bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel PU‐type polymeric photoinitiator comprising side‐chain benzophenone and coinitiator amine for photopolymerization of PU acrylate
Authors: Wei Jun , Liu Fang , Lu Zhimin , Song Ling , Cai Dongdong 
Published: July 2008

AbstractA novel diamine 3,5‐diamino‐4′‐phenoxylbenzophenone (DAPBP) was synthesized from the reaction of 3,5‐diamino‐4′‐chlorobenzophenone (DACBP) and phenol. Then through the polycondensation of DAPBP, toluene‐2,4‐diisocyanate (TDI), and N‐methyldiethanolamine (MDEA), we obtained a PU‐type polymeric photoinitiator containing side‐chain benzophenone (BP) and tertiary amine in the same macromolecule (PUSOA). Another polymeric photoinitiator without coinitiator amine in polymer chain (PUSO) was also synthesized for comparison. FT‐IR, 1H NMR, and GPC analyses confirmed the structures of monomer and polymeric photoinitiators. The UV–Vis spectra of PUSOA, PUSO, and DAPBP are similar, and all exhibit the maximal absorption near 290 nm. ESR spectra indicate that PUSOA can generate active species most efficiently. The photopolymerization of PU acrylate, initiated by PUSOA, PUSO/MDEA, DAPBP/MDEA, and BP/MDEA, was studied by differential scanning photocalorimetry (photo‐DSC). The results show that the in‐chain coinitiator amine can significantly improve the photoefficiency of the polymeric photoinitiator and the PUSOA is more efficient for the polymerization of PU acrylate than its low‐molecular‐weight counterpart. Copyright © 2008 John Wiley & Sons, Ltd.
Columnar liquid‐crystalline assemblies composed of spiropyran derivatives and sulfonic acids
Authors: Tan Boon‐Hooi , Yoshio Masafumi , Watanabe Kazuki , Hamasaki Atsushi , Ohno Hiroyuki , Kato Takashi 
Published: July 2008

AbstractA series of fan‐shaped spiropyran derivatives with different length of alkyl chains has been synthesized. Liquid‐crystalline (LC) assemblies of spiropyran derivatives have been formed by the addition of organic sulfonic acids such as trifluoromethylsulfonic acid, 10‐camphorsulfonic acid, 4‐methylbenzenesulfonic acid, and imidazolium‐based ionic liquids (ILs) having a sulfonic acid group. Equimolar mixtures of a fan‐shaped spiropyran derivative with the acidic imidazolium‐based ILs exhibit columnar phases with wider LC temperature ranges as compared to those of other mixtures. The ionic interactions formed by the ionic imidazolium moieties should contribute to the stabilization of the columnar phases. On the other hand, equimolar mixtures of the spiropyran derivative with decane‐1‐sulfonic acid having a long alkyl chain and poly(4‐styrenesulfonic acid) do not show mesomorphism. The chemical structure of organic sulfonic acids is a key factor for the induction and stabilization of the LC phases. Copyright © 2008 John Wiley & Sons, Ltd.
Ionic liquid‐based luminescent composite materials
Authors: Nakashima Takuya , Nonoguchi Yoshiyuki , Kawai Tsuyoshi 
Published: July 2008

AbstractLuminescent composite materials based on semiconductor nanocrystals (NCs) with ionic liquid and subsequently with an ionic liquid‐based polymer have been prepared. Cationic CdTe NCs passivated with thiocholine bromide (TCB) were prepared in an aqueous phase and easily transferred to hydrophobic ionic liquids by means of a simple biphasic extraction process without using any surfactant. TCB‐capped CdTe NCs were stably dispersed in hydrophobic ionic liquids and their absorption spectra and optical density (extinction coefficient) were maintained even after the extraction. While the emission peak position was also identical with the original one, its intensity increased almost twice. The efficient extraction and photoluminescence enhancement of CdTe NCs were generally observed for the hydrophobic ionic liquids based on both bis(trifluoromethanesulfonyl)imide (TFSI) and hexafluorophosphate (PF6) anions. However, the generation of a trace of hydrofluoric acid gradually collapsed the CdTe NCs in a PF6‐based ionic liquid. A polymerizable ionic liquid which possesses an acrylate group could also extract the CdTe NCs from water and gave a CdTe NC‐polymer composite with strong luminescence by the polymerization of ionic liquid. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis of oligomer with carbonate and ether unit from phenyl glycidyl ether and carbon dioxide, using immobilized imidazolium salt catalyst
Authors: Shim Hye‐Lim , Lee Mi‐Kyung , Kim Kyung‐Hoon , Park Dae‐Won , Park Sang‐Wook 
Published: July 2008

AbstractA silica‐supported imidazolium salt (Im‐IM) was proved to be an effective heterogeneous catalyst for the solventless synthesis of oligomer with carbonate and ether unit from phenyl glycidyl ether (PGE) and CO2. Im‐IM catalysts were prepared by sol–gel method. The catalyst prepared with butyl bromide showed the highest conversion of PGE and the highest carbonate content [f(CO2)] and molecular weight for the oligomer. However, they decreased for Im‐IM prepared with longer alkyl chain (hexyl and octyl bromide) probably due to the steric hindrance for the formation of an intermediate between the catalyst and PGE. High reaction temperature increased PGE conversion, polymer formation, and f(CO2). The average molecular weight of the oligomer decreased with increase in reaction temperature. A high CO2 pressure was favorable for the PGE conversion and f(CO2). But a very high pressure decreased both of them. Im‐IM can be reused for the reaction up to four consecutive runs without considerable loss of its catalytic activity. Copyright © 2008 John Wiley & Sons, Ltd.
Propargyl silicon‐cyclopentadiene oligomeric resin with high temperature resistance
Authors: Wang Mingcun , Yang Ming , Zhao Tong 
Published: July 2008

AbstractMultiple propargyl substituted cyclopentadiene was synthesized by phase transfer reaction between cyclopentadiene and propargyl bromide in an aqueous solution mediated by sodium hydroxide. It was found that propargylated cyclopentadiene (PCp) could be thermally cured with a mass loss of ca 28%, while the cured material showed a high char yield of ca 76% at 900°C. In order to overcome the processing problems of PCp, a condensation reaction between PCp di‐anion and dimethyldichlorosilane was performed to make a silicon‐PCp (SiPCp) oligomeric resin. SiPCp resin has an acceptable processability, attributed to its organosolubility, low viscosity, and broad processing window. SiPCp resin can readily undergo thermal cure via addition polymerization of ethynyl groups in the temperature range of 170–270°C with an exothermic maximum at ca 240°C, and the mass loss upon cure was less than 5%. Evidenced by the results of dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) in a nitrogen atmosphere, the cured SiPCp resin exhibited stable thermo‐mechanical properties up to 320°C, and possessed an anerobic char yield of ca 77% at 900°C. The results of TGA in air atmosphere revealed the higher oxidation resistance of SiPCp resin. Copyright © 2008 John Wiley & Sons, Ltd.
Anionic polymerization of methyl methacrylate in an ionic liquid
Authors: Kokubo Hisashi , Watanabe Masayoshi 
Published: July 2008

AbstractAnionic polymerization reactions of methyl methacrylate (MMA) in ionic liquids were carried out by utilizing alkyl lithium initiators such as n‐butyl lithium (n‐BuLi) and diphenylhexyl lithium (DPHLi). The polymerization in ionic liquids having bis(trifluoromethyl sulfonyl)amide ([NTf2]) anion did not yield poly(MMA) (PMMA), because of the deactivation of the initiator due to an attack on the trifluoromethyl group. By using 1‐butyl‐3‐methylimidazolium hexafluorophosphate ([C4mim][PF6]), the polymerization reactions proceeded. The PMMA prepared in [C4mim][PF6] gave low yields (5–9%), as compared with those (15–62%) obtained for PMMA prepared in tetrahydrofuran (THF), and the prepared PMMA had large polydispersity indices (≅2.0). The results obtained can be attributed to the high reaction temperature (0°C), in comparison to the common anionic polymerization temperature of MMA, −78°C, and the reaction between the initiator and the imidazolium cation. The initiator was considered to be deactivated because the hydrogen atom at the 2‐position of the imidazolium ring was withdrawn by the alkyl lithium initiator. The tacticity of the obtained PMMA, prepared in [C4mim][PF6] by utilizing DPHLi, was rich in mm triads, similar to that polymerized in toluene. Copyright © 2008 John Wiley & Sons, Ltd.
Electrical transport properties of an organic semiconductor on polyaniline doped by boric acid
Authors: Yakuphanoglu Fahrettin , Şenkal B. Filiz 
Published: July 2008

AbstractThe electrical conductivity, thermoelectric power, and dielectric properties of polyaniline doped by boric acid (PANI‐B) have been investigated. The room temperature electrical conductivity of PANI‐B was found to be 1.02 × 10−4 S cm−1. The thermoelectric power factor for the polymer was found to be 0.64 µW m−1 K−2. The optical band gap of the PANI‐B was determined by optical absorption method, and the PANI‐B has a direct optical band gap of 3.71 eV. The alternating charge transport mechanism of the polymer is based on the correlated barrier hopping (CBH) model. The imaginary part of the dielectric modulus for the PANI‐B suggests a temperature dependent dielectric relaxation mechanism. Electrical conductivity and thermoelectric power results indicate that the PANI‐B is an organic semiconductor with thermally activated conduction mechanism. Copyright © 2008 John Wiley & Sons, Ltd.
Current–voltage and capacitance–voltage characteristics of the ITO/polyaniline doped boron trifloride/Al Schottky diode
Authors: Yakuphanoglu Fahrettin , Şenkal B. Filiz 
Published: July 2008

AbstractThe electrical characteristics of the ITO/polyaniline (PANI) doped boron trifloride (BF3)/Al Schottky diode have been investigated by current–voltage (I–V) and capacitance–voltage (C–V) methods. The diode indicates a rectification behavior with the ideality factor of 4.78. An ideality factor higher than unity can result from the interface state and electronic properties of the PANI doped BF3 organic semiconductor. The barrier height of the diode was determined from both I–V and C–V characteristics. The barrier height obtained from the C–V measurements is higher than that obtained from the I–V measurements. At higher forward bias voltages, the space charge‐limited current is the dominant transport mechanism, whereas at reverse bias voltages, the current flow in the ITO/PANIBF3/Al diode is controlled by Schottky emission mechanism. Copyright © 2008 John Wiley & Sons, Ltd.
In utero therapy for fetal thoracic abnormalities
Authors: Wilson R. Douglas 
Published: July 2008

AbstractFetal thoracic lung anomalies are rare. The specific diagnosis can be made by utilizing ultrasound, magnetic resonance imaging (MRI), and Doppler studies. Perinatal surveillance is required for large lesions and mediastinal shift regardless of the pathological diagnosis. These can cause physiological changes in the cardiovascular system with resulting hydrops. In utero therapies are variable but with no large randomized trials to compare risks and benefits. In most cases of fetal lung lesions, continued observation with postnatal therapy is the outcome. When fetal hydrops is present or impending, in utero fetal therapy is required to try to reverse that pathological course associated with fetal or neonatal death. Maternal morbidity is increased with the development of MIRROR syndrome following the presence of long‐standing fetal hydrops and possible surgical procedures. Copyright © 2008 John Wiley & Sons, Ltd.
Prenatal and postnatal management of omphalocele
Authors: Mann Stephanie , Blinman Thane A. , Douglas Wilson R. 
Published: July 2008

AbstractOmphalocele is one of the most common abdominal wall defects seen in the prenatal period. Once this diagnosis is confirmed, it is important to check the fetal karyotype and thoroughly assess the fetus for other malformations. Prenatal management involves serial assessment of fetal growth and prenatal testing to ensure fetal well‐being. Closure of the abdominal wall and replacement of organs into the abdominal cavity can be done directly if the omphalocele is small or in a staged manner if the omphalocele is large. Successful outcomes for these neonates can be optimized with a multidisciplinary team approach to prenatal and postnatal management. Copyright © 2008 John Wiley & Sons, Ltd.
Syndromic associations with congenital anomalies of the fetal thorax and abdomen
Authors: Hurst Jane , Firth Helen V. , Chitty Lyn S. 
Published: July 2008

AbstractAnomalies of the thorax and abdomen can be found in a number of genetic syndromes. Whilst it may not be possible to make a definitive diagnosis before birth, knowledge of the potential associations can be useful for the prenatal diagnostician when examining the fetus and counselling the parents. In this article, we describe conditions where other features may be detectable using prenatal ultrasound. We describe the features, potential diagnostic aids and prognosis. The tables list other potential features that may be identified. The range of conditions that can occur emphasises the value of genetic input in the management of a fetus with an apparently normal karyotype and multiple anomalies, the need to save material for future molecular analysis and the requirement of a detailed examination after delivery. These are needed in order to make accurate diagnoses and advise parents with regard to recurrence risks and the potential for prenatal diagnosis in future pregnancies. Copyright © 2008 John Wiley & Sons, Ltd.
Prenatal diagnosis, prediction of outcome and in utero therapy of isolated congenital diaphragmatic hernia
Authors: Doné Elisa , Gucciardo Leonardo , Van Mieghem Tim , Jani Jacques , Cannie Mieke , Van Schoubroeck Dominique , Devlieger Roland , Catte Luc De , Klaritsch Philipp , Mayer Steffi , Beck Veronika , Debeer Anne , Gratacos Eduardo , Nicolaides Kypros , Deprest Jan 
Published: July 2008

AbstractCongenital diaphragmatic hernia (CDH) can be associated with genetic or structural anomalies with poor prognosis. In isolated cases, survival is dependent on the degree of lung hypoplasia and liver position. Cases should be referred in utero to tertiary care centers familiar with this condition both for prediction of outcome as well as timed delivery. The best validated prognostic indicator is the lung area to head circumference ratio. Ultrasound is used to measure the lung area of the index case, which is then expressed as a proportion of what is expected normally (observed/expected LHR). When O/E LHR is < 25% survival chances are < 15%. Prenatal intervention, aiming to stimulate lung growth, can be achieved by temporary fetal endoscopic tracheal occlusion (FETO). A balloon is percutaneously inserted into the trachea at 26–28 weeks, and reversal of occlusion is planned at 34 weeks. Growing experience has demonstrated the feasibility and safety of the technique with a survival rate of about 50%. The lung response to, and outcome after FETO, is dependent on pre‐existing lung size as well gestational age at birth. Early data show that FETO does not increase morbidity in survivors, when compared to historical controls. Several trials are currently under design. Copyright © 2008 John Wiley & Sons, Ltd.
Nitrogen Atmospheric Pressure Post Discharges for Surface Biological Decontamination inside Small Diameter Tubes
Authors: Pointu Anne‐Marie , Ricard André , Odic Emmanuel , Ganciu Mihai 
Published: July 2008

AbstractA nitrogen afterglow at atmospheric pressure has recently been described as able to transport active species over long distances in small diameter tubes, with a biocidal effect. For a discharge gas composed of nitrogen, either of high purity or with some controlled ppm of oxygen, survival curves are presented. The afterglow, flowing at 40 slm in a cylindrical quartz tube with 8 mm internal diameter is studied using emission spectroscopy. Fundamental or excited states of atomic or molecular species of parent gases are detected and evaluated. Their absolute concentration is measured along the tube axis. Correlated to transport equations, results give information on the creation and destruction reactions of these species, especially of the O(1S) metastable state of O, the species that has been shown to boost the biocidal effect.magnified image
The influence of the solution composition including additives on the structure and composition of electrochemical Ni–B coatings
Authors: Szeptycka B. , Gajewska‐Midzialek A. 
Published: July 2008

AbstractThe structure and internal stresses were investigated for d.c.‐plated Ni composite deposits prepared from a low‐concen‐tration Watts electrolyte, with and without additive agents and dispersive B particles. The dispersed phase and additives used in the bath were shown to affect the composition and structure of the electrodeposited composite layer. An increase in the content of B particles in the coating and in the size of [111] nickel crystallites led to increased roughness of Ni‐B coatings. The microhardness of the deposited Ni‐B layers increased as the size of [111] nickel crystallites decreased. The internal stresses of the deposited composite coatings depended to a large degree on the additive in the bath. Ni‐B coatings had a (100) texture, with texture (111) and (311) also frequently occurring. Orientation (100) developed even more strongly than in coatings deposited without additives. This shows that in the presence of 3‐(1‐pyridinio)‐propanesulfonate inner salt (PPS), the development of (110), (111) and (311) orientation is blocked. When the additives were used together, the dimensions of the [111] nickel crystallites in all coatings decreased to the smallest dimension in any of the studied coatings. The results suggest that as the effect of the organic compounds employed the nanostructure of the nickel matrix was developed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical study of the radiation effect on the flowing of mixed convection along a vertical channel
Authors: Aggoune S. , Amara E. H. , Hamadi F. 
Published: July 2008

AbstractRadiation effect and mixed convection flow are solved numerically in two‐dimensional vertical channel. The main objective is to study the effect of radiation on the flow using radiation models available in Fluent software. The study is done for a Richardson number (Ri = 2.5). Our results when the radiation is ignored are compared with those of the article: Mixed convection in ducts with asymmetric wall heat fluxes [W. Aung and G. Worku, J. Heat Transfer 109, 947 (1987)]. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Prospective crystallization of amorphous Si films for new Si TFTs
Authors: Noguchi Takashi 
Published: July 2008

AbstractProspective crystallization results of amorphous silicon film are reviewed and are discussed. Silicon TFTs are playing an important role for Active‐Matrix Flat Panel Displays (AM‐FPD) based on amorphous or poly‐Si thin‐film transistors (TFTs). Poly‐Si TFTs provide a possibility to develop highly functional system on pane (SoP) applications. In order to get a high performance TFT, large poly‐crystal grains or high cystallinity for the film is required. Two basic crystallization techniques namely solid phase crystallization (SPC) and excimer laser crystallization (ELC) are reviewed and relating issues are described. A grain growth technique has been developed based on the two crystallization techniques, so far. In order to mount a poly‐Si TFT system on a flexible panel such as a plastic, an excimer laser of UV pulse beam has an advantage for the TFT channel as well as for the source and drain contacts as a ultra‐low temperature poly‐Si (U‐LTPS) process. To realize a high performance TFT of uniform and high carrier mobility, location control crystallization had been proposed. Some of the distinctive results for crystal orientation control of (100) and (111) face using the laser crystallization techniques are described. In the future, single‐crystalline Si TFT of a functional 3D structure is expected to realize an advanced SoP for ubiquitous electronics era. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ultraviolet laser structuring of silicon carbide for cold cathode applications
Authors: Spanakis E. , Dialektos J. , Stratakis E. , Zorba V. , Tzanetakis P. , Fotakis C. 
Published: July 2008

AbstractWe present results of the first attempt to produce arrays of sharp Silicon Carbide (SiC) electron emitters by ultraviolet pulsed‐laser processing of single‐crystal SiC surfaces. This simple one‐step technique, performed under controlled pressure of a reactive gas, has demonstrated efficient silicon cold cathodes both in terms of current density and of emission threshold. SiC has been found to produce the best emitters when treated in air. The corresponding cathodes have a lower emission threshold and produce higher current densities than their Si‐based counterparts. The role of surface morphology on the electron emission properties obtained is discussed in comparison to silicon. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Homoepitaxial ZnO thin films by PLD: Structural properties
Authors: Lorenz M. , Wagner G. , Rahm A. , Schmidt H. , Hochmuth H. , Schmid H. , Mader W. , Brandt M. , von Wenckstern H. , Grundmann M. 
Published: July 2008

AbstractHomoepitaxial ZnO films deposited on annealed hydrothermal O‐face ZnO single crystals show superior structural quality. This is demonstrated by narrow ZnO(00.2) rocking curves with FWHM of typically 23 to 35 arcsec, and nearly dislocation‐free TEM cross sections. Nominally undoped ZnO films indicate a minor in‐plane strain of about 250 ppm and no out‐of‐plane strain. Target doping by 0.01% P2O5 or 0.5% Li3N results in pseudomorphic film growth without in‐plane strain. Increasing doping concentration of 0.1 and 1% P2O5 results in both in‐plane and out‐of‐plane strain up to 0.9% indicating relaxed films. The O‐face polarity of the homoepitaxial ZnO films is confirmed by convergent beam electron diffraction. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of laser crystallization on hydrogen bonding in poly‐Si
Authors: Nickel N. H. , von Maydell K. 
Published: July 2008

AbstractWe investigate the influence of the hydrogen content in the amorphous starting material on hydrogen bonding and defect passivation in laser crystallized poly‐Si using electron‐spin‐resonance and hydrogen effusion measurements. After laser dehydrogenation and crystallization the specimens contain a residual H concentration of 8×1021 cm–3 to 1.5×1022 cm–3. During a vacuum anneal at least 1.5×1021 cm–3 H atoms are mobile in the lattice, however, only about 3.7×1018 cm–3 H atoms passivate Si dangling‐bonds. Our results show that the annealing treatment can cause the vast majority of H atoms to accumulate in H stabilized platelets. Since defect passivation preferentially occurs at grain boundaries and platelet nucleation and growth is confined to the interior of single crystal grains, H equilibration is governed by two spatially separated processes. Moreover, our data demonstrate that the hydrogen density‐of‐states distribution derived from H effusion data is dynamic and changes in response to experimental parameters. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)