state Fe(3+)/Fe(2+) of the initially precipitated primary titanomagnetites increases with falling equilibrium temperature from the flow margins to a maximum near the center, the position of lowest equilibrium temperature. In contrast, Curie temperature measurements indicate that titanomagnetite oxidation increases with height in the flow. Modification of the initially symmetric equilibrium titanomagnetite compositions was caused by subsolidus high-temperature oxidation possibly due to hydrogen loss produced by dissociation of magmatic water, as well as unknown contributions of circulating air and percolating water from above. The titanomagnetites of the basal layer of the flow remain essentially unaltered.

  14. Equivalent-spherical-shield neutron dose calculations

    International Nuclear Information System (INIS)

    Russell, G.J.; Robinson, H.

    1988-01-01

    Neutron doses through 162-cm-thick spherical shields were calculated to be 1090 and 448 mrem/h for regular and magnetite concrete, respectively. These results bracket the measured data, for reinforced regular concrete, of /approximately/600 mrem/h. The calculated fraction of the high-energy (>20 MeV) dose component also bracketed the experimental data. The measured and calculated doses were for a graphite beam stop bombarded with 100 nA of 800-MeV protons. 6 refs., 2 figs., 1 tab

  15. Limits to the adherence of oxide scales

    International Nuclear Information System (INIS)

    Robertson, J.; Manning, M.I.

    1989-10-01

    Fracture mechanics is used to identify criteria under which uniform oxide scales may be expected to fail due to rapidly applied strains. The most common failure mode occurs when the strain, ε, builds up in the scale until the strain energy density per unit area exceeds the fracture surface energy, γ, of the oxide. This produces spalling when ε > (2γ/hE) 1/2 , where h is the scale thickness and E is the oxide Youngs modulus. In thin scales, as the external strain is applied to the oxide via the metal substrate, it is clear that no further strain can be applied to the oxide if the substrate has itself been strained beyond yield. This gives rise to extended oxide adherence in which the oxide cracks and forms a series of islands but remains attached to the deformed metal. When the oxide thickness is less than its comminution limit, the flaw size necessary for brittle fracture exceeds the oxide thickness and the oxide yields in a ductile manner without cracking. The results are presented as maps of failure strain versus oxide thickness for various oxide systems such as Fe 3 O 4 , Cr 2 O 3 , Al 2 O 3 , SiO 2 and NiO. The observed cases of spalling are found to lie within the predicted regions. (author)

  16. Thickly Syndetical Sensitivity of Topological Dynamical System

    Directory of Open Access Journals (Sweden)

    Heng Liu

    2014-01-01

    Full Text Available Consider the surjective continuous map f:X→X, where X is a compact metric space. In this paper we give several stronger versions of sensitivity, such as thick sensitivity, syndetic sensitivity, thickly syndetic sensitivity, and strong sensitivity. We establish the following. (1 If (X,f is minimal and sensitive, then (X,f is syndetically sensitive. (2 Weak mixing implies thick sensitivity. (3 If (X,f is minimal and weakly mixing, then it is thickly syndetically sensitive. (4 If (X,f is a nonminimal M-system, then it is thickly syndetically sensitive. Devaney chaos implies thickly periodic sensitivity. (5 We give a syndetically sensitive system which is not thickly sensitive. (6 We give thickly syndetically sensitive examples but not cofinitely sensitive ones.

  17. three dimensional photoelastic investigations on thick rectangular

    African Journals Online (AJOL)

    user

    1983-09-01

    Sep 1, 1983 ... Thick rectangular plates are investigated by means of three-dimensional photoelasticity ... a thin plate theory and a higher order thick plate theory. 1. ..... number of fringes lest the accuracy of the results will be considerably.

  18. Non-contact radiation thickness gauge

    International Nuclear Information System (INIS)

    Tsujii, T.; Okino, T.

    1983-01-01

    A noncontact thickness gauge system for measuring the thickness of a material comprising a source of radiation, a detector for detecting the amount of radiation transmitted through the material which is a function of the absorptance and thickness of the material, a memory for storing the output signals of the detector and curve-defining parameters for a plurality of quadratic calibration curves which correspond to respective thickness ranges, and a processor for processing the signals and curve defining parameters to determine the thickness of the material. Measurements are made after precalibration to obtain calibration curves and these are stored in the memory, providing signals representative of a nominal thickness and an alloy compensation coefficient for the material. The calibration curve corresponding to a particular thickness range is selected and the curve compensated for drift; the material is inserted into the radiation path and the detector output signal processed with the compensated calibration curve to determine the thickness of the material. (author)

  19. Borel equivalence relations structure and classification

    CERN Document Server

    Kanovei, Vladimir

    2008-01-01

    Over the last 20 years, the theory of Borel equivalence relations and related topics have been very active areas of research in set theory and have important interactions with other fields of mathematics, like ergodic theory and topological dynamics, group theory, combinatorics, functional analysis, and model theory. The book presents, for the first time in mathematical literature, all major aspects of this theory and its applications. This book should be of interest to a wide spectrum of mathematicians working in set theory as well as the other areas mentioned. It provides a systematic exposition of results that so far have been only available in journals or are even unpublished. The book presents unified and in some cases significantly streamlined proofs of several difficult results, especially dichotomy theorems. It has rather minimal overlap with other books published in this subject.

  20. Characterization of Destrins with Different Dextrose Equivalents

    Directory of Open Access Journals (Sweden)

    Guanglei Li

    2010-07-01

    Full Text Available Dextrins are widely used for their functional properties and prepared by partial hydrolysis of starch using acid, enzymes, or combinations of both. The physiochemical properties of dextrins are dependent on their molecular distribution and oligosaccharide profiles. In this study, scanning electron microscopy (SEM, X-ray diffractometry (XRD, rapid viscoanalysis (RVA, high-performance Liquid Chromatography (HPLC and gel permeation chromatography (GPC were used to characterize dextrins prepared by common neutral and thermostable α-amylase hydrolysis. The dextrin granules displayed irregular surfaces and were badly damaged by the enzyme treatment. They displayed A-type X-ray diffraction patterns with a decrease of intensity of the characteristic diffraction peaks. The RVA profiles showed that the viscosity of dextrin decreased with the increase of its Dextrose Equivalent (DE value. According to HPLC analysis, the molecular weight, degree of polymerization and the composition of oligosaccharides in dextrins were different.

  1. Multiplicities of states od equivalent fermion shells

    International Nuclear Information System (INIS)

    Savukinas, A.Yu.; Glembotskij, I.I.

    1980-01-01

    Classification of states of three or four equivalent fermions has been studied, i.e. possible terms and their multiplicities have been determined. For this purpose either the group theory or evident expressions for the fractional-parentage coefficients have been used. In the first approach the formulas obtained by other authors for the multiplicities of terms through the characters of the transformation matrices of bond moments have been used. This approach happens to be more general as compared with the second one, as expressions for the fractional-parentage coefficients in many cases are not known. The multiplicities of separate terms have been determined. It has been shown that the number of terms of any multiplicity becomes constant when l or j is increased [ru

  2. Sample size allocation in multiregional equivalence studies.

    Science.gov (United States)

    Liao, Jason J Z; Yu, Ziji; Li, Yulan

    2018-06-17

    With the increasing globalization of drug development, the multiregional clinical trial (MRCT) has gained extensive use. The data from MRCTs could be accepted by regulatory authorities across regions and countries as the primary sources of evidence to support global marketing drug approval simultaneously. The MRCT can speed up patient enrollment and drug approval, and it makes the effective therapies available to patients all over the world simultaneously. However, there are many challenges both operationally and scientifically in conducting a drug development globally. One of many important questions to answer for the design of a multiregional study is how to partition sample size into each individual region. In this paper, two systematic approaches are proposed for the sample size allocation in a multiregional equivalence trial. A numerical evaluation and a biosimilar trial are used to illustrate the characteristics of the proposed approaches. Copyright © 2018 John Wiley & Sons, Ltd.

  3. Equivalence principle and the baryon acoustic peak

    Science.gov (United States)

    Baldauf, Tobias; Mirbabayi, Mehrdad; Simonović, Marko; Zaldarriaga, Matias

    2015-08-01

    We study the dominant effect of a long wavelength density perturbation δ (λL) on short distance physics. In the nonrelativistic limit, the result is a uniform acceleration, fixed by the equivalence principle, and typically has no effect on statistical averages due to translational invariance. This same reasoning has been formalized to obtain a "consistency condition" on the cosmological correlation functions. In the presence of a feature, such as the acoustic peak at ℓBAO, this naive expectation breaks down for λLexplicitly applied to the one-loop calculation of the power spectrum. Finally, the success of baryon acoustic oscillation reconstruction schemes is argued to be another empirical evidence for the validity of the results.

  4. Development of air equivalent gamma dose monitor

    International Nuclear Information System (INIS)

    Alex, Mary; Bhattacharya, Sadhana; Karpagam, R.; Prasad, D.N.; Jakati, R.K.; Mukhopadhyay, P.K.; Patil, R.K.

    2010-01-01

    The paper describes design and development of air equivalent gamma absorbed dose monitor. The monitor has gamma sensitivity of 84 pA/R/h for 60 Co source. The characterization of the monitor has been done to get energy dependence on gamma sensitivity and response to gamma radiation field from 1 R/hr to 5000 R/hr. The gamma sensitivity in the energy range of 0.06 to 1.25MeV relative to 137 Cs nuclide was within 2.5%. The linearity of the monitor response as a function of gamma field from 10 R/h to 3.8 kR/h was within 6%. The monitor has been designed for its application in harsh environment. It has been successfully qualified to meet environmental requirements of shock. (author)

  5. A new concept of equivalent homogenization method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Jin; Pogoskekyan, Leonid; Kim, Young Il; Ju, Hyung Kook; Chang, Moon Hee [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-07-01

    A new concept of equivalent homogenization is proposed. The concept employs new set of homogenized parameters: homogenized cross sections (XS) and interface matrix (IM), which relates partial currents at the cell interfaces. The idea of interface matrix generalizes the idea of discontinuity factors (DFs), proposed and developed by K. Koebke and K. Smith. The offered concept covers both those of K. Koebke and K. Smith; both of them can be simulated within framework of new concept. Also, the offered concept covers Siemens KWU approach for baffle/reflector simulation, where the equivalent homogenized reflector XS are derived from the conservation of response matrix at the interface in 1D simi-infinite slab geometry. The IM and XS of new concept satisfy the same assumption about response matrix conservation in 1D semi-infinite slab geometry. It is expected that the new concept provides more accurate approximation of heterogeneous cell, especially in case of the steep flux gradients at the cell interfaces. The attractive shapes of new concept are: improved accuracy, simplicity of incorporation in the existing codes, equal numerical expenses in comparison to the K. Smith`s approach. The new concept is useful for: (a) explicit reflector/baffle simulation; (b) control blades simulation; (c) mixed UO{sub 2}/MOX core simulation. The offered model has been incorporated in the finite difference code and in the nodal code PANDOX. The numerical results show good accuracy of core calculations and insensitivity of homogenized parameters with respect to in-core conditions. 9 figs., 7 refs. (Author).

  6. Equivalence principle implications of modified gravity models

    International Nuclear Information System (INIS)

    Hui, Lam; Nicolis, Alberto; Stubbs, Christopher W.

    2009-01-01

    Theories that attempt to explain the observed cosmic acceleration by modifying general relativity all introduce a new scalar degree of freedom that is active on large scales, but is screened on small scales to match experiments. We demonstrate that if such screening occurs via the chameleon mechanism, such as in f(R) theory, it is possible to have order unity violation of the equivalence principle, despite the absence of explicit violation in the microscopic action. Namely, extended objects such as galaxies or constituents thereof do not all fall at the same rate. The chameleon mechanism can screen the scalar charge for large objects but not for small ones (large/small is defined by the depth of the gravitational potential and is controlled by the scalar coupling). This leads to order one fluctuations in the ratio of the inertial mass to gravitational mass. We provide derivations in both Einstein and Jordan frames. In Jordan frame, it is no longer true that all objects move on geodesics; only unscreened ones, such as test particles, do. In contrast, if the scalar screening occurs via strong coupling, such as in the Dvali-Gabadadze-Porrati braneworld model, equivalence principle violation occurs at a much reduced level. We propose several observational tests of the chameleon mechanism: 1. small galaxies should accelerate faster than large galaxies, even in environments where dynamical friction is negligible; 2. voids defined by small galaxies would appear larger compared to standard expectations; 3. stars and diffuse gas in small galaxies should have different velocities, even if they are on the same orbits; 4. lensing and dynamical mass estimates should agree for large galaxies but disagree for small ones. We discuss possible pitfalls in some of these tests. The cleanest is the third one where the mass estimate from HI rotational velocity could exceed that from stars by 30% or more. To avoid blanket screening of all objects, the most promising place to look is in

  7. Autonomous Sea-Ice Thickness Survey

    Science.gov (United States)

    2016-06-01

    the conductivity of an infinitely thick slab of sea ice. Ice thickness, Hice, is then obtained by subtracting the height of the ...Thickness Survey of Sea Ice Runway” ERDC/CRREL SR-16-4 ii Abstract We conducted an autonomous survey of sea -ice thickness using the Polar rover Yeti...efficiency relative to manual surveys routinely con- ducted to assess the safety of roads and runways constructed on the sea ice. Yeti executed the

  8. Macular thickness and volume in the elderly

    DEFF Research Database (Denmark)

    Subhi, Yousif; Forshaw, Thomas; Sørensen, Torben Lykke

    2016-01-01

    manifests in the macula of the elderly focusing on clinical relevant measures that are thicknesses and volumes of different macular areas. Ageing seems to increase center point foveal thickness. Ageing does not seem to change the center subfield thickness significantly. Ageing decreases the inner and outer...

  9. Effective radiation attenuation calibration for breast density: compression thickness influences and correction

    Directory of Open Access Journals (Sweden)

    Thomas Jerry A

    2010-11-01

    Full Text Available Abstract Background Calibrating mammograms to produce a standardized breast density measurement for breast cancer risk analysis requires an accurate spatial measure of the compressed breast thickness. Thickness inaccuracies due to the nominal system readout value and compression paddle orientation induce unacceptable errors in the calibration. Method A thickness correction was developed and evaluated using a fully specified two-component surrogate breast model. A previously developed calibration approach based on effective radiation attenuation coefficient measurements was used in the analysis. Water and oil were used to construct phantoms to replicate the deformable properties of the breast. Phantoms consisting of measured proportions of water and oil were used to estimate calibration errors without correction, evaluate the thickness correction, and investigate the reproducibility of the various calibration representations under compression thickness variations. Results The average thickness uncertainty due to compression paddle warp was characterized to within 0.5 mm. The relative calibration error was reduced to 7% from 48-68% with the correction. The normalized effective radiation attenuation coefficient (planar representation was reproducible under intra-sample compression thickness variations compared with calibrated volume measures. Conclusion Incorporating this thickness correction into the rigid breast tissue equivalent calibration method should improve the calibration accuracy of mammograms for risk assessments using the reproducible planar calibration measure.

  10. High-throughput measurement of polymer film thickness using optical dyes

    Science.gov (United States)

    Grunlan, Jaime C.; Mehrabi, Ali R.; Ly, Tien

    2005-01-01

    Optical dyes were added to polymer solutions in an effort to create a technique for high-throughput screening of dry polymer film thickness. Arrays of polystyrene films, cast from a toluene solution, containing methyl red or solvent green were used to demonstrate the feasibility of this technique. Measurements of the peak visible absorbance of each film were converted to thickness using the Beer-Lambert relationship. These absorbance-based thickness calculations agreed within 10% of thickness measured using a micrometer for polystyrene films that were 10-50 µm. At these thicknesses it is believed that the absorbance values are actually more accurate. At least for this solvent-based system, thickness was shown to be accurately measured in a high-throughput manner that could potentially be applied to other equivalent systems. Similar water-based films made with poly(sodium 4-styrenesulfonate) dyed with malachite green oxalate or congo red did not show the same level of agreement with the micrometer measurements. Extensive phase separation between polymer and dye resulted in inflated absorbance values and calculated thickness that was often more than 25% greater than that measured with the micrometer. Only at thicknesses below 15 µm could reasonable accuracy be achieved for the water-based films.

  11. 49 CFR 391.33 - Equivalent of road test.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Equivalent of road test. 391.33 Section 391.33... AND LONGER COMBINATION VEHICLE (LCV) DRIVER INSTRUCTORS Tests § 391.33 Equivalent of road test. (a) In place of, and as equivalent to, the road test required by § 391.31, a person who seeks to drive a...

  12. A bicategorical approach to Morita equivalence for Von Neumann algebras

    NARCIS (Netherlands)

    R.M. Brouwer (Rachel)

    2003-01-01

    textabstractWe relate Morita equivalence for von Neumann algebras to the ``Connes fusion'' tensor product between correspondences. In the purely algebraic setting, it is well known that rings are Morita equivalent if and only if they are equivalent objects in a bicategory whose 1-cells are

  13. Problems of Equivalence in Shona- English Bilingual Dictionaries

    African Journals Online (AJOL)

    rbr

    Page 1 ... translation equivalents in Shona-English dictionaries where lexicographers will be dealing with divergent languages and cultures, traditional practices of lexicography and the absence of reliable ... ideal in translation is to achieve structural and semantic equivalence. Absolute equivalence between any two ...

  14. The equivalence principle in classical mechanics and quantum mechanics

    OpenAIRE

    Mannheim, Philip D.

    1998-01-01

    We discuss our understanding of the equivalence principle in both classical mechanics and quantum mechanics. We show that not only does the equivalence principle hold for the trajectories of quantum particles in a background gravitational field, but also that it is only because of this that the equivalence principle is even to be expected to hold for classical particles at all.

  15. Effect of the thickness and hydrogen treatment on the properties of Ga-doped ZnO transparent conductive films

    International Nuclear Information System (INIS)

    Lee, Min-Jung; Lim, Jinhyong; Bang, Jungsik; Lee, Woong; Myoung, Jae-Min

    2008-01-01

    Combined effects of the thickness and hydrogen post-annealing treatment on the structural, electrical, and optical properties of Ga-doped ZnO (GZO) films were investigated as a potential substitute for indium tin oxide transparent conductive oxide. In the as-deposited films, microstructural evolution initially improved the crystallinity up to the thickness of 160 nm accompanying enhanced electrical and optical properties, but further thickness increase resulted in the deterioration of these properties attributable to the development of ZnGa 2 O 4 and Ga 2 O 3 phases originating from the excessive amount of the Ga dopant. Post-annealing treatment of the GZO films in a hydrogen atmosphere improved the electrical and optical properties substantially through possible reduction of the oxide phases and passivation of the surfaces and grain boundaries. In this case, electrical and optical properties remained almost similar for the thickness above 160 nm indicating that there exists a certain optimal film thickness.

  16. Monitoring the oxidation of nuclear fuel cladding using Raman spectroscopy

    International Nuclear Information System (INIS)

    Mi, Hongyi; Mikael, Solomon; Allen, Todd; Sridharan, Kumar; Butt, Darryl; Blanchard, James P.; Ma, Zhenqiang

    2014-01-01

    In order to observe Zircaloy-4 (Zr-4) cladding oxidation within a spent fuel canister, cladding oxidized in air at 500 °C was investigated by micro-Raman spectroscopy to measure the oxide layer thickness. Systematic Raman scans were performed to study the relationship between typical Raman spectra and various oxide layer thicknesses. The thicknesses of the oxide layers developed for various exposure times were measured by cross-sectional Scanning Electron Microscopy (SEM). The results of this work reveal that each oxide layer thickness has a corresponding typical Raman spectrum. Detailed analysis suggests that the Raman scattering peaks around wave numbers of 180 cm −1 and 630 cm −1 are the best choices for accurately determining the oxide layer thickness. After Gaussian–Lorentzian deconvolution, these two peaks can be quantitatively represented by four peaks. The intensities of the deconvoluted peaks increase consistently as the oxide layer becomes thicker and sufficiently strong signals are produced, allowing one to distinguish the bare and oxidized cladding samples, as well as samples with different oxide layer thicknesses. Hence, a process that converts sample oxide layer thickness to optical signals can be achieved

  17. Review Of Plutonium Oxidation Literature

    International Nuclear Information System (INIS)

    Korinko, P.

    2009-01-01

    A brief review of plutonium oxidation literature was conducted. The purpose of the review was to ascertain the effect of oxidation conditions on oxide morphology to support the design and operation of the PDCF direct metal oxidation (DMO) furnace. The interest in the review was due to a new furnace design that resulted in oxide characteristics that are different than those of the original furnace. Very little of the published literature is directly relevant to the DMO furnace operation, which makes assimilation of the literature data with operating conditions and data a convoluted task. The oxidation behavior can be distilled into three regimes, a low temperature regime (RT to 350 C) with a relatively slow oxidation rate that is influenced by moisture, a moderate temperature regime (350-450 C) that is temperature dependent and relies on more or less conventional oxidation growth of a partially protective oxide scale, and high temperature oxidation (> 500 C) where the metal autocatalytically combusts and oxidizes. The particle sizes obtained from these three regimes vary with the finest being from the lowest temperature. It is surmised that the slow growth rate permits significant stress levels to be achieved that help break up the oxides. The intermediate temperatures result in a fairly compact scale that is partially protective and that grows to critical thickness prior to fracturing. The growth rate in this regime may be parabolic or paralinear, depending on the oxidation time and consequently the oxide thickness. The high temperature oxidation is invariant in quiescent or nearly quiescent conditions due to gas blanketing while it accelerates with temperature under flowing conditions. The oxide morphology will generally consist of fine particles ( 250 (micro)m). The particle size ratio is expected to be < 5%, 25%, and 70% for fine, medium and large particles, respectively, for metal temperatures in the 500-600 C range.

  18. Equivalent circuit and optimum design of a multilayer laminated piezoelectric transformer.

    Science.gov (United States)

    Dong, Shuxiang; Carazo, Alfredo Vazquez; Park, Seung Ho

    2011-12-01

    A multilayer laminated piezoelectric Pb(Zr(1-x)Ti(x))O(3) (PZT) ceramic transformer, operating in a half- wavelength longitudinal resonant mode (λ/2 mode), has been analyzed. This piezoelectric transformer is composed of one thickness-polarized section (T-section) for exciting the longitudinal mechanical vibrations, two longitudinally polarized sections (L-section) for generating high-voltage output, and two insulating layers laminated between the T-section and L-section layers to provide insulation between the input and output sections. Based on the piezoelectric constitutive and motion equations, an electro-elasto-electric (EEE) equivalent circuit has been developed, and correspondingly, an effective EEE coupling coefficient was proposed for optimum design of this multilayer transformer. Commercial finite element analysis software is used to determine the validity of the developed equivalent circuit. Finally, a prototype sample was manufactured and experimental data was collected to verify the model's validity.

  19. Neutron measurements with a tissue-equivalent phantom

    Energy Technology Data Exchange (ETDEWEB)

    Smith, J W [Health Physics Division, Atomic Energy Establishment, Harwell (United Kingdom)

    1962-03-15

    This Appendix 3E of the dosimetry experiment at the R-B reactor describes the apparatus used and presents the obtained results. The phantom used was a 1/4-inch thick polythene container, 60 cm high, of elliptical cross-section, with a major axis of 36 cm and a minor axis of 20 cm. This was filled with an approximately tissue-equivalent liquid. A light but rigid internal framework of Perspex supported a series of small detectors through the phantom. The detectors used in the first high-level run at Vinca, to measure flux above 0.5 MeV, were 0.5-cm wide track plates wrapped in cadmium foil. Each track plate was a sandwich of two Ilford El 50 - mu emulsions, with glass backing, separated by a 250-mu polythene radiator, and was oriented at an angle of 45 deg to the front surface of the phantom. Under these conditions the response is constant with neutron energy between 0.5 MeV and 8 MeV at 1.26 X 10 sup - sup 3 tracks/neutron to within +- 15%. The detectors used in the second high-level run were gold foils (260 mg/cm sup 2 thick) for determination of the show neutron distribution. Previous experiments with 0.13 MeV, 2.5 MeV, 14 MeV and Po-Be neutrons have shown that the shape of the curve through a phantom obtained from these gold foils is the same as that given by either manganese foils or sodium samples despite the difference in resonance integrals. From the relaxation length of the neutron flux in the phantom, as measured by the track plates, the mean energy of the neutrons with energies greater than 0.5 MeV may be found by comparison with the relaxation lengths obtained by irradiation of the phantom with monoenergetic neutrons. The results of these experiments are given. Track plate results from the Vinca experiment are shown. It can be seen that the backscattered fast flux is about one-third of the incident fast flux and that the energy indicated by the shape of the curve is considerably lower than the energy of the direct neutrons. It seems possible that the high

  20. Neutron measurements with a tissue-equivalent phantom

    Energy Technology Data Exchange (ETDEWEB)

    Smith, J W [Health Physics Division, Atomic Energy Establishment, Harwell (United Kingdom)

    1962-03-01

    This Appendix 3E of the dosimetry experiment at the R-B reactor describes the apparatus used and presents the obtained results. The phantom used was a 1/4-inch thick polythene container, 60 cm high, of elliptical cross-section, with a major axis of 36 cm and a minor axis of 20 cm. This was filled with an approximately tissue-equivalent liquid. A light but rigid internal framework of Perspex supported a series of small detectors through the phantom. The detectors used in the first high-level run at Vinca, to measure flux above 0.5 MeV, were 0.5-cm wide track plates wrapped in cadmium foil. Each track plate was a sandwich of two Ilford El 50 - {mu} emulsions, with glass backing, separated by a 250-{mu} polythene radiator, and was oriented at an angle of 45 deg to the front surface of the phantom. Under these conditions the response is constant with neutron energy between 0.5 MeV and 8 MeV at 1.26 X 10{sup -3} tracks/neutron to within {+-} 15%. The detectors used in the second high-level run were gold foils (260 mg/cm{sup 2} thick) for determination of the show neutron distribution. Previous experiments with 0.13 MeV, 2.5 MeV, 14 MeV and Po-Be neutrons have shown that the shape of the curve through a phantom obtained from these gold foils is the same as that given by either manganese foils or sodium samples despite the difference in resonance integrals. From the relaxation length of the neutron flux in the phantom, as measured by the track plates, the mean energy of the neutrons with energies greater than 0.5 MeV may be found by comparison with the relaxation lengths obtained by irradiation of the phantom with monoenergetic neutrons. The results of these experiments are given. Track plate results from the Vinca experiment are shown. It can be seen that the backscattered fast flux is about one-third of the incident fast flux and that the energy indicated by the shape of the curve is considerably lower than the energy of the direct neutrons. It seems possible that the

  1. Study of buffer layer thickness on bulk heterojunction solar cell.

    Science.gov (United States)

    Noh, Seunguk; Suman, C K; Lee, Donggu; Kim, Seohee; Lee, Changhee

    2010-10-01

    We studied the effect of the buffer layer (molybdenum-oxide (MoO3)) thickness on the performance of organic solar cell based on blends of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61 butyric acid methyl ester fullerene derivative (PCBM). The thickness of MoO3 was varied from 1 nm to 30 nm for optimization of device performance. The photocurrent-voltage and impedance spectroscopy were measured under dark and AM1.5G solar simulated illumination of 100 mW/cm2 for exploring the role of the buffer layer thickness on carrier collection at an anode. The MoO3 thickness of the optimized device (efficiency approximately 3.7%) was found to be in the range of 5 approximately 10 nm. The short-circuit current and the shunt resistance decrease gradually for thicker MoO3 layer over 5 nm. The device can be modeled as the combination of three RC parallel circuits (each one for the active layer, buffer layer and interface between the buffer layer and the active layer) in series with contact resistance (Rs approximately 60 ohm).

  2. Effects of Complex Structured Anodic Oxide Dielectric Layer Grown in Pore Matrix for Aluminum Capacitor.

    Science.gov (United States)

    Shin, Jin-Ha; Yun, Sook Young; Lee, Chang Hyoung; Park, Hwa-Sun; Suh, Su-Jeong

    2015-11-01

    Anodization of aluminum is generally divided up into two types of anodic aluminum oxide structures depending on electrolyte type. In this study, an anodization process was carried out in two steps to obtain high dielectric strength and break down voltage. In the first step, evaporated high purity Al on Si wafer was anodized in oxalic acidic aqueous solution at various times at a constant temperature of 5 degrees C. In the second step, citric acidic aqueous solution was used to obtain a thickly grown sub-barrier layer. During the second anodization process, the anodizing potential of various ranges was applied at room temperature. An increased thickness of the sub-barrier layer in the porous matrix was obtained according to the increment of the applied anodizing potential. The microstructures and the growth of the sub-barrier layer were then observed with an increasing anodizing potential of 40 to 300 V by using a scanning electron microscope (SEM). An impedance analyzer was used to observe the change of electrical properties, including the capacitance, dissipation factor, impedance, and equivalent series resistance (ESR) depending on the thickness increase of the sub-barrier layer. In addition, the breakdown voltage was measured. The results revealed that dielectric strength was improved with the increase of sub-barrier layer thickness.

  3. The one-dimensional normalised generalised equivalence theory (NGET) for generating equivalent diffusion theory group constants for PWR reflector regions

    International Nuclear Information System (INIS)

    Mueller, E.Z.

    1991-01-01

    An equivalent diffusion theory PWR reflector model is presented, which has as its basis Smith's generalisation of Koebke's Equivalent Theory. This method is an adaptation, in one-dimensional slab geometry, of the Generalised Equivalence Theory (GET). Since the method involves the renormalisation of the GET discontinuity factors at nodal interfaces, it is called the Normalised Generalised Equivalence Theory (NGET) method. The advantages of the NGET method for modelling the ex-core nodes of a PWR are summarized. 23 refs

  4. Determination of the thickness of Al2O3 barriers in magnetic tunnel junctions

    International Nuclear Information System (INIS)

    Buchanan, J.D.R.; Hase, T.P.A.; Tanner, B.K.; Hughes, N.D.; Hicken, R.J.

    2002-01-01

    The barrier thickness in magnetic spin-dependent tunnel junctions with Al 2 O 3 barriers has been measured using grazing incidence x-ray reflectivity and by fitting the tunneling current to the Simmons model. We have studied the effect of glow discharge oxidation time on the barrier structure, revealing a substantial increase in Al 2 O 3 thickness with oxidation. The greater thickness of barrier measured using grazing incidence x-ray reflectivity compared with that obtained by fitting current density-voltage to the Simmons electron tunneling model suggests that electron tunneling is localized to specific regions across the barrier, where the thickness is reduced by fluctuations due to nonconformal roughness

  5. Influence of colorant and film thickness on thermal aging characteristics of oxo-biodegradable plastic bags

    Science.gov (United States)

    Leuterio, Giselle Lou D.; Pajarito, Bryan B.; Domingo, Carla Marie C.; Lim, Anna Patricia G.

    2016-05-01

    Functional, lightweight, strong and cheap plastic bags incorporated with pro-oxidants undergo accelerated degradation under exposure to heat and oxygen. This work investigated the effect of colorant and film thickness on thermal aging characteristics of commercial oxo-biodegradable plastic bag films at 70 °C. Degradation is monitored through changes in infrared absorption, weight, and tensile properties of thermally aged films. The presence of carbonyl band in infrared spectrum after 672 h of thermal aging supports the degradation behavior of exposed films. Results show that incorporation of colorant and increasing thickness exhibit low maximum weight uptake. Titanium dioxide as white colorant in films lowers the susceptibility of films to oxygen uptake but enhances physical degradation. Higher amount of pro-oxidant loading also contributes to faster degradation. Opaque films are characterized by low tensile strength and high elastic modulus. Decreasing the thickness contributes to lower tensile strength of films. Thermally aged films with colorant and low thickness promote enhanced degradation.

  6. Influence of Thickness on Ethanol Sensing Characteristics of Doctor-bladed Thick Film from Flame-made ZnO Nanoparticles

    Directory of Open Access Journals (Sweden)

    Sukon Phanichphant

    2007-02-01

    Full Text Available ZnO nanoparticles were produced by flame spray pyrolysis (FSP using zincnaphthenate as a precursor dissolved in toluene/acetonitrile (80/20 vol%. The particleproperties were analyzed by XRD, BET, and HR-TEM. The sensing films were produced bymixing the particles into an organic paste composed of terpineol and ethyl cellulose as avehicle binder and were fabricated by doctor-blade technique with various thicknesses (5,10, 15 μm. The morphology of the sensing films was analyzed by SEM and EDS analyses.The gas sensing characteristics to ethanol (25-250 ppm were evaluated as a function of filmthickness at 400°C in dry air. The relationship between thickness and ethanol sensingcharacteristics of ZnO thick film on Al2O3 substrate interdigitated with Au electrodes wereinvestigated. The effects of film thickness, as well as the cracking phenomenon, though,many cracks were observed for thicker sensing films. Crack widths increased withincreasing film thickness. The film thickness, cracking and ethanol concentration havesignificant effect on the sensing characteristics. The sensing characteristics with variousthicknesses were compared, showing the tendency of the sensitivity to ethanol decreasedwith increasing film thickness and response time. The relationship between gas sensingproperties and film thickness was discussed on the basis of diffusively and reactivity of thegases inside the oxide films. The thinnest sensing film (5 μm showed the highest sensitivityand the fastest response time (within seconds.

  7. Intelligent processing for thick composites

    Science.gov (United States)

    Shin, Daniel Dong-Ok

    2000-10-01

    Manufacturing thick composite parts are associated with adverse curing conditions such as large in-plane temperature gradient and exotherms. The condition is further aggravated because the manufacturer's cycle and the existing cure control systems do not adequately counter such affects. In response, the forecast-based thermal control system is developed to have better cure control for thick composites. Accurate cure kinetic model is crucial for correctly identifying the amount of heat generated for composite process simulation. A new technique for identifying cure parameters for Hercules AS4/3502 prepreg is presented by normalizing the DSC data. The cure kinetics is based on an autocatalytic model for the proposed method, which uses dynamic and isothermal DSC data to determine its parameters. Existing models are also used to determine kinetic parameters but rendered inadequate because of the material's temperature dependent final degree of cure. The model predictions determined from the new technique showed good agreement to both isothermal and dynamic DSC data. The final degree of cure was also in good agreement with experimental data. A realistic cure simulation model including bleeder ply analysis and compaction is validated with Hercules AS4/3501-6 based laminates. The nonsymmetrical temperature distribution resulting from the presence of bleeder plies agreed well to the model prediction. Some of the discrepancies in the predicted compaction behavior were attributed to inaccurate viscosity and permeability models. The temperature prediction was quite good for the 3cm laminate. The validated process simulation model along with cure kinetics model for AS4/3502 prepreg were integrated into the thermal control system. The 3cm Hercules AS4/3501-6 and AS4/3502 laminate were fabricated. The resulting cure cycles satisfied all imposed requirements by minimizing exotherms and temperature gradient. Although the duration of the cure cycles increased, such phenomena was

  8. A bicategorical approach to Morita equivalence for von Neumann algebras

    International Nuclear Information System (INIS)

    Brouwer, R. M.

    2003-01-01

    We relate Morita equivalence for von Neumann algebras to the ''Connes fusion'' tensor product between correspondences. In the purely algebraic setting, it is well known that rings are Morita equivalent if they are equivalent objects in a bicategory whose 1-cells are bimodules. We present a similar result for von Neumann algebras. We show that von Neumann algebras form a bicategory, having Connes's correspondences as 1-morphisms, and (bounded) intertwiners as 2-morphisms. Further, we prove that two von Neumann algebras are Morita equivalent iff they are equivalent objects in the bicategory. The proofs make extensive use of the Tomita-Takesaki modular theory

  9. MOSFET dosimeter depth-dose measurements in heterogeneous tissue-equivalent phantoms at diagnostic x-ray energies

    International Nuclear Information System (INIS)

    Jones, A.K.; Pazik, F.D.; Hintenlang, D.E.; Bolch, W.E.

    2005-01-01

    The objective of the present study was to explore the use of the TN-1002RD metal-oxide-semiconductor field effect transistor (MOSFET) dosimeter for measuring tissue depth dose at diagnostic photon energies in both homogeneous and heterogeneous tissue-equivalent materials. Three cylindrical phantoms were constructed and utilized as a prelude to more complex measurements within tomographic physical phantoms of pediatric patients. Each cylindrical phantom was constructed as a stack of seven 5-cm-diameter and 1-cm-thick discs of materials radiographically representative of either soft tissue (S), bone (B), or lung tissue (L) at diagnostic photon energies. In addition to a homogeneous phantom of soft tissue (SSSSSSS), two heterogeneous phantoms were constructed: SSBBSSS and SBLLBSS. MOSFET dosimeters were then positioned at the interface of each disc, and the phantoms were then irradiated at 66 kVp and 200 mAs. Measured values of absorbed dose at depth were then compared to predicated values of point tissue dose as determined via Monte Carlo radiation transport modeling. At depths exceeding 2 cm, experimental results matched the computed values of dose with high accuracy regardless of the dosimeter orientation (epoxy bubble facing toward or away from the x-ray beam). Discrepancies were noted, however, between measured and calculated point doses near the surface of the phantom (surface to 2 cm depth) when the dosimeters were oriented with the epoxy bubble facing the x-ray beam. These discrepancies were largely eliminated when the dosimeters were placed with the flat side facing the x-ray beam. It is therefore recommended that the MOSFET dosimeters be oriented with their flat sides facing the beam when they are used at shallow depths or on the surface of either phantoms or patients

  10. The equivalent width as a figure of merit for XPS narrow scans

    International Nuclear Information System (INIS)

    Singh, Bhupinder; Velázquez, Daniel; Terry, Jeff; Linford, Matthew R.

    2014-01-01

    Highlights: • We introduce a new figure of merit for XPS narrow scans: the equivalent width (EW XPS ). • EW XPS is less subjective and involves lesser user bias than traditional peak fitting. • EW XPS is responsive to changes in chemical states of materials. • EW XPS could be used for quality control and comparing spectra from similar samples. • EW XPS has the potential to be part of an expert software system for machine interpretation of spectra. - Abstract: X-ray Photoelectron Spectroscopy (XPS) is a widely used surface analytical tool that provides information about the near surface regions of materials. And while indispensable for XPS data analysis, peak fitting of narrow scans is often a fairly subjective exercise. Herein we introduce the equivalent width (EW) as an additional and less subjective figure of merit for XPS narrow scans. We believe that this parameter will prove particularly useful for analyzing series of similar or nominally identical spectra, perhaps as a component of an expert software system for the machine interpretation of spectra. It also appears to be useful, shedding light on the chemical state of materials, when additional information about a sample is known. The EW XPS is simply defined as the area of a narrow scan divided by the height of the maximum of its peak envelope. To limit any ambiguity in EW XPS for a series of spectra, we may also list the peak position of the maximum of the envelope (PE max ). The potential usefulness and limitations of the EW XPS and PE max parameters are demonstrated by their application to the narrow scans of: (i) four sets of ozone-treated carbon nanotubes (EW XPS ∼ 2.11–2.16 eV for a Shirley background, and up to 2.88 eV for no background, PE max ∼ 284.4–284.5 eV), (ii) a series of silicon wafers with different oxide thicknesses (EW XPS ∼ 1.5–2.8 eV, PE max ∼ 99–103 eV), (iii) hydrogen-terminated silicon before and after derivatization with pentyl groups, and after annealing of

  11. The equivalent width as a figure of merit for XPS narrow scans

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Bhupinder [Department of Chemistry and Biochemistry, C-100 BNSN, Brigham Young University, Provo, UT 84602 (United States); Velázquez, Daniel [Department of Physics, Illinois Institute of Technology, Chicago, IL 60616 (United States); Terry, Jeff, E-mail: terryj@iit.edu [Department of Physics, Illinois Institute of Technology, Chicago, IL 60616 (United States); Linford, Matthew R., E-mail: mrlinford@chem.byu.edu [Department of Chemistry and Biochemistry, C-100 BNSN, Brigham Young University, Provo, UT 84602 (United States)

    2014-12-15

    Highlights: • We introduce a new figure of merit for XPS narrow scans: the equivalent width (EW{sub XPS}). • EW{sub XPS} is less subjective and involves lesser user bias than traditional peak fitting. • EW{sub XPS} is responsive to changes in chemical states of materials. • EW{sub XPS} could be used for quality control and comparing spectra from similar samples. • EW{sub XPS} has the potential to be part of an expert software system for machine interpretation of spectra. - Abstract: X-ray Photoelectron Spectroscopy (XPS) is a widely used surface analytical tool that provides information about the near surface regions of materials. And while indispensable for XPS data analysis, peak fitting of narrow scans is often a fairly subjective exercise. Herein we introduce the equivalent width (EW) as an additional and less subjective figure of merit for XPS narrow scans. We believe that this parameter will prove particularly useful for analyzing series of similar or nominally identical spectra, perhaps as a component of an expert software system for the machine interpretation of spectra. It also appears to be useful, shedding light on the chemical state of materials, when additional information about a sample is known. The EW{sub XPS} is simply defined as the area of a narrow scan divided by the height of the maximum of its peak envelope. To limit any ambiguity in EW{sub XPS} for a series of spectra, we may also list the peak position of the maximum of the envelope (PE{sub max}). The potential usefulness and limitations of the EW{sub XPS} and PE{sub max} parameters are demonstrated by their application to the narrow scans of: (i) four sets of ozone-treated carbon nanotubes (EW{sub XPS} ∼ 2.11–2.16 eV for a Shirley background, and up to 2.88 eV for no background, PE{sub max} ∼ 284.4–284.5 eV), (ii) a series of silicon wafers with different oxide thicknesses (EW{sub XPS} ∼ 1.5–2.8 eV, PE{sub max} ∼ 99–103 eV), (iii) hydrogen-terminated silicon before

  12. Theoretical aspects of the equivalence principle

    International Nuclear Information System (INIS)

    Damour, Thibault

    2012-01-01

    We review several theoretical aspects of the equivalence principle (EP). We emphasize the unsatisfactory fact that the EP maintains the absolute character of the coupling constants of physics, while general relativity and its generalizations (Kaluza–Klein, …, string theory) suggest that all absolute structures should be replaced by dynamical entities. We discuss the EP-violation phenomenology of dilaton-like models, which is likely to be dominated by the linear superposition of two effects: a signal proportional to the nuclear Coulomb energy, related to the variation of the fine-structure constant, and a signal proportional to the surface nuclear binding energy, related to the variation of the light quark masses. We recall various theoretical arguments (including a recently proposed anthropic argument) suggesting that the EP be violated at a small, but not unmeasurably small level. This motivates the need for improved tests of the EP. These tests are probing new territories in physics that are related to deep, and mysterious, issues in fundamental physics. (paper)

  13. Biomonitoring Equivalents for interpretation of urinary fluoride.

    Science.gov (United States)

    Aylward, L L; Hays, S M; Vezina, A; Deveau, M; St-Amand, A; Nong, A

    2015-06-01

    Exposure to fluoride is widespread due to its natural occurrence in the environment and addition to drinking water and dental products for the prevention of dental caries. The potential health risks of excess fluoride exposure include aesthetically unacceptable dental fluorosis (tooth mottling) and increased skeletal fragility. Numerous organizations have conducted risk assessments and set guidance values to represent maximum recommended exposure levels as well as recommended adequate intake levels based on potential public health benefits of fluoride exposure. Biomonitoring Equivalents (BEs) are estimates of the average biomarker concentrations corresponding to such exposure guidance values. The literature on daily urinary fluoride excretion rates as a function of daily fluoride exposure was reviewed and BE values corresponding to the available US and Canadian exposure guidance values were derived for fluoride in urine. The derived BE values range from 1.1 to 2.1mg/L (1.2-2.5μg/g creatinine). Concentrations of fluoride in single urinary spot samples from individuals, even under exposure conditions consistent with the exposure guidance values, may vary from the predicted average concentrations by several-fold due to within- and across-individual variation in urinary flow and creatinine excretion rates and due to the rapid elimination kinetics of fluoride. Thus, the BE values are most appropriately applied to screen population central tendency estimates for biomarker concentrations rather than interpretation of individual spot sample concentrations. Copyright © 2015. Published by Elsevier Inc.

  14. VERSE - Virtual Equivalent Real-time Simulation

    Science.gov (United States)

    Zheng, Yang; Martin, Bryan J.; Villaume, Nathaniel

    2005-01-01

    Distributed real-time simulations provide important timing validation and hardware in the- loop results for the spacecraft flight software development cycle. Occasionally, the need for higher fidelity modeling and more comprehensive debugging capabilities - combined with a limited amount of computational resources - calls for a non real-time simulation environment that mimics the real-time environment. By creating a non real-time environment that accommodates simulations and flight software designed for a multi-CPU real-time system, we can save development time, cut mission costs, and reduce the likelihood of errors. This paper presents such a solution: Virtual Equivalent Real-time Simulation Environment (VERSE). VERSE turns the real-time operating system RTAI (Real-time Application Interface) into an event driven simulator that runs in virtual real time. Designed to keep the original RTAI architecture as intact as possible, and therefore inheriting RTAI's many capabilities, VERSE was implemented with remarkably little change to the RTAI source code. This small footprint together with use of the same API allows users to easily run the same application in both real-time and virtual time environments. VERSE has been used to build a workstation testbed for NASA's Space Interferometry Mission (SIM PlanetQuest) instrument flight software. With its flexible simulation controls and inexpensive setup and replication costs, VERSE will become an invaluable tool in future mission development.

  15. Challenging a culture of racial equivalence.

    Science.gov (United States)

    Song, Miri

    2014-03-01

    We live at a time when our understandings and conceptualizations of 'racism' are often highly imprecise, broad, and used to describe a wide range of racialized phenomena. In this article, I raise some important questions about how the term racism is used and understood in contemporary British society by drawing on some recent cases of alleged racism in football and politics, many of which have been played out via new media technologies. A broader understanding of racism, through the use of the term 'racialization', has been helpful in articulating a more nuanced and complex understanding of racial incidents, especially of people's (often ambivalent) beliefs and behaviours. However, the growing emphasis upon 'racialization' has led to a conceptualization of racism which increasingly involves multiple perpetrators, victims, and practices without enough consideration of how and why particular interactions and practices constitute racism as such. The trend toward a growing culture of racial equivalence is worrying, as it denudes the idea of racism of its historical basis, severity and power. These frequent and commonplace assertions of racism in the public sphere paradoxically end up trivializing and homogenizing quite different forms of racialized interactions. I conclude that we need to retain the term 'racism', but we need to differentiate more clearly between 'racism' (as an historical and structured system of domination) from the broader notion of 'racialization'. © London School of Economics and Political Science 2014.

  16. Testing the equivalence principle on a trampoline

    Science.gov (United States)

    Reasenberg, Robert D.; Phillips, James D.

    2001-07-01

    We are developing a Galilean test of the equivalence principle in which two pairs of test mass assemblies (TMA) are in free fall in a comoving vacuum chamber for about 0.9 s. The TMA are tossed upward, and the process repeats at 1.2 s intervals. Each TMA carries a solid quartz retroreflector and a payload mass of about one-third of the total TMA mass. The relative vertical motion of the TMA of each pair is monitored by a laser gauge working in an optical cavity formed by the retroreflectors. Single-toss precision of the relative acceleration of a single pair of TMA is 3.5×10-12 g. The project goal of Δg/g = 10-13 can be reached in a single night's run, but repetition with altered configurations will be required to ensure the correction of systematic error to the nominal accuracy level. Because the measurements can be made quickly, we plan to study several pairs of materials.

  17. Testing the equivalence principle on cosmological scales

    Science.gov (United States)

    Bonvin, Camille; Fleury, Pierre

    2018-05-01

    The equivalence principle, that is one of the main pillars of general relativity, is very well tested in the Solar system; however, its validity is more uncertain on cosmological scales, or when dark matter is concerned. This article shows that relativistic effects in the large-scale structure can be used to directly test whether dark matter satisfies Euler's equation, i.e. whether its free fall is characterised by geodesic motion, just like baryons and light. After having proposed a general parametrisation for deviations from Euler's equation, we perform Fisher-matrix forecasts for future surveys like DESI and the SKA, and show that such deviations can be constrained with a precision of order 10%. Deviations from Euler's equation cannot be tested directly with standard methods like redshift-space distortions and gravitational lensing, since these observables are not sensitive to the time component of the metric. Our analysis shows therefore that relativistic effects bring new and complementary constraints to alternative theories of gravity.

  18. A Bayesian equivalency test for two independent binomial proportions.

    Science.gov (United States)

    Kawasaki, Yohei; Shimokawa, Asanao; Yamada, Hiroshi; Miyaoka, Etsuo

    2016-01-01

    In clinical trials, it is often necessary to perform an equivalence study. The equivalence study requires actively denoting equivalence between two different drugs or treatments. Since it is not possible to assert equivalence that is not rejected by a superiority test, statistical methods known as equivalency tests have been suggested. These methods for equivalency tests are based on the frequency framework; however, there are few such methods in the Bayesian framework. Hence, this article proposes a new index that suggests the equivalency of binomial proportions, which is constructed based on the Bayesian framework. In this study, we provide two methods for calculating the index and compare the probabilities that have been calculated by these two calculation methods. Moreover, we apply this index to the results of actual clinical trials to demonstrate the utility of the index.

  19. Design of Thermal Barrier Coatings Thickness for Gas Turbine Blade Based on Finite Element Analysis

    OpenAIRE

    Li, Biao; Fan, Xueling; Li, Dingjun; Jiang, Peng

    2017-01-01

    Thermal barrier coatings (TBCs) are deposited on the turbine blade to reduce the temperature of underlying substrate, as well as providing protection against the oxidation and hot corrosion from high temperature gas. Optimal ceramic top-coat thickness distribution on the blade can improve the performance and efficiency of the coatings. Design of the coatings thickness is a multiobjective optimization problem due to the conflicts among objectives of high thermal insulation performance, long op...

  20. Comparison of high temperature steam oxidation behavior of Zircaloy-4 versus austenitic and ferritic steels under light water reactor safety aspects

    International Nuclear Information System (INIS)

    Leistikow, S.; Schanz, G.; Zurek, Z.

    1985-12-01

    A comparative study of the oxidation behavior of Zy-4 versus steel No. 1.4914 and steel No. 1.4970 was performed in high temperature steam. Reactor typical tube sections of all three materials were exposed on both sides to superheated steam at temperatures ranging from 600 to 1300 0 C for up to 6 h. The specimens were evaluated by gravimetry, metallography, and other methods. The results are presented in terms of weight gain, corresponding metal (wall) penetration and consumption as function of time and temperature. Concerning the corrosion resistance the ranking position of Zy-4 was between the austenitic and the ferritic steel. Because of the chosen wall dimensions Zy-4 and the austenitic steel behaved similarly in that the faster oxidation of the thicker Zy-4 cladding consumed the total wall thickness in a time equivalent to the slower oxidation of the thinner austenitic steel cladding. The ferritic steel cladding however was faster consumed because of the lower oxidation resistance and the thinner wall thickness compared to the austenitic steel. So besides oxide scale formation, oxygen diffusion into the bulk of the metal forming various oxygen-containing phases were evaluated - also in respect to their influence on mechanical cladding properties and the dimensional changes. (orig./HP) [de

  1. Retinal vessel diameters decrease with macular ganglion cell layer thickness in autosomal dominant optic atrophy and in healthy subjects

    DEFF Research Database (Denmark)

    Rönnbäck, Cecilia; Grønskov, Karen; Larsen, Michael

    2014-01-01

    diameters (central retinal artery equivalent, CRAE, and central retinal vein equivalent, CRVE). Statistical analysis was corrected for age, gender, spherical equivalent refraction, axial length and mean arterial blood pressure (MABP) in a mixed model analysis. RESULTS: Retinal arteries and veins were...... ganglion cell-inner plexiform layer (GC-IPL) thickness (p = 0.0017 and p = 0.0057, respectively). CONCLUSION: Narrow retinal arteries and veins were associated not only with the severity of ADOA but with ganglion cell volume in patients with ADOA and in healthy subjects. This suggests that narrow vessels...

  2. Three-dimensional primate molar enamel thickness.

    Science.gov (United States)

    Olejniczak, Anthony J; Tafforeau, Paul; Feeney, Robin N M; Martin, Lawrence B

    2008-02-01

    Molar enamel thickness has played an important role in the taxonomic, phylogenetic, and dietary assessments of fossil primate teeth for nearly 90 years. Despite the frequency with which enamel thickness is discussed in paleoanthropological discourse, methods used to attain information about enamel thickness are destructive and record information from only a single plane of section. Such semidestructive planar methods limit sample sizes and ignore dimensional data that may be culled from the entire length of a tooth. In light of recently developed techniques to investigate enamel thickness in 3D and the frequent use of enamel thickness in dietary and phylogenetic interpretations of living and fossil primates, the study presented here aims to produce and make available to other researchers a database of 3D enamel thickness measurements of primate molars (n=182 molars). The 3D enamel thickness measurements reported here generally agree with 2D studies. Hominoids show a broad range of relative enamel thicknesses, and cercopithecoids have relatively thicker enamel than ceboids, which in turn have relatively thicker enamel than strepsirrhine primates, on average. Past studies performed using 2D sections appear to have accurately diagnosed the 3D relative enamel thickness condition in great apes and humans: Gorilla has the relatively thinnest enamel, Pan has relatively thinner enamel than Pongo, and Homo has the relatively thickest enamel. Although the data set presented here has some taxonomic gaps, it may serve as a useful reference for researchers investigating enamel thickness in fossil taxa and studies of primate gnathic biology.

  3. A calculational method of photon dose equivalent based on the revised technical standards of radiological protection law

    International Nuclear Information System (INIS)

    Tanaka, Shun-ichi; Suzuki, Tomoo

    1991-03-01

    The effective conversion factor for photons from 0.03 to 10 MeV were calculated to convert the absorbed dose in air to the 1 cm, 3 mm, and 70 μm depth dose equivalents behind iron, lead, concrete, and water shields up to 30 mfp thickness. The effective conversion factor changes slightly with thickness of the shields and becomes nearly constant at 5 to 10 mfp. The difference of the effective conversion factor was less than 2% between plane normal and point isotropic geometries. It is suggested that the present method, making the data base of the exposure buildup factors useful, would be very effective as compared to a new evaluation of the dose equivalent buildup factors. 5 refs., 7 figs., 22 tabs

  4. Equivalence between Born–Infeld tachyon and effective real scalar field theories for brane structures in warped geometry

    International Nuclear Information System (INIS)

    Bernardini, A.E.; Bertolami, O.

    2013-01-01

    An equivalence between Born–Infeld and effective real scalar field theories for brane structures is built in some specific warped space–time scenarios. Once the equations of motion for tachyon fields related to the Born–Infeld action are written as first-order equations, a simple analytical connection with a particular class of real scalar field superpotentials can be found. This equivalence leads to the conclusion that, for a certain class of superpotentials, both systems can support identical thick brane solutions as well as brane structures described through localized energy densities, T 00 (y), in the 5th dimension, y. Our results indicate that thick brane solutions realized by the Born–Infeld cosmology can be connected to real scalar field brane scenarios which can be used to effectively map the tachyon condensation mechanism

  5. Study on the application of 50 mm thick welded joints without PWHT for containment vessels

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Nozomu; Sakai, Yoshiyuki; Hayashi, Kazutoshi; Higashikubo, Tomohiro (Mitsubishi Heavy Industries. Ltd., Kobe Shipyard and Machinery Works (Japan)); Iida, Kunihiro (Shibaura Inst. of Tech., Dept. of Mechanical Engineering, Tokyo (Japan)); Satou, Masanobu (Mitsubishi Heavy Industries. Ltd., Tkasago Research and Development Center (Japan))

    1992-01-01

    In order to investigate the propriety of the use of 50 mm thick SGV480 carbon steel which is equivalent to ASTM A516 Gr. 70 without post weld heat treatment for containment vessels, the authors have certified the basic properties of base metal and welded joints of 50 mm thick SGV480 steel plates. The results showed that fracture thoughness of welded joints is high without PWHT and the steel is safe enough without PWHT against embrittlement fracture under the operating conditions. (orig.).

  6. Study on the application of 50 mm thick welded joints without PWHT for containment vessels

    International Nuclear Information System (INIS)

    Watanabe, Nozomu; Sakai, Yoshiyuki; Hayashi, Kazutoshi; Higashikubo, Tomohiro; Iida, Kunihiro; Satou, Masanobu

    1992-01-01

    In order to investigate the propriety of the use of 50 mm thick SGV480 carbon steel which is equivalent to ASTM A516 Gr. 70 without post weld heat treatment for containment vessels, the authors have certified the basic properties of base metal and welded joints of 50 mm thick SGV480 steel plates. The results showed that fracture thoughness of welded joints is high without PWHT and the steel is safe enough without PWHT against embrittlement fracture under the operating conditions. (orig.)

  7. Method of working thick beds

    Energy Technology Data Exchange (ETDEWEB)

    Giezynski, A; Bialasik, A; Krawiec, A; Wylenzek, A

    1981-12-30

    The patented method of working thick coal beds in layers consists of creating in the collapsed rocks or from the fill material a bearing rock plate by strengthening these rocks with a hardening composition made of wastes of raw material, resin and water injected into the rock through wells. The difference in the suggestion is that through boreholes drilled in the lower part of the rock roofing on a previously calculated network, a solution is regularly injected which consists of dust wastes obtained in electric filters during production of clinker from mineral raw material in a quantity of 60-70% by volume, wastes of open-hearth production in a quantity of 15-20% and natural sand in a quantity of 15-20%, and water in a quantity of 35-55% of the volume of mineral components. In the second variant, the injected compostion contains: wastes from production of clinker 55-57%, open-hearth wastes 20-23%, natural sand 12-14%, asbestos fine particles 7-8% and water 38-45% of the volume of mineral components. In addition, the difference is that in the boreholes drilled in the coal block directly under the roofing, a composition is injected which consists of natural sand and catalyst in the form of powder and individually supplied liquid synthetic resin in a quantity of 3-5% by weight in relation to the sand. The hardening time with normal temperature is 1-1.5 h, after which strength is reached of 80 kg-f/cm/sup 2/.

  8. Radiation equivalency: For the radiation recall phenomenon

    International Nuclear Information System (INIS)

    Stevens, R.H.; Cole, D.A.

    1983-01-01

    Experimental and clinico-epidemiological investigations have unequivocally established the risk of an offspring in later years developing cancer after experiencing an in utero carcinogenic insult. The present studies have focused upon identifying whether the biological effects of iodine-131 and the colon carcinogen 1,2-dimethylhydrazine (DMH) when administered during pregnancy in the Fischer F344 inbred rat are remembered in the offsprings at a later age. The investigations have been based upon the premise that after exposure to a carcinogen ''foreign-like'' tumor cells develop which result in the host mounting active antitumor immune responses. The authors have now measured at 2 to 3 months post-exposure, the antitumor cell-mediated immunity (CMI) induced by intraperitoneal administration of the radionuclide or chemical at 16-18 days of gestation. Their findings indicate a positive sex relationship existing in those offsprings exposed to the radioiodine with the female being much less sensitive. In contrast, no such difference was observed between responsiveness of the males and females born from dams exposed to the DMH. Significantly, the dams exposed to either the radionuclide or DMH expressed no measurable CMI suggesting that either the fetus acted as a carcinogen trap or else the state of pregnancy altered the mother's immune system in such a fashion to no longer respond to the insult. A Radiation Equivalency value has now been determined for the transplacental DMH exposures with the calculations suggesting the fetus is significantly more sensitive (over 10 times) than the adult animals. The results of this study now demonstrate that carcinogenic memory remains for exposures to both the iodine-131 and DMH in the first offspring generation and suggest that the effects may be recalled at a later age with the expected overt results being the development of cancer

  9. Biomonitoring Equivalents for bisphenol A (BPA).

    Science.gov (United States)

    Krishnan, Kannan; Gagné, Michelle; Nong, Andy; Aylward, Lesa L; Hays, Sean M

    2010-10-01

    Recent efforts worldwide have resulted in a growing database of measured concentrations of chemicals in blood and urine samples taken from the general population. However, few tools exist to assist in the interpretation of the measured values in a health risk context. Biomonitoring Equivalents (BEs) are defined as the concentration or range of concentrations of a chemical or its metabolite in a biological medium (blood, urine, or other medium) that is consistent with an existing health-based exposure guideline. BE values are derived by integrating available data on pharmacokinetics with existing chemical risk assessments. This study reviews available health-based exposure guidance values for bisphenol A (BPA) from Health Canada, the United States Environmental Protection Agency (USEPA) and the European Food Safety Authority (EFSA). BE values were derived based on data on BPA urinary excretion in humans. The BE value corresponding to the oral provisional tolerable daily intake (pTDI) of 25 microg/kg-d from Health Canada is 1mg/L (1.3mg/g creatinine); value corresponding to the US EPA reference dose (RfD) and EFSA tolerable daily intake (TDI) estimates (both of which are equal to 50 microg/kg-d) is 2mg/L (2.6 mg/g creatinine). These values are estimates of the 24-h average urinary BPA concentrations that are consistent with steady-state exposure at the respective exposure guidance values. These BE values may be used as screening tools for evaluation of central tendency measures of population biomonitoring data for BPA in a risk assessment context and can assist in prioritization of the potential need for additional risk assessment efforts for BPA relative to other chemicals. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  10. Comparison of different methods for measuring the passive film thickness on metals

    International Nuclear Information System (INIS)

    Benoit, Marie; Bataillon, Christian; Gwinner, Benoit; Miserque, Frédéric; Orazem, Mark E.; Sánchez-Sánchez, Carlos M.; Tribollet, Bernard; Vivier, Vincent

    2016-01-01

    Highlights: • In situ EIS and ex situ XPS were used for the characterization of zirconium oxide films. • The film thicknesses can be obtained from the analysis of a single EIS diagram. • A convenient graphical method to extract film properties is proposed. - Abstract: In situ electrochemical impedance spectroscopy (EIS) and ex situ X-ray photoelectron spectroscopy (XPS) measurements on electrogenerated zirconium oxide films on zirconium (Zr/ZrO_2) were used to quantify the oxide film thickness and resistivity profiles through the oxide. The EIS analysis presented here takes advantage of the high-frequency domain at which the constant-phase element (CPE) behavior of the oxide film reverts to a capacitive response and the Cole-Cole representations of the complex capacitance to extract the high-frequency capacitance of the oxide film without reference to the nature of the time-constant distribution within the oxide film. The film thickness of the ZrO_2 samples measured from the high-frequency capacitance of EIS were in good agreement with the thickness obtained from XPS. Moreover, the EIS analysis presented is based on the use of the integral solution of the power law model, which allows to obtain in one single EIS experiment, both the film thickness and the resistivity profile in the ZrO_2 film. This work suggests a convenient graphical method to extract film properties and serves to validate a key assumption of the power-law model for interpretation of CPE parameters in terms of physical properties.

  11. General Dynamic Equivalent Modeling of Microgrid Based on Physical Background

    Directory of Open Access Journals (Sweden)

    Changchun Cai

    2015-11-01

    Full Text Available Microgrid is a new power system concept consisting of small-scale distributed energy resources; storage devices and loads. It is necessary to employ a simplified model of microgrid in the simulation of a distribution network integrating large-scale microgrids. Based on the detailed model of the components, an equivalent model of microgrid is proposed in this paper. The equivalent model comprises two parts: namely, equivalent machine component and equivalent static component. Equivalent machine component describes the dynamics of synchronous generator, asynchronous wind turbine and induction motor, equivalent static component describes the dynamics of photovoltaic, storage and static load. The trajectory sensitivities of the equivalent model parameters with respect to the output variables are analyzed. The key parameters that play important roles in the dynamics of the output variables of the equivalent model are identified and included in further parameter estimation. Particle Swarm Optimization (PSO is improved for the parameter estimation of the equivalent model. Simulations are performed in different microgrid operation conditions to evaluate the effectiveness of the equivalent model of microgrid.

  12. Characteristics of the thick, compound refractive lens

    International Nuclear Information System (INIS)

    Pantell, Richard H.; Feinstein, Joseph; Beguiristain, H. Raul; Piestrup, Melvin A.; Gary, Charles K.; Cremer, Jay T.

    2003-01-01

    A compound refractive lens (CRL), consisting of a series of N closely spaced lens elements each of which contributes a small fraction of the total focusing, can be used to focus x rays or neutrons. The thickness of a CRL can be comparable to its focal length, whereupon a thick-lens analysis must be performed. In contrast with the conventional optical lens, where the ray inside the lens follows a straight line, the ray inside the CRL is continually changing direction because of the multiple refracting surfaces. Thus the matrix representation for the thick CRL is quite different from that for the thick optical lens. Principal planes can be defined such that the thick-lens matrix can be converted to that of a thin lens. For a thick lens the focal length is greater than for a thin lens with the same lens curvature, but this lengthening effect is less for the CRL than for the conventional optical lens

  13. The effect of thickness in the through-diffusion experiment

    International Nuclear Information System (INIS)

    Lehikoinen, J.; Uusheimo, K.; Valkiainen, M.

    1994-01-01

    The publication contains an experimental study of diffusion in the water filled pores of rock samples. The samples studied are rapakivi granite from Loviisa, southern Finland. The drill-core sample was sectioned perpendicularly with diamond saw and three cylinder formed samples were obtained. The nominal thicknesses (heights of the cylinders) are 2, 4 and 6 cm. For the diffusion measurement the sample holders were pressed between two chambers. One of the chambers was filled with 0.0044 molar sodium chloride solution spiked with tracers. Another chamber was filled with inactive solution. Tritium (HTO) considered to be water equivalent tracer and anionic 36 Cl were used as tracers. (9 refs., 19 figs., 2 tabs.)

  14. Development of a thick gas electron multiplier for microdosimetry

    International Nuclear Information System (INIS)

    Orchard, G.M.; Chin, K.; Prestwich, W.V.; Waker, A.J.; Byun, S.H.

    2011-01-01

    A new tissue-equivalent proportional counter based on a thick gas electron multiplier (THGEM) was developed and tested for microdosimetry. A systematic test was conducted at the McMaster Accelerator Laboratory to investigate the overall performance of the prototype detector. A mixed neutron-gamma-ray radiation field was generated using the 7 Li(p,n) reaction. The detector was operated at low voltage initially to test the stability and then the relative multiplication gain was measured as a function of the operating high voltage. A drift potential of 100 V and a THGEM bias of 727 V generated a multiplication gain sufficient for the detection of both neutron and gamma-ray radiation. A consistent microdosimetric pattern was observed between the THGEM detector and standard TEPC for microdosimetry.

  15. Magnetic properties and microstructure investigation of electrodeposited FeNi/ITO films with different thickness

    International Nuclear Information System (INIS)

    Cao, Derang; Wang, Zhenkun; Feng, Erxi; Wei, Jinwu; Wang, Jianbo; Liu, Qingfang

    2013-01-01

    Highlights: •FeNi alloy thin films with different thickness deposited on Indium Tin Oxides (ITOs) conductive glass substrates by electrodeposition method. •A columnar crystalline microstructure and domain structure were obtained in FeNi thin films. •Particular FMR spectra of FeNi alloy with different thickness were studied. -- Abstract: FeNi alloy thin films with different thickness deposited on Indium Tin Oxides (ITOs) conductive glass substrates from the electrolytes by electrodeposition method have been studied by magnetic force microscopy (MFM), scanning electron microscopy (SEM) and ferromagnetic resonance (FMR) technique. For these films possessing an in-plane isotropy, the remanence decreases with the increasing of film thickness and the critical thickness that a stripe domain structure emerges is about 116 nm. Characteristic differences of the FMR spectra of different thickness are also observed. The results show that the resonance field at high measured angle increases firstly then decreases with increasing thickness, which may be related to the striped domain structure

  16. Graph Treewidth and Geometric Thickness Parameters

    OpenAIRE

    Dujmović, Vida; Wood, David R.

    2005-01-01

    Consider a drawing of a graph $G$ in the plane such that crossing edges are coloured differently. The minimum number of colours, taken over all drawings of $G$, is the classical graph parameter "thickness". By restricting the edges to be straight, we obtain the "geometric thickness". By further restricting the vertices to be in convex position, we obtain the "book thickness". This paper studies the relationship between these parameters and treewidth. Our first main result states that for grap...

  17. Localizing gravity on exotic thick 3-branes

    International Nuclear Information System (INIS)

    Castillo-Felisola, Oscar; Melfo, Alejandra; Pantoja, Nelson; Ramirez, Alba

    2004-01-01

    We consider localization of gravity on thick branes with a nontrivial structure. Double walls that generalize the thick Randall-Sundrum solution, and asymmetric walls that arise from a Z 2 symmetric scalar potential, are considered. We present a new asymmetric solution: a thick brane interpolating between two AdS 5 spacetimes with different cosmological constants, which can be derived from a 'fake supergravity' superpotential, and show that it is possible to confine gravity on such branes

  18. Does cement mantle thickness really matter?

    OpenAIRE

    Caruana, J.

    2008-01-01

    The thickness of the cement mantle around the femoral component of total hip replacements is a contributing factor to aseptic loosening and revision. Nevertheless, various designs of stems and surgical tooling lead to cement mantles of differing thicknesses. This thesis is concerned with variability in cement thickness around the Stanmore Hip, due to surgical approach, broach size and stem orientation, and its effects on stress and cracking in the cement. The extent to which cement mantle thi...

  19. Radiation transmission pipe thickness measurement system

    International Nuclear Information System (INIS)

    Higashi, Yasuhiko

    2010-01-01

    Fuji Electric Systems can be measured from the outer insulation of the transmission Characteristics and radiation detection equipment had been developed that can measure pipe wall thinning in plant and running, the recruitment of another three-beam calculation method by pipe thickness measurement system was developed to measure the thickness of the pipe side. This equipment has been possible to measure the thickness of the circumferential profile of the pipe attachment by adopting automatic rotation. (author)

  20. Comparison and interchangeability of macular thickness measured with Cirrus OCT and Stratus OCT in myopic eyes

    Directory of Open Access Journals (Sweden)

    Geng Wang

    2015-12-01

    Full Text Available AIM: To investigate the difference of macular thickness measurements between stratus optical coherence tomography (OCT and Cirrus OCT (Carl Zeiss Meditec, Dublin, CA, USA in the same myopic patient and to develop a conversion equation to interchange macular thickness obtained with these two OCT devices. METHODS: Eighty-nine healthy Chinese adults with spherical equivalent (SE ranging from -1.13 D to -9.63 D were recruited. The macular thickness was measured by Cirrus OCT and Stratus OCT. The correlation between macular thickness and axial length and the agreement between two OCT measurements were evaluated. A formula was generated to interchange macular thickness obtained with two OCT devices. RESULTS: Average macular thickness measured with Stratus OCT (r=-0.280, P=0.008 and Cirrus OCT (r=-0.224, P=0.034 were found to be negatively correlated with axial length. No statistically significant correlation was found between axial length and central subfield macular thickness (CMT measured with Stratus OCT (r=0.191, P=0.073 and Cirrus OCT (r=0.169, P=0.113. The mean CMT measured with Cirrus OCT was 53.63±7.94 μm thicker than with Stratus OCT. The formula CMTCirrus OCT=78.328+0.874×CMTStratus OCT was generated to interchange macular thickness obtained with two OCT devices. CONCLUSION: Macular thickness measured with Cirrus OCT were thicker than with Stratus OCT in myopic eyes. A formula can be used to interchange macular thickness measured with two OCT devices in myopic eyes. Studies with different OCT devices and larger samples are warranted to enable the comparison of macular values measured with different OCT devices.

  1. Heterogeneous Oxidation of Laboratory-generated Mixed Composition and Biomass Burning Particles

    Science.gov (United States)

    Lim, C. Y.; Sugrue, R. A.; Hagan, D. H.; Cappa, C. D.; Kroll, J. H.; Browne, E. C.

    2016-12-01

    Heterogeneous oxidation of organic aerosol (OA) can significantly transform the chemical and physical properties of particulate matter in the atmosphere, leading to changes to the chemical composition of OA and potential volatilization of organic compounds. It has become increasingly apparent that the heterogeneous oxidation kinetics of OA depend on the phase and morphology of the particles. However, most laboratory experiments to date have been performed on single-component, purely organic precursors, which may exhibit fundamentally different behavior than more complex particles in the atmosphere. Here we present laboratory studies of the heterogeneous oxidation of two more complex chemical systems: thin, organic coatings on inorganic seed particles and biomass burning OA. In the first system, squalane (C30H62), a model compound for reduced OA, is coated onto dry ammonium sulfate particles at various thicknesses (10-20 nm) and exposed to hydroxyl radical (OH) in a flow tube reactor. In the second, we use a semi-batch reactor to study the heterogeneous OH-initiated oxidation of biomass burning particles as a part of the 2016 FIREX campaign in Missoula, MT. The resulting changes in chemical composition are monitored with an Aerodyne High Resolution Time-of-flight Aerosol Mass Spectrometer (AMS) and a soot-particle AMS for the non-refractory and refractory systems, respectively. We show that the heterogeneous oxidation kinetics of these multicomponent particles are substantially different than that of the single-component particles. The oxidation of organic coatings is rapid, undergoing dramatic changes to carbon oxidation state and losing a significant amount of organic mass after relatively low OH exposures (equivalent to several days of atmospheric processing). In the case of biomass burning particles, the kinetics are complex, with different components (inferred by aerosol mass spectrometry) undergoing oxidation at different rates.

  2. Dual beam x-ray thickness gauge

    International Nuclear Information System (INIS)

    Allport, J.J.

    1977-01-01

    The apparatus and method for continuous measurement of thickness of a sheet at a rolling mill or the like without contacting the sheet are described. A system directing radiation through the sheet in two energy bands and providing a measure of change in composition of the material as it passes the thickness gauging station is included. A system providing for changing the absorption coefficient of the material in the thickness measurement as a function of the change in composition so that the measured thickness is substantially independent of variations in composition is described

  3. Card controlled beta backscatter thickness measuring instrument

    International Nuclear Information System (INIS)

    Schlesinger, J.

    1978-01-01

    An improved beta backscatter instrument for the nondestructive measurement of the thickness of thin coatings on a substrate is described. Included therein is the utilization of a bank of memory stored data representative of isotope, substrate, coating material and thickness range characteristics in association with a control card having predetermined indicia thereon selectively representative of a particular isotope, substrate material, coating material and thickness range for conditioning electronic circuit means by memory stored data selected in accord with the predetermined indicia on a control card for converting backscattered beta particle counts into indicia of coating thickness

  4. Uncertainties in thick-target PIXE analysis

    International Nuclear Information System (INIS)

    Campbell, J.L.; Cookson, J.A.; Paul, H.

    1983-01-01

    Thick-target PIXE analysis insolves uncertainties arising from the calculation of thick-target X-ray production in addition to the usual PIXE uncertainties. The calculation demands knowledge of ionization cross-sections, stopping powers and photon attenuation coefficients. Information on these is reviewed critically and a computational method is used to estimate the uncertainties transmitted from this data base into results of thick-target PIXE analyses with reference to particular specimen types using beams of 2-3 MeV protons. A detailed assessment of the accuracy of thick-target PIXE is presented. (orig.)

  5. Thin Solid Oxide Cell

    DEFF Research Database (Denmark)

    2010-01-01

    The present invention relates to a thin and in principle unsupported solid oxide cell, comprising at least a porous anode layer, an electrolyte layer and a porous cathode layer, wherein the anode layer and the cathode layer comprise an electrolyte material, at least one metal and a catalyst...... material, and wherein the overall thickness of the thin reversible cell is about 150 [mu]m or less, and to a method for producing same. The present invention also relates to a thin and in principle unsupported solid oxide cell, comprising at least a porous anode layer, an electrolyte layer and a porous...... cathode layer, wherein the anode layer and the cathode layer comprise an electrolyte material and a catalyst material, wherein the electrolyte material is doper zirconia, and wherein the overall thickness of the thin reversible cell is about 150 [mu]m or less, and to a method for producing same...

  6. XPS studies of the oxide formed on pure Ti

    International Nuclear Information System (INIS)

    Cremery, P.; David, D.; Beranger, G.; Oviedo, C.; Garcia, E.A.

    1980-01-01

    The XPS technique was used to study titanium samples oxidized at 200 ton of pure oxigen at different times and temperatures with the aim of producing variable oxide thicknesses. The thicknesses of different oxigen layers were determined by the nuclear reaction O 16 (d,p) O 17 *. (author) [pt

  7. Oxide impedance characteristics of the Zr-xNb alloys

    International Nuclear Information System (INIS)

    Park, S. Y.; Choi, B. K.; Jung, Y. H.; Jung, Y. H.

    2002-01-01

    To elucidate the correlation between the oxide impedance and corrosion characteristics of the Zr-xNb alloys, the long term corrosion test in high temperature / high pressure aqueous solution and the impedance test in the room temperature sulfate solution were performed. β-quenched plate specimens were heat-treated at 570 .deg. C for 500 hours to get the α+β Nb phase and the at 640 .deg. C for 10 hours to get the α+β Zr phase. The impedance test was conducted in sulfate solution for the initial corrosion test specimen (WG = 30 mg/dm 2 ). To evaluate the impedance date, 4 types of equivalent circuits were constructed by 5 parallel and serial RC elements. By using the equivalent circuits, the thickness of the inner and outer layers were calculated and the electric resistance of each layers were estimated. The corrosion behaviour of Zr-xNb alloys were quite different depending of the annealing condition and Nb-content. The corrosion resistance of the β Nb phase contained high Nb alloys were excellent rather than β Zr phase contained high Nb alloys. The electric resistance of the outer layer of β Zr phase contained high Nb alloy was twice larger than that of β Zr phase contained high Nb alloy, and in the case of outer layer 30% larger. So, the long term corrosion behaviors in high temperature could be estimated well by using the impedance test results

  8. Dose sculpting with generalized equivalent uniform dose

    International Nuclear Information System (INIS)

    Wu Qiuwen; Djajaputra, David; Liu, Helen H.; Dong Lei; Mohan, Radhe; Wu, Yan

    2005-01-01

    With intensity-modulated radiotherapy (IMRT), a variety of user-defined dose distribution can be produced using inverse planning. The generalized equivalent uniform dose (gEUD) has been used in IMRT optimization as an alternative objective function to the conventional dose-volume-based criteria. The purpose of this study was to investigate the effectiveness of gEUD optimization to fine tune the dose distributions of IMRT plans. We analyzed the effect of gEUD-based optimization parameters on plan quality. The objective was to determine whether dose distribution to selected structures could be improved using gEUD optimization without adversely altering the doses delivered to other structures, as in sculpting. We hypothesized that by carefully defining gEUD parameters (EUD 0 and n) based on the current dose distributions, the optimization system could be instructed to search for alternative solutions in the neighborhood, and we could maintain the dose distributions for structures already satisfactory and improve dose for structures that need enhancement. We started with an already acceptable IMRT plan optimized with any objective function. The dose distribution was analyzed first. For structures that dose should not be changed, a higher value of n was used and EUD 0 was set slightly higher/lower than the EUD value at the current dose distribution for critical structures/targets. For structures that needed improvement in dose, a higher to medium value of n was used, and EUD 0 was set to the EUD value or slightly lower/higher for the critical structure/target at the current dose distribution. We evaluated this method in one clinical case each of head and neck, lung and prostate cancer. Dose volume histograms, isodose distributions, and relevant tolerance doses for critical structures were used for the assessment. We found that by adjusting gEUD optimization parameters, the dose distribution could be improved with only a few iterations. A larger value of n could lead to

  9. The radiobiology of boron neutron capture therapy: Are ''photon-equivalent'' doses really photon-equivalent?

    International Nuclear Information System (INIS)

    Coderre, J.A.; Diaz, A.Z.; Ma, R.

    2001-01-01

    Boron neutron capture therapy (BNCT) produces a mixture of radiation dose components. The high-linear energy transfer (LET) particles are more damaging in tissue than equal doses of low-LET radiation. Each of the high-LET components can multiplied by an experimentally determined factor to adjust for the increased biological effectiveness and the resulting sum expressed in photon-equivalent units (Gy-Eq). BNCT doses in photon-equivalent units are based on a number of assumptions. It may be possible to test the validity of these assumptions and the accuracy of the calculated BNCT doses by 1) comparing the effects of BNCT in other animal or biological models where the effects of photon radiation are known, or 2) if there are endpoints reached in the BNCT dose escalation clinical trials that can be related to the known response to photons of the tissue in question. The calculated Gy-Eq BNCT doses delivered to dogs and to humans with BPA and the epithermal neutron beam of the Brookhaven Medical Research Reactor were compared to expected responses to photon irradiation. The data indicate that Gy-Eq doses in brain may be underestimated. Doses to skin are consistent with the expected response to photons. Gy-Eq doses to tumor are significantly overestimated. A model system of cells in culture irradiated at various depths in a lucite phantom using the epithermal beam is under development. Preliminary data indicate that this approach can be used to detect differences in the relative biological effectiveness of the beam. The rat 9L gliosarcoma cell survival data was converted to photon-equivalent doses using the same factors assumed in the clinical studies. The results superimposed on the survival curve derived from irradiation with Cs-137 photons indicating the potential utility of this model system. (author)

  10. Evaluation of the water equivalence of solid phantoms using gamma ray transmission measurements

    International Nuclear Information System (INIS)

    Hill, R.F.; Brown, S.; Baldock, C.

    2008-01-01

    Gamma ray transmission measurements have been used to evaluate the water equivalence of solid phantoms. Technetium-99m was used in narrow beam geometry and the transmission of photons measured, using a gamma camera, through varying thickness of the solid phantom material and water. Measured transmission values were compared with Monte Carlo calculated transmission data using the EGSnrc Monte Carlo code to score fluence in a geometry similar to that of the measurements. The results indicate that the RMI457 Solid Water, CMNC Plastic Water and PTW RW3 solid phantoms had similar transmission values as compared to water to within ±1.5%. However, Perspex had a greater deviation in the transmission values up to ±4%. The agreement between the measured and EGSnrc calculated transmission values agreed to within ±1% over the range of phantom thickness studied. The linear attenuation coefficients at the gamma ray energy of 140.5 keV were determined from the measured and EGSnrc calculated transmission data and compared with predicted values derived from data provided by the National Institute of Standards and Technology (NIST) using the XCOM program. The coefficients derived from the measured data were up to 6% lower than those predicted by the XCOM program, while the coefficients determined from the Monte Carlo calculations were between measured and XCOM values. The results indicate that a similar process can be followed to determine the water equivalency of other solid phantoms and at other photon energies

  11. Development of Equivalent Material Properties of Microbump for Simulating Chip Stacking Packaging

    Directory of Open Access Journals (Sweden)

    Chang-Chun Lee

    2015-08-01

    Full Text Available three-dimensional integrated circuit (3D-IC structure with a significant scale mismatch causes difficulty in analytic model construction. This paper proposes a simulation technique to introduce an equivalent material composed of microbumps and their surrounding wafer level underfill (WLUF. The mechanical properties of this equivalent material, including Young’s modulus (E, Poisson’s ratio, shear modulus, and coefficient of thermal expansion (CTE, are directly obtained by applying either a tensile load or a constant displacement, and by increasing the temperature during simulations, respectively. Analytic results indicate that at least eight microbumps at the outermost region of the chip stacking structure need to be considered as an accurate stress/strain contour in the concerned region. In addition, a factorial experimental design with analysis of variance is proposed to optimize chip stacking structure reliability with four factors: chip thickness, substrate thickness, CTE, and E-value. Analytic results show that the most significant factor is CTE of WLUF. This factor affects microbump reliability and structural warpage under a temperature cycling load and high-temperature bonding process. WLUF with low CTE and high E-value are recommended to enhance the assembly reliability of the 3D-IC architecture.

  12. Dynamic equivalence relation on the fuzzy measure algebras

    Directory of Open Access Journals (Sweden)

    Roya Ghasemkhani

    2017-04-01

    Full Text Available The main goal of the present paper is to extend classical results from the measure theory and dynamical systems to the fuzzy subset setting. In this paper, the notion of  dynamic equivalence relation is introduced and then it is proved that this relation is an equivalence relation. Also, a new metric on the collection of all equivalence classes is introduced and it is proved that this metric is complete.

  13. Dose equivalent distributions in the AAEC total body nitrogen facility

    International Nuclear Information System (INIS)

    Allen, B.J.; Bailey, G.M.; McGregor, B.J.

    1985-01-01

    The incident neutron dose equivalent in the AAEC total body nitrogen facility is measured by a calibrated remmeter. Dose equivalent rates and distributions are calculated by Monte Carlo techniques which take account of the secondary neutron flux from the collimator. Experiment and calculation are found to be in satisfactory agreement. The effective dose equivalent per exposure is determined by weighting organ doses, and the potential detriment per exposure is calculated from ICRP risk factors

  14. Equivalence principle violations and couplings of a light dilaton

    International Nuclear Information System (INIS)

    Damour, Thibault; Donoghue, John F.

    2010-01-01

    We consider possible violations of the equivalence principle through the exchange of a light 'dilaton-like' scalar field. Using recent work on the quark-mass dependence of nuclear binding, we find that the dilaton-quark-mass coupling induces significant equivalence-principle-violating effects varying like the inverse cubic root of the atomic number - A -1/3 . We provide a general parametrization of the scalar couplings, but argue that two parameters are likely to dominate the equivalence-principle phenomenology. We indicate the implications of this framework for comparing the sensitivities of current and planned experimental tests of the equivalence principle.

  15. Eggshell thickness in mourning dove populations

    Science.gov (United States)

    Kreitzer, J.F.

    1971-01-01

    Eggs (n = 452) of the mourning dove (Zenaidura macroura) were collected from 9 states in 1969 and 11 states in 1970, and shell thickness was compared with that of eggs (n = 97) collected from 24 states during the years 1861 to 1935. Mean shell thickness did not differ significantly in the test groups.

  16. Applications of precision ultrasonic thickness gauging

    International Nuclear Information System (INIS)

    Fowler, K.A.; Elfbaum, G.M.; Husarek, V.; Castel, J.G.

    1976-01-01

    Pulse-echo ultrasonic thickness gauging is now recognized as an accurate method of measuring thickness of a product from one side when the velocity of ultrasound in the material is known. The advantages and present limitation of this gauging technique are presented, together with several applications of industrial interest [fr

  17. Skull thickness in patients with clefts

    DEFF Research Database (Denmark)

    Arntsen, T; Kjaer, I; Sonnesen, L

    2010-01-01

    The purpose was to analyze skull thickness in incomplete cleft lip (CL), cleft palate (CP), and combined cleft lip and palate (UCLP).......The purpose was to analyze skull thickness in incomplete cleft lip (CL), cleft palate (CP), and combined cleft lip and palate (UCLP)....

  18. Equivalent Sensor Radiance Generation and Remote Sensing from Model Parameters. Part 1; Equivalent Sensor Radiance Formulation

    Science.gov (United States)

    Wind, Galina; DaSilva, Arlindo M.; Norris, Peter M.; Platnick, Steven E.

    2013-01-01

    In this paper we describe a general procedure for calculating equivalent sensor radiances from variables output from a global atmospheric forecast model. In order to take proper account of the discrepancies between model resolution and sensor footprint the algorithm takes explicit account of the model subgrid variability, in particular its description of the probably density function of total water (vapor and cloud condensate.) The equivalent sensor radiances are then substituted into an operational remote sensing algorithm processing chain to produce a variety of remote sensing products that would normally be produced from actual sensor output. This output can then be used for a wide variety of purposes such as model parameter verification, remote sensing algorithm validation, testing of new retrieval methods and future sensor studies. We show a specific implementation using the GEOS-5 model, the MODIS instrument and the MODIS Adaptive Processing System (MODAPS) Data Collection 5.1 operational remote sensing cloud algorithm processing chain (including the cloud mask, cloud top properties and cloud optical and microphysical properties products.) We focus on clouds and cloud/aerosol interactions, because they are very important to model development and improvement.

  19. The equivalent thermal conductivity of lattice core sandwich structure: A predictive model

    International Nuclear Information System (INIS)

    Cheng, Xiangmeng; Wei, Kai; He, Rujie; Pei, Yongmao; Fang, Daining

    2016-01-01

    Highlights: • A predictive model of the equivalent thermal conductivity was established. • Both the heat conduction and radiation were considered. • The predictive results were in good agreement with experiment and FEM. • Some methods for improving the thermal protection performance were proposed. - Abstract: The equivalent thermal conductivity of lattice core sandwich structure was predicted using a novel model. The predictive results were in good agreement with experimental and Finite Element Method results. The thermal conductivity of the lattice core sandwich structure was attributed to both core conduction and radiation. The core conduction caused thermal conductivity only relied on the relative density of the structure. And the radiation caused thermal conductivity increased linearly with the thickness of the core. It was found that the equivalent thermal conductivity of the lattice core sandwich structure showed a highly dependent relationship on temperature. At low temperatures, the structure exhibited a nearly thermal insulated behavior. With the temperature increasing, the thermal conductivity of the structure increased owing to radiation. Therefore, some attempts, such as reducing the emissivity of the core or designing multilayered structure, are believe to be of benefit for improving the thermal protection performance of the structure at high temperatures.

  20. Distributed ice thickness and glacier volume in southern South America

    Science.gov (United States)

    Carrivick, Jonathan L.; Davies, Bethan J.; James, William H. M.; Quincey, Duncan J.; Glasser, Neil F.

    2016-11-01

    South American glaciers, including those in Patagonia, presently contribute the largest amount of meltwater to sea level rise per unit glacier area in the world. Yet understanding of the mechanisms behind the associated glacier mass balance changes remains unquantified partly because models are hindered by a lack of knowledge of subglacial topography. This study applied a perfect-plasticity model along glacier centre-lines to derive a first-order estimate of ice thickness and then interpolated these thickness estimates across glacier areas. This produced the first complete coverage of distributed ice thickness, bed topography and volume for 617 glaciers between 41°S and 55°S and in 24 major glacier regions. Maximum modelled ice thicknesses reach 1631 m ± 179 m in the South Patagonian Icefield (SPI), 1315 m ± 145 m in the North Patagonian Icefield (NPI) and 936 m ± 103 m in Cordillera Darwin. The total modelled volume of ice is 1234.6 km3 ± 246.8 km3 for the NPI, 4326.6 km3 ± 865.2 km3 for the SPI and 151.9 km3 ± 30.38 km3 for Cordillera Darwin. The total volume was modelled to be 5955 km3 ± 1191 km3, which equates to 5458.3 Gt ± 1091.6 Gt ice and to 15.08 mm ± 3.01 mm sea level equivalent (SLE). However, a total area of 655 km2 contains ice below sea level and there are 282 individual overdeepenings with a mean depth of 38 m and a total volume if filled with water to the brim of 102 km3. Adjusting the potential SLE for the ice volume below sea level and for the maximum potential storage of meltwater in these overdeepenings produces a maximum potential sea level rise (SLR) of 14.71 mm ± 2.94 mm. We provide a calculation of the present ice volume per major river catchment and we discuss likely changes to southern South America glaciers in the future. The ice thickness and subglacial topography modelled by this study will facilitate future studies of ice dynamics and glacier isostatic adjustment, and will be important for projecting water resources and