bluuebunny/crossref_metadata_2025 huggingface dataset:
Theory for the Conductivity of Nanoparticle-Infiltrated SOFC Electrode
Authors: Chen Meina , Liu Tianyu , Lin Zijing
Published: October 2013

Based on the physical picture of nanoparticle-infiltrated electrode of SOFC, a new theory for the electronic conductivity of the electrode is developed. The theory provides a clear explanation for the observed conductivity below the conventional percolation threshold. The observed dependences of the electrode conductivity on the content of nano Ni particles as well as the operating temperature are well reproduced by the theory. The theory is also used in a multi physics numerical model and excellent agreement between the theoretical and experimental I-V curves is obtained. The new theory allows for in-depth analysis and design optimization of the nanoparticle-infiltrated electrode.
Computational Study of Performance Drop Phenomena Based on Sulfur Adsorption and Desorption Model in Planar-Type SOFCs
Authors: Tachikawa Yuya , Hosoi Takami , Nishimura Takashi , Shiratori Yusuke , Taniguchi Shunsuke , Sasaki Kazunari
Published: October 2013

For solid oxide fuel cell (SOFC) systems operating with practical fuels, it is important to simulate the distribution of sulfur poisoning and its dependence on the operating conditions in planar-type SOFCs. In this paper, by taking into account the sulfur poisoning effect and its distribution in planar-type SOFC simulation, numerical analysis is performed using anode exchange current density data and Temkin-like sulfur adsorption isotherm on Ni surface. From this numerical analysis, it is found that the distribution of current density after sulfur poisoning is changed, depending on operating temperature and fuel utilization.
Static Performance Model for ASCs with Different Sizes and Its Experimental Validation
Authors: Klotz Dino , Schmidt Jan Philipp , Weber André , Ivers-Tiffée Ellen
Published: October 2013

Anode supported SOFC single cells of different sizes – 1cm² and 16cm² – were measured and a 1D spatially resolved model was established accounting for the evolving operating parameters along the gas channel of the large cell. The model is calibrated with measurements on the 1cm² cell and reproduces the current/voltage characteristics of the 16cm² cell with very good accuracy. This is a first step of a scalability analysis towards establishing an SOFC stack model.
SOFC Long Term Operation in Pure Methane by Gradual Internal Reforming
Authors: Georges Samuel , Bailly Nicolas , Steil M. C. , Bultel Yann , Hadjar A. , Viricelle Jean-Paul , Rieu Mathilde
Published: October 2013

A solid oxide fuel cell was designed to be operated in pure methane, without external reforming or carrier gas. The fuel cell was built up from conventional NiO-YSZ anode supported cell with a specific Pt screen-printed anodic collecting system and a Ir-CGO catalytic layer. The operation principle is based on Gradual Internal Reforming. After an initiation in H2 for 30 minutes, the cell was operated for almost 2000 hours in pure and dry CH4 with a fuel utilization rate of 30 %. Intrinsic gradual degradation of 15 %/1000 h was observed, but no coking occurred at the anodic side.
Electrochemistry of Reformate Fueled Ni/8YSZ Anodes for Solid Oxide Fuel Cells
Authors: Kromp Alexander , Weber André , Ivers-Tiffée Ellen
Published: October 2013

This paper reports a comprehensive understanding of the electrochemical polarization processes that determine the performance of reformate fueled Solid Oxide Fuel Cells with Ni/8YSZ anodes. State-of-the-art anode supported cells manufactured by Research Center Jülich (FZJ) were analyzed via electrochemical impedance spectroscopy (EIS). A detailed EIS study with the help of the distribution of relaxation times (DRT) method has lead to the identification of the individual polarization processes for reformate operation and the subsequent setup of a physically meaningful equivalent circuit. Quantitative kinetic analysis via a complex nonlinear least-squares (CNLS) fit-method revealed the mechanism of the electrochemical fuel oxidation at the anode. Numerical simulation demonstrates the coupling of reforming chemistry and gas transport in the anode structure. As an outlook, it is shown how the gained insights are applied to monitor the impact of sulfur-poisoning on (i) the electrochemistry and on (ii) the reforming chemistry in the anodes.
Reversing and Repairing Microstructure Degradation in Solid Oxide Cells during Operation
Authors: Graves Christopher
Published: October 2013

The elevated operating temperature of solid oxide electrochemical cells (SOCs) can lead to long-term degradation of cell components due to instability of materials and microstructures. However, this unique possibility for microstructural changes to occur can also be advantageously exploited to counteract performance loss, by careful control of operating parameters and cell design. This paper describes four recently discovered methods of in situ reversal or repair of microstructure degradation: (1) The newest method is the elimination of severe electrolysis-induced degradation at high current density by reversible battery-like operation, cycling between electrolysis mode and fuel-cell mode. Also reported are new examples of beneficial effects of (2) redox cycling, (3) exsolution of nano-catalysts, and (4) high cathodic polarization, all of which can be used to maintain or even improve the activity of fuel-electrodes. Possible mechanisms behind these four phenomena are considered. The experimental results illustrate the promise of these strategies for enhancing SOC lifetime.
SmBaCo2O5+δ as High Efficient Oxygen Electrode of Solid Oxide Electrolysis Cells
Authors: Wei Bo , Chen Kongfa , Zhao Ling , Ai Na , Lü Zhe , Jiang San Ping
Published: October 2013

Oxygen electrode is a key component for solid oxide electrolysis cells (SOECs). Double perovksite oxide SmBaCo2O5+
d (SBCO) exhibits both high electrical conductivity and fast oxygen transport properties, herein we proposed SBCO as a novel high efficient SOEC oxygen electrode based on Ce0.9Gd0.1O1.9 (GDC) electrolyte. Preliminary study showed that an area specific resistance 0.024 W cm2 was achieved under OCV condition at 900°C and a stable operation of 20h was performed at an anodic polarization current density of 200mA×cm-2.
Durability of Solid Oxide Electrolysis Cell and Interconnects for Steam Electrolysis
Authors: Sun Xiufu , Chen Ming , Liu Yi-Lin , Hendriksen Peter Vang , Mogensen Mogens
Published: October 2013

Durability of a solid oxide electrolysis cell tested at -1.5A/cm2 for high temperature steam electrolysis was investigated in the present work under stack relevant conditions. Detailed electrochemical and microstructural analyses were carried out. The results show that both the hydrogen and the oxygen electrodes degraded during the durability test. The degree of percolation loss in the active Ni-YSZ hydrogen electrode is found to decrease along the steam flow direction whereas the formation of cracks or cavities/pores within the electrolyte shows the opposite trend. The influence of sealing and interconnects on cell degradation under harsh electrolysis conditions is further discussed.
Electrode Performance in a Solid Oxide Electrolyzer Cell (SOEC)
Authors: Lee Kyoung Jin , Seo J. W. , Yoon Jong Seol , Hwang Hae Jin
Published: October 2013

An electrolyte-supported solid oxide electrolysis cell (SOEC) consisting of a ScSZ (Sc2O3-stabilized ZrO2) electrolyte, Ni-YSZ cathode and LSCF (lanthanum strontium cobalt ferrite)-GDC (Gd2O3-doped CeO2) anode was fabricated. Current density-voltage (j-V) curves were obtained for the cell under SOFC and SOEC modes and the cell performance was discussed in combination with corresponding EIS measurements. It was possible to determine the ohmic, cathodic and anodic contributions to the total polarization loss using the three-electrode technique. It was found that the overpotential of the Ni-YSZ electrode contributed largely to the performance of the cell.
Differences in Muscle Activation Patterns during Sit to Stand Task among Subjects with and without Intellectual Disability
Authors: Cuesta-Vargas Antonio I. , González-Sánchez Manuel
Published: October 2013

The aim of this study is to analyse the differences in muscle activity between subjects who have intellectual disability and healthy subjects when they make the transition from sitting to standing positions. A cross-sectional study. A group of adults was divided into two subgroups: with and without intellectual disability (ID). The means of the basic features in both groups were 22.13 and 22.83 for age, 66.38 and 67.67 for weight, and 173.38 and 174.33 for height, for the ID () and without ID () groups, respectively. Each subject performed three sets of five repetitions during which, starting from sitting, they had to get up and sit on the chair. The recording of muscle activity was performed using surface electromyography taking the measures of muscle activity of different muscles of the lower limbs. The results showed differences in the pattern of muscle activity between groups during sitting to standing movement.
A Numerical Study to Compare Stimulations by Intraoperative Microelectrodes and Chronic Macroelectrodes in the DBS Technique
Authors: Paffi A. , Apollonio F. , Puxeddu M. G. , Parazzini M. , d’Inzeo G. , Ravazzani P. , Liberti M.
Published: October 2013

Deep brain stimulation is a clinical technique for the treatment of parkinson’s disease based on the electric stimulation, through an implanted electrode, of specific basal ganglia in the brain. To identify the correct target of stimulation and to choose the optimal parameters for the stimulating signal, intraoperative microelectrodes are generally used. However, when they are replaced with the chronic macroelectrode, the effect of the stimulation is often very different. Here, we used numerical simulations to predict the stimulation of neuronal fibers induced by microelectrodes and macroelectrodes placed in different positions with respect to each other. Results indicate that comparable stimulations can be obtained if the chronic macroelectrode is correctly positioned with the same electric center of the intraoperative microelectrode. Otherwise, some groups of fibers may experience a completely different electric stimulation.
Pattern Formation of a Keller-Segel Model with the Source Termup(1-u)
Authors: Fu Shengmao , Cao Fenli
Published: October 2013

Nonlinear dynamics near an unstable constant equilibrium in a Keller-Segel model with the source termup(1-u)is considered. It is proved that nonlinear dynamics of a general perturbation is determined by the finite number of linear growing modes over a time scale ofln(1/δ), whereδis a strength of the initial perturbation.
A Node Deployment Algorithm Based on Van Der Waals Force in Wireless Sensor Networks
Authors: Yu Xiangyu , Liu Ninghao , Huang Weipeng , Qian Xin , Zhang Tao
Published: October 2013

The effectiveness of wireless sensor networks (WSN) depends on the regional coverage provided by node deployment, which is one of the key topics in WSN. Virtual force-based algorithms (VFA) are popular approaches for this problem. In VFA, all nodes are seen as points subject to repulsive and attractive force exerted among them and can move according to the calculated force. In this paper, a sensor deployment algorithm for mobile WSN based on van der Waals force is proposed. Friction force is introduced into the equation of force, the relationship of adjacency of nodes is defined by Delaunay triangulation, and the force calculated produce acceleration for nodes to move. An evaluation metric called pair correlation function is introduced here to evaluate the uniformity of the node distribution. Simulation results and comparisons have showed that the proposed approach has higher coverage rate, more uniformity in configuration, and moderate convergence time compared to some other virtual force algorithms.
Real-Time Monitoring System for Workers' Behaviour Analysis on a Large-Dam Construction Site
Authors: Lin Peng , Li Qingbin , Fan Qixiang , Gao Xiangyou
Published: October 2013

This paper studies the feasibility of a real-time monitoring system to provide prompt analysis support of workers' behaviour on dam construction sites. The system makes use of wireless sensor tracking technology and a set of servers for the running of software, handling collected data, real-time site state visualization, and remote interaction communications. The low-level ZigBee-based tracking technology network hardware utilizing fingerprinting software technology was employed. The system was found to be able to cover a large field whilst retaining its simple and easily deployable features. The proposed system was successfully implemented on the Xiluodu arch dam construction site and ultimately helped overcome the original shortcomings in worker safety management and has advanced the means of administration and management's awareness and culture to new levels. The field tests also show that the received signal strength indicator (RSSI)-based localization algorithm implemented on ZigBee devices is reliable and is accurate enough at 3 to 5 meters. In conclusion, the system proved to be very useful for the management of field safety worker behaviour analyses in the case of such a high arch dam and also for similar hydraulic projects.
Influence of Wheat-Milled Products and Their Additive Blends on Pasta Dough Rheological, Microstructure, and Product Quality Characteristics
Authors: Dhiraj B. , Prabhasankar P.
Published: October 2013

This study is aimed to assess the suitability ofT. aestivumwheat milled products and its combinations withT. durumsemolina with additives such as ascorbic acid, vital gluten and HPMC (Hydroxypropyl methyl cellulose) for pasta processing quality characteristics such as pasta dough rheology, microstructure, cooking quality, and sensory evaluation. Rheological studies showed maximum dough stability in Comb1 (T. aestivumwheat flour and semolina). Colour and cooking quality of Comb2 (T. durumsemolina andT. aestivumwheat flour) and Comb3 (T. aestivumwheat semolina andT. durumsemolina) were comparable with control. Pasting results indicated thatT. aestivumsemolina gave the lowest onset gelatinization temperature (66.9°C) but the highest peak viscosity (1.053 BU). Starch release was maximum in Comb1 (53.45%) when compared with control (44.9%) as also proved by microstructure studies. Firmness was seen to be slightly high in Comb3 (2.430 N) when compared with control (2.304 N), and sensory evaluations were also in the acceptable range for the same. The present study concludes that Comb3 comprising 50%T. durumsemolina and 50%T. aestivumrefined wheat flour with additives would be optimal alternate for 100%T. durumsemolina for production of financially viable pasta.
Molecular Imaging in Traditional Chinese Medicine Therapy for Neurological Diseases
Authors: Wang Zefeng , Wan Haitong , Li Jinhui , Zhang Hong , Tian Mei
Published: October 2013

With the speeding tendency of aging society, human neurological disorders have posed an ever increasing threat to public health care. Human neurological diseases include ischemic brain injury, Alzheimer’s disease, Parkinson’s disease, and spinal cord injury, which are induced by impairment or specific degeneration of different types of neurons in central nervous system. Currently, there are no more effective treatments against these diseases. Traditional Chinese medicine (TCM) is focused on, which can provide new strategies for the therapy in neurological disorders. TCM, including Chinese herb medicine, acupuncture, and other nonmedication therapies, has its unique therapies in treating neurological diseases. In order to improve the treatment of these disorders by optimizing strategies using TCM and evaluate the therapeutic effects, we have summarized molecular imaging, a new promising technology, to assess noninvasively disease specific in cellular and molecular levels of living models in vivo, that was applied in TCM therapy for neurological diseases. In this review, we mainly focus on applying diverse molecular imaging methodologies in different TCM therapies and monitoring neurological disease, and unveiling the mysteries of TCM.
Hepatic Portal Venous Gas: Comparison of Two Cases
Authors: Rankin Iain , Sheth Hemant
Published: October 2013

Context.Hepatic portal venous gas (HPVG) is a rare and sinister finding. Its mortality is associated with the underlying causative condition. When secondary to bowel ischaemia, mortality rates exceed 50%.Case Report.Two cases of HPVG are described. One case describes HPVG in association with gastric ischaemia, with complete resolution following conservative management. The second case describes HPVG in association with widespread intra-abdominal ischaemia, with resultant mortality.Conclusion.A “watch and wait” management of HPVG associated with gastric ischaemia is suggested in certain patients, with a low threshold for surgical intervention. HPVG associated with bowel ischaemia is an absolute indication for surgical intervention, where intervention may change the clinical course.
Neuro-Fuzzy Model for the Prediction and Classification of the Fused Zone Levels of Imperfections in Ti6Al4V Alloy Butt Weld
Authors: Casalino Giuseppe , Campanelli Sabina Luisa , Memola Capece Minutolo Fabrizio
Published: October 2013

Weld imperfections are tolerable defects as stated from the international standard. Nevertheless they can produce a set of drawbacks like difficulty to assembly, reworking, limited fatigue life, and surface imperfections. In this paper Ti6Al4V titanium butt welds were produced by CO2laser welding. The following tolerable defects were analysed: weld undercut, excess weld metal, excessive penetration, incomplete filled groove, root concavity, and lack of penetration. A neuro-fuzzy model for the prediction and classification of the defects in the fused zone was built up using the experimental data. Weld imperfections were connected to the welding parameters by feed forward neural networks. Then the imperfections were clustered using the C-means fuzzy clustering algorithm. The clusters were named after the ISO standard classification of the levels of imperfection for electron and laser beam welding of aluminium alloys and steels. Finally, a single-value metric was proposed for the assessment of the overall bead geometry quality. It combined an index for each defect and functioned according to the criterion “the-smallest-the-best.”
The Importance of the Model Choice for Experimental Semivariogram Modeling and Its Consequence in Evaluation Process
Authors: Mazzella Alessandro , Mazzella Antonio
Published: October 2013

Geostatistics was created during the second half of 20th century by Georges Matheron, on the basis of Danie Krige’s and Herbert Sichel’s theories. The purpose of this new science was to achieve an optimal evaluation of mining ore bodies. The interest in geostatistical tools has grown, and nowadays its techniques are applied in many branches of engineering where data analysis, interpolation, and evaluation are necessary. This paper presents an overview of the geostatistics approach in data analysis and describes each operative step from experimental semivariogram calculation to kriging interpolation, focusing and underlining the experimental semivariogram modeling step. To help any data analysts during geostatistical analysis process, an innovative geostatistical software was created. This new software, named “Kriging Assistant” (KA) and developed within the Department of Geoengineering and Environmental Technologies University of Cagliari, is able, with a marginal support of the user, to produce 2D and 3D grids and contour maps of sampled data. A comparison between kriging results obtained by KA and two of the most common data analysis softwares (Golden Software Surfer and ESRI Geostatistical Analyst for ArcMap) is presented in this paper. Reported data showed that KA minimizes interpolation errors and, for this reason, provides better interpolation results.
Macrophages: Gatekeepers of Tissue Integrity
Authors: Lavin Yonit , Merad Miriam
Published: October 2013

Macrophages form a heterogeneous group of hematopoietic cells that reside in tissues, where they are required to maintain organ integrity. Tissue macrophages contribute to tissue formation, metabolism, homeostasis, and repair. They have a unique ability to sense and respond to tissue damage. They serve as the first line of defense during infection and help promote immune tolerance in the steady state. Although most tissue macrophages share a high phagocytic and degradative potential, they are heterogeneous in origin, as well as in homeostatic function and response to insults. Here, we will discuss recent developments in our understanding of the origin of tissue macrophages and their functional specialization in tissues. Cancer Immunol Res; 1(4); 201–9. ©2013 AACR.
High-Latitude Atmospheric Motion Vectors from Composite Satellite Data
Authors: Lazzara Matthew A. , Dworak Richard , Santek David A. , Hoover Brett T. , Velden Christopher S. , Key Jeffrey R.
Published: October 2013

Atmospheric motion vectors (AMVs) are derived from satellite-observed motions of clouds and water vapor features. They provide crucial information in regions void of conventional observations and contribute to forecaster diagnostics of meteorological conditions, as well as numerical weather prediction. AMVs derived from geostationary (GEO) satellite observations over the middle latitudes and tropics have been utilized operationally since the 1980s; AMVs over the polar regions derived from low‐earth (polar)‐orbiting (LEO) satellites have been utilized since the early 2000s. There still exists a gap in AMV coverage between these two sources in the latitude band poleward of 60° and equatorward of 70° (both hemispheres). To address this AMV gap, the use of a novel approach to create image sequences that consist of composites derived from a combination of LEO and GEO observations that extend into the deep middle latitudes is explored. Experiments are performed to determine whether the satellite composite images can be employed to generate AMVs over the gap regions. The derived AMVs are validated over both the Southern Ocean/Antarctic and the Arctic gap regions over a multiyear period using rawinsonde wind observations. In addition, a two-season numerical model impact study using the Global Forecast System indicates that the assimilation of these AMVs can improve upon the control (operational) forecasts, particularly during lower-skill (dropout) events.
A Compressible Nonhydrostatic Cell-Integrated Semi-Lagrangian Semi-Implicit Solver (CSLAM-NH) with Consistent and Conservative Transport
Authors: Wong May , Skamarock William C. , Lauritzen Peter H. , Klemp Joseph B. , Stull Roland B.
Published: October 2013

A cell-integrated semi-Lagrangian (CISL) semi-implicit nonhydrostatic solver for the fully compressible moist Euler equations in two-dimensional Cartesian (x–z) geometry is presented. The semi-implicit CISL solver uses the inherently conservative semi-Lagrangian multitracer transport scheme (CSLAM) and a new flux-form semi-implicit formulation of the continuity equation that ensures numerically consistent transport. The flux-form semi-implicit formulation is based on a recent successful approach in a shallow-water equations (SWE) solver (CSLAM-SW). With the new approach, the CISL semi-implicit nonhydrostatic solver (CSLAM-NH) is able to ensure conservative and consistent transport by avoiding the need for a time-independent mean reference state. Like its SWE counterpart, the nonhydrostatic solver presented here is designed to be similar to typical semi-Lagrangian semi-implicit schemes, such that only a single linear Helmholtz equation solution and a single call to CSLAM are required per time step. To demonstrate its stability and accuracy, the solver is applied to a set of three idealized test cases: a density current (dry), a gravity wave (dry), and a squall line (moist). A fourth test case shows that shape preservation of passive tracers is ensured by coupling the semi-implicit CISL formulation with existing shape-preserving filters. Results show that CSLAM-NH solutions compare well with other existing solvers for the three test cases, and that it is shape preserving.
Lessons for leaders: Positive organization studies meets Niccolò Machiavelli
Authors: Cunha Miguel Pina e , Clegg Stewart , Rego Arménio
Published: October 2013

Machiavelli should be a central and canonical text for management education, even in the age of positive organizational literatures. We give it this role by considering the case of the virtuous leader. Our proposition is simple: virtuous leaders live and act, like anybody else, in the power circuits that are constitutive of reality. Therefore, they participate in power dynamics that sometimes make them face the need to decide in ways that do not correspond to normative positive precepts. Machiavelli shows that even virtuous leaders must do what needs to be done, while trying to preserve one’s values and move in the direction of noble, high purpose goals.
Evaluation of age-dependent susceptibility in calves infected with two doses of Mycobacterium avium subspecies paratuberculosis using pathology and tissue culture
Authors: Mortier Rienske AR , Barkema Herman W , Bystrom Janet M , Illanes Oscar , Orsel Karin , Wolf Robert , Atkins Gordon , De Buck Jeroen
Published: October 2013

The longstanding assumption that calves of more than 6 months of age are more resistant to Mycobacterium avium subspecies paratuberculosis (MAP) infection has recently been challenged. In order to elucidate this, a challenge experiment was performed to evaluate age- and dose-dependent susceptibility to MAP infection in dairy calves. Fifty-six calves from MAP-negative dams were randomly allocated to 10 MAP challenge groups (5 animals per group) and a negative control group (6 calves). Calves were inoculated orally on 2 consecutive days at 5 ages: 2 weeks and 3, 6, 9 or 12 months. Within each age group 5 calves received either a high – or low – dose of 5 × 109 CFU or 5 × 107 CFU, respectively. All calves were euthanized at 17 months of age. Macroscopic and histological lesions were assessed and bacterial culture was done on numerous tissue samples. Within all 5 age groups, calves were successfully infected with either dose of MAP. Calves inoculated at < 6 months usually had more culture-positive tissue locations and higher histological lesion scores. Furthermore, those infected with a high dose had more severe scores for histologic and macroscopic lesions as well as more culture-positive tissue locations compared to calves infected with a low dose. In conclusion, calves to 1 year of age were susceptible to MAP infection and a high infection dose produced more severe lesions than a low dose.
Advances in the REDCAT software package
Authors: Schmidt Chris , Irausquin Stephanie J , Valafar Homayoun
Published: October 2013

Background

Residual Dipolar Couplings (RDCs) have emerged in the past two decades as an informative source of experimental restraints for the study of structure and dynamics of biological macromolecules and complexes. The REDCAT software package was previously introduced for the analysis of molecular structures using RDC data. Here we report additional features that have been included in this software package in order to expand the scope of its analyses. We first discuss the features that enhance REDCATs user-friendly nature, such as the integration of a number of analyses into one single operation and enabling convenient examination of a structural ensemble in order to identify the most suitable structure. We then describe the new features which expand the scope of RDC analyses, performing exercises that utilize both synthetic and experimental data to illustrate and evaluate different features with regard to structure refinement and structure validation.

Results

We establish the seamless interaction that takes place between REDCAT, VMD, and Xplor-NIH in demonstrations that utilize our newly developed REDCAT-VMD and XplorGUI interfaces. These modules enable visualization of RDC analysis results on the molecular structure displayed in VMD and refinement of structures with Xplor-NIH, respectively. We also highlight REDCAT’s Error-Analysis feature in reporting the localized fitness of a structure to RDC data, which provides a more effective means of recognizing local structural anomalies. This allows for structurally sound regions of a molecule to be identified, and for any refinement efforts to be focused solely on locally distorted regions.

Conclusions

The newly engineered REDCAT software package, which is available for download via the WWW from http://ifestos.cse.sc.edu, has been developed in the Object Oriented C++ environment. Our most recent enhancements to REDCAT serve to provide a more complete RDC analysis suite, while also accommodating a more user-friendly experience, and will be of great interest to the community of researchers and developers since it hides the complications of software development.
The effect of cultivar, sowing date and transplant location in field on bolting of Welsh onion (Allium fistulosumL.)
Authors: Dong Yinxin , Cheng Zhihui , Meng Huanwen , Liu Hanqiang , Wu Cuinan , Khan Abdul Rehman
Published: October 2013

Background

Bolting reduces the quality and commercial yield of Welsh onion (Allium fistulosum L.) in production. However, seed production is directly dependent on flower induction and bolting. The Welsh onion belongs to the green plant vernalisation type, specific seedling characteristics and sufficient accumulated time at low temperature are indispensible for the completion of its vernalisation process. Only if these conditions for vernalisation are fulfilled, the plants will bolt in the following year. The present investigation evaluated the effects of cultivar, sowing date and transplant location in field on the bolting of Welsh onion at the Horticultural Farm of the College of Horticulture, Northwest A&F University, Yangling, Shannxi Province, China in two succeeding production years: 2010–2011 and 2011–2012. A strip split plot layout within a randomised complete block design with three replications was used.

Results

The results revealed that all three factors (cultivar, sowing date and transplant location) and their interaction had significant effects on the initiation and final rate of bolting observed by 30 April. The earliest bolting date (14 February, 2011 and 15 February, 2012) and the highest bolting rate (100% in 2011 and 62% in 2012) occurred when the JinGuan cultivar was sown on 20 August and transplanted in a plastic tunnel, whereas the latest date and lowest rate (no bolting observed until 30 April) of bolting occurred when the XiaHei cultivar was sown on 29 September and transplanted in an open field.

Conclusions

These results suggest that we can control bolting in Welsh onion production by choosing an appropriate cultivar, sowing date and transplant location. Choosing a late bolting cultivar, such as cultivar XiaHei, sowing around October, and transplanting in the open field can significantly delay bolting, while a sowing date in late August should be selected for seed production, and the seedlings should be transplanted in a plastic tunnel to accelerate development of the flower buds.
Stable superhydrophobic surface of hierarchical carbon nanotubes on Si micropillar arrays
Authors: He Shaoqing , Wei Jinquan , Wang Haifan , Sun Deshun , Yao Zhaohui , Fu Chengsong , Xu Ruiqiao , Jia Yi , Zhu Hongwei , Wang Kunlin , Wu Dehai
Published: October 2013

It is of great importance to construct a stable superhydrophobic surface with low sliding angle (SA) for various applications. We used hydrophobic carbon nanotubes (CNTs) to construct the superhydrophobic hierarchical architecture of CNTs on silicon micropillar array (CNTs/Si-μp), which have a large contact angle of 153° to 155° and an ultralow SA of 3° to 5°. Small water droplets with a volume larger than 0.3 μL can slide on the CNTs/Si-μp with a tilted angle of approximately 5°. The CNTs growing on planar Si wafer lose their superhydrophobic properties after exposing to tiny water droplets. However, the CNTs/Si-μp still show superhydrophobic properties even after wetting using tiny water droplets. The CNTs/Si-μp still have a hierarchical structure after wetting, resulting in a stable superhydrophobic surface.
NaviCell: a web-based environment for navigation, curation and maintenance of large molecular interaction maps
Authors: Kuperstein Inna , Cohen David PA , Pook Stuart , Viara Eric , Calzone Laurence , Barillot Emmanuel , Zinovyev Andrei
Published: October 2013

Background

Molecular biology knowledge can be formalized and systematically represented in a computer-readable form as a comprehensive map of molecular interactions. There exist an increasing number of maps of molecular interactions containing detailed and step-wise description of various cell mechanisms. It is difficult to explore these large maps, to organize discussion of their content and to maintain them. Several efforts were recently made to combine these capabilities together in one environment, and NaviCell is one of them.

Results

NaviCell is a web-based environment for exploiting large maps of molecular interactions, created in CellDesigner, allowing their easy exploration, curation and maintenance. It is characterized by a combination of three essential features: (1) efficient map browsing based on Google Maps; (2) semantic zooming for viewing different levels of details or of abstraction of the map and (3) integrated web-based blog for collecting community feedback. NaviCell can be easily used by experts in the field of molecular biology for studying molecular entities of interest in the context of signaling pathways and crosstalk between pathways within a global signaling network. NaviCell allows both exploration of detailed molecular mechanisms represented on the map and a more abstract view of the map up to a top-level modular representation. NaviCell greatly facilitates curation, maintenance and updating the comprehensive maps of molecular interactions in an interactive and user-friendly fashion due to an imbedded blogging system.

Conclusions

NaviCell provides user-friendly exploration of large-scale maps of molecular interactions, thanks to Google Maps and WordPress interfaces, with which many users are already familiar. Semantic zooming which is used for navigating geographical maps is adopted for molecular maps in NaviCell, making any level of visualization readable. In addition, NaviCell provides a framework for community-based curation of maps.
Selection of reference genes for quantitative real-time PCR analysis in chicken embryo fibroblasts infected with avian leukosis virus subgroup J
Authors: Yang Falong , Lei Xiaowen , Rodriguez-Palacios Alexander , Tang Cheng , Yue Hua
Published: October 2013

Background

The selection of stably expressed reference genes is a prerequisite when evaluating gene expression, via real-time PCR, in cells in response to viral infections. The objective of our study was to identify suitable reference genes for mRNA expression analysis in chicken embryonic fibroblasts (CEF) after infection with avian leukosis virus subgroup J (ALV-J).

Findings

The expression levels of 11 potential reference genes in CEF infected with ALV-J were determined by real-time PCR. The expression stability of these genes were analyzed and ranked using the geNorm tool. Analysis indicated that the genes RPL30 (ribosomal protein L30) and SDHA (succinate dehydrogenase complex, subunit A) were the most stably expressed genes in the ALV-J infected CEF.

Conclusions

The RPL30 and SDHA were deemed suitable for use as reference genes for real-time PCR analysis of mRNA gene expression during ALV-J infection, whereas commonly used ACTB and GAPDH are unsuitable to be reference genes.
Repeated autologous intraarticular blood injections as an animal model for joint pain in haemophilic arthropathy
Authors: Boettger Michael Karl , Krucker Susanne , Gajda Mieczyslaw , Schaible Hans-Georg , Hilberg Thomas
Published: October 2013

Introduction

Haemophilic arthropathy following recurrent joint bleedings is one of the major disease-related complications in people with haemophilia (PWH), leading to mostly chronic joint pain. Since many antinociceptive principles interfere with the clotting system, PWH are restricted in treatment options, thereby defining a medical need for novel therapeutic principles. However, we lack the availability of an animal model for joint pain in haemophilic arthropathy for testing these.

Methods

In this study, we aimed to validate the rat model of repeated autologous intraarticular blood injections specifically for pain-related behavior. During an observation period of 50 days, groups of animals were injected weekly into one knee joint with either whole blood or cellular/plasma components.

Results

Injections induced primary hyperalgesia starting after the third injection, accompanied by mild functional gait changes and joint swelling. Secondary hyperalgesia and quantitative gait disturbances were not observed. This phenotype was most prominent in whole blood injected animals, with effect sizes of cells and plasma being additive. In order to differentiate haemophilia-related arthropathy from traumatic joint bleeding, another group was injected with whole blood only once, which did not cause any alterations.

Conclusions

Repeated autologous intraarticular injections of blood showed a time course, inflammatory response and reduction in pain thresholds similar to the signs and symptoms observed in PWH. Therefore, this model may be utilised in the future for testing novel antinociceptive principles in haemophilia-associated joint pain.
A critical appraisal of asymptotic 3D-to-2D data transformation in full-waveform seismic crosshole tomography
Authors: Auer Ludwig , Nuber André Marc , Greenhalgh Stewart Alan , Maurer Hansruedi , Marelli Stefano
Published: October 2013

Seismic full-waveform inversion (FWI) is often based on forward modeling in the computationally attractive 2D domain. This implies the assumption of a line source extended in the out-of-plane medium invariant direction, with far-field amplitudes decaying inversely with the square root of distance. Realistic point sources, however, generate amplitudes that decay approximately with the inverse of distance. Conventionally, practitioners correct for this amplitude difference and the associated phase shift by transforming the recorded 3D field data to the approximate 2D equivalent by using simplistic asymptotic filter algorithms. Such filters assume straight raypaths, a constant velocity medium, and far-field recordings. We have assessed the validity of 3D-to-2D data transformation in the context of crosshole seismic full-waveform tomography by propagating 3D and 2D wavefields through 2D media and comparing 2D reference synthetics with their filtered 3D equivalent. The filter performs well in simple situations, which confirms the general applicability of the conventional asymptotic approach. However, we have observed substantial errors in more complex elastic models, associated with overlapping arrivals and strongly curved raypaths. To test if this error translates into deficient model reconstruction in FWI, we performed complementary inversion experiments using a frequency-domain algorithm. Purely acoustic waveform inversions of 3D-to-2D filtered data are only weakly affected, but in the case of elastic FWI, in which an S-wave influence is present, adverse effects increase substantially. Two-dimensional FWI in combination with filtering seems to be an acceptable strategy as long as the model is two-dimensional, the recording geometry is straight and perpendicular to strike, and only slight S-wave energy is contained in the data. The latter two conditions are generally met in exploration-type marine seismic surveys at short offsets and in some crosswell applications using explosive sources and nondirectional pressure receivers.
Helicopter time-domain electromagnetics — Newmont and the NEWTEM experience
Authors: Eaton Perry A. , Anderson Robert G. , Queen Steven V. , Nilsson Bruno Y. , Lauritsen Eric , Barnett Colin T. , Olm Mark , Mitchell Steven
Published: October 2013

Over the past two decades, the use of time-domain electromagnetic (EM) surveying systems, designed for an airborne helicopter-based platform, has risen in popularity. One of the first of these systems was developed and has been operated by Newmont Mining Corporation. The original system (NEWTEM I) and its more capable successor (NEWTEM II) were created to help our company explore for different types of mineral deposits, primarily gold bearing, as well as to provide general geologic mapping information in parts of the world that are often very difficult or expensive to explore otherwise. The NEWTEM system has some characteristics that have proven to be advantageous in terms of safety, cost of operation, spatial resolution, and the ability to map effectively at both ends of the resistivity scale. Our approach to the acquisition, processing, and interpretation of airborne EM data is specific to this system and to the goals of our gold-focused exploration programs. Using what is most often a locally derived helicopter, we are able to carry out a survey of whatever size our exploration program dictates and on a schedule that meets our company’s needs. Results from NEWTEM surveys have been used to identify conductive and resistive targets but more importantly to advance our general understanding of an area’s potential to host mineralization of interest to this company. We intended to provide a brief written account of the NEWTEM story for the scientific and exploration communities, including information about its design and capabilities, as well as how we process this type of data. Hopefully, this documentation will serve to inspire future developers, explorers, geoscientists, and airborne EM enthusiasts.
Wave-equation reflection traveltime inversion with dynamic warping and full-waveform inversion
Authors: Ma Yong , Hale Dave
Published: October 2013

In reflection seismology, full-waveform inversion (FWI) can generate high-wavenumber subsurface velocity models but often suffers from an objective function with local minima caused mainly by the absence of low frequencies in seismograms. These local minima cause cycle skipping when the low-wavenumber component in the initial velocity model for FWI is far from the true model. To avoid cycle skipping, we discovered a new wave-equation reflection traveltime inversion (WERTI) to update the low-wavenumber component of the velocity model, while using FWI to only update high-wavenumber details of the model. We implemented the low- and high-wavenumber inversions in an alternating way. In WERTI, we used dynamic image warping (DIW) to estimate the time shifts between recorded data and synthetic data. When compared with correlation-based techniques often used in traveltime estimation, DIW can avoid cycle skipping and estimate the time shifts accurately, even when shifts vary rapidly. Hence, by minimizing traveltime shifts estimated by dynamic warping, WERTI reduces errors in reflection traveltime inversion. Then, conventional FWI uses the low-wavenumber component estimated by WERTI as a new initial model and thereby refines the model with high-wavenumber details. The alternating combination of WERTI and FWI mitigates the velocity-depth ambiguity and can recover subsurface velocities using only high-frequency reflection data.
Imaging scatterers in landfills using seismic interferometry
Authors: Konstantaki Laura Amalia , Draganov Deyan , Heimovaara Timo , Ghose Ranajit
Published: October 2013

A significant problem with landfills is their aftercare period. A landfill is considered to be safe for the environment only after a relatively long period of time. Until it reaches such a condition, it has to be periodically treated. Not only are treatments very expensive, but they could be dangerous as well; for example, when barriers limiting the waste break. So far, there is no established technique that can predict the leachate and gas-emission potential of a landfill, especially in time-lapse monitoring. This potential depends on the channeling of fluids due to the presence of high-density waste areas and the redistribution of the channels with time. We propose to use seismic interferometry (SI) applied to active reflection seismics to help improve the image of the waste areas (scatterers) and to monitor the subsurface changes in time. Normally, application of SI to reflection recordings from active sources at the surface would result in an erroneous retrieved result, but secondary illumination of the receivers from strongly scattering subsurface, like a landfill, would remedy this problem. We conduct modeling studies to examine the possible benefits of this approach compared to using the conventional seismic reflection method. We show that the reflections retrieved from SI can be used to obtain a clearer image of the shallower scatterers. In addition, we illustrate that time-lapse monitoring using reflections retrieved by SI shows a more repeatable result than the conventional approach in case of source nonrepeatability.
Selecting an optimal aperture in Kirchhoff migration using dip-angle images
Authors: Klokov Alexander , Fomel Sergey
Published: October 2013

We present a method for selecting a migration aperture in Kirchhoff migration. We first split migrated data into constant-dip-angle partial images. Then, in every partial image, we estimate the consistency between each event and the constant dip of the analyzed section. We filter out events whose slope is far from the corresponding dip. Stacking of the filtered partial images corresponds to migration having an optimal aperture. Synthetic and real data examples demonstrate that the proposed approach to migration-aperture optimization is able to reduce migration noise while preserving diffraction energy, which characterizes small geologic objects and brings additional resolution to the image.
Repeatability issues of high-frequency signals emitted by air-gun arrays
Authors: Landrø Martin , Amundsen Lasse , Langhammer Jan
Published: October 2013

Recent field measurements of the acoustic signals generated by marine seismic air-gun arrays showed that the amount of high-frequency signals (above 10 kHz) increased with the size and total volume of the gun array. We found that for frequencies between 10 and 20 kHz, a strong signal is observed 7–14 ms after the main peak of the source signal. We believe that this signal was generated by ghost cavitation. We observed that this signal was significantly stronger than the high-frequency signal generated at the same time as the peak signal occurs within the bandwidth between 10 and 20 kHz. We found that this high-frequency signal was fairly repeatable from one shot to another. By “fairly,” we mean that individual high-frequency events were not repeatable; however, the envelope energy of this cascade of events was repeatable from one shot to another. The typical feature of the envelope of the high-frequency signal was that it lasted for approximately 6–7 ms and showed a monotonic increase in amplitude for the first 5–6 ms, followed by a sudden drop. The sea surface reflection coefficient for these high-frequency events seemed to decrease in magnitude as the frequency increased.
Digitalisierung in der ULB Halle: Prozesse, Kosten, Ergebnisse am Beispiel der Pilotphase des VD 18
Authors: Sommer Dorothea
Published: October 2013

In dem Beitrag1 werden die an der ULB Halle durchgeführten Digitalisierungsprozesse für verschiedene elektronische Geschäftsgänge dargelegt. Hierbei wird die Rolle und Bedeutung von Strukturdaten für die Erschließung von Netzpublikationen besonders erörtert. Die bei Digitalisierungsverfahren entstehenden Kosten werden exemplarisch am Beispiel der Pilotphase des VD 18 untersucht. Die Ergebnisse basieren auf einer Kosten-Leistungsrechnung, die parallel während des Projekts in den Pilotbibliotheken durchgeführt wurde, um einen Vergleich der zum Einsatz kommenden technischen Verfahren und eine Kalkulation der Kosten für das Gesamtprojekt anhand von Praxiswerten zu ermöglichen.