bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of the Dynamic Performance of Serial 3R Orthogonal Manipulators
Authors: Nguyen Dinh Quan , Briot Sébastien , Wenger Philippe 
Published: August 2013

Serial 3R orthogonal manipulators have been studied recently and it has been proved that they can exhibit good performances in term of workspace size and kinematic properties. The aim of this work is to analyze their dynamic performances, and compare them with anthropomorphic manipulators, which are very popular in industry.
Static and dynamic analyses based on the evaluation of the maximal input torques required for moving the manipulator are achieved. It is shown that, as in kinematics, the dynamic performances of the serial 3R orthogonal manipulators are better.
Elasto-Dynamic Model of Robotic Milling Process Considering Interaction Between Tool and Workpiece
Authors: Bondarenko D. , Pashkevich A. , Briot S. , Ritou M. , Furet B. 
Published: August 2013

In this paper, a reduced elasto-dynamic model of the robotic based milling process is presented. In contrast to previous works, it takes into account the interaction between the milling tool and the workpiece that depends on the end-effector position, process parameters and cutting conditions (spindle rotation, feed rate, geometry of the tool, etc.). To reduce the dimension of the problem, the robot dynamics is described as an equivalent mass-spring-damper system with six dimensions. This approach, based on the Rayleigh-Ritz approximation, aims at decreasing computational cost and at avoiding inaccuracy due to ill-conditioning in the full size model. To achieve a realistic modeling of the milling process, the machining efforts due to the interaction between robot, tool and working material are introduced into the robot model and calculated at each time instant. Using this global model that integrates the robot dynamics and the milling process particularities, it is possible to obtain the movement of the robot end-effector and corresponding quality of the final product (profile, macro geometry, etc.). In addition, this model allows selecting the best process parameters and avoiding the vibratory behavior of this machining system which can dramatically affect the milling quality.
The developed model is applied to the behavior analysis of KUKA KR270 robot used for milling applications. This allows finding acceptable range for robot motion profile parameters.
A Multibody System Approach to Drill String Dynamics Modeling
Authors: Pogorelov Dmitry , Mikheev Gennady , Lysikov Nikolay , Ring Lev , Gandikota Raju , Abedrabbo Nader 
Published: August 2013

The selection of optimal operational parameters for drilling oil and gas wells is a complex dynamic problem that depends on multiple parameters. Numerous physical and mechanical processes such as rock cutting, friction, hydraulics, and different modes of vibrations, occur during drilling, which should be accounted for in numerical models. It is widely accepted that bottom hole assembly (BHA) vibrations are the primary source of drilling equipment premature failure. Over the last 30 years, progress of computational sciences has enabled the use of numerical simulations of drillstring dynamics as a useful tool to understand and mitigate sources of harmful vibrations. The majority of these models have been based on nonlinear finite elements. There are several significant limitations with this approach, including an extremely high number of degree of freedom (DOF) required to represent geometries with 105 ratio of axial to lateral dimensions and also the complexity of modeling variable contacts in bifurcating systems. While it is relatively new for simulating drilling dynamics, the advantage of the proposed rigid-flexible multibody system approach has been proven for modeling complex dynamic systems in other industries. Using a rigid-flexible multibody system approach to analyze dynamic effects both in frequency and time domains, dynamic modeling of BHA and drillstring is proposed.
Drillstring is simulated as a set of uniform flexible beams connected via linear viscous-elastic force elements. Each beam can undergo arbitrary large displacements as absolutely rigid body, but its flexible displacements due to elastic deformations are small. A method of floating frame of reference for flexible bodies and component mode synthesis is used for modeling beams dynamics. Parameters of the coupling force elements are calculated automatically based on stiffness and inertia characteristics of the connected beams.
This paper discusses the development of the rigid-flexible multibody system for modeling drillstring dynamics and the influence of model parameters on simulation accuracy and calculation time.
A close match is shown between theoretical and numerical results for static and buckling problems as well as resonant frequency values. Several transient drillstring dynamics problems are analyzed for wellbores with uniform diameter. Examples of the analysis of resonant conditions during drilling planning stage are also presented. It is also shown how transient time domain analysis can provide further insights into lateral and torsional vibrations, whirl behavior, and effect of local wellbore curvatures on the drillstring performance.
Design for Manufacture Using Functional Analysis and CAD Mould Simulation for Rapid Prototyping and Rapid Tooling
Authors: Lupeanu Mihaela E. , Brooks Hadley , Rennie Allan E. W. , Celik H. Kursat , Neagu Corneliu , Akinci Ibrahim 
Published: August 2013

The pressure of time, quality and cost, together with increasing product variety, more customised products and worldwide competition is driving technology development and implementation in the area of Rapid Manufacturing (RM). Traditionally, the manufacture of tooling for both prototype parts and production components represents one of the longest and most costly phases in the development of most new products. The cost and time implications of the tooling process are particularly problematic for low-volume products aimed at niche markets, or alternatively for rapidly changing high-volume products.
Rapid Prototyping (RP) and Rapid Tooling (RT) have the potential to dramatically shorten the time required to produce functional prototypes or products. Functional Analysis (FA) plays a key role in the design process of the actual tools, allowing for innovative solutions that can be achieved with RP and RT.
This paper presents a FA methodology to design for manufacture (DFM) based on RP- and RT-specific characteristics, aimed at improving process efficiency, streamline energy consumption, use of volume material, usage of structural innovative lightweight materials, decrease overall costs and improve product quality. Design for Rapid Manufacturing (DFRM) allows for geometric freedom, leading to changes of the overall design process, thus enhancing the FA process. FA begins with stating the need, in a DFRM case that translates into diagnosis, the determination of the manufacturability of the present product and comparison with similar products on the market. Setting objectives, in terms of production costs, quality, flexibility, risk, lead-time, efficiency, and environment are other milestones in FA. Actual function definition involves defining the main functions of the product and their interactions. Clarifying the evaluation parameters, setting criteria levels and technical dimensioning is done for each of the main product functions. The conceptual design process then follows a top-down sequence: corporate, family, structural and component levels. Evaluation and selection of the optimal concept resulting from the FA consists of assessing the manufacturability of the proposed concepts in terms of the DFM objectives. The selected best fit concept is translated to design in the last stage, when the chosen concept is communicated to the development team. The detailed design is carried out in parallel to marketing and product development.
Targeted FA is shown to enable generation of innovative solutions, while improving manufacturability. The present research stands as a starting point in the development of product design methodologies that use RP and RT applications for manufacturing physical products.
A Manufacturing System for Advanced Multi-Process Manufacturing Based on Step-NC
Authors: Rauch Matthieu , Hascoet Jean-Yves 
Published: August 2013

Companies have to propose flexibility and interoperability in addition to robustness and efficiency to meet today demand of high customized products. The rise of high level object-oriented data models such as ISO 14649 — know as STEP-NC — enables manufacturing engineers to meet these requirements. In parallel, new manufacturing processes are now available. Theses processes, such as incremental sheet forming or cladding, are mature enough to be used in the industry. In addition to that, they are CNC controlled. They can be totally integrated into manufacturing data chains. It is consequently possible to use several processes on the same part and develop multi-process manufacturing approaches. Their success lies mainly upon the ability to select the best process with the best parameterization. The use of intelligent manufacturing systems is of great help to achieve this goal.
The objective of this paper is to propose an intelligent manufacturing environment for multi-process manufacturing. Simulation and optimization approaches, advanced CNC programming methods are implemented in a coordinate way. Current CAD/CAM/CNC data chains limitations are overtaken by using STEP-NC. Finally, a practical implementation of such system is introduced. This experimental platform enables multi-process manufacturing with the industrial manufacturing equipment of the laboratory.
Fast and Adaptive Hopping Height Control of Single-Legged Robot
Authors: Bhatti Jawaad , Plummer Andrew R. , Sahinkaya M. Necip , Iravani Pejman , Guglielmino Emanuele , Caldwell Darwin G. 
Published: August 2013

Research on running robots has generally focussed on the steady-state. When the ground has limited foot placement surfaces or there are sudden changes in height then steady-state running is not possible. It becomes necessary to make step-by-step adjustments to place the foot.
In this paper a mass-spring-damper model of a robot’s leg is used to develop a hopping controller capable of meeting rapid changes in demand height or flight time. Analysis of the model provides a simple method to select control parameters for effective height control without tuning or iteration. Additionally, a simple adaptive algorithm is introduced and demonstrated in simulation. The adaptive control algorithm allows rapid changes of height even when ground characteristics change. Experimental validation is ongoing and some preliminary results are provided.
Computer Aided Electroforming for Rapid Manufacturing Applications
Authors: Hernández Castellano Pedro M. , Socas Sánchez Ayoze , Benítez Vega Antonio N. , Monzón Verona Mario , Ortega García Fernando , Marrero Alemán M. Dolores 
Published: August 2013

Electroforming enables the manufacture metallic parts with good mechanical properties and high level of accuracy and reproducibility. A thin metallic shell is deposited on a model and later released from it. There are several applications of electroforming combined with rapid manufacturing (RM) technologies. However the two main disadvantages of electroforming are the non-uniformity thickness distribution and long time span of shell manufacturing.
The goal of this research is the evolution of Elecform3D™ product. It is a numerical simulation tool of electroforming process, in order to facilitate design and manufacturing tasks for metallic shells production. This software also controls the automatic device of cathodic orientation (ADCO) inside electrolytic baths. High quality of part is obtained, taking advantage of electroforming properties and improving manufacturing speed.
The methodology is based on the well-known potentials model of LaPlace, it enables deposited metal distribution prediction with high grade of precision, being experimentally validated with cathodic polarization curves. Moreover this has also created a subroutine for solving this problem for this application using the boundary element method (BEM). This tool has been tested and validated for the simulation of metal electroplating by using reference solutions of problems in the literature. It also examines changes in the geometry of the cathode as a result of the process of electro-deposition of the metal and the influence of this phenomenon on the simulation routine developed considering variables such as the metal thickness distribution and the rate of deposition. All these tasks work and carry out processes complementing simulation with experimental work in the laboratory in order to create a tool that will give greater potential to this product.
The results obtained with the first version of this product were very promising, and also indicated the need for a more precise analysis of electrochemical phenomena in the process of electroforming. Elecform3D™ is an important step beyond electroforming so far, and combined with additive manufacturing (AM) 3D printer, is a cheaper alternative for high quality metallic parts manufacturing in comparison with other RM technologies.
Modeling and Simulation of Void Formation During the Resin Transfer Molding Process
Authors: Lebel-Lavacry Aurélie , Park Chung-Hae , Saouab Abdelghani , Guéroult Sébastien , Bizet Laurent , Bréard Joël 
Published: August 2013

We present modeling and simulation of air void formation in composite materials manufactured by the Resin Transfer Molding (RTM) process. The prediction of air void formation has been an important topic because air voids in composite materials deteriorate the mechanical properties of the part.
It has been found by experimental observations that the void content, for a specific preform, can be correlated with capillary number which is the ratio of the viscous force and the surface tension. It is still difficult, however, to predict the void formation without experimental measurement. Moreover, the capillary number may not be the exclusive parameter in practical cases, because the modeling by the capillary number does not work well for large and complex parts.
In this context, we propose a mathematical model to predict the air void formation in the channel which is on open gap between fiber tows and inside the fiber tow. Moreover, the void formation in the warp and the weft are modeled separately by considering the tow orientation with respect to the flow direction. We also modeled two other important phenomena, namely air void compression or expansion, and void migration. To validate the model, void content was experimentally measured by injecting an electrically conductive liquid into a preform. The voltage drop was correlated with the air void content considering the air as a non-conducting material. For a unidirectional fabric, a good agreement was obtained between the model prediction and the experimental result.
Best Practices Assessment in Requirements Engineering Tools Integration
Authors: Mahut Stéphanie Glatard , Eynard Benoit , Merlo Christophe , Minel Stéphanie , Beaujon Thierry 
Published: August 2013

Companies can use methodological software tools to perform requirement engineering. Those methodological tools are increasingly developped by external software editors and integrators. The performance of the tools is not enough to ensure efficiency of methodology application.
This paper is part of a PhD research programm. This research program focuses on the way of integrating requirement engineering tools into product design department with a provider perspective. To be more precise, this research project emphasizes on modifications occuring during integration phases. In order to evaluate and to improve integration process, key indicators can be proposed. From the first stage of integration to the moment the user is autonomous, key integration factors often change. For example, requirements of the user, user environment, product life cycle, delay for integration, actors, … This paper aims at proposing surveys to identify those changing key factors. Then, first best practices elements are given to counteract the possible negative impact on efficiency of requirement engineering tools integration and thus, on product development. In fact, this paper goes further into the way to analyze the existing system. It notably deals with first elements from industrial survey on IT vendor and their customer perspectives on tools integration. In addition, preliminary survey results on customer dissatisfaction are proposed and analyzed. It also proposes a short case study and further research work in order to assume those first results and to bring to the definition of integration approach for methodological tools in engineering domain.
Study of the Effect of Mechanical Loading on Cell Cultures in Bone Tissue Engineering
Authors: Cruel Magali , Bensidhoum Morad , Sudre Laure , Puel Guillaume , Dumas Virginie , Hoc Thierry 
Published: August 2013

Bone tissue engineering currently represents one of the most interesting alternatives to autologous transplants and their drawbacks in the treatment of large bone defects. Mesenchymal stem cells are used to build new bone in vitro in a bioreactor. Their stimulation and our understanding of the mechanisms of mechanotransduction need to be improved in order to optimize the design of bioreactors.
In this study, several geometries of bioreactor were analyzed experimentally and biological results were linked with numerical simulations of the flow inside the bioreactor. These results will constitute a base for an improved design of the existing bioreactor.
Detection of Escherichia coli O157 by Peptide Nucleic Acid Fluorescence
In Situ
Hybridization (PNA-FISH) and Comparison to a Standard Culture Method
Authors: Almeida C. , Sousa J. M. , Rocha R. , Cerqueira L. , Fanning S. , Azevedo N. F. , Vieira M. J. 
Published: August 2013

ABSTRACT

Despite the emergence of non-O157 Shiga toxin-producing
Escherichia coli
(STEC) infections,
E. coli
serotype O157 is still the most commonly identified STEC in the world. It causes high morbidity and mortality and has been responsible for a number of outbreaks in many parts of the world. Various methods have been developed to detect this particular serotype, but standard bacteriological methods remain the gold standard. Here, we propose a new peptide nucleic acid fluorescence
in situ
hybridization (PNA-FISH) method for the rapid detection of
E. coli
O157. Testing on 54 representative strains showed that the PNA probe is highly sensitive and specific to
E. coli
O157. The method then was optimized for detection in food samples. Ground beef and unpasteurized milk samples were artificially contaminated with
E. coli
O157 concentrations ranging from 1 × 10
−2
to 1 × 10
2
CFU per 25 g or ml of food. Samples were then preenriched and analyzed by both the traditional bacteriological method (ISO 16654:2001) and PNA-FISH. The PNA-FISH method performed well in both types of food matrices with a detection limit of 1 CFU/25 g or ml of food samples. Tests on 60 food samples have shown a specificity value of 100% (95% confidence interval [CI], 82.83 to 100), a sensitivity of 97.22% (95% CI, 83.79 to 99.85%), and an accuracy of 98.33% (CI 95%, 83.41 to 99.91%). Results indicate that PNA-FISH performed as well as the traditional culture methods and can reduce the diagnosis time to 1 day.
The Periplasmic HrpB1 Protein from Xanthomonas spp. Binds to Peptidoglycan and to Components of the Type III Secretion System
Authors: Hausner Jens , Hartmann Nadine , Lorenz Christian , Büttner Daniela 
Published: August 2013

ABSTRACT

The plant-pathogenic bacterium
Xanthomonas campestris
pv. vesicatoria employs a type III secretion (T3S) system to translocate bacterial effector proteins into eukaryotic host cells. The membrane-spanning secretion apparatus consists of 11 core components and several associated proteins with yet unknown functions. In this study, we analyzed the role of HrpB1, which was previously shown to be essential for T3S and the formation of the extracellular T3S pilus. We provide experimental evidence that HrpB1 localizes to the bacterial periplasm and binds to peptidoglycan, which is in agreement with its predicted structural similarity to the putative peptidoglycan-binding domain of the lytic transglycosylase Slt70 from
Escherichia coli
. Interaction studies revealed that HrpB1 forms protein complexes and binds to T3S system components, including the inner membrane protein HrcD, the secretin HrcC, the pilus protein HrpE, and the putative inner rod protein HrpB2. The analysis of deletion and point mutant derivatives of HrpB1 led to the identification of amino acid residues that contribute to the interaction of HrpB1 with itself and HrcD and/or to protein function. The finding that HrpB1 and HrpB2 colocalize to the periplasm and both interact with HrcD suggests that they are part of a periplasmic substructure of the T3S system.
Fecal Shedding of Zoonotic Food-Borne Pathogens by Wild Rodents in a Major Agricultural Region of the Central California Coast
Authors: Kilonzo Christopher , Li Xunde , Vivas Eduardo J. , Jay-Russell Michele T. , Fernandez Kristine L. , Atwill Edward R. 
Published: August 2013

ABSTRACTRecent outbreaks of food-borne illness associated with the consumption of produce have increased concern over wildlife reservoirs of food-borne pathogens. Wild rodents are ubiquitous, and those living close to agricultural farms may pose a food safety risk should they shed zoonotic microorganisms in their feces near or on agricultural commodities. Fecal samples from wild rodents trapped on 13 agricultural farms (9 produce, 3 cow-calf operations, and 1 beef cattle feedlot) in Monterey and San Benito Counties, CA, were screened to determine the prevalence and risk factors for shedding of several food-borne pathogens. Deer mice (Peromyscus maniculatus) were the most abundant rodent species trapped (72.5%).Cryptosporidiumspecies (26.0%) andGiardiaspecies (24.2%) were the predominant isolates from rodent feces, followed bySalmonella entericaserovars (2.9%) andEscherichia coliO157:H7 (0.2%). Rodent trap success was significantly associated with detection ofSalmonellain rodent feces, while farm type was associated with fecal shedding ofCryptosporidiumandGiardia. Seasonal shedding patterns were evident, with rodents trapped during the spring and summer months being significantly less likely to be sheddingCryptosporidiumoocysts than those trapped during autumn. Higher rodent species diversity tended to correlate with lower fecal microbial prevalence, and most spatiotemporal pathogen clusters involved deer mice. Rodents in the study area posed a minimal risk as environmental reservoirs ofE. coliO157:H7, but they may play a role in environmental dissemination ofSalmonellaand protozoa. Rodent control efforts that potentially reduce biodiversity may increase pathogen shedding, possibly through promotion of intraspecific microbial transmission.