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1

Photoluminescence Quenching under Reverse Bias in Organic Multilayer Structure Utilizing 8-Hydroxyquinoline Aluminum and Aromatic Diamine  

NASA Astrophysics Data System (ADS)

Photoluminescence intensity from an organic multilayer structure utilizing 8-hydroxyquinoline aluminum ( Alq3) and aromatic diamine (TPD) has been modulated by applying reverse bias voltage. Photoluminescence intensity decreases with increasing reverse bias voltage. The decrease of photoluminescence intensity is enhanced in the thinner multilayer structure compared with the thicker multilayer. The mechanism of photoluminescence quenching in the organic multilayer structure has been discussed.

Fujii, Akihiko; Ohmori, Yutaka; Morishima, Chikayoshi; Yoshino, Katsumi

1994-03-01

2

Efficient Energy Transfer in Organic Multilayer Structure Utilizing 8-Hydroxyquinoline Aluminum and Aromatic Diamine  

NASA Astrophysics Data System (ADS)

Photoluminescence from an organic multilayer structure utilizing 8-hydroxyquinoline aluminum ( Alq3) and aromatic diamine has been discussed in terms of the wavelength of the excitation light and the layer thickness. The photoluminescence intensity from Alq3 layers is enhanced in the thinner multilayer structure compared with the thicker one as a result of efficient energy transfer at the heterointerfaces. The mechanism behind the increase of photoluminescence intensity in the organic multilayer structure is discussed.

Fujii, Akihiko; Morishima, Chikayoshi; Yoshida, Masayoshi; Ohmori, Yutaka; Yoshino, Katsumi

1994-09-01

3

Polarization Anisotropy of Organic Electroluminescent Diode with Periodic Multilayer Structure Utilizing 8-Hydroxyquinoline Aluminum and Aromatic Diamine  

NASA Astrophysics Data System (ADS)

An electroluminescent diode with periodic multilayer structure consisting of alternating layers of 8-hydroxyquinoline aluminum and aromatic diamine has been fabricated by organic molecular beam deposition. Polarization anisotropy of emission spectrum and intensity of light propagating in the diode organic layer have been observed. The mechanism of the emission anisotropy has been discussed in the periodic multilayer structure.

Fujii, Akihiko; Yoshida, Masayoshi; Ohmori, Yutaka; Yoshino, Katsumi

1995-05-01

4

Color-Variable Electroluminescent Diode with Single Quantum Well Structure Utilizing 8-Hydroxyquinoline Aluminum and Aromatic Diamine  

NASA Astrophysics Data System (ADS)

A color-variable electroluminescent diode has been realized utilizing a 1-nm-thick dye molecule layer with single-quantum-well (SQW) structure. The electroluminescent (EL) spectrum changes with increasing applied voltage from 8 V to 20 V. The result is discussed in terms of the shift of the recombination region toward the ITO electrode, depending on applied voltage.

Fujii, Akihiko; Yoshida, Masayoshi; Ohmori, Yutaka; Yoshino, Katsumi

1995-04-01

5

Synthesis and structure-activity relationship study of 8-hydroxyquinoline-derived Mannich bases as anticancer agents.  

PubMed

To continue our early study on the structural modifications of clioquinol, more 8-hydroxyquinoline-derived Mannich bases were synthesized and examined for growth-inhibitory effect. Taken Mannich base 1 as our lead compound, upon replacement of either sulfonyl group with methylene group or piperazine ring with ethylenediamine group resulted in an appreciable increase in potency. On the other hand, as 8-hydroxyquinoline was replaced with phenol, 3-hydroxypyridine and 1-naphthol, a dramatic decrease in activity was observed, indicating that 8-hydroxyquinoline is a crucial scaffold for activity. Further 3D-QSAR analysis on HeLa cells revealed that both steric and electronic effects contributed equally to growth inhibition. Taken together, the structure-activity relationships obtained from both in vitro data and CoMFA model warrant a valuable reference for further study. PMID:20359788

Shaw, Arthur Y; Chang, Chun-Yi; Hsu, Mei-Yuan; Lu, Pei-Jung; Yang, Chia-Ning; Chen, Hui-Ling; Lo, Cheng-Wei; Shiau, Chung-Wai; Chern, Ming-Kai

2010-07-01

6

Self-assembly of five 8-hydroxyquinolinate-based complexes: tunable core, supramolecular structure, and photoluminescence properties.  

PubMed

Five new Zn(II) complexes, namely [Zn3 (L)6 ] (1), [Zn2 (Cl)2 (L)2 (py)2 ] (2), [Zn2 (Br)2 (L)2 (py)2 ] (3), [Zn(L)2 (py)] (4), and [Zn2 (OAc)2 (L)2 (py)2 ] (5), were prepared by the solvothermal reaction of ZnX2 (X(-) =Cl(-) , Br(-) , F(-) , and OAc(-) ) salts with a 8-hydroxyquinolinate ligand (HL) that contained a trifluorophenyl group. All of the complexes were characterized by elemental analysis, IR spectroscopy, and powder and single-crystal X-ray crystallography. The building blocks exhibited unprecedented structural diversification and their self-assembly afforded one mononuclear, three binuclear, and one trinuclear Zn(II) structures in response to different anions and solvent systems. Complexes 1-5 featured four types of supramolecular network controlled by non-covalent interactions, such as ?????-stacking, C?H????, hydrogen-bonding, and halogen-related interactions. Investigation of their photoluminescence properties exhibited disparate emission wavelengths, lifetimes, and quantum yields in the solid state. PMID:24817667

Yuan, Guozan; Shan, Weilong; Qiao, Xuelong; Ma, Li; Huo, Yanping

2014-07-01

7

Studies on the growth, structural, optical, mechanical properties of 8-hydroxyquinoline single crystal by vertical Bridgman technique  

SciTech Connect

Highlights: {yields} Growth of bulk single crystal of 8-hydroxyquinoline (8-HQ) by vertical Bridgman technique for the first time. {yields} The crystalline perfection is reasonably good. {yields} The photoluminescence spectrum shows that the material is suitable for blue light emission. -- Abstract: Single crystal of organic nonlinear optical material, 8-hydroxyquinoline (8-HQ) of dimension 52 mm (length) x 12 mm (dia.) was grown from melt using vertical Bridgman technique. The crystal system of the material was confirmed by powder X-ray diffraction analysis. The crystalline perfection of the grown crystal was examined by high-resolution X-ray diffraction study. Low angular spread around 400'' of the diffraction curve and the low full width half maximum values show that the crystalline perfection is reasonably good. The recorded photoluminescence spectrum shows that the material is suitable for blue light emission. Optical transmittance for the UV and visible region was measured and mechanical strength was estimated from Vicker's microhardness test along the growth face of the grown crystal.

Prabhakaran, SP. [Crystal Growth and Thin Film Laboratory, Department of Physics, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu (India)] [Crystal Growth and Thin Film Laboratory, Department of Physics, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu (India); Babu, R. Ramesh, E-mail: rampap2k@yahoo.co.in [Crystal Growth and Thin Film Laboratory, Department of Physics, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu (India); Velusamy, P.; Ramamurthi, K. [Crystal Growth and Thin Film Laboratory, Department of Physics, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu (India)] [Crystal Growth and Thin Film Laboratory, Department of Physics, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu (India)

2011-11-15

8

Influence of the deposition temperature on the structure and performance of tris(8-hydroxyquinoline) aluminum based flexible organic light-emitting devices  

NASA Astrophysics Data System (ADS)

Based on indium tin oxide (ITO)/ N, N'diphenyl- N- N'-di( m-tdyl) benzidine (TPD)/Alq 3/Al structure, flexible OLEDs on polyethylene terephthalate (PET) substrates were fabricated by physical vapor deposition (PVD) method. Tris(8-hydroxyquinoline)aluminum (Alq 3) films were deposited at 90, 120 and 150 °C to examine the influence of the deposition temperature on the structure and performance of OLEDs. Electroluminescence (EL) spectra and current-voltage-luminance ( I- V- L) characteristics of the OLEDs were examined. It was found that the device fabricated at a high temperature had a higher external efficiency and longer lifetime. Atomic force microscope (AFM) was adopted to characterize the surface morphology of ITO/TPD/Alq 3. The higher uniform morphology of the Alq 3 formed at high temperature might contribute to the performance improvement of the OLEDs.

Wang, Guang Feng; Tao, Xiao Ming; Huang, Hong Min

2007-03-01

9

Electronic structure of the organic semiconductor Alq3 (aluminum tris-8-hydroxyquinoline) from soft x-ray spectroscopies and density functional theory calculations.  

PubMed

The element-specific electronic structure of the organic semiconductor aluminum tris-8-hydroxyquinoline (Alq(3)) has been studied using a combination of resonant x-ray emission spectroscopy, x-ray photoelectron spectroscopy, x-ray absorption spectroscopy, and density functional theory (DFT) calculations. Resonant and nonresonant x-ray emission spectroscopy were used to measure directly the carbon, nitrogen and oxygen 2p partial densities of states in Alq(3), and good agreement was found with the results of DFT calculations. Furthermore, resonant x-ray emission at the carbon K-edge is shown to be able to measure the partial density of states associated with individual C sites. Finally, comparison of previous x-ray emission studies and the present data reveal the presence of clear photon-induced damage in the former. PMID:19071937

DeMasi, A; Piper, L F J; Zhang, Y; Reid, I; Wang, S; Smith, K E; Downes, J E; Peltekis, N; McGuinness, C; Matsuura, A

2008-12-14

10

Luminance mechanisms in green organic light-emitting devices fabricated utilizing tris(8-hydroxyquinoline)aluminum/4,7-diphenyl-1, 10-phenanthroline multiple heterostructures acting as an electron transport layer.  

PubMed

The electrical and the optical properties in green organic light-emitting devices (OLEDs) fabricated utilizing tris(8-hydroxyquinoline)aluminum (Alq3)/4,7-diphenyl-1,10-phenanthroline (BPhen) multiple heterostructures acting as an electron transport layer (ETL) were investigated. The operating voltage of the OLEDs with a multiple heterostructure ETL increased with increasing the number of the Alq3/BPhen heterostructures because more electrons were accumulated at the Alq3/BPhen heterointerfaces. The number of the leakage holes existing in the multiple heterostructure ETL of the OLEDs at a low voltage range slightly increased due to an increase of the internal electric field generated from the accumulated electrons at the Alq3/BPhen heterointerface. The luminance efficiency of the OLEDs with a multiple heterostructure ETL at a high voltage range became stabilized because the increase of the number of the heterointerface decreased the quantity of electrons accumulated at each heterointerface. PMID:20359011

Choo, Dong Chul; Seo, Su Yul; Kim, Tae Whan; Jin, You Young; Seo, Ji Hyun; Kim, Young Kwan

2010-05-01

11

Exciton dynamics in an aromatic diamine at the interface with 8-hydroxyquinoline aluminum  

NASA Astrophysics Data System (ADS)

Exciton dynamics parameters such as diffusion length, ld, and surface quenching velocity, ?, in an amorphous film of an aromatic diamine (TPD) have been measured utilizing both the quenching effect exerted on its fluorescence by a thin layer of 8-hydroxyquinoline aluminum (Alq 3) deposited on the film as well as the exciton detector layer radiative emission itself. It is found that ld = (30 ± 10) nm and ? = (2 ± 1) × 10 3 cm/s. Using independent data on the intrinsic lifetime in TPD yields the diffusion coefficient of excitons D = (5±1) × 10 -3 cm 2/s. The results are discussed in connection with the operation mechanism of the double-layer electroluminescent structure based on the TPD/Alq 3 junction.

Kalinowski, J.; Giro, G.; Di Marco, P.; Camaioni, N.; Fattori, V.

1997-02-01

12

Simulating charge transport in tris(8-hydroxyquinoline) aluminium (Alq(3)).  

PubMed

We present a model of charge transport in organic solids which explicitly considers the packing and electronic structure of individual molecules. We simulate the time-of-flight mobility measurement in crystalline and disordered films of tris(8-hydroxyquinoline) aluminium (Alq(3)). The morphology of disordered Alq(3) is modelled on a molecular scale, and density functional theory is used to determine the electronic couplings between molecules. Without any fitting parameters we predict electron mobilities in the crystalline and disordered phases of approximately 1 and approximately 10(-4) cm(2) V(-1) s(-1), respectively. In good agreement with experiment we find that electron mobilities are two orders of magnitude greater than those of holes. We explain this difference in terms of the spatial extent of the frontier orbitals. Our results suggest that charge transport in disordered Alq(3) is dominated by a few highly conducting pathways. PMID:18368176

Kwiatkowski, J J; Nelson, J; Li, H; Bredas, J L; Wenzel, W; Lennartz, C

2008-04-14

13

Synthesis of Tetraazacrown Ethers Containing Two 8-Hydroxyquinoline Side Arms.  

National Technical Information Service (NTIS)

Four new tetraazacrown ethers containing two 8-hydroxyquinoline side arms were prepared first by reductive amination of 8-acetoxyquinolin-2-carbaldehyde with the appropriate tetraazacrown ether containing two microring NH functions. The resulting bis(8-ac...

Z. Yang J. S. Bradshaw P. B. Savage K. E. Krakowiak R. M. Izatt

1999-01-01

14

Electronic property and molecule design for luminescent metal complexes of tris(8-hydroxyquinoline) gallium  

Microsoft Academic Search

By means ofab initio HF and DFT B3LYP methods, the structure of Gaq3 (q = 8-hydroxyquinoline) was optimized. The frontier molecular orbital characteristics and energy levels of Gaq3 have been analyzed systematically in order to study the electronic transition mechanism in Gaq3. Three derivatives of Gaq3 and their polymers were designed and the possibilities that they were employed as luminescent

Zhongmin Su; Hongze Gao; Hong Cheng; Bei Chu; Lihua Chen; Rongshun Wang; Yue Wang; Jiacong Shen

2000-01-01

15

Complexation efficiency of differently fixed 8-hydroxyquinoline and salicylic acid ligand groups for labile aluminium species determination in soils—comparison of two methods  

Microsoft Academic Search

Two methods utilizing the complexation of labile Al species by 8-hydroxyquinoline (HQN) and salicylic acid (SA) ligand groups were developed for aluminium operationally defined fractionation in acid soils. First, the solid phase extraction (SPE) procedure by a short-term ion-exchange batch reaction with chelating resins Iontosorb Oxin and Iontosorb Salicyl containing both ligand groups was used previously. Second, the 8-hydroxyquinoline, salicylic

Peter Matúš; Jana Kubová

2006-01-01

16

New approach to synthesize 8-hydroxyquinoline-based complexes with Zn2+ and their luminescent properties  

NASA Astrophysics Data System (ADS)

In this paper, zinc(II) bis-(8-hydroxyquinoline) dihydrate (ZnQ2·2H2O) and zinc(II) bis-(2-methyl-8-hydroxyquinoline) monohydrate (Zn(MQ)2·H2O) were successfully prepared by a room-temperature solid-state chemical reaction using zinc acetate (Zn(CH3COO)2·2H2O), 8-hydroxyquinoline (HQ) and 2-methyl-8-hydroxyquinoline (2-methyl-8-HQ) as the starting materials. The results of X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and thermal analysis (TG/DSC) demonstrated that the chemical composition of the products were ZnQ2·2H2O and Zn(MQ)2·H2O. The scanning electron microscopy (SEM) images and the transmission electron microscopy (TEM) images showed that the products ZnQ2·2H2O and Zn(MQ)2·H2O had sheet-like morphology with a thickness of about 50 nm. The UV-vis absorption spectra of ZnQ2·2H2O and Zn(MQ)2·H2O indicated that they existed charge transfer from the metal to the ligand (MLCT bands). The room-temperature photoluminescence (PL) spectra of ZnQ2·2H2O revealed that the sample possessed largely blue shift compared with the previous reports. Besides, the two complexes presented a consistent decline situation along with the decline concentration in chloroform solution, which due to solvate effect and structural similarity. The fluorescence quantum yields were measured at 36.58% and 0.07%, and the emission colors were blue-green and light-blue, respectively. The fluorescence quantum yield of ZnQ2·2H2O was higher than some reported similar structure. The method was believed to largely facilitate the fabrication and application of organometallic complex nanomaterials.

Wang, Ruifang; Cao, Yali; Jia, Dianzeng; Liu, Lang; Li, Fang

2013-12-01

17

New cyclodextrin-bearing 8-hydroxyquinoline ligands as multifunctional molecules.  

PubMed

Recent investigations have rekindled interest in 8-hydroxyquinolines as therapeutic agents for cancer, Alzheimer's disease, and other neurodegenerative disorders. Three new ?-cyclodextrin conjugates of 8-hydroxyquinolines and their copper(II) and zinc(II) complexes have been synthesized and characterized spectroscopically. In addition to improving aqueous solubility, due to the presence of the cyclodextrin moiety, the hybrid systems have interesting characteristics including antioxidant activity, and their copper(II) complexes are efficient superoxide dismutase (SOD) mimics. The ligands and their copper(II) complexes show low cytotoxicity, attributed to the presence of the cyclodextrin moiety. These compounds have potential as therapeutic agents in diseases related both to metal dyshomeostasis and oxidative stress. PMID:24038335

Oliveri, Valentina; Puglisi, Antonino; Viale, Maurizio; Aiello, Cinzia; Sgarlata, Carmelo; Vecchio, Graziella; Clarke, James; Milton, John; Spencer, John

2013-10-01

18

Gluconjugates of 8-hydroxyquinolines as potential anti-cancer prodrugs.  

PubMed

8-Hydroxyquinolines are systems of great interest in the field of inorganic and bioinorganic chemistry. They are metal-binding compounds and are known to exhibit a variety of biological activities, such as antibacterial and anticancer activities. Among these systems, clioquinol has been the focus of a renewed interest in recent years. In this scenario, we synthesized and characterized the new clioquinol glucoconjugate, 5-chloro-7-iodo-8-quinolinyl-?-D-glucopyranoside in order to compare this system to that of clioquinol. We also synthesized, 8-quinolinyl-?-D-glucopyranoside, an 8-hydroxyquinoline glucoconjugate. The reason for the development of glucoconjugates is the glucose avidity, and the over-expression of glucose transporters in cancer cells. Here we demonstrate that glycoconjugates are cleaved in vitro by ?-glucosidase and these systems exhibit antiproliferative activity against different tumor cell lines in the presence of copper(II) ions. PMID:22354329

Oliveri, Valentina; Giuffrida, Maria Laura; Vecchio, Graziella; Aiello, Cinzia; Viale, Maurizio

2012-04-21

19

Spin Polarization Properties of Na Doped Meridianal Tris(8-Hydroxyquinoline) Aluminum Studied by First Principles Calculations  

NASA Astrophysics Data System (ADS)

We theoretically investigate the electronic structure and spin polarization properties of Na-doped meridianal tris(8-hydroxyquinoline) aluminum (Alq3) by first principles calculations. It is found that the spin density is distributed mainly in the Alq3 part in the Alq3:Na complex. Electron charge transfer takes place from the Na atom to the Alq3 molecule, which induces asymmetric changing of the molecule bond lengths, thus the spin density distribution becomes asymmetric. Spin polarization of the complex originates from the preferable filling of the spin-split nitrogen and carbon p-orbitals because of the different bond length changes of the Alq3 molecule upon Na doping.

Ren, Jun-Feng; Yuan, Xiao-Bo; Hu, Gui-Chao

2014-04-01

20

Pyrithione and 8-hydroxyquinolines transport lead across erythrocyte membranes.  

PubMed

Acute and chronic lead poisoning remains a significant health problem. Although chelating agents can bind to plasma lead, they cannot cross cell membranes where the total body lead burden resides, and are thus inefficient at reducing the total body lead burden. Recently, calcium and sodium ionophores have been shown to transport lead across cell membranes providing a novel method for reducing total body lead stores. We recently found that clioquinol, an 8-hydroxyquinoline derivative, can act as a zinc ionophore. We postulated that zinc ionophores might also be able to transport lead across biological membranes. To study this, we loaded lead in vitro into human erythrocytes and then studied the ability of zinc ionophores to transport lead into the extracellular space, where it was trapped with a lead chelator. Using inductively coupled plasma mass spectrometry (ICP-MS), we found that several 8-hydroxyquinoline derivatives, as well as the zinc and sodium salts of pyrithione (N-hydroxypyridine-2-thione), reduced erythrocyte lead content. The water-soluble compound, sodium pyrithione, was able to reduce lead in citrated whole blood, without partitioning into the erythrocytes. These results indicate that two classes of zinc ionophores can transport lead across a biological membrane, and they confirm that these ionophores are not cation-specific. Lead ionophores may prove useful in mobilizing lead into the extracellular space, thereby improving the efficacy of chelation therapy, in vivo or ex vivo. PMID:19665691

Lind, Stuart E; Park, Jong Sung; Drexler, John W

2009-09-01

21

Re-condensation and decomposition of Tris(8-hydroxyquinoline)-aluminum in a vapor transport ampoule  

NASA Astrophysics Data System (ADS)

By choosing various crystalline forms of tris(8-hydroxyquinoline)-aluminum (Alq3) source powders and using different transport gases under various inside-pressures pin, two constitutional supersaturation (CSS) zones were observed in a vapor transport ampoule with a source temperature of 300 °C and a growth period of 5.0 h. From UV-visible spectra, the material in the lower CSS zone (with sidewall temperature Tside?130-270 °C) was the re-condensed Alq3, while that in the upper zone (Tside around room temperature) was the decomposed 8-hydroxyquinoline (8Hq). With increasing pin from 1.3×102 to 9.3×104 Pa, the decomposition of Alq3 into 8Hq was enhanced, and the deposition of 8Hq CSS zone became apparent with the formation of several 8Hq needle crystals. In addition, a dependence of the crystal structure formed in the Alq3 CSS zone on the initial phase of the source powder was observed and discussed.

Kao, Fan-Hsuan; Lin, Ku-Yen; Jan, Da-Jeng; Tang, Shiow-Jing; Yang, Chun-Chuen; Lin, Chia-Her; Yeh, Jui-Ming; Chiu, Kuan-Cheng

2012-10-01

22

Polynorbornene derived 8-hydroxyquinoline paper strips for ultrasensitive chemical nerve agent surrogate sensing.  

PubMed

The detection of nerve agent simulants is achieved by the photoinduced electron transfer (PET) mechanism. A "turn-on" fluorescence response upon phosphorylation at 8-hydroxyquinoline of norbornene-based triazolyl functionalized 8-hydroxyquinoline () followed by intramolecular rearrangement provides very intense green emission. The detection limit of polymer () coated paper strips is 25 ppb with instantaneous response. PMID:24948420

Sarkar, Santu; Shunmugam, Raja

2014-07-01

23

Hole transporting properties of tris(8-hydroxyquinoline) aluminum (Alq3)  

NASA Astrophysics Data System (ADS)

The hole transporting properties of tris (8-hydroxyquinoline) aluminum (Alq3) were investigated by time-of-flight (TOF) technique between 278 and 373 K, and under an applied field range of 0.6-1.3 MV/cm. At room temperature, the hole mobility has a value between 10-9 and 10-8 cm2 V-1 s-1. The hole mobility is at least two orders of magnitude less than electron under identical preparation and measurement conditions. Generally, all hole TOF transients of Alq3 exhibit a nondispersive behavior, with a clear plateau region and a dispersion tail. Two disorder transport models, namely, the Gaussian disorder model (GDM) and the correlated disorder model (CDM), were applied to analyze the temperature and field dependent hole mobility data. The GDM, however, is found to be invalid because it fails to produce a meaningful positional disorder parameter. The CDM gives a better fit to the data, yet the model is still not satisfactory.

Fong, H. H.; So, S. K.

2006-11-01

24

[Preparation and characterization of 2(8-hydroxyquinoline)-2( phenol) zirconium thin film].  

PubMed

In this paper, the new emitting material zirconium complex with 8-hydroxyquinoline and phenol (Zr(OPh)2 q2), which can form high quality nano-scale amorphous thin films at glass substrates cleaned by vacuum evaporation, was synthesized. Its crystallization, thermal stability, the structure of energy band and PL mechanism were investigated respectively by FTIR spectra, DTA-TG analysis, SEM, XRD spectra, UV-Vis absorption spectra and fluorescence spectra. Results show that the Zr(OPh)2 q2 is a thermally stable material, whose melting point is 381.2 degrees C, decomposition temperature is 467.1 degrees C, whose film can emits intense yellow-green fluorescence with peak wavelength at 525 nm and a full width at half-maximum of 107.6 nm under UV excitation (390 nm), powder has intense yellow fluorescence, therefore it may be a excellent electroluminescent material. PMID:15828317

Hao, Yu-ying; Hao, Hai-tao; Wang, Hua; Zhou, He-feng; Liu, Xu-guang; Xu, Bing-she

2004-12-01

25

Ion-beam-induced surface damages on tris-(8-hydroxyquinoline) aluminum  

NASA Astrophysics Data System (ADS)

Surface damage of tris-(8-hydroxyquinoline) aluminum (Alq3) film by 100 eV Ar+ irradiation has been studied by using both x-ray and ultraviolet photoelectron spectroscopies (XPS and UPS). XPS core level electron density curves revealed that some N-Al and C-O-Al bonds in Alq3 molecules were broken by the irradiation. Correspondingly, the valence band structure of the Alq3 molecule, as measured by UPS, was tremendously changed. The highest occupied state extended towards the Fermi level (EF), implying that a metal-like conducting surface was formed. This kind of damaged surface would cause nonradiative quenching in an electroluminescence device when electrons are injected from the cathode into the Alq3 layer, and possibly result in electrical shorts.

Liao, L. S.; Hung, L. S.; Chan, W. C.; Ding, X. M.; Sham, T. K.; Bello, I.; Lee, C. S.; Lee, S. T.

1999-09-01

26

Complexation efficiency of differently fixed 8-hydroxyquinoline and salicylic acid ligand groups for labile aluminium species determination in soils--comparison of two methods.  

PubMed

Two methods utilizing the complexation of labile Al species by 8-hydroxyquinoline (HQN) and salicylic acid (SA) ligand groups were developed for aluminium operationally defined fractionation in acid soils. First, the solid phase extraction (SPE) procedure by a short-term ion-exchange batch reaction with chelating resins Iontosorb Oxin and Iontosorb Salicyl containing both ligand groups was used previously. Second, the 8-hydroxyquinoline, salicylic acid and ammonium salicylate agents with different concentrations by a single extraction protocol were applied in this paper. The flame atomic absorption spectrometry (FAAS) and optical emission spectrometry with inductively coupled plasma were used for aluminium quantification. The comparison of results from both methods show the possibility to supersede the first laborious method for the second simpler one in Al environmental risk assessment. The use of 1% 8-hydroxyquinoline in 2% acetic acid and 0.2% salicylic acid by a single extraction protocol without a need of sample filtration can supersede the SPE procedure in the Al pollution soil monitoring. Finally, the new scheme usable in a laboratory and moreover, directly in a field was proposed for Al fractionation in solid and liquid environmental samples. The labile Al species in soils and sediments are separated after their single leaching by 8-hydroxyquinoline or salicylic acid without a need of sample filtration. The labile Al species in soil solutions and natural waters are separated after their ultrafiltration followed by the SPE procedure with Iontosorb Oxin or Iontosorb Salicyl. PMID:17723563

Matús, Peter; Kubová, Jana

2006-07-28

27

New Tetraazacrown Ethers Containing Two Pyridine, Quinoline, 8-Hydroxyquinoline, or 8-Aminoquinoline Sidearms.  

National Technical Information Service (NTIS)

A series of macrocyclic tetraazacrown ethers containing two pyridine, quinoline, 8-hydroxyquinoline, or 8-aminoquinoline sidearms has been prepared. Crab-like cyclization of bis(alpha-chloroacetamide)s and diamines followed by reduction of the cyclic diam...

Z. Yang J. S. Bradshaw X. X. Zhang P. B. Savage K. E. Krakowiak

1999-01-01

28

Distribution of alkaline earth elements between aqueous solutions and polymeric sorbent impregnated with 8-hydroxyquinoline  

SciTech Connect

The interphase distribution of microimpurities of alkaline earth elements (AEE) between solutions of alkali metal chlorides and a macroporous styrene-divinyl-benzene copolymer impregnated with 8-hydroxyquinoline was studied. The influence of the phase composition on the distribution coefficients of AEE and 8-hydroxyquinoline was examined. The advantages of sorption of the impurities by an impregnated sorbent over liquid extraction for thorough purification of salt solutions were shown.

Turanov, A.N.; Kremenskaya, I.N.; Putrya, L.V.

1987-07-01

29

Influence of high hydrostatic pressure on Alq3, Gaq3, and Inq3 (q = 8-hydroxyquinoline).  

PubMed

We have studied the spectroscopic properties of OLED materials Alq(3), Gaq(3) and Inq(3) (q = 8-hydroxyquinoline) under pressure. We discuss the results in terms of the influence of structural modifications, the isomeric state and the enhancement of the intermolecular interaction. As-grown Alq(3), Gaq(3), Inq(3) containing meridional (mer) isomer experience a red shift of nearly 90 nm (2400 cm(-1)) in the 0-8 GPa range. Abrupt changes in the photoluminescence occur during compression at intermediate pressures for all materials. We assign them to a phase transition, its critical pressure depending on the central cation. All three samples experience an amorphization at P approximately 6 GPa, with associated changes in the spectroscopic properties. The pressure-induced phase transitions present hysteresis to ambient conditions. Photoluminescence lifetime decreases in all cases in the explored pressure range. In the case of facial isomer containing polymorphs of Alq(3), luminescence does not change its energy significantly. The most significant spectroscopic change observed in fac-isomer containing materials corresponds to gamma-Alq(3), which presents a low energy component that gains relative importance when pressure is increased. We ascribe this phenomenon to the presence of sensitized mer isomer impurities. PMID:19795819

Hernández, Ignacio; Gillin, William P

2009-10-29

30

A dinuclear aluminum 8-hydroxyquinoline complex with high electron mobility for organic light-emitting diodes  

NASA Astrophysics Data System (ADS)

A dinuclear aluminum 8-hydroxyquinoline complex (DAlq3) with improved electron mobility was designed for organic light-emitting diodes. The electron mobility in DAlq3 was determined via transient electroluminescence (EL) from bilayer devices with structure of indium tin oxide (ITO)/N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPB)/DAlq3/Mg:Ag. It was found that the electron mobility in DAlq3 is between 3.7-8.4×10-6 cm2/Vs at electric fields ranging between 1.2×106 and 4.0×106 V/cm, which is a factor of two higher than that in Alq3. The DAlq3 also shows a higher EL efficiency of 2.2 cd/A (1.2 Lm/W), as compared to Alq3 with an EL efficiency of 2.0 cd/A (1.0 Lm/W), which is attributed to more balanced electron and hole recombination due to the improved electron mobility of DAlq3.

Ma, Dongge; Wang, Guang; Hu, Yufeng; Zhang, Yanguang; Wang, Lixiang; Jing, Xiabin; Wang, Fosong; Lee, C. S.; Lee, S. T.

2003-02-01

31

Synthesis, characterization and DFT calculation of 4-fluorophenyl substituted tris(8-hydroxyquinoline)aluminum(III) complexes.  

PubMed

New 4-fluorophenyl substituted 8-hydroxyquinoline derivatives, 5-(4-fluorophenyl)quinolin-8-ol and 5,7-bis(4-fluorophenyl)quinolin-8-ol, were synthesized and characterized by spectroscopic methods. The aluminum complexes of 5-(4-fluorophenyl)quinolin-8-ol (AlQF) and of 5,7-bis(4-fluorophenyl)quinolin-8-ol (AlQF2) exhibit strong fluorescence emission centered at 525 nm and 530 nm respectively. The quantum yield of both complexes were enhanced compared to the parent tris(8-hydroxyquinolinato)aluminum(III) complex. Electronic structures and photophysical properties of the new complexes were investigated theoretically by ab initio and density functional theory (DFT) and time dependent DFT (TD-DFT). Geometries of the ground state (S0) and the first excited state (S1) of the new complexes were optimized at the B3LYP/6-31G(d) functional and configuration interaction singles (CIS) method respectively. The aryl substituents were found to contribute significantly to the frontier molecular orbitals (FMOs). We have observed that in both cases the lowest occupied molecular orbital (LUMO) energy decreases while the energy of the highest occupied molecular orbital is slightly increased. The most significant increase was observed for AlQF2. PMID:24036308

Suliman, Fakhreldin O; Al-Nafai, Isehaq; Al-Busafi, Saleh N

2014-01-24

32

Metal Ion Complexation Studies of Novel 8-Hydroxyquinoline-Containing Diaza-18-Crown-6 Ligands and Analogues.  

National Technical Information Service (NTIS)

Interaction of some 8-hydroxyquinoline-substituted and related ligands with various metal ions was evaluated by a calorimetric titration technique at 25 deg C in MeOH. Bis-(8-hydroxyquinoline- 2-ylmethyl)- substituted ligand 13 forms a very strong complex...

J. S. Bradshaw X. X. Zhang P. B. Savage K. E. Krakowiak R. M. Izaft

1999-01-01

33

Preliminary Complexation Studies of Bis-(8-Hydroxyquinoline) -substituted Tetraaza-15-crown-5 with Various Metal Ions.  

National Technical Information Service (NTIS)

Complexation of bis(8-hydroxyquinoline) -substituted tetraaza-15- crown-5 with Cu(2+), Co(2+), Ni(2+), Zn(2+), Cd(2+), and Pb(2+) was evaluated potentiometrically in aqueous solution (0.10 M Me4NCl) at 25 deg C. Ligand 1 formed very stable complexes with ...

X. X. Zhang J. S. Bradshaw R. T. Bronson P. B. Savage R. M. Izatt

1999-01-01

34

In vitro studies on the antioxidant and protective effect of 2-substituted -8-hydroxyquinoline derivatives against H(2)O(2)-induced oxidative stress in BMSCs.  

PubMed

Novel 2-vinyl-8-hydroxyquinoline derivatives as potential antioxidants and regulators of H(2)O(2)-induced oxidative stress in rat bone marrow mesenchymal stem cells (MSCs) are first reported. The antiradical properties and the reducing power of these compounds were assessed using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and auto-oxidation of pyrogallol method, respectively. The activity against lipid peroxidation was determined using ammonium thiocyanate method. The results revealed that introduction of electron-donating groups at 2nd position decreased the antioxidant activities of 8-hydroxyquinoline derivatives. In addition, compound 4, the structure of which is similar to melatonin, exhibited superior antioxidant activities in scavenging DPPH free radical, O(2) free radical, and anti-LPO activities. Except for compounds 7, 12, and 15, the other compounds exhibited a stimulatory effect on MSCs growth. Using hydrogen peroxide (H(2)O(2)), we also investigated the protective efficacy of 2-vinyl-8-hydroxyquinoline derivatives against oxidative stress-induced cell death of MSCs. Cell viability assayed by MTT method indicated that exposure of MSCs cultures to hydrogen peroxide resulted in a concentration-dependent decrease in cell viability, and compounds 4 and 5 at given concentration (2.62 x 10(-3) m) could protect MSCs against H(2)O(2)-induced oxidative stress in bone mesenchymal stem cell (BMSCs). PMID:20028394

Wang, Ting-Ting; Zeng, Gong-Chang; Li, Xi-Can; Zeng, He-Ping

2010-02-01

35

The reduction of effective doping with extra dopant: n-Type doping of tris(8-hydroxyquinoline) aluminum with K  

NASA Astrophysics Data System (ADS)

We studied the n-type doping effect of K deposited on tris(8-hydroxyquinoline) aluminum (Alq3), which has been used for efficient organic semiconducting devices for the last decade. The K doped or inserted at the interface region of the Alq3/cathode has shown highly enhanced device characteristics and yet, peculiarly, extra doping of K has always deteriorated the device properties. We study the interfacial electronic structures of the Alq3-K system using in situ photoemission spectroscopy and a theoretical model to understand the origin of such deterioration. As the K doping progresses, the lowest unoccupied molecular orbital (LUMO) of pristine Alq3 is gradually filled and it becomes an occupied gap state. This reduction of LUMO density of states makes the electron injection diminished, which is the origin of the device deterioration.

Lee, Hyunbok; Cho, Sang Wan; Lee, Jeihyun; Jeon, Pyung Eun; Jeong, Kwangho; Lee, Jin Woo; Yi, Yeonjin

2012-02-01

36

Swift heavy ion irradiation-induced modifications of tris-(8-hydroxyquinoline)aluminum thin films  

Microsoft Academic Search

Tris-(8-hydroxyquinoline)aluminum (Alq3), one of the most widely used light emitting and electron transport materials in organic luminescent devices, has been synthesized. Alq3 thin films have been deposited by a thermal evaporation process on glass substrates. The effect of swift heavy ion (SHI) irradiation using 40 MeV Li3+ on the Alq3 thin films has been studied by UV-visible, infrared, photoluminescence (PL)

K. Thangaraju; R. Kumaran; T. Mohanty; K. Asokan; P. Ramamurthy; D. Kanjilal; J. Kumar

2006-01-01

37

Study on photoluminescence from tris-(8-hydroxyquinoline)indium thin films and influence of light  

Microsoft Academic Search

Tris-(8-hydroxyquinoline)indium (Inq3) thin films, one of the metal chelates used in organic electroluminescent (EL) devices, were deposited by thermal evaporation process on glass substrates and were exposed to light for various time periods under the normal ambient. The influence of light exposure on the optical properties of Inq3 thin films were studied by UV–visible absorption, photoluminescence and time-resolved photoluminescence (TRPL)

K. Thangaraju; R. Kumaran; P. Ramamoorthy; V. Narayanan; J. Kumar

38

Studies on the Fluorescence of Tris(8-hydroxyquinoline)Aluminum and the Effect of Light Exposure  

Microsoft Academic Search

Organic Tris-(8-hydroxyquinoline)aluminum (Alq3) thin films, one of the most widely used electron transport as well as emissive materials in the organic electroluminescent (EL) devices, have been deposited on glass substrates by thermal evaporation process. The deposited Alq3 thin films were exposed to light in the normal ambient. The effect of light exposure on the fluorescence of Alq3 sample and formation

K. Thangaraju; P. Amaladass; A. K. Mohanakrishnan; V. Narayanan; J. Kumar

2010-01-01

39

Study on photoluminescence from tris-(8-hydroxyquinoline)aluminum thin films and influence of light  

Microsoft Academic Search

Tris-(8-hydroxyquinoline)aluminum (Alq3), which is the most widely used material in organic electroluminescent devices, has been synthesized. Alq3 thin films have been deposited on glass and silicon substrates. The influence of light exposure on the optical properties of Alq3 thin films has been studied. It is confirmed that the photoluminescence (PL) of Alq3 thin film originates from its two geometrical isomers,

K. Thangaraju; J. Kumar; P. Amaladass; A. K. Mohanakrishnan; V. Narayanan

2006-01-01

40

Studies on influence of light on fluorescence of Tris(8-hydroxyquinoline)aluminum thin films  

Microsoft Academic Search

Tris-(8-hydroxyquinoline)aluminum (Alq3) thin films, the most widely used electron transport\\/emissive material in the organic electroluminescent (EL) devices, have been deposited on glass substrates by thermal evaporation process. Alq3 thin films were exposed to light for various time periods under normal ambient. The fluorescence of as-prepared and light exposed Alq3 thin films and formation of luminescent quencher have been studied using

K. Thangaraju; P. Amaladass; K. Shanmuga Bharathi; A. K. Mohanakrishnan; V. Narayanan; J. Kumar

2009-01-01

41

In vitro selective inhibitory effect of 8-hydroxyquinoline against bifidobacteria and clostridia.  

PubMed

8-Hydroxyquinoline (8HQ) inhibited Clostridium tertium, Clostridium clostridioforme, Clostridium difficile and Clostridium perfringens in vitro with MICs of 8, 16, 32 and 32 ?g/mL, respectively. In contrast, MICs of most bifidobacteria (84%) were 512 ?g/mL or higher. Thus, 8HQ could be used as anti-clostridial agent or in selective media for bifidobacteria isolation. PMID:23770542

Novakova, Jitka; Vlkova, Eva; Bonusova, Bela; Rada, Vojtech; Kokoska, Ladislav

2013-08-01

42

Effect of Swift heavy ion irradiation on Tris(8-hydroxyquinoline) aluminum thin films  

Microsoft Academic Search

Tris-(8-hydroxyquinoline)aluminum (Alq3) is the most widely used light-emitting and electron transport materials in organic electroluminescent (EL) devices to date. Alq3 thin films have been deposited on glass substrates by thermal evaporation process. The deposited Alq3 thin films have been irradiated with Swift heavy ion (SHI) of Li3+ 40 MeV with various ion fluences. The effect of SHI irradiation on Alq3

K. Thangaraju; D. Kanjilal; J. Kumar

43

Magnetic resonance studies of tris-(8-hydroxyquinoline) aluminum-based organic light-emitting devices  

Microsoft Academic Search

The electroluminescence (EL)-, electrical current density (J)-, and photoluminescence (PL)- detected magnetic resonance (ELDMR, EDMR, and PLDMR, respectively) of tris-(8-hydroxyquinoline) aluminum (Alq3)-based organic light-emitting devices (OLEDs) and Alq3 films is described. At low temperatures, a positive spin-1\\/2 resonance is observed, i.e., the changes in J, the EL intensity IEL, and the PL intensity IPL are positive (DeltaJ\\/J, DeltaIEL\\/IEL, and DeltaIPL\\/IPL>0).

G. Li; C. H. Kim; J. Shinar

2004-01-01

44

Metal 8-Hydroxyquinoline-Functionalized Polymers and Related Materials and Methods of Making and Using the Same.  

National Technical Information Service (NTIS)

This invention relates to the synthesis of Mq.sub.n-containing monomeric compounds, comprising a polymerizable moiety, an Mq.sub.n-moiety, and an optional chemical spacer therebetween, wherein q, in each instance, comprises an 8-hydroxyquinoline residue, ...

A. Meyers M. Weck

2004-01-01

45

Stability of tris(8-hydroxyquinoline)-aluminum(III) films investigated by vacuum ultraviolet spectroscopic ellipsometry  

NASA Astrophysics Data System (ADS)

The optical constants of tris(8-hydroxyquinoline)-aluminum(III) (Alq3) thin films were determined in the vacuum ultraviolet range up to 9.5 eV by in situ spectroscopic ellipsometry measurements performed using synchrotron radiation. The exposure to atmosphere of the Alq3 films grown by organic molecular-beam deposition induces changes in ellipsometric spectra that are interpreted in terms of surface morphology changes. Alq3 films deposited by organic vapor phase deposition were found to be more stable upon exposure to atmosphere. Employing time-dependent density functional theory calculations, the features of the extinction coefficient were assigned to singlet-singlet transitions.

Himcinschi, C.; Gordan, O.; Salvan, G.; Müller, F.; Zahn, D. R. T.; Cobet, C.; Esser, N.; Braun, W.

2005-03-01

46

Synthesis and luminescence properties of polymeric complexes of Cu(II), Zn(II) and Al(III) with 8-hydroxyquinoline side group-containing polystyrene  

NASA Astrophysics Data System (ADS)

Three kinds of metalloquinolate-containing polystyrene were prepared via a polymer reaction and a coordination reaction. 5-Chloromethyl-8-hydroxyquinoline (CHQ) was first prepared through the chloromethylation reaction of 8-hydroxyquinoline (HQ) with 1,4-bichloromethoxy-butane as chloromethylation reagent. A polymer reaction, Friedel-Crafts alkylation reaction, was carried out between polystyrene (PS) and CHQ in the presence of Lewis catalyst, and HQ was bonded onto the side chains of PS, obtaining 8-hydroxyquinoline-functionalized Polystyrene, HQ-PS. And then, by using one-pot method with two-stage procedures, the coordination reaction of HQ-PS and small molecule HQ with metal ions including Al(III), Zn(II) and Cu(II) ions, was allowed to be carried out, and three polymeric metalloquinolates, AlQ3-PS, ZnQ2-PS and CuQ2-PS, were successfully prepared, respectively. In the chemical structures of these polymeric metalloquinolates, metalloquinolates were chemically attached onto the side chains of PS. HQ-PS and three polymeric metalloquinolates were fully characterized by FTIR, 1H NMR and TGA. The luminescence properties of the three polymeric metalloquinolates were mainly investigated by UV/Vis absorption spectra and fluorescence emission spectra in solutions and in solid film states. When excited by the ray at about 365 nm, the three polymeric metalloquinolates have blue-green luminescence, and the main emission peaks in the DMF solutions are located at 490, 482 and 502 nm for AlQ3-PS, ZnQ2-PS and CuQ2-PS, respectively. As compared with their emissions in solutions, the emissions in solid film states are red-shifted to some extent, and the main emission peaks are located at 500, 488 and 510 nm for AlQ3-PS, ZnQ2-PS and CuQ2-PS, respectively. Besides, these polymeric metalloquinolates have higher thermal stability than PS as polymeric skeleton.

Gao, Baojiao; Wei, Xiaopeng; Zhang, Yanyan

2013-01-01

47

Write once read many memory device from Tris-8 (-hydroxyquinoline) aluminum and Indium tin oxide nano particles  

NASA Astrophysics Data System (ADS)

Consequent to the fast increase in data storage requirements new materials and device structures are explored in a war footing. Organic memory devices are attracting lot of interest among the researchers and are becoming a hot topic of investigations. This study is an attempt to develop a tri-layer organic memory device using indium tin oxide (ITO) nanoparticles as charge trapping middle layer between tris-8(-hydroxyquinoline)aluminum (Alq3) layers employing spin coating technique. Device switching is studied by applying a current-voltage (I-V) sweep. On increasing the applied bias the device switched from the initial high resistance (OFF) state to a low resistance (ON) state at a switch on voltage of around 4 V. ON/OFF ratio is of the order of 100 at a read voltage of 2 V. The device is found to remain in the low resistance state on further scans, showing the applicability of this device as a write once read many times (WORM) memory.

Aneesh, J.; Predeep, P.

2011-10-01

48

Magneto-Conductance in Tri-(8-Hydroxyquinoline) Aluminum-Based Organic Light Emitting Diodes  

NASA Astrophysics Data System (ADS)

The origin of magneto-conductance (MC) in tri-(8-hydroxyquinoline)-aluminum (Alq3)-based organic light emitting diodes is investigated. Our results clearly show that the generated MC is related to the singlet polaron pair dissociation. Further studies on the MC in an electron blocking layer N,N?-bis(lnaphthyl)-N,N?-diphenyl-l,l?-biphentl-4,4?-diamine (NPB) and a hole blocking layer 2,2?,2?-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole (TPBi)-based devices indicate that the holes reaching the cathode from the dissociation of singlet polaron pairs on Alq3 are the main cause of the MC generation. It is found that the MC can be significantly reduced by doping a red fluorescence dye DCJTB as a hole trapper in Alq3.

Xu, Kai; Yang, De-Zhi; Ma, Dong-Ge

2013-08-01

49

Fluorescence properties of metal complexes of 8-hydroxyquinoline-5-sulfonic acid and chromatographic applications  

SciTech Connect

Seventy-eight metal species are examined for fluorescence properties of their chelates with 8-hydroxyquinoline-5-sulfonic acid (HQS); 42 of these fluoresce, many intensely. The optimum pH, determined by ligand ionization vs. hydroxo complex formation, lies between 5 and 8. Cadmium forms the most fluorescent complex in a purely aqueous solution. Fluorescence is enhanced for many metals in surfactant (hexadecyltrimethylammonium ion, HTA/sup +/) containing media and in a water:dimethylformamide solvent. A number of metal ions quench the fluorescence of other metal-HQS chelates, Fe(III) being by far the most effective, and such quenching is accentuated in media containing HTA/sup +/. The fluorescence properties can be exploited by introducing the ligand through a postcolumn reactor or by incorporating it in the eluent in a chromatographic system. Subpicomole detection limits are attainable for Cd, Mg, and Zn.

Soroka, K.; Vithanage, R.S.; Phillips, D.A.; Walker, B.; Dasgupta, P.K.

1987-02-15

50

Trap levels in tris(8-hydroxyquinoline) aluminum studied by deep-level optical spectroscopy  

NASA Astrophysics Data System (ADS)

We have investigated band gap states in tris(8-hydroxyquinoline) aluminum on fabricated indium tin oxide/Alq3/LiF/Al devices by using a deep-level optical spectroscopy (DLOS) technique. DLOS measurements after double-carrier injection into the Alq3 layer revealed a discrete trap level located at ~1.39 eV below the lowest unoccupied molecular orbital band. The pronounced 1.39 eV level is attributable to an intrinsic nature of Alq3 and can be active as an efficient generation-recombination center that may impact the photophysical properties. Additionally, the effective band gap of the Alq3 layer became narrow from 3.05 to 2.80 eV with increasing double-carrier injection rate.

Nakano, Yoshitaka; Noda, Koji; Fujikawa, Hisayoshi; Morikawa, Takeshi; Ohwaki, Takeshi; Taga, Yasunori

2006-06-01

51

Synthesis of Bis-8-Hydroxyquinoline-Armed Diazatrithia-15-Crown-5 and Diazatrithia-16-Crown-5 Ligands.  

National Technical Information Service (NTIS)

The synthesis of a series of diazatrithia-15-crown-5 and diazatrithia-16- crown-5 ligands containing two 8-hydroxyquinoline side arms are reported. The ligands were prepared by a two-step process. First, diazatrithiacrown ethers 11 and 12 were prepared by...

R. T. Bronson J. S. Bradshaw P. B. Savage K. E. Krakowiak R. M. Izatt

2001-01-01

52

Adsorption and solid phase extraction of 8-hydroxyquinoline from aqueous solutions by using natural bentonite  

NASA Astrophysics Data System (ADS)

The nitrogen-heterocyclic compound 8-hydroxyquinoline (8HQ) is one of the components of coal tar and has a wide variety of uses in industry. Because of its toxicity for aquatic organisms and harmful effects for human health, the removal of 8HQ from aqueous solutions by adsorption onto natural bentonite was investigated in the present work. The experimental results show that the optimum pH value of 2.5 is favourable for the 8HQ adsorption. The experimental data were fitted well with the pseudo-second-order kinetic and Langmuir adsorption isotherm models at all studied temperatures. The maximum adsorption capacity obtained from the Langmuir isotherm model at 20 °C was 120.6 mg g -1. The calculated thermodynamic results such as ? G° (-24.3 kJ mol -1) and ? H° (-9.56 kJ mol -1) indicate that the adsorption process is spontaneous and exothermic in nature. Solid phase extraction of 8HQ was also performed. The X-ray diffractometry (XRD), Fourier Transform Infrared (FTIR) and thermogravimetric (TG) analyses were carried out in order to confirm the 8HQ adsorption onto bentonite. According to the obtained results, natural bentonite can be a reusable and effective adsorbent for the removal of 8HQ.

Erdem, Bilge; Özcan, Adnan; Özcan, A. Safa

2010-06-01

53

White light emission from exciplex using tris-(8-hydroxyquinoline)aluminum as chromaticity-tuning layer  

SciTech Connect

We demonstrate efficient organic white light-emitting devices (LEDs), using N,N{prime}-diphenyl-N,N{prime}-bis(1-naphthyl){endash}(1,1{prime}-biphenyl)-4,4{prime}-diamine (NPB) as the hole-transporting layer, 1,6-bis(2-hydroxyphenyl)pyridine boron complex [(dppy)BF] as the emitting layer, tris-(8-hydroxyquinoline)aluminum (Alq) as the electron-transporting and chromaticity-tuning layer. The white light comes from exciplex emission at the solid-state interface between (dppy)BF and NPB in addition to the exciton emission from NPB and (dppy)BF, respectively. The chromaticity of white emission can be tuned by adjusting the thickness of the Alq layer. The white LEDs with an Alq thickness of 15 nm exhibit a maximum luminescence of 2000 cd/m2 and efficiency of 0.58 lm/W, and the Commission Internationale De l{close_quote}Eclairage coordinates of resulting emission vary from (0.29,0.33) to (0.31,0.35) with increasing forward bias from 10 to 25 V. The region is very close to the equienergy white point (0.33,0.33). {copyright} 2001 American Institute of Physics.

Feng, Jing; Li, Feng; Gao, Wenbao; Liu, Shiyong; Liu, Yu; Wang, Yue

2001-06-18

54

Different 8-Hydroxyquinolines Protect Models of TDP-43 Protein, ?-Synuclein, and Polyglutamine Proteotoxicity through Distinct Mechanisms*  

PubMed Central

No current therapies target the underlying cellular pathologies of age-related neurodegenerative diseases. Model organisms provide a platform for discovering compounds that protect against the toxic, misfolded proteins that initiate these diseases. One such protein, TDP-43, is implicated in multiple neurodegenerative diseases, including amyotrophic lateral sclerosis and frontotemporal lobar degeneration. In yeast, TDP-43 expression is toxic, and genetic modifiers first discovered in yeast have proven to modulate TDP-43 toxicity in both neurons and humans. Here, we describe a phenotypic screen for small molecules that reverse TDP-43 toxicity in yeast. One group of hit compounds was 8-hydroxyquinolines (8-OHQ), a class of clinically relevant bioactive metal chelators related to clioquinol. Surprisingly, in otherwise wild-type yeast cells, different 8-OHQs had selectivity for rescuing the distinct toxicities caused by the expression of TDP-43, ?-synuclein, or polyglutamine proteins. In fact, each 8-OHQ synergized with the other, clearly establishing that they function in different ways. Comparative growth and molecular analyses also revealed that 8-OHQs have distinct metal chelation and ionophore activities. The diverse bioactivity of 8-OHQs indicates that altering different aspects of metal homeostasis and/or metalloprotein activity elicits distinct protective mechanisms against several neurotoxic proteins. Indeed, phase II clinical trials of an 8-OHQ has produced encouraging results in modifying Alzheimer disease. Our unbiased identification of 8-OHQs in a yeast TDP-43 toxicity model suggests that tailoring 8-OHQ activity to a particular neurodegenerative disease may be a viable therapeutic strategy.

Tardiff, Daniel F.; Tucci, Michelle L.; Caldwell, Kim A.; Caldwell, Guy A.; Lindquist, Susan

2012-01-01

55

Deep-Level Characterization of Tris(8-hydroxyquinoline) Aluminum with and without Quinacridone Doping  

NASA Astrophysics Data System (ADS)

We have investigated band gap states in tris(8-hydroxyquinoline) aluminum (Alq3) with and without quinacridone (Qd) doping on fabricated indium-tin-oxide (ITO)/Alq3(:Qd)/LiF/Al devices by a deep-level optical spectroscopy (DLOS) technique. A nondoped Alq3 sample shows a discrete trap level located at ˜1.39 eV below the lowest unoccupied molecular orbital band in addition to near-band-edge transitions at 2.2-3.6 eV. This pronounced 1.39 eV level is attributable to the intrinsic nature of Alq3 and can be activated as an efficient generation-recombination (GR) center that may affect photophysical properties. On the other hand, a Qd-doped Alq3 sample exhibits a new deep level at ˜2.40 eV with increasing double-carrier injection rate, corresponding to the highest occupied molecular orbital band of Qd. Simultaneously, this GR center is subject to charge up positively owing to the presence of holes injected into the Qd doping level of the Qd-doped Alq3 sample.

Nakano, Yoshitaka; Noda, Koji; Fujikawa, Hisayoshi; Morikawa, Takeshi; Ohwaki, Takeshi

2007-04-01

56

Different 8-hydroxyquinolines protect models of TDP-43 protein, ?-synuclein, and polyglutamine proteotoxicity through distinct mechanisms.  

PubMed

No current therapies target the underlying cellular pathologies of age-related neurodegenerative diseases. Model organisms provide a platform for discovering compounds that protect against the toxic, misfolded proteins that initiate these diseases. One such protein, TDP-43, is implicated in multiple neurodegenerative diseases, including amyotrophic lateral sclerosis and frontotemporal lobar degeneration. In yeast, TDP-43 expression is toxic, and genetic modifiers first discovered in yeast have proven to modulate TDP-43 toxicity in both neurons and humans. Here, we describe a phenotypic screen for small molecules that reverse TDP-43 toxicity in yeast. One group of hit compounds was 8-hydroxyquinolines (8-OHQ), a class of clinically relevant bioactive metal chelators related to clioquinol. Surprisingly, in otherwise wild-type yeast cells, different 8-OHQs had selectivity for rescuing the distinct toxicities caused by the expression of TDP-43, ?-synuclein, or polyglutamine proteins. In fact, each 8-OHQ synergized with the other, clearly establishing that they function in different ways. Comparative growth and molecular analyses also revealed that 8-OHQs have distinct metal chelation and ionophore activities. The diverse bioactivity of 8-OHQs indicates that altering different aspects of metal homeostasis and/or metalloprotein activity elicits distinct protective mechanisms against several neurotoxic proteins. Indeed, phase II clinical trials of an 8-OHQ has produced encouraging results in modifying Alzheimer disease. Our unbiased identification of 8-OHQs in a yeast TDP-43 toxicity model suggests that tailoring 8-OHQ activity to a particular neurodegenerative disease may be a viable therapeutic strategy. PMID:22147697

Tardiff, Daniel F; Tucci, Michelle L; Caldwell, Kim A; Caldwell, Guy A; Lindquist, Susan

2012-02-01

57

High response organic ultraviolet photodetector based on blend of 4,4',4''-tri-(2-methylphenyl phenylamino) triphenylaine and tris-(8-hydroxyquinoline) gallium  

NASA Astrophysics Data System (ADS)

The authors demonstrate high response organic ultraviolet (UV) photodetector (PD) using 4,4',4''-tri-(2-methylphenyl phenylamino) triphenylaine (m-MTDATA) and tris-(8-hydroxyquinoline) gallium (Gaq3) to act as the electron donor and acceptor, respectively. The m-MTDATA:Gaq3 blend device shows a photocurrent of 405 ?A/cm-2 at -8 V, corresponding to a response of 338 mA/W under an illumination of 365 nm UV light with an intensity of 1.2 mW/cm2. The high response is attributed to the enhanced dissociation of geminate hole-electron pairs in the distributed heterojunction of the blend and suppression of radiative decay. Photophysics of the PD involved is also discussed in terms of the performance and device structures.

Su, Zisheng; Li, Wenlian; Chu, Bei; Li, Tianle; Zhu, Jianzhuo; Zhang, Guang; Yan, Fei; Li, Xiao; Chen, Yiren; Lee, Chun-Sing

2008-09-01

58

Electroluminescence degradation study of tris-(8-hydroxyquinoline)aluminum-based organic light emitting diode and influence of light  

Microsoft Academic Search

Organic light emitting diodes (OLEDs) based on tris-(8-hydroxyquinoline)aluminum (Alq3), the most widely used electroluminescent material in organic electroluminescent devices, have been fabricated. The electroluminescence degradation of Alq3-based OLED during the light exposure under the normal ambient has been studied. It is found that, during the light exposure of OLEDs in the normal ambient, luminescent quencher is formed in Alq3 thin

K. Thangaraju; M. P. Patankar; K. L. Narasimhan; J. Kumar

2007-01-01

59

DIRECT COMPLEXOMETRIC TITRATION OF GALLIUM IN THE PRESENCE OF 7-(1- NAPHTHYLAZO)-8HYDROXYQUINOLINE5SULPHONIC ACID AS AN INDICATOR  

Microsoft Academic Search

The interaction of gallium ions with 7-(1-naphthylazo)-8hydroxyquinoline-; 5-sulfonic acid was studied. It was found that gallium reacts with 7-(1-; naphthylazo)-8-hydl oxyquinoline-5-sulfonic acid in a molar ratio 1: 1, the molar ; extinction coefficient of the compound formed is 1.56 x 10⁴, and the ; equilibrium constant of the reaction studied is 0.96 x 10². It is shown ; that 7-(1-naphthylazo)-8-hydroxyquinoline5-sulfonic

A. I. Busev; L. L. Talipova; L. M. Skrebkova

1962-01-01

60

Magnetic resonance studies of tris-(8-hydroxyquinoline) aluminum-based organic light-emitting devices  

NASA Astrophysics Data System (ADS)

The electroluminescence (EL)-, electrical current density (J)-, and photoluminescence (PL)- detected magnetic resonance (ELDMR, EDMR, and PLDMR, respectively) of tris-(8-hydroxyquinoline) aluminum (Alq3)-based organic light-emitting devices (OLEDs) and Alq3 films is described. At low temperatures, a positive spin-1/2 resonance is observed, i.e., the changes in J, the EL intensity IEL, and the PL intensity IPL are positive (?J/J, ?IEL/IEL, and ?IPL/IPL>0). ?J/J and ?IEL/IEL are insensitive to the nature of the Alq3/cathode interface. They weaken with increasing T and become unobservable above 60 K. ?IPL/IPL also decreases with T, but is still observable at 250 K. Since the resonances all have the same g value, similar linewidths, and a similar dependence on T and the excitation level (J or the laser power), they are all attributed to the same mechanism. That mechanism is either the reduction of singlet exciton (SE) quenching by a reduced population of polarons in the bulk of the Alq3 layer (“the quenching mechanism”), or the enhanced formation of SEs from singlet polaron pairs at the expense of triplet excitons (TEs) (“the delayed PL mechanism”). However, the latter mechanism implies that the yield of SEs in Alq3-based OLEDs is greater than 25%. Due to evidence to the contrary, and other evidence which is inconsistent with the delayed PL mechanism, we conclude that the positive spin-1/2 resonance is due to the quenching mechanism. At T?60 K, another spin-1/2 resonance, which reduces both J and IEL (but is unobservable in the PL), emerges and grows with increasing T. This negative EDMR and ELDMR is sensitive to the buffer layer between Alq3 and the cathode, and is attributed to the magnetic resonance enhancement of the spin-dependent formation of negative spinless bipolarons from spin-1/2 negative polarons at the organic/cathode interface. The increased trapping of injected electrons at the interface reduces J and consequently IEL. However, at 295 K, the ratio |?IEL/IEL| in Alq3/AlOx/Al devices to that in Alq3/CsF/Al devices is significantly lower than the ratio of |?J/J| in these devices. Hence we suspect that other mechanisms, unidentified at this point, are also contributing to the negative ELDMR.

Li, G.; Kim, C. H.; Lane, P. A.; Shinar, J.

2004-04-01

61

Some features of electro-optical properties of polymeric compositions doped with 8-hydroxyquinoline based azodyes and their cobalt complexes  

NASA Astrophysics Data System (ADS)

Polymeric composites based on the copolymer butyl methacrylate: nonyl methacrylate (3:1) doped 8-hydroxyquinoline azo dyes with donor and acceptor substitutes and their complexes with cobalt are obtained. The influence of the external electric field on the polymeric films transmission of linear polarized light in the long-wave part of the azo dyes absorption range, (corresponding ??* azo fragments absorption range) and their metal complexes are observed. The influence of the electric field on the transmission is connected with the aligning forces for dipole moments of azobenzene groups and metal ions.

Davidenko, N. A.; Davidenko, I. I.; Savchenko, I. A.; Sinyugina, A. T.; Studzinsky, S. L.; Tonkopieva, L. S.; Deberdeev, T. R.; Kolendo, A. Yu.; Zaikov, G. E.

2014-05-01

62

Ultrasonic Spray-Assisted Solution-Based Vapor-Deposition of Aluminum Tris(8-hydroxyquinoline) Thin Films  

NASA Astrophysics Data System (ADS)

Aluminum tris(8-hydroxyquinoline) (Alq3) thin films were fabricated by a vapor-deposition technique from its methanol solution, that is, by the ultrasonic-assisted mist deposition technique. The application of high ultrasonic power to the Alq3--methanol mixture resulted in a stable and transparent solution. Mist particles formed by ultrasonic atomization of the solution were used as the source for vapor-deposition at the substrate temperature of 100--200 °C. Optical absorption and photoluminescence characteristics indicated the formation of Alq3 thin films. The results promise the formation of thin films of a variety of organic materials by the solution-based technique.

Piao, Jinchun; Katori, Shigetaka; Ikenoue, Takumi; Fujita, Shizuo

2011-02-01

63

The importance of holes in aluminium tris-8-hydroxyquinoline (Alq3) devices with Fe and NiFe contacts  

NASA Astrophysics Data System (ADS)

To study the dominant charge carrier polarity in aluminium tris-8-hydroxyquinoline (Alq3) based spin valves, single Alq3 layer devices with NiFe, ITO, Fe, and aluminium electrodes were fabricated and characterised by Time of Flight (ToF) and Dark Injection (DI) techniques, yielding a lower hole mobility compared to electron mobility. We compare the mobility measured by DI for the dominant carrier injected from NiFe and Fe electrodes into Alq3, to that of holes measured by ToF. This comparison leads us to conclude that the dominant charge carriers in Alq3 based spin valves with NiFe or Fe electrodes are holes.

Zhang, Hongtao; Desai, P.; Zhan, Y. Q.; Drew, A. J.; Gillin, W. P.; Kreouzis, T.

2014-01-01

64

Antimicrobial Activity of Metal & Metal Oxide Nanoparticles Interfaced With Ligand Complexes Of 8-Hydroxyquinoline And ?-Amino Acids  

NASA Astrophysics Data System (ADS)

Antimicrobial nanotechnology is a recent addition to the fight against disease causing organisms, replacing heavy metals and toxins. In the present work, mixed ligand complexes of metals like zinc, silver etc. and metal oxide have been synthesized using 8-hydroxyquinoline (HQ) as a primary ligand and N-and/O-donor amino acids such as L-serine, L-alanine, glycine, cysteine and histidine as secondary ligands. These complexes were characterized using different spectroscopic techniques. The complexes were tested for antifungal and antibacterial activity by using agar well diffusion bioassay.

Bhanjana, Gaurav; Kumar, Neeraj; Thakur, Rajesh; Dilbaghi, Neeraj; Kumar, Sandeep

2011-12-01

65

Modeling of Space-Charge and Field Distribution in Tris-8-Hydroxyquinoline Aluminum based Organic Light Emitting Devices  

NASA Astrophysics Data System (ADS)

Modeling of Space-Charge and Field Distribution in Tris-8-Hydroxyquinoline Aluminum based Organic Light Emitting Devices Vincent V. Dinh, Univ of California, Dept of Applied Science, Davis at Livermore, CA; Gil R. Delgado, Louis J. Terminello, Howard W. Lee, Tony Van Buuren, Lawrence Livermore National Laboratory, Chemistry and Material Science Directorate, Livermore, CA. Tris-8-Hydroxyquinoline Aluminum (Alq3) has been the subject of much interest due to its use as an electron transport and light emissive host in organic light emitting devices (OLEDs). Carrier injection and transport properties are of great importance in determining device performance and lifetime. But the fundamental charge and field distributions in Alq3 are not well understood. In this report we study the effects of variable electron and hole lifetimes on the distribution functions. In addition we also look at the effects of various injection rates. Our first order approximation predicts narrow recombination regions. This and the effects of injection rates and lifetimes on the charge and field distributions will be discussed in the context of OLED degradation. Vincent V. Dinh acknowledges a fellowship from Lawrence Livermore National Laboratory. The work is supported by the US-DOE, BES Material Science under contract W-7405-ENG-48, LLNL.

Dinh, Vincent; Delgado, Gil; Terminello, Louis; van Buuren, Tony; Lee, Howard

2000-03-01

66

High-performance supercapacitor based on nitrogen-doped porous carbon derived from zinc(II)-bis(8-hydroxyquinoline) coordination polymer.  

PubMed

Nitrogen-doped porous carbon electrodes with remarkable specific capacitance have been fabricated by the rational carbonization of zinc(II)-bis(8-hydroxyquinoline) (abbr. Znq(2)) coordination polymer, and heating treatment with CO(NH(2))(2). The experimental results demonstrate that the mass ratio of carbon precursor and CO(NH(2))(2) plays a key role in the formation of porous carbon with various nitrogen content as well as specific surface areas and pore structures. The cyclic voltammetry and galvanostatic charge-discharge measurements show that the capacitive performance has been remarkably improved by doping with nitrogen. The specific capacitance of 219.2 F g(-1) is achieved at the current density of 1 A g(-1) with nitrogen-doped porous carbon, increasing up to ca. 56.8% compared to that with pristine porous carbon. The nitrogen-doped porous carbon electrode exhibits enhance capacitance retention as ca. 45.2% at 20 A g(-1) as well as cycling stability (ca. 7.6% loss after 3000 cycles). The present carbonization method as well as the nitrogen-doping method for porous carbon from coordination polymer can enrich the strategies for the production of carbon-based electrodes materials in the application of electrochemical capacitors. PMID:23137906

Chen, Xiang Ying; Xie, Dong Hua; Chen, Chong; Liu, Jian Wei

2013-03-01

67

Synthesis and photophysics of novel 8-hydroxyquinoline aluminum metal complex with 1,3,4-oxadiazole units  

NASA Astrophysics Data System (ADS)

A novel luminescent metal complex, (OXHQ) 3Al, with 8-hydroxyquinoline aluminum and electron-transporting 1,3,4-oxadiazole unit was designed and synthesized. The photophysical processes were investigated by UV-vis absorption and fluorescence emission spectra in diluent solution. The results showed that the luminescence quantum yield of (OXHQ) 3Al was 0.67 in DMSO and it emitted blue light with the band gap of 3.13 eV estimated from the onset absorption. In addition, the light-emitting of (OXHQ) 3Al can be quenched by electron acceptor (dimethylterephalate), where the processes followed the Stern-Volmer equation. However, with the addition of electron donor ( N, N-dimethylaniline) fluorescent intensity of (OXHQ) 3Al was increased and emission peak was lightly blue-shift. Furthermore, the molecular interactions of (OXHQ) 3Al with fullerene (C 60) or carbon nanotubes (CNTs) were also carefully investigated.

Feng, Liheng; Wang, Xiaoju; Chen, Zhaobin

2008-11-01

68

In situ monitoring of thermal crystallization of ultrathin tris(8-hydroxyquinoline) aluminum films using surface-enhanced Raman scattering.  

PubMed

Thermal crystallization of 3, 10, and 60 nm-thick tris(8-hydroxyquinoline)aluminum (Alq3) films is studied using surface-enhanced Raman scattering with a constant heating rate. An abrupt higher frequency shift of the quinoline-stretching mode is found to be an indication of a phase transition of Alq3 molecules from amorphous to crystalline. While the 60 nm-thick film shows the same crystallization temperature as a bulk sample, the thinner films were found to have a lower crystallization temperature and slower rate of crystallization. Non-isothermal kinetics analysis is performed to quantify kinetic properties such as the Avrami exponent constants and crystallization rates of ultrathin Alq3 films. PMID:24405952

Muraki, Naoki

2014-01-01

69

A new metallostar complex based on an aluminum(III) 8-hydroxyquinoline core as a potential bimodal contrast agent.  

PubMed

A ditopic DTPA monoamide derivative containing an 8-hydroxyquinoline moiety was synthesized and the corresponding gadolinium(III) complex ([Gd(H5)(H(2)O)](-)) was prepared. After adding aluminum(III), the 8-hydroxyquinoline part self-assembled into a heteropolymetallic triscomplex [(Gd5)(3)Al(H(2)O)(3)](3-). The magnetic and optical properties of this metallostar compound were investigated in order to classify it as a potential in vitro bimodal contrast agent. The proton nuclear magnetic relaxation dispersion measurements indicated that the relaxivity r(1) of [Gd(H5)(H(2)O)](-) and [(Gd5)(3)Al(H(2)O)(3)](3-) at 20 MHz and 310 K equaled 6.17 s(-1) mM(-1) and 10.9 s(-1) mM(-1) per Gd(III) ion respectively. This corresponds to a relaxivity value of 32.7 s(-1) mM(-1) for the supramolecular complex containing three Gd(III) ions. The high relaxivity value is prominently caused by an increase of the rotational tumbling time ?(R) by a factor of 2.7 and 5.5 respectively, in comparison with the commercially used MRI contrast agent Gd(III)-DTPA (Magnevist®). Furthermore, upon UV irradiation, [(Gd5)(3)Al(H(2)O)(3)](3-) exposes green broad-band emission with a maximum at 543 nm. Regarding the high relaxivity and the photophysical properties of the [(Gd5)(3)Al(H(2)O)(3)](3-) metallostar compound, it can be considered as a lead compound for in vitro bimodal applications. PMID:22829068

Debroye, Elke; Dehaen, Geert; Eliseeva, Svetlana V; Laurent, Sophie; Vander Elst, Luce; Muller, Robert N; Binnemans, Koen; Parac-Vogt, Tatjana N

2012-09-21

70

Characterization of Bis-8-hydroxyquinoline-Armed Diazatrithia-16-crown-5 and Diazadibenzo-18-crown-6 Ligands as Fluorescent Chemosensors for Zinc.  

National Technical Information Service (NTIS)

Bis-8-hydroxyquinoline-armed diazatrithia-16-crown-5 (1) and diazadibenzo-18-crown-6 (2a) ligands selectivity respond to Zn(2+) over other tested metal ions, including Cd(2+), via large increases in fluorescence, while other side-armed diazadibenzo-18-cro...

J. Kawakami R. T. Bronson G. Xue J. S. Bradshaw R. M. Izatt

2002-01-01

71

An Introduction to Multivariate Curve Resolution-Alternating Least Squares: Spectrophotometric Study of the Acid-Base Equilibria of 8-Hydroxyquinoline-5-Sulfonic Acid  

ERIC Educational Resources Information Center

A spectrophotometric study of the acid-base equilibria of 8-hydroxyquinoline-5-sulfonic acid to describe the multivariate curve resolution-alternating least squares algorithm (MCR-ALS) is described. The algorithm provides a lot of information and hence is of great importance for the chemometrics research.

Rodriguez-Rodriguez, Cristina; Amigo, Jose Manuel; Coello, Jordi; Maspoch, Santiago

2007-01-01

72

Kinetics and equilibria of the interaction of 8-hydroxyquinoline with gallium(III) in water and sodium dodecyl sulfate solution.  

PubMed

The kinetics and equilibria of binding of gallium(III) to the 8-hydroxyquinoline (HQ) have been investigated in water and in the presence of sodium dodecyl sulfate (SDS) micelles. Moreover, the pKA1 and pKA2 of HQ and first hydrolysis constant of Ga3+ ion have been measured in water and SDS solution. The analysis of the kinetic and thermodynamic behavior reveals that the reactive form of Ga(III) is GaOH2+ in both cases. Although in water the only bound form of Ga(III) appears to be the deprotonated complex GaL, evidence for stabilization of the protonated form, GaHL on the micelle surface and stabilization of Ga3+ with respect to GaOH2+ is provided by the kinetic behavior in SDS. The addition of SDS at concentrations around the critical micellar concentration, results in a large enhancement of the rate of complex formation. The large catalytic effect produced by the SDS micellar solution provides a promising basis for the extraction of gallium from water using the HQ/SDS system. A procedure for gallium(III) extraction and recovery based on ligand modified-micellar enhanced ultrafiltration method, using the HQ/SDS system, is described. PMID:19146470

Biver, Tarita; Ghezzi, Lisa; Malvaldi, Veronica; Secco, Fernando; Tiné, Maria Rosaria; Venturini, Marcella

2009-02-12

73

Direct Observation of Charge Carriers in Highly Magnesium-Doped Tris(8-hydroxyquinoline) Aluminum Thin Film by Electron Spin Resonance  

NASA Astrophysics Data System (ADS)

We report on an electron spin resonance (ESR) study of a tris(8-hydroxyquinoline) aluminum (Alq3) thin film doped highly with Mg. We observed a clear ESR signal of radical anions in the film prepared by coevaporating Alq3 and Mg (Alq3:Mg= 1:3). The g value and peak-to-peak ESR linewidth ? Hpp are obtained as 2.0030 and 2.24 mT, respectively, which coincide well with the reported values of an Alq3 thin film with a low Mg doping concentration. The spin susceptibility of the film was found to obey Curie's law, which indicates that no interaction exists between spins of Alq3 anions. The doped charges are found to be localized at deep trapping sites by lineshape analysis and from the temperature dependence of ? Hpp. The doping concentration was evaluated to be 4.3%. This low doping concentration can be explained by the formation of Mg clusters in the film, which was directly confirmed by transmission electron microscopy.

Son, Donghyun; Shimoi, Yukihiro; Kizuka, Tokushi; Marumoto, Kazuhiro

2013-05-01

74

Photoluminescence of Alq3 - and Tb-activated aluminium-tris(8-hydroxyquinoline) complex for blue chip-excited OLEDs.  

PubMed

The tris(8-hydroxyquinoline)-aluminium complex is the most important and widely studied as electron transporting and green light emitting material. Alq(3) and Tb(x) Al((1-x)) q(3) have been synthesized (where x = 0.1, 0.3, 0.5, 0.7 and 0.9) and blended films of Alq(3) and Tb(x) Al((1-x)) q(3) with PMMA and PS at different percentage weight (wt%) concentrations (e.g., 0.1, 1, 5, 10, 25 and 50 wt%) have been prepared. The synthesized materials and their blended thin films have been characterized by a photoluminescence (PL) technique; the synthesis and PL characterization are reported in this paper. The synthesized metal complex shows bright emission of green light with blue light excitation (440 nm) and the prepared Tb(x) Al((1-x)) q(3) phosphor may be applicable in blue chip-excited OLEDs for the newly developed wallpaper lighting technology. PMID:22733610

Yawalkar, P W; Dhoble, S J; Thejo Kalyani, N; Atram, R G; Kokode, N S

2013-01-01

75

A tris(8-hydroxyquinoline) aluminum-based organic bistable device using ITO surfaces modified by Ag nanoparticles  

NASA Astrophysics Data System (ADS)

A tris (8-hydroxyquinoline) aluminum (Alq3)-based organic bistable device (OBD) using Al electrode and ITO electrode modified by Ag nanoparticles (NPs) was reported. The OBD exhibits high ON/OFF switching ratios in the range of 102-103 and long retention time over 104 s. The influence of the Ag NPs densities, as well as the Alq3 film thickness on the switch performance current-voltage (I-V) of the OBDs was studied. Correlation between filament formation mechanism and charge storage mechanism was observed by analysing the I-V characteristics of OBDs with different Alq3 film thickness. As for the Alq3 film with thickness of 300 nm, the trapping effect of Ag NPs leads to both ON and OFF states for OBD; for 100 nm thick Alq3 film, the effect of filamentation dominates in the ON and OFF states of OBD. For the case of 200 nm thick Alq3 film, however, the ON state results from the filamentation effect, while trapping effect is responsible for the OFF state. In addition, the diffusion effect of Al atoms in Alq3 film in the devices was discussed and was expected to explain this thickness-dependence relationship.

Jiao, Bo; Wu, Zhaoxin; Dong, Hua; Ning, Shuya; Hou, Xun

2013-11-01

76

Nanoscale investigation of moisture-induced degradation mechanisms of tris(8-hydroxyquinoline) aluminium-based organic light-emitting diodes  

NASA Astrophysics Data System (ADS)

By exploiting tapping mode atomic force microscopy, the moisture-induced degradation mechanisms of ITO (indium tin oxide)-coated glass/CuPc (copper phthalocyanine)/NPB (N, N'-di(naphthalene-1-yl)-N, N'-diphthalbenzidine)/Alq3 (tris(8-hydroxyquinoline) aluminium)-based organic light-emitting diodes without cathode were investigated. It is found that three types of degradation mechanisms are associated with moisture-exposed Alq3 films, when the device is exposed to moisture, namely, hydration of Alq3, crystallization of Alq3 and reaction of the Alq3 complex with H2O. Crystallization of the NPB layer of ITO/CuPc/NPB was observed on exposure to moisture, and de-wetting simultaneously takes place at the interface of CuPc/NPB. Indium and/or oxygen may diffuse from ITO into the organic layers. These observations provide a clear picture of the moisture-induced degradation mechanisms of the ITO/CuPc/NPB/Alq3-based OLEDs.

Xu, M. S.; Xu, J. B.; Chen, H. Z.; Wang, M.

2004-09-01

77

Silica-modified magnetic nanoparticles functionalized with cetylpyridinium bromide for the preconcentration of metals after complexation with 8-hydroxyquinoline.  

PubMed

Magnetically driven separation technology has received considerable attention in recent decade for its great potential application. In this study, we investigate the application of silica-modified magnetite nanoparticles (NPs) coated with a cationic surfactant as adsorbent for microextraction and determination of trace amounts of Cu(II), Ni(II), Co(II), Cd(II), Pb(II) and Mn(II) from environmental water samples. The synthesized silica-coated NPs in combination with cetylpyridinium bromide have the ability to adsolubilize the metal ions after complexation with 8-hydroxyquinoline. The NPs bearing the target metals are easily separated from the aqueous solution by applying an external magnetic field and the complexed metals were desorbed using acidic methanol. The desorbed analytes are introduced into the graphite furnace of an atomic absorption spectrometer. The effect of pH, complexing agent, amount of cetylpyridinium bromide, microextraction time, desorption conditions, ionic strength on extraction efficiency of the metal ions are investigated and optimized. Under the optimized conditions, the detection limits for Cu(II), Ni(II), Co(II), Cd(II), Pb(II) and Mn(II) are 4.7, 9.1, 9.5, 2.3, 7.4 and 15.3 ng L(-1), respectively and the relative standard deviations (n=6) are less than 3.6%. The accuracy of the method was evaluated by recovery measurements on the spiked samples and good recoveries (93-113%) with low RSDs were achieved. PMID:21482290

Karatapanis, Andreas E; Fiamegos, Yiannis; Stalikas, Constantine D

2011-05-15

78

Cloud point extraction of vanadium in pharmaceutical formulations, dialysate and parenteral solutions using 8-hydroxyquinoline and nonionic surfactant.  

PubMed

A cloud point extraction (CPE) method has been developed for the determination of trace quantity of vanadium ions in pharmaceutical formulations (PF), dialysate (DS) and parenteral solutions (PS). The CPE of vanadium (V) using 8-hydroxyquinoline (oxine) as complexing reagent and mediated by nonionic surfactant (Triton X-114) was investigated. The parameters that affect the extraction efficiency of CPE, such as pH of sample solution, concentration of oxine and Triton X-114, equilibration temperature and time period for shaking were investigated in detail. The validity of CPE of V was checked by standard addition method in real samples. The extracted surfactant-rich phase was diluted with nitric acid in ethanol, prior to subjecting electrothermal atomic absorption spectrometry. Under these conditions, the preconcentration of 50 mL sample solutions, allowed raising an enrichment factor of 125-fold. The lower limit of detection obtained under the optimal conditions was 42 ng/L. The proposed method has been successfully applied to the determination of trace quantity of V in various pharmaceutical preparations with satisfactory results. The concentration ranges of V in PF, DS and PS samples were found in the range of 10.5-15.2, 0.65-1.32 and 1.76-6.93 microg/L, respectively. PMID:20619536

Khan, Sumaira; Kazi, Tasneem G; Baig, Jameel A; Kolachi, Nida F; Afridi, Hassan I; Wadhwa, Sham Kumar; Shah, Abdul Q; Kandhro, Ghulam A; Shah, Faheem

2010-10-15

79

Sensor-containing microspheres of chitosan crosslinked with 8-hydroxyquinoline-5-sulphonic acid for determination of Cu(II) in instant coffee  

Microsoft Academic Search

A novel carbon paste electrode containing chitosan microspheres for the determination of Cu(II) in instant coffee by anodic stripping voltammetry was developed. Chitosan was crosslinked with the chelating agent 8-hydroxyquinoline-5-sulphonic acid and glutaraldehyde. The microspheres of the crosslinked chitosan biopolymer were obtained by the spray drying technique and employed in the construction of the sensor. In acetate buffer solution (0.1molL?1,

Luciano Vitali; Iolanda Cruz Vieira; Almir Spinelli

2011-01-01

80

Sonochemical fabrication of 8-hydroxyquinoline aluminum (Alq3) nanoflowers with high electrogenerated chemiluminescence.  

PubMed

Well-defined Alq(3) nanoflowers were fabricated via a facile and fast sonochemical route. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the structure and shape of the as-prepared product. The results showed that the resulting Alq(3) was composed of nanobelts with thickness about 50 nm, average widths of 200 nm, and length up to 10 ?m. The Alq(3) nanoflowers exhibited good electrogenerated chemiluminescence behavior. PMID:20805037

Mao, Chang-Jie; Wang, Dan-Chen; Pan, Hong-Cheng; Zhu, Jun-Jie

2011-03-01

81

Investigation of an efficient YbF 3\\/Al cathode for tris-(8-hydroxyquinoline)aluminum-based small molecular organic light-emitting diodes  

Microsoft Academic Search

Efficient tris-(8-hydroxyquinoline)aluminum (Alq3)-based organic light-emitting diodes (OLEDs) using YbF3 as the electron injection layer have been investigated. With an YbF3 (3.0nm)\\/Al cathode, the device with Alq3 as the emitting layer achieved a better performance than the control device with a LiF (0.5nm)\\/Al cathode. The release of the low-work-function metal Yb is responsible for the performance enhancement. From the analysis by

Yang Li; Lian Duan; Qian Liu; Rui Zhang; Deqiang Zhang; Liduo Wang; Juan Qiao; Yong Qiu

2008-01-01

82

Evaluation of cyclohexenoesculetin-beta-D-galactoside and 8-hydroxyquinoline-beta-D-galactoside as substrates for the detection of beta-galactosidase.  

PubMed Central

We describe the synthesis of two new substrates for the detection of beta-galactosidase and evaluate their performance in comparison with that of 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-Gal). Of 171 Enterobacteriaceae strains that were able to hydrolyze X-Gal, 166 (97.1%) also hydrolyzed cyclohexenoesculetin-beta-D-galactoside whereas only 96 (56.1%) showed evidence of hydrolysis of 8-hydroxyquinoline-beta-D-galactoside. No false-positive results were observed with either substrate.

James, A L; Perry, J D; Ford, M; Armstrong, L; Gould, F K

1996-01-01

83

Determination of aluminium with 8-hydroxyquinoline-5-sulfonic acid in presence of a cationic surfactant by first and second derivative synchronous fluorimetry  

SciTech Connect

An analytical method has been developed for the fluorimetric determination of nanogram amounts of aluminium in solution. The method is based on the reaction of aluminium with 8-hydroxyquinoline-5-sulfonic acid presence of hexadeciltrimethylammonium bromide as a surfactant agent. Synchronous scanned first and second derivative fluorimetry has been employed to increase the sensitivity of the method. The influence of reaction variables as well as instrumental parameters is discussed. The interference of various foreign ions has also been examined and in some cases eliminated or reduced by addition of 1,10-phenanthroline.

Salinas, F.; de la Pena, A.; Duran, M.S.

1988-08-01

84

Solid Phase Extraction of Inorganic Mercury Using 5-Phenylazo-8-hydroxyquinoline and Determination by Cold Vapor Atomic Fluorescence Spectroscopy in Natural Water Samples  

PubMed Central

8-Hydroxyquinoline (8-HQ) was chosen as a powerful ligand for Hg solid phase extraction. Among several chelating resins based on 8-HQ, 5-phenylazo-8-hydroxyquinoline (5Ph8HQ) is used for mercury extraction in which the adsorption dynamics were fully studied. It has been shown that Hg(II) is totally absorbed by 5Ph8HQ within the first 30 minutes of contact time with t1/2 5 minutes, following Langmuir adsorption model. At pH 4, the affinity of mercury is unchallenged by other metals except, for Cu(II), which have shown higher Kd value. With these latter characteristics, 5Ph8HQ was examined for the preconcentration of trace levels of Hg(II). The developed method showed quantitative recoveries of Hg(II) with LOD = 0.21?pg?mL?1 and RSD = 3–6% using cold vapor atomic fluorescence spectroscopy (CV-AFS) with a preconcentration factor greater than 250.

Daye, Mirna; Halwani, Jalal; Hamzeh, Mariam

2013-01-01

85

High-efficiency tris(8-hydroxyquinoline)aluminum (Alq3) complexes for organic white-light-emitting diodes and solid-state lighting.  

PubMed

Combinations of electron-withdrawing and -donating substituents on the 8-hydroxyquinoline ligand of the tris(8-hydroxyquinoline)aluminum (Alq(3)) complexes allow for control of the HOMO and LUMO energies and the HOMO-LUMO gap responsible for emission from the complexes. Here, we present a systematic study on tuning the emission and electroluminescence (EL) from Alq(3) complexes from the green to blue region. In this study, we explored the combination of electron-donating substituents on C4 and C6. Compounds 1-6 displayed the emission tuning between 478 and 526 nm, and fluorescence quantum yield between 0.15 and 0.57. The compounds 2-6 were used as emitters and hosts in organic light-emitting diodes (OLEDs). The highest OLED external quantum efficiency (EQE) observed was 4.6%, which is among the highest observed for Alq(3) complexes. Also, the compounds 3-5 were used as hosts for red phosphorescent dopants to obtain white light-emitting diodes (WOLED). The WOLEDs displayed high efficiency (EQE up to 19%) and high white color purity (color rendering index (CRI?85). PMID:21780202

Pérez-Bolívar, César; Takizawa, Shin-ya; Nishimura, Go; Montes, Victor A; Anzenbacher, Pavel

2011-08-01

86

Donepezil + propargylamine + 8-hydroxyquinoline hybrids as new multifunctional metal-chelators, ChE and MAO inhibitors for the potential treatment of Alzheimer's disease.  

PubMed

The synthesis, biochemical evaluation, ADMET, toxicity and molecular modeling of novel multi-target-directed Donepezil + Propargylamine + 8-Hydroxyquinoline (DPH) hybrids 1-7 for the potential prevention and treatment of Alzheimer's disease is described. The most interesting derivative was racemic ?-aminotrile4-(1-benzylpiperidin-4-yl)-2-(((8-hydroxyquinolin-5-yl)methyl)(prop-2-yn-1-yl)amino) butanenitrile (DPH6) [MAO A (IC50 = 6.2 ± 0.7 ?M; MAO B (IC50 = 10.2 ± 0.9 ?M); AChE (IC50 = 1.8 ± 0.1 ?M); BuChE (IC50 = 1.6 ± 0.25 ?M)], an irreversible MAO A/B inhibitor and mixed-type AChE inhibitor with metal-chelating properties. According to docking studies, both DPH6 enantiomers interact simultaneously with the catalytic and peripheral site of EeAChE through a linker of appropriate length, supporting the observed mixed-type AChE inhibition. Both enantiomers exhibited a relatively similar position of both hydroxyquinoline and benzyl moieties with the rest of the molecule easily accommodated in the relatively large cavity of MAO A. For MAO B, the quinoline system was hosted at the cavity entrance whereas for MAO A this system occupied the substrate cavity. In this disposition the quinoline moiety interacted directly with the FAD aromatic ring. Very similar binding affinity values were also observed for both enantiomers with ChE and MAO enzymes. DPH derivatives exhibited moderate to good ADMET properties and brain penetration capacity for CNS activity. DPH6 was less toxic than donepezil at high concentrations; while at low concentrations both displayed a similar cell viability profile. Finally, in a passive avoidance task, the antiamnesic effect of DPH6 was tested on mice with experimentally induced amnesia. DPH6 was capable to significantly decrease scopolamine-induced learning deficits in healthy adult mice. PMID:24813882

Wang, Li; Esteban, Gerard; Ojima, Masaki; Bautista-Aguilera, Oscar M; Inokuchi, Tsutomu; Moraleda, Ignacio; Iriepa, Isabel; Samadi, Abdelouahid; Youdim, Moussa B H; Romero, Alejandro; Soriano, Elena; Herrero, Raquel; Fernández Fernández, Ana Patricia; Ricardo-Martínez-Murillo; Marco-Contelles, José; Unzeta, Mercedes

2014-06-10

87

Characterization of gold-thiol-8-hydroxyquinoline self-assembled monolayers for selective recognition of aluminum ion using voltammetry and electrochemical impedance spectroscopy.  

PubMed

Gold electrode surface is modified via covalent attachment of a synthesized thiol functionalized with 8-hydroxyquinoline, p-((8-hydroxyquinoline)azo) benzenethiol (SHQ), for the first time. The behavior of the nanostructured electrode surface (Au-SHQ) is characterized by electrochemical techniques including cyclic and differential pulse voltammetry (CV and DPV), and electrochemical impedance spectroscopy (EIS). The modified surface is stable in a wide range of potentials and pHs. A surface pKa of 6.0±0.1 is obtained for Au-SHQ electrode using surface acid/base titration curves constructed by CV and EIS measurements as a function of pH. These results helped to determine the charge state of the surface as a function of pH. The gold modified electrode surface showed good affinity for sensing the Al(III) ion at pH 5.5. The sensing process is based on (i) accumulation and complex formation between Al(III) from the solution phase and 8HQ function on the Au electrode surface (recognition step) and (ii) monitoring the impedance of the Au-SHQ-Al(III) complex against redox reaction rate of parabenzoquinone (PBQ) (signal transduction step). The PBQ is found to be a more suitable probe for this purpose, after testing several others. Thus, the sensor was tested for quantitative determination of Al(III) from the solution phase. At the optimized conditions, a linear response, from 1.0×10(-11) to 1.2×10(-5)M Al(III) in semi-logarithmic scale, with a detection limit of 8.32×10(-12)M and mean relative standard deviation of 3.2% for n=3 at 1.0×10(-7)M Al(III) is obtained. Possible interferences from coexisting cations and anions are also studied. The results show that many ions do not interfere significantly with the sensor response for Al(III). Validity of the method and applicability of the sensor are successfully tested by determination of Al(III) in human blood serum samples. PMID:24767148

Shervedani, Reza Karimi; Rezvaninia, Zeinab; Sabzyan, Hassan; Zali Boeini, Hassan

2014-05-12

88

Synthesis, spectroscopic, thermal, voltammetric studies and biological activity of crystalline complexes of pyridine-2,6-dicarboxylic acid and 8-hydroxyquinoline  

NASA Astrophysics Data System (ADS)

Two new compounds (8-H 2Q) 2[M(dipic) 2]·6H 2O (M = Co ( 1) and Ni ( 2), 8-HQ = 8-hydroxyquinoline, dipic = dipicolinate) have been prepared and characterized by elemental analysis, spectral (IR and UV-vis), thermal analyses, magnetic measurements and single-crystal X-ray diffraction techniques. Both 1 and 2 consist two 8-hydroxyquinolinium cations, one bis(dipicolinate)M(II) anion [M = Co(II), Ni(II)] and six uncoordinated water molecules. Both 1 and 2 crystallize in the monoclinic space group C2/c. In the compounds anion, each dipic ligand simultaneously exhibits tridentate coordination modes through N atom of pyridine ring and oxygen atoms of the carboxylate groups. The crystal packing of 1 and 2 is a composite of intermolecular hydrogen bonding and C-O⋯? interactions. The in vitro antibacterial and antifungal activities of 1 and 2 were evaluated by the agar well diffusion method by MIC tests. Both new compounds showed the same antimicrobial activity against Gram-positive bacteria and yeast and fungi expect Gram-negative bacteria.

Çolak, Alper Tolga; Çolak, Ferda?; Ye?ilel, Okan Zafer; Büyükgüngör, Orhan

89

The eradication of breast cancer cells and stem cells by 8-hydroxyquinoline-loaded hyaluronan modified mesoporous silica nanoparticle-supported lipid bilayers containing docetaxel.  

PubMed

Breast cancer stem cells (BCSCs), which can fully recapitulate the tumor origin and are often resistant to chemotherapy and radiotherapy, are currently considered as a major obstacle for breast cancer treatment. To achieve the goal of both targeting BCSCs and bulk breast cancer cells, we developed 8-hydroxyquinoline-loaded hyaluronan modified mesoporous silica nanoparticles (MSN)-supported lipid bilayers (HA-MSS) and docetaxel-loaded MSS. The results showed that the size of all the nanoparticles was smaller than 200 nm. BCSCs were enriched from MCF-7 cells by a sphere formation method and identified with the CD44(+)/CD24(-) phenotype. Quantitative and qualitative analysis demonstrated that HA promotes the uptake of HA-MSS in CD44-overexpressing MCF-7 mammospheres, revealing the mechanism of receptor-mediated endocytosis. DTX or DTX-loaded MSS showed much enhanced cytotoxicity against MCF-7 cells compared with MCF-7 mammospheres, whereas 8-HQ or 8-HQ-loaded HA-MSS showed much enhanced cytotoxicity against MCF-7 mammospheres compared with MCF-7 cells. In the MCF-7 xenografts in mice, the combination therapy with DTX-loaded MSS plus 8-HQ-loaded HA-MSS produced the strongest antitumor efficacy, with little systemic toxicity (reflecting by loss of body weight) in mice. Thus, this combination therapy may provide a potential strategy to improve the therapy of breast cancer by eradication of breast cancer cells together with BCSCs. PMID:23859657

Wang, Dong; Huang, Jingbin; Wang, Xinxia; Yu, Yuan; Zhang, He; Chen, Yan; Liu, Junjie; Sun, Zhiguo; Zou, Hao; Sun, Duxin; Zhou, Guichen; Zhang, Guoqing; Lu, Ying; Zhong, Yanqiang

2013-10-01

90

Detection of charge storage on molecular thin films of tris(8-hydroxyquinoline) aluminum (Alq3) by Kelvin force microscopy: a candidate system for high storage capacity memory cells.  

PubMed

Retention and diffusion of charge in tris(8-hydroxyquinoline) aluminum (Alq(3)) molecular thin films are investigated by injecting electrons and holes via a biased conductive atomic force microscopy tip into the Alq(3) films. After the charge injection, Kelvin force microscopy measurements reveal minimal changes with time in the spatial extent of the trapped charge domains within Alq(3) films, even for high hole and electron densities of >10(12) cm(-2). We show that this finding is consistent with the very low mobility of charge carriers in Alq(3) thin films (<10(-7) cm(2)/(Vs)) and that it can benefit from the use of Alq(3) films as nanosegmented floating gates in flash memory cells. Memory capacitors using Alq(3) molecules as the floating gate are fabricated and measured, showing durability over more than 10(4) program/erase cycles and the hysteresis window of up to 7.8 V, corresponding to stored charge densities as high as 5.4 × 10(13) cm(-2). These results demonstrate the potential for use of molecular films in high storage capacity nonvolatile memory cells. PMID:22332966

Paydavosi, Sarah; Aidala, Katherine E; Brown, Patrick R; Hashemi, Pouya; Supran, Geoffrey J; Osedach, Timothy P; Hoyt, Judy L; Bulovi?, Vladimir

2012-03-14

91

Preconcentration of cobalt with 8-hydroxyquinoline and gas chromatographic stationary phase Chromosorb 105 and its determination by graphite furnace atomic absorption spectrometry.  

PubMed

This paper presents a study of the adsorption characteristics of a commercially available GC stationary phase Chromosorb 105 for Co(2+), which can be successfully applied to the preconcentration of Co(2+) in water samples followed by GFAAS determination. After reacting with 8-hydroxyquinoline to form a complex at pH 8.0, Co(2+) in water can be retained on a minicolumn packed with Chromosorb 105 and eluted with 2.5 ml of a mixture of ethanol and 2 moll(-1) HNO(3) (2+1, v/v). The recoveries of Co(2+) from 200 ml of tap water, river water and bottled natural mineral water samples are quantitative. Conditions for quantitative and reproducible preconcentration, elution and subsequent GFAAS determination were studied. A highly sensitive, simple method for preconcentration and GFAAS determination of trace amount of cobalt in natural water samples using a Chromosorb 105 packed minicolumn has been proposed. The high retention efficiency ( approximately 95%) for Co(2+) provides a sensitivity enhancement of 80 for a 200 ml sample volume with a detection limit of 13.4 ngl(-1) (3sigma) and a quantification limit of 44.5 ngl(-1) (10sigma). PMID:18968723

Cai, Yaqi; Jiang, Guibin; Liu, Jingfu

2002-07-19

92

Synthesis and photovoltaic properties of polymeric metal complexes containing 8-hydroxyquinoline as dye sensitizers for dye-sensitized solar cells  

Microsoft Academic Search

Four new donor–acceptor type polymeric metal complexes (P1, P2, P3, and P4) with the same Cd(II) complex in side chain and different conjugated backbone structures were synthesized by Yamamoto coupling and applied in dye-sensitized solar cells (DSSCs) as photosensitizers. The photophysical, electrochemical, and thermal properties were investigated in detail, showing that conjugated backbone containing fluorene improved intramolecular charge transfer and

Lirong Zhang; Gaojun Wen; Qian Xiu; Lihui Guo; Jinyan Deng; Chaofan Zhong

2012-01-01

93

Novel polymeric metal complexes as dye sensitizers for Dye-sensitized solar cells based on poly thiophene containing complexes of 8-hydroxyquinoline with Zn(II),Cu(II) and Eu(III) in the side chain  

Microsoft Academic Search

Novel polymeric metal complexes as dye sensitizer for dye-sensitized solar cells (DSSCs) based on poly thiophene containing complexes of 8-hydroxyquinoline with Zn(II),Cu(II), and Eu(III) in the side chain have been synthesized according to the Stille coupling method and characterized by FTIR, GPC, and Elemental analysis. The UV–vis absorption spectroscopy, photoluminescence spectroscopy, cyclic voltammetry, and the applications in dye-sensitized solar cells

Lifen Xiao; Yuan Liu; Qian Xiu; Lirong Zhang; Lihui Guo; Hailiang Zhang; Chaofan Zhong

2010-01-01

94

Large magnetic field effects in organic light emitting diodes based on tris(8-hydroxyquinoline aluminum) (Alq3)\\/N,N'Di(naphthalen-1-yl)-N,N'diphenylbenzidine (NPB) bilayers  

Microsoft Academic Search

Magnetic field effects (MFEs) in the luminescence and photoconductivity of organic crystals such as anthracene have been known since the 1960s. While engaged in a project to use spin polarized current to manipulate electroluminescence (EL) in organic light emitting diodes based on a bilayer of tris(8-hydroxyquinoline) aluminum (Alq3) and N,N'-Di(naphthalen-1-yl)-N,N'diphenyl-benzidine (NPB), we observed MFE similar to those reported in anthracene.

Albert H. Davis; Konrad Bussmann

2004-01-01

95

Copper-dependent cytotoxicity of 8-hydroxyquinoline derivatives correlates with their hydrophobicity and does not require caspase activation.  

PubMed

This study reports the structure-activity relationship of a series of 8-hydroxoquinoline derivatives (8-HQs) and focuses on the cytotoxic activity of 5-Cl-7-I-8-HQ (clioquinol, CQ) copper complex (Cu(CQ)). 8-HQs alone cause a dose-dependent loss of viability of the human tumor HeLa and PC3 cells, but the coadministration of copper increases the ligands effects, with extensive cell death occurring in both cell lines. Cytotoxic doses of Cu(CQ) promote intracellular copper accumulation and massive endoplasmic reticulum vacuolization that precede a nonapoptotic (paraptotic) cell death. The cytotoxic effect of Cu(CQ) is reproduced in normal human endothelial cells (HUVEC) at concentrations double those effective in tumor cells, pointing to a potential therapeutic window for Cu(CQ). Finally, the results show that the paraptotic cell death induced by Cu(CQ) does not require nor involve caspases, giving an indication for the current clinical assessment of clioquinol as an antineoplastic agent. PMID:23170953

Tardito, Saverio; Barilli, Amelia; Bassanetti, Irene; Tegoni, Matteo; Bussolati, Ovidio; Franchi-Gazzola, Renata; Mucchino, Claudio; Marchiò, Luciano

2012-12-13

96

Oxidative stress induced by copper and iron complexes with 8-hydroxyquinoline derivatives causes paraptotic death of HeLa cancer cells.  

PubMed

Here, we report the antiproliferative/cytotoxic properties of 8-hydroxyquinoline (8-HQ) derivatives on HeLa cells in the presence of transition metal ions (Cu(2+), Fe(3+), Co(2+), Ni(2+)). Two series of ligands were tested, the arylvinylquinolinic L1-L8 and the arylethylenequinolinic L9-L16, which can all interact with metal ions by virtue of the N,O donor set of 8-HQ; however, only L9-L16 are flexible enough to bind the metal in a multidentate fashion, thus exploiting the additional donor functions. L1-L16 were tested for their cytotoxicity on HeLa cancer cells, both in the absence and in the presence of copper. Among them, the symmetric L14 exhibits the highest differential activity between the ligand alone (IC50 = 23.7 ?M) and its copper complex (IC50 = 1.8 ?M). This latter, besides causing a significant reduction of cell viability, is associated with a considerable accumulation of the metal inside the cells. Metal accumulation is also observed when the cells are incubated with L14 complexed with other late transition metal ions (Fe(3+), Co(2+), Ni(2+)), although the biological response of HeLa cells is different. In fact, while Ni/L14 and Co/L14 exert a cytostatic effect, both Cu/L14 and Fe/L14 trigger a caspase-independent paraptotic process, which results from the induction of a severe oxidative stress and the unfolded protein response. PMID:24592930

Barilli, Amelia; Atzeri, Corrado; Bassanetti, Irene; Ingoglia, Filippo; Dall'Asta, Valeria; Bussolati, Ovidio; Maffini, Monica; Mucchino, Claudio; Marchiò, Luciano

2014-04-01

97

A Potent (R)-alpha-bis-lipoyl Derivative Containing 8-Hydroxyquinoline Scaffold: Synthesis and Biological Evaluation of Its Neuroprotective Capabilities in SH-SY5Y Human Neuroblastoma Cells  

PubMed Central

A novel bis-lipoyl derivative containing 8-hydroxyquinoline scaffold (LA-HQ-LA, 5) was synthesized as a new multifunctional drug candidate with antioxidant, chelant, and neuroprotective properties for the treatment of neurodegenerative diseases. We have investigated the potential effectiveness of LA-HQ-LA against the cytotoxicity induced by 6-OHDA and H2O2 on human neuroblastoma SH-SY5Y cell line. Our outcomes showed that LA-HQ-LA resulted in significant neuroprotective and antioxidant effects against H2O2- and 6-OHDA-induced neurotoxicity in human neuroblastoma SH-SY5Y cells, as assessed by MTT assay. In particular, it showed potent neuroprotective effects against 6-OHDA in RA/PMA differentiated cells at all the tested concentrations.

Cacciatore, Ivana; Fornasari, Erika; Baldassarre, Leonardo; Cornacchia, Catia; Fulle, Stefania; Di Filippo, Ester Sara; Pietrangelo, Tiziana; Pinnen, Francesco

2013-01-01

98

Housing structure utilizing solar energy  

SciTech Connect

A solar cell array consisting of individually rotatable elongated segments is flexibly supported beneath a translucent panel in the exterior roof of a building. A thermal solar collector is supported beneath the solar cell array for maximum utilization of the solar energy received through the roof opening.

Whittaker, R.E.

1983-02-15

99

ICP-AES detection of ultratrace aluminum(III) and chromium(III) ions with a microcolumn preconcentration system using dynamically immobilized 8-hydroxyquinoline on TiO2 nanoparticles.  

PubMed

Titanium dioxide nanoparticle dynamically loaded with 8-hydroxyquinoline (nanometer TiO2-Oxine) was used as a solid-phase extractant for the preconcentration of trace amounts of aluminum(III) and chromium(III) prior to their determination by inductively coupled plasma atomic emission spectrometry (ICP-AES). The optimal conditions for preparing nanometer TiO2-Oxine were obtained. Also, the separation/preconcentration conditions of analytes, including the effects of the pH, the sample flow rate and the volume, the elution solution and the interfering ions on the recovery of the analytes were investigated. At pH 6.0, the adsorption capacity of nanometer TiO2-Oxine was found to be 5.23 mg g(-1) and 9.58 mg g(-1) for Al(III) and Cr(III), respectively. An enrichment factor of 50 was achieved by this method, and the detection limits (3sigma) for Al(III) and Cr(III) were 1.96 and 0.32 microg L(-1) respectively. The proposed method was applied for the determination of trace Al(III) and Cr(III) in biological samples and lake water with satisfactory results. PMID:12945671

Liang, Pei; Yang, Lanhao; Hu, Bin; Jiang, Zucheng

2003-08-01

100

Light-emitting devices based on ruthenium(II)(4,7-diphenyl-1,10-phenanthroline)3: Device response rate and efficiency by use of tris-(8-hydroxyquinoline) aluminum  

NASA Astrophysics Data System (ADS)

Light-emitting devices based on ruthenium(II)(4,7-diphenyl-1,10-phenanthroline)3 ([Ru(dphphen)3]2+) as emitter have been fabricated. The effect of an electron transport layer of tris-(8-hydroxyquinoline) aluminum (Alq3) on device performance has been investigated. The emission, peaking at 630 nm, for the indium-tin-oxide (ITO)glass/[Ru(dphphen)3]2+/Ag device reaches maximum luminance after about 15 min at a turn on voltage of 2.5 V. The use of an ITO/[Ru(dphphen)3]2+/Alq3/Ag device reduces this response time to about 120 s at a turn on voltage of 7 V. A maximum brightness of 1300 cd/m2 can be obtained at 15 V within 2 s, with a luminous efficiency of 0.27 cd/A. Based on the charge transporting characteristics of [Ru(dphphen)3]2+ and Alq3 films determined by surface photovoltage spectroscopy, the improved device response time and efficiency are attributed to the enhanced electron injection at [Ru(dphphen)3]2+/Alq3 interface.

Yang, Jihua; Gordon, Keith C.; Zidon, Yigal; Shapira, Yoram

2003-11-01

101

Enhanced electron injection into tris(8-hydroxyquinoline) aluminum (Alq 3) thin films by tetrathianaphthacene (TTN) doping revealed by current-voltage characteristics  

NASA Astrophysics Data System (ADS)

We report on the current-voltage ( J- V) characteristics of single-layer devices employing pure and heavily TTN-doped Alq 3 films as active layers. In the undoped device, the current is limited by the carrier injection at the Mg/Alq 3 interface with a small injection barrier. In the uniformly-doped device, the current flow is much larger and behaves as space-charge-limited current (SCLC). This means a conversion from injection-limited to bulk-limited current. As the interface- and uniformly-doped devices show similar magnitude of current, the improvement of the current is ascribed to the large enhancement of electron injection due to the doping-induced modification of the interfacial electronic structure.

Wang, S. D.; Kanai, K.; Kawabe, E.; Ouchi, Y.; Seki, K.

2006-05-01

102

Structural design utilizing updated, approximate sensitivity derivatives  

NASA Technical Reports Server (NTRS)

A method to improve the computational efficiency of structural optimization algorithms is investigated. In this method, the calculations of 'exact' sensitivity derivatives of constraint functions are performed only at selected iterations during the optimization process. The sensitivity derivatives utilized within other iterations are approximate derivatives which are calculated using an inexpensive derivative update formula. Optimization results are presented for an analytic optimization problem (i.e., one having simple polynomial expressions for the objective and constraint functions) and for two structural optimization problems. The structural optimization results indicate that up to a factor of three improvement in computation time is possible when using the updated sensitivity derivatives.

Scotti, Stephen J.

1993-01-01

103

Spacecraft hazard avoidance utilizing structured light  

NASA Technical Reports Server (NTRS)

At JPL, a <5 kg free-flying micro-inspector spacecraft is being designed for host-vehicle inspection. The spacecraft includes a hazard avoidance sensor to navigate relative to the vehicle being inspected. Structured light was selected for hazard avoidance because of its low mass and cost. Structured light is a method of remote sensing 3-dimensional structure of the proximity utilizing a laser, a grating, and a single regular APS camera. The laser beam is split into 400 different beams by a grating to form a regular spaced grid of laser beams that are projected into the field of view of an APS camera. The laser source and the APS camera are separated forming the base of a triangle. The distance to all beam intersections of the host are calculated based on triangulation.

Liebe, Carl Christian; Padgett, Curtis; Chapsky, Jacob; Wilson, Daniel; Brown, Kenneth; Jerebets, Sergei; Goldberg, Hannah; Schroeder, Jeffrey

2006-01-01

104

Improving resource utilization in hierarchy network by optimizing topological structure  

NASA Astrophysics Data System (ADS)

We study the performance of peer-to-peer (P2P) network built on the top of hierarchy topological structure of local area networks (LAN). We find that the topological structure of the underlying physical network has significant impacts on the resource utilization of the P2P overlay network. The larger size of the physical network is, the lower resource utilization of the overlay network is. Through optimizing the topological structure of physical network, we propose two novel schemes to improve the resource utilization. The experimental results show that in any case the resource utilization of P2P network can always achieve 100% by these two schemes.

Liu, G. L.; Peng, H. P.; Li, L. X.; Sun, F.; Yang, Y. X.

2012-02-01

105

Large platform assembler non-structural system requirements. [installing utilities  

NASA Technical Reports Server (NTRS)

The impact on the design and operation of an automated structure assembler of requiring the assembler to also install the platform electrical and/or fluid utility circuits was examined. Possible utility requirements were defined and examined in conjunction with the automated assembler. Preliminary concepts are presented which permit the electrical and fluid circuits to be installed with the structural elements.

Vernon, R. M.

1981-01-01

106

Utilization of Protein Crystal Structures in Industry  

NASA Astrophysics Data System (ADS)

In industry, protein crystallography is used in mainly two technologies. One is structure-based drug design, and the other is structure-based enzyme engineering. Some successful cases together with recent advances are presented in this article. The cases include the development of an anti-influenza drug, and the introduction of engineered acid phosphatase to the manufacturing process of nucleotides used as umami seasoning.

Ishikawa, Kohki

107

Utilization survey of prototype structural test article  

NASA Technical Reports Server (NTRS)

A survey was conducted of six aerospace companies and two NASA agencies to determine how prototype structural test articles are used in flight operations. The prototype structures are airframes and similar devices which are used for testing and generally are not flown. The survey indicated the following: (1) prototype test articles are not being discarded after development testing is complete, but are used for other purposes, (2) only two cases of prototypes being refurbished and flown were identified, (3) protective devices and inspection techniques are available to prevent or minimize test article damage, (4) substitute programs from design verification are availabel in lieu of using prototype structural articles, and (5) there is a trend away from dedicated test articles. Four options based on these study results were identified to reduce test and hardware costs without compromising reliability of the flight program.

Baber, S.; Mcdaniel, H. M.; Berry, M. J.

1974-01-01

108

Laminated multilayer sheet structure and its utilization  

Microsoft Academic Search

A laminated multilayer sheet structure is described comprising (A) an opaque flexible sheet layer, and (B) a flexible layer laminated on the surface of layer (A) and composed of a transparent thermic ray reflecting layer (Bâ) bonded to a transparent synthetic resin layer (Bâ), said layer (Bâ) being a transparent thermic ray reflecting layer composed of (I) a layer of

K. Chiba; K. Itoh; Y. Mitani; S. Sobajima; U. Yonemura

1980-01-01

109

UAV sensor platforms utilizing pressurized structures technology  

Microsoft Academic Search

Several areas of unmanned aerial vehicle (UAV) performance need to be improved for the next generation of UAVs to be used successfully in expanded future combat roles. This paper describes the initial research to improve the performance of UAVs through the use of pressurized structures-based (PSB) technologies. Basically, the UAV will be constructed in such a way that a considerable

Harris L. Edge

2009-01-01

110

UAV sensor platforms utilizing pressurized structures technology  

NASA Astrophysics Data System (ADS)

Several areas of unmanned aerial vehicle (UAV) performance need to be improved for the next generation of UAVs to be used successfully in expanded future combat roles. This paper describes the initial research to improve the performance of UAVs through the use of pressurized structures-based (PSB) technologies. Basically, the UAV will be constructed in such a way that a considerable percentage of its weight will be supported by or composed of inflatable structures containing air or helium. PSB technology will reduce the amount of energy required to keep the UAV aloft thus allowing the use of smaller, slower, and quieter motors. Using PSB technology in tandem with improving technologies in electronics, energy storage, and materials should provide a substantial increase over current UAV performance in areas of need to the military.

Edge, Harris L.

2009-05-01

111

MCHF atomic-structure package: support libraries and utilities  

NASA Astrophysics Data System (ADS)

The libraries and utilities that form part of the MCHF atomic-structure package are described. Among the utilities is a LEVELS program that produces an energy level table and a LINES program that process the transition data from a series of LSJ calculations as a line list.

Fischer, Charlotte Froese

1991-06-01

112

Fiber Stress Values for Design of Glulam Timber Utility Structures.  

National Technical Information Service (NTIS)

In this study, we developed a simple equation to calculate average fiber stress values for design of glue-laminated (glulam) timber utility structures as a function of design bending stress. We took design stress in bending values specified by the America...

R. Hernandez R. C. Moody R. H. Falk

1995-01-01

113

Dynamic and structural control utilizing smart materials and structures  

NASA Technical Reports Server (NTRS)

An account is given of several novel 'smart material' structural control concepts that are currently under development. The thrust of these investigations is the evolution of intelligent materials and structures superceding the recently defined variable-geometry trusses and shape memory alloy-reinforced composites; the substances envisioned will be able to autonomously evaluate emergent environmental conditions and adapt to them, and even change their operational objectives. While until now the primary objective of the developmental efforts presently discussed has been materials that mimic biological functions, entirely novel concepts may be formulated in due course.

Rogers, C. A.; Robertshaw, H. H.

1989-01-01

114

48 CFR 52.236-9 - Protection of Existing Vegetation, Structures, Equipment, Utilities, and Improvements.  

Code of Federal Regulations, 2013 CFR

...Structures, Equipment, Utilities, and Improvements...Structures, Equipment, Utilities, and Improvements (APR 1984) (a) The Contractor shall preserve...Officer. (b) The Contractor shall protect from...existing improvements and utilities (1) at or near...

2013-10-01

115

Synthesis of 8-Hydroxyquinoline Derivatives as Novel Antitumor Agents  

PubMed Central

This letter describes the preparation of quinoline derivatives and their cytotoxic potentials toward human carcinoma cell lines. Among the selected compounds, 8-hydroxy-2-quinolinecarbaldehyde (3) showed the best in vitro cytotoxicity against the human cancer cell lines, including MDA231, T-47D, Hs578t, SaoS2, K562, SKHep1 (with a MTS50 range of 12.5–25 ?g/mL) and Hep3B (with a MTS50 range of 6.25±0.034 ?g/mL). The in vivo antitumor activity of compound 3 on subcutenaous Hep3B hepatocellular carcinoma xenograft in athymic nude mice was then studied. The results showed that the dose of 10 mg/kg/day of compound 3 with intraperitoneal injection for 9 days totally abolished the growth of the xenograft tumor of Hep3B with no histological damage on vital organs as compared with the control. The experimental results suggested that compound 3 has a good potential as an antitumor agent.

2012-01-01

116

Study on the structure and luminescence properties of the coordinated ZnO crystallites  

NASA Astrophysics Data System (ADS)

The coordinated ZnO nanoparticles and crystallites have been produced by focused pulsed laser ablation of ZnO target submerged in the ethanol solution of 8-hydroxyquinoline. The structure of the nanoparticles was characterized by high-resolution transmission electron microscopy (HRTEM). The ZnO crystallites properties were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis coupled to differential scanning calorimetry (TG/DSC), X-ray photoelectron spectroscopy (XPS) and luminescence spectrometry. The results show the surface Zn2+ ions of the ZnO nanoparticles are coordinated by the 8-hydroxyquinoline. The crystal class and the space group of the coordinated ZnO crystallites are triclinic and P-1(2), respectively. The lattice parameters are refined to a=1.1904 nm, b=1.2135 nm, c=0.8586 nm, ?=108.28?, ?=100.27? and ?=85.50?, respectively. The coordinated ZnO crystallites have better thermo stability than bis(8-hydroxyquinoline)zinc and can emit yellow-green light under UV and visible radiations.

Chen, Qian-huo; Liu, Qing; Li, Qing; Sheng, Yu; Zhang, Wen-gong

2013-10-01

117

Vibration Based Structural Health Monitoring for Utility Scale Wind Turbines  

NASA Astrophysics Data System (ADS)

Structural health monitoring (SHM) is a process of implementing a damage detection strategy for a mechanical system. Wind turbine machinery stands to benefit from SHM significantly as the ability to detect early stages of damage before serious malfunction or collapse reduces the overall operating costs of wind power projects. Vibration analysis of dynamic structural response is an approach to SHM that has been successfully applied to mechanical and civil systems and shows promise for wind turbine application due to availability of instruments, ease of installation, and overall affordability. This study presents the development of vibration based wind turbine structural health monitoring through experimental analysis of an operating wind turbine. A database of acquired vibration response signals detailing over 3 hours of turbine operation was assembled and a Daubachies 6th order wavelet was used to perform a 12 level discrete wavelet decomposition such that general trends and patterns within the signals could be identified. After determining response behavior of a healthy turbine, a novel vibration based SHM scheme is developed based on findings from experimental work. Specific interest has been paid to monitoring yaw and braking systems as they have been identified as problematic. With further development this vibration scheme can be applied by wind farm operators to reduce downtime and failure frequency of utility scale wind turbines.

Bassett, Kyle

118

Design of intelligent mesoscale periodic array structures utilizing smart hydrogel  

NASA Technical Reports Server (NTRS)

Mesoscale Periodic Array Structures (MPAS, also known as crystalline colloidal arrays), composed of aqueous or nonaqueous dispersions of self-assembled submicron colloidal spheres are emerging toward the development of advanced optical devices for technological applications. This is because of their unique optical diffraction properties and the ease with which these intriguing properties can be modulated experimentally. Moreover our recent advancements in this area which include 'locking' the liquid MPAS into solid or semisolid polymer matrices for greater stability with longer life span, and incorporation of CdS quantum dots and laser dyes into colloidal spheres to obtain nonlinear optical (NLO) responses further corroborate the use of MPAS in optical technology. Our long term goal is fabrication of all-optical and electro-optical devices such as spatial light modulators for optical signal processing and flat panel display devices by utilizing intelligent nonlinear periodic array structural materials. Here we show further progress in the design of novel linear MPAS which have the ability to sense and respond to an external source such as temperature. This is achieved by combining the self-assembly properties of polymer colloidal spheres and thermoshrinking properties of smart polymer gels. At selected temperatures the periodic array efficiently Bragg diffracts light and transmits most of the light at other temperatures. Hence these intelligent systems are of potential use as fixed notch filters optical switches or limiters to protect delicate optical sensors from high intensity laser radiation.

Sunkara, H. B.; Penn, B. G.; Frazier, D. O.; Weissman, J. M.; Asher, S. A.

1996-01-01

119

Utilities as Random Variables: Density Estimation and Structure Discovery.  

National Technical Information Service (NTIS)

Decision theory does not traditionally include uncertainty over utility functions. We argue that a person's utility value for a given outcome can be treated as we treat other domain attributes: as a random variable with a density function over its possibl...

U. Chajewska D. Koller

2000-01-01

120

Dynamic insight into protein structure utilizing red edge excitation shift.  

PubMed

Proteins are considered the workhorses in the cellular machinery. They are often organized in a highly ordered conformation in the crowded cellular environment. These conformations display characteristic dynamics over a range of time scales. An emerging consensus is that protein function is critically dependent on its dynamics. The subtle interplay between structure and dynamics is a hallmark of protein organization and is essential for its function. Depending on the environmental context, proteins can adopt a range of conformations such as native, molten globule, unfolded (denatured), and misfolded states. Although protein crystallography is a well established technique, it is not always possible to characterize various protein conformations by X-ray crystallography due to transient nature of these states. Even in cases where structural characterization is possible, the information obtained lacks dynamic component, which is needed to understand protein function. In this overall scenario, approaches that reveal information on protein dynamics are much appreciated. Dynamics of confined water has interesting implications in protein folding. Interfacial hydration combines the motion of water molecules with the slow moving protein molecules. The red edge excitation shift (REES) approach becomes relevant in this context. REES is defined as the shift in the wavelength of maximum fluorescence emission toward higher wavelengths, caused by a shift in the excitation wavelength toward the red edge of absorption spectrum. REES arises due to slow rates (relative to fluorescence lifetime) of solvent relaxation (reorientation) around an excited state fluorophore in organized assemblies such as proteins. Consequently, REES depends on the environment-induced motional restriction imposed on the solvent molecules in the immediate vicinity of the fluorophore. In the case of a protein, the confined water in the protein creates a dipolar field that acts as the solvent for a fluorophore in the protein. In this Account, we focus on REES to monitor organization and dynamics of soluble and membrane proteins utilizing intrinsic protein fluorescence. We discuss here the application of REES in various conformations of proteins. While application of REES to proteins in native conformation has been in use for a long time, our work highlights the potential of this approach in case of molten globule and denatured conformations. For example, we have demonstrated the presence of residual structure, that could not be detected using other methods, by REES of denatured spectrin. Given the functional relevance of such residual structures, these results are very far reaching. We discuss here the application of REES to molten globule conformation and to the green fluorescent protein (GFP). The case of GFP is particularly interesting since the dipolar field in this case is provided by the protein matrix itself and not confined water. We envision that future applications of REES in proteins will involve generating a dynamic hydration map of the protein, which would allow us to explore protein function in terms of local dynamics and hydration. PMID:23981188

Chattopadhyay, Amitabha; Haldar, Sourav

2014-01-21

121

Cutting of Structural Materials Utilizing Hiqh Powered CO2 Laser.  

National Technical Information Service (NTIS)

The method most commonly used for cutting thick 1.90cm (.75in) steel material where edge quality is not of concern is flame cutting which utilizes an oxyacetylene torch. It provides the energy to heat the steel beyond its melting point and gas pressure fo...

N. Eutizzi, P. E. Denney

1992-01-01

122

Utility of Structured Care Approaches in Education and Clinical Practice.  

ERIC Educational Resources Information Center

Describes structured care approaches, such as protocols, clinical pathways, and algorithms, which are being used increasingly to organize clinical knowledge and guide patient care. Reviews the types of structured care approaches available to the clinician and explores the value of structured care approaches in practice and education. (Contains 32…

O'Neill, Eileen S.; Dluhy, Nancy M.

2000-01-01

123

Structure of Co-Doped Alq3 thin films investigated by grazing incidence X-ray absorption fine structure and Fourier transform infrared spectroscopy.  

PubMed

The structural properties of Co-doped tris(8-hydroxyquinoline)aluminum (Alq(3)) have been studied by grazing incidence X-ray absorption fine structure (GIXAFS) and Fourier transform infrared spectroscopy (FTIR). GIXAFS analysis suggests that there are multivalent Co-Alq(3) complexes and the doped Co atoms tend to locate at the attraction center with respect to N and O atoms and bond with them. The FTIR spectra indicate that the Co atoms interact with the meridional (mer) isomer of Alq(3) rather than forming inorganic compounds. PMID:21214213

Lin, Liang; Pang, Zhiyong; Fang, Shaojie; Wang, Fenggong; Song, Shumei; Huang, Yuying; Wei, Xiangjun; Yu, Haisheng; Han, Shenghao

2011-02-10

124

Structural Damage Alarm Utilizing Modified Back-Propagation Neural Networks  

NASA Astrophysics Data System (ADS)

Damage alarm is an important step among structure damage identification. Its objective is to evaluate the structure health. The existing damage alarm methods are mostly based on Back-Propagation Neural Networks without thinking over testing noise. Therefore, in order to avoid the disadvantages of conventional Back-Propagation Neural Networks, a modified Back-Propagation Neural Networks was proposed for structure damage alarm system in this paper. The experiment results of steel truss girder bridge show that the improved method is better than BPNN for structural damage alarm.

Dong, Xiaoma

125

Vibration Based Structural Health Monitoring for Utility Scale Wind Turbines  

Microsoft Academic Search

Structural health monitoring (SHM) is a process of implementing a damage detection strategy for a mechanical system. Wind turbine machinery stands to benefit from SHM significantly as the ability to detect early stages of damage before serious malfunction or collapse reduces the overall operating costs of wind power projects. Vibration analysis of dynamic structural response is an approach to SHM

Kyle Bassett

2010-01-01

126

Hierarchical Behavior Structure for NAO Robot Utilizing Fuzzy Inference Systems  

Microsoft Academic Search

Playing soccer is not a simple task, and robot needs a hierarchical behavior structure to decide how to play at any situation during the game, in our previous work, we introduced a behavior structure for NAO humanoid robot. One significant task in playing soccer is proper decision making during the game, in this paper, to achieve better decision making, we

Bahram Jozi; Ahamd Fakharian; Armita Karachi

2010-01-01

127

Vibration suppression of planar truss structures utilizing uniform damping control  

NASA Technical Reports Server (NTRS)

A variety of methods has been devised for vibrational control of a structure using both passive and active controls. Presented in this paper is a relatively new method for vibration suppression, uniform damping control. This method consists of implementing a control law which tends to dampen each vibrational mode of the structure at the same desirable exponential rate. The unique aspects of this method are that the control law is not explicitly dependent on the structural stiffness, the control forces are directly proportional to the distribution of the structural mass, and the control law is natural and decentralized. The control law was applied to a flexible planar truss structure and the various aspects of implementation of the control law examined are: actuator/sensor number, placement, and the impact of the actuator/sensor number and placement on the necessary control 'power' requirements such as peak power loads, total power requirements, etc. Also examined are the effects of using a limited number of active members in terms of the vibrational performance when compared with the 'ideal' distributed control law.

Andersen, G. C.; Silverberg, L. M.

1986-01-01

128

Cellular structure of detonation utilized in propulsion system  

NASA Astrophysics Data System (ADS)

How to confine a detonation in a combustor is a key issue of detonation applications in propulsion systems. Based on achieving schemes, detonations applied in the combustor, including pulse detonation wave (PDW), oblique detonation wave (ODW) and rotating detonation wave (RDW), are different from that described by the classic CJ theory in fine structures and its self-sustaining mechanisms. In this work, the cellular structures and flow fields of ODW and RDW were obtained numerically, and the fundamental characteristics and self-sustaining mechanisms of the detonations were analyzed and discussed. ODW front consists of three parts: the ZND-like front, the single-headed triple point front and the dual-headed triple point front. Cellular structures of RDW are heterogeneous, and the cell size near the outer wall is smaller than that near the inner wall.

Zhang, XuDong; Fan, BaoChun; Gui, MingYue; Pan, ZhenHua

2012-10-01

129

Impacts of Commercial Electric Utility Rate Structure Elements on the Economics of Photovoltaic Systems.  

National Technical Information Service (NTIS)

This analysis uses simulated building data, simulated solar photovoltaic (PV) data, and actual electric utility tariff data from 25 cities to understand better the impacts of different commercial rate structures on the value of solar PV systems. By analyz...

E. Doris P. Denholm S. Ong

2010-01-01

130

High Efficient Green Emission from Organic Multi-quantum Wells Structure  

NASA Astrophysics Data System (ADS)

Organic green light emitting devices (LEDs) with multi-quantum wells (MQWs) structure were fabricated. Aromatic diamine was used as hole-transporting layer and potential barrier layer; tris (8-hydroxyquinoline) aluminum acted as electron transporting layer and MQWs green emitting layer. The influence of the barrier layer thickness and quantum well number to the device performance was also investigated. The barrier thickness must be thin (such as 4 nm) enough to tunnel through and distribute charge carriers uniformly in different wells (mainly electrons). The organic MQWs LEDs showed enhanced electroluminescent efficiencies. Maximum luminous efficiency and external quantum efficiency were 1.24 lm/W and 1.04%, respectively.

Xie, Zhi-yuan; Huang, Jing-song; Li, Chuan-nan; Chen, Bai-jun; Liu, Shi-yong; Li, Yan-qin; Wang, Yue; Shen, Jia-cong

1999-02-01

131

Method for Molding Structural Parts Utilizing Modified Silicone Rubber  

NASA Technical Reports Server (NTRS)

This invention improves upon a method for molding structural parts from preform material. Preform material to be used for the part is provided. A silicone rubber composition containing entrained air voids is prepared. The silicone rubber and preform material assembly is situated within a rigid mold cavity used to shape the preform material to die desired shape. The entire assembly is heated in a standard heating device so that the thermal expansion of the silicone rubber exerts the pressure necessary to force the preform material into contact with the mold container. The introduction of discrete air voids into the silicone rubber allows for accurately controlled pressure application on the preform material at the cure temperature.

Weiser, Erik S. (Inventor); Baucom, Robert M. (Inventor); Snoha, John J. (Inventor)

1998-01-01

132

Investigation of Coronal Large Scale Structures Utilizing Spartan 201 Data  

NASA Technical Reports Server (NTRS)

Two telescopes aboard Spartan 201, a small satellite has been launched from the Space Shuttles, on April 8th, 1993, September 8th, 1994, September 7th, 1995 and November 20th, 1997. The main objective of the mission was to answer some of the most fundamental unanswered questions of solar physics-What accelerates the solar wind and what heats the corona? The two telescopes are 1) Ultraviolet Coronal Spectrometer (UVCS) provided by the Smithsonian Astrophysical Observatory which uses ultraviolet emissions from neutral hydrogen and ions in the corona to determine velocities of the coronal plasma within the solar wind source region, and the temperature and density distributions of protons and 2) White Light Coronagraph (WLC) provided by NASA's Goddard Space Flight Center which measures visible light to determine the density distribution of coronal electrons within the same region. The PI has had the primary responsibility in the development and application of computer codes necessary for scientific data analysis activities, end instrument calibration for the white-light coronagraph for the entire Spartan mission. The PI was responsible for the science output from the WLC instrument. PI has also been involved in the investigation of coronal density distributions in large-scale structures by use of numerical models which are (mathematically) sufficient to reproduce the details of the observed brightness and polarized brightness distributions found in SPARTAN 201 data.

Guhathakurta, Madhulika

1998-01-01

133

Utilization of a very large mobile offshore structure for clean energy conversion  

Microsoft Academic Search

We proposed a new design concepts of a very large floating structure with thrusters (we call it VLMOS; Very Large Mobile Offshore Structure) that is utilized as a carrier of the renewable energy plant In order to get good mobility, VLMOS has a configuration that a broad deck is supported by many slender lower hulls and vertical columns. Green function

Ken Takagi; Wataru Yano; Koichi Yamamoto

2003-01-01

134

Study on utilization of advanced composites in commercial aircraft wing structures, volume 2  

NASA Technical Reports Server (NTRS)

A plan is defined for a composite wing development effort which will assist commercial transport manufacturers in reaching a level of technology readiness where the utilization of composite wing structure is a cost competitive option for a new aircraft production plan. The recommended development effort consists of two programs: a joint government/industry material development program and a wing structure development program. Both programs are described in detail.

Sakata, I. F.; Ostrom, R. B.

1978-01-01

135

Resonant Enhancement of Radiation from a Backward Wave Oscillator Utilizing Large Diameter Corrugated Metal Structure  

Microsoft Academic Search

An experiment on a backward wave oscillator (BWO) utilizing a largediameter corrugated metal wall slow wave structure (SWS) has beenpresented. Measurements are made above and below the starting beamenergy for conventional BWO operation. For the latter case, an excitednoise-level backward wave at 20 GHz (TM01 mode) is coupled at theends of the SWS to a forward anomalous Doppler shifted electroncyclotron

Kazuo Minami; Kazuo Ogura; Xiaodong Zheng; Tsuguhiro Watanabe

1995-01-01

136

Assessment of Multiple Physician Competencies in Postgraduate Training: Utility of the Structured Oral Examination  

ERIC Educational Resources Information Center

Competency based medical education involves assessing physicians-in-training in multiple roles. Training programs are challenged by the need to introduce appropriate yet feasible assessment methods. We therefore examined the utility of a structured oral examination (SOE) in the assessment of the 7 CanMEDS roles (Medical Expert, Communicator,…

Jefferies, Ann; Simmons, Brian; Ng, Eugene; Skidmore, Martin

2011-01-01

137

Model tool to describe chemical structures in XML format utilizing structural fragments and chemical ontology.  

PubMed

We have developed a model structure-editing tool, ChemEd, programmed in JAVA, which allows drawing chemical structures on a graphical user interface (GUI) by selecting appropriate structural fragments defined in a fragment library. The terms representing the structural fragments are organized in fragment ontology to provide a conceptual support. ChemEd describes the chemical structure in an XML document (ChemFul) with rich semantics explicitly encoding the details of the chemical bonding, the hybridization status, and the electron environment around each atom. The document can be further processed through suitable algorithms and with the support of external chemical ontologies to generate understandable reports about the functional groups present in the structure and their specific environment. PMID:20429589

Sankar, Punnaivanam; Alain, Krief; Aghila, Gnanasekaran

2010-05-24

138

Federal and State Structures to Support Financing Utility-Scale Solar Projects and the Business Models Designed to Utilize Themm..  

National Technical Information Service (NTIS)

Utility-scale solar projects have grown rapidly in number and size over the last few years, driven in part by strong renewable portfolio standards (RPS) and federal incentives designed to stimulate investment in renewable energy technologies. This report ...

C. Kreycik M. Mendelsohn

2012-01-01

139

Effects of a major earthquake on the PEP housing, structures, and utilities  

SciTech Connect

The PEP tunnel, above-ground structures, and utility structures have been designed to withstand a major earthquake. This means they will experience minor or moderate damage in an earthquake which will cause widespread devastation in the surrounding region. The earthquake on October 17, 1989, which was not very severe locally, caused no damage to the PEP tunnel, buildings, or utilities. There was apparently some permanent displacement of the PEP tunnel. The PEP ring magnets moved enough to require re-alignment. A major earthquake will probably cause sufficient displacement of the PEP tunnel and magnet systems to necessitate extensive re-alignment. This may be the dominant factor determining the length of the shutdown after the quake.

Weidner, H.

1990-08-01

140

Optimizing storage utilization in R-tree dynamic index structure for spatial databases  

Microsoft Academic Search

Spatial databases have been increasingly and widely used in recent years. The R-tree proposed by Guttman is probably the most popular dynamic index structure for eÅciently retrieving objects from a spatial database according to their spatial locations. However, experiments show that only about 70% storage utilization can be achieved in Guttman's R-tree and its variants. In this paper, we propose

Po-whei Huang; Phen-lan Lin; H. Y. Lin

2001-01-01

141

A study on the utilization of advanced composites in commercial aircraft wing structure  

NASA Technical Reports Server (NTRS)

A study was conducted to define the technology and data needed to support the introduction of advanced composite materials in the wing structure of future production aircraft. The study accomplished the following: (1) definition of acceptance factors, (2) identification of technology issues, (3) evaluation of six candidate wing structures, (4) evaluation of five program options, (5) definition of a composite wing technology development plan, (6) identification of full-scale tests, (7) estimation of program costs for the total development plan, (8) forecast of future utilization of composites in commercial transport aircraft and (9) identification of critical technologies for timely program planning.

Watts, D. J.

1978-01-01

142

A graph theoretic approach to utilizing protein structure to identify non-random somatic mutations  

PubMed Central

Background It is well known that the development of cancer is caused by the accumulation of somatic mutations within the genome. For oncogenes specifically, current research suggests that there is a small set of "driver" mutations that are primarily responsible for tumorigenesis. Further, due to recent pharmacological successes in treating these driver mutations and their resulting tumors, a variety of approaches have been developed to identify potential driver mutations using methods such as machine learning and mutational clustering. We propose a novel methodology that increases our power to identify mutational clusters by taking into account protein tertiary structure via a graph theoretical approach. Results We have designed and implemented GraphPAC (Graph Protein Amino acid Clustering) to identify mutational clustering while considering protein spatial structure. Using GraphPAC, we are able to detect novel clusters in proteins that are known to exhibit mutation clustering as well as identify clusters in proteins without evidence of prior clustering based on current methods. Specifically, by utilizing the spatial information available in the Protein Data Bank (PDB) along with the mutational data in the Catalogue of Somatic Mutations in Cancer (COSMIC), GraphPAC identifies new mutational clusters in well known oncogenes such as EGFR and KRAS. Further, by utilizing graph theory to account for the tertiary structure, GraphPAC discovers clusters in DPP4, NRP1 and other proteins not identified by existing methods. The R package is available at: http://bioconductor.org/packages/release/bioc/html/GraphPAC.html. Conclusion GraphPAC provides an alternative to iPAC and an extension to current methodology when identifying potential activating driver mutations by utilizing a graph theoretic approach when considering protein tertiary structure.

2014-01-01

143

Study on utilization of advanced composites in fuselage structures of large transports  

NASA Technical Reports Server (NTRS)

The potential for utilizing advanced composites in fuselage structures of large transports was assessed. Six fuselage design concepts were selected and evaluated in terms of structural performance, weight, and manufacturing development and costs. Two concepts were selected that merit further consideration for composite fuselage application. These concepts are: (1) a full depth honeycomb design with no stringers, and (2) an I section stringer stiffened laminate skin design. Weight reductions due to applying composites to the fuselages of commercial and military transports were calculated. The benefits of applying composites to a fleet of military transports were determined. Significant technology issues pertinent to composite fuselage structures were identified and evaluated. Program plans for resolving the technology issues were developed.

Johnson, R. W.; Thomson, L. W.; Wilson, R. D.

1985-01-01

144

Utilizing the Dyn2 Dimerization-Zipper as a Tool to Probe NPC Structure and Function.  

PubMed

The discovery of dynein light chain 2 (Dyn2) as a member of the nucleoporins in yeast led to a series of applications to study NPC structure and function. Its intriguing ability to act as a hub for the parallel dimerization of two short amino acid sequence motifs (DID) prompted us to utilize it as a tool for probing nucleocytoplasmic transport in vivo. Further, the distinct structure of the Dyn2-DID rod, which is easily visible in the electron microscope, allowed us to develop a precise structural label on proteins or protein complexes. This label was used to identify the position of subunits in NPC subcomplexes or to derive at pseudo-atomic models of single large Nups. The versatility for various applications of the DID-Dyn2 system makes it an attractive molecular tool beyond the nuclear pore and transport field. PMID:24857727

Flemming, Dirk; Stelter, Philipp; Hurt, Ed

2014-01-01

145

Process Developed for Fabricating Engineered Pore Structures for High- Fuel-Utilization Solid Oxide Fuel Cells  

NASA Technical Reports Server (NTRS)

Solid oxide fuel cells (SOFCs) have tremendous commercial potential because of their high efficiency, high energy density, and flexible fuel capability (ability to use fossil fuels). The drive for high-power-utilizing, ultrathin electrolytes (less than 10 microns), has placed an increased demand on the anode to provide structural support, yet allow sufficient fuel entry for sustained power generation. Concentration polarization, a condition where the fuel demand exceeds the supply, is evident in all commercial-based anode-supported cells, and it presents a significant roadblock to SOFC commercialization.

Sofie, Stephen W.; Cable, Thomas L.; Salamone, Sam M.

2005-01-01

146

A study on the utilization of advanced composites in commercial aircraft wing structure: Executive summary  

NASA Technical Reports Server (NTRS)

The overall wing study objectives are to study and plan the effort by commercial transport aircraft manufacturers to accomplish the transition from current conventional materials and practices to extensive use of advanced composites in wings of aircraft that will enter service in the 1985-1990 time period. Specific wing study objectives are to define the technology and data needed to support an aircraft manufacturer's commitment to utilize composites primary wing structure in future production aircraft and to develop plans for a composite wing technology program which will provide the needed technology and data.

Watts, D. J.

1978-01-01

147

In silico determination and validation of baumannii acinetobactin utilization a structure and ligand binding site.  

PubMed

Acinetobacter baumannii is a deadly nosocomial pathogen. Iron is an essential element for the pathogen. Under iron-restricted conditions, the bacterium expresses iron-regulated outer membrane proteins (IROMPs). Baumannii acinetobactin utilization (BauA) is the most important member of IROMPs in A. baumannii. Determination of its tertiary structure could help deduction of its functions and its interactions with ligands. The present study unveils BauA 3D structure via in silico approaches. Apart from ab initio, other rational methods such as homology modeling and threading were invoked to achieve the purpose. For homology modeling, BLAST was run on the sequence in order to find the best template. The template was then served to model the 3D structure. All the models built were evaluated qualitatively. The best model predicted by LOMETS was selected for analyses. Refinement of 3D structure as well as determination of its clefts and ligand binding sites was carried out on the structure. In contrast to the typical trimeric arrangement found in porins, BauA is monomeric. The barrel is formed by 22 antiparallel transmembrane ? -strands. There are short periplasmic turns and longer surface-located loops. An N-terminal domain referred to either as the cork, the plug, or the hatch domain occludes the ? -barrel. PMID:24106696

Sefid, Fatemeh; Rasooli, Iraj; Jahangiri, Abolfazl

2013-01-01

148

In Silico Determination and Validation of Baumannii Acinetobactin Utilization A Structure and Ligand Binding Site  

PubMed Central

Acinetobacter baumannii is a deadly nosocomial pathogen. Iron is an essential element for the pathogen. Under iron-restricted conditions, the bacterium expresses iron-regulated outer membrane proteins (IROMPs). Baumannii acinetobactin utilization (BauA) is the most important member of IROMPs in A. baumannii. Determination of its tertiary structure could help deduction of its functions and its interactions with ligands. The present study unveils BauA 3D structure via in silico approaches. Apart from ab initio, other rational methods such as homology modeling and threading were invoked to achieve the purpose. For homology modeling, BLAST was run on the sequence in order to find the best template. The template was then served to model the 3D structure. All the models built were evaluated qualitatively. The best model predicted by LOMETS was selected for analyses. Refinement of 3D structure as well as determination of its clefts and ligand binding sites was carried out on the structure. In contrast to the typical trimeric arrangement found in porins, BauA is monomeric. The barrel is formed by 22 antiparallel transmembrane ?-strands. There are short periplasmic turns and longer surface-located loops. An N-terminal domain referred to either as the cork, the plug, or the hatch domain occludes the ?-barrel.

Sefid, Fatemeh

2013-01-01

149

Utilization of the Building-Block Approach in Structural Mechanics Research  

NASA Technical Reports Server (NTRS)

In the last 20 years NASA has worked in collaboration with industry to develop enabling technologies needed to make aircraft safer and more affordable, extend their lifetime, improve their reliability, better understand their behavior, and reduce their weight. To support these efforts, research programs starting with ideas and culminating in full-scale structural testing were conducted at the NASA Langley Research Center. Each program contained development efforts that (a) started with selecting the material system and manufacturing approach; (b) moved on to experimentation and analysis of small samples to characterize the system and quantify behavior in the presence of defects like damage and imperfections; (c) progressed on to examining larger structures to examine buckling behavior, combined loadings, and built-up structures; and (d) finally moved to complicated subcomponents and full-scale components. Each step along the way was supported by detailed analysis, including tool development, to prove that the behavior of these structures was well-understood and predictable. This approach for developing technology became known as the "building-block" approach. In the Advanced Composites Technology Program and the High Speed Research Program the building-block approach was used to develop a true understanding of the response of the structures involved through experimentation and analysis. The philosophy that if the structural response couldn't be accurately predicted, it wasn't really understood, was critical to the progression of these programs. To this end, analytical techniques including closed-form and finite elements were employed and experimentation used to verify assumptions at each step along the way. This paper presents a discussion of the utilization of the building-block approach described previously in structural mechanics research and development programs at NASA Langley Research Center. Specific examples that illustrate the use of this approach are included from recent research and development programs for both subsonic and supersonic transports.

Rouse, Marshall; Jegley, Dawn C.; McGowan, David M.; Bush, Harold G.; Waters, W. Allen

2005-01-01

150

On the utility of isotopic fine structure mass spectrometry in protein identification.  

PubMed

Modern mass spectrometry (MS)-based protein identification and characterization relies upon accurate mass measurements of the (13)C isotopic distributions of the enzymatically produced peptides. Interestingly, obtaining peptide elemental composition information from its isotopic fine structure mass spectrum to increase the confidence in peptide and protein identification has not yet been developed into a bottom-up proteomics-grade analytical approach. Here, we discuss the possible utility and limitations of the isotopic fine structure MS for peptide and protein identification. First, we in silico identify the peptides from the E. coli tryptic digest and show the increased confidence in peptide identification by consideration of the isotopic fine structures of these peptides as a function of mass and abundance accuracies. In the following, we demonstrate that the state-of-the-art high magnetic field Fourier transform ion cyclotron resonance (FT-ICR) MS allows a routine acquisition of the isotopic fine structure information of a number of isobaric peptide pairs, including a pair of peptides originating from E. coli. Finally, we address the practical limitation of the isotopic fine structure MS implementation in the time-constraint experiments by applying an advanced signal processing technique, filter diagonalization method, to the experimental transients to overcome the resolution barrier set by the typically applied Fourier transformation. We thus demonstrate that the isotopic fine structures of peptides may indeed improve the peptide and possibly protein identification, can be produced in a routine experiment by the state-of-the-art high resolution mass spectrometers, and can be potentially obtained on a chromatographic time-scale of a typical bottom-up proteomics experiment. The latter one requires at least an order of magnitude increase in sensitivity of ion detection, which presumably can be realized using high-field Orbitrap FTMS and/or future generation of ultrahigh magnetic field FT-ICR MS equipped with harmonized ICR cells. PMID:22468966

Miladinovi?, Saša M; Kozhinov, Anton N; Gorshkov, Mikhail V; Tsybin, Yury O

2012-05-01

151

Preparation of 8-hydroxyquinoline derivatives as potential antibiotics against Staphylococcus aureus.  

PubMed

This work describes the preparation of quinoline compounds as possible anti-bacterial agents. The synthesized quinoline derivatives show anti-bacterial activity towards Staphylococcus aureus. It is interesting to observe that the synthetic 5,7-dibromo-2-methylquinolin-8-ol (4) shows a similar minimum inhibitory concentration of 6.25?g/mL as compared to that of methicillin (3.125?g/mL) against Staphylococcus aureus. PMID:24269165

Lam, Kim-Hung; Gambari, Roberto; Lee, Kenneth Ka-Ho; Chen, Yi-Xin; Kok, Stanton Hon-Lung; Wong, Raymond Siu-Ming; Lau, Fung-Yi; Cheng, Chor-Hing; Wong, Wai-Yeung; Bian, Zhao-Xiang; Chan, Albert Sun-Chi; Tang, Johnny Cheuk-On; Chui, Chung-Hin

2014-01-01

152

Photoluminescence of Tris(8-hydroxyquinoline)aluminum Thin Films and Influence of Swift Heavy Ion Irradiation  

Microsoft Academic Search

The effect of swift heavy ion (SHI) irradiation on the optical properties of Tris-(8-hydraxyquinoline) aluminum (Alq3) thin films has been studied. It is confirmed that PL and lifetime of SHI irradiated Alq3 thin films irradiated both at room temperature and low temperature decrease for increasing ion fluences indicating the transfer of excitons energy to unstable cationic Alq3 species. It is

K. Thangaraju; R. Kumaran; K. Asokan; P. Ramamoorthy; D. Kanjilal; J. Kumar

2008-01-01

153

Effect of swift heavy ion irradiation on photoluminescence of Tris(8-hydroxyquinoline)aluminum thin films  

Microsoft Academic Search

We report the effect of swift heavy ions (SHI) of 40 MeV Li3+ ions on Tris-(8-hydraxyquinoline) aluminum (Alq3) thin films deposited by thermal evaporation process on glass substrates. To understand the effect of the temperature-dependent optical properties, these thin films were irradiated both at 300 K and ~77 K and were characterized by photoluminescence (PL), Infrared (IR) and time resolved photoluminescence (TRPL) spectroscopy.

K. Thangaraju; R. Kumaran; K. Asokan; P. Ramamoorthy; D. Kanjilal; J. Kumar

2009-01-01

154

Overcoming Structural Constraints to Patient Utilization of Electronic Medical Records: A Critical Review and Proposal for an Evaluation Framework  

Microsoft Academic Search

There are constraints embedded in medical record structure that limit use by patients in self-directed disease management. Through systematic review of the literature from a critical perspective, four characteristics that either enhance or mitigate the influence of medical record structure on patient utilization of an electronic patient record (EPR) system have been identified: environmental pressures, physician centeredness, collaborative organizational culture,

Warren J Winkelman; Kevin J Leonard

2004-01-01

155

Assessing the Size, Stability, and Utility of Isotropically Tumbling Bicelle Systems for Structural Biology  

PubMed Central

Aqueous phospholipid mixtures that form bilayered micelles (bicelles) have gained wide use by molecular biophysicists during the past 20 years for spectroscopic studies of membrane-bound peptides and structural refinement of soluble protein structures. Nonetheless, the utility of bicelle systems may be compromised by considerations of cost, chemical stability, and preservation of the bicelle aggregate organization under a broad range of temperature, concentration, pH, and ionic strength conditions. In the current work, 31P nuclear magnetic resonance (NMR) and atomic force microscopy (AFM) have been used to monitor the size and morphology of isotropically tumbling small bicelles formed by mixtures of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) or 1,2-di-O-tetradecyl-sn-glycero-3-phosphocholine (DIOMPC) with either 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC) or 1,2-di-O-hexyl-sn-glycero-3-phospho-choline (DIOHPC), testing their tolerance of variations in commonly used experimental conditions. 1H-15N 2D NMR has been used to demonstrate the usefulness of the robust DMPC-DIOHPC system for conformational studies of a fatty acid-binding protein that shuttles small ligands to and from biological membranes.

Wu, Hongwei; Su, Kai; Guan, Xudong; Sublette, M. Elizabeth; Stark, Ruth E.

2009-01-01

156

Variations in methanobactin structure influences copper utilization by methane-oxidizing bacteria.  

PubMed

Methane-oxidizing bacteria are nature's primary biological mechanism for suppressing atmospheric levels of the second-most important greenhouse gas via methane monooxygenases (MMOs). The copper-containing particulate enzyme is the most widespread and efficient MMO. Under low-copper conditions methane-oxidizing bacteria secrete the small copper-binding peptide methanobactin (mbtin) to acquire copper, but how variations in the structures of mbtins influence copper metabolism and species selection are unknown. Methanobactins have been isolated from Methylocystis strains M and hirsuta CSC1, organisms that can switch to using an iron-containing soluble MMO when copper is limiting, and the nonswitchover Methylocystis rosea. These mbtins are shorter, and have different amino acid compositions, than the characterized mbtin from Methylosinus trichosporium OB3b. A coordinating pyrazinedione ring in the Methylocystis mbtins has little influence on the Cu(I) site structure. The Methylocystis mbtins have a sulfate group that helps stabilize the Cu(I) forms, resulting in affinities of approximately 10(21) M(-1). The Cu(II) affinities vary over three orders of magnitude with reduction potentials covering approximately 250 mV, which may dictate the mechanism of intracellular copper release. Copper uptake and the switchover from using the iron-containing soluble MMO to the copper-containing particulate enzyme is faster when mediated by the native mbtin, suggesting that the amino acid sequence is important for the interaction of mbtins with receptors. The differences in structures and properties of mbtins, and their influence on copper utilization by methane-oxidizing bacteria, have important implications for the ecology and global function of these environmentally vital organisms. PMID:22582172

El Ghazouani, Abdelnasser; Baslé, Arnaud; Gray, Joe; Graham, David W; Firbank, Susan J; Dennison, Christopher

2012-05-29

157

Effect of questionnaire structure on recall of drug utilization in a population of university students  

PubMed Central

Background Self-reported data are a common source of information about drug exposure. Modes of data collection differ considerably and the questionnaire's structure may affect prevalence estimates. We compared the recall of medication use evaluated by means of two questionnaires differing in structure and length. Methods Drug utilization was assessed by two alternative versions of a questionnaire (A – 4 pages, including specific questions for 12 indications/pharmacological groups and one question for "other medicines"; B – 1 page, including 1 open-ended question to cover overall drug consumption). Each of 32 classes in a private University in Maputo, Mozambique, was randomly assigned questionnaire A (233 participants) or B (276 participants). Logistic regression (allowing for clustering by classroom) was used to compare the two groups in terms of socio-demographic characteristics and medication used during the previous month. Results Overall, 67.4% of the subjects had used at least one drug during the previous month. The following prevalences were greater among participants completing questionnaire A: use of drugs from two or more pharmacological groups (60.5% vs. 34.4%, p < 0.001), use of two or more drugs (66.2% vs. 43.0%, p < 0.001), and use of antibiotics (14.6% vs. 6.9%, p = 0.001), antifungals (9.4% vs. 4.0%, p = 0.013), antiparasitics (5.6% vs. 1.8%, p = 0.031) and antacids (8.6% vs. 3.6%, p = 0.024). Information about duration of treatment and medical advice was more complete with version A. Conclusion The indication/drug-specific questions (questionnaire A) revealed a significantly higher prevalence of use of medicines – antibiotics, antifungals, antiparasitics and antacids – without compromising the completeness of the information.

2009-01-01

158

A latching millimeter-wave T-circulator utilizing a single ferrite located inside the waveguide structure  

Microsoft Academic Search

A latching T-circulator utilizing a bulk ferrite located inside the waveguide T-structure was fabricated and tested at a wavelength of 8 mm. Circuit arrangements for efficient testing are presented. The reverse attenuation and the reverse-to-forward attenuation ratio are approximately 20 dB and 13, respectively, at the present stage.

N. Ogasawara

1967-01-01

159

Biomass utilization  

Microsoft Academic Search

Forty papers are presented in 6 sections: Biomass utilization - the concept; The raw material and its preparation; The structure and chemical composition of biomass; Conversion methods - biological; Conversion methods - thermochemical; and Engineering and economics in biomass utilization. Ten papers are of particular forestry interest: Forest inventories as the basis for a continuous monitoring of forest biomass resources

Coute

1983-01-01

160

Structural and optical properties of 6,13-pentacenequinone thin films  

NASA Astrophysics Data System (ADS)

We report on the structural and optical properties of 6,13-pentacenequinone thin films deposited on n-Si substrates by thermal evaporation at room temperature. X-ray diffraction data indicate excellent crystallinity but the films have two crystalline phases mixed. Photoluminescence (PL) spectra exhibited double peaks at 1.97 and 2.09 eV while the corresponding (double) peaks, associated with the highest occupied molecular orbital-lowest unoccupied molecular orbital transition, were also observed from direct absorption spectra at 2.94 and 3.11 eV. The yellow PL band was quite intense under UV illumination; the intensity was comparable to that from Tris-(8-hydroxyquinoline) aluminum (Alq3) thin films. A large Stokes shift of ~1 eV found in our 6,13-pentacenequinone thin films suggests potential applications to UV-detectors and UV-detecting cards.

Hwang, D. K.; Kim, Kibum; Kim, Jae Hoon; Im, Seongil; Jung, Duk-Young; Kim, Eugene

2004-12-01

161

Restriction of enhanced (2-/sup 14/C)deoxyglucose utilization to rhinencephalic structures in immature amygdala-kindled rats  

SciTech Connect

Sixteen-day-old albino rat pups were kindled to varying degrees of seizure severity with amygdala stimulations spaced 15 to 20 min apart. Subsequently, each rat pup was injected (ip) with 10 microCi of (2-/sup 14/C)-deoxyglucose, and received several additional kindled seizures at regular intervals throughout the following 80 min, at which time it was killed and processed for deoxyglucose autoradiography. Increased seizure severity was associated with correspondingly increased deoxyglucose utilization in many rhinencephalic limbic structures. However, unlike adults, rat pups did not show discernibly increased neocortical, thalamic, or substantia nigra utilization. We postulate that the apparent confinement of seizure activity to limbic structures in pups is related to their relative lack of postictal seizure refractoriness, as well as to other indices of increased seizure susceptibility in immature animals.

Ackermann, R.F.; Moshe, S.L.; Albala, B.J.

1989-04-01

162

Fiber Stress Values for Design of Glulam Timber Utility Structures: A Data Base.  

National Technical Information Service (NTIS)

The decreased availability of large timbers for structural applications has led to the development of engineered structural wood products such as glulam. To determine fiber stresses for glulam beams manufactured with visually graded or E-rated lumber, we ...

R. Hernandez, R. C. Moody, R. H. Falk

1995-01-01

163

Structural characterization and biological evaluation of a clioquinol-ruthenium complex with copper-independent antileukaemic activity.  

PubMed

In this study, we present the synthesis, biological characterization, and first crystal structure of an organometallic-clioquinol complex. Combining ruthenium with the established apoptotic agent and 8-hydroxyquinoline derivative, clioquinol, resulted in a complex that induces caspase-dependent cell death in leukaemia cells. This activity is copper independent and is improved compared to the parent compound, clioquinol. The study of the mode of action reveals that this clioquinol-ruthenium complex does not intercalate between DNA base pairs. Additionally, this clioquinol-ruthenium complex shows proteasome-independent inhibition of the NF?B signalling pathway, with no effects on cell-cycle distribution. These data suggest a mechanism of action that involves a target profile that is different from that for clioquinol alone. PMID:24781711

Gobec, Martina; Kljun, Jakob; Sosi?, Izidor; Mlinari?-Raš?an, Irena; Urši?, Matija; Gobec, Stanislav; Turel, Iztok

2014-06-28

164

ToxRefDB: Classifying ToxCast? Phase I Chemicals Utilizing Structured Toxicity Information  

EPA Science Inventory

There is an essential need for highly detailed chemicals classifications within the ToxCast? research program. In order to develop predictive models and biological signatures utilizing high-throughput screening (HTS) and in vitro genomic data, relevant endpoints and toxicities m...

165

Design of high performance missile structures utilizing advanced composite material technologies  

Microsoft Academic Search

The U.S. Army Aviation and Missile Command (AMCOM) has demonstrated the ability to develop and utilize advanced composite material technologies for the design and fabrication of hypervelocity kinetic energy missiles for the next generation of Army air defense and anti-tank applications. Future kinetic energy missiles must be small, fast, lethal, and maneuverable, which requires the delivery vehicles to operate in

J. R. Esslinger; R. N. Evans; G. W. Snyder

1999-01-01

166

A strategic analysis for successful open source software utilization based on a structural equation model  

Microsoft Academic Search

Commercial software companies face many challenges when competing in today’s fast moving and competitive industry environment. Recently, the use of open source software (OSS) has been proposed as a possible way to address those challenges. OSS provides many benefits, including high-quality software and substantial profits. Nevertheless, OSS has not been effectively utilized in real business. The purpose of this paper

So Young Sohn; Min Seok Mok

2008-01-01

167

Integration and utilization of different visualization methods and devices in a structure-based drug design process  

NASA Astrophysics Data System (ADS)

Molecular visualization techniques are used in various stages in the computer-aided drug design process. Here, we report on utilization of a four wall immersive virtual room in the visualization of protein - drug complexes. The advantage of a virtual room compared to desktop graphics is that it provides a high-resolution large field of view, helping the observers of the visualization to dissect the individual important structural features more easily than while using only conventional molecular graphics visualizations.

Gröhn, Matti T.; Nyrönen, Tommi N.

2003-05-01

168

Accounting for the Hierarchical Structure in Veterans Health Administration Data: Differences in Healthcare Utilization between Men and Women Veterans  

PubMed Central

Women currently constitute 15% of active United States of America military service personnel, and this proportion is expected to double in the next 5 years. Previous research has shown that healthcare utilization and costs differ in women US Veterans Health Administration (VA) patients compared to men. However, none have accounted for the potential effects of clustering on their estimates of healthcare utilization. US Women Veterans are more likely to serve in specific military branches (e.g. Army), components (e.g. National Guard), and ranks (e.g. officer) than men. These factors may confer different risk and protection that can affect subsequent healthcare needs. Our study investigates the effects of accounting for the hierarchical structure of data on estimates of the association between gender and VA healthcare utilization. The sample consisted of data on 406,406 Veterans obtained from VA's Operation Enduring Freedom/Operation Iraqi Freedom roster provided by Defense Manpower Data Center — Contingency Tracking System Deployment File. We compared three statistical models, ordinary, fixed and random effects hierarchical logistic regression, in order to assess the association of gender with healthcare utilization, controlling for branch of service, component, rank, age, race, and marital status. Gender was associated with utilization in ordinary logistic and, but not in fixed effects hierarchical logistic or random effects hierarchical logistic regression models. This point out that incomplete inference could be drawn by ignoring the military structure that may influence combat exposure and subsequent healthcare needs. Researchers should consider modeling VA data using methods that account for the potential clustering effect of hierarchy.

Allore, Heather G.; Ning, Yuming; Brandt, Cynthia A.; Goulet, Joseph L.

2013-01-01

169

Utility diversification  

SciTech Connect

After reviewing the pros and cons of public utility diversification, the author concludes that the balance of public interest is on the side of permitting public utility companies greater freedom to diversify than they now enjoy. He would eliminate the review of individual proposed investments outside of the public utility area on the grounds that regulators have no particular competence in this area. He would also eliminate the regulation of security issuances and dividend payments by the nonpublic utility entities. Regulation should see that the diversifying enterprise is structured and regulation of the utility entity so conducted as to insulate monoply ratepayers from risks as much as possible. This would limit regulation of the nonutility entity to seeing that the total size of the company's commitment to new diversification ventures does not threaten deterioration of the credit of the entire enterprise. 3 references.

Kahn, A.E.

1983-01-01

170

Habitat utilization by Hawaiian stream fishes with reference to community structure in oceanic island streams  

Microsoft Academic Search

Synopsis  Much of the freshwater biota on high Pacific islands is derived from marine ancestors. Traces of this marine origin are seen\\u000a in the amphidromous life history patterns of these species. Investigation of the habitat utilization of an assemblage of freshwater\\u000a gobies in the Hawaiian Islands indicates some resource partitioning within this group. The three major stream species appear\\u000a to exhibit

Robert A. Kinzie

1988-01-01

171

Assessing the utility of coevolution-based residue-residue contact predictions in a sequence- and structure-rich era.  

PubMed

Recently developed methods have shown considerable promise in predicting residue-residue contacts in protein 3D structures using evolutionary covariance information. However, these methods require large numbers of evolutionarily related sequences to robustly assess the extent of residue covariation, and the larger the protein family, the more likely that contact information is unnecessary because a reasonable model can be built based on the structure of a homolog. Here we describe a method that integrates sequence coevolution and structural context information using a pseudolikelihood approach, allowing more accurate contact predictions from fewer homologous sequences. We rigorously assess the utility of predicted contacts for protein structure prediction using large and representative sequence and structure databases from recent structure prediction experiments. We find that contact predictions are likely to be accurate when the number of aligned sequences (with sequence redundancy reduced to 90%) is greater than five times the length of the protein, and that accurate predictions are likely to be useful for structure modeling if the aligned sequences are more similar to the protein of interest than to the closest homolog of known structure. These conditions are currently met by 422 of the protein families collected in the Pfam database. PMID:24009338

Kamisetty, Hetunandan; Ovchinnikov, Sergey; Baker, David

2013-09-24

172

Undoped White Organic Light-Emitting Diodes Utilizing Two Sources of Excitons  

NASA Astrophysics Data System (ADS)

We report two undoped white organic light-emitting diodes with the structures of ITO/m-MTDATA/Alq3/NPB/BCP/Alq3/Mg:Ag (device A), and ITO/NPB/DCM/NPB/Alq3/NPB/BCP/Alq3/Mg:Ag (device B), where ITO is indium tin oxide, m-MTDATA is 4,4',4''-tris{N,(3-methylphenyl)-N-phenylamino}-triphenylamine, Alq3 is tris(8-hydroxyquinoline) aluminum, NPB is N,N'-di(naphth-2-yl)-N,N'-diphenyl-benzidine, BCP is 2,9-dimethyl-4,7-diphenylphenanthroline, and DCM is 4-(dicyanomethylene)-2-methyl-6-(p-dimethyl aminostyryl)-4H-pyran. Red emission was harvested from the exciplex at the m-MTDATA/Alq3 interface and DCM (0.5 nm) for devices A and B, respectively, while green and blue emissions were from Alq3 and NPB respectively, for both devices. A maximum brightness of 1100 and 4500 cd/m2 was achieved at a current density of 270 mA/cm2 (12 V) for devices A and B, respectively. Device B showed a maximum external quantum efficiency of 0.89% photon/electron (2 cd/A), which is about four times of that of device A.

Divayana, Yoga; Sun, Xiao Wei; Chen, Baijun; Lo, Guo Qiang; Jiang, Changyun; Kwong, Dim Lee; Sarma, Kalluri R.

2007-08-01

173

The intellectual structure and substance of the knowledge utilization field: A longitudinal author co-citation analysis, 1945 to 2004  

PubMed Central

Background It has been argued that science and society are in the midst of a far-reaching renegotiation of the social contract between science and society, with society becoming a far more active partner in the creation of knowledge. On the one hand, new forms of knowledge production are emerging, and on the other, both science and society are experiencing a rapid acceleration in new forms of knowledge utilization. Concomitantly since the Second World War, the science underpinning the knowledge utilization field has had exponential growth. Few in-depth examinations of this field exist, and no comprehensive analyses have used bibliometric methods. Methods Using bibliometric analysis, specifically first author co-citation analysis, our group undertook a domain analysis of the knowledge utilization field, tracing its historical development between 1945 and 2004. Our purposes were to map the historical development of knowledge utilization as a field, and to identify the changing intellectual structure of its scientific domains. We analyzed more than 5,000 articles using citation data drawn from the Web of Science®. Search terms were combinations of knowledge, research, evidence, guidelines, ideas, science, innovation, technology, information theory and use, utilization, and uptake. Results We provide an overview of the intellectual structure and how it changed over six decades. The field does not become large enough to represent with a co-citation map until the mid-1960s. Our findings demonstrate vigorous growth from the mid-1960s through 2004, as well as the emergence of specialized domains reflecting distinct collectives of intellectual activity and thought. Until the mid-1980s, the major domains were focused on innovation diffusion, technology transfer, and knowledge utilization. Beginning slowly in the mid-1980s and then growing rapidly, a fourth scientific domain, evidence-based medicine, emerged. The field is dominated in all decades by one individual, Everett Rogers, and by one paradigm, innovation diffusion. Conclusion We conclude that the received view that social science disciplines are in a state where no accepted set of principles or theories guide research (i.e., that they are pre-paradigmatic) could not be supported for this field. Second, we document the emergence of a new domain within the knowledge utilization field, evidence-based medicine. Third, we conclude that Everett Rogers was the dominant figure in the field and, until the emergence of evidence-based medicine, his representation of the general diffusion model was the dominant paradigm in the field.

Estabrooks, Carole A; Derksen, Linda; Winther, Connie; Lavis, John N; Scott, Shannon D; Wallin, Lars; Profetto-McGrath, Joanne

2008-01-01

174

Novel emissive podands based on 8-OH-quinoline: Synthesis, fluorescence materials, DFT and complexation studies  

Microsoft Academic Search

Two novel chemosensors with podand structures (L1 and L2) derived from 1,5-bis(2-aminophenoxy)-3-oxopenthane bearing two flexible 8-hydroxyquinoline units have been synthesized and characterized.Several nitrate complexes of transition (Cu2+), post-transition (Zn2+) and lanthanide (Eu3+ and Sm3+) metal ions have been synthesized with tetrafluoroborate salts and characterized. In order to study their potential utility as fluorescent probes, the coordination ability of chemosensors (L1

Javier Fernández-Lodeiro; Cristina Núñez; Olalla Nieto Faza; Jose Luis Capelo; Carlos Lodeiro; J. Sérgio Seixas de Melo; Carlos Silva López

175

Novel Optical and Electroluminescent Characteristics in Organic Superlattice Structure Utilizing Cyclopentadiene Derivative and Aromatic Diamine  

NASA Astrophysics Data System (ADS)

A superlattice structure electroluminescent diode consisting of alternating layers of organic cyclopentadiene derivative and aromatic diamine has been fabricated by organic molecular beam deposition. The electroluminescent spectrum of the diode depends on the layer thickness of cyclopentadiene derivative. The polarization anisotropy of the emission spectrum of the diode is also observed. The mechanism of emission anisotropy has been discussed in the superlattice structure.

Morishima, Chikayoshi; Yoshida, Masayoshi; Fujii, Akihiko; Ohmori, Yutaka; Yoshino, Katsumi

1994-09-01

176

Direct in situ observation of structural transition driven actuation in VO2 utilizing electron transparent cantilevers  

NASA Astrophysics Data System (ADS)

Direct imaging and quantification of actuation in nanostructures that undergo structural phase transitions could advance our understanding of collective phenomena in the solid state. Here, we demonstrate visualization of structural phase transition induced actuation in a model correlated insulator vanadium dioxide by in situ Fresnel contrast imaging of electron transparent cantilevers. We quantify abrupt, reversible cantilever motion occurring due to the stress relaxation across the structural transition from a monoclinic to tetragonal phase with increasing temperature. Deflections measured in such nanoscale cantilevers can be directly correlated with macroscopic stress measurements by wafer curvature studies as well as temperature dependent electrical conduction allowing one to interrogate lattice dynamics across length scales.

Viswanath, B.; Ramanathan, Shriram

2013-07-01

177

Unique Dynamic Characteristics of Electroluminescent Diode with Superlattice Structure Utilizing Cyclopentadiene Derivative and Aromatic Diamine  

NASA Astrophysics Data System (ADS)

The pulse response of an organic electroluminescent (EL) diode with superlattice structure which consists of alternating layers of cyclopentadiene derivative and aromatic diamine has been investigated. The EL emission from the superlattice structure with increased layer thickness shows fast response, whereas that from reduced layer thickness shows both slow response and decay upon application of a rectangular-shaped pulse current. The origin of the slow response and decay has been discussed in terms of the layer thickness and the energy band model of the superlattice structure.

Ohmori, Yutaka; Yoshida, Masayoshi; Morishima, Chikayoshi; Fujii, Akihiko; Yoshino, Katsumi

1994-09-01

178

Structural Aspects of Molecular Photoionization Efficiency in Micelles and Vesicles as Models for Solar Energy Utilization.  

National Technical Information Service (NTIS)

The structural aspects controlling charge separation in molecular photoionization reactions in organized molecular assemblies involving micelles and vesicles are being studied by optical and electron magnetic resonance techniques including the time domain...

L. Kevan

1983-01-01

179

A novel RF-insensitive EED utilizing an integrated metal-oxide-semiconductor structure  

NASA Astrophysics Data System (ADS)

The description and characterization of an electroexplosive device (EED) are presented. The structure is designed, using microelectric fabrication techniques, to be inherently immune to radio frequency (RF) radiation and also offers protection against stray signals associated with RF-induced arcing. A detailed discussion of the structure, which includes the fundamental mechanisms of operation, fabrication techniques, the device's frequency response and sensitivity to RF-induced arcing, and its compatibility with present fire control systems, is provided. Preliminary test results of the prototype device are discussed and show a significant improvement in the system's overall EMI immunity. These results include bench and field measurements of the structure's RF response for frequencies of 10-225 MHz and field measurements of the device's sensitivity to RF-induced arcing. The measurements indicate a significant reduction in real power dissipated by an EED employing the structure over an EED employing a conventional bridgewire (20 dB at 90 MHz).

Baginski, Thomas A.; Baginski, Michael E.

1990-05-01

180

Convergence or Divergence of Expert Mental Models: The Utility of Knowledge Structure Assessment in Training Research.  

National Technical Information Service (NTIS)

In this paper we discuss the impact of differing knowledge structure measurement techniques on assessing instructor mental models for behaviors associated with Situation Awareness. Our goals were, first, to investigate the degree to which an expert model ...

J. Fowlkes L. Martin-Milham R. L. Oser S. M. Fiore

2000-01-01

181

Utility of 1H NMR Chemical Shifts in Determining RNA Structure and Dynamics  

PubMed Central

The development of methods for predicting NMR chemical shifts with high accuracy and speed is increasingly allowing use of these abundant, readily accessible measurements in determining the structure and dynamics of proteins. For nucleic acids, however, despite the availability of semi-empirical methods for predicting 1H chemical shifts, their use in determining the structure and dynamics has not yet been examined. Here, we show that 1H chemical shifts offer powerful restraints for RNA structure determination, allowing discrimination of native structure from non-native states to within 2–4 Å, and <3 Å when ignoring highly flexible residues. Theoretical simulations shows that while 1H chemical shifts can provide valuable information for constructing RNA dynamic ensembles, large uncertainties in the chemical shift predictions and inherent degeneracies lead to higher uncertainties as compared to residual dipolar couplings.

Frank, Aaron T.; Horowitz, Scott; Andricioaei, Ioan; Al-Hashimi, Hashim M.

2013-01-01

182

LETTER TO THE EDITOR: High colour rendering index non-doped-type white organic light-emitting devices with a RGB-stacked multilayer structure  

Microsoft Academic Search

A non-doped-type white organic light-emitting device with high colour rendering index has been reported. The structure of the device is ITO\\/NPB (50 nm)\\/TPBI (3 nm)\\/Alq3 (d nm)\\/DCM2 (0.1 nm)\\/TPBI (40 - d nm)\\/Alq3 (10 nm)\\/LiF\\/Al, where NPB is N, N'-bis-(1-naphthyl)-N, N'-diphenyl-1, 1'-biph-enyl-4, 4'-diamine, TPBI is 2, 2', 2''-(1, 3, 5-phenylene) tris(1-phenyl-1H-benzimidazole), Alq3 is tris (8-hydroxyquinoline) aluminium, DCM2 is [2-methyl-6-[2-(2, 3,

Wenfa Xie; Yi Zhao; Chuannan Li; Shiyong Liu

2005-01-01

183

History of biological metal utilization inferred through phylogenomic analysis of protein structures  

PubMed Central

The fundamental chemistry of trace elements dictates the molecular speciation and reactivity both within cells and the environment at large. Using protein structure and comparative genomics, we elucidate several major influences this chemistry has had upon biology. All of life exhibits the same proteome size-dependent scaling for the number of metal-binding proteins within a proteome. This fundamental evolutionary constant shows that the selection of one element occurs at the exclusion of another, with the eschewal of Fe for Zn and Ca being a defining feature of eukaryotic proteomes. Early life lacked both the structures required to control intracellular metal concentrations and the metal-binding proteins that catalyze electron transport and redox transformations. The development of protein structures for metal homeostasis coincided with the emergence of metal-specific structures, which predominantly bound metals abundant in the Archean ocean. Potentially, this promoted the diversification of emerging lineages of Archaea and Bacteria through the establishment of biogeochemical cycles. In contrast, structures binding Cu and Zn evolved much later, providing further evidence that environmental availability influenced the selection of the elements. The late evolving Zn-binding proteins are fundamental to eukaryotic cellular biology, and Zn bioavailability may have been a limiting factor in eukaryotic evolution. The results presented here provide an evolutionary timeline based on genomic characteristics, and key hypotheses can be tested by alternative geochemical methods.

Dupont, Christopher L.; Butcher, Andrew; Valas, Ruben E.; Bourne, Philip E.; Caetano-Anolles, Gustavo

2010-01-01

184

Parameter and structure-activity data bases: management for maximum utility.  

PubMed Central

Quantitative structure-activity relationships (QSAR) in the fields of medicinal chemistry, pesticide science, biochemistry and toxicology are being published at an ever increasing rate. In addition to these biological correlation equations, thousands of such equations have been published for all kinds of organic reactions. There is a great need to develop a computerized system to enable one to make comparisons and to draw generalizations about the effects of structure on chemical and biological activity. A proposal is made for a systematic approach to this problem based on the physicochemical properties of organic compounds.

Leo, A

1985-01-01

185

850nm vertical cavity surface emitting lasers utilizing the self-planar mesa structure  

NASA Astrophysics Data System (ADS)

We presented the self-planar mesa structure for improving the performances of 850-nm oxide-confined vertical cavity surface emitting lasers (VCSELs). Thermal simulation results demonstrated that the enhanced lateral heat dissipation and decreased series resistance within VCSELs could be gained using the self-planar mesa structure. By employing the selfplanar mesa, the maximum output power was increased from 8mW to more than 11mW, and the maximum wall-plug efficiency was improved from 26% to 36% for the VCSEL with an oxide aperture size of 13 ?m at 15°C.

Zhang, Jianwei; Ning, Yongqiang; Zhang, Xing; Zhang, Jian; Wang, Lijun

2013-09-01

186

Human Cytochrome P450 1A1 Structure and Utility in Understanding Drug and Xenobiotic Metabolism*  

PubMed Central

Cytochrome P450 (CYP) 1A1 is an extrahepatic monooxygenase involved in the metabolism of endogenous substrates and drugs, as well as the activation of certain toxins and environmental pollutants. CYP1A1 is particularly well known for its ability to biotransform polycyclic aromatic hydrocarbons, such as benzo[a]pyrene in tobacco smoke, into carcinogens. CYP1A1 possesses functional similarities and differences with human CYP1A2 and CYP1B1 enzymes, but the structural basis for this has been unclear. We determined a 2.6 ? structure of human CYP1A1 with the inhibitor ?-naphthoflavone. ?-Naphthoflavone binds within an enclosed active site, with the planar benzochromen-4-one core packed flat against the I helix that composes one wall of the active site, and the 2-phenyl substituent oriented toward the catalytic heme iron. Comparisons with previously determined structures of the related cytochrome P450 1A2 and 1B1 enzymes reveal distinct features among the active sites that may underlie the functional variability of these enzymes. Finally, docking studies probed the ability of CYP1A structures to assist in understanding their known in vitro interactions with several typical substrates and inhibitors.

Walsh, Agnes A.; Szklarz, Grazyna D.; Scott, Emily E.

2013-01-01

187

A Study of the Utilization of Advanced Composites in Fuselage Structures of Commercial Aircraft  

NASA Technical Reports Server (NTRS)

A study was conducted to define the technology and data needed to support the introduction of advanced composites in the future production of fuselage structure in large transport aircraft. Fuselage structures of six candidate airplanes were evaluated for the baseline component. The MD-100 was selected on the basis of its representation of 1990s fuselage structure, an available data base, its impact on the schedule and cost of the development program, and its availability and suitability for flight service evaluation. Acceptance criteria were defined, technology issues were identified, and a composite fuselage technology development plan, including full-scale tests, was identified. The plan was based on composite materials to be available in the mid to late 1980s. Program resources required to develop composite fuselage technology are estimated at a rough order of magnitude to be 877 man-years exclusive of the bird strike and impact dynamic test components. A conceptual composite fuselage was designed, retaining the basic MD-100 structural arrangement for doors, windows, wing, wheel wells, cockpit enclosure, major bulkheads, etc., resulting in a 32 percent weight savings.

Watts, D. J.; Sumida, P. T.; Bunin, B. L.; Janicki, G. S.; Walker, J. V.; Fox, B. R.

1985-01-01

188

An assessment of children's concepts of the earth utilizing structured interviews  

Microsoft Academic Search

Structured interviews with second graders in the U.S. about the shape of Earth and the effects of gravity at the surface. Describes a highly effective and systematic interviewing strategy aropriate for investigating student conceptions. Most students consistently hold one of five notions: Earth is flat, Earth is round with flat places where people live, Earth is round and people can

Joseph Nussbaum; Joseph D. Novak

1976-01-01

189

The Development of Robust Structural Health Monitoring Sensors Utilizing TRIP Steel  

Microsoft Academic Search

The feasibility of using the inherently smart properties of transformation-induced plasticity (TRIP) steels as a basis for low cost, robust smart structural health monitoring sensors has been investigated. These steels undergo an irreversible strain-induced phase transformation from paramagnetic austenite to ferromagnetic martensite. Specific needs were identified in the geotechnical industry, and a primary aim of the project was the development

Clinton P. Bemont

2009-01-01

190

Utilizing Semantic Networks and Fuzzy Logic for the Creation of the Planning Coordinator's Primitive Structure Database  

Microsoft Academic Search

Previous work has introduced the planning coordinator, a logical extension to the coordination level of the intelligent machine model that provides a platform for error recovery and online planning by autonomous and semi-autonomous robotic systems. This paper refines the design architecture of the planning coordinator focusing on the primitive structure database and node\\/link weighting mechanism. This architecture facilitates the role

Jeffrey J. Farah; Robert B. Kelley

1993-01-01

191

A study on utilizing a chloride bath to electroform MEMS devices with high aspect ratio structures  

NASA Astrophysics Data System (ADS)

Addressing the problems that occurred for electroforming of MEMS devices with high aspect ratio and geometry-complex structures, the electrochemical properties of a chloride bath are studied in this paper. It has been found that the tensile stress of nickel film from the chloride bath with the addition of saccharine is significantly reduced. Our results also suggested that, compared to the commonly used sulfamate bath, the chloride bath has higher throwing power and covering power, possibly due to its higher conductivity and polarizability. In addition, the presence of saccharine provided a finer grain nickel film with a smoother surface. Furthermore, the MEMS-based latching devices with narrow bars of 50 µm width and 500 µm thickness were obtained from the chloride bath, while the same devices with structure deficiency (incomplete structures) were frequently observed from the sulfamate bath. The finite element method simulations using the ANSYS software for the current density distribution on the surface of different aspect ratio latching structures were carried out. After considering the electrochemical perspectives from both baths, the mechanisms for the deficiency formation from the sulfamate bath and the absence of the deficiencies from the chloride bath were proposed and discussed.

Wang, Hong; Tang, Jun; Li, Guangyang; Zhang, Congchun; Zhu, Jun; Wang, Zhimin; Ding, GuiFu; Zhao, Xiaolin

2010-11-01

192

INNOVATIVE METHOD UTILIZING HYBRID FRP SYSTEM FOR SHEAR STRENGTHENING OF CONCRETE STRUCTURES  

Microsoft Academic Search

Fiber reinforced polymer (FRP) materials have widespread use in many different areas of repair and strengthening of RC structures due to their many merits such as low unit weight, excellent corrosion resistance, high strength and ease of handling and application. However, these systems are scarcely applied for enhancing punching shear resistance for RC flat slabs. Moreover, the internationally available codes

M. Serry; Arab Contractors; I. Mahfouz; G. Hamdy; M. Aboul Nour; Y. Abdel Maguid

193

Aging Influence on Gray Matter Structural Associations within the Default Mode Network Utilizing Bayesian Network Modeling  

PubMed Central

Recent neuroimaging studies have revealed normal aging-related alterations in functional and structural brain networks such as the default mode network (DMN). However, less is understood about specific brain structural dependencies or interactions between brain regions within the DMN in the normal aging process. In this study, using Bayesian network (BN) modeling, we analyzed gray matter volume data from 109 young and 82 old subjects to characterize the influence of aging on associations between core brain regions within the DMN. Furthermore, we investigated the discriminability of the aging-associated BN models for the young and old groups. Compared to their young counterparts, the old subjects showed significant reductions in connections from right inferior temporal cortex (ITC) to medial prefrontal cortex (mPFC), right hippocampus (HP) to right ITC, and mPFC to posterior cingulate cortex and increases in connections from left HP to mPFC and right inferior parietal cortex to right ITC. Moreover, the classification results showed that the aging-related BN models could predict group membership with 88.48% accuracy, 88.07% sensitivity, and 89.02% specificity. Our findings suggest that structural associations within the DMN may be affected by normal aging and provide crucial information about aging effects on brain structural networks.

Wang, Yan; Chen, Kewei; Zhang, Jiacai; Yao, Li; Li, Ke; Jin, Zhen; Ye, Qing; Guo, Xiaojuan

2014-01-01

194

Nitrogen isotope variations in the subarctic northeast Pacific: relationships to nitrate utilization and trophic structure  

NASA Astrophysics Data System (ADS)

The isotopic composition of dissolved nitrate, size-fractionated suspended particulate organic matter (SPOM) and zooplankton was determined on a transect (Line P) between a coastal upwwelling domain and Station Papa in the subarctic northeast Pacific. Station Papa lies in one of the three extensive high-nutrient low-chlorophyll (HNLC) domains of the open ocean, where plankton standing stocks are seasonally uniform and production is lower than the potential production based on available nutrients. In spring 1993, surface water ?15NO 3- decreased from east to west along the transect, from ca 12%. in the coastal domain to 8%. at Station Papa, while nitrate concentration ([N0 3-) increased from 3 to 12 ?M in the same direction. Concurrently, ?15NO 3- at 400 m depth showed a much smaller change, from 5.3 to 3.1%., indicating a larger ?15N difference between deep and surface waters at the coastal end of the transect. The isotopic trend for SPOM was similar, from approximately 11 to 3%. for bulk SPOM, 8.5 to 3%. for the < 5 ?m fraction, 10 to 4%. for the 50-253 ?m fraction, and 12 to 5%. for the < 253 ?m fraction. Zooplankton had ?15N values ranging from 12%. off the coast to 8%. at Station Papa. The fractionation factor for the nitrogen isotopes from these field observations was estimated to be 5%. from the change in ?15NO 3- between surface and deep water and from the difference between ?15N SPOM and ?15NO 3- and assuming the SPOM represents an instantaneous product. Seasonal transects of ?15N SPOM and [N0 3-] show that there are different relationships between these two parameters depending on the availability and relative utilization of N0 3-; ?15N SPOM is more or less constant in the open ocean where [NO 3-] > 7 ?M, it increases rapidly where nitrate utilization is high (that is, where biological uptake is greater than physical supply), and it decreases during upwelling events when physical supply of nutrients overwhelms the biological uptake rate. Finally, the nitrogen isotopes show the expected trophic enrichment 15N, with bulk zooplankton being isotopically heavier than SPOM by 3.9%. at Station Papa and 2.2%. in the coastal domain. This difference possibly reflects the existence of a relatively short food chain in the coastal domain and a longer food chain, involving microzooplanktonic grazers, at Station Papa. The range of ?15N among seven zooplankton groups was 3.7%., the data suggesting an increasing trophic hierarchy: pteropods, salps, euphausiids, copepods-medusaeamphipods, chaetognaths.

Wu, Jinping; Calvert, S. E.; Wong, C. S.

1997-02-01

195

Quantification of urban structure on building block level utilizing multisensoral remote sensing data  

NASA Astrophysics Data System (ADS)

Dynamics of urban environments are a challenge to a sustainable development. Urban areas promise wealth, realization of individual dreams and power. Hence, many cities are characterized by a population growth as well as physical development. Traditional, visual mapping and updating of urban structure information of cities is a very laborious and cost-intensive task, especially for large urban areas. For this purpose, we developed a workflow for the extraction of the relevant information by means of object-based image classification. In this manner, multisensoral remote sensing data has been analyzed in terms of very high resolution optical satellite imagery together with height information by a digital surface model to retrieve a detailed 3D city model with the relevant land-use / land-cover information. This information has been aggregated on the level of the building block to describe the urban structure by physical indicators. A comparison between the indicators derived by the classification and a reference classification has been accomplished to show the correlation between the individual indicators and a reference classification of urban structure types. The indicators have been used to apply a cluster analysis to group the individual blocks into similar clusters.

Wurm, Michael; Taubenböck, Hannes; Dech, Stefan

2010-10-01

196

Structural and Functional Insights into (S)-Ureidoglycolate Dehydrogenase, a Metabolic Branch Point Enzyme in Nitrogen Utilization  

PubMed Central

Nitrogen metabolism is one of essential processes in living organisms. The catabolic pathways of nitrogenous compounds play a pivotal role in the storage and recovery of nitrogen. In Escherichia coli, two different, interconnecting metabolic routes drive nitrogen utilization through purine degradation metabolites. The enzyme (S)-ureidoglycolate dehydrogenase (AllD), which is a member of l-sulfolactate dehydrogenase-like family, converts (S)-ureidoglycolate, a key intermediate in the purine degradation pathway, to oxalurate in an NAD(P)-dependent manner. Therefore, AllD is a metabolic branch-point enzyme for nitrogen metabolism in E. coli. Here, we report crystal structures of AllD in its apo form, in a binary complex with NADH cofactor, and in a ternary complex with NADH and glyoxylate, a possible spontaneous degradation product of oxalurate. Structural analyses revealed that NADH in an extended conformation is bound to an NADH-binding fold with three distinct domains that differ from those of the canonical NADH-binding fold. We also characterized ligand-induced structural changes, as well as the binding mode of glyoxylate, in the active site near the NADH nicotinamide ring. Based on structural and kinetic analyses, we concluded that AllD selectively utilizes NAD+ as a cofactor, and further propose that His116 acts as a general catalytic base and that a hydride transfer is possible on the B-face of the nicotinamide ring of the cofactor. Other residues conserved in the active sites of this novel l-sulfolactate dehydrogenase-like family also play essential roles in catalysis.

Kim, Myung-Il; Shin, Inchul; Cho, Suhee; Lee, Jeehyun; Rhee, Sangkee

2012-01-01

197

Study of utilization of advanced composites in fuselage structures of large transports  

NASA Technical Reports Server (NTRS)

The effort required by the transport aircraft manufacturers to support the introduction of advanced composite materials into the fuselage structure of future commercial and military transport aircraft is investigated. Technology issues, potential benefits to military life cycle costs and commercial operating costs, and development plans are examined. The most urgent technology issues defined are impact dynamics, acoustic transmission, pressure containment and damage tolerance, post-buckling, cutouts, and joints and splices. A technology demonstration program is defined and a rough cost and schedule identified. The fabrication and test of a full-scale fuselage barrel section is presented. Commercial and military benefits are identified. Fuselage structure weight savings from use of advanced composites are 16.4 percent for the commercial and 21.8 percent for the military. For the all-composite airplanes the savings are 26 percent and 29 percent, respectively. Commercial/operating costs are reduced by 5 percent for the all-composite airplane and military life cycle costs by 10 percent.

Jackson, A. C.; Campion, M. C.; Pei, G.

1984-01-01

198

Innovative design of composite structures: Design, manufacturing, and testing of plates utilizing curvilinear fiber trajectories  

NASA Technical Reports Server (NTRS)

As a means of improving structural design, the concept of fabricating flat plates containing holes by incorporating curvilinear fiber trajectories to transmit loads around the hole is studied. In the present discussion this concept is viewed from a structural level, where access holes, windows, doors, and other openings are of significant size. This is opposed to holes sized for mechanical fasteners. Instead of cutting the important load-bearing fibers at the hole edge, as a conventional straightline design does, the curvilinear design preserves the load-bearing fibers by orienting them in smooth trajectories around the holes, their loading not ending abruptly at the hole edge. Though the concept of curvilinear fiber trajectories has been studied before, attempts to manufacture and test such plates have been limited. This report describes a cooperative effort between Cincinnati Milacron Inc., NASA Langley Research Center, and Virginia Polytechnic Institute and State University to design, manufacture, and test plates using the curvilinear fiber trajectory concept. The paper discusses details of the plate design, details of the manufacturing, and a summary of results from testing the plates with inplane compressive buckling loads and tensile loads. Comparisons between the curvilinear and conventional straightline fiber designs based on measurements and observation are made. Failure modes, failure loads, strains, deflections, and other key responses are compared.

Hyer, M. W.; Rust, R. J.; Waters, W. A., Jr.

1994-01-01

199

The relationship of lateral anatomic structures to exiting guide pins during femoral tunnel preparation utilizing an accessory medial portal.  

PubMed

Anatomic reconstruction of the anterior cruciate ligament through an accessory medial portal has become increasingly popular. The purpose of this study is to describe the relationship of guide pin exit points to the lateral anatomic structures when preparing the anterior cruciate ligament femoral tunnel through an accessory medial portal. We utilized seven fresh frozen cadaveric knees. Utilizing an anteromedial approach, a guide wire was placed into the center of each bundle's footprint. Each guide wire was advanced through the lateral femoral cortex. The guide pins were passed at 90, 110, and 130 degrees of knee flexion. The distances from each guide pin to the closest relevant structures on the lateral side of the knee were measured. At 90 degrees the posterolateral bundle guide pin was closest to the lateral condyle articular cartilage (mean 5.4 +/- 2.2 mm) and gastrocnemius tendon (mean 5.7 +/- 2.1 mm). At 110 degrees the posterolateral bundle pin was closest to the gastrocnemius tendon (mean 4.5 +/- 3.4 mm). At 130 degrees the posterolateral bundle pin was closest to the gastrocnemius tendon (mean 7.2 +/- 5.5 mm) and lateral collateral ligament (mean 6.8 +/- 2.1 mm). At 90 degrees the anteromedial bundle guide pin was closest to the articular cartilage (mean 2.0 +/- 2.0 mm). At 110 degrees the anteromedial bundle pin was closest to the articular cartilage (mean 7.4 +/- 3.5 mm) and gastrocnemius tendon (mean 12.3 +/- 3.1 mm). At 130 degrees the AM bundle pin was closest to the gastrocnemius tendon (mean 8.2 +/- 3.2 mm) and LCL (mean 15.1 +/- 2.9 mm). Neither guide pin (anteromedial or posterolateral bundle) put the peroneal nerve at risk at any knee flexion angle. At low knee flexion angles the anteromedial and posterolateral bundle guide pins closely approximated multiple lateral structures when using an accessory medial arthroscopic portal. Utilizing higher flexion angles increases the margin of error when preparing both femoral tunnels. During preparation of the anterior cruciate ligament femoral tunnel through an accessory anteromedial portal the tunnels should be drilled in at least 110 degrees of knee flexion in order to move guide pin exit points away from important lateral knee structures. PMID:19760398

Farrow, Lutul D; Parker, Richard D

2010-06-01

200

Maximizing the utilization of computer-aided technology for fabrication of composite structures  

NASA Astrophysics Data System (ADS)

The introduction of the computer in today's engineering environment presents new opportunities for the optimization of the product definition process. The certification effort on McDonnell Douglas Helicopter Company's MD 520N Program is used as a case study to show how the management of digital data can be used as a tool to dramatically reduce the cycle time of producing advanced composite structures. The MD 520N Product Definition Team used MDHC's Unigraphics 3-D CAD/CAM System to develop, design, fabricate, and test a production thruster assembly in just 74 days. This paper documents that effort and discusses the application this process may have in the normal production design environment.

Pyle, Glenn T.; Rao, Carlo S.

201

Nonlinear vibrational spectroscopy of water structures utilizing laser-induced phase transition phenomena in liquid water  

NASA Astrophysics Data System (ADS)

Anomalous enhancement of the stimulated Raman scattering (SRS) of water molecules in the OH stretching vibrational region is observed when a laser-induced phase transition from liquid to plasma takes place in liquid water. The SRS is emitted before the phase transition and has a duration of several tens of picoseconds full width at half maximum. From the spectroscopic analysis of the SRS, it is suggested that the excess electrons, which are generated in a few picoseconds before the phase transition, play an important role in the transient SRS enhancement through the change of the nonlinear polarizability induced around the electrons in liquid water. Several applications of the enhanced vibrational spectra in the OH stretching vibrational region to the spectroscopic analyses of local water structures in various environments are also described.

Yui, Hiroharu; Sawada, Tsuguo

2003-01-01

202

End-to-end communication test on variable length packet structures utilizing AOS testbed  

NASA Astrophysics Data System (ADS)

This paper describes a communication test, which successfully demonstrated the transfer of losslessly compressed images in an end-to-end system. These compressed images were first formatted into variable length Consultative Committee for Space Data Systems (CCSDS) packets in the Advanced Orbiting System Testbed (AOST). The CCSDS data Structures were transferred from the AOST to the Radio Frequency Simulations Operations Center (RFSOC), via a fiber optic link, where data was then transmitted through the Tracking and Data Relay Satellite System (TDRSS). The received data acquired at the White Sands Complex (WSC) was transferred back to the AOST where the data was captured and decompressed back to the original images. This paper describes the compression algorithm, the AOST configuration, key flight components, data formats, and the communication link characteristics and test results.

Miller, Warner H.; Sank, V.; Fong, Wai; Miko, J.; Powers, M.; Folk, John; Conaway, B.; Michael, K.; Yeh, Pen-Shu

1994-11-01

203

Study on utilization of advanced composites in commercial aircraft wing structures. Volume 1: Executive summary  

NASA Technical Reports Server (NTRS)

The effort required by commercial transport manufacturers to accomplish the transition from current construction materials and practices to extensive use of composites in aircraft wings was investigated. The engineering and manufacturing disciplines which normally participate in the design, development, and production of an aircraft were employed to ensure that all of the factors that would enter a decision to commit to production of a composite wing structure were addressed. A conceptual design of an advanced technology reduced energy aircraft provided the framework for identifying and investigating unique design aspects. A plan development effort defined the essential technology needs and formulated approaches for effecting the required wing development. The wing development program plans, resource needs, and recommendations are summarized.

Sakata, I. F.; Ostrom, R. B.; Cardinale, S. V.

1978-01-01

204

Sensor Array Devices Utilizing Nano-structured Metal-oxides for Hazardous Gas Detection  

NASA Astrophysics Data System (ADS)

Methane and carbon monoxide are two hazardous gases which require continuous monitoring by gas sensors in underground coal mines for explosion prevention and toxicity, respectively. This work explored implementing miniaturized gas sensors in this area to simultaneously detect both gases for benefits of increased portability and reduced power consumption of the chemiresistive gas sensor device. The focus of this research was to understand how the particle size, morphology, and microstructure of the metaloxide film affected the gas sensor performance to the two gases of interest on miniaturized gas sensor devices in the form of microhotplate platforms. This was done through three main research studies. The first was conducted by growing SnO2 nanowires from SnO 2 particles using an Au-catalyst. Growth conditions including temperature, time, and oxygen partial pressure were explored to determine the formation aspects of the SnO2 nanowires. Gas sensor studies were completed that provided evidence that the SnO2 nanowires increased detection to a fixed concentration of carbon monoxide compared to SnO2 particles without nano-structure formation. A second research study was performed to compare the gas sensor performance of SnO2 nanoparticles, hierarchical particles, and micron-size particles. The nanoparticles were developed into an ink and deposited via ink-jet printing on the microhotplate substrates to control the microstructure of the metal-oxide film. By preventing agglomeration of the nanoparticle film, the SnO2 nanoparticles displayed similar gas sensor performance to methane and carbon monoxide as the hierarchical particles. Both nano-structures had much higher gas sensor response than the micron-size particles which confirms the surface area of the metal-oxide film is critical for reaction of the analyte gas at the surface. The last research study presented in the dissertation describes an oxide nanoparticle array developed for detecting methane and carbon monoxide in the presence of one another. A design of experiments was constructed and principal component analysis was used for determining the optimum temperatures of the metal-oxide elements. A four element array was developed with the SnO 2 and TiO2 sensor elements able to detect methane concentrations of interest and the ZnO and NiO sensor elements able to detect the carbon monoxide concentrations. A linear based prediction model was developed and tested for accuracy and reproducibility of the model to a series of random gas concentrations.

Andio, Mark A.

205

Ert Applied to the Characterization of Subsidence in Mexico City: Ancient Structures Affecting Urban Utilities  

NASA Astrophysics Data System (ADS)

The problem of subsidence in Mexico City is basically due to the rapid extraction of groundwater for water supply in addition to the geological conditions. The most typical manifestations of the phenomena are presented as cracks and fractures due to compaction of ancient lake clayish sediments. This phenomenon has caused major affectations to city infrastructure because of the differential subsidence. Fractured buildings, sinkholes, among others manifestations, are potentially sources of collapses, which exposes the population to a serious risk. A small portion of Iztacalco County is being affected by this problem, specifically, in a crossroad formed by two important avenues: La Viga and Plutarco Elias Calles, where the area apparently increases its topographical level. The Electrical Resistivity Tomography technique was selected in order to obtain a resistivity image of the subsoil, which allows identify the main features associated to the terrain uprising. Three (ERT) profiles 200 m, were deployed on the mentioned crossroad in order to characterize the subsurface structures affecting the topographical level of the avenues. A big resistivity anomaly (~ 1000 ohm-m) could be observed towards the central part of the crossroad, coinciding with the major lifting level on surface. This feature appears at 15 m deep in all the profiles and depicts an approximate extension of 100 m in the E-W direction and 60 m in N-S axis. On the other hand, the surrounding material seems to correspond to a higher-saturated environment (lacustrine sediments <10 ohm-m). Shallow anomalies were also detected related to urban artifacts (pipes, sewers, etcetera). The apparently terrain uprising can be associated to a differential subsidence. However, the mentioned avenues were ancient water channels since pre-Hispanic times, where the caudal was enough to allow small steam boating at late nineteenth century. These waterways served as main routes for the exchange of goods during colonial times until the early twentieth century, and just at the junction of the channels, there was a custom gate, where the merchandise used to be registered before its arrival to the downtown market. We suspect that these high resistivity structures could be remains of those buildings that were not removed when the authorities decided to drain the channels in 1921.

Arango, C.; Chavez, R. E.; Cifuentes-Nava, G.; Hernández-Quintero, E.

2013-05-01

206

Full equations utilities (FEQUTL) model for the approximation of hydraulic characteristics of open channels and control structures during unsteady flow  

USGS Publications Warehouse

The Full EQuations UTiLities (FEQUTL) model is a computer program for computation of tables that list the hydraulic characteristics of open channels and control structures as a function of upstream and downstream depths; these tables facilitate the simulation of unsteady flow in a stream system with the Full Equations (FEQ) model. Simulation of unsteady flow requires many iterations for each time period computed. Thus, computation of hydraulic characteristics during the simulations is impractical, and preparation of function tables and application of table look-up procedures facilitates simulation of unsteady flow. Three general types of function tables are computed: one-dimensional tables that relate hydraulic characteristics to upstream flow depth, two-dimensional tables that relate flow through control structures to upstream and downstream flow depth, and three-dimensional tables that relate flow through gated structures to upstream and downstream flow depth and gate setting. For open-channel reaches, six types of one-dimensional function tables contain different combinations of the top width of flow, area, first moment of area with respect to the water surface, conveyance, flux coefficients, and correction coefficients for channel curvilinearity. For hydraulic control structures, one type of one-dimensional function table contains relations between flow and upstream depth, and two types of two-dimensional function tables contain relations among flow and upstream and downstream flow depths. For hydraulic control structures with gates, a three-dimensional function table lists the system of two-dimensional tables that contain the relations among flow and upstream and downstream flow depths that correspond to different gate openings. Hydraulic control structures for which function tables containing flow relations are prepared in FEQUTL include expansions, contractions, bridges, culverts, embankments, weirs, closed conduits (circular, rectangular, and pipe-arch shapes), dam failures, floodways, and underflow gates (sluice and tainter gates). The theory for computation of the hydraulic characteristics is presented for open channels and for each hydraulic control structure. For the hydraulic control structures, the theory is developed from the results of experimental tests of flow through the structure for different upstream and downstream flow depths. These tests were done to describe flow hydraulics for a single, steady-flow design condition and, thus, do not provide complete information on flow transitions (for example, between free- and submerged-weir flow) that may result in simulation of unsteady flow. Therefore, new procedures are developed to approximate the hydraulics of flow transitions for culverts, embankments, weirs, and underflow gates.

Franz, Delbert D.; Melching, Charles S.

1997-01-01

207

How funding structures for HIV/AIDS research shape outputs and utilization: a Swiss case study  

PubMed Central

Background Research policy in the field of HIV has changed substantially in recent decades in Switzerland. Until 2004, social science research on HIV/AIDS was funded by specialized funding agencies. After 2004, funding of such research was “normalized” and integrated into the Swiss National Science Foundation as the main funding agency for scientific research in Switzerland. This paper offers a longitudinal analysis of the relationship between the changing nature of funding structures on the one hand and the production and communication of policy-relevant scientific knowledge in the field of HIV on the other hand. Methods The analysis relies on an inventory of all social sciences research projects on HIV in Switzerland that were funded between 1987 and 2010, including topics covered and disciplines involved, as well as financial data. In addition, in-depth interviews were conducted with 18 stakeholders. Results The analysis highlights that the pre-2004 funding policy ensured good coverage of important social science research themes. Specific incentives and explicit promotion of social science research related to HIV gave rise to a multidisciplinary, integrative and health-oriented approach. The abolition of a specific funding policy in 2004 was paralleled by a drastic reduction in the number of social science research projects submitted for funding, and a decline of public money dedicated to such research. Although the public administration in charge of HIV policy still acknowledges the relevance of findings from social sciences for the development of prevention, treatment and care, HIV-related social science research does not flourish under current funding conditions. Conclusions The Swiss experience sheds light on the difficulties of sustaining social science research and multidisciplinary approaches related to HIV without specialized funding agencies. Future funding policy might not necessarily require specialized agencies, but should better take into account research dynamics and motivations in the field of social sciences.

2011-01-01

208

Biomass utilization  

SciTech Connect

Forty papers are presented in 6 sections: Biomass utilization - the concept; The raw material and its preparation; The structure and chemical composition of biomass; Conversion methods - biological; Conversion methods - thermochemical; and Engineering and economics in biomass utilization. Ten papers are of particular forestry interest: Forest inventories as the basis for a continuous monitoring of forest biomass resources (Cunia, T.); Aerial photo biomass equation (Kasile, J.); Forest biomass utilization in Greece (Tsoumis, C.); Mass propagation of selected trees for biomass by tissue culture (Venketeswaran, S. et al.); The anatomy, ultrastructure and chemical composition of wood (Coete, W.A.); Some structural characteristics of acid hydrolysis lignins (Papadopoulos, J.); Thermochemical routes to chemicals, fuels and energy from forestry and agricultural residues (Soltes, E.J.); Pyrolysis of wood wastes (Figueiredo, J.L. et al.); Efficient utilization of woody biomass: a cellulose-particleboard-synfuels model (Young, R.A.; Achmadi, S.); and Methanol from wood, a state of the art review (Beenackers, A.A.C.M.; Swaaij, W.P.M. van).

Coute, W.A. (ed.)

1983-01-01

209

Pubic Bone Injuries after First Childbirth: Utility of MR in detection and differential diagnosis of structural injury  

PubMed Central

Objective Evaluate utility of MR in diagnosing structural injury in primiparous women with pelvic floor injury risks. Methods Observational study of 77 women with 3T MR imaging after delivery. Women (n=45) were operationally defined as High Risk for levator ani muscle tears (2nd stage labor> 150 minutes, anal sphincter tear, forceps, age> 35, birth weight > 4000 grams) or Low Risk (n=32): vaginally delivered without these risk factors (n=12); delivered by cesarean after 2nd stage labor >150 minutes (n=14), and cesarean without labor (n=6). All women were imaged using MR fluid sensitive sequences. Two musculoskeletal radiologists reviewed images for bone marrow edema, fracture, pubic symphysis measurements, and levator ani tear. Results MR imaging showed pubic bone fractures in 38% of women at High Risk and 13% of at Low Risk for pelvic floor injury (?2(3)= 9.27, p=0.03). Levator ani muscle tears were present in 44% of the High Risk and 9% of Low Risk women (X2(3)=11.57, p=0.010). Bone marrow edema in the pubic bones was present in 61% of women studied across delivery categories. Complex patterns of injury included combinations of bone marrow edema, fractures, levator ani tears and pubic symphysis injuries. No MR documented injuries were present in 18% of women at High Risk and 44% at Low Risk (?2(1)=6.2, p=.013). Conclusions Criteria identifying primiparous women at risk for pelvic floor injury can predict increased risk of bone and soft tissues changes at the pubic symphysis. Fluid sensitive MR imaging has utility for differential diagnosis of structural injury in postpartum women.

Brandon, Catherine; Jacobson, Jon A.; Low, Lisa Kane; Park, Lee; DeLancey, John; Miller, Janis

2013-01-01

210

Photoionization of methylphenothiazine and photoluminescence of erbium 8-hydroxyquinolinate in transparent mesoporous silica films by spin-coating on silicon  

Microsoft Academic Search

Transparent mesoporous silica films were successfully prepared by spin-coating on silicon wafers at room temperature. The X-ray diffraction patterns of the films indicate that both hexagonal and cubic mesoporous films can be formed by varying the surfactant to silicon mole ratio. These films have reasonable thermal stability and are calcinable up to 670 °C and crack free when thickness is

Jae Young Bae; Oun-Ho Park; Ji-In Jung; Koodali T Ranjit; Byeong-Soo Bae

2004-01-01

211

Understanding the role of electron and hole trions on current transport in aluminium tris(8-hydroxyquinoline) using organic magnetoresistance  

NASA Astrophysics Data System (ADS)

The change in current through an organic light emitting diode (OLED) when it is placed in a magnetic field has been dubbed organic magnetoresistance and provides a means to understand the spin interactions that are occurring in working devices. Whilst there are a wide range of interactions that have been proposed to be the cause of the measured effects, there is still a need to identify their individual roles and in particular how they respond to an applied magnetic field. In this work, we investigate the effect of changing the balance of electron and hole injection in a simple aluminium tris(8-hydroxyqinoline) based OLED and demonstrate that the triplet polaron interaction appears to be much stronger for electrons than for holes in this material.

Zhang, Sijie; Willis, M.; Gotto, R.; Roy, K. A.; Rolfe, N. J.; Kreouzis, T.; Gillin, W. P.

2014-01-01

212

Atomistic simulation on charge mobility of amorphous tris(8-hydroxyquinoline) aluminum (Alq3): origin of Poole-Frenkel-type behavior.  

PubMed

The atomistic simulation of charge transfer process for an amorphous Alq(3) system is reported. By employing electrostatic potential charges, we calculate site energies and find that the standard deviation of site energy distribution is about twice as large as predicted in previous research. The charge mobility is calculated via the Miller-Abrahams formalism and the master equation approach. We find that the wide site energy distribution governs Poole-Frenkel-type behavior of charge mobility against electric field, while the spatially correlated site energy is not a dominant mechanism of Poole-Frenkel behavior in the range from 2x10(5) to 1.4x10(6) V/cm. Also we reveal that randomly meshed connectivities are, in principle, required to account for the Poole-Frenkel mechanism. Charge carriers find a zigzag pathway at low electric field, while they find a straight pathway along electric field when a high electric field is applied. In the space-charge-limited current scheme, the charge-carrier density increases with electric field strength so that the nonlinear behavior of charge mobility is enhanced through the strong charge-carrier density dependence of charge mobility. PMID:18647040

Nagata, Yuki; Lennartz, Christian

2008-07-21

213

New Insight into the Transcarbamylase Family: The Structure of Putrescine Transcarbamylase, a Key Catalyst for Fermentative Utilization of Agmatine  

PubMed Central

Transcarbamylases reversibly transfer a carbamyl group from carbamylphosphate (CP) to an amine. Although aspartate transcarbamylase and ornithine transcarbamylase (OTC) are well characterized, little was known about putrescine transcarbamylase (PTC), the enzyme that generates CP for ATP production in the fermentative catabolism of agmatine. We demonstrate that PTC (from Enterococcus faecalis), in addition to using putrescine, can utilize L-ornithine as a poor substrate. Crystal structures at 2.5 Å and 2.0 Å resolutions of PTC bound to its respective bisubstrate analog inhibitors for putrescine and ornithine use, N-(phosphonoacetyl)-putrescine and ?-N-(phosphonoacetyl)-L-ornithine, shed light on PTC preference for putrescine. Except for a highly prominent C-terminal helix that projects away and embraces an adjacent subunit, PTC closely resembles OTCs, suggesting recent divergence of the two enzymes. Since differences between the respective 230 and SMG loops of PTC and OTC appeared to account for the differential preference of these enzymes for putrescine and ornithine, we engineered the 230-loop of PTC to make it to resemble the SMG loop of OTCs, increasing the activity with ornithine and greatly decreasing the activity with putrescine. We also examined the role of the C-terminal helix that appears a constant and exclusive PTC trait. The enzyme lacking this helix remained active but the PTC trimer stability appeared decreased, since some of the enzyme eluted as monomers from a gel filtration column. In addition, truncated PTC tended to aggregate to hexamers, as shown both chromatographically and by X-ray crystallography. Therefore, the extra C-terminal helix plays a dual role: it stabilizes the PTC trimer and, by shielding helix 1 of an adjacent subunit, it prevents the supratrimeric oligomerizations of obscure significance observed with some OTCs. Guided by the structural data we identify signature traits that permit easy and unambiguous annotation of PTC sequences.

Polo, Luis Mariano; Gil-Ortiz, Fernando; Cantin, Angel; Rubio, Vicente

2012-01-01

214

The Incremental Utility of Behavioral Rating Scales and a Structured Diagnostic Interview in the Assessment of Attention-Deficit/Hyperactivity Disorder  

ERIC Educational Resources Information Center

The current study examined the incremental utility of rating scales, a structured diagnostic interview, and multiple informants in a comprehensive assessment of attention-deficit/hyperactivity disorder (ADHD). The sample included 185 children with ADHD (M[subscript age] = 9.22, SD = 0.95) and 82 children without ADHD (M[subscript age] = 9.24, SD =…

Vaughn, Aaron J.; Hoza, Betsy

2013-01-01

215

Influencing Self-Reported Health among Rural Low-Income Women through Health Care and Social Service Utilization: A Structural Equation Model  

ERIC Educational Resources Information Center

Using structural equation modeling, this study examined the mesosystemic processes among rural low-income women, and how these processes subsequently influenced self-reported health. Acknowledging the behavioral processes inherent in utilization of health care and formal social support services, this study moved beyond a behavioral focus by…

Bice-Wigington, Tiffany; Huddleston-Casas, Catherine

2012-01-01

216

Lignin-based monomers: Utilization in high-performance polymers and the effects of their structures on polymer properties  

NASA Astrophysics Data System (ADS)

With the uncertainty of petroleum reserves and future crude oil prices, lignocellulosic biomass is becoming an increasingly valuable resource for the sustainable development of fuels, chemicals, and materials, including vinyl ester resins (VERs). Petroleum-based VERs are used to produce polymer composites for a wide variety of commercial applications. Although possessing relatively high moduli, strengths, and glass transition temperatures, commercial VERs typically contain high concentrations of a reactive diluent, such as styrene. However, these reactive diluents are often considered hazardous air pollutants (HAPs), volatile organic compounds (VOCs), and anticipated carcinogens. Moreover, bisphenol-A, which has gained considerable attention due to potential associated health-related issues, is utilized as a precursor in the synthesis of VERs. A green chemistry and engineering approach in the development of new VERs and renewable reactive diluents that are based on lignin is presented in this dissertation. Lignin, which is currently an abundant, renewable waste product of the paper and pulping industry, is primarily burned as a low value fuel. However, lignin has the potential to be a low cost feedstock in future lignocellulosic biorefineries that could yield highly valuable aromatic chemicals (lignin model compounds, LMCs) when strategically depolymerized. The incorporation of aromaticity in a resin's chemical structure is known to improve overall polymer composite performance and the high aromatic content found in lignin is ideal for novel resin development. Highlighted in this dissertation are three projects: (1) the synthesis and characterization of a lignin-based bio-oil resin/reactive diluent, (2) the use of functionalized LMCs as styrene replacements in VERs, and (3) the synthesis and characterization of a vanillin-based resin. Through the use of traditional and new polymer theory coupled with spectroscopic, thermal, and mechanical techniques, structure-property relationships are identified and related to polymer performance. These findings have important implications for the optimization and design of polymer composites that are based on sustainable resources and processes, are petroleum-independent, and have reduced toxicity with beneficial environmental impacts. In addition, these findings provide the incentive for continued investment in using lignin as a respected materials' feedstock. Lastly, several lignin-related research opportunities of scientific and commercial interest are recommended.

Stanzione, Joseph F., III

217

The solution structure of the copper clioquinol complex.  

PubMed

Clioquinol (5-chloro-7-iodo-8-hydroxyquinoline) recently has shown promising results in the treatment of Alzheimer's disease and in cancer therapy, both of which also are thought to be due to clioquinol's ability as a lipophilic copper chelator. Previously, clioquinol was used as an anti-fungal and anti-protozoal drug that was responsible for an epidemic of subacute myelo-optic neuropathy (SMON) in Japan during the 1960s, probably a myeloneuropathy arising from a clioquinol-induced copper deficiency. Previous X-ray absorption spectroscopy of solutions of copper chelates of clioquinol suggested unusual coordination chemistry. Here we use a combination of electron paramagnetic, UV-visible and X-ray absorption spectroscopies to provide clarification of the chelation chemistry between clioquinol and copper. We find that the solution structures for the copper complexes formed with stoichiometric and excess clioquinol are conventional 8-hydroxyquinolate chelates. Thus, the promise of clioquinol in new treatments for Alzheimer's disease and in cancer therapy is not likely to be due to any novel chelation chemistry, but rather due to other factors including the high lipophilicity of the free ligand and chelate complexes. PMID:24503514

Pushie, M Jake; Nienaber, Kurt H; Summers, Kelly L; Cotelesage, Julien J H; Ponomarenko, Olena; Nichol, Helen K; Pickering, Ingrid J; George, Graham N

2014-04-01

218

Distribution, utilization structure and potential of biomass resources in rural China: With special references of crop residues  

Microsoft Academic Search

As the largest developing country in the world, China is urgently in short of energy and natural resources. However, biological resources such as crop residues are burnt in the field, which cause serious environmental pollution. Still it is not clear how much storage and potential of these huge crop residues are in China. This paper firstly reported the distribution, utilization

H. Liu; G. M. Jiang; H. Y. Zhuang; K. J. Wang

2008-01-01

219

Molecular cloning, structure, promoters and regulatory elements for transcription of the Bacillus licheniformis encoded regulon for xylose utilization  

Microsoft Academic Search

In this article we describe the cloning of the xyl regulon encoding xylose utilization from Bacillus licheniformis by complementation of a xyl mutant of B. subtilis. The xylose isomerase encoding gene, xylA, was sequenced and identified by its extensive homology to other xylose isomerases. The expression of xylA is regulated on the level of transcription by a repressor protein encoded

A. Scheler; T. Rygus; R. Allmansberger; W. Hillen

1991-01-01

220

Impact crash analyses of an off-road utility vehicle – part I: validation of finite-element model for body structure  

Microsoft Academic Search

A Taiwanese manufacturer of off-road utility vehicles (OUVs) was so concerned by the increased number in U.S. accidents and federal probes, involving OUVs from other manufacturers in the industry that it recently funded a thorough, analytical crashworthiness evaluation of its production vehicle body structure. The approach is to employ a transient dynamic, large-strain, material nonlinear finite-element modelling and analysis using

Huiwen Hu; Zhenyuan Lu; Jieming Wang; Wei-Jun Lu

2012-01-01

221

Impact crash analyses of an off-road utility vehicle – part I: validation of finite-element model for body structure  

Microsoft Academic Search

A Taiwanese manufacturer of off-road utility vehicles (OUVs) was so concerned by the increased number in U.S. accidents and federal probes, involving OUVs from other manufacturers in the industry that it recently funded a thorough, analytical crashworthiness evaluation of its production vehicle body structure. The approach is to employ a transient dynamic, large-strain, material nonlinear finite-element modelling and analysis using

Huiwen Hu; Zhenyuan Lu; Jieming Wang; Wei-Jun Lu

2011-01-01

222

Molecular cloning, structure, promoters and regulatory elements for transcription of the Bacillus megaterium encoded regulon for xylose utilization  

Microsoft Academic Search

The xylA and xylB genes of Bacillus subtilis BR151 encoding xylose isomerase and xylulokinase, respectively, were disrupted by gene replacement rendering the constructed mutant strain unable to grow on xylose as the sole carbon source. The Bacillus megaterium encoded xyl genes were cloned by complementation of this strain to xylose utilization. The nucleotide sequence of about 4 kbp of the

T. Rygus; A. Scheler; R. Allmansberger; W. Hillen

1991-01-01

223

Crystallographic Insights into the Pore Structures and Mechanisms of the EutL and EutM Shell Proteins of the Ethanolamine-Utilizing Microcompartment of Escherichia coli? †  

PubMed Central

The ethanolamine-utilizing bacterial microcompartment (Eut-BMC) of Escherichia coli is a polyhedral organelle that harbors specific enzymes for the catabolic degradation of ethanolamine. The compartment is composed of a proteinaceous shell structure that maintains a highly specialized environment for the biochemical reactions inside. Recent structural investigations have revealed hexagonal assemblies of shell proteins that form a tightly packed two-dimensional lattice that is likely to function as a selectively permeable protein membrane, wherein small channels are thought to permit controlled exchange of specific solutes. Here, we show with two nonisomorphous crystal structures that EutM also forms a two-dimensional protein membrane. As its architecture is highly similar to the membrane structure of EutL, it is likely that the structure represents a physiologically relevant form. Thus far, of all Eut proteins, only EutM and EutL have been shown to form such proteinaceous membranes. Despite their similar architectures, however, both proteins exhibit dramatically different pore structures. In contrast to EutL, the pore of EutM appears to be positively charged, indicating specificity for different solutes. Furthermore, we also show that the central pore structure of the EutL shell protein can be triggered to open specifically upon exposure to zinc ions, suggesting a specific gating mechanism.

Takenoya, Mihoko; Nikolakakis, Kiel; Sagermann, Martin

2010-01-01

224

Chemical structure of Al/LiF/Alq interfaces in organic light-emitting diodes  

NASA Astrophysics Data System (ADS)

Al/LiF cathode/organic is known to form an excellent interface for electron injection into the organic active layer, resulting in excellent performing organic light-emitting diodes (OLEDs). Here, the chemical structure of the interface between the Al/LiF bilayer cathode and tris (8-hydroxyquinoline) aluminum (Alq) of working OLED devices was investigated by using x-ray photoelectron spectroscopy (XPS). Using a in situ peel-off technique, we are able to characterize the buried interface structure without disturbing the chemical states of each element probed. The data show that there are two types of F at the interface; one is attributed to LiF and the other to F attached to the Alq. This F-doped Alq layer could induce a downshift in molecular orbital levels and thus leads to a reduced electron injection barrier. XPS depth profile results show significant O diffusion through Al layer to the interface, and the diffusion of O ends abruptly at the Al/LiF interface.

Grozea, D.; Turak, A.; Feng, X. D.; Lu, Z. H.; Johnson, D.; Wood, R.

2002-10-01

225

Molecular modeling of metal hydrides: 2. Calculation of lattice defect structures and energies utilizing the Embedded Atom Method.  

National Technical Information Service (NTIS)

Lattice defect structures and energies for palladium, nickel and aluminum computed include: single vacancy, self-interstitial, intrinsic stacking fault, coherent twin boundary and (100), (110), and (111) free surfaces. The importance of considering lattic...

R. J. Wolf K. A. Mansour

1990-01-01

226

Effect of high loading on substrate utilization kinetics and microbial community structure in super fast submerged membrane bioreactor.  

PubMed

The study investigated the effect of high substrate loading on substrate utilization kinetics, and changes inflicted on the composition of the microbial community in a superfast submerged membrane bioreactor. Submerged MBR was sequentially fed with a substrate mixture and acetate; its performance was monitored at steady-state, at extremely low sludge age values of 2.0, 1.0 and 0.5d, all adjusted to a single hydraulic retention time of 8.0 h. Each MBR run was repeated when substrate feeding was increased from 200 mg COD/L to 1000 mg COD/L. Substrate utilization kinetics was altered to significantly lower levels when the MBR was adjusted to higher substrate loadings. Molecular analysis of the biomass revealed that variable process kinetics could be correlated with parallel changes in the composition of the microbial community, mainly by a replacement mechanism, where newer species, better adapted to the new growth conditions, substituted others that are washed out from the system. PMID:24632634

Sözen, S; Çokgör, E U; Ba?aran, S Teksoy; Aysel, M; Akarsuba??, A; Ergal, I; Kurt, H; Pala-Ozkok, I; Orhon, D

2014-05-01

227

Enzymology and Structure of the GH13_31 Glucan 1,6-?-Glucosidase That Confers Isomaltooligosaccharide Utilization in the Probiotic Lactobacillus acidophilus NCFM  

PubMed Central

Isomaltooligosaccharides (IMO) have been suggested as promising prebiotics that stimulate the growth of probiotic bacteria. Genomes of probiotic lactobacilli from the acidophilus group, as represented by Lactobacillus acidophilus NCFM, encode ?-1,6 glucosidases of the family GH13_31 (glycoside hydrolase family 13 subfamily 31) that confer degradation of IMO. These genes reside frequently within maltooligosaccharide utilization operons, which include an ATP-binding cassette transporter and ?-glucan active enzymes, e.g., maltogenic amylases and maltose phosphorylases, and they also occur separated from any carbohydrate transport or catabolism genes on the genomes of some acidophilus complex members, as in L. acidophilus NCFM. Besides the isolated locus encoding a GH13_31 enzyme, the ABC transporter and another GH13 in the maltooligosaccharide operon were induced in response to IMO or maltotetraose, as determined by reverse transcription-PCR (RT-PCR) transcriptional analysis, suggesting coregulation of ?-1,6- and ?-1,4-glucooligosaccharide utilization loci in L. acidophilus NCFM. The L. acidophilus NCFM GH13_31 (LaGH13_31) was produced recombinantly and shown to be a glucan 1,6-?-glucosidase active on IMO and dextran and product-inhibited by glucose. The catalytic efficiency of LaGH13_31 on dextran and the dextran/panose (trisaccharide) efficiency ratio were the highest reported for this class of enzymes, suggesting higher affinity at distal substrate binding sites. The crystal structure of LaGH13_31 was determined to a resolution of 2.05 Å and revealed additional substrate contacts at the +2 subsite in LaGH13_31 compared to the GH13_31 from Streptococcus mutans (SmGH13_31), providing a possible structural rationale to the relatively high affinity for dextran. A comprehensive phylogenetic and activity motif analysis mapped IMO utilization enzymes from gut microbiota to rationalize preferential utilization of IMO by gut residents.

M?ller, Marie S.; Fredslund, Folmer; Majumder, Avishek; Nakai, Hiroyuki; Poulsen, Jens-Christian N.; Lo Leggio, Leila; Svensson, Birte

2012-01-01

228

THE CONSTRUCTION COST ESTIMATE SYSTEM THAT UTILIZES TECHINICAL PROPOSALS IN THE IMPROVEMENT CONSTRUCTION OF THE RAILWAY STRUCTURES  

NASA Astrophysics Data System (ADS)

JR East has been made start as a new railway company in line with the reform policy of the Japan national railway in 1987. Along with it, JR have beam required the management emphasizing on the efficiency and quickness as a private enterprise. On the other hand, construction companies have remarkably made progress on the construction technology in recent years. Under the circumstance, we tried to establish the construction cost estimates of the railway improvements utilizing the technical proposals based on high technologies by innovative construction companies. In conclusion, we obtained a construction cost reduction and process speeded by the number of technical proposals and we also had acquired the effect of quality and efficiency in the construction cost estimates.

Seki, Yutaka

229

Spatial Characterization of the Dynamic Response of Frequencies Utilizing Structural Partition Procedure for Large-Scale Power System  

NASA Astrophysics Data System (ADS)

The aim of this paper is to present an algorithm for analysing the actual spatial characterization of the dynamic responses of frequencies for large-scale power system. Based on the distribution feature of disturbance power, the measure of interaction (MI) is employed to analyse and quantify the strength of connection among the busses and generation units. The MI takes into account the interconnection constraints among network structure and parameters. In particular, only the network parameters are used in the proposed structural partition procedure. Case Studies carried out on the IEEE 68-bus system are presented to demonstrate the application and effectiveness of the technique developed. Investigations show that the spatial characterization of the dynamic responses of frequencies can be accurately obtained with the procedure, independent of fault location and the size of disturbance, since the proposed technique is based on the structural feature of the system.

Yang, Deyou

2013-05-01

230

Spectroscopic study of Pbs nano-structured layer prepared by Pld utilized as a Hall-effect magnetic sensor  

NASA Astrophysics Data System (ADS)

Lead sulfide (PbS) nano-structured films have been grown on quartz substrates using PLD technique. The deposited films were characterized by several structural techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Selected-area electron diffraction patterns (SAED). The results prove the formation of cubic phase of PbS nanocrystals. Elemental analysis of the deposited films compared to the bulk target was obtained via laser induced fluorescence of the produced plasma particles and the energy dispersive X-ray "EDX" technique. The Hall coefficient measurements indicate an efficient performance of the deposited films as a magnetic sensor.

Atwa, D. M.; Aboulfotoh, N.; El-magd, A. Abo; Badr, Y.

2013-10-01

231

Utility of the sperm chromatin structure assay as a diagnostic and prognostic tool in the human fertility clinic  

Microsoft Academic Search

The sperm chromatin structure assay (SCSA) was used to measure over 500 human semen samples from two independent studies: Study I, 402 samples from 165 presumably fertile couples wishing to achieve pregnancy over 12 menstrual cycles; Study II, samples from 115 patients seeking fertility counselling. The SCSA measures susceptibility to DNA denaturation in situ in spermatozoa exposed to acid for

D. P. Evenson; L. K. Jost; D. Marshall; M. J. Zinaman; E. Clegg; K. Purvis; P. de Angelis; O. P. Claussen

1999-01-01

232

An Inverse Interpolation Method Utilizing In-Flight Strain Measurements for Determining Loads and Structural Response of Aerospace Vehicles  

NASA Technical Reports Server (NTRS)

An important and challenging technology aimed at the next generation of aerospace vehicles is that of structural health monitoring. The key problem is to determine accurately, reliably, and in real time the applied loads, stresses, and displacements experienced in flight, with such data establishing an information database for structural health monitoring. The present effort is aimed at developing a finite element-based methodology involving an inverse formulation that employs measured surface strains to recover the applied loads, stresses, and displacements in an aerospace vehicle in real time. The computational procedure uses a standard finite element model (i.e., "direct analysis") of a given airframe, with the subsequent application of the inverse interpolation approach. The inverse interpolation formulation is based on a parametric approximation of the loading and is further constructed through a least-squares minimization of calculated and measured strains. This procedure results in the governing system of linear algebraic equations, providing the unknown coefficients that accurately define the load approximation. Numerical simulations are carried out for problems involving various levels of structural approximation. These include plate-loading examples and an aircraft wing box. Accuracy and computational efficiency of the proposed method are discussed in detail. The experimental validation of the methodology by way of structural testing of an aircraft wing is also discussed.

Shkarayev, S.; Krashantisa, R.; Tessler, A.

2004-01-01

233

Load monitoring of aerospace structures utilizing micro-electro-mechanical systems for static and quasi-static loading conditions  

NASA Astrophysics Data System (ADS)

The National Research Council Canada (NRC) has worked on the development of structural health monitoring (SHM) test platforms for assessing the performance of sensor systems for load monitoring applications. The first SHM platform consists of a 5.5 m cantilever aluminum beam that provides an optimal scenario for evaluating the ability of a load monitoring system to measure bending, torsion and shear loads. The second SHM platform contains an added level of structural complexity, by consisting of aluminum skins with bonded/riveted stringers, typical of an aircraft lower wing structure. These two load monitoring platforms are well characterized and documented, providing loading conditions similar to those encountered during service. In this study, a micro-electro-mechanical system (MEMS) for acquiring data from triads of gyroscopes, accelerometers and magnetometers is described. The system was used to compute changes in angles at discrete stations along the platforms. The angles obtained from the MEMS were used to compute a second, third or fourth order degree polynomial surface from which displacements at every point could be computed. The use of a new Kalman filter was evaluated for angle estimation, from which displacements in the structure were computed. The outputs of the newly developed algorithms were then compared to the displacements obtained from the linear variable displacement transducers connected to the platforms. The displacement curves were subsequently post-processed either analytically, or with the help of a finite element model of the structure, to estimate strains and loads. The estimated strains were compared with baseline strain gauge instrumentation installed on the platforms. This new approach for load monitoring was able to provide accurate estimates of applied strains and shear loads.

Martinez, M.; Rocha, B.; Li, M.; Shi, G.; Beltempo, A.; Rutledge, R.; Yanishevsky, M.

2012-11-01

234

Influence of the Photorhabdus luminescens Phosphomannose Isomerase Gene, manA, on Mannose Utilization, Exopolysaccharide Structure, and Biofilm Formation ?  

PubMed Central

Extracellular polysaccharide (EPS) is produced by diverse bacterial pathogens and fulfills assorted roles, including providing a structural matrix for biofilm formation and more specific functions in virulence, such as protection against immune defenses. We report here the first investigation of some of the genes important for biofilm formation in Photorhabdus luminescens and demonstrate the key role of the phosphomannose isomerase gene, manA, in the structure of functional EPS. Phenotypic analyses of a manA-deficient mutant showed the importance of EPS in motility, insect virulence, and biofilm formation on abiotic surfaces as well as the requirement of this gene for the use of mannose as the sole carbon source. Conversely, this defect had no apparent impact on symbiosis with the heterorhabditid nematode vector. A more detailed analysis of biofilm formation revealed that the manA mutant was able to attach to surfaces with the same efficiency as that of the wild-type strain but could not develop the more extended biofilm matrix structures. A compositional analysis of P. luminescens EPS reveals how the manA mutation has a major effect on the formation of a complete, branched EPS.

Amos, Matthew R.; Sanchez-Contreras, Maria; Jackson, Robert W.; Munoz-Berbel, Xavier; Ciche, Todd A.; Yang, Guowei; Cooper, Richard M.; Waterfield, Nicholas R.

2011-01-01

235

Investigation of dye-doped red emitting organic electroluminescent devices with metal-mirror microcavity structure  

NASA Astrophysics Data System (ADS)

Organic electroluminescent (EL) devices with planar microcavity structure, indium-tin-oxide/Ag/N,N'-diphenyl-N , N '-bis(3-methylphenyl)-1,1'-biphenyl-4 , 4'-diamine/tris(8-hydroxyquinoline)-aluminum (AlQ):4-(dicyanomethylene)-2-methyl-6-(p-dimethyl aminostyryl)-4H-pyran/AlQ/LiF/Al, were fabricated. The Ag and Al layers acted as not only hole-injection layer and cathode, respectively, but reflective mirrors, resulting in strong microcavity effects, such as spectral narrowing and directional emission. The effects of device parameters on the EL performance were studied in detail and were discussed in terms of conventional microcavity theory. On-axis light magnification with a coefficient (EL enhancement ratio between cavity and noncavity devices) of ~5 was observed, which was consistent with the theoretical calculation. At the same time, optimized microcavity device with bright pure red emission showed maximum luminance of 5140 cd/m2, peak at 624 nm, Commission International de I'Eclairage coordinates of x=0.663 and y=0.336, and high EL efficiency of 1.71 cd/A were obtained.

Sun, X. Y.; Li, W. L.; Hong, Z. R.; Wei, H. Z.; Zang, F. X.; Chen, L. L.; Shi, Z.; Bi, D. F.; Li, B.; Zhang, Z. Q.; Hu, Z. Z.

2005-05-01

236

Utility diversification  

SciTech Connect

A review of the available evidence of the effect of diversification on a utility's financial attractiveness suggests that diversified gas companies have higher earnings, better credit ratings, and more marketable securities than do the less diversified utilities. Regulatory commissions must, however, always be alert to ways in which a company's unregulated activities might adversely affect recipients of the regulated service. Once assured that the service customers are adequately protected, the commission should neither review the specific ventures of unregulated subsidiaries nor become involved in regulating their security issuances or dividend payments. In general, utility diversification should be subject only to managerial discretion and the discipline of the market.

Kahn, A.E.

1983-01-01

237

Utility diversification  

SciTech Connect

A review of the available evidence of the effect of diversification on a utility's financial attractiveness suggests that diversified gas companies have higher earnings, better credit ratings, and more marketable securities than do the less diversified utilities. Regulatory commissions must, however, always be alert to ways in which a company's unregulated activities might adversely affect consumers of the regulated service. Once assured that the service customers are adequately protected, the commission should neither review the specific ventures of unregulated subsidiaries nor become involved in regulating their security issuances or dividend payments. In general, utility diversification should be subject only to managerial discretion and the discipline of the market.

Kahn, A.E.

1982-01-01

238

Edge geometry superconducting tunnel junctions utilizing an NbN/MgO/NbN thin film structure  

NASA Technical Reports Server (NTRS)

An edge defined geometry is used to produce very small area tunnel junctions in a structure with niobium nitride superconducting electrodes and a magnesium oxide tunnel barrier. The incorporation of an MgO tunnel barrier with two NbN electrodes results in improved current-voltage characteristics, and may lead to better junction noise characteristics. The NbN electrodes are preferably sputter-deposited, with the first NbN electrode deposited on an insulating substrate maintained at about 250 to 500 C for improved quality of the electrode.

Hunt, Brian D. (inventor); Leduc, Henry G. (inventor)

1989-01-01

239

Edge geometry superconducting tunnel junctions utilizing an NbN/MgO/NbN thin film structure  

NASA Astrophysics Data System (ADS)

An edge defined geometry is used to produce very small area tunnel junctions in a structure with niobium nitride superconducting electrodes and a magnesium oxide tunnel barrier. The incorporation of an MgO tunnel barrier with two NbN electrodes results in improved current-voltage characteristics, and may lead to better junction noise characteristics. The NbN electrodes are preferably sputter-deposited, with the first NbN electrode deposited on an insulating substrate maintained at about 250 C to 500 C for improved quality of the electrode.

Hunt, Brian D.; Leduc, Henry G.

1992-03-01

240

Edge geometry superconducting tunnel junctions utilizing an NbN/MgO/NbN thin film structure  

NASA Astrophysics Data System (ADS)

An edge defined geometry is used to produce very small area tunnel junctions in a structure with niobium nitride superconducting electrodes and a magnesium oxide tunnel barrier. The incorporation of an MgO tunnel barrier with two NbN electrodes results in improved current-voltage characteristics, and may lead to better junction noise characteristics. The NbN electrodes are preferably sputter-deposited, with the first NbN electrode deposited on an insulating substrate maintained at about 250 to 500 C for improved quality of the electrode.

Hunt, Brian D.; Leduc, Henry G.

1989-08-01

241

Control of sound and vibration for cylindrical shells by utilizing a periodic structure of functionally graded material  

NASA Astrophysics Data System (ADS)

A periodic shell made of functionally graded material (FGM) is proposed in this Letter. Wave propagation and vibration transmission in the FGM periodic shell for different circumferential modes are investigated. By illustrating the dynamical behavior of the periodic FGM shell within the pass/stop band frequency ranges, the mechanism of wave propagation and vibration transmission in the shell are illuminated. Moreover, the suppression characteristics of structure-borne sound in the internal field of the shell, either within the stop or pass band frequency ranges, are studied.

Shen, Huijie; Wen, Jihong; Païdoussis, Michael P.; Yu, Dianlong; Asgari, Meisam; Wen, Xisen

2012-10-01

242

Edge geometry superconducting tunnel junctions utilizing an NbN/MgO/NbN thin film structure  

NASA Technical Reports Server (NTRS)

An edge defined geometry is used to produce very small area tunnel junctions in a structure with niobium nitride superconducting electrodes and a magnesium oxide tunnel barrier. The incorporation of an MgO tunnel barrier with two NbN electrodes results in improved current-voltage characteristics, and may lead to better junction noise characteristics. The NbN electrodes are preferably sputter-deposited, with the first NbN electrode deposited on an insulating substrate maintained at about 250 C to 500 C for improved quality of the electrode.

Hunt, Brian D. (inventor); Leduc, Henry G. (inventor)

1992-01-01

243

Offset fed utilization of four quadrants of an axially symmetrical antenna structure. [beam topologies for Comsat c-band coverage  

NASA Technical Reports Server (NTRS)

Theoretical calculations conducted for the use of the hoop column structure were in a quad antenna configuration. The coverage of the US 48 states by a C band Comsat system, which operates in the 3.7 - 4.2 GHz downlink and 5.925 - 6.425 GHz uplink frequency band is considered. This system provides most of its coverage toward major cities (10 or 18 spot beams) and the rest of its coverage on a contiguous basis for the remaining of the country. An alpha = .5 and .3 cell size (approximate component bandwidth) is assumed. Among the practically infinite possible beam topologies one plan for the area coverage and three plans for the spot beam coverage are analyzed.

Foldes, P.

1981-01-01

244

Analytical studies of a parabolic line concentrator utilizing an aluminum honeycomb support structure and a thin glass reflector laminate  

SciTech Connect

Results (stresses, displacements, and equivalent slope errors) are presented from finite element analyses made to evaluate a design for a parabolic trough solar concentrator. The concentrator consists of a reflector laminate (made of thin glass bonded to sheet metal backing) which is mechanically formed and bonded to a stiff parabolic support (made of aluminum honeycomb bonded to steel skins) with a 2 meter (6.6 foot) aperture. Analyses were first made to determine a length for the concentrator such that it would meet certain performance and survivability criteria under wind and gravity loadings. These studies were made with a model for the concentrator only. The concentrator model was then combined with a model for a support mechanism, and this combined structure was studied for several wind and gravity loadings. A design characterized by a six meter (twenty foot) long concentrator was found to meet performance criteria and had sufficiently low glass stresses in a 40.23 meter per second ((ninety mile per hour) wind.

Koteras, J.R.

1981-03-01

245

Limited clinical utility of endomyocardial biopsy in patients presenting with ventricular tachycardia without apparent structural heart disease.  

PubMed

To determine the cardiac pathology underlying ventricular tachyarrhythmias, endomyocardial biopsy was performed in 14 patients, 10 men and 4 women, with a mean age of 40 years (range 17-63) and no apparent structural heart disease, presenting with high-density symptomatic nonsustained ventricular tachycardia (VT) (n = 4), sustained VT (n = 6), and ventricular fibrillation (n = 4). The absence of coronary or valvular heart disease was documented by cardiac catheterization. The mean left ventricular ejection fraction was 56 +/- 10%. Noninvasive assessment of the ventricular arrhythmia was made in all patients with Holter monitoring and/or exercise testing, while invasive evaluation with programmed electrical stimulation was performed in 13 patients. Biopsy findings included subendocardial and interstitial fibrosis in 7 patients, and monocytes containing periodic acid Schiff (PAS) positive vacuoles in 1 patient; biopsy was normal in 6 patients. There was no relationship between the presence or absence of pathologic abnormalities on biopsy and left ventricular ejection fraction, presenting or induced arrhythmias, or prognosis. Pathologic evidence supporting a specific treatable diagnosis was not present in any biopsy. Drugs to suppress spontaneous (3 patients) or induced (8 patients) VT were instituted, while 2 patients were not treated. In 1 patient who was resuscitated from out-of-hospital cardiac arrest an automatic defibrillator was implanted. In 24.6 months of mean follow-up there was 1 nonfatal arrhythmia recurrence, 1 noncardiac death, and 1 sudden death in a patient with fibrosis on biopsy, an ejection fraction of 45%, and both inducible and spontaneous sustained VT suppressed with an antiarrhythmic agent.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1541071

Oakes, D F; Manolis, A S; Estes, N A

1992-01-01

246

Glary Utilities  

NSDL National Science Digital Library

Glary Utilities offers this free application to help users improve their system's performance and also protect their privacy. After installing the application, users can remove and back up faculty registry entries, along with offering a secure file deletion feature. This version is compatible with computers running Windows 98 and newer.

2008-01-01

247

Ash Utilization.  

National Technical Information Service (NTIS)

Contents: Production and utilization of ash in the United States; The inhibitory effect of fly ash with respect to the corrosion of steel in concretes; Fly ash concrete in buildings in Chicago; A review of ash specifications; Prediction of fly ash perform...

J. D. Spencer J. H. Faber N. H. Coates

1970-01-01

248

Structure of a SusD Homologue, BT1043, Involved in Mucin O-Glycan Utilization in a Prominent Human Gut Symbiont  

SciTech Connect

Mammalian distal gut bacteria have an expanded capacity to utilize glycans. In the absence of dietary sources, some species rely on host-derived mucosal glycans. The ability of Bacteroides thetaiotaomicron, a prominent human gut symbiont, to forage host glycans contributes to both its ability to persist within an individual host and its ability to be transmitted naturally to new hosts at birth. The molecular basis of host glycan recognition by this species is still unknown but likely occurs through an expanded suite of outermembrane glycan-binding proteins that are the primary interface between B. thetaiotaomicron and its environment. Presented here is the atomic structure of the B. thetaiotaomicron protein BT1043, an outer membrane lipoprotein involved in host glycan metabolism. Despite a lack of detectable amino acid sequence similarity, BT1043 is a structural homologue of the B. thetaiotaomicron starch-binding protein SusD. Both structures are dominated by tetratrico peptide repeats that may facilitate association with outer membrane {beta}-barrel transporters required for glycan uptake. The structure of BT1043 complexed with N-acetyllactosamine reveals that recognition is mediated via hydrogen bonding interactions with the reducing end of {beta}-N-acetylglucosamine, suggesting a role in binding glycans liberated from the mucin polypeptide. This is in contrast to CBM 32 family members that target the terminal nonreducing galactose residue of mucin glycans. The highly articulated glycan-binding pocket of BT1043 suggests that binding of ligands to BT1043 relies more upon interactions with the composite sugar residues than upon overall ligand conformation as previously observed for SusD. The diversity in amino acid sequence level likely reflects early divergence from a common ancestor, while the unique and conserved {alpha}-helical fold the SusD family suggests a similar function in glycan uptake.

Koropatkin, Nicole; Martens, Eric C.; Gordon, Jeffrey I.; Smith, Thomas J.; (Danforth); (WU-MED)

2009-05-21

249

LETTER TO THE EDITOR: High colour rendering index non-doped-type white organic light-emitting devices with a RGB-stacked multilayer structure  

NASA Astrophysics Data System (ADS)

A non-doped-type white organic light-emitting device with high colour rendering index has been reported. The structure of the device is ITO/NPB (50 nm)/TPBI (3 nm)/Alq3 (d nm)/DCM2 (0.1 nm)/TPBI (40 - d nm)/Alq3 (10 nm)/LiF/Al, where NPB is N, N'-bis-(1-naphthyl)-N, N'-diphenyl-1, 1'-biph-enyl-4, 4'-diamine, TPBI is 2, 2', 2''-(1, 3, 5-phenylene) tris(1-phenyl-1H-benzimidazole), Alq3 is tris (8-hydroxyquinoline) aluminium, DCM2 is [2-methyl-6-[2-(2, 3, 6, 7-tetrahydro-1H, 5H-benzo[ij] quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene] propane-dinitrile. Through the optimization of d, pure white emission with CIE coordinates of (0.3198, 0.3400) at 9 V was obtained, at which the colour temperature and colour rendering index were 6080 K and 97, respectively. The CIE coordinates of the device change from (0.4552, 0.3867) at 4 V to (0.2864, 0.2865) at 19 V that are well in the white region. Its maximum luminance was 10 855 cd m-2 at 19 V and maximum power efficiency was 1.31 lm W-1 at 5 V.

Xie, Wenfa; Zhao, Yi; Li, Chuannan; Liu, Shiyong

2005-12-01

250

Molecular depth profiling of multilayer structures of organic semiconductor materials by secondary ion mass spectrometry with large argon cluster ion beams.  

PubMed

In this study, we present molecular depth profiling of multilayer structures composed of organic semiconductor materials such as tris(8-hydroxyquinoline)aluminum (Alq3) and 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPD). Molecular ions produced from Alq3 and NPD were measured by linear-type time-of-flight (TOF) mass spectrometry under 5.5 keV Ar70) ion bombardment. The organic multilayer films were analyzed and etched with large Ar cluster ion beams, and the interfaces between the organic layers were clearly distinguished. The effect of temperature on the diffusion of these materials was also investigated by the depth profiling analysis with Ar cluster ion beams. The thermal diffusion behavior was found to depend on the specific materials, and the diffusion of Alq3 molecules was observed to start at a lower temperature than that of NPD molecules. These results prove the great potential of large gas cluster ion beams for molecular depth profiling of organic multilayer samples. PMID:19757450

Ninomiya, Satoshi; Ichiki, Kazuya; Yamada, Hideaki; Nakata, Yoshihiko; Seki, Toshio; Aoki, Takaaki; Matsuo, Jiro

2009-10-30

251

3D imaging of geological structures by R-VSP utilizing vibrations caused by shaft excavations at the Mizunami Underground Research Laboratory in Japan  

NASA Astrophysics Data System (ADS)

Japan Atomic Energy Agency is now conducting the Mizunami Underground Research Laboratory (MIU) project. The MIU consists of two shafts (main shaft: 6.5m, ventilation shaft: 4.5m diameter) and horizontal research galleries, in sedimentary and granitic rocks at Mizunami City, Central Japan. The MIU project is a broad scientific study of the deep geological environment providing the basis for research and development for geological disposal of high level radioactive waste. One of the main goals is to establish techniques for investigation, analysis and assessment of the deep geological environment in fractured crystalline rock. As a part of the MIU project, we carried out the Reverse-Vertical Seismic Profile (R-VSP) using vibrations from the blasting for the shaft excavations and drilling of boreholes in the horizontal research galleries and examined the applicability of this method to imaging of geological structures around underground facilities, such as the unconformity between the sedimentary rocks and the basal granite, and faults and fracture zones in the granite. R-VSP method is a seismic method utilizing the receiver arrays on surface and seismic sources underground (e.g. in boreholes). This method is advantageous in that planning of 3-dimensional surveys is easy compared with reflection seismic surveying and conventional VSP because seismic source arrays that are major constraint for conducting surveys on surface are unnecessary. The receiver arrays consist of six radial lines on surface with a central focus on the main shaft. Seven blast rounds for the main shaft excavation from GL-52.8m to GL-250m and the borehole drilling in the GL-200m horizontal research gallery were observed. Three types of data processing, conventional VSP data processing (VSP-CDP transform and VSP migration), Reflection data processing utilizing Seismic interferometry method (“Seismic interferometry”) and Reflection mapping utilizing Image Point transform method (“IP transform”), were performed to obtain reflection images from heterogeneous geological structure. As the results, the reflective events that seemed to correspond with sedimentary layers, the unconformity between sedimentary rocks and granite, and fracture zones in granite could be detected by reflection profiles using “conventional VSP data processing” and “Seismic interferometry”. However, it is difficult to identify the faults around the MIU because they are generally at a high-angle. “IP transform” is one type of Radon transform which change common shot gather to IP domain. Image Points are defined through geometries of sources and reflectors. Reflection signals in time domain can be accumulated and enhanced in IP domain by “IP transform” on the condition of the right angle to a fault. So, by a search of the direction that reflection signals are enhanced using “IP transform”, the locations of faults can be inferred. By this method, the distribution of faults that correspond with faults in the current geological model constructed from investigation data in the MIU project could be detected.

Matsuoka, T.; Hodotsuka, Y.; Ishigaki, K.; Lee, C.

2009-12-01

252

Structure of the Proline Utilization A Proline Dehydrogenase Domain Inactivated by N-propargylglycine Provides Insight into Conformational Changes Induced by Substrate Binding and Flavin Reduction†,‡  

PubMed Central

Proline utilization A (PutA) from Escherichia coli is a flavoprotein that has mutually exclusive roles as a transcriptional repressor of the put regulon and a membrane-associated enzyme that catalyzes the oxidation of proline to glutamate. Previous studies have shown that the binding of proline in the proline dehydrogenase (PRODH) active site and subsequent reduction of the FAD trigger global conformational changes that enhance PutA-membrane affinity. These events cause PutA to switch from its repressor to enzymatic role, but the mechanism by which this signal is propagated from the active site to the distal membrane-binding domain is largely unknown. Here, it is shown that N-propargylglycine irreversibly inactivates PutA by covalently linking the flavin N(5) atom to the ?-amino of Lys329. Furthermore, inactivation locks PutA into a conformation that may mimic the proline reduced, membrane-associated form. The 2.15 Å resolution structure of the inactivated PRODH domain suggests that the initial events involved in broadcasting the reduced flavin state to the distal membrane binding domain include major reorganization of the flavin ribityl chain, severe (35 degree) butterfly bending of the isoalloxazine ring, and disruption of an electrostatic network involving the flavin N(5), Arg431, and Asp370. The structure also provides information about conformational changes associated with substrate binding. This analysis suggests that the active site is incompletely assembled in the absence of the substrate, and the binding of proline draws together conserved residues in helix 8 and the ?1-?l loop to complete the active site.

Srivastava, Dhiraj; Zhu, Weidong; Johnson, William H.; Whitman, Christian P.; Becker, Donald F.; Tanner, John J.

2013-01-01

253

COMPARISON OF SILICA IMMOBILIZED POLY-L-CYSTEINE AND 8-HYDROXYQUINOLINE FOR TRACE METAL CHELATION AND PRECONCENTRATION. (R826694C651)  

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

254

Transport of lipophilic metal complexes through permeation liquid membrane, in relation to natural water analysis: Cu(II)–8-hydroxyquinoline complex as a model compound  

Microsoft Academic Search

Lipophilic metal complexes are potentially toxic or bioavailable. These complexes may be present in natural waters but, due to lack of sensitive methods for their detection, their contribution to biouptake is poorly understood. Hence, an analytical technique, based on permeation liquid membrane (or supported liquid membrane) (PLM or SLM) has been investigated for the determination of lipophilic metal complexes. For

Nalini Parthasarathy; Michel Pelletier; Jacques Buffle

2010-01-01

255

Amberlite IR120 Modified with 8Hydroxyquinoline as Efficient Adsorbent for SolidPhase Extraction and Flame Atomic Absorption Determination of Trace Amounts of Some Metal Ions  

Microsoft Academic Search

In this study, a solid-phase extraction method combined with atomic absorption spectrometry for extraction, preconcentration,\\u000a and determination of iron (Fe3+), copper (Cu2+), and lead (Pb2+) ions at trace levels in water samples has been reported. The influences of effective parameters such as flow rate, pH, eluent\\u000a conditions (type, volume, and concentration), sample volumes, and interference of matrix ions on metal

Ali Daneshfar; M. Ghaedi; S. Vafafard; L. Shiri; R. Sahrai; M. Soylak

256

A simple visual and highly selective colorimetric detection of Hg2+ based on gold nanoparticles modified by 8-hydroxyquinolines and oxalates.  

PubMed

Gold nanoparticles (AuNPs) modified by 8-hydroxy-quinoline (8-HQ) and stabilized by polyvinylpyrrolidone (PVP) were used for highly selective and sensitive colorimetric detection of Hg(2+) based on the quick aggregation of AuNPs leading to a color change from wine red to gray. The limit of Hg(2+) detection in real environmental water samples is 4.0 × 10(-7) M by the naked eyes and 1.0 × 10(-8) M by UV-vis spectroscopy. PMID:24622578

Gao, Yuexia; Li, Xing; Li, Yonglong; Li, Tianhua; Zhao, Yayun; Wu, Aiguo

2014-06-21

257

Model for nonequilibrium binding and affinity chromatography: characterization of 8-hydroxyquinoline immobilized on controlled pore glass using a flow injection system with a packed microcolumn  

PubMed

This paper discusses the use of pulse techniques for analysis of zonal elution data for the determination of mass-transfer and axial dispersion constants for porous support materials with adsorption to the surface or to a surface-bonded phase. As an example, this paper considers the case of controlled pore glass (CPG) with a bonded phase that is used with microcolumns and a flow injection analysis system. For the CPG, axial dispersion in the form of eddy mixing can be described by l = 0.203, and the overall mass-transfer term, K(OL) = 3.9 x 10(-6) cm/s. Additionally, an affinity chromatography model was adapted to effectively describe systems employing CPG as the support material through modification of equations describing typical affinity chromatography systems and by inclusion of an axial dispersion term in the calculation of N. This model was used to predict breakthrough curves for cadmium adsorption by 8-hydroxyquinolinol immobilized on CPG packed in microcolumns. In general, the information from the model can be used to extract equilibrium-based constants (binding strengths and site capacities) from a nonequilibrium flow system. The data and model can also be employed in determining the performance for scaled-up extraction systems. The modified model is available in EXCEL spreadsheet format as Supporting Information. PMID:10959984

Howard; Holcombe

2000-08-15

258

Xylose utilization in recombinant Zymomonas  

DOEpatents

Zymomonas expressing xylose isomerase from A. missouriensis was found to have improved xylose utilization, growth, and ethanol production when grown in media containing xylose. Xylose isomerases related to that of A. missouriensis were identified structurally through molecular phylogenetic and Profile Hidden Markov Model analyses, providing xylose isomerases that may be used to improve xylose utilization.

Kahsay, Robel Y; Qi, Min; Tao, Luan; Viitanen, Paul V; Yang, Jianjun

2013-01-07

259

Structural and functional investigation into acetyl-coenzyme A synthase and methyltransferase from human pathogen Clostridium difficile.  

PubMed

Methyltransferase (MeTrCd) and acetyl-coenzyme A synthase (ACSCd) are two key enzymes in the acetyl-coenzyme A synthesis pathway of the human pathogen Clostridium difficile. The pathway is absent in humans and is essential for the survival of the pathogen. MeTrCd and ACSCd were cloned, expressed in E. coli, and characterized for the first time. Structural and functional investigations of the two enzymes were performed using homology structure modeling, fluorescence spectroscopy, and steady state/pre-steady state kinetics. The conformational change and methyl transfer activity of MeTrCd were shown to be pH dependent. The kinetic studies of MeTrCd at the optimal pH 5.1 yield the parameters kcat (2.63 s(-1)), Km (17.8 ?M) and kcat/Km (0.15 ?M(-1) s(-1)). The active site metal cluster (A-cluster) of ACSCd, [Fe4S4][NipNid], was characterized using metal analysis, structural modeling, and UV/Vis spectra of the characteristic features of [Fe4S4] cubane. Nip, as a labile metal, can be removed by treatment with chelators, resulting in the loss of ACS activity. Three bidentate chelators (1,10-phenanthroline, 8-hydroxyquinoline, and 2,2-dipyridyl) exhibited excellent inhibition effects on ACSCd methyl group transfer and acetyl-coenzyme A synthesis activity. These inhibitory effects were further examined using antibacterial activity assays against Clostridium difficile. These results provide a new strategy to find new potential antibiotics for the treatment of CDI. PMID:23599026

Zhu, Xiaofei; Li, Tiejun; Gu, Xiang; Zhang, Sixue; Liu, Yi; Wang, Yu; Tan, Xiangshi

2013-05-01

260

Identification of the interior noise generated by sport utility vehicle axles and structural modification of the axle system for noise reduction  

Microsoft Academic Search

This paper presents experimental and analytical methods for reducing the interior noise generated by the axle system of a sport utility vehicle. The test vehicle has a whine noise problem at the passenger seats. To identify the transfer path of the interior noise caused by the axle system, a vibration path analysis, modal analysis, and operational deflection shape analysis are

2008-01-01

261

Implicit Negative Feedback in Adult NS-NNS Conversation: Its Availability, Utility, and the Discourse Structure of the Information-Gap Task.  

ERIC Educational Resources Information Center

Examines the availability and utility of implicit negative feedback provided in task-based conversations between pre-academic, intermediate-level English-as-a- Second-Language (ESL) learners and native-speaker (NS) interlocutors. The tasks being used were the information gap tasks in which nonnative speakers (NNS) gave directions to the NS…

Izumi, Shinichi

2000-01-01

262

Improving active-material utilization  

Microsoft Academic Search

A major factor controlling the specific energy of a lead\\/acid battery is the utilization of active material. If this could be increased, the specific energy would be increased, with a corresponding increase in range of electric vehicles using the lead\\/acid battery. The main parameters that affect active-material utilization are examined, namely, current density, plate thickness, active-material structure, conductivity of active

N. E. Bagshaw

1997-01-01

263

Supramolecular structure and substituents effect on the spectral studies of dioxouranium(VI) azodyes complexes  

NASA Astrophysics Data System (ADS)

The synthesis of several coordination azo compounds of dioxouranium(VI) heterochelates with bidentate azo compounds derived from 4-alkylphenylazo-5-sulfo-8-hydroxyquinoline (HL n) ligands, are described. The ligands and structural composition of azo complexes were confirmed and characterized by various physico-chemical techniques. The bonding sites of the azo compounds are deduced from IR and 1H NMR spectra and the ligands were found to bond to the UO22+ ion in a bidentate fashion. The ligands obtained contain N dbnd N and phenolic functional groups in different positions with respect to the quinoline group. IR spectra show that the azo compounds (HL n) acts as a monobasic bidentate ligand by coordinating via the azo nitrogen atom of azodye ( sbnd N dbnd N sbnd ) and oxygen atom of the phenolic group forming thereby a six-membered chelating ring and concomitant formation of an intramolecular hydrogen bond. The ?3 frequency of UO22+ has been shown to be an excellent molecular probe for studying the coordinating power of the ligands. The values of ?3 of the prepared complexes containing UO22+ were successfully used to calculate the force constant, FUO (1n 10 -8 N/Å) and the bond length RUO (in Å) of the U sbnd O bond. A strategy based upon both theoretical and experimental investigations has been adopted. The theoretical aspects are described in terms of the well-known theory of 5d-4f transitions. Wilson's, matrix method, Badger's formula, and Jones and El-Sonbati equations were used to calculate the U sbnd O bond distances from the values of the stretching and interaction force constants. The most probable correlation between U sbnd O force constant to U sbnd O bond distance were satisfactorily discussed in term of Badger's rule and the equations suggested by Jones and El-Sonbati. The effect of Hamette's constant is also discussed.

Diab, M. A.; El-Bindary, A. A.; El-Sonbati, A. Z.; Salem, O. L.

2012-01-01

264

Model-based Utility Functions  

NASA Astrophysics Data System (ADS)

Orseau and Ring, as well as Dewey, have recently described problems, including self-delusion, with the behavior of agents using various definitions of utility functions. An agent's utility function is defined in terms of the agent's history of interactions with its environment. This paper argues, via two examples, that the behavior problems can be avoided by formulating the utility function in two steps: 1) inferring a model of the environment from interactions, and 2) computing utility as a function of the environment model. Basing a utility function on a model that the agent must learn implies that the utility function must initially be expressed in terms of specifications to be matched to structures in the learned model. These specifications constitute prior assumptions about the environment so this approach will not work with arbitrary environments. But the approach should work for agents designed by humans to act in the physical world. The paper also addresses the issue of self-modifying agents and shows that if provided with the possibility to modify their utility functions agents will not choose to do so, under some usual assumptions.

Hibbard, Bill

2012-05-01

265

Electric utility companies and geothermal power  

NASA Technical Reports Server (NTRS)

The requirements of the electric utility industry as the primary potential market for geothermal energy are analyzed, based on a series of structured interviews with utility companies and financial institution executives. The interviews were designed to determine what information and technologies would be required before utilities would make investment decisions in favor of geothermal energy, the time frame in which the information and technologies would have to be available, and the influence of the governmental politics. The paper describes the geothermal resources, electric utility industry, its structure, the forces influencing utility companies, and their relationship to geothermal energy. A strategy for federal stimulation of utility investment in geothermal energy is suggested. Possibilities are discussed for stimulating utility investment through financial incentives, amelioration of institutional barriers, and technological improvements.

Pivirotto, D. S.

1976-01-01

266

Materials and structure synergistic with in-space materials utilization. [as means of reducing costs of space missions, colonization, and settlements  

NASA Technical Reports Server (NTRS)

The significant advances made recently toward actual hardware realizations of various concepts for the application of in-space materials utilization (ISMU) are demonstrated. The overall plan for taking innovative concepts through technical feasibility, small-scale tests, scale-up, computer modeling, and larger-scale execution is outlined. Two specific fields of endeavor are surveyed: one has direct applications to construction on the moon, while the other has more basic implications, in addition to the practical aspects of lunar colonies. Several fundamental scientific advances made in the characterization of the physical and chemical processes that need to be elucidated for any intelligent application of the ISMU concepts in future space missions are described. A rigorous quantitative technique for the unambiguous evaluation of various components and component technology that form any space (or terrestrial mission) is also described.

Ramohalli, Kumar; Shadman, Farhang; Sridhar, K. R.

1992-01-01

267

Structural aspects of molecular photoionization efficiency in micelles and vesicles as models for solar energy utilization. [N,N,N',N'-tetramethylbenzidine  

SciTech Connect

The structural aspects controlling charge separation in molecular photoionization reactions in organized molecular assemblies involving micelles and vesicles are being studied by optical and electron magnetic resonance techniques including the time domain technique of electron spin echo modulation (ESEM). Photoionization of N,N,N',N'-tetramethylbenzidine (TMB) to give the cation radical has been carried out in both liquid and frozen micellar and vesicular solutions. Cation-water interactions have been detected by ESEM analysis and indicate that the cation is localized asymmetrically within these organized molecular assemblies. Stearic acid nitroxide spin probes have also been used to determine that the neutral TMB molecule before photoionization is also localized asymmetrically within such organized molecular assemblies. Electron spin echo detection of laser photogenerated TMB cation in liquid micellar solutions gives a direct measurement of the phase memory magnetic relaxation time which gives additional structural information. The relationship of this structural data to the efficiency of photoionization in these systems is discussed.

Kevan, L.

1983-01-01

268

Evaluation of pyridine-3-carboxylic acid as a drug carrier by utilizing multivariate methods, structure property correlations, and pattern recognition techniques.  

PubMed

Multivariate methods and molecular properties are utilized to show similarity of pyridine-3-carboxylic acid (nicotinic acid) to seven drugs that penetrate the central nervous system. Multivariate methods applied include cluster analysis, discriminant analysis, correspondence analysis, self organizing tree algorithm (SOTA) analysis, factor analysis, and principal component analysis. Numerical values of properties for nicotinic acid showed very high correlation with the values from dihydropyridine, barbital, metharbital, phenobarbital, methohexital, 4-aminohex-5-enoic acid, and (4-chlorophenyl)(5-fluoro-2-hydroxyphenyl)methanone. Descriptive statistics of property values for these drugs showed overlapping numerical values for partition coefficients, index of refraction, and nOnN. Principal component analysis and factor analysis of molecular properties showed that nicotinic acid is highly similar to dihydropyridine as well as to other members of this group of drugs. Applying cluster analysis utilizing standard euclidean distance with single linkage and centroid linkage showed that nicotinic acid is highly similar to dihydropyridine and both are consistently grouped into the identical cluster (indicating high similarity). Both nicotinic acid and dihydropyridine show zero violations of the Rule of 5, which indicates good bioavailability characteristics. Discriminant analysis of molecular properties for these eight compounds could not demonstrate differentiation between nicotinic acid and dihydropyridine within the properties applied, this indicating high level of similarity. Neural cluster analysis of molecular properties showed that nicotinic acid and dihydropyridine are included into the same cluster (indicating very strong similarity). SOTA analysis also placed nicotinic acid and dihydropyridine into the same cluster unit. SOTA analysis of molecular properties indicates high similarity between nicotinic acid and dihydropyridine. Correspondence analysis was performed on the molecular properties and showed that there exists considerable association between dihydropyridine and nicotinic acid. Multiple regression analysis of these molecular properties produced a mathematical equation to predict the formula weight of similar compounds for use as drug carriers. PMID:15204036

Bartzatt, Ronald L

2004-01-01

269

I-III-VI.sub.2 based solar cell utilizing the structure CuInGaSe.sub.2 CdZnS/ZnO  

DOEpatents

A thin film I-III-VI.sub.2 based solar cell having a first layer of copper indium gallium selenide, a second layer of cadmium zinc sulfide, a double layer of zinc oxide, and a metallization structure comprised of a layer of nickel covered by a layer of aluminum. An optional antireflective coating may be placed on said metallization structure. The cadmium zinc sulfide layer is deposited by means of an aqueous solution growth deposition process and may actually consist of two layers: a low zinc content layer and a high zinc content layer. Photovoltaic efficiencies of 12.5% at Air Mass 1.5 illumination conditions and 10.4% under AMO illumination can be achieved.

Chen, Wen S. (Seattle, WA); Stewart, John M. (Seattle, WA)

1992-01-07

270

Secondary Structure Analyses of the Nuclear rRNA Internal Transcribed Spacers and Assessment of Its Phylogenetic Utility across the Brassicaceae (Mustards)  

PubMed Central

The internal transcribed spacers of the nuclear ribosomal RNA gene cluster, termed ITS1 and ITS2, are the most frequently used nuclear markers for phylogenetic analyses across many eukaryotic groups including most plant families. The reasons for the popularity of these markers include: 1.) Ease of amplification due to high copy number of the gene clusters, 2.) Available cost-effective methods and highly conserved primers, 3.) Rapidly evolving markers (i.e. variable between closely related species), and 4.) The assumption (and/or treatment) that these sequences are non-functional, neutrally evolving phylogenetic markers. Here, our analyses of ITS1 and ITS2 for 50 species suggest that both sequences are instead under selective constraints to preserve proper secondary structure, likely to maintain complete self-splicing functions, and thus are not neutrally-evolving phylogenetic markers. Our results indicate the majority of sequence sites are co-evolving with other positions to form proper secondary structure, which has implications for phylogenetic inference. We also found that the lowest energy state and total number of possible alternate secondary structures are highly significantly different between ITS regions and random sequences with an identical overall length and Guanine-Cytosine (GC) content. Lastly, we review recent evidence highlighting some additional problematic issues with using these regions as the sole markers for phylogenetic studies, and thus strongly recommend additional markers and cost-effective approaches for future studies to estimate phylogenetic relationships.

Bird, Kevin A.; Mayfield, Dustin R.; Conant, Gavin; Mummenhoff, Klaus; Koch, Marcus A.; Pires, J. Chris

2014-01-01

271

Structural and functional characterization of an orphan ATP-binding cassette ATPase involved in manganese utilization and tolerance in Leptospira spp.  

PubMed

Pathogenic Leptospira species are the etiological agents of the widespread zoonotic disease leptospirosis. Most organisms, including Leptospira, require divalent cations for proper growth, but because of their high reactivity, these metals are toxic at high concentrations. Therefore, bacteria have acquired strategies to maintain metal homeostasis, such as metal import and efflux. By screening Leptospira biflexa transposon mutants for their ability to use Mn(2+), we have identified a gene encoding a putative orphan ATP-binding cassette (ABC) ATPase of unknown function. Inactivation of this gene in both L. biflexa and L. interrogans strains led to mutants unable to grow in medium in which iron was replaced by Mn(2+), suggesting an involvement of this ABC ATPase in divalent cation uptake. A mutation in this ATPase-coding gene increased susceptibility to Mn(2+) toxicity. Recombinant ABC ATPase of the pathogen L. interrogans exhibited Mg(2+)-dependent ATPase activity involving a P-loop motif. The structure of this ATPase was solved from a crystal containing two monomers in the asymmetric unit. Each monomer adopted a canonical two-subdomain organization of the ABC ATPase fold with an ?/? subdomain containing the Walker motifs and an ? subdomain containing the ABC signature motif (LSSGE). The two monomers were arranged in a head-to-tail orientation, forming a V-shaped particle with all the conserved ABC motifs at the dimer interface, similar to functional ABC ATPases. These results provide the first structural and functional characterization of a leptospiral ABC ATPase. PMID:24123817

Benaroudj, Nadia; Saul, Frederick; Bellalou, Jacques; Miras, Isabelle; Weber, Patrick; Bondet, Vincent; Murray, Gerald L; Adler, Ben; Ristow, Paula; Louvel, Hélène; Haouz, Ahmed; Picardeau, Mathieu

2013-12-01

272

ERTS-1 imagery use in reconnaissance prospecting: Evaluation of commercial utility of ERTS-1 imagery in structural reconnaissance for minerals and petroleum  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. This study was performed to investigate applications of ERTS-1 imagery in commercial reconnaissance for mineral and hydrocarbon resources. ERTS-1 imagery collected over five areas in North America (Montana; Colorado; New Mexico-West Texas; Superior Province, Canada; and North Slope, Alaska) has been analyzed for data content including linears, lineaments, and curvilinear anomalies. Locations of these features were mapped and compared with known locations of mineral and hydrocarbon accumulations. Results were analyzed in the context of a simple-shear, block-coupling model. Data analyses have resulted in detection of new lineaments, some of which may be continental in extent, detection of many curvilinear patterns not generally seen on aerial photos, strong evidence of continental regmatic fracture patterns, and realization that geological features can be explained in terms of a simple-shear, block-coupling model. The conculsions are that ERTS-1 imagery is of great value in photogeologic/geomorphic interpretations of regional features, and the simple-shear, block-coupling model provides a means of relating data from ERTS imagery to structures that have controlled emplacement of ore deposits and hydrocarbon accumulations, thus providing a basis for a new approach for reconnaissance for mineral, uranium, gas, and oil deposits and structures.

Saunders, D. F.; Thomas, G. E. (principal investigators); Kinsman, F. E.; Beatty, D. F.

1973-01-01

273

New method for obtaining position and time structure of source in HDR remote afterloading brachytherapy unit utilizing light emission from scintillator.  

PubMed

When using a HDR remote afterloading brachytherapy unit, results of treatment can be greatly influenced by both source position and treatment time. The purpose of this study is to obtain information on the source of the HDR remote afterloading unit, such as its position and time structure, with the use of a simple system consisting of a plastic scintillator block and a charge-coupled device (CCD) camera. The CCD camera was used for recording images of scintillation luminescence at a fixed rate of 30 frames per second in real time. The source position and time structure were obtained by analyzing the recorded images. For a preset source-step-interval of 5 mm, the measured value of the source position was 5.0 +/- 1.0 mm with a pixel resolution of 0.07 mm in the recorded images. For a preset transit time of 30 s, the measured value was 30.0 +/- 0.6 s, when the time resolution of the CCD camera was 1/30 s. This system enables us to obtain the source dwell time and movement time. Therefore, parameters such as 192Ir source position, transit time, dwell time, and movement time at each dwell position can be determined quantitatively using this plastic scintillator-CCD camera system. PMID:19692981

Kojima, Haruna; Hanada, Takashi; Katsuta, Shoichi; Yorozu, Atsunori; Maruyama, Koichi

2009-01-01

274

Strain-reduced GaN thick-film grown by hydride vapor phase epitaxy utilizing dot air-bridged structure  

NASA Astrophysics Data System (ADS)

A 300 ?m GaN thick-film, in diameter 1.5 in, was demonstrated without any crack by hydride vapor phase epitaxy (HVPE) growth. The technique used in relaxing the residual stress caused by differences of thermal expansion coefficients (TEC) and lattice constants between GaN and sapphire substrate to prevent GaN film from crack is called a dot air-bridged structure. After the laser lift-off process, 300-?m-thick freestanding GaN wafer, in diameter 1.5 in, could be fabricated. The compressive stress in the dot air-bridged structure was measured by micro-Raman spectroscopy with the E2(high) phonon mode. The compressive stress could be reduced to as small as 0.04 GPa, which could prevent the crack during the epitaxial process for GaN growth by HVPE. It is important to obtain a large-area crack-free GaN thick-film, which can be used for fabricating freestanding GaN wafer.

Huang, Hsin-Hsiung; Chao, Chu-Li; Chi, Tung-Wei; Chang, Yu-Lin; Liu, Po-Chun; Tu, Li-Wei; Tsay, Jenq-Dar; Kuo, Hao-Chung; Cheng, Shun-Jen; Lee, Wei-I.

2009-05-01

275

ERTS-1 imagery use in reconnaissance prospecting: Evaluation of commercial utility of ERTS-1 imagery in structural reconnaissance for minerals and petroleum  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. Five areas in North America (North Slope-Alaska, Superior Province-Canada, Williston Basin-Montana, Colorado, and New Mexico-West Texas) are being studied for discernibility of geological evidence on ERTS-1 imagery. Evidence mapped is compared with known mineral/hydrocarbon accumulations to determine the value of the imagery in commercial exploration programs. Evaluation has proceeded in the New Mexico-Texas area, and to date, results have been better than expected. Clearly discernible structural lineaments in this area are evident on the photographs. Comparison of this evidence with known major mining localities in New Mexico indicates a clear pattern of coincidence between the lineaments and mining localities. In West Texas, lineament and geomorphological evidence obtainable from the photographs define the petroleum-productive Central Basin Platform. Based on evaluation of results in the New Mexico-West Texas area and on cursory results in the other four areas of North America, it is concluded that ERTS-1 imagery will be extremely valuable in defining the regional and local structure in any commercial exploration program.

Saunders, D. F. (principal investigator); Thomas, G. L.; Kinsman, F. E.

1973-01-01

276

Structural and Functional Characterization of an Orphan ATP-Binding Cassette ATPase Involved in Manganese Utilization and Tolerance in Leptospira spp.  

PubMed Central

Pathogenic Leptospira species are the etiological agents of the widespread zoonotic disease leptospirosis. Most organisms, including Leptospira, require divalent cations for proper growth, but because of their high reactivity, these metals are toxic at high concentrations. Therefore, bacteria have acquired strategies to maintain metal homeostasis, such as metal import and efflux. By screening Leptospira biflexa transposon mutants for their ability to use Mn2+, we have identified a gene encoding a putative orphan ATP-binding cassette (ABC) ATPase of unknown function. Inactivation of this gene in both L. biflexa and L. interrogans strains led to mutants unable to grow in medium in which iron was replaced by Mn2+, suggesting an involvement of this ABC ATPase in divalent cation uptake. A mutation in this ATPase-coding gene increased susceptibility to Mn2+ toxicity. Recombinant ABC ATPase of the pathogen L. interrogans exhibited Mg2+-dependent ATPase activity involving a P-loop motif. The structure of this ATPase was solved from a crystal containing two monomers in the asymmetric unit. Each monomer adopted a canonical two-subdomain organization of the ABC ATPase fold with an ?/? subdomain containing the Walker motifs and an ? subdomain containing the ABC signature motif (LSSGE). The two monomers were arranged in a head-to-tail orientation, forming a V-shaped particle with all the conserved ABC motifs at the dimer interface, similar to functional ABC ATPases. These results provide the first structural and functional characterization of a leptospiral ABC ATPase.

Saul, Frederick; Bellalou, Jacques; Miras, Isabelle; Weber, Patrick; Bondet, Vincent; Murray, Gerald L.; Adler, Ben; Ristow, Paula; Louvel, Helene; Haouz, Ahmed

2013-01-01

277

Identification of novel HSP90?/? isoform selective inhibitors using structure-based drug design. demonstration of potential utility in treating CNS disorders such as Huntington's disease.  

PubMed

A structure-based drug design strategy was used to optimize a novel benzolactam series of HSP90?/? inhibitors to achieve >1000-fold selectivity versus the HSP90 endoplasmic reticulum and mitochondrial isoforms (GRP94 and TRAP1, respectively). Selective HSP90?/? inhibitors were found to be equipotent to pan-HSP90 inhibitors in promoting the clearance of mutant huntingtin protein (mHtt) in vitro, however with less cellular toxicity. Improved tolerability profiles may enable the use of HSP90?/? selective inhibitors in treating chronic neurodegenerative indications such as Huntington's disease (HD). A potent, selective, orally available HSP90?/? inhibitor was identified (compound 31) that crosses the blood-brain barrier. Compound 31 demonstrated proof of concept by successfully reducing brain Htt levels following oral dosing in rats. PMID:24673104

Ernst, Justin T; Neubert, Timothy; Liu, Michael; Sperry, Samuel; Zuccola, Harmon; Turnbull, Amy; Fleck, Beth; Kargo, William; Woody, Lisa; Chiang, Peggy; Tran, Dao; Chen, Weichao; Snyder, Phillip; Alcacio, Timothy; Nezami, Azin; Reynolds, James; Alvi, Khisal; Goulet, Lance; Stamos, Dean

2014-04-24

278

Miscellaneous Mathematical Utilities  

NSDL National Science Digital Library

Several online mathematical utilities intended for college and university students (math, physics, engineering, etc. students). Numerical utilities to solve (among others): N Equations in N Unknowns, Eigenvalues and Eigenvectors, Roots of Functions, and Numerical Integration. More utilities are constantly being added.

2007-08-09

279

Aberrant 3? splice sites in human disease genes: mutation pattern, nucleotide structure and comparison of computational tools that predict their utilization  

PubMed Central

The frequency distribution of mutation-induced aberrant 3? splice sites (3?ss) in exons and introns is more complex than for 5? splice sites, largely owing to sequence constraints upstream of intron/exon boundaries. As a result, prediction of their localization remains a challenging task. Here, nucleotide sequences of previously reported 218 aberrant 3?ss activated by disease-causing mutations in 131 human genes were compared with their authentic counterparts using currently available splice site prediction tools. Each tested algorithm distinguished authentic 3?ss from cryptic sites more effectively than from de novo sites. The best discrimination between aberrant and authentic 3?ss was achieved by the maximum entropy model. Almost one half of aberrant 3?ss was activated by AG-creating mutations and ?95% of the newly created AGs were selected in vivo. The overall nucleotide structure upstream of aberrant 3?ss was characterized by higher purine content than for authentic sites, particularly in position ?3, that may be compensated by more stringent requirements for positive and negative nucleotide signatures centred around position ?11. A newly developed online database of aberrant 3?ss will facilitate identification of splicing mutations in a gene or phenotype of interest and future optimization of splice site prediction tools.

Vorechovsky, Igor

2006-01-01

280

The preparation of an elastomer/silicate layer nanocompound with an exfoliated structure and a strong ionic interfacial interaction by utilizing an elastomer latex containing pyridine groups.  

PubMed

A great variety of polymer/layered silicate (PLS) nanocomposites have been reported, however, there are few exfoliated PLS nanocomposites and their inorganic-organic interfaces are still a great problem, especially for the elastomers. In this research, a kind of exfoliated elastomer/silicate layer nanocompound was prepared and proved by XRD and TEM, in which 10 phr Na(+)-montmorillonite was dispersed in butadiene-styrene-vinyl pyridine rubber by latex compounding method with acidic flocculants. Moreover, a dynamic mechanical thermal analyzer (DMTA) suggested a strong interfacial interaction (interaction parameter B(H) = 4.91) between the silicate layers and macromolecules in addition to the weak inorganic-organic interfacial interaction, and solid state (15)N NMR indicated the formation of a strong ionic interface through the acidifying pyridine. Subsequently, a remarkable improvement of the dispersing morphology, mechanical performance and gas barrier property appeared, compared to that using calcium ion flocculants. This supports the formation of an exfoliated structure and an improved interfacial interaction. PMID:20173242

He, Shao-jian; Wang, Yi-qing; Feng, Yi-ping; Liu, Qing-sheng; Zhang, Li-qun

2010-03-19

281

A Utility Model for Teaching Load Decisions in Academic Departments.  

ERIC Educational Resources Information Center

Presents a utility model for academic department decision making and describes the structural specifications for analyzing it. The model confirms the class-size utility asymmetry predicted by the authors' academic rachet theory, but shows that marginal utility associated with college teaching loads is always negative. Curricular structure and…

Massey, William F.; Zemsky, Robert

1997-01-01

282

Structure and expression profile of the sucrose synthase gene family in the rubber tree: indicative of roles in stress response and sucrose utilization in the laticifers.  

PubMed

Sucrose synthase (Sus, EC 2.4.1.13) is widely recognized as a key enzyme in sucrose metabolism in plants. However, nothing is known about this gene family in Hevea brasiliensis (para rubber tree). Here, we identified six Sus genes in H. brasiliensis that comprise the entire Sus family in this species. Analysis of the gene structure and phylogeny of the Sus genes demonstrates evolutionary conservation in the Sus families across Hevea and other plant species. The expression of Sus genes was investigated via Solexa sequencing and quantitative PCR in various tissues, at various phases of leaf development, and under abiotic stresses and ethylene treatment. The Sus genes exhibited distinct but partially redundant expression profiles. Each tissue has one abundant Sus isoform, with HbSus3, 4 and 5 being the predominant isoforms in latex (cytoplasm of rubber-producing laticifers), bark and root, respectively. HbSus1 and 6 were barely expressed in any tissue examined. In mature leaves (source), all HbSus genes were expressed at low levels, but HbSus3 and 4 were abundantly expressed in immature leaves (sink). Low temperature and drought treatments conspicuously induced HbSus5 expression in root and leaf, suggesting a role in stress responses. HbSus2 and 3 transcripts were decreased by ethylene treatment, consistent with the reduced sucrose-synthesizing activity of Sus enzymes in the latex in response to ethylene stimulation. Our results are beneficial to further determination of functions for the Sus genes in Hevea trees, especially roles in regulating latex regeneration. PMID:24279382

Xiao, Xiaohu; Tang, Chaorong; Fang, Yongjun; Yang, Meng; Zhou, Binhui; Qi, Jiyan; Zhang, Yi

2014-01-01

283

Voltage reduction in organic light-emitting diodes  

SciTech Connect

For practical applications, it is important to operate organic light-emitting devices at low voltages and low power consumption. When both the cathode and anode are perfectly injecting, low electron mobility in electron-transport materials, such as tris-(8-hydroxyquinoline)aluminum (Alq), becomes a limiting factor on voltage reduction. In this letter copper phthalocyanine (CuPc) is replaced for Alq as an electron-transport layer, and interfacial modification is utilized to enhance electron injection from the CuPc electron-transport layer into the Alq emissive layer. The outcome of this structure significantly facilitates electron transport through the organic materials, thus resulting in substantial reduction in operating voltages and power consumption. {copyright} 2001 American Institute of Physics.

Hung, L. S.; Mason, M. G.

2001-06-04

284

Structuralism.  

ERIC Educational Resources Information Center

Provided is an overview of the analytical method known as structuralism. The first chapter discusses the three key components of the concept of a structure: the view of a system as a whole instead of so many parts; the study of the transformations in the system; and the fact that these transformations never lead beyond the system but always…

Piaget, Jean

285

Utility\\/solar conection  

Microsoft Academic Search

Utility-related solar energy projects that assess application, develop a methodology, and regulate indistry have a high priority at the Solar Energy Research Institute (SERI). The assessments are aimed at determining the value of solar technology to users and analyzing the economic and legal impact of commercialization. Valid arguments can be made for and against utility involvement, with several approaches available

1980-01-01

286

Instructional Facility Utilization.  

ERIC Educational Resources Information Center

Data describing campus facility use for instructional and related purposes for one week of activity in Fall 1978 were collected and evaluated at Kalamazoo Valley Community College. Four measures of space utilization were used: (1) percent of available time used; (2) percent of available space used; (3) percent of scheduled space utilized; and (4)…

Kalamazoo Valley Community Coll., MI.

287

Synchrotron-based soft X-ray spectroscopic studies of the electronic structure of organic semiconducting molecules  

NASA Astrophysics Data System (ADS)

Organic molecules have been the subject of many scientific studies due to their potential for use in a new generation of optoelectronic and semiconducting devices, such as organic photovoltaics and organic light emitting diodes. These studies are motivated by the fact that organic semiconductor devices have several advantages over traditional inorganic semiconductor devices. Unlike inorganic semiconductors, where the electronic properties are a result of the deliberate introduction of dopants to the material, the properties of organic semiconductors are often intrinsic to the molecules themselves. As a result, organic semiconductor devices are frequently less susceptible to contamination by impurities than their inorganic counterparts, which results in the relatively lower cost of producing such devices. Accurate experimental determination of the bulk and surface electronic structure of organic semiconductors is a prerequisite in developing a comprehensive understanding of such materials. The organic materials studied in this thesis were N,N-Ethylene-bis(1,1,1trifluoropentane-2,4-dioneiminato)-copper(ii) (abbreviated Cu-TFAC), aluminum tris-8hydroxyquinoline (A1g3), lithium quinolate (Liq), tetracyanoquinodimethane (TCNQ), and tetrafluorotetracyanoquinodimethane (F4TCNQ). The electronic structures of these materials were measured with several synchrotron-based x-ray spectroscopies. X-ray photoemission spectroscopy was used to measure the occupied total density of states and the core-level states of the aforementioned materials. X-ray absorption spectroscopy (XAS) was used to probe the element-specific unoccupied partial density of states (PDOS); its angle-resolved variant was used to measure the orientation of the molecules in a film and, in some circumstances, to gauge the extent of an organic film's crystallinity. Most notably, x-ray emission spectroscopy (XES) measures the element- specific occupied PDOS and, when aided by XAS, resonant XES can additionally be used to probe the electronic structure of individual atomic sites within a molecule. Most of the results in this thesis are accompanied by the results of electronic structure calculations determined with density functional theory (DFT). DFT is a useful aid in interpreting the results of the x-ray spectroscopies employed. The experimental results, combined with DFT calculations, provide a wealth of information regarding the electronic structures of these organic materials. v

Demasi, Alexander

288

SCD Graphics Utilities.  

National Technical Information Service (NTIS)

The technical note is an overview of the SCD graphics utilities AUTOGRAPH, CONRAN, CONRAQ, CONRAS, CONREC, CONRECQCK, CONRECSMTH, CONRECSUPR, DASHCHAR, DASHLINE, DASHSMTH, DASHSUPR, EZMAP, HAFTON, ISOSRF, ISOSRFHR, PWRITX, PWRITY, PWRZI, PWRZS, PWRZT, SCR...

G. R. McArthur

1981-01-01

289

Technology Utilization Program Report.  

National Technical Information Service (NTIS)

The application of aerospace technology to the solution of public health and industrial problems is reported. Data cover: (1) development of an externally rechargeable cardiac pacemaker, (2) utilization of ferrofluids-colloidal suspensions of ferrite part...

1974-01-01

290

Utilization of Solar Energy.  

National Technical Information Service (NTIS)

Comments are presented on an international conference concerned with solar energy utilization. The difficulties of harnessing solar energy are outlined in terms of three basic properties: (1) high dilution, (2) intermittent nature, and (3) high entropy. T...

I. Oshida

1974-01-01

291

Nonexpected Utility in Macroeconomics  

Microsoft Academic Search

This paper introduces, within the context of an infinite optimal consumption problem, a parametric class of Kreps-Porteus nonexpected utility preferences--generalized isoelastic utility--which distinguishes attitudes toward risk from behavior toward intertemporal substitution. Some of the theoretical and empirical implications for macroeconomics of these state- and time-nonseparable preferences are examined. Copyright 1990, the President and Fellows of Harvard College and the Massachusetts

Philippe Weil

1990-01-01

292

Organocatalytic photoreduction of Zn(II) to zinc metal.  

PubMed

The photoreduction of Zn(II) to Zn metal catalyzed by 8-hydroxyquinoline derivatives is reported. Structure-activity relationships, ideal reaction conditions, and the reaction kinetics are described and a mechanism involving an in situ formed quinolate complex is portrayed. PMID:24445658

Brooks, Anthony C; Basore, Katherine; Bernhard, Stefan

2014-05-25

293

Utility terrestrial biodiversity issues  

SciTech Connect

Results from a survey of power utility biologists indicate that terrestrial biodiversity is considered a major issued by only a few utilities; however, a majority believe it may be a future issue. Over half of the respondents indicated that their company is involved in some management for biodiversity, and nearly all feel that it should be a goal for resource management. Only a few utilities are funding biodiversity research, but a majority felt more research was needed. Generally, larger utilities with extensive land holdings had greater opportunities and resources for biodiversity management. Biodiversity will most likely be a concern with transmission rights-of-way construction and maintenance, endangered species issues and general land resource management, including mining reclamation and hydro relicensing commitments. Over half of the companies surveyed have established voluntary partnerships with management groups, and biodiversity is a goal in nearly all the joint projects. Endangered species management and protection, prevention of forest fragmentation, wetland protection, and habitat creation and protection are the most common partnerships involving utility companies. Common management practices and unique approaches are presented, along with details of the survey. 4 refs.

Breece, G.A. [Southern Company, Atlanta, GA (United States); Ward, B.J. [Carolina Power and Light Company, Raleigh, NC (United States)

1996-11-01

294

Sucrose-Utilizing Transglucosidases for Biocatalysis  

NASA Astrophysics Data System (ADS)

Sucrose-utilizing transglucosidases are valued tools in chemistry to generate glycodiversification. Not only do these enzymes use as substrate an abundant agroresource, sucrose, but they also share a remarkable versatility regarding the acceptor substrate, allowing the structurally-controlled synthesis of diverse glucosylated products. Latest research has demonstrated the potential of enzyme engineering to tailor novel sucrose-utilizing transglucosidases that give access to original carbohydrate-based structures. This chapter gives an overview of the recent achievements in biocatalysis using these enzymes.

André, Isabelle; Potocki-Véronèse, Gabrielle; Morel, Sandrine; Monsan, Pierre; Remaud-Siméon, Magali

295

Theoretical investigations of the structures and electronic spectra of 8-hydroxylquinoline derivatives.  

PubMed

The spectroscopic properties of 8-hydroxyquinoline derivatives are theoretically investigated by means of density functional theory (DFT) and time-dependent density functional theory (TD-DFT) methods. The target molecules are divided into two groups: group (I): (E)-2-(2-(3,5-dimethyl-1-phenyl-1H-pyrazol-4-yl)vinyl)quinolin-8-ol (A), together with corresponding potential reaction products of A with acetic acid, i.e., (E)-2-(2-(3,5-dimethyl-1-phenyl-1H-pyrazol-4-yl)vinyl)quinolin-8-yl acetate (AR1), and (E)-2-(2-(3,5-dimethyl-1-phenyl-1H-pyrazol-4-yl)vinyl)-8-hydroxyquinolinium (AR2); group (II): (E)-2-(2-(1-(4-chlorophenyl)-3,5-dimethyl-1H-pyrazol-4-yl)vinyl)quinolin-8-ol (B), as well as potential reaction products of B with acetic acid, i.e., (E)-2-(2-(1-(4-chlorophenyl)-3,5-dimethyl-1H-pyrazol-4-yl)vinyl)quinolin-8-yl acetate (BR1), and (E)-2-(2-(1-(4-chlorophenyl)-3,5-dimethyl-1H-pyrazol-4-yl)vinyl)-8-hydroxyquinolinium (BR2). The geometries are optimized by B3LYP and M06 methods. The results indicate that product molecules tend to be effectively planar compared with reactants. Subsequently, UV absorption spectra are simulated through TD-DFT method with PCM model to further confirm the reasonable products of two reactions. AR2 and BR2 are identified as the target molecules through the experimental spectra for the real products. It is worth noting that the maximum absorption wavelengths of compounds AR2 and BR2 present prominent red shift compared the initial reactants A and B, respectively, which should be ascribed to the enhancive planarity of products that mentioned above and the decreased HOMO-LUMO energy gap. Geometric structures and optical properties for corresponding compounds are discussed in detail. PMID:23871972

Ning, Pan; Ren, Tiegang; Zhang, Yanxin; Zhang, Jinglai

2013-11-01

296

Debating Clinical Utility  

Microsoft Academic Search

The clinical utility of genetic tests is determined by the outcomes following test use. Like other measures of value, it is often contested. Stakeholders may have different views about benefits and risks and about the importance of social versus health outcomes. They also commonly disagree about the evidence needed to determine whether a test is effective in achieving a specific

W. Burke; A.-M. Laberge

2010-01-01

297

Administrative Utility Analysis: Appendices.  

ERIC Educational Resources Information Center

Appendixes to a study on administrative utility analysis and vocational education programs for the Area of Vocational and Technical Education (AVTE) in the Puerto Rico Department of Education contain the planning and budgeting system elements, position descriptions, and information on the growth of vocational education in Puerto Rico. The elements…

Peat, Marwick, Mitchell and Co., San Juan, Puerto Rico.

298

Technology utilization program report  

NASA Technical Reports Server (NTRS)

The application of aerospace technology to the solution of public health and industrial problems is reported. Data cover: (1) development of an externally rechargeable cardiac pacemaker, (2) utilization of ferrofluids-colloidal suspensions of ferrite particles - in the efficient separation of nonferrous metals as Ni, Zn, Cu, and Al from shredded automobile scrap, and (3) development of a breathing system for fire fighters.

1974-01-01

299

Biogas: Production and utilization  

Microsoft Academic Search

Among the aspects of biogas production and utilization covered are: (1) the microbiology and biochemistry of the acid and methane production stages in the anaerobic process; (2) factors affecting the process, such as temperature, acidity and alkalinity, nutrients, and cations; (3) denitrification processes and systems; and (4) the process kinetics of suspended growth systems, packed columns, and fluidized beds. Also

E. C. Price; P. N. Cheremisinoff

1981-01-01

300

Knowledge Production and Utilization.  

ERIC Educational Resources Information Center

The study of knowledge production and utilization deals with the problems of how to translate theoretical concepts and knowledge into practical solutions to people's problems. Many criticisms have been leveled at aspects of previous information system models, including their linearity, one-way communication paths, overdependence on scientific…

Beal, George M.; Meehan, Peter

301

Module utilization committee  

NASA Technical Reports Server (NTRS)

Photovoltaic collector modules were declared surplus to the needs of the U.S. Dept. of Energy. The Module Utilization Committee was formed to make appropriate disposition of the surplus modules on a national basis and to act as a broker for requests for these modules originating outside of the National Photovoltaics Program.

Volkmer, K.; Praver, G.

1984-01-01

302

Classroom Use and Utilization.  

ERIC Educational Resources Information Center

Discusses how classrooms are distributed by size on a campus, how well they are used, and how their use changes with faculty and student needs and desires. Details how to analyze classroom space, use, and utilization, taking into account such factors as scheduling and classroom stations. (EV)

Fink, Ira

2002-01-01

303

Solar refrigeration utilizing zeolites  

Microsoft Academic Search

Zeolites offer a unique opportunity for a solid-gas adsorption refrigeration system because of their unusual sorption properties, in particular, extremely nonlinear adsorption isotherms. The operating principle of the zeolite system and experimental results are presented. The study demonstrates a zeolite system capable of providing refrigeration and ice production with very good engineering efficiency. This system utilizes natural zeolites as the

D. I. Tchernev

1979-01-01

304

Buoy Tender Utilization Study.  

National Technical Information Service (NTIS)

Because of an indication that the cost per navigational aid was rising rapidly, the Coast Guard conducted an analysis of the utilization of buoy tenders, which are the primary and most costly facility for the servicing of navigational aids. Based upon an ...

I. B. Ing

1967-01-01

305

YEAR 2 BIOMASS UTILIZATION  

Microsoft Academic Search

This Energy & Environmental Research Center (EERC) Year 2 Biomass Utilization Final Technical Report summarizes multiple projects in biopower or bioenergy, transportation biofuels, and bioproducts. A prototype of a novel advanced power system, termed the high-temperature air furnace (HITAF), was tested for performance while converting biomass and coal blends to energy. Three biomass fuels--wood residue or hog fuel, corn stover,

Christopher J. Zygarlicke

2004-01-01

306

Helping Water Utilities Grapple with Climate Change  

NASA Astrophysics Data System (ADS)

The Water Research Foundation (WRF), serving the drinking water industry and the National Center for Atmospheric Research (NCAR) are collaborating on an effort to develop and implement locally-relevant, structured processes to help water utilities consider the impacts and adaptation options that climate variability and change might have on their water systems. Adopting a case-study approach, the structured process include 1) a problem definition phase, focused on identifying goals, information needs, utility vulnerabilities and possible adaptation options in the face of climate and hydrologic uncertainty; 2) developing and/or modifying system-specific Integrated Water Resource Management (IWRM) models and conducting sensitivity analysis to identify critical variables; 3) developing probabilistic climate change scenarios focused on exploring uncertainties identified as important in the sensitivity analysis in step 2; and 4) implementing the structured process and examining approaches decision making under uncertainty. Collaborators include seven drinking water utilities and two state agencies: 1) The Inland Empire Utility Agency, CA; 2) The El Dorado Irrigation District, Placerville CA; 2) Portland Water Bureau, Portland OR; 3) Colorado Springs Utilities, Colo Spgs, CO; 4) Cincinnati Water, Cincinnati, OH; 5) Massachusetts Water Resources Authority (MWRA), Boston, MA; 6) Durham Water, Durham, NC; and 7) Palm Beach County Water (PBCW), Palm Beach, FL. The California Department of Water Resources and the Colorado Water Conservation Board were the state agencies that we have collaborated with.

Yates, D.; Gracely, B.; Miller, K.

2008-12-01

307

Microbial Cellulose Utilization: Fundamentals and Biotechnology  

PubMed Central

Fundamental features of microbial cellulose utilization are examined at successively higher levels of aggregation encompassing the structure and composition of cellulosic biomass, taxonomic diversity, cellulase enzyme systems, molecular biology of cellulase enzymes, physiology of cellulolytic microorganisms, ecological aspects of cellulase-degrading communities, and rate-limiting factors in nature. The methodological basis for studying microbial cellulose utilization is considered relative to quantification of cells and enzymes in the presence of solid substrates as well as apparatus and analysis for cellulose-grown continuous cultures. Quantitative description of cellulose hydrolysis is addressed with respect to adsorption of cellulase enzymes, rates of enzymatic hydrolysis, bioenergetics of microbial cellulose utilization, kinetics of microbial cellulose utilization, and contrasting features compared to soluble substrate kinetics. A biological perspective on processing cellulosic biomass is presented, including features of pretreated substrates and alternative process configurations. Organism development is considered for “consolidated bioprocessing” (CBP), in which the production of cellulolytic enzymes, hydrolysis of biomass, and fermentation of resulting sugars to desired products occur in one step. Two organism development strategies for CBP are examined: (i) improve product yield and tolerance in microorganisms able to utilize cellulose, or (ii) express a heterologous system for cellulose hydrolysis and utilization in microorganisms that exhibit high product yield and tolerance. A concluding discussion identifies unresolved issues pertaining to microbial cellulose utilization, suggests approaches by which such issues might be resolved, and contrasts a microbially oriented cellulose hydrolysis paradigm to the more conventional enzymatically oriented paradigm in both fundamental and applied contexts.

Lynd, Lee R.; Weimer, Paul J.; van Zyl, Willem H.; Pretorius, Isak S.

2002-01-01

308

Double Shell Tank (DST) Utilities Specification  

SciTech Connect

This specification establishes the performance requirements and provides the references to the requisite codes and standards to he applied during the design of the Double-Shell Tank (DST) Utilities Subsystems that support the first phase of waste feed delivery (WFD). The DST Utilities Subsystems provide electrical power, raw/potable water, and service/instrument air to the equipment and structures used to transfer low-activity waste (LAW) and high-level waste (HLW) to designated DST staging tanks. The DST Utilities Subsystems also support the equipment and structures used to deliver blended LAW and HLW feed from these staging tanks to the River Protection Project (RPP) Privatization Contractor facility where the waste will be immobilized. This specification is intended to be the basis for new projects/installations. This specification is not intended to retroactively affect previously established project design criteria without specific direction by the program.

SUSIENE, W.T.

2000-04-27

309

Special report: Utility boilers  

SciTech Connect

The boiler technologies available for both new and repowering applications embrace the well-known - subcritical drum-type and supercritical once-through pulverized-coal-fired boilers, fluidized-bed boilers, and heat-recovery steam generators (HRSGs) - and the less familiar gasification cycles. Additionally, modifications to existing boilers and their auxiliaries figure prominently in utility operating plans. Reason: Meeting environmental and capacity demands often dictates extensive boiler work as part of a larger, more comprehensive undertaking. The remainder of this report reviews several recent utility boiler projects, including modifications to meet increased environmental and capacity demands, new equipment options from boiler OEMs, and installations recently completed or under way. 7 figs.

Bretz, E.A.

1994-05-01

310

Seasat data utilization project  

NASA Technical Reports Server (NTRS)

During the three months of orbital operations, the satellite returned data from the world's oceans. Dozens of tropical storms, hurricanes and typhoons were observed, and two planned major intensive surface truth experiments were conducted. The utility of the Seasat-A microwave sensors as oceanographic tools was determined. Sensor and geophysical evaluations are discussed, including surface observations, and evaluation summaries of an altimeter, a scatterometer, a scanning multichannel microwave radiometer, a synthetic aperture radar, and a visible and infrared radiometer.

Born, G. H.; Held, D. N.; Lame, D. B.; Lipes, R. G.; Montgomery, D. R.; Rygh, P. J.; Scott, J. F.

1981-01-01

311

NASA's Technology Utilization Program.  

NASA Technical Reports Server (NTRS)

NASA's Technology Utilization Program is described, illustrating how it can be useful in achieving improved productivity, providing more jobs, solving public sector challenges, and strengthening the international competitive situation. Underlying the program is the fact that research and development conducted in NASA's aeronautics and space programs have generated much technical information concerning processes, products, or techniques which may be useful to engineers, doctors, or to others. The program is based on acquisition and publication, working with the user, and applications engineering.

Farley, C. F.

1972-01-01

312

Ethics for electic utilities  

SciTech Connect

This article examines the ethical challenges of remaining honest and fair when the playing field of competition does not appear to be level. Topics discussed include measuring performance, monitoring use of services, public opinion of utility integrity and commitment to service, making ethical concerns and language a part of the management decision process, and communication of moral issues to a place where resolution can occur.

Powers, C.W.; Toffler, B.L. (Resources for Responsible Management, Boston, MA (United States))

1991-05-15

313

Electric utilities in 2007  

SciTech Connect

A century ago--in the year J.J. Thomson discovered the electron--electricity, gas and traction companies battled for markets, and corrupt city councils demanded their fair share of the take. One tycoon became so disgusted with the confusion and dishonesty that he decided to bribe the legislature to set up an honest, state-run regulatory agency that would bring order to chaos. But he was found out. The scandal set back the cause of regulation until 1907, the year in which the electric washing machine and the vacuum cleaner were invented. By then, electricity sales had septupled from 1897 levels, and three states had established utility regulation. In the coming decade, 1997 to 2007, the utility business could undergo similar dramatic change, but it will move toward less regulation and more competition during a period of slow growth. Management will have to work harder to achieve success, however, because much of the profits will have to come not from a growing market but from the pockets of competitors. By 2007, electricity will constitute a component of a larger energy and utility services industry that sells electricity, natural gas and possibly water, propane and telecommunications. Customized service will meet the needs of consumers of all sizes. The dominant firm in the industry, the virtual utility, may look more like a financial organization or a mass marketer than the traditional converter of raw material to energy. Emphasis on market-based pricing should lead to more efficient use of resources. If the process works right, the consumer wins.

Hyman, L.S. [Smith Barney Inc., New York, NY (United States)

1998-10-01

314

Utilization of biomass in Slovakia  

Microsoft Academic Search

At present, approximately 400?000 ton of biomass annually are utilized for energy. It is a question of fuel wood utilized mainly by inhabitants. Utilization of the rest of forest biomass is small even though an annual utilizable potential is almost 7000 TJ. Increase and higher effectiveness of biomass utilization for energy in Slovakia requires development of preparation technology for fuel

Ján Ilavský; Milan Oravec

2000-01-01

315

Space Resources Utilization Roundtable  

NASA Technical Reports Server (NTRS)

This volume contains abstracts that have been accepted for presentation at the Space Resources Utilization Roundtable, October 27-29, 1999, in Golden, Colorado. The program committee consisted of M. B. Duke (Lunar and Planetary Institute), G. Baughman (Colorado School of Mines), D. Criswell (University of Houston), C. Graham (Canadian Mining Industry Research Organization), H. H. Schmitt (Apollo Astronaut), W. Sharp (Colorado School of Mines), L. Taylor (University of Tennessee), and a space manufacturing representative. Administration and publications support for this meeting were provided by the staff of the Publications and Program Services Department at the Lunar and Planetary Institute.

1999-01-01

316

Biogas: Production and utilization  

NASA Astrophysics Data System (ADS)

Among the aspects of biogas production and utilization covered are: (1) the microbiology and biochemistry of the acid and methane production stages in the anaerobic process; (2) factors affecting the process, such as temperature, acidity and alkalinity, nutrients, and cations; (3) denitrification processes and systems; and (4) the process kinetics of suspended growth systems, packed columns, and fluidized beds. Also considered are such issues in the application of this technology as the digestion of municipal treatment plant sludges, animal wastes, food processing wastes and energy crops. Attention is in addition given to anaerobic digester design, offgas measurement of anaerobic digesters, and sludge treatment through soil conditioning and composting.

Price, E. C.; Cheremisinoff, P. N.

317

Tribal Utility Feasibility Study  

SciTech Connect

The Schatz Energy Research Center (SERC) assisted the Yurok Tribe in investigating the feasibility of creating a permanent energy services program for the Tribe. The original purpose of the DOE grant that funded this project was to determine the feasibility of creating a full-blown Yurok Tribal electric utility to buy and sell electric power and own and maintain all electric power infrastructure on the Reservation. The original project consultant found this opportunity to be infeasible for the Tribe. When SERC took over as project consultant, we took a different approach. We explored opportunities for the Tribe to develop its own renewable energy resources for use on the Reservation and/or off-Reservation sales as a means of generating revenue for the Tribe. We also looked at ways the Tribe can provide energy services to its members and how to fund such efforts. We identified opportunities for the development of renewable energy resources and energy services on the Yurok Reservation that fall into five basic categories: • Demand-side management – This refers to efforts to reduce energy use through energy efficiency and conservation measures. • Off-grid, facility and household scale renewable energy systems – These systems can provide electricity to individual homes and Tribal facilities in areas of the Reservation that do not currently have access to the electric utility grid. • Village scale, micro-grid renewable energy systems - These are larger scale systems that can provide electricity to interconnected groups of homes and Tribal facilities in areas of the Reservation that do not have access to the conventional electric grid. This will require the development of miniature electric grids to serve these interconnected facilities. • Medium to large scale renewable energy development for sale to the grid – In areas where viable renewable energy resources exist and there is access to the conventional electric utility grid, these resources can be developed and sold to the wholesale electricity market. • Facility scale, net metered renewable energy systems – These are renewable energy systems that provide power to individual households or facilities that are connected to conventional electric utility grid.

Engel, R. A.; Zoellick, J. J.

2007-06-30

318

Cost-utility analysis.  

PubMed Central

Decisions have to be made about allocating health resources. Currently the best economic evaluation method for doing this is cost-utility analysis. This compares the costs of different procedures with their outcomes measured in "utility based" units--that is, units that relate to a person's level of wellbeing. The most commonly used unit is the quality adjusted life year (QALY). QALYs are calculated by estimating the total life years gained from a procedure and weighting each year to reflect the quality of life in that year. To compare outcomes of different programmes the Rosser index is one measure that is widely used to assign quality of life scores to patients. Combined with a measure of life years gained from a procedure, this enables QALYs to be calculated and procedures ranked according to cost per QALY gained. In this article Ray Robinson explains the measures used and discusses how QALY league tables can be used to guide decisions on resource allocation. Images p862-a

Robinson, R

1993-01-01

319

Phosphonate utilization by bacteria.  

PubMed

Bacteria able to use at least one of 13 ionic alkylphosphonates of O-alkyl or O,O-dialkyl alkylphosphonates as phosphorus sources were isolated from sewage and soil. Four of these isolates used 2-aminoethylphosphonic acid (AEP) as a sole carbon, nitrogen, and phosphorus source. None of the other phosphonates served as a carbon source for the organisms. One isolate, identified as Pseudomonas putida, grew with AEP as its sole carbon, nitrogen, and phosphorus source and released nearly all of the organic phosphorus as orthophosphate and 72% of the AEP nitrogen as ammonium. This is the first demonstration of utilization of a phosphonoalkyl moiety as a sole carbon source. Cell-free extracts of P. putida contained an inducible enzyme system that required pyruvate and pyridoxal phosphate to release orthophosphate from AEP; acetaldehyde was tentatively identified as a second product. Phosphite inhibited the enzyme system. PMID:618850

Cook, A M; Daughton, C G; Alexander, M

1978-01-01

320

Marital Separation and Medical Utilization.  

National Technical Information Service (NTIS)

Changes in health care utilization which were consequent or related to the stress of marital separation were studied. A psychoeducational intervention, seminars for the separated, was tested to determine if inappropriate medical utilization would be reduc...

S. H. Budman

1982-01-01

321

Construction utilization of foamed waste glass.  

PubMed

Foamed waste glass (FWG) material is newly developed for the purpose to utilize the waste glassware and other waste glass. FWG has a multi-porous structure that consists of continuous or discontinuous voids. Hence lightweight but considerable stiffness can be achieved. In the present study, the manufacture and engineering properties of FWG are introduced first. Then, the utilizations of FWG are investigated in laboratory tests and field tests. Some case studies on design and construction work are also reported here. Through these studies we know that the discontinuous void material can be utilized as a lightweight fill material, ground improvement material and lightweight aggregate for concrete. On the other hand, the continuous void material can be used as water holding material for the greening of ground slope and rooftop, and as clarification material for water. PMID:15137660

Lu, Jiang; Onitsuka, Katsutada

2004-01-01

322

Ash handling, storage, and utilization  

Microsoft Academic Search

Current power plant practices are increasing the amount of ash production. Therefore, utilization and storage of this byproduct become more important. An overview is presented of various techniques for the handling, utilization, and storage of ash generated by large utility coal-fired generating stations in sizes of 600 MW and above.

Loftus

1976-01-01

323

Knowledge Utilization: Implications for Evaluation  

ERIC Educational Resources Information Center

Knowledge utilization is a field crossing many sectors, from agriculture, since the 1920s, to health care today. Evaluators have made long-standing contributions to understanding knowledge utilization. Different models or ways to think about knowledge utilization have evolved to reflect different perspectives, contexts, and stages of the process,…

Blake, Sarah C.; Ottoson, Judith M.

2009-01-01

324

The evolution of utilization management.  

PubMed

Utilization management has been one of the most useful managed care tools since the early days of this health delivery model. Recently, utilization management has come under siege, not directly as a result of public outcry, but from within the industry itself. One expert describes how utilization management must evolve to keep pace with the changing managed care environment. PMID:11141731

Carneal, G

2000-12-01

325

Administrative Utility Analysis.  

ERIC Educational Resources Information Center

Puerto Rico's economic growth has accentuated the need for a larger vocational education program capable of handling the demand for occupationally-trained personnel. The Area of Vocational and Technical Education (AVTE) operates within the general structure of the Puerto Rico Department of Education, and AVTE programs must be adapted to the growth…

Peat, Marwick, Mitchell and Co., San Juan, Puerto Rico.

326

Coal science: An introduction to chemistry, technology and utilization  

SciTech Connect

This book presents the chemistry and geology of coal. It describes aspects of the petrology and petrographic characterization of coal, the processes involved in coal conversion and utilization, and the testing and analysis of coal. It includes recent statistics regarding production and utilization, as well as recent developments in structure, reactivity and routine analysis.

Hessley, R.K.; Reasoner, J.W.; Riley, J.T.

1986-01-01

327

PFBC Utility Demonstration Project  

SciTech Connect

This report provides a summary of activities by American Electric Power Service Corporation during the first budget period of the PFBC Utility Demonstration Project. In April 1990, AEP signed a Cooperative Agreement with the US Department of Energy to repower the Philip Sporn Plant, Units 3 4 in New Haven, West Virginia, with a 330 KW PFBC plant. The purpose of the program was to demonstrate and verify PFBC in a full-scale commercial plant. The technical and cost baselines of the Cooperative Agreement were based on a preliminary engineering and design and a cost estimate developed by AEP subsequent to AEP's proposal submittal in May 1988, and prior to the signing of the Cooperative Agreement. The Statement of Work in the first budget period of the Cooperative Agreement included a task to develop a preliminary design and cost estimate for erecting a Greenfield plant and to conduct a comparison with the repowering option. The comparative assessment of the options concluded that erecting a Greenfield plant rather than repowering the existing Sporn Plant could be the technically and economically superior alternative. The Greenfield plant would have a capacity of 340 MW. The ten additional MW output is due to the ability to better match the steam cycle to the PFBC system with a new balance of plant design. In addition to this study, the conceptual design of the Sporn Repowering led to several items which warranted optimization studies with the goal to develop a more cost effective design.

Not Available

1992-11-01

328

Leak detection utilizing analog binaural (VLSI) techniques  

NASA Technical Reports Server (NTRS)

A detection method and system utilizing silicon models of the traveling wave structure of the human cochlea to spatially and temporally locate a specific sound source in the presence of high noise pandemonium. The detection system combines two-dimensional stereausis representations, which are output by at least three VLSI binaural hearing chips, to generate a three-dimensional stereausis representation including both binaural and spectral information which is then used to locate the sound source.

Hartley, Frank T. (inventor)

1995-01-01

329

wssa_utils: WSSA 12 micron dust map utilities  

NASA Astrophysics Data System (ADS)

wssa_utils contains utilities for accessing the full-sky, high-resolution maps of the WSSA 12 micron data release. Implementations in both Python and IDL are included. The code allows users to sample values at (longitude, latitude) coordinates of interest with ease, transparently mapping coordinates to WSSA tiles and performing interpolation. The wssa_utils software also serves to define a unique WSSA 12 micron flux at every location on the sky.

Meisner, Aaron M.; Finkbeiner, Douglas P.

2014-02-01

330

Reactions of in situ generated hydrated organotin cations with chelating O,O- or O,N-ligands: a possible structure-directing influence of the organic substituent on tin.  

PubMed

The reaction of [n-Bu(2)SnO](n) with 1,5-naphthalenedisulfonic acid tetrahydrate in a 1:1 stoichiometry followed by reaction with 2,2'-bipyridine-N,N'-dioxide (BPDO-I) afforded a 1D-coordination polymer [n-Bu(2)Sn(BPDO-I)(1,5-C(10)H(6)(SO(3))(2))](n) (1) where the disulfonate ligand acts as a bridging ligand between two tin centers. An analogous reaction involving [Ph(2)SnO](n) afforded a trihydrated O,O'-chelated diorganotin cation [{Ph(2)Sn(BPDO-I)(H(2)O)(3)}(2+)][C(10)H(6)(SO(3)(-))(2)]·2CH(3)OH (2·2CH(3)OH). Utilizing two equivalents of BPDO-I in this reaction resulted in the ionic complex [{Ph(2)Sn(BPDO-I)(2)(H(2)O)}(2+)][C(10)H(6)(SO(3)(-))(2)]·3H(2)O (3·3H(2)O). In 2 and 3 the sulfonate ligands are not present in the coordination sphere of tin. Reaction of [n-Bu(2)SnO](n) and 1,5-naphthalenedisulfonic acid tetrahydrate, followed by reaction with [bis(diphenylphosphoryl)methane (DPPOM)] resulted in the formation of, [{n-Bu(2)Sn(DPPOM)(2)(H(2)O)(1,5-C(10)H(6)(SO(3))(SO(3)(-))}]·H(2)O (4·H(2)O). Of the two coordinating groups present in DPPOM, only one P=O group is coordinated to the tin atom. The remaining P=O motif is free and is involved in intramolecular H-bonding with the tin-bound water molecule. Using [Ph(2)SnO](n) instead of [n-Bu(2)SnO](n) afforded the ionic complex [{Ph(2)Sn(DPPOM)(2)}(2+){1,5-C(10)H(6)(SO(3)(-))(2)}] (5) where the DPPOM functions as a chelating ligand. The reaction of [n-Bu(2)SnO](n) with 1,5-naphthalenedisulfonic acid tetrahydrate followed by addition of one equivalent of 8-hydroxyquinoline (8-HQ) in presence of triethylamine afforded the neutral dinuclear complex, [(H(2)O)(8-Q)n-Bu(2)Sn(?-1,5-C(10)H(6)(SO(3))(2))n-Bu(2)Sn(8-Q)(H(2)O)] (6) where the two tin atoms are bridged by the disulfonate ligand. Compounds 1-6 are thermally stable as shown by their thermogravimetric analyses. PMID:21085724

Chandrasekhar, Vadapalli; Singh, Puja

2011-01-01

331

System 80+ - the utility perspective  

SciTech Connect

To ensure that utilities views are reflected in the System 80+ standard design, ABB Combustion Engineering (ABB C-E) organized the System 80+ Executive Advisory Committee in 1989. The committee includes utility executives with substantial nuclear experience from the United States, Europe, and Asia as well as ABB C-E's president of nuclear systems. The primary functions of the committee are to review the design and licensing activities being performed for System 80+ and to provide advice, from a utility management perspective, on how ABB C-E's program should be directed to address utility needs. Much of the committee's attention has been focused on the major policy issues that affect the System 80+ program. Because the System 80+ design is being certified by the US Nuclear Regulatory Commission (NRC) before any purchase by a utility, it is essential that ABB C-E be given input about utility needs before the design features are locked in by a commission rulemaking.

Bliss, H. (Commonwealth Edison Co., Downers Grove, IL (United States)); Priory, R. (Duke Power Co., Charlotte, NC (United States)); Burn, J. (Washington Public Power Supply System, Richland, WA (United States))

1992-01-01

332

Utility solar water heating workshops  

SciTech Connect

The objective of this project was to explore the problems and opportunities for utility participation with solar water heating as a DSM measure. Expected benefits from the workshops included an increased awareness and interest by utilities in solar water heating as well as greater understanding by federal research and policy officials of utility perspectives for purposes of planning and programming. Ultimately, the project could result in better information transfer, increased implementation of solar water heating programs, greater penetration of solar systems, and more effective research projects. The objective of the workshops was satisfied. Each workshop succeeded in exploring the problems and opportunities for utility participation with solar water heating as a DSM option. The participants provided a range of ideas and suggestions regarding useful next steps for utilities and NREL. According to evaluations, the participants believed the workshops were very valuable, and they returned to their utilities with new information, ideas, and commitment.

Barrett, L.B. (Barrett Consulting Associates, Inc., Colorado Springs, CO (United States))

1992-01-01

333

Utility for determining competitive restaurants  

US Patent & Trademark Office Database

A utility for determining the competitors of a subject restaurant accesses a database that contains information about other, nearby restaurants. The utility assigns a competitor score to each restaurant within the maximum radius based on the distance from the subject restaurant, as well as the cuisine types, menus, and order histories of the subject and competitor restaurants.

2013-11-26

334

Running a Research Utilization Laboratory  

ERIC Educational Resources Information Center

This article discusses the experiences of the Research Utilization Laboratory (RUL) of the Chicago Jewish Vocational Service over a five-year period. The topic is approached in terms of the elements involved in the utilization of research and in terms of the problems the RUL encountered. (Author)

Soloff, Asher; And Others

1975-01-01

335

Methods of Estimating Additive Utilities  

Microsoft Academic Search

Additive utility formulations for risky and nonrisky multiple-factor decision situations are reviewed. Twenty-four methods of estimating additive utilities are listed and classified. References to the theory and technique of each method are given along with a short discussion of each. A number of examples are used to illustrate the methods.

Peter C. Fishburn

1967-01-01

336

Utility Scoring of Product Reviews  

Microsoft Academic Search

We identify a new task in the ongoing research in text sentiment analysis: predicting utility of product reviews, which is orthogonal to polarity classification and opinion extraction. We build regression models by incorporating a diverse set of features, and achieve highly competitive performance for utility scoring on three real-world data sets.

Zhu Zhang; Balaji Varadarajan

2006-01-01

337

Chinese Manned Space Utility Project  

Microsoft Academic Search

Since 1992 China has been carrying out a conspicuous manned space mission A utility project has been defined and created during the same period The Utility Project of the Chinese Manned Space Mission involves wide science areas such as earth observation life science micro-gravity fluid physics and material science astronomy space environment etc In the earth observation area it is

Y. Gu

2006-01-01

338

PC Magazine 1999 Utility Guide  

NSDL National Science Digital Library

PC Magazine Online has recently released its 1999 guide to the best PC utilities. Organized in fifteen categories, the reviews feature links to the companies' sites and to related sites or articles. Users can also view the Editor's Choice of top utilities and obtain demo or full share- or freeware copies for themselves in the Download Center.

339

Facile and green fabrication of organic single-crystal hollow micro/nanostructures  

NASA Astrophysics Data System (ADS)

Under high humidity and appropriate temperature, tris (8-hydroxyquinoline) aluminum (Alq3) solid micro/nanostructures may be etched into hollow structures and still retain their crystalline structures and surface morphologies. The shapes and sizes of the hollow structures are easily adjusted by varying the experimental parameters. Throughout the entire process, water is introduced into the system instead of organic or corrosive solvents, making this method convenient and environmentally friendly; it can also be extended to application in other materials such as TCNQ.

Yang, Jun; Chen, Yingzhi; Zhang, Xiujuan; Ou, Xuemei; Zhang, Xiaohong

2011-07-01

340

Utilization of the EBIS with RFQ linacs  

SciTech Connect

The radio-frequency quadrupole (RFQ) is a new linear accelerator structure in which rf electric fields are used to simultaneously focus, bunch, and accelerate an ion beam. Since the RFQ can provide strong focusing and adiabatic bunching at low velocities, it can capture almost all of the ions extracted from an Electron Beam Ion Source (EBIS) at a low voltage and accelerate them to an energy of 1 to 2 MeV/nucleon in a distance of only a few meters. A successful test at the Los Alamos National Laboratory has confirmed the calculated performance of this structure and has stimulated interest in its use with the EBIS for a variety of applications. The general properties of the RFQ are reviewed, and the utilization of the EBIS with this structure is discussed. Several design examples of this combination are also presented.

Hamm, R.W.; Wangler, T.P.

1981-01-01

341

Special Section: The Value and Utility of Presence-Absence Data to Wildlife Monitoring and Research MODELING PATCH OCCUPANCY BY FOREST RODENTS: INCORPORATING DETECTABILITY AND SPATIAL AUTOCORRELATION WITH HIERARCHICALLY STRUCTURED DATA  

Microsoft Academic Search

Widespread conversion of deciduous forests to agriculture in the midwestern United States has resulted in landscapes whose remaining native habitats are highly fragmented, with well-documented consequences for wildlife community structure. We analyzed trap data for 5 forest rodent species from 525 sites in 35 study land- scapes throughout the upper Wabash River basin, which is dominated by agricultural use and

JEFFREY E. MOORE; ROBERT K. SWIHART

342

Subsurface Utility Engineering: An Initial Step in Project Development  

Microsoft Academic Search

The accurate location of underground structures is a serious problem in construction. Subsurface Utility Engineering (SUE) is an emerging solution to this subsurface structures problem. SUE is a process that incorporates new and existing technologies to accurately locate underground facilities during early development of a project. This paper discusses the current locating practices and the benefits that can be obtained

Jeffrey J. Lew

1997-01-01

343

Properties of an alpha-galactosidase, and structure of its gene galA, within an alpha-and beta-galactoside utilization gene cluster of the hyperthermophilic bacterium Thermotoga maritima.  

PubMed

Thermotoga maritima represents one of the few hyperthermophilic bacteria currently known. The chromosomal alpha-galactosidase gene of T. maritima strain MSB8 has been cloned and its nucleotide sequence was determined. The gene, designated galA, has coding capacity for a 552 residue polypeptide with a calculated molecular mass of 63,653 Da. GalA was found to be flanked by other genes probably involved in galactoside breakdown and utilization. The previously sequenced beta-galactosidase gene, lacZ, is localized immediately upstream of galA while two open reading frames that putatively encode enzymes of galactose catabolism, i.e. galactose-1-phosphate uridylytransferase (galT) and galactokinase (galK), were found downstream of galA. The identified genes are extremely close together or even overlap and have the same orientation, so they could all be part of one galactoside utilization operon of T. maritima MSB8. GalA displayed low-level amino acid sequence similarity with alpha-galactoside of glycosyl hydrolase family 36. However, GalA is smaller than the other members of this enzyme family. The galA gene was expressed in Escherichia coli and the recombinant alpha-galactosidase was purified and characterized. The molecular mass of the recombinant enzyme was estimated at about 62 kDa by denaturting gel electrophoresis. Maximal hydrolysis of the chromogenic substrate p-nitrophenyl-alpha-D-galactopyranoside was measured at pH 5.0-5.5 and 90-95 degrees C (5 min assay). Divalent cations were not required for activity. The enzyme released galactose from raffinose, melibiose and the synthetic substrates p-nitrophenyl-and omicron-nitrophenyl-alpha-D-galactopyranoside. The T. maritima alpha-galactosidase thus was highly specific for the galactose moiety and the alpha-anomeric configuration of the glycosidic linkage. Its extreme thermal stability (t 1/2 = 6.5 h at 85 degrees C) makes this enzyme an interesting candidate for biotechnological applications. PMID:9741105

Liebl, W; Wagner, B; Schellhase, J

1998-03-01

344

Kinesthetic Structures  

NSDL National Science Digital Library

This paper describes how students are engaged in hands-on activities that reinforce complex engineering principles. In addition to utilizing chalk board examples for design and analysis problems, physical modeling, not necessarily traditional laboratory testing, is implemented to link engineering theory with building behavior. Students design, build, and learn how structures behave in three dimensions.

Dong, Kevin

2009-09-15

345

Implementation and Utilization of Biogas.  

National Technical Information Service (NTIS)

A review of the characteristics and problems encountered during production, transportation and utilization of biogas is presented: chemical analysis of the biogas (Instruments), corrosiveness of biogas and its effects on ducts, design of the ducts and duc...

J. P. Perret

1983-01-01

346

Efficacy of Utility Database Management.  

National Technical Information Service (NTIS)

Research is needed to justify changes in current Law, Rules, Policy, Processes and Utility Data Management Requirements to affect savings in time and dollars to the Department's work Program. The purpose of this research is to investigate whether the five...

A. Yalcin N. O. Collier S. Tsalatsanis S. C. Kranc

2007-01-01

347

Wisconsin Emergency Department Utilization Study.  

National Technical Information Service (NTIS)

Data are presented from an emergency department utilization study initiated by the Wisconsin Emergency Medical Services Program to evaluate demands placed on the emergency medical service system in the State. The following characteristics of emergency dep...

E. Agisim M. Woll D. Giovannini

1973-01-01

348

A System Utilizing Solar Energy.  

National Technical Information Service (NTIS)

The possibilities of using solar energy as a future energy source are discussed. A system utilizing solar energy is described and discussed. The factors necessary for a solar energy system are listed. (Author)

1974-01-01

349

Photovoltaics: New opportunities for utilities  

SciTech Connect

This publication presents information on photovoltaics. The following topics are discussed: Residential Photovoltaics: The New England Experience Builds Confidence in PV; Austin's 300-kW Photovoltaic Power Station: Evaluating the Breakeven Costs; Residential Photovoltaics: The Lessons Learned; Photovoltaics for Electric Utility Use; Least-Cost Planning: The Environmental Link; Photovoltaics in the Distribution System; Photovoltaic Systems for the Rural Consumer; The Issues of Utility-Intertied Photovoltaics; and Photovoltaics for Large-Scale Use: Costs Ready to Drop Again.

Not Available

1991-07-01

350

Aspects concerning entropy and utility  

Microsoft Academic Search

Expected utility maximization problem is one of the most useful tools in mathematical finance, decision analysis and economics.\\u000a Motivated by statistical model selection, via the principle of expected utility maximization, Friedman and Sandow (J Mach\\u000a Learn Res 4:257–291, 2003a) considered the model performance question from the point of view of an investor who evaluates\\u000a models based on the performance of

A. R. Hoseinzadeh; G. R. Mohtashami Borzadaran; G. H. Yari

2012-01-01

351

Regulatory reform and public utilities  

SciTech Connect

This book results from two seminars regarding the subject title that were held at Rutgers the State University, New Brunswick, NJ on October 30, 1981 and March 26, 1982. The seminars received financial support from leading New Jersey utilities. The introductory chapter (by the editor) and the other nine chapters are all written within the context of the pressures facing regulated utilities and their regulators. A separate abstract was prepared for each chapter.

Crew, M.A. (ed.)

1982-01-01

352

Structure of L-Xylulose-5-Phosphate 3-Epimerase (UlaE) from the Anaerobic L-Ascorbate Utilization Pathway of Escherichia coli: Identification of a Novel Phosphate Binding Motif within a TIM Barrel Fold  

SciTech Connect

Three catabolic enzymes, UlaD, UlaE, and UlaF, are involved in a pathway leading to fermentation of L-ascorbate under anaerobic conditions. UlaD catalyzes a {beta}-keto acid decarboxylation reaction to produce L-xylulose-5-phosphate, which undergoes successive epimerization reactions with UlaE (L-xylulose-5-phosphate 3-epimerase) and UlaF (L-ribulose-5-phosphate 4-epimerase), yielding D-xylulose-5-phosphate, an intermediate in the pentose phosphate pathway. We describe here crystallographic studies of UlaE from Escherichia coli O157:H7 that complete the structural characterization of this pathway. UlaE has a triosephosphate isomerase (TIM) barrel fold and forms dimers. The active site is located at the C-terminal ends of the parallel {beta}-strands. The enzyme binds Zn{sup 2+}, which is coordinated by Glu155, Asp185, His211, and Glu251. We identified a phosphate-binding site formed by residues from the {beta}1/{alpha}1 loop and {alpha}3' helix in the N-terminal region. This site differs from the well-characterized phosphate-binding motif found in several TIM barrel superfamilies that is located at strands {beta}7 and {beta}8. The intrinsic flexibility of the active site region is reflected by two different conformations of loops forming part of the substrate-binding site. Based on computational docking of the L-xylulose 5-phosphate substrate to UlaE and structural similarities of the active site of this enzyme to the active sites of other epimerases, a metal-dependent epimerization mechanism for UlaE is proposed, and Glu155 and Glu251 are implicated as catalytic residues. Mutation and activity measurements for structurally equivalent residues in related epimerases supported this mechanistic proposal.

Shi, Rong; Pineda, Marco; Ajamian, Eunice; Cui, Qizhi; Matte, Allan; Cygler, Miroslaw (McGill); (NRC-Canada)

2009-01-15

353

Renewable energy and utility regulation  

SciTech Connect

This report summarizes the results of a joint project on renewable energy of the National Association of Regulatory Utility Commissioners (NARUC) and the US DOE. NARUC`S Task Force on Renewable Energy conducted a review of the current state of renewable energy technologies to evaluate their potential and extract key policy lessons from experience already gained in deployment of these technologies in numerous states. The main focus of this effort has been to clarify how utility regulators affect the development of renewable energy resources. The goal of the project was twofold: (1) identify the factors that have led to success or failure or renewable energy technologies in various energy markets, and (2) to develop an agenda on renewable energy and utility regulation for NARUC and the DOE. This report consists of three sections: renewable energy contributions, costs and potential; factors affecting development of renewable energy resources; and a renewable energy agenda for NARUC.

Not Available

1991-04-10

354

Renewable energy and utility regulation  

SciTech Connect

This report summarizes the results of a joint project on renewable energy of the National Association of Regulatory Utility Commissioners (NARUC) and the US DOE. NARUC'S Task Force on Renewable Energy conducted a review of the current state of renewable energy technologies to evaluate their potential and extract key policy lessons from experience already gained in deployment of these technologies in numerous states. The main focus of this effort has been to clarify how utility regulators affect the development of renewable energy resources. The goal of the project was twofold: (1) identify the factors that have led to success or failure or renewable energy technologies in various energy markets, and (2) to develop an agenda on renewable energy and utility regulation for NARUC and the DOE. This report consists of three sections: renewable energy contributions, costs and potential; factors affecting development of renewable energy resources; and a renewable energy agenda for NARUC.

Not Available

1991-04-10

355

Ethanolamine utilization in Vibrio alginolyticus  

PubMed Central

Abstract Ethanolamine is used as an energy source by phylogenetically diverse bacteria including pathogens, by the concerted action of proteins from the eut-operon. Previous studies have revealed the presence of eutBC genes encoding ethanolamine-ammonia lyase, a key enzyme that breaks ethanolamine into acetaldehyde and ammonia, in about 100 bacterial genomes including members of gamma-proteobacteria. However, ethanolamine utilization has not been reported for any member of the Vibrio genus. Our comparative genomics study reveals the presence of genes that are involved in ethanolamine utilization in several Vibrio species. Using Vibrio alginolyticus as a model system we demonstrate that ethanolamine is better utilized as a nitrogen source than as a carbon source. Reviewers This article was reviewed by Dr. Lakshminarayan Iyer and Dr. Vivek Anantharaman (nominated by Dr. L Aravind).

2012-01-01

356

Competition and utility financial risks  

SciTech Connect

While competition for electric utilities has grown steadily for over a decade, the inroads have been small. Utilities have lost load by being forced to buy power from cogenerators. They have foregone some of their normal growth by choosing to buy power from independent power producers instead of building generating facilities themselves. They have absorbed earnings erosion by giving discounts to large industrial customers to avoid having them move production outside their service areas. Yet although competition in these areas can be expected to intensity, the real financial risk for utilities lies on other fronts, principally direct price competition. The type of competition experienced thus far will constrain utility financial progress, but utilities will no doubt find ways to mitigate its impact, an example being investment in demand-side management (DSM) programs. Direct price competition, on the other hand, offers few if any avenues of escape, and it is only a matter of time before the barriers that prevent it are removed. One of the largest is the prohibition of retail wheeling, which is the principal source of price protection for utilities. Significantly, over the course of the last year the prohibition of retail wheeling has been transformed from an untouchable issue into the central issue in the struggle over competition. Price competition, when it develops, will be driven by the cost of producing electric power with new generating facilities and whatever excess generating capacity exists in the industry. How important price competition becomes will depend on what customers want. If low-cost power turns out to be a top priority, price competition will be a very important part of the competitive picture. The experience of industries that have been deregulated, such as the airlines, suggests that low prices will have a high priority.

Studness, C.M.

1993-07-01

357

Developing technologies for coal utilization  

NASA Astrophysics Data System (ADS)

The utilization of coal slurries in place of oil in utility and industrial boilers; the development of improved atmospheric and pressurized fluidized bed combustors; the designs of integrated combined cycle systems; and coal gasification and liquefaction to augment supplies of natural gas and liquid fuels, respectively are discussed. The worldwide coal resource base is so large that the necessity to manufacture liquid fuels from coals must be realized. An initiative proposed by the International Energy Agency defines several specific direct coal liquefaction designs and sites where direct coal liquefaction may be implemented.

Penner, S. S.

358

Space platform utilities distribution study  

NASA Technical Reports Server (NTRS)

Generic concepts for the installation of power data and thermal fluid distribution lines on large space platforms were discussed. Connections with central utility subsystem modules and pallet interfaces were also considered. Three system concept study platforms were used as basepoints for the detail development. The tradeoff of high voltage low voltage power distribution and the impact of fiber optics as a data distribution mechanism were analyzed. Thermal expansion and temperature control of utility lines and ducts were considered. Technology developments required for implementation of the generic distribution concepts were identified.

Lefever, A. E.

1980-01-01

359

Composite isogrid structures for parabolic surfaces  

NASA Technical Reports Server (NTRS)

The invention relates to high stiffness parabolic structures utilizing integral reinforced grids. The parabolic structures implement the use of isogrid structures which incorporate unique and efficient orthotropic patterns for efficient stiffness and structural stability.

Silverman, Edward M. (Inventor); Boyd, Jr., William E. (Inventor); Rhodes, Marvin D. (Inventor); Dyer, Jack E. (Inventor)

2000-01-01

360

The development of chelate metal complexes as an organic electroluminescent material  

Microsoft Academic Search

The chelate metal complexes, such as tris(8-hydroxyquinolinate)aluminum (Alq3), have excellent electroluminescent (EL) properties. Several chelate metal complexes were developed and the experimental rule of molecular design for use in an organic EL device was found. When the chelate metal complex has the structure of an inner complex sell, the EL device is fabricated by conventional vacuum-vapor deposition. This rule was

Yuji Hamada

1997-01-01

361

Effect of oblique angle deposition of ?-naphthylphenylbiphenyl diamine on the performance of organic light-emitting diodes  

Microsoft Academic Search

We report the effect of oblique angle deposition of ?-naphthylphenylbiphenyl diamine (?-NPD) on the performance of organic light-emitting diodes (OLEDs) based on tris-(8-hydroxyquinoline) aluminium (Alq3). OLEDs were fabricated by depositing ?-NPD using both conventional and oblique angles of incidence ? = 85° from the substrate normal. Due to oblique angle deposition tilted granular nano-structures of ?-NPD were observed. It was

Kanchan Saxena; Dalip Singh Mehta; Ritu Srivastava; M N Kamalasanan

2008-01-01

362

Syntheses of Pd(II)/Pt(II) complexes with non-chelating 4-pyridylselenolate ligand ranging from mononuclear to macrocyclic structures and their utility as catalysts in Suzuki C-C coupling reaction.  

PubMed

Treatment of Na2PdCl4 or [MCl2(PhCN)2] with bis(4-pyridyl)diselenide yielded an insoluble product of composition [MCl2(4,4?-(C5H4N)2Se2)]n (1). The reactions of Na2PdCl4 with one and two eq. of Na(4-SeC5H4N) afforded insoluble products [PdCl(4-SeC5H4N)]n (2) and [Pd(4-SeC5H4N)2]n (3), respectively. On treatment with PPh3, 2 and 3 gave trans-[PdCl(4-SeC5H4N)(PPh3)2] (4a) and trans-[Pd(4-SeC5H4N)2(PPh3)2] (5a), respectively. The oxidative addition of bis(4-pyridyl)diselenide to Pt(PPh3)4 exclusively yielded trans-[Pt(4-SeC5H4N)2(PPh3)2] (5b). The treatment of two eq. of Na(4-SeC5H4N) with cis-[PtX2(PR3)2] afforded 5b (X = Cl) and trans-[Pt(4-SeC5H4N)2(PEt3)2] (5c) (X = Cl or CF3SO3). The reactions of cis-[MCl2(P?P)] and [M2Cl2(?-Cl)2(PR3)2] with two eq. of Na(4-SeC5H4N) exclusively yielded cis-[M(4-SeC5H4N)2(P?P)] (M/P?P = Pd/dppe (6a), Pt/dppm (6b) and Pt/dppp (6c)) and [MCl(4-SeC5H4N)(PR3)]n (7), respectively. The complex trans-[PtCl(4-SeC5H4N)(PEt3)2] (4b) was isolated from the redistribution reaction between 5c and cis-[PtCl2(PEt3)2]. The complex [PdCl(4-SeC5H4N)(PPh3)]n (7b) exists in bi- and tri-nuclear forms, whereas [MCl(4-SeC5H4N)(PEt3)]n (7a, 7c) and [PtCl(4-SeC5H4N)(PMe2Ph)]n (7d) retain their trinuclear structure in solution. Molecular structures of 4a, 4b, 5a, 5c, 6a, 6c, 7a, 7b and 7c were established by single crystal X-ray diffraction analyses. The complexes trans-[PdCl(4-SeC5H4N)(PPh3)2] and [PdCl(4-SeC5H4N)(PPh3)]n can act as catalysts for Suzuki C–C cross coupling reaction. PMID:23942808

Vivekananda, K V; Dey, S; Wadawale, A; Bhuvanesh, N; Jain, V K

2013-10-21

363

In-depth study of tripeptide-based alpha-ketoheterocycles as inhibitors of thrombin. Effective utilization of the S1' subsite and its implications to structure-based drug design.  

PubMed

Thrombin inhibitors are potentially useful in medicine for their anticoagulant and antithrombotic effects. We synthesized and evaluated diverse heterocycle-activated ketones based on the d-Phe-Pro-Arg, and related thrombin active-site recognition motifs, as candidate inhibitors. The peptide-based alpha-ketoheterocycles were typically prepared by either an imidate or a Weinreb amide route (Schemes 1 and 2), the latter of which proved to be more general. Test compounds were generally assayed for inhibition of human alpha-thrombin and bovine trypsin. From a structure-based design standpoint, the heterocycle allows one to explore and adjust interactions within the S1' subsite of thrombin. The preferred alpha-ketoheterocycle is a pi-rich 2-substituted azole with at least two heteroatoms proximal to the carbon bearing the keto group, and a preferred thrombin inhibitor is 2-ketobenzothiazole 3, with a potent K(i) value of 0.2 nM and ca. 15-fold selectivity over trypsin. 2-Ketobenzothiazole 13 exhibited exceedingly potent thrombin inhibition (K(i) = 0.000 65 nM; slow tight binding). Several alpha-ketoheterocycles had thrombin K(i) values in the range 0.1-400 nM. The "Arg" unit in the alpha-ketoheterocycles can be sensitive to stereomutation under mildy basic conditions. For example, 2-ketothiazoles 4 and 59 readily epimerize at pH 7.4, although they are fairly stable stereochemically at pH 3-4; thus, suitable conditions had to be selected for the enzymatic assays. Lead d-Phe-Pro-Arg 2-benzothiazoles 3, 4, and 68 displayed good selectivity for thrombin over other key coagulation enzymes (e.g., factor Xa, plasmin, protein Ca, uPA, tPA, and streptokinase); however, their selectivity for thrombin over trypsin was modest (<25-fold). Compounds 3, 4, and 68 exhibited potent in vitro antithrombotic activity as measured by inhibition of gel-filtered platelet aggregation induced by alpha-thrombin (IC(50) = 30-40 nM). They also proved to be potent anticoagulant/antithrombotic agents in vivo on intravenous administration, as determined in the canine arteriovenous shunt (ED(50) = 0.45-0.65 mg/kg) and the rabbit deep vein thrombosis (ED(50) = 0.1-0.4 mg/kg) models. Intravenous administration of 3, and several analogues, to guinea pigs caused hypotension and electrocardiogram abnormalities. Such cardiovascular side effects were also observed with some nonguanidine inhibitors and inhibitors having recognition motifs other than d-Phe-Pro-Arg. 2-Benzothiazolecarboxylates 4 and 68 exhibited significantly diminished cardiovascular side effects, and benzothiazolecarboxylic acid 4 had the best profile with respect to therapeutic index. The X-ray crystal structures of the ternary complexes 3-thrombin-hirugen and 4-thrombin-hirugen depict novel interactions in the S(1)' region, with the benzothiazole ring forming a hydrogen bond with His-57 and an aromatic stacking interaction with Trp-60D of thrombin's insertion loop. The benzothiazole ring of 3 displaces the Lys-60F side chain into a U-shaped gauche conformation, whereas the benzothiazole carboxylate of 4 forms a salt bridge with the side chain of Lys-60F such that it adopts an extended anti conformation. Since 3 has a 10-fold greater affinity for thrombin than does 4, any increase in binding energy resulting from this salt bridge is apparently offset by perturbations across the enzyme (viz. Figure 4). The increased affinity and selectivity of 2-ketobenzothiazole inhibitors, such as 3, may be primarily due to the aromatic stacking interaction with Trp-60D. However, energy contour calculations with the computer program GRID also indicate a favorable interaction between the benzothiazole sulfur atom and a hydrophobic patch on the surface of thrombin. PMID:15771442

Costanzo, Michael J; Almond, Harold R; Hecker, Leonard R; Schott, Mary R; Yabut, Stephen C; Zhang, Han-Cheng; Andrade-Gordon, Patricia; Corcoran, Thomas W; Giardino, Edward C; Kauffman, Jack A; Lewis, Joan M; de Garavilla, Lawrence; Haertlein, Barbara J; Maryanoff, Bruce E

2005-03-24

364

Analysis of Electric Utility Load Forecasting.  

National Technical Information Service (NTIS)

Electric utility load forecasting is the process by which utilities project the demand for electricity at various points of time. The forecasts are then used by utilities to decide the amount of resources needed to meet projected demand. Load forecasting ...

1983-01-01

365

Administrative Utility Analysis: Study Summary.  

ERIC Educational Resources Information Center

This document summarizes the recommendations made as a result of a study on administrative utility analysis and vocational education programs for Puerto Rico. The major recommendation was that the Area of Vocational and Technical Education (AVTE) in the Puerto Rico Department of Education be restructured at the central organizational level, for…

Peat, Marwick, Mitchell and Co., San Juan, Puerto Rico.

366

Electrochemical utilization of metal hydrides  

SciTech Connect

The electrochemical utilization of metal hydrides is reviewed. Metal hydrides were investigated for hydrogen storage in nickel hydrogen batteries. The use of hydrides lowered the operating pressures in nickel hydrogen cells, which leads to improved energy density. Metal hydrides used as reversible hydrogen electrodes are discussed. Thermodynamic and kinetic investigations of a variety of hydriding materials are reviewed.

Bittner, H.F.; Badcock, C.C.

1982-04-01

367

Zymomonas with improved xylose utilization  

SciTech Connect

Strains of Zymomonas were engineered by introducing a chimeric xylose isomerase gene that contains a mutant promoter of the Z. mobilis glyceraldehyde-3-phosphate dehydrogenase gene. The promoter directs increased expression of xylose isomerase, and when the strain is in addition engineered for expression of xylulokinase, transaldolase and transketolase, improved utilization of xylose is obtained.

Viitanen, Paul V. (West Chester, PA); Tao, Luan (Havertown, PA); Zhang, Yuying (New Hope, PA); Caimi, Perry G. (Kennett Square, PA); McCutchen, Carol M. (Wilmington, DE); McCole, Laura (East Fallowfield, PA); Zhang, Min (Lakewood, CO); Chou, Yat-Chen (Lakewood, CO); Franden, Mary Ann (Centennial, CO)

2011-08-16

368

Expected utility with lower probabilities  

Microsoft Academic Search

An uncertain and not just risky situation may be modeled using so-called belief functions assigning lower probabilities to subsets of outcomes. In this article we extend the von Neumann-Morgenstern expected utility theory from probability measures to belief functions. We use this theory to characterize uncertainty neutrality and different degrees of uncertainty aversion.

Hans JØrgen Jacobsen; Birgitte Sloth; TORBEN TRANAES

1994-01-01

369

Utilizing Inheritance in Requirements Engineering.  

National Technical Information Service (NTIS)

The scope of this paper is the utilization of inheritance for requirements specification, i.e., the tasks of analyzing and modeling the domain, as well as forming and defining requirements. Our approach and the tool supporting it are named RETH (Requireme...

H. Kaindl

1994-01-01

370

Demand forecasting for electric utilities  

SciTech Connect

For electric utilities, probably the most important element of providing reliable power supplies is the ability to forecast the demands of commercial, industrial and residential customers. The discipline of electric utility demand forecasting has evolved at a vigorous pace over the past two decades. The straight-line extrapolations of historical energy consumption trends that served well enough for the years of steady prices and steady growth became inadequate with the onset of inflation and rapidly rising energy prices. This book describes the most effective and accurate methods for forecasting of energy services appropriate for the parameters which can be expected to prevail in the 90s and beyond. The techniques which are described reflect the knowledge that the composite needs of utility customers can no longer be adequately represented by forecasts of peak demand and total energy use. Written specifically to meet the needs of utility managers, analysts, and planners, this authoritative presentation covers every aspect of state-of-the-art forecasting methods, addressing data acquisition and database construction, forecasting to innovative rates, load shape and forecasting, forecasting the impact of DSM strategies, and assessment of software systems available.

Gellings, C.W. (ed.)

1992-01-01

371

Renewable energy and utility regulation.  

National Technical Information Service (NTIS)

This report summarizes the results of a joint project on renewable energy of the National Association of Regulatory Utility Commissioners (NARUC) and the US DOE. NARUC'S Task Force on Renewable Energy conducted a review of the current state of renewable e...

1991-01-01

372

Injecting utility into anonymized datasets  

Microsoft Academic Search

Limiting disclosure in data publishing requires a careful balance between privacy and utility. Information about individuals must not be revealed, but a dataset should still be useful for studying the characteristics of a population. Privacy requirements such as k-anonymity and '-diversity are designed to thwart attacks that at- tempt to identify individuals in the data and to discover their sensi-

Daniel Kifer; Johannes Gehrke

2006-01-01

373

Space Station Freedom Utilization Conference  

NASA Technical Reports Server (NTRS)

The topics addressed in Space Station Freedom Utilization Conference are: (1) space station freedom overview and research capabilities; (2) space station freedom research plans and opportunities; (3) life sciences research on space station freedom; (4) technology research on space station freedom; (5) microgravity research and biotechnology on space station freedom; and (6) closing plenary.

1992-01-01

374

Western utilities opt for filters  

Microsoft Academic Search

Experiences at two western utilities with fabric filters and electrostatic precipitators are summarized. Southwestern Public Service Company installed electrostatic precipitators in its first Harrington unit, but in the 350-MW Harrington unit 2, a filter system is being installed. The filter system purchased for Harrington unit 2 has 28 compartments, of which 25 are needed for full-load operation. Each compartment has

Smock

1978-01-01

375

Limits to Wind Power Utilization.  

ERIC Educational Resources Information Center

Discusses noneconomic factors limiting the total power that can be extracted from the wind. These factors are examined with a macroscopic approach. Some general conclusions are also reached regarding the sites that would have to be utilized and the usable wind energy potentials. (HM)

Gustavson, M. R.

1979-01-01

376

Utility Maximization: Framework and Applications  

Microsoft Academic Search

Network utility maximization (NUM) problem formulations provide an important approach to conduct network resource allocation and to view layering as optimization decomposition. In the existing literature, distributed implementations are typically achieved by means of the so-called dual decomposition technique. However, the span of decomposition possibilities includes many other elements that thus far have not been fully exploited, such as the

Daniel P. Palomar; Mung Chiang

377

TWRS LDUA utilization study report  

SciTech Connect

Tank Waste Remediation Systems functional requirements were reviewed. The Light Duty Utility Arm capabilities were considered as a means to support completion of these functional requirements. The recommendation is made to continue to develop the LDUA, integrating TWRS functional needs into the design to better support completion of TWRS mission needs.

Rieck, R.H.

1994-09-01

378

Evaluating the Research Utilization Specialist  

ERIC Educational Resources Information Center

From June 1972 through June 1975, the authors conducted an evaluation of the National Research Utilization Specialists (RUS) Demonstration Program. This five-year program installed an RUS in nine state vocational rehabilitation agencies to test the value of this innovative job function for getting new knowledge put to practical use. (Author)

Glaser, Edward M.; Backer, Thomas E.

1975-01-01

379

Solar thermal utilization in China  

Microsoft Academic Search

With the rapid development of the Chinese economy, energy consumption has increased considerably, and this has increased pressure on energy production. On the other hand, this pressure has greatly assisted in the development of the renewable energy in the past two decades. This paper reports the latest developments in the solar thermal utilization in China. A great deal of successful

Chaofeng Xiao; Huilong Luo; Runsheng Tang; Hao Zhong

2004-01-01

380

Annual Electric Generator Report - Utility  

NSDL National Science Digital Library

This recently updated database from the Energy Information Administration contains the information reported on the Annual Electric Generator Report - Utility form, or Form EIA-860A. The database holds information from 1992 to January 2000 and includes the fields capacity, energy source, and initial year of operation.

381

Module Utilization Committee. Final report  

SciTech Connect

Photovoltaic collector modules were declared surplus to the needs of the US Department of Energy. The Module Utilization Committee was formed to make appropriate disposition of the surplus modules. The final report of that committee accounts for that disposition. The membership and activities of the committee are set forth and the results of its activities are reported.

None

1984-03-01

382

Vibration analysis utilizing Mossbauer effect  

NASA Technical Reports Server (NTRS)

Measuring instrument analyzes mechanical vibrations in transducers at amplitudes in the range of a few to 100 angstroms. This instrument utilizes the Mossbauer effect, the phenomenon of the recoil-free emission and resonant absorption of nuclear gamma rays in solids.

Roughton, N. A.

1967-01-01

383

Wind energy utilization: A bibliography  

NASA Technical Reports Server (NTRS)

Bibliography cites documents published to and including 1974 with abstracts and references, and is indexed by topic, author, organization, title, and keywords. Topics include: Wind Energy Potential and Economic Feasibility, Utilization, Wind Power Plants and Generators, Wind Machines, Wind Data and Properties, Energy Storage, and related topics.

1975-01-01

384

Program Improvement Through Knowledge Utilization.  

National Technical Information Service (NTIS)

This is a report on the last three years of operation of the Research Utilization Laboratory (RUL) of the Chicago Jewish Vocational Service. The emphasis during that period was on helping facilities and VR agencies deal with specified problems and improve...

A. Soloff P. Cheeks G. Burger R. Reeder

1981-01-01

385

Support for 5-HT2C receptor functional selectivity in vivo utilizing structurally diverse, selective 5-HT2C receptor ligands and the 2,5-dimethoxy-4-iodoamphetamine elicited head-twitch response model  

PubMed Central

There are seemingly conflicting data in the literature regarding the role of serotonin (5-HT) 5-HT2C receptors in the mouse head-twitch response (HTR) elicited by the hallucinogenic 5-HT2A/2B/2C receptor agonist 2,5-dimethoxy-4-iodoamphetamine (DOI). Namely, both 5-HT2C receptor agonists and antagonists, regarding 5-HT2C receptor-mediated Gq-phospholipase C (PLC) signaling, reportedly attenuate the HTR response. The present experiments tested the hypothesis that both classes of 5-HT2C receptor compounds could attenuate the DOI-elicited-HTR in a single strain of mice, C57Bl/6J. The expected results were considered in accordance with ligand functional selectivity. Commercially-available 5-HT2C agonists (CP 809101, Ro 60-0175, WAY 161503, mCPP, and 1-methylpsilocin), novel 4-phenyl-2-N,N-dimethyl-aminotetralin (PAT)-type 5-HT2C agonists (with 5-HT2A/2B antagonist activity), and antagonists selective for 5-HT2A (M100907), 5-HT2C (SB-242084), and 5-HT2B/2C (SB-206553) receptors attenuated the DOI-elicited-HTR. In contrast, there were differential effects on locomotion across classes of compounds. The 5-HT2C agonists and M100907 decreased locomotion, SB-242084 increased locomotion, SB-206553 resulted in dose-dependent biphasic effects on locomotion, and the PATs did not alter locomotion. In vitro molecular pharmacology studies showed that 5-HT2C agonists potent for attenuating the DOI-elicited-HTR also reduced the efficacy of DOI to activate mouse 5-HT2C receptor-mediated PLC signaling in HEK cells. Although there were differences in affinities of a few compounds at mouse compared to human 5-HT2A or 5-HT2C receptors, all compounds tested retained their selectivity for either receptor, regardless of receptor species. Results indicate that 5-HT2C receptor agonists and antagonists attenuate the DOI-elicited-HTR in C57Bl/6J mice, and suggest that structurally diverse 5-HT2C ligands result in different 5-HT2C receptor signaling outcomes compared to DOI.

Canal, Clinton E.; Booth, Raymond G.; Morgan, Drake

2013-01-01

386

High efficient organic ultraviolet photovoltaic devices based on gallium complex  

NASA Astrophysics Data System (ADS)

High efficient organic ultraviolet (UV) photovoltaic devices comprising 4,4',4?-tri-(2-methylphenyl phenylamino) triphenylamine (m-MTDATA) and tris-(8-hydroxyquinoline) gallium (Gaq 3) as the electron donor and acceptor, respectively, are demonstrated. The m-MTDATA/Gaq 3 bilayer device shows a short-circuit current density of 59.3 ?A/cm 2, a open-circuit voltage of 1.85 V, a fill factor of 0.41, and a power conversion efficiency of 3.74% under illumination of a 1.2 mW/cm 2 365 nm UV light. And this power conversion efficiency is superior than that of the device based on tris-(8-hydroxyquinoline) aluminum with the same device structure, which is attributed to the high electron mobility of Gaq 3 and the low exciton loss via radiation decay and hence more exciton dissociation in m-MTDATA/Gaq 3 device.

Su, Zisheng; Chu, Bei; Li, Wenlian

2010-05-01

387

Uses and Applications of Climate Forecasts for Power Utilities.  

NASA Astrophysics Data System (ADS)

The uses and potential applications of climate forecasts for electric and gas utilities were assessed 1) to discern needs for improving climate forecasts and guiding future research, and 2) to assist utilities in making wise use of forecasts. In-depth structured interviews were conducted with 56 decision makers in six utilities to assess existing and potential uses of climate forecasts. Only 3 of the 56 use forecasts. Eighty percent of those sampled envisioned applications of climate forecasts, given certain changes and additional information. Primary applications exist in power trading, load forecasting, fuel acquisition, and systems planning, with slight differences in interests between utilities. Utility staff understand probability-based forecasts but desire climatological information related to forecasted outcomes, including analogs similar to the forecasts, and explanations of the forecasts. Desired lead times vary from a week to three months, along with forecasts of up to four seasons ahead. The new NOAA forecasts initiated in 1995 provide the lead times and longer-term forecasts desired. Major hindrances to use of forecasts are hard-to-understand formats, lack of corporate acceptance, and lack of access to expertise. Recent changes in government regulations altered the utility industry, leading to a more competitive world wherein information about future weather conditions assumes much more value. Outreach efforts by government forecast agencies appear valuable to help achieve the appropriate and enhanced use of climate forecasts by the utility industry. An opportunity for service exists also for the private weather sector.

Changnon, Stanley A.; Changnon, Joyce M.; Changnon, David

1995-05-01

388

Power Sales to Electric Utilities  

SciTech Connect

The Public Utilities Regulatory Policies Act (PURPA) of 1979 requires that electrical utilities interconnect with qualifying facilities and purchase electricity at a rate based upon their full avoided costs (i.e., costs of providing both capacity and energy). Qualifying facilities (QF) include solar or geothermal electric units, hydropower, municipal solid waste or biomass-fired power plants, and cogeneration projects that satisfy maximum size, fuel use, ownership, location, and/or efficiency criteria. In Washington State, neither standard power purchase prices based upon a proxy ''avoided plant'', standard contracts, or a standard offer process have been used. Instead, a variety of power purchase contracts have been negotiated by developers of qualifying facilities with investor-owned utilities, public utility districts, and municipally-owned and operated utilities. With a hydro-based system, benefits associated with resource acquisition are determined in large part by how compatible the resource is with a utility's existing generation mix. Power purchase rates are negotiated and vary according to firm energy production, guarantees, ability to schedule maintenance or downtime, rights of refusal, power plant purchase options, project start date and length of contract; front-loading or levelization provisions; and the ability of the project to provide ''demonstrated'' capacity. Legislation was also enacted which allows PURPA to work effectively. Initial laws established ownership rights and provided irrigation districts, PUDs, and municipalities with expanded enabling powers. Financial processes were streamlined and, in some cases, simplified. Finally, laws were passed which are designed to ensure that development proceeds in an environmentally acceptable manner. In retrospect, PURPA has worked well within Washington. In the state of Washington, 20 small-scale hydroelectric projects with a combined generating capacity of 77 MW, 3 solid waste-to-energy facilities with 55 MW of electrical output, 4 cogeneration projects with 34.5 MW of generating capability, and 4 wastewater treatment facility digester gas-to-energy projects with 5 MW of electrical production have come on-line (or are in the final stages of construction) since the passage of PURPA. These numbers represent only a small portion of Washington's untapped and underutilized cogeneration and renewable resource generating potentials. [DJE-2005

None

1989-02-01

389

Japanese plan for SSF utilization  

NASA Technical Reports Server (NTRS)

The Japanese Experiment Module (JEM) program has made significant progress. The JEM preliminary design review was completed in July 1992; construction of JEM operation facilities has begun; and the micro-G airplane, drop shaft, and micro-G experiment rocket are all operational. The national policy for JEM utilization was also established. The Space Experiment Laboratory (SEL) opened in June '92 and will function as a user support center. Eight JEM multiuser facilities are in phase B, and scientific requirements are being defined for 17 candidate multiuser facilities. The National Joint Research Program is about to start. Precursor missions and early Space Station utilization activities are being defined. This paper summarizes the program in outline and graphic form.

Mizuno, Toshio

1992-01-01

390

Rig activity strengthening, utilization high  

SciTech Connect

Strong, stable gas prices have increased demand for offshore rigs worldwide. Several regions have been 100% utilization rates for both jack ups and semisubmersibles. Onshore markets have also improved because of increased gas drilling, but in the US the number of contractors continues to dwindle. The paper gives data on the worldwide demand for jackups and semisubmersibles, US drilling rigs, directional and horizontal drilling activity, rig replacement costs, and new construction.

Rappold, K.

1996-09-23

391

Electric utility system master plan  

SciTech Connect

This publication contains the electric utility system plan and guidelines for providing adequate electric power to the various facilities of Lawrence Livermore National Laboratory in support of the mission of the Laboratory. The topics of the publication include general information on the current systems and their operation, a planning analysis for current and future growth in energy demand, proposed improvements and expansions required to meet long range site development and the site`s five-year plan.

Erickson, O.M.

1992-10-01

392

Electric utility systems and practices  

Microsoft Academic Search

This book is a text for a college-level course or an in-house seminar for power system engineers, it also provides an in-depth survey of the electric utility system. It achieves its objectives of providing an overview of the technical challenges and opportunities in power system engineering by presenting a description of each power system component and how it integrates into

Rustebakke

1983-01-01

393

Optimization approach to electric utility corporate models  

SciTech Connect

This dissertation is a nonlinear programming approach to electric utility corporate models. The constraints of the model are of two types - plant sector (P) and financial (F). The model is driven via the P constraints by demand for electrical energy supplied as a load duration curve. The management decision is to configure new and existing plant so as to meet energy and power requirements for each period of a ten year planning horizon. There is a variable cost of operating the system and a capital cost for new plant. These costs as well as depreciation expenses link with the F constraints. These include equations that set the price of electricity using the cost-of-service method, limits on the interest coverage ratio on debt and bounds on the capital structure. The regulators' decision is endogenized by setting the allowed return on equity as a proportion of the market cost of equity capital. The model calculates the optimal issue of new securities, earned return on equity, market to book ratios of common stock, and optimal dividend payments. Two objective functions are examined - maximization of the total discounted consumers' and producers' surplus. The resulting nonlinear program is solved for parameter values typical of the investor-owned electric utility industry. The model provides insights into the effect of alternative regulatory policies on optimal investment and financing strategies for the firm. It is a useful supplement to the simulation results of the standard utility corporate model. The model, as formulated, is one of the largest problems solved by the nonlinear programming code GRG2, and is also a test of its capabilities.

Bose, R.

1982-01-01

394

Research of the model on recycling utilization of oil sludge  

Microsoft Academic Search

The research object of our study is oil sludge produced in petrochemical wastewater treatment. A technical option is proposed in conditioning and dewatering of oil sludge, recycling of gas condensate and malysite so as to minimize the oil containing sludge, fully utilize resources and to protect environment. Results show that the structure of oil sludge is improved and the dewatering

Bo Zhou; Nairui Liu

2012-01-01

395

Nanofabrication of polymer surfaces utilizing colloidal lithography and ion etching  

Microsoft Academic Search

In this paper, we utilize colloidal lithography based on electrostatic self-assembly of polystyrene colloidal particles onto a polymer surface as a nanoscale mask. The pattern is then transferred to the surface by ion beam etching. Each particle acts as an individual mask, resulting in an array of identical structure. Ion beam exposure etches away the unmasked surface between the particles,

H. Agheli; D. S. Sutherland

2006-01-01

396

Recent progress in techniques utilized for particle accelerator  

NASA Astrophysics Data System (ADS)

Particle accelerators are widely used in scientific research and industry. Recently, techniques utilized for accelerator are developed rapidly in China. We briefly review the recent progress in this field and primarily focus on superconducting RF, innovative structures for particle production and acceleration and beam diagnosis. Several advanced compact user facilities are also introduced.

Liu, KeXin

2012-12-01

397

Inventory of utility-sponsored indoor air quality research  

Microsoft Academic Search

Indoor air quality is being investigated in several studies sponsored by the Electric Power Research Institute (EPRI) and various electric utility companies in the US. A survey, sponsored by EPRI, identified 38 recent and on-going studies. Five upcoming projects were also identified. The projects range in scope from research studies in a few structures to air quality measurements in thousands

Nagda

1990-01-01

398

Kaa: an autonomous serpentine robot utilizes behavior control  

Microsoft Academic Search

This paper describes the development of an autonomous serpentine robot. This robot is a 12 degree of freedom, untethered, hyper-redundant planar robot, named Kaa. Experiments were conducted in its application to mobility tasks that would be useful in locomotion among parallel pipe structures similar to those found in industrial plants. Kaa utilizes a behavior control system. Unlike classical approaches, that

Rajiv S. Desai; Charles J. Rosenberg; Joseph L. Jones

1995-01-01

399

Fully automated hot embossing processes utilizing high resolution working stamps  

Microsoft Academic Search

Nanoimprint lithography (NIL) is a fast replication technology for structures with sizes ranging from micrometer down to few nanometers range. This paper describes the technology for imprinting of polymer substrates as well as spin-on polymers by using soft working stamp materials. A fully automated hot embossing system, the EVG®750 was built to use this rapid replication processes. By utilizing soft

T. Glinsner; T. Veres; G. Kreindl; E. Roy; K. Morton; T. Wieser; C. Thanner; D. Treiblmayr; R. Miller; P. Lindner

2010-01-01

400

Expected utility theory without the completeness axiom  

Microsoft Academic Search

We study the problem of obtaining an expected utility representation for a potentially incomplete preference relation over lotteries by means of a set of von Neumann–Morgenstern utility functions. It is shown that, when the prize space is a compact metric space, a preference relation admits such a multi-utility representation provided that it satisfies the standard axioms of expected utility theory.

Juan Dubra; Fabio Maccheroni; Efe A. Ok

2004-01-01

401

Utility-Optimal Random-Access Control  

Microsoft Academic Search

This paper designs medium access control (MAC) protocols for wireless networks through the network utility maximization (NUM) framework. A network-wide utility max- imization problem is formulated, using a collision\\/persistence- probabilistic model and aligning selfish utility with total social welfare. By adjusting the parameters in the utility objective functions of the NUM problem, we can also control the tradeoff between efficiency

Jang-won Lee; Mung Chiang; A. Robert Calderbank

2007-01-01

402

Commercial opportunities utilizing the International Space Station  

NASA Astrophysics Data System (ADS)

The International Space Station (ISS) has the unique capability of providing a low-g environment for both short- and long-duration experimentation. This environment can provide a unique and competitive research capability to industry; but until recently, utilization of this environment by the private sector has been limited if not totally unavailable. NASA has recently expressed an interest in the commercial development of space and this is now an integral part of the Agency's enabling legislation through the Space Act. NASA's objective is to foster the use of the space environment for the development of commercial products and processes. Through alliances and agreements with several commercial companies and universities, SPACEHAB, Inc., has built a comprehensive package of services designed to provide low-cost reliable access to space for experimenters. These services provide opportunities to support engineering test beds for materials exposure analysis, to mitigate structural failures as observed on the Hubble Space Telescope; materials processing, remote sensing; space environment definition; and electronic experiments. The intent of this paper is to identify commercial opportunities for utilizing the International Space Station and provide examples of several facilities currently being designed and manufactured by commercial companies with the purpose of providing access to the space environment for commercial users.

Kearney, Michael E.; Mongan, Phil; Overmyer, Carolyn M.; Jackson, Kenneth

1998-01-01

403

Utilization of health care databases for pharmacoepidemiology.  

PubMed

Pharmacoepidemiology is the study of the utilization and effects of drugs in clinical and population settings, and the outcomes of drug therapy. The growing trend of recording computerized data that will increasingly be automated into health care delivery is making the use of large datasets more and more common in pharmacoepidemiologic research. Most retrospective databases offer large populations and longer observation periods with real-world practice and can answer a variety of research questions quickly and cost-effectively. Observational studies, specifically using large databases, can complement findings from randomized clinical trials (RCTs) by assessing treatment effectiveness in patients encountered in daily clinical practice, although they are more exposed to bias and certainly are lower on the hierarchy of evidence than RCTs. Furthermore, careful defining of the research question with appropriate design and application of advanced statistical techniques, e.g., propensity-score analysis or marginal structural models, can yield findings with validity and improve causal inference of treatment effects. Some existing guidelines for comparative effectiveness help decision makers to evaluate the quality of observational studies comparing the effectiveness of various medical products and services. Thus, the trend for utilization of databases for pharmacoepidemiology will continue to grow in coming years. PMID:21808989

Takahashi, Yasuo; Nishida, Yayoi; Asai, Satoshi

2012-02-01

404

Integrating photovoltaics into utility distribution systems  

SciTech Connect

Electric utility distribution system impacts associated with the integration of distributed photovoltaic (PV) energy sources vary from site to site and utility to utility. The objective of this paper is to examine several utility- and site-specific conditions which may affect economic viability of distributed PV applications to utility systems. Assessment methodology compatible with technical and economic assessment techniques employed by utility engineers and planners is employed to determine PV benefits for seven different utility systems. The seven case studies are performed using utility system characteristics and assumptions obtained from appropriate utility personnel. The resulting site-specific distributed PV benefits increase nonsite-specific generation system benefits available to central station PV plants as much as 46%, for one utility located in the Southwest.

Zaininger, H.W. [Zaininger Engineering Co., Inc., San Jose, CA (United States); Barnes, P.R. [Oak Ridge National Lab., TN (United States)

1995-03-01

405

Other Fabric Structures  

NASA Technical Reports Server (NTRS)

Architects, engineers and building owners are turning increasingly to fabric structures because of their aesthetic appeal, relatively low initial cost, low maintenance outlays, energy efficiency and good space utilization. Several examples are shown.

1982-01-01

406

Improving electric power utility efficiency: Issues and recommendations. World Bank technical paper  

SciTech Connect

The volume presents the issues and recommendations that emerged from the Electric Power Utility Efficiency Improvement Study conducted by the World Bank and nine other internatinal technical and financial assistance organizations during 1989-91. The present volume extracts from the main study a set of efficiency guidelines for power utility planners and policymakers emphasizing the objectives of developing the power sector (including appropriate demand-side management) while sustaining the financial/commercial viability of the utilities; rationalizing the organizational and fiscal interactions between utilities and governments; enhancing the utilities' institutional capacity for governance and staff management; structuring utility organizations for operational efficiency; and coordinating utility activities with financing agencies' policies and procedures. A checklist, presented as an annex, provides point-by-point review of quantitative and qualitative factors that can be used to rate the performance of a utility. Quantitative measures are accompanied by target values where appropriate. (Copyright (c) 1994 The International Bank for Reconstruction and Development).

Menke, C.; Fazzari, P.G.

1994-01-01

407

An Exploration of the Utility of a Knowledge Utilization Framework to Study the Gap between Reading Disabilities Research and Practice  

ERIC Educational Resources Information Center

This pre-pilot study explored the usefulness of a knowledge utilization framework comprised of Knott and Wildavsky's (1980) seven stages of knowledge use and Stone's (2002) three routes to knowledge use to investigate the gap between reading disabilities research and teachers' self-reported use of that research. Semi-structured interviews of ten…

Davidson, Katherine; Nowicki, Elizabeth

2012-01-01

408

Preparation of highly dispersed Pt-SnO x nanoparticles supported on multi-walled carbon nanotubes for methanol oxidation  

NASA Astrophysics Data System (ADS)

To maximize the utilization of catalysts and thereby reduce the high price, a new strategy was developed to prepare highly dispersed Pt-SnO x nanoparticles supported on 8-Hydroxyquinoline (HQ) functionalized multi-walled carbon nanotubes (MWCNTs). HQ functionalized MWCNTs (HQ-MWCNTs) provide an ideal support for improving the utilization of platinum-based catalysts, and the introduction of SnO x to the catalyst prevents the CO poisoning effectively. The as-prepared catalysts are characterized by Transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. It is found that the HQ functionalization process preserves the integrity and electronic structure of MWCNTs, and the resulting Pt-SnO x particles are well dispersed on the HQ-MWCNTs with an average diameter of ca. 2.2 nm. Based on the electrochemical properties characterized by cyclic voltammetry and chronoamperometry, the Pt-SnO x/HQ-MWCNTs catalyst displays better electrocatalytic activity and stability for the methanol oxidation. It is worth mentioning that the forward peak current density of Pt-SnO x/HQ-MWCNTs catalyst is ca. 1.9 times of that of JM commercial 20% Pt/C catalyst, which makes it the preferable catalyst for direct methanol fuel cells.

Hu, Chuangang; Cao, Yanxia; Yang, Lin; Bai, Zhengyu; Guo, Yuming; Wang, Kui; Xu, Pengle; zhou, Jianguo

2011-07-01

409

A Novel Biomedical Device Utilizing Light Emitting Nano-Structures  

NASA Technical Reports Server (NTRS)

This paper will discuss the development of a novel biomedical detection device that will be used to detect microorganisms with the use of infrared fluorochrome polymers attached to antibodies in fluids such as water. The fluorochrome polymers emit light in the near inferred region (NIR), approximately 805 nm, when excited by an NIR laser at 778 nm. The device could remarkably change the way laboratory testing is done today. The testing process is usually performed on a time scale of days while our device will be able to detect microorganisms in minutes. This type of time efficient analysis is ideal for use aboard the International Space Station and the Space Shuttle (ISS/SS) and has many useful commercial applications, for instance at a water treatment plant and food processing plants. With more research and experimentation the testing might also one day be used to detect bacteria and viruses in complex fluids such as blood, which would revolutionize blood analysis as it is performed today. My contribution to the project has been to develop a process which will allow an antibody/fluorescent dye pair to be conjugated to a specific bacteria or virus and than to to be separated from a sample body of water for detection. The antibody being used in this experiment is anti beta galactosidase and its complement enzyme is beta galactosidase, a non harmful derivative of E. Coli. The anti beta galactosidase has been conjugated to the fluorochrome polymer, IRDye800, which emits at approximately 806 nm. The dye when excited by the NIR laser emits a signal which is detected by a spectrometer and then is read by state of the art computer software. The state-of-the-art process includes incubating the anti beta galactosidase and beta galactosidase in a phosphate buffer solution in a test tube, allowing the antibody to bind to specific sites on the enzyme. After the antibody is bound to the enzyme, it is centrifuged in specific filters that will allow free antibody to wash away and leave the antibody-enzyme complexes on top in solution for testing and analysis. This solution is pipetted into a cuvette, a special plastic test tube, which will then be excited by the laser. The signal read will tell US that an antibody is present and since it is bound to the enzyme, that the bacteria is also present.

Varaljay, Vanessa A.

2004-01-01

410

Cutting of Structural Materials Utilizing High Powered CO2 Laser.  

National Technical Information Service (NTIS)

A search for a better method of cutting thick steel sections, including those with coating materials attached, centered around a high powered CO2 laser. The CO2 laser had successfully demonstrated its ability to weld heavy sections of steel with 100% pene...

N. Eutizzi, P. E. Denney

1992-01-01

411

Botulinum and tetanus neurotoxins: structure, function and therapeutic utility  

Microsoft Academic Search

The toxic products of the anaerobic bacteria Clostridium botulinum, Clostridium butyricum,Clostridium barati and Clostridium tetani are the causative agents of botulism and tetanus. The ability of botulinum neurotoxins to disrupt neurotransmission, often for prolonged periods, has been exploited for use in several medical applications and the toxins, as licensed pharmaceutical products, now represent the therapeutics of choice for the treatment

Kathryn Turton; John A Chaddock; K. Ravi Acharya

2002-01-01

412

Utilizing Problem Structure in Optimization of Radiation Therapy.  

National Technical Information Service (NTIS)

In this thesis, optimization approaches for intensity-modulated radiation therapy are developed and evaluated with focus on numerical efficiency and treatment delivery aspects. The first two papers deal with strategies for solving fluence map optimization...

F. Carlsson

2008-01-01

413

Microbial Utilization and Selectivity of Pectin Fractions with Various Structures ?  

PubMed Central

To evaluate the fermentation properties of oligosaccharides derived from pectins and their parent polysaccharides, a 5-ml-working-volume, pH- and temperature-controlled fermentor was tested. Six pectic oligosaccharides representing specific substructures found within pectins were prepared. These consisted of oligogalacturonides (average degrees of polymerization [DP] of 5 and 9), methylated oligogalacturonides (average DP of 5), oligorhamnogalacturonides (average DP of 10 as a disaccharide unit of galacturonic acid and rhamnose), oligogalactosides (average DP of 5), and oligoarabinosides (average DP of 6). The influence of these carbohydrates on the human fecal microbiota was evaluated. Use of neutral sugar fractions resulted in an increase in Bifidobacterium populations and gave higher organic acid yields. The Bacteroides-Prevotella group significantly increased on all oligosaccharides except oligogalacturonides with an average DP of 5. The most selective substrates for bifidobacteria were arabinan, galactan, oligoarabinosides, and oligogalactosides.

Onumpai, Chatchaya; Kolida, Sofia; Bonnin, Estelle; Rastall, Robert A.

2011-01-01

414

Orbiter utilization as an ACRV  

NASA Technical Reports Server (NTRS)

Assuming that a Shuttle Orbiter could be qualified to serve long duration missions attached to Space Station Freedom in the capacity as an Assured Crew Return Vehicle (ACRV), a study was conducted to identify and examine candidate attach locations. Baseline, modified hardware, and new hardware design configurations were considered. Dual simultaneous Orbiter docking accommodation were required. Resulting flight characteristics analyzed included torque equilibrium attitude (TEA), microgravity environment, attitude controllability, and reboost fuel requirements. The baseline Station could not accommodate two Orbiters. Modified hardware configurations analyzed had large TEA's. The utilization of an oblique docking mechanism best accommodated an Orbiter as an ACRV.

Cruz, Jonathan N.; Heck, Michael L.; Kumar, Renjith R.; Mazanek, Daniel D.; Troutman, Patrick A.

1990-01-01

415

Integrated utility system design concept  

NASA Technical Reports Server (NTRS)

Conceptual design studies are performed to investigate the feasibility of the MIUS concept as an alternate method of providing utility services to communities and/or community facilities having advantages over current practices. Procured and operated is a large scale testbed of the MIUS concept in order to evaluate and test those integrated system technical details that do not lend themselves to analysis. These include materials compatibility, process instrumentation and control, predictability of water and air effluents, techniques of heat recovery, method of thermal distribution, etc.

Hays, E. L.

1974-01-01

416

Solar energy research and utilization  

NASA Technical Reports Server (NTRS)

The role of solar energy is visualized in the heating and cooling of buildings, in the production of renewable gaseous, liquid and solid fuels, and in the production of electric power over the next 45 years. Potential impacts of solar energy on various energy markets, and estimated costs of such solar energy systems are discussed. Some typical solar energy utilization processes are described in detail. It is expected that at least 20% of the U.S. total energy requirements by 2020 will be delivered from solar energy.

Cherry, W. R.

1974-01-01

417

Orbiter electrical equipment utilization baseline  

NASA Technical Reports Server (NTRS)

The baseline for utilization of Orbiter electrical equipment in both electrical and Environmental Control and Life Support System (ECLSS) thermal analyses is established. It is a composite catalog of Space Shuttle equipment, as defined in the Shuttle Operational Data Book. The major functions and expected usage of each component type are described. Functional descriptions are designed to provide a fundamental understanding of the Orbiter electrical equipment, to insure correlation of equipment usage within nominal analyses, and to aid analysts in the formulation of off-nominal, contingency analyses.

1980-01-01

418

Physicians’ utilization of health care  

Microsoft Academic Search

OBJECTIVE: To describe how physicians attend to their own health care needs.\\u000a \\u000a \\u000a SETTING: Rhode Island.\\u000a \\u000a \\u000a \\u000a \\u000a PARTICIPANTS: A random sample of Blue Cross\\/Blue Shield providers. The 306 respondents (67% of 458) primarily (92%) had MD or DO degrees.\\u000a The nonphysician providers were chiropractors, dentists, optometrists, and podiatrists.\\u000a \\u000a \\u000a \\u000a \\u000a DESIGN: A mailed survey provided data describing the respondents’ medical conditions and utilization of

Tom J. Wachtel; Victoria L. Wilcox; Anne W. Moulton; Dominick Tammaro; Michael D. Stein

1995-01-01

419

Astropysics: Astrophysics utilities for python  

NASA Astrophysics Data System (ADS)

Astropysics is a library containing a variety of utilities and algorithms for reducing, analyzing, and visualizing astronomical data. Best of all, it encourages the user to leverage the existing capabilities of Python to make this quick, easy, and as painless as cutting-edge science can even actually be. There do exist other Python packages with some of the capabilities of this project, but the goal of this project is to integrate all these tools together and make them interact in the most straightforward ways possible.

Tollerud, Erik

2012-07-01

420

Resource utilization during software development  

NASA Technical Reports Server (NTRS)

This paper discusses resource utilization over the life cycle of software development and discusses the role that the current 'waterfall' model plays in the actual software life cycle. Software production in the NASA environment was analyzed to measure these differences. The data from 13 different projects were collected by the Software Engineering Laboratory at NASA Goddard Space Flight Center and analyzed for similarities and differences. The results indicate that the waterfall model is not very realistic in practice, and that as technology introduces further perturbations to this model with concepts like executable specifications, rapid prototyping, and wide-spectrum languages, we need to modify our model of this process.

Zelkowitz, Marvin V.

1988-01-01

421

Identifying Chelators for Metalloprotein Inhibitors Using a Fragment-Based Approach  

PubMed Central

Fragment-based lead design (FBLD) has been used to identify new metal-binding groups for metalloenzyme inhibitors. When screened at 1 mM, a chelator fragment library (CFL-1.1) of 96 compounds produced hit rates ranging from 29–43% for five matrix metalloproteases (MMPs), 24% for anthrax lethal factor (LF), 49% for 5-lipoxygenase (5-LO), and 60% for tyrosinase (TY). The ligand efficiencies (LE) of the fragment hits are excellent, in the range of 0.4–0.8 kcal/mol. The MMP enzymes all generally elicit the same chelators as hits from CFL-1.1; however, the chelator fragments that inhibit structurally unrelated metalloenzymes (LF, 5-LO, TY) vary considerably. To develop more advanced hits, one hit from CFL-1.1, 8-hydroxyquinoline, was elaborated at four different positions around the ring system to generate new fragments. 8-Hydroxyquinoline fragments substituted at either the 5- or 7-positions gave potent hits against MMP-2, with IC50 values in the low micromolar range. The 8-hydroxyquinoline represents a promising, new chelator scaffold for the development of MMP inhibitors that was discovered by use of a metalloprotein-focused chelator fragment library.

Jacobsen, Jennifer A.; Fullagar, Jessica; Miller, Melissa T.; Cohen, Seth M.

2011-01-01

422

Utilizing inheritance in requirements engineering  

NASA Technical Reports Server (NTRS)

The scope of this paper is the utilization of inheritance for requirements specification, i.e., the tasks of analyzing and modeling the domain, as well as forming and defining requirements. Our approach and the tool supporting it are named RETH (Requirements Engineering Through Hypertext). Actually, RETH uses a combination of various technologies, including object-oriented approaches and artificial intelligence (in particular frames). We do not attempt to exclude or replace formal representations, but try to complement and provide means for gradually developing them. Among others, RETH has been applied in the CERN (Conseil Europeen pour la Rechereche Nucleaire) Cortex project. While it would be impossible to explain this project in detail here, it should be sufficient to know that it deals with a generic distributed control system. Since this project is not finished yet, it is difficult to state its size precisely. In order to give an idea, its final goal is to substitute the many existing similar control systems at CERN by this generic approach. Currently, RETH is also tested using real-world requirements for the Pastel Mission Planning System at ESOC in Darmstadt. First, we outline how hypertext is integrated into a frame system in our approach. Moreover, the usefulness of inheritance is demonstrated as performed by the tool RETH. We then summarize our experiences of utilizing inheritance in the Cortex project. Lastly, RETH will be related to existing work.

Kaindl, Hermann

1994-01-01

423

Ethanolamine utilization in Salmonella typhimurium.  

PubMed Central

Ethanolamine can serve as the sole source of carbon and nitrogen for Salmonella typhimurium if vitamin B12 is present to serve as a cofactor. The pathway for ethanolamine utilization has been investigated in order to understand its regulation and determine whether the pathway is important to the selective forces that have maintained the ability to synthesize B12 in S. typhimurium. We isolated mutants that are defective in ethanolamine utilization (eut mutants). These mutants defined a cluster of genes located between purC and cysA at 50 min on the Salmonella chromosome. A genetic map of the eut region was constructed. Included in the map are mutations which affect ethanolamine ammonia lyase, the first degradative enzyme, and mutations which affect the second enzyme in the pathway, acetaldehyde dehydrogenase. Transcriptional regulation of the eut genes was studied by using eut-lac operon fusions created by insertion of Mu d lac. Transcription is induced by the simultaneous presence of ethanolamine and B12 in the growth medium. The eut genes constitute a single unit of transcription. One class of mutations located at the promoter-distal end of the eut operon prevent induction of transcription.

Roof, D M; Roth, J R

1988-01-01

424

Nitrogen Utilization in Lemna1  

PubMed Central

The effects of ammonium application on nitrate utilization were studied in N-limited cultures of Lemna gibba L. G3. Addition of ammonium instantaneously inhibited net nitrate uptake by at least 60%, followed by a slight recovery. The inhibition was equally clear after near-complete inactivation of glutamine synthetase by application of l-methionine-d,l-sulfoximine. Experiments where 13N-labeled nitrate was used as an influx tracer revealed that ammonium specifically inhibited influx, but did not promote nitrate efflux. Nitrate accumulation was relatively more inhibited than nitrate reduction and net uptake. Nitrate reductase, extracted and assayed in vitro in the presence of the thiol proteinase inhibitor leupeptin, was unaffected by short-term treatment of the plants with either nitrate, ammonium, or ammonium nitrate. Nitrate reductase activity recovered in the absence of leupeptin was considerably lower; however, it was enhanced by all the nitrogen sources, with ammonium as the most potent. It is argued that the effect of ammonium on nitrate utilization in Lemna is due to inhibition of nitrate influx, and that the effect should be attributed to ammonium itself, not to a newly formed nitrogen derivative. The decreased nitrate flux caused a decrease in nitrate reduction, whereas the activity of nitrate reductase per se rather is stabilized by presence of ammonium.

Ingemarsson, Bjorn; Oscarson, Petter; af Ugglas, Magnus; Larsson, Carl-Magnus

1987-01-01

425

Trade-off decisions in distribution utility management  

NASA Astrophysics Data System (ADS)

As a result of the "unbundling" of traditional monopolistic electricity generation and transmission enterprises into a free-market economy, power distribution utilities are faced with very difficult decisions pertaining to electricity supply options and quality of service to the customers. The management of distribution utilities has become increasingly complex, versatile, and dynamic to the extent that conventional, non-automated management tools are almost useless and obsolete. This thesis presents a novel and unified approach to managing electricity supply options and quality of service to customers. The technique formulates the problem in terms of variables, parameters, and constraints. An advanced Mixed Integer Programming (MIP) optimization formulation is developed together with novel, logical, decision-making algorithms. These tools enable the utility management to optimize various cost components and assess their time-trend impacts, taking into account the intangible issues such as customer perception, customer expectation, social pressures, and public response to service deterioration. The above concepts are further generalized and a Logical Proportion Analysis (LPA) methodology and associated software have been developed. Solutions using numbers are replaced with solutions using words (character strings) which more closely emulate the human decision-making process and advance the art of decision-making in the power utility environment. Using practical distribution utility operation data and customer surveys, the developments outlined in this thesis are successfully applied to several important utility management problems. These involve the evaluation of alternative electricity supply options, the impact of rate structures on utility business, and the decision of whether to continue to purchase from a main grid or generate locally (partially or totally) by building Non-Utility Generation (NUG).

Slavickas, Rimas Anthony

426

ACOSS Fifteen (Active Control of Space Structures).  

National Technical Information Service (NTIS)

To study active structure control technology as applied to Large Space Structures (LSS). In particular, to develop analysis and design techniques for utilization of practicing control system engineers in their investigations of future Large Space Structur...

S. M. Seltzer E. H. Worley R. J. York

1982-01-01

427

SAGEWASP. Optimal Electric Utility Expansion  

SciTech Connect

SAGE-WASP is designed to find the optimal generation expansion policy for an electrical utility system. New units can be automatically selected from a user-supplied list of expansion candidates which can include hydroelectric and pumped storage projects. The existing system is modeled. The calculational procedure takes into account user restrictions to limit generation configurations to an area of economic interest. The optimization program reports whether the restrictions acted as a constraint on the solution. All expansion configurations considered are required to pass a user supplied reliability criterion. The discount rate and escalation rate are treated separately for each expansion candidate and for each fuel type. All expenditures are separated into local and foreign accounts, and a weighting factor can be applied to foreign expenditures.

Clark, P.D.II; Ullrich, C.J. [Lakeland Electric and Water, FL (United States)

1989-10-10

428

Serine utilization by Klebsiella aerogenes.  

PubMed Central

Klebsiella aerogenes was found to contain a specific L-serine dehydrase that was induced by threonine, glycine or leucine, but not by its substrate. Cellular concentrations were sensitive to carbon rather than nitrogen sources in the growth medium. A nonspecific isoleucine-sensitive L-threonine dehydrase supplemented the specific L-serine dehydrase activity. K. aerogenes also contains a leucine-inducible L-threonine dehydrogenase which probably initiated a threonine-utilization pathway in which the serine-specific dehydrate participated. Strains that were altered in their ability to metabolize serine differed in either L-serine dehydrase or L-threonine dehydrase activity. Thus, K. aerogenes growing on L-serine as a sole nitrogen source relies upon two enzymes that metabolize the amino acid as subsidiary functions.

Vining, L C; Magasanik, B

1981-01-01

429

Utility and energy cost containment  

SciTech Connect

One of the most lucrative areas for improving bottom line profitability is related to an organization`s costs for utilities and energy. Such things as gas, electric, water, and telephones are treasure chests of cost reduction opportunities. In the past, these items have been viewed as a fixed expense or basic mundane commodity. In recent years, these items have become a large portion of product cost and now must be examined on a continual basis. A formal income improvement program to capture and report on the savings is a requirement for remaining competitive in a global economy. This paper describes areas of potential inefficiency in terms of energy useage and resulting costs to industry.

Newhouse, R. [Tompkins Associates, Roswell, GA (United States)] [Tompkins Associates, Roswell, GA (United States)

1996-09-01

430

San Francisco Public Utilities Commission  

NSDL National Science Digital Library

The San Francisco Public Utilities Commission (PUC) digital collection is based at the San Francisco Public Library. It includes over 300 images, spanning 1887 to 1968, of significant events and projects such as the building of the Hetch Hetchy Railroad and O'Shaughnessey Dam, the construction of the Golden Gate International Exposition on Treasure Island, and so on. These fascinating historic industrial photographs document the pipelines, tunnels, reservoirs, dams, powerhouses, and pumping stations that the PUC has built and maintained in order "to provide water, sewerage and municipal services to the City and County of San Francisco." Visitors can click on the link provided here to view the images, or perform their own detailed search across the entire collection. The views of the Calaveras Dam are quite dramatic and there are many photos documenting the Golden Gate International Exposition as well.

2012-07-13

431

Ribose Utilization by Veillonella alcalescens  

PubMed Central

The utilization of ribose by Veillonella alcalescens has been further investigated. Nonfermentation of ribose is not a result of a phosphorylation lesion since ribose-phosphorylating activity was measured in cell extracts. Resting cells accumulated ribose-5-phosphate and nucleotides when 14C-ribose was provided; no other sugar phosphates were detectable. Resting cells that were shifted to growth conditions polymerized rather than degraded the accumulated ribose compounds. Cell extracts contained a fructose diphosphate phosphatase. Ribose-5-phosphate, glucose-6-phosphate, and fructose-6-phosphate were not hydrolyzed. It is postulated that the nonfermentation of ribose is not due to any metabolic lesions, but is a consequence of metabolic control at the fructose diphosphate level of glycolysis.

Kafkewitz, David; Delwiche, E. A.

1972-01-01

432

Physician Assistant Utilization in Seven Group Practices.  

National Technical Information Service (NTIS)

The objectives of this study on physician assistant utilization in seven multispecialty group practices were (1) to define and analyze common patterns of physician assistant utilization in group practices; (2) to explore the question of whether this new t...

P. O'Donoghue T. Gatch M. Culverwell

1977-01-01

433

Administration Utilization Field, AFSC 70XX.  

National Technical Information Service (NTIS)

This is a report of an occupational survey of the Administration utilization field completed by the Occupational Analysis Division, USAF Occupational Measurement Center. The Administration utilization field originated in 1954 as two AFSs; Administrative S...

1988-01-01

434

DEVELOPMENT OF THE ADVANCED UTILITY SIMULATION MODEL  

EPA Science Inventory

The paper discusses the development of the Advanced Utility Simulation Model (AUSM), developed for the National Acid Precipitation Assessment Program (NAPAP), to forecast air emissions of pollutants from electric utilities. USM integrates generating unit engineering detail with d...

435

Electric Utility Solar Energy Activities. 1976 Survey.  

National Technical Information Service (NTIS)

The report presents the results of a survey to determine the scope and extent of solar energy projects sponsored by electric utilities. Brief descriptions of the active operations along with information contacts are listed for each participating utility. ...

L. D. Cleary

1977-01-01

436

Utility Interconnection Issues for Wind Power Generation.  

National Technical Information Service (NTIS)

This document organizes the total range of utility related issues, reviews wind turbine control and dynamic characteristics, identifies the interaction of wind turbines to electric utility systems, and identifies areas for future research. The material is...

J. I. Herrera J. S. Lawler T. W. Reddoch R. L. Sullivan

1986-01-01

437

Railroad Electrification on Utility Systems. Final Report.  

National Technical Information Service (NTIS)

A nine-month project was undertaken on the subject of the impact of railroad electrification on utility systems. The objectives of this study were achieved by a review of the literature, discussions with railroads and electric utilities with electrificati...

J. J. Burke J. W. Feltes

1983-01-01

438

Program Improvement Through Knowledge Utilization: Executive Summary.  

National Technical Information Service (NTIS)

This report has been written with the following purposes: (1) To report the JVS Research Utilization Laboratory's conclusions about knowledge utilization in vocational rehabilitation. These conclusions are drawn from RUL's full 12 year history. They inclu...

A. Soloff P. Cheeks G. Burger R. Reeder

1981-01-01

439

Utility Energy Services Contracts: Lessons Learned  

SciTech Connect

This document describes best practices in the use of Utility Energy Services Contracts. The recommendations were generated by a group of innovative energy managers in many successful projects. The topics include project financing, competition between utility franchises, and water conservation.

Not Available

2001-08-01

440

Federal Utility Program Overview (Fact Sheet)  

SciTech Connect

Fact sheet overview of the U.S. Department of Energy (DOE) Federal Energy Management Program's (FEMP) Federal Utility Program, including common contracts and services available to Federal agencies through local serving utilities.

Not Available

2009-07-01

441

U.S. Refining Capacity Utilization  

EIA Publications

This article briefly reviews recent trends in domestic refining capacity utilization and examines in detail the differences in reported crude oil distillation capacities and utilization rates among different classes of refineries.

Tancred Lidderdale

1995-10-01

442

Integrating Community Utilities for Resource Conservation.  

National Technical Information Service (NTIS)

A Modular Integrated Utility System (MIUS) provides the utility services of electrical power, space heating and cooling, potable water heating, solid waste processing, sanitary sewage treatment, potable water treatment, and the site distribution, collecti...

J. R. Schaefgen

1976-01-01

443

Handbook of evaluation of utility DSM programs.  

National Technical Information Service (NTIS)

Program evaluation has become a central issue in the world of utility integrated resource planning. The DSM programs that utilities were operating to meet federal requirements or to improve customer relations are now becoming big business. DSM is being co...

E. Hirst J. Reed B. Bronfman G. Fitzpatrick E. Hicks

1991-01-01

444

Synthesis and Characterization of Silicon Complexes of Donar Ligands.  

National Technical Information Service (NTIS)

The synthesis of 8-(trimethylsiloxy)quinoline has been done by two methods: (A) By treatment of 8-hydroxyquinoline with trimethylchlorosilane in presence of triethylamine; (B) By treatment of 8-hydroxyquinoline with butyllithium at -20 C in ether. Lithium...

M. Javid

1992-01-01

445

Synthesis and Characterization of Some Mixed-Ligand Cyanonitrosyl {CrNO} Chelates of Chromium(I) with 8-Hydroxyquinolinesulphonamides  

Microsoft Academic Search

New mixed-ligand cyanonitrosyl {CrNO} chelates of chromium(I) of the type [cr (NO) (CN)2 (L-L) (H2O)] have been synthesized by the interaction of the potassium pentacyano-nitrosylchromate (I) monohydrate with 8-hydroxyquinolinesulpho-namides (L-L), viz., 8-hydroxyquinoline-4- (4? -tolyl)sulphonamide, 8-hydroxyquinoline-4- (phenyl) sulphonamide, 5-iodo-8-hydroxyquinoline-4-(4? -tolyl)sulphonamide, 5, 7-diiodo-8-hydroxyquinoline-4-(4? -tolyl)-sulphonamide, 5, 7-diiodo-8-hydroxyquinoline-4- (3? -ethoxyphenyl) -sulphonamide, 5, 7-diiodo-8-hydroxyquinoline-4- (3? -methoxyphenyl) -sulphonamide, 5, 7-dichloro-2-methyl-8-hydroxyquinoline-4-(3? -methoxy-phenyl)sulphonamide or 5, 7-dichloro-2-methyl-8-hydroxyquinoline-4-(3?-ethoxyphenyl)sulphonamide in aqueous

R. C. Maurya; D. D. Mishra

1991-01-01

446

Solar energy utilization by physical methods.  

PubMed

On the basis of the estimated contributions of these differing methods of the utilization of solar energy, their total energy delivery impact on the projected U.S. energy economy (9) can be evaluated (Fig. 5). Despite this late energy impact, the actual sales of solar energy utilization equipment will be significant at an early date. Potential sales in photovoltaic arrays alone could exceed $400 million by 1980, in order to meet the projected capacity buildup (10). Ultimately, the total energy utilization equipment industry should attain an annual sales volume of several tens of billion dollars in the United States, comparable to that of several other energy related industries. Varying amounts of technology development are required to assure the technical and economic feasibility of the different solar energy utilization methods. Several of these developments are far enough along that the paths can be analyzed from the present time to the time of demonstration of technical and economic feasibility, and from there to production and marketing readiness. After that point, a period of market introduction will follow, which will differ in duration according to the type of market addressed. It may be noted that the present rush to find relief from the current energy problem, or to be an early leader in entering a new market, can entail shortcuts in sound engineering practice, particularly in the areas of design for durability and easy maintenance, or of proper application engineering. The result can be loss of customer acceptance, as has been experienced in the past with various products, including solar water heaters. Since this could cause considerable delay in achieving the expected total energy impact, it will be important to spend adequate time at this stage for thorough development. Two other aspects are worth mentioning. The first is concerned with the economic impacts. Upon reflection on this point, one will observe that largescale solar energy utilization will not cause a greater impact than other new energy sources, based on the reasoning that a self-consistent set of conditions will have to be fulfilled in order to achieve such large-scale use. Without cost competitiveness, other energy resources would fill the requirements, or, if their resource and cost structure also would create severe problems, the economic forecasts simply cannot be fulfilled. We also should not think of a "solar-only" energy future. First, there is still enough coal to last for several hundred years. Second, there should be enough fissionable fuel available to operate breeder reactors for a similar time span, and geothermal energy could satisfy some requirements for a long time. And finally, there may be fusion. It would be unlikely that any one of the available options should play a really dominant role. Rather, we should expect to be using an energy mix, just as we do now, with each energy source supplying the requirements which it can satisfy in the most suitable way, and solar energy should play an important role in this long-range future. PMID:17792569

Wolf, M

1974-04-19

447

Utility competition with small business. Final report  

Microsoft Academic Search

The purpose of the study is to take a further, and broader, look at the competition issue between utilities and small businesses of energy-related utility programs. The contractor examined in greater depth the reasons for utility interest in diversifying into nonregulated, and competitive, energy-related fields; the elements of utility subsidization of these non-regulated activities; the potential remedies that small businesses

DAddario

1986-01-01

448

Utilizing Internet Technologies in Observatory Control Systems  

NASA Astrophysics Data System (ADS)

The 'Internet boom' of the past few years has spurred the development of a number of technologies to provide services such as secure communications, reliable messaging, information publishing and application distribution for commercial applications. Over the same period, a new generation of computer languages have also developed to provide object oriented design and development, improved reliability, and cross platform compatibility. Whilst the business models of the 'dot.com' era proved to be largely unviable, the technologies that they were based upon have survived and have matured to the point were they can now be utilized to build secure, robust and complete observatory control control systems. This paper will describe how Electro Optic Systems has utilized these technologies in the development of its third generation Robotic Observatory Control System (ROCS). ROCS provides an extremely flexible configuration capability within a control system structure to provide truly autonomous robotic observatory operation including observation scheduling. ROCS was built using Internet technologies such as Java, Java Messaging Service (JMS), Lightweight Directory Access Protocol (LDAP), Secure Sockets Layer (SSL), eXtendible Markup Language (XML), Hypertext Transport Protocol (HTTP) and Java WebStart. ROCS was designed to be capable of controlling all aspects of an observatory and be able to be reconfigured to handle changing equipment configurations or user requirements without the need for an expert computer programmer. ROCS consists of many small components, each designed to perform a specific task, with the configuration of the system specified using a simple meta language. The use of small components facilitates testing and makes it possible to prove that the system is correct.

Cording, Dean

2002-12-01

449

Insider Models with Finite Utility in Markets with Jumps  

SciTech Connect

In this article we consider, under a Levy process model for the stock price, the utility optimization problem for an insider agent whose additional information is the final price of the stock blurred with an additional independent noise which vanishes as the final time approaches. Our main interest is establishing conditions under which the utility of the insider is finite. Mathematically, the problem entails the study of a 'progressive' enlargement of filtration with respect to random measures. We study the jump structure of the process which leads to the conclusion that in most cases the utility of the insider is finite and his optimal portfolio is bounded. This can be explained financially by the high risks involved in models with jumps.

Kohatsu-Higa, Arturo, E-mail: arturokohatsu@gmail.com [Ritsumeikan University, Department of Mathematical Sciences (Japan); Yamazato, Makoto, E-mail: yamazato@math.u-ryukyu.ac.jp [University of the Ryukyus, Department of Mathematics, Faculty of Science (Japan)

2011-10-15

450

Wind turbine value analysis for electric utilities  

Microsoft Academic Search

A methodology for the analysis of the value of large-scale wind turbines to electric utilities, and its application to utility, socioeconomic and meteorological data in two case studies is described. The value analysis was carried out for the year of reference 1985 and included different levels of wind turbine penetration. Results of the value analysis are given. The utility planning

W. Dub

1982-01-01

451

Waiting Time versus Utility to Download Images  

Microsoft Academic Search

The utility of a contents delivery network depends on the waiting time. This paper deals with the priority control of contents delivery networks from the view- point of utility. First, a subjective evaluation exper- iment on image downloading is carried out to obtain the relationship between the waiting time and the util- ity. From the results, a function of the

Kazutomo NOMURA; Kyoko YAMORI; Eiji TAKAHASHI; Takumi MIYOSHI; Yoshiaki TANAKA

452

Proceedings: 1989 fuel oil utilization workshop  

Microsoft Academic Search

A workshop to review current problems relating to fuel oil utilization by electric utilities was held in Clearwater Beach, Florida on November 1--2, 1989. The 1989 Workshop was the sixth in a series dealing primarily or in part with the utilization of fuel oils. Previous workshops were held in 1983, 1985, 1986, and 1988. The fundamental objective of the 1989

C. F. Sanders; B. L. McDonald; M. N. Miller

1990-01-01

453

1986 fuel oil utilization workshop: Proceedings  

Microsoft Academic Search

A workshop to consider problems related to fuel oil utilization was held in Philadelphia, Pennsylvania, on October 7-9, 1986. The 77 participants included fuels, engineering, and operating representatives of 21 US utilities<