bluuebunny/crossref_metadata_2025 huggingface dataset:
Marine Ducted Propeller Blade Fracture Fault Diagnosis Technology Based on CFD
Authors: Ou Li Jian , Wang Feng Hong , Zhang Wei
Published: January 2014

The numerical model of the unsteady flow field of ducted propellers is based on CFD (computational fluid dynamics). By applying the numerical model, the unsteady flow field of the ducted propeller with the fracture in different positions of a certain blade is simulated and its unsteady hydrodynamic performance is numerically analyzed. By extracting the fluctuating pressure data of the duct inner wall monitoring points,the fluctuating pressure-time oscillogram of ducted propellers is obtained, and then the spectrum is obtained by FFT transformation of the oscillogram. A blade fracture fault diagnosis technology of ducted propellers, which combines oscillogram analysis method with spectrum analysis method, is put forward by analyzing and studying the oscillogram and the spectrum.
Targeted Advertising Based on Social Network Analysis
Authors: Fang Jing
Published: January 2014

Adverting is one of the most important profit models in internet world. With more than ten years development, internet advertisement becomes smarter than ever and RTB (Real Time Bidding) is becoming the major share in the whole internet advertisement. Under RTB environment, advertisers need more accurate and efficient advertising technology than before. Targeted advertising integrates game theory, big data analysis, data mining and advertising technology and helps to publish advertisement to audiences precisely. Social network is the reflection of real world on internet built on six degrees of separation theory, and it has massive users and enormous access every day and thus collects massive personal information which can help to improve targeted advertising. This paper presents a framework to use social network analysis to improve targeted advertising and introduces clustering and cosine similarity as specified algorithm in the framework.
Exploration and Study on Reducing Regional Distribution Network Losses
Authors: Zhao Xiang Dong , Li Xian Feng , Liu Feng Zhen , Zhao De Li , Zhang Chang Bo , Chang Xiu Yan
Published: January 2014

Network loss rate is an important technical power system economic indicators used to measure power integrated enterprise management level, but also an important symbol of the development of the electric power industry is one of great significance to control them. Strengthen the network loss management, implementation of loss reduction measures, has become an important power supply enterprise content management one. The regional distribution network loss reduction and feasibility of specific measures are given in this paper, to ensure the safe and reliable operation of the grid under the premise of reducing losses from management and technical measures two aspects in detail, in a bid to obtain the actual operation of the grid better social and economic benefits.
The Relationship between the Urban Road Flood Protection Capacity and the Lake Sandbox Based on Internet of Things
Authors: Shi Heng Hua , Chen Tao , Wang Guo Dong , Liu Yong
Published: January 2014

The urban road flood protection capacity is related with a lot of elements such as human factors and natural environment as the lake. The lake can storage water temporarily and improves the urban road flood protection capacity. Based on Internet of Things technology, we establish an urban road drainage system sandbox with the near lake to simulate the relationship between the urban road flood protection capacity and the lake. The experiment simulates urban road drainage with the near lake in different rainfall level. Simulation results show that the near lake can obviously improve the urban road flood protection capacity in Heavy Rain and Rainstorm, and partly improve the urban road flood protection capacity heavy rainstorm and big heavy rainstorm. This can interchange for the urban road drainage system design to improve urban road flood protection capacity, promote the urban natural environment protection including the lake protection.
Photodegradation of Microcystine-LR Uising BiOBr under UV and Visible Light Irradiation
Authors: Fang Yan Fen , Li Xin Yu , Jia Man Ke , Huang Ying Ping
Published: January 2014

BiOBr photocatalyst was prepared by cetyl pyridine bromide (CPB). The characterization of BiOBr was measured by DRS UV-Vis, XRD, BET, TEM/HRTEM, XPS and IR. The energy gap of BiOBr was merely 2.62eV which can absorb visible light (λ473nm), BiOBr was identified to the tetragonal phase exhibits significantly enhanced structural properties and the ration of the amount of Bi and Br on the surface of BiOBr is 1. The BET of BiOBr was 12.03 m2/g and was layered structure. Compared with traditional catalyst TiO2(P25), the prepared BiOBr has good visible light activity and can degradated Microcystine-LR(MC-LR) under UV and Visible light irradation. The degradation time of MC-LR between UV and vis-light irradiation is respectively 60min and 150min under the same condition. It was indicated that the oxidizing rate of O2- in UV system is obviously higher than that of·OH in the vis-light system by ESR experiments, which is also proved in the differences of reaction intermediates in the degradation process under the two lamps.
Research on the Cutting Performance and Parameter Optimization of TiAlN Coated Cutting Tools in Cutting Stainless Steel
Authors: Wei Sha Sha , Wei Wei , Lu Ping Shan , Lin Rong Chuan
Published: January 2014

TiAlN coated cemented carbide is a new style material and enjoys many advantages such as high wear resistance ,good physical and mechanics performance. Through cutting tests of machining stainless steel S17700, we study the effects of different cutting performance on tool life to get optimum cutting performance when tool life is constant. The study shows that this cutter is a better material in cutting stainless steel.
Research on the Effective Rules for the Impact Toughness and Hardness of Austempered Ductile Iron (ADI) by Austempering Parameters
Authors: Shi Gao Lian , Wu Shao Hua , Guo Xu Hong , Huang Xing
Published: January 2014

With the common engineering-purpose ductile iron used as research subject, the research on rules of austempering parameters to influence the impact toughness and hardness of austempered ductile iron (ADI) was implemented in this paper by adopting the combination of theoretical, experimental and numerical simulation methods, and setting series of austempering parameters; After the impact tests and hardness tests simulated by the finite element software - ANSYS Workbench, the simulation data were analyzed by comparing with the experimental data. The experimental results showed that: austenitizing time was longer, ADI hardness was smaller while impact toughness remained unchanged; hardness was in linearly-decreasing trend with rise of austempering temperature, while impact toughness first increased and then decreased as the austempering temperature rose, with the maximum at the temperature 350°C; The effect of austempering time on the impact toughness was very few; extension of austempering time allows the hardness to increase slightly, but only a little.
Strength Characteristic of Ordovician Limestone under Unloading Condition
Authors: Cheng Xiang Min , Yang Yu Chun , Zhao Guo Bin , Qu Zhi Yong , Chen Shu Wen
Published: January 2014

The Strength characteristic of rock are different from them under unloading condition. The Strength characteristic of Ordovician limestone under loading and unloading condition of high compress which were taken from North Tian Mountain. It indicated that : Under unloading condition cohesion c and inner friction angle decrease according to loading condition, and the residual strength has more decrease than peak strength. Under unloading, peak compress strength and residual compress strength decrease distinctly, and the decrease reduces along with confining compress increasing.
Thermal Conducting Silicone Rubber Composites Filled with Aligned Nickel Nanoparticles Induced by Magnetic Field
Authors: Ma Jie , Wang Zhou , Jing Mao Xiang , Shen Xiang Qian
Published: January 2014

Thermal conducting silicone rubber composites filled with aligned nickel (Ni) nanoparticles induced by magnetic field were prepared by the solution mixing process. The structure, thermal, dielectric and magnetic properties of the silicone rubber composites were investigated by optical microscopy, laser flash thermal diffusivity analyzer, LCR digital meter and vibrating sample magnetometer. The results show that with the induction of magnetic field, Ni nanoparticles aligned form thermal conducting networks resulting in increase of the thermal diffusivity and relative dielectric constant of the silicone rubber composites.
Application of Finite Element Method for Prestressed Reinforced Concrete Trench-Buried Inverted Siphon Analysis
Authors: Liu Ke Ding
Published: January 2014

This paper adopt universal finite element calculation software to carry out simulation analysis for Jinliang river of Mianyou canal trench-buried inverted siphon. Deducing variation law of the inverted siphons stress and displacement in construction process and operating process. The calculation results further shown design schemes rationality and safety. Which provide reliable reference of design and construction for the trench-buried inverted siphon.
Study on Structure Analysis of Prestressed Reinforced Concrete Inverted Siphon
Authors: Ren Zhen
Published: January 2014

This paper adopt universal finite element calculation software to carry out force analysis for Shayubeigou prestressed reinforced concrete inverted siphon,computer is applied in analysis of prestressed reinforced concrete inverted siphon. Deducing variation law of the inverted siphons stress and displacement in construction process and operating process. The calculation results further shown design schemes rationality and safety. which provide reliable reference of design and construction for the prestressed reinforced concrete inverted siphon.
The Experiment on how the Ratio of Diameter to Height D/H Influences the Bearing Capacity of Bucket Foundation
Authors: Liu Shuai , Liu Wen Bai , Yang Liang
Published: January 2014

Through eight groups of room model experiments based on bucket foundation, P-S curve can be plotted for each group according to the experiments results and be able to get the ultimate strength and ultimate displacement for them. Therefore how the ratio of the ultimate vertical bearing capacity and the ultimate displacement changes with the ratio of diameter to height can be analyzed. When the ratio of diameter to height is less than 1.2, the ratio of the ultimate vertical bearing capacity and the ultimate displacement changes significantly; and when the ratio of diameter to height is greater than 1.2, the ratio of ultimate vertical bearing capacity and ultimate displacement is not affected obviously. When the ratio of diameter to height is 1.2, it reaches the maximum utilization of the materials, and the cost of the project can be effectively reduced. So the paper considers that the ratio of diameter to height = 1.2 can be used as the optimum point of the ratio of diameter to height of the bucket foundation.
Study on the Vortex-Induced Vibration of a Long-Span Arch Bridge
Authors: Tang Chun Ping , Zhang Liang Liang
Published: January 2014

This study focuses on a super-large bridge in mountainous terrain. Through field measurement, it explored the wind environment characteristics on the location of this bridge, simulated the three-dimensional wind field of long-span half-through arch bridge, and deduced the motion equation and amplitude expression formula of the vortex-induced vibration of large-span half-through arch bridge. By numerical analysis, the vortex-induced vibration response values in completion state and maximum cantilever state are calculated.
Study on Vulcanizing and Asphalt Modifying of Eucommia Ulmoides Gum
Authors: Li Zhi Gang , Li Cong
Published: January 2014

How to exploiture and apply environmentally friendly and low carbon asphalt modifier is one of technicality problems which are exigent to solved in highway construction. Based on the introduction of vulcanizing process of eucommia ulmoides gum (EUG) and the physical and mechanical properties of vulcanized gum, and the explains of its desirable engineering characteristics as well as its engineering application foreground.,the new approach is presented to use modified asphalt which is a blend of vulcanized EUG and asphalt as new pavement materials of highway. With sweep electron microscope (SEM) and analysis on the improvements of the asphalt`s performance, the best crosslinking degree of asphalt modified vulcanized EUG was studied, and the result indicates that vulcanized EUG has a range of the best crosslinking degree. When the crosslinking degree of vulcanized EUG reaches the range, the vulcanized EUG can improve asphalt`s performances in both low temperature and high temperature, which means it is feasible to use vulcanized EUG for asphalt modifying.
Influence of the Heat Treatment on the Structure and Property of the Foam Glass
Authors: Wu Long , Zhao Yi Hong , Chen Rong Fa , Yang Hua , Li Qing Qing , Li Zhi Long , Lu Hua Feng
Published: January 2014

In this paper, the foam glass was made with 5 wt % calcium carbonate used as foaming agent. The macro morphology, physical properties and the metallurgical structure are discussed in detail by the modern means of DTA, SEM and XRD analysis. The results indicated that when the powders were foamed at 800°C for 20min, the property of the samples was best, the density was 0.706 g/cm3,and the compressive strength was 3.36Mpa.
Prediction of Vehicle Fuel Consumption Model Based on Artificial Neural Network
Authors: Amer A. , Abdalla Ahmed , Noraziah A. , Fauzi Ainul Azila Che
Published: January 2014

With the increasing cost of fuel price minimizing fuel consumption is a major concern as far as sustainable engineering is concerned It is apparent that effective techniques for estimating fuel consumption costs are essential in order to avoid unnecessary fuel wastage and make use the most out of it In this paper an Artificial Neural Network (ANN) 2approach is used to fuel consumption model was proposed First few estimation calculator techniques have2 been briefly described Second the proposed optimization objective is to minimize the travel distance which is the corresponding to vehicle 2routing problem The neural network model has 5 input nodes at layer first which are representing engine size distance fuel type speed and passenger 15 nodes at hidden layer and one output node representing the fuel consumption costs. Finally calculations results are compared with other fuel model which indicate that estimation of fuel cost can be more accurate to optimize the fuel consumption usage accurate to optimize the fuel consumption usage.
Graphene/Nylon-6 Chemiresistor Sensor for Trimethylamine Gas Sensing
Authors: Rañola Rey Alfred G. , Kalaw Justine M. , Sevilla Fortunato B.
Published: January 2014

A graphene/nylon-6 nanocomposite was fabricated by incorporating reduced graphene oxide onto a nylon-6 (N6) membrane via vacuum assisted self-assembly (VASA) method. The graphene oxide was synthesised through acid dissolution according to the method of Marcano & Tour and subsequently reduced to graphene using L-ascorbic acid. The surface morphology and electrical characteristic of graphene and its nanocomposites was characterized. The percolation threshold of the prepared nanocomposites was around 1.92% (w/w) with a sheet resistance of 3.839 x 103Ω per square (rsd= 0.22%, n=4). Different weight ratios of the nanocomposite were tested for its sensitivity towards the amine vapour. The final sensor for trimethylamine concentration has a working concentration range between 23 and 230 mg/L. The sensor exhibited linearity between 45 to 230 mg/L (r2= 0.9917) while the detection and quantitation limit was calculated at 0.39 mg/L and 1.30 mg/L, respectively. This nanocomposite demonstrates that it can be used as a chemiresistor gas sensor that is sensitive and selective to trimethylamine vapour.
The Design of Airport Flood Lighting Energy-Saving Control System
Authors: Yang Le , Li Kai , Yang Ge , Zhang Xin Chan
Published: January 2014

An airport flood lighting system is priority in the airport energy-saving and reducing emissions. Airport flood lighting energy-saving control system is presented by using configuration software, realizing the power acquisition, monitoring and centralized control of the ramp high-pole lamp. In automatic mode, it can integrate dynamic airport flight information to switch high-pole lamp. In the premise of ensuring flight safety at night, keeping the lights turn-on time accurately, so as to achieve the purpose of saving electricity.
Development of the Low Cost Harmonic and Power Instrument by Using Fourier Series Method with Microcontroller
Authors: Watjanatepin Napat , Boonmee Chaiyant , Kantaphayao Yutthana
Published: January 2014

The objective of this paper is to present the application of microcontroller dsPIC30F6012A to measure the harmonics current and electrical power by using the Fourier series method to calculate the electrical parameters. This design is to develop the low cost harmonics instrument and to focus on working with the single phase AC system. The prototype was then developed to measure the harmonics current and power factor, and the result was compared with the standard instrument. The result is that most electrical parameters have the measurement errors of less than 4.0%. However, this idea could be developed so that it applies in the related work with the power quality measurement.
Fracture Failure Mechanism Analysis of LP Second Stage Blades of a Gas Turbine
Authors: Liu Ben Wu , Wang Jian Jun , Yuan Hui Yi
Published: January 2014

To systematically study the root cause of the fracture failure on a gas turbine LP(low pressure) second stage blade, the damage impression, fractography, material composition and metallurgical structure of the fractured section were studied. Vibration characteristic calcultaion analysis to the blade was performed under considering the working condition and structure characteristic. The analysis results revealed that the LP second stage Blade fracture is high cycled fracture (HCF), and mainly caused by furrowed manufacturing defects close to the fatigue source. Preventive measures were presented accordingly. The studied work is valuable for being a reference to fracture failure analysis and structure design for gas compressor blades.
Effect of Tool Tilt Angle and Tool Plunge Depth on Mechanical Properties of Friction Stir Welded AA 5083 Joints
Authors: Muhayat Nurul , Zubaydi Achmad , Sulistijono Sulistijono , Yuliadi M. Zaed
Published: January 2014

The influences of tool tilt angle and tool plunge depth on tensile properties of friction stir welded AA 5083-H116 with the thickness of 4 mm were studied. Four different values of tool tilt angle of 1΀ 2°, 3°, and 4° were used to fabricate the joints. The tool plunge depths were choosen 3.85 mm, 3.90 mm and 3.95 mm. The FSW rotational speed and welding speed were 1125 rpm and 30 mm/min, respectively. The temperature, macrostructure, hardness and tensile strength of joints were compared and discussed. Results show that the increase of tool tilt angle and tool plunge depth resulted the welding temperature increase. Due to the increase of welding temperature, the hole defect become smaller. Tensile testing results indicated that the tensile strength of joints increased with increasing both the tool tilt angle and tool plunge depth.
The Influence of Electrospark and Laser Treatment upon Corrosive Resistance of Carbon Steel
Authors: Scendo Mieczysław , Radek Norbert , Trela Joanna
Published: January 2014

The influence on corrosion resistance of C45 carbon steel in chloride environment covered by coats of tungsten carbide and copper were examined. The coats were put on the surface of steel by electrospark method. The potentiodynamic polarization technique for corrosive investigations was applied. The topography of surface by scanning electron microscope (SEM) was observed. The most corrosion resistance was exhibited for steel covered by mixture of the 25% WC and 75% Cu nanopowders. The top layer of coating is not homogeneous and consists of copper, WC2, tungsten carbide and iron. The laser treatment modifies of the electrospark layer and influences on the correct it usable properties.
Influence of Laser Surface Texturing on Scuffing Resistance of Sliding Pairs
Authors: Antoszewski Bogdan
Published: January 2014

This paper presents the results of experimental research on the impact assessment texture on scuffing resistance. The results showed that the texturing increases the resistance to scuffing. Above it has been shown that texture having a smaller surface energy and having a larger volume are more resistant to scuffing.
Investigations of Magnetorheological Elastomers Subjected to Cyclic Loading
Authors: Kaleta Jerzy , Królewicz Michał , Lewandowski Daniel , Przybylski Michał
Published: January 2014

This paper describes investigations of magnetorheological elastomers subjected to cyclic loading. The procedure comprised over 1 million of loading cycles per specimen. Mechanical properties of the manufactured composites have a tendency to stabilize in time. This leads to the conclusion that these MRE have a high application potential in the areas which are connected with energy dissipation, such as damping of vibrations.
Biogenic volatile organic compound emissions during BEARPEX 2009 measured by eddy covariance and flux–gradient similarity methods
Authors: Park J.-H. , Fares S. , Weber R. , Goldstein A. H.
Published: January 2014

Abstract. The Biosphere Effects on AeRosols and Photochemistry EXperiment (BEARPEX) took place in Blodgett Forest, a Ponderosa pine forest in the Sierra Nevada of California, USA, during summer 2009. We deployed a proton transfer reaction–quadrupole mass spectrometer (PTR-QMS) to measure fluxes and concentrations of biogenic volatile organic compounds (BVOCs). Eighteen ion species, including the major BVOC expected at the site, were measured sequentially at 5 heights to observe their vertical gradient from the forest floor to above the canopy. Fluxes of the 3 dominant BVOCs methanol, 2-Methyl-3-butene-2-ol (MBO), and monoterpenes were measured above the canopy by the disjunct eddy covariance (EC) method. Canopy-scale fluxes were also determined by the flux–gradient similarity method (K-theory). A universal K (Kuniv) was determined as the mean of individual K's calculated from the measured fluxes divided by vertical gradients for methanol, MBO, and monoterpenes. This Kuniv was then multiplied by the gradients of each observed ion species to compute their fluxes. The flux–gradient similarity method showed very good agreement with the disjunct EC method. Fluxes are presented for all measured species and compared to historical measurements from the same site, and used to test emission algorithms used to model fluxes at the regional scale. MBO was the dominant emission observed, followed by methanol, monoterpenes, acetone, and acetaldehyde. The flux–gradient similarity method is shown to be tenable, and we recommend its use, especially in experimental conditions when fast measurement of BVOC species is not available.
Heterogeneous reaction of N2O5 with illite and Arizona test dust particles
Authors: Tang M. J. , Schuster G. , Crowley J. N.
Published: January 2014

Abstract. The heterogeneous reaction of N2O5 with airborne illite and Arizona test dust (ATD) particles was investigated at room temperature and at different relative humidities using an atmospheric pressure aerosol flow tube. N2O5 at concentrations in the range 8 to 24 × 1012 molecule cm−3 was monitored using thermal-dissociation cavity ring-down spectroscopy at 662 nm. At zero relative humidity a large uptake coefficient of N2O5 to illite was obtained, γ(N2O5) = 0.09, which decreased to 0.04 as relative humidity was increased to 67%. In contrast, the uptake coefficient derived for ATD is much lower (~0.006) and displays a weaker (if any) dependence on relative humidity (0–67%). Potential explanations are given for the significant differences between the uptake behaviour for ATD and illite and the results are compared with uptake coefficients for N2O5 on other mineral surfaces.
Impact of black carbon aerosol over Italian basin valleys: high resolution measurements along vertical profiles, radiative forcing and heating rate
Authors: Ferrero L. , Castelli M. , Ferrini B. S. , Moscatelli M. , Perrone M. G. , Sangiorgi G. , Rovelli G. , D'Angelo L. , Moroni B. , Scardazza F. , Mocnik G. , Bolzacchini E. , Petitta M. , Cappelletti D.
Published: January 2014

Abstract. This study presents the first measured high resolution vertical profiles of black carbon and calculation of aerosol radiative forcing and atmospheric heating rates in the lower troposphere, over Italy and Europe. The calculation is based on vertical profiles of black carbon, aerosol number size distribution and chemical composition measured over three Italian basin valleys (Po Valley, Terni Valley and Passiria Valley) by means of a tethered balloon equipped with a micro-Aethalometer, an optical particle counter (OPC), a cascade impactor and a meteorological station. Experimental measurements allowed first the calculation of the aerosol optical properties. In this respect, the aerosol refractive index was calculated along height using the effective medium approximation applied to aerosol chemical composition; Mie calculations were performed on the base of the OPC number-size distribution which was corrected for the ambient aerosol refractive index. The obtained vertical profiles of aerosol optical properties were validated with AERONET data and were used as input to the radiative transfer model libRadtran. Vertical profiles of direct aerosol radiative forcing, atmospheric absorption and heating rate were calculated. Reported results evidenced common behaviours along height over the investigated basin valleys (an orographic feature present elsewhere in Europe): at the mixing height a marked a concentration drop of both BC (range: −48.4 ± 5.3% to −69.1 ± 5.5%) and particle number concentration (range: −23.9 ± 4.3% to −46.5 ± 7.3%) was evidenced. More in details, the percentage decrease of BC along height was higher than that measured for aerosol and thus, the BC content of the aerosol decreased along height; correspondingly the Single Scattering Albedo increased along height (range: +4.9 ± 2.2% to +7.4 ± 1.0%). Therefore, the highest atmospheric absorption was observed below the mixing height (range: +0.5 ± 0.1 W m−2 to +2.5 ± 0.2 W m−2) with the associated heating rate characterized by a vertical negative gradient (range: −0.5 K day−1 km−1 to −6.8 K day−1 km−1). As a result, the Black Carbon loaded below the mixing height potentially weakens the ground-based thermal inversions (common over basin valleys) thus promoting an increase of the atmospheric dispersal conditions.
Assimilation of decomposed in situ directional wave spectra into a numerical wave model of typhoon waves
Authors: Fan Y. M. , Günther H. , Kao C. C. , Lee B. C.
Published: January 2014

Abstract. The purpose of this study was to enhance the accuracy of numerical wave forecasts through data assimilation during typhoon periods. A sequential data assimilation scheme was modified to enable its use with partitions of directional wave spectra. The performance of the system was investigated with respect to operational applications, specifically for typhoon waves. Two typhoons that occurred in 2006 around Taiwan (Kaemi and Shanshan) were used for this case study. The proposed data assimilation method increased the forecast accuracy in terms of wave parameters, such as wave height and period. After assimilation, the shapes of directional spectra were much closer to those reported from independent observations.
Financing increasing flood risk: evidence from millions of buildings
Authors: Jongman B. , Koks E. E. , Husby T. G. , Ward P. J.
Published: January 2014

Abstract. The effectiveness of disaster risk management and financing mechanisms depends on the accurate assessment of current and future hazard exposure. The increasing availability of detailed data offers policy makers and the insurance sector new opportunities to understand trends in risk, and to make informed decisions on the ways to deal with these trends. In this paper we show how comprehensive property level information can be used for the assessment of exposure to flooding on a national scale, and how this information can contribute to discussions on possible risk financing practices. The case-study used is the Netherlands, which is one of the countries most exposed to flooding globally, and which is currently undergoing a debate on strategies for the compensation of potential losses. Our results show that flood exposure has increased rapidly between 1960 and 2012, and that the growth of the building stock and its economic value in flood prone areas has been higher than in not flood prone areas. We also find that property values in flood prone areas are lower than those in not flood prone areas. We argue that the increase in the share of economic value located in potential flood prone areas can have a negative effect on the feasibility of private insurance schemes in the Netherlands. The methodologies and results presented in this study are relevant for many regions around the world where the effects of rising flood exposure create a challenge for risk financing.
The influence of edge effects on crack propagation in snow stability tests
Authors: Bair E. H. , Simenhois R. , van Herwijnen A. , Birkeland K.
Published: January 2014

Abstract. Propagation tests are used to assess the likelihood of crack propagation in a snowpack, yet little is known about how test length affects propagation. Guidelines suggest beams with lengths around 1 m for Extended Column Tests (ECTs) and Propagation Saw Tests (PSTs). To examine how test length affects propagation, we performed 163 ECTs and PSTs 1 to 10 m long. On days with full crack propagation in 1.0 to 1.5 m tests, we then made videos of tests 2 to 10 m long. We inserted markers for particle tracking to measure collapse amplitude, collapse wave speed, and wavelength. We also used a finite element model to simulate the strain energy release rate at fixed crack lengths. We find that: (1) the proportion of tests with full propagation decreased with test length; (2) collapse was greater at the ends of the beams than in the centers; (3) collapse amplitudes in the longer tests were consistent with the shorter tests and did not reach a constant value; (4) collapse wavelengths in the longer tests were around 3 m, 2 × greater than what is predicted by the anticrack model. Based on our field tests and FE models, we conclude that the shorter tests fully propagated more frequently because of increased stress concentration from the far edge. The FE model suggests this edge effect occurs for PSTs up to 2 m long or a crack to beam length ratio ≥ 0.20. Our results suggest that ECT and PST length guidelines may need to be revisited.
L’opposition des missionnaires catholiques à la scolarisation des Autochtones au Bas-Canada, 1826-1845
Authors: Chaurette Mathieu
Published: January 2014

De 1826 à 1845, le développement de nouvelles écoles pour les Autochtones de la vallée du Saint-Laurent est marqué par des luttes de pouvoir entre missionnaires catholiques, sociétés protestantes et instituteurs autochtones. Si les missionnaires s’opposent d’abord aux protestants, qui tentent de faire de nouveaux convertis dans les communautés autochtones en créant des écoles, ils cherchent aussi à limiter l’accès à la scolarisation des Amérindiens, même lorsque celle-ci est catholique, afin de maintenir leur rôle politique au sein des villages. Lors de cette période, les missionnaires catholiques font face à certains Autochtones qui utilisent l’éducation, soit pour diffuser la religion protestante, soit pour contester leur autorité au sein des communautés. Ces missionnaires décident de s’opposer à tous les nouveaux projets scolaires qui émergent à Kahnawake, Akwesasne et Odanak, sans jamais tenter eux-mêmes de fonder des écoles catholiques.
Registration of X‐rays at 2500 m altitude in association with lightning flashes and thunderstorms
Authors: Montanyà Joan , Fabró Ferran , van der Velde Oscar , Romero David , Solà Gloria , Hermoso Juan Ramon , Soula Serge , Williams Earle R. , Pineda Nicolau
Published: January 2014

Electric fields and high‐energy radiation of natural lightning measured at close range from a mountaintop tower are discussed. In none of the 12 negative cloud‐to‐ground upward flashes were X‐rays observed. Also no energetic radiation was found in one negative upward leader at close range (20 m). In the first of two consecutive negative cloud‐to‐ground flashes, X‐rays were detected during the last ~1.75 ms of the leader. During the time of energetic radiation in the flash an intense burst of intracloud VHF sources was located by the interferometers. The X‐ray production is attributed to the high electric field runaway electron mechanism during leader stepping. Even though the second flash struck closer than the previous one, no X‐rays were detected. The absence of energetic radiation is attributed to being outside of the beam of X‐ray photons from the leader tip or to the stepping process not allowing sufficiently intense electric fields ahead of the leader tip. High‐speed video of downward negative leaders at the time when X‐rays are commonly detected on the ground revealed the increase of speed and luminosity of the leader. Both phenomena allow higher electric fields at the leader front favoring energetic radiation. Background radiation was also measured during thunderstorms. The count rate of a particular day is presented and discussed. The increases in the radiation count rate are more coincident with radar reflectivity levels above ~30 dBZ than with the total lightning activity close to the site. The increases of dose are attributed to radon daughter‐ion precipitation.
Transport of NOx in East Asia identified by satellite and in situ measurements and Lagrangian particle dispersion model simulations
Authors: Lee H.‐J. , Kim S.‐W. , Brioude J. , Cooper O. R. , Frost G. J. , Kim C.‐H. , Park R. J. , Trainer M. , Woo J.‐H.
Published: January 2014

Nitrogen dioxide (NO2) columns observed from space have been useful in detecting the increase of nitrogen oxides (NOx) emissions in East Asia, particularly China, coinciding with rapid economic growth during the past several decades. NO2 columns retrieved above a particular location reflect a combination of local NOx emissions and transported NOx from upwind sources. In this study, we demonstrate the transport of NOx emitted in East Asia using satellite and surface in situ measurements and Lagrangian particle dispersion model simulations. Enhanced satellite NO2 columns in the Yellow Sea (between China and South Korea) and the East Sea (between South Korea and Japan), and different seasonal variations of NO2 in China, North and South Korea, and Japan, suggest the importance of NOx transport in understanding the local NOx budget. Lagrangian transport model simulations with tracers of different chemical lifetimes identify source‐receptor relationships that explain high NO2 over the oceans and springtime peaks in Korea and Japan, with China being the most likely source region. Our results have important implications for studies using satellite NO2 retrievals to derive NOx emissions at local scales in regions adjacent to large sources, such as in East Asia, Europe, and the Eastern U.S.
The use of radiocarbon to constrain current and future soil organic matter turnover and transport in a temperate forest
Authors: Braakhekke Maarten C. , Beer Christian , Schrumpf Marion , Ekici Altug , Ahrens Bernhard , Hoosbeek Marcel R. , Kruijt Bart , Kabat Pavel , Reichstein Markus
Published: January 2014

We investigated the merits of radiocarbon measurements for estimating soil organic matter (SOM) turnover and vertical transport for a temperate deciduous forest in Germany. Eleven parameters, defining decomposition and transport in the soil carbon model SOMPROF, were estimated using a Bayesian approach based on organic carbon measurements and radiocarbon concentration of SOM and heterotrophic respiration. The addition of radiocarbon data had strong effects on the parameters, most importantly a reduction of the decomposition and production rate of the slowest SOM pool by an order of magnitude, and a similar reduction in advective SOM transport. The modified parameters further led to changes in the partitioning of SOM over the different model pools. The calibration results were subsequently used to perform transient soil carbon projections for the period 1901–2100. These simulations were run with parameter sets from calibrations both with and without radiocarbon. The results show an increase over time of topsoil carbon and a decrease in the subsoil, adding to a net gain overall. Near the end of the 21st century, total carbon stocks stabilize and—for the radiocarbon‐constrained model—start to decrease. However, the changes are small compared to the total stocks. The model results for the calibrations with and without radiocarbon are in general quite similar, but the latter shows notably higher heterotrophic respiration fluxes. Constraining the model with radiocarbon yielded only a small reduction of uncertainty for the total carbon stocks, while for the individual depth compartments, the uncertainty was increased.
Spontaneous sphenoid lateral recess cerebrospinal fluid leaks arise from intracranial hypertension, not Sternberg's canal
Authors: Illing Elisa , Schlosser Rodney J. , Palmer James N. , Curé Joel , Fox Nyssa , Woodworth Bradford A.
Published: January 2014

Background

Spontaneous cerebrospinal fluid (CSF) leaks/encephaloceles are proven to be associated with intracranial hypertension by objective measurements of CSF pressure during or following endoscopic repair. A common area of involvement is a pneumatized lateral recess of the sphenoid (LRS) sinus, where prolonged intracranial pressures lead to arachnoid pits and subsequent development of skull‐base defects. Even though the LRS is never present at birth, a “congenital” cause of these leaks due to a persistent Sternberg's (lateral craniopharyngeal) canal continues to be erroneously perpetuated in the literature. The objective of this study was to eliminate the myths defining these leaks as congenital in nature.

Methods

Evaluation of LRS CSF leaks present within a multiinstitutional case series was performed. Data regarding demographics, body mass index (BMI), radiologic evaluation of intracranial hypertension, and direct intracranial pressure measurements (when available) were collected.

Results

Data evaluation identified 77 LRS CSF leaks in 59 patients (mean age 52 years). Obesity was present in 83% of individuals (mean BMI 36) and 81% were females. Radiologic evidence of intracranial hypertension (eg, empty sella, dilated optic nerve sheaths, and scalloped/attenuated bone) was present on 96% of preoperative computed tomography (CT) and/or magnetic resonance imaging (MRI) scans. Opening or postsurgical lumbar drain or ventriculostomy pressure measurements were elevated in 95% of patients (mean 27.7; range, 9–50 cmH2O).

Conclusion

This study provides objective evidence that LRS CSF leaks are secondary to erosions from intracranial hypertension and refutes the myth regarding a congenital origin from Sternberg's canal.
EFFECTS OF DIURETIC HORMONE 31, DROSOKININ, AND ALLATOSTATIN A ON TRANSEPITHELIAL K+TRANSPORT AND CONTRACTION FREQUENCY IN THE MIDGUT AND HINDGUT OF LARVALDrosophila melanogaster
Authors: Vanderveken Mark , O'Donnell Michael J.
Published: January 2014

Recent studies have identified paracrine and endocrine cells in the midgut of larval Drosophila melanogaster as well as midgut and hindgut receptors for multiple neuropeptides implicated in the control of fluid and ion balance. Although the effects of diuretic factors on fluid secretion by isolated Malpighian tubules of D. melanogaster have been examined extensively, relatively little is known about the effects of such factors on gut peristalsis or ion transport across the gut. We have measured the effects of diuretic hormone 31 (DH31), drosokinin and allatostatin A (AST‐A) on both K+transport and muscle contraction frequency in the isolated gut of larval D. melanogaster. K+absorption across the gut was measured using K+‐selective microelectrodes and the scanning ion‐selective electrode technique. Allatostatin A (AST‐A; 1 μM) increased K+absorption across the anterior midgut but reduced K+absorption across the copper cells and large flat cells of the middle midgut. AST‐A strongly inhibited gut contractions in the anterior midgut but had no effect on contractions of the pyloric sphincter induced by proctolin. DH31 (1 μM) increased the contraction frequency in the anterior midgut, but had no effect on K+flux across the anterior, middle, or posterior midgut or across the ileum. Drosokinin (1 μM) did not affect either contraction frequency or K+flux across any of the gut regions examined. Possible functions of AST‐A, DH31, and drosokinin in regulating midgut physiology are discussed.
Analysis of Fmr1 Deletion in a Subpopulation of Post‐Mitotic Neurons in Mouse Cortex and Hippocampus
Authors: Amiri Anahita , Sanchez‐Ortiz Efrain , Cho Woosung , Birnbaum Shari G. , Xu Jing , McKay Renée M. , Parada Luis F.
Published: January 2014

Fragile X syndrome (FXS) is the most common form of inherited mental retardation and the leading cause of autism. FXS is caused by mutation in a single gene, FMR1, which encodes an RNA‐binding protein FMRP. FMRP is highly expressed in neurons and is hypothesized to have a role in synaptic structure, function, and plasticity by regulating mRNAs that encode pre‐ and post‐synaptic proteins. Fmr1 knockout (KO) mice have been used as a model to study FXS. These mice have been reported to show a great degree of phenotypic variability based on the genetic background, environmental signals, and experimental methods. In this study, we sought to restrict FMRP deletion to two brain regions that have been implicated in FXS and autism. We show that ablating Fmr1 in differentiated neurons of hippocampus and cortex results in dendritic alterations and changes in synaptic marker intensity that are brain region specific. In our conditional mutant mice, FMRP‐deleted neurons have activated AKT‐mTOR pathway signaling in hippocampus but display no apparent behavioral phenotypes. These results highlight the importance of identifying additional factors that interact with Fmr1 to develop FXS. Autism Res 2014, 7: 60–71. © 2013 International Society for Autism Research, Wiley Periodicals, Inc. © 2013 INSAR/Wiley Periodicals, Inc.
Bovine serum albumin‐confined silver nanoclusters as fluorometric probe for detection of biothiols
Authors: Chen Zhen , Lu Dongtao , Cai Zongwei , Dong Chuan , Shuang Shaomin
Published: January 2014

Fluorescent bovine serum albumin‐confined silver nanoclusters (BSA–AgNCs) were demonstrated to be a novel and environmentally friendly probe for the rapid detection of biothiols such as cysteine (Cys), homocysteine (Hcy) and glutathione (GSH). The sensing was ascribed to the strong affinity between the mercapto group of the biothiols and the silver nanoclusters. The fluorescence intensity of BSA–AgNCs was quenched efficiently on increasing the concentration of biothiol, corresponding with a red‐shift in emission wavelength. However, the fluorescence of the silver nanoclusters was almost unchanged in the presence of other α‐amino acids at 10‐fold higher concentrations. By virtue of this specific response, a new, simple and rapid fluorescent method for detecting biothiols has been developed. The linear ranges for Cys, Hcy and GSH were 2.0 × 10‐6 to 9.0 × 10‐5 M (R2 = 0.994), 2.0 × 10‐6 to 1.2 × 10‐4 M (R2 = 0.996) and 1.0 × 10‐5 to 8.0 × 10‐5 M (R2 = 0.980), respectively. The detection limits were 8.1 × 10‐7 M for Cys, 1.0 × 10‐6 M for Hcy and 1.1 × 10‐6 M for GSH. Our proposed method was successfully applied to the determination of thiols in human plasma and the recovery was 94.83–105.24%. It is potentially applicable to protein‐stabilized silver nanoclusters in a chemical or biochemical sensing system. Copyright © 2014 John Wiley & Sons, Ltd.
Exploring the Impact of Informal Practices on Social Exclusion and Age‐Friendliness for Older People in Rural Communities
Authors: Walsh Kieran , O′Shea Eamon , Scharf Thomas , Shucksmith Mark
Published: January 2014

This article explores the role of informal practices, across the state, private, voluntary, and family and friend systems, in addressing social exclusion in rural communities in Ireland and Northern Ireland. In doing so, we examine the relevance of the ‘age‐friendly’ concept to rural settings. Using focus group discussions, involving 62 community stakeholders from 10 communities across the two jurisdictions, we explore the four systems and their limitations in the communities and the informal practices that underlie system interactions and older adult supports and engagement. Informal practices, such as cooperative working between system actors and the performance of tasks outside professional and organisational remits, were found to underpin many community responses to supporting older people and arose from collective interdependencies, the multiplicity of individual roles (e.g. professional, community member and volunteer) and positions of need. Informal practices strengthened the capacity of these rural communities to address social exclusion of older people and enhanced local aspects of age‐friendliness. The findings are discussed in light of the diversity of rural older people and their communities, transformative process of change and the need for a more nuanced understanding of age‐friendliness in rural settings. Copyright © 2013 John Wiley & Sons, Ltd.
Sex differences in postprocedural aortic regurgitation and mid‐term mortality after transcatheter aortic valve implantation
Authors: Ferrante Giuseppe , Pagnotta Paolo , Petronio Anna Sonia , Bedogni Francesco , Brambilla Nedy , Fiorina Claudia , Giannini Cristina , Mennuni Marco , De Marco Federico , Klugmann Silvio , Ettori Federica , Presbitero Patrizia
Published: January 2014

Background

The impact of female sex on mortality after transcatheter aortic valve implantation (TAVI) is controversial. Post‐procedural aortic regurgitation (AR) ≥ 2 has been associated with poor outcomes. Whether sex differences in post‐procedural AR ≥ 2 could contribute to a mortality difference between women and men is not known.

Methods

Six hundred fifty‐six patients, women (53.1%), men (46.9%), with aortic stenosis underwent TAVI with the CoreValve system (92.8%) or the Edwards SAPIEN valve system (7.2%). AR was graded semiquantitatively as 0 = none, 1 = trivial, 2 = mild, 3 = moderate, and 4 = severe. The incidence of post‐procedural AR ≥ 2 was reported.

Results

Procedural success was similar in women as compared to men (97.9 vs 96.7%, P = 0.32). Post‐procedural AR ≥ 2 occurred less frequently in women than in men (20.9 vs 29.6%, P = 0.01). After a median follow‐up of 434 days, all‐cause mortality tended to be lower in women than in men (20.7 vs 26.6%, logrank P = 0.10), and was significantly higher in patients with AR ≥ 2 than in those without (34.8 vs 19.7%, logrank P < 0.001). AR ≥ 2 [hazard ratio (HR) 1.73, 95% confidence interval (CI) 1.22–2.43, P = 0.002], but not female sex (P = 0.17) was an independent predictor of all‐cause death at multivariable Cox regression. The predictive value of AR ≥ 2 was restricted to men (HR 2.96, P < 0.001 among men; HR 0.86, P = 0.60 among women; P for interaction = 0.002).

Conclusions

Women, as compared to men, present a trend toward lower mortality. A significant lower incidence of post‐procedural AR ≥ 2 among women contributes to this finding. Female sex, however, was not a significant independent predictor of death. © 2014 Wiley Periodicals, Inc.