bluuebunny/crossref_metadata_2025 huggingface dataset:
Fatigue Life Assessment of Self-Expandable NiTi Stent
Authors: Nes Cristian Sorin , Enkelhardt Angelica , Bogdan Lucian , Faur Nicolae
Published: September 2014

Objectives: This paper presents a numerical fatigue life assessment of a self-expandable Nitinol stent. The analysis was performed using the ANSYS 11 software. Methods: Stent durability is an issue which must be addressed during the design of implants. Given the corrosive properties of blood and the cyclic loads that are applied on the stent (the cyclic variation of blood pressure), the determination of fracture parameters and fatigue characteristics of the implant is highly recommended. Breaking of the stent’s wire is particularly dangerous because it can cause the dislocation of a piece of stenotic plaque, which in turn can block a smaller artery, causing a heart attack. On the other hand, any discontinuity in stent structure acts as an accumulating place for stenosis particles, significantly shortening the life of the implant. The stent consists of a cylindrical tube 22.42 mm long, with a diameter of 8.3 millimeters. The wire section is square, 0.2x0.2 millimeters. The stent is only subjected to the pressure generated by the stenoted arterial wall. This evenly distributed pressure is defined at the outer surface of the stent and has a value of 2.5 MPa, corresponding to a 56% blood vessel stenosis. This way, the most severe loading conditions for the stent could be simulated. The stress distribution was then used to asses the fatigue life of the stent. Results and conclusions: The results showed that, in normal conditions (with the maximal internal pressure of 139 mm Hg = 18533 Pa), no damage appears on the stent after 107 cycles.
Simulations of Bending Experiments of Concrete Beams by Stochastic Discrete Model
Authors: Kaděrová Jana , Eliáš Jan
Published: September 2014

The paper describes results of numerical simulations of experiments on concrete beams loaded in three-point bending. Stochastic lattice-particle model has been applied in which the material was represented by discrete particles of random size and location. Additional spatial variability of material properties was introduced by stationary autocorrelated random field. Three different types of geometrically similar beams were modeled: half-notched, fifth-notched and unnotched, each in four different sizes. The deterministic and stochastic model parameters were identified via automatic procedure based on comparison to a subset of experimental data, so that the adequacy of the model response could be validated by comparison with the remaining experimental data.
Evaluation of Slip Resistance of Safety Footwear Using Novel Equipment
Authors: Bang C.H. , Kim Tae Gu , Kim J.S.
Published: September 2014

There are several causes of slip and fall accidents, such as floor and outsole surface characteristics, contaminants, environmental and human factors, and cognition. In relation to controllable causes, floor and outsole surface characteristics have been frequently investigated over the past decades. The characteristics of safety footwear outsoles, such as roughness, hardness, and tread pattern, tend to differ from those of casual shoes on the Korean market. The aim of this study is to investigate the slip resistance of safety footwear on the Korean market and determine the major design factors to improve the slip resistance. All friction tests were performed using the Korean Occupational Safety and Health Agency’s newly developed testing machine. Twenty-eight safety shoes were used in this experiment, and all friction tests were conducted under three different contamination conditions, namely water, detergent, and glycerol. The friction measurement results show that the hardness, material, and patterns of outsoles had a major effect on the slip resistance, but the effects were not statistically significant for some safety footwear. In general, safety footwear that had a number of small extruded blocks shows good slip resistance. Safety footwear patterns that have many small raised blocks on the heel have a higher friction coefficient than the others. A lower outsole hardness also gives a higher coefficient of friction.
Influence of Different Crack Propagation Rate Descriptions on the Residual Fatigue Lifetime of Railway Axles
Authors: Pokorný Pavel , Náhlík Luboš , Hutař Pavel
Published: September 2014

The paper deals with an estimation of the residual fatigue lifetime of the railway axles. The railway axles can include some cracks either from manufacturing process or from previous loading operation. Because of cyclic loading of the railway axles there is a risk of fatigue failure of the railway axles with unacceptable consequences. Based on this fact, for conservative establishment of the residual fatigue lifetime of the railway axle is necessary to consider an existing crack in the railway axle during design process. The fatigue lifetime estimation of railway axles is very sensitive to used crack propagation rate description (e.g. v-K curve). Typical bending of this curve (knee) can be found in the vicinity of the threshold value in fatigue crack propagation rate dependence (typically v-K curve expressed in log-log coordinates). For accurate estimation of residual fatigue lifetime of the railway axle is necessary to use approximation of v-K curve that takes into account existence of the knee close to the threshold value of the stress intensity factor. The paper shows important differences between different crack propagation rate descriptions on the residual fatigue lifetime estimation of the railway axles. Results obtained can be used for safer design and operation of the railway axles.
FE Analysis of Functionally Graded Material Plate during Debonding Case with Different Boundary Conditions
Authors: Helal Wasim M.K. , Shi Dong Yan
Published: September 2014

Functionally graded materials (FGMs) have become helpful in our engineering applications. Analysis of functionally graded material (FGM) plate during debonding case with different boundary conditions is the main purpose of this investigation. Elastic modulus (E) of functionally graded (FG) plate is assumed to vary continuously throughout the height of the plate, according the volume fraction of the constituent materials based on a modified sigmoid function, but the value of Poisson coefficient is constant. In this research, the finite element method (FEM) is used in order to show the shape of a plate made of FGM during debonding case with different boundary conditions. In the present investigation, the displacement value applied to the FGM plate is changed in order to find the relationship between the maximum von Mises stress and the displacement. Also, the relationship between the maximum shear stress and the displacement is carried out in the present work. The material gradient indexes of the FGM plate are changed from 1 to 10. The stress distributions around the debonding zone with all the material gradient indexes of the FGM plate are investigated in this work.
High Magnification Studies of Fatigue Crack Propagation
Authors: Moreno Belen , Garcia-Gonzalez A. , Cobos-Rodriguez P. , Martinez M. , Lopez-Prieto M. , Lopez-Crespo Pablo
Published: September 2014

This work presents a set of experiments devoted to studying the crack initiation stage under different combined tension-compression and torsion loads. Two different load levels were applied, producing very different fatigue lives. Lower strains generated lives approximately 10 times longer than higher strains. Results allowed retardation and acceleration effects due to microstructure to be clearly visualised.
Polymethylmethacrylate Data from U-Notched Specimens and V-Notches with End Holes: A Synthesis by Means of Local Energy
Authors: Campagnolo A. , Berto F. , Lazzarin P. , Elices M.
Published: September 2014

In this paper a volume criterion based on a simple scalar quantity, the mean value of the strain energy (SED), has been used to assess the static strength of notched components made of Polymethylmethacrylate (PMMA). The local-strain-energy based approach has been applied to a well-documented set of experimental data recently reported in the literature. Data refer to blunt U-notched cylindrical specimens of commercial PMMA subjected to static loads and characterised by a large variability of notch tip radius (from 0.67 mm to 2.20 mm). Critical loads obtained experimentally have been compared with the theoretical ones, estimated by keeping constant the mean value of the strain energy in a well-defined small size volume. In addition, some new tests dealing with V-notched specimens with end holes have been carried out to investigate the effect of the notch opening angle.
Pt Etching Method at Low Temperature Using Electrolyzed Sulfuric Acid Solution
Authors: Ogawa Yuichi , Uchida Minoru , Otsu Toru , Nagai Tatsuo , Morita Hiroshi
Published: September 2014

Recently, in the semiconductor manufacturing industry, NiPt silicide with high conductivity is adopted. However, when removing the NiPt residues in NiPt silicide processing, there is a possibility to damage other metals and silicide. Removal of residual substances must be done with special care. As a conventional method, processing by SPM has been reported by Chur [1]. However, when Pt content is 10% or more, in this method, the wafers must be processed at 150°C for a long period of time. Then, this method may damage a metal gate and silicide. As another method, aqua regia can be used. However, in this method, it takes long time to dissolve NiPt. This paper reports, newly develped Pt etching method using one-step processing of ESA (Electrolyzed Sulfuric Acid) and HCl, and two-step processing using ESA and HCl mixture after HNO3 and H2O2 mixture. This method can treat NiPt silicide at lower temperature within a shorter time than in conventional methods.
Study of Wetting of Nanostructures Using Decoration by Etching
Authors: Vereecke Guy , Xu Xiu Mei , Kesters Els , Simms Ishan , Nafus Kathleen , Haensel Leander , Kim Tae Gon , Lismont Mark , Holsteyns Frank , De Gendt Stefan
Published: September 2014

Recent studies have shown that even inherently hydrophilic surfaces (θ< 90 ̊) can become hydrophobic as a consequence of nanopatterning (1-4). This creates an issue in semiconductor manufacturing as aqueous chemistries (e.g. dilute HF solutions) are preferred to organic chemistries for their lower cost of ownership and greener environmental profile.
Effect of Nozzle Distance and Fluid Flow Rate in Jet Spray Wafer Cleaning Process
Authors: Seo Kwang Min , Kim Dae Heon , Cho Yu Jin , Kim Tae Hyung
Published: September 2014

Recently the reduction of the devise sizes causing the semiconductor processes more complicated and becoming more and more sensitive to the particle contamination [1]. Numerous studies have been carried out to improve the device yield with high particle removal efficiency (PRE) and Wet cleaning process along with megasonic is one of the well-established techniques used for particle removal in the semiconductor industry [1, 2]. However as the pattern size is reduced bellow 60 nm this method is not effective to improve the PRE. Recently, two-flow jet spray cleaning process became popular in semiconductor manufacturing processes due to its many advantages [2]. In this process, micron size water droplets are jetted onto a wafer surface at high velocity, which can remove the particles which are on the wafer surface. It consists of two separate nozzles for liquids and carrier gases which are concurrently delivered on the wafer surface during cleaning process. However, there is still lot of scope to improve the PRE during jet spray wet cleaning process by optimizing the process parametrs. Hence in the present study we focused on the jet spray wet cleaning parameters such as nozzle distance from the wafer and the flow rate of the carrier gas to improve the PRE with minimum pattern damage.
Prevention of Unexpected Oxidation of Metal Layer by Removing Hydrogen Peroxide from Ultrapure Water and Diluted Hydrofluoric Acid
Authors: Yaon Daisaku , Murayama Masami , Kobayashi Hikaru , Yamanaka Koji
Published: September 2014

Ultrapure water (UPW) is widely used for rinsing wafers and diluting chemicals in semiconductor manufacturing processes. The quality of UPW is severely controlled, but the generation of hydrogen peroxide (H2O2) as a impurity is inevitable due to the ultraviolet irradiation in a UPW production system (Figure 1). In our survey, it is revealed that the concentration of H2O2 in UPW reaches to 10~40 μg/L level. Considering the situation, we have developed a palladium-loaded monolithic anion exchange resin (Pd-M) as a catalyst that is able to remove H2O2 from UPW down to below 1 μg/L at an extremely high flow rate (space velocity SV = 6,000 h-1), with no detectable elution of impurities [1, 2]. Furthermore, we have found that the dissolution rate of copper which is easy to be corroded oxidatively in CO2-dissolved water (CO2 UPW) [3] can be decreased to one-third by removal of H2O2 from CO2 UPW using Pd-M catalyst [4]. In this study, we present the effects of H2O2 removal from UPW and diluted hydrofluoric acid (DHF) on the surfaces of copper, molybdenum and silicon.
Quantitative Analysis of Transition Metals Penetrating Silicon Substrate through SiN Film by Dopant Ion Implantation and Annealing
Authors: Saga Koichiro , Kobayashi Shunsuke , Sueoka Koji
Published: September 2014

Metallic contamination on silicon surfaces has a detrimental impact on the performance and yield of ULSI devices. Surface metal impurities degrade the gate oxide integrity while metal impurities dissolved in silicon cause recombination centers and this results in junction leakage. The diffusion behavior of these metal impurities in silicon is well-known [1]. On the other hand, these metal impurities often penetrate the silicon through the silicon oxide or silicon nitride films in ULSI processing. The surface metal impurities penetrate the silicon by colliding with the dopant during ion implantation and are also diffused in silicon by subsequent annealing [2]. While the diffusion behavior of the metal impurities penetrating silicon substrates through the silicon oxide films has been reported [3], little work has been reported on the diffusion behavior of the metal impurities penetrating silicon nitride films. We demonstrated the diffusion behavior of the metal impurities penetrating silicon substrates through a CVD SiN film due to the collision with dopant during ion implantation.
Aluminum Reduction in SC1
Authors: Kweskin Sasha J. , Shive Larry W.
Published: September 2014

RCA clean has evolved since 1965 [1]. Typically used before critical thermal steps, depositions/etches, or after strip operations, these solutions are robust and reliable. Stringent semiconductor demands of shrinking feature size, increased contamination sensitivity and cost pressure have led to cleaning projects that improve performance and reduce chemical usage. One of the sources of contamination is the process chemicals themselves, where wafers are exposed to chemicals for etching or cleaning. Concerns over contamination are compounded in wet benches where chemical baths are re-circulated for periods up to 24 hours. Metal impurities can arise from insufficiently pure chemicals or water, tanks, carriers, plumbing components, chemical containers, incoming wafers and handling equipment. Strict chemical, DIW and material specifications as well as dilute chemistry and reduced temperature have benefited the industry as a whole. Trends such as lower temperature/concentration SC1, and higher temperature/concentration SC2 have reached a point of diminishing returns for metal contamination reduction. In the same way, chemical and water purity are well below detection, so improvements are difficult to quantify.[2]
Necessity of Cleaning and its Application in Future Memory Devices
Authors: Choi Geun Min
Published: September 2014

Concerning the processes of the semiconductor industry, device integration is increasing and cell structure is becoming more complicated, which brings many new kinds of challenges. The basic requirements for a future integration device are minimum feature size reduction with device integration and high-speed operation with sufficient cell capacitance. Many kinds of conventional films including electrode and dielectric materials should be altered to meet device requirements. Moreover, as the allowance level for contaminants on substrate surfaces becomes more stringent, the importance of removing them becomes even greater. Because of this, the semiconductor process for high quality device fabrication will never be realized without perfect cleaning on all surfaces. It is reported that the conventional cleaning solutions such as a NH4OH/H2O2/H2O (SC-1) solution (1:4:20, 80 °C), H2SO4/H2O2 (SPM) solution (4:1, 90 to 120°C), and HCl/H2O2/H2O (HPM) solution (1:1:6, 80 to 90°C) are not compatible with metal film exposed surfaces with very tiny patterns, due to the fast etching rate of metal films [1] . In 1995, at the base of the mechanism of the removal of the adhered contaminants such as metallic impurities, particles and organics, T. Ohmi proposed a total room temperature wet cleaning process (so called “UCT cleaning”) [2]. As a result of the continuous research on developed cleaning, the five steps process was revised to a four step room temperature wet cleaning for real device cleaning. The cleaning consists of 1) CO2 added O3-UPW cleaning for removing organic and metallic impurities, 2) NH3 added H2-UPW+MS cleaning for removing of particles, 3) HF/H2O2(FPM) cleaning for removing metallic impurities, and 4) H2-UPW+MS rinse for the removal of chemical residues, prevention of particle re-adhesion, suppression of native oxide growth, and enhancement of H-termination.
Surface Cleaning of Graphene by CO2 Cluster
Authors: Choi Hoo Mi , Kim Jang Ah , Cho Yu Jin , Hwang Taeh Yun , Lee Jon Woo , Kim Tae Sung
Published: September 2014

Graphene has attracted researchers due to its unique physical properties [1]. However, residues on surface can act as contaminants which further have adverse effects on its performance. As synthetic graphene has inherent surface roughness which can also affect the weak adhesion of layers and leakage points. In order to improve the mechanical and electrical properties, the graphene surface should be uncontaminated. In general practice wet cleaning methods, containing hazardous chemical and solvents are used to remove the residues from graphene surface [2, 3]. To avoid chemicals, mechanical cleaning of graphene using contact mode atomic force microscopy (AFM) has been tried. However, the contact mode AFM cleaning is a limited in cleaning area and the cleaning procedure takes a long time. Recently, CO2 cluster cleaning shows benefits that overcomes these problems. Herein we report the use of CO2 cluster to clean the graphene surface without affecting its inherent properties for the first time. The CO2 cluster treated graphene samples were evaluated by AFM for its roughness change and residual contamination.
Endoscopic ultrasound: An all in one technique vibrates virtually around the whole internal medical field
Authors: Ge Nan , Sun Siyu
Published: September 2014

The imaging obtained by endoscopic ultrasound (EUS) has improved our understanding of many disease states of the digestive tract. It was mostly utilized by gastroenterologists and surgeons. In this article, we highlight some of the indications and applications that may be noticed by other specialists such as non-small cell lung cancer (by a special EUS technique, i.e., endobronchial ultrasound), pancreatic neuroendocrine tumors, kidney and adrenal masses, rectosigmoid endometriosis, celiac plexus neurolysis and pseudocyst drainage.
A New Family of High Order Unstructured MOOD and ADER Finite Volume Schemes for Multidimensional Systems of Hyperbolic Conservation Laws
Authors: Loubère Raphaël , Dumbser Michael , Diot Steven
Published: September 2014

In this paper, we investigate the coupling of the Multi-dimensional Optimal Order Detection (MOOD) method and the Arbitrary high order DERivatives (ADER) approach in order to design a new high order accurate, robust and computationally efficient Finite Volume (FV) scheme dedicated to solve nonlinear systems of hyperbolic conservation laws on unstructured triangular and tetrahedral meshes in two and three space dimensions, respectively. The Multi-dimensional Optimal Order Detection (MOOD) method for 2D and 3D geometries has been introduced in a recent series of papers for mixed unstructured meshes. It is an arbitrary high-order accurate Finite Volume scheme in space, using polynomial reconstructions witha posterioridetection and polynomial degree decrementing processes to deal with shock waves and other discontinuities. In the following work, the time discretization is performed with an elegant and efficient one-step ADER procedure. Doing so, we retain the good properties of the MOOD scheme, that is to say the optimal high-order of accuracy is reached on smooth solutions, while spurious oscillations near singularities are prevented. The ADER technique permits not only to reduce the cost of the overall scheme as shown on a set of numerical tests in 2D and 3D, but it also increases the stability of the overall scheme. A systematic comparison between classical unstructured ADER-WENO schemes and the new ADER-MOOD approach has been carried out for high-order schemes in space and time in terms of cost, robustness, accuracy and efficiency. The main finding of this paper is that the combination of ADER with MOOD generally outperforms the one of ADER and WENO either because at given accuracy MOOD is less expensive (memory and/or CPU time), or because it is more accurate for a given grid resolution. A large suite of classical numerical test problems has been solved on unstructured meshes for three challenging multi-dimensional systems of conservation laws: the Euler equations of compressible gas dynamics, the classical equations of ideal magneto-Hydrodynamics (MHD) and finally the relativistic MHD equations (RMHD), which constitutes a particularly challenging nonlinear system of hyperbolic partial differential equation. All tests are run on genuinely unstructured grids composed of simplex elements.
The New Real: Iggy Azalea and the Reality Performance
Authors: Morrissey Tara
Published: September 2014

Questions of realness, authenticity, and legitimacy, are deeply invested in a politics of identity that polices the purity of its central categories. The creative potential of performative modes such as rap performance and reality television is thus complicated by expectations of authenticity that are frequently embroiled in broader projects of identity delineation and regulation. This paper considers correlations between hip hop culture’s ethos of realness and authenticity, and the ‘real’ as manifested in the cultural phenomenon of reality television, for the ways in which they are bound by but also strive to reconfigure the limits of realness. With particular attention to the work and self-styling of Australian female rapper Iggy Azalea, I emphasise the tension between performance and authenticity, and point to the ostensibly disparate subcultural forms of hip hop and reality television as distinctly engaged in the renegotiation of this tension. I invoke the critical imperatives of whiteness theory to critique the normative channels of realness that remain at the forefront of hip hop’s self-conceptualisation and general promotion, in particular the role of gender and race in the construction of hip hop authenticity. I then examine reality television and its relationship with shame and intimacy as crucial to understanding its devalued status in studies of television and popular culture more broadly. Ultimately, I propose the explorations of ‘real’ in these works as indicative of a contemporary shift in the evaluation and justification of authenticity that points to a revised appreciation of the power of performativity.
Stigma, Trauma and the Social Forces Shaping Memory Transmission in Argentina
Authors: Stockwell Jill
Published: September 2014

Since the return to democratic rule in Argentina in 1983, competing claims about how the period of political and state violence of the 1970s and 1980s might be collectively remembered by the nation have caused deep political and societal divisions. This paper explores the personal memories of Argentine women from two ideologically-opposed groups—those on the political Left affected by military repression during the 1976-1983 military dictatorship and those on the political Right affected by the armed guerrilla violence predominantly in the years leading up to the 1976 military coup. In contemporary Argentina, the memories of enduring personal trauma which both groups of women carry are commonly perceived as unable to co-exist in a shared mnemonic space – as if remembering one history of violence is seen as an attempt to forget or violate the other history of violence and trauma.
Reliable, robust and realistic: the three R's of next-generation land surface modelling
Authors: Prentice I. C. , Liang X. , Medlyn B. E. , Wang Y.-P.
Published: September 2014

Abstract. Land surface models (LSMs) are increasingly called upon to represent not only the exchanges of energy, water and momentum across the land-atmosphere interface (their original purpose in climate models), but also how ecosystems and water resources respond to climate and atmospheric environment, and how these responses in turn influence land-atmosphere fluxes of carbon dioxide (CO2), trace gases and other species that affect the composition and chemistry of the atmosphere. However, the LSMs embedded in state-of-the-art climate models differ in how they represent fundamental aspects of the hydrological and carbon cycles, resulting in large inter-model differences and sometimes faulty predictions. These "third-generation" LSMs respect the close coupling of the carbon and water cycles through plants, but otherwise tend to be under-constrained, and have not taken full advantage of robust hydrological parameterizations that were independently developed in offline models. Benchmarking, combining multiple sources of atmospheric, biospheric and hydrological data, should be a required component of LSM development, but this field has been relatively poorly supported and intermittently pursued. Moreover, benchmarking alone is not sufficient to ensure that models improve. Increasing complexity may increase realism but decrease reliability and robustness, by increasing the number of poorly known model parameters. In contrast, simplifying the representation of complex processes by stochastic parameterization (the representation of unresolved processes by statistical distributions of values) has been shown to improve model reliability and realism in both atmospheric and land-surface modelling contexts. We provide examples for important processes in hydrology (the generation of runoff and flow routing in heterogeneous catchments) and biology (carbon uptake by species-diverse ecosystems). We propose that the way forward for next-generation complex LSMs will include: (a) representations of biological and hydrological processes based on the implementation of multiple internal constraints; (b) systematic application of benchmarking and data assimilation techniques to optimize parameter values and thereby test the structural adequacy of models; and (c) stochastic parameterization of unresolved variability, applied in both the hydrological and the biological domains.
The AquaVIT-1 intercomparison of atmospheric water vapor measurement techniques
Authors: Fahey D. W. , Gao R.-S. , Möhler O. , Saathoff H. , Schiller C. , Ebert V. , Krämer M. , Peter T. , Amarouche N. , Avallone L. M. , Bauer R. , Bozóki Z. , Christensen L. E. , Davis S. M. , Durry G. , Dyroff C. , Herman R. L. , Hunsmann S. , Khaykin S. M. , Mackrodt P. , Meyer J. , Smith J. B. , Spelten N. , Troy R. F. , Vömel H. , Wagner S. , Wienhold F. G.
Published: September 2014

Abstract. The AquaVIT-1 intercomparison of atmospheric water vapor measurement techniques was conducted at the aerosol and cloud simulation chamber AIDA (Aerosol Interaction and Dynamics in the Atmosphere) at the Karlsruhe Institute of Technology, Germany, in October 2007. The overall objective was to intercompare state-of-the-art and prototype atmospheric hygrometers with each other and with independent humidity standards under controlled conditions. This activity was conducted as a blind intercomparison with coordination by selected referees. The effort was motivated by persistent discrepancies found in atmospheric measurements involving multiple instruments operating on research aircraft and balloon platforms, particularly in the upper troposphere and lower stratosphere, where water vapor reaches its lowest atmospheric values (less than 10 ppm). With the AIDA chamber volume of 84 m3, multiple instruments analyzed air with a common water vapor mixing ratio, by extracting air into instrument flow systems, by locating instruments inside the chamber, or by sampling the chamber volume optically. The intercomparison was successfully conducted over 10 days during which pressure, temperature, and mixing ratio were systematically varied (50 to 500 hPa, 185 to 243 K, and 0.3 to 152 ppm). In the absence of an accepted reference instrument, the absolute accuracy of the instruments was not established. To evaluate the intercomparison, the reference value was taken to be the ensemble mean of a core subset of the measurements. For these core instruments, the agreement between 10 and 150 ppm of water vapor is considered good with variation about the reference value of about ±10% (±1σ). In the region of most interest between 1 and 10 ppm, the core subset agreement is fair with variation about the reference value of ±20% (±1σ). The upper limit of precision was also derived for each instrument from the reported data. The implication for atmospheric measurements is that the substantially larger differences observed during in-flight intercomparisons stem from other factors associated with the moving platforms or the non-laboratory environment. The success of AquaVIT-1 provides a template for future intercomparison efforts with water vapor or other species that are focused on improving the analytical quality of atmospheric measurements on moving platforms.
Evidence for vivianite formation and its contribution to long-term phosphorus retention in a recent lake sediment: a novel analytical approach
Authors: Rothe M. , Frederichs T. , Eder M. , Kleeberg A. , Hupfer M.
Published: September 2014

Abstract. Vivianite, Fe3(PO4)2 · 8 H2O, is a ferrous iron phosphate mineral which forms in waterlogged soils and sediments. The phosphorus (P) bound in its crystal lattice is considered to be immobilised because vivianite is stable under anoxic, reducing, sedimentary conditions. Thus, vivianite formation can make a major contribution to P retention during early diagenesis. Much remains unknown about vivianite in sediments, because technical challenges have rendered direct identification and quantification difficult. To identify vivianite and assess its significance for P burial during early diagenesis we studied the consequences of a 1992/1993 in-lake application of FeCl3 and Fe(OH)3 aimed at restoring Lake Groß-Glienicke (Berlin, Germany). In a novel approach, we firstly applied a heavy-liquid separation to the iron-rich surface sediments which allowed direct identification of vivianite by X-ray diffraction in the high-density (ρ > 2.3 g cm−3) sediment fraction. Secondly, we assessed the contribution of vivianite to P retention, combining results from chemical digestion with magnetic susceptibility data derived from magnetic hysteresis measurements. Scanning electron microscopy revealed that the dark blue spherical vivianite nodules were 40–180 μm in diameter, and formed of platy- and needle-shaped crystal aggregates. Although equilibrium calculations indicated supersaturation of vivianite throughout the upper 30 cm of the sediment, the vivianite deposits were homogeneously distributed within, and restricted to, the upper 23 cm only. Thus, supersaturated pore water alone cannot serve as a reliable predictor for the in situ formation of vivianite. In Lake Groß -Glienicke, vivianite formation continues to be triggered by the artificial iron amendment more than 20 yr ago, significantly contributing to P retention in surface sediments.
Evaluation of surface properties and atmospheric disturbances caused by post-dam alterations of land use/land cover
Authors: Woldemichael A. T. , Hossain F. , Pielke Sr. R.
Published: September 2014

Abstract. This study adopted a differential land-use/land-cover (LULC) analysis to evaluate dam-triggered land–atmosphere interactions for a number of LULC scenarios. Two specific questions were addressed: (1) can dam-triggered LULC heterogeneities modify surface and energy budget, which, in turn, change regional convergence and precipitation patterns? (2) How extensive is the modification in surface moisture and energy budget altered by dam-triggered LULC changes occurring in different climate and terrain features? The Regional Atmospheric Modeling System (RAMS, version 6.0) was set up for two climatologically and topographically contrasting regions: the American River watershed (ARW), located in California, and the Owyhee River watershed (ORW), located in eastern Oregon. For the selected atmospheric river precipitation event of 29 December 1996 to 3 January 1997, simulations of three pre-defined LULC scenarios are performed. The definition of the scenarios are (1) the "control" scenario, representing the contemporary land use, (2) the "pre-dam" scenario, representing the natural landscape before the construction of the dams and (3) the "non-irrigation" scenario, representing the condition where previously irrigated landscape in the control is transformed to the nearby land-use type. Results indicated that the ARW energy and moisture fluxes were more extensively affected by dam-induced changes in LULC than the ORW. Both regions, however, displayed commonalities in the modification of land–atmosphere processes due to LULC changes, with the control–non-irrigation scenario creating more change than the control–pre-dam scenarios. These commonalities were: (1) the combination of a decrease in temperature (up to 0.15 °C) and an increase at dew point (up to 0.25 °C) was observed; (2) there was a larger fraction of energy partitioned to latent heat flux (up to 10 W m−2) that increased the amount of water vapor in the atmosphere and resulted in a larger convective available potential energy (CAPE); (3) low-level wind-flow variation was found to be responsible for pressure gradients that affected localized circulations, moisture advection and convergence. At some locations, an increase in wind speed up to 1.6 m s−1 maximum was observed; (4) there were also areas of well-developed vertical motions responsible for moisture transport from the surface to higher altitudes that enhanced precipitation patterns in the study regions.
Impacto del uso de biomasa en la bioeconomía de los ingenios azucareros Centroamericanos
Authors: Blanco Napoleón , Zúniga González Carlos A , Sierra Pablo , Dios Palomares Rafaela , Curbelo Alonso Alfredo José
Published: September 2014

El propósito de este estudio fue medir el impacto del uso de Biomasa del sendero productivo de la Bioeconomía de las Biorefinerías azucareras de la región centroamericana, mediante el estudio de la productividad total de los factores. Se utilizaron los datos disponibles en la FAO que fueron organizados en un panel de datos y se aplicó el análisis envolvente de datos con la herramienta de los índices de Malmquist, se agregó el enfoque de eficiencia técnica ambiental, se consideró un modelo con tres componentes: productivo, ambiental y social. Así también, se indagó sobre la incidencia de actividad geomagnética solar planetaria sobre la productividad de las biorefinerias. Los resultados se evaluaron considerando la actividad solar y omitiéndola, los primeros evidencian que solo los países Belice, El salvador (11 %), Nicaragua (4 %) y Cuba (3%) muestran un crecimiento promedio en productividad, al contrario Costa Rica, Guatemala, Honduras y Panamá presentaron un decrecimiento en productividad. El cambio de la PTF se explicó por el desarrollo tecnológico de los ingenios más que por la eficiencia técnica de la mano de obra. Además, se concluye que la productividad de la bioeconomía tiene cierta relación con la actividad geomagnética planetaria y por consiguiente se debe tener en cuenta la relación entre la productividad de las biorefinerías y la tasa de crecimiento poblacional. Es importante que los inversionista de los ingenios azucaremos consideren estas evidencias dado que conociendo las variaciones de la actividad solar pueden reducir costos no invirtiendo en economía de escala cuando la actividad solar proyecte una tendencia decreciente. DOI: http://dx.doi.org/10.5377/universitas.v5i1.1478 UNIVERSITAS (León): Revista Científica de la UNAN León Vol.5(1) 2014, pp 26-58
El capital social comunitario en el reparto San Jerónimo de la ciudad de León
Authors: Argueta Jaen Julio
Published: September 2014

La investigación trata sobre el nivel de capital social comunitario en el reparto San Jerónimo de la ciudad de León, en 2010. Este reparto es uno de los más antiguos de la periferia norte de la ciudad con bajos niveles de progreso social en relación a otros barrios que surgieron con posterioridad al mismo. Los objetivos se centran en la identificación de indicadores de capital social, en el análisis de los factores que limitan el desarrollo de éste y en la valoración de las posibilidades de mejora del capital social como activo que facilite el desarrollo comunitario. La información se obtuvo de encuestas a jefes de familias y entrevistas a líderes comunitarios y a una representante de las instituciones que intervienen. Entre los hallazgos en el reparto están: aislamiento estructural, estructura tradicional formal, conformismo, desconfianza en las instituciones y, no obstante, un capital social de tipo intermedio dado el alto grado de unidad y sentido de pertenencia y las notables relaciones interpersonales, tolerancia, solidaridad y cooperación vecinal expresada en una singular cooperativa de servicios fúnebres y una brigada de jóvenes que garantiza la seguridad ciudadana del reparto. DOI: http://dx.doi.org/10.5377/universitas.v5i1.1480 UNIVERSITAS (León): Revista Científica de la UNAN León Vol.5(1) 2014, pp 83-90
The Morphology of Ordered Block Copolymer Patterns as Probed by High Resolution Imaging
Authors: Borah D , Ghoshal T , Shaw M T , Chaudhari A , Petkov N , Bell A P , Holmes J D , Morris M A
Published: September 2014

The microphase separation of block copolymer (BCP) thin films can afford a simple and cost-effective means to studying nanopattern surfaces, and especially the fabrication of nanocircuitry. However, because of complex interface effects and other complications, their 3D morphology, which is often critical for application, can be more complex than first thought. Here, we describe how emerging microscopic methods may be used to study complex BCP patterns and reveal their rich detail. These methods include helium ion microscopy (HIM) and high resolution x-section transmission electron microscopy (XTEM), and complement conventional secondary electron and atomic force microscopies (SEM and TEM). These techniques reveal that these structures are quite different to what might be expected. We illustrate the advances in the understanding of BCP thin film morphology in several systems, which result from this characterization. The systems described include symmetric, lamellar forming polystyrene-b-polymethylmethacrylate (PS-b-PMMA), cylinder forming polystyrene-b-polydimethylsiloxane (PS-b-PDMS), as well as lamellar and cylinder forming patterns of polystyrene-b-polyethylene oxide (PS-b-PEO) and polystyrene-b-poly-4-vinylpyridine (PS-b-P4VP). Each of these systems exhibits more complex arrangements than might be first thought. Finding and developing techniques whereby complex morphologies, particularly at very small dimensions, can be determined is critical to the practical use of these materials in many applications. The importance of quantifying these complex morphologies has implications for their use in integrated circuit manufacture, where they are being explored as alternative pattern forming methods to conventional UV lithography.
2014: Strategic directions for US water and wastewater utilities
Authors: Wallis‐Lage Cindy
Published: September 2014

Smart water‐grid technologies combined with asset management best practices can increase customer engagement, reduce operational costs, and help justify capital investment needs.
Making Homework More Meaningful
Authors: Wieman Rob , Arbaugh Fran
Published: September 2014

Create homework assignments that both engage middle-grades students and strengthen their mathematical understandings and skills.
Building a math Village: Developing Partnerships among School, Home, and Community
Authors: Breyfogle M. Lynn , Quander Judith
Published: September 2014

Share news about happenings in the field of elementary school mathematics education, views on matters pertaining to teaching and learning mathematics in the early childhood or elementary school years, and reactions to previously published opinion pieces or articles. Find detailed department submission guidelines at www.nctm.org/tcmdepartments.
Les technologies de l’information et de la communication (TIC) et la promotion de la santé sexuelle chez les jeunes autochtones du Québec
Authors: Adoun M.A. Serge Djossa , Roy Bernard , McHugh Nancy Gros-Louis , Caron Marie-Noëlle , Gagnon Marie-Pierre
Published: September 2014

Cette étude visait à documenter les habitudes et préférences des jeunes (13-25 ans) des Premières Nations (PN) du Québec en regard des technologies de l'information et de la communication (TIC). Elle fut réalisée dans le cadre d'une évaluation de faisabilité d'interventions utilisant les TIC pour la promotion de la santé sexuelle et reproductive (SSR). Selon le questionnaire qui a été présenté à 192 participants par sondage électronique, plus de 60 % des répondants ont un accès régulier aux outils technologiques les plus mentionnés dans la littérature portant sur les interventions utilisant les TIC pour la promotion de la SSR et la prévention des ITSS/VIH/sida auprès des adolescents. Toutefois, ils préfèrent Internet comme canal pour recevoir de l'information sur la SSR.
Le Canada français vit par ses oeuvres : la Saint-Jean-Baptiste vue par le journal Le Droit, 1950-1960
Authors: Gagnon Marc-André
Published: September 2014

Les activités entourant la Saint-Jean-Baptiste ont joué un rôle déterminant dans l’affirmation des francophones en Outaouais en leur donnant l’occasion de se rassembler et d’exprimer leur fierté. Cet article propose une étude des cahiers spéciaux publiés par le journal Le Droit lors de cette fête annuelle. Par les éditoriaux, les articles et la publicité, ces cahiers témoignent des représentations symboliques de l’événement et de l’engagement des acteurs sociaux impliqués dans sa réalisation, que ce soit les organisateurs ou les annonceurs. Notre étude met en lumière le rôle de la presse dans la construction et la diffusion des discours entourant la fête nationale.
Les rapports entre les jeunes et La Liberté
Authors: Keller Michelle
Published: September 2014

Cet article propose une étude des rapports entre les jeunes et le journal francophone La Liberté. Dans un premier temps, nous en faisons l’historique depuis la fin des années 1960, en nous basant sur les collaborations journalistiques ponctuelles avant et après la création du Conseil jeunesse provincial en 1974. À la lumière de cet historique et à partir de l’analyse de la couverture de certaines « causes jeunesse » des dernières années, nous tenterons, dans un deuxième temps, de cerner les raisons qui expliquent la distance entre les jeunes et La Liberté aujourd’hui, au-delà de la popularité des médias sociaux.
Tutorial Session and Sunday Classes an Ideal Approach to Enhance Academic Performance
Authors: Garcia Gary C.
Published: September 2014

To leave no child behind, educators must initiate a program that would address students' problem on the Academic and educational promotion. Intervention such as tracking students' weakness and identifying factors that affect most of their focus towards educational standards is definitely part of the plan. In most cases, tutorial turn out to be the conduit variables to learning. However, the behavior of an individual was considered a key to success in education. Thus, religious students were assumed to behave more and will perform better during classes, religious activity engagement appears to offer a positive influence in learning process. The study was intended to determine the effects of Saturday Tutorial Session and Sunday Religious Classes in the academic performance of the Child Development Program (CDP) beneficiaries. Descriptive-survey method of research using purposive sampling was utilized. Only the high school CDP beneficiaries and their teachers were chosen as the respondents. Results reveal that sickness, as the cause of the students' low performance in academic is still dominant in basic education. It also reveal that the diversity in teaching is not 100 percent acquired up to this very moment considering that the traditional teaching strategies of teacher was considered as one of the causes of the students low performance in academic. Generally, results implied that the combined tutorial class and religious attendance are very good recipe to enhance academic performance of students.
The immersion mode ice nucleation behavior of mineral dusts: A comparison of different pure and surface modified dusts
Authors: Augustin‐Bauditz S. , Wex H. , Kanter S. , Ebert M. , Niedermeier D. , Stolz F. , Prager A. , Stratmann F.
Published: September 2014

In this study we present results from immersion freezing experiments with size‐segregated mineral dust particles. Besides two already existing data sets for Arizona Test Dust (ATD), and Fluka kaolinite, we show two new data sets for illite‐NX, which consists mainly of illite, a clay mineral, and feldspar, a common crustal material. The experiments were carried out with the Leipzig Aerosol Cloud Interaction Simulator. After comparing the different dust samples, it became obvious that the freezing ability was positively correlated with the K‐feldspar content. Furthermore, a comparison of the composition of the ATD, illite‐NX, and feldspar samples suggests that within the K‐feldspars, microcline is more ice nucleation active than orthoclase. A coating with sulfuric acid leads to a decrease in the ice nucleation ability of all mineral dusts, with the effect being more pronounced for the feldspar sample.
First observations of polarized scattering over ice clouds at close‐to‐millimeter wavelengths (157 GHz) with MADRAS on board the Megha‐Tropiques mission
Authors: Defer Eric , Galligani Victoria S. , Prigent Catherine , Jimenez Carlos
Published: September 2014

Polarized scattering by frozen hydrometeors is investigated for the first time up to 157 GHz, based on the passive microwave observations of the Microwave Analysis and Detection of Rain and Atmospheric Structures (MADRAS) instrument on board the Indo‐French Megha‐Tropiques satellite mission. A comparison with time‐coincident Tropical Rainfall Measurement Mission Microwave Imager records confirms the consistency of the coincident observations collected independently by the two instruments up to 89 GHz. The MADRAS noise levels of 1.2 K at 89 GHz and of 2.5 K at 157 GHz are in agreement with the required specifications of the mission. Compared to the 89 GHz polarized channels that mainly sense large ice particles (snow and graupel), the 157 GHz polarized channel is sensitive to smaller particles and provides additional information on the cloud systems. The analysis of the radiometric signal at 157 GHz reveals that the ice scattering can induce a polarization difference of the order of 10 K at that frequency. Based on radiative transfer modeling the specific signature is interpreted as the effect of mainly horizontally oriented ice cloud particles. This suggests that the effects of the cloud particle orientation should be considered in rain and cloud retrievals using passive radiometry at microwave and millimeter wavelengths.