bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Approach to the Reaction Analysis of Non-UV-Absorbing Crown Ether with Alkali Metal Ions in Aqueous Solution by Capillary Zone Electrophoresis Using Indirect Photometric Detection
Authors: Takayanagi Toshio , Motomizu Shoji
Published: June 2003

A novel analysis method for complex formation reactions of such a non-UV-absorbing crown ether as 1,4,7,10,13,16-hexaoxacyclooctadecane (18-crown-6 ether, 18C6) with alkali metal ions was established through the mobility change in capillary zone electrophoresis. Alkali metal ions at their concentrations of 1 × 10−4 mol dm−3 were photometrically detected by using 1-ethylquinolinium ion as an indirect photometric reagent. The apparent electrophoretic mobility of alkali metal ions decreased along with the increase in the concentrations of 18C6 in migrating solutions. The complex formation constants analyzed and determined by using the mobility change agreed well with the reported values.
Calcium Phosphate Formation on Highly-oriented Collagen Fibrils
Authors: Yokogawa Yoshiyuki , Nagata Fukue , Toriyama Motohiro
Published: June 2003

Calcium phosphate formation on collagen fibrils was studied. Collagen fibrils deposited from a collagen solution were insolubilized by UV-irradiation. The collagen fibrils looked to be precipitated and arranged in one direction in a narrow space due to convection stream from bottom to top of test tube. Highly-oriented collagen fibrils precipitated were soaked in simulated body fluid (SBF) solution at 36.5 °C. After immersion of SBF solution at 36.5 °C for 3 days, calcium phosphate was formed on insolubilized collagen fibrils. In contrast, no calcium phosphate was formed on collagen fibrils without insolubilization treatment.
Crystal Field Effect on the Chemical Shift in Cu LIII XANES Spectra of Cu(II) Compounds
Authors: Shimizu Ken-ichi , Maeshima Hajime , Yoshida Hisao , Satsuma Atsushi , Hattori Tadashi
Published: June 2003

Chemical shifts of the 2p3/2→ 3d peaks in the Cu LIII XANES spectra of copper(II) compounds were correlated with the crystal field parameter, 10Dq, and were understood in terms of the simple crystal field concept.
On the Azide Effect Regenerating the Proton Channel of Mutated Bacteriorhodpsins
Authors: Koyama Koichi , Miyasaka Tsutomu
Published: June 2003

Effect of azide on proton transfer of bacteriorhodopsin (bR) mutants that lack the proton donor Asp-96 and/or proton acceptor Asp-85 was investigated by a photoelectrochemical method. In the presence of azide, D96N completely recovered the response profile of the wild type and D96N/D85N gave a very small current with the same amplitude as in D85N. On the contrary, D85N showed no azide effect. These results indicate that azide affects the process of shuttling protons from D96 to the Schiff base rather than does the proton transfer from the Schiff base to D85.
Electron Transfer Process of lonically Dimeric Cobalt Porphyrin Accompanied with Dissociation Equilibrium
Authors: Yamamoto Kimihisa , Nakazawa Sinsuke
Published: June 2003

The ionically dimeric cobalt porphyrin with a II-II valence state undergoes a stepwise two-electron transfer accompanied with dissociation equilibrium (Kd = 1.3 × 10−6 M) with redox potentials at −0.37 and −0.17 V vs. Fc/Fc+.
Synthesis, Structure, and Photochemistry of Tetrakis(trimethylsilyl)-p-benzoquinone
Authors: Sakamoto Kenkichi , Tsutsui Shinobu , Ebata Keisuke , Kabuto Chizuko , Sakurai Hideki
Published: June 2003

Tetrakis(trimethylsilyl)-p-benzoquinone (1) was obtained by oxidation of hexakis(trimethylsilyl)hydroquinone with pyridinium chlorochromate. X-Ray crystallographic analysis of 1 showed the quinone ring was distorted into a chair form by steric hindrance. Photolysis resulted in a rearrangement of the quinone ring and produced a ketene derivative.
Novel Silane Coupling Agents Containing a Photolabile 2-Nitrobenzyl Ester for Introduction of a Carboxy Group on the Surface of Silica Gel
Authors: Yamaguchi Kazuo , Kitabatake Takashi , Izawa Masashi , Fujiwara Tomomichi , Nishimura Hiroki , Futami Tatsuhiro
Published: June 2003

Silane coupling agents containing a carboxy group are not known because the chloro- or alkoxy group is reactive to the carboxylic acid. In this study, silane coupling agents bearing a 2-nitrobenzyl ester as a protecting group of carboxylic acid were synthesized and applied for surface modification of silica gel followed by uv irradiation under neutral conditions to generate carboxy groups on the surface.
Phosphorus Ylide Migration from Fe to a Phosphenium Phosphorus
Authors: Nakazawa Hiroshi , Kishishita Mitsuru , Nakamoto Tadahiro , Nakamura Norihiko , Ishiyama Takeshi , Miyoshi Katsuhiko
Published: June 2003

The reaction of a phosphorus ylide complex [(C5H4R)(CO)(CH2PR′3)Fe{PNN(Ome)}]BF4 (R = H, Me; R′ = Me, Et, Ph; PNN = PN(Me)CH2CH2Nme) with TMSOTf and then nBu4NBr gave [(C5H4R)(CO)BrFe{PNN(CH2PR′3)}]Otf through intramolecular migration of a cationic phosphorus ylide ligand from Fe to a cationic phosphenium phosphorus.
Novel Emitting Materials for Organic Electroluminescent Device: 1-Aryl-2,5-di(2-thienyl)pyrrole Derivatives Having an Electron-withdrawing Group
Authors: Yanai Hiroyuki , Yoshizawa Daisuke , Tanaka Satoshi , Fukuda Tatsuo , Akazome Motohiro , Ogura Katsuyuki
Published: June 2003

Since 1-aryl-2,5-di(2-thienyl)pyrrole derivatives having an electron-withdrawing group emit strong fluorescence, they could be utilized as an efficient dopant in the emitting layer of an organic EL device. Especially, 1-aryl-2,5-di(2-thienyl)pyrrole having a ketene dithioacetal S,S-dioxide group showed extremely high performance (the highest luminous efficiency: 5.9 cd/A).
A Spontaneous Aggregate Formed by Polypeptide-based Amphiphile in Water
Authors: Doi Tomokiyo , Kinoshita Takatoshi , Kamiya Hiroki , Tsujita Yoshiharu , Yoshimizu Hiroaki
Published: June 2003

In order to construct a molecular aggregate with well-defined structure, a novel amphiphile consisting of a phosphate head group and hydrophobic polypeptide tail was prepared. This amphiphilic polypeptide was soluble in water and spontaneously assembled to form a ribbon-like molecular aggregate. FT-IR and circular dichroism (CD) spectra showed that the aggregated polypeptide adopts an anti-parallel β-form conformation.
Near-infrared Electroluminescence from Ytterbium(III) Complex
Authors: Kawamura Yuichiro , Wada Yuji , Iwamuro Mitsunori , Kitamura Takayuki , Yanagida Shozo
Published: June 2003

The room temperature near-infrared electroluminescence(EL) was observed from organic EL devices using the ytterbium(III) [Yb(III)] complex as an emitter over 15 V, though there was no spectral overlap between the lowest triplet state of ligand and the emissive level of Yb(III) ion needed for the intramolecular energy transfer. The EL emission with a peak at 985 nm was assigned to the 2F5/2 → 2F7/2 transition of Yb(III) ion.
A New Method for Preparing Nickel Oxide Supported Silica Pillared Phosphates with High Surface Area
Authors: Wang Wenhan , Tang Yi , Xiao Jinbing , Hua Weiming , He Nan , Gao Zi
Published: June 2003

A novel procedure was developed to prepare nickel oxide supported silica pillared zirconium phosphates whose surface areas and d-spacings are 125-198 m2/g and 2.1-2.3 nm respectively, whereas the samples prepared by conventional method only have surface areas less than 20 m2/g and d-spacings 1.8 nm. X-Ray diffraction (XRD), N2 adsorption and temperature programmed reduction (TPR) indicated that the materials obtained by the new method have better nickel oxide dispersion than those obtained by the conventional method.
Hydrothermal Soft Chemical Synthesis of Tunnel Manganese Oxides with Na+ as Template
Authors: Feng Qi , Horiuchi Tohru , Liu Lihui , Yanagisawa Kazumichi , Mitsushio Taikou
Published: June 2003

Na+ was used as template in the synthesis of tunnel manganese oxides from a layered manganese oxide under hydrothermal conditions. Two types of tunnel manganese oxides were obtained by the hydrothermal reaction. The manganese oxide with a one-dimensional (2 × 4) tunnel structure formed under low temperature conditions, and Na0.44MnO2 with a one-dimension complex tunnel structure under high temperature conditions. The mechanism of the transformation reaction can be explained from the structures of the products and template size.
Molecular Reorientation Induced by Sunshine Suggesting the Generation of Absolute Chirality
Authors: Ichimura Kunihiro , Han Mina
Published: June 2003

Both azimuthal and polar directions of azobenzene chromophores tethered to liquid-crystalline polymer backbones follow the orbital motion of the sun upon exposure of a film of the polymer to sunlight. The possibility to generate absolute chirality by the orbital motion of the sun is suggested.
Unusual [2+2] Photocycloaddition between Tryptamine and 3-Nitrocinnamic Acid in the Solid State
Authors: Ito Yoshikatsu , Fujita Haruo
Published: June 2003

A crystalline salt of tryptamine with trans-3-nitrocinnamic acid underwent cross photocycloaddition, leading to a cyclobutane adduct 1. Their solid mixture failed to give 1. This is the first [2+2] photocycloaddition of alkene to “N-unsubstituted” indoles.
Low Frequency Sound as a Navigational Tool for People with Visual Impairments
Authors: Ashmead Daniel , Wall Robert
Published: May 2003

For decades, a mistaken assumption in the habilitation of travel for people with visual impairments has been that the use of “echolocation” is a dominant feature of acoustic information for the guidance of locomotion. This paper outlines a theoretical model of acoustic information available in many travel situations. The acoustic information consists of a build up of low frequency sound along large structures such as walls. Useful frequencies are low enough that the experience of this build up is often one of feeling rather than hearing. Experimental validation of this model was accomplished by having participants with visual impairments walk along walls with varying types of auditory occlusion and through laboratory based manipulations of acoustic information. Results indicate that the model is appropriate. Useful acoustic information appears to extend up to 1 m from a wall. There is strong evidence that participants make use of binaural information, gauging the similarity of acoustic information reaching each ear to maintain orientation to a wall. Motion through the sound field near the wall makes the information more useful but it is unclear whether motion in certain directions or conditions is more useful than others.
Engine Test Cell Noise Emission Design with Performance Validation Results
Authors: Evans Jack B.
Published: May 2003

An existing industrial test facility was proposed to be relocated from a plant site in a high ambient noise environment to a community with low ambient noise. The existing facility contained engine test cells and support equipment with loud noise emissions. The original location was in an industrial park, adjacent to a high-speed multi-lane divided highway, but residential communities were nearby. Few noise complaints had been received at the existing location. The proposed future site was in a semi-rural area, near a two lane, moderate speed roadway. Although some moderate environmental noise emissions existed from an industrial installation on the existing site, the potential was recognised for community noise disturbance from the introduction of a new noise source. JEAcoustics was retained to assess the ambient noise environments and noise emission characteristics for the purpose of determining attenuation requirements for the new facility. A consultant's confidentiality agreement with the owner prevents disclosure of the facility name, plant locations, discussion of plant processes or revelation of other proprietary information. This case study presents the findings of that effort and the noise criteria that were established. Noise control designs and product applications are discussed with results of postconstruction noise validation measurements.
Initialisation of Grid-Connected Wind Turbine Models in Power-System Simulations
Authors: Hansen Anca D. , Sørensen Poul , Iov Florin , Blaabjerg Frede
Published: May 2003

This paper describes a method of initialising dynamic wind turbine models in power-system simulations. The method uses grid-status information to initialise the grid-connected wind turbine model. The goal is to start a power-system simulation in a stationary state, without unnecessary transient behaviour at the beginning of the simulation. Correct initialisation is necessary to reach quickly the steady state of the grid-connected wind turbine, before a real transient on the grid occurs. Consequently, the dynamic performance of the system can be independently and accurately evaluated. The method presented considers wind turbines with directly grid-connected induction generators, with constant or variable blade angle (passive stall control, blade angle control or active stall control). These aspects apply to both constant and variable speed wind turbines. The investigation is performed in the commercial dedicated power-system simulation-tool DIgSILENT. Attention is especially drawn to the initialisation of the non-electrical parts of the wind turbine. The suitability of this initialisation strategy is illustrated by an example.
Pre-Feasibility Study of a Wind-Diesel System for St. Brendan's, Newfoundland
Authors: Iqbal M. T.
Published: May 2003

St. Brendan's is an isolated rural community in the north of New foundland. It has an installed diesel generated electricity capacity of 735 kW with an annual average energy consumption of 3185 kWh/day. The average annual wind speed in the area is estimated at 7.6m/s. This paper describes the primary design, simulation and pre-feasibility of adding wind turbines to the exiting diesel electrical system of St. Brendan's. Year round hourly power consumption data recorded in St. Brendan's are used for the selection and analysis of wind-diesel hybrid energy system. National Renewable Energy Laboratory's HOMER and Hybrid2 software were used to determine the best configuration of the wind-diesel system. Site data, system description and expected performance of the system are presented in this paper. The results indicate that retrofitting of diesel plants for St. Brendan's using wind turbines will result in significant fuel savings.
Aircraft Noise
Authors: Tandon N.
Published: May 2003

Various noise measurement parameters/indices used to define aircraft and airport noise are explained. The noise zone limits used around airports in some countries are given. Noise prediction software can be used to generate noise contours around airports. New aircraft noise certification standards have been developed to encourage control of aircraft noise at source. Aircraft noise can also be reduced if noise abatement landing and take-off procedures are followed.
Geochemical Signatures of Paleodepositional and Diagenetic Environments: A STEM/AEM Study of Authigenic Clay Minerals from an Arid Rift Basin, Olduvai Gorge, Tanzania
Authors: Hover Victoria C. , Ashley Gail M.
Published: May 2003

Olduvai Gorge, Tanzania (East African Rift) exposes a 100 m thick Plio-Pleistocene sequence of dominantly volcaniclastic sediments deposited in a 50 km wide closed basin containing a playa lake. A scanning transmission electron and analytical electron microscopy (STEM/AEM) study of authigenic clay minerals in sediments from representative depositional environments in the basin (pyroclastic fan, fluvial plain, wetland, lake margin and lake basin) was undertaken to determine whether clay compositions and textures could provide unique geochemical fingerprints characteristic of source area (Plio-Pleistocene trachytic volcanicsvs.Precambrian quartzose-feldspathic basement) or paleoenvironmental conditions.

Our study shows that compositional signatures obtained by clay minerals during early pedogenesis are inherited from their parent source rocks. Sediments sourced from volcanics contain highly disordered, dioctahedral smectite. Those sourced from Precambrian basement are similar, but are more Al-rich. Subsequent neoformation in the pedogenic (soil) or diagenetic (lake-margin, lake) environments results in the modification of original clay mineralogy, compositions, and textures, and unique paleoenvironmental fingerprints are acquired. Soils developed on the distal pyroclastic fan contain smectite with more Fe(III) and Mg than smectite from the proximal pyroclastic fan sediments. A trend of decreasing Al and increasing Mg content occurs in smectite compositions in samples from the fluvial to lake-margin and lake environments as a result of partial replacement of original dioctahedral Al-rich smectite by neoformed trioctahedral Mg-rich smectite (stevensite). Neoformed celadonite replaces smectite in the most saline lake sediments.

The STEM/AEM data collectively indicate that diagenesis in the saline-alkaline lake results in the replacement of Al-rich dioctahedral smectite by Mg-rich trioctahedral smectite (stevensite) and Mg- and Al-rich celadonite. Thus, determination of clay mineral compositions at a basin-wide scale provides a useful tool for interpreting the spatial distribution of depositional and diagenetic environments.
The Crystal Structure of Roscoelite-1M
Authors: Brigatti Maria Franca , Caprilli Enrico , Marchesini Marco , Poppi Luciano
Published: May 2003

Single-crystal X-ray diffraction experiments were carried out on roscoelite crystals from Reppia, Val Graveglia, Italy. Roscoelite [structural formula: XII(Ba0.006K0.994)IV(Si3.150Al0.850) VI(Al0.040Fe0.150Mg0.100Mn0.062V1.696Ti0.003)O10(OH)2] shows a near-perfect three-dimensional stacking order with cell parameters a = 5.292(1), b = 9.131(2), c = 10.206(3) Å, β = 100.98(2)° and space group C2/m, which indicate a 1M polytype. The crystal structure was refined on the basis of Fo2 for 846 unique reflections to R1 = 3.29% calculated using 746 unique observed reflections [|Fo| ⩾ 4σ(Fo)]. The mean tetrahedral cation–oxygen atom distance,  = 1.641 Å, is close to the mean  value obtained for dioctahedral true micas from the literature, whereas the octahedral sheet is characterized by a larger cis-octahedral cation–oxygen atom bond distance  = 2.020 Å which, together with the mean electron count, is consistent with V occupancy. The presence of V within the octahedral sheet produces the smallest tetrahedral rotation (α = 2.3°), the lowest flattening of the basal oxygen surface (Δz = 0.118 Å) and the narrowest interlayer separation (3.030 Å) in dioctahedral micas.
Structural Study of Maya Blue: Textural, Thermal and Solid-State Multinuclear Magnetic Resonance Characterization of the Palygorskite-Indigo and Sepiolite-Indigo Adducts
Authors: Hubbard Basil , Kuang Wenxing , Moser Arvin , Facey Glenn A. , Detellier Christian
Published: May 2003

Palygorskite-indigo and sepiolite-indigo adducts (2 wt.% indigo) were prepared by crushing the two compounds together in a mortar and heating the resulting mixtures at 150 and 120°C, respectively, for 20 h. The samples were tested chemically to ensure that they displayed the characteristic properties of Maya Blue. Textural analysis revealed that no apparent changes in microporosity occurred in sepiolite or palygorskite after thermal treatment at 120°C (sepiolite) and 150°C (palygorskite) for 20 h. Micropore measurements showed a loss of microporosity in both sepiolite and palygorskite after reaction with indigo. The TGA-DTG curves of the sepiolite-indigo and palygorskite-indigo adducts were similar to their pure clay mineral counterparts except for an additional weight loss at ∼360°C due to indigo.

The 29Si CP/MAS-NMR spectrum of the heated sepiolite-indigo adduct is very reminiscent of the spectrum of dehydrated sepiolite. Crushing indigo and sepiolite together initiates a complexation, clearly seen in the 13C CP/MAS-NMR spectrum, which can be driven to completion by heat application. In contrast to the broad peaks of the pure indigo 13C CP/MAS-NMR spectrum, the sepiolite-indigo adduct spectrum consists of a well-defined series of six narrow peaks in the 120.0–125.0 ppm range. In addition, the sepiolite-indigo spectrum has two narrow, shifted peaks corresponding to the carbonyl group and the C-7 (C-16) of indigo. A model is proposed in which indigo molecules are rigidly fixed to the clay mineral surface through hydrogen bonds with edge silanol groups, and these molecules act to block the nano-tunnel entrances.
Decolorization of Vegetable Oils: A Study of the Mechanism of Adsorption of β-Carotene by an Acid-Activated Bentonite from Cyprus
Authors: Christidis George E. , Kosiari Sotiria
Published: May 2003

The mechanism of decolorization of crude maize and sunflower oils was studied by means of adsorption of β-carotene by a low-grade bentonite, containing mixed-layered illite-smectite. Decolorization depends on temperature and the time required for equilibrium decreases with increasing temperature. The study of the kinetics of adsorption showed that decolorization of maize oil is a first-order process which occurs in two steps: a first fast step with higher activation energy (25.6 kJ mol−1), indicating the influence of a chemical interaction between the pigment and the clay surface, followed by a second slow step with low activation energy (12.3 kJ mol−1), characteristic of physical adsorption on the previously adsorbed molecules. Decolorization of sunflower oil is also a first-order process, described by a single mechanism with intermediate activation energy (19.0 kJ mol−1). Adsorption isotherms of decolorization of maize oil follow the Freundlich equation, indicating the existence of heterogeneous adsorption sites on the solid's surface. Heterogeneity is attributed both to different active centers on the smectite surface (Brönsted and Lewis centers) and to the different phases present in bentonite, such as illitic layers and clinoptilolite, which also have active centers on their surfaces.
Geordnete mesoskopische Strukturen durch Selbstorganisation und Transformation von Hybrid‐Nanostrukturen
Authors: Cölfen Helmut , Mann Stephen
Published: May 2003

Die Organisation von Nanostrukturen über mehrere Längenskalen ist eine Schlüsselherausforderung im Design von integrierten Materialien mit verbesserten Funktionen. Derzeitige Ansätze greifen bevorzugt auf physikalische Methoden wie Musterbildung zurück, und nicht auf Methoden wie spontane chemische Selbstorganisation und Umwandlung von Baueinheiten über mehrere Längenskalen. Es sollte möglich sein, eine Chemie der organisierten Materie zu entwickeln, die auf Prozessen beruht, in denen die Zeit‐ und Längenskalenkopplung wechselwirkender Komponenten übergeordnete Architekturen mit eingebetteter Struktur hervorbringt. In diesem Aufsatz zeigen wir, wie das Wechselspiel von Aggregation und Kristallisation die Selbstorganisation auf der Mesoskala, kooperative Umwandlung und Reorganisation von organisch‐anorganischen Hybridbaueinheiten unter Bildung von Einkristallen mit Mosaikstruktur, Nanopartikelarrays und emergenten Nanostrukturen mit komplexer Form und Hierarchie auslösen kann. Wir schlagen vor, dass ähnliche Prozesse, die auf der Mesoskala wirksam sind, auch für Modelle der matrixvermittelten Keimbildung bei der Biomineralisation relevant sind.
From the first Gregory‐Coudé Telescope to Gregor
Authors: Wiehr E.
Published: May 2003

The historic development of the Göttingen Gregory‐Coudé Telescope is sketched. The use of a Gregory system for a solar telescope was driven by the severe disadvantages of an existing Cassegrain solar telescope. The possibility of placing a (water‐cooled) field‐stop at the prime‐focus diminishes heat stress as well as straylight on the mirrors behind the field‐stop. The measured aureole intensity of the first solar Gregory telescope, installed 1959 near Locarno, classifies that instrument as a ‘quasi coronograph’ and makes it particularly suitable for straylight‐sensitive observations. The coudé mounting with two folding flat mirrors (‘German type’) assures small and daily constant instrumental polarization. This was compensated in a first step with a co‐rotating tilted glass‐plate and a modified Bowen compensator fixed to the hour axis. In a later step, a halfwave plate between both folding flat mirrors simulates the polarimetric situation of zero‐declination. The Gregory‐Coudé Telescope was then particularly suitable for polarimetry; it operated 25 years near Locarno and finally 15 years on Tenerife.
POLIS: A spectropolarimeter for the VTT and for GREGOR
Authors: Schmidt W. , Beck C. , Kentischer T. , Elmore D. , Lites B.
Published: May 2003

The polarimetric Littrow Spectrograph POLIS is designed for vector polarimetry at high angular and spectral resolution. It measures the magnetic field simultaneously in the photosphere and the chromosphere of the sun. Both branches of the polarimetry unit are dual beam systems with a single rotating modulator for both wavelengths and polarizing beam splitters in front of each CCD camera. POLIS has been installed at the VTT on Tenerife and has seen First Light on 17 May 2002. A modified version of POLIS will be developed for the balloon mission Sunrise. That version will have UV capabilities down to 200 nm.
A CCD‐based guiding and control system for solar telescopes
Authors: Klvaňa M. , Bumba V. , Sobotka M.
Published: May 2003

We describe a system for guiding and control of motion of solar telescopes based on a determination of the position of the full solar disk on a CCD chip. The system computes the position of the disk center and, according to the difference between the instantaneous and required positions, it controls the motion of the telescope to compensate the deviation. The instantaneous position of the disk center is the basic input for the telescope's guiding and coordinate system. Brightness inhomogeneities of the solar limb caused by clouds are checked in real time. The function of the system can be suspended automatically if the clouds degrade the accuracy of guiding. The system also makes possible to check the correct focus and to evaluate the image quality.
High sensitivity polarimetry
Authors: Gandorfer A.M.
Published: May 2003

Over the last decade spectro‐polarimetry evolved to ever higher sensitivity levels. New techniques and instruments allow us to address weak polarization signals, which are caused by scattering in the solar atmosphere. In this paper a review on the development of spectro‐polarimetric investigations of scattering physics and its coupling to the solar magnetic field will be given. Starting from a technical point of view it will be demonstrated how our understanding of scattering phenomena and their role in solar physics in general has reached its current state. An outlook on future spectro‐polarimetry with new large solar telescopes concludes this review.
Solar observations from space and from the ground
Authors: Curdt W.
Published: May 2003

Recent results from space missions like YOHKOH, SOHO or TRACE as well as ground‐based observations clearly indicate that physical processes of most solar phenomena take place on small scales, which are still below the resolution of the instruments employed. There is an urgent need for observations at higher resolution and also for their extension to multi‐wavelength regimes. Space‐borne as well as ground‐based instruments have limitations of the present‐day technology, although in a different way. In this communication, an overview of space instruments currently in operation or in the preparation phase is presented and references to more detailed information are given.
Spectroscopy of solar prominences from space and ground
Authors: Dammasch I.E. , Stellmacher G. , Wiehr E.
Published: May 2003

Two quiescent solar prominences were observed in July 2000 from SUMER aboard SOHO and from the two German solar telescopes at Tenerife. Two‐dimensional images taken at the VTT simultaneously in the spectral lines Hβ at 4862 Å and Ca II at 8542 Å show no significant spatial variation of their pressure‐sensitive emission ratio. Slit spectra of the Ca II 8542 Å and He I 10830 Å lines obtained at the Gregory‐Coudé telescope yield 8000 K < Tkin < 9000 K and 3 km/s < Vn–th < 8 km/s. Among the various spectral ranges observed with SUMER, we first investigate the Lyman emission lines, which were fitted by Gaussians yielding reliable spectral radiances and line widths for the series members 5 < k < 18. A determination of the level population gives for the lower series members a Boltzmann temperature of 60 000 K, the higher members being over‐populated. This temperature indicates an origin of the Lyman lines from hot surroundings of the cool prominence body seen in the ground‐based data; this also holds for the ‘hotter’ SUMER lines.
Does the ion cyclotron exist in the inner corona?
Authors: Raouafi N.‐E.
Published: May 2003

The present work is about the interpretation of the linear polarization of the O VI D2 (λ1032) coronal line observed by SUMER/SoHO. We take into account the effect of the Doppler redistribution due to the scattering ions motion. We consider the cases of isotropic and anisotropic velocity field distributions. The latter can be interpreted by the ioncyclotron effect that affects heavy ions in the solar corona. The comparison of the numerical results with the observations yields constraints on the solar wind outflow speed and on the velocity field distribution of the O5+ ions at low coronal altitudes in the polar holes.
Granulation and waves
Authors: Hirzberger J.
Published: May 2003

A summary of the most recent observational results on the solar granulation phenomenon is given and its physical interpretation with respect to theoretical and numerical models is briefly discussed. Special attention is paid to unsolved questions concerning the relation between convective motions and related solar features.
Models of a mean granular cell
Authors: Puschmann K. , Ruiz Cobo B. , Vázquez M. , Bonet J.A. , Hanslmeier A.
Published: May 2003

From inversion of a time series of slit spectra, observed in a quiet region of the solar photosphere, averaged models of a granular cell have been obtained showing the stratification of physical quantities versus optical depth and geometrical height. Furthermore a semi‐empiric dynamic model of a mean granular cell has been derived and the results are presented.
Magnetic and velocity fields of active regions
Authors: Choudhary D.P. , Gosain S.
Published: May 2003

We have observed about 15 active regions on the Sun, with the Advanced Stokes Polarimeter and Dick Dunn Telescope at NSO/SP to map the Stokes parameters in the photospheric Fe 6302.5 Å and chromospheric Mg I 5173 Å lines, during 1999‐2002. The observations are corrected for dark current, gain, instrumental polarization and cross‐talk using ASP pipeline. The wavelength calibration is carried out using the O2 telluric line 6302 Å which is also present in the observations. The photospheric and chromospheric longitudinal magnetograms are made from the Stokes V profiles, which were intercalibrated with the Kitt Peak magnetograms. The plasma motions are inferred from the line bisector measurements at different positions of the spectral line. In this paper we present the height dependence of Doppler velocity scatter plots of a sunspot in the photospheric Fe I 6302 Å line.
Study of bright points in the off‐band Hα filtergrams of active regions
Authors: Choudhary D.P. , Gosain S.
Published: May 2003

Hα filtergrams of selected active regions are obtained by the six inch refractor telescope at Udaipur Solar Observatory through a birefringent filter of 0.5 Å full width at half maximum. The field of view is ∼4 × 5 arcmin with a spatial resolution of better than one arc sec. The filtergrams are obtained in the wavelength range of ‐1 to +1 Å centered at 6563 Å at steps of 0.1 ° A. A complete scan takes about 5 seconds (occasionally longer). The images are recorded with a cooled CCD camera and corrected for dark current and flat field. We observe the bright points in the filtergrams beyond 0.5 Å off line center. In general, these features are located away from the strong field regions. We study their property with respect to the co‐temporal photospheric magnetograms obtained with the GONG instrument at Udaipur. This might help in understanding their relation with the magnetic flux emergence and annihilation.
Infrared photometry of a sunspot near the disk center
Authors: Stangl S. , Sobotka M. , Bonet J. A. , Vázquez M. , Hanslmeier A.
Published: May 2003

A time series of broadband images of a sunspot near the disk center was obtained simultaneously in two wavelength bands at 0.56 μm and 1.55 μm at the German VTT on June 17, 1998. We computed intensity difference images of the best frame pairs which reveal information about the facular distribution in the present field of view. Faculae are found around pores, in the quiet granulation and as well around the sunspot penumbra.
Interpretation of observations by inversion
Authors: del Toro Iniesta J.C.
Published: May 2003

The most recent developments in inversion techniques of the radiative transfer equation are critically reviewed and some of their findings are summarized to illustrating their achievements. Two significantly different approaches are currently being used that deserve consideration, each characterized by whether or not the model solar atmospheres are changed iteratively by the algorithm. The comparison between the two may help in finding future inversion techniques that can solve many challenging problems of solar physics that still need to be properly settled. These problems themselves suggest strategies that look more suitable than others.
High‐frequency waves and granulation
Authors: Zhugzhda Y.D.
Published: May 2003

The theory of periodical shear flow is applied for the exploration of the effect of solar granulation on highfrequency waves in the solar photosphere. It is shown that upgoing and downgoing waves are trapped in intergranular spaces and granules, respectively. Upgoing waves in fast downflows are unstable. The theory is in a good agreement with observations.
3‐D hydrodynamic simulations of the solar chromosphere
Authors: Wedemeyer S. , Freytag B. , Steffen M. , Ludwig H.‐G. , Holweger H.
Published: May 2003

We present first results of three‐dimensional numerical simulations of the non‐magnetic solar chromosphere, computed with the radiation hydrodynamics code CO5BOLD. Acoustic waves which are excited at the top of the convection zone propagate upwards into the chromosphere where the waves steepen into shocks. The interaction of the waves leads to the formation of complex structures which evolve on short time scales. Consequently, the model chromosphere is highly dynamical, inhomogeneous, and thermally bifurcated.
European businesses, national priorities: pioneers and laggards of ecological modernization
Authors: Drake Frances , Purvis Martin , Hunt Jane , Millard Debbie
Published: May 2003

Ecological modernization has been widely adopted by western politicians as a means to achieving a balance between continued economic growth and sustainable development. Countries with consensual forms of government, such as Germany, seem to be leading the field in developing such policies. Thus, it might be expected that it will be the industries within these states that reap the win–win benefits of greater attention to the environment. This paper explores the reality of these expectations through semi‐structured interviews with business managers in three EU countries: France, Germany and the United Kingdom. Contrary to expectations the attitudes of German managers to the environment did not differ significantly from their French and British counterparts. Differences in behaviour were perceived as a product of stricter environmental regulation in Germany rather than any deep‐seated changes in outlook. Ecological modernization was not seen as an answer to Germany's current economic predicament. Copyright © 2003 John Wiley & Sons, Ltd. and ERP Environment
Cyclodextrin‐modified micellar electrokinetic chromatography for the analysis of Esterom®, a topical product consisting of hydrolyzed benzoylecgonine in propylene glycol
Authors: Razak Jennifer L. , Doyen Heidi J. , Lunte Craig E.
Published: May 2003

Esterom®, a new drug currently in human clinical trials, is a mixture of compounds in a propylene glycol vehicle. It is being evaluated as a topical treatment to aid in the relief of muscle pain and to increase range of motion. Benzoylecgonine is the major component of Esterom and there are at least nine other minor constituents, including four hydroxypropyl esters that have multiple diasteriomers. The aim of the study was to develop a capillary electrophoresis method for the simultaneous separation of the main components in Esterom, including the multiple proposed diastereomers of the esters. Due to the complex sample composition, the use of micelles and cyclodextrins as buffer modifiers was evaluated. A cyclodextrin‐modified micellar electrokinetic chromatography method was able to determine 7 of the 8 UV‐active Esterom components, with baseline separation of 7 of the 10 diastereomers of the hydroxypropyl esters.
Size‐exclusion capillary electrochromatographic separation of polysaccharides using polymeric stationary phases
Authors: Mistry Kavita , Krull Ira , Grinberg Nelu
Published: May 2003

We report the successful size‐based separations of large, neutral polysaccharides using capillary electrochromatography (CEC). As the polysaccharides possessed little chromophore for photometric detection, two separate approaches were taken. In the first approach, indirect detection was combined with size‐exclusion chromatography using a sulfonated polystyrene/divinylbenzene stationary phase. The separations were performed using a 300 Å pore size stationary phase under aqueous conditions. Non‐size based interactions were minimal using this material, resulting in an effective calibration range of molecular masses 180 to 112 000 g·mol−1 for pullulans. In the second approach, the polysaccharides were derivatized with phenylisocyanate and were subsequently separated on columns made using a combination of high capacity ion‐exchanger and a neutral polystyrene/divinylbenzene material of various pore sizes. The sulfonated ion‐exchange phase provided the electroosmotic flow, while the mixed pore size material provided the extended calibration range. The linear range for this primarily nonaqueous system using tetrahydrofuran was determined to be from molecular masses 738 to 404 000 g·mol−1 of the original, untagged pullulan. This approach overcame the limited solubility issue associated with analysis of some polysaccharides. Analysis of pullulan and amylose samples by CEC correlated well with results obtained by conventional high‐performance liquid chromatography (HPLC). The size‐exclusion electrochromatographic separations provide an alternative mode for determining the relative molecular weights of polysaccharides with reduced sample and solvent consumption, as well as analysis times.
An optimized method for the isolation and identification of membrane proteins
Authors: Lehner Ines , Niehof Monika , Borlak Jürgen
Published: May 2003

The purpose of this study was to develop a protocol suitable for membrane protein extraction from limited starting material and to identify appropriate conditions for two‐dimensional (2‐D) gel electrophoresis. We used A549 cells, a human alveolar type II cell line, and evaluated three protein extraction methods based on different separation principles, namely protein solubility, detergent‐based and density‐based organelle separation. Detergent‐based extraction achieved the highest yield with 14.64% ± 2.35 membrane proteins but sequential extraction with 7.35% ± 0.78 yield and centrifugal extraction with 4.1% ± 0.54 yield produced the purest fractionation of membrane proteins. Only the sequential and the detergent‐based extraction proved suitable for small volumes of starting material. We identified annexin I + II, electron transfer flavoprotein β‐chain, H+‐transporting ATP synthase, mitofilin and protein disulfide isomerase A3 as membrane and cytokeratin 8 + 18, actin and others as soluble proteins using matrix assisted laser desorption/ionization‐time of flight (MALDI‐TOF) analysis and started to map the A549 cell proteome. Our data suggest that membrane proteins can be extracted efficiently from small samples using a simple sequential protein extraction method. They can be separated and identified successfully using optimized conditions in 2‐D gel electrophoresis. The presented methods will be useful for further investigations of membrane proteins of alveolar and bronchial carcinomas.
Improved resolution with microchip‐based enhanced field inversion electrophoresis
Authors: Backhouse Christopher J. , Gajdal Ania , Pilarski Linda M. , Crabtree H. John
Published: May 2003

We present an improvement of the field inversion electrophoresis (FIE) method in which the passage of sample such as DNA back and forth within a short length of a microchannel can provide a similar resolution to that of a significantly longer microchannel. In constant field FIE the application of an alternating potential (e.g., +/− V) over short periods of time (e.g., several Hz) can provide enhanced separations of DNA fragments. In contrast, the present method consists of a series of separations, each of much longer duration, under high and low fields in such a way that the resolution is enhanced. This method is readily modeled and allows improved resolution to be obtained from extremely short microchannels (e.g., 8 mm) while requiring relatively low applied voltages (e.g., less than 600 V). An additional advantage is that this method can allow for the same equipment to be used in a rapid, low‐resolution mode or in a slower, high‐resolution mode through what might be referred to as an automated “zoom” capability. We believe that this method may facilitate the integration of microfluidic devices and microelectronic devices by allowing these devices to be of a similar small scale (< 1 cm).
A versatile electrophoresis system for the analysis of high‐ and low‐molecular‐weight proteins
Authors: Tastet Christophe , Lescuyer Pierre , Diemer Hélène , Luche Sylvie , van Dorsselaer Alain , Rabilloud Thierry
Published: May 2003

A new, versatile, multiphasic buffer system for high‐resolution sodium dodecyl sulfate‐polyacrylamide gel electrophoresis of proteins in the relative molecular weight range of 300 000–3000 Da is described. The system, based on the theory of multiphasic zone electrophoresis, allows complete stacking and destacking of proteins in the above Mr range. The buffer system uses taurine and chloride as trailing and leading ion, respectively, and Tris, at a pH close to its pKa, as the buffering counterion. Coupled with limited variation in the acrylamide concentration, this electrophoresis system allows to tailor the resolution in the 6–200 kDa Mr range, with minimal difficulties in the post electrophoretic identification processes.
A rat brain protein expression map including cytosolic and enriched mitochondrial and microsomal fractions
Authors: Krapfenbauer Kurt , Fountoulakis Michael , Lubec Gert
Published: May 2003

Proteomics is a powerful tool to screen brain protein expression but the methodology is hampered by low abundance of proteins or compartmentalization or overload of high‐abundance proteins. It was therefore the aim of the study to determine the expression of brain proteins by using enriched cellular subfractions and pre‐electrophoretic chromatographical separation of brain homogenates. We used two‐dimensional electrophoresis with subsequent matrix‐assisted laser desorption/ionization (MALDI) detection and characterization of brain proteins. Subfractionation into cytosolic, mitochondrial and microsomal compartments was performed by ultracentrifugation. Pre‐electrophoretic fractionation of the cytosolic fractions was carried out by ion exchange column chromatography. We detected and identified a large series of 437 proteins in rat brain and have shown proteins specific for the individual subcellular compartments. These proteins included housekeeping, signaling, cytoskeletal, intermediary metabolism, antioxidant proteins on the one and neuron and synaptosomal specific proteins on the other hand. Using fractionations of brain homogenates we were able to improve the power of the method on forming the basis for brain protein expressional studies and providing a reference map as a powerful tool for the neuroscientist.
Electrophoretic separation and confocal laser‐induced fluorescence detection at ultralow concentrations in constricted fused‐silica capillaries
Authors: Lundqvist Anders , Chiu Daniel T. , Orwar Owe
Published: May 2003

Laser‐induced fluorescence detection of labeled amino acids in a flowing stream at femtomolar (10−15M) concentrations was achieved by using a fused‐silica capillary flow‐cell comprising a constricted thin‐walled detection region with inner diameters (IDs) ranging from 2 to 8 μm. The diameter of the constricted region was made to match a diffraction‐limited focus of a uniphase transverse electromagnetic mode (TEM00) laser beam. Optimization of capillary dimensions and geometries (i.e., curvature, wall thickness, and outer‐inner diameter ratio were performed in order to minimize cylindrical lensing of the focused laser beam. The fluorescence was collected in a confocal optical setup using a 1.3 numerical aperture (NA), 100× oil‐immersion objective and a single‐photon‐counting avalanche diode (SPAD). Under conditions of fluid flow, the constriction in the capillary forces all analytes to traverse across the laser probe volume, resulting in a high sampling efficiency. Fluorescein isothiocyanate‐labeled glutamate (FITC‐Glu) was electrophoretically separated and detected in capillaries having an ID of 2 μm at the constricted region with detection limits of 250 fM (signal‐to‐noise ratio (S/N) = 3) in the injected solution.
Method for clone checking
Authors: Nourizad Nader , Gharizadeh Baback , Nyrén Pål
Published: May 2003

A new method for simple and fast clone checking is described. We combined the Pyrosequencing™ technology with a preprogrammed nucleotide dispensation strategy for fast analysis of DNA constructs. To test this method, the N‐terminus region of plasmids constructed for the production of recombinant apyrase was analyzed. Of the ten plasmids tested, seven constructs were correct, two constructs showed one base deletion, and one construct showed deletion of a 195 bp fragment. The preprogrammed nucleotide dispensation strategy allowed the identification of the sequence downstream of the deletions. Thus, this method determines both the location and nature of possible artifacts.
On the convergence of the finite integration technique for the anisotropic boundary value problem of magnetic tomography
Authors: Potthast Roland , Kühn Lars
Published: May 2003

The reconstruction of a current distribution from measurements of the magnetic field is an important problem of current research in inverse problems. Here, we study an appropriate solution to the forward problem, i.e. the calculation of a current distribution given some resistance or conductivity distribution, respectively, and prescribed boundary currents. We briefly describe the well‐known solution of the continuous problem, then employ the finite integration technique as developed by Weiland et al. since 1977 for the solution of the problem. Since this method can be physically realized it offers the possibility to develop special tests in the area of inverse problems. Our main point is to provide a new and rigorous study of convergence for the boundary value problem under consideration. In particular, we will show how the arguments which are used in the proof of the continuous case can be carried over to study the finite‐dimensional numerical scheme. Finally, we will describe a program package which has been developed for the numerical implementation of the scheme using Matlab. Copyright © 2003 John Wiley & Sons, Ltd.