bluuebunny/crossref_metadata_2025 huggingface dataset:
The mechanism of ultrasonic improvement of weld line strength of injection molded polystyrene and polystyrene/polyethylene blend parts
Authors: Lu Chang , Yu Xiaofeng , Guo Shaoyun
Published: April 2006

The effect of ultrasonic oscillations and ultrasonic oscillation‐induced modes on weld line strength of polystyrene(PS) and polystyrene/polyethylene(PS/HDPE) blend was investigated. And the mechanism of ultrasonic improvement of weld line strength of PS and PS/HDPE blend was also studied. The presence of ultrasonic oscillations can enhance the weld line strength of PS and PS/HDPE blend. Compared with mode I(ultrasonic oscillations were induced into mold at the whole process of injection molding), the induced ultrasonic oscillations as mode II(ultrasonic oscillations were induced into mold after injection mold filling) is more effective to increase weld line strength of PS and PS/HDPE blend. The mechanism for ultrasonic improvement of weld line strength of PS and PS/HDPE blend is that the ultrasonic oscillations can improve the molecular diffusion across weld line of the melt at the core, and make against the fusion of melt at the skin. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1520–1530, 2006
An infiltration method for preparing single‐wall nanotube/epoxy composites with improved thermal conductivity
Authors: Du Fangming , Guthy Csaba , Kashiwagi Takashi , Fischer John E. , Winey Karen I.
Published: April 2006

Recent studies of SWNT/polymer nanocomposites identify the large interfacial thermal resistance at nanotube/nanotube junctions as a primary cause for the only modest increases in thermal conductivity relative to the polymer matrix. To reduce this interfacial thermal resistance, we prepared a freestanding nanotube framework by removing the polymer matrix from a 1 wt % SWNT/PMMA composite by nitrogen gasification and then infiltrated it with epoxy resin and cured. The SWNT/epoxy composite made by this infiltration method has a micron‐scale, bicontinuous morphology and much improved thermal conductivity (220% relative to epoxy) due to the more effective heat transfer within the nanotube‐rich phase. By applying a linear mixing rule to the bicontinuous composite, we conclude that even at high loadings the nanotube framework more effectively transports phonons than well‐dispersed SWNT bundles. Contrary to the widely accepted approaches, these findings suggest that better thermal and electrical conductivities can be accomplished via heterogeneous distributions of SWNT in polymer matrices. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1513–1519, 2006
Disulfide connectivity prediction with 70% accuracy using two‐level models
Authors: Chen Bo‐Juen , Tsai Chi‐Hung , Chan Chen‐hsiung , Kao Cheng‐Yan
Published: April 2006

Disulfide bridges stabilize protein structures covalently and play an important role in protein folding. Predicting disulfide connectivity precisely helps towards the solution of protein structure prediction. Previous methods for disulfide connectivity prediction either infer the bonding potential of cysteine pairs or rank alternative disulfide bonding patterns. As a result, these methods encode data according to cysteine pairs (pair‐wise) or disulfide bonding patterns (pattern‐wise). However, using either encoding scheme alone cannot fully utilize the local and global information of proteins, so the accuracies of previous methods are limited. In this work, we propose a novel two‐level framework to predict disulfide connectivity. With this framework, both the pair‐wise and pattern‐wise encoding schemes are considered. Our models were validated on the datasets derived from SWISS‐PROT 39 and 43, and the results demonstrate that our models can combine both local and global information. Compared to previous methods, significant improvements were obtained by our models. Our work may also provide insights to further improvements of disulfide connectivity prediction and increase its applicability in protein structure analysis and prediction. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Diagnostics for confounding in PK/PD models for oxcarbazepine
Authors: Nedelman Jerry R. , Rubin Donald B. , Sheiner Lewis B.
Published: April 2006

One type of pharmacokinetic/pharmacodynamic (PK/PD) relationship that is used to characterize the therapeutic action of a drug is the relationship between some univariate summary of the plasma‐concentration‐versus‐time profile and the drug effect on a response outcome. Operationally, such a relationship may be observed in a large clinical trial where randomly sampled patients are randomized to different values of the concentration summary. If, under such conditions, the relationship between concentration and effect does not depend on the dose needed to attain the target concentration, such a relationship will be called a true PK/PD relationship. When the true PK/PD relationship is assessed as an object of estimation in a dose‐controlled clinical trial (i.e. when dose is randomized), observed drug concentration is an outcome variable. The estimated PK/PD relationship between observed outcome and observed concentration, which we then refer to as the conventional PK/PD relationship, may be biased for the true PK/PD relationship. Because of this bias, the conventional relationship is called confounded for the true one. We show that diagnostics for confounding can be devised under reasonable assumptions. We then apply these diagnostics to PK/PD assessments of adults and children on oxcarbazepine adjunctive therapy. It was necessary to demonstrate the similarity of the true PK/PD relationships of adults and children on adjunctive therapy in order to support the approval of oxcarbazepine monotherapy in children by a bridging argument. Copyright © 2006 John Wiley & Sons, Ltd.
A note on parameter estimation for variant Creutzfeldt–Jakob disease epidemic models
Authors: Clarke Paul S. , Ghani Azra C.
Published: April 2006

A recent series of papers has raised issues regarding estimation of the key epidemiological parameters of variant Creutzfeldt–Jakob disease (vCJD) from fitting survival models to case data. In particular, it was stated that the scale of the epidemic cannot be estimated and must be fixed in any analysis. We show that this problem is an artefact of the approximate likelihood used in these papers to facilitate model‐fitting, and is not a concern if estimation is based on the full likelihood. We also address comments in these papers regarding the choice of incubation period distribution. Copyright © 2006 John Wiley & Sons, Ltd.
Measurement of inter‐rater agreement for transient events using Monte Carlo sampled permutations
Authors: Norman Robert G. , Scott Marc A.
Published: April 2006

In this paper we demonstrate the adverse effect of serially observed data sequences containing transient events on the calculation of Cohen's κ as an index of inter‐rater agreement in the detection of these events. We develop and use a Monte‐Carlo‐based permutation technique to produce an empiric distribution of κ in the presence of serial dependence. We find that the empiric confidence intervals for κ tend to be wider than parametrically derived intervals and in the case of longer event lengths, are markedly so. We evaluate the effect of number and length of events, and further, describe and evaluate three permutation methods which match specific rating situations. Finally, we apply these techniques to the measurement of inter‐rater agreement for sleep disordered breathing events, a transient event identified during nocturnal polysomnography, for which traditionally computed confidence intervals for κ are incorrect. Copyright © 2006 John Wiley & Sons, Ltd.
Knowledge management in OSS—an enterprise information system for the telecommunications industry
Authors: Qi Jiayin , Da Xu Li , Shu Huaying , Li Huaizu
Published: April 2006

Knowledge management in Enterprise Information Systems (EIS) has become one of the hottest research topics in the last few years. Operations Support Systems (OSS) is one kind of EIS, which is becoming increasingly popular in the telecommunications industry. However, the academic research on knowledge management in OSS is sparse. In this paper, a knowledge management system for OSS is proposed in the framework of systems theory. Knowledge, knowledge management, organization and information technology are the four main interactive elements in the knowledge management system. The paper proposes that each subsystem of the OSS is to be equipped with knowledge management capacity, and the knowledge management of the OSS is to be realized through its subsystems. Copyright © 2006 John Wiley & Sons, Ltd.
Enterprise resource planning for large‐scale engineering projects from systems engineering perspectives
Authors: Yang Tianshe , Huang Huijing , Chaudhry Sohail
Published: April 2006

ERP systems for the manufacturing sector are commercially available and research on ERP systems for manufacturing enterprises is prevalent now. However, little attention has so far been paid on how to establish ERP systems for large scale engineering projects. An ERP system for a specific engineering project is usually not available commercially. In this paper, the methods and models for establishing an ERP system for a large‐scale engineering project with unique features are discussed in systems engineering perspectives. First, the necessity for establishing ERP system is analysed; second, the methods and models for developing, implementing and maintaining the ERP system are discussed; third, the successful experiences of establishing the ERP system are illustrated and finally, a conclusion is provided. Copyright © 2006 John Wiley & Sons, Ltd.
Deriving information from CRM for knowledge management—a note on a commercial bank
Authors: Chen Yarong , Li Ling
Published: April 2006

In today's highly competitive global economy, many companies are enhancing their enterprise information systems that include enterprise resource planning (ERP), customer relationship management (CRM) and supply chain management (SCM). In this study, we report some preliminary results of integrating customer satisfaction index into knowledge management in a commercial bank in Shanghai, China. The result of the study indicates that the most influential factors that affect corporate customers' satisfaction are customer relationship and service process. Both factors are served as inputs to knowledge management which generates some new ideas for improving customer services. CRM is a component of enterprise information systems. The study can be a reference to other commercial banks to improve their competence of CRM and knowledge management. Copyright © 2006 John Wiley & Sons, Ltd.
A systems approach to developing and implementing an ERP financial subsystem
Authors: Zhu Zhuqiang
Published: April 2006

In recent years, progress has been made in applying ERP financial subsystems to business enterprises despite that certain obstacles still exist. For example, a number of internal functions have not been fully realized yet, and integration with other subsystems has not been fully realized. The main problems include the implementation goal being not well set, sufficient attention has not been paid by senior management, lack of qualified staff, and the limited scope of system integration. In this paper, the implementation of an ERP financial subsystem is studied in terms of systems research, with the emphasis on two aspects: optimizing the system and its elements, and better integration of the system with its environment. Copyright © 2006 John Wiley & Sons, Ltd.
Designing ERP systems with knowledge management capacity
Authors: Li Zongbin , Chaudhry Sohail S. , Zhao Shanshan
Published: April 2006

Globally, over the past decade, there has been a tremendous proliferation of the traditional enterprise resource planning systems in businesses. In addition, the economy has evolved into a knowledge‐based economy that has made knowledge a valuable asset for businesses. As knowledge‐based economy evolves and businesses implement enterprise resource planning systems, it is inevitable that there is a need to integrate enterprise resource planning systems and knowledge management. In this paper, we discuss the design issues of enterprise resource planning systems in the knowledge‐based economy environment. Enterprise resource planning systems based on knowledge management combine traditional enterprise resource planning and knowledge management effectively and are suitable in the knowledge‐based economy as the new requirement of enterprises. Copyright © 2006 John Wiley & Sons, Ltd.
Protein kinase PKC delta and c‐Abl are required for mitochondrial apoptosis induction by genotoxic stress in the absence of p53, p73 and Fas receptor
Authors: Lasfer Malika , Davenne Lise , Vadrot Nathalie , Alexia Catherine , Sadji-Ouatas Zahia , Bringuier Annie-France , Feldmann Gérard , Pessayre Dominique , Reyl-Desmars Florence
Published: April 2006

Doxorubicin, cis‐diamminedichloroplatinum (II) and 5‐fluorouracil used in chemotherapy induce apoptosis in Hep3B cells in the absence of p53, p73, and functional Fas. Since mediators remain unknown, the requirement of PKC delta (PKCδ) and c‐Abl was investigated. Suppression of c‐Abl or PKCδ expression using SiRNAs impaired PARP cleavage, Gleevec® and/or rottlerin inhibited the induction of the subG1 phase and the increase of reactive oxygen species level. Co‐precipitations and phosphorylations to mitochondria of c‐Abl, PKCδ and Bcl‐XL/s were induced. A depolarization of the mitochondrial membrane and activations of caspase‐2 and ‐9 were observed. We propose that, in the absence of p53, p73 and Fas, genotoxic drugs could require both PKCδ and c‐Abl to induce apoptosis through the mitochondrial pathway.
Visualization and sensing of intermolecular interactions with two‐color fluorescent probes
Authors: Demchenko Alexander P.
Published: April 2006

We developed a new generic fluorescence sensing technology based on the change of relative intensities between two well‐separated emission bands of the novel functional 3‐hydroxychromone (3HC) dyes. A greatly enhanced self‐calibrating wavelength‐ratiometric response is obtained to all major types of non‐covalent interactions that can be used in sensing – to polarity, hydrogen bonding ability and to local electrostatic fields. This technology may find a broad range of applications – from homogeneous assays in solutions to microarrays, microfluidic devices, nanosensors and whole cell imaging systems. It allows transforming micelles or phospholipid vesicles into nanosensor devices. In cellular research a high sensitivity to membrane potentials can be obtained and the membrane changes during apoptosis detected.
YIL042c and YOR090c encode the kinase and phosphatase of the Saccharomyces cerevisiae pyruvate dehydrogenase complex
Authors: Krause-Buchholz Udo , Gey Uta , Wünschmann Jana , Becker Susanne , Rödel Gerhard
Published: April 2006

In Saccharomyces cerevisiae the pyruvate dehydrogenase (PDH) complex is regulated by reversible phosphorylation of its Pda1p subunit. We here provide evidence that Pda1p is phosphorylated by the mitochondrial kinase Yil042cp. Deletion of YOR090c, encoding a putative mitochondrial phosphatase, results in a decreased PDH activity, indicating that Yor090cp acts as the corresponding PDH phosphatase. We demonstrate by means of blue native gel electrophoresis and tandem affinity purification that both enzymes are associated with the PDH complex.
DETERMINANTS OF CONDOM USE AMONG YOUTH IN MADAGASCAR
Authors: MEEKERS DOMINIQUE , SILVA MARTHA , KLEIN MEGAN
Published: April 2006

The objective of this study was to identify the key determinants of condom use with regular and casual partners among youth in Madagascar. Data stem from a reproductive health survey conducted in October–December 2000 among a representative sample of 2440 youth aged 15–24 living in Toamasina province. Following theoretical models of behaviour change, logistic regression was used to assess the effect of AIDS awareness, personal risk perception, condom access, perceived condom effectiveness, self-efficacy and social support on condom use. Among sexually experienced youth, only about four in ten males and two in ten females have ever used condoms. Fewer than 15% of youth used a condom in last intercourse with their regular partner. Whether youth will try condoms appears to depend largely on the perceived effectiveness of condoms for family planning, access to a nearby condom source, parental support for condom use, and patterns of risky sexual behaviour. Young males’ likelihood of using a condom with a regular partner increases significantly if they perceive condoms to be effective for family planning (OR=11·4; p=0·019). For females, it increases with level of self-efficacy (OR=2·1; p=0·042) and having discussed HIV prevention with someone in the last year (OR=2·8; p=0·022). Among males, condom use with casual partners is significantly higher among those who perceive themselves to be at high risk of sexually transmitted infections (OR=2·3; p=0·014), who believe condoms are effective for family planning (OR=2·8; p=0·048), who have good access to condoms (OR=2·9; p=0·002) and who perceive their parents support condom use (OR=1·7; p=0·048). In conclusion, very few youth in Toamasina are using condoms, highlighting the need to continue and expand adolescent reproductive health interventions. In this low HIV prevalence setting, it is important for these programmes to emphasize that condoms are effective for both pregnancy prevention and STI/HIV prevention.
ISONYMIC RELATIONSHIPS IN ETHNO-SOCIAL CATEGORIES (ARGENTINIAN COLONIAL PERIOD) INCLUDING ILLEGITIMATE REPRODUCTION
Authors: COLANTONIO SONIA E. , FUSTER VICENTE , DEL CARMEN MARÍA , LASCANO JAVIER G.
Published: April 2006

Surnames provide a useful method to study the structure of human populations for which biological data are not available. The isonymic method has had multiple applications, but difficulties emerge when dealing with groups where extramarital reproduction is common and the sample size is small, and even more so when only paternal surnames are taken into account. Therefore, it could be of interest to retain female surnames, including those of unmarried mothers. This study was carried out using all birth records from an Argentinian population in the colonial period, which was characterized by the presence of different ethno-social groups (Spanish, Indian and ‘Mestizo’ or mixed Spanish–Indian) and various reproductive patterns regarding legitimacy. Coefficient of relationship by isonymy (Ri) kinship matrices between geographical populations were obtained, and the results derived from sets of surnames (paternal, maternal of legitimate and illegitimate children, and all surnames in the registers) compared. The results show similar surname distribution regardless of the set of surnames and group considered. Kinship Ri matrices using paternal surnames, maternal surnames of legitimate children, maternal surnames of illegitimate children, and the set of whole surnames showed the same relationships among populations, indicating a similar pattern for Spanish, Indian and Mixed ethno-social groups. Mantel test correlation between all pairs of matrices was significant in all different ethno-social groups. The results suggest that in populations with high illegitimacy, such as that studied here, it is possible to include maternal surnames, even corresponding to single mothers, in order to consider total reproduction and therefore maximize sample size.
FACTORS AFFECTING THE CHOICE OF COOKING FUEL, COOKING PLACE AND RESPIRATORY HEALTH IN THE ACCRA METROPOLITAN AREA, GHANA
Authors: OWUSU BOADI KWASI , KUITUNEN MARKKU
Published: April 2006

Indoor air pollution resulting from the combustion of solid fuels has been identified as a major health threat in the developing world. This study examines how the choice of cooking fuel, place of cooking and behavioural risk factors affect respiratory health infections in Accra, Ghana. About 65·3% of respondents use charcoal and 4·2% use unprocessed wood. A total of 241 (25·4%) respondents who cook had had respiratory health symptoms in the two weeks preceding the study. Household socioeconomic status and educational attainment of respondents were found to have a significant impact on respiratory health through their particular influence on the choice of cooking fuel. Households that use wood and charcoal have a high incidence of respiratory health symptoms. The poor are more affected by respiratory health problems due to their heavy dependence on solid fuels as compared with their wealthy counterparts. Households that cook in multiple purpose rooms are more affected by respiratory health problems than those that cook outdoors. There is a positive correlation between the presence of children in the kitchen during cooking and the incidence of respiratory health symptoms among children (r=0·31, p<0·0001). Poverty and lack of education and awareness are the major factors affecting the choice of cooking fuel, place of cooking and respiratory health in Accra.
Mechanisms of ocean heat uptake in a coupled climate model and the implications for tracer based predictions of ocean heat uptake
Authors: Banks Helene T. , Gregory Jonathan M.
Published: April 2006

The distribution of tracers in the ocean is often taken as an indication of the ventilation pathways for oceanic water masses. It has been suggested that under anthropogenic forcing heat will be taken up into the interior of the ocean along isopycnal ventilation pathways. This notion is investigated by examining distributions of potential temperature and a passive anomaly temperature tracer in a coupled climate experiment where CO2 is increased at a rate of 2% per year. We show that interior temperature changes cannot be explained solely by passive tracer transport along isopycnals. Heat uptake is strongly affected by changes in circulation and has a substantial diapycnal component.
Aerosol climatology using a tunable spectral variability cloud screening of AERONET data
Authors: Kaufman Yoram J. , Gobbi Gian Paolo , Koren Ilan
Published: April 2006

Aerosols, humidity and clouds are often correlated. Therefore, rigorous cloud screening can systematically bias toward less cloudy and drier conditions, underestimating the average aerosol optical thickness (AOT). Here, using AERONET data we show that systematic rejection of variable atmospheric optical conditions can generate such bias in the average AOT. Therefore we recommend two approaches to deal with cloud contamination: (1) to introduce more powerful spectral variability cloud screening and (2) to retain most of the data despite cloud contamination, estimate average cloud contamination and to correct for it. Both methods are applied to aerosol with Ångström exponent > 0.3 and compared with the AERONET cloud screened level 1.5 data. The new methods do not apply for pure dust. Analysis for 10 AERONET stations with ∼4 years of data, shows almost no change for Rome (Italy), but up to a change in AOT of 0.12 or +30% in Beijing (PRC).
Impact of latent heat release on polar climate
Authors: Solomon Amy
Published: April 2006

In this study we use model output from a range of coupled climate models, as well as, focused AGCM experiments to support the hypothesis that in a warmer climate increased moisture availability will cause a warming of the Polar Regions through increased dynamical heat transports. Projections of climate change due to increased greenhouse gases predict significant warming of the Polar Regions. This change in polar temperatures has been primarily attributed to ice‐albedo feedbacks. However, in this study we show that in our AGCM experiments the temporal and spatial coherence between developing extratropical cyclones and latent heat release causes a greater than 2°C warming of the poles.
Global upper‐mantle structure from finite‐frequency surface‐wave tomography
Authors: Zhou Ying , Nolet Guust , Dahlen F. A. , Laske Gabi
Published: April 2006

We report global shear‐wave velocity structure and radial anisotropy in the upper mantle obtained using finite‐frequency surface‐wave tomography, based upon complete three‐dimensional Born sensitivity kernels. Because wavefront healing effects are properly taken into account, finite‐frequency surface‐wave tomography improves the resolution of small‐scale mantle heterogeneities, especially for deep anomalies that are constrained by the longest‐period surface waves. In our finite‐frequency model FFSW1, the globally averaged radial anisotropy shows a transition from positive (SH > SV) to negative anisotropy (SV > SH) at about 220 km, consistent with a change in the dominant mantle circulation pattern from predominantly horizontal flow at shallow depths to vertical flow at greater depths. The radial anisotropy beneath cratons and the old Pacific plate agrees well with previous studies. However, our model exhibits a strong negative radial anisotropy at depths greater than 120 km beneath mid‐ocean ridges, a feature that is not present in previous upper‐mantle models. More interestingly, the depth extent of the ridge anomalies is distinctly different beneath fast‐ and slow‐spreading centers; anomalies beneath fast‐spreading centers are stronger, but the strength decreases rapidly below 250 km. In contrast, beneath slow‐spreading centers such as the northern Mid‐Atlantic Ridge and the Red Sea, anomalies extend down at least to the top of the transition zone. The different depth extent of the ridge anomalies suggests that the primary driving force of slow‐spreading seafloor may be different from that of fast‐spreading seafloor and that active upwelling beneath slow‐spreading ridges may play a major role in the opening of the seafloor.
Svalbard summer melting, continentality, and sea ice extent from the Lomonosovfonna ice core
Authors: Grinsted Aslak , Moore John C. , Pohjola Veijo , Martma Tõnu , Isaksson Elisabeth
Published: April 2006

We develop a continentality proxy (1600–1930) based on amplitudes of the annual signal in oxygen isotopes in an ice core. We show via modeling that by using 5 and 15 year average amplitudes the effects of diffusion and varying layer thickness can be minimized, such that amplitudes then reflect real seasonal changes in δ18O under the influence of melt. A model of chemical fractionation in ice based on differing elution rates for pairs of ions is developed as a proxy for summer melt (1130–1990). The best pairs are sodium with magnesium and potassium with chloride. The continentality and melt proxies are validated against twentieth‐century instrumental records and longer historical climate proxies. In addition to summer temperature, the melt proxy also appears to reflect sea ice extent, likely as a result of sodium chloride fractionation in the oceanic sea ice margin source area that is dependent on winter temperatures. We show that the climate history they depict is consistent with what we see from isotopic paleothermometry. Continentality was greatest during the Little Ice Age but decreased around 1870, 20–30 years before the rise in temperatures indicated by the δ18O profile. The degree of summer melt was significantly larger during the period 1130–1300 than in the 1990s.
Generalized fractal‐based laws for scattering from planetary surfaces: A unifying scale‐explicit paradigm
Authors: Sultan‐Salem Ahmed K. , Tyler G. Leonard
Published: April 2006

Fractal‐based scattering laws, when used to fit radar observations, provide an estimate for surface root‐mean‐square (RMS) slope that is explicit in its scale dependence. Furthermore, fractal‐based laws outperform, in a minimum residual sense, the widely used Hagfors' and Gaussian laws, which they subsume as special cases when their Hurst exponent parameter, H, takes the values 1/2 and 1, respectively. The use of a fixed, scale‐independent value for H restricts the modeling capacity of the fractal‐based laws. Allowing H to be a function of the horizontal scale R leads to a generalized scattering law that unifies the fractal‐based laws with fixed H and the conventional Hagfors, Gaussian, and exponential laws. A new procedure employing the generalized fractal‐based laws is applied to Magellan altimetry data for the surface of Venus at 12.6 cm −λ. Near‐nadir Magellan backscatter data are modeled using a linear combination of two conventional scattering laws in order to obtain statistically significant fits. The Hankel transform is used to obtain a scale‐explicit interpretation that gives the surface RMS slope as a function of horizontal scale. An analysis of the scattering integral gives insights into the range of scales which are effective in the scattering process and for which the RMS slope estimate can be considered reliable.
Vertical wind shear on Jupiter from Cassini images
Authors: Li Liming , Ingersoll Andrew P. , Vasavada Ashwin R. , Simon‐Miller Amy A. , Del Genio Anthony D. , Ewald Shawn P. , Porco Carolyn C. , West Robert A.
Published: April 2006

Multifilter images of Jupiter acquired by the Cassini Imaging Science Subsystem (ISS) are used to derive zonal winds at altitudes above and below the visible cloud deck. Small features unique to the ultraviolet images of ISS are tracked to get the systematic high‐altitude zonal winds. Comparison between the zonal winds from ultraviolet images and the vertical profile of zonal winds from the Cassini Composite Infrared Spectrometer (CIRS) shows that the zonal winds from the ultraviolet images are from a pressure level that is ∼0.2 scale heights higher than the pressure level of the zonal winds from continuum‐band images. Deeper zonal winds at different latitudes of the equatorial region are measured by tracking cloud features observed within hot spots on continuum‐band images. The deeper zonal winds in this study extend the measurement of the Galileo probe to different latitudes of the equatorial region. Comparison between the Galileo probe and this study suggests that these fast‐moving clouds within hot spots are deeper than 3 bars and are therefore probably water clouds.
Distribution of switching field fluctuations in Fe-rich wires under tensile stress
Authors: Gawronski P. , Zhukov A. , Zhukova V. , González J. , Blanco J. M. , Kulakowski K.
Published: April 2006

We present experimental results on the influence of the applied tensile stress on switching-field distribution in as-cast Fe-rich amorphous wires. The fluctuation spectrum of the switching field reveals two different mechanisms, namely (i) magnetoelastic coupling of the domain wall with internal stresses, which significantly varies with the applied stress, and (ii) pinning of the domain wall at defects of the atomic scale.
Adsorption of pentacene on filled d-band metal surfaces: Long-range ordering and adsorption energy
Authors: Baldacchini Chiara , Mariani Carlo , Betti Maria Grazia
Published: April 2006

The growth of pentacene on suitable metallic templates is studied by means of low-energy electron diffraction and ultraviolet photoelectron spectroscopy. Highly ordered pentacene single layers can be prepared by deposition on filled d-band metal templates kept at 370K. The presence of the steps for the Cu(119) vicinal surface and of the Au troughs for the Au(110)-(1×2) surface allows the formation of commensurate long-range ordered structures with (3×7) and (3×6) periodicities, respectively. A detailed analysis of the molecular induced electronic states evolution is performed for different growth morphologies. The adsorption energy of the ordered molecular single layers on the Au(110) surface is lower (1.90eV) than on the Cu vicinal surface (2.36eV), where the steps enhance the molecule adsorption energy.
Epitaxial GaN nanorods free from strain and luminescent defects
Authors: Seo H. W. , Chen Q. Y. , Iliev M. N. , Tu L. W. , Hsiao C. L. , Mean James K. , Chu Wei-Kan
Published: April 2006

Raman spectroscopy, cathodoluminescence imaging, and electron backscatter diffraction have been used to characterize the GaN nanorods as compared to their supporting matrix. The nanorods are strain free, distinguished from the mechanically and thermally stressed matrix that bears the brunt of all lattice mismatch and thermal strain, strain relaxation, and the related defect generation. This thus allows the loosely attached nanorods to grow to measurable perfection in electronic and crystal structures. The nanorods are crystallographically aligned with the matrix as well as the substrate.
Improved light outcoupling for phosphorescent top-emitting organic light-emitting devices
Authors: Chen Shufen , Zhao Yi , Cheng Gang , Li Jiang , Liu Chunli , Zhao Zhenyuan , Jie Zhonghai , Liu Shiyong
Published: April 2006

Light outcoupling for top-emitting organic light-emitting devices is improved by using a semitransparent multilayer cathode structure of Al(2.5nm)∕Ag(0.5nm)∕Al(1nm)∕Ag(0.5nm)∕Al(0.5nm)∕Ag(11nm). In addition, an excellent transparency of 70% is achieved with a 78-nm-thick tris-(8-hydroxyquinoline) aluminum (Alq3) film as a top-capping layer, which is overlaid onto the cathode. The electroluminescence intensity with this Alq3-covered cathode is increased by a factor of 1.9∼3.1 (applied voltage from 7 to 21V) compared with the conventional cathode Al(4nm)∕Ag(12nm). This enhancement can be attributed to a gradual change of index refraction and extinction coefficient in the multilayer cathode (actually, not multilayer Al∕Ag, but an Al:Ag alloylike configuration) and to the reduction of top Ag reflection by overlaying an Alq3-capping layer onto the cathode. Besides, photoluminescence of the top-capping Alq3 layer is helpful to improve device luminance.
Low-temperature ordering of L1 FePt by PtMn underlayer
Authors: Chiang C. C. , Lai Chih-Huang , Wu Y. C.
Published: April 2006

The ordering temperature of FePt films grown on PtMn underlayers was reduced due to phase transformation of the PtMn L10 phase. The in-plane coercivity of 10nm FePt on 50nm PtMn underlayers was 7688Oe after annealing at 325°C. An exchange field of 554Oe was also observed, which indicates that PtMn may not only induce the ordering of FePt at a reduced temperature, but also may provide extra anisotropy. A large coercivity of 10500Oe can be achieved for 35nm FePt films on PtMn underlayers after 325°C annealing.
Time-resolved photoelectron spectroscopy of proton transfer in the ground state of chloromalonaldehyde: Wave-packet dynamics on effective potential surfaces of reduced dimensionality
Authors: Varella Márcio T. do N. , Arasaki Yasuki , Ushiyama Hiroshi , McKoy Vincent , Takatsuka Kazuo
Published: April 2006

We report on a simple but widely useful method for obtaining time-independent potential surfaces of reduced dimensionality wherein the coupling between reaction and substrate modes is embedded by averaging over an ensemble of classical trajectories. While these classically averaged potentials with their reduced dimensionality should be useful whenever a separation between reaction and substrate modes is meaningful, their use brings about significant simplification in studies of time-resolved photoelectron spectra in polyatomic systems where full-dimensional studies of skeletal and photoelectron dynamics can be prohibitive. Here we report on the use of these effective potentials in the studies of dump-probe photoelectron spectra of intramolecular proton transfer in chloromalonaldehyde. In these applications the effective potentials should provide a more realistic description of proton-substrate couplings than the sudden or adiabatic approximations commonly employed in studies of proton transfer. The resulting time-dependent photoelectron signals, obtained here assuming a constant value of the photoelectron matrix element for ionization of the wave packet, are seen to track the proton transfer.
Stability of surfaces in the chalcopyrite system
Authors: Siebentritt Susanne , Papathanasiou Niklas , Albert Jürgen , Lux-Steiner Martha Ch.
Published: April 2006

The stable surfaces in chalcopyrites are the polar {112} surfaces. We present an electron microscopy study of epitaxial films of different compositions. It is shown that for both CuGaSe2 and CuInSe2 the {001} surfaces form {112} facets. With increasing Cu excess the faceting is suppressed. This indicates a lower surface energy of the {001} surface than the energy of the {112} surface in the Cu-rich regime, but the {001} surface is higher in energy than the {112} surface in the Cu-poor regime.
Ni Schottky diodes on cubic GaN
Authors: As D. J. , Potthast S. , Fernandez J. , Schörmann J. , Lischka K. , Nagasawa H. , Abe M.
Published: April 2006

Schottky diodes were fabricated by thermal evaporation of nickel on phase-pure cubic GaN(c-GaN) layers grown by plasma assisted molecular beam epitaxy on freestanding 3C-SiC. Detailed analysis of the I-V characteristics revealed the existence of a thin surface barrier at the Ni-semiconductor interface. Thermal annealing in air at 200°C alters the composition of this thin surface barrier, reduces the leakage current by three orders of magnitude, and increases the breakdown voltage. The dependence of the breakdown voltage on the doping density of the c-GaN layers is in good agreement with calculated values. We obtain a critical electric-field strength of Ecrit≅2.5×106V∕cm for c-GaN.
General thermal-field emission equation
Authors: Jensen Kevin L. , Cahay Marc
Published: April 2006

A general electron emission equation is developed to account for both tunneling and thermal emission for general potentials, particularly when both processes are non-negligible. It is then applied to the image charge potential that is the basis for the Fowler-Nordheim (FN) [Proc. R. Soc. London A119, 173 (1928)] and the Richardson-Laue-Dushman (RLD) equations of electron emission [Proc. R. Soc. London A107, 377 (1925)]. The leading order terms in a series expansion are used to derive a “refined” FN-RLD equation that extends the range of validity of the FN and RLD equations for parameters where the traditional forms either fail or perform poorly.
System for measuring the junction temperature of a light emitting diode immersed in liquid nitrogen
Authors: Kirkup L. , Kalceff W. , McCredie G.
Published: April 2006

A versatile system has been developed for the measurement under LABVIEW™ control of junction temperatures in a light emitting diode (LED). Measurements are reported on a commercially available high-intensity InGaAlP LED immersed in liquid nitrogen and driven by currents in the range of 18.5–204mA. The measured junction temperature has an expanded uncertainty of ±2K at the 95% level of confidence for temperatures from 70to298K. Using the measured junction temperatures, the junction-to-case thermal resistance of the LED was established as 440K∕W for devices with intact encapsulation and 307K∕W for partial encapsulation.
Sample holder for small-angle x-ray scattering static and flow cell measurements
Authors: Lipfert Jan , Millett Ian S. , Seifert Sönke , Doniach Sebastian
Published: April 2006

We present the design of a sample holder for small-angle x-ray scattering (SAXS) that can be used for both static and flow cell measurements, allowing to switch between these two types of measurement without having to realign the detector and camera geometry. The device makes possible high signal-to-noise experiments with sample volumes as small as 16μl and can be thermocontrolled using a standard circulating water bath. The setup has been used successfully for a range of biological SAXS measurements, including peptides, detergent micelles, membrane proteins, and nucleic acids. As a performance test, we present scattering data for horse heart cytochrome c, collected at the BESSRC CAT beam line 12-ID of the Advanced Photon Source. The design drawings are provided in the supplementary material.
Palpationlike soft-material elastic modulus measurement using piezoelectric cantilevers
Authors: Szewczyk Steven T. , Shih Wan Y. , Shih Wei-Heng
Published: April 2006

We have developed an all-electrical piezoelectric cantilever sensor that can self-excite and self-detect for tissue elastic modulus measurement. An all-electrical piezoelectric cantilever is consisted of a sandwich of piezoelectric layer, e.g., lead zirconate titanate (PZT), a nonpiezoelectric layer, e.g., stainless steel, and a second piezoelectric layer. The top piezoelectric layer serves as the driving layer (self-exciting) and the second piezoelectric layer as the sensing layer (self-sensing). The driving and sensing piezoelectric layers may be of different lengths. Applying a dc voltage across the driving PZT layer causes the piezoelectric cantilever to bend. The resultant bending stress in the sensing PZT layer generates a piezoelectric voltage across the sensing PZT layer that rises rapidly to a maximum before it decays with time. The maximum induced voltage was used to measure the axial displacement of the piezoelectric cantilever. With its force generation and displacement sensing capability, we show that an all-electrical piezoelectric cantilever can measure the elastic modulus of tissues both under the regular compression geometry and the flat-punch indentation geometry. In addition, the sensor can map the local elastic modulus variations of tissues much like palpation.
Design and operation of a versatile, ultrahigh vacuum, low temperature scanning probe microscope
Authors: Lakhani A. M. , Kelly S. J. , Pearl T. P.
Published: April 2006

The design and operation of an ultrahigh vacuum, liquid nitrogen or helium cooled scanning probe microscope system are presented. Key construction features that reflect crucial experimental criteria will be highlighted. Following from a recently devised approach to low temperature microscopy, cooling of the Besocke-style [Surf. Sci. 181, 145 (1987)] microscope assembly is performed by housing the microscope assembly in cryogenic shields which are coupled to a low vibration flow cryostat. The microscope, however, has been designed to accommodate different types of probes including tunneling and force sensors, and this functionality offers significant flexibility. As a demonstration of temperature and microscope stability, scanning tunneling microscopy measurements at 83K, using liquid nitrogen as the cryogen, will be shown on a flat metallic Ag(111) surface. In this temperature range, we measure a drift rate of 0.34Å∕h in the distance between the tip and sample as a result of ∼2mK∕h temperature drift at the microscope base, and we enumerate the procedure for establishing this stability.
Characterization and cross calibration of Agfa D4, D7, and D8 and Kodak SR45 x-ray films against direct exposure film at 4.0–5.5keV
Authors: Lanier N. E. , Cowan J. S. , Workman J.
Published: April 2006

Kodak direct exposure film (DEF) [B. L. Henke et al., J. Opt. Soc. Am. B 3, 1540 (1986)] has been the standard for moderate energy (1–10keV) x-ray diagnostic applications among the high-energy-density and inertial confinement fusion research communities. However, market forces have prompted Kodak to discontinue production of DEF, leaving these specialized communities searching for a replacement. We have conducted cross-calibration experiments and film characterizations on five possible substitutes for Kodak DEF. The film types studied were Kodak’s Biomax MR (BMR) and SR45 along with Agfa’s D8, D7, and D4sc. None of the films tested matched the speed of DEF. BMR and D8 were closest but D8 exhibited lower noise, with superior resolution and dynamic range. Agfa D7, Agfa D4sc, and Kodak SR45 were significantly less sensitive than BMR and D8, however, the improvements they yielded in resolution and dynamic range warrant their use if experimental constraints allow.
Terahertz wave reciprocal imaging
Authors: Xu Jingzhou , Zhang X.-C.
Published: April 2006

A reciprocal imaging technology with an encoding/decoding image readout method allows a single detector (such as a heterodyne detector) to produce a two dimensional (2D) image simultaneously. Applying it in a pulsed terahertz imaging system could create a 2D terahertz image with 100pixels per frame which produces the same signal to noise ratio as a signal spot measurement.
Pump-probe spectroscopy of interminiband relaxation and electron cooling in doped superlattices
Authors: Stehr D. , Winnerl S. , Helm M. , Dekorsy T. , Roch T. , Strasser G.
Published: April 2006

The picosecond dynamics of electrons in a doped GaAs∕AlGaAs superlattice have been investigated by pump-probe experiments using an infrared free-electron laser. We observe a fast bleaching of the interminiband absorption followed by thermalization and a slower cooling component. The latter can lead to a positive or negative transmission change, resulting from the temperature dependence of the linear absorption spectrum at the respective wavelength. We show that the superlattice in contrast to quantum wells provides a unique picosecond thermometer for the electron temperature based on the dependence of the absorption on the electron distribution function.
Guiding light in fluids
Authors: Schmidt Oliver , Bassler Michael , Kiesel Peter , Johnson Noble M. , Döhler Gottfried H.
Published: April 2006

In contrast to conventional waveguides with high-refractive-index core, we describe a concept for guiding light within a low-refractive-index medium surrounded by a medium with higher refractive index. This concept is especially compatible with fluidic sensors because the channel itself can be used as the core of the waveguide and thereby enabling a strong light-analyte interaction over an extended distance. The concept is based on antiresonant modes, and experiments have shown that these modes can be excited by collimating excitation light under an appropriate angle onto the waveguide structure.
High-temperature interstitial oxygen diffusion retardation in epitaxial-layered heavily arsenic- or boron-doped Czochralski silicon wafers
Authors: Wang Q. , Ho Ihsiu
Published: April 2006

Interstitial oxygen (Oi) diffusivity was examined in epitaxial-layered silicon substrates of various types (heavily doped arsenic and heavily doped boron) in varying annealing conditions. When a heavily doped arsenic substrate was annealed at up to 1125°C, the Oi diffusion slowed by 28% compared to that in the epilayer or a lightly doped boron substrate. When a heavily doped arsenic substrate is annealed at 1200°C in N2, Oi accumulates in the epilayer subsurface. A heavily doped boron substrate annealed at 1200°C shows both significantly reduced Oi outdiffusion in the substrate and Oi segregation at the epilayer-substrate interface due to misfit dislocation.