bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth of HfO2 by Liquid Injection MOCVD and ALD Using New Hafnium‐Cyclopentadienyl Precursors
Authors: O'Kane R. , Gaskell J. , Jones A. C. , Chalker P. R. , Black K. , Werner M. , Taechakumput P. , Taylor S. , Heys P. N. , Odedra R. 
Published: November 2007

AbstractThin films of HfO2 are deposited by liquid injection metal‐organic (MO) CVD and atomic layer deposition (ALD) using the new cyclopentadienyl precursors [(MeCp)2HfMe(OiPr)] and [(MeCp)2HfMe(mmp)] (mmp = OCMe2CH2OMe). Both precursors evaporate at moderate temperatures, making them very suitable for MOCVD and ALD applications. Thin films of HfO2 are deposited by MOCVD in the temperature range 400–650 °C, and by ALD in the temperature range 300–450 °C, using both [(MeCp)2HfMe(OiPr)] and [(MeCp)2HfMe(mmp)] . Analysis by X‐ray diffraction (XRD) shows that the films are deposited with an essentially amorphous microstructure, but subsequent annealing above 700 °C in dry air crystallizes the films into the α‐ or monoclinic phase. Auger electron spectroscopy (AES) shows that residual carbon (0–5 at.‐ %) is present in the oxide films and that the HfO2 films grown by MOCVD generally contain more carbon than those grown by ALD. The dielectric properties of the as‐deposited HfO2 films are evaluated using [Al/HfO2/SiO2/n‐Si] MOS capacitor structures with various HfO2 thicknesses ranging from 1.7 nm to 102 nm. The calculated permittivity (ϵox), assuming the presence of a 1 nm native SiO2 interlayer, is found to be ϵox ∼ 14 for a HfO2 film grown by ALD using [(MeCp)2HfMe(OiPr)], whilst for a film grown by ALD using [(MeCp)2HfMe(mmp)], ϵox is found to be ∼10. Equivalent oxide thicknesses of 2.5 and 0.78 nm are measured for HfO2 films deposited by ALD using [(MeCp)2HfMe(OiPr)] and [(MeCp)2HfMe(mmp)], respectively. The leakage current density for a film grown by ALD using [(MeCp)2HfMe(OiPr)] remains very low (<10–6 A cm–2) up to 2.5 MV cm–1, whereas the leakage current density is significantly higher for the MOCVD‐grown films.
Temperature‐Controlled Synthesis and Photocatalytic Performance of ZnO Nanoplatelets
Authors: Barreca D. , Ferrucci A. P. , Gasparotto A. , Maccato C. , Maragno C. , Tondello E. 
Published: November 2007

AbstractZinc oxide nanoplatelets are successfully grown on Si(100) by CVD starting from a second‐generation ZnII precursor, Zn(hfa)2·TMEDA (Hhfa = 1,1,1,5,5,5‐hexafluoro‐2,4‐pentanedione; TMEDA = N,N,N′,N′‐tetramethylethylenediamine). The synthesis is performed in a nitrogen + wet oxygen atmosphere under optimized conditions, at temperatures between 250 and 500 °C. Field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and glancing incidence X‐ray diffraction (GIXRD) analyses indicate a direct correlation between morphology and microstructure. The formation of ZnO nanoplatelets, whose characteristics depend on the deposition temperature, is proposed to result from the synergistic combination of a vapor/solid (VS) mechanism and a preferential direction‐conducting growth. The chemical composition is analyzed by means of X‐ray photoelectron and energy dispersive X‐ray spectroscopies (XPS, EDXS). Finally, the photocatalytic performances of ZnO nanoplatelets in the decomposition of the azo‐dye Orange II are investigated and compared to those of uniform ZnO coatings synthesized in the absence of water vapor. The obtained results show a higher activity in the case of nanoplatelets due to their peculiar morphology.
Overview of Coating Growth Mechanisms in MOCVD Processes as Observed in Pt Group Metals
Authors: Igumenov I. K. , Gelfond N. V. , Morozova N. B. , Nizard H. 
Published: November 2007

AbstractRhodium, palladium, iridium, and platinum are deposited by means of metal‐organic (MO)CVD using metal beta‐diketonates as precursors. Under some conditions, the microstructure of the deposited metals changes from compact to columnar. The potential causes of structural changes are investigated and a mechanism of contamination is proposed, based on the observation of growth singularities. Several Rh, Pd, Ir, and Pt coatings are analyzed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), high‐resolution (HR)TEM, energy dispersive X‐ray (EDX), and Gratan™ image filter (GIF) in order to observe composition, structure, and to identify the source of eventual structural changes.
Copper Films Deposited by Hot‐Wire CVD and Direct Liquid Injection of CupraSelect
Authors: Papadimitropoulos G. , Davazoglou D. 
Published: November 2007

AbstractCopper films are deposited on Si substrates covered with W, TiN, and SiLK® using a novel CVD reactor in which reactions are assisted by a heated tungsten filament (hot‐wire (HW)CVD). Liquid hexafluoroacetylacetonate CuI trimethylvinylsilane ((hfac) CuI (tmvs), CupraSelect®) is directly injected at room temperature into the reactor with the aid of a direct liquid injection system using N2 as the carrier gas. The deposition rates of HWCVD Cu films obtained on W and TiN covered substrates are found to increase with filament temperature (65 and 170 °C are used). Moreover, high quality Cu films are deposited on SiLK®, which cannot be done by conventional thermal CVD. Independent of the nature of the substrate, resistivities of HWCVD Cu films are higher than for thermally grown films due to carbon and oxygen contamination caused by the incomplete dissociation of the precursor. W impurities are detected in the HWCVD Cu films confined near the interface Cu film/substrate due to the presence of the filament. Their presence does not, however, degrade catastrophically the film conductivity.
Palladium‐Catalyzed Suzuki–Miyaura Cross‐Coupling of Various Aryl Halides Using ortho‐Alkyl‐Substituted Arylphosphanes and (ortho‐Alkylphenyl)alkylphosphanes under Microwave Heating
Authors: Vuoti Sauli , Autio Juho , Laitila Minna , Haukka Matti , Pursiainen Jouni 
Published: November 2007

AbstractMono‐ and dinuclear palladium(II) chloride complexes of various ortho‐alkyl‐substituted aryl‐ and alkylphosphanes were prepared. Subsequently, these were characterized by 1H NMR and 31P{1H} NMR spectroscopy, X‐ray crystallographic studies and mass spectroscopy. The palladium complexes were screened as potential catalysts for the microwave‐assisted Suzuki–Miyaura coupling reaction of several aryl halides under aerobic conditions. A preliminary study showed that excellent results can be obtained even for electron‐rich bromides and unactivated aryl chlorides with an optimized solvent, base and catalyst loading using specific phosphane ligands. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Coordination Compounds of Alkali Metal Tetrahydroborates with Ethers and Amines
Authors: Gálvez Ruiz Juan Carlos , Nöth Heinrich , Warchhold Marcus 
Published: November 2007

AbstractThe crystal structure of LiBH4(thf) is of the same type as that of LiBH4(OEt2) in that it forms double chains containing seven‐coordinate Li atoms and BH4 groups where one H atom coordinates to three Li atoms. In addition, three H atoms form Li–H–B bridges to three different Li atoms. (NaBH4)2(triglyme) shows a sheet structure with eight‐coordinate Na atoms (2 O and 6 H atoms). All H atoms of the BH4 groups are in bridging positions (1 μ32 and 3 μ21 types) and each triglyme molecule acts as a tris(bidentate) ligand. A more precise structure determination is reported for NaBH4(15‐crown‐5), which contains an asymmetric tridentate BH4 group. The compound crystallizes with half a molecule of pyridine. A tridentate BH4 group is also present in KBH4(18‐crown‐6). In contrast, crystallization of NaBH4(18‐crown‐6) from pyridine gives the salt [Na(py)2(18‐crown‐6)]BH4. The crown ether complex KH2BC5H10(18‐crown‐6) binds through its BH hydrogen atoms to the K atom and there is also a weak K···H–C interaction. In contrast to the bidentate BH4 group in LiBH4(py)3, the BH4 group in LiBH4(py‐4‐Me)3 is tridentate. LiBH4 reacts with py‐2‐Me to produce LiBH4(py‐2‐Me)2, which is dimeric in the solid state with BH4 groups bonding to the Li atoms in a μ32/μ22 manner. The reaction of LiBH4 with 2‐aminopyridine in THF gives the complex LiBH4(thf)2(py‐2‐NH2) in which only the pyridine N atom coordinates to the Li atom. NaBH4 crystallizes from pyridine as NaBH4(py)3, which has a chain structure in the solid state where the BH4 groups show one three‐coordinate H atom of the μ32 type and two two‐coordinate H atoms of the μ22 type. The 1:1 dialkylamine complexes of LiBH4 with HNiPr2 and HNiBu2 have different structures. The former shows a chain structure with BH4 groups bridging two Li atoms with bridges of the μ32 and μ22 type, whereas the latter compound forms double strands with one μ43‐ and μ23‐coordinated H atoms. NaBH4(morpholine)2 forms a three‐dimensional structure with four different Na atoms linked by BH4 groups in a rather unusual manner ― they exhibit mono‐, bi‐, and tridentate functions. LiBH4 adds MeHN‐NH2 in a 2:3 ratio to form the salt [Li2(H2N‐NHMe)3](BH4)2, which contains chains of [Li2(H2N‐NHMe)3]2+ cations separated from BH4– anions. In contrast, LiBH4 reacts with PhNH‐NH2 to give the adduct LiBH4(H2N‐NHPh)2, which associates into chains containing H2BH2LiH2BH2Li units. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Peculiarities of CaO·6Al2O3 Formation by using Low‐Temperature Combustion Synthesis
Authors: Ianoş Robert , Lazău Ioan , Păcurariu Cornelia , Barvinschi Paul 
Published: November 2007

AbstractThe preparation of calcium hexaaluminate, CaO·6Al2O3, by solution combustion synthesis was achieved. It was shown that calcium nitrate and aluminium nitrate develop an essentially different behaviour with respect to urea or β‐alanine: urea is the most suitable fuel for aluminium nitrate, whereas β‐alanine is more appropriate for calcium nitrate. An innovative alternative for the combustion synthesis was presented: instead of using a single fuel for both metal nitrates, a two‐fuel mixture containing the most suitable fuel for each metal nitrate was used. It was proved that by using the fuel mixture containing both urea and β‐alanine, the exothermic effect of the combustion reaction was maximized, which ensured the direct formation of pure CaO·6Al2O3 without the need of any additional calcination. Further thermal analysis of the powder evidenced that at around 600 °C the as‐synthesized CaO·6Al2O3 undergoes polymorphic transformation. The use of a single fuel, urea or β‐alanine, does not allow the straight formation of pure calcium hexaaluminate, as X‐ray diffraction analysis showed. Urea leads to the formation of a calcium hexaaluminate contaminated with α‐Al2O3 whereas β‐alanine leads to the formation of an amorphous reaction product, which after annealing at 900 °C with 1 h soaking time turns into γ‐Al2O3.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
A Mild Synthetic Route to Zinc, Cadmium, and Silver Polymers with (2‐Pyridyl)phosphonic Acid: Synthesis and Analysis
Authors: Fry Julie A. , Samanamu Christian R. , Montchamp Jean‐Luc , Richards Anne F. 
Published: November 2007

AbstractFive new metal pyridylphosphonate polymers have been prepared, fully characterized, and their room‐temperature luminescence probed. The reaction of (2‐pyridyl)phosphonic acid (2pypo) with ZnX2 (X = Br, Cl) afforded two‐dimensional polymers [Zn(X)(2pypo)]n {X = Cl = (1), X = Br = (2)}, which feature cyclic 12‐membered Zn–O–P cores that are interlinked by bridged oxygen atoms from the phosphonate moiety. From the room–temperature, aqueous reactions of 2pypo and the corresponding metal salts, the one‐dimensional polymers [Cd(μ‐Cl)2(2pypo)]n (3) and [Hg(2pypo)]n (4) were isolated in moderate yield. The one‐dimensional structure of 3 is supported through bridging chlorides and two η2‐phosphonate oxygen atoms, while 4 is a highly symmetrical polymer that exhibits pyridyl nitrogen coordination to the mercury center and uses two μ2‐oxygen atoms to polymerize. Reaction of silver triflate (CF3SO3Ag) with 2pypo afforded a crystalline silver polymer that displays a zig‐zag arrangement of silver atoms with argentophilic interactions and that is stablized through bridged triflate and phosphonate moieties. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Enantioselective Synthesis of the Hydroazulene Core of 3α‐Hydroxy‐15‐rippertene
Authors: Kreuzer Thomas , Metz Peter 
Published: November 2007

AbstractAs part of a project directed toward the total synthesis of the tetracyclic diterpene 3α‐hydroxy‐15‐rippertene, a constituent of the defense secretion of higher termites, a fast access to two advanced hydroazulene key intermediates has been achieved by starting from (–)‐isopulegol. A regio‐ and diastereoselective formal hydromethallylation and a regioselective ring expansion served as the key steps in the formation of the seven‐membered ring. Completion of the bicyclic title compounds was then achieved by cyclopentene annulation through diastereoselective conjugate addition of organocuprates and subsequent intramolecular aldol condensations.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Label‐Free Detection of Bisphenol A Using a Potentiometric Immunosensor
Authors: Piao Ming‐Hua , Noh Hui‐Bog , Rahman Md Aminur , Won Mi‐Sook , Shim Yoon‐Bo 
Published: November 2007

AbstractA potentiometric immunosensor for the label‐free detection of bisphenol A (BPA) was developed by covalently immobilizing a polyclonal antibody (PAb) onto the surface of a carboxylated poly(vinyl chloride) (PVC‐COOH) membrane. The immunosensor was characterized using scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS), and electrochemical impedance spectroscopy. The immobilization of PAb and its interaction with antigen (Ag) and BPA were also confirmed by quartz crystal microbalance (QCM) studies. Experimental parameters affecting the immuno‐interaction between PAb and its Ag or BPA were examined in terms of pH, antibody concentration, and temperature. The immunosensor showed a specific recognition of BPA with less interference than 4.8% from other common phenolic compounds. A calibration plot was obtained between 1.0 and 30.0 ng/mL and the detection limit was determined to be 0.6 ng/mL. The proposed immunosensor was applied for a real water sample spiked with BPA and the recoveries were in the range between 102.5 and 105.7%.
Sonographic evaluation of visceral fat by measuring para‐ and perirenal fat
Authors: Kawasaki Satsuki , Aoki Kazutaka , Hasegawa Osamu , Numata Kazushi , Tanaka Katsuaki , Shibata Naomi , Shimada Sumiko , Okamura Atsushi , Terauchi Yasuo 
Published: November 2007

AbstractPurpose.To evaluate a new method of determining visceral fat amount by measuring para‐ and perirenal fat on abdominal sonography.Methods.Fifty‐seven patients hospitalized for treatment of their diabetes were examined via waist circumference, abdominal sonography, and CT. On sonography, the thickness of combined para‐ and perirenal fat was measured between the kidney and the inner aspect of the abdominal musculature. Measurements on both sides were averaged as the ultrasound fat thickness (UFT). The visceral fat area was measured on abdominal CT scans at the umbilicus level. Visceral fat deposition was considered elevated above 100 cm2.Results.UFT correlated significantly with VFA and waist circumference (p < 0.0001). A VFA of 100 cm2 was equivalent to a UFT of 10 mm. Waist circumference values of 85 cm in males and 90 cm in females were equivalent to UFT measurements of 11 and 10 mm, respectively.Conclusion.A UFT of ≥10 mm reflects increased visceral fat deposition. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Electron microscopy and morphometric analyses of microtubules in two differently sized types of axons in the protocerebral tract of a crustacean
Authors: Corrêa Clynton Lourenço , da Silva Paula Grazielle Chaves , Pereira Mário José dos Santos , Allodi Silvana , Martinez Ana Maria Blanco 
Published: November 2007

AbstractDespite several reports on the morphology and functions associated with the morphometry of the vertebrate axoplasm cytoskeleton, the subject has not been thoroughly explored in invertebrates. In vertebrates, among many other functions, microtubules (MTs) serve as scaffolding for axon assembly, and neurofilaments (NFs) as the elements that determine the axon caliber. Intermediate filaments have never been described by electron microscopy in arthropods, although NF proteins have been revealed in the MT side‐arms of the axoplasm of certain species, such as the crab Ucides cordatus. Thus, it is not known which elements of the cytoskeleton of invertebrates are responsible for determination of the axon caliber. We studied, by electron microscopy and morphometric analyses, the MT and axon area variability in differently sized axons of the protocerebral tract of the crab Ucides cordatus. Our results revealed differences in the distance between MTs, in MT density and number, and in the areas of differently sized axons. The number of MTs increases with the axon area, but this relationship is not directly proportional. Therefore, MT density is greater in smaller axons than in medium axons, similar to the morphometry of the vertebrate axon MT. The distance between MTs is, however, directly related to the axonal area. On the basis of the results shown here, and on previous reports by us and others, we suggest that MTs may be involved in the determination of the axon caliber, possibly due to the presence of NF proteins found in the side‐arms. Microsc. Res. Tech., 2008. © 2007 Wiley‐Liss, Inc.
Cell number and sex ratio in unfertilized chicken eggs (Gallus gallus domesticus)
Authors: Klein Sabine , Grossmann Roland 
Published: November 2007

AbstractIn chickens and other birds, females have two different sex chromosomes (ZW), whereas males carry two homologous sex chromosomes (ZZ). The primary sex ratio can thus be determined by genetic analysis of the sex chromosome of the ovum before fertilization. Sex diagnosis is more reliable when there are more cells, i.e. sufficient DNA, for the analysis. In this study, eggs from virgin hens were incubated for 3 days and the number of cells in the germinal discs was counted. A median of 2.5 cells was counted with a range of two to 20 cells. We also counted cells in the germinal discs of unfertilized eggs of inseminated hens and recorded a median of three cells and a range of two to 40 cells. Sex diagnosis based on polymerase chain reaction (PCR) amplification of Z and W chromosomes specific fragments from the CHD1 gene in 30 incubated eggs obtained from 35‐week‐old virgin hens gave a ratio of 13 Z to 15 W chromosomes with two samples undetermined.The unfertilized eggs of three groups of chickens were subjected to sex diagnosis to supplement the sex ratio data of an incubation experiment (see companion paper). The high proportion of Z chromosomes diagnosed in all three groups by two independent gene products suggests a sex difference on developmental potential and/or a sex chromosome segregation biased toward males in unfertilized eggs especially at the beginning of reproduction. J. Exp. Zool. 309:47–54, 2008. © 2007 Wiley‐Liss, Inc.
Partial correction of the CFTR‐dependent ABPA mouse model with recombinant adeno‐associated virus gene transfer of truncated CFTR gene
Authors: Mueller Christian , Torrez Daniel , Braag Sofia , Martino Ashley , Clarke Tracy , Campbell‐Thompson Martha , Flotte Terence R. 
Published: November 2007

AbstractRecently, we have developed a model of airway inflammation in a CFTR knockout mouse utilizing Aspergillus fumigatus crude protein extract (Af‐cpe) to mimic allergic bronchopulmonary aspergillosis (ABPA) 1, an unusual IgE‐mediated hypersensitivity syndrome seen in up to 15% of cystic fibrosis (CF) patients and rarely elsewhere. We hypothesized that replacement of CFTR via targeted gene delivery to airway epithelium would correct aberrant epithelial cytokine signaling and ameliorate the ABPA phenotype in CFTR‐deficient (CFTR 489X − /−, FABP‐hCFTR + / +) mice. CFTR knockout mice underwent intra‐tracheal (IT) delivery of recombinant adeno‐associated virus serotype 5 (rAAV5Δ‐264CFTR) or rAAV5‐GFP at 2.58 × 1012 viral genomes/mouse. All mice were then sensitized with two serial injections (200 µg) of crude Af antigen via the intra‐peritoneal (IP) route. Untreated mice were sensitized without virus exposure. Challenges were performed 2 weeks after final sensitization, using a 0.25% solution containing Aspergillus fumigatus crude protein extract delivered by inhalation on three consecutive days. The rAAV5Δ‐264CFTR‐treated mice had lower total serum IgE levels (172513 ng/ml ± 1312) than rAAV5‐GFP controls (26 892 ng/ml ± 3715) (p = 0.037) and non‐treated, sensitized controls (24 816 ± 4219 ng/ml). Serum IgG1 levels also were lower in mice receiving the CFTR vector. Interestingly, splenocytes from rAAV5Δ‐264CFTR‐treated mice secreted less IL‐13, INFg, TNFa, RANTES and GM‐CSF after ConA stimulation. Gene therapy with rAAV5Δ‐264CFTR attenuated the hyper‐IgE response in this reproducible CF mouse model of ABPA, with systemic effects also evident in the cytokine response of stimulated splenocytes. Copyright © 2007 John Wiley & Sons, Ltd.
An empirical investigation of the antecedents, behaviors, and outcomes of bad leadership
Authors: Erickson Anthony , Shaw James B. , Agabe Zha 
Published: November 2007

AbstractThis exploratory study identifies actions and behaviors that subordinates attribute to bad leadership and explores the implications these factors have for organizations. Data were obtained through a Web‐based survey that generated 335 respondents who completed at least some of the questions. Results identified the prevalence of bad leaders, behaviors causing a leader to be perceived as bad, the impact of bad leaders on the employee and organization, whether these bad leaders had always been bad, and what happened to the bad leader. An interesting discovery was that the majority of bad leaders were either promoted or rewarded by the organization.
Implications to ethics education of recent neuroscience research on emotions
Authors: Mccuen Richard H. , Shah Gaurav 
Published: November 2007

AbstractAs it is currently taught, instruction in engineering ethics centers on cognitive learning even to the extent of suppressing the involvement of emotions in ethical decision making. The common belief is that emotional involvement will increase the likelihood of poor judgment. Recent neuroscience research with positron emission tomography and functional magnetic resonance imaging indicates that emotions actually play a significant role in ethical decision making. It then follows that emotions should be part of ethics education: That is, discussions of ethics should not be limited to cognitive thought. Instruction to improve emotional maturity must be accompanied by teaching of cognitive subject matter if long‐term learning is to occur. Emotions influence the solution of ethical problems as they affect the accuracy of the problem assessment and the accuracy, intensity, and duration of an emotive response. Specific emotions that relate to ethical decisions are listed. A theory of emotive learning is presented, and its application to the teaching of engineering ethics is discussed. Strategies for emotive learning are also presented.