bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parallel‐connected monolithic dye‐sensitised solar modules
Authors: Pettersson Henrik , Gruszecki Tadeusz , Schnetz Christine , Streit Micha , Xu Yunhua , Sun Licheng , Gorlov Mikhail , Kloo Lars , Boschloo Gerrit , Häggman Leif , Hagfeldt Anders 
Published: April 2010

AbstractLight‐soaking and high‐temperature storage testing of monolithic dye‐sensitised solar modules with total area module efficiencies above 5% have been performed. Our experiences from the development of a four‐layer monolithic dye‐sensitised solar test cell for comparative testing of material components for dye‐sensitised solar cells have directed our module development to a novel device design consisting of parallel‐connection of individual monolithic cells. The results from the accelerated testing of the modules (total area of 17.0 cm2) with four parallel‐connected cells (active area of 3.38 cm2/cell) are equivalent to those obtained for the monolithic single test cells when using identical device components. The successful transfer from cell to module stability is an important milestone in our ambition to develop a low‐cost Photovoltaic (PV) technology. Moreover, our results indicate that intensified research and development to define the procedures for relevant accelerated testing of dye‐sensitised solar modules is urgently required. Copyright © 2010 John Wiley & Sons, Ltd.
Lambertian matched absorption enhancement in PECVD poly‐Si thin film on aluminum induced textured glass superstrates for solar cell applications
Authors: Jin Guangyao , Widenborg Per I. , Campbell Patrick , Varlamov Sergey 
Published: April 2010

AbstractThis paper examines the effectiveness of a range of aluminum induced textured (AIT) glass topographies at enhancing light absorption in silicon thin film diode structures deposited on the textured glass side, operating in the superstrate configuration. The aluminum layer used to produce the AIT can be deposited either by thermal evaporation or magnetron sputtering. Varying AIT process parameters produces a wide range of feature roughness and uniformity, providing scope to optimize texture effectiveness and process repeatability. We report strong correlation between the degree of absorption enhancement from these textures and both dark field microscope images of the AIT glass and reduction of the interference envelope in spectral reflectance of the deposited silicon films. Our findings corroborate earlier modeling work based on ray tracing, which predicted that the best enhancement occurs when the feature size is close to the film thickness. In this paper we investigate AIT samples in the 1 – 3 µm film thickness range, some of which trap light in silicon as strongly as at the Lambertian limit. Copyright © 2010 John Wiley & Sons, Ltd.
Two‐state conformational equilibrium in the Par‐4 leucine zipper domain
Authors: Schwalbe Martin , Dutta Kaushik , Libich David S. , Venugopal Hariprasad , Claridge Jolyon K. , Gell David A. , Mackay Joel P. , Edwards Patrick J. B. , Pascal Steven M. 
Published: April 2010

AbstractProstate apoptosis response factor‐4 (Par‐4) is a pro‐apoptotic and tumor‐suppressive protein. A highly conserved heptad repeat sequence at the Par‐4 C‐terminus suggests the presence of a leucine zipper (LZ). This C‐terminal region is essential for Par‐4 self‐association and interaction with various effector proteins. We have used nuclear magnetic resonance (NMR) spectroscopy to fully assign the chemical shift resonances of a peptide comprising the LZ domain of Par‐4 at neutral pH. Further, we have investigated the properties of the Par‐4 LZ domain and two point mutants under a variety of conditions using NMR, circular dichroism (CD), light scattering, and bioinformatics. Results indicate an environment‐dependent conformational equilibrium between a partially ordered monomer (POM) and a predominantly coiled coil dimer (CCD). The combination of techniques used allows the time scales of the equilibrium to be probed and also helps to identify features of the amino acid sequence that may influence the equilibrium. Proteins 2010. © 2010 Wiley‐Liss, Inc.
Structure and interactions of the C‐terminal metal binding domain of Archaeoglobus fulgidus CopA
Authors: Agarwal Sorabh , Hong Deli , Desai Nirav K. , Sazinsky Matthew H. , Argüello José M. , Rosenzweig Amy C. 
Published: April 2010

AbstractThe Cu+‐ATPase CopA from Archaeoglobus fulgidus belongs to the P1B family of the P‐type ATPases. These integral membrane proteins couple the energy of ATP hydrolysis to heavy metal ion translocation across membranes. A defining feature of P1B‐1‐type ATPases is the presence of soluble metal binding domains at the N‐terminus (N‐MBDs). The N‐MBDs exhibit a conserved ferredoxin‐like fold, similar to that of soluble copper chaperones, and bind metal ions via a conserved CXXC motif. The N‐MBDs enable Cu+ regulation of turnover rates apparently through Cu‐sensitive interactions with catalytic domains. A. fulgidus CopA is unusual in that it contains both an N‐terminal MBD and a C‐terminal MBD (C‐MBD). The functional role of the unique C‐MBD has not been established. Here, we report the crystal structure of the apo, oxidized C‐MBD to 2.0 Å resolution. In the structure, two C‐MBD monomers form a domain‐swapped dimer, which has not been observed previously for similar domains. In addition, the interaction of the C‐MBD with the other cytoplasmic domains of CopA, the ATP binding domain (ATPBD) and actuator domain (A‐domain), has been investigated. Interestingly, the C‐MBD interacts specifically with both of these domains, independent of the presence of Cu+ or nucleotides. These data reinforce the uniqueness of the C‐MBD and suggest a distinct structural role for the C‐MBD in CopA transport. Proteins 2010. © 2010 Wiley‐Liss, Inc.
Growth of pattern‐free InN micropyramids by metalorganic chemical vapor deposition
Authors: Jamil Muhammad , Xu Tianming , Zaidi Tahir , Melton Andrew , Jampana Balakrishnam , Tan Chee‐Loon , Ooi Boon S. , Ferguson Ian T. 
Published: April 2010

AbstractWe report on the growth of unidirectional InN micropyramids by using a simple pattern‐free epitaxial technique. These pyramids were grown on a GaN layer deposited on sapphire via metalorganic chemical vapor deposition (MOCVD). The XRD full width at half maximum (FWHM) was observed to be as low as 0.16° for the InN (0002)ωrocking curve which indicates very good crystal quality of these InN pyramids. The Photoluminescence (PL) emission of InN micropyramids is ∼0.78 eV. The dependency on growth conditions of pyramid density, facet stabilization, and pyramid structural quality have been evaluated and discussed.
Sol–gel derived metal oxides doped with silver nanoparticles as tunable plasmonic materials
Authors: Dolgov Leonid , Kiisk Valter , Reedo Valter , Maaroos Aarne , Sildos Ilmo , Kikas Jaak 
Published: April 2010

AbstractNew composite materials made of transition metal oxides doped with silver nanoparticles are proposed. Titanium and zirconium dioxide matrices were prepared by sol–gel method adjusted for addition of silver nanodopants. Commercially available silver nanoparticles in the form of powder (30–50 nm) or colloidal solution (5–15 nm) were used for doping of oxide hosts. To recover plasmonic properties of silver after annealing in air, reduction of samples in the H2:Ar atmosphere was performed. As a result, the silver‐containing TiO2 and ZrO2 films of good optical quality with plasmonic absorption near 400 nm were obtained. The potential of embedding of luminescent markers (like rare earth ions) into considered films is discussed.
Lean neodymium Nd–Fe–B magnets containing minor addition of titanium
Authors: Spyra Marzena , Derewnicka Daniela , Leonowicz Marcin 
Published: April 2010

AbstractThe effect of titanium addition on the structure and magnetic properties was studied for the nanocomposite Nd7Fe79–xB14Tix and Nd8Fe78–xB14Tix systems. The alloys were rapidly solidified by melt‐spinning with the roll speed 20 m/s. The overquenched, amorphous ribbons were subsequently crystallization annealed for 20 min at 953–973 K. It was found that the addition of 2 and 4 at% of Ti leads to a substantial increase of the coercivity and maximum energy product of the nanocomposite magnets while maintaining the remanence unchanged. The highest properties were obtained for the alloys containing 4 at% of Ti. The maximum energy product of 143 kJ/m3 was achieved for the Nd8Fe74B14Ti4 alloy. The TEM studies showed substantial differences in the morphology of the alloys. The ternary alloys contain grains of various sizes of approximately 300 nm. The alloys containing 4 at% of Ti exhibit more homogeneous structure with the crystal sizes up to 30 and 50 nm for the Nd8Fe74B14Ti4 and Nd7Fe75B14Ti4 alloys, respectively. More detailed information on the phase constitution was obtained from the Mössbauer spectroscopy. Comparison of the Ti‐free and 4 at% Ti alloys revealed that the amount of the hard magnetic Nd2Fe14B phase decreases from 84.53 to 69.88% for the Nd7Fe79–xB14Tix system and increased from 66.60 to 82.48% for Nd8Fe78–xB14Tix system.
Corrosion resistance of nickel‐free austenitic stainless steels/hydroxyapatite composites
Authors: Tulinski Maciej , Jurczyk Mieczyslaw 
Published: April 2010

AbstractIn a newly introduced manufacturing process of nickel‐free austenitic stainless steels with nitrogen absorption treatment (M. Sumita et al., Mater. Sci. Eng. C 24, 753 (2004) [1]), small devices can be precisely machined in a ferritic phase and than during nitrogenization of their surfaces in nitrogen gas at temperature approx. 1200 °C they become nickel‐free austenitic stainles steels with better mechanical and corrosion resistance properties. Using the combination of mechanical alloying (MA), heat treatment and nitrogenation of elemental microcrystalline Fe, Cr, Mn and Mo powders it is possible to synthesize a nanocrystalline nickel‐free stainless steels. Nanocomposites with addition of hydroxyapatite (HA) have been prepared for the best samples. Phase transformation from ferritic to austenitic was confirmed by XRD analysis. Also the microhardness of the final bulk material was studied using Vickers method. The result is almost two times greater than in austenitic steel obtained by conventional methods. This effect is directly connected with structure refinement and nitriding. Mechanical alloying and nitriding are very effective technologies to improve also the corrosion resistance of stainless steel. Decreasing the corrosion current density is a distinct advantage for prevention of ion release and it leads to better cytocompatibility. According to existing conceptions, decreasing of material's crystallites size to nanometric scale allows to achieve much better mechanical properties (e.g. microhardness) compared to conventional materials (A.S. Edelstain et al., Prog. Mater. Sci. 42, 5 (1997) [2]). The results show that from mechanical and corrosion properties point of view nanocrystalline nickel‐free stainless steels and nickel‐free stainless steel/hydroxyapatite nanocomposites could be promising bionanomaterials for use as a hard tissue replacement implants, e.g. orthopedic implants. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of palladium addition on the electrochemical properties of amorphous 2Mg + 3d alloys doped by nickel atoms (3d = Fe, Ni)
Authors: Jarzebski Maciej , Okonska Izabela , Jurczyk Mieczyslaw 
Published: April 2010

AbstractAmorphous 2Mg+ 3d/x wt% Ni materials were prepared by mechanical alloying (MA) of Mg and 3d elemental powders (3d = Fe, Ni x =0, 100 and 200 wt.%) under high purity argon atmosphere in SPEX 8000 Mixer Mill. The effect of the Ni addition on the electrochemical properties of the synthesized nanostructured alloys was investigated in details. The discharge capacity of amorphous 2Mg+Fe (Ni) high energy ball milled with Ni was improved. With increasing nickel content in the studied 2Mg+Fe (Ni) materials, at first cycle, the discharge capacity increases first and then decreases, and for example, for x = 100 in 2Mg+Fe reaches a maximum value of 155 mAh g–1. Additionally, when coated with palladium, the discharge capacity of an amorphous 2Mg+Fe (Ni) powders was increased as well. The catalytic elements (Ni, Pd) were distributed on the surface of ball milled alloy particles homogenously and role of these particles is to catalyze the dissociation of molecular hydrogen on the surface of studied alloy. Mechanical coating with palladium effectively reduced the degradation rate of the studied electrode materials. Compared to that of the uncoated powders, the degradation of the coated was suppressed. The amorphous Mg‐based hydrides offer a breakthrough in prospects for practical applications (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
XRD study of the transformation characteristics of severely plastic deformed Ni‐Ti SMAs
Authors: Braz Fernandes Francisco M. , Mahesh Karimbi K. , Silva Rui J. C. , Gurau Carmela , Gurau Gheorghe 
Published: April 2010

AbstractSevere plastic deformation (SPD) of Ni‐Ti alloys (Ti‐rich and Ni‐rich) has been performed by High Pressure Torsion (HPT). Aim of the study was to follow the structural evolution in the samples subjected to SPD, in the martensite ↔ austenite phase transformation temperature region. HPT is carried out at room temperature (RT) on two separate Ni‐Ti alloy samples, Ti‐rich alloy with martensite finish temperature (Mf) above and Ni‐rich with austenite finish temperature (Af) below RT. The samples have been studied by in situ X‐ray diffraction (XRD) in order to get information about (i) the transformation characteristics and (ii) the structural evolution after annealing. The results showed that the Ti‐rich alloy retained one step phase transformation (Martensite ↔ Austenite) after HPT, as well as HPT followed by heat treatment. In the HPT condition, Ni‐rich alloy were found to undergo one step phase transformation (Martensite ↔ Austenite), whereas, heat treatment after HPT resulted in the presence of intermediate R‐phase transformation both while heating and cooling in the diffraction chamber. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
FeCoBSiNb bulk metallic glasses with Cu additions
Authors: Stoica Mihai , Roth Stefan , Eckert Jürgen , Karan Trisha , Ram Shanker , Vaughan Gavin , Yavari Alain Reza 
Published: April 2010

AbstractThe effect of Cu additions (1, 2 and 3 at.%) on the glass forming ability (GFA) and magnetic properties of [(Fe0.5Co0.5)0.75Si0.05B0.20]96Nb4 is studied. As the Cu content increases, the GFA deteriorates. The structure of the samples, as well as the crystallization behavior was in‐situ studied by means of synchrotron beam. The as‐cast 1 mm diameter rods are characterized by a mixture of (nano)‐crystals and amorphous matrix. Upon heating, the pre‐existing nuclei grow, without forming new crystalline phases. The magnetic properties are characteristic for soft magnetic materials. Despite that several crystalline magnetic phases can be identified in the as‐cast samples, only one single magnetic transition prior to complete crystallization could be identified upon heating. The values for saturation magnetization and for Curie temperature are relatively close for all samples. The initial permeability of the Cu containing samples seems to be higher than that for the fully amorphous [(Fe0.5Co0.5)0.75Si0.05B0.20]96Nb4 alloy (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ab‐initio modeling of a‐Si and a‐Si:H
Authors: Ribeiro Ricardo M. , Torres Vítor J B. , Vasilevskiy Mikhail I. , Barros André , Briddon Patrick R. 
Published: April 2010

AbstractThe simulation of a‐Si is complicated because there is no direct experimental data, as there are for crystals. Our approach to simulate a‐Si is to build several relatively small amorphous samples and, later, the properties we wish to calculate are averaged over all samples. We applied the Wooten, Winer and Weaire bond switch to 64 atom cubic supercell of crystalline silicon. This mechanism was used to create 15 samples of continuous random network of silicon. For each supercell, the volume and atomic relaxation were allowed in order to minimize the total energy, using a density functional‐pseudopotential code. The radial and angular distributions, the electronic and vibrational density of states, and the Raman spectra were calculated. The radial distribution agrees very well with experimental data. The angular distribution has its maximum at 109.4 degree. The experimental positions and relative intensities of the Transverse Optical (TO) and Transverse Acoustic vibrational modes are well reproduced, with 14 and 25 cm‐1 peak deviations, respectively. The shape of the calculated Raman spectra agrees well with experimental data, being the intense TO peak shifted by 50 cm‐1. The TO width at half‐weight is very well reproduced. Introducing hydrogen in the a‐Si samples, decorating all the undercoordinated Si atoms and at bond centres of floating bonds, the hydrogen vibrational frequencies of the relaxed structures agree very well with experimental data. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural elucidation ofN‐oxidized clemastine metabolites by liquid chromatography/tandem mass spectrometry and the use ofCunninghamella elegansto facilitate drug metabolite identification
Authors: Åberg Annica Tevell , Löfgren Helena , Bondesson Ulf , Hedeland Mikael 
Published: April 2010

AbstractCunninghamella elegansis a filamentous fungus that has been shown to biotransform drugs into the same metabolites as mammals. In this paper we describe the use ofC. elegansto aid the identification of clemastine metabolites since high concentrations of the metabolites were produced and MSnexperiments were facilitated. The combination of liquid chromatography and tandem mass spectrometry with two different ionization techniques and hydrogen/deuterium exchange were used for structural elucidation of the clemastine metabolites. Norclemastine, four isomers of hydroxylated clemastine, and twoN‐oxide metabolites were described for the first time inC. elegansincubations. TheN‐oxidations were confirmed by hydrogen/deuterium exchange and deoxygenation (−16 Da) upon atmospheric pressure chemical ionization mass spectrometry. By MSnfragmentation it was concluded that two of the hydroxylated metabolites were oxidized on the methylpyrridyl moiety, one on the aromatic ring with the chloro substituent, and one on the aromatic ring without the chlorine. Copyright © 2010 John Wiley & Sons, Ltd.
Behaviour of tetraalkylammonium ions in high‐field asymmetric waveform ion mobility spectrometry
Authors: Aksenov Alexander A. , Kapron James T. 
Published: April 2010

AbstractHigh‐field asymmetric waveform ion mobility spectrometry (FAIMS) is an ion‐filtering technique recently adapted for use with liquid chromatography/mass spectrometry (LC/MS) to remove interferences during analysis of complex matrices. This is the first systematic study of a series of singly charged tetraalkylammonium ions by FAIMS‐MS. The compensation voltage (CV) is the DC offset of the waveform which permits the ion to emerge from FAIMS and it was determined for each member of the series under various conditions. The electrospray ionization conditions explored included spray voltage, vaporizer temperature, and sheath and auxiliary gas pressure. The FAIMS conditions explored included carrier gas flow rate, electrode temperature and composition of the carrier gas. Optimum desolvation was achieved using sufficient carrier gas (flow rate ≥2 L/min) to ensure stable response. Low‐mass ions (m/z 100–200) are more susceptible to changes in electrode temperature and gas composition than high mass ions (m/z 200–700). As a result of this study, ions are reliably analyzed using standard FAIMS conditions (dispersion voltage −5000 V, carrier gas flow rate 3 L/min, 50% helium/50%nitrogen, inner electrode temperature 70°C and outer electrode temperature 90°C). Variation of FAIMS conditions may be of great use for the separation of very low mass tetraalkylammonium (TAA) ions from other TAA ions. The FAIMS conditions do not appear to have a major effect on higher mass ions. Copyright © 2010 John Wiley & Sons, Ltd.
Sequential Fe3O4/TiO2 enrichment for phosphopeptide analysis by liquid chromatography/tandem mass spectrometry
Authors: Choi Sunkyu , Kim Jaeyoon , Cho Kun , Park Gunwook , Yoon Jong Hyuk , Park Sehoon , Yoo Jong Shin , Ryu Sung Ho , Kim Young Hwan , Kim Jeongkwon 
Published: April 2010

AbstractProtein phosphorylation regulates a wide range of cellular functions and is associated with signaling pathways in cells. Various strategies for enrichment of phosphoproteins or phosphopeptides have been developed. Here, we developed a novel sequential phosphopeptide enrichment method, using magnetic iron oxide (Fe3O4) and titanium dioxide (TiO2) particles, to detect mono‐ and multi‐phosphorylated peptides. In the first step, phosphopeptides were captured on Fe3O4 particles. In a subsequent step, any residual phosphopeptides were captured on TiO2 particles. The particles were eluted and rinsed to yield phosphopeptide‐enriched fractions that were combined and analyzed using liquid chromatography/tandem mass spectrometry (LC/MS/MS). The validity of this sequential Fe3O4/TiO2 enrichment strategy was demonstrated by the successful enrichment of bovine α‐casein phosphopeptides. We then applied the sequential Fe3O4/TiO2 enrichment method to the analysis of phosphopeptides in L6 muscle cell lysates and successfully identified mono‐ and multi‐phosphorylated peptides. Copyright © 2010 John Wiley & Sons, Ltd.
Accelerator mass spectrometry offers new opportunities for microdosing of peptide and protein pharmaceuticals
Authors: Salehpour Mehran , Ekblom Jonas , Sabetsky Vladimir , Håkansson Karl , Possnert Göran 
Published: April 2010

AbstractAccelerator Mass Spectrometry (AMS) is an ultra‐sensitive analytical method which has been instrumental in developing microdosing as a strategic tool in early drug development. Considerable data is available for AMS microdosing using typical pharmaceutical drugs with a molecular weight of a few hundred Daltons. The so‐called biopharmaceuticals such as proteins offer interesting possibilities as drug candidates; however, experimental data for protein microdosing and AMS is scarce. The analysis of proteins in conjunction with early drug development and microdosing is overviewed and three case studies are presented on the topic. In the first case study AMS experimental data is presented, for the measured concentration of orally administered recombinant insulin in the blood stream of laboratory rabbits. Case study 2 concerns minimum sample size requirements. AMS samples normally require about 1 mg of carbon (10 µL of blood) which makes AMS analysis unsuitable in some applications due to the limited availability of samples such as human biopsies or DNA from specific cells. Experimental results are presented where the sample size requirements have been reduced by about two orders of magnitude. The third case study concerns low concentration studies. It is generally accepted that protein pharmaceuticals may be potentially more hazardous than smaller molecules because of immunological reactions. Therefore, future first‐in‐man microdosing studies might require even lower exposure concentrations than is feasible today, in order to increase the safety margin. This issue is discussed based on the current available analytical capabilities. Copyright © 2010 John Wiley & Sons, Ltd.