bluuebunny/crossref_metadata_2025_split huggingface dataset:
Return period calculation and passive structure design at the Taconnaz avalanche path, France
Authors: Naaim Mohamed , Faug Thierry , Naaim Florence , Eckert Nicolas 
Published: May 2010

AbstractThis paper aims to show how recent knowledge developed in the field of avalanche research can be used for a real case study, the Taconnaz avalanche path, where passive structures already existed but had to be improved. First a morphological analysis of the site is done and historical data are analysed. Second, each recorded event is back-calculated using a numerical model of dense-flow avalanches. For each surveyed avalanche, parameters at the entry of the runout zone upstream of the defence structures are defined. Third, a statistical analysis of these parameters allows characterization of 100 year return period events. Fourth, physical and numerical models of dense avalanches interacting with defence structures are combined in order to design the most effective passive structure able to contain the reference scenarios. Finally, physical and numerical modelling of the interaction between the powder avalanche and the designed defence structure is performed, to show that the proposed improvements do not increase the residual risk due to the powder part in areas downstream of the defence structures.
Review of topographic analysis methods for the western Himalaya using AWiFS and MODIS satellite imagery
Authors: Mishra V.D. , Sharma J.K. , Khanna R. 
Published: May 2010

AbstractThe topographic effects of differential terrain illumination in optical satellite imagery of rugged mountainous regions have serious consequences for qualitative and quantitative analysis for various snow applications. Therefore, effective removal or minimization of topographic effects is necessary in satellite image data of mountainous regions. Different methods for topographic corrections, including C-correction, Minnaert corrections (including slope) and slope-matching method, are analysed in the context of snow reflectance. Combination of dark-object subtraction models DOS1 and DOS3 is used for image-based atmospheric corrections while considering the effect of Rayleigh scattering on the transmissivity in different spectral bands of AWiFS and MODIS image data. The performance of different models is evaluated using (1) visual analysis, (2) change in snow reflectance on sunny and shady slopes after the corrections, (3) validation with in situ observations and (4) graphical analysis. The results show that the slope-matching technique could eliminate most of the shadowing effects in Himalayan rugged terrain and correctly estimate snow reflectance from AWiFS and MODIS imagery. The validation of results with in situ observations for both types of imagery suggests that all other methods significantly underestimate reflectance values after the corrections.
Spatial scales of snow texture as indicator for snow class
Authors: Satyawali P.K. , Schneebeli M. 
Published: May 2010

AbstractA method for automated and fast classification of snow texture would be useful for applications where snow structure must be quantified. Large numbers of field measurements were carried out on natural snow in order to investigate small-scale variations of the micro-penetration force. Snow characterization was done for snow from the Himalaya and the Alps, using a high-resolution snow penetrometer (SnowMicroPen). Measurements of snow resistance at equal intervals of 4 μm were geostatistically evaluated. The range parameter (correlation length, or CL) of penetration force was estimated for all major snow classes from the sample semivariogram. Average CL was lowest for new snow and highest for melt–freeze snow. For major snow classes, CL was found to increase with snow density. Ground-perpendicular and ground-parallel snow profiles were also obtained for homogeneous snow, and CL was estimated along these directions. New snow showed larger CL in the ground-parallel direction, and depth-hoar snow showed larger CL in the ground-perpendicular direction. Based on CL, the directional anisotropy was calculated. An attempt was also made to show the relationship between CL and texture index. The semivariogram was used to estimate the fractal dimension. Both CL and fractal dimension were found to be potential parameters to describe snow.
Velocity measurements of wet snow avalanche on the Dhundi snow chute
Authors: Upadhyay Agraj , Kumar Amod , Chaudhary Arun 
Published: May 2010

AbstractWet snow avalanches in India are common during the mid- and late winter in the Pir Panjal Range (2000–3000ma.s.l.) and during the late winter in the Great Himalayan Range (3000 ma.s.l. and above). Although it is well known that the presence of liquid water in snow makes the flow behaviour of wet snow avalanches different from that of dry snow avalanches, there exist few actual flow measurements with wet snow. The aim of this investigation is to understand the dynamics of wet snow avalanches by conducting medium-scale experiments (volumes of 3, 6 and 11 m3) on the Dhundi snow chute in Himachal Pradesh, India. We measured flow velocities using video data, as well as optical velocity sensors installed on the side walls and running surface. Measurement results relating to the slip velocity of the front and tail of the moving snow mass, as well as the average slip velocity, are presented. In addition, we use the results of the vertical velocity profile measurements to calculate the effective viscosity of snow at two locations within the flow. We identified a shear thinning type of behaviour, suggesting that a single avalanche rheology cannot describe wet snow avalanche behaviour.
Using stability tests and regional avalanche danger to estimate the local avalanche danger
Authors: Bakermans Laura , Jamieson Bruce , Schweizer Jürg , Haegeli Pascal 
Published: May 2010

AbstractBecause public avalanche forecast regions in Canada are large, ranging from 100 to >30 000 km2, there are often areas within each region where the current local avalanche danger differs from the forecast regional danger. Identifying areas where the local danger is higher or lower than the regional rating is useful for recreational backcountry travellers; for those with limited experience, however, this is not always practical. During four winters in the Columbia, Coast and Rocky Mountains of western Canada, field teams performed stability tests and undertook local avalanche danger assessments for comparison against the regional danger ratings. Significant correlations between stability test variables and the local avalanche danger, and between stability test variables and the difference between local and regional danger, indicate potential for improved evaluation of the local danger if stability test results are considered with the regional bulletin rating. Although our analysis shows that a single stability test result cannot reliably be used to estimate the local avalanche danger, it does identify circumstances under which stability tests can help backcountry recreationists identify an area of locally higher avalanche danger.
Using RESOURCESAT-1 data for determination of snow cover and snowline altitude, Baspa Basin, India
Authors: Kaur Rakesh , Kulkarni Anil V. , Chaudhary B.S. 
Published: May 2010

AbstractThis paper presents a method for deriving the snowline altitude using a combined analysis of terrain elevation and multispectral Advanced Wide Field Sensor (AWiFS) data from the RESOURCESAT-1 satellite, launched by India on 17 October 2003. AWiFS is a unique instrument capable of acquiring imagery of the world repeatedly every 5 days with very high radiometric resolution. It provides a wide swath width, which is very useful for snow-cover mapping. Snowline altitude is a good indicator of snow coverage. Snowline altitude for the period from October 2004 to June 2005, and from October 2006 to June 2007, is determined for the Baspa Basin, which is located in the Kinnaur district of Himachal Pradesh, India. It is observed that snowline altitude is generally higher during the year 2006/07 than during 2004/05, except in December 2006 and March 2007. The results obtained with the analysis presented here are validated using available meteorological data and are found to be satisfactory. This thus establishes a method that can be applied to other terrains and over longer periods of time within the coverage of the AWiFS sensor data.
Velocity profile inversion in dense avalanche flow
Authors: Kern Martin A. , Bartelt Perry A. , Sovilla Betty 
Published: May 2010

AbstractWe present a velocity time series of a dry-mixed real-scale avalanche that was recorded at different heights on a mast at the Swiss Vallée de la Sionne avalanche test site. The dataset is of extraordinary quality in terms of completeness and spatio-temporal resolution, and allows the evolution of distinct flow phases of the avalanche to be traced. In particular, we found velocity profile inversions at the transition from the avalanche front to the avalanche body. We provide a tentative empirical description of the profile inversions and briefly discuss our observations in the light of theoretical considerations.
Synthesis of Zwitterionic Water‐Soluble Oligofluorenes with Good Light‐Harvesting Ability
Authors: Xing Chengfen , Liu Libing , Shi Zhiqiang , Li Yuliang , Wang Shu 
Published: May 2010

AbstractA new water‐soluble zwitterionic oligofluorene bearing carboxylic acid and quaternary ammonium as pendant groups (OF‐1) is synthesized and characterized. It forms aggregates by intermolecular electrostatic interactions and exhibits similar light‐harvesting ability as that of conjugated polymers. Efficient fluorescence resonance energy transfer (FRET) occurs from OF‐1 to double‐stranded DNA tagged with fluorescein (dsDNA‐F1). A photoresponsive oligofluorene (OF‐3) is also synthesized by protecting OF‐1 with 1‐(2‐nitrophenyl)ethanol. Photolysis of OF‐3 can produce OF‐1 to result in a fluorescence “turn‐on” response, thus the FRET from OF‐3 to dsDNA‐Fl can be turned on by light irradiation. OF‐3 offers the potential for remote DNA sensing.
Oxidative Inorganic Multilayers for Polypyrrole Film Generation
Authors: Salomäki Mikko , Räsänen Markus , Leiro Jarkko , Huti Terhi , Tenho Mikko , Lukkari Jukka , Kankare Jouko 
Published: May 2010

AbstractA controlled nanoscale fabrication of conducting polymer films sets severe requirements for the preparation method and substrate. A new and versatile approach for producing thin polypyrrole films on a variety of surfaces is presented. Purely inorganic thin films are first prepared from poly(metaphosphate) and tetravalent metal ions using a sequential layer‐by‐layer technique. Redox‐active cerium(IV) polyphosphate multilayer and redox‐inactive zirconium(IV) and hafnium(IV) polyphosphate multilayers are prepared. Cerium‐based polyphosphate films grow exponentially with the number of layers but multilayers containing zirconium or hafnium exhibit a linear buildup process. All the studied systems produce relatively smooth films with initial bilayer thickness less than 2 nm. The cerium(IV) containing film is redox‐active, which is shown by its capability to form a polypyrrole layer on its surface by oxidation of pyrrole monomers in the adjacent aqueous solution. This is a general method to produce thin oxidative films of arbitrary size and form on a wide variety of surfaces.
Planarization of Polymeric Field‐Effect Transistors: Improvement of Nanomorphology and Enhancement of Electrical Performance
Authors: Singh Kumar A. , Young Tomasz , McCullough Richard D. , Kowalewski Tomasz , Porter Lisa M. 
Published: May 2010

AbstractThe planarization of bottom‐contact organic field‐effect transistors (OFETs) resulting in dramatic improvement in the nanomorphology and an associated enhancement in charge injection and transport is reported. Planar OFETs based on regioregular poly(3‐hexylthiophene) (rr‐P3HT) are fabricated wherein the Au bottom‐contacts are recessed completely in the gate‐dielectric. Normal OFETs having a conventional bottom‐contact configuration with 50‐nm‐high contacts are used for comparison purpose. A modified solvent‐assisted drop‐casting process is utilized to form extremely thin rr‐P3HT films. This process is critical for direct visualization of the effect of planarization on the polymer morphology. Atomic force micrographs (AFM) show that in a normal OFET the step between the surface of the contacts and the gate dielectric disrupts the self‐assembly of the rr‐P3HT film, resulting in poor morphology at the contact edges. The planarization of contacts results in notable improvement of the nanomorphology of rr‐P3HT, resulting in lower resistance to charge injection. However, an improvement in field‐effect mobility is observed only at short channel lengths. AFM shows the presence of well‐ordered nanofibrils extending over short channel lengths. At longer channel lengths the presence of grain boundaries significantly minimizes the effect of improvement in contact geometry as the charge transport becomes channel‐limited.
Survival of farms in the Veneto region of Italy 1999–2004
Authors: Bassi Francesca , Chillemi Ottorino , Paggiaro Adriano 
Published: May 2010

AbstractAt a micro level, the authors model the survival of farms in the Veneto Region (Italy) for the period 1999–2004, by means of a new database that links information on survival histories in the Official Registers of the Chamber of Commerce with information on socioeconomic and structural characteristics of farms and farmers collected for the 2000 Census of Agriculture. First, the cohort of farms founded in 1999 is considered, and then the analysis is extended to all farms registered at the end of 1999. The model performs quite well in selecting farms with a high probability of survival. [EconLit citations: C41, Q12]. © 2010 Wiley Periodicals, Inc.
A pattern matching method for large‐scale multipurpose process scheduling
Authors: He Yaohua , Hui Chi‐Wai 
Published: May 2010

AbstractThis article proposes a novel pattern matching method for the large‐scale multipurpose process scheduling with variable or constant processing times. For the commonly used mathematical programming models, large‐scale scheduling with long‐time horizons implies a large number of binary variables and time sequence constraints, which makes the models intractable. Hence, decomposition and cyclic scheduling are often applied to such scheduling. In this work, a long‐time horizon of scheduling is divided into two phases. Phase one is duplicated from a pattern schedule constructed according to the principle that crucial units work continuously, in parallel and/or with full load as possible, exclusive of time‐consuming optimization. Phase two involves a small‐size subproblem that can be optimized easily by a heuristic method. The computational effort of the proposed method does not increase with the problem size. The pattern schedule can be not only used for production/profit maximization but also for makespan estimation and minimization. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Nonlinear stochastic modeling to improve state estimation in process monitoring and control
Authors: Lima Fernando V. , Rawlings James B. 
Published: May 2010

AbstractState estimation from plant measurements plays an important role in advanced monitoring and control technologies, especially for chemical processes with nonlinear dynamics and significant levels of process and sensor noise. Several types of state estimators have been shown to provide high‐quality estimates that are robust to significant process disturbances and model errors. These estimators require a dynamic model of the process, including the statistics of the stochastic disturbances affecting the states and measurements. The goal of this article is to introduce a design method for nonlinear state estimation including the following steps: (i) nonlinear process model selection, (ii) stochastic disturbance model selection, (iii) covariance identification from operating data, and (iv) estimator selection and implementation. Results on the implementation of this design method in nonlinear examples (CSTR and large dimensional polymerization process) show that the linear time‐varying autocovariance least‐squares technique accurately estimates the noise covariances for the examples analyzed, providing a good set of such covariances for the state estimators implemented. On the estimation implementation, a case study of a chemical reactor demonstrates the better capabilities of MHE when compared with the extended Kalman filter. © 2010 American Institute of Chemical Engineers AIChE J, 2011
On the use of the Iodide Iodate Reaction Method for assessing mixing times in continuous flow mixers
Authors: Kölbl A. , Kraut M. 
Published: May 2010

AbstractIt is demonstrated experimentally by example of simple, commercially available T‐junctions and by ”unsymmetrical” V‐type micromixers that mixing times cannot be derived by applying the Iodide Iodate Reaction Method without considering the specific mixer geometry. Experimental results differ depending on the orientation of the feeds with respect to the inlets. An explanation for the observed effects is suggested. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Ocular adnexal lymphoma and Helicobacter pylori gastric infection
Authors: Decaudin Didier , Ferroni Agnès , Vincent‐Salomon Anne , Beldjord Kheira , Validire Pierre , de Cremoux Patricia , Validire Patricia , Plancher Corine , Mathiot Claire , Macintyre Elizabeth , Asselain Bernard , Girodet Jacques , Mal Frédéric , Brousse Nicole , Beretti Jean‐Luc , Dendale Rémi , Lumbroso‐Le Rouic Livia , Hermine Olivier , Lecuit Marc 
Published: May 2010

AbstractThere is a causal association between Helicobacter pylori (Hp) gastric infection and the development of gastric MALT lymphoma. In contrast, the link between Hp gastric infection and the development of extragastric lymphoma has not been thoroughly investigated. We, therefore, studied the prevalence of gastric Hp infection at initial diagnosis of ophthalmologic and nonophthalmologic extragastric lymphoma patients. Three cohorts of patients were studied: a first one of 83 patients with OAL, a second one of 101 patients with extraophthalmologic extragastric lymphoma, and a third one of 156 control individuals (control) without malignant lymphoma. Gastric Hp infection was investigated by histopathological analysis and Hp‐specific PCR assay on gastric biopsy tissue samples. We found gastric Hp infection in 37 OAL patients (45%), in 25 extraophthalmologic extragastric lymphoma cases (25%), and in 18 controls individuals (12%) (P < 0.0001 OAL/C and P < 0.01 OAL/extra‐OAL cases). Gastritis was found in 51% and 9% of Hp‐positive and Hp‐negative lymphoma patients, respectively (P < 10−4). Gastric Hp infection only correlated with MALT/LPL lymphoma (P = 0.03). There is a significant association between gastric Hp infection and MALT/LPL OAL. This suggests a novel mechanism of indirect infection‐associated lymphomagenesis whereby chronic local antigen stimulation would lead to the emergence of ectopic B‐cell lymphoma. © 2010 Wiley‐Liss, Inc. Am. J. Hematol.
Relation between C‐reactive protein levels and body composition in a multiethnic sample of school children in Hawaii
Authors: Brown Daniel E. , Mautz William J. , Warrington Miyako , Allen Lenard , Tefft Harold A.T. , Gotshalk Lincoln , Katzmarzyk Peter T. 
Published: May 2010

AbstractObjectives:Adipose cells secrete proinflammatory cytokines that stimulate hepatic production of C‐reactive protein (CRP). CRP levels are associated with adiposity levels in adults, adolescents, and older children but not in young children (age 2–3). This study examined the relation between CRP, adiposity, and cardiovascular and metabolic variables including blood pressure, glucose, and blood lipids in two young cohorts of children, averaging ∼5.5 and 8.5 years, respectively.Methods:Children (N = 125) from eight elementary schools in the multiethnic community of Hilo Hawaii were recruited to fill out questionnaires, undergo anthropometrics and air displacement plethysmography, have resting blood pressure measured, and provide a finger stick blood sample for analysis of CRP, glucose, and blood lipids.Results:There were no significant differences between the cohorts in ethnic make up, household income, or parents' educational attainment. No significant relation was found between CRP and either adiposity or cardiovascular/metabolic variables in the younger cohort. However, significant correlations were found between CRP and adiposity measures and blood pressure in the older cohort. There was no marked difference in association of CRP with BMI versus waist circumference or waist‐to‐hip ratio. In neither cohort was CRP significantly related to glucose or blood lipids.Conclusions:Both amount of fat mass and time duration for possessing the adipose tissue may be important factors in determining the relation between CRP and both adiposity and blood pressure. Am. J. Hum. Biol. 22:675–679, 2010. © 2010 Wiley‐Liss, Inc.
Sex influence on myocardial function with exercise in adolescents
Authors: Rowland Thomas , Unnithan Viswanath , Garrard Max , Roche Denise , Holloway Kathryn , Sandoval Julie , Marwood Simon 
Published: May 2010

AbstractObjectives:Ventricular systolic functional response to exercise has been reported to be superior in adult men compared to women. This study explored myocardial responses to maximal upright progressive exercise in late pubertal males and females.Methods:Doppler echocardiographic techniques were utilized to estimate myocardial function response to a bout of progressive cycle exercise.Results:Systolic functional capacity, as indicated by ejection rate (12.5 ± 2.8 and 13.1 ± 1.0 [×10−2] ml s−1 cm−2 for boys and girls, respectively) and peak aortic velocity (208 ± 45 and 196 ± 12 cm s−1, respectively) at maximal exercise, did not differ between the two groups. Similarly, peak values as well as increases in transmitral pressure gradient (mitral E flow velocity), ventricular relaxation (tissue Doppler imaging E′), and left ventricular filling pressure (E/E′ ratio) as estimates of diastolic function were similar in males and females.Conclusions:This study failed to reveal qualitative or quantitative differences between adolescent boys and girls in ventricular systolic or diastolic functional responses to maximal cycle exercise. Am. J. Hum. Biol. 22:680–682, 2010. © 2010 Wiley‐Liss, Inc.