bluuebunny/crossref_metadata_2025 huggingface dataset:
Polyarteritis Nodosa in Childhood: Recognition of Early Dermatologic Signs May Prevent Morbidity
Authors: Beckum Kathleen M. , Kim David J. , Kelly David R. , Weiser Peter , Lara Diego A. , Theos Amy
Published: August 2013

Systemic polyarteritis nodosa (PAN) is a vasculitis that affects small to medium‐size arteries. Onset in childhood is rare and can cause significant morbidity. Often, cutaneous manifestations can provide early clues toward diagnosis. This article describes a case of childhood systemic PAN that presented with fever, a necrotic skin lesion, and oral ulceration. Intestinal perforation complicated this case. Prompt recognition of childhood PAN is important to prevent serious complications.
Loose Anagen Hair Syndrome in Black‐Haired Indian Children
Authors: Dey Vivek , Thawani Manasi
Published: August 2013

Loose anagen hair syndrome (LAHS) is an uncommonly reported autosomal dominant hair disorder with incomplete penetrance that primarily affects children but is occasionally seen in adults. LAHS is characterized by the ability to easily and painlessly extract unsheathed anagen hairs from the scalp with gentle traction. The hair is sparse and does not grow long. Usually the hairs are not fragile and do not have areas of breakage. Initially it was considered a rare, sporadic condition found predominantly in young white girls with blonde hair. Because autosomal dominant inheritance has been reported, it was suspected that the condition might be equally common in boys but was probably underdiagnosed.
Growth and bone mineralization in small‐for‐gestational‐age preterm infants
Authors: Kitazawa Shigetaka , Itabashi Kazuo , Umeda You , Inoue Makoto , Nishioka Takashi
Published: August 2013

Background

Preterm infants are at risk for metabolic bone disease and suboptimal growth. This study examined the hypothesis that, apart from prematurity, intrauterine growth status (expressed as gestational age‐specific birthweight standard deviation score) influences bone mineralization and body composition in early infancy.

Methods

In this retrospective study, the groups consisted of preterm small‐for‐gestational‐age (SGA) infants (n = 18; SGA group) and preterm appropriate‐for‐gestational‐age (AGA) infants (n = 24; AGA group). Postnatal bone mineralization was measured at term‐adjusted age (postmenstrual age, 37–42 weeks). Bone mineral content (BMC) and body composition were determined on dual‐energy X‐ray absorptiometry of the whole body.

Results

BMC and lean mass were significantly lower in the SGA group than in the AGA group at term‐adjusted age (37–42 weeks postmenstrual age). Stepwise regression analysis identified weight at examination as the most significant factor, accounting for 51% of the variance in BMC.

Conclusion

Bodyweight at term‐adjusted age, rather than intrauterine growth, may affect postnatal bone mineralization in preterm low‐birthweight infants. Therefore, promoting an increase in body size might increase postnatal bone mineralization in preterm SGA infants.
Diagnostic markers of serious bacterial infections in febrile infants younger than 90 days old
Authors: Nosrati Adi , Ben Tov Amir , Reif Shimon
Published: August 2013

Background

The aim of this study was to assess correlations between demographic, clinical and laboratory characteristics and the risk of serious bacterial infection (SBI) in febrile <90‐day‐old infants.

Methods

Medical records of all infants younger than 90 days old hospitalized at Dana‐Dwek Children's Hospital (2006–2008) for evaluation of fever were retrospectively reviewed. Data on clinical, laboratory and demographic characteristics were retrieved and evaluated.

Results

Forty‐eight of the 401 study infants (12%) had SBI: most of them had urinary tract infection (43 infants; 90% of all SBI), three infants had bacteremia, one had bacterial pneumonia and one had bacterial meningitis. Significant independent clinical predictors for the diagnosis of SBI included duration of fever, absence of rhinitis and the absence of lung and skin manifestations. Significant independent laboratory predictors were absolute neutrophil count (ANC), platelets, blood urea nitrogen and C‐reactive protein (CRP) level. On receiver operating characteristic curve analysis, the CRP area under the curve (0.819) was significantly superior to ANC and leukocyte count.

Conclusion

Of the clinical and laboratory variables selected for evaluation, qualitative CRP was the strongest independent predictor for diagnosing SBI and a significantly better diagnostic marker than clinical characteristics, ANC and white blood cell count.
Evaluation of non‐surgical causes of cardiac tamponade in children at a cardiac surgery center
Authors: Ozturk Erkut , Tanidir Ibrahim Cansaran , Saygi Murat , Ergul Yakup , Guzeltas Alper , Odemis Ender
Published: August 2013

Background

The aim of this study was to examine the causes of cardiac tamponade in children undergoing percutaneous pericardiocentesis.

Method

Patients who presented with other complaints but were diagnosed with cardiac tamponade based on clinical and echocardiographic findings between January 2010 and January 2013 were retrospectively investigated. Electrocardiography, telecardiography and transthoracic echocardiography were performed. Pericardiocentesis was performed percutaneously under continuous blood pressure and rhythm monitoring with echocardiography and fluoroscopy. Pericardial fluid was analyzed on hemography and biochemistry.

Results

Fourteen patients (six boys, eight girls; median age, 7 years) underwent pericardiocentesis for cardiac tamponade. At presentation, 78% had dyspnea, 56% chest pain, and 49% fever. All had cardiomegaly, and their cardiothoracic index was 0.56–0.72. Also, all patients had sinus tachycardia; 78%, low QRS voltage; 70%, ST‐T changes; and 50% QRS alternans. On echocardiography the widest diameter of pericardial effusion was between 12 mm and 36 mm depth around the heart. The pericardial fluid was purulent in one, serohemorrhagic in seven, serofibrinous in two, and serous in four cases. Pericardiocentesis was unsuccessful in two patients, who underwent open surgical drainage, with no complications. Based on pericardial fluid characteristics and additional tests, cardiac tamponade was caused by an infection in five patients, hypothyroidism in two, familial Mediterranean fever in two, malignancy in one, acute rheumatic fever in one, collagen tissue disease (systemic lupus erythematosus) in one, catheter placement‐associated damage in one, and idiopathic pulmonary arterial hypertension in one patient.

Conclusion

Pericardial effusion and cardiac tamponade in children have varied causes, and early treatment is life saving.
Integration of ultrasound findings with Alvarado score in children with suspected appendicitis
Authors: Toprak Huseyin , Kilincaslan Huseyin , Ahmad Issam Cheikh , Yildiz Seyma , Bilgin Mehmet , Sharifov Rasul , Acar Murat
Published: August 2013

Background

The aim of this study was to investigate the integration of ultrasound (US) findings with Alvarado score in diagnosing or excluding acute appendicitis.

Methods

Data were analyzed in 122 pediatric patients with suspected appendicitis who had undergone US. The US findings were classified into four groups, and the patients were classified into three groups according to Alvarado score. US results and Alvarado score were compared.

Results

Alvarado score was a good predictor of appendicitis for scores ≥7.

Conclusion

In the case of non‐visualization of the appendix without a high Alvarado score, appendicitis can be safely ruled out.
How to increase quality of care during coercive admission? A review of literature
Authors: van den Hooff Susanne , Goossensen Anne
Published: August 2013

Background

Involuntary admission is still raising in numbers and as a procedure a widely discussed subject from ethical point of view. A common dilemma is the tension between individual freedom and the need to protect the patient. Patients who are coerced during the admission process often report negative feelings or trauma. Finding out quality issues remains a challenge for providing good care during coercive admission.

Aim

This study aims to explore themes from patients' and professionals' perspectives within scientific literature on involuntary admission.

Methods

A literature review of English articles using Academic Search Elite, Cinahl, Medline, PubMed and Social Science Journals for the period 1995–2012 was conducted. Additional studies were identified using the National Centre for Biotechnology Information (NCBI). Search terms included involuntary, hospitalisation, ethical, admission, nursing home, coercion and factor. Finally, twenty‐two articles were included and analysed out of 1216.

Results and conclusion

Articles were divided between those describing themes from patients' perspective and articles describing themes from professionals' perspective. Findings show that most experiences of patients can be traced back to one core experience: not being listened to or listened to. When patients experience being listened to genuinely, they feel more respected as a human being. The challenge for the professional carer seems to explicitly pay attention and stay in touch with the patients' emotional struggles while making the necessarily decision to admit the patient to prevent harm. Quality of care during coercive admission improves when professionals are able to do justice to both inside and outside perspectives simultaneously.
Deconvolution Estimation of Onset of Pregnancy with Replicate Observations
Authors: Comte Fabienne , Samson Adeline , Stirnemann Julien J
Published: August 2013

In general, the precise date of onset of pregnancy is unknown and may only be estimated from ultrasound biometric measurements of the embryo. We want to estimate the density of the random variables corresponding to the interval between last menstrual period and true onset of pregnancy. The observations correspond to the variables of interest up to an additive noise. We suggest an estimation procedure based on deconvolution. It requires the knowledge of the density of the noise which is not available. But we have at our disposal another specific sample with replicate observations for twin pregnancies. This allows both to estimate the noise density and to improve the deconvolution step. Convergence rates of the final estimator are studied and compared with other settings. Our estimator involves a cut‐off parameter for which we propose a cross‐validation type procedure. Lastly, we estimate the target density in spontaneous pregnancies with an estimation of the noise obtained from replicate observations in twin pregnancies.
Socio‐economic determinants of HIV testing and counselling: a comparative study in four African countries
Authors: Obermeyer Carla Makhlouf , Neuman Melissa , Hardon Anita , Desclaux Alice , Wanyenze Rhoda , Ky‐Zerbo Odette , Cherutich Peter , Namakhoma Ireen
Published: August 2013

Objectives

Research indicates that individuals tested for HIV have higher socio‐economic status than those not tested, but less is known about how socio‐economic status is associated with modes of testing. We compared individuals tested through provider‐initiated testing and counselling (PITC), those tested through voluntary counselling and testing (VCT) and those never tested.

Methods

Cross‐sectional surveys were conducted at health facilities in Burkina Faso, Kenya, Malawi and Uganda, as part of the Multi‐country African Testing and Counselling for HIV (MATCH) study. A total of 3659 clients were asked about testing status, type of facility of most recent test and socio‐economic status. Two outcome measures were analysed: ever tested for HIV and mode of testing. We compared VCT at stand‐alone facilities and PITC, which includes integrated facilities where testing is provided with medical care, and prevention of mother‐to‐child transmission (PMTCT) facilities. The determinants of ever testing and of using a particular mode of testing were analysed using modified Poisson regression and multinomial logistic analyses.

Results

Higher socio‐economic status was associated with the likelihood of testing at VCT rather than other facilities or not testing. There were no significant differences in socio‐economic characteristics between those tested through PITC (integrated and PMTCT facilities) and those not tested.

Conclusions

Provider‐initiated modes of testing make testing accessible to individuals from lower socio‐economic groups to a greater extent than traditional VCT. Expanding testing through PMTCT reduces socio‐economic obstacles, especially for women. Continued efforts are needed to encourage testing and counselling among men and the less affluent.
Estimation of content of anti‐TB drugs supplied at centres of the Revised National TB Control Programme in Tamil Nadu, India
Authors: Ramachandran Geetha , Chandrasekaran Vedachalam , Hemanth Kumar Agibothu Kupparam , Dewan Puneet , Swaminathan Soumya , Thomas Aleyamma
Published: August 2013

Objective

To determine the content of certain antituberculosis (TB) drugs supplied at TB treatment centres of the Revised National TB Control Programme (RNTCP) in the state of Tamil Nadu, India.

Methods

Eight districts across the state were selected, and the following drugs were collected from five settings (District TB centre, TB unit, designated microscopy centres, DOT providers) in each district: rifampicin (150 and 450 mg), isoniazid (300 mg), pyrazinamide (500 and 750 mg), ethambutol (400 and 600 mg), ethionamide (250 mg), levofloxacin (500 mg) and cycloserine (250 mg). A maximum of 10 tablets/capsules were collected from each setting. The drugs were coded prior to analysis. All drugs were assayed by validated spectrophotometric methods. The acceptable limits for drug content were taken as 90–110% of the stated content.

Results

More than 90% of tablets of rifampicin 450 mg, isoniazid 300 mg, pyrazinamide 500 and 750 mg, ethambutol 400 and 600 mg and ethionamide 250 mg were within acceptable limits. Eighty per cent of rifampicin 150 mg, 21% of cycloserine 250 mg and 87% of levofloxacin 500 mg were within acceptable limits. The mean cycloserine content was below the acceptable limit in all districts, the mean drug content being 200 mg (range: 108–245 mg).

Conclusion

This systematic study showed that the stated drug content of cycloserine was not reached in all districts. Deterioration of cycloserine could be minimised by storing the drug in refrigerators. The geographical location of the districts had no influence on the drug content.
Type III hypersensitivity reaction with immune complex deposition in 2 critically ill dogs administered human serum albumin
Authors: Powell Cassandra , Thompson Lisa , Murtaugh Robert J.
Published: August 2013

Objective

To describe 2 cases of vasculitis that were attributed to a type III hypersensitivity reaction in critically ill dogs occurring 8–16 days postadministration of human serum albumin (HSA).

Case or Series Summary

Skin biopsies were obtained from 3 different sites in 2 critically ill dogs that developed vasculitis 8–16 days following treatment with HSA. Histopathological findings from both dogs indicated epidermal pallor, widespread edema and hemorrhage, degenerative neutrophilic perivascular infiltrates, and multifocal areas of neutrophilic or leukocytoclastic vasculitis. Immunohistochemical staining using an anti‐human serum albumin rabbit antibody suggested that the antigen‐antibody complexes seen in the dermis were associated with the administration of HSA.

New or Unique Information Provided

In this case series, we documented a leukocytoclastic vasculitis and probable antigen‐antibody complexes to human albumin in the dermis of 2 critically ill dogs after administration of HSA. Previously, type III hypersensitivity reactions had only been reported in healthy dogs that had received HSA. This report also describes the potential use of immunohistochemical staining to detect the HSA antigen in tissue sections through the use of specifically labeled antibodies.
Modulation of synaptic depression of the calyx of Held synapse by GABAB receptors and spontaneous activity
Authors: Wang Tiantian , Rusu Silviu I. , Hruskova Bohdana , Turecek Rostislav , Borst J. Gerard G.
Published: August 2013

Key points

Spontaneous activity contributes to low synaptic depression of the calyx of Held synapse in vivo.

Application of a reversible blocker in combination with juxtacellular recordings allows a relatively good estimate of local drug concentrations reached during microiontophoresis.

Activation of the GABAB receptor on the young‐adult calyx of Held can reduce short‐term depression, both in vivo and in slices.

The ambient concentration of GABA in the auditory brainstem is low.

Abstract  The calyx of Held synapse of the medial nucleus of the trapezoid body is a giant axosomatic synapse in the auditory brainstem, which acts as a relay synapse showing little dependence of its synaptic strength on firing frequency. The main mechanism that is responsible for its resistance to synaptic depression is its large number of release sites with low release probability. Here, we investigated the contribution of presynaptic GABAB receptors and spontaneous activity to release probability both in vivo and in vitro in young‐adult mice. Maximal activation of presynaptic GABAB receptors by baclofen reduced synaptic output by about 45% in whole‐cell voltage clamp slice recordings, which was accompanied by a reduction in short‐term depression. A similar reduction in transmission was observed when baclofen was applied in vivo by microiontophoresis during juxtacellular recordings using piggyback electrodes. No significant change in synaptic transmission was observed during application of the GABAB receptor antagonist CGP54626 both during in vivo and slice recordings, suggesting a low ambient GABA concentration. Interestingly, we observed that synapses with a high spontaneous frequency showed almost no synaptic depression during auditory stimulation, whereas synapses with a low spontaneous frequency did depress during noise bursts. Our data thus suggest that spontaneous firing can tonically reduce release probability in vivo. In addition, our data show that the ambient GABA concentration in the auditory brainstem is too low to activate the GABAB receptor at the calyx of Held significantly, but that activation of GABAB receptors can reduce sound‐evoked synaptic depression.
Study on the Formability of Magnesium Alloy Parts Under Hot Forging Process
Authors: Hsiang Su-Hai , Hong Yi-Cheng , Ho Huey-Lin , Yang Shiuh-Kuang
Published: August 2013

This study investigates the formability of AZ31 and AZ61 magnesium alloy for bicycle parts under hot forging process. Firstly, finite element software DEFORM is applied to simulate the deformation behaviors of magnesium alloys bicycle parts under different process parameters. The process parameters considered in the simulation are materials heating temperatures, lubricants and punch speeds. Changes in process parameters, the forging loads and the completeness of filling of material in die cavity are discussed. The optimal forging condition can be obtained from evaluation of the completeness of filling of material in die cavity, forging load and distribution of stress and strain. The experimental conditions are set according to the optimal simulation results. Hot forging experiments are carried out under the condition of heating range from 240°C to 350°C, different kind of lubricants, constant punch speeds 0.9mm/s to study the formability of magnesium alloy for bicycle parts. The experimental results are compare with the DEFORM simulation results. The obtained forging loads and completeness of filling are in good agreement with the simulation results. The validity of the simulation model established in this study can be confirmed. Finally, from the measured result of hardness and metallographic observation of forged part, the influence of forging temperatures on the strength and microstructures of magnesium alloy for bicycle parts under forging process can be evaluated.
Numerical Implementation of Higher-Order Homogenization Problems and Computation of Gradient Elasticity Coefficients
Authors: Monchiet V. , Tran T. H. , Bonnet G.
Published: August 2013

A micromechanics-based approach for the derivation of the effective properties of periodic linear elastic composites which exhibit strain gradient effects at the macroscopic level is presented. At the local scale, all phases of the composite obey the classic equations of tridimensional elasticity, but, since the assumption of strict separation of scale is not verified, the macroscopic behavior is described by the equations of strain gradient elasticity. The methodology uses the series expansions at the local scale, for which, higher-order terms (which are generally neglected in standard homogenization framework) are kept, in order to take into account the microstructural effects. All these terms are then obtained by solving a hierarchy of higher-order elasticity problems with prescribed body forces and eigen-strains whose expression depends on the solution at the lower-order. An energy based micro-macro transition is then proposed for the change of scale and constitutes, in fact, a generalization of the Hill-Mandel lemma to the case of higher-order homogenization problems. The constitutive relations and the definitions for higher-order elasticity tensors are retrieved by means of the “state law” associated to the derived macroscopic potential. It is rigorously proved that the macroscopic quantities derived from this homogenization procedure comply with the equations of strain gradient elasticity. As an illustration, we derive the closed-form expressions for the components of the gradient elasticity tensors in the particular case of a stratified periodic composite. For handling the problems with an arbitrary microstructure, a FFT-based computational iterative scheme is proposed whose efficiency is shown in the particular case of composites reinforced by long fibers.
Development of a Tilt Sensor Data Glove to Wirelessly Control a Multi-Fingered Robotic Hand
Authors: Laimon Hamzah N.
Published: August 2013

Electronic gloves are one of the most common methods used as human hand input devices. They proved to be useful in various applications such virtual reality, sign language interpretation and robotic systems. However, many of these electronic gloves tend to be either economically or computationally expensive. In contrast, this article discusses the development of a data glove that is practical and cost efficient with wireless control capabilities. It is based on placing tri-axial tilt accelerometers on the glove to map the movement of human fingers. All data acquired from the glove is transmitted wirelessly via Bluetooth connection to a computer where it can be used for various applications. The glove was used to control a five-motor tendon driven robotic hand. Tests were carried out to correlate tilt angles acquired from the glove with the appropriate motor values that will move the robotic fingers to the same position as that of the glove fingers. As a result, the robotic hand was able to mimic each human hand finger and thereby perform sign and grasp movements.
Methodology Applied to Integrate a Viscosity Model for Liquid Composites Molding Simulation in PAM-RTM®
Authors: Skordos Alex A. , Kergomard Yann Duplessis , Marquette Pierre , De Luca Patrick
Published: August 2013

This work was performed in the frame of the european project INFUCOMP. This paper focuses on the development of a viscosity model for the epoxy systems Hexcel RTM6 and Cycom 890RTM, and the associated experimental data sets. A new modelling approach was developed based on the use of reference viscosity as a state variable instead of the conventionally used degree of cure. The new approach focuses on the time-temperature window of infusion processes, thus yielding higher accuracy results and a more efficient representation of rheological behaviour. Furthermore, the model can be integrated analytically under isothermal conditions, which carries advantages with regard to both parameter estimation and implementation within the context of process simulation. The model was then implemented in PAM-RTM simulation software. To do so, not only the aging of the resin had to be taken into account, but also the transport of this information with the flow. Last verification simulation tests were performed with LCM simulations.
Toward the Use of Pareto Performance Solutions and Pareto Robustness Solutions for Multi-Objective Robust Optimization Problems
Authors: Wang Weijun , Caro Stéphane , Bennis Fouad , Augusto Oscar Brito
Published: August 2013

For Multi-Objective Robust Optimization Problem (MOROP), it is important to obtain design solutions that are both optimal and robust. To find these solutions, usually, the designer need to set a threshold of the variation of Performance Functions (PFs) before optimization, or add the effects of uncertainties on the original PFs to generate a new Pareto robust front. In this paper, we divide a MOROP into two Multi-Objective Optimization Problems (MOOPs). One is the original MOOP, another one is that we take the Robustness Functions (RFs), robust counterparts of the original PFs, as optimization objectives. After solving these two MOOPs separately, two sets of solutions come out, namely the Pareto Performance Solutions (PP) and the Pareto Robustness Solutions (PR). Make a further development on these two sets, we can get two types of solutions, namely the Pareto Robustness Solutions among the Pareto Performance Solutions (PR(PP)), and the Pareto Performance Solutions among the Pareto Robustness Solutions (PP(PR)). Further more, the intersection of PR(PP) and PP(PR) can represent the intersection of PR and PP well. Then the designer can choose good solutions by comparing the results of PR(PP) and PP(PR). Thanks to this method, we can find out the optimal and robust solutions without setting the threshold of the variation of PFs nor losing the initial Pareto front. Finally, an illustrative example highlights the contributions of the paper.
Planning Continuous-Jerk Trajectories for Industrial Manipulators
Authors: Boscariol Paolo , Gasparetto Alessandro , Vidoni Renato
Published: August 2013

Planning smooth trajectories is crucial in the most advanced robotic applications in industrial environments. In this paper two novel trajectory planning methods for robotic manipulators are introduced, named “545” and “5455”. Both methods are based on an interpolation of a sequence of via points using a combination of 4th and 5th order polynomial functions. These techniques allow to obtain a continuous-jerk trajectory for improved smoothness and minimum excitation of vibration. By using the “545” method, null jerk at initial time can be achieved, while with the “5455” method one can impose an arbitrary value of jerk at both the first and the last via-point. The outcome of both methods is the optimal time distribution of the via points, with respect to a predefined objective function. Results are provided for a 3 d.o.f. Cartesian manipulator, but the techniques may be applied to any industrial robot.
Method of Assessment of Casting Accuracy and Minimization of Machining Allowances
Authors: Gessner Andrzej , Staniek Roman
Published: August 2013

The publication demonstrates an accuracy assessment method for machine tool body casting utilizing an optical scanner and a reference design of the machine tool body. The process allows assessing the casting shape accuracy, as well as determining whether the size of the allowances of all work surfaces is sufficient for appropriate machining, corresponding to the construction design. The described method allows dispensing with the arduous manual operation - marking out. Marking out, depending on the size and complexity, might take several working shifts for prototype casting. In case of large and elaborate casts, as those of machine tool bodies, marking out is often restricted only to the first cast of the desired body produced in a given casting mold. Such course of action is based on an assumption that casting is reproducible; hence, no need to assess each and every individual cast. While this approach saves time, it often results in late detection of casting errors (allowance shifts or insufficiencies) during the actual machining process. That, in turn, results in considerable losses due to the disruption of the work process and often demands cast repair. The aim of the hereby presented study is to introduce a new technological premise dispensing with manual marking out as well as allowing fast verification of the cast shapes.
Design and Implementation of a Simulator for 3D Flexible-Link Serial Robots
Authors: Boscariol P. , Gasparetto A. , Giovagnoni M. , Moosavi A. K. , Vidoni R.
Published: August 2013

In this paper, an effective method in dynamic modeling of spatial flexible-link robots under large displacements and small deformations is discussed and a generic Matlab™ software simulator based on it is presented and validated. The adopted method is based on an Equivalent Rigid Link System (ERLS) that enables to decouple the kinematic equations of the ERLS from the compatibility equations of the displacements at the joints allowing an easy and recursive procedure to build the robot dynamic matrices.

The simulator is suitable for dynamic modelling of generic 3D serial flexible-link robots. The Matlab™ software simulator is validated with respect to the Adams-Flex™ commercial software, which implements Floating Frame of Reference (FFR) formulation, one of the most used methods for dynamic modeling of multibody flexible-link mechanisms with large displacements and small deformations.
Theoretical Foundations Supporting the Implementation of Complementary Information Structures Across the Life of a Product
Authors: Huet Greg , Fortin Clément , Zeng Yong
Published: August 2013

This paper presents a formalization of the complementary information structures approach, which was originally derived from the practical implementation of a Manufacturing Process Management solution. The Environment-based Design methodology has been chosen to generalize the Manufacturing Process Management experience and the resulting theoretical foundations are then used to propose a complementary information framework between customer needs and product descriptions. The definition of the relationships between the structures is derived from the “customer job mapping” approach used in Outcome Driven Innovation marketing techniques.
A Comprehensive Framework for Skin Model Simulation
Authors: Schleich Benjamin , Walter Michael , Wartzack Sandro , Anwer Nabil , Mathieu Luc
Published: August 2013

The need for geometrical variations management is an important issue in design, manufacturing and all other phases of product development. Two main axioms cover geometrical variations, namely the axiom of manufacturing imprecision and the axiom of measurement uncertainty. Therefore, this paper reviews common models for the description of non-ideal geometry (shape with geometric deviations) and shows how the random field theory can be applied to create more realistic skin models (a model which comprises these geometric deviations).

Furthermore, methods to estimate and to express the underlying random field from a sample population are shown. These can be used to create and simulate random shapes considering systematic and random deviations observed through measurement or gathered from manufacturing process simulations.

The proposed approach incorporates given information from manufacturing process simulations or prototypes. Based on these information, skin model samples are created which can represent the “realistic” part in assembly simulations or other geometrical analyses. This can help to identify the optimal tolerance sets within every stage of the product development process. The efficiency of the introduced approaches is shown in a case study.
Satisfying Piping Stress and Flexibility Requirements With the Implementation of Expansion Joints: Techno-Economical Optimization
Authors: Jocic Misa
Published: August 2013

There have been various attempts to deal with the optimization of solutions which involve expansion joints in piping systems where sufficient flexibility can’t be found using suitable pipe routing.

The difficulty of piping designs which involve expansion joints is that they rely upon two engineering expertises: Pipe Flexibility and Stress Analysis on one side and Expansion Joint Design and Construction on the other. Arguably distinctively different, they have been looked upon as totally detached engineering disciplines and it is rarely that companies have two of these experts residing under the same roof. Pipe Stress Engineers basically relied on support form Expansion Joint Experts on “as required basis” and called upon their knowledge only when needed. Thus, we have the situation where knowledge related to the design and construction of expansion joints sits with expansion joints manufacturing companies, which are totally separate and often remote entities in the piping design process.

Even so, the ever present demand for techno-economical optimizations, points us to the following observations.

The “Traditional method”, where Pipe Stress Engineer defines on his own the requirements for expansion joints and describes them in the technical specification for purchasing is, or should be, a theme of the past.

This approach may be used only as a first attempt in search for the solution, but given that it never heads in the direction of achieving optimal techno-economical results, needs to be upgraded with additional steps.
Stability of Manipulator Configuration Under External Loading
Authors: Klimchik Alexandr , Pashkevich Anatol , Chablat Damien
Published: August 2013

The paper is devoted to the analysis of robotic manipulator behavior under internal and external loadings. The main contributions are in the area of stability analysis of manipulator configurations corresponding to the loaded static equilibrium. In contrast to other works, in addition to usually studied the end-platform behavior with respect to the disturbance forces, the problem of configuration stability for each kinematic chain is considered. The proposed approach extends the classical notion of the stability for the static equilibrium configuration that is completely defined the properties of the Cartesian stiffness matrix only. The advantages and practical significance of the proposed approach are illustrated by several examples that deal with serial kinematic chains and parallel manipulators. It is shown that under the loading the manipulator workspace may include some specific points that are referred to as elastostatic singularities where the chain configurations become unstable.
Experimental Analysis of Viscoelastic Properties of High Density Polyethylene (PE100)
Authors: Celikkan Ozan , Palabiyik I. Mehmet , Gemici Zafer , Gökgöz Isminur
Published: August 2013

A High-density polyethylene has been used for buried plastic pipe production for over a decade. The structural performance of these pipes mainly depends on the viscoelastic properties of using materials. The aim of this study is to determine the creep behavior of PE100 material under constant tensile and flexural stress within 24 hours. In both tests, large deformation occurs within the first 1000 seconds and then very little or no deformation is observed. Primary and secondary creep stages have also been observed. At highest stress level, maximum strain is 5%, approximately.

At the flexural creep experiments, modulus of the material has been obtained from total deflection value at the end of 24 hours by using three point bending experiment under constant load. Large deflection occurs within in first 1000 seconds, after that, continues to increase slowly. Maximum strain is about 2%. The material exhibits linear viscoelastic response to 8 MPa stress level.
A Macroscopic Model of the Thermo-Chemo-Mechanical Behaviour of Mixed Ionic and Electronic Conductors
Authors: Valentin O. , Gazeau C. , Blond E. , Geffroy P. M. , Richet N.
Published: August 2013

This paper suggests a macroscopic model describing the thermo-chemo-mechanical behaviour of ceramic dense membrane for oxygen separation application. This work takes in account to oxygen permeation and strain induced by stoichiometry variation with working conditions. This model, developed within the traditional framework of phenomenological approach, is based on the assumption of strain partitions and requires only three state variables: oxygen activity, temperature and total strain. Oxygen bulk diffusion and surface exchanges are described thanks to the thermodynamic approach developed by Onsager. While many works focused on semi-permeation induced strain, the proposed model also includes the temperature effect on chemical expansion. Strains predicted by the proposed model are validated thanks to experimental test on La0.8Sr0.2Fe0.7Ga0.3O3−δ. Implemented in F.E.A code Abaqus, this model permits studying the design and the process management effects such as chemical shocks on the membrane reliability.
Design and Optimization for a Cardiac Active Stabilizer Based on Planar Parallel Compliant Mechanisms
Authors: Rubbert L. , Renaud P. , Gangloff J.
Published: August 2013

Giving assistance to surgeons during beating heart procedures is currently a great challenge in medical robotics: a high level of safety is required while the beating heart yields high forces and dynamics. In this article, we investigate the design of an active cardiac stabilizer that will provide a motionless area of interest during the surgery. A device architecture is introduced that is based on planar parallel mechanisms. Such mechanisms are particularly interesting for their manufacturing simplicity and compactness. With the considered architecture, spherical compliant joints based on a planar structure need to be designed. Here we present the use of a 3-RRR spherical parallel mechanism. Its kinematic and stiffness analysis are performed using pseudo-rigid body modeling. An optimization of the mechanism is then achieved, using a modified ant colony optimization technique. The achievable performance of this type of compliant spherical joint is then discussed before concluding on the device adequacy with respect to the surgical requirements.
Uncertainty Model for Systems Based on Wireless Sensor Networks for Large Scale Dimensional Metrology
Authors: Franceschini Fiorenzo , Galetto Maurizio , Maisano Domenico , Mastrogiacomo Luca
Published: August 2013

Verification of dimensional compliance is becoming a crucial aspect in every kind of production, even when the size of the product to be checked is in the order of several meters. To this purpose, several tools based on different technologies, working principles, functionalities and architectures have been recently designed. Among these, a distributed flexible system based on a network of low cost infrared (IR) cameras — the Mobile Spatial coordinate Measuring System (MScMS) — has been developed. This paper proposes a model for the real time assessment of the system uncertainty referring to the measured point coordinates in the 3D space. The paper focuses on the sources of measurement uncertainty and, basing on the multivariate law of propagation of uncertainty, suggests a model for relating them to the uncertainty of a measured point.
Applications for a New Production Technology: Analysis of Linear Flow-Split Linear Guides
Authors: Karin Ivan , Lommatzsch Nils , Lipp Klaus , Landersheim Volker , Hanselka Holger , Bohn Andrea
Published: August 2013

Within the collaborative research centre 666 “Integral Sheet Metal Design with Higher Order Bifurcations” the innovative manufacturing technologies linear flow-splitting and linear bend-splitting are researched that allow the continuous production of multi-chambered steel profiles in integral style. The massive forming processes create an ultra-fine grained microstructure in the forming area that is characterized by an increased hardness and lower surface roughness compared to as received material. These properties predestine the technology to be used in the production of linear guides. Additionally, the multi-chambered structure of the linear flow-split and -bend components can be used for function integration. To design and evaluate linear guides that use the whole technological potential, the research is focused on a macroscopic and a microscopic point of view.

The macroscopic approach is targeting the development of linear flow-split linear guides with integrated functions to provide additional performance values to the established machine parts. Continuously produced guidance systems with innovative functionality can be introduced to a new market with the technology push approach. Preliminary designs of linear flow-split guidance systems and integrated functions are promising. Therefore, an approach to develop new functions for linear flow-split linear guides basing on calculation models and property networks is shown [1]. With this approach, optimized solutions can be created and possible design modifications can be derived. In this contribution, the development and integration of a clamping function for decelerating the slide is presented. Calculation models for analyzing the functionality are presented and validated by finite element models and experiments.

The microscopic examination of the profiles aims to investigate the material behavior, particularly of the formed areas. Beside the conventional mechanical and fatigue properties of linear flow-split material ZStE500 [2], the present work focuses on the rolling contact fatigue. This is necessary to evaluate linear flow-split components regarding their eligibility with regard to the rolling contact fatigue behaviour. The Hertz theory for rolling contact fatigue is only valid for homogeneous materials [3]. The flow-split material ZStE500 shows a non-homogeneous behaviour and has to be analyzed with the Finite Element Method in order to determine stresses and strains. In comparison to simulation results with unformed and therefore homogeneous material, the effect of linear flow-split surfaces on the rolling contact behavior is demonstrated. Based on these results, it is possible to start experimental investigations on rolling contact fatigue of linear flow-split components to validate the FE model and determine the performance of linear flow-split flanges for rolling contact fatigue.
Complementary Use of BG and EMR Formalisms for Multiphysics Systems Analysis and Control
Authors: Chikhaoui Zeineb , Gomand Julien , Malburet François , Barre Pierre-Jean
Published: August 2013

In this paper, a complex multiphysics system is modeled using two different energy-based graphical techniques: Bond Graph and Energetic Macroscopic Representation. These formalisms can be used together to analyze, model and control a system. The BG is used to support physical, lumped-parameter modeling and analysis processes, and then EMR is used to facilitate definition of a control structure through inversion-based methodology. This complementarity between both of these tools is set out through a helicopter flight control subsystem.
State of the Art in the Eco-Design Field: Toward Specifications for the Integration of Eco-Design in the Automotive Sector
Authors: Garcia Julien , Millet Dominique , Tonnelier Pierre
Published: August 2013

This paper lies within the integration of an eco-design method adapted to the Innovation structure at a car manufacturer. The environmental constraints in the automotive industry are more and more important (European emission standards for exhaust emissions, European directive on end-of life vehicles …). Eco-design is a new manner to design products related to the concept of sustainable development, which combines economy and ecology and put the environmental criterion alongside the classical criterions of design. The goal of this study is to identify the specifications of a strategy for integrating the dimension “Environment”. This strategy is applied in the innovation process thanks to eco-design tools which are the learning vectors for an organization, and therefore support a learning process. This process is structured with the interactions between the management of firm, the environment department, and the design team. Therefore we first make a synthesis of the different classifications of eco-design tools and use two categories: diagnosis and improvement. Second, as our goal is the integration in the Innovation structure and within a design process, we analyze some design process models and highlight the RID (Research, Innovation structure, Development) concept. Third, the main practices of several car makers are synthetized and a focus on three of them (Volvo, Ford, and Volkswagen) is made; we link their strategies with the concept of RID. Finally in the fourth part, we propose a model of a strategy for integrating eco-design practices based on the three examples and supported by a learning process.
Model-Based Design of Mechatronic Systems by Means of Semantic Web Ontologies and Reusable Solution Elements
Authors: Oestersötebier Felix , Just Viktor , Trächtler Ansgar , Bauer Frank , Dziwok Stefan
Published: August 2013

When designing complex mechatronic systems, a team of developers will be facing many challenges that can impede progress and innovation if not tackled properly. In meeting them simulation tools play a central role. Yet it is often impossible for a single developer to foresee the overall impact a design decision will have on the system and on the other domains involved. For this task multi-domain simulation tools exists, but because of its complexity and the different levels of detail that are needed, the effort to specify a complete system from scratch is very high. Another challenge is the selection of the most suitable solution elements provided by the manufacturers. Currently they are often chosen manually from catalogues. The development engineer is therefore usually inclined to employ well-known solution elements and suppliers. To tackle both challenges our aim is an increase in efficiency and innovation by means of generally available solution knowledge, such as well-proven solution patterns, ready-to-use solution elements, and established simulation models [1].

Our paper presents a tool-supported, sequential design process. From the outset, the comprehensive functional capability of the designed system is supervised by means of multi-domain simulation. At significant points in the design process, solution knowledge can be accessed as it is stored in ontologies and therefore available via Semantic Web [2]. Thus, one can overcome barriers resulting from different terminologies or referential systems and furthermore infer further knowledge from the stored knowledge. The paper focuses on an early testing in the conceptual design stage and on the subsequent semantic search for suitable solution elements. After the specification of a principle solution for the mechatronic system by combining solution patterns, an initial multi-domain model of the system is created. This is done on the basis of the active structure and of idealized simulation models which are part of a free library and associated with the chosen solution patterns via the ontologies. In further designing the controlled system and its parameters with the completed model, the developer defines additional criteria to be fed into the subsequent semantic search for solution elements. Information on the latter is provided by the manufacturers as well as detailed simulation models, which are used to analyze the functional capability of the concretized system. Therefore, the corresponding idealized models are replaced automatically with the parameterized models of the solution elements containing for example the specific friction model for the chosen motor. We show this process using the concrete example of a dough-production system. In particular, we focus on its transport system. Resulting requirements for the simulation models and their level of detail are expound, as well as the architecture and benefits of the ontologies.