Curcumin modifies Apc(min) apoptosis resistance and inhibits 2-amino 1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) induced tumour formation in Apc(min) mice.

PubMed

Collett, G P; Robson, C N; Mathers, J C; Campbell, F C

2001-05-01

Curcumin, the active ingredient of the rhizome of Curcuma longa, promotes apoptosis and may have chemopreventive properties. This study investigates the effects of curcumin on apoptosis and tumorigenesis in male Apc(min) mice treated with the human dietary carcinogen, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). Intestinal epithelial apoptotic index in response to PhIP treatment was approximately twice as great in the wild-type C57BL/6 APC(+/+) strain than in Apc(min) mice (3.7% Apc(+/+) versus 1.9% Apc(min); P < 0.001). PhIP promoted tumour formation in Apc(min) proximal small intestine (4.6 tumours per mouse, PhIP treated versus 2.1 tumours per mouse, control untreated; P < 0.05). Curcumin enhanced PhIP-induced apoptosis (4.0% curcumin + PhIP versus 2.1% PhIP alone; P < 0.01) and inhibited PhIP-induced tumorigenesis in the proximal small intestine of Apc(min) mice (2.2 tumours per mouse, curcumin + PhIP versus 4.6 tumours per mouse PhIP alone; P < 0.05). This study shows that the Apc(min) genotype is associated with resistance to PhIP-induced apoptosis in intestinal epithelium. Curcumin attenuates Apc(min) resistance to PhIP-induced apoptosis and inhibits PhIP-induced tumorigenesis in proximal Apc(min) mouse small intestine.

Coordination changes and auto-hydroxylation of FIH-1: uncoupled O2-activation in a human hypoxia sensor

PubMed Central

Chen, Yuan-Han; Comeaux, Lindsay M.; Herbst, Robert W.; Saban, Evren; Kennedy, David C.; Maroney, Michael J.; Knapp, Michael J.

2008-01-01

Hypoxia sensing is the generic term for pO2-sensing in humans and other higher organisms. These cellular responses to pO2 are largely controlled by enzymes that belong to the Fe(II) α-ketoglutarate (αKG) dependent dioxygenase superfamily, including the human enzyme called the Factor Inhibiting HIF (FIH-1), which couples O2-activation to the hydroxylation of the Hypoxia Inducible Factor α (HIFα). Uncoupled O2-activation by human FIH-1 was studied by exposing the resting form of FIH-1, (αKG+Fe)FIH-1, to air in the absence of HIFα. Uncoupling lead to two distinct enzyme oxidations, one a purple chromophore (λmax = 583 nm) arising from enzyme auto-hydroxylation of Trp296, forming an Fe(III)–O–Trp296 chromophore (Y.-H. Chen, L. M. Comeaux, S. J. Eyles, M. J. Knapp, Chem. Commun. (2008) DOI:10.1039/B809099H); the other a yellow chromophore due to Fe(III) in the active site, which under some conditions also contained variable levels of an oxygenated surface residue, (oxo)Met275. The kinetics of purple FIH-1 formation were independent of Fe(II) and αKG concentrations, however product yield was saturable with increasing [αKG] and required excess Fe(II). Yellow FIH-1 was formed from (succinate+Fe)FIH-1, or by glycerol addition to (αKG+Fe)FIH-1, suggesting that glycerol could intercept the active oxidant from the FIH-1 active site and prevent hydroxylation. Both purple and yellow FIH-1 contained high-spin, rhombic Fe(III) centers, as shown by low temperature EPR. XAS indicated distorted octahedral Fe(III) geometries, with subtle differences in inner-shell ligands for yellow and purple FIH-1. EPR of Co(II)-substituted FIH-1, (αKG+Co)FIH-1, indicated a mixture of 5-coordinate and 6-coordinate enzyme forms, suggesting that resting FIH-1 can readily undergo uncoupled O2-activation by loss of an H2O ligand from the metal center. PMID:18805587

40 CFR 180.483 - O-[2-(1,1-Dimethylethyl)-5-pyrimidinyl] O-ethyl-O-(1-methyl-ethyl) phosphorothioate; tolerances...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false O-[2-(1,1-Dimethylethyl)-5-pyrimidinyl] O-ethyl-O-(1-methyl-ethyl) phosphorothioate; tolerances for residues. 180.483 Section 180.483... EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.483 O-[2-(1,1-Dimethylethyl)-5...

Comparative analysis of efficacy of lignocaine 1.5 mg/kg and two different doses of dexmedetomidine (0.5 μg/kg and 1 μg/kg) in attenuating the hemodynamic pressure response to laryngoscopy and intubation

PubMed Central

Gulabani, Michell; Gurha, Pavan; Dass, Prashant; Kulshreshtha, Nishi

2015-01-01

Context: Laryngoscopy and intubation cause an intense reflex increase in heart rate, blood pressure, due to an increased sympathoadrenal pressor response. Lignoocaine has shown blunting of pressor response to intubation. Dexmedetomidine has sympatholytic effects. Aims: To the best of our knowledge there is no study comparing the efficacy of lignocaine with two different doses of dexmedetomidine for attenuating the pressor response. With this idea, we planned to conduct the present study. Materials and Methods: After approval by the Hospital Ethics committee, 90 consenting adults aged 18-65 years of age of either sex of non-hypertensive ASA Grade I or II were randomly allocated into three groups. Group D1- IV Dexmedetomidine 0.5μg/kg over 10 minutes Group D2- IV Dexmedetomidine 1μg/kg over 10 minutes Group X- IV Lignocaine 1.5mg/kg in 10 ml normal saline Statistical Analysis Used: ANOVA and Student's t test used for analysis. Results: Dexmedetomidine 1µg/kg was more effective than 0.5µg/kg and lignocaine 1.5mg/kg in attenuating the pressor response. Conclusions: We conclude that dexmedetomidine 1μg/kg adequately attenuates the hemodynamic response to laryngoscopy and endotracheal intubation when compared with dexmedetomidine 0.5μg/kg and lignocaine 1.5mg/kg. PMID:25886414

Achieving 1% NMR polarization in water in less than 1 min using SABRE

NASA Astrophysics Data System (ADS)

Zeng, Haifeng; Xu, Jiadi; McMahon, Michael T.; Lohman, Joost A. B.; van Zijl, Peter C. M.

2014-09-01

The development of biocompatible hyperpolarized media is a crucial step towards application of hyperpolarization in vivo. This article describes the achievement of 1% hyperpolarization of 3-amino-1,2,4-triazine protons in water using the parahydrogen induced polarization technique based on signal amplification by reversible exchange (SABRE). Polarization was achieved in less than 1 min.

Long-range ordering in the Bi 1-xAe xFeO 3-x/2 perovskites: Bi 1/3Sr 2/3FeO 2.67 and Bi 1/2Ca 1/2FeO 2.75

NASA Astrophysics Data System (ADS)

Lepoittevin, C.; Malo, S.; Barrier, N.; Nguyen, N.; Van Tendeloo, G.; Hervieu, M.

2008-10-01

Two-ordered perovskites, Bi 1/3Sr 2/3FeO 2.67 and Bi 1/2Ca 1/2FeO 2.75, have been stabilized and characterized by transmission electron microscopy, Mössbauer spectroscopy and X-ray powder diffraction techniques. They both exhibit orthorhombic superstructures, one with a≈ b≈2 ap and c≈3 ap (S.G.: Pb2 n or Pbmn) for the Sr-based compound and one with a≈ b≈2 ap and c≈8 ap (S.G.: B222, Bmm2, B2 mm or Bmmm) for the Ca-based one. The high-resolution transmission electron microscopy (HRTEM) images evidence the existence of one deficient [FeO x] ∞ layer, suggesting that Bi 1/3Sr 2/3FeO 2.67 and Bi 1/2Ca 1/2FeO 2.75 behave differently compared to their Ln-based homolog. The HAADF-STEM images allow to propose a model of cation ordering on the A sites of the perovskite. The Mössbauer analyses confirm the trivalent state of iron and its complex environment with three types of coordination. Both compounds exhibit a high value of resistivity and the inverse molar susceptibility versus temperature curves evidence a magnetic transition at about 730 K for the Bi 1/3Sr 2/3FeO 2.67 and a smooth reversible transition between 590 and 650 K for Bi 1/2Ca 1/2FeO 2.75.

Haemolysis caused by alterations of alpha- and beta-spectrin after 10 to 35 min of severe exercise.

PubMed

Beneke, Ralph; Bihn, Detlef; Hütler, Matthias; Leithäuser, Renate M

2005-10-01

The pathophysiology of exercise related haemolysis is not thoroughly understood. We investigated whether exercise related haemolysis (1) is associated with alterations of red blood cell (RBC) membrane proteins similar to those found in inherited anaemic diseases, (2) can be induced with a non-running exercise mode, (3) is related to exercise intensity, and (4) coincides with indicators of oxidative stress. In ten triathletes [median (P25/P75-percentiles) age: 28.0 (26.3/28.5) years, height: 1.84 (1.78/1.87) m, body mass: 78.5 (74.8/80.8) kg, maximal oxygen uptake: 60.0 (57.3/64.8) ml kg(-1) min(-1)], haptoglobin, alpha- and beta-spectrin bands, malondialdehyde (MDA) and H2O2-induced chemiluminescence (H2O2-Chem) were determined immediately pre- and post-both, a 35 min low intensity and a high intensity cycling exercise [240 (218/253) vs 290 (270/300) W, P<0.05) requiring similar amounts of metabolic energy [28.3 (25.9/29.9) vs 24.9 (18.4/30.5) kJ kg(-1), P>0.05]. At high exercise intensity haptoglobin [1.10 (0.81/2.53) vs 1.01 (0.75/2.00) g l(-1)] decreased (P<0.05) whilst MDA [2.80 (2.65/3.20) vs 3.13 (2.78/3.31) nmol ml(-1)] and H2O2-Chem [29.70 (22.55/37.10) vs 37.25 (35.20/52.63) rel. U min] increased (P<0.05), coinciding with the disappearance of the spectrin bands in six out of ten gels. No corresponding changes were found at low intensity exercise. Ten to 35 min of non-running exercise in a regularly used intensity domain causes intra-vascular haemolysis associated with alterations in the RBC membrane proteins similar to those found after in vitro oxidative stress and in inherited anaemic diseases like Sphaerocytosis and Fanconi's anaemia.

Achieving 1% NMR polarization in water in less than 1min using SABRE.

PubMed

Zeng, Haifeng; Xu, Jiadi; McMahon, Michael T; Lohman, Joost A B; van Zijl, Peter C M

2014-09-01

The development of biocompatible hyperpolarized media is a crucial step towards application of hyperpolarization in vivo. This article describes the achievement of 1% hyperpolarization of 3-amino-1,2,4-triazine protons in water using the parahydrogen induced polarization technique based on signal amplification by reversible exchange (SABRE). Polarization was achieved in less than 1 min. Copyright © 2014 Elsevier Inc. All rights reserved.

Kinetic study of Bi 1.8Pb 0.4Ca 2Sr 2Cu 3O y superconductor in water

NASA Astrophysics Data System (ADS)

Wang, C. M.; Wei, T. P.; Kao, H.-C. I.

1993-10-01

The reaction of Bi 1.8Pb 0.4Ca 2Sr 2Cu 3O y powder in water was studied quantitatively. It was found that the [H 3O +] ion would act as a catalyst in this reaction and the initial rate equation was R 0 = - {d[A] 0}/{dt } = k[A] 0[ H3O+] 0.20, where [ A] represented the surface area of the superconducting powder. The rate constant, k, obtained at 10, 25 and 40°C was 3.98, 8.8 and 19.6 × 10 -4 mol min -1 cm -2 M 0.8, respectively. The activation energy and pre-exponential factor calculated from the Arrhenius equation were respectively 39.1 kJ mol -1 and 6.4 × 10 3 mol min -1 cm -2 M 0.8.

Oxidation-etching preparation of MnO2 tubular nanostructures for high-performance supercapacitors.

PubMed

Zhu, Jixin; Shi, Wenhui; Xiao, Ni; Rui, Xianhong; Tan, Huiteng; Lu, Xuehong; Hng, Huey Hoon; Ma, Jan; Yan, Qingyu

2012-05-01

1D hierarchical tubular MnO(2) nanostructures have been prepared through a facile hydrothermal method using carbon nanofibres (CNFs) as sacrificial template. The morphology of MnO(2) nanostructures can be adjusted by changing the reaction time or annealing process. Polycrystalline MnO(2) nanotubes are formed with a short reaction time (e.g., 10 min) while hierarchical tubular MnO(2) nanostructures composed of assembled nanosheets are obtained at longer reaction times (>45 min). The polycrystalline MnO(2) nanotubes can be further converted to porous nanobelts and sponge-like nanowires by annealing in air. Among all the types of MnO(2) nanostructures prepared, tubular MnO(2) nanostructures composed of assembled nanosheets show optimized charge storage performance when tested as supercapacitor electrodes, for example, delivering an power density of 13.33 kW·kg(-1) and a energy density of 21.1 Wh·kg(-1) with a long cycling life over 3000 cycles, which is mainly related to their features of large specific surface area and optimized charge transfer pathway.

Increased plasma O2 solubility improves O2 uptake of in situ dog muscle working maximally.

PubMed

Hogan, M C; Willford, D C; Keipert, P E; Faithfull, N S; Wagner, P D

1992-12-01

A perfluorocarbon emulsion [formulation containing 90% wt/vol perflubron (perfluorooctylbromide); Alliance Pharmaceutical] was used to increase O2 solubility in the plasma compartment during hyperoxic low hemoglobin concentration ([Hb]) perfusion of a maximally working dog muscle in situ. Our hypothesis was that the increased plasma O2 solubility would increase the muscle O2 diffusing capacity (DO2) by augmenting the capillary surface area in contact with high [O2]. Oxygen uptake (VO2) was measured in isolated in situ canine gastrocnemius (n = 4) while working for 6 min at a maximal stimulation rate of 1 Hz (isometric tetanic contractions) on three to four separate occasions for each muscle. On each occasion, the last 4 min of the 6-min work period was split into 2 min of a control treatment (only emulsifying agent mixed into blood) and 2 min of perflubron treatment (6 g/kg body wt), reversing the order for each subsequent work bout. Before contractions, the [Hb] of the dog was decreased to 8-9 g/100 ml and arterial PO2 was increased to 500-600 Torr by having the dog breathe 100% O2 to maximize the effect of the perflubron. Muscle blood flow was held constant between the two experimental conditions. Plasma O2 solubility was almost doubled to 0.005 ml O2 x 100 ml blood-1 x Torr-1 by the addition of the perflubron. Muscle O2 delivery and maximal VO2 were significantly improved (at the same blood flow and [Hb]) by 11 and 12.6%, respectively (P < 0.05), during the perflubron treatment compared with the control. O2 extraction by the muscle remained the same between the two treatments, as did the estimate of DO2.(ABSTRACT TRUNCATED AT 250 WORDS)

Collisional relaxation of O2(X^3Σ _g^ -, υ = 1) and O2(a1Δg, υ = 1) by atmospherically relevant species

NASA Astrophysics Data System (ADS)

Pejaković, Dušan A.; Campbell, Zachary; Kalogerakis, Konstantinos S.; Copeland, Richard A.; Slanger, Tom G.

2011-09-01

Laboratory measurements are reported of the rate coefficient for collisional removal of O2(X^3Σ _g^ -, υ = 1) by O(3P), and the rate coefficients for removal of O2(a1Δg, υ = 1) by O2, CO2, and O(3P). A two-laser method is employed, in which the pulsed output of the first laser at 285 nm photolyzes ozone to produce oxygen atoms and O2(a1Δg, υ = 1), and the output of the second laser detects O2(a1Δg, υ = 1) via resonance-enhanced multiphoton ionization. The kinetics of O2(X^3Σ _g^ -, υ = 1) + O(3P) relaxation is inferred from the temporal evolution of O2(a1Δg, υ = 1), an approach enabled by the rapid collision-induced equilibration of the O2(X^3Σ _g^ -, υ = 1) and O2(a1Δg, υ = 1) populations in the system. The measured O2(X^3Σ _g^ -, υ = 1) + O(3P) rate coefficient is (2.9 ± 0.6) × 10-12 cm3 s-1 at 295 K and (3.4 ± 0.6) × 10-12 cm3 s-1 at 240 K. These values are consistent with the previously reported result of (3.2 ± 1.0) × 10-12 cm3 s-1, which was obtained at 315 K using a different experimental approach [K. S. Kalogerakis, R. A. Copeland, and T. G. Slanger, J. Chem. Phys. 123, 194303 (2005)]. For removal of O2(a1Δg, υ = 1) by O(3P), the upper limits for the rate coefficient are 4 × 10-13 cm3 s-1 at 295 K and 6 × 10-13 cm3 s-1 at 240 K. The rate coefficient for removal of O2(a1Δg, υ = 1) by O2 is (5.6 ± 0.6) × 10-11 cm3 s-1 at 295 K and (5.9 ± 0.5) × 10-11 cm3 s-1 at 240 K. The O2(a1Δg, υ = 1) + CO2 rate coefficient is (1.5 ± 0.2) × 10-14 cm3 s-1 at 295 K and (1.2 ± 0.1) × 10-14 cm3 s-1 at 240 K. The implications of the measured rate coefficients for modeling of atmospheric emissions are discussed.

Establishment of Class e1 Mass Standard of 50 kg

NASA Astrophysics Data System (ADS)

Yao, Hong; Wang, Jian; Ding, Jingan; Zhong, Ruilin; Ren, Xiaoping

Because of the equipment limit, the dissemination of large mass has been realized by a large amount of higher class of 20 kg weights since 1950s in China. But with improvement of the technique and customer's requirements, it is necessary to establish the mass standard of 50 kg weight. In 1990s, mass standard laboratory has set up Class E1 weight sets from 20 kg to 1 mg. To extend the mass capacity up to 50 kg of Class E1, it is not only to produce Class E1 50 kg weight and import a mass comparator, but also need to lift the heavy weight from weight box to balance receptor safely. Up to now, the mass comparator has been installed in Hepingli campus of NIM. Two pieces of Class E1 50 kg weights are determined by combination weighing method. A lifting device has been mounted close to the mass comparator in order to move the 50 kg easily.

Density Measurement System for Weights of 1 kg to 20 kg Using Hydrostatic Weighing

NASA Astrophysics Data System (ADS)

Lee, Yong Jae; Lee, Woo Gab; Abdurahman, Mohammed; Kim, Kwang Pyo

This paper presents a density measurement system to determine density of weights from 1 kg to 20 kg using hydrostatic weighing. The system works based on Archimedes principle. The density of reference liquid is determined using this setup while determining the density of the test weight. Density sphere is used as standard density ball to determine density of the reference liquid. A new immersion pan is designed for dual purpose to carry the density sphere and the cylindrical test weight for weighing in liquid. Main parts of the setup are an electronic balance, a thermostat controlled liquid bath, reference weights designed for bottom weighing, dual purpose immersion pans and stepping motors to load and unload in weighing process. The results of density measurement will be evaluated as uncertainties for weights of 1 kg to 20 kg.

Crystal structure of aqua-1κO-{μ-2-[(2-hydroxy-ethyl)methylamino]ethanolato-2:1κ(4) O (1),N,O (2):O (1)}[μ-2,2'-(methylimino)diethanolato-1:2κ(4) O,N,O':O]dithiocyanato-1κN,2κN-chromium(III)copper(II).

PubMed

Rusanova, Julia A; Semenaka, Valentina V; Dyakonenko, Viktoriya V; Shishkin, Oleg V

2015-09-01

The title compound, [CrCu(C5H11NO2)(C5H12NO2)(NCS)2(H2O)] or [Cr(μ-mdea)Cu(μ-Hmdea)(NCS)2H2O], (where mdeaH2 is N-methylethanolamine, C5H13NO2) is formed as a neutral heterometal Cu(II)/Cr(III) complex. The mol-ecular structure of the complex is based on a binuclear {CuCr(μ-O)2} core. The coordination environment of each metal atom involves the N,O,O atoms of the tridentate ligand, one bridging O atom of the ligand and the N atom of the thio-cyanato ligands. The Cu(II) ion adopts a distorted square-pyramidal coordination while the Cr(III) ion has a distorted octa-hedral coordination geometry completed by the aqua ligand. In the crystal, the binuclear complexes are linked via two pairs of O-H⋯O hydrogen bonds to form inversion dimers, which are arranged in columns parallel to the a axis. In the μ-mdea ligand two -CH2 groups and the methyl group were refined as disordered over two sets of sites with equal occupancies. The structure was refined as a two-component twin with a twin scale factor of 0.242 (1).

Impact of Sleeve Gastrectomy on Type 2 Diabetes Mellitus, Gastric Emptying Time, Glucagon-Like Peptide 1 (GLP-1), Ghrelin and Leptin in Non-morbidly Obese Subjects with BMI 30-35.0 kg/m2: a Prospective Study.

PubMed

Vigneshwaran, B; Wahal, Akshat; Aggarwal, Sandeep; Priyadarshini, Pratyusha; Bhattacharjee, Hemanga; Khadgawat, Rajesh; Yadav, Rajkumar

2016-12-01

The study was conducted to evaluate the impact of laparoscopic sleeve gastrectomy (LSG) on type 2 diabetes mellitus (T2DM) in patients with a body mass index (BMI) of 30.0-35.0 kg/m 2 . Possible mechanisms, including alterations in gastric emptying time (GET), glucagon-like peptide 1 (GLP-1), ghrelin and leptin, were evaluated. Twenty obese patients with T2DM and with a BMI of 30.0-35.0 kg/m 2 underwent LSG during March 2012 to February 2015. Glycosylated haemoglobin (HbA1c), fasting plasma glucose (FPG) and GET were measured at baseline, 3 months, 6 months, 12 months and 24 months after surgery. Fasting and post-prandial levels of serum GLP-1, ghrelin and leptin were measured pre-operatively and after 3 and 6 months. The average duration of follow-up was 17.6 months, and 10 patients had completed 2 years of follow-up. After 2 years, the average BMI decreased from 33.4 ± 1.2 to 26.7 ± 1.8 kg/m 2 . The mean HbA1c decreased from 8.7 ± 1.6 to 6.7 ± 1.5 %, respectively. Ten patients achieved complete remission. Insulin could be stopped in all six patients who were on it pre-operatively. Meal-stimulated GLP-1 response and serum insulin at 30 min showed a significant increase following surgery. There was a significant decrease in GET. This prospective study confirms the positive impact of LSG on diabetic status of non-morbidly obese patients. The possible mechanisms include the rise in post-prandial GLP-1 level induced by accelerated gastric emptying, leading to an increase in insulin secretion. LSG also leads to decreased ghrelin and leptin levels which may have a role in improving glucose homeostasis after surgery.

Measurement of a True [Formula: see text]O2max during a Ramp Incremental Test Is Not Confirmed by a Verification Phase.

PubMed

Murias, Juan M; Pogliaghi, Silvia; Paterson, Donald H

2018-01-01

The accuracy of an exhaustive ramp incremental (RI) test to determine maximal oxygen uptake ([Formula: see text]O 2max ) was recently questioned and the utilization of a verification phase proposed as a gold standard. This study compared the oxygen uptake ([Formula: see text]O 2 ) during a RI test to that obtained during a verification phase aimed to confirm attainment of [Formula: see text]O 2max . Sixty-one healthy males [31 older (O) 65 ± 5 yrs; 30 younger (Y) 25 ± 4 yrs] performed a RI test (15-20 W/min for O and 25 W/min for Y). At the end of the RI test, a 5-min recovery period was followed by a verification phase of constant load cycling to fatigue at either 85% ( n = 16) or 105% ( n = 45) of the peak power output obtained from the RI test. The highest [Formula: see text]O 2 after the RI test (39.8 ± 11.5 mL·kg -1 ·min -1 ) and the verification phase (40.1 ± 11.2 mL·kg -1 ·min -1 ) were not different ( p = 0.33) and they were highly correlated ( r = 0.99; p < 0.01). This response was not affected by age or intensity of the verification phase. The Bland-Altman analysis revealed a very small absolute bias (-0.25 mL·kg -1 ·min -1 , not different from 0) and a precision of ±1.56 mL·kg -1 ·min -1 between measures. This study indicated that a verification phase does not highlight an under-estimation of [Formula: see text]O 2max derived from a RI test, in a large and heterogeneous group of healthy younger and older men naïve to laboratory testing procedures. Moreover, only minor within-individual differences were observed between the maximal [Formula: see text]O 2 elicited during the RI and the verification phase. Thus a verification phase does not add any validation of the determination of a [Formula: see text]O 2max . Therefore, the recommendation that a verification phase should become a gold standard procedure, although initially appealing, is not supported by the experimental data.

O2(a1Δ) Quenching In The O/O2/O3 System

NASA Astrophysics Data System (ADS)

Azyazov, V. N.; Mikheyev, P. A.; Postell, D.; Heaven, M. C.

2010-10-01

The development of discharge singlet oxygen generators (DSOG's) that can operate at high pressures is required for the power scaling of the discharge oxygen iodine laser. In order to achieve efficient high-pressure DSOG operation it is important to understand the mechanisms by which singlet oxygen (O2(a1Δ)) is quenched in these devices. It has been proposed that three-body deactivation processes of the type O2(a1Δ)+O+M→2O2+M provide significant energy loss channels. To further explore these reactions the physical and reactive quenching of O2(a1Δ) in O(3P)/O2/O3/CO2/He/Ar mixtures has been investigated. Oxygen atoms and singlet oxygen molecules were produced by the 248 nm laser photolysis of ozone. The kinetics of O2(a1Δ) quenching were followed by observing the 1268 nm fluorescence of the O2a1Δ-X3∑ transition. Fast quenching of O2(a1Δ) in the presence of oxygen atoms and molecules was observed. The mechanism of the process has been examined using kinetic models, which indicate that quenching by vibrationally excited ozone is the dominant reaction.

Seasonal variations in VO2max, O2-cost, O2-deficit, and performance in elite cross-country skiers.

PubMed

Losnegard, Thomas; Myklebust, Håvard; Spencer, Matt; Hallén, Jostein

2013-07-01

Long-term effects of training are important information for athletes, coaches, and scientists when associating changes in physiological indices with changes in performance. Therefore, this study monitored changes in aerobic and anaerobic capacities and performance in a group of elite cross-country skiers during a full sport season. Thirteen men (age, 23 ± 2 years; height, 182 ± 6 cm; body mass, 76 ± 8 kg; V2 roller ski skating VO2max, 79.3 ± 4.4 ml·kg·min or 6.0 ± 0.5 L·min) were tested during the early, middle, and late preparation phase: June (T1), August (T2), and October (T3); during the competition phase: January/February (T4); and after early precompetition phase: June (T5). O2-cost during submaximal efforts, V[Combining Dot Above]O2peak, accumulated oxygen deficit (ΣO2-deficit), and performance during a 1,000-m test were determined in the V2 ski skating technique on a roller ski treadmill. Subjects performed their training on an individual basis, and detailed training logs were categorized into different intensity zones and exercise modes. Total training volume was highest during the summer months (early preseason) and decreased toward and through the winter season, whereas the volume of high-intensity training increased (all p < 0.05). There was a significant main effect among testing sessions for 1,000 m time, O2-cost, and ΣO2-deficit (Cohen's d effect size; ES = 0.63-1.37, moderate to large, all p < 0.05). In general, the changes occurred between T1 and T3 with minor changes in the competitive season (T3 to T4). No significant changes were found in V[Combining Dot Above]O2peak across the year (ES = 0.17, trivial). In conclusion, the training performed by elite cross-country skiers induced no significant changes in V[Combining Dot Above]O2peak but improved performance, O2-cost, and ΣO2-deficit.

Electric Properties of Pb(Sb1/2Nb1/2)O3 PbTiO3 PbZrO3 Ceramics

NASA Astrophysics Data System (ADS)

Kawamura, Yasushi; Ohuchi, Hiromu

1994-09-01

Solid-solution ceramics of ternary system xPb(Sb1/2Nb1/2)O3 yPbTiO3 zPbZrO3 were prepared by the solid-state reaction of powder materials. Ceramic, electric, dielectric and piezoelectric properties and crystal structures of the system were studied. Sintering of the system xPb(Sb1/2Nb1/2)O3 yPbTiO3 zPbZrO3 is much easier than that of each end composition, and well-sintered high-density ceramics were obtained for the compositions near the morphotropic transformation. Piezoelectric ceramics with high relative dielectric constants, high radial coupling coefficient and low resonant resistance were obtained for the composition near the morphotropic transformation. The composition Pb(Sb1/2Nb1/2)0.075Ti0.45Zr0.475O3 showed the highest dielectric constant (ɛr=1690), and the composition Pb(Sb1/2Nb1/2)0.05Ti0.45Zr0.5O3 showed the highest radial coupling coefficient (kp=64%).

Three-volt lithium-ion battery with Li[Ni 1/2Mn 3/2]O 4 and the zero-strain insertion material of Li[Li 1/3Ti 5/3]O 4

NASA Astrophysics Data System (ADS)

Ariyoshi, Kingo; Yamamoto, Satoshi; Ohzuku, Tsutomu

A 3 V lithium-ion cell with Li[Ni 1/2Mn 3/2]O 4 ( Fd 3¯m ; a=8.17 Å) and the zero-strain insertion material of Li[Li 1/3Ti 5/3]O 4 ( Fd 3¯m ; a=8.36 Å) was examined with an emphasis on rate-capability and cycle life. This cell showed a quite flat operating voltage of 3.2 V with excellent cycleability. Accelerated cycle tests indicated that 83% of the initial capacity was delivered and stored even after 1100 cycles. Although the calculated energy density of a Li[Li 1/3Ti 5/3]O 4/Li[Ni 1/2Mn 3/2]O 4 cell was about 250 Wh kg -1 or 1000 Wh dm -3 based on the active material weight or volume, the 3 V lithium-ion battery exhibited positive characteristic features, such as flatness in operating voltage, high rate capability, and cycle life.

Structure and temperature-dependent phase transitions of lead-free Bi 1/2Na 1/2TiO 3-Bi 1/2K 1/2TiO 3-K 0.5Na 0.5NbO 3 piezoceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anton, Eva-Maria; Schmitt, Ljubomira Ana; Hinterstein, Manuel

2014-05-28

Structure and phase transitions of (1-y)((1-x)Bi 1/2Na 1/2TiO 3-xBi 1/2K 1/2TiO 3)-yK 0.5Na 0.5NbO 3 (x; y) piezoceramics (0.1 ≤ x ≤ 0.4; 0 ≤ y ≤ 0.05) were investigated by transmission electron microscopy, neutron diffraction, temperature-dependent x-ray diffraction, and Raman spectroscopy. The local crystallographic structure at room temperature (RT) does not change by adding K 0.5Na 0.5NbO 3 to Bi 1/2Na 1/2TiO 3-xBi 1/2K 1/2TiO 3 for x = 0.2 and 0.4. The average crystal structure and microstructure on the other hand develop from mainly long-range polar order with ferroelectric domains to short-range order with polar nanoregions displaying amore » more pronounced relaxor character. The (0.1; 0) and (0.1; 0.02) compositions exhibit monoclinic Cc space group symmetry, which transform into Cc + P4bm at 185 and 130 °C, respectively. This high temperature phase is stable at RT for the morphotropic phase boundary compositions of (0.1; 0.05) and all compositions with x = 0.2. For the compositions of (0.1; 0) and (0.1; 0.02), local structural changes on heating are evidenced by Raman; for all other compositions, changes in the long-range average crystal structure were observed.« less

Breast MRI at Very Short TE (minTE): Image Analysis of minTE Sequences on Non-Fat-Saturated, Subtracted T1-Weighted Images.

PubMed

Wenkel, Evelyn; Janka, Rolf; Geppert, Christian; Kaemmerer, Nadine; Hartmann, Arndt; Uder, Michael; Hammon, Matthias; Brand, Michael

2017-02-01

Purpose  The aim was to evaluate a minimum echo time (minTE) protocol for breast magnetic resonance imaging (MRI) in patients with breast lesions compared to a standard TE (nTE) time protocol. Methods  Breasts of 144 women were examined with a 1.5 Tesla MRI scanner. Additionally to the standard gradient-echo sequence with nTE (4.8 ms), a variant with minimum TE (1.2 ms) was used in an interleaved fashion which leads to a better temporal resolution and should reduce the scan time by approximately 50 %. Lesion sizes were measured and the signal-to-noise ratio (SNR) as well as the contrast-to-noise ratio (CNR) were calculated. Subjective confidence was evaluated using a 3-point scale before looking at the nTE sequences (1 = very sure that I can identify a lesion and classify it, 2 = quite sure that I can identify a lesion and classify it, 3 = definitely want to see nTE for final assessment) and the subjective image quality of all examinations was evaluated using a four-grade scale (1 = sharp, 2 = slight blur, 3 = moderate blur and 4 = severe blur/not evaluable) for lesion and skin sharpness. Lesion morphology and contrast enhancement were also evaluated. Results  With minTE sequences, no lesion was rated with "definitely want to see nTE sequences for final assessment". The difference of the longitudinal and transverse diameter did not differ significantly (p > 0.05). With minTE, lesions and skin were rated to be significantly more blurry (p < 0.01 for lesions and p < 0.05 for skin). There was no difference between both sequences with respect to SNR, CNR, lesion morphology, contrast enhancement and detection of multifocal disease. Conclusion  Dynamic breast MRI with a minTE protocol is feasible without a major loss of information (SNR, CNR, lesion morphology, contrast enhancement and lesion sizes) and the temporal resolution can be increased by a factor of 2 using minTE sequences. Key points   · Increase of

Aquabis[1-hydroxy-2-(imidazol-3-ium-1-yl)-1,1′-ethylidenediphophonato-κ2 O,O′]zinc(II) dihydrate

PubMed Central

Freire, Eleonora; Vega, Daniel R.

2009-01-01

In the title complex, [Zn(C5H9NO7P2)2(H2O)]·2H2O, the zinc atom is coordinated by two zoledronate anions [zoledronate = (2-(1-imidazole)-1-hydr­oxy-1,1′-ethyl­idenediphophonate)] and one water mol­ecule. The coordination number is 5. There is one half-mol­ecule in the asymmetric unit, the zinc atom being located on a twofold rotation axis passing through the metal centre and the coordinating water O atom. The anion exists as a zwitterion with an overall charge of −1; the protonated nitro­gen in the ring has a positive charge and the two phospho­nates groups each have a single negative charge. Inter­molecular O—H⋯O hydrogen bonds link the mol­ecules. An N—H⋯O inter­action is also present. PMID:21578165

Switching characteristics of (Bi 1/2Na 1/2)TiO 3-BaTiO 3-(Bi 1/2K 1/2)TiO 3 lead-free ferroelectric ceramics

NASA Astrophysics Data System (ADS)

Shieh, J.; Wu, K. C.; Chen, C. S.

2007-04-01

The polarization switching characteristics of lead-free a(Bi 1/2Na 1/2)TiO 3-bBaTiO 3-c(Bi 1/2K 1/2)TiO 3 (abbreviated as BNBK 100a/100b/100c) ferroelectric ceramics are investigated. This is achieved through examining their polarization and strain hystereses inside and outside the morphotropic phase boundary (MPB). The total induced electrostrain (ɛ 33,total) and apparent piezoelectric charge coefficient (d 33) first increase dramatically and then decrease gradually as the BNBK composition moves from the tetragonal phase to the MPB and then to the rhombohedral phase. The measured polarization hystereses indicate that the BNBK compositions situated near the rhombohedral side of the MPB typically possess higher coercive field (E c) and remanent polarization (P r), while the compositions situated near the tetragonal side of the MPB possess higher apparent permittivity. Adverse effects on the ferroelectric properties are observed when BNBK is doped with donor dopants such as La and Nb. On the contrary, intricate hysteresis behaviors are observed when acceptor dopant Mn is introduced into BNBK. Under an alternating electric field of +/-5.0 MVm -1, BNBK 85.4/2.6/12, a composition well within the MPB, exhibits an ɛ 33,total of ~0.14%, an apparent d 33 of 295 pCN -1, an E c of 2.5 MVm -1 and a Pr of 22.5 μCcm -2. These notable ferroelectric property values suggest a candidate material for lead-free actuator applications. The present study provides a systematic set of hysteresis measurements which can be used to characterize the switching behaviors of BNBK-based lead-free ferroelectrics.

ASC Methylation and Interleukin-1β Are Associated with Aerobic Capacity in Heart Failure.

PubMed

Butts, Brittany; Butler, Javed; Dunbar, Sandra B; Corwin, Elizabeth J; Gary, Rebecca A

2017-06-01

Aerobic capacity, as measured by peak oxygen uptake (V˙O2), is one of the most powerful predictors of prognosis in heart failure (HF). Inflammation is a key factor contributing to alterations in aerobic capacity, and interleukin (IL)-1 cytokines are implicated in this process. The adaptor protein ASC is necessary for inflammasome activation of IL-1β and IL-18. ASC expression is controlled through epigenetic modification; lower ASC methylation is associated with worse outcomes in HF. The purpose of this study is to examine the relationships between ASC methylation, IL-1β, and IL-18 with V˙O2peak in persons with HF. This study examined the relationship between ASC methylation, IL-1β, and IL-18 with V˙O2peak in 54 stable outpatients with HF. All participants were NYHA class II or III, not engaged in an exercise program, and physically able to complete an exercise treadmill test. Mean V˙O2peak was 16.68 ± 4.7 mL·kg·min. V˙O2peak was positively associated with mean percent ASC methylation (r = 0.47, P = 0.001) and negatively associated with IL-1β (r = -0.38, P = 0.007). Multiple linear regression models demonstrated that V˙O2peak increased by 2.30 mL·kg·min for every 1% increase in ASC methylation and decreased by 1.91 mL·kg·min for every 1 pg·mL increase in plasma IL-1β. Mean percent ASC methylation and plasma IL-1β levels are associated with clinically meaningful differences in V˙O2peak in persons with HF. Inflammasome activation may play a mechanistic role in determining aerobic capacity. ASC methylation is a potentially modifiable mechanism for reducing the inflammatory response, thereby improving aerobic capacity in HF.

The dissociative recombination of O2(+) - The quantum yield of O(1S) and O(1D)

NASA Technical Reports Server (NTRS)

Abreu, V. J.; Solomon, S. C.; Sharp, W. E.; Hays, P. B.

1983-01-01

Data from the visible airglow experiment on the Atmosphere Explorer-E satellite have been used to determine the quantum yield of O(1S) and O(1D) from the dissociative recombination of O2(+). A range of values between 0.09 and 0.23 has been obtained for the quantum yield of O(1S). It is shown that the quantum yield of O(1S) depends on the ratio of electron density to atomic oxygen density. This suggests that the quantum yield of O(1S) may depend on the degree of vibrational excitation of the recombining O2(+). The quantum yield of O(1D) has been measured to be 1.23 + or - 0.42, with no dependence on the electron-oxygen ratio.

O2(a1Δ) quenching in O/O2/O3/CO2/He/Ar mixtures

NASA Astrophysics Data System (ADS)

Azyazov, V. N.; Mikheyev, P. A.; Postell, D.; Heaven, M. C.

2010-02-01

The development of discharge singlet oxygen generators (DSOG's) that can operate at high pressures is required for the power scaling of the discharge oxygen iodine laser. In order to achieve efficient high-pressure DSOG operation it is important to understand the mechanisms by which singlet oxygen (O2(a1Δ)) is quenched in these devices. It has been proposed that three-body deactivation processes of the type O2(a1Δ))+O+M-->2O2+M provide significant energy loss channels. To further explore these reactions the physical and reactive quenching of O2(a1Δ)) in O(3P)/O2/O3/CO2/He/Ar mixtures has been investigated. Oxygen atoms and singlet oxygen molecules were produced by the 248 nm laser photolysis of ozone. The kinetics of O2(a1Δ)) quenching were followed by observing the 1268 nm fluorescence of the O2 a1Δ-X3Ε transition. Fast quenching of O2(a1Δ)) in the presence of oxygen atoms and molecules was observed. The mechanism of the process has been examined using kinetic models, which indicate that quenching by vibrationally excited ozone is the dominant reaction.

Catalytic dehydrofluorination of 1,1,1,3,3-pentafluoropropane to 1,3,3,3-tetrafluoropropene over fluorinated NiO/Cr2O3 catalysts

NASA Astrophysics Data System (ADS)

Luo, Jian-Wei; Song, Jian-Dong; Jia, Wen-Zhi; Pu, Zhi-Ying; Lu, Ji-Qing; Luo, Meng-Fei

2018-03-01

Catalytic dehydrofluorination of 1,1,1,3,3-pentafluoropropane to 1,3,3,3-tetrafluoropropene was performed on a series of fluorinated NiO/Cr2O3 catalysts. The NiO/Cr2O3 catalysts were more active than the Cr2O3 because the new acid sites provided by NiF2 had higher turnover frequencies (9.43 × 10-3 - 12.08 × 10-3 s-1) than those on the Cr2O3 (4.55 × 10-3 s-1). Also, the NiO/Cr2O3 was more stable than the Cr2O3 due to its lower density of surface acid sites, which alleviated the coke deposition on the catalyst as evidenced by the Raman spectroscopic results. The kinetic results revealed that the15NiO/Cr2O3 had much lower activation energy (63.6 ± 4.5 kJ mol-1) than the Cr2O3 (127.6 ± 3.8 kJ mol-1). Accordingly, different reaction pathways on the two catalysts were proposed, which involved the cleavage of the Csbnd F and Csbnd H bonds on the surface acid and base sites, respectively.

Leaching process for recovering valuable metals from the LiNi1/3Co1/3Mn1/3O2 cathode of lithium-ion batteries.

PubMed

He, Li-Po; Sun, Shu-Ying; Song, Xing-Fu; Yu, Jian-Guo

2017-06-01

In view of the importance of environmental protection and resource recovery, recycling of spent lithium-ion batteries (LIBs) and electrode scraps generated during manufacturing processes is quite necessary. An environmentally sound leaching process for the recovery of Li, Ni, Co, and Mn from spent LiNi 1/3 Co 1/3 Mn 1/3 O 2 -based LIBs and cathode scraps was investigated in this study. Eh-pH diagrams were used to determine suitable leaching conditions. Operating variables affecting the leaching efficiencies for Li, Ni, Co, and Mn from LiNi 1/3 Co 1/3 Mn 1/3 O 2 , such as the H 2 SO 4 concentration, temperature, H 2 O 2 concentration, stirring speed, and pulp density, were investigated to determine the most efficient conditions for leaching. The leaching efficiencies for Li, Ni, Co, and Mn reached 99.7% under the optimized conditions of 1M H 2 SO 4 , 1vol% H 2 O 2 , 400rpm stirring speed, 40g/L pulp density, and 60min leaching time at 40°C. The leaching kinetics of LiNi 1/3 Co 1/3 Mn 1/3 O 2 were found to be significantly faster than those of LiCoO 2 . Based on the variation in the weight fraction of the metal in the residue, the "cubic rate law" was revised as follows: θ(1-f) 1/3 =(1-kt/r 0 ρ), which could characterize the leaching kinetics optimally. The activation energies were determined to be 64.98, 65.16, 66.12, and 66.04kJ/mol for Li, Ni, Co, and Mn, respectively, indicating that the leaching process was controlled by the rate of surface chemical reactions. Finally, a simple process was proposed for the recovery of valuable metals from spent LiNi 1/3 Co 1/3 Mn 1/3 O 2 -based LIBs and cathode scraps. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fluorite Ce0.8Sm0.2O2- δ porous layer coating to enhance the oxygen permeation behavior of a BaCo0.7Fe0.2Nb0.1O3- δ mixed conductor

NASA Astrophysics Data System (ADS)

Wang, Tai-he; Song, Wei-jia; Li, Rong; Zhen, Qiang

2016-06-01

Fluorite Ce0.8Sm0.2O2- δ (SDC) nanopowder with a crystallite size of 15 nm was synthesized by a co-precipitation method. An SDC porous layer was coated onto a BaCo0.7Fe0.2Nb0.1O3- δ (BCFN) mixed conductor to improve its oxygen transport behavior. The results show that the SDC-coated BCFN membrane exhibits a remarkably higher oxygen permeation flux ({J_{{O_2}}}) than the uncoated BCFN in the partial oxidation of coke oven gas (COG). The maximum {J_{{O_2}}} value of the SDC-coated BCFN is 18.28 mL·min-1·cm-2 under a COG/air flux of 177 mL·min-1/353 mL·min-1 at 875°C when the thickness of the BCFN membrane is 1 mm; this {J_{{O_2}}} value is 23% higher than that of the uncoated BCFN membrane. This enhancement is likely because of the higher oxygen ionic conductivity of SDC, which supplies oxygen vacancies and accelerates oxygen exchange on the membrane/coating layer/gas three-phase boundary.

Chemistry of CCl 4 on Fe 3O 4(1 1 1)-(2 × 2) surfaces in the presence of adsorbed D 2O studied by temperature programmed desorption

NASA Astrophysics Data System (ADS)

Adib, K.; Totir, G. G.; Fitts, J. P.; Rim, K. T.; Mueller, T.; Flynn, G. W.; Joyce, S. A.; Osgood, R. M.

2003-07-01

Temperature programmed desorption (TPD) was used to study surface reactions of Fe 3O 4(1 1 1)-(2 × 2) sequentially exposed, at ˜100 K, to vapor-phase D 2O and CCl 4. Previous TPD and XPS results have indicated that in the absence of D 2O, CCl 4 dissociatively adsorbs on Fe 3O 4(1 1 1) producing chemisorbed Cl and CCl 2. Subsequent heating of the surface results in abstraction of lattice iron and oxygen atoms and causes them to desorb as FeCl 2 and OCCl 2, respectively. This study shows that when this Fe 3O 4 surface is exposed only to D 2O, TPD measures a rich surface chemistry with multiple desorption events extending as high as ˜800 K, indicating dissociative adsorption of D 2O on the Fe 3O 4(1 1 1) surface. After sequential exposure to D 2O and then CCl 4, the production of FeCl 2 and OCCl 2 from adsorbed CCl 4 is suppressed, indicating that D 2O fragments block the surface reactive sites.

Zolpidem generalization and antagonism in male and female cynomolgus monkeys trained to discriminate 1.0 or 2.0 g/kg ethanol.

PubMed

Helms, Christa M; Rogers, Laura S M; Waters, Courtney A; Grant, Kathleen A

2008-07-01

The subtypes of gamma-aminobutyric acid (GABA)(A) receptors mediating the discriminative stimulus effects of ethanol in nonhuman primates are not completely identified. The GABA(A) receptor positive modulator zolpidem has high, intermediate, and low activity at receptors containing alpha(1), alpha(2/3), and alpha(5) subunits, respectively, and partially generalizes from ethanol in several species. The partial inverse agonist Ro15-4513 has the greatest affinity for alpha(4/6)-containing receptors, higher affinity for alpha(5)- and lower, but equal, affinity for alpha(1)- and alpha(2/3)-, containing GABA(A) receptors, and antagonizes the discriminative stimulus effects of ethanol. This study assessed Ro15-4513 antagonism of the generalization of zolpidem from ethanol in male (n = 9) and female (n = 8) cynomolgus monkeys (Macaca fascicularis) trained to discriminate 1.0 g/kg (n = 10) or 2.0 g/kg (n = 7) ethanol (i.g.) from water with a 30-minute pretreatment interval. Zolpidem (0.017 to 5.6 mg/kg, i.m.) completely generalized from ethanol (>or=80% of total session responses on the ethanol-appropriate lever) for 6/7 monkeys trained to discriminate 2.0 g/kg and 4/10 monkeys trained to discriminate 1.0 g/kg ethanol. Zolpidem partially generalized from 1.0 or 2.0 g/kg ethanol in 6/7 remaining monkeys. Ro15-4513 (0.003 to 0.30 mg/kg, i.m., 5-minute pretreatment) shifted the zolpidem dose-response curve to the right in all monkeys showing generalization. Analysis of apparent pK(B) from antagonism tests suggested that the discriminative stimulus effects of ethanol common with zolpidem are mediated by low-affinity Ro15-4513 binding sites. Main effects of sex and training dose indicated greater potency of Ro15-4513 in males and in monkeys trained to discriminate 1.0 g/kg ethanol. Ethanol and zolpidem share similar discriminative stimulus effects most likely through GABA(A) receptors that contain alpha(1) subunits, however, antagonism by Ro15-4513 of zolpidem generalization

Measuring CO 2 and N 2 O Mass Transfer into GAP-1 CO 2 –Capture Solvents at Varied Water Loadings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whyatt, Greg A.; Zwoster, Andy; Zheng, Feng

This paper investigates the CO 2 and N 2 O absorption behavior in the water-lean gamma amino propyl (GAP)-1/TEG solvent system using a wetted-wall contactor. Testing was performed on a blend of GAP-1 aminosilicone in triethylene glycol at varied water loadings in the solvent. Measurements were made with CO 2 and N 2 O at representative lean (0.04 mol CO 2/mol alkalinity), middle (0.13 mol CO 2 /mol alkalinity) and rich (0.46 mol CO 2 /mol alkalinity) solvent loadings at 0, 5, 10 and 15 wt% water loadings at 40, 60 and 80C° and N 2 O at (0.08-0.09 molmore » CO 2 /mol alkalinity) at 5 wt% water at 40, 60 and 80C°. CO 2 flux was found to be non-linear with respect to log mean pressure driving force (LMPD). Liquid-film mass transfer coefficients (k'g) were calculated by subtracting the gas film resistance (determined from a correlation from literature) from the overall mass transfer measurement. The resulting k'g values for CO 2 and N 2 O in GAP-1/TEG mixtures were found to be higher than that of 5M aqueous monoethanolamine under comparable driving force albeit at higher solvent viscosities. The k'g values for CO 2 were also found to decrease with increasing solvent water content and increase with a decrease in temperature. These observations indicate that mass transfer of CO 2 in GAP-1/TEG is linked to the physical solubility of CO 2 , which is higher in organic solvents compared to water. This paper expands on the understanding of the unique mass transfer behavior and kinetics of CO 2 capture in water-lean solvents.« less

Crystal structure of aqua-1κO-{μ-2-[(2-hydroxy­ethyl)methylamino]ethanolato-2:1κ4 O 1,N,O 2:O 1}[μ-2,2′-(methylimino)diethanolato-1:2κ4 O,N,O′:O]dithiocyanato-1κN,2κN-chromium(III)copper(II)

PubMed Central

Rusanova, Julia A.; Semenaka, Valentina V.; Dyakonenko, Viktoriya V.; Shishkin, Oleg V.

2015-01-01

The title compound, [CrCu(C5H11NO2)(C5H12NO2)(NCS)2(H2O)] or [Cr(μ-mdea)Cu(μ-Hmdea)(NCS)2H2O], (where mdeaH2 is N-methylethanolamine, C5H13NO2) is formed as a neutral heterometal CuII/CrIII complex. The mol­ecular structure of the complex is based on a binuclear {CuCr(μ-O)2} core. The coordination environment of each metal atom involves the N,O,O atoms of the tridentate ligand, one bridging O atom of the ligand and the N atom of the thio­cyanato ligands. The CuII ion adopts a distorted square-pyramidal coordination while the CrIII ion has a distorted octa­hedral coordination geometry completed by the aqua ligand. In the crystal, the binuclear complexes are linked via two pairs of O—H⋯O hydrogen bonds to form inversion dimers, which are arranged in columns parallel to the a axis. In the μ-mdea ligand two –CH2 groups and the methyl group were refined as disordered over two sets of sites with equal occupancies. The structure was refined as a two-component twin with a twin scale factor of 0.242 (1). PMID:26396853

Collisional relaxation of O2(a1Δ, υ = 1, 2, 3) by CO2

NASA Astrophysics Data System (ADS)

Torbin, A. P.; Pershin, A. A.; Mebel, A. M.; Zagidullin, M. V.; Heaven, M. C.; Azyazov, V. N.

2018-01-01

Rate coefficients for the vibrational relaxation of O2(a1Δ, υ) by CO2 have been determined from the decay of fluorescence of the a1Δg → X3 Σg- (υ-υ‧) transitions with υ = υ‧ = 1, 2 and 3. O2(a1Δ, υ) molecules were produced by pulsed laser photolysis of ozone at a wavelength of 266 nm. The rate coefficients were measured to be (1.9 ± 0.2) × 10-14 cm3/s, (2.4 ± 0.2) × 10-14 cm3/s and (2.7 ± 0.3) × 10-14 cm3/s for υ = 1, 2 and 3 respectively.

The Dangers of Estimating V˙O2max Using Linear, Nonexercise Prediction Models.

PubMed

Nevill, Alan M; Cooke, Carlton B

2017-05-01

This study aimed to compare the accuracy and goodness of fit of two competing models (linear vs allometric) when estimating V˙O2max (mL·kg·min) using nonexercise prediction models. The two competing models were fitted to the V˙O2max (mL·kg·min) data taken from two previously published studies. Study 1 (the Allied Dunbar National Fitness Survey) recruited 1732 randomly selected healthy participants, 16 yr and older, from 30 English parliamentary constituencies. Estimates of V˙O2max were obtained using a progressive incremental test on a motorized treadmill. In study 2, maximal oxygen uptake was measured directly during a fatigue limited treadmill test in older men (n = 152) and women (n = 146) 55 to 86 yr old. In both studies, the quality of fit associated with estimating V˙O2max (mL·kg·min) was superior using allometric rather than linear (additive) models based on all criteria (R, maximum log-likelihood, and Akaike information criteria). Results suggest that linear models will systematically overestimate V˙O2max for participants in their 20s and underestimate V˙O2max for participants in their 60s and older. The residuals saved from the linear models were neither normally distributed nor independent of the predicted values nor age. This will probably explain the absence of a key quadratic age term in the linear models, crucially identified using allometric models. Not only does the curvilinear age decline within an exponential function follow a more realistic age decline (the right-hand side of a bell-shaped curve), but the allometric models identified either a stature-to-body mass ratio (study 1) or a fat-free mass-to-body mass ratio (study 2), both associated with leanness when estimating V˙O2max. Adopting allometric models will provide more accurate predictions of V˙O2max (mL·kg·min) using plausible, biologically sound, and interpretable models.

Determination of O2(a1 delta g) and O2(b1 sigma+ g) yields in the reaction O + ClO --> Cl + O2: implications for photochemistry in the atmosphere of Venus

NASA Technical Reports Server (NTRS)

Leu, M. T.; Yung, Y. L.

1987-01-01

A discharge flow apparatus with chemiluminescence detector has been used to study the reaction O + ClO --> Cl + O2, where O2 = O2(a1 delta g) or O2(b1 sigma+ g). The measured quantum yields for producing O2(a1 delta g) and O2(b1 sigma+ g) in the above reaction are less than 2.5 x 10(-2) and equal to (4.4 +/- 1.1) x 10(-4), respectively. The observed O2(a1 delta g) airglow of Venus cannot be explained in the context of standard photochemistry using our experimental results and those reported in recent literature. The possibility of an alternative source of O atoms derived from SO2 photolysis in the mesosphere of Venus is suggested.

Pregnane X receptor-dependent induction of the CYP3A4 gene by o,p'-1,1,1,-trichloro-2,2-bis (p-chlorophenyl)ethane.

PubMed

Medina-Díaz, Irma M; Arteaga-Illán, Georgina; de León, Mario Bermudez; Cisneros, Bulmaro; Sierra-Santoyo, Adolfo; Vega, Libia; Gonzalez, Frank J; Elizondo, Guillermo

2007-01-01

CYP3A4, the predominant cytochrome P450 (P450) expressed in human liver and intestine, contributes to the metabolism of approximately half the drugs in clinical use today. CYP3A4 catalyzes the 6beta-hydroxylation of a number of steroid hormones and is involved in the bioactivation of environmental procarcinogens. The expression of CYP3A4 is affected by several stimuli, including environmental factors such as insecticides and pesticides. The o,p'-1,1,1,-trichloro-2,2-bis (p-chlorophenyl)ethane (DDT) isomer of DDT comprises approximately 20% of technical grade DDT, which is an organochloride pesticide. We have recently shown that o,p'-DDT exposure increases CYP3A4 mRNA levels in HepG2 cells. To determine the mechanism by which o,p'-DDT induces CYP3A4 expression, transactivation and electrophoretic mobility shift assays were carried out, revealing that o,p'-DDT activates the CYP3A4 gene promoter through the pregnane X receptor (PXR). CYP3A4 gene promoter activation resulted in both an increase in CYP3A4 mRNA levels and an increase in the total CYP3A4 activity in HepG2 cells. We also observed induction of CYP3A4 and mouse Cyp3a11 mRNA in the intestine of CYP3A4-transgenic mice after exposure to 1 mg/kg o,p'-DDT. At higher doses, a decrease of CYP3A4 inducibility was observed together with an increase in levels of interleukin 6 mRNA, a proinflammatory cytokine that strongly represses CYP3A4 transcription. The present study indicates that regulation of other genes under PXR control may be altered by o,p'-DDT exposure.

Low-Temperature Desorption of N2O from NO on Rutile TiO2(110)-1x1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Boseong; Li, Zhenjun; Kay, Bruce D.

2014-05-08

We find that NO dosed on rutile TiO2(110)-1×1 at substrate temperatures as low as 50 K readily reacts to produce N2O which desorbs promptly from the surface leaving an oxygen adatom behind. The desorption rate of N2O reaches a maximum value after 1 – 2 sec at an NO flux of 1.2 ×1014 NO/cm2∙sec and then decreases rapidly as the initially clean, reduced TiO2(110) surface with ~5% oxygen vacancies (VO’s) becomes covered with oxygen adatoms and unreacted NO. The maximum desorption rate is also found to increase as the substrate temperature is raised up to about 100 K. Interestingly, themore » N2O desorption during the low-temperature (LT) NO dose is strongly suppressed when molecular oxygen is predosed, whereas it persists on the surface with VO’s passivated by surface hydroxyls. Our results show that the surface charge, not the VO sites, plays a dominant role in the LT N2O desorption induced by a facile NO reduction at such low temperatures.« less

Research on c-HfO2 (0 0 1)/α -Al2O3 (1 -1 0 2) interface in CTM devices based on first principle theory

NASA Astrophysics Data System (ADS)

Lu, Wenjuan; Dai, Yuehua; Wang, Feifei; Yang, Fei; Ma, Chengzhi; Zhang, Xu; Jiang, Xianwei

2017-12-01

With the growing application of high-k dielectrics, the interface between HfO2 and Al2O3 play a crucial role in CTM devices. To clearly understand the interaction of the HfO-AlO interface at the atomic and electronic scale, the bonding feature, electronic properties and charge localized character of c- HfO2 (0 0 1)/α-Al2O3 (1 -1 0 2) interface has been investigated by first principle calculations. The c- HfO2 (0 0 1)/α-Al2O3 (1 -1 0 2) interface has adhesive energy about -1.754 J/m2, suggesting that this interface can exist stably. Through analysis of Bader charge and charge density difference, the intrinsic interfacial gap states are mainly originated from the OII and OIII types oxygen atoms at the interface, and only OIII type oxygen atoms can localized electrons effectively and are provided with good reliability during P/E cycles, which theoretically validate the experimental results that HfO2/Al2O3 multi-layered charge trapping layer can generate more effective traps in memory device. Furthermore, the influence of interfacial gap states during P/E cycles in the defective interface system have also been studied, and the results imply that defective system displays the degradation on the reliability during P/E cycles, while, the charge localized ability of interfacial states is stronger than intrinsic oxygen vacancy in the trapping layer. Besides, these charge localized characters are further explained by the analysis of the density of states correspondingly. In sum, our results compare well with similar experimental observations in other literatures, and the study of the interfacial gap states in this work would facilitate further development of interface passivation.

Modelling the thermal conductivity of (U xTh 1-x)O 2 and (U xPu 1-x)O 2

DOE PAGES

Cooper, M. W. D.; Middleburgh, S. C.; Grimes, R. W.

2015-07-15

The degradation of thermal conductivity due to the non-uniform cation lattice of (U xTh 1-x)O 2 and (U xPu 1-x)O 2 solid solutions has been investigated by molecular dynamics, using the non-equilibrium method, from 300 to 2000 K. Degradation of thermal conductivity is predicted in (U xTh 1-x)O 2 and (U xPu 1-x)O 2 as compositions deviate from the pure end members: UO 2, PuO 2 and ThO 2. The reduction in thermal conductivity is most apparent at low temperatures where phonon-defect scattering dominates over phonon-phonon interactions. The effect is greater for (U xTh 1-x)O 2 than U xPu 1-x)Omore » 2 due to the greater mismatch in cation size. Parameters for an analytical expressions have been developed that describe the predicted thermal conductivities over the full temperature and compositional ranges. Finally, these expressions may be used in higher level fuel performance codes.« less

Argon plasma coagulation in the right and left colon: safety-risk profile of the 60W-1.2 l/min setting.

PubMed

Panos, Marios Z; Koumi, Andriani

2014-05-01

The 40W-0.8 l/min setting is widely recommended for argon plasma coagulation (APC) in the right colon. Until March 2012, we used the 60W-1.2 l/min setting for all sites of the colon. By auditing our experience, we assessed the safety-risk profile of the 60W-1.2 l/min setting in the right and left colon. All cases treated with APC by a single endoscopist, using the 60W-1.2 l/min setting for all sites of the colon between October 2001 and December 2007 were identified retrospectively and site, type, number of lesions, and complications were recorded. Between January 2008 and March 2012, information was recorded prospectively. In the retrospective audit, 290 lesions (101 cecum/ascending, 120 sigmoid/descending, 69 transverse) were treated in 241 patient endoscopies. There were no perforations. In the prospective audit, 156 lesions (83 cecum/ascending, 47 sigmoid/descending, 26 transverse) were treated in 132 patient endoscopies. There was 1/83 (1.2%) perforation in the cecum/ascending colon and none in the transverse or sigmoid/descending (n.s.). Combined, the results yield a cecal/ascending perforation rate of 1/153 (0.6%) patient endoscopies, 1/184 (0.5%) lesions treated and overall perforation rate for all sites of the colon of 1/373 (0.3%) patient endoscopies and 1/446 (0.2%) lesions. Post-polypectomy syndrome and delayed bleeding each occurred in 3/373 (0.8%) patient endoscopies and 3/446 (0.7%) lesions. There were no deaths. In the cecum and ascending colon, the APC perforation rate at the 60W-1.2 l/min setting was no higher than in the left colon and is similar to that reported in previously published series. Therefore, it appears safe, provided the precautions we describe are strictly followed.

Study of 1-min rain rate integration statistic in South Korea

NASA Astrophysics Data System (ADS)

Shrestha, Sujan; Choi, Dong-You

2017-03-01

The design of millimeter wave communication links and the study of propagation impairments at higher frequencies due to a hydrometeor, particularly rain, require the knowledge of 1-min. rainfall rate data. Signal attenuation in space communication results are due to absorption and scattering of radio wave energy. Radio wave attenuation due to rain depends on the relevance of a 1-min. integration time for the rain rate. However, in practice, securing these data over a wide range of areas is difficult. Long term precipitation data are readily available. However, there is a need for a 1-min. rainfall rate in the rain attenuation prediction models for a better estimation of the attenuation. In this paper, we classify and survey the prominent 1-min. rain rate models. Regression analysis was performed for the study of cumulative rainfall data measured experimentally for a decade in nine different regions in South Korea, with 93 different locations, using the experimental 1-min. rainfall accumulation. To visualize the 1-min. rainfall rate applicable for the whole region for 0.01% of the time, we have considered the variation in the rain rate for 40 stations across South Korea. The Kriging interpolation method was used for spatial interpolation of the rain rate values for 0.01% of the time into a regular grid to obtain a highly consistent and predictable rainfall variation. The rain rate exceeded the 1-min. interval that was measured through the rain gauge compared to the rainfall data estimated using the International Telecommunication Union Radio Communication Sector model (ITU-R P.837-6) along with the empirical methods as Segal, Burgueno et al., Chebil and Rahman, logarithmic, exponential and global coefficients, second and third order polynomial fits, and Model 1 for Icheon regions under the regional and average coefficient set. The ITU-R P. 837-6 exhibits a lower relative error percentage of 3.32% and 12.59% in the 5- and 10-min. to 1-min. conversion, whereas the

Microwave Observations and Modeling of O2 (1-delta(sub g)) and O3 Diurnal Variation in the Mesosphere

NASA Technical Reports Server (NTRS)

Sandor, Brad J.; Clancy, R. Todd; Rusch, David W.; Randall, Cora E.; Eckman, Richard S.; Siskind, David S.; Muhleman, Duane O.

1997-01-01

The first microwave measurements of an electronically excited molecular species in the Earth's atmosphere are presented. Local thermodynamic equilibrium (LTE) rotational line emission from mesospheric O2(1-del(sub g)) was observed at a frequency of 255.01794 GHz (lambda is approx. 1.2 mm), employing the National Radio Astronomy Observatory (NRAO) millimeter facility at Kitt Peak, Arizona (32 N, 111 W). The pressure broadened line shapes of the O2(1-del(sub g)) spectra, which were obtained in January and April 1992 and in January and November 1993, are inverted to retrieve O2(1-del(sub g)) mixing profiles over the 50-70 km altitude region. The observed daytime abundances exceed ozone abundances in the lower mesosphere, which are separately retrieved with coincident O3 spectral line (249.7886 GHz) observations. The January and November 1993 observations are binned into 20-60 min time intervals to study O2(1-del(sub g)) diurnal behavior. Derived abundances of O2(1-del(sub g)) between 50 and 70 km for the four observation dates are 9%, 31%, 3%, and 26%, respectively, each +/- 10% higher than predicted, based on the simple photochemistry of lower mesospheric O2(1-del(sub g)). Modeled variation of [O2(1-del(sub g))] with time of day agrees with observed variation in that the observed difference between model and data abundances is constant throughout the daylight hours of each observation date. Model underprediction Of [02(lAg)] is consistent with similar model underprediction of mesospheric [O3]. A perturbation to the photochemical model that forces decreased ozone chemical loss brings brings both model [O3] and [O2(1-del(sub g))] into agreement with the observations. O2(1-del(sub g)) abundances derived from these 1.2 mm observations agree with [O2(1-del(sub g))] values derived from comparable SME observations of the 1.27 micrometers emission, with assumption of a 3880 sec O2(1-del(sub g)) radiative lifetime. The 6800 sec O2(1-del(sub g)) radiative lifetime proposed by

Performance analysis of 60-min to 1-min integration time rain rate conversion models in Malaysia

NASA Astrophysics Data System (ADS)

Ng, Yun-Yann; Singh, Mandeep Singh Jit; Thiruchelvam, Vinesh

2018-01-01

Utilizing the frequency band above 10 GHz is in focus nowadays as a result of the fast expansion of radio communication systems in Malaysia. However, rain fade is the critical factor in attenuation of signal propagation for frequencies above 10 GHz. Malaysia is located in a tropical and equatorial region with high rain intensity throughout the year, and this study will review rain distribution and evaluate the performance of 60-min to 1-min integration time rain rate conversion methods for Malaysia. Several conversion methods such as Segal, Chebil & Rahman, Burgeono, Emiliani, Lavergnat and Gole (LG), Simplified Moupfouma, Joo et al., fourth order polynomial fit and logarithmic model have been chosen to evaluate the performance to predict 1-min rain rate for 10 sites in Malaysia. After the completion of this research, the results show that Chebil & Rahman model, Lavergnat & Gole model, Fourth order polynomial fit and Logarithmic model have shown the best performances in 60-min to 1-min rain rate conversion over 10 sites. In conclusion, it is proven that there is no single model which can claim to perform the best across 10 sites. By averaging RMSE and SC-RMSE over 10 sites, Chebil and Rahman model is the best method.

Synthesis and Electrochemical Properties Characterization of SnO2-coated LiNi1/3Co1/3Mn1/3O2 Cathode Material for Lithium Ion Batteries

DTIC Science & Technology

2009-01-01

Synthesis and electrochemical properties characterization of SnO2-coated LiNi1/3Co1/3Mn1/3O2 cathode material for lithium ion batteries Ping Yang...electrochemical properties characterization of SnO2-coated LiNi1/3Co1/3Mn1/3O2 cathode material for lithium ion batteries 5a. CONTRACT NUMBER 5b. GRANT NUMBER...electrochemical reaction. References 1. N Yabuuchi, T Ohzuku, “Novel lithium insertion material of LiCo1/3Ni1/3Mn1/3O2 for advanced lithium - ion batteries ”, J

Effects of carbohydrate ingestion 15 min before exercise on endurance running capacity.

PubMed

Tokmakidis, Savvas P; Karamanolis, Ioannis A

2008-06-01

This study examined the effects of pre-exercise carbohydrate ingestion on exercise metabolism and endurance running capacity. Eleven active subjects (VO(2) (max) 49.0 +/- 1.7 mL x kg(-1) x min(-1), mean +/- SE) performed two exercise trials 15 min after ingesting glucose (G; 1 g x kg body mass(-1)) and placebo (CON). Each subject ran on a level treadmill for 5 min at 60%, 45 min at 70%, and then at 80% of VO(2) (max) until exhaustion. Serum glucose and plasma insulin reached their peak concentrations (p < 0.01) 15 min after glucose ingestion and declined at the onset of exercise. Serum glycerol concentrations were lower (p < 0.01) in the G trial than in the CON trial after 30 min of exercise to exhaustion. In addition, after 45 min of exercise to exhaustion, the levels of free fatty acids were lower in G than in CON (p < 0.05). No differences were observed in carbohydrate oxidation rates during exercise between treatments (G, 2.53 +/- 0.08 g x min(-1); CON, 2.40 +/- 0.09 g x min(-1)). Time to exhaustion was 12.8% longer in G (p < 0.01) than in CON. These results suggest that glucose ingestion 15 min before prolonged exercise provides an additional carbohydrate source to the exercising muscle, thus improving endurance running capacity.

Dielectric properties and phase transition behaviors in (1-x)PbZrO3-xPb(Mg1/2W1/2)O3 ceramics

NASA Astrophysics Data System (ADS)

Vittayakorn, Naratip; Charoonsuk, Piyanut; Kasiansin, Panisara; Wirunchit, Supamas; Boonchom, Banjong

2009-09-01

The solid solution of lead zirconate [PbZrO3 (PZ)] and lead magnesium tungstate [Pb(Mg1/2W1/2)O3 (PMW)] has been synthesized by the wolframite precursor method. The crystal structure, phase transformations, dielectric and thermal properties of (1-x)PZ-xPMW, where x =0.00-0.10, were investigated. The crystal structure of sintered ceramics was analyzed by x-ray diffraction. Phase-pure perovskite was obtained for all compositions. Furthermore, a change from orthorhombic to rhombohedral symmetry was observed as the mole fraction of increased PMW. As a result, it was found that PbZrO3-Pb(Mg1/2W1/2)O3 undergoes successive transitions from the antiferroelectric phase to the ferroelectric phase to the paraelectric state. The coexistence of orthorhombic and rhombohedral phases in this binary system is located near the composition x =0.1.

Abnormal glomerular filtration rate in children, adolescents and young adults starts below 75 mL/min/1.73 m(2).

PubMed

Pottel, Hans; Hoste, Liesbeth; Delanaye, Pierre

2015-05-01

The chronic kidney disease (CKD) classification system for children is similar to that for adults, with both mainly based on estimated glomerular filtration rate (eGFR) combined with fixed cut-off values. The main cut-off eGFR value used to define CKD is 60 mL/min/1.73 m(2), a value that is also applied for children older than 2 years of age, adolescents and young adults. Based on a literature search, we evaluated inclusion criteria for eGFR in clinical trials or research studies on CKD for children. We also collected information on direct measurements of GFR (mGFR) in children and adolescents, with the aim to estimate the normal reference range for GFR. Using serum creatinine (Scr) normal reference values and Scr-based eGFR-equations, we also evaluated the correspondence between Scr normal reference values and (e)GFR normal reference values. Based on our literature search, the inclusion of children in published CKD studies has been based on cut-off values for eGFR of >60 mL/min/1.73 m(2). The lower reference limits for mGFR far exceed this adult threshold. Using eGFR values calculated using Scr-based formulas, we found that abnormal Scr levels in children already correspond to eGFR values that are below a cut-off of 75 mL/min/1.73 m(2). Abnormal GFR in children, adolescents and young adults starts below 75 mL/min/1.73 m(2), and as abnormality is a sign of disease, we recommend referring children, adolescents and young adults with an (e)GFR of <75 mL/min/1.73 m(2) for further clinical assessment.

40 CFR 721.10033 - Zinc, [ethanedioato(2-)-. kappa. O1, . kappa. O2]-.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Zinc, [ethanedioato(2-)-. kappa. O1... Specific Chemical Substances § 721.10033 Zinc, [ethanedioato(2-)-. kappa. O1, . kappa. O2]-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as zinc...

40 CFR 721.10033 - Zinc, [ethanedioato(2-)-. kappa. O1, . kappa. O2]-.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Zinc, [ethanedioato(2-)-. kappa. O1... Specific Chemical Substances § 721.10033 Zinc, [ethanedioato(2-)-. kappa. O1, . kappa. O2]-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as zinc...

Epitaxy of Zn{sub 2}TiO{sub 4} (1 1 1) thin films on GaN (0 0 1)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsiao, Chu-Yun; Wu, Jhih-Cheng; Shih, Chuan-Feng, E-mail: cfshih@mail.ncku.edu.tw

2013-03-15

Highlights: ► High-permittivity spinel Zn{sub 2}TiO{sub 4} thin films were grown on GaN (0 0 1) by sputtering. ► Oxygen atmosphere and post heat-treatment annealing effectively enhanced epitaxy. ► The epitaxial Zn{sub 2}TiO{sub 4} modifies the dielectric properties of ceramic oxide. - Abstract: High-permittivity spinel Zn{sub 2}TiO{sub 4} thin films were grown on GaN (0 0 1) by rf-sputtering. Grazing-angle, powder, and pole-figure X-ray diffractometries (XRD) were performed to identify the crystallinity and the preferred orientation of the Zn{sub 2}TiO{sub 4} films. Lattice image at the Zn{sub 2}TiO{sub 4} (1 1 1)/GaN (0 0 1) interface was obtained by high-resolutionmore » transmission-electron microscopy (HR-TEM). An oxygen atmosphere in sputtering and post heat-treatment using rapid thermal annealing effectively enhanced the epitaxy. The epitaxial relationship was determined from the XRD and HR-TEM results: (111){sub Zn{sub 2TiO{sub 4}}}||(001){sub GaN}, (202{sup ¯}){sub Zn{sub 2TiO{sub 4}}}||(110){sub GaN},and[21{sup ¯}1{sup ¯}]{sub Zn{sub 2TiO{sub 4}}}||[01{sup ¯}10]{sub GaN}. Finally, the relative permittivity, interfacial trap density and the flat-band voltage of the Zn{sub 2}TiO{sub 4} based capacitor were ∼18.9, 8.38 × 10{sup 11} eV{sup −1} cm{sup −2}, and 1.1 V, respectively, indicating the potential applications of the Zn{sub 2}TiO{sub 4} thin film to the GaN-based metal-oxide-semiconductor capacitor.« less

Aeronomical determinations of the quantum yields of O (1S) and O (1D) from dissociative recombination of O2(+)

NASA Technical Reports Server (NTRS)

Yee, Jeng-Hwa; Abreu, Vincent J.; Colwell, William B.

1989-01-01

Data from the visible-airglow experiment on the Atmosphere Explorer-E satellite have been used to determine the quantum yields of O (1S) and O (1D) from the dissociative recombination of O2(+) based on a constant total recombination rate from each vibrational level. A range of values between 0.05 and 0.18 has been obtained for the quantum yield of O (1S) and shows a positive correlation with the extent of the vibrational excitation of O2(+). The quantum yield of O (1D) has been measured to be 0.9 + or - 0.2, with no apparent dependence on the vibrational distribution of O2(+).

Excitation of O 2(a 1Δ g, b 1Σ g+) and I( 2P 1/2) by energy transfer from I 2(A, A' 3Π 1,2u) in solid rare gases

NASA Astrophysics Data System (ADS)

Böhling, R.; Becker, A. C.; Minaev, B. F.; Seranski, K.; Schurath, U.

1990-04-01

O 2a 1Δ g, b 1Σ g+ → X 3Σ g- and I 2P 1/2→ 2P 3/4 fluorescence occurs in I 2/O 2-doped rare gas matrices when I 2 is excited with visible laser light. O 2(a 1Δ g) and I( 2P 1/2) are populated independently by near-resonant energy transfer from the metastable triplet states of I 2. The doublet splitting of the O 2a→X band, which peaks at 7879 and 7863 cm -1 in argon, is interpreted as sensitized emission from O 2 trapped in distinct nearest neighbour positions of the donor 3I 2. Annealing reverses the intensity of the doublet, showing that the sites can be interconverted. It is suggested that the a→X emission rate is enhanced by the sensitizer, causing a lifetime reduction of the a 1Δ g state from 79 s in pure argon to 21 and 3±1 s next to I 2. The long-lived O 2(a 1Δ g) state is the precursor of I 2-sensitized emission from O 2(b 1Σ g+). The lifetime of O 2(b 1Σ g+) is reduced from 24.5 ms in pure argon to 17±1 ms in the presence of I 2.

A novel process for recycling and resynthesizing LiNi1/3Co1/3Mn1/3O2 from the cathode scraps intended for lithium-ion batteries.

PubMed

Zhang, Xihua; Xie, Yongbing; Cao, Hongbin; Nawaz, Faheem; Zhang, Yi

2014-09-01

To solve the recycling challenge for aqueous binder based lithium-ion batteries (LIBs), a novel process for recycling and resynthesizing LiNi1/3Co1/3Mn1/3O2 from the cathode scraps generated during manufacturing process is proposed in this study. Trifluoroacetic acid (TFA) is employed to separate the cathode material from the aluminum foil. The effects of TFA concentration, liquid/solid (L/S) ratio, reaction temperature and time on the separation efficiencies of the cathode material and aluminum foil are investigated systematically. The cathode material can be separated completely under the optimal experimental condition of 15vol.% TFA solution, L/S ratio of 8.0 mL g(-1), reacting at 40°C for 180 min along with appropriate agitation. LiNi1/3Co1/3Mn1/3O2 is successfully resynthesized from the separated cathode material by solid state reaction method. Several kinds of characterizations are performed to verify the typical properties of the resynthesized LiNi1/3Co1/3Mn1/3O2 powder. Electrochemical tests show that the initial charge and discharge capacities of the resynthesized LiNi1/3Co1/3Mn1/3O2 are 201 mAh g(-)(1) and 155.4 mAh g(-1) (2.8-4.5 V, 0.1C), respectively. The discharge capacity remains at 129 mAh g(-1) even after 30 cycles with a capacity retention ratio of 83.01%. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of training on muscle O2 transport at VO2max

NASA Technical Reports Server (NTRS)

Roca, J.; Agusti, A. G.; Alonso, A.; Poole, D. C.; Viegas, C.; Barbera, J. A.; Rodriguez-Roisin, R.; Ferrer, A.; Wagner, P. D.

1992-01-01

To quantify the relative contributions of convective and peripheral diffusive components of O2 transport to the increase in leg O2 uptake (VO2leg) at maximum O2 uptake (VO2max) after 9 wk of endurance training, 12 sedentary subjects (age 21.8 +/- 3.4 yr, VO2max 36.9 +/- 5.9 ml.min-1.kg-1) were studied. VO2max, leg blood flow (Qleg), and arterial and femoral venous PO2, and thus VO2leg, were measured while the subjects breathed room air, 15% O2, and 12% O2. The sequence of the three inspirates was balanced. After training, VO2max and VO2leg increased at each inspired O2 concentration [FIO2; mean over the 3 FIO2 values 25.2 +/- 17.8 and 36.5 +/- 33% (SD), respectively]. Before training, VO2leg and mean capillary PO2 were linearly related through the origin during hypoxia but not during room air breathing, suggesting that, at 21% O2, VO2max was not limited by O2 supply. After training, VO2leg and mean capillary PO2 at each FIO2 fell along a straight line with zero intercept, just as in athletes (Roca et al. J. Appl. Physiol. 67: 291-299, 1989). Calculated muscle O2 diffusing capacity (DO2) rose 34% while Qleg increased 19%. The relatively greater rise in DO2 increased the DO2/Qleg, which led to 9.9% greater O2 extraction. By numerical analysis, the increase in Qleg alone (constant DO2) would have raised VO2leg by 35 ml/min (mean), but that of DO2 (constant Qleg) would have increased VO2leg by 85 ml/min, more than twice as much. The sum of these individual effects (120 ml/min) was less (P = 0.013) than the observed rise of 164 ml/min (mean). This synergism (explained by the increase in DO2/Qleg) seems to be an important contribution to increases in VO2max with training.

Functionalizing carbon nitride with heavy atom-free spin converters for enhanced 1 O 2 generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Wenting; Han, Congcong; Zhang, Qinhua

advanced photosensitizers for singlet oxygen (1O2) generation. However, the intersystem crossing (ISC) process is quite insufficient in carbon nitride, limiting the 1O2 generation. Here, we report a facile and general strategy to confined benzophenone as a heavy atom-free spin converter dopant in carbon nitride via the facile copolymerization. With proper energy level matching between the heavy atom-free spin converter and various ligands based on carbon nitride precursors, the proper combination can decrease the singlet-triplet energy gap (DEST) and hence generate 1O2 effectively. Due to its significant and selectivity for 1O2 generation, the as-prepared carbon nitride-based photosensitizer shows a high selectivemore » photooxidation activity for 1,5-dihydroxy-naphthalene (1,5-DHN). The product yield reached 71.8% after irradiation for 60 min, which was higher than that of cyclometalated PtII complexes (53.6%) in homogeneous photooxidation. This study can broaden the application of carbon nitride in the field of selective heterogeneous photooxidation due to simple operation, low cost, and high efficiency, making it a strong candidate for future industrialization.« less

Metabolic abnormalities associated with elevated serum cystatin C in adults with an estimated GFR ≥ 60 ml/min/1.73m2

PubMed Central

Muntner, Paul; Vupputuri, Suma; Coresh, Josef; Uribarri, Jaime; Fox, Caroline S.

2011-01-01

Elevated serum cystatin C may represent an early stage of kidney disease. It is unclear whether metabolic abnormalities typically seen in advanced chronic kidney disease are present in adults with estimated glomerular filtration rate ≥60 ml/min/1.73m2 and elevated cystatin C. Participants of the Third National Health and Nutrition Examination Survey (n=6722) were categorized into three groups: estimated glomerular filtration rate ≥ 60 ml/min/1.73m2 and cystatin C <1.09 mg/L (normal cystatin C); estimated glomerular filtration rate ≥60 ml/min/1.73m2 and cystatin C ≥1.09 mg/L (elevated cystatin C); and estimated glomerular filtration rate of 15-59 ml/min/1.73m2 (stage 3 or 4 chronic kidney disease). Among those with normal cystatin C, elevated cystatin C, and stage 3 or 4 chronic kidney disease, the age, race-ethnicity, sex standardized prevalence of serum hemoglobin <12 g/dL (<13 g/dL for men) was 4.3%, 8.2%, and 13.8%; serum uric acid ≥ 5.9 mg/dL (≥7.4 mg/dL for men) was 12.6%, 30.0%, and 45.0%; serum homocysteine ≥13 μmol/L was 12.1%, 25.1%, and 41.0%; serum phosphorus ≥3.9 mg/dL was 17.2%, 23.2%, and 25.8%; serum albumin <3.8 mg/dL was 14.5%, 20.0%, and 20.4%; plasma fibrinogen ≥352 mg/dL was 10.5%, 21.7%, and 23.2%; and C-reactive protein ≥1.0 g/dL was 7.5%, 22.5%, and 21.6% (each p-trend<0.001). Among adults with estimated glomerular filtration rate ≥60 ml/min/1.73m2, elevated serum cystatin C is associated with an increased prevalence of several metabolic abnormalities. PMID:19295502

Synthesis of mesoporous TS-1 using a hybrid SiO{sub 2}–TiO{sub 2} xerogel for catalytic oxidative desulfurization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Seung-Tae; Jeong, Kwang-Eun; Jeong, Soon-Yong

2012-12-15

Graphical abstract: Display Omitted Highlights: ► Meso-TS-1 catalyst was synthesized using a SiO{sub 2}–TiO{sub 2} xerogel with an organosilane precursor. ► Hierarchical pore structure was confirmed by characterization of the materials. ► Catalytic activity was tested using oxidative desulfurization of the model sulfur compounds. ► Meso-TS-1 demonstrated significantly improved catalytic activity than TS-1. -- Abstract: Mesoporous TS-1 (M-TS-1) was synthesized using a hybrid SiO{sub 2}–TiO{sub 2} xerogel combined with an organosilane precursor. Prepared samples were characterized by XRD, UV–vis spectroscopy, SEM, and N{sub 2} adsorption–desorption measurement. M-TS-1, prepared in 2 days, showed high crystallinity and the best textural properties amongmore » the samples. The N{sub 2} adsorption–desorption isotherms of M-TS-1 exhibited a hysteresis loop at pressure higher than P/P{sub 0} = 0.4, clearly indicating the existence of mesopores. M-TS-1 has significantly larger mesopore volume (0.48 cm{sup 3}/g) than that of conventional TS-1 (0.07 cm{sup 3}/g), and showed a narrow peak centered at ca. 6.3 nm. In the oxidative desulfurization reaction, M-TS-1 was more active than conventional TS-1 at the same Ti-loading; M-TS-1 produced a dibenzothiophene (DBT) conversion of 96%, whereas conventional TS-1 produced a final DBT conversion of 5.6% after a reaction time of 180 min. Oxidative desulfurization over TS-1 was influenced both by electron density and steric hindrance in the sulfur compounds tested.« less

Dissociative adsorption of CCl 4 on the Fe 3O 4(1 1 1)-(2×2) selvedge of α-Fe 2O 3(0 0 0 1)

NASA Astrophysics Data System (ADS)

Adib, K.; Mullins, D. R.; Totir, G.; Camillone, N.; Fitts, J. P.; Rim, K. T.; Flynn, G. W.; Osgood, R. M.

2003-02-01

The surface reactions of CCl 4 with the Fe 3O 4(1 1 1)-(2×2) selvedge of naturally occurring α-Fe 2O 3(0 0 0 1) single-crystals have been investigated using synchrotron X-ray photoelectron spectroscopy (XPS) and temperature-programmed desorption (TPD). CCl 4 was found to dissociate on the Fe 3O 4 surface at 100 K producing chemisorbed Cl and adsorbed CCl 2. TPD shows that the large majority of the dissociatively adsorbed CCl 2 fragments extract lattice oxygen and desorb as phosgene at >275 K. However, the XPS spectra show no evidence for the formation of surface-bound phosgene, at 100 K, indicating that its formation involves two steps. The first step, dissociation, is spontaneous at 100 K, whereas the second, oxygen atom abstraction to form phosgene, requires thermal excitation. Cl chemisorption yielded two separate species, the mono- and dichloride terminations of surface iron sites. The identification of these two surface terminations is based on the coverage dependence and the surface temperature history of their Cl 2p 3/2 peak intensity. For example, heating to >450 K allows the monochloride to transform into iron dichloride, indicating Cl adatom mobility at these temperatures.

Diaqua­bis[1-hydroxy-2-(imidazol-3-ium-1-yl)-1,1′-ethyl­idenediphophonato-κ2 O,O′]zinc(II)

PubMed Central

Freire, Eleonora; Vega, Daniel R.

2009-01-01

In the title complex, [Zn(C5H9NO7P2)2(H2O)2], the zinc atom is coordinated by two bidentate zoledronate [zoledronate = (2-(1-imidazole)-1-hydr­oxy-1,1′-ethyl­idenediphophonate)] ligands and two water mol­ecules. The coordination number is 6. There is one half-mol­ecule in the asymmetric unit with the zinc atom located on a crystallographic inversion centre. The anion exists as a zwitterion with an overall charge of −1; the protonated nitro­gen in the ring has a positive charge and the two phospho­nates groups each have a single negative charge. There are two intra­molecular O—H⋯O hydrogen bonds. The mol­ecules are linked into a chain by inter­molecular O—H⋯O hydrogen bonds. Adjacent chains are further linked by O—H⋯O hydrogen bonds involving the aqua ligands. An N—H⋯O inter­action is also observed. PMID:21578164

Quenching of I(2P1/2) by O3 and O(3P).

PubMed

Azyazov, Valeriy N; Antonov, Ivan O; Heaven, Michael C

2007-04-26

Oxygen-iodine lasers that utilize electrical or microwave discharges to produce singlet oxygen are currently being developed. The discharge generators differ from conventional chemical singlet oxygen generators in that they produce significant amounts of atomic oxygen. Post-discharge chemistry includes channels that lead to the formation of ozone. Consequently, removal of I(2P1/2) by O atoms and O3 may impact the efficiency of discharge driven iodine lasers. In the present study, we have measured the rate constants for quenching of I(2P1/2) by O(3P) atoms and O3 using pulsed laser photolysis techniques. The rate constant for quenching by O3, (1.8 +/- 0.4) x 10(-12) cm3 s-1, was found to be a factor of 5 smaller than the literature value. The rate constant for quenching by O(3P) was (1.2 +/- 0.2) x 10(-11) cm3 s-1.

Structural and ferroelectric phase evolution in [KNbO3]1-x[BaNi1/2Nb1/2O3-δ]x (x = 0, 0.1)

NASA Astrophysics Data System (ADS)

Hawley, Christopher; Wu, Liyan; Xiao, Geoffrey; Grinberg, Ilya; Rappe, Andrew; Davies, Peter; Spanier, Jonathan

The phase transition evolution for [KNbO3]1-x[BaNi1/2Nb1/2O3-δ]x (x=0, 0.1) is determined via complementary dielectric constant and Raman scattering measurements. Raman scattering by optical phonons over the range of 100-1000 cm-1 for -190°C < T < 600°C reveals six discernible zone-center optical phonon modes. They are assigned to structural and ferroelectric phases in the solid solution x = 0.1 and compared with those for end member x = 0 and with the results of temperature-dependent dielectric permittivity. Rigorous peak fitting analyses of spectra collected from the solid solution and end member indicate structural and ferroelectric phase transition temperatures that are quite close to those for the KNbO3 end member. Remarkably, despite the inclusion of 5 atomic Work supported by US ARO under W911NF-14-1-0500, NSF 1123696, and DoE BES under DE-FG02-07ER46431. Equipment acquisitions and computational support under DURIP and DoE NERSCC.

Quenching of I(2P1/2) by NO2, N2O4, and N2O.

PubMed

Kabir, Md Humayun; Azyazov, Valeriy N; Heaven, Michael C

2007-10-11

Quenching of excited iodine atoms (I(5p5, 2P1/2)) by nitrogen oxides are processes of relevance to discharge-driven oxygen iodine lasers. Rate constants at ambient and elevated temperatures (293-380 K) for quenching of I(2P1/2) atoms by NO2, N2O4, and N2O have been measured using time-resolved I(2P1/2) --> I(2P3/2) 1315 nm emission. The excited atoms were generated by pulsed laser photodissociation of CF3I at 248 nm. The rate constants for I(2P1/2) quenching by NO2 and N2O were found to be independent of temperature over the range examined with average values of (2.9 +/- 0.3) x 10(-15) and (1.4 +/- 0.1) x 10(-15) cm3 s(-1), respectively. The rate constant for quenching of I(2P1/2) by N2O4 was found to be (3.5 +/- 0.5) x 10(-13) cm3 s(-1) at ambient temperature.

Pulsed-field magnetization of frustrated S = 1/2 Cu(pyrimidine) 1.5(H 2O)(BF 4) 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manson, J. L.; Jasen, D. M.; Singleton, John

2017-02-13

Cu(pym) 1.5(H 2O)(BF 4) 2 (pym = pyrimidine) was synthesized and its structure determined by synchrotron single crystal X-ray diffraction. The compound contains S = 1/2 Cu(II) ions arranged in a distorted triangular array (Fig. 1). Each Cu(II) ion is coordinated to three pym ligands, two weakly held BF 4 - anions and one H 2O. To get a sense to the extent (i.e., strength) of possible frustrated exchange interactions in this new compound we measured the magnetization of Cu(pym) 1.5(H 2O)(BF 4) 2 in pulsed magnetic fields up to 60 T.

Determination of O2(a1Delta g) and O2(b1Sigma + g) yields in the reaction O + ClO yields Cl + O2 - Implications for photochemistry in the atmosphere of Venus

NASA Technical Reports Server (NTRS)

Leu, Ming-Taun; Yung, Yuk L.

1987-01-01

A discharge flow apparatus with a chemiluminescence detector was used to investigate the reaction O + ClO yields Cl + O2(asterisk), where O2(asterisk) = O2(a1Delta g) or O2(b1Sigma + g). It is found that the observed O2(a1Delta g) airglow of Venus cannot be explained in the framework of standard photochemistry using the experimental results obtained here and those reported in the recent literature. The possibility of an alternative source of O atoms derived from SO2 photolysis in the Venus mesosphere is suggested.

The Effects of Non-Contingent Feedback on the Incidence of Plateau at V̇O2max.

PubMed

Gordon, Dan; Gernigon, Marie; Baker, James; Merzbach, Viviane; Scruton, Adrian

2017-03-01

The purpose of this study was to examine the effects of non-contingent feedback in the form of heart rate (HR) on the incidence of plateau at V̇O 2max . Ten physically active males (age 24.8 yrs ± 4.2; mass 81.4 ± 9.0 kg; stature 1.80 ± 0.11 m, V̇O 2max 53.2 ± 5.8 ml·kg -1. min -1 ) who were V̇O 2max testing naïve but were cognisant as to the heart rate responses to exercise completed four incremental tests to volitional exhaustion, separated by ~72 h for the determination of V̇O 2max and gas exchange threshold. The first trial served as a familiarisation with the remaining three being experimental conditions where HR was presented in a screen projection as either the actual response (HR-A) or 10 b·min -1 higher than recorded (HR-H) or 10 b·min -1 lower (HR-L). Throughout all trials V̇O 2 was recorded on a breath-by-breath basis with plateau criteria of ≤ 50 ml·min -1 . A significant difference was observed for Δ V̇O 2 over the final two consecutive 30s sampling periods between HR-A, both HR-L and HR-H (p = 0.049) and for the incidence of plateau response between condition (p = 0.021). An additional significant difference was observed for sub-maximal Δ V̇O 2 responses between HR-A and HR-H (p = 0.049) and HR-A and HR-L (p = 0.006). Non-significant differences were observed for all other criteria. These data indicate that when presented with non-contingent feedback in the form of HR, that the perceptually orientated pacing schema becomes disrupted promoting a sparing of the finite anaerobic capacity to compensate for the imbalance between the afferent signal and perception of effort.

Three-Dimensional NiCo2O4@MnMoO4 Core-Shell Nanoarrays for High-Performance Asymmetric Supercapacitors.

PubMed

Yuan, Yuliang; Wang, Weicheng; Yang, Jie; Tang, Haichao; Ye, Zhizhen; Zeng, Yujia; Lu, Jianguo

2017-10-10

Design of new materials with sophisticated nanostructure has been proven to be an efficient strategy to improve their properties in many applications. Herein, we demonstrate the successful combination of high electron conductive materials of NiCo 2 O 4 with high capacitance materials of MnMoO 4 by forming a core-shell nanostructure. The NiCo 2 O 4 @MnMoO 4 core-shell nanoarrays (CSNAs) electrode possesses high capacitance of 1169 F g -1 (4.24 F cm -2 ) at a current density of 2.5 mA cm -2 , obviously larger than the pristine NiCo 2 O 4 electrode. The asymmetric supercapacitors (ASCs), assembled with NiCo 2 O 4 @MnMoO 4 CSNAs as binder-free cathode and active carbon (AC) as anode, exhibit high energy density of 15 Wh kg -1 and high power density of 6734 W kg -1 . Cycle performance of NiCo 2 O 4 @MnMoO 4 CSNAs//AC ASCs, conducted at current density of 20 mA cm -2 , remain 96.45% of the initial capacitance after 10,000 cycles, demonstrating its excellent long-term cycle stability. Kinetically decoupled analysis reveals that the capacitive capacitance is dominant in the total capacitance of NiCo 2 O 4 @MnMoO 4 CSNAs electrode, which may be the reason for ultra long cycle stability of ASCs. Our assembled button ASC can easily light up a red LED for 30 min and a green LED for 10 min after being charged for 30 s. The remarkable electrochemical performance of NiCo 2 O 4 @MnMoO 4 CSNAs//AC ASCs is attributed to its enhanced surface area, abundant electroactive sites, facile electrolyte infiltration into the 3D NiCo 2 O 4 @MnMnO 4 nanoarrays and fast electron and ion transport path.

Enhanced texture evolution and piezoelectric properties in CuO-doped Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 grain-oriented ceramics

NASA Astrophysics Data System (ADS)

Chang, Yunfei; Watson, Beecher; Fanton, Mark; Meyer, Richard J.; Messing, Gary L.

2017-12-01

In this work, both crystallographic texture and doping engineering strategies were integrated to develop relaxor-PbTiO3 (PT) based ternary ferroelectric ceramics with enhanced texture evolution and superior electromechanical properties. CuO-doped Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) piezoelectric ceramics with [001]c texture fraction ≥97% were synthesized by templated grain growth. The addition of CuO significantly promotes densification and oriented grain growth in the templated ceramics, leading to full texture development at dramatically reduced times and temperatures. Moreover, the CuO dopant remarkably enhances the piezoelectric properties of the textured ceramics while maintaining high phase transition temperatures and large coercive fields. Doping 0.125 wt. % CuO yields the electromechanical properties of d33 = 927 pC/N, d33* = 1510 pm/V, g33 = 43.2 × 10-3 Vm/N, Kp = 0.87, Ec=8.8 kV/cm, and tan δ = 1.3%, which are the best values reported so far in PIN-PMN-PT based ceramics. The high piezoelectric coefficient is mainly from the reversible piezoelectric response, with the irreversible contribution being on the order of 13.1%. We believe that this work not only facilitates closing the performance gap between ceramics and single crystals but also can expand relaxor-PT based piezoelectric application fields.

Quenching of I(2P 1/2) by O 3 and O( 3P)

NASA Astrophysics Data System (ADS)

Azyazov, V. N.; Antonov, I. O.; Ruffner, S.; Heaven, M. C.

2006-02-01

Oxygen-iodine lasers that utilize electrical or microwave discharges to produce singlet oxygen are currently being developed. The discharge generators differ from conventional chemical singlet oxygen generators in that they produce significant amounts of atomic oxygen. Post-discharge chemistry includes channels that lead to the formation of ozone. Consequently, removal of I(2P 1/2) by O atoms and O 3 may impact the efficiency of discharge driven iodine lasers. In the present study we have measured the rate constants for quenching of I(2P 1/2) by O( 3P) atoms and O 3 using pulsed laser photolysis techniques. The rate constant for quenching by O 3, 1.8x10 -12 cm 3 s -1, was found to be a factor of five smaller than the literature value. The rate constant for quenching by O( 3P) was 1.2x10 -11 cm 3 s -1. This was six times larger than a previously reported upper bound, but consistent with estimates obtained by modeling the kinetics of discharge-driven laser systems.

Variable character of O—O and M—O bonding in side-on (η2) 1:1 metal complexes of O2

PubMed Central

Cramer, Christopher J.; Tolman, William B.; Theopold, Klaus H.; Rheingold, Arnold L.

2003-01-01

The structures and the O—O and M—O bonding characters of a series of reported side-on (η2) 1:1 metal complexes of O2 are analyzed by using density functional theory calculations. Comparison of the calculated and experimental systems with respect to O—O bond distance, O—O stretching frequency, and O—O and M—O bond orders provides new insights into subtle influences relevant to O2 activation processes in biology and catalysis. The degree of charge transfer from the generally electron-rich metals to the dioxygen fragment is found to be variable, such that there are species well described as superoxides, others well described as peroxides, and several cases having intermediate character. Increased charge transfer to dioxygen takes place via overlap of the metal dxy orbital with the in-plane π* orbital of O2 and results in increased M—O bond orders and decreased O—O bond orders. Comparison of theory and experiment over the full range of compounds studied suggests that reevaluation of the O—O bond lengths determined from certain x-ray crystal structures is warranted; in one instance, an x-ray crystal structure redetermination was performed at low temperature, confirming the theoretical prediction. Librational motion of the coordinated O2 is identified as a basis for significant underestimation of the O—O distance at high temperature. PMID:12634422

A new recipe for preparing oxidized TiO2(1 1 0) surfaces: An STM study

NASA Astrophysics Data System (ADS)

Hansen, Jonas Ø.; Matthiesen, Jesper; Lira, Estephania; Lammich, Lutz; Wendt, Stefan

2017-12-01

Using high-resolution scanning tunneling microscopy (STM), we have studied the oxidation of rutile TiO2(1 1 0)-(1 × 1) surfaces with Had species at room temperature. We followed the evolution of various stable species as function of the O2 exposure, and the nature of the ultimately dominating species in the Ti troughs is described. When O2 saturation was accomplished using a glass-capillary array doser, we found that on-top O (Oot) adatoms are the predominant surface species. In contrast, when O2 was supplied via backfilling of the chamber the predominant surface species are tentatively assigned to terminal OH groups. We argue that unintended reactions with the chamber walls have a strong influence on the formed surface species, explaining scattered results in the literature. On the basis of our STM data we propose an alternative, easy way of preparing oxidized TiO2(1 1 0) surfaces with Oot adatoms (o-TiO2). It is certain that o-TiO2(1 1 0) surfaces prepared according to this recipe do not have any residual surface O vacancies. This contradicts the situation when oxidizing reduced TiO2(1 1 0) surfaces with O vacancies, where some O vacancies persist.

Three-Dimensional Hierarchical NixCo1-xO/NiyCo2-yP@C Hybrids on Nickel Foam for Excellent Supercapacitors.

PubMed

Shao, Yubo; Zhao, Yongqing; Li, Hua; Xu, Cailing

2016-12-28

Active materials and special structures of the electrode have decisive influence on the electrochemical properties of supercapacitors. Herein, three-dimensional (3D) hierarchical Ni x Co 1-x O/Ni y Co 2-y P@C (denoted as NiCoOP@C) hybrids have been successfully prepared by a phosphorization treatment of hierarchical Ni x Co 1-x O@C grown on nickel foam. The resulting NiCoOP@C hybrids exhibit an outstanding specific capacitance and cycle performance because they couple the merits of the superior cycling stability of Ni x Co 1-x O, the high specific capacitance of Ni y Co 2-y P, the mechanical stability of carbon layer, and the 3D hierarchical structure. The specific capacitance of 2638 F g -1 can be obtained at the current density of 1 A g -1 , and even at the current density of 20 A g -1 , the NiCoOP@C electrode still possesses a specific capacitance of 1144 F g -1 . After 3000 cycles at 10 A g -1 , 84% of the initial specific capacitance is still remained. In addition, an asymmetric ultracapacitor (ASC) is assembled through using NiCoOP@C hybrids as anode and activated carbon as cathode. The as-prepared ASC obtains a maximum energy density of 39.4 Wh kg -1 at a power density of 394 W kg -1 and still holds 21 Wh kg -1 at 7500 W kg -1 .

Primary standards for measuring flow rates from 100 nl/min to 1 ml/min - gravimetric principle.

PubMed

Bissig, Hugo; Petter, Harm Tido; Lucas, Peter; Batista, Elsa; Filipe, Eduarda; Almeida, Nelson; Ribeiro, Luis Filipe; Gala, João; Martins, Rui; Savanier, Benoit; Ogheard, Florestan; Niemann, Anders Koustrup; Lötters, Joost; Sparreboom, Wouter

2015-08-01

Microflow and nanoflow rate calibrations are important in several applications such as liquid chromatography, (scaled-down) process technology, and special health-care applications. However, traceability in the microflow and nanoflow range does not go below 16 μl/min in Europe. Furthermore, the European metrology organization EURAMET did not yet validate this traceability by means of an intercomparison between different National Metrology Institutes (NMIs). The NMIs METAS, Centre Technique des Industries Aérauliques et Thermiques, IPQ, Danish Technological Institute, and VSL have therefore developed and validated primary standards to cover the flow rate range from 0.1 μl/min to at least 1 ml/min. In this article, we describe the different designs and methods of the primary standards of the gravimetric principle and the results obtained at the intercomparison for the upper flow rate range for the various NMIs and Bronkhorst High-Tech, the manufacturer of the transfer standards used.

Structural and ferroelectric phase evolution in [KNbO3]1-x[BaNi1/2Nb1/2O3 -δ] x (x =0 ,0.1 )

NASA Astrophysics Data System (ADS)

Hawley, Christopher J.; Wu, Liyan; Xiao, Geoffrey; Grinberg, Ilya; Rappe, Andrew M.; Davies, Peter K.; Spanier, Jonathan E.

2017-08-01

The phase transition evolution for [KNbO3]1-x[BaNi1/2Nb1/2O3 -δ] x(x =0 ,0.1 ) is determined via complementary dielectric permittivity and Raman-scattering measurements. Raman scattering by optical phonons over the range of 100-1000 cm-1 for 83 K 1 and compared with those for end member x =0 and with the results of temperature-dependent dielectric permittivity. Rigorous peak fitting analyses of spectra collected from the solid solution and end member indicate structural and ferroelectric phase transition temperatures that are close to those for the KNbO3 end member despite the inclusion of 5 atomic % of ferroelectrically inactive Ni cations. Density functional theory calculations were performed in the solid solution and end member using both cation displacement and Berry phase-based methods. Differences in the electronic and polar properties between the solid solution and the end member highlights local and nonlocal characteristics, which are discussed in relation to the experimental data.

O2(b1Σg+) Quenching by O2, CO2, H2O, and N2 at Temperatures of 300-800 K.

PubMed

Zagidullin, M V; Khvatov, N A; Medvedkov, I A; Tolstov, G I; Mebel, A M; Heaven, M C; Azyazov, V N

2017-10-05

Rate constants for the removal of O 2 (b 1 Σ g + ) by collisions with O 2 , N 2 , CO 2 , and H 2 O have been determined over the temperature range from 297 to 800 K. O 2 (b 1 Σ g + ) was excited by pulses from a tunable dye laser, and the deactivation kinetics were followed by observing the temporal behavior of the b 1 Σ g + -X 3 Σ g - fluorescence. The removal rate constants for CO 2 , N 2 , and H 2 O were not strongly dependent on temperature and could be represented by the expressions k CO2 = (1.18 ± 0.05) × 10 -17 × T 1.5 × exp[Formula: see text], k N2 = (8 ± 0.3) × 10 -20 × T 1.5 × exp[Formula: see text], and k H2O = (1.27 ± 0.08) × 10 -16 × T 1.5 × exp[Formula: see text] cm 3 molecule -1 s -1 . Rate constants for O 2 (b 1 Σ g + ) removal by O 2 (X), being orders of magnitude lower, demonstrated a sharp increase with temperature, represented by the fitted expression k O2 = (7.4 ± 0.8) × 10 -17 × T 0.5 × exp[Formula: see text] cm 3 molecule -1 s -1 . All of the rate constants measured at room temperature were found to be in good agreement with previously reported values.

40 CFR 721.9511 - Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium and europium-doped.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Silicic acid (H6SiO2O7), magnesium...), magnesium, strontium salt(1:1:2), dysprosium and europium-doped. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as silicic acid (H6SiO2O7) magnesium...

40 CFR 721.9511 - Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium and europium-doped.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Silicic acid (H6SiO2O7), magnesium...), magnesium, strontium salt(1:1:2), dysprosium and europium-doped. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as silicic acid (H6SiO2O7) magnesium...

40 CFR 721.9511 - Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium and europium-doped.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Silicic acid (H6SiO2O7), magnesium...), magnesium, strontium salt(1:1:2), dysprosium and europium-doped. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as silicic acid (H6SiO2O7) magnesium...

40 CFR 721.9511 - Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium and europium-doped.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Silicic acid (H6SiO2O7), magnesium...), magnesium, strontium salt(1:1:2), dysprosium and europium-doped. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as silicic acid (H6SiO2O7) magnesium...

Remineralization Effect of Topical NovaMin Versus Sodium Fluoride (1.1%) on Caries-Like Lesions in Permanent Teeth

PubMed Central

Vahid Golpayegani, M.; Sohrabi, A.; Biria, M.; Ansari, G.

2012-01-01

Objective: NovaMin, a synthetic mineral composed of calcium, sodium, phosphorous and silica releases deposits of crystalline hydroxyl-carbonate apatite (HCA) structurally similar to tooth mineral composition. The aim of this investigation was to compare the potential remineralization effect of topical NovaMin and Sodium Fluoride gel on caries like lesions in permanent teeth. Materials and Methods: A total of 60 sound human freshly extracted teeth were subjected to a pH-cycling protocol. Specimens were randomly assigned to one of the two treatment groups with NovaMin contained dentifrice applied to group 1, while group 2 received a dentifrice containing 1.1% neutral Sodium Fluoride. Pastes were applied five times after the samples received a demineralization from an earlier cariogenic challenge. Specimens were then evaluated by a Surface Micro Hardness test (SMH, 25G, 5s). Post-treatment SMH measurements were conducted and Mann Whitney test was employed for statistical analysis. Results: Mean post lesion SMH values were 221.99±26.27 and 224.50±28.64 for the first and second groups, respectively. Post treatment SMH values were 232.52±24.34 for NovaMin and 232.03 ±24.46 for the fluoride group. Two way ANOVA test showed a highly significant difference between the two different treatment protocols (p<0.001). Conclusion: NovaMin dentifrice appears to have a greater effect on remineralization of carious-like lesions when compared to that of fluoride containing dentifrice in permanent teeth. PMID:22924104

Formation of epitaxial Al 2O 3/NiAl(1 1 0) films: aluminium deposition

NASA Astrophysics Data System (ADS)

Lykhach, Y.; Moroz, V.; Yoshitake, M.

2005-02-01

Structure of epitaxial Al 2O 3 layers formed on NiAl(1 1 0) substrates has been studied by means of reflection high-energy electron diffraction (RHEED). The elucidated structure was compared to the model suggested for 0.5 nm-thick Al 2O 3 layers [K. Müller, H. Lindner, D.M. Zehner, G. Ownby, Verh. Dtsch. Phys. Ges. 25 (1990) 1130; R.M. Jaeger, H. Kuhlenbeck, H.J. Freund, Surf. Sci. 259 (1991) 235]. The stepwise growth of Al 2O 3 film, involving deposition and subsequent oxidation of aluminium onto epitaxial 0.5 nm-thick Al 2O 3 layers, has been investigated. Aluminium was deposited at room temperature, whereas its oxidation took place during annealing at 1070 K. The Al 2O 3 thickness was monitored by means of Auger electron spectroscopy (AES). It was found that Al 2O 3 layer follows the structure of 0.5 nm thick Al 2O 3 film, although a tilting of Al 2O 3(1 1 1) surface plane with respect to NiAl(1 1 0) surface appeared after Al deposition.

Unification of the negative electrocaloric effect in Bi{sub 1/2}Na{sub 1/2}TiO{sub 3}-BaTiO{sub 3} solid solutions by Ba{sub 1/2}Sr{sub 1/2}TiO{sub 3} doping

DOE Office of Scientific and Technical Information (OSTI.GOV)

Uddin, Sarir; Materials Research Laboratory, Institute of Physics and Electronics, University of Peshawar, Peshawar 25120; Zheng, Guang-Ping, E-mail: mmzheng@polyu.edu.hk

2013-12-07

The microscopic mechanisms of the negative electrocaloric effect (ECE) of the single-phase (1−x)(0.94Bi{sub 1/2}Na{sub 1/2}TiO{sub 3}-0.06BaTiO{sub 3})-xBa{sub 1/2}Sr{sub 1/2}TiO{sub 3} (BNT-BT-BST) perovskite solid solutions fabricated via the sol-gel technique are explored in this study. Dielectric and mechanical relaxation analyses are employed to investigate the ferroelectric and structural transitions of the samples. The electrocaloric properties of the samples were measured by thermodynamics Maxwell relations. The difference between the depolarization temperature (T{sub d}) and the maximum dielectric constant temperature (T{sub m}) was found to decrease with increasing BST content. Doping with BST stabilized the ferroelectric phase along with unifying the EC temperaturemore » changes (ΔT) to only negative values. The origin of the uniform negative ECE of BNT-BT-BST is discussed.« less

The stability of N-[2-(4-o-fluorophenylpiperazin-1-yl)ethyl]-2,5-dimethyl-1 -phenylpyrrole-3,4-dicarboximide in aqueous-organic solutions.

PubMed

Zajac, Marianna; Sobczak, Agnieszka; Malinka, Wiesław; Redzicka, Aleksandra

2010-01-01

The first-order reaction of solvolysis of N-[2-(4-o-fluorophenylpiperazin-1-yl)ethyl]-2,5-dimethyl-1-phenylpyrrole-3,4-dicarboximide (PDI) was investigated as a function of pH at 333, 328, 323, 318 and 308 K in the pH range 1.11 - 12.78. The decomposition of PDI was followed by the HPLC method (Nucleosil 10-C8 column (250 x 4 mm I.D., dp = 10 microm), mobile phase: 0.018 mol/L ammonia acetate - acetonitrile (40: 60 v/v), UV detector: 240 nm, flow rate: 1 mL/min. Specific acid-base catalysis involves solvolysis of the undissociated molecules of PDI catalyzed by hydroxide ions and spontaneous solvolysis of the undissociated and monoprotonated forms of PDI under the influence of solvents. The thermodynamic parameters of the reactions--activation energy (E(a)), enthalpy (DH(#)), entropy (DS(#))--were calculated.

Role of alkali carbonate and salt in topochemical synthesis of K1/2Na1/2NbO3 and NaNbO3 templates

NASA Astrophysics Data System (ADS)

Lee, Jae-Seok; Jeon, Jae-Ho; Choi, Si-Young

2013-11-01

Since the properties of lead-free piezoelectric materials have thus far failed to meet those of lead-based materials, either chemical doping or morphological texturing should be employed to improve the piezoelectric properties of lead-free piezoelectric ceramics. The goal of this study was to synthesize plate-like K1/2Na1/2NbO3 and NaNbO3 particles, which are the most favorable templates for morphological texturing of K1/2Na1/2NbO3 ceramics. To achieve this goal, Bi2.5Na3.5Nb5O18 precursors in a plate-like shape were first synthesized and subsequently converted into K1/2Na1/2NbO3 or NaNbO3 particles that retain the morphology of Bi2.5Na3.5Nb5O18. In this study, we found that sodium or potassium carbonate does not play a major role in converting the Bi2.5Na3.5Nb5O18 precursor to K1/2Na1/2NbO3 or NaNbO3, on the contrary to previous reports; however, the salt contributes to the conversion reaction. All synthesis processes have been performed via a molten salt method, and scanning electron microscopy, scanning probe microscopy, and inductively coupled plasma mass spectroscopy were used to characterize the synthesized K1/2Na1/2NbO3 or NaNbO3 templates.

Anti-epileptic activity of group II metabotropic glutamate receptor agonists (--)-2-oxa-4-aminobicyclo[3.1.0]hexane-4,6-dicarboxylate (LY379268) and (--)-2-thia-4-aminobicyclo[3.1.0]hexane-4,6-dicarboxylate (LY389795).

PubMed

Moldrich, R X; Jeffrey, M; Talebi, A; Beart, P M; Chapman, A G; Meldrum, B S

2001-07-01

The selective group II metabotropic glutamate receptor (mGlu(2/3)) agonists (-)-2-oxa-4-aminobicyclo[3.1.0]hexane-4,6-dicarboxylate (LY379268) and (-)-2-thia-4-aminobicyclo[3.1.0]hexane-4,6-dicarboxylate (LY389795) have been evaluated as anti-epileptic drugs in dilute brown agouti (DBA/2) mice, lethargic (lh/lh) mice, genetically epilepsy-prone-9 (GEP) rats and amygdala-kindled rats. Sound-induced clonic seizures in DBA/2 mice were transiently inhibited by both agonists intracerebroventricularly (i.c.v.), LY379268 ED(50)=0.08 [0.02-0.33]nmol and LY389795 ED(50)=0.82 [0.27-3.24]nmol or intraperitoneally (i.p.), LY379268 ED(50)=2.9 [0.9-9.6]mg/kg and LY389795 ED(50)=3.4 [1.0-11.7]mg/kg. Both mGlu(2/3) agonists inhibited seizures induced by the group I mGlu receptor agonist (R,S)-3,5-dihydroxyphenylglycine (DHPG), where LY379268, i.c.v. ED(50)=0.3 [0.02-5.0]pmol and LY389795, i.c.v. ED(50)=0.03 [0.05-0.19]nmol. The spike and wave discharge (SWD) duration of absence seizures in lh/lh mice was significantly reduced by both agonists at 1 and 10nmol (i.c.v.) up to 90min following infusion. The electrically induced seizure score and afterdischarge duration of amygdala-kindled rats was partially inhibited by the agonists 30min after i.p. injection of 10mg/kg. The agonists did not inhibit sound-induced seizures in GEP rats (0.1-1mg/kg, 30min 1h, i.p.), but were proconvulsant following sound stimulus (> or =0.1mg/kg). These findings identify a potential role for mGlu(2/3) agonists in the amelioration of generalised and partial epileptic seizures.

Changes in Energy Demand of Dance Activity and Cardiorespiratory Fitness During 1 Year of Vocational Contemporary Dance Training.

PubMed

Beck, Sarah; Wyon, Matthew A; Redding, Emma

2018-03-01

Beck, S, Wyon, MA, and Redding, E. Changes in energy demand of dance activity and cardiorespiratory fitness during 1 year of vocational contemporary dance training. J Strength Cond Res 32(3): 841-848, 2018-Previous literature has demonstrated that the intensity of dance class as well as its discontinuous nature is not sufficient to elicit an aerobic training response and that the aerobic capacity of dancers is relatively low. These findings have raised questions on the suitability of training, through class and rehearsal, as adequate preparation for the physical demands of performance and a sustained, successful career in dance. The aim of this study was to describe changes in aerobic fitness and energy cost of dance movement occurring throughout 1 year of training. Subjects were 13 female dance students; 7 first-year undergraduate (UG) students, and 6 postgraduate (PG) students. At 3 time points (TP1, TP2, and TP3) during 1 academic year, each subject completed a treadmill test to determine V[Combining Dot Above]O2peak (ml·kg·min) and lactate threshold (LT) (ml·kg·min and %V[Combining Dot Above]O2peak) and a standardized 4-minute dance sequence, where the mean demand was expressed as V[Combining Dot Above]O2 (ml·kg·min), heart rate (b·min), %V[Combining Dot Above]O2peak, and %LT. Both groups displayed an overall decrease in mean V[Combining Dot Above]O2peak throughout the year, despite a peak in fitness at TP2 in the PG students. No significant changes in LT were noted over time for either group. A significant reduction in the relative intensity of the dance sequence, particularly in relation to mean VO2 (ml·kg·min) and %LT data, was observed over time in both groups, although the degree of change was less in the UG group than the PG group. Apparent adaptations during a rehearsal period in the PG group are presented in contrast to previous research findings. Recommendations for future research include further investigation into the energy demand of

Preparation and study of (1 - x)CuFe2O4-xBaTiO3 (x = 0, 0.1 and 1) composite multiferroics

NASA Astrophysics Data System (ADS)

Murtaza, Tahir; Ali, Javid; Khan, M. S.

2018-07-01

The parent and mixed spinel-perovskite composite of (1 - x)CuFe2O4-xBaTiO3 (x = 0, 0.1 and 1) has been prepared by solid-state reaction method and studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), Mössbauer spectroscopy, magnetometry and P-E lope tracer. The XRD results showed the formation of single phase tetragonal spinel CuFe2O4 and tetragonal perovskite BaTiO3 at room temperature, further XRD of composite 0.1CuFe2O4-0.9BaTiO3 reflects the two crystallographic phases with 1:9 ratio. The SEM micrographs show the homogeneous and uniform formation of the samples. Through EDAX analysis, the chemical composition of the sample is found to be same as the nominal composition. The high field Mossbauer data of CuFe2O4 sample shows the ferrimagnetic ordering in the sample. The observed M-H and P-E loops of the composite 0.1CuFe2O4-0.9BaTiO3 sample show the presence of spontaneous magnetization and spontaneous electric polarization indicating the multiferroic nature of the sample.

The phase structure and electrochemical performance of xLi2MnO3·(1 - x)LiNi1/3Co1/3Mn1/3O2 during the synthesis and charge-discharge process

NASA Astrophysics Data System (ADS)

Yuan, Ting; Liu, HongQuan; Gu, YiJie; Cui, HongZhi; Wang, YanMin

2016-09-01

The lithium-rich layered xLi2MnO3·(1 - x)LiNi1/3Co1/3Mn1/3O2 materials were simply prepared by the molten-salt method. The effects of reaction temperature and x value on the phase structure and electrochemistry were systemically studied by X-ray diffraction, galvanostatical charge/discharge and electrochemical impedance spectroscopy (EIS). It has been found that the obtained phase is sensitive to the reaction temperature and composition. A layered rock-salt form with hexagonal α-NaFeO2-type structure occurs at 700 °C, while a spinel LiMn2O4 becomes the main phase at 800 °C. Besides, a spinel Li4Mn5O12 component can be found in the lithium-rich layered material when x value decreases to 0.4. The 0.4Li2MnO3·0.6LiNi1/3Co1/3Mn1/3O2 material can deliver a high initial discharge capacity of 218 mAhg-1 under 20 mAg-1 current rate, then increase to the maximum 241 mAhg-1 after 4 cycles. It is confirmed by different cycle d Q/d V profile change that the layer rock-salt transforms into the two phases with the layer rock-salt phase and the spinel phase step by step. According to the EIS analysis, the 0.4Li2MnO3·0.6LiNi1/3Co1/3Mn1/3O2 sample with the better electrochemical performance shows the smaller charge transfer resistance and Warburg impedance associated with Li-ion diffusion through cathode, which is attributed to contribution from a fast 3D Li-ion diffusion channel of appropriate Li4Mn5O12 phase.

Production, purification and characterization of fibrinolytic enzyme from Serratia sp. KG-2-1 using optimized media.

PubMed

Taneja, Kapila; Bajaj, Bijender Kumar; Kumar, Sandeep; Dilbaghi, Neeraj

2017-07-01

Intravascular thrombosis is one of the major causes of variety of cardiovascular disorders leading to high mortality worldwide. Fibrinolytic enzymes from microbial sources possess ability to dissolve these clots and help to circumvent these problems in more efficient and safer way. In the present study, fibrinolytic protease with higher fibrinolytic activity than plasmin was obtained from Serratia sp. KG-2-1 isolated from garbage dump soil. Response surface methodology was used to study the interactive effect of concentration of maltose, yeast extract + peptone (1:1), incubation time, and pH on enzyme production and biomass. Maximum enzyme production was achieved at 33 °C after 24 h at neutral pH in media containing 1.5% Maltose, 4.0% yeast extract + peptone and other trace elements resulting in 1.82 folds increased production. The enzyme was purified from crude extract using ammonium sulfate precipitation and DEAE-Sephadex chromatography resulting in 12.9 fold purification with 14.9% yield. The purified enzyme belongs to metalloprotease class and had optimal activity in conditions similar to physiological environment with temperature optima of 40 °C and pH optima of 8. The enzyme was found to be stable in various solvents and its activity was enhanced in presence of Na + , K + , Ba 2+ , Cu 2+ , Mn 2+ , Hg 2+ but inhibited by Ca 2+ and Fe 3+ . Hence, the obtained enzyme may be used as potential therapeutic agent in combating various thrombolytic disorders.

Comparison of Three Popular Exercise Modalities on V˙O2max in Overweight and Obese.

PubMed

Bækkerud, Fredrik Hjulstad; Solberg, Frederic; Leinan, Ingeborg Megård; Wisløff, Ulrik; Karlsen, Trine; Rognmo, Øivind

2016-03-01

In this prospective randomized trial, we examined the effect of three popular exercise training modalities on maximal oxygen uptake (V˙O2max) in overweight and obese individuals. In addition, we examined possible concomitant adaptations in endurance exercise performance (time to exhaustion (TTE)), citrate synthase (CS) activity, venous and arterial function, blood volume, and calculated stroke volume (SV). Thirty subjects were recruited (age, 41 ± 9 yr; weight, 91 ± 14 kg; height, 173 ± 8 cm; body mass index, 30 ± 4 kg·m(-2)) and randomized to either 6 wk of 4 × 4-min high-intensity interval training (4HIIT) at 85%-95% of HRmax, 10 × 1-min HIIT (1HIIT) at V˙O2max load, or 45-min moderate-intensity continuous training (MICT) at 70% of HRmax. V˙O2max, TTE, CS activity, venous and arterial function, as well as blood volume were measured before and after the training period. O2 pulse was calculated and used to estimate SV. Analysis was conducted per protocol. Only 4HIIT increased V˙O2max (P < 0.01) and significantly more compared with 1HIIT (P = 0.04) and MICT (P = 0.03) (4HIIT, 10%; 1HIIT, 3.3%; and MICT, 3.1%). All groups increased TTE (4HIIT, 198%; 1HIIT, 116%; MICT, 52%), with a higher increase after 4HIIT compared with that after MICT (P = 0.02). Calculated SV increased only after 4HIIT (14.4%). Plasma volume and hemoglobin mass increased after 1HIIT only (5.6% and 6.5%); however, no group differences were found. All groups increased CS activity (4HIIT, 35%; 1HIIT, 35%; MICT, 56%), with no group differences. Arterial inflow (15.7%) and venous outflow (22.7%) decreased after MICT, but there were no group differences. 4HIIT was superior to 1HIIT and MICT in improving V˙O2max likely because of an increased SV.

Hierarchical domain structure of lead-free piezoelectric (Na{sub 1/2} Bi{sub 1/2})TiO{sub 3}-(K{sub 1/2} Bi{sub 1/2})TiO{sub 3} single crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Chengtao, E-mail: lchentao@vt.edu; Wang, Yaojin; Ge, Wenwei

2016-05-07

We report a unique hierarchical domain structure in single crystals of (Na{sub 1/2}Bi{sub 1/2})TiO{sub 3}-xat. %(K{sub 1/2}Bi{sub 1/2})TiO{sub 3} for x = 5 and 8 by transmission electron microscopy (TEM). A high density of polar nano-domains with a lamellar morphology was found, which were self-assembled into a quadrant-like configuration, which then assembled into conventional ferroelectric macro-domains. Studies by high resolution TEM revealed that the polar lamellar regions contained a coexistence of in-phase and anti-phase oxygen octahedral tilt regions of a few nanometers in size. Domain frustration over multiple length scales may play an important role in the stabilization of the hierarchy, andmore » in reducing the piezoelectric response of this Pb-free piezoelectric solid solution.« less

The flux jumps in high Tc Bi(1.7)Pb(0.3)Sr2 Ca2Cu3O(y) bulk superconductor

NASA Astrophysics Data System (ADS)

Cao, Xiaowen; Huang, Sunli

1989-11-01

There were giant flux jumps in high T sub c Bi(1.7)Pb(0.3)Sr2Ca2Cu3O(v) bulk superconductor. The relaxation time, tau, decreased with both the increase of magnetic field and the rise of temperature. The maximum tau was about 40 min. The average -dM/dt increased with both the increase of magnetic field and the rise of temperature. The minimum average -dM/dt was about 4.1 x 10(exp -2) G/min. The flux jump weakened with time. It was dependent on the decrease of gradient of magnetic flux density dn/dx in the sample.

Isometric strength training lowers the O2 cost of cycling during moderate-intensity exercise.

PubMed

Zoladz, Jerzy A; Szkutnik, Zbigniew; Majerczak, Joanna; Grandys, Marcin; Duda, Krzysztof; Grassi, Bruno

2012-12-01

The effect of maximal voluntary isometric strength training of knee extensor muscles on pulmonary V'O(2) on-kinetics, the O(2) cost of cycling and peak oxygen uptake (V'O(2peak)) in humans was studied. Seven healthy males (mean ± SD, age 22.3 ± 2.0 years, body weight 75.0 ± 9.2 kg, V'O(2peak) 49.5 ± 3.8 ml kg(-1) min(-1)) performed maximal isometric strength training lasting 7 weeks (4 sessions per week). Force during maximal voluntary contraction (MVC) increased by 15 % (P < 0.001) after 1 week of training, and by 19 % (P < 0.001) after 7 weeks of training. This increase in MVC was accompanied by no significant changes in the time constant of the V'O(2) on-kinetics during 6 min of moderate and heavy cycling intensities. Strength training resulted in a significant decrease (by ~7 %; P < 0.02) in the amplitude of the fundamental component of the V'O(2) on-kinetics, and therefore in a lower O(2) cost of cycling during moderate cycling intensity. The amplitude of the slow component of V'O(2) on-kinetics during heavy cycling intensity did not change with training. Training had no effect on the V'O(2peak), whereas the maximal power output reached at V'O(2peak) was slightly but significantly increased (P < 0.05). Isometric strength training rapidly (i.e., after 1 week) decreases the O(2) cost of cycling during moderate-intensity exercise, whereas it does not affect the amplitude of the slow component of the V'O(2) on-kinetics during heavy-intensity exercise. Isometric strength training can have beneficial effects on performance during endurance events.

High-pressure synthesis and electrochemical behavior of layered (1-a)LiNi{sub 1-y}Al{sub y}O{sub 2}.aLi[Li{sub 1/3}Ni{sub 2/3}]O{sub 2} oxides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shinova, E.; Zhecheva, E.; Stoyanova, R.

Layered (1-a)LiNi{sub 1-y}Al{sub y}O{sub 2}.aLi[Li{sub 1/3}Ni{sub 2/3}]O{sub 2} oxides, 0=O, Al{sub 2}O{sub 3} and Li{sub 2}O{sub 2} under high pressure. The structural characterization of the layered oxides was performed using powder XRD, IR spectroscopy and EPR spectroscopy at 9.23 and 115GHz. It has been found that the high-pressure favors Al substitution for Ni in the NiO{sub 2}-layers of layered LiNiO{sub 2}. A random Al/Ni distribution in the layer was found. The incorporation of extra Li in the Ni{sub 1-y}Al{sub y}O{sub 2}-layer starts at a precursor composition Li/(Ni+Al)>1.2. While pure NiO{sub 2}-layersmore » are able to incorporate under high-pressure up to 1/3Li, the appearance of Al in the NiO{sub 2}-layers hinders Li{sup +} dissolution (Li<(1-y)/3). In addition, with increasing Al content there is a strong cationic mixing between the layers. High-frequency EPR of Ni{sup 3+} indicates that the structural interaction of LiAl{sub y}Ni{sub 1-y}O{sub 2} with Li[Li{sub 1/3}Ni{sub 2/3}]O{sub 2} proceeds via the formation of domains comprising different amount of Ni{sup 3+} ions. The use of Li{sub 1.08}Al{sub 0.09}Ni{sub 0.83}O{sub 2} as a cathode material in a lithium ion cells displays a first irreversible Li extraction at 4.8V, after which a reversible lithium insertion/extraction between 3.0 and 4.5V is observed on further cycling.« less

Effect of Bi(Mg1/2Ti1/2)O3 addition on the electrical properties of Si-Mn modified on SrTiO3

NASA Astrophysics Data System (ADS)

Roh, Yoon-ah; Masaki, Takaki; Yoon, Dae-Ho

2015-05-01

Single-Crystalline Strontium titanate (SrTiO3) has been widely used in many fields such as catalyst, semiconductors and dielectrics. SrTiO3 is a typical perovskite-type oxide, the physical properties of which strongly depend on its chemical composition, structure, shape, size, and crystallinity. In this work, the effects of Bi(Mg1/2Ti1/2)O3 addition on the nanostructure and the dielectric properties of Si-Mn modified SrTiO3 were investigated to develop nano-sized particles and low-temperature-fired SrTiO3-based ceramics with stable temperature characteristics. The dielectric constant of SrTiO3-Bi(Mg1/2Ti1/2)O3 was found to range from 900 to 1200 at 1 kHz for samples sintered at 1200°C. This new composition, SrTiO3-Bi(Mg1/2Ti1/2)O3, can be applied as a nano-sized dielectric materials in various fields.

Infrared predissociation spectroscopy of M+ (C6H6)(1-4)(H2O)(1-2)Ar(0-1) cluster ions, M = Li, Na.

PubMed

Beck, Jordan P; Lisy, James M

2011-05-05

Infrared predissociation (IRPD) spectra of Li(+)(C(6)H(6))(1-4)(H(2)O)(1-2)Ar(0-1) and Na(+)(C(6)H(6))(2-4)(H(2)O)(1-2)Ar(1) are presented along with ab initio calculations. The results indicate that the global minimum energy structure for Li(+)(C(6)H(6))(2)(H(2)O)(2) has each water forming a π-hydrogen bond with the same benzene molecule. This bonding motif is preserved in Li(+)(C(6)H(6))(3-4)(H(2)O)(2)Ar(0-1) with the additional benzene ligands binding to the available free OH groups. Argon tagging allows high-energy Li(+)(C(6)H(6))(2-4)(H(2)O)(2)Ar isomers containing water-water hydrogen bonds to be trapped and detected. The monohydrated, Li(+) containing clusters contain benzene-water interactions with varying strength as indicated by shifts in OH stretching frequencies. The IRPD spectra of M(+)(C(6)H(6))(1-4)(H(2)O)(1-2)Ar are very different for lithium-bearing versus sodium-bearing cluster ions emphasizing the important role of ion size in determining the most favorable balance of competing noncovalent interactions.

The influence of excess K2O on the electrical properties of (K,Na)1/2Bi1/2TiO3 ceramics

NASA Astrophysics Data System (ADS)

Li, Linhao; Li, Ming; Sinclair, Derek C.

2018-04-01

The solid solution (KxNa0.50-x)Bi0.50TiO3 (KNBT) between Na1/2Bi1/2TiO3 and K1/2Bi1/2TiO3 (KBT) has been extensively researched as a candidate lead-free piezoelectric material because of its relatively high Curie temperature and good piezoelectric properties, especially near the morphotropic phase boundary (MPB) at x ˜ 0.10 (20 mol. % KBT). Here, we show that low levels of excess K2O in the starting compositions, i.e., (Ky+0.03Na0.50-y)Bi0.50TiO3.015 (y-series), can significantly change the conduction mechanism and electrical properties compared to a nominally stoichiometric KNBT series (KxNa0.50-x)Bi0.50TiO3 (x-series). Impedance spectroscopy measurements reveal significantly higher bulk conductivity (σb) values for y ≥ 0.10 samples [activation energy (Ea) ≤ 0.95 eV] compared to the corresponding x-series samples which possess bandgap type electronic conduction (Ea ˜ 1.26-1.85 eV). The largest difference in electrical properties occurs close to the MPB composition (20 mol. % KBT) where y = 0.10 ceramics possess σb (at 300 °C) that is 4 orders of magnitude higher than that of x = 0.10 and the oxide-ion transport number in the former is ˜0.70-0.75 compared to <0.05 in the latter (between 600 and 800 °C). The effect of excess K2O can be rationalised on the basis of the (K + Na):Bi ratio in the starting composition prior to ceramic processing. This demonstrates the electrical properties of KNBT to be sensitive to low levels of A-site nonstoichiometry and indicates that excess K2O in KNBT starting compositions to compensate for volatilisation can lead to undesirable high dielectric loss and leakage currents at elevated temperatures.

Gamma-hydroxybutyric acid in male and female cynomolgus monkeys trained to discriminate 1.0 or 2.0 g/kg ethanol.

PubMed

Helms, Christa M; Rogers, Laura S M; Grant, Kathleen A

2008-07-01

Gamma-hydroxybutyric acid has been proposed as a pharmacotherapy for alcoholism in part based on similar discriminative stimulus effects as ethanol. To date, drug discrimination studies with gamma-hydroxybutyric acid and ethanol have exclusively used rodents or pigeons as subjects. To evaluate possible differences between species, sex, and route of administration, this study investigated the substitution of gamma-hydroxybutyric acid (intragastrically or intramuscularly) for ethanol 30 or 60 min after administration in male (n=6) and female (n=7) cynomolgus monkeys trained to discriminate 1.0 and 2.0 g/kg ethanol. At least one dose of gamma-hydroxybutyric acid completely or partially substituted for ethanol in three of the 13 monkeys tested, with each case occurring in female monkeys. Ethanol-appropriate responding did not increase with gamma-hydroxybutyric acid dose. Monkeys were more sensitive to the response rate decreasing effects of gamma-hydroxybutyric acid administered intramuscularly compared with intragastrically. The lack of gamma-hydroxybutyric acid substitution for ethanol suggests that these drugs have different receptor bases for discrimination. Furthermore, the data do not strongly support shared discriminative stimulus effects as the rationale for gamma-hydroxybutyric acid pharmacotherapy for alcoholism.

Prevalence of O1/K1- and O2/K3-Reactive Actinobacillus suis in Healthy and Diseased Swine

PubMed Central

Slavić, ĐurĐa; Toffner, Tania L.; Monteiro, Mario A.; Perry, Malcolm B.; MacInnes, Janet I.

2000-01-01

A cell surface antigen-typing system was devised for the swine pathogen Actinobacillus suis and used to examine the prevalence of different lipopolysaccharide (O) types in healthy and diseased pigs. The strains examined in this study were isolated from a variety of locations in Canada and from Kansas. Lipopolysaccharide preparations of 151 isolates of A. suis were characterized by immunoblotting using polyclonal antisera generated to strains SO4 (O1/K1), H89-1173 (O2/K3), and VSB 3714, a rough strain. Approximately 54% (62 of 114) of A. suis isolates from diseased pigs, all (11 of 11) isolates from healthy pigs, and all (4 of 4) reference strains reacted with O1/K1 antiserum. More than 80% (18 of 22) of A. suis strains used for bacterin production and approximately 41% (47 of 114) of isolates from diseased pigs bound O2/K3 antiserum. One isolate appeared to be rough, and five were untypeable. O1/K1- and O2/K3-reactive strains were equally prevalent in Kansas, whereas O2/K3-reactive strains were more common in Québec and western Canada and O1/K1 strains were most common in Ontario. The fact that virtually all of the strains submitted for bacterin production were O2/K3-reactive strains is consistent with the notion that these strains may be more virulent than O1/K1 strains; alternatively, this may reflect geographic or other biases. In addition, we observed cross-reactivity between A. suis cell surface antigens and swine antisera to several other important pathogens. This finding may explain why previous attempts to develop a simple serodiagnostic test for A. suis have been unsuccessful. PMID:11015398

Poly[[sesqui[mu2-1,4-bis(imidazol-1-ylmethyl)benzene-kappa(2)N:N'](carbonato-kappa(2)O,O')copper(II)] 1,4-bis(imidazol-1-ylmethyl)benzene hemisolvate pentahydrate].

PubMed

Dai, Yu-Mei; Tang, En; Huang, Jin-Feng; Yang, Qiu-Yan

2008-10-01

The asymmetric unit of the title compound, {[Cu(CO(3))(C(14)H(14)N(4))(1.5)] x 0.5 C(14)H(14)N(4) x 5 H(2)O}(n), contains one Cu(II) cation in a slightly distorted square-pyramidal coordination environment, one CO(3)(2-) anion, one full and two half 1,4-bis(imidazol-1-ylmethyl)benzene (bix) ligands, one half-molecule of which is uncoordinated, and five uncoordinated water molecules. One of the coordinated bix ligands and the uncoordinated bix molecule are situated about centers of symmetry, located at the centers of the benzene rings. The coordinated bix ligands link the copper(II) ions into a [Cu(bix)(1.5)](n) molecular ladder. These molecular ladders do not form interpenetrated ladders but are arranged in an ABAB parallel terrace, i.e. with the ladders arranged one above another, with sequence A translated with respect to B by 8 A. To best of our knowledge, this arrangement has not been observed in any of the molecular ladder frameworks synthesized to date. The coordination environment of the Cu(II) atom is completed by two O atoms of the CO(3)(2-) anion. The framework is further strengthened by extensive O-H...O and O-H...N hydrogen bonds involving the water molecules, the O atoms of the CO(3)(2-) anion and the N atoms of the bix ligands. This study describes the first example of a molecular ladder coordination polymer based on bix and therefore demonstrates further the usefulness of bix as a versatile multidentate ligand for constructing coordination polymers with interesting architectures.

Theoretical prediction of morphotropic compositions in Na1/2Bi1/2TiO3-based solid solutions from transition pressures

NASA Astrophysics Data System (ADS)

Gröting, Melanie; Albe, Karsten

2014-02-01

In this article we present a method based on ab initio calculations to predict compositions at morphotropic phase boundaries in lead-free perovskite solid solutions. This method utilizes the concept of flat free energy surfaces and involves the monitoring of pressure-induced phase transitions as a function of composition. As model systems, solid solutions of Na1/2Bi1/2TiO3 with the alkali substituted Li1/2Bi1/2TiO3 and K1/2Bi1/2TiO3 and the alkaline earth substituted CaTiO3 and BaTiO3 are chosen. The morphotropic compositions are identified by determining the composition at which the phase transition pressure equals zero. In addition, we discuss the different effects of hydrostatic pressure (compression and tension) and chemical substitution on the antiphase tilts about the [111] axis (a-a-a-) present in pure Na1/2Bi1/2TiO3 and how they develop in the two solid solutions Na1/2Bi1/2TiO3-CaTiO3 and Na1/2Bi1/2TiO3-BaTiO3. Finally, we discuss the advantages and shortcomings of this simple computational approach.

Plant Aquaporin AtPIP1;4 Links Apoplastic H2O2 Induction to Disease Immunity Pathways1[OPEN

PubMed Central

Tian, Shan; Wang, Xiaobing; Li, Ping; Wang, Hao; Ji, Hongtao; Xie, Junyi; Qiu, Qinglei

2016-01-01

Hydrogen peroxide (H2O2) is a stable component of reactive oxygen species, and its production in plants represents the successful recognition of pathogen infection and pathogen-associated molecular patterns (PAMPs). This production of H2O2 is typically apoplastic but is subsequently associated with intracellular immunity pathways that regulate disease resistance, such as systemic acquired resistance and PAMP-triggered immunity. Here, we elucidate that an Arabidopsis (Arabidopsis thaliana) aquaporin (i.e. the plasma membrane intrinsic protein AtPIP1;4) acts to close the cytological distance between H2O2 production and functional performance. Expression of the AtPIP1;4 gene in plant leaves is inducible by a bacterial pathogen, and the expression accompanies H2O2 accumulation in the cytoplasm. Under de novo expression conditions, AtPIP1;4 is able to mediate the translocation of externally applied H2O2 into the cytoplasm of yeast (Saccharomyces cerevisiae) cells. In plant cells treated with H2O2, AtPIP1;4 functions as an effective facilitator of H2O2 transport across plasma membranes and mediates the translocation of externally applied H2O2 from the apoplast to the cytoplasm. The H2O2-transport role of AtPIP1;4 is essentially required for the cytoplasmic import of apoplastic H2O2 induced by the bacterial pathogen and two typical PAMPs in the absence of induced production of intracellular H2O2. As a consequence, cytoplasmic H2O2 quantities increase substantially while systemic acquired resistance and PAMP-triggered immunity are activated to repress the bacterial pathogenicity. By contrast, loss-of-function mutation at the AtPIP1;4 gene locus not only nullifies the cytoplasmic import of pathogen- and PAMP-induced apoplastic H2O2 but also cancels the subsequent immune responses, suggesting a pivotal role of AtPIP1;4 in apocytoplastic signal transduction in immunity pathways. PMID:26945050

Role of point defects in bipolar fatigue behavior of Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3} modified (Bi{sub 1/2}K{sub 1/2})TiO{sub 3}-(Bi{sub 1/2}Na{sub 1/2})TiO{sub 3} relaxor ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Nitish, E-mail: nitishkumar.iitk@gmail.com; Ansell, Troy Y.; Cann, David P.

Lead-free Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3}-(Bi{sub 1/2}K{sub 1/2})TiO{sub 3}-(Bi{sub 1/2}Na{sub 1/2})TiO{sub 3} (BMT-BKT-BNT) ceramics have been shown to exhibit large electromechanical strains under high electric fields along with negligible fatigue under strong electric fields. To investigate the role of point defects on the fatigue characteristics, the composition 5BMT-40BKT-55BNT was doped to incorporate acceptor and donor defects on the A and B sites by adjusting the Bi/Na and Ti/Mg stoichiometries. All samples had pseudo-cubic symmetries based on x-ray diffraction, typical of relaxors. Dielectric measurements showed that the high and low temperature phase transitions were largely unaffected by doping. Acceptor doping resulted inmore » the observation of a typical ferroelectric-like polarization with a remnant polarization and strain hysteresis loops with significant negative strain. Donor-doped compositions exhibited characteristics that were indicative of an ergodic relaxor phase. Fatigue measurements were carried out on all of the compositions. While the A-site acceptor-doped composition showed a small degradation in maximum strain after 10{sup 6} cycles, the other compositions were essentially fatigue free. Impedance measurements were used to identify the important conduction mechanisms in these compositions. As expected, the presence of defects did not strongly influence the fatigue behavior in donor-doped compositions owing to the nature of their reversible field-induced phase transformation. Even for the acceptor-doped compositions, which had stable domains in the absence of an electric field at room temperature, there was negligible degradation in the maximum strain due to fatigue. This suggests that either the defects introduced through stoichiometric variations do not play a prominent role in fatigue in these systems or it is compensated by factors like decrease in coercive field, an increase in ergodicity, symmetry change, or other factors.« less

[Determination of fumonisins B1 and B2 in corn by high performance liquid chromatography with post-column derivatization method].

PubMed

Zhang, Xiaoxu; Xiao, Zhiyong; Zhang, Hongyan; Yang, Lili; Ma, Liyan

2012-08-01

A high performance liquid chromatography-fluorescence detection with post-column derivatization method was developed to detect fumonisin B1 (FB1) and fumonisin B2 (FB2) in corn. Several factors, such as the pH of derivatization buffer, concentration and flow rate of derivatization reagents, excitation wavelength, emission wavelength, which affected the detection of fumonisins were optimized. The separation was performed on a ZORBAX SB C18 column operated at 40 degrees C with the gradient elution by two mobile phases of 0.1 mol/L sodium dihydrogen phosphate solution (pH 3.3) and methanol at a flow rate of 0.8 mL/min. The derivatization was performed at ambient temperature. The o-phthalaldehyde (OPA) flow rate was 0.4 mL/min. The results showed that the optimum conditions were pH 10.5 of the derivatization reagent, OPA concentration at 2 g/L, and excitation wavelength of 335 nm, emission wavelength of 440 nm. The linear plots of FB1 and FB2 were obtained between 0.2 to 20 mg/L, with the correlation coefficients above 0.999 for both FB1 and FB2. The limits of detection of fumonisins B1 and B2 were 0.02 mg/kg. The mean recoveries at the three spiked levels of 0.1 - 4.0 mg/kg were 82.5% - 89.8%. This method is accurate, simple, rapid and suitable for the determination of fumonisins B1 and B2 in corn.

Calcite Phase Conversion Prediction Model for CaO-Al2O3-SiO2 Slag: An Aqueous Carbonation Process at Ambient Pressure

NASA Astrophysics Data System (ADS)

Zhang, Huining; Dong, Jianhong; Li, Hui; Xiong, Huihui; Xu, Anjun

2018-06-01

To evaluate the effect of the mineralogical phase on carbonation efficiency for CaO-Al2O3-SiO2 slag, a calcite phase conversion prediction model is proposed. This model combines carbon dioxide solubility with carbonation reaction kinetic analysis to improve the prediction capability. The effect of temperature and carbonation time on the carbonation degree is studied in detail. Results show that the reaction rate constant ranges from 0.0135 h-1 to 0.0458 h-1 and that the mineralogical phase contribution sequence for the carbonation degree is C2S, CaO, C3A and CS. The model accurately predicts the effect of temperature and carbonation time on the simulated calcite conversion, and the results agree with the experimental data. The optimal carbonation temperature and reaction time are 333 K and 90 min, respectively. The maximum carbonation efficiency is about 184.3 g/kg slag, and the simulation result of the calcite phase content in carbonated slag is about 20%.

1H,1H,5H-Perfluoropentyl-1,1,2,2-tetrafluoroethylether as a co-solvent for high voltage LiNi1/3Co1/3Mn1/3O2/graphite cells

NASA Astrophysics Data System (ADS)

Wang, Chengyun; Zuo, Xiaoxi; Zhao, Minkai; Xiao, Xin; Yu, Le; Nan, Junmin

2016-03-01

1H,1H,5H-Perfluoropentyl-1,1,2,2-tetrafluoroethylether (F-EAE) mixed with ethylene carbonate (EC), diethyl carbonate (DEC), and lithium hexafluorophosphate (LiPF6) is evaluated as a co-solvent high-potential electrolyte of LiNi1/3Co1/3Mn1/3O2/graphite batteries. Linear sweep voltammetry (LSV) and cyclic voltammetry (CV) indicate that the EC/DEC-based electrolyte with F-EAE possesses a high oxidation potential (>5.2 V vs. Li/Li+) and excellent film-forming characteristics. With 40 wt% F-EAE in the electrolyte, the capacity retention of the LiNi1/3Co1/3Mn1/3O2/graphite pouch cells that are cycled between 3.0 and 4.5 V is significantly improved from 28.8% to 86.8% after 100 cycles. In addition, electrochemical impedance spectroscopy (EIS) of three-electrode pouch cells, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) are used to characterize the effects of F-EAE on the enhanced capacity retention. It is demonstrated that F-EAE facilitates the formation of a stable surface electrolyte interface (SEI) layer with low impedance on the anode and effectively suppresses an increase in the charge-transfer resistance on the cathode. These results suggest that F-EAE can serve as an alternative electrolyte solvent for 4.5 V high voltage rechargeable lithium-ion batteries.

Structure of (Ga2O3)2(ZnO)13 and a unified description of the homologous series (Ga2O3)2(ZnO)(2n + 1).

PubMed

Michiue, Yuichi; Kimizuka, Noboru; Kanke, Yasushi; Mori, Takao

2012-06-01

The structure of (Ga(2)O(3))(2)(ZnO)(13) has been determined by a single-crystal X-ray diffraction technique. In the monoclinic structure of the space group C2/m with cell parameters a = 19.66 (4), b = 3.2487 (5), c = 27.31 (2) Å, and β = 105.9 (1)°, a unit cell is constructed by combining the halves of the unit cell of Ga(2)O(3)(ZnO)(6) and Ga(2)O(3)(ZnO)(7) in the homologous series Ga(2)O(3)(ZnO)(m). The homologous series (Ga(2)O(3))(2)(ZnO)(2n + 1) is derived and a unified description for structures in the series is presented using the (3+1)-dimensional superspace formalism. The phases are treated as compositely modulated structures consisting of two subsystems. One is constructed by metal ions and another is by O ions. In the (3 + 1)-dimensional model, displacive modulations of ions are described by the asymmetric zigzag function with large amplitudes, which was replaced by a combination of the sawtooth function in refinements. Similarities and differences between the two homologous series (Ga(2)O(3))(2)(ZnO)(2n + 1) and Ga(2)O(3)(ZnO)(m) are clarified in (3 + 1)-dimensional superspace. The validity of the (3 + 1)-dimensional model is confirmed by the refinements of (Ga(2)O(3))(2)(ZnO)(13), while a few complex phenomena in the real structure are taken into account by modifying the model.

MinION Analysis and Reference Consortium: Phase 1 data release and analysis

PubMed Central

Eccles, David A.; Zalunin, Vadim; Urban, John M.; Piazza, Paolo; Bowden, Rory J.; Paten, Benedict; Mwaigwisya, Solomon; Batty, Elizabeth M.; Simpson, Jared T.; Snutch, Terrance P.

2015-01-01

The advent of a miniaturized DNA sequencing device with a high-throughput contextual sequencing capability embodies the next generation of large scale sequencing tools. The MinION™ Access Programme (MAP) was initiated by Oxford Nanopore Technologies™ in April 2014, giving public access to their USB-attached miniature sequencing device. The MinION Analysis and Reference Consortium (MARC) was formed by a subset of MAP participants, with the aim of evaluating and providing standard protocols and reference data to the community. Envisaged as a multi-phased project, this study provides the global community with the Phase 1 data from MARC, where the reproducibility of the performance of the MinION was evaluated at multiple sites. Five laboratories on two continents generated data using a control strain of Escherichia coli K-12, preparing and sequencing samples according to a revised ONT protocol. Here, we provide the details of the protocol used, along with a preliminary analysis of the characteristics of typical runs including the consistency, rate, volume and quality of data produced. Further analysis of the Phase 1 data presented here, and additional experiments in Phase 2 of E. coli from MARC are already underway to identify ways to improve and enhance MinION performance. PMID:26834992

Heat capacities and thermal conductivities of AmO 2 and AmO 1.5

NASA Astrophysics Data System (ADS)

Nishi, Tsuyoshi; Itoh, Akinori; Ichise, Kenichi; Arai, Yasuo

2011-07-01

The thermal diffusivity of AmO 2 was measured from 473 to 773 K and that of AmO 1.5 between 473 and 1373 K using a laser flash method. The enthalpy increment of AmO 2 was measured from 335 to 1081 K and that of AmO 1.5 between 335 and 1086 K using drop calorimetry. The heat capacities of AmO 2 and AmO 1.5 were derived from the enthalpy increment measurements. The thermal conductivity was determined from the measured thermal diffusivity, heat capacity and bulk density. The heat capacities of AmO 2 was found larger than that of AmO 1.5. The thermal conductivities of AmO 2 and AmO 1.5 were found to decrease with increasing temperature in the investigated temperature range. The thermal conductivity of AmO 1.5 with A -type hexagonal structure was smaller than that of AmO 2 with C-type fluorite structure but larger than that of sub-stoichiometric AmO 1.73.

A Sequential Method to Prepare Polymorphs and Solvatomorphs of [Fe(1,3-bpp)2 ](ClO4 )2 ⋅nH2 O (n=0, 1, 2) with Varying Spin-Crossover Behaviour.

PubMed

Bartual-Murgui, Carlos; Codina, Carlota; Roubeau, Olivier; Aromí, Guillem

2016-08-26

Two polymorphs of the spin crossover (SCO) compound [Fe(1,3-bpp)2 ](ClO4 )2 (1 and 2; 1,3-bpp=2-(pyrazol-1-yl)-6-(pyrazol-3-yl)pyridine) were prepared using a novel, stepwise procedure. Crystals of 1 deposit from dry solvents, while 2 is obtained from a solid-state procedure, by sequentially removing lattice H2 O molecules from the solvatomorph [Fe(1,3-bpp)2 ](ClO4 )2 ⋅2 H2 O (2⋅2 H2 O), using single-crystal-to-single-crystal (SCSC) transformations. Hydrate 2⋅2 H2 O is obtained through the same reaction as 1, now with 2.5 % of water added. Compounds 2 and 2⋅2 H2 O are unstable in the atmosphere and absorb or lose one equivalent of water, respectively, to both yield the stable solvatomorph [Fe(1,3-bpp)2 ](ClO4 )2 ⋅H2 O (2⋅H2 O), also following SCSC processes. The four derivatives have been characterised by single-crystal X-ray diffraction (SCXRD). Furthermore, the homogeneity of the various compounds as well as their SCSC interconversions have been confirmed by powder X-ray diffraction (PXRD). Polymorphs 1 and 2 exhibit abrupt SCO behaviour near room temperature with T1/2↑ =279/316 K and T1/2↓ =276/314 K (near 40 K of shift) and different cooperativity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Vibrational mode frequencies of H2S and H2O adsorbed on Ge(0 0 1)-(2 × 1) surfaces

NASA Astrophysics Data System (ADS)

Hartnett, M.; Fahy, S.

2015-02-01

The equilibrium geometry and vibrational modes of H2S and H2O-terminated Ge(0 0 1)-(2 × 1) surfaces are calculated in a supercell approach using first-principles density functional theory in the local density (LDA), generalized gradient (GGA) approximations and van der Waals (vdW) interactions. Mode frequencies are found using the frozen phonon method. For the H2S-passivated surface, the calculated frequencies in LDA (GGA) are 2429 cm-1 (2490) for the Hsbnd S stretch mode, 712 cm-1 (706) for the Hsbnd S bond bending mode, 377 cm-1 (36) for the Gesbnd S stretch mode and 328 cm-1 (337) for Hsbnd S wag mode. Frequencies for the H2O passivated surface are 3590 cm-1 (3600) for the Hsbnd O stretch mode, 921 cm-1 (947) for the bending mode, 609 cm-1 (559) for the Gesbnd O stretch, 1995 cm-1 (1991) for the Gesbnd H stretch mode, 498 cm-1 (478) for the Gesbnd H bending mode and 342 cm-1 (336) for the Hsbnd O wag mode. The differences between the functionals including vdW terms and the LDA or GGA are less than the differences between LDA and GGA for the vibrational mode frequencies.

Preparation of Fe3O4/SiO2-guanidine organobase catalyst for 1,5-diphenylpenta-2,4-dien-1-one synthesis

NASA Astrophysics Data System (ADS)

Cahyana, A. H.; Fitria, D.; Ardiansah, B.; Rahayu, D. U. C.

2017-04-01

A novel heterogeneous organobase catalyst of Fe3O4/SiO2-guanidine was prepared in three stages. First, Fe3O4 nanoparticle was obtained by co-precipitation method using seaweed Sargassum Sp. as natural reductant. Fe3O4 was then coated by SiO2 using TEOS as silica source, resulting Fe3O4/SiO2. Finally, Fe3O4/SiO2-Guanidine was obtained by modifying Fe3O4/SiO2 with guanidine in the suitable reaction condition. This organobase catalyst was characterized by Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDS), and Particle Size Analyzer (PSA). The material was then used as a highly active catalyst in aldol condensation reaction between acetophenone and cinnamaldehyde to produce 1,5-diphenylpenta-2,4-dien-1-one. The structure elucidation of the organic product was confirmed by UV-Vis, FTIR, and LC-MS.

O2(a1Δ) vibrational kinetics in oxygen-iodine laser

NASA Astrophysics Data System (ADS)

Torbin, A. P.; Pershin, A. A.; Heaven, M. C.; Azyazov, V. N.; Mebel, A. M.

2018-04-01

Kinetics of vibrationally-excited singlet oxygen O2(a1Δ,ν) in gas mixture O3/N2/CO2 was studied using a pulse laser technique. Molecules O2(a1Δ,ν) were produced by laser photolysis of ozone at 266 nm. The O3 molecules number density was followed using time-resolved absorption spectroscopy. It was found that an upper bound for the rate constant of chemical reaction O2(a1Δ,ν)+ O3 is about 10-15 cm3/s. The rate constants of O2(a1Δ,ν= 1, 2 and 3) quenching by CO2 are presented.

Achieving ADA/ISPAD clinical guideline goals is associated with higher insulin sensitivity and cardiopulmonary fitness in adolescents with type 1 diabetes: Results from RESistance to InSulin in Type 1 ANd Type 2 diabetes (RESISTANT) and Effects of MEtformin on CardiovasculaR Function in AdoLescents with Type 1 Diabetes (EMERALD) Studies.

PubMed

Bjornstad, Petter; Cree-Green, Melanie; Baumgartner, Amy; Coe, Gregory; Reyes, Yesenia Garcia; Schäfer, Michal; Pyle, Laura; Regensteiner, Judith G; Reusch, Jane Eb; Nadeau, Kristen J

2018-05-01

Most youth with type 1 diabetes do not meet the American Diabetes Association (ADA) and International Society for Pediatric and Adolescent Diabetes (ISPAD) targets for hemoglobin A1c (HbA1c), blood pressure (BP), lipids, and body mass index (BMI). We hypothesized that ISPAD/ADA goal achievement would be associated with better insulin sensitivity (IS) and cardiopulmonary fitness. IS was quantified as glucose infusion rate (GIR) from a hyperinsulinemic-euglycemic clamp in youth with type 1 diabetes from the RESistance to InSulin in Type 1 ANd Type 2 diabetes (RESISTANT) (n = 86) and Effects of MEtformin on CardiovasculaR Function in AdoLescents with Type 1 Diabetes (EMERALD) (n = 41) cohorts (n = 127; age 15.7 ± 2.2 years, 52% girls). Cardiopulmonary fitness was measured as peak oxygen consumption (VO 2 peak/kg) during upright (RESISTANT) or supine (EMERALD) cycle ergometry and were stratified by cycle type. Goal achievement was defined as HbA1c < 7.5%, BP < 90th percentile, LDL-cholesterol < 100 mg/dL, HDL-cholesterol > 35 mg/dL, triglycerides < 150 mg/dL and BMI < 85th percentile. Participants were stratified into 3 groups: achieving 0-3 goals (n = 52), 4 goals (n = 48), and 5-6 goals (n = 27). Differences between groups were examined with generalized linear models. IS was lower in youth who met 0-3 goals (5.2 ± 3.4 mg/kg/min) vs those who met 4 goals (7.4 ± 4.1 mg/kg/min, P = .04) and those who met 5-6 goals (8.5 ± 4.3 mg/kg/min, P = .003), and remained significant after adjustments for sex and diabetes duration. Upright VO 2 peak was lower in youth who met 0-3 goals (25.8 ± 4.6 mL/kg/min) vs those who met 4 goals (33.0 ± 7.8 mL/kg/min, P = .01) and those who met 5-6 goals (33.2 ± 4.4 mL/kg/min, P = .004). Similar and significant relationships were observed in EMERALD participants for supine VO 2 peak. ADA/ISPAD goal achievement was associated with greater IS and cardiopulmonary fitness. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

On the production of N2O from the reaction of O(1 D) with N2

NASA Technical Reports Server (NTRS)

Simonaitis, R.; Lissi, E.; Heicklen, J.

1972-01-01

Ozone was photolyzed at 2537 A and 25 C in the presence of 42-115 torr of O2 and about 880 torr of N2 to test the relative importance of the two reactions: (1) O(1D) + N2 + M yields N2O + M, and (2) O(1D) + N2 yields O(3P) + N2. N2O was not found as a product. Thus from our detectability limit for N2O (0.3 micron), an upper limit to the efficiency of the first reaction relative to the second of 0.0000025 at 1000 torr total pressure was computed. This corresponds to k1/k2 smaller than 0.8 x 10 to the minus 25 power cu cm/particle.

The production of O(1D) from dissociative recombination of O2(+)

NASA Technical Reports Server (NTRS)

Guberman, Steven L.

1987-01-01

The results of large scale ab initio calculations of the rates for production of O(1D) by dissociative combination of O2(+) are presented for electron temperatures in the range 100 to 3000 K. A 1-delta-u state is the dominant dissociative route from v = 0 and a 3-sigma-u(-) state is the most important route from v = 1 and v = 2. The calculated total rate for O(1D) production from v = 0 is 2.21(+0.21,-0.24) x 10(-7) x (T sub e/300) exp -.46 near room temperature. The v = 1 and v = 2 rates are about 17% and 47% smaller respectively, than the v = 0 rate at 300 K.

Note: High-power piezoelectric transformer fabricated with ternary relaxor ferroelectric Pb(Mg(1/3)Nb(2/3))O3-Pb(In(1/2)Nb(1/2))O3-PbTiO3 single crystal.

PubMed

Wang, Qing; Ma, Chuanguo; Wang, Feifei; Liu, Bao; Chen, Jianwei; Luo, Haosu; Wang, Tao; Shi, Wangzhou

2016-03-01

A plate-shaped piezoelectric transformer was designed and fabricated using ternary relaxor ferroelectric single crystal Pb(Mg(1/3)Nb(2/3))O3-Pb(In(1/2)Nb(1/2))O3-PbTiO3. Both the input and output sections utilized the transverse-extensional vibration mode. The frequency and load dependences of the electrical properties for the proposed transformer were systematically studied. Results indicated that under a matching load resistance of 14.9 kΩ, a maximum output power of 2.56 W was obtained with the temperature rise less than 5 °C. The corresponding power density reached up to 50 W/cm(3). This ternary single-crystal transformer had potential applications in compact-size converters requiring high power density.

Tetra­kis(1,1,1-trifluoro­acetyl­acetonato-κ2 O,O′)hafnium(IV) toluene disolvate

PubMed Central

Viljoen, J. Augustinus; Muller, Alfred; Roodt, Andreas

2008-01-01

In the title compound, [Hf(C5H4F3O2)4]·2C7H8, the HfIV atom, lying on a twofold rotation axis, is coordinated by eight O atoms from four 1,1,1-trifluoro­acetyl­acetonate ligands with an average Hf—O distance of 2.173 (1) Å and O—Hf—O bite angles of 75.69 (5) and 75.54 (5)°. The coordination polyhedron shows a slightly distorted Archimedean square antiprismatic geometry. The asymmetric unit contains a toluene solvent mol­ecule. The crystal structure involves C—H⋯.F hydrogen bonds. PMID:21202519

Improving the Efficiency of DASC by Adding CeO2/CuO Hybrid Nanoparticles in Water

NASA Astrophysics Data System (ADS)

Midhun Mohan, V.; Sajeeb, A. M.

Solar energy is the abundantly available source of renewable energy with least impact on environment. Direct absorption solar collector (DASC) is the commonly used device to absorb heat directly from sun and make use of it for different heating applications. In the past, many experiments have been done to increase the efficiency of DASC using nanofluids. In this paper, an examination of solar collector efficiency for hybrid CeO2/CuO-water (0.1% by volume) nanofluid under various flow rates and proportions of CeO2/CuO nanoparticles is investigated. The experiments were conducted at flow rates spanning from 20cc/min to 100cc/min and with CeO2/CuO nanoparticles proportions of 1:0, 1:0.5, 1:1, 0.5:1 and 0:1. The efficiency increases from 16.5% to 51.6% when the flow rate is increased from 20cc/min to 100cc/min for hybrid CeO2/CuO (1:1)-water nanofluid. The results also showed an increase in efficiency of 13.8%, 18.1%, 24.3%, 24.9% and 26.1% with hybrid combination of CeO2/CuO at ratios 1:0, 1:0.5, 1:1, 0.5:1 and 0:1, respectively, in comparison with water at a flow rate of 100cc/min.

Retrieval of O2(1Σ) and O2(1Δ) volume emission rates in the mesosphere and lower thermosphere using SCIAMACHY MLT limb scans

NASA Astrophysics Data System (ADS)

Zarboo, Amirmahdi; Bender, Stefan; Burrows, John P.; Orphal, Johannes; Sinnhuber, Miriam

2018-01-01

We present the retrieved volume emission rates (VERs) from the airglow of both the daytime and twilight O2(1Σ) band and O2(1Δ) band emissions in the mesosphere and lower thermosphere (MLT). The SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) onboard the European Space Agency Envisat satellite observes upwelling radiances in limb-viewing geometry during its special MLT mode over the range 50-150 km. In this study we use the limb observations in the visible (595-811 nm) and near-infrared (1200-1360 nm) bands. We have investigated the daily mean latitudinal distributions and the time series of the retrieved VER in the altitude range from 53 to 149 km. The maximal observed VERs of O2(1Δ) during daytime are typically 1 to 2 orders of magnitude larger than those of O2(1Σ). The latter peaks at around 90 km, whereas the O2(1Δ) emissivity decreases with altitude, with the largest values at the lower edge of the observations (about 53 km). The VER values in the upper mesosphere (above 80 km) are found to depend on the position of the sun, with pronounced high values occurring during summer for O2(1Δ). O2(1Σ) emissions show additional high values at polar latitudes during winter and spring. These additional high values are presumably related to the downwelling of atomic oxygen after large sudden stratospheric warmings (SSWs). Accurate measurements of the O2(1Σ) and O2(1Δ) airglow, provided that the mechanism of their production is understood, yield valuable information about both the chemistry and dynamics in the MLT. For example, they can be used to infer the amounts and distribution of ozone, solar heating rates, and temperature in the MLT.

Pressure-induced phase transition of KTa1/2Nb1/2O3 solid solutions: A first-principles study

NASA Astrophysics Data System (ADS)

Zhang, Huadi; Liu, Bing; Zhang, Cong; Qiu, Chengcheng; Wang, Xuping; Zhang, Yuanyuan; Lv, Xianshun; Wei, Lei; Li, Qinggang

2018-05-01

The structures and electronic properties of KTa1/2Nb1/2O3 under high pressures have been investigated using the first-principles calculations. Three candidates with B site cation ordered along the [1 0 0], [1 1 0] and [1 1 1] directions are found stable under different pressures by thermodynamics, mechanics and dynamics stability criteria. Further electronic analysis indicates that three structures are semiconductors with different band-gap characteristics. The peculiar chemical bonds of Nb-O and Ta-O are expected to be related to the different electronegativity of the corresponding cations.

40 CFR 721.10012 - Manganate (MnO21-), calcium (2:1).

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Manganate (MnO21-), calcium (2:1). 721... Substances § 721.10012 Manganate (MnO2 1-), calcium (2:1). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as manganate (MnO2 1−), calcium (2:1) (PMN P...

40 CFR 721.10012 - Manganate (MnO21-), calcium (2:1).

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Manganate (MnO21-), calcium (2:1). 721... Substances § 721.10012 Manganate (MnO2 1-), calcium (2:1). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as manganate (MnO2 1−), calcium (2:1) (PMN P...

40 CFR 721.10012 - Manganate (MnO21-), calcium (2:1).

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Manganate (MnO21-), calcium (2:1). 721... Substances § 721.10012 Manganate (MnO2 1-), calcium (2:1). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as manganate (MnO2 1−), calcium (2:1) (PMN P...

Mass: 100 mg, 10 g, 100 g, 1 kg, 10 kg and 50 kg

NASA Astrophysics Data System (ADS)

Kaçmaz, Sevda; Davidson, Stuart

2017-01-01

Bilateral mass comparison of mass standards of 100 mg, 2 g, 20 g, 500 g and 10 kg was carried out in 2011 to 2012 between UME and NPL. UME was the pilot laboratory. For all mass standards, the results show adequate agreement between the laboratories. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Rapid detection of TiO2 (E171) in table sugar using Raman spectroscopy.

PubMed

Tan, Chen; Zhao, Bin; Zhang, Zhiyun; He, Lili

2017-02-01

The potential toxic effects of titanium dioxide (TiO 2 ) to humans remain debatable despite its broad application as a food additive. Thus, confirmation of the existence of TiO 2 particles in food matrices and subsequently quantifying them are becoming increasingly critical. This study developed a facile, rapid (< 30 min) and highly reliable method to detect and quantify TiO 2 particles (E171) from food products (e.g., table sugar) by Raman spectroscopy. To detect TiO 2 particles from sugar solution, sequential centrifugation and washing procedures were effectively applied to separate and recover 97% of TiO 2 particles from the sugar solution. The peak intensity of TiO 2 sensitively responded to the concentration of TiO 2 with a limit of detection (LOD) of 0.073 mg kg -1 . In the case of sugar granules, a mapping technique was applied to directly estimate the level of TiO 2 , which can be potentially used for rapid online monitoring. The plot of averaged intensity to TiO 2 concentration in the sugar granules exhibited a good linear relationship in the wide range of 5-2000 mg kg -1 , with an LOD of 8.46 mg kg -1 . Additionally, we applied Raman spectroscopy to prove the presence of TiO 2 in sugar-coated doughnuts. This study begins to fill in the analytical gaps that exist regarding the rapid detection and quantification of TiO 2 in food, which facilitate the risk assessment of TiO 2 through food exposure.

The production of O(1D) from dissociative recombination of O2(+)

NASA Technical Reports Server (NTRS)

Guberman, Steven L.

1988-01-01

The results of large scale ab initio calculations of the rates for production of O(1D) by dissociative combination of O2(+) are presented for electron temperatures in the range 100 to 3000 K. A 1-delta-u state is the dominant dissociative route from v = 0 and a 3-sigma-u(-) state is the most important route from v = 1 and v = 2. The calculated total rate for O(1D) production from v = 0 is 2.21(+0.21, -0.24) x 10(-7) x (T sub e/300) exp -.46 near room temperature. The v = 1 and v = 2 rates are about 17 percent and 47 percent smaller respectively, than the v = 0 rate at 300 K.

Temperature-independent ferroelectric property and characterization of high-TC 0.2Bi(Mg1/2Ti1/2)O3-0.8PbTiO3 thin films

NASA Astrophysics Data System (ADS)

Zhang, Linxing; Chen, Jun; Zhao, Hanqing; Fan, Longlong; Rong, Yangchun; Deng, Jinxia; Yu, Ranbo; Xing, Xianran

2013-08-01

Ferroelectric property stability against elevated temperature is significant for ferroelectric film applications, such as non-volatile ferroelectric random access memories. The high-TC 0.2Bi(Mg1/2Ti1/2)O3-0.8PbTiO3 thin films show the temperature-independent ferroelectric properties, which were fabricated on Pt(111)/Ti/SiO2/Si substrates via sol-gel method. The present thin films were well crystallized in a phase-pure perovskite structure with a high (100) orientation and uniform texture. A remanent polarization (2Pr) of 77 μC cm-2 and a local effective piezoelectric coefficient d33* of 60 pm/V were observed in the 0.2Bi(Mg1/2Ti1/2)O3-0.8PbTiO3 thin films. It is interesting to observe a behavior of temperature-independent ferroelectric property in the temperature range of room temperature to 125 °C. The remanent polarization, coercive field, and polarization at the maximum field are almost constant in the investigated temperature range. Furthermore, the dielectric loss and fatigue properties of 0.2Bi(Mg1/2Ti1/2)O3-0.8PbTiO3 thin films have been effectively improved by the Mn-doping.

The pharmacokinetics and disposition of MK-0524, a Prosglandin D2 Receptor 1 antagonist, in rats, dogs and monkeys.

PubMed

Chang, S W; Reddy, V; Pereira, T; Dean, B J; Xia, Y-Q; Seto, C; Franklin, R B; Karanam, B V

2007-05-01

MK-0524 is a potent, selective and orally active Prosglandin D(2) Receptor 1 (DP(1)) antagonist currently under clinical development for the treatment of niacin-induced flushing. Experiments to study the pharmacokinetics, metabolism and excretion of MK-0524 were conducted in rats, dogs and monkeys. MK-0524 displayed linear kinetics and rapid absorption following an oral dose. Following intravenous (i.v.) administration of MK-0524 to rats and dogs (1 and 5 mg/kg), the mean Cl(p) was approximately 2 and approximately 6 ml/min/kg, the T(1/2) was approximately 7 and approximately 13 h and the Vd(ss) was approximately 1 and approximately 5 L/kg, respectively. In monkeys dosed i.v. at 3 mg/kg, the corresponding values were 8 ml/min/kg, 3 h and 1 L/kg, respectively. Following oral dosing of MK-0524 to rats (5, 25 and 100 mg/kg), dogs (5 mg/kg) and monkeys (3 mg/kg), the absorption was rapid with the mean C(max) occurring between 1 and 4 h. Absolute oral bioavailability values in rats, dogs and monkeys were 50, 70 and 8%, respectively. The major circulating metabolite was the acyl glucuronide of MK-0524 (M2), with ratios of glucuronide to the parent aglycone being highest in the monkey followed by dog and rat. In bile duct-cannulated rats and dogs, MK-0524 was eliminated primarily via acyl glucuronidation followed by biliary excretion of the acyl glucuronide, M2, the major drug-related entity in bile.

Intravenous rocuronium 0.3 mg/kg improves the conditions for tracheal intubation in cats: a randomized, placebo-controlled trial.

PubMed

Sakai, Daniel M; Zornow, Kailee Anne; Campoy, Luis; Cable, Christina; Appel, Leslie D; Putnam, Holly J; Martin-Flores, Manuel

2018-01-01

Objectives We evaluated the use of rocuronium 0.3 mg/kg intravenously (IV) to facilitate tracheal intubation in cats anesthetized for elective ovariohysterectomy. Methods Thirty female cats were randomly allocated to receive rocuronium 0.3 mg/kg IV or an equal volume of normal saline, following induction of anesthesia with ketamine and midazolam. Thirty seconds after induction, a single investigator, unaware of treatment allocation, attempted tracheal intubation. The number of attempts and the time to complete intubation were measured. Intubating conditions were assessed as acceptable or unacceptable based on a composite score consisting of five different components. Duration of apnea after induction was measured and cases of hemoglobin desaturation (SpO 2 <90%) were identified. Results Intubation was completed faster (rocuronium 12 s [range 8-75 s]; saline 60 s [range 9-120 s]) and with fewer attempts (rocuronium 1 [range 1-2]; saline 2 [range 1-3], both P = 0.006) in cats receiving rocuronium. Unacceptable intubating conditions on the first attempt occurred in 3/15 cats with rocuronium and in 10/15 with saline ( P = 0.01). Apnea lasted 4 ± 1.6 mins with rocuronium and 2.3 ± 0.5 mins with saline ( P = 0.0007). No cases of desaturation were observed. Conclusions and relevance Rocuronium 0.3 mg/kg IV improves intubating conditions compared with saline and reduces the time and number of attempts to intubate with only a short period of apnea in cats.

Multiplexed Lateral Flow Test for Detection and Differentiation of Cronobacter sakazakii Serotypes O1 and O2

PubMed Central

Scharinger, Eva J.; Dietrich, Richard; Wittwer, Tobias; Märtlbauer, Erwin; Schauer, Kristina

2017-01-01

The ubiquitous and opportunistic pathogen Cronobacter sakazakii is responsible for severe meningitis, sepsis, and necrotizing enterocolitis in neonates and infants associated with ingestion of contaminated powdered infant formula (PIF). The current ISO method for isolation and detection of Cronobacter spp. is laborious, time-consuming and expensive. In this study, a multiplexed lateral flow test strip was developed to rapidly detect and simultaneously serotype O1 and O2 C. sakazakii serotypes. The assay is based on two monoclonal antibodies (MAb) that specifically bind to the lipopolysaccharides (LPS) of these pathogens. The test strip provides results very quickly; C. sakazakii could be detected in pure culture within 15 min with a sensitivity of 107 CFU/ml. After non-selective enrichment for 18 h as low as one Cronobacter cell per g PIF could be detected. Moreover, the established lateral flow assay (LFA) offers excellent specificity showing no cross-reactivity with other C. sakazakii serotypes, Cronobacter species or Enterobacteriaceae tested. These characteristics, together with several advantages such as speed, simplicity in performance, low analysis cost, and no requirement of specialized skills or sophisticated equipment make the developed multiplexed LFA suitable for reliable detection and serotyping of C. sakazakii serotypes O1 and O2. PMID:28979257

Multiplexed Lateral Flow Test for Detection and Differentiation of Cronobacter sakazakii Serotypes O1 and O2.

PubMed

Scharinger, Eva J; Dietrich, Richard; Wittwer, Tobias; Märtlbauer, Erwin; Schauer, Kristina

2017-01-01

The ubiquitous and opportunistic pathogen Cronobacter sakazakii is responsible for severe meningitis, sepsis, and necrotizing enterocolitis in neonates and infants associated with ingestion of contaminated powdered infant formula (PIF). The current ISO method for isolation and detection of Cronobacter spp. is laborious, time-consuming and expensive. In this study, a multiplexed lateral flow test strip was developed to rapidly detect and simultaneously serotype O1 and O2 C. sakazakii serotypes. The assay is based on two monoclonal antibodies (MAb) that specifically bind to the lipopolysaccharides (LPS) of these pathogens. The test strip provides results very quickly; C. sakazakii could be detected in pure culture within 15 min with a sensitivity of 10 7 CFU/ml. After non-selective enrichment for 18 h as low as one Cronobacter cell per g PIF could be detected. Moreover, the established lateral flow assay (LFA) offers excellent specificity showing no cross-reactivity with other C. sakazakii serotypes, Cronobacter species or Enterobacteriaceae tested. These characteristics, together with several advantages such as speed, simplicity in performance, low analysis cost, and no requirement of specialized skills or sophisticated equipment make the developed multiplexed LFA suitable for reliable detection and serotyping of C. sakazakii serotypes O1 and O2.

A novel process for recycling and resynthesizing LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2} from the cathode scraps intended for lithium-ion batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Xihua; Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190; Beijing Engineering Research Center of Process Pollution Control, Beijing 100190

Highlights: • A simple process to recycle cathode scraps intended for lithium-ion batteries. • Complete separation of the cathode material from the aluminum foil is achieved. • The recovered aluminum foil is highly pure. • LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2} is directly resynthesized from the separated cathode material. - Abstract: To solve the recycling challenge for aqueous binder based lithium-ion batteries (LIBs), a novel process for recycling and resynthesizing LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2} from the cathode scraps generated during manufacturing process is proposed in this study. Trifluoroacetic acid (TFA) is employed to separate the cathode material from the aluminummore » foil. The effects of TFA concentration, liquid/solid (L/S) ratio, reaction temperature and time on the separation efficiencies of the cathode material and aluminum foil are investigated systematically. The cathode material can be separated completely under the optimal experimental condition of 15 vol.% TFA solution, L/S ratio of 8.0 mL g{sup −1}, reacting at 40 °C for 180 min along with appropriate agitation. LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2} is successfully resynthesized from the separated cathode material by solid state reaction method. Several kinds of characterizations are performed to verify the typical properties of the resynthesized LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2} powder. Electrochemical tests show that the initial charge and discharge capacities of the resynthesized LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2} are 201 mAh g{sup −1} and 155.4 mAh g{sup −1} (2.8–4.5 V, 0.1 C), respectively. The discharge capacity remains at 129 mAh g{sup −1} even after 30 cycles with a capacity retention ratio of 83.01%.« less

Electrodeposited Porous Mn1.5Co1.5O4/Ni Composite Electrodes for High-Voltage Asymmetric Supercapacitors

PubMed Central

Pan, Guan-Ting; Chong, Siewhui; Yang, Thomas C.-K.; Huang, Chao-Ming

2017-01-01

Mesoporous Mn1.5Co1.5O4 (MCO) spinel films were prepared directly on a conductive nickel (Ni) foam substrate via electrodeposition and an annealing treatment as supercapacitor electrodes. The electrodeposition time markedly influenced the surface morphological, textural, and supercapacitive properties of MCO/Ni electrodes. The (MCO/Ni)-15 min electrode (electrodeposition time: 15 min) exhibited the highest capacitance among three electrodes (electrodeposition times of 7.5, 15, and 30 min, respectively). Further, an asymmetric supercapacitor that utilizes (MCO/Ni)-15 min as a positive electrode, a plasma-treated activated carbon (PAC)/Ni electrode as a negative electrode, and carboxymethyl cellulose-lithium nitrate (LiNO3) gel electrolyte (denoted as (PAC/Ni)//(MCO/Ni)-15 min) was fabricated. In a stable operation window of 2.0 V, the device exhibited an energy density of 27.6 Wh·kg−1 and a power density of 1.01 kW·kg−1 at 1 A·g−1. After 5000 cycles, the specific energy density retention and power density retention were 96% and 92%, respectively, demonstrating exceptional cycling stability. The good supercapacitive performance and excellent stability of the (PAC/Ni)//(MCO/Ni)-15 min device can be ascribed to the hierarchical structure and high surface area of the (MCO/Ni)-15 min electrode, which facilitate lithium ion intercalation and deintercalation at the electrode/electrolyte interface and mitigate volume change during long-term charge/discharge cycling. PMID:28772727

Metabolism of 1-fluoro-1,1,2-trichloroethane, 1,2-dichloro-1,1-difluoroethane, and 1,1,1-trifluoro-2-chloroethane.

PubMed

Yin, H; Jones, J P; Anders, M W

1995-03-01

1-Fluoro-1,1,2-trichloroethane (HCFC-131a), 1,2-dichloro-1,1-difluoroethane (HCFC-132b), and 1,1,1-trifluoro-2-chloroethane (HCFC-133a) were chosen as models for comparative metabolism studies on 1,1,1,2-tetrahaloethanes, which are under consideration as replacements for ozone-depleting chlorofluorocarbons (CFCs). Male Fischer 344 rats were given 10 mmol/kg ip HCFC-131a or HCFC-132b or exposed by inhalation to 1% HCFC-133a for 2 h. Urine collected in the first 24 h after exposure was analyzed by 19F NMR and GC/MS and with a fluoride-selective ion electrode for the formation of fluorine-containing metabolites. Metabolites of HCFC-131a included 2,2-dichloro-2-fluoroethyl glucuronide, 2,2-dichloro-2-fluoroethyl sulfate, dichlorofluoroacetic acid, and inorganic fluoride. Metabolites of HCFC-132b were characterized as 2-chloro-2,2-difluoroethyl glucuronide, 2-chloro-2,2-difluoroethyl sulfate, chlorodifluoroacetic acid, chlorodifluoroacetaldehyde hydrate, chlorodifluoroacetaldehyde-urea adduct, and inorganic fluoride. HCFC-133a was metabolized to 2,2,2-trifluoroethyl glucuronide, trifluoroacetic acid, trifluoroacetaldehyde hydrate, trifluoroacetaldehyde-urea adduct, inorganic fluoride, and a minor, unidentified metabolite. With HCFC-131a and HCFC-132b, glucuronide conjugates of 2,2,2-trihaloethanols were the major urinary metabolites, whereas with HCFC-133a, a trifluoroacetaldehyde-urea adduct was the major urinary metabolite. Analysis of metabolite distribution in vivo indicated that aldehydic metabolites increased as fluorine substitution increased in the order HCFC-131a < HCFC-132b < HCFC-133a. With NADPH-fortified rat liver microsomes, HCFC-133a and HCFC-132b were biotransformed to trifluoroacetaldehyde and chlorodifluoroacetaldehyde, respectively, whereas HCFC-131a was converted to dichlorofluoroacetic acid. No covalently bound metabolites were detected by 19F NMR spectroscopy.(ABSTRACT TRUNCATED AT 250 WORDS)

40 CFR 721.10012 - Manganate (MnO21-), calcium (2:1).

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Manganate (MnO21-), calcium (2:1). 721... Substances § 721.10012 Manganate (MnO21-), calcium (2:1). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as manganate (MnO2 1 -), calcium (2:1) (PMN P...

40 CFR 721.10012 - Manganate (MnO21-), calcium (2:1).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Manganate (MnO21-), calcium (2:1). 721... Substances § 721.10012 Manganate (MnO21-), calcium (2:1). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as manganate (MnO2 1 -), calcium (2:1) (PMN P...

Neutron and electron diffraction studies of La(Zn1/2Ti1/2)O3 perovskite.

PubMed

Ubic, Rick; Hu, Yi; Abrahams, Isaac

2006-08-01

The crystallography and microwave dielectric properties of La(Zn(1/2)Ti(1/2))O(3) (LZT) ceramics prepared via the mixed-oxide route were investigated in this study. While samples were largely single phase, small amounts of ZnO impurity were detected in sintered pellets. Observed reflections in electron and neutron diffraction patterns indicate that the symmetry of LZT is P2(1)/n. The B site is ordered on {110} or pseudocubic {111}, but the presence of the pseudocubic 1/2(111) reflection is in itself insufficient to indicate the existence of such order. Rietveld refinements of the neutron diffraction data yield an excellent fit for such a model. The structure is highly twinned, with variants related through common {211} composition planes and 90 degrees rotations about <011>. The microwave dielectric properties measured were epsilon(r) = 34, Qf = 36,090 and tau(f) = -70 MK(-1).

Metabolism of 1-Fluro-1,1,2-trichloroethane, 1,2-dichloro-1,1-difluoroethane, and 1,1,1-trifluoro-2-chloroethane

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yin, H.; Jones, J.P.; Anders, M.W.

1995-03-01

1-Fluoro-1,1,2-trichloroethane (HCFC-131a), 1,2-dichloro-1,1-difluoroethane (HCFC-132b), and 1,1,1-trifluoro-2-chloroethane (HCFC-133a) were chosen as models for comparative metabolism studies on 1,1,1,2-tetrahaloethanes, which are under consideration as replacements for ozone-depleting chlorofluorocarbons (CFCs). Male Fischer 344 rats were given 10 mmol/kg ip HCFC-131a or HCFC-132b or exposed by inhalation to 1% HCFC-133a for 2 h. Urine collected in the first 24 h after exposure was analyzed by {sup 19}F NMR and GC/MS and with a fluoride-selective ion electrode for the formation of fluorine-containing metabolites. Metabolites of HCFC-131a included 2,2-dichloro-2-fluoroethyl glucuronide, 2,2-dichloro-2-fluorethyl sulfate, dichlorofluoroacetic acid, and inorganic fluoride. Metabolites of HCFC-132b were characterized as 2-chloro-2,2-difluoroethyl glucuronide, 2-chloro-2,2-difluoroethylmore » sulfate, chlorodifluoroacetic acid, chlorodifluoroacetaldehyde hydrate, chlorodifluoroacetaldehyde-urea adduct, inorganic fluoride, and a minor, unidentified metabolite. With HCFC-131a and HCFC-132b, glucuronide conjugates of 2,2,2-trihaloethanols were the major urinary metabolites, whereas with HCFC-133a, a trifluroacetaldehyde-urea adduct was the major urinary metabolite. Analysis of metabolite distribution in vivo indicated that aldehydic metabolites increased as fluorine substitution increased in the order HCFC-131a < HCFC-132b < HCFC-133a. With NADPH-fortified rat liver microsomes, HCFC-133a and HCFC-133a and HCFC-132b were biotransformed to trifluoroacetaldehyde and chlorodifluoroacetaldehyde, respectively, whereas HCFC-131a was converted to dichlorofluoroacetic acid. No covalently bound metabolites of HCFC-131a and HCFC-133a metabolites were detected by {sup 19}F NMR spectroscopy. 18 refs., 2 figs., 3 tabs.« less

Photoemission study of absorption mechanisms in Bi2.0Sr1.8Ca0.8La0.3Cu2.1O8+δ, BaBiO3, and Nd1.85Ce0.15CuO4

NASA Astrophysics Data System (ADS)

Lindberg, P. A. P.; Shen, Z.-X.; Wells, B. O.; Dessau, D. S.; Ellis, W. P.; Borg, A.; Kang, J.-S.; Mitzi, D. B.; Lindau, I.; Spicer, W. E.; Kapitulnik, A.

1989-11-01

Photoemission measurements in the constant-final-state (absorption) mode were performed on three different classes of high-temperature superconductors Bi2.0Sr1.8Ca0.8La0.3Cu2.1O8+δ, BaBiO3, and Nd1.85Ce0.15CuO4 using synchrotron radiation from 20 to 200 eV. Absorption signals from all elements but Ce are identified. The results firmly show that the Bi 6s electrons are more delocalized in BaBiO3 than in Bi2.0Sr1.8Ca0.8La0.3Cu2.1O8+δ, in agreement with the results of band-structure calculations. Differences in the absorption signals due to O and Bi excitations between BaBiO3 and Bi2.0Sr1.8Ca0.8La0.3Cu2.1O8+δ are discussed. Delayed absorption onsets attributed to giant resonances (Ba 4d-->4f, La 4d-->4f, and Nd 4d-->4f transitions) are also reported.

An Autoregulatory Loop Controlling CYP1A1 Gene Expression: Role of H2O2 and NFI

PubMed Central

Morel, Yannick; Mermod, Nicolas; Barouki, Robert

1999-01-01

Cytochrome P450 1A1 (CYP1A1), like many monooxygenases, can produce reactive oxygen species during its catalytic cycle. Apart from the well-characterized xenobiotic-elicited induction, the regulatory mechanisms involved in the control of the steady-state activity of CYP1A1 have not been elucidated. We show here that reactive oxygen species generated from the activity of CYP1A1 limit the levels of induced CYP1A1 mRNAs. The mechanism involves the repression of the CYP1A1 gene promoter activity in a negative-feedback autoregulatory loop. Indeed, increasing the CYP1A1 activity by transfecting CYP1A1 expression vectors into hepatoma cells elicited an oxidative stress and led to the repression of a reporter gene driven by the CYP1A1 gene promoter. This negative autoregulation is abolished by ellipticine (an inhibitor of CYP1A1) and by catalase (which catalyzes H2O2 catabolism), thus implying that H2O2 is an intermediate. Down-regulation is also abolished by the mutation of the proximal nuclear factor I (NFI) site in the promoter. The transactivating domain of NFI/CTF was found to act in synergy with the arylhydrocarbon receptor pathway during the induction of CYP1A1 by 2,3,7,8-tetrachloro-p-dibenzodioxin. Using an NFI/CTF-Gal4 fusion, we show that NFI/CTF transactivating function is decreased by a high activity of CYP1A1. This regulation is also abolished by catalase or ellipticine. Consistently, the transactivating function of NFI/CTF is repressed in cells treated with H2O2, a novel finding indicating that the transactivating domain of a transcription factor can be targeted by oxidative stress. In conclusion, an autoregulatory loop leads to the fine tuning of the CYP1A1 gene expression through the down-regulation of NFI activity by CYP1A1-based H2O2 production. This mechanism allows a limitation of the potentially toxic CYP1A1 activity within the cell. PMID:10490621

Thermodynamic modeling of melts in the system Na 2O-NaAlO 2-SiO 2-F 2O -1

NASA Astrophysics Data System (ADS)

Dolejš, David; Baker, Don R.

2005-12-01

Fluorine is a common volatile element in magmatic-hydrothermal systems, but its solution mechanisms and thermodynamic description in highly polymerized silicate melts are poorly known. We have developed a thermodynamic model for fluorosilicate liquids that links experimentally determined phase equilibria and spectroscopic information on melt structure. The model is applicable to crystallization of fluoride minerals, fluoride-silicate immiscibility in natural felsic melts, and metallurgical processes. Configurational properties of fluorosilicate melts are described by mixing on three site levels (sublattices): (1) alkali fluoride, polyhedral aluminofluoride and silicofluoride species and nonbridging terminations of the aluminosilicate network, (2) alkali-aluminate and silicate tetrahedra within the network and (3) bridging oxygen, nonbridging oxygen and terminal fluorine atoms on tetrahedral apices of the network. Abundances of individual chemical species are described by a homogeneous equilibrium representing melt depolymerization: F - (free) + O 0 (bridging) = F 0 (terminal) + O - (nonbridging) which corresponds to a replacement of an oxygen bridging two tetrahedra by a pair of terminations, one with F and the other with an O and a charge-balancing Na. In cryolite-bearing systems two additional interaction mechanisms occur: (1) the self-dissociation of octahedral aluminofluoride complexes: [AlF 6] = [AlF 4] + 2 [F], and (2) the short-range order between (O,F)-corners and (Si,NaAl)-centers of tetrahedra: Si-O-Si + 2 [NaAl]-F = [NaAl]-O-[NaAl] + 2 Si-F. Portrayal of these equilibria in ternary Thompson reaction space allows for the decrease in the number of interaction mechanisms by linearly combining melt depolymerization with tetrahedral short-range order. In this formulation, the nonideal thermodynamic properties are represented by reaction energies of homogeneous equilibria, thus defining directly individual chemical species concentrations and configurational

Li1.2Mn0.6Ni0.1Co0.1O2 microspheres constructed by hierarchically arranged nanoparticles as lithium battery cathode with enhanced electrochemical performance

NASA Astrophysics Data System (ADS)

Remith, P.; Kalaiselvi, N.

2014-11-01

Novel lithium-rich layered Li1.2Mn0.6Ni0.1Co0.1O2 microspheres containing hierarchically arranged and interconnected nanostructures have been synthesized by a combination of template-free co-precipitation and solid-state methods. The in situ formed γ-MnO2 spherical template upon co-precipitation gets sacrificed during the course of solid-state fusion of cobalt, nickel and lithium precursors to produce the title compound in the form of microspheres constructed by nanoparticles as building blocks. Porous and hollow microspheres of Li1.2Mn0.6Ni0.1Co0.1O2 are formed out of the spontaneous aggregation of nanoparticles, obtained from the custom-designed synthesis protocol. The growth mechanism of Li1.2Mn0.6Ni0.1Co0.1O2 spheres could be understood in terms of the Kirkendall effect and Ostwald ripening. The nanocrystalline Li1.2Mn0.6Ni0.1Co0.1O2 compound is obtained as a solid solution consisting of rhombohedral R3&cmb.macr;m and monoclinic C2/m group symmetries, as evidenced by XRD, Raman spectra and HRTEM equipped with FFT and STEM. The currently synthesized Li1.2Mn0.6Ni0.1Co0.1O2 cathode exhibits an appreciable discharge capacity of 242 mA h g-1 at a current density of 50 mA g-1, due to the synergistic effect of the capacity obtained from the rhombohedral and monoclinic phases.Novel lithium-rich layered Li1.2Mn0.6Ni0.1Co0.1O2 microspheres containing hierarchically arranged and interconnected nanostructures have been synthesized by a combination of template-free co-precipitation and solid-state methods. The in situ formed γ-MnO2 spherical template upon co-precipitation gets sacrificed during the course of solid-state fusion of cobalt, nickel and lithium precursors to produce the title compound in the form of microspheres constructed by nanoparticles as building blocks. Porous and hollow microspheres of Li1.2Mn0.6Ni0.1Co0.1O2 are formed out of the spontaneous aggregation of nanoparticles, obtained from the custom-designed synthesis protocol. The growth mechanism of Li1.2

Transient responses of SFG spectra of D 2O ice/CO/Pt(1 1 1) interface with irradiation of ultra-short NIR pump pulses

NASA Astrophysics Data System (ADS)

Kubota, Jun; Wada, Akihide; Domen, Kazunari; Kano, Satoru S.

2002-08-01

The behavior of D 2O ice on CO/Pt(1 1 1) and Pt(1 1 1) under the irradiation of near-IR pulses (NIR) was studied by sum-frequency generation (SFG) spectroscopy. The peaks assigned to the O-D stretching modes of ice were obtained for the first 30 molecular layers on Pt(1 1 1). When the D2O/ CO/ Pt(1 1 1) was irradiated, the signal of D 2O was weakened after 500 ps, but that of CO was weakened immediately after the pumping. A similar time response was observed for the D 2O peak in D2O/ Pt(1 1 1) . The weakening of SFG is attributed to the broadening of bands due to thermal excitation. This indicates that the energy of the pump pulse is deposited on the Pt(1 1 1) surface and diffused into the layers of D 2O ice in the 500 ps timescale.

Temperature-programmed desorption study of NO reactions on rutile TiO 2(110)-1×1

DOE PAGES

Kim, Boseong; Dohnalek, Zdenek; Szanyi, Janos; ...

2016-02-24

In this study, systematic temperature-programmed desorption (TPD) studies of NO adsorption and reactions on rutile TiO 2(110)-1 × 1 surface reveal several distinct reaction channels in a temperature range of 50–500 K. NO readily reacts on TiO 2(110) to form N 2O, which desorbs between 50 and 200 K (LT N 2O channels), which leaves the TiO 2 surface populated with adsorbed oxygen atoms (O a) as a by-product of N 2O formation. In addition, we observe simultaneous desorption peaks of NO and N 2O at 270 K (HT1 N 2O) and 400 K (HT2 N 2O), respectively, both ofmore » which are attributed to reaction-limited processes. No N-derived reaction product desorbs from TiO 2(110) surface above 500 K or higher, while the surface may be populated with Oa's and oxidized products such as NO 2 and NO 3. The adsorbate-free TiO 2 surface with oxygen vacancies can be regenerated by prolonged annealing at 850 K or higher. Detailed analysis of the three N 2O desorption yields reveals that the surface species for the HT channels are likely to be various forms of NO dimers.« less

Extraction of astaxanthin from Euphausia pacific using subcritical 1, 1, 1, 2-tetrafluoroethane

NASA Astrophysics Data System (ADS)

Han, Yuqian; Ma, Qinchuan; Wang, Lan; Xue, Changhu

2012-12-01

Euphausia pacific is an important source of natural astaxanthin. Studies were carried out to assess the extractability of astaxanthin from E. pacific using subcritical 1, 1, 1, 2-tetrafluoroethane (R134a). To examine the effects of multiple process variables on the extraction yield, astaxanthin was extracted under various conditions of pressure (30-150 bar), temperature (303-343 K), time (10-50 min), flow rate (2-10 g min-1), moisture content (5.5%-63.61%), and particle size (0.25-0.109 mm). The results showed that the extraction yield increased with temperature, pressure, time and flow rate, but decreased with moisture content and particle size. A maximum yield of 87.74% was obtained under conditions of 100 bar, 333 K, and 30 min with a flow rate of 6 g min-1 and a moisture content of 5.5%. The substantial astaxanthin yield obtained under low-pressure conditions demonstrates that subcritical R134a is a good alternative to CO2 for extraction of astaxanthin from E. pacific.

Multielectronic conduction in La1-xSrxGa1/2Mn1/2O3-δ as solid oxide fuel cell cathode

NASA Astrophysics Data System (ADS)

Iguchi, E.; Hashimoto, Y.; Kurumada, M.; Munakata, F.

2003-08-01

Four-probe dc conductivities, capacitances, and thermopower have been measured in the temperature range of 80-1123 K for La1-xSrxGa1/2Mn1/2O3-δ, which is a desirable cathode material for lanthanum-gallate electrolytes of solid oxide fuel cells. The dc conductivities in the specimens (0.1⩽x⩽0.3) are insensitive to x but the thermopower is very sensitive to x, although the x=0 specimen exhibits a somewhat different conduction behavior. At T<300 K, a relaxation process has shown in dielectric loss factor with the activation energy higher than that for dc conduction in every specimen. These results at T<300 K have been numerically analyzed within the framework of the multielectronic conduction consisting of the polaronic conduction of Mn 3d eg holes created by Sr doping, the band conduction of O 2p holes and the hopping conduction of Mn 3d eg electrons, where the O 2p holes and Mn 3d eg electrons are created by thermal excitation of electrons from O 2p bands to Mn 3d eg narrow bands. At T>500 K, the band conduction dominates the electronic transports. The ionic conduction due to O2- migration seems difficult to contribute directly to the dc conduction even at high temperature.

Electronic structure of Pr{sub 1{minus}x}Y{sub x}Ba{sub 2}Cu{sub 3}O{sub y} (x=0, 0.5, and 1.0)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kakinuma, K.; Fueki, K.

1997-08-01

In order to elucidate the reason why PrBa{sub 2}Cu{sub 3}O{sub y}is not a superconductor, we examined the Pr valence and measured the oxygen nonstoichiometry and the conductivity at temperatures up to 1200 K for three kinds of oxides, PrBa{sub 2}Cu{sub 3}O{sub y}, (Pr{sub 0.5}Y{sub 0.5})Ba{sub 2}Cu{sub 3}O{sub y}, and YBa{sub 2}Cu{sub 3}O{sub y}. The valence of Pr was found to be +3. Any difference was not found in oxygen nonstoichiometry and conductivity among three kinds of oxides. We analyzed the data of oxygen nonstoichiometry on the basis of defect thermodynamics and calculated the numbers of Cu{sup +}, Cu{sup 2+}, andmore » Cu{sup 3+} ions in the unit cell as a function of y. The number of Cu{sup 3+} ions (the amount of holes) was found to be proportional to ({Delta}y){sup 1.6}({Delta}y=y{minus}6.0), whereas the conductivity was found to be proportional to ({Delta}y){sup 3.2} in these oxides. We interpreted the remarkable increase of {sigma} with {Delta}y as an evidence of the increase of both mobility and hole concentration with {Delta}y. At high temperatures, we detected the conductivity minimum {sigma}{sub min} which was found in the log{sub 10}{sigma}{minus}log{sub 10}P{sub O{sub 2}} plot at constant temperatures. From the slope of the Arrhenius plot for {sigma}{sub min}, the band gap was determined to be 1.21, 1.32, and 1.37 eV for PrBa{sub 2}Cu{sub 3}O{sub y}, (Pr{sub 0.5}Y{sub 0.5})Ba{sub 2}Cu{sub 3}O{sub y} and YBa{sub 2}Cu{sub 3}O{sub y}, respectively. We determined the conductivity of the same oxygen content as a function of temperature from 4.2 to 1200 K. The energy gap {Delta}E between the acceptor level and the top of the valence band was calculated from the slope of the Arrhenius plot for conductivity. {Delta}E for superconducting YBa{sub 2}Cu{sub 3}O{sub y} and (Pr{sub 0.5}Y{sub 0.5})Ba{sub 2}Cu{sub 3}O{sub y} were zero at 300 K but that for nonsuperconducting PrBa{sub 2}Cu{sub 3}O{sub y} was 20 meV at 100 K even for y=6.93. (Abstract

The Effects of Non-Contingent Feedback on the Incidence of Plateau at V̇O2max

PubMed Central

Gordon, Dan; Gernigon, Marie; Baker, James; Merzbach, Viviane; Scruton, Adrian

2017-01-01

The purpose of this study was to examine the effects of non-contingent feedback in the form of heart rate (HR) on the incidence of plateau at V̇O2max. Ten physically active males (age 24.8 yrs ± 4.2; mass 81.4 ± 9.0 kg; stature 1.80 ± 0.11 m, V̇O2max 53.2 ± 5.8 ml·kg-1.min-1) who were V̇O2max testing naïve but were cognisant as to the heart rate responses to exercise completed four incremental tests to volitional exhaustion, separated by ~72 h for the determination of V̇O2max and gas exchange threshold. The first trial served as a familiarisation with the remaining three being experimental conditions where HR was presented in a screen projection as either the actual response (HR-A) or 10 b·min-1 higher than recorded (HR-H) or 10 b·min-1 lower (HR-L). Throughout all trials V̇O2 was recorded on a breath-by-breath basis with plateau criteria of ≤ 50 ml·min-1. RESULTS: A significant difference was observed for Δ V̇O2 over the final two consecutive 30s sampling periods between HR-A, both HR-L and HR-H (p = 0.049) and for the incidence of plateau response between condition (p = 0.021). An additional significant difference was observed for sub-maximal Δ V̇O2 responses between HR-A and HR-H (p = 0.049) and HR-A and HR-L (p = 0.006). Non-significant differences were observed for all other criteria. These data indicate that when presented with non-contingent feedback in the form of HR, that the perceptually orientated pacing schema becomes disrupted promoting a sparing of the finite anaerobic capacity to compensate for the imbalance between the afferent signal and perception of effort. Key points The manifestation of the plateau at V̇O2max is disrupted (lower incidence rates) when participants are exposed to non-contingent feedback in the form of heart rate. Non-contingent feedback in the form of heart rate does not affect the V̇O2max score or associated cardio-respiratory parameters. Given the association between the V̇O2-plateau and the finite

Validity of the 6 min walk test in prediction of the anaerobic threshold before major non-cardiac surgery.

PubMed

Sinclair, R C F; Batterham, A M; Davies, S; Cawthorn, L; Danjoux, G R

2012-01-01

For perioperative risk stratification, a robust, practical test could be used where cardiopulmonary exercise testing (CPET) is unavailable. The aim of this study was to assess the utility of the 6 min walk test (6MWT) distance to discriminate between low and high anaerobic threshold (AT) in patients awaiting major non-cardiac surgery. In 110 participants, we obtained oxygen consumption at the AT from CPET and recorded the distance walked (in m) during a 6MWT. Receiver operating characteristic (ROC) curve analysis was used to derive two different cut-points for 6MWT distance in predicting an AT of <11 ml O(2) kg(-1) min(-1); one using the highest sum of sensitivity and specificity (conventional method) and the other adopting a 2:1 weighting in favour of sensitivity. In addition, using a novel linear regression-based technique, we obtained lower and upper cut-points for 6MWT distance that are predictive of an AT that is likely to be (P≥0.75) <11 or >11 ml O(2) kg(-1) min(-1). The ROC curve analysis revealed an area under the curve of 0.85 (95% confidence interval, 0.77-0.91). The optimum cut-points were <440 m (conventional method) and <502 m (sensitivity-weighted approach). The regression-based lower and upper 6MWT distance cut-points were <427 and >563 m, respectively. Patients walking >563 m in the 6MWT do not routinely require CPET; those walking <427 m should be referred for further evaluation. In situations of 'clinical uncertainty' (≥427 but ≤563 m), the number of clinical risk factors and magnitude of surgery should be incorporated into the decision-making process. The 6MWT is a useful clinical tool to screen and risk stratify patients in departments where CPET is unavailable.

Temperature-programmed desorption study of NO reactions on rutile TiO2(110)-1×1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Boseong; Dohnálek, Zdenek; Szanyi, János

2016-10-01

Systematic temperature-programmed desorption (TPD) studies of NO adsorption and reactions on rutile TiO2(110)-1×1 surface reveal several distinct reaction channels in a temperature range of 50 – 500 K. NO readily reacts on TiO2(110) to form N2O which desorbs between 50 and 200 K (LT N2O channels), which leaves the TiO2 surface populated with adsorbed oxygen atoms (Oa) as a byproduct of N2O formation. In addition, we observe simultaneous desorption peaks of NO and N2O at 270 K (HT1 N2O) and 400 K (HT2 N2O), respectively, both of which are attributed to reaction-limited processes. No N-derived reaction product desorbs from TiO2(110)more » surface above 500 K or higher, while the surface may be populated with Oa’s and oxidized products such as NO2 and NO3. The adsorbate-free TiO2 surface with oxygen vacancies can be regenerated by prolonged annealing at 850 K or higher. Detailed analysis of the three N2O desorption yields reveals that the surface species for the HT channels are likely to be various forms of NO dimers.« less

The role of tachykinin NK1 and NK2 receptors in atropine-resistant colonic propulsion in anaesthetized guinea-pigs.

PubMed

Lecci, A; Giuliani, S; Tramontana, M; Giorgio, R D; Maggi, C A

1998-05-01

1. The role of endogenous tachykinins on guinea-pig colonic propulsion was investigated by using potent and selective tachykinin NK1 and NK2 receptor antagonists. Colonic propulsion and contractions were determined by means of a balloon-catheter device, inserted into the rectum of guanethidine (68 micromol kg(-1), s.c., 18 and 2 h before)-pretreated, urethane-anaesthetized guinea-pigs. Propulsion of the device (dynamic model) was determined by measuring the length of the catheter expelled during 60 min filling of the balloon (flow rate 5 microl min(-1)). 2. In control conditions the tachykinin NK1 receptor antagonist SR 140333 (1 micromol kg(-1), i.v.) did not affect either colonic propulsion or the amplitude of contractions. The tachykinin NK2 receptor antagonists MEN 10627 and MEN 11420 (1 micromol kg(-1), i.v.) increased colonic propulsion at 10 min (+120% and 150%, respectively) but at 60 min the effect was significant only for MEN 10627 (+84%). SR 48968 (1 micromol kg(-1), i.v.) did not significantly enhance the colonic propulsion. None of these tachykinin NK2 receptor antagonists modified the amplitude of colonic contractions. In contrast, both atropine (6 micromol kg(-1), i.v., plus infusion of 1.8 micromol h(-1)) and hexamethonium (55 micromol kg(-1), i.v., plus infusion of 17 micromol h(-1)) abolished propulsion (81% and 87% inhibition, respectively) and decreased the amplitude of contractions (68% inhibition for either treatment). 3. In atropine-treated animals (6 micromol kg(-1), i.v., plus infusion of 1.8 micromol h(-1)), apamin (30 nmol kg(-1), i.v.) restored colonic propulsion (+416%) and increased the amplitude of contractions (+367% as compared to atropine alone). Hexamethonium (55 micromol kg(-1), i.v., plus infusion of 17 micromol h(-1)) abolished the apamin-induced, atropine-resistant colonic propulsion (97% inhibition) and reduced the amplitude of the atropine-resistant contractions (52% inhibition). 4. The apamin-induced, atropine

Estimating 1 min rain rate distributions from numerical weather prediction

NASA Astrophysics Data System (ADS)

Paulson, Kevin S.

2017-01-01

Internationally recognized prognostic models of rain fade on terrestrial and Earth-space EHF links rely fundamentally on distributions of 1 min rain rates. Currently, in Rec. ITU-R P.837-6, these distributions are generated using the Salonen-Poiares Baptista method where 1 min rain rate distributions are estimated from long-term average annual accumulations provided by numerical weather prediction (NWP). This paper investigates an alternative to this method based on the distribution of 6 h accumulations available from the same NWPs. Rain rate fields covering the UK, produced by the Nimrod network of radars, are integrated to estimate the accumulations provided by NWP, and these are linked to distributions of fine-scale rain rates. The proposed method makes better use of the available data. It is verified on 15 NWP regions spanning the UK, and the extension to other regions is discussed.

Dielectric relaxation in 0-3 PVDF-Ba(Fe{sub 1/2}Nb{sub 1/2})O{sub 3} composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chandra, K. P., E-mail: kpchandra23@gmail.com; Singh, Rajan; Kulkarni, A. R., E-mail: ajit2957@gmail.com

2016-05-06

(1-x)PVDF-xBa(Fe{sub 1/2}Nb{sub 1/2})O{sub 3} ceramic-polymer composites with x = 0.025, 0.05, 0.10, 0.15 were prepared using melt-mixing technique. The crystal symmetry, space group and unit cell dimensions were determined from the XRD data of Ba(Fe{sub 1/2}Nb{sub 1/2})O{sub 3} using FullProf software, whereas crystallite size and lattice strain were estimated using Williamson-Hall approach. The distribution of Ba(Fe{sub 1/2}Nb{sub 1/2})O{sub 3} particles in the PVDF matrix were examined on the cryo-fractured surfaces using a scanning electron microscope. Cole-Cole and pseudo Cole-Cole analysis suggested the dielectric relaxation in this system to be of non-Debye type. Filler concentration dependent real and imaginary parts ofmore » dielectric constant as well as ac conductivity data followed definite trends of exponential growth types of variation.« less

Bacterial treatment of alkaline cement kiln dust using Bacillus halodurans strain KG1.

PubMed

Kunal; Rajor, Anita; Siddique, Rafat

2016-01-01

This study was conducted to isolate an acid-producing, alkaliphilic bacterium to reduce the alkalinity of cement industry waste (cement kiln dust). Gram-positive isolate KG1 grew well at pH values of 6-12, temperatures of 28-50°C, and NaCl concentrations of 0-16% and thus was further screened for its potential to reduce the pH of an alkaline medium. Phenotypic characteristics of the KG1 isolate were consistent with those of the genus Bacillus, and the highest level of 16S rRNA gene sequence similarity was found with Bacillus halodurans strain DSM 497 (94.7%). On the basis of its phenotypic characteristics and genotypic distinctiveness from other phylogenetic neighbors belonging to alkaliphilic Bacillus species, the isolated strain was designated B. halodurans strain KG1, with GenBank accession number JQ307184 (= NCIM 5439). Isolate KG1 reduced the alkalinity (by 83.64%) and the chloride content (by 86.96%) of cement kiln dust and showed a potential to be used in the cement industry for a variety of applications. Copyright © 2015 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Uptake and distribution of the abused inhalant 1,1-difluoroethane in the rat.

PubMed

Avella, Joseph; Kunaparaju, Naveen; Kumar, Sunil; Lehrer, Michael; Zito, S William; Barletta, Michael

2010-09-01

1,1-Difluoroethane (DFE) is a halogenated hydrocarbon used as a propellant in products designed for dusting electronic equipment and air brush painting. When abused, inhaled DFE produces intoxication and loss of muscular coordination. To investigate DFE toxicokinetics, groups (n = 3) of Sprague-Dawley rats were exposed to 30 s of 20 L/min DFE. The experimental model was designed to mimic exposure during abuse, a protocol which has not been conducted. Tissue collection (blood, brain, heart, liver, and kidney) occurred at 0, 10, 20, 30, 45, 60, 120, 240, 480, and 900 s. Average peak DFE levels were blood 352, brain 519, heart 338, liver 187, and kidney 364 mg/L or mg/kg. The total percent uptake of the administered dose was 4.0%. Uptake into individual compartments was 2.72, 0.38, 0.15, 0.41, and 0.32% for blood, brain, heart, liver, and kidney, respectively. All animals showed signs of intoxication within 20 s manifested as lethargy, prostration and loss of righting reflex. Marked intoxication continued for about 4 min when DFE averaged 21 mg/L in blood and 17 mg/kg in brain. Between 4 and 8 min, animals continued to show signs of sedation as evidenced by reduced aggression and excitement during handling. No discernable intoxication was evident after 8 min and blood and brain levels had fallen to 10 and 6 mg/L or kg, respectively. Plots of concentration (log) versus time were consistent with a two compartment model. Initial distribution was rapid with average half life (t((1/2))) during the alpha phase of 9 s for blood, 18 s for brain and 27 s in cardiac tissue. During beta slope elimination average t((1/2)) was 86 s in blood, 110 s in brain and 168 s in heart. Late elimination half lives were longer with blood gamma = 240 s, brain gamma = 340 s, and heart gamma = 231 s. Following acute exposure the Vd = 0.06 L, beta = 0.48 min(-1), AUC = 409.8 mg.min L(-1), and CL from blood was 0.03 L min(-1). The calculated toxicokinetic data may underestimate these parameters if

40 CFR 721.9511 - Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium and europium-doped.

Code of Federal Regulations, 2010 CFR

2010-07-01

... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9511 Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium and europium-doped. (a) Chemical substance and significant new...

Determination of Anaerobic Threshold by Monitoring the O2 Pulse Changes in Endurance Cyclists.

PubMed

Nikooie, Rohollah

2016-06-01

The purpose of this study was to determine the validity of anaerobic threshold (AnT)-equivalent to the second turn point for lactate (LTP2)-estimation using the O2 pulse changes in highly trained endurance cyclists who do not show heart rate deflection point (HRDP) during incremental testing. Sixteen endurance cyclists (age, 24.8 ± 4.7 years) and fifteen active men (age, 24.8 ± 3.7 years) performed an incremental cycling test to exhaustion. Pulmonary oxygen uptake (V[Combining Dot Above]O2) and other hemodynamic variables, heart rate, and blood lactate concentration were measured continuously throughout the test. O2 pulse anaerobic threshold (O2 pulse-AnT) was defined as the second turn point in O2 pulse-workload curve. LTP2 was considered as gold standard assessment of AnT and was applied to confirm the validity of O2 pulse-AnT. Intraclass correlation coefficients and the Bland-Altman method were used to determine the relationship and agreement between the O2 corresponding to LTP2 and O2 pulse-AnT, respectively. The active men and 68.7% of the endurance cyclists showed HRDP, whereas all subjects showed O2 pulse-AnT during incremental testing. In both groups, the values for V[Combining Dot Above]O2 corresponding to LTP2 were not significantly different from the V[Combining Dot Above]O2 at O2 pulse-AnT. The V[Combining Dot Above]O2 at LTP2 and O2 pulse-AnT were highly correlated (endurance cyclists: R = 0.68; standard error of estimate [SEE] = 3.74 ml·kg·min and active men: R = 0.58; SEE = 2.91 ml·kg·min) and Bland-Altman plot revealed the limit of agreement of O2 at LTP2 and O2 pulse-AnT differences between 5.1 and 8.6 ml·kg·min (95% CI). In summary, results of this study showed that the second turn point in the O2 pulse-workload curve occurs around LTP2. Therefore, using O2 pulse-AnT is recommended for the noninvasive determination of AnT in highly trained endurance cyclists who do not show HRDP during incremental exercise.

Experimental Determination of Air Density Using a 1 kg Mass Comparator in Vacuum

NASA Astrophysics Data System (ADS)

Gläser, M.; Schwartz, R.; Mecke, M.

1991-01-01

The density of ambient air has been determined by a straightforward experimental method. The apparent masses of two artefacts having about the same mass and surface, but different well-known volumes, have been compared by using a 1 kg balance in vacuum and in air. The differences of apparent masses and volumes yield the air density with a relative uncertainty (1σ) of 5 × 10-5. From measurements made using a third artefact, surface sorption effects caused by the change between vacuum and air conditions gave a coefficient of about 0,2 μg cm-2.

MRI quantification of human fetal O2 delivery rate in the second and third trimesters of pregnancy.

PubMed

Rodríguez-Soto, Ana E; Langham, Michael C; Abdulmalik, Osheiza; Englund, Erin K; Schwartz, Nadav; Wehrli, Felix W

2018-01-22

The purpose of this study was to estimate fetal O 2 delivery rate in vivo across a range of gestational ages. Toward this, a calibration equation for T 2 -based oximetry was derived. Umbilical cord blood of varying hematocrit (Hct) and oxygen saturation (HbO 2 ) levels was prepared and T 2 measured using a T 2 -prepared balanced steady-state free-precession sequence at 1.5 T. The relationship between blood R 2  = 1/T 2 , HbO 2 and Hct was established based on the model R2=(1-Hct)R2,plasma+Hct R2,RBC+k·Hct·(1-Hct)·(1-HbO2)2. Experimental R 2 , HbO 2 , and Hct levels were fit to the model-yielding values of k, R2,plasma, and R2,RBC (R 2 of plasma and erythrocytes). Umbilical vein T 2 measured in vivo was then converted to HbO 2 , yielding-together with blood flow rate-the fetal O 2 delivery rate in 22 pregnancies (gestational age 30 ± 3 weeks). Constants derived from the fit (R 2  = 0.94) were k = 83.1 s -1 , R2,plasma=1.1  s-1, and R2,RBC=12.9  s-1. The R2,RBC and k were found to be larger than those obtained for adult blood, likely the result of differences in dominant hemoglobin type. Data suggest that the use of adult blood calibration could entail errors up 10% in fetal blood HbO 2 . The average umbilical vein blood flow rate (89.5 ± 17.2 mL/min/kg), HbO 2 (84 ± 7%,), and fetal O 2 delivery rate (15.1 ± 3.8 mL O 2 /min/kg) were independent of gestational age. The fetal O 2 delivery rate agreed well with the results obtained with invasive methods at term. The present work describes strategies for measuring umbilical vein blood flow rate and HbO 2 in vivo and estimates fetal O 2 delivery rate noninvasively with quantitative MRI during the second and third trimesters of pregnancy. Magn Reson Med, 2018. © 2018 International Society for Magnetic Resonance in Medicine. © 2018 International Society for Magnetic Resonance in Medicine.

The Escherichia coli Serogroup O1 and O2 Lipopolysaccharides Are Encoded by Multiple O-antigen Gene Clusters.

PubMed

Delannoy, Sabine; Beutin, Lothar; Mariani-Kurkdjian, Patricia; Fleiss, Aubin; Bonacorsi, Stéphane; Fach, Patrick

2017-01-01

Escherichia coli strains belonging to serogroups O1 and O2 are frequently associated with human infections, especially extra-intestinal infections such as bloodstream infections or urinary tract infections. These strains can be associated with a large array of flagellar antigens. Because of their frequency and clinical importance, a reliable detection of E. coli O1 and O2 strains and also the frequently associated K1 capsule is important for diagnosis and source attribution of E. coli infections in humans and animals. By sequencing the O-antigen clusters of various O1 and O2 strains we showed that the serogroups O1 and O2 are encoded by different sets of O-antigen encoding genes and identified potentially new O-groups. We developed qPCR-assays to detect the various O1 and O2 variants and the K1-encoding gene. These qPCR assays proved to be 100% sensitive and 100% specific and could be valuable tools for the investigations of zoonotic and food-borne infection of humans with O1 and O2 extra-intestinal (ExPEC) or Shiga toxin-producing E. coli (STEC) strains.

The Escherichia coli Serogroup O1 and O2 Lipopolysaccharides Are Encoded by Multiple O-antigen Gene Clusters

PubMed Central

Delannoy, Sabine; Beutin, Lothar; Mariani-Kurkdjian, Patricia; Fleiss, Aubin; Bonacorsi, Stéphane; Fach, Patrick

2017-01-01

Escherichia coli strains belonging to serogroups O1 and O2 are frequently associated with human infections, especially extra-intestinal infections such as bloodstream infections or urinary tract infections. These strains can be associated with a large array of flagellar antigens. Because of their frequency and clinical importance, a reliable detection of E. coli O1 and O2 strains and also the frequently associated K1 capsule is important for diagnosis and source attribution of E. coli infections in humans and animals. By sequencing the O-antigen clusters of various O1 and O2 strains we showed that the serogroups O1 and O2 are encoded by different sets of O-antigen encoding genes and identified potentially new O-groups. We developed qPCR-assays to detect the various O1 and O2 variants and the K1-encoding gene. These qPCR assays proved to be 100% sensitive and 100% specific and could be valuable tools for the investigations of zoonotic and food-borne infection of humans with O1 and O2 extra-intestinal (ExPEC) or Shiga toxin-producing E. coli (STEC) strains. PMID:28224115

Novel Organophosphate Ligand O-(2-Fluoroethyl)-O-(p-Nitrophenyl)Methylphosphonate: Synthesis, Hydrolytic Stability and Analysis of the Inhibition and Reactivation of Cholinesterases.

PubMed

Chao, Chih-Kai; Ahmed, S Kaleem; Gerdes, John M; Thompson, Charles M

2016-11-21

The organophosphate O-(2-fluoroethyl)-O-(p-nitrophenyl) methyphosphonate 1 is the first-in-class, fluorine-18 radiolabeled organophosphate inhibitor ([ 18 F]1) of acetylcholinesterase (AChE). In rats, [ 18 F]1 localizes in AChE rich regions of the brain and other tissues where it likely exists as the (CH 3 )( 18 FCH 2 CH 2 O)P(O)-AChE adduct (ChE-1). Characterization of this adduct would define the inhibition mechanism and subsequent postinhibitory pathways and reactivation rates. To validate this adduct, the stability (hydrolysis) of 1 and ChE-1 reactivation rates were determined. Base hydrolysis of 1 yields p-nitrophenol and (CH 3 ) (FCH 2 CH 2 O)P(O)OH with pseudo first order rate constants (k obsd ) at pH 7.4 (PBS) of 3.25 × 10 -4 min -1 (t 1/2 = 35.5 h) at 25 °C and 8.70 × 10 -4 min -1 (t 1/2 = 13.3 h) at 37 °C. Compound 1 was a potent inhibitor of human acetylcholinesterase (HuAChE; k i = 7.5 × 10 5 M -1 min -1 ), electric eel acetylcholinesterase (EEAChE) (k i = 3.0 × 10 6 M -1 min -1 ), and human serum butyrylcholinesterase (HuBChE; 1.95 × 10 5 M -1 min -1 ). Spontaneous and oxime-mediated reactivation rates for the (CH 3 ) (FCH 2 CH 2 O)P(O)-serine ChE adducts using 2-PAM (10 μM) were (a) HuAChE 8.8 × 10 -5 min -1 (t 1/2 = 131.2 h) and 2.41 × 10 -2 min -1 (t 1/2 = 0.48 h), (b) EEAChE 9.32 × 10 -3 min -1 (t 1/2 = 1.24 h) and 3.33 × 10 -2 min -1 (t 1/2 = 0.35 h), and (c) HuBChE 1.16 × 10 -4 min -1 (t 1/2 = 99.6 h) and 4.19 × 10 -2 min -1 (t 1/2 = 0.27 h). All ChE-1 adducts undergo rapid and near complete restoration of enzyme activity following addition of 2-PAM (30 min), and no aging was observed for either reactivation process. The fast reactivation rates and absence of aging of ChE-1 adducts are explained on the basis of the electron-withdrawing fluorine group that favors the nucleophilic reactivation processes but disfavors cation-based dealkylation aging mechanisms. Therefore, the likely fate of radiolabeled compound 1 in vivo is the

The 590 cm-1 B_1g feature in underdoped Bi_2Sr_2CaCu_2O_8+δ

NASA Astrophysics Data System (ADS)

Hewitt, Kevin C.; Wang, N. L.; Irwin, J. C.; Pooke, D. M.; Pantoja, A. E.; Trodahl, H. J.

1999-05-01

Raman scattering studies have been performed on underdoped Bi_2Sr_2CaCu_2O_8+δ. In single crystals underdoped by oxygen removal, a 590 cm-1 peak is observed in the B_1g spectrum. The feature is observed to soften in frequency by 3.8% with isotopic exchange of ^16O by ^18O. In contrast, the 590 cm-1 peak is not observed in crystals underdoped by Y substitution which suggests that it corresponds to a disorder induced vibrational mode. We have also found that underdoping leads to a depletion of low energy spectral weight from regions of the Fermi surface located near the Brillouin zone axes.

40 CFR 721.10033 - Zinc, [ethanedioato(2-)-. kappa. O1, . kappa. O2]-.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Zinc, [ethanedioato(2-)-. kappa. O1, . kappa. O2]-. 721.10033 Section 721.10033 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1003...

40 CFR 721.10033 - Zinc, [ethanedioato(2-)-. kappa. O1, . kappa. O2]-.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Zinc, [ethanedioato(2-)-. kappa. O1, . kappa. O2]-. 721.10033 Section 721.10033 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1003...

40 CFR 721.10033 - Zinc, [ethanedioato(2-)-. kappa. O1, . kappa. O2]-.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Zinc, [ethanedioato(2-)-. kappa. O1, . kappa. O2]-. 721.10033 Section 721.10033 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1003...

Conversion of 1,2-Propylene Glycol on Rutile TiO2(110)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Long; Li, Zhenjun; Smith, R. Scott

2014-07-17

We have studied the reactions of 1,2-propylene glycol (1,2-PG), DOCH(CH3)CH2OD, on partially reduced, hydroxylated and oxidized TiO2(110) surfaces using temperature programmed desorption. On reduced TiO2(110), propylene, propanal, and acetone are identified as primary carbon-containing products. While the propylene formation channel dominates at low 1,2-PG coverages, all of the above-mentioned products are observed at high coverages. The carbon-containing products are accompanied by the formation of D2O and D2. The observation of only deuterated products shows that the source of hydrogen (D) is from the 1,2-PG hydroxyls. The role of bridging oxygen vacancy (VO) sites was further investigated by titrating them viamore » hydroxylation and oxidation. The results show that hydroxylation does not change the reactivity because the VO sites are regenerated at 500 K, which is a temperature lower than the 1,2-PG product formation temperature. In contrast, surface oxidation causes significant changes in the product distribution, with increased acetone and propanal formation and decreased propylene formation. Additionally D2 is completely eliminated as an observed product at the expense of D2O formation.« less

Ab initio and transition state theory study of the OH + HO2 → H2O + O2(3Σg-)/O2(1Δg) reactions: yield and role of O2(1Δg) in H2O2 decomposition and in combustion of H2.

PubMed

Monge-Palacios, M; Sarathy, S Mani

2018-02-07

Reactions of hydroxyl (OH) and hydroperoxyl (HO 2 ) are important for governing the reactivity of combustion systems. We performed post-CCSD(T) ab initio calculations at the W3X-L//CCSD = FC/cc-pVTZ level to explore the triplet ground-state and singlet excited-state potential energy surfaces of the OH + HO 2 → H 2 O + O 2 ( 3 Σ g - )/O 2 ( 1 Δ g ) reactions. Using microcanonical and multistructural canonical transition state theories, we calculated the rate constant for the triplet and singlet channels over the temperature range 200-2500 K, represented by k(T) = 3.08 × 10 12 T 0.07  exp(1151/RT) + 8.00 × 10 12 T 0.32  exp(-6896/RT) and k(T) = 2.14 × 10 6 T 1.65  exp(-2180/RT) in cm 3 mol -1 s -1 , respectively. The branching ratios show that the yield of singlet excited oxygen is small (<0.5% below 1000 K). To ascertain the importance of singlet oxygen channel, our new kinetic information was implemented into the kinetic model for hydrogen combustion recently updated by Konnov (Combust. Flame, 2015, 162, 3755-3772). The updated kinetic model was used to perform H 2 O 2 thermal decomposition simulations for comparison against shock tube experiments performed by Hong et al. (Proc. Combust. Inst., 2013, 34, 565-571), and to estimate flame speeds and ignition delay times in H 2 mixtures. The simulation predicted a larger amount of O 2 ( 1 Δ g ) in H 2 O 2 decomposition than that predicted by Konnov's original model. These differences in the O 2 ( 1 Δ g ) yield are due to the use of a higher ab initio level and a more sophisticated methodology to compute the rate constant than those used in previous studies, thereby predicting a significantly larger rate constant. No effect was observed on the rate of the H 2 O 2 decomposition and on the flame speeds and ignition delay times of different H 2 -oxidizer mixtures. However, if the oxidizer is seeded with O 3 , small differences appear in the flame speed. Given that O 2 ( 1 Δ g ) is much more reactive than O

Metabolism of the hydrochlorofluorocarbon 1,2-dichloro-1,1-difluoroethane.

PubMed

Harris, J W; Anders, M W

1991-01-01

1,2-Dichloro-1,1-difluoroethane (HCFC-132b) is a potential substitute for some ozone-depleting chlorofluorocarbons and a model for other 1,1,1,2-tetrahaloethanes under consideration as chlorofluorocarbon substitutes. Male Fischer 344 rats were given 10 mmol/kg HCFC-132b dissolved in corn oil by intraperitoneal injection. An NMR assay for covalent binding of HCFC-132b metabolites to liver proteins was negative, whereas binding was observed in halothane-treated rats. Total urinary metabolites excreted by rats given HCFC-132b during the first 24 h amounted to 1.8 +/- 0.1% of the injected dose, as determined by 19F NMR. During the first 6 h, metabolites of HCFC-132b corresponding to 2-chloro-2,2-difluoroethyl glucuronide, unknown metabolite A, chlorodifluoroacetic acid, and chlorodifluoroacetaldehyde hydrate [both free and conjugated (unknown metabolite B)] were excreted in urine in the approximate ratio 100:9:3:7, respectively. Metabolite A is apparently an O-conjugate of 2-chloro-2,2-difluoroethanol; unconjugated 2-chloro-2,2-difluoroethanol was not detected in urine. The 19F NMR spectrum of metabolite B indicates the formation of a hemiacetal of chlorodifluoroacetaldehyde. Repeated exposure of rats to HCFC-132b significantly increased both the rate of chlorodifluoroacetic acid excretion and the relative fraction of the HCFC-132b dose excreted as chlorodifluoroacetic acid in urine. Incubation of HCFC-132b with rat hepatic microsomes yielded chlorodifluoroacetaldehyde hydrate as the only fluorinated product. The in vitro metabolism of HCFC-132b was increased in microsomes from pyridine-treated rats as compared with control rats, and HCFC-132b metabolism was inhibited by p-nitrophenol, indicating that the cytochrome P-450 isoform IIE1 is largely responsible for the initial hydroxylation of HCFC-132b.

The roles of 5-HT1A and 5-HT2 receptors in the effects of 5-MeO-DMT on locomotor activity and prepulse inhibition in rats.

PubMed

Krebs-Thomson, Kirsten; Ruiz, Erbert M; Masten, Virginia; Buell, Mahalah; Geyer, Mark A

2006-12-01

The hallucinogen 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) is structurally similar to other indoleamine hallucinogens such as LSD. The present study examined the effects of 5-MeO-DMT in rats using the Behavioral Pattern Monitor (BPM), which enables analyses of patterns of locomotor activity and exploration, and the prepulse inhibition of startle (PPI) paradigm. A series of interaction studies using the serotonin (5-HT)(1A) antagonist WAY-100635 (1.0 mg/kg), the 5-HT(2A) antagonist M100907 (1.0 mg/kg), and the 5-HT(2C) antagonist SER-082 (0.5 mg/kg) were performed to assess the respective contributions of these receptors to the behavioral effects of 5-MeO-DMT (0.01, 0.1, and 1.0 mg/kg) in the BPM and PPI paradigms. 5-MeO-DMT decreased locomotor activity, investigatory behavior, the time spent in the center of the BPM chamber, and disrupted PPI. All of these effects were antagonized by WAY-100635 pretreatment. M100907 pretreatment failed to attenuate any of these effects, while SER-082 pretreatment only antagonized the PPI disruption produced by 5-MeO-DMT. While the prevailing view was that the activation of 5-HT(2) receptors is solely responsible for hallucinogenic drug effects, these results support a role for 5-HT(1A) receptors in the effects of the indoleamine hallucinogen 5-MeO-DMT on locomotor activity and PPI in rats.

SSR240612 [(2R)-2-[((3R)-3-(1,3-benzodioxol-5-yl)-3-[[(6-methoxy-2-naphthyl)sulfonyl]amino]propanoyl)amino]-3-(4-[[2R,6S)-2,6-dimethylpiperidinyl]methyl]phenyl)-N-isopropyl-N-methylpropanamide hydrochloride], a new nonpeptide antagonist of the bradykinin B1 receptor: biochemical and pharmacological characterization.

PubMed

Gougat, Jean; Ferrari, Bernard; Sarran, Lionel; Planchenault, Claudine; Poncelet, Martine; Maruani, Jeanne; Alonso, Richard; Cudennec, Annie; Croci, Tiziano; Guagnini, Fabio; Urban-Szabo, Katalin; Martinolle, Jean-Pierre; Soubrié, Philippe; Finance, Olivier; Le Fur, Gérard

2004-05-01

The biochemical and pharmacological properties of a novel non-peptide antagonist of the bradykinin (BK) B(1) receptor, SSR240612 [(2R)-2-[((3R)-3-(1,3-benzodioxol-5-yl)-3-[[(6-methoxy-2-naphthyl)sulfonyl]amino]propanoyl)amino]-3-(4-[[2R,6S)-2,6-dimethylpiperidinyl]methyl]phenyl)-N-isopropyl-N-methylpropanamide hydrochloride] were evaluated. SSR240612 inhibited the binding of [(3)H]Lys(0)-des-Arg(9)-BK to the B(1) receptor in human fibroblast MRC5 and to recombinant human B(1) receptor expressed in human embryonic kidney cells with inhibition constants (K(i)) of 0.48 and 0.73 nM, respectively. The compound selectivity for B(1) versus B(2) receptors was in the range of 500- to 1000-fold. SSR240612 inhibited Lys(0)-desAr(9)-BK (10 nM)-induced inositol monophosphate formation in human fibroblast MRC5, with an IC(50) of 1.9 nM. It also antagonized des-Arg(9)-BK-induced contractions of isolated rabbit aorta and mesenteric plexus of rat ileum with a pA(2) of 8.9 and 9.4, respectively. Antagonistic properties of SSR240612 were also demonstrated in vivo. SSR240612 inhibited des-Arg(9)-BK-induced paw edema in mice (3 and 10 mg/kg p.o. and 0.3 and 1 mg/kg i.p.). Moreover, SSR240612 reduced capsaicin-induced ear edema in mice (0.3, 3 and 30 mg/kg p.o.) and tissue destruction and neutrophil accumulation in the rat intestine following splanchnic artery occlusion/reperfusion (0.3 mg/kg i.v.). The compound also inhibited thermal hyperalgesia induced by UV irradiation (1 and 3 mg/kg p.o.) and the late phase of nociceptive response to formalin in rats (10 and 30 mg/kg p.o.). Finally, SSR240612 (20 and 30 mg/kg p.o.) prevented neuropathic thermal pain induced by sciatic nerve constriction in the rat. In conclusion, SSR240612 is a new, potent, and orally active specific non-peptide bradykinin B(1) receptor antagonist.

Global statistical maps of extreme-event magnetic observatory 1 min first differences in horizontal intensity

USGS Publications Warehouse

Love, Jeffrey J.; Coisson, Pierdavide; Pulkkinen, Antti

2016-01-01

Analysis is made of the long-term statistics of three different measures of ground level, storm time geomagnetic activity: instantaneous 1 min first differences in horizontal intensity ΔBh, the root-mean-square of 10 consecutive 1 min differences S, and the ramp change R over 10 min. Geomagnetic latitude maps of the cumulative exceedances of these three quantities are constructed, giving the threshold (nT/min) for which activity within a 24 h period can be expected to occur once per year, decade, and century. Specifically, at geomagnetic 55°, we estimate once-per-century ΔBh, S, and R exceedances and a site-to-site, proportional, 1 standard deviation range [1 σ, lower and upper] to be, respectively, 1000, [690, 1450]; 500, [350, 720]; and 200, [140, 280] nT/min. At 40°, we estimate once-per-century ΔBh, S, and R exceedances and 1 σ values to be 200, [140, 290]; 100, [70, 140]; and 40, [30, 60] nT/min.

Characterization of ZrO2 and (ZrO2)x(Al2O3)1-X thin films on Si substrates: effect of the Al2O3 component

NASA Astrophysics Data System (ADS)

Vitanov, P.; Harizanova, A.; Ivanova, T.

2014-05-01

ZrO2 and (ZrO2)x(Al2O3)1-x films were deposited by the sol-gel technique on Si substrates. The effect of the Al2O3 additive on the film surface morphology was studied by atomic force microscopy (AFM). The mixed oxide films showed a smoother morphology and lower values of the root-mean-square (RMS) roughness compared to ZrO2. Further, FTIR spectra indicated that ZrO2 underwent crystallization. The electrical measurements of the MIS structure revealed that the presence of Al2O3 and the amorphization affects its dielectric properties. The MIS structure with (ZrO2)x(Al2O3)1-x showed a lower fixed charge (~ 6×1010 cm-2) and an interface state density in the middle of the band gap of 6×1011 eV-1 cm-2). The dielectric constant measured was 22, with the leakage current density decreasing to 2×10-8 A cm-2 at 1×106 V cm-1.

Rational design of octahedron and nanowire CeO2@MnO2 core-shell heterostructures with outstanding rate capability for asymmetric supercapacitors.

PubMed

Zhu, Shi Jin; Jia, Jia Qi; Wang, Tian; Zhao, Dong; Yang, Jian; Dong, Fan; Shang, Zheng Guo; Zhang, Yu Xin

2015-10-14

Two kinds of novel CeO2@MnO2 nanostructures have been synthesized via a self-assembly strategy. The as-prepared CeO2 nanowire@MnO2 nanostructures exhibited unprecedented pseudocapacitance performance (255 F g(-1)) with outstanding rate capability. A new mechanism based on the synergistic effect between CeO2 and MnO2 was proposed to interpret this phenomenon. When assembled as an asymmetric supercapacitor, an energy density of 27.5 W h kg(-1) with a maximum power density of 1.6 kW kg(-1) was achieved for CeO2 nanowire@MnO2 nanostructures.

Layered oxides-LiNi1/3Co1/3Mn1/3O2 as anode electrode for symmetric rechargeable lithium-ion batteries

NASA Astrophysics Data System (ADS)

Wang, Yuesheng; Feng, Zimin; Yang, Shi-Ze; Gagnon, Catherine; Gariépy, Vincent; Laul, Dharminder; Zhu, Wen; Veillette, René; Trudeau, Michel L.; Guerfi, Abdelbast; Zaghib, Karim

2018-02-01

High-performance and long-cycling rechargeable lithium-ion batteries have been in steadily increasing demand for the past decades. Nevertheless, the two dominant anodes at the moment, graphite and L4T5O12, suffer from a safety issue of lithium plating (operating voltage at ∼ 0.1 V vs. Li+/Li) and low capacity (175 mAh/g), respectively. Here, we report LiNi1/3Co1/3Mn1/3O2 as an alternative anode material which has a working voltage of ∼1.1 V and a capacity as high as 330 mAh/g at the current rate of C/15. Symmetric cells with both electrodes containing LiNi1/3Co1/3Mn1/3O2 can deliver average discharge voltage of 2.2 V. In-situ XRD, HRTEM and first principles calculations indicate that the reaction mechanism of a LiNi1/3Co1/3Mn1/3O2 anode is comprised mainly of conversion. Both the fundamental understanding and practical demonstrations suggest that LiNi1/3Co1/3Mn1/3O2 is a promising negative electrode material for lithium-ion batteries.

On the production of N2O from the reaction of O/1D/with N2.

NASA Technical Reports Server (NTRS)

Simonaitis, R.; Lissi, E.; Heicklen, J.

1972-01-01

Ozone was photolyzed at 2537 A and at 25 C in the presence of 42-115 torr of O2 and about 880 torr of N2 to test the relative importance of the two reactions O(1D) + N2 + M leading to N2O + M and O(1D) + N2 leading to O(3P) + N2. In this study N2O was not found as a product. Thus from our detectability limit for N2O an upper limit to the efficiency of the first reaction relative to the second of 2.5 times 10 to the -6 power at 1000-torr total pressure was computed.

Determining the Magnetic Properties of 1 kg Mass Standards

PubMed Central

Davis, Richard S.

1995-01-01

Magnetic interactions may lead to errors in precision mass metrology. An analytical description of such magnetic errors is presented in which the roles of both the volume magnetic susceptibility and permanent magnetization are discussed. The same formalism is then used to describe in detail the calibration and operation of a susceptometer developed at the Bureau International des Poids et Mesures (BIPM). The device has been optimized for the determination of the magnetic properties of 1 kg mass standards. PMID:29151735

Structural and dielectric properties of A(Fe{sub 1/2}Ta{sub 1/2})O{sub 3} [A = Ba, Sr, Ca

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dutta, Alo; Sinha, T.P., E-mail: sinha_tp@yahoo.com

2011-04-15

Graphical abstract: FTIR spectra of BFT, SFT and CFT at room temperature. Research highlights: {yields} The structural and dielectric properties of BaFe{sub 1/2}Ta{sub 1/2}O{sub 3}, SrFe{sub 1/2}Ta{sub 1/2}O{sub 3} and CaFe{sub 1/2}Ta{sub 1/2}O{sub 3}. {yields} Fourier transform infrared spectra show two primary phonon modes of the samples at around 450 cm{sup -1} and 620 cm{sup -1}. {yields} The compounds show significant frequency dispersion in its dielectric properties. {yields} The relaxation mechanism of the samples is modelled by Cole-Cole equation. -- Abstract: The complex perovskite oxide barium iron tantalate (BFT), BaFe{sub 1/2}Ta{sub 1/2}O{sub 3}, strontium iron tantalate (SFT), SrFe{sub 1/2}Ta{sub 1/2}O{submore » 3} and calcium iron tantalate (CFT), CaFe{sub 1/2}Ta{sub 1/2}O{sub 3} are synthesized by a solid-state reaction technique. Rietveld refinement of the X-ray diffraction data of the samples shows that BFT and SFT crystallize in cubic structure, with lattice parameter a = 4.06 A for BFT and 3.959 A for SFT, whereas CFT crystallizes in orthorhombic structure having lattice parameters a = 5.443 A, b = 5.542 A and c = 7.757 A. Fourier transform infrared spectra show two primary phonon modes of the samples at around 450 cm{sup -1} and 620 cm{sup -1}. The compounds show significant frequency dispersion in its dielectric properties. The complex impedance plane plots of the samples show that the relaxation (conduction) mechanism in these materials is purely a bulk effect arising from the semiconductive grains. The relaxation mechanism of the samples is modelled by Cole-Cole equation. The frequency dependent conductivity spectra are found to follow the power law.« less

Evidence for core 2 to core 1 O-glycan remodeling during the recycling of MUC1

PubMed Central

Razawi, Hanieh; Kinlough, Carol L; Staubach, Simon; Poland, Paul A; Rbaibi, Youssef; Weisz, Ora A; Hughey, Rebecca P; Hanisch, Franz-Georg

2013-01-01

The apical transmembrane glycoprotein MUC1 is endocytosed to recycle through the trans-Golgi network (TGN) or Golgi complex to the plasma membrane. We followed the hypothesis that not only the known follow-up sialylation of MUC1 in the TGN is associated with this process, but also a remodeling of O-glycan core structures, which would explain the previously described differential core 2- vs core 1-based O-glycosylation of secreted, single Golgi passage and recycling membrane MUC1 isoforms (Engelmann K, Kinlough CL, Müller S, Razawi H, Baldus SE, Hughey RP, Hanisch F-G. 2005. Glycobiology. 15:1111–1124). Transmembrane and secreted MUC1 probes show trafficking-dependent changes in O-glycan core profiles. To address this novel observation, we used recombinant epitope-tagged MUC1 (MUC1-M) and mutant forms with abrogated clathrin-mediated endocytosis (MUC1-M-Y20,60N) or blocked recycling (palmitoylation-defective MUC1-M-CQC/AQA). We show that the CQC/AQA mutant transits the TGN at significantly lower levels, concomitant with a strongly reduced shedding from the plasma membrane and its accumulation in endosomal compartments. Intriguingly, the O-glycosylation of the shed MUC1 ectodomain subunit changes from preponderant sialylated core 1 (MUC1-M) to core 2 glycans on the non-recycling CQC/AQA mutant. The O-glycoprofile of the non-recycling CQC/AQA mutant resembles the core 2 glycoprofile on a secretory MUC1 probe that transits the Golgi complex only once. In contrast, the MUC1-M-Y20,60N mutant recycles via flotillin-dependent pathways and shows the wild-type phenotype with dominant core 1 expression. Differential radiolabeling of protein with [35S]Met/Cys or glycans with [3H]GlcNH2 in pulse-chase experiments of surface biotinylated MUC1 revealed a significantly shorter half-life of [3H]MUC1 when compared with [35S]MUC1, whereas the same ratio for the CQC/AQA mutant was close to one. This finding further supports the novel possibility of a recycling-associated O

Detailed studies of a high-capacity electrode material for rechargeable batteries, Li2MnO3-LiCo(1/3)Ni(1/3)Mn(1/3)O2.

PubMed

Yabuuchi, Naoaki; Yoshii, Kazuhiro; Myung, Seung-Taek; Nakai, Izumi; Komaba, Shinichi

2011-03-30

Lithium-excess manganese layered oxides, which are commonly described by the chemical formula zLi(2)MnO(3)-(1-z)LiMeO(2) (Me = Co, Ni, Mn, etc.), are of great importance as positive electrode materials for rechargeable lithium batteries. In this Article, Li(x)Co(0.13)Ni(0.13)Mn(0.54)O(2-δ) samples are prepared from Li(1.2)Ni(0.13)Co(0.13)Mn(0.54)O(2) (or 0.5Li(2)MnO(3)-0.5LiCo(1/3)Ni(1/3)Mn(1/3)O(2)) by an electrochemical oxidation/reduction process in an electrochemical cell to study a reaction mechanism in detail before and after charging across a voltage plateau at 4.5 V vs Li/Li(+). Changes of the bulk and surface structures are examined by synchrotron X-ray diffraction (SXRD), X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectroscopy (SIMS). SXRD data show that simultaneous oxygen and lithium removal at the voltage plateau upon initial charge causes the structural rearrangement, including a cation migration process from metal to lithium layers, which is also supported by XAS. This is consistent with the mechanism proposed in the literature related to the Li-excess manganese layered oxides. Oxygen removal associated with the initial charge on the high voltage plateau causes oxygen molecule generation in the electrochemical cells. The oxygen molecules in the cell are electrochemically reduced in the subsequent discharge below 3.0 V, leading to the extra capacity. Surface analysis confirms the formation of the oxygen containing species, such as lithium carbonate, which accumulates on the electrode surface. The oxygen containing species are electrochemically decomposed upon second charge above 4.0 V. The results suggest that, in addition to the conventional transition metal redox reactions, at least some of the reversible capacity for the Li-excess manganese layered oxides originates from the electrochemical redox reaction of the oxygen molecules at the electrode surface.

Thermospheric production of O(1S) by dissociative recombination of vibrationally excited O2(+)

NASA Technical Reports Server (NTRS)

Yee, Jeng-Hwa; Killeen, T. L.

1986-01-01

High spectral resolution line profiles at 5577 A of the nighttime, F-region O(1S) emission measured by the Fabry-Perot interferometer on board the Dynamics Explorer satellite are analyzed using a continuous O(1S) relaxation model. The model is an improvement over the previous model of Killeen and Hays (1981) in that energy loss via elastic collision is considered in addition to the single collision, excitation exchange thermalization process. The results show that the active channel for O(1S) production is capture into the 1Sigma(+)u repulsive state of O2 and that the main contributor to its production is the dissociative recombination of O2(+) ions in vibrational levels v = 1 and 2 in agreement with the quantal calculations of Guberman (1983).

Complete matrix properties of [001](c) and [011](c) poled 0.33Pb(In(1/2)Nb(1/2))O(3)-0.38Pb(Mg(1/3)Nb(2/3))O(3)-0.29PbTiO(3) single crystals.

PubMed

Sun, Enwei; Zhang, Rui; Wu, Fengmin; Cao, Wenwu

2013-03-15

The elastic, piezoelectric, and dielectric properties of [001](c) and [011](c) poled 0.33Pb(In(1/2)Nb(1/2))O(3)-0.38Pb(Mg(1/3)Nb(2/3))O(3)-0.29PbTiO(3) single crystals have been fully characterized at room temperature, and the temperature and frequency dependence of the dielectric susceptibility ε(33) were also measured. The depoling temperature of this crystal is more than 20 °C higher than that of the corresponding binary 0.71Pb(Mg(1/3)Nb(2/3))O(3)-0.29PbTiO(3) system. From the measured P-E hysteresis loops, the coercive fields along [001](c) and [011](c) directions have been determined to be 6.0 kV/cm and 6.6 kV/cm, respectively, which indicate that these domain engineered ternary relaxor-based ferroelectric single crystals are excellent candidates for high-power applications.

Therapeutic efficacy of the adenosine A1 receptor agonist N6-cyclopentyladenosine (CPA) against organophosphate intoxication.

PubMed

Bueters, Tjerk J H; Groen, Bas; Danhof, Meindert; IJzerman, Ad P; Van Helden, Herman P M

2002-11-01

The objective of the present study was to investigate whether reduction of central acetylcholine (ACh) accumulation by adenosine receptor agonists could serve as a generic treatment against organophosphate (OP) poisoning. The OPs studied were tabun ( O-ethyl- N-dimethylphosphoramidocyanidate), sarin (isopropylmethylphosphonofluoridate), VX ( O-ethyl- S-2-diisopropylaminoethylmethylphosphonothiolate) and parathion ( O, O-diethyl- O-(4-nitrophenyl)phosphorothioate). The efficacy of the adenosine A(1) receptor agonist N(6)-cyclopentyladenosine (CPA) against an OP intoxication was examined on the basis of the occurrence of clinical symptoms that are directly associated with such intoxication. CPA (1-2 mg/kg) effectively attenuated the cholinergic symptoms and prevented mortality in lethally tabun- or sarin-intoxicated rats. In contrast, CPA (2 mg/kg) proved to be ineffective against VX or parathion intoxication. Intracerebral microdialysis studies revealed that survival of sarin-poisoned and CPA-treated animals coincided with a minor elevation of extracellular ACh concentrations in the brain relative to the baseline value, whereas an 11-fold increase in transmitter levels was observed in animals not treated with CPA. In VX-intoxicated rats, however, the ACh amounts increased 18-fold, irrespective of treatment with CPA. The striatal acetylcholinesterase (AChE) activity following a lethal sarin intoxication was completely abolished in the vehicle-treated animals, whereas 10% and 60% AChE activity remained in animals treated with 2 mg/kg CPA 1 min after or 2 min prior to the poisoning, respectively. In VX-intoxicated animals the AChE activity in the brain was strongly reduced (striatum 10%, hippocampus 1%) regardless of the CPA treatment. These results demonstrate that CPA is highly effective against tabun or sarin poisoning, but fails to protect against VX or parathion. Survival and attenuation of clinical signs in tabun- or sarin-poisoned animals are associated with a

Effect of dispersion correction on the Au(1 1 1)-H2O interface: A first-principles study

NASA Astrophysics Data System (ADS)

Nadler, Roger; Sanz, Javier Fdez.

2012-09-01

A theoretical study of the H2O-Au(1 1 1) interface based on first principles density functional theory (DFT) calculations with and without inclusion of dispersion correction is reported. Three different computational approaches are considered. First, the standard generalized gradient approximation (GGA) functional PBE is employed. Second, an additional energy term is further included that adds a semi-empirically derived dispersion correction (PBE-D2), and, finally, a recently proposed functional that includes van der Waals (vdW) interactions directly in its functional form (optB86b-vdW) was used to represent the state-of-the art of DFT functionals. The monomeric water adsorption was first considered in order to explore the dependency of geometry on the details of the model slab used to represent it (size, thickness, coverage). When the dispersion corrections are included the Au-H2O interaction is stronger, as manifested by the smaller dAu-O and stronger adsorption energies. Additionally, the interfacial region between Au(1 1 1) slab surfaces and a liquid water layer was investigated with Born-Oppenheimer molecular dynamics (BOMD) using the same functionals. Two or three interfacial orientations can be determined, depending on the theoretical methodology applied. Closest to the surface, H2O is adsorbed O-down, whereas further away it is oriented with one OH bond pointing to the surface and the molecular plane parallel to the normal direction. For the optB86b-vdW functional a third orientation is found where one H atom points into the bulk water layer and the second OH bond is oriented parallel to the metal surface. As for the water density in the first adsorption layer we find a very small increase of roughly 8%. From the analysis of vibrational spectra a weakening of the H-bond network is observed upon the inclusion of the Au(1 1 1) slab, however, no disruption of H-bonds is observed. While the PBE and PBE-D2 spectra are very similar, the optB86b-vdW spectrum shows

Positron annihilation 2D-ACAR study of semi-coherent Li nanoclusters in MgO( 1 0 0 ) and MgO( 1 1 0 )

NASA Astrophysics Data System (ADS)

Falub, C. V.; Mijnarends, P. E.; Eijt, S. W. H.; van Huis, M. A.; van Veen, A.; Schut, H.

2002-05-01

Depth selective positron annihilation two-dimensional angular correlation of annihilation radiation (2D-ACAR) is used to determine the electronic structure of Li nanoclusters formed by implantation of 10 16 cm -26Li ions (with an energy of 30 keV) in MgO(1 0 0) and (1 1 0) crystals, and subsequently annealed at 950 K. The 2D-ACAR spectra of Li-implanted MgO obtained with 4 keV positrons reveal the semi-coherent ordering state of the embedded metallic Li nanoclusters. The results agree with ab initio Korringa-Kohn-Rostoker calculations.

Characterization of hMTr1, a Human Cap1 2′-O-Ribose Methyltransferase*

PubMed Central

Bélanger, François; Stepinski, Janusz; Darzynkiewicz, Edward; Pelletier, Jerry

2010-01-01

Cellular eukaryotic mRNAs are capped at their 5′ ends with a 7-methylguanosine nucleotide, a structural feature that has been shown to be important for conferring mRNA stability, stimulating mRNA biogenesis (splicing, poly(A) addition, nucleocytoplasmic transport), and increasing translational efficiency. Whereas yeast mRNAs have no additional modifications to the cap, called cap0, higher eukaryotes are methylated at the 2′-O-ribose of the first or the first and second transcribed nucleotides, called cap1 and cap2, respectively. In the present study, we identify the methyltransferase responsible for cap1 formation in human cells, which we call hMTr1 (also known as FTSJD2 and ISG95). We show in vitro that hMTr1 catalyzes specific methylation of the 2′-O-ribose of the first nucleotide of a capped RNA transcript. Using siRNA-mediated knockdown of hMTr1 in HeLa cells, we demonstrate that hMTr1 is responsible for cap1 formation in vivo. PMID:20713356

In 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated primates, the selective 5-hydroxytryptamine 1a agonist (R)-(+)-8-OHDPAT inhibits levodopa-induced dyskinesia but only with\\ increased motor disability.

PubMed

Iravani, Mahmoud M; Tayarani-Binazir, Kayhan; Chu, Wing B; Jackson, Michael J; Jenner, Peter

2006-12-01

5-Hydroxytryptamine 1a (5-HT(1a)) receptor agonists, such as sarizotan and tandospirone, are reported to reduce levodopa-induced dyskinesia in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated macaques and in Parkinson's disease without worsening motor disability. However, these compounds are not specific for 5-HT(1a) receptors and also possess dopamine antagonist actions. We now report on the effects of (2R)-(+)-8-hydroxy-2-(di-n-propylamino)tetralin [(R)-(+)-8-OHDPAT], a selective 5-HT(1a) agonist lacking dopaminergic activity, on motor disability and dyskinesia (chorea and dystonia) in levodopa-primed MPTP-treated common marmosets. Administration of (R)-(+)-8-OHDPAT (0.2, 0.6, and 2.0 mg/kg s.c), in conjunction with levodopa/carbidopa (12.5 mg/kg each p.o.) to levodopa-primed animals, dose-dependently reduced levodopa-induced chorea but did not affect dystonic movements. However, (R)-(+)-8-OHDPAT treatment also reduced locomotor activity and the reversal of motor disability. Administration of (R)-(+)-8-OHDPAT alone had no effects of motor behaviors. The effects of (R)-(+)-8-OHDPAT on levodopa-induced motor behaviors were antagonized by the 5-HT(1a) receptor antagonist N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-2-pyridinylcyclohexanecarboxamide maleate (WAY-100635) (1.0 mg/kg s.c.). Administration of (R)-(+)-8-OHDPAT (0.6 mg/kg s.c.) also reduced chorea produced by the administration of the D(2)/D(3) dopamine receptor agonist pramipexole (0.06 mg/kg p.o.) to levodopa-primed MPTP-treated animals. However, again the increase in locomotor activity and reversal of motor disability produced by pramipexole were also inhibited. These data suggest that selective 5-HT(1a) agonists do not provide an effective means of suppressing levodopa-induced dyskinesia, except with worsening of parkinsonism.

The energetics of semicontact 3 x 2-min amateur boxing.

PubMed

Davis, Philip; Leithäuser, Renate M; Beneke, Ralph

2014-03-01

The energy expenditure of amateur boxing is unknown. Total metabolic cost (Wtot) as an aggregate of aerobic (Waer), anaerobic lactic (W[lactate]), and anaerobic alactic (WPCr) energy of a 3 × 2-min semicontact amateur boxing bout was analyzed. Ten boxers (mean ± SD [lower/upper 95% confidence intervals]) age 23.7 ± 4.1 (20.8/26.6) y, height 180.2 ± 7.0 (175.2/185.2) cm, body mass 70.6 ± 5.7 (66.5/74.7) kg performed a semicontact bout against handheld pads created from previously analyzed video footage of competitive bouts. Net metabolic energy was calculated using respiratory gases and blood [lactate]. Waer, 526.0 ± 57.1 (485.1/566.9) kJ, was higher (P < .001) than WPCr, 58.1 ± 13.6 (48.4/67.8) kJ. W[lactate], 26.2 ± 7.1 (21.1/31.3) kJ, was lower (P < .001) than Waer and WPCr. An ~70-kJ fraction of the aerobic energy expenditure reflects rephosphorylation of high-energy phosphates during the breaks between rounds, which elevated Wtot to ~680 kJ with relative contributions of 77% Waer, 19% WPCr, and 4% W[lactate]. The results indicate that the metabolic profile of amateur boxing is predominantly aerobic. They also highlight the importance of a highly developed aerobic capacity as a prerequisite of a high activity rate during rounds and recovery of the high-energy phosphate system during breaks as interrelated requirements of successful boxing.

Milestone Report - Demonstrate Braided Material with 3.5 g U/kg Sorption Capacity under Seawater Testing Condition (Milestone M2FT-15OR0310041 - 1/30/2015)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Janke, Christopher James; Das, Sadananda; Oyola, Yatsandra

This report describes work on the successful completion of Milestone M2FT-15OR0310041 (1/30/2015) entitled, Demonstrate braided material with 3.5 g U/kg sorption capacity under seawater testing condition . This effort is part of the Seawater Uranium Recovery Program, sponsored by the U.S. Department of Energy, Office of Nuclear Energy, and involved the development of new adsorbent braided materials at the Oak Ridge National Laboratory (ORNL) and marine testing at the Pacific Northwest National Laboratory (PNNL). ORNL has recently developed four braided fiber adsorbents that have demonstrated uranium adsorption capacities greater than 3.5 g U/kg adsorbent after marine testing at PNNL. Themore » braided adsorbents were synthesized by braiding or leno weaving high surface area polyethylene fibers and conducting radiation-induced graft polymerization of itaconic acid and acrylonitrile monomers onto the braided materials followed by amidoximation and base conditioning. The four braided adsorbents demonstrated capacity values ranging from 3.7 to 4.2 g U/kg adsorbent after 56 days of exposure in natural coastal seawater at 20 oC. All data are normalized to a salinity of 35 psu.« less

Ethane-1,1,2-trisphosphonic acid hemihydrate.

PubMed

Delain-Bioton, Lise; Lohier, Jean François; Villemin, Didier; Sopková-de Oliveira Santos, Jana; Hix, Gary; Jaffrès, Paul Alain

2008-02-01

Ethane-1,1,2-trisphosphonic acid crystallizes as a hemihydrate, C(2)H(9)O(9)P(3).0.5H(2)O, in which the water O atom lies on an inversion centre in the space group P2(1)/c. The acid component, which contains a short but noncentred O-H...O hydrogen bond, adopts a gauche conformation. The acid components are linked by an extensive series of O-H...O hydrogen bonds to form layers, which are linked into pairs by the water molecules.

On the differences between 1.5oC and 2oC of global warming

NASA Astrophysics Data System (ADS)

King, A.

2017-12-01

The Paris Agreement of 2015 has resulted in a drive to limit global warming to 2oC with an aim for a lower 1.5oC target. It is therefore vital that we understand some of the differences we would expect between these two levels of global warming. My research uses coupled climate model projections to investigate where and for what variables we can differentiate between worlds of 1.5oC and 2oC global warming. I place a particular focus on climate extremes and population exposure to those extremes. I have found that there are perceptible benefits in limiting global warming to 1.5oC as opposed to 2oC through reduced frequency and intensity of heat extremes, both over land and in ocean areas where thermal stress on coral has resulted in bleaching. Differences in high and low precipitation extremes between the 1.5oC and 2oC global warming levels are projected for some regions. I have also examined how "scalable" changes from the 1.5oC to 2oC level are. In areas of the world such as Eastern China I find that changes in anthropogenic aerosol concentrations will influence the level of change projected at 1.5oC and 2oC, such that past warming is likely to be a poor indicator of future changes. Overall, my research finds clear benefits to limiting global warming to 1.5oC relative to higher levels.

Romifidine, medetomidine or xylazine before propofol-halothane-N2O anesthesia in dogs.

PubMed Central

Redondo, J I; Gómez-Villamandos, R J; Santisteban, J M; Domínguez, J M; Ruiz, I; Avila, I

1999-01-01

The objective of this paper was to evaluate romifidine as a premedicant in dogs prior to propofol-halothane-N2O anesthesia, and to compare it with the other alpha2-agonists (medetomidine and xylazine). For this, ten healthy dogs were anesthetized. Each dog received 3 preanesthetic protocols: atropine (10 microg/kg BW, IM), and as a sedative, romifidine (ROM; 40 microg/kg BW, IM), xylazine (XYL; 1 microg/kg, IM), or medetomidine (MED; 20 microg/kg BW, IM). Induction of anesthesia was delivered with propofol 15 min later and maintained with halothane and N2O for one hour in all cases. The following variables were registered before preanesthesia, 10 min after the administration of preanesthesia, and at 5-minute intervals during maintenance: PR, RR, rectal temperature (RT), MAP, SAP, and DAP. During maintenance, arterial oxygen saturation (SpO2), end-tidal CO2 (EtCO2) and percentage of halothane necessary for maintaining anesthesia (%HAL) were also recorded. Induction dose of propofol (DOSE), time to extubation (TE), time to sternal recumbency (TSR) and time to standing (TS) were also registered. The statistical analysis was carried out during the anesthetic period. ANOVA for repeat measures revealed no differences between the 3 groups for PR and RR; however, MAP, SAP and DAP were higher in the MED group; SpO2 was lower in MED and EtCO2 was lower in ROM; %HAL was higher in XYL. No statistical differences were observed in DOSE, TE, TSR or TS. Percentage of halothane was lower in romifidine and medetomidine than in xylazine premedicated dogs also anesthetized with propofol. All the cardiorespiratory variables measured were within normal limits. The studied combination of romifidine, atropine, propofol, halothane and N2O appears to be a safe and effective drug combination for inducing and maintaining general anesthesia in healthy dogs. PMID:9918331

Mesospheric ionization and O2 1Delta(g) depletion

NASA Technical Reports Server (NTRS)

Spear, K. A.; Solomon, S.

1987-01-01

Observations of O2 1Delta(g) emission during solar proton events reveal large depletions below 80 and near 90 km. The lower-altitude depletions are believed to be due to odd hydrogen production and associated depletion of ozone, but the mechanism producing the depletion near 90 km has not yet been established. In this paper, it is proposed that an exothermic charge exchange reaction between O2(+) and O2 1Delta(g) is likely to be responsible for these high-altitude depletions. In particular, it is shown that the vertical structure of the observed change in airglow emission is consistent with this mechanism.

Binding of 3O2 and 1O2 to dyes used in photodynamic therapy in gas phase and aqueous media

NASA Astrophysics Data System (ADS)

Kushwaha, P. S.; Mishra, P. C.

Density functional theory (DFT) was employed at the B3LYP/6-31+G* level to study complexes of 1O2 and 3O2 with the dye molecules proflavine, methylene blue, and acridine orange, which are useful in photodynamic therapy. It was found that the most stable complex between 1O2 and proflavine are formed when 1O2 is located above the central ring, while the most stable complex between 1O2 and methylene blue is formed when 1O2 is located above the molecular plane, but not above any of the rings, near the sulfur atom. 1O2 can make a stable complex with acridine orange, as it is located above the outer ring of the dye. The binding energies of the complexes of 1O2 with all three dyes are enhanced considerably in going from gas phase to aqueous media. The complexes of 3O2 with the dyes will be unstable in all cases, while those of 1O2 with the same will be quite stable and will not be dissociated due to thermal fluctuations at room temperature. In the complexes of 1O2 and 3O2 with the dyes, charge transfer occurs from the dyes to the O2 moiety, the amount of charge transfer being much more to 1O2 than to 3O2 in each case.

Triaqua-1κO,2κ2 O-bis­(2,2′-bipyridine)-1κ2 N,N′;2κ2 N,N′-chlorido-1κCl-μ-terephthalato-1:2κ2 O 1:O 4-dicopper(II) nitrate monohydrate

PubMed Central

Liu, Yang; Feng, Yong-Lan; Kuang, Dai-Zhi

2012-01-01

In the binuclear title compound, [Cu2(C8H4O4)Cl(C10H8N2)2(H2O)3]NO3·H2O, the two crystallographically independent CuII ions have similar coordination environments. One of the CuII ions has a square-pyramidal arrangement, which is defined by a water mol­ecule occupying the apical position, with the equatorial ligators consisting of two N atoms from a 2,2′-bipyridine mol­ecule, one carboxyl­ate O atom from a terephthalate ligand and one O atom from a water mol­ecule. The other CuII ion has a similar coordination environment, except that the apical position is occupied by a chloride ligand instead of a water mol­ecule. An O—H⋯O and O—H⋯Cl hydrogen-bonded three-dimensional network is formed between the components. PMID:22719307

Origin of colossal permittivity in (In1/2Nb1/2)TiO2via broadband dielectric spectroscopy.

PubMed

Zhao, Xiao-gang; Liu, Peng; Song, Yue-Chan; Zhang, An-ping; Chen, Xiao-ming; Zhou, Jian-ping

2015-09-21

(In1/2Nb1/2)TiO2 (IN-T) ceramics were prepared via a solid-state reaction route. X-ray diffraction (XRD) and Raman spectroscopy were used for the structural and compositional characterization of the synthesized compounds. The results indicated that the sintered ceramics have a single phase of rutile TiO2. Dielectric spectroscopy (frequency range from 20 Hz to 1 MHz and temperature range from 10 K to 270 K) was performed on these ceramics. The IN-T ceramics showed extremely high permittivities of up to ∼10(3), which can be referred to as colossal permittivity, with relatively low dielectric losses of ∼0.05. Most importantly, detailed impedance data analyses of IN-T demonstrated that electron-pinned defect-dipoles, interfacial polarization and polaron hopping polarization contribute to the colossal permittivity at high temperatures (270 K); however, only the complexes (pinned electron) and polaron hopping polarization are active at low temperatures (below 180 K), which is consistent with UDR analysis.

Study of the ion--molecule half reactions O/sup +//sub 2/(a /sup 4/Pi/sub u/, v)xxx(O/sub 2/)/sub m/. -->. O/sup +//sub 2m/+1+O, m=1, 2, or 3, using the molecular beam photoionization method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Linn, S.H.; Ono, Y.; Ng, C.Y.

1981-03-15

The photoionization efficiency (PIE) curve for (O/sub 2/)/sup +//sub 2/ has been obtained in the region 650--1 080 A using the molecular beam photoionization method. The ionization energy (IE) for (O/sub 2/)/sub 2/ is determined to be 11.66 +- 0.03 eV. From the measured IE for (O/sub 2/)/sup +//sub 2/, the known IE for O/sub 2/, and the estimated dissociation energy (0.01 eV) of (O/sub 2/)/sub 2/, the binding energy for (O/sub 2/)/sup +//sub 2/ is deduced to be 0.42 +- 0.03 eV. Comparisons of the PIE spectra for O/sup +//sub 2/ and (O/sub 2/)/sup +//sub m/, where m=2, 3,more » and 4 indicate that the excited dimer complexes O(/sub 2/(n,v)x(O/sub 2/)/sub m/ (m=1, 2, and 3) formed in this wavelength region are almost completely dissociative, and the cluster ions are predominately formed by the direct photoionization processes (O/sub 2/)/sub m/=2, 3, or 4+h..nu -->..(O/sub 2/)/sup +//sub m/=2, 3, or 4+e. The PIE curves for O/sup +//sub 3/, O/sup +//sub 5/, and O/sup +//sub 7/ are measured in the region 650--780 A. The appearance energy 16.66 +- 0.03 eV (744 +- 1.5 A) for O/sup +//sub 3/ is found to be consistent with a zero activation energy for the ion-molecule reaction O/sup +//sub 2/(X/sup 2/Pi/sub g/)+O/sub 2/..-->..O/sup +//sub 3/+O. The appearance energy for O/sup +//sub 5/ is determined to be 16.41 +- 0.06 eV (755.5 +- 3 A). This value has allowed the determination of a binding energy of 0.26 eV for O/sup +//sub 3/xO/sub 2/. The nearly structureless PIE spectra observed for O/sup +//sub 3/, O/sup +//sub 5/, and O/sup +//sub 7/ also suggests that these ions originate mainly from (O/sub 2/)/sup +//sub 2/, (O/sub 2/)/sup +//sub 3/, and (O/sub 2/)/sup +//sub 4/ which are formed by direct ionization processes. Using the relative Franck--Condon factors for the O/sub 2/ a/sup 4/Pi/sub u/reverse arrowX/sup 3/..sigma../sup -//sub g/ transitions, the relative reaction probabilities for the ion--molecule half reactions O/sup +//sub 2/(a/sup 2/Pi/sub u/, v)x(O/sub 2

Comparative Genomic Analysis Shows That Avian Pathogenic Escherichia coli Isolate IMT5155 (O2:K1:H5; ST Complex 95, ST140) Shares Close Relationship with ST95 APEC O1:K1 and Human ExPEC O18:K1 Strains

PubMed Central

Pan, Zihao; Hu, Lin; Wang, Shaohui; Wang, Haojin; Leung, Frederick C.; Dai, Jianjun; Fan, Hongjie

2014-01-01

Avian pathogenic E. coli and human extraintestinal pathogenic E. coli serotypes O1, O2 and O18 strains isolated from different hosts are generally located in phylogroup B2 and ST complex 95, and they share similar genetic characteristics and pathogenicity, with no or minimal host specificity. They are popular objects for the study of ExPEC genetic characteristics and pathogenesis in recent years. Here, we investigated the evolution and genetic blueprint of APEC pathotype by performing phylogenetic and comparative genome analysis of avian pathogenic E. coli strain IMT5155 (O2:K1:H5; ST complex 95, ST140) with other E. coli pathotypes. Phylogeny analyses indicated that IMT5155 has closest evolutionary relationship with APEC O1, IHE3034, and UTI89. Comparative genomic analysis showed that IMT5155 and APEC O1 shared significant genetic overlap/similarities with human ExPEC dominant O18:K1 strains (IHE3034 and UTI89). Furthermore, the unique PAI I5155 (GI-12) was identified and found to be conserved in APEC O2 serotype isolates. GI-7 and GI-16 encoding two typical T6SSs in IMT5155 might be useful markers for the identification of ExPEC dominant serotypes (O1, O2, and O18) strains. IMT5155 contained a ColV plasmid p1ColV5155, which defined the APEC pathotype. The distribution analysis of 10 sequenced ExPEC pan-genome virulence factors among 47 sequenced E. coli strains provided meaningful information for B2 APEC/ExPEC-specific virulence factors, including several adhesins, invasins, toxins, iron acquisition systems, and so on. The pathogenicity tests of IMT5155 and other APEC O1:K1 and O2:K1 serotypes strains (isolated in China) through four animal models showed that they were highly virulent for avian colisepticemia and able to cause septicemia and meningitis in neonatal rats, suggesting zoonotic potential of these APEC O1:K1 and O2:K1 isolates. PMID:25397580

Comparative genomic analysis shows that avian pathogenic Escherichia coli isolate IMT5155 (O2:K1:H5; ST complex 95, ST140) shares close relationship with ST95 APEC O1:K1 and human ExPEC O18:K1 strains.