bluuebunny/crossref_metadata_2025_split huggingface dataset:
Poly‐α‐olefin‐based synthetic lubricants: a short review on various synthetic routes
Authors: Ray Saptarshi , Rao Peddy V. C. , Choudary Nettem V. 
Published: September 2011

ABSTRACTThis paper reviews various synthetic protocols for poly‐α‐olefin (PAO) synthetic lubricant base stocks that have evolved over the years. Apart from conventional Lewis acid catalysts known for the synthesis of poly‐α‐olefins, such as aluminium trichloride and boron trifluoride, several new catalysts such as metallocenes and ionic liquids have been reported by various researchers. With increasing options of catalytic processes available, it is now possible to produce tailor made PAOs and thus control the properties of the end products, such as viscosity and the viscosity index. Although 1‐decene is the most widely used monomer for PAO application, researchers have used a wide range of monomers from 1‐hexene to 1‐tetradecene and internal olefins in some cases. Copyright © 2011 John Wiley & Sons, Ltd.
Visual Interpretation of Kernel‐Based Prediction Models
Authors: Hansen Katja , Baehrens David , Schroeter Timon , Rupp Matthias , Müller Klaus‐Robert 
Published: September 2011

AbstractStatistical models are frequently used to estimate molecular properties, e.g., to establish quantitative structure‐activity and structure‐property relationships. For such models, interpretability, knowledge of the domain of applicability, and an estimate of confidence in the predictions are essential. We develop and validate a method for the interpretation of kernel‐based prediction models. As a consequence of interpretability, the method helps to assess the domain of applicability of a model, to judge the reliability of a prediction, and to determine relevant molecular features. Increased interpretability also facilitates the acceptance of such models. Our method is based on visualization: For each prediction, the most contributing training samples are computed and visualized. We quantitatively show the effectiveness of our approach by conducting a questionnaire study with 71 participants, resulting in significant improvements of the participants’ ability to distinguish between correct and incorrect predictions of a Gaussian process model for Ames mutagenicity.
Tree and Hashing Data Structures to Speed up Chemical Searches: Analysis and Experiments
Authors: Nasr Ramzi , Kristensen Thomas , Baldi Pierre 
Published: September 2011

AbstractIn many large chemoinformatics database systems, molecules are represented by long binary fingerprint vectors whose components record the presence or absence of particular functional groups or combinatorial features. For a given query molecule, one is interested in retrieving all the molecules in the database with a similarity to the query above a certain threshold. Here we describe a method for speeding up chemical searches in these large databases of small molecules by combining previously developed tree and hashing data structures to prune the search space without any false negatives. More importantly, we provide a mathematical analysis that allows one to predict the level of pruning, and validate the quality of the predictions of the method through simulation experiments.
Operation of series‐connected silicon‐based photovoltaic modules under partial shading conditions
Authors: Mäki Anssi , Valkealahti Seppo , Leppäaho Jari 
Published: September 2011

ABSTRACTPartial shading has been recognized as a major cause of energy losses in photovoltaic (PV) power generators. Partial shading has severe effects on the electrical characteristics of the PV power generator, because it causes multiple maximum power points (MPPs) to the power‐voltage curve. Multiple maxima complicate MPP tracking, and the tracking algorithms are often unable to detect the global maximum. Considerable amount of available electrical energy may be lost, when a local MPP with low power is tracked instead of the global MPP. In this paper, the electrical characteristics of series‐connected silicon‐based PV modules under various partial shading conditions are studied by using a Matlab/Simulink simulation model. The simulation model consists of 18 series‐connected PV modules, corresponding to a single‐phase grid‐connected PV power generator. The validity of the simulation model has been verified by experimental measurements. The voltage and power characteristics of the PV power generator have been investigated under various system shading and shading strength conditions. The results can be utilized to develop new MPP tracking algorithms and in designing, for example, building integrated PV power generators. Copyright © 2011 John Wiley & Sons, Ltd.
Radiative efficiency of state‐of‐the‐art photovoltaic cells
Authors: Green Martin A. 
Published: September 2011

ABSTRACTMaximum possible photovoltaic performance is reached when solar cells are 100% radiatively efficient, with different photovoltaic technologies at different stages in their evolution towards this ideal. An external radiative efficiency is defined, which can be unambiguously determined from standard cell efficiency measurements. Comparisons between state‐of‐the‐art devices from the representative cell technologies produce some interesting conclusions. Copyright © 2011 John Wiley & Sons, Ltd.
Self‐efficacy and fear of cancer progression during the year following diagnosis of breast cancer
Authors: Melchior Hanne , Büscher Cathrin , Thorenz Andrea , Grochocka Anna , Koch Uwe , Watzke Birgit 
Published: September 2011

AbstractObjectiveThe aim of this study was to investigate fear of disease progression (FoP) during the year following diagnosis of breast cancer and its association with general self‐efficacy (SE).MethodsIn a prospective study, 118 breast cancer patients were recruited shortly after diagnosis disclosure (response rate: 54%) and at 1‐year follow‐up (follow‐up rate: 90%). Participants completed self‐report measures of general self‐efficacy (General Self‐Efficacy Scale) and fear of progression (short form of the Fear of Progression Questionnaire).ResultsCross‐sectional regression analysis revealed that high FoP is significantly associated with low SE, even when controlling for demographic and medical characteristics (total R² = 0.17). Having children and a relatively short time since diagnosis also significantly predicted higher FoP. Longitudinal analyses showed that FoP decreased significantly over time (p = 0.001; d = 0.25), but a significant decrease was only observed for patients with high initial FoP (p < 0.001; d = 0.74) and not for those with low initial FoP (p = 0.688; d = 0.08). SE was not a significant predictor of FoP at follow‐up when controlling for initial FoP and other patient characteristics (incremental R² = 0.001; p = 0.674; total R² = 0.47). Overall, only initial FoP significantly predicted FoP at follow‐up (p < 0.001; β = 0.671).ConclusionFindings that low SE is associated with high FoP can help to improve the treatment of dysfunctional fears in breast cancer patients. As FoP changes only slightly over time, treatment to enhance SE and reduce FoP should be initiated soon after disease disclosure. Copyright © 2011 John Wiley & Sons, Ltd.
A G4MP2 and G4 Theoretical Study into the Thermochemical Properties of Explosophore Substituted Tetrahedranes and Cubanes
Authors: Rayne Sierra , Forest Kaya 
Published: September 2011

AbstractHigh level G4MP2/G4 composite theoretical method thermochemical calculations were conducted on the parent tetrahedrane and cubane compounds and a suite of 20 mono‐ and polyfunctionalized derivatives with azo, nitro, and peroxo explosophoric substituents. The novel azo and peroxo derivatives of these Platonic solid hydrocarbons are likely to be local minima on their respective potential energy surfaces, suggesting these compounds may be priority synthetic targets. The high, mass normalized gas phase enthalpies of formation for both the tetrahedranes and cubanes exceed those of well‐established primary (mercury fulminate and lead azide) and secondary (RDX and HMX) explosives by up to an order of magnitude. Other known (TNT, HMX, CL‐20, octanitrocubane) or proposed (aminonitroalkanes and acetylenes, nitroboranes) high energy materials generally have substantially less favorable mass normalized gas phase enthalpies of decomposition than the most promising tetrahedrane or cubane derivatives presented herein.
Benefits of pharmacist prescribing in a primary‐care setting
Authors: Kinsey Jacqui , Bashford James 
Published: September 2011

AbstractJacqui Kinsey qualified as a pharmacist nonmedical prescriber in 2008 and has since been working in a medical practice in Stoke‐on‐Trent. She provides two sessions per week, running predominantly hypertension clinics. Jacqui also works four days a week at Keele University as the Prescribing Studies Programme Manager within the School of Pharmacy. Copyright © 2011 Wiley Interface Ltd
Concurrent macrolide and statin – a common interaction
Authors: Spencer Rachel , Serumaga Brian 
Published: September 2011

AbstractIn this series we present a number of prescribing safety indicators developed as part of an RCGP project.1 The evidence base behind each of the indicators is given along with information to illustrate their clinical significance. We provide a ‘real‐life’ audit based on the indicator to show how practices could begin to analyse their own prescribing data. Copyright © 2011 Wiley Interface Ltd
Maximum likelihood estimation of inflation factors on error covariance matrices for ensemble Kalman filter assimilation
Authors: Liang Xiao , Zheng Xiaogu , Zhang Shupeng , Wu Guocan , Dai Yongjiu , Li Yong 
Published: September 2011

AbstractIn the ensemble Kalman filter, the forecast error covariance matrix is estimated as the sampling covariance matrix of the forecast ensemble. However, it is well known that such estimations may be far from the true forecast error covariance matrix. In this paper, an inflation approach on forecast error covariance matrix based on the maximum likelihood estimation theory is developed and compared to an existing time‐dependent inflation method and the best‐tuned constant inflation. Our method was first tested on a 40‐variable Lorenz model using spatially correlated observation errors. Specifically, when the observation error variance is incorrectly specified, our proposed method can simultaneously inflate on both forecast and observation error covariance matrices. We then assessed our approach on the two‐dimensional Shallow Water Equation model with higher state dimensions and a larger correlated observation system. The results confirmed that our method is effective in retrieving the true states and correcting observation error variances. Copyright © 2011 Royal Meteorological Society
Conditional nonlinear optimal perturbations: behaviour during the evolution of cold vortices over northeast China
Authors: Jiang Zhina , Wang Donghai 
Published: September 2011

AbstractConditional nonlinear optimal perturbations (CNOPs) are the initial perturbations that acquire the largest nonlinear evolution at the forecast time with some initial constraint condition. These CNOPs are calculated and examined during the development of two cold vortices with a regional mesoscale primitive‐equation model. Computation is carried out over a 48‐hour optimization time interval with a dry total perturbation energy norm. Attention is given to the CNOPs in terms of structure and evolution. For the particular cases studied, it was found that the CNOPs, similar to the first linear singular vectors, exhibit localness, in which the wind, temperature and surface pressure perturbation fields match the thermal wind balance qualitatively. The primary perturbation regions of CNOPs are closely related to the source regions of high potential vorticity corresponding to the cold vortices. What is more, CNOPs have deep baroclinic structures, which extend throughout the whole troposphere. With time, CNOPs increase their spatial size over larger areas and become quasi‐barotropic at the optimization time. In addition, we found that the kinetic energy contributions are much larger than the potential energy contributions to the final perturbation energy. A noteworthy property is that although the dry total energy norm is used to measure the perturbation growth, the moisture perturbation energy appears early on, which is smaller than the kinetic energy but larger than the potential energy in the lower troposphere at the forecast time. The above numerical experiments are helpful for understanding the mechanism of perturbation growth during the formation of cold vortices. Copyright © 2011 Royal Meteorological Society
The use of variable CO2 in the data assimilation of AIRS and IASI radiances
Authors: Engelen R. J. , Bauer P. 
Published: September 2011

AbstractAn important component of the assimilation of radiance observations from the AIRS and IASI satellite instruments is the radiative transfer modelling. Currently, the RTTOV model used in the ECMWF IFS system uses a fixed value for CO2. Neglecting the spatio‐temporal variability of CO2 introduces an error in the simulation of the satellite radiances, which could affect the quality of the analyses and forecasts. The current assumption is that variational bias correction corrects most of this error and therefore minimizes the impact on the forecast scores. This paper investigates the possibility of modelling CO2 within the IFS to improve the radiative transfer modelling. Results show that the required bias correction is significantly reduced when using more realistic CO2 values. The impact on the analysis quality and forecast scores is mostly neutral with some indication of improvement in the Tropics and the stratosphere.
Design and implementation of grouped rescue robot system using self‐deploy networks
Authors: Kamegawa Tetsushi , Sato Noritaka , Hatayama Michinori , Uo Yojiro , Matsuno Fumitoshi 
Published: September 2011

AbstractIn this study, we propose a new system for searching the inside of a damaged building using grouped rescue robots. Because the assumed target environment is broad and variable, the proposed system is designed to have adaptability, scalability, and usability. The system consists of robots, sensors, a network, a communication protocol, user interfaces, and database management systems; their complementary capabilities allow them to satisfy the requirements for the system. This study presents the requirements and design of the proposed system, briefly describes each element, and provides examples of how the elements function as an integrated system. © 2011 Wiley Periodicals, Inc.
A scheme for reliable real‐time messaging with bounded delays
Authors: Kim Kwang‐Hae (Kane) , Qian Jing , Zhang Zhen , Zhou Qian , Moon Kyung‐Deok , Park Jun‐Hee , Park Kwang‐Roh , Kim Doo‐Hyun 
Published: September 2011

SUMMARYNetwork‐based real‐time computing applications that require tightly bounded end‐to‐end delays have been increasing at a steady rate in recent years. A messaging layer that yields tight bounds on the latencies in detecting message losses and enables the application layer to initiate a timely recovery action has thus become highly desirable. In this paper, we present a new reliable real‐time messaging scheme called the Delay‐Bounded Reliable Messaging Scheme (DB‐RMS) that is aimed at meeting such requirements. It is built on top of the User Datagram Protocol sub‐layer. DB‐RMS provides multiple service options, each with different fault detection/recovery capabilities and different costs in terms of the execution overhead. This feature makes DB‐RMS suitable for a variety of applications. In this paper, the DB‐RMS service options and the corresponding support protocols are presented first followed by a formal analysis on the detection and reaction latency bounds under various service options. A messaging layer prototype using DB‐RMS has been implemented. To demonstrate the practice of the DB‐RMS, we implemented a clock synchronization algorithm for 802.11 wireless local area networks on top of the DB‐RMS messaging layer. Performance measurements of the prototype implementation have been taken, and the positive results obtained are also presented. Copyright © 2011 John Wiley & Sons, Ltd.
Influence of Temperature and Time of Austempering Treatment on Mechanical Properties of SAE 9254 Commercial Steel
Authors: Cruz J. A. , Rodrigues T. F. M. , Viana V. D. C. , Abreu H. , Santos D. B. 
Published: September 2011

AbstractThis work describes the steps in the study and development of the high content of C, Si, and Cr in commercial steel with a nanostructured matrix of martensite, bainite and retained austenite. Specimens of this steel were austenitized at 900 °C for 5 min and isothermally heat treated at different times (0.5, 2, 24, 48 h) and temperatures (200, 220, 270  °C). Different mechanical behavior was observed for the samples treated under different conditions due to their microstructural constitution. Specimens treated for 2 h at 200 °C showed lower yield strength of 979 MPa. On the other hand a high tensile strength of 2248 MPa was reached. The sample treated at 270 °C showed higher yield strength of 1363 MPa with the same treatment time. As for the fracture analysis, the brittle fracture mechanism was predominant for the samples treated at 200 °C, while the ductile fracture mechanism was predominant for the samples treated at 270 °C.
Preparation of highly substituted carboxymethyl starch using a twin‐screw extruder
Authors: Bhandari Pratik N. , Hanna Milford A. 
Published: September 2011

AbstractCarboxymethyl starch was prepared by reacting corn starch with sodium mono chloro acetate (SMCA) in a Brabender TSE‐20 co‐rotating twin screw extruder. The effects of the SMCA/starch ratio (theoretical degrees of substitutions 2.73, 3.62, and 4.53), aqueous ethanol/(starch + SMCA) ratio (0.13 and 0.25) and the screw configuration (0, 1, and 2 kneading blocks) on the degree of substitution (DS) and reaction efficiency were studied. A 3 × 2 factorial design with 3 levels of the starch/SMCA ratio and 2 levels of the aqueous ethanol/(starch + SMCA) ratio were used. This 3 × 2 factorial design was blocked, with the screw configuration as the blocking variable. The effects of the SMCA/starch ratio and the screw configuration were found to be significant. The carboxymethylated starches were characterized using FTIR, SEM, and XRD. The microstructure of the carboxymethylated starches, studied using SEM, revealed that the integrity of the starch granules was partially preserved at low aqueous ethanol levels when no kneading block was used. However, for all other reaction conditions either granule agglomeration or fusion was observed. XRD analysis indicated substantial loss of crystallinity in the carboxymethylated starches, irrespective of the damage to the granule structure. The highest DS and the highest reaction efficiency obtained were 1.54 and 0.42, respectively.
Synthesis of soluble N‐functionalized polysaccharide derivatives using phenyl carbonate precursor and their application as catalysts
Authors: Pourjavadi Ali , Seidi Farzad , Afjeh Soofieh S. , Nikoseresht Navid , Salimi Hamid , Nemati Navid 
Published: September 2011

AbstractSoluble N‐functionalized basic and cationic polysaccharides have been synthesized using polysaccharide phenyl carbonate as a precursor. The products and intermediates were thoroughly characterized by conventional methods. The quaternization of amino intermediates in various conditions was studied. Moreover, the potential of basic polymers as green and selective catalysts in Knoevenagel reaction was investigated. In all cases, only one isomer was obtained.
What are the limits of accuracy in fetal weight estimation with conventional biometry in two‐dimensional ultrasound? A novel postpartum study
Authors: Kehl S. , Schmidt U. , Spaich S. , Schild R. L. , Sütterlin M. , Siemer J. 
Published: September 2011

AbstractObjectiveCommonly used formulae for fetal weight estimation, including combinations of several biometric parameters, lack accuracy despite efforts to improve them. This study aimed to investigate the limits of fetal weight estimation based on conventional biometric parameters on two‐dimensional (2D) ultrasound by developing and evaluating new weight equations using postpartum biometric parameters.MethodsThis was a prospective multicenter study including 628 singleton pregnancies at term. Inclusion criteria were healthy newborns with no physical or chromosomal malformations. Postpartum measurement of head circumference, abdominal circumference and thigh length was performed. Six ‘best‐fit’ formulae were derived using forward regression analysis in a formula‐finding group (n = 419), and their accuracy was compared with birth weight in an evaluation group (n = 209) using percentage error, absolute percentage error, limits of agreement and the proportion of weight estimations falling within a discrepancy level of ± 10%.ResultsThe new formulae showed no systematic error, with SD for the percentage error between 7.42 and 8.77 and no significant differences between median absolute percentage errors (4.84–5.71). They included 74.6–81.3% of neonates within a discrepancy level of 10%. With regard to the 95% limits of agreement, weight estimates were within a range of about ± 500 g.ConclusionThese results show that a good sonographic weight formula has the following features: no systematic error, an SD of about 7% and inclusion of 80% of cases within a discrepancy level of 10%. The study indicates that the current accuracy of fetal weight estimation with conventional biometric parameters by 2D ultrasound has reached its limits. Further improvement will probably only be achieved through new approaches in ultrasonography. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Multiuser two‐way relay processing and power control methods for cognitive radio networks
Authors: Jiang Dongmei , Zhang Haixia , Yuan Dongfeng 
Published: September 2011

ABSTRACTWe consider a cognitive radio system where a secondary network shares the spectrum band with a primary network. Aiming at improving the frequency efficiency of the secondary network, we set a multiantenna relay station in the secondary network to perform two‐way relaying. Three linear processing schemes at the relay station based on zero forcing, zero forcing‐maximum ratio transmission, and minimum mean square error criteria are derived to guarantee the quality of service of primary users and to suppress the intrapair and interpair interference among secondary users (SUs). In addition, the transmit power of SUs is optimized to maximize the sum rate of SUs and to limit the interference brought to PUs. Numerical results show that the proposed multiuser two‐way relay processing schemes and the optimal power control policies can efficiently limit the interference caused by the secondary network to primary users, and the sum rate of SUs can also be greatly improved. Copyright © 2011 John Wiley & Sons, Ltd.
Unconditional, on the directions of arrival, statistics of the adaptive antenna arrays
Authors: Kaifas Theodoros N. 
Published: September 2011

ABSTRACTA comprehensive study on the statistics of adaptive antenna arrays is presented. The main contribution is the derivation of the probability distribution function of the cochannel interference for the uplink of mobile communications systems, unconditioned on the interferers' directions of arrival. Closed‐form results for the cumulative distribution function, moment generating function, and outage probability are also reported. Numerical verification is provided, utilizing both simulation and published data. Copyright © 2011 John Wiley & Sons, Ltd.