bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on Ducted Propeller and Rudder Interactions in Extreme Conditions
Authors: Islam Mohammed F. , Townsend Corning , Hill Robert , Hedd Lee 
Published: October 2017

This paper presents the results and analyses of a combined numerical-experimental study into the performance of three types of rudders to quantify the interactions between propeller, nozzle, and rudder at extreme rudder angles. Conventional, flapped and triple rudders are studied numerically as well as experimentally to evaluate the drag, lift, and moment generated by the rudders at moderate-to-extreme rudder angles and at forward propeller shaft speeds and inflow speeds. The experiments were carried out to evaluate the suitability of the three rudder types for a proposed cargo carrier in terms of controllability. The experiments were carried out at the selfpropulsion condition of the model equipped with twin stock ducted propellers along with each of the rudder systems. An extensive numerical study was carried out to evaluate the performance of the three rudders in terms of flow velocity, pressure, and wake fields. Drag and lift for different angles of attack are obtained for complicated propeller-nozzle-rudder arrangements. Investigations are carried out to study the effects of the interaction of the rudder with the propeller-nozzle assembly at extreme rudder angles as high as ±40°. For simplicity, the geometry of the vessel was not modeled in these simulations.
The experimental results are presented along with the computational results for all three rudder cases. The lift and drag measurements are in good agreement with the corresponding predictions for each of the rudder arrangements. The mutual interactions between the rudder and the propulsion system were captured in the simulations and were comparable with the corresponding measurements. The research reveals the nature of the velocity and pressure fields due to the complex interactions between the propeller, nozzle, and rudders at extreme rudder angles. It is expected that the current investigation will assist naval architects, at the early design stage, to select the rudder type for their ships such that suitable maneuvering characteristics are obtained and stringent International Maritime Organization maneuvering criteria are met.
Lean Methodology to Transform Shipbuilding Panel Assembly
Authors: Kolich Damir , Storch Richard L. , Fafandjel Niksa 
Published: October 2017

The core competence of any medium-to-large sized shipyard includes the panel assembly line. Ship panels are the basic building blocks of well over 60% of the interim products of typical commercial ships. Therefore the improvement of the panel assembly process could greatly reduce the number of man-hours of all assembled panels, thereby yielding significant savings to the shipyard. Using a lean methodology to make kaizen improvements to traditional panel assembly lines will greatly reduce the costs in ship production. This means that shipyards, which are barely keeping earnings above costs, will be able to increase profits. Value stream mapping is a key way of determining how lean a production process is. The wastes in production assembly are readily identified as well as the takt time and the areas where there is push as opposed to pull. In this paper, a case study of a typical commercial shipyard, which builds a product mix of vessels is analyzed. The present state panel assembly line is mapped and then using lean tools and avantgarde technologies, such as hybrid laser arc welding, the new transformed panel assembly line is demonstrated to bring man-hour reductions of over 80%, so that a typical panel is assembled using 12 man-hours as opposed to the present 72 man-hours.

1. Introduction
The core competence of virtually any medium-to-large sized shipyard includes a panel assembly line. Many times shipyard management takes for granted that the panel assembly line is just fine as is and therefore it is not necessary to make analysis to improve this core shipbuilding assembly process any further. However, since flat panels make up well over 60% of the building blocks of most commercial ships, any type of significant improvement to the panel assembly line will result in important cost savings for the shipyard.
Response of Water Use Efficiency to Global Environmental Change Based on Output From Terrestrial Biosphere Models
Authors: Zhou Sha , Yu Bofu , Schwalm Christopher R. , Ciais Philippe , Zhang Yao , Fisher Joshua B. , Michalak Anna M. , Wang Weile , Poulter Benjamin , Huntzinger Deborah N. , Niu Shuli , Mao Jiafu , Jain Atul , Ricciuto Daniel M. , Shi Xiaoying , Ito Akihiko , Wei Yaxing , Huang Yuefei , Wang Guangqian 
Published: October 2017

AbstractWater use efficiency (WUE), defined as the ratio of gross primary productivity and evapotranspiration at the ecosystem scale, is a critical variable linking the carbon and water cycles. Incorporating a dependency on vapor pressure deficit, apparent underlying WUE (uWUE) provides a better indicator of how terrestrial ecosystems respond to environmental changes than other WUE formulations. Here we used 20th century simulations from four terrestrial biosphere models to develop a novel variance decomposition method. With this method, we attributed variations in apparent uWUE to both the trend and interannual variation of environmental drivers. The secular increase in atmospheric CO2 explained a clear majority of total variation (66 ± 32%: mean ± one standard deviation), followed by positive trends in nitrogen deposition and climate, as well as a negative trend in land use change. In contrast, interannual variation was mostly driven by interannual climate variability. To analyze the mechanism of the CO2 effect, we partitioned the apparent uWUE into the transpiration ratio (transpiration over evapotranspiration) and potential uWUE. The relative increase in potential uWUE parallels that of CO2, but this direct CO2 effect was offset by 20 ± 4% by changes in ecosystem structure, that is, leaf area index for different vegetation types. However, the decrease in transpiration due to stomatal closure with rising CO2 was reduced by 84% by an increase in leaf area index, resulting in small changes in the transpiration ratio. CO2 concentration thus plays a dominant role in driving apparent uWUE variations over time, but its role differs for the two constituent components: potential uWUE and transpiration.
Variations of the Antarctic Ice Sheet in a Coupled Ice Sheet‐Earth‐Sea Level Model: Sensitivity to Viscoelastic Earth Properties
Authors: Pollard David , Gomez Natalya , Deconto Robert M. 
Published: October 2017

AbstractA coupled ice sheet‐solid Earth‐sea level model is applied to long‐term variations of the Antarctic ice sheet. A set of radially varying viscoelastic profiles in the global Earth model is used to explore feedbacks on ice sheet variability, including one with a very weak upper mantle zone and thin lithosphere representative of West Antarctic regions. Simulations are performed for (1) the deglacial retreat over the last ~20,000 years, (2) the future 5,000 years with greenhouse‐gas scenario Representative Concentration Pathway 8.5 (RCP8.5), and (3) the warm Pliocene ~3 Ma. For the deglacial period a large ensemble of 625 simulations is analyzed, with a score computed for each run based on comparisons to geologic and modern data. For each of the five Earth profiles, the top‐scoring combinations of the other model parameters in the ensemble are used to perform future and Pliocene simulations. For the last deglacial retreat, the viscoelastic Earth profiles produce relatively small differences in overall ice volume and equivalent sea level. In contrast, profiles with weak upper mantle and thin lithosphere produce strong negative feedback and less ice retreat in the future and Pliocene runs. This is due to the faster pace of ice sheet retreat in these runs, leading to greater lags in the viscous bedrock rebound behind the unloading, which allows for greater influence of the viscosity profiles. However, the differences in grounding‐line retreat are located primarily in East Antarctic basins, where a weak upper mantle and thin lithosphere may not be realistic, emphasizing the need for lateral heterogeneity in the Earth model.
A Robust Automatic Ionospheric O/X Mode Separation Technique for Vertical Incidence Sounders
Authors: Harris T. J. , Pederick L. H. 
Published: October 2017

AbstractThe sounding of the ionosphere by a vertical incidence sounder (VIS) is the oldest and most common technique for determining the state of the ionosphere. The automatic extraction of relevant ionospheric parameters from the ionogram image, referred to as scaling, is important for the effective utilization of data from large ionospheric sounder networks. Due to the Earth's magnetic field, the ionosphere is birefringent at radio frequencies, so a VIS will typically see two distinct returns for each frequency. For the automatic scaling of ionograms, it is highly desirable to be able to separate the two modes. Defence Science and Technology Group has developed a new VIS solution which is based on direct digital receiver technology and includes an algorithm to separate the O and X modes. This algorithm can provide high‐quality separation even in difficult ionospheric conditions. In this paper we describe the algorithm and demonstrate its consistency and reliability in successfully separating 99.4% of the ionograms during a 27 day experimental campaign under sometimes demanding ionospheric conditions.
Biological Imaging with Medium‐Sensitive Bichromatic Flexible Fluorescent Dyes
Authors: Cao Yang , Wang Xiaozhu , Shi Xiaolei , Clee Susanne M. , McGeer Patrick L. , Wolf Michael O. , Orvig Chris 
Published: October 2017

AbstractA family of environment‐sensitive shape‐shifting molecules have been developed as flexible fluorescent (FlexFluor) dyes for biological imaging applications. These compounds feature a flexible bithiophene‐based fluorophore that gives rise to different emission colors in lipophilic or hydrophilic environments, as well as side groups that can be synthetically modified with ease. FlexFluor dyes are the first fluorescent dyes in which emission color can be used to indicate lipid/water environments. The behavior of these dyes in different solvents was studied, and used to simultaneously highlight lipid and water contents in adipose and brain tissues using optical fluorescence microscopy.
Oxidation of Organic Molecules with a Redox‐Active Guanidine Catalyst
Authors: Wild Ute , Schön Florian , Himmel Hans‐Jörg 
Published: October 2017

AbstractHerein, we report the first examples of the use of redox‐active guanidines as catalysts in the green oxidation of organic molecules with dioxygen. In one half‐reaction, the oxidized form of the redox‐active guanidine is converted into the reduced, protonated state, thereby enabling dehydrogenative oxidation of the substrate (3,5‐di‐tert‐butylcatechol→ortho‐benzoquinone, benzoin→benzil, and 2,4‐di‐tert‐butylphenol→biphenol). In the other half‐reaction, efficient re‐oxidation of the guanidine to the oxidized state is achieved with dioxygen in the presence of a copper catalyst. These results pave the way for the broader use of redox‐active guanidines as oxidation catalysts.
Step‐Up Synthesis of Periodic Mesoporous Organosilicas with a Tyrosine Framework and Performance in Horseradish Peroxidase Immobilization
Authors: Wang Jianqiang , Zhang Wenqi , Gu Changqing , Zhang Wenpei , Zhou Man , Wang Zhiwei , Guo Cheng , Sun Linbing 
Published: October 2017

AbstractNew amino‐acid‐bridged periodic mesoporous organosilicas (PMOs) were constructed by hydrolysis and condensation reactions under acid conditions in the presence of a template. The tyrosine bissilylated organic precursor (TBOS) was first prepared through a multistep reaction by using tyrosine (a natural amino acid) as the starting material. PMOs with the tyrosine framework (Tyr‐PMOs) were constructed by simultaneously using TBOS and tetraethoxysilane as complex silicon sources in the condensation process. All the Tyr‐PMOs materials were characterized by XRD, FTIR spectroscopy, N2 adsorption–desorption, TEM, SEM, and solid‐state 29Si NMR spectroscopy to confirm the structure. The horseradish peroxidase (HRP) enzyme was first immobilized on these new Tyr‐PMOs materials. Optimal conditions for enzyme adsorption included a temperature of 40 °C, a time of 8 h, and a pH value of 7. Furthermore, the novel Tyr‐PMOs materials could store HRP for approximately 40 days and maintained the enzymatic activity, and the Tyr‐PMOs–10 % HRP with the best immobilization effect could be reused at least eight times.
Iterative Learning Control for Nonlinear Systems with Data Dropouts at Both Measurement and Actuator Sides
Authors: Jin Yanqiong , Shen Dong 
Published: October 2017

AbstractThis paper discusses the iterative learning control (ILC) for nonlinear systems under a general networked control structure, in which random data dropouts occur independently at both measurement and actuator sides. Both updating algorithms are proposed for the computed input signal at the learning controller and the real input signal at the plant, respectively. The system output is strictly proved to converge to the desired reference with probability one as the iteration number goes to infinity. A numerical simulation is provided to verify the effectiveness of the proposed mechanism and algorithms.
Adaptive Iterated Extended KALMAN Filter for Relative Spacecraft Attitude and Position Estimation
Authors: Xiong Kai , Wei Chunling 
Published: October 2017

AbstractThis paper presents a novel adaptive iterated extended Kalman filter (AIEKF) for relative position and attitude estimation, taking into account the influence of model uncertainty. Considering a nonlinear stochastic discrete‐time system with unknown disturbance, the AIEKF algorithm adopts the Gauss‐Newton iterative optimization steps to implement a maximum a posteriori (MAP) estimation, and the switch‐mode combination technique is used to achieve the adaptive capability. The mean‐square estimation error (MSE) of the state estimate is derived. It is proved that the AIEKF can yield a smaller MSE than that of the traditional extended Kalman filter (EKF) or iterated extended Kalman filter (IEKF). The performance advantage of the AIEKF is illustrated via Monte Carlo simulations on a typical relative position and attitude estimation application. Through comparisons in different scenarios, the presented algorithm is shown to improve adaptability and ensure estimation accuracy.
Delayed effect of Arctic stratospheric ozone on tropical rainfall
Authors: Xie Fei , Zhang Jiankai , Sang Wenjun , Li Yang , Qi Yulei , Sun Cheng , Li Yang , Shu Jianchuan 
Published: October 2017

AbstractThe tropical precipitation has a wide effect on the tropical economics and social life. Many studies made efforts to improve the tropical precipitation forecast using tropical climate factors. This study, based on observations, found that Arctic stratospheric ozone (ASO) could exert a significant effect on the tropical precipitation, i.e. there is more (less) rainfall over the eastern Pacific and less (more) precipitation over the western Pacific when the ASO anomalies are lower (larger) than normal. It is because a decrease (increase) in ASO could affect El Niño (La Niña) events and lead to a weakened (enhanced) Walker circulation. Time‐slice experiments confirmed that the ASO anomalies can force El Niño–Southern Oscillation‐like anomalies of tropical sea surface temperature and subsequent tropical precipitation anomalies. In addition, the ASO variations could also change the occurrence probability of extreme precipitation in the tropics. During the anomalously low (high) ASO events, there are more occurrences of heavier precipitation over the eastern Pacific (western Pacific) and of lighter precipitation over the western Pacific (eastern Pacific). Furthermore, the ASO variations lead tropical rainfall by approximately 21 months, suggesting that the ASO can serve as a potentially effective predictor of tropical rainfall.
Di(hydroperoxy)alkane Adducts of Phosphine Oxides: Safe, Solid, Stoichiometric, and Soluble Oxidizing Agents
Authors: Ahn Shin Hye , Bhuvanesh Nattamai , Blümel Janet 
Published: October 2017

AbstractInvited for the cover of this issue is the group of Janet Blümel at Texas A&M University. The image depicts the crystals and crystal structures of novel oxidizing agents: di(hydroperoxy)alkane adducts of phosphine oxides. Read the full text of the article at 10.1002/chem.201703676.
Analysis and Annotation of Whole‐Genome or Whole‐Exome Sequencing Derived Variants for Clinical Diagnosis
Authors: Worthey Elizabeth A. 
Published: October 2017

AbstractOver the last 10 years, next‐generation sequencing (NGS) has transformed genomic research through substantial advances in technology and reduction in the cost of sequencing, and also in the systems required for analysis of these large volumes of data. This technology is now being used as a standard molecular diagnostic test in some clinical settings. The advances in sequencing have come so rapidly that the major bottleneck in identification of causal variants is no longer the sequencing or analysis (given access to appropriate tools), but rather clinical interpretation. Interpretation of genetic findings in a complex and ever changing clinical setting is scarcely a new challenge, but the task is increasingly complex in clinical genome‐wide sequencing given the dramatic increase in dataset size and complexity. This increase requires application of appropriate interpretation tools, as well as development and application of appropriate methodologies and standard procedures. This unit provides an overview of these items. Specific challenges related to implementation of genome‐wide sequencing in a clinical setting are discussed. © 2017 by John Wiley & Sons, Inc.
SPICE simulation of memristive circuits based on memdiodes with sigmoidal threshold functions
Authors: Patterson German A. , Suñé Jordi , Miranda Enrique 
Published: October 2017

SUMMARYIn this paper, a SPICE implementation of a memristive model is presented and put under test by means of different circuit configurations. The model is based on sigmoidal threshold functions that switch the parameters involved in the transport equation. Results show that the model is stable under different driving signals, in particular, in multielement circuits. Antiparallel and anti‐series configurations are investigated as well as its application to thresholding devices and 1R1S structures. Copyright © 2017 John Wiley & Sons, Ltd.
Policy Mixes and their Alignment over Time: Patching and stretching in the oil sands reclamation regime in Alberta, Canada
Authors: Rayner Jeremy , Howlett Michael , Wellstead Adam 
Published: October 2017

AbstractWhen, why and how do policy mixes change and evolve? Much of the contemporary interest in such mixes is focused on distinguishing simple policies from more complex policy mixes, evaluating the relationships between single and multiple policy tools within a mix, and developing criteria to assess the likely performance of particular mixes. These are important and necessary analytical tasks. However, another required step in understanding policy mixes is to understand how and why mixes evolve and change over time and to determine whether any changes are an improvement. In this paper, we analyse the development of a complex policy mix in the case of reclamation and remediation of the Alberta oil sands from an earlier ‘simple goal, single instrument’ policy regime to a more complex one. This case study reveals the presence of at least two dynamic processes at work in policy mix development, with significant implications for the nature of the changes that result from them. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment
Pre‐discharge and early post‐discharge troponin elevation among patients hospitalized for heart failure with reduced ejection fraction: findings from the ASTRONAUT trial
Authors: Greene Stephen J. , Butler Javed , Fonarow Gregg C. , Subacius Haris P. , Ambrosy Andrew P. , Vaduganathan Muthiah , Triggiani Marco , Solomon Scott D. , Lewis Eldrin F. , Maggioni Aldo P. , Böhm Michael , Chioncel Ovidiu , Nodari Savina , Senni Michele , Zannad Faiez , Gheorghiade Mihai ,   for the ASTRONAUT Investigators and Coordinators
Published: October 2017

AimsTroponin levels are commonly elevated among patients hospitalized for heart failure (HF), but the prevalence and prognostic significance of early post‐discharge troponin elevation are unclear. This study sought to describe the frequency and prognostic value of pre‐discharge and post‐discharge troponin elevation, including persistent troponin elevation from the inpatient to outpatient settings.Methods and resultsThe ASTRONAUT trial (NCT00894387;
http://www.clinicaltrials.gov) enrolled hospitalized HF patients with ejection fraction ≤40% and measured troponin I prior to discharge (i.e. study baseline) and at 1‐month follow‐up in a core laboratory (elevation defined as >0.04 ng/mL). This analysis included 1469 (91.0%) patients with pre‐discharge troponin data. Overall, 41.5% and 29.9% of patients had elevated pre‐discharge [median: 0.09 ng/mL; interquartile range (IQR): 0.06–0.19 ng/mL] and 1‐month (median: 0.09 ng/mL; IQR: 0.06–0.15 ng/mL) troponin levels, respectively. Among patients with pre‐discharge troponin elevation, 60.4% had persistent elevation at 1 month. After adjustment, pre‐discharge troponin elevation was not associated with 12‐month clinical outcomes. In contrast, 1‐month troponin elevation was independently predictive of increased all‐cause mortality [hazard ratio (HR) 1.59, 95% confidence interval (CI) 1.18–2.13] and cardiovascular mortality or HF hospitalization (HR 1.28, 95% CI 1.03–1.58) at 12 months. Associations between 1‐month troponin elevation and outcomes were similar among patients with newly elevated (i.e. normal pre‐discharge) and persistently elevated levels (interaction P ≥ 0.16). The prognostic value of 1‐month troponin elevation for 12‐month mortality was driven by a pronounced association among patients with coronary artery disease (interaction P = 0.009).ConclusionsIn this hospitalized HF population, troponin I elevation was common during index hospitalization and at 1‐month follow‐up. Elevated troponin I level at 1 month, but not pre‐discharge, was independently predictive of increased clinical events at 12 months. Early post‐discharge troponin I measurement may offer a practical means of risk stratification and should be investigated as a therapeutic target.