bluuebunny/crossref_metadata_2025_split huggingface dataset:
All that is iron‐ink is not always iron‐gall!
Authors: Bicchieri Marina , Monti Michela , Piantanida Giovanna , Sodo Armida 
Published: April 2008

AbstractA number of different inks were used, with the type and precise composition depending on geographical area and historical period. China, iron‐gall and logwood were the most widespread, although a number of other graphic media were also used at particular times and places. Because of a problem encountered while planning the restoration of a manuscript apparently written with different media, we have carried out a systematic characterization of the inks involved. The manuscript (Francesco Maria da Ponticelli, ‘Nova Rhetorica’, 18th century) showed alternately, sometimes in the same page, dark‐black well‐defined inks and reddish‐brown smudged ones. The latter ones were very difficult to be read and historians identified it as an iron‐gall. Our first investigations of the document revealed that the ink had variable composition, but it always showed some typical features of logwood ink. To obtain a better understanding, we prepared, following ancient recipes, logwood inks with the addition of various metallic (Fe, Cr and Cu) salts or amorphous carbon. Iron‐gall ink was also used for comparison and in order to obtain an unambiguous and full characterization of the most widespread inks used in manuscripts. Raman and infrared spectroscopies allowed us to identify the characteristic vibrational features of each prepared medium. These techniques, together with X‐ray fluorescence (XRF) and multispectral investigations of the original document led us to hypothesize that iron salts were periodically added to the original logwood ink. These sequences of ink quality can be ascribed to a shortage of ink during the writing of the manuscript. A small amount of iron salt immediately darkens the logwood extract, allowing its prolonged use. The presence of iron complexes produces a reddish‐brown coloration and causes ink migration in the paper. Combining all the information, we were able to suggest an appropriate restoration treatment and to choose infrared illumination to maximize the readability of the text. Copyright © 2008 John Wiley & Sons, Ltd.
Surgical treatment of invasive squamous cell carcinoma of the penis: Brazilian national cancer institute long‐term experience
Authors: Ornellas Antonio Augusto , Chin Eduardo Wei Kin , Nóbrega Bernardo Lindenberg Braga , Wisnescky Aristóteles , Koifman Nelson , Quirino Raul 
Published: April 2008

AbstractBackground and ObjectivesWe reviewed our long‐term experience with surgical treatment of patients with penile carcinoma.MethodsFrom 1960 to 2006, 688 patients with penile carcinoma underwent surgical treatment at our Institute. Several forms of surgical treatment were compared and follow‐up data analyzed.ResultsStage stratification demonstrated a better survival rate for patients with stages T1N0 and T1N1,T2N0‐1. Patients with well differentiated carcinoma had a higher survival rate than those with moderately and poorly differentiated carcinoma (P < 0.0001 and P = 0.006). Risk stratification showed a better survival rate for patients in the low‐risk group (T1G1,T1G2) (P = 0.013 and P < 0.00001). Patients in the intermediate group (T2G1,T2G2,T3G1,T3G2) presented a higher survival rate than patients in the high‐risk group (T1‐3G3,T4G1‐3) (P < 0.00001). Patients who underwent immediate lymphadenectomy had a better survival rate than those who underwent delayed lymphadenectomy (P = 0.002).ConclusionsStage and tumor grade affected the prognosis of the disease. The presence and the extent of metastasis to the inguinal region were the most important prognostic factors for survival in our patients. Immediate lymphadenectomy is indicated in all patients. Since recurrences were noted within 8, 10, and 25 years after primary treatment, a frequent and lasting follow‐up is essential for all patients. J. Surg. Oncol. 2008;97:487–495. © 2008 Wiley‐Liss, Inc.
A comparative study of nanocomposites based on a recycled poly(methyl methacrylate) matrix containing several nanoclays
Authors: Martin L. , Kortaberria G. , Vazquez A. , Fermeglia M. , Martinelli L. , Sinesi S. , Jimeno A. , de la Caba K. , Mondragon I. 
Published: April 2008

AbstractNanocomposites of recycled poly(methyl methacrylate) (PMMA) and both natural (Nanomer PGV MMT), and organically modified Nanomer I44P, Nanomer I30P and Cloisite 30B montmorillonites (O‐MMT) were prepared by solution dispersion method with the use of two miscible solvents, followed by melt intercalation process in a twin‐screw miniextruder. The final product has been found to show a homogeneous structure with a uniform dispersion/intercalation of the silicate layers. The effect of MMT and O‐MMT layers on the properties of the nanocomposites was investigated and characterized by UV–vis spectroscopy, differential scanning calorimetry, atomic force microscopy, and mechanical testing. Higher contents of nanoclay in nanocomposites exhibited worse light transmittance capacity but higher tensile modulus. Properties of the samples depended not only on the clay contents (up to 10 wt%) but also on the clay type employed. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Three‐body abrasive wear behavior of E‐glass fabric reinforced/graphite‐filled epoxy composites
Authors: Suresha B. , Chandramohan G. , Siddaramaiah  , Jayaraju T. 
Published: April 2008

AbstractThe present article summarizes an experimental study on three‐body abrasive wear behavior of glass fabric reinforced/graphite particulate‐filled epoxy composites. The wear behavior was assessed by rubber wheel abrasion tests (RWAT). The angular silica sand particle sizes in the range 200–250 μm were used as dry and loose abrasives. The tests were carried out for 270, 540, 810, and 1,080 m abrading distances at 22 and 32 N loads. The worn surfaces were examined using scanning electron microscopy (SEM). The results showed varied responses under different abrading distance due to the addition of glass fabric/graphite filler into neat epoxy. It was observed that the glass fabric reinforcement to epoxy matrix (G‐E) is not beneficial to abrasive wear resistance. Further, inclusion of graphite filler to glass fabric reinforced epoxy composite performed poorly resulting in significant deterioration in wear performance while the neat epoxy showed better wear performance. Selected mechanical properties such as hardness, ultimate tensile strength, and elongation at fracture were analyzed for investigating wear property correlations. The worn surface features were studied using SEM to give insight into the wear mechanisms. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Optical resolution of phenylalanine using D‐Phe‐imprinted poly(acrylic acid‐co‐acrylonitrile) membrane—Racemate solution concentration effect
Authors: Ul‐Haq Noaman , Park Joong Kon 
Published: April 2008

AbstractA novel nanoporous molecularly imprinting copolymer [Poly(acrylic acid‐co‐acrylonitrile)] membrane (DICMI) has been synthesized by the wet phase inversion method, using D‐Phenylalanine as template, for the optical resolution of amino acid. The membrane prepared is intended for the selective separation of phenylalanine. The racemate solutions of different concentrations (10‐ppm, 50‐ppm, 100‐ppm, and 200‐ppm) were filtered through the membrane fixed in an ultrafiltration kit at 98 kPa pressure to investigate the concentration effect on optical resolution of amino acid using DICMI. Adsorption selectivities of 0.37, 0.45, 0.57, and 0.71 were achieved after 25 ml of filtration of 10‐ppm, 50‐ppm, 100‐ppm, and 200‐ppm racemate solutions respectively. Scanning electron microscopy was used to study the morphological structure of membrane. Chemical structure was studied by Fourier transmission infrared spectroscopy. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
A systematic approach to identify STRE‐binding proteins of the gsn glycogen synthase gene promoter in Neurospora crassa
Authors: Freitas Fernanda Zanolli , Chapeaurouge Alex , Perales Jonas , Bertolini Maria Célia 
Published: April 2008

AbstractThe gene encoding glycogen synthase in Neurospora crassa (gsn) is transcriptionally down‐regulated when mycelium is exposed to a heat shock from 30 to 45°C. The gsn promoter has one stress response element (STRE) motif that is specifically bound by heat shock activated nuclear proteins. In this work, we used biochemical approaches together with mass spectrometric analysis to identify the proteins that bind to the STRE motif and could participate in the gsn transcription regulation during heat shock. Crude nuclear extract of heat‐shocked mycelium was prepared and fractionated by affinity chromatography. The fractions exhibiting DNA‐binding activity were identified by electrophoretic mobility shift assay (EMSA) using as probe a DNA fragment containing the STRE motif. DNA–protein binding activity was confirmed by Southwestern analysis. The molecular mass (MM) of proteins was estimated by fractionating the crude nuclear extract by SDS‐PAGE followed by EMSA analysis of the proteins corresponding to different MM intervals. Binding activity was detected at the 30–50 MM kDa interval. Fractionation of the crude nuclear proteins by IEF followed by EMSA analysis led to the identification of two active fractions belonging to the pIs intervals 3.54–4.08 and 6.77–7.31. The proteins comprising the MM and pI intervals previously identified were excised from a 2‐DE gel, and subjected to mass spectrometric analysis (MALDI‐TOF/TOF) after tryptic digestion. The proteins were identified by search against the MIPS and MIT N. crassa databases and five promising candidates were identified. Their structural characteristics and putative roles in the gsn transcription regulation are discussed.
Half‐titanocene complexes bearing dianionic 6‐benzimidazolylpyridyl‐2‐carboximidate ligands: Synthesis, characterization, and their ethylene polymerization
Authors: Zuo Weiwei , Zhang Shu , Liu Shaofeng , Liu Xijie , Sun Wen‐Hua 
Published: April 2008

Abstract6‐Benzimidazolylpyridyl‐2‐carboximidic half‐titanocene complexes, Cp′TiLCl (Cp′ = C5H5, MeC5H4, C5Me5, L = 6‐benzimidazolylpyridine‐2‐carboxylimidic, C1–C13), were synthesized and characterized along with single‐crystal X‐ray diffraction. The half‐titanocene chlorides containing substituted cyclopentadienyl groups, especially pentamethylcyclopentadienyl groups were more stable, while those without substituents on the cyclopentadienyl groups were easily transformed into their dimeric oxo‐bridged complexes, (CpTiL)2O (C14 and C15). In the presence of excessive amounts of methylaluminoxane (MAO) or modified methylaluminoxane (MMAO), all half‐titanocene complexes showed high catalytic activities for ethylene polymerization. The substituents on the Cp groups affected the catalytic behaviors of the complexes significantly, with less substituents favoring increased activities and higher molecular weights of the resultant polyethylenes. Effects of reaction conditions on catalytic behaviors were systematically investigated with catalytic systems of mononuclear C1 and dimeric C14. With C1/MAO, large MAO amount significantly increases the catalytic activity, while the temperature only has a slight effect on the productivity. In the case of C14/MAO catalytic system, temperature above 60 °C and Al/Ti value higher than 5000 were necessary to observe good catalytic activities. In both systems, higher reaction temperature and low cocatalyst amount gave the polyethylenes with higher molecular weights. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3396–3410, 2008
Effect of the variation in the composition on the adsorption and desorption performance for the Zr(Vx Ni1–x)2+α (0 ≤ x ≤ 1; 0 ≤ α ≤ 1) family of alloys
Authors: Huang R. Z. , Wang Y. M. 
Published: April 2008

AbstractWe have performed first‐principles calculations of cubic C15‐type Laves phase Zr(Vx Ni1–x )2+α (0 ≤ x ≤ 1; 0 ≤ α ≤ 1) alloys to understand their hydrogen storage properties. Our calculations have shown that hydrogen atoms tend to occupy 2A2B sites for these alloys. It has been found that hydrogen desorption performance for these alloys can be improved by the partial substitution of Ni for V and the partial substitution of V for Zr, which agrees with experimental results. The effect of the variation in the compositions of these alloys on the hydride formation energy is revealed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Successful fabrication of white light emitting diodes by using extremely high external quantum efficiency blue chips
Authors: Narukawa Yukio , Sano Masahiko , Sakamoto Takahiko , Yamada Takao , Mukai Takashi 
Published: April 2008

AbstractWe fabricated three types of high luminous efficiency white light emitting diodes (LEDs). The first is the white LED, which had a high luminous efficiency (ηL) of 161 lm/W with the high luminous flux (ϕv) of 9.89 lm at a forwardbias current of 20 mA. The blue LED had a high power (ϕe) of 42.2 mW and high external quantum efficiency (ηex) of 75.5%. The second is the high luminous efficiency white LED with a low voltage (Vf) of 2.80 V, which was almost equal to the theoretical limit. ηL and wall‐plug efficiency (WPE) is 169 lm/W and 50.8%, respectively, at 20 mA. They are approximately twice higher than those of a tri‐phosphor fluorescent lamp (90 lm/W and 25%). The third is the high power white LED fabricated from the high power blue LED with high ϕe of 651 mW at 350 mA. ϕv, ηL and WPE of the high power white LED are 145 lm, 134 lm/W and 39.6% at 350 mA, respectively. Moreover, at 1 A, ϕv and ηL were 361 lm and 97 lm/W, respectively. Thus ϕv is equivalent to that of a 30 W‐class incandescent lamp. And, ηL is slightly higher than that of a tri‐phosphor fluorescent lamp. Moreover, we fabricated the high power near ultra‐violet, bluish‐green and green LEDs, whose ϕe at 350 mA were 675 mA, 325 mW, and 236 mW, respectively. ϕv of the green LED was 128 lm at 350 mA. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐quality nonpolar m ‐plane GaN substrates grown by HVPE
Authors: Fujito Kenji , Kiyomi Kazumasa , Mochizuki Tae , Oota Hirotaka , Namita Hideo , Nagao Satoru , Fujimura Isao 
Published: April 2008

AbstractRelatively large size (about 10 mm × 10 mm) m ‐plane GaN substrates are grown by hydride vapor phase epitaxy (HVPE). The high crystalline quality of the substrates was observed by X‐ray diffraction analysis. Typical full widths at half maximum values of X‐ray rocking curves measured for the (10$ \bar 1 $0) and (10$ \bar 1 $2) reflections were 25–35 arcsec and 30–40 arcsec, respectively. The defect density distribution was analyzed from the [10$ \bar 1 $0] direction by the cathodeluminescence method. The dark spot density decreased in the growth direction and could be as low as 2.5 × 105 cm–2. No stacking faults could be seen. The surface roughness after the lapping, polishing and cleaning was measured by atomic force microscopy and the RMS roughness was 0.072 nm. All of the phonon modes that the selection rules allow have been observed in polarized Raman measurements. High‐quality large‐size m ‐plane GaN substrates will enable the realization of commercial production of nonpolar devices. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Green ThinGaN power‐LED demonstrates 100 lm
Authors: Peter M. , Laubsch A. , Stauss P. , Walter A. , Baur J. , Hahn B. 
Published: April 2008

AbstractRecent progress in the epitaxy of InGaN LEDs leads to a significant improvement of output power for green LEDs: 100 lm at 350 mA and 189 lm at 1 A are demonstrated for a 1 mm2 ThinGaN Chip at 531 nm, mounted in an OSRAM Dragon package with spherical silicone lens and OSRAM Argus lens. The chip is especially designed for low current applications like LCD backlighting where high efficiencies are needed. Efficacies of 123 lm/W at 100 mA and 80 lm/W at 350 mA have been achieved with this LED. The Influence of Multi Quantum Well emission on LED brightness was investigated in respect of driving current and temperature. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The reduction of threading dislocations in GaN using a GaN nanocolumn interlayer
Authors: Meshi L. , Cherns D. , Griffiths I. , Khongphetsak S. , Gott A. , Liu C. , Denchitcharoen S. , Shields P. , Wang W. , Campion R. , Novikov S. , Foxon T. 
Published: April 2008

AbstractEpitaxial lateral overgrowth (ELO) has been used to reduce threading dislocation (TD) densities in GaN. This paper reports transmission and scanning electron microscopy studies of TDs in GaN films grown by ELO on GaN nanocolumns produced either during growth by MBE (method 1), or by self‐organised patterning on a uniform layer grown by MOCVD (method 2). In method 1, isolated nanocolumns grew without TDs, but some TDs formed when nanocolumns coalesced. Although some of these TDs extended through the overlayer, extensive lateral migration of others, depending on the dislocation type, led to dislocation annihilation, lowering the overall TD density. In method 2, a similar process of lateral migration of TDs was observed during ELO, resulting in a continuous GaN overlayer with TD densities less than 108 cm–2. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
InGaN/GaN light emitting diode with R‐plane polygonal facet deflectors
Authors: Kim Hyung Gu , Cuong Tran Viet , Kim Hyun Kyu , Kim Hee Yun , Ryu Jae Hyung , Na Min Gyu , Hong Chang‐Hee 
Published: April 2008

AbstractUnder DOI 10.1002/pssc.200778568 erroneously a duplicate of the paper “InGaN/GaN light emitting diode with R‐plane polygonal facet deflectors” by Hyung Gu Kim, Tran Viet Cuong, Hyun Kyu Kim, Hee Yun Kim, Jae Hyung Ryu, Min Gyu Na, and Chang‐Hee Hong was published. Please find the valid version of the paper with DOI 10.1002/pssc.200778674 in phys. stat. sol. (c) Vol. 5, No. 6, 2267–2269 (2008). (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of patterned ion implanted sapphire substrate for LED
Authors: Jhin Junggeun , Baek Jong Hyeob , Lee Jae Sang 
Published: April 2008

AbstractLight‐emitting diodes (LEDs) were fabricated on patterned ion implanted sapphire substrates using metal organic chemical vapor deposition. The crystal quality of the u‐GaN and n‐GaN epilayers grown on the patterned N+‐ion implanted sapphire substrate was improved compared to that of the u‐GaN and n‐GaN epilayers grown on a conventional sapphire substrate. The optical properties of the u‐GaN and n‐GaN epilayers grown on the patterned ion implanted sapphire substrate were also improved. The light intensity of the LED at 100mA on the patterned ion implanted sapphire chip was up to 78% higher than that of the conventional LED chip according to the quick test on the wafer. The increase in the light intensity is due to the relaxation of the misfit strain at high temperature and the contribution of the internal free energies to the enhancement of structural and optical prop‐ erties. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication of GaN‐based Schottky‐type light‐emitting diodes for micropixels in flat‐panel displays
Authors: Honda T. , Kobayashi T. , Komiyama S. , Mashiyama Y. , Arai M. , Yoshioka K. 
Published: April 2008

AbstractMicrosize integrated light‐emitting diodes (LEDs) that operate in the UV spectral region were fabricated using GaN layers grown on sapphire substrates by metal‐organic vapor phase epitaxy (MOVPE). Schottky‐type (ST) and metal‐oxide‐semiconductor (MOS) LEDs were realized. The near‐band‐edge emission of GaN was observed in the electroluminescent spectra with reversed bias under pulsed‐voltage conditions. The insertion of an aluminum oxide layer in the GaN‐based LED led to an increase in electroluminescent intensity. The internal optical absorption in the GaN layer of the GaN‐based ST‐LEDs was also estimated to be 75% of the emission light power. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Time‐resolved electro‐luminescence studies of InGaN blue LEDs with chip size variations
Authors: Feng Shih‐Wei , Tsai Tzong‐Liang , Lan Wen‐How , Huang C. J. , Shih Ming‐Chang 
Published: April 2008

AbstractIn this study, we report carrier dynamics of three InGaN Blue LEDs with three chip sizes by time‐resolved electroluminescence (TREL) measurements. Experiments results show that the sample with the largest chip size has the smallest EL width and longest response time among the three samples. It implies that the current spreading for larger chip size need more time. It is partially attributed to the fact that carrier relaxation into the strongly localized states (high‐indium clusters) need more time. Furthermore, the long decay times are due to the carrier recombination from the deep trapped localization states and/or the high defect density inside the samples. Also, the decay times of the three samples are nearly independent of the chip size and applied voltage. This implies that the sum densities of localization states and defects of the three samples have nearly the same order of magnitude. By reducing the density of the defects, the quantum efficiency of the LEDs can be increased at least by a factor of 10. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Luminescence and vibrational properties of erbium‐implanted nanoporous GaN
Authors: Soh C. B. , Chua S. J. , Sim S. H. , Tripathy S. , Alves E. 
Published: April 2008

AbstractImplantation of erbium (Er) into GaN is useful in creating selected areas to emit at the green, yellow and infrared wavelengths. Enhanced erbium activation is obtained when erbium is implanted into porous GaN formed by electrochemical etching than into as‐grown GaN. This is due to the increase in surface areas for light extraction and the availability of more free surfaces to accommodate strain when it is annealed. Furnace annealing at 1100 °C for 30 mins in nitrogen gives rise to higher band‐edge photoluminescence intensity. Apart from the host GaN phonon modes, we have also observed disorder‐induced lattice vibrations at 170, 200 and 350‐365 cm–1 from Er‐implanted porous GaN. The E2 (high) mode of GaN also shifts towards higher energy at higher annealing temperatures, indicative of more erbium occupying the VGa site (ionic radii of Er > Ga) and hence increasing the compressive stress in the GaN crystal lattice. The prominent defect‐induced local vibrational modes in Er‐doped nanoporous GaN are also observed in ultraviolet resonant Raman scattering. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication of a GaN p/n lateral polarity junction by polar doping selectivity
Authors: Collazo Ramón , Mita Seiji , Rice Anthony , Dalmau Rafael , Wellenius Patrick , Muth John , Sitar Zlatko 
Published: April 2008

AbstractThe difference in surface energy between the Ga‐polar orientation and the N‐polar orientation of GaN translates into a completely different behavior for the incorporation of intentional and unintentional impurities. Oxygen is found to be an impurity with higher concentration in N‐polar films than in Ga‐polar films and is the cause for the high carrier concentration observed in N‐polar films. We fabricated a lateral p/n junction in GaN by the simultaneous growth of p‐ and n‐type regions, utilizing the doping selectivity of the two different polar domains, which resulted in an n‐type carrier concentration of 1.7x1019 cm–3 with an electron hall mobility of 99 cm2/Vs in the N‐polar domains, and a p‐type carrier concentration of 1.1x1017 cm–3 with a hole hall mobility of 12 cm2/Vs in the Ga‐polar domains. These junctions showed the characteristics that define a p/n junction: current rectification, electroluminescence, and photo‐effect. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)