bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of a Hydroelastic Instability Phenomenon: Flutter of Racing Yacht Keels
Authors: Balze Rémy , Devaux Hervé , Jézéquel Louis 
Published: August 2013

In the field of aeroelasticity, flutter is a well known instability phenomenon. Flutter is a synchronized vibration which takes place in a flexible structure moving through a fluid medium. It occurs when two regular, rhythmic motions coincide in such a way that one feeds the other, drawing additional energy from surrounding flow. A classic case of wing flutter might combine wing bending with either wing twisting.
This article explores the flutter phenomenon in water. An important difference from the flutter phenomenon in air is the fact that the flexible structure is evolving in heavy fluid; this implies in particular added mass effects and important fluid damping.
Flutter appeared for the first time on racing yacht keels with composite fins, so in water, in 2004:
• On the IMOCA 60 feet boat POUJOULAT-ARMORLUX of Bernard STAMM during the transatlantic race ‘The Transat’: he lost his keel and capsized.
• On the IMOCA 60 feet boat SILL Rolland JOURDAIN: the keel and the boat were saved.
Following these problems — particularly following the loss of the keel of Bernard STAMM sailboat, accident that could have dramatic consequences for the skipper — HDS company focused on the phenomenon.
Flutter has occurred only for canting keels with composite fins on IMOCA 60 feet and Volvo 70 feet racing yacht. The main questions asked are “Why are composite keels susceptible to flutter, and is it possible to predict and prevent this behaviour?”, then “Can a fair indication of the flutter critical speed of the keel be given at low cost?”.
This presentation will introduce the strategy of HDS faced to the problem and the analytical and numerical methods implemented to estimate the flutter critical speed. Our model is based on a truncated modal basis for the most energetic modes which are generally, for a bulb keel, the lateral bending predominant mode and the torsion predominant mode. One of our requirements was to make a simple model in order to integrate the calculation of the flutter critical speed in the first design loops of a composite or steel keel.
This model has worked well for the two cases of flutter appeared on IMOCA sailboat keels. Besides, to verify the quality of the model and to complete our analysis of flutter phenomenon on racing yacht keels, a 3 dimensional multi-physics simulation has been developed using the software ADINA.
Consideration of the Manufacturing Trajectories in a Global Design for Additive Manufacturing Methodology
Authors: Ponche R. , Kerbrat O. , Mognol P. , Hascoet J. Y. 
Published: August 2013

Additive Manufacturing (AM) is a new way of part production which opens up new perspectives of conception as mass and cost reduction and increase of functionalities. However these processes have their own characteristics which as for all the manufacturing processes have a direct impact on the manufactured parts quality. Especially, because the manufacturing trajectories have a influence on the physical phenomena during the process, they have also a strong impact on the quality of the produced parts in terms of geometry.
In this paper, the choice of manufacturing trajectories and their impacts on the final shape and quality of the parts is integrated into a global Design For Additive Manufacturing (DFAM) methodology which allows to move from functional specifications of a design problem to a proposition of an adapted part for AM processes.
Effect of Axial Preload on Double-Lap Bolted Joints: Numerical Study
Authors: Benhaddou Taha , Stephan Pierre , Daidie Alain , Chirol Clément , Tuery Jean-Baptiste 
Published: August 2013

This paper presents the numerical study of double-lap bolted joint behavior. This type of joint is mainly used in aeronautical structures to transfer the given loads (by both adhesion and by deformation-shearing). Recent articles, based on experimental fatigue tests conducted by AIRBUS, have shown the beneficial effects of preloading on the fatigue life of these joints.
Finite element analyses were performed using ABAQUS® to study the behavior of a double-lap single-bolted joint with different plate thicknesses (joint thickness = 0.5d, 1d, 1.5d, 2d 2.5d, 3d, 3.5d and 4d, where d is the bolt diameter).
The numerical model provides several important results. In the case of static loads, elasto-plastic constitutive laws of the bolt and the plate materials allowed the process to be simulated on the basis of tension tests.
Mechanical aspects of this type of assembly are numerically identified; from the initial state of adhesion to the state of plastic deformation of parts in contact including the stage of generalized slippage. We note that the fracture load increases slightly when the bolted joint is preloaded while the failure area remains the same. In the case of large plate thickness, the connection is subjected to significant bending stresses and this involves strong local plasticization associated with the loss of preload.
In the case of cyclic loading, we consider a numerical model based on the simulation of one loading/unloading cycle. A noticeable decrease in initial preload is observed for certain configurations, in particular those with the largest plate thickness. This phenomenon is related to the effect of strain hardening of the bolt during the first loading cycles. Some experimental work by AIRBUS has shown that the fatigue life of assemblies is dependent on the material plate thicknesses.
An extension to the case of a multiple-bolted joint (three rows of three bolts) is finally discussed and highlights the evolution of the rate of load transmission with respect to the applied load.
A Knowledge Capitalization Methodology Based on Automatic Knowledge Extraction From 3D CAD Models
Authors: Lebouteiller Mathieu , Boxberger Jérémy , Gomes Samuel , Lebaal Nadhir , Schlegel Daniel 
Published: August 2013

The issue of improving quality, costs and delays indicators in design and manufacturing is more relevant than ever in the industry. After lean manufacturing, well known in production process, the lean engineering approach is being implemented today in the field of design, taking the name of lean product development.
The management of knowledge and know-how (existing, new or to be acquired) is the heart of lean engineering. In our suggested methodology this is implemented through a new generation of tools called Knowledge Configuration Management (KCM) and Knowledge Extraction Assistant (KEA).
KCM tools are lean engineering components that provide analytical approach to knowledge management and knowledge-based engineering. These tools require a highly integrated approach that involves, for example, predefined geometrical parametric 3D models, such as CAD templates. But this approach cannot be deployed in all engineering sites.
We propose to complete this KCM approach introducing a semantic network approach, coupling with Feature Identity Card (FIC). FIC contains a set of metadata and information existing in the Product Data Management (PDM), connected with information extracted from 3D CAD (Computer Aided Design) models. It allows contextualizing information and ensures semantic connections, in order to manipulate the right parameters with mathematical algorithms. Those algorithms will search candidate relationships between design parameters extracted from CAD models.
Our suggested approach aims at extracting knowledge in cases where design never came out of Knowledge Based Engineering (KBE) applications. In those situations, it seems important to complete classical knowledge management approach, and to find out the implicit knowledge embedded in 3D CAD models. This is achieved through a global approach, focusing on the product’s 3D definitions.
We suggest introducing the latter approach by a suite of digital KEA tools (interfaced with KCM tools). Extracting knowledge from projects information stored in the Product Data Management does this.
More precisely, the methodology is based on a commercial 3D similarity search tools for CAD models and on mathematical algorithms that search relationships between extracted design parameters. The goal is to submit new rules to the process and design experts.
Implementing this methodology, a deeper knowledge of the product and its associated process can be acquired. This ensures a more productive and efficient design process.
Intelligent Reverse-Engineering Segmentation: Automatic Semantic Recognition of Large 3D Digitalized Cloud of Points Dedicated to Heritage Objects
Authors: Laroche Florent , Lefèvre Daniel , Servières Myriam , Hervy Benjamin , Bernard Alain 
Published: August 2013

In this article we present a multidisciplinary experimentation realized between a mechanical laboratory, a computer scientist laboratory and a museum.
Our goal is to provide automatic tools for non-expert people who want to use 3D digitized elements. After scanning an objet, we obtain a huge amount of points. In order to manipulate it, it is necessary to decimate it. However, when doing this operation, we can optimize the algorithms for creating semantic topology; obviously we can do it automatically. Consequently, we are going to do what we name segmentation: we extract meaning from 3D points and meshes.
Our experimentation deals with a physical mock-up of Nantes city that have been designed in 1900. After digitalization, we have created a software that can:
1. use the whole 3D cloud of points as an input;
2. fill a knowledge database with an intelligent segmentation of the 3D virtual models: ground, walls, roofs…
This use case is the first step of our research. At the end, we aim to deploy our method to complex mechanical parts. Nowadays, when designing CAD parts we use as well as volume parts than surface parts or meshes. We know is it not necessary to reconstruct all the triangles. It is a lost of time and we can directly use cloud of points for CAD design. However, the design tree will not be updated. So, with our method, imagine that one day we can digitalize a motor and a system could automatically create the 3D mock-up and the design tree.
Knowledge Based Reverse Engineering Methodology
Authors: Remy Sébastien , Laroche Florent , Durupt Alexandre , Bernard Alain 
Published: August 2013

In Reverse Engineering, commercial solutions such as Geomagic™ or RapidForm™ or CAD software such as CATIA™ provide very efficient toolboxes that enable to rebuild geometry. Moreover, some of them provide segmentation algorithms, sketchers and/or many other facilities rebuilding tools in order to help to recover the original surface. Those software’s enable to rebuild the geometry of a technical object as a set of functions (protrusion, revolution, sweep…), they enable to add colours and textures, and they enable realistic kinematical animation and many other things. Unfortunately, all those toolboxes present a lack of geometry analysis tools. The geometry of a given product is the consequence of a complete process, it is important, considering Reverse Engineering activities, to try to recover any evidence of its past life (including socio-economical aspects, the design intents of the former designer, its different uses…) from its geometry in order to produce a good quality 3D model. Such models can provide important possibilities for Reverse Engineering. It enables to study the product more efficiently than a geometrical model based on a mesh or on free form surfaces.
This paper proposes approaches and methodologies for using knowledge to rebuild CAD model to the best closer to the original CAD model that could have been obtained by the original designer. Such a model is feature based. They can be functional features or manufacturing features. For a good rebuilt of 3D model, the geometry of these features is driven by parameters, rules and relationships that are provided by the former designer.
Evaluation of CT‐based lean‐body SUV
Authors: Hamill James J. , Sunderland John J. , LeBlanc Amy K. , Kojima Cheryl J. , Wall Jonathan , Martin Emily B. 
Published: August 2013

Purpose:The authors introduce a novel method for defining standardized uptake values (SUVs) in PET/CT based on routinely collected CT data. The goal of the study is to reduce, if possible, the variability of SUV in a heterogeneous population. Two well established methods for defining SUV are based on body weight (BW) and lean body mass, calculated as a function of height, weight, and sex with an empirical formula (LBM). The authors investigate two novel models, CT1 and CT2, that estimate the lean mass from CT Hounsfield Unit values. The authors compare the four methods, assessing the variability of hepatic SUV in18F‐FDG studies.Methods:CT images from 252 cancer patients were segmented into regions representing lean tissues, fat, and bone. The fraction of lean tissue in the scanned region was extrapolated to the entire body with a naive method (CT1) and a method that modeled typical FDG uptake patterns (CT2). For each method, SUV‐based measurements of the liver were calculated for all patients and dependence on body weight was assessed. Coefficients of variation (CVs) were evaluated. Several sub‐cohorts were analyzed, including those with low and high body mass index (BMI). The extrapolation technique was tested in 19 melanoma patients who received head to toe PET/CT scans. CT‐based weight predictions were compared with actual patient weight in melanoma studies and in PET/CT scans of pigs.Results:Only the SUV based on BW method depended significantly on body weight. CVs for the BW, LBM, CT1, and CT2 methods were, respectively, 18.0%, 15.5%, 15.9%, and 14.9%. In the high‐BMI cohort, CVs were 18.2%, 16.2%, 16.2%, and 15.1%. Mean SUV of the 14 most obese patients agreed most closely with mean SUV of 120 lean patients when the CT2 method was used. SUV based on truncated CT agreed with head to toe predictions within 5% for the CT1 method and 1% for the CT2 method. CT‐based weight estimate recovered 97.4% of the weight in head to toe studies of humans and 99.7% in pig studies.Conclusions:The novel CT1 and CT2 methods were less variable than the BW method and were comparable to the LBM method. SUV were little affected by missing CT data.
Quantification of Brain Voriconazole Levels in Healthy Adults Using Fluorine Magnetic Resonance Spectroscopy
Authors: Henry Michael E. , Bolo Nicolas R. , Zuo Chun S. , Villafuerte Rosemond A. , Cayetano Kenroy , Glue Paul , Damle Bharat D. , Andrews Emma , Lauriat Tara L. , Rana Namoode S. , Churchill Jeffrey H. , Renshaw Perry F. 
Published: August 2013

ABSTRACT

Voriconazole is more effective for aspergillosis infections with central nervous system involvement than other antifungal agents. The clinical efficacy of voriconazole for central nervous system infections has been attributed to its ability to cross the blood-brain barrier. However, pharmacokinetic studies are limited to plasma and cerebrospinal fluid, so it remains unclear how much of the drug enters the brain. Fluorinated compounds such as voriconazole can be quantified in the brain using fluorine-19 magnetic resonance spectroscopy (MRS). Twelve healthy adult males participated in a pharmacokinetic analysis of voriconazole levels in the brain and plasma. Open-label voriconazole was dosed per clinical protocol with a loading dose of 400 mg every 12 h on day 1, followed by 200 mg every 12 h administered orally over a 3-day period. MRS was performed before and after dosing on the third day. Voriconazole levels in the brain exceeded the MIC for
Aspergillus
. The brain/plasma ratios were 3.0 at steady state on day 3 (predose) and 1.9 postdose. We found that voriconazole is able to penetrate the brain tissue, which can be quantified using a noninvasive MRS technique. (This study has been registered at ClinicalTrials.gov under registration no. NCT00300677.)
Activities of Psilostachyin A and Cynaropicrin against Trypanosoma cruzi
In Vitro
and
In Vivo
Authors: da Silva Cristiane França , Batista Denise da Gama Jaen , De Araújo Julianna Siciliano , Batista Marcos Meuser , Lionel Jessica , de Souza Elen Mello , Hammer Erica Ripoll , da Silva Patricia Bernardino , De Mieri Maria , Adams Michael , Zimmermann Stefanie , Hamburger Matthias , Brun Reto , Schühly Wolfgang , Soeiro Maria de Nazaré Correia 
Published: August 2013

ABSTRACT

In vitro
and
in vivo
activities against
Trypanosoma cruzi
were evaluated for two sesquiterpene lactones: psilostachyin A and cynaropicrin. Cynaropicrin had previously been shown to potently inhibit African trypanosomes
in vivo
, and psilostachyin A had been reported to show
in vivo
effects against
T. cruzi
, albeit in another test design.
In vitro
data showed that cynaropicrin was more effective than psilostachyin A. Ultrastructural alterations induced by cynaropicrin included shedding events, detachment of large portions of the plasma membrane, and vesicular bodies and large vacuoles containing membranous structures, suggestive of parasite autophagy. Acute toxicity studies showed that one of two mice died at a cynaropicrin dose of 400 mg/kg of body weight given intraperitoneally (i.p.). Although no major plasma biochemical alterations could be detected, histopathology demonstrated that the liver was the most affected organ in cynaropicrin-treated animals. Although cynaropicrin was as effective as benznidazole against trypomastigotes
in vitro
, the treatment (once or twice a day) of
T. cruzi
-infected mice (up to 50 mg/kg/day cynaropicrin) did not suppress parasitemia or protect against mortality induced by the Y and Colombiana strains. Psilostachyin A (0.5 to 50 mg/kg/day given once a day) was not effective in the acute model of
T. cruzi
infection (Y strain), reaching 100% animal mortality. Our data demonstrate that although it is very promising against African trypanosomes, cynaropicrin does not show efficacy compared to benznidazole in acute mouse models of
T. cruzi
infection.
Contribution of Efflux Pumps, Porins, and β-Lactamases to Multidrug Resistance in Clinical Isolates of Acinetobacter baumannii
Authors: Rumbo C. , Gato E. , López M. , Ruiz de Alegría C. , Fernández-Cuenca F. , Martínez-Martínez L. , Vila J. , Pachón J. , Cisneros J. M. , Rodríguez-Baño J. , Pascual A. , Bou G. , Tomás M. 
Published: August 2013

ABSTRACT

We investigated the mechanisms of resistance to carbapenems, aminoglycosides, glycylcyclines, tetracyclines, and quinolones in 90 multiresistant clinical strains of
Acinetobacter baumannii
isolated from two genetically unrelated
A. baumannii
clones: clone PFGE-ROC-1 (53 strains producing the OXA-58 β-lactamase enzyme and 18 strains with the OXA-24 β-lactamase) and clone PFGE-HUI-1 (19 strains susceptible to carbapenems). We used real-time reverse transcriptase PCR to correlate antimicrobial resistance (MICs) with expression of genes encoding chromosomal β-lactamases (AmpC and OXA-51), porins (OmpA, CarO, Omp33, Dcap-like, OprB, Omp25, OprC, OprD, and OmpW), and proteins integral to six efflux systems (AdeABC, AdeIJK, AdeFGH, CraA, AbeM, and AmvA). Overexpression of the AdeABC system (level of expression relative to that by
A. baumannii
ATCC 17978, 30- to 45-fold) was significantly associated with resistance to tigecycline, minocycline, and gentamicin and other biological functions. However, hyperexpression of the AdeIJK efflux pump (level of expression relative to that by
A. baumannii
ATCC 17978, 8- to 10-fold) was significantly associated only with resistance to tigecycline and minocycline (to which the TetB efflux system also contributed). TetB and TetA(39) efflux pumps were detected in clinical strains and were associated with resistance to tetracyclines and doxycycline. The absence of the AdeABC system and the lack of expression of other mechanisms suggest that tigecycline-resistant strains of the PFGE-HUI-1 clone may be associated with a novel resistance-nodulation-cell efflux pump (decreased MICs in the presence of the inhibitor Phe-Arg β-naphthylamide dihydrochloride) and the TetA(39) system.
Antimicrobial Resistance and Molecular Typing of Neisseria gonorrhoeae Isolates in Kyoto and Osaka, Japan, 2010 to 2012: Intensified Surveillance after Identification of the First Strain (H041) with High-Level Ceftriaxone Resistance
Authors: Shimuta Ken , Unemo Magnus , Nakayama Shu-ichi , Morita-Ishihara Tomoko , Dorin Misato , Kawahata Takuya , Ohnishi Makoto 
Published: August 2013

ABSTRACT

In 2009, the first high-level ceftriaxone-resistant
Neisseria gonorrhoeae
strain (H041) was isolated in Kyoto, Japan. The present study describes an intensified surveillance (antimicrobial resistance and molecular typing) of
Neisseria gonorrhoeae
isolates in Kyoto and its neighboring prefecture Osaka, Japan, in 2010 to 2012, which was initiated after the identification of H041. From April 2010 to March 2012, 193
N. gonorrhoeae
isolates were collected and the MICs (μg/ml) to six antimicrobials, including ceftriaxone, were determined. All isolates showed susceptibility to ceftriaxone and cefixime (MIC values, <0.5 μg/ml), and spectinomycin. The rates of resistance (intermediate susceptibility) to azithromycin, penicillin G, and ciprofloxacin were 3.6% (19.7%), 24.4% (71.0%), and 78.2% (0.5%), respectively. Multilocus sequence typing (MLST) showed that 40.9%, 19.2%, and 17.1% of isolates belonged to ST1901, ST7359, and ST7363, respectively. Furthermore,
N. gonorrhoeae
multiantigen sequence typing (NG-MAST) revealed that 12 (63%) of the 19 isolates with decreased susceptibility to ceftriaxone (MIC > 0.064 μg/ml) were of ST1407. NG-MAST ST1407 was also the most prevalent ST (16.1%; 31 of 193 isolates). In those NG-MAST ST1407 strains, several mosaic type
penA
alleles were found, including SF-A type (penicillin binding protein 2 allele XXXIV) and its derivatives. These were confirmed using transformation of the
penA
mosaic alleles as critical determinants for enhanced cefixime and ceftriaxone MICs. The intensified surveillance in Kyoto and Osaka, Japan, did not identify any dissemination of the high-level ceftriaxone-resistant
N. gonorrhoeae
strain H041, suggesting that H041 might have caused only a sporadic case and has not spread further.
Augmentation of Epithelial Resistance to Invading Bacteria by Using mRNA Transfections
Authors: Zou Xianqiong , Sorenson Brent S. , Ross Karen F. , Herzberg Mark C. 
Published: August 2013

ABSTRACT

To protect against invading bacteria, oral epithelial cells appear to use two effector antimicrobial peptides (AMPs): calprotectin (S100A8-S100A9 heterodimer [S100A8/A9]) in the cytosol and cathelicidin antimicrobial protein (CAMP) in endosomes. We sought to learn whether innate immunity might be augmented benignly to increase resistance against invasive bacteria. Epithelial cells were transiently transfected with mRNA constructs containing either the
CAMP
,
S100A8
, and
S100A9
open reading frames,
A8-IRES-A9
(fusion sequence), or
A8-nIRES-A9
(fusion with native internal ribosome entry site [IRES] sequence). CAMP, S100A8, and S100A9 protein levels generally peaked between 16 and 44 h after mRNA transfection, depending on the construct; CAMP was processed to LL-37 over time. Following transfection with the respective mRNAs, CAMP and S100A8/A9 each independently increased resistance of epithelial cells to invasion by
Listeria
and
Salmonella
for up to 48 h; tandem S100A8/A9 constructs were also effective. Cotransfection to express S100A8/A9 and CAMP together augmented resistance, but synergy was not seen. Independent of the new proteins produced, transfection reduced cell viability after 48 h by 20%, with only 2% attributable to apoptosis. Taken together, these results suggest that epithelial cell resistance to invasive pathogens can be augmented by transient transfection of antimicrobial mRNAs into epithelial cells.