bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of two new blood group systems, Langereis (LAN) and Junior (JR)
Authors: Arnaud L.
Published: June 2012

Background  The high‐prevalence erythrocyte blood group antigens Lan and Jra were first reported in 1962 and 1970 respectively. While both anti‐Lan and anti‐Jra can cause acute transfusion reactions, anti‐Jra is of particular concern in obstetrics as it can cause fatal hemolytic disease of the fetus and the newborn (HDFN). The biochemical and genetic bases of Jra and Lan have not yet been elucidated despite the isolation of two hybridoma secreting human monoclonal antibodies specific for Jra (HMR0921) and Lan (OSK43).

Results  Using the OSK43 antibody, we were able to immunoprecipitate a single protein from the erythrocytes of a random (Lan+) blood donor. This protein was identified by mass spectrometry as ABCB6, a member of the ATP binding cassette (ABC) transporter family. In order to validate ABCB6 as a novel genetic locus encoding blood group antigens, we first confirmed by immunoblot analysis that ABCB6 was present in the membrane of Lan+ erythrocytes. In contrast, we detected no ABCB6 products in Lan− erythrocytes, suggesting that null alleles of ABCB6 may be responsible for the Lan− phenotype. We then established K‐562 cells stably transfected with a construct encoding ABCB6 and showed that exogenous expression of ABCB6 correlated with cell surface expression of the Lan antigen. Targeted sequencing of ABCB6 in 12 unrelated Lan− individuals identified 10 different null mutations. All these Lan− individuals were either homozygous for a single null mutation or heterozygous for two null mutations in ABCB6, confirming that null alleles of ABCB6 are responsible for the Lan− phenotype. Using the HMR0921 antibody, we similarly purified and identified the ABC transporter ABCG2 as the carrier of the Jra antigen. Analysis of Jr(a+) or Jr(a−) erythrocytes, as well as K‐562 cells transfected with ABCG2 cDNA, showed that the Jra antigen is encoded by ABCG2 and that Jr(a−) erythrocytes lack ABCG2. Targeted sequencing of ABCG2 in 18 unrelated Jr(a−) individuals identified eight different null mutations, which were responsible for their Jr(a−) phenotype, and revealed that the prevalence of the Jr(a−) phenotype in the Japanese and European Gypsy populations is related to the mutations p.Q126X and p.R236X in ABCG2, respectively.

Conclusions  We demonstrated that the related transporters ABCB6 and ABCG2 specify two new blood group systems called Langereis (LAN) and Junior (JR), respectively. The elucidation of their molecular bases will facilitate the detection of individuals with the rare Lan− and Jr(a−) phenotypes and hence improve their transfusion security and/or their pregnancy follow‐up.
The JR blood group system: genetic and molecular investigations
Authors: Coghlan G.
Published: June 2012

Background  Jra is a high‐incidence erythrocyte antigen previously designated ISBT 901.005. The rare Jr(a−) phenotype appeared to be inherited as an autosomal recessive trait, but the gene controlling the expression of Jra was not known. We conducted genetic and molecular investigations in an attempt to resolve this issue.

Aim  This lecture and accompanying manuscript will detail the homozygosity by descent (HBD) gene mapping strategy we used to establish that ABCG2 null alleles define the Jr(a−) phenotype (Zelinski et al., Nat Genet 2012;44:131–132).

Materials and Methods  Genomic DNA was genotyped for single nucleotide polymorphisms (SNPs) using a Human GeneChip (Affymetrix, 250K NspI) Mapping array. The six Jr (a−) study subjects were two Caucasian sisters, two Asian siblings and two unrelated Asian individuals referred for serologic testing. Anti‐Jra was identified in the plasma from four of the six. Intronic primers flanking exons 2–16 of ABCG2 were designed and used for PCR amplification. Both the forward and reverse strands of each purified product were Sanger sequenced at The Centre for Applied Genomics (Toronto, Canada).

Results  Analysis of the SNP genotype data revealed that the Caucasian sisters were identically homozygous for large tracts of consecutive SNPs in seven different chromosomal regions; chromosome 1q (3·3 Mb), 3q (8·8 Mb), 4q (28·9 Mb), 7q (10·5 and 7·7 Mb), 9q (3·1 Mb) and 10q (2·0 Mb). DNA from the four Asian individuals did not consistently contain homozygous SNP haplotypes in any of these regions except for chromosome 4q22.1. In this region, the siblings and one unrelated Asian had blocks of homozygosity that overlapped for approximately 400 000 bp and were identical to each other, but, different from the Caucasians. The remaining unrelated Asian was homozygous (approximately 520 000 bp) for a third SNP haplotype. The 4q22.1 region of homozygosity identified in all six study subjects contains four validated genes, only one of which, ABCG2, is known to be highly expressed on erythrocytes. DNA sequencing revealed that homozygosity for each of the three SNP haplotypes corresponded with homozygosity for a different nonsense (c.736C>T or c.376C>T) or missense (c.34G>A) mutation in ABCG2.

Conclusion  The genetic and molecular evidence revealed by this study proves that ABCG2 null alleles define the Jr(a−) blood group phenotype. Independently, our French colleagues established that Jra was carried on the ABCG2 protein (Saison et al., Nat Genet 2012;44:174–177). Based on these results the JR blood group system (ISBT 032) has been established.
Noninvasive prenatal screening for RHD: the 1st national antenatal directed anti‐D prophylaxis program – the Danish model or a guide to robust prediction of need of anti‐D
Authors: Dziegiel M. Hanefeld ,   On behalf of the Danish Network for Antenatal RHD Screening
Published: June 2012

Background  As of January 1, 2010, Denmark implemented a national antenatal directed anti‐D prophylaxis program. Prior to this, only postnatal prophylaxis directed by serology of cord blood was practiced.

A preparatory work for modernization and optimization of fetal care was carried out by the National Board of Health with participation of leading obstetricians, specialists in fetal medicine, general practitioners, midwives, clinical immunologists and administrators.

The promising results of non‐invasive prenatal diagnosis based on cell free fetal DNA enabled an antenatal directed use of anti‐D to those with a D positive fetus, thus eliminating approximately 40% of the antenatal use of anti‐D.

The complete program now includes an antenatal RHD screening in gestational week 25, and a postnatal serological RhD typing of cord blood, in both instances followed by administration of anti‐D to those found positive.

Aim  The explicit aim of the RHD screening was to obtain the highest possible sensitivity to recommend anti‐D in all cases where it might be indicated whereas specificity was of secondary priority.

Methods  Health services in Denmark are organized in five regions; accordingly screening has been implemented in every region, each using its own in‐house screening methodology. However, all regions have implemented automated DNA purification and the assays are variations over a theme of multiple PCRs covering several exons. A control reaction for DNA purification is obligatory. However, a control for fetal DNA is not included. A working group with members from all regions has implemented a national scheme for quality control. Digital on‐line delivery of results to general practitioners, midwives and obstetricians is implemented in most regions thus cutting down on cost and time.

Results  The continuation of postnatal serology has allowed a quality control of RHD screening. During the first six months of screening only two false negative results occurred out of 2312 tested (0·087%) suggesting a sensitivity of 99·9%. Due to the sacrifice of specificity some unnecessary use of anti‐D occurred, 39 cases or 1·7%.

Discussion  The elimination of 38·3% of the use of anti‐D, that is unnecessary and the related clinical contacts balances the expenses for the screening. An unforeseen benefit of the screening has emerged. The availability of the antenatal RHD results at the time of delivery has simplified logistics and preliminary clinical action is taken based on the antenatal result. Only in the very rare occasions of a (false negative) discrepancy between antenatal and postnatal results is communication needed between laboratory, clinician, and patient.

The challenge will be to maintain the high standards in a possible future setting without serology serving as a benchmark for quality control.
New insights in mechanisms of transfusion‐related acute lung injury
Authors: Santoso S. , Sachs U. J.
Published: June 2012

Transfusion‐related acute lung injury (TRALI) is a syndrome characterized by acute respiratory distress following the transfusion of blood components. The pathophysiological hallmark of TRALI is an increased pulmonary microvascular permeability. Several reports demonstrate that the majority of TRALI cases are precipitated by the transfusion of donor antibodies directed against HLA (human leukocyte antigens) or HNA (human neutrophil antigens) expressed on the neutrophils’ surface of the recipient. This antibody‐ antigen interaction is thought to directly cause neutrophil activation and release of cytotoxic agents, with subsequent endothelial damage and capillary leak. Recent observations, however, indicate that other cells may also play a significant role in TRALI. This review will introduce several possible mechanisms of TRALI including the involvement of other blood cells and of the pulmonary endothelium.
Donor vigilance: progress and challenges
Authors: Wiersum‐Osselton J. C. , Marijt‐van der Kreek T. , de Kort W. L. A. M.
Published: June 2012

Background  Internationally, there is increased interest in reporting, treating and attempting to reduce complications of blood donation. Donor haemovigilance is the systematic monitoring of adverse reactions and incidents in the whole chain of blood donor care, with a view to improving quality and safety for blood donors.

International Developments  Several studies have described the risk factors for vasovagal reactions – female donors, young age, first‐time status, low body weight, etc. A water drink before donation, use of applied muscle tension and social support during donation have been found effective in reducing minor vasovagal reactions and/or increasing the likelihood of donors returning for subsequent donations. Haematomas and other venepuncture‐related complications are frequent and are the predominant cause of long‐term morbidity from complications of blood donation. International surveillance data on donor complications are captured in ‘ISTARE’ International Surveillance database for Transfusion‐associated Adverse Reactions and Events, which is being developed by the International Hemovigilance Network.

Experience in The Netherlands: Better Monitoring of Donor Complications, Where Next?  All donor complications and procedural problems are routinely recorded in the computer system eProgesa. Since 2009, the results have been monitored. An improved coding list was introduced in 2010 in order to record more details and cover new procedures such as Rhesus immunizations. The overall rate of donor complications increased from 0·64 in 2009 to 0·80 per 1000 whole blood collections (second half of 2010) and from 1·34 to 1·40 per 1000 plasmaphereses; there were no changes in donor demographics or procedures to explain this, so better recording is presumed. The recorded complications and procedural problems are regularly presented in team leaders’ and regional directors’ meetings. The data have been used to analyse the effect of a procedural modification: increasing the concentration of citrate solution used in plasmapheresis. The rate of terminating procedures because of citrate reactions was 0·14 per 1000 collections [95% confidence interval (CI) 0·018–0·27] before and 0·09 (95% CI 0·018–0·17) after the modification, signifying no relevant change. It is hoped that in 2012 a revised donor information brochure with instructions on avoiding vasovagal reactions will be piloted and subsequently tested. Nevertheless, only immediate and short‐term complications can be effectively addressed by the recording and analysis of complications. Longer term issues such as whole blood donor iron status are the subject of research in our country and abroad.

Conclusion  In our country as well as elsewhere, recording and monitoring the incidence of complications of blood donation has become the norm. Knowledge of risk factors and evidence‐based interventions will enable blood establishments worldwide to reduce donor complications. As yet, longer term complications are not well addressed.
The steps taken for establishing a blood service in Chile
Authors: Contreras M. , Martínez C. , Larrondo M. , Cárdenas C.
Published: June 2012

In 2007, there were 59 public organizations collecting, processing and testing blood in Chile, all based on mainly replacement donors. The Ministry of Health (MINSAL) created a National Blood Commission (NBC) to support the national health authorities in establishing a National Service for Blood and Tissues. Hence, a unique opportunity was created to undertake a comprehensive strategic situation analysis of the Chilean blood system.

Details of the services available across the country were gathered via a detailed questionnaire sent to the two blood centres, all blood banks and Transfusion Medicine Units, to identify resources (human, financial, equipment, facilities), activities, demand, supply, etc. A development plan was drawn up using the results of this questionnaire, and the details are summarized here. Further plans for the future are also being developed.
Bacterial contamination, screening and follow up: clinical aspects
Authors: Wood E. M. , Borosak M.
Published: June 2012

Bacterial contamination remains an important infectious complication of blood transfusion, with potentially fatal outcome. Platelets are at greatest risk, especially due to their current storage requirements. Many measures have been implemented to reduce risks, including routine screening of platelet components prior to release in some countries. Experience from screening programs is now accumulating in the peer‐reviewed literature and reports from haemovigilance programs. However, methodological differences in pre‐release platelet screening can make interpretation and comparison of published data difficult. These differences include product type and shelf‐life; volume, method and timing of sampling/inoculation; use of aerobic bottles alone or with anaerobic bottles; type of test system in use; duration of culture; definition of confirmed positives; and processes for management of results and communication to clinicians and patients.

Important clinical questions remain regarding notification of platelet screening results to hospital laboratories, treating clinical staff and patients, and subsequent management. Contexts and logistics are different in different countries, and no single approach will suit all settings, but these practicalities will influence the reported outcomes. For example, findings will be affected by whether notification is made at the stage of an “initial machine positive” result or only once confirmed, and whether follow up of patients is active or passive. Transfusing laboratories often have limited information on which to base decisions about patients at particular risk, and many platelets are transfused to outpatients, meaning that patients are not in the hospital when screening results become available.

This presentation will explore a number of important questions. For example, should treating clinicians always be notified about initial machine positive results? Should all patients be contacted to be assessed for evidence of sepsis? If so, at what stage, and what clinical assessments and/or investigations should be performed? Which, if any, patients should receive prophylactic antibiotics, and when? What are the implications for informed consent regarding transfusion? What procedures do blood services and hospitals need to have in place for notification of clinicians and patients regarding platelets and any associated components? What are the resource implications? How should events be reviewed within hospitals, and what information should be reported to haemovigilance programs?
Generation of platelet progeny
Authors: Schwertz Hansjörg , Weyrich Andrew S.
Published: June 2012

Platelets are derived from the cytoplasm of bone marrow megakaryocytes through a process referred to as proplatelet formation. Recent studies demonstrate that circulating anucleate mouse and human platelets retain the capacity to form bulbar extensions, which resemble megakaryocyte‐derived proplatelets. Newly‐formed platelets display typical morphology, possess classic platelet constituents, and functional normally. Here we review what is currently known about the formation of platelet progeny.
The ISBT code of Ethics and the altruistic donor
Authors: Flanagan P.
Published: June 2012

Abstract The ISBT code of Ethics was first published in 1980 and aimed to define the principles and rules to be observed in the field of transfusion. Subsequently updated in 2000 it is acknowledged as a core document for the Society. The Code focusses on the importance of voluntary non‐remunerated blood donation. This concept continues to be challenged particularly in the area of collection of plasma for fractionation. The background to the development of the Code is reviewed and assessed in the context of recent developments with the aim of determining whether a further revision of the Code is now needed.
What is the appropriate size of the worldwide cord blood inventory?
Authors: Querol S. , Marsh S. G. E. , Palou E. , Gomez S. G. , Torrabadella M. , Ortiz P. , Puig L. , Madrigal A.
Published: June 2012

In spite HLA polymorphism distribution has some variations between major ethnic groups, in a US study by Beatty et al. (Human Immunology, 2000), 10 000 donors provided a 4/6 HLA‐match for patient in every group using the conventional CB match criteria (low resolution for HLA‐A,‐B and high resolution for HLA‐DRB1). This was also shown in our UK study where 10 000 randomly selected donors allowed finding a match for almost all patients (Querol, Haematologica, 2009). For better match level (5/6) a bigger inventory was required but enlarging size showed a progressive decrease on its efficiency. Thus, only 5000 units were required to find a donor for 50% of patients; but to achieve 65%, we then need to triplicate size (15 000), and growth up to 50 000, to match 80%. Further increase has only marginal benefit. We can then speculate that an optimal world size inventory be the addition of fractions of 5–15 000 donors for each major ethnic group considered, depending on their anticipated diversity, to at least provide options of finding a 5/6 donor for more than half of the patients but assuring a 4/6 match donor for almost any of them. In addition, inter‐ethnic cross matching and other HLA favorable interactions like use of HLA homozygous for mixed ethnicities, and consideration of Non‐Inherited Maternal Antigen (NIMA) match effect, if confirmed, would further increase donor availability. If we consider 23 major ethnic groups as proposed by the allele frequency net database (Gonzalez‐Galarza, Nucleic Acid Research 2011), a worldwide CB inventory would be in the region of 300 000 units. This would suffice to provide an optimal compatible donor for any patient in need. To be effective, all units within the inventory should be larger than 1·5E9 total nucleated cells (20% of those collected) to serve patients up to 100 kg using the double CBT strategy (threshold 1·5E7 TNC/kg). A central world cord blood bank may achieve this equalitarian goal with €300 million budget and a proper world distribution and size of regional collection programmes.
Performance of the 2010 rheumatoid arthritis classification criteria
Authors: Davatchi Fereydoun , Abari Iraj Salehi , Soroosh Soosan , Soroosh Mohsen , Abdollahi Bahar Sadeghi
Published: June 2012

Objectives

Rheumatoid arthritis (RA) needs early treatment to improve clinical outcome by reducing joint damage, radiographic progression and disability. The aim of this study was to evaluate the 2010 Rheumatoid Arthritis Classification Criteria for its ability to classify RA patients, in their early stages, not exceeding 12 months of disease progression.

Methods

Rheumatoid arthritis (RA) patients were selected from August to December 2010, among those coming for their follow‐up. The inclusion criteria were patients with not more than 12 months of disease progression at their first evaluation. Patients were selected from four rheumatology subspecialty clinics.

Results

Nine hundred and ninety‐seven patients with a confirmed diagnosis of RA entered the study. The female‐to‐male ratio was 4.3/1.0. Mean age was 46.4 years. Mean disease progression at first visit was 6.3 months. The mean follow‐up of their disease was 5.9 years. The 1987 American College of Rheumatology (ACR) criteria were fulfilled for 74% of patients. The ACR/EULAR (European League Against Rheumatism) criteria were fulfilled for 69% of patients. Ten percent had involvement of 2–10 large joints, 29% 1–3 small joints, 25% 4–10 small joints and 32% more than 10 joints. Low rheumatoid factor (RF)/anticytoplasmic antibodies (ACPA) were discovered in 30%, high RF/ACPA in 37%; high erythrocyte sedimentation rate/C‐reactive protein in 77%, and duration of 6 weeks or more in 92% of patients. There was no significant difference between men and women.

Conclusions

The 2010 ACR/EULAR criteria have good performance: sensitivity of 69% in early disease (first year), with the same sensitivity in both genders.
Supercritical Carbon Dioxide Heat Transfer in Horizontal Semicircular Channels
Authors: Kruizenga Alan , Li Hongzhi , Anderson Mark , Corradini Michael
Published: June 2012

Competitive cycles must have a minimal initial cost and be inherently efficient. Currently, the supercritical carbon dioxide (S-CO2) Brayton cycle is under consideration for these very reasons. This paper examines one major challenge of the S-CO2 Brayton cycle: the complexity of heat exchanger design due to the vast change in thermophysical properties near a fluid’s critical point. Turbulent heat transfer experiments using carbon dioxide, with Reynolds numbers up to 100 K, were performed at pressures of 7.5–10.1 MPa, at temperatures spanning the pseudocritical temperature. The geometry employed nine semicircular, parallel channels to aide in the understanding of current printed circuit heat exchanger designs. Computational fluid dynamics was performed using FLUENT and compared to the experimental results. Existing correlations were compared, and predicted the data within 20% for pressures of 8.1 MPa and 10.2 MPa. However, near the critical pressure and temperature, heat transfer correlations tended to over predict the heat transfer behavior. It was found that FLUENT gave the best prediction of heat transfer results, provided meshing was at a y+ ∼ 1.
Study on Derailment Mechanism and Safety Operation Area of High-Speed Trains Under Earthquake
Authors: Ling Liang , Xiao Xinbiao , Jin Xuesong
Published: June 2012

In order to investigate the derailment mechanism and safety operation area of high-speed trains under earthquake, a coupled vehicle-track dynamic model considering earthquake effect is developed, in which the vehicle is modeled as a 35 degrees of freedom (DOF) multibody system with nonlinear suspension characteristic and the slab track is modeled as a discrete elastic support model. The rails of the track are assumed to be Timoshenko beams supported by discrete rail fasteners, and the slabs are modeled with solid finite elements. The system motion equations are solved by means of an explicit integration method in time domain. The present work analyzes in detail the effect of earthquake characteristics on the dynamical behaviors of a vehicle-track coupling system and the transient derailment criteria. The considered derailment criteria include the ratio of the wheel/rail lateral force to the vertical force, the wheel loading reduction, the wheel/rail contact point traces on the wheel tread, and the wheel rise with respect to the rail top, respectively. The present work also finds the safety operation area, the derailment area, and the warning area of high-speed trains under earthquake, and their boundaries. These areas consist of three key parameters influencing the dynamical behavior of high-speed train and track under earthquake. The three key influencing parameters are, respectively, the vehicle speed and the lateral and vertical peak ground acceleration (PGA) of an earthquake. The results obtained indicate that the lateral earthquake motion has a greater influence on the vehicle dynamic behavior and its running safety compared to the vertical earthquake motion. The risk of derailment increases quickly with the increasing of lateral earthquake motion amplitude. The lateral earthquake motion is dominant in the vehicle running safety influenced by an earthquake. While the vertical earthquake motion promotes jumping of the wheels easily, not easy is flange climb derailment. And the effect of the vehicle speed is not significant under earthquake.
Nadal’s Formula and High Speed Rail Derailments
Authors: Shabana Ahmed A.
Published: June 2012

Several railroad vehicle derailment criteria are based on the (L/LVV) ratio where L is the lateral force and V is the vertical force acting on the wheelset. Derailment is assumed to occur if this ratio exceeds a certain limit. The (L/LVV) ratio has its roots in Nadal’s formula which was introduced more than a century ago. When a planar analysis that corresponds to zero angle of attack is used, Nadal’s formula can be derived using a geometric approach, while a Nadal-like formula can be derived using a kinetic approach. In the geometric approach, a coordinate transformation is used to define the normal and friction forces in another coordinate system. In this case, the lateral and vertical forces are interpreted as the components of a vector that defines the normal and friction forces in another coordinate system without consideration of other external forces that are applied to the wheelset. Because the geometric approach does not account for other forces, it should not be used as the basis for derailment studies. In the kinetic approach, on the other hand, the L and V forces are interpreted as the resultant of the forces excluding the normal and friction forces at the contact point. That is, in both approaches discussed in this paper, the L and V forces cannot be interpreted as the resultant forces acting on the wheelset. The condition for the wheel climb using the kinetic approach is obtained and examined. It is shown that formulas obtained in this paper are based on assumptions that do not capture the gyroscopic moments, and therefore, these formulas should not be used as the basis for general high speed rail derailment criteria. It is also shown that in the case of zero angle of attack and using single degree of freedom planar kinetic model assumptions, an increase in the lateral force L can reduce the tendency for wheel climb, while reducing L can increase the wheel climb risk. Furthermore, the single degree of freedom assumptions used to obtain the wheel climb formula presented in this paper do not allow for wheel lift, and as a consequence, wheel lift derailment scenarios that can be the result of large moment should not be investigated using Nadal’s formula or one of its derivatives that employ the same assumptions. Furthermore, since the analysis presented in this paper assumes zero angle of attack, the conclusions obtained in this investigation do not apply to the wheel climb scenarios with nonzero angle of attack. It is also important to point out that this paper is not intended as a discussion on how Nadal’s formula is interpreted by researchers and engineers; instead, the paper is mainly focused on examining the roots of this formula and the problems that can arise from the assumptions used in its derivation.
Estimation of Dynamic Contact Force Between a Pantograph and Catenary Using the Finite Element Method
Authors: Pil Jung Sung , Guk Kim Young , Sung Paik Jin , Won Park Tae
Published: June 2012

This paper presents a model of the catenary and pantograph and an analysis of their dynamic interaction, using the finite element method. An analytical procedure to calculate the length of droppers is introduced. The calculated dropper length is applied to the catenary model and the static deformation due to gravity is simulated. The presag result of the contact wire is validated by comparison with the design specification. The wave propagation speed of the catenary model is acquired by applying the impact force to the contact wire. The result, regarding the wave propagation speed, agrees well with the reference speed as defined by the UIC code. On the contrary, the pantograph model is unified with the finite element catenary model, and the dynamic interaction of the catenary-pantograph is simulated. An optimization technique to find the material properties of the pantograph model is proposed. Based on the following performance test data, the optimum values of the material properties are found by using the response surface analysis method. The reliability of the pantograph-catenary model is verified by comparing the contact force results obtained from the simulation and test. When the pantograph drives at 305 km/h, 370 km/h, and 430 km/h, the contact force variation and the possibility of loss of contact are discussed.
Statistical Evaluation of Chassis Load Variations for Heavy Trucks
Authors: Sundell Per , O¨ijer Fredrik , Olofsson Martin
Published: June 2012

A statistical evaluation of the different sources of scatter and uncertainties contributing to the load variations for heavy trucks is presented. Based on the evaluation of the load scatter, we propose an approach for design analysis utilizing a combination of measurements and complete vehicle simulations.
Prosthetics for Transtibial Amputees: A Literature Survey
Authors: Powelson Thomas , Yang Jingzhou James
Published: June 2012

Approximately 82 percent of all amputations performed in the United States are transtibial amputations, in which the leg is removed below the hiee. Because the knee joint is left intact the use of prosthetics is one of the most preferred methods for returning mobility to amputees. The improvement of prosthetics for transtibial amputees is currently an area of intense research. This paper summarizes the state of the art of prosthetics for transtibial amputees by focusing on the four major components associated with standard transtibial prosthetic. The socket transfers the forces between the residual limb and the prosthetic. A suspension system ensures that solid contact is maintained between the leg and the artificial limb. The prosthetic foot is attached to the socket by a pylon, which also accounts for length of limb lost during amputation. Prosthetic feet come in many forms ranging from little more than wooden blocks to carbon fiber sprinting feet. Two recent advances in transtibial prosthetics include the procedures of direct skeletal attachment, and distal tibiofibular bone bridging which increases the weight bearing capability of the residual limb.
Practical Aspects of Tuning and Implementation of Fractional-Order Controllers
Authors: Petra´sˇ Ivo
Published: June 2012

This paper presents practical aspects of tuning and implementation of Fractional-Order Controllers (FOC). In the article are presented tuning, auto-tuning and self-tuning methods for the FOC. As the FOC are considered fractional PID controllers, the CRONE controller and fractional-order lead-lag compensators. As implementation techniques are described the FIR and FIRforms of approximation methods, which can be easily implemented in microprocessor devices such as for example the PLC, IPC, etc. The possibility for analogue implementation of such kind of controllers is also mentioned. An example of practical implementation of the FOC together with all problems and restrictions is shown as well.
Low-Speed Wind Turbine Design and Fabrication
Authors: Zeamer Michael , Zeamer Matthew , Amano R. S. , Mohan Das Pradeep Mohan , Welsh Andrew , Polly Brian
Published: June 2012

A wind energy has getting more attention due to its free-source, its nature of renewable energy, and free of carbon dioxide emission. As the wind map varies area to area, the wind energy collection strongly depends on the site. In order to maximize the amount of energy captured, an improved, low airspeed wind turbines are demanded to be designed. A wind turbine studied was created using the NACA 4412 foil shape and a decreasing chord length with increasing distance from the center of the turbine. The pitch was also varied along the span of the blade. The blade was analyzed using CFD and tested in a wind tunnel facility. The turbine was connected to a motor which was connected to a resistor and current and voltage meters. Using the voltage and current data at a prescribed rate of rotation, the model generated decent power output. The study focused mostly for a low-speed wind up to 2m/s (or 3.4 mph). For practical use the turbine would need to be scaled to a greater size and a proportional-integral-derivative controller (PID controller) that can generate higher resistance would need to be employed.
Time-Based Modeling of Linguistic Preference to Preferential Probability
Authors: Dong Andy , Honda Tomonori , Yang Maria C.
Published: June 2012

In this paper, we present a method to estimate the likely concept a committee of designers will select given their verbalized preferences toward each alternative. In order to perform this estimation, we present a new method of preference elicitation based on natural language. First, we show a way to model preference in the natural language of appraisal, which describes the degree of intensity and the uncertainty of preference based upon gradable semantic resources to express appraisals. We then show a way to map linguistic appraisals into probability distribution functions. Finally, we present a Markov model that utilizes these probability distribution functions in state transition matrices to calculate in a time-varying manner the change of preference over time. We present a case study to illustrate the validity of the method.
Efficient Energy Transfer and Redirection in Weakly Interacting Granular Lens
Authors: Starosvetsky Yuli , Hasan M. A. , Vakakis A. F.
Published: June 2012

One of the main challenging tasks in the modern design of highly adaptive granular material is in ability to passively control the flow of energy through it by means of trapping, redirection and scattering. In the present work we demonstrate that one of the possible mechanisms to achieve efficient control over the propagating shock wave in the material is the usage of weakly interacting, non-compressed granular lens (granular chains). In the latest computational studies we have demonstrated that the shock waves initially localized on a finite amount of chains may be efficiently redirected to the neighboring granular chains. In this study it is also shown that the amplitude of the shock wave redirected to the neighboring chains may be passively controlled by choosing appropriate parameters of coupling which makes this type of granular structure highly adaptive for the required control of mechanical energy flow. The mechanism for efficient transport of energy from one chain to another are also found. It corresponds to a simple exchange of energy between the weakly interacting granular chains providing equi-partition of Nesterenko solitary waves through the chains. This mechanism of energy transfer and redirection in highly nonlinear granular chains are conceptually new. Analytical and computational studies of all the mechanisms are performed in the present study.
Resonance and Anti-Resonance Phenomenon in Granular Dimer Chains With No Pre-Compression
Authors: Jayaprakash K. R. , Starosvetsky Yuli , Vakakis Alexander F.
Published: June 2012

It is a well known fact that many interesting phenomena in the theory of waves in nonlinear lattices, e.g., the significant reduction of the amplitude of a propagating primary pulse or the essential growth of the phase velocity, may be explained in terms of various resonant mechanisms existing in the system (e.g. Frankel-Kontorova model). Recently, we have demonstrated analytically and numerically that similar resonant mechanisms also exist in periodically disordered granular chains with no pre-compression. Moreover, these mechanisms are responsible for the aforementioned phenomena of intensive pulse attenuation as well as speeding up of solitary waves in periodic granular chains. In our studies we have considered regular dimer chains consisting of pairs of ‘heavy’ and ‘light’ beads with no pre compression and with elastic Hertzian interaction between beads. A new family of solitary waves was discovered for these systems. These solitary waves may be considered analogous to the solitary wave of a homogeneous chain studied by Nesterenko [1], in the sense that they do not involve separations between beads, but rather satisfy special symmetries or, equivalently resonances in the dynamics. We show that these solitary waves arise from a countable infinity (we conjecture) of nonlinear anti-resonances in the dimer chains. Moreover, solitary waves in the dimers propagate faster than solitary waves in the homogeneous granular chain obtained in the limit of no mass mismatch (i.e., composed of only ‘heavy’ beads). This finding, which might seem to be counter intuitive, indicates that under certain conditions nonlinear anti-resonances can increase the speed of disturbance propagation in disordered granular media, by generating new ways of transferring energy to the far field in these media. Finally, we discuss a contrasting resonance mechanism that leads to the opposite effect, that is, very efficient shock attenuation in the dimer chain. Indeed, we show that under a certain nonlinear resonance condition a granular dimer chain can greatly reduce the amplitude of propagating pulses, through effective scattering of the energy of the pulse to higher frequencies and excitation of alternative intrinsic dynamics of the dimer. This resonance condition may be theoretically predicted and explained, and a very fair correspondence is observed between the analytical solutions and direct numerical simulations. From a practical point of view, these results can have interesting implications in applications where granular media are employed as shock transmitters or attenuators.
A Novel Continuous Contact Force Model for Multibody Dynamics
Authors: Machado Margarida , Flores Paulo
Published: June 2012

A general and comprehensive analysis on the continuous contact force models in multibody dynamics is presented and a novel contact force model is proposed. The force models are developed based on the foundation of the Hertz law together with a hysteresis damping parameter that accounts for the energy dissipation during the contact process. In a simple way, these contact force models are based on the analysis and development of three main issues: (i) the dissipated energy associated with the coefficient of restitution that includes the balance of kinetic energy and the conservation of the linear momentum between the initial and final instant of contact; (ii) the stored elastic energy, representing part of initial kinetic energy, which is evaluated as the work done by the contact force developed during the contact process; (iii) the dissipated energy due to internal damping, which is evaluated by modeling the contact process as a single degree-of-freedom system to obtain a hysteresis damping factor. This factor takes into account the geometrical and material properties, as well as the kinematic characteristics of the contacting bodies. The proposed contact force model has the great merit that can be used for contact problems involving materials with low or moderate values of coefficient of restitution. This contact force model is suitable to be included into the equations of motion of a multibody system and contributes to their stable numerical resolution. Two demonstrative examples of application are used to provide the results that support the analysis and discussion of procedures and methodologies adopted in this work.
Soil Modeling Using FEA and SPH Techniques for a Tire-Soil Interaction
Authors: El-Gindy Moustafa , Lescoe Ryan , O¨ijer Fredrik , Johansson Inge , Trivedi Mukesh
Published: June 2012

In recent years, the advancement of computerized modeling has allowed for the creation of extensive pneumatic tire models. These models have been used to determine many tire properties and tire-road interaction parameters which are either prohibitively expensive or unavailable with physical models. More recently, computerized modeling has been used to explore tire-soil interactions. The new parameters created by these interactions were defined for these models, but accurate soil constitutive equations were lacking. With the previous models, the soil was simulated using Finite Element Analysis (FEA). However, the meshless modeling method of Smooth Particle Hydrodynamics (SPH) may be a viable approach to more accurately simulating large soil deformations and complex tire-soil interactions. With both the FEA and SPH soils modeled as elastic-plastic solids, simplified soil tests are conducted. First, pressure-sinkage tests are used to explore the differences in the two soil-modeling methods. From these tests, it is found that the FEA model supports a surface pressure via the tensile forces created by the stretching of the surface elements. Conversely, for the SPH model, the surface pressure is supported via the compressive forces created by the compacting of particles. Next, shear-displacement tests are conducted with the SPH soil (as this test cannot easily be performed with an FEA soil model). These shear tests show that the SPH soil behaves more like clay in initial shearing and more like sand by exhibiting increased shearing due to vertical loading. While both the pressure-sinkage and shear-displacement tests still show that a larger particle density is unnecessary for SPH soil modeling, the shear-displacement tests indicate that an elastic-plastic material model may not be the best choice.
The Existence of Solutions for Fractional Functional Differential Equations With Boundary Value Conditions
Authors: Kou Chunhai , Zhou Huacheng , Wu Sijia
Published: June 2012

In this paper, we are concerned with the existence of solutions for a class of nonlinear fractional functional differential equations with boundary value conditions. Some existence results of solutions are obtained. Our analysis relies on some fixed point theorems. Finally, some examples are presented to illustrate the main results.
Analysis and Synthesis of Multi-Rotor Aerial Vehicles
Authors: Jiang Qimi , Mellinger Daniel , Kappeyne Christine , Kumar Vijay
Published: June 2012

This work addresses two basic problems of the multi-rotor aerial vehicle (MRAV). The first problem is the force analysis of the rotors. In order to save energy and maximize the lifetime of a given MRAV, the force distribution of the rotors is analyzed. As a result, an optimal set of angular velocities is obtained. The second problem is the configuration synthesis of the MRAV. In order to maximize the acceleration and improve the maneuverability of the MRAV, the geometric configuration (position and orientation) of the rotors is synthesized. The approaches for analysis and synthesis are presented and demonstrated by several case studies. The obtained results can be applied in the design of the MRAV and used as a guide for experimental studies.
Nonlinear Dynamics of an Extensible Flexible Pipe Conveying Fluid and Subjected to External Axial Flow
Authors: Ghaith F. A. , Khulief Y. A.
Published: June 2012

In this paper, the nonlinear equations representing the dynamics of a slender flexible pipe conveying fluid and subjected to external axial flow are formulated using the extended Hamilton’s principle. The internal flow is assumed to be steady, fully developed turbulent and approximated by a plug flow, while the external flow is represented by the induced hydrodynamic forces associated with friction, hydrostatic and inviscid components. The pipe centerline is considered to be extensible, and hence two coupled nonlinear equations of motion associated with longitudinal and transverse displacements are derived to describe the dynamics of the system. The developed model takes into account the fluid pressurization force and the tension in the pipe, which may be externally applied or associated with the frictional forces. For verification purpose, comparisons were performed, wherein the developed formulation was reduced to some published linear models. Numerical solutions were obtained for a case study of a double-pipe heat exchanger, wherein the effects of internal flow, external flow, flowrate, and radial gap on the dynamic characteristics of the system were addressed.
A Research for the Planetary Gear Noise Development in FF 6th Speed Automatic Transmission
Authors: Lee Hyun-Ku , Kang Koo-Tae , Kim Moo-Suk , Hur Jin-Wook
Published: June 2012

In order to improve the planetary gear noise of the new developed 6th speed automatic transmission, it needs to understand noise mechanism. Basically, many transmission’s components have an effect on the gear noise. In this paper, planetary gear noise sources which are influenced by gear tooth shapes and backlash among the gears, position of pinion gears, and misalignment of the sun gear are studied and experimented. Also, transfer-path likewise one-way clutch contacted between the carrier and case, and valve-body covers are also researched to reduce the transferred vibration and radiated noise levels. After developing the planetary gear noise, its evaluation specification is adapted to EOL (end of line) equipment to check the transmission’s noise quality in the factory.
Addressing Uncertainties Within Product Redesign for Sustainability: A Function Based Framework
Authors: Ramanujan Devarajan , Bernstein William Z. , Zhao Fu , Ramani Karthik
Published: June 2012

The Function Impact Method (FIM) is a semi-quantitative eco-design methodology that is targeted specifically towards the early stages of the design process. The FIM allows a designer to predict the environmental impacts associated with a new functional embodiment by extrapolating knowledge from Life cycle assessment (LCA) of similar existing designs. LCA however, is associated with substantial sources of uncertainty. Furthermore, the FIM uses a subjective weighting scheme for representing function-structure affinities. In the authors’ previous work, a Monte-Carlo variation analysis was used to estimate sensitivity of the input data and select the preferred redesign strategy. This paper proposes a method to formalize the input uncertainties in the FIM by modeling the uncertainties present in the results of the LCA’s and the involved function-structure affinities using Info-gap decision theory. The desirability of redesigning a particular function based on the magnitude of its function-connectivity and eco-impact is estimated, and a decision making methodology based on robust satisficing is discussed. This method is applied for making robust redesign decisions with regards to re-designing a pneumatic impact wrench for sustainability.
A Measurement System for Electric Vehicle Powered by Supercapacitors
Authors: Zou Zhongyue , Cao Junyi , Ma Chengbin , Zhang Huarong
Published: June 2012

Due to the high power density of supercapacitors, it is adopted in electric vehicles to essentially guarantee to recover more regenerative energy. However, there is still not a valid set of measurement methods to gauge the energy absorbed from regeneration system, the measurement and evaluation system for regenerative energy require to be investigated in order to estimate the performance of electric vehicles. Based on the analysis of the regenerative braking energy system of a supercapacitor truck, a measurement and evaluation system for recycling energy in the braking process is established. Meanwhile, the experiments of supercapacitor vehicle under various braking condition are carried out. The results show the effectiveness of the proposed braking energy recycling measurement method.