bluuebunny/crossref_metadata_2025 huggingface dataset:
Minority donation in the United States
Authors: Shaz B. H.
Published: June 2012

Background and Objective  In the United States, approximately 15 million whole blood products are collected each year from 10 million volunteer donors. African Americans are underrepresented in the donor pool. In 2008, 7% of white versus 4% of African American and Hispanics adults donated in the previous year. The donor rates vary by region in the United States: 77–93% for whites, 1–16% for African Americans and 1–13% for Hispanics. In the Atlanta metropolitan area whose donor pool is 77% white, 16% African American and 4% Hispanic, the blood donor rate (number of blood donors per population) was 11/1000 population for whites, 6/1000 for African Americans and 3/1000 population for Hispanics; and the blood donation rate (number of units donated by population over the total population) was 77 donations/1000 population for whites, 22/1000 population for African Americans and 10/1000 population for Hispanics. Thus, African Americans and Hispanics represent half of the donors as whites when adjusted for their percentage of the population and more strikingly donate a significantly fewer number of units per each donor.

Materials and Methods  Literature on reasons for racial/ethnic differences in donation rates and methods to address these differences was reviewed.

Results  The reasons for these differences are multifactorial. First, although 41% of the total US population is estimated to be eligible to donate, African Americans and Hispanics have lower eligibility rates (whites 46%, African Americans 36%, and Hispanics 41%). Second, donor deferral rates are higher for minorities: whites 11%, African Americans 18%, Hispanics 14% and Asians 16%. Deferral is most commonly secondary to temporary deferral reasons such as low hemoglobin level, yet donors are less likely to return once deferred, and thus deferral affects donor and donation rates. Third, minorities may have different motivators and barriers. The most cited motivators to blood donation are more convenient place and times, and being asked; and the most cited barriers are fear of catching a disease and feeling faint/dizzy, and not have time or knowing where to donate. Racial differences in motivating factors identified include African Americans are more likely than whites to donate to receive an item/gift and be tested for infectious disease, and if assured that donating is safe. Notably, these motivators are not the primary cited motivators. African Americans compared with whites more commonly cite fear, difficulty finding veins and not knowing where to donate as deterrents. In addition, African Americans have distrust in the healthcare system, which is correlated with lower donation rates. Fourth, different racial/ethnic groups may have different preferred marketing strategies, including methods of contact, as well as culturally specific motivators for behavioural change.

Conclusion  Thus, with an improved understanding of these differences as well as accurate tools to measure the outcomes, culturally targeted recruitment programs can be developed to increase donation rates.
Plasma fractionation
Authors: Burnouf T.
Published: June 2012

The first plasma fractionation process was developed in the 1940s by Cohn and co‐workers to prepare albumin and immunoglobulins. It relies on sequential precipitation steps at negative temperatures, different ethanol concentrations and various pH to segregate bulk plasma proteins. The ‘Cohn procedure’ has been modified over the years but largely remains the core fractionation process in use up to now. The introduction of cryoprecipitation (thawing of plasma at 2–4°C), as the first plasma fractionation step, to isolate a crude factor‐VIII fraction, and the integration of chromatographic steps to extract labile plasma or trace plasma proteins, have eventually shaped the modern fractionation technologies into complex procedures. Viral inactivation and removal treatments are performed to prevent the risks of transmission of enveloped and non‐enveloped viruses. Viral inactivation steps are applied most often on pre‐purified fractions, the downstream steps being used to remove protein contaminants and viral inactivation agents. Depending upon products and protein stability, treatments include incubations with combinations of solvent (TnBP) and detergent (e.g. Tween 80 or Triton X‐100) (S/D), pasteurization (heat‐treatment in the liquid state at 60°C for 10 h in the presence of stabilizers), as well as low pH or caprylic acid treatments (these last two treatments are restricted to immunoglobulins). Nanofiltration, to capture viruses on nm‐membranes, is typically performed on the final purified protein fractions prior to sterile filtration and aseptic filling. Terminal dry‐heat treatment at 80–100°C is used for some coagulation factor preparations. Modern plasma protein products have an unprecedented level of quality and safety when there is careful process control and monitoring together with sensitive test methods to detect potentially harmful contaminants, such as procoagulant impurities. Since the implementation of validated robust viral reduction treatments, plasma products have a high viral safety profile including against emerging agents (WNV, Dengue virus, Chikungunya virus). Experimental spiking studies suggest that several fractionation steps are capable of removing prions causing variant Creutzfeldt‐Jakob disease. Alternative fractionation processes based exclusively on chromatography have been developed at pilot scale and need further validations to demonstrate the quality, safety and consistency of resulting plasma products. A mini‐pool viral inactivation and fractionation process relying on single‐use equipment is also being developed to facilitate the access to safer plasma components, including plasma for transfusion, cryoprecipitate, prothrombin complex, immunoglobulins and fibrin sealant, in particular in developing countries.
Thrombotic Thrombocytopenic Purpura and atypical Haemolytic‐Uremic Syndrome: current management issues
Authors: Kiss J. E.
Published: June 2012

Thrombotic hromocyopenic purpura(TTP) is a life‐threatening thrombotic disorder in which platelet/von Willebrand factor deposits occur in the microcirculation of many organs including the brain, kidney, heart and abdominal viscera. A related thrombotic microangiopathy, atypical Hemolytic‐Uremic Syndrome(aHUS), is characterized by platelet/fibrin deposition predominantly in the kidneys, with acute renal failure as the major presenting clinical manifestation. Key advances in understanding the pathophysiology of these disorders now allow a better classification, with ADAMTS13 deficiency associated with TTP and defects in complement regulating proteins or complement factors identified in aHUS. Therapeutic plasma exchange has markedly improved mortality in TTP from more than 90% in the past to 10% to 20% currently. Immunosuppressive therapy with corticosteroids and the anti‐CD20 monoclonal antibody rituximab has assumed even greater importance in the management of TTP patients with autoantibodies to ADAMTS13. Although plasma exchange is also useful in aHUS, the advent of the anti‐C5 complement pathway inhibitor eculizumab promises to further improve clinical outcomes in these patients.
NK cell therapy in cancer and transplantation
Authors: Miller J. S.
Published: June 2012

NK cells have unique properties including memory. Although initially described as MHC unrestricted killers, NK cells have several families of receptors that directly recognize MHC Inhibitory receptors to protect “self” expressing normal tissue from being killed by NK cells and protecting against autoimmunity. Therefore, for NK cells to kill and produce cytokines they must encounter activating receptor ligands in the context of “missing self” that occurs with malignant transformation. The second property of inhibitory receptors is to educate or license NK cells to acquire function. This is best demonstrated in the mouse and in humans by enhanced function on self inhibitory receptor expressing NK cells when in a host expressing cognate ligate. In contrast, NK cells without inhibitory receptors or with non‐self inhibitory receptors are relatively hyporesponsive. Understanding the biology of NK cells will translate into strategies to manipulate NK cells for therapeutic purposes in cancer and transplantation.
Red blood cell alloimmunization and antigen matching in sickle cell disease – the African perspective
Authors: Natukunda B.
Published: June 2012

In sickle cell disease (SCD), blood transfusion facilitates improved blood and tissue oxygenation, reduces the propensity to sickling by diluting host cells, and suppresses the production of red blood cells (RBCs) containing sickle haemoglobin (HbS). Delivery of RBC transfusions to patients with SCD varies by method (simple vs. exchange) and frequency (episodic vs. chronic). However, due to the genetic differences between blood donors and recipients, repeated transfusions increase the risk of developing alloantibodies to RBC antigens. The antigens most frequently involved belong to the Rh, Kell, Kidd, Duffy, Lewis, and MNS blood group systems. Consequences of RBC alloimmunization include delays and difficulties in obtaining compatible blood for future transfusions, the occurrence of delayed haemolytic transfusion reactions (DHTRs), the hyperhaemolysis syndrome and autoimmunization. In Europe and USA, RBC alloimmunization rates ranging from 18% to 76% have been reported in SCD while other multiply transfused (OMT) patients had alloimmunization rates of 5% to 20% indicating that SCD patients are at a higher risk of developing RBC alloantibodies. To prevent alloimmunization in SCD patients, the standard practice in Europe and USA is to determine their extended RBC phenotype (ABO, Rh, Kell, Kidd, Duffy, Lewis, MNS) before commencing transfusion therapy and perform antigen matching for C, E and K antigens for patients without prior alloantibody formation. However in Africa, lower RBC alloimmunization prevalence rates of 6–10% have been reported in SCD patients and no differences were observed between SCD and OMT patients. This may be explained by the presumed high phenotypic compatibility between donors and SCD patients who were all Black Africans. Also, a low transfusion load (a median 3 U of blood were transfused) in SCD patients might have led to the poor response to alloantigenic challenge. Anti‐K alloimmunization was notably rare among African SCD patients compared to anti‐S. In many African countries, pre‐transfusion immunohaematologic testing includes neither the detection of RBC alloimmunization nor preventive antigen matching. Most transfusion laboratories are understaffed and underequipped; they perform ABO/D typing plus room temperature saline cross‐matches and do not screen for RBC alloantibodies. Hence, immunized SCD patients are not diagnosed and do not have the opportunity of receiving antigen‐negative blood. Furthermore, data on the occurrence of DHTRs are lacking. Introducing pre‐transfusion RBC alloantibody screening in all African countries will significantly improve the transfusion management of SCD patients. A program of limited phenotype matching for C, E and S antigens is recommended to prevent additional alloantibody formation in immunized SCD patients in Africa.
Massive haemorrhage: findings from the consensus conference for the Canadian National Advisory Committee on blood and blood products
Authors: Stanworth S. J. ,   On behalf of the Panel for the Massive Transfusion Consensus Conference (2011; Chair W. Dzik)
Published: June 2012

The Canadian National Advisory Committee on Blood and Blood Products convened a consensus conference on transfusion and trauma in June 2011. Key findings included a lack of evidence to support the use of 1:1:1 blood component ratios as the standard of care, the importance of early use of tranexamic acid, and the expected value of an organized response plan in trauma. Practical massive haemorrhage plans must be developed locally and reiterate the importance of communication, education, and the role of audit and monitoring of cases. Generalising findings from trauma to other settings of major bleeding is limited by lack of relevant clinical studies.
Blood donation from adolescents point of view
Authors: Zito E , Alfieri S , Cremonesi G , Marconi M , Saturni V
Published: June 2012

Background Adolescents are a very interesting potential source for recruiting new blood donors. People who start giving blood as soon as they are adults are likely to donate for longer. Interest in this age group is also connected to several factors: the spread of healthy lifestyles; facilitate access of healthy people to the healthcare service; help develop a responsible mindset in terms of public spirit.

Study design and methods Focus groups and analysis of the written results permitted the construction of an explorative questionnaire, administered to 3050 students in ten secondary schools in northern Italy; the participants were from 13 to 21 years old (M = 16.5, SD = 1.65; male = 47.7%, female = 52.3%). The elements covered by the questionnaire concern the tangible and psychological aspects of what could motivate or prevent donation. Descriptive analyses (frequencies, means and standard deviations) were conduced.

Results A comprehensive interpretation of the data shows the key roles played by school, figures of reference, peer groups, what the group shares and independent choice.

Conclusion This study provides tangible recommendations for appropriate promotion strategies to dedicate to adolescents; they are an important target to involve in recruitment programmes in order to make them aware of blood donation a long time before they can actually give blood.
Management of over anti‐coagulation by transfusion
Authors: Wallis J. P.
Published: June 2012

Increasing use of anticoagulants especially in an elderly population may complicate management of trauma, surgery and spontaneous bleeds. Reversal of warfarin and standard heparin are both effective and relatively easy. Newer agents are associated with fewer spontaneous bleeds but reversal when necessary may be difficult. Use of labile blood components has a very limited role in active reversal of anticoagulation for most agents but are often requested, usually inappropriately. This brief review looks at the options available for older and some newer agents.
What is a clinically significant antibody?
Authors: Garratty G.
Published: June 2012

Blood transfusion scientists have different definitions of ‘clinical significance’. For instance, is clinical significance judged by shortened RBC survival, laboratory evidence of haemolysis (e.g. increased bilirubin, LDH, etc.), and/or clinical signs (e.g. jaundice) of a haemolytic transfusion reaction (HTR)? Are one, two, or all three of these criteria needed to make an antibody significant? For instance, is a shortened RBC survival with no obvious laboratory abnormalities and/or or clinical signs really clinically significant? The answer may be different for a haematology patient requiring regular transfusions and a surgical patient with normal erythropoiesis. It is important to answer these questions in one’s own institution as they are the basis for our choice of compatibility tests and needed for interpretation of assays predicting clinical significance.

Several approaches are valuable in predicting clinical significance: (1) specificity and thermal amplitude of the antibody; (2) 1 h survival of 51Cr‐labelled incompatible RBCs; (3) functional cellular assays. Only antibodies reactive at 37°C in vitro are of potential significance. The 51Cr survival and cellular assays [e.g. monocyte monolayer assay (MMA)] are usually used to help decide if incompatible RBCs can be transfused to patients with antibodies to high‐incidence antigens that are sometimes significant but often are not. When the MMA = 5·1–20%, 33% of patients showed no clinical reactions, but 67%, with no clinical signs showed laboratory signs of a reaction. If the MMA is >20%, most patients show clinical (64%) or laboratory (75%) reactions. It is of interest to note that regardless of MMA or 1 h 51Cr results, most patients with antibodies to high‐incidence antigens have abnormal full RBC survival studies (T50Cr), but only one‐third show any clinical signs of a reaction. Thus, when interpreting results for clinicians, it is important to clearly define what you mean by ‘clinical significance’ so that they can balance decisions of transfusing incompatible blood versus time and expense of obtaining rare units lacking the cognate antigen. Cellular assays are not available for many people, so historical data on whether certain specificities have caused HTRs are the only practical approach for many.
Clinical expansion of cytokine induced killer (CIK) cells
Authors: Koh M. B. C. , Ching Linn Y.
Published: June 2012

Cytokine induced killer (CIK) cells are polyclonal T cells that can be expanded from marrow or peripheral blood lymphocytes with potent non‐MHC‐restricted cytotoxicity against a variety of tumor target cells. Earlier work had established the superiority of CIK cells over LAK cells in terms expansion and cytotoxicity. It has been studied extensively both in vitro and in murine experiments with promising killing activity against a wide range of haematological malignancies. Early clinical trials of CIK cells have reported safety and feasibility data as well as possible efficacy and have provided the framework for further clinical studies. As a robust and easily expandable cell population, its role in clinical adoptive immunotherapy should be investigated for translation into a good manufacturing practice (GMP) manufacturing process. Large scale culture to generate adequate number of CIK cells for clinical use involves up‐scaling from flasks to culture bags carried out in a GMP compliant cell therapy facility, use of GMP compliant materials and reagents, efficient harvesting procedures to remove foreign elements and strict release criteria with respect to viability, sterility and potency of the product. All the steps should preferably to be done in a closed system, in order to minimize the chance of contamination. A phase I/II clinical study on the use of allogeneic CIK cells has been conducted to define the role of CIK cells in the management of relapse post stem cell transplant with the aim of looking at feasibility of GMP expansion, toxicity and efficacy. A separate trial looking at autologous CIK cells was also conducted. Allogeneic CIK cells were successfully generated for a total of 24 patients including from patients’ own leukepheresed cells in 5 patients who have no access to further donor cells. The median CD3 +  T cell expansion was 9·33 (1·3–38·97) fold and CD3 + CD56 +  NK‐like T cells expansion was 27·77 (2·59–438·93) fold. CIK cells were infused into 16 patients who have either failed or progressed after initial response to various individualized chemotherapy regimen and donor lymphocyte infusion (DLI), for a total of 55 infusions at doses ranging from 10 to 200 million CD3/kg. Evidence of efficacy as defined by a demonstrable response attributable to CIK cell infusion was observed in five patients with minimal toxicity. Other published examples to augment CIK efficacy include co‐culture of CIK with myeloma idiotype or CA19‐9 peptide‐pulsed autologous dendritic cells. Redirecting CIK cells by bispecific antibodies to target has been shown for ovarian carcinoma and B cell lymphoma, as well as B cell ALL by engineering CIK cells to express anti‐CD19 receptor. Exploiting the heterogeneous subsets within the bulk CIK cell culture is another avenue for enhancing its potency.
Surgical and anaesthetic management of anaemia: pros and cons of cell salvage devices
Authors: Thomas D.
Published: June 2012

Autologous cell salvaged blood can be an effective way of minimising allogeneic blood transfusion in the elective and emergency surgical setting.

The controlled use of such devices does require training and assessment of the operator's competence. There remains a reluctance to use in all surgical situations due to clinical objections about the likelihood of contamination of the blood by bacteria, malignant cells and fetal debris.

A well led cell salvage service can ensure that quality assurance is achieved and provides a ready source of red cells for transfusion.
Management of preoperative anemia: The NATA consensus statements
Authors: Bisbe E. , Muñoz M.
Published: June 2012

Preoperative anemia is highly prevalent in major surgery. The haemoglobin (Hb) level is the main independent risk factor for allogeneic blood transfusion (ABT) in surgeries with moderate to high risk of bleeding. Transfusion and preoperative anemia have been associated with worse postoperative outcome and higher mortality in patients undergoing major surgery. On the other hand, hematinic deficiency without anemia may blunt the recovery from postoperative anemia. Thus, early detection and appropriated treatment of anemia in the preoperative setting may reduce the need for transfusion and its negative consequences.

Two multidisciplinary panels of physicians were convened by the ‘Network for the Advancement of Transfusion Alternatives’ (NATA) with the aim of developing practice guidelines for the detection and management of preoperative anemia, reviewing the role of intravenous iron, and formulating recommendations using the GRADE working group methodology. The panels recommend that: (1) elective orthopedic surgical patients should have an Hb level determination 4 weeks before surgery, if possible (Grade 1C); (2) further laboratory testing for differential diagnosis in those with anemia (Grade 1C) and (3) nutritional deficiencies should be treated to rising Hb before surgery to be within the normal range (Grade 1C). Finally, the panels suggest that: (1) erythropoiesis‐stimulating agents be used for anaemic patients in whom nutritional deficiencies have been ruled out, corrected, or both (Grade 2A) and (2) intravenous iron administration during the preoperative period for patients undergoing orthopedic surgery who are expected to develop severe postoperative anemia (Grade 2B).
Developing haemovigilance in Latin American countries
Authors: Faber J.‐C.
Published: June 2012

Haemovigilance is seen nowadays as a potent tool to improve quality and safety in blood transfusion. It needs to be integrated into the quality systems of the institutions active along the blood chain (blood establishments ‐ producers of blood and blood components, hospitals ‐ users of blood transfusions). Not many details are known about haemovigilance systems and activities in countries of Central and South America. A short survey has been undertaken in order to gain a general synoptic overview of haemovigilance in Latin American countries. The results obtained are encouraging, but show at the same time that gaps and weaknesses in the national systems need to overcome. It is obvious that a more detailed and structured study is necessary to assess the actual situation and differences and to consider measures to strengthen haemovigilance in the different national systems.
Evaluation of the efficacy of the Allegretto Wave and the Wavefront‐optimized ablation profile in non‐anterior astigmatisms
Authors: Labiris Georgios , Gatzioufas Zisis , Giarmoukakis Athanassios , Sideroudi Haris , Kozobolis Vassilios
Published: June 2012

Purpose:  To assess the efficacy of the Allegretto Wave and the wavefront‐optimized ablation profile (WFO) in non‐anterior astigmatism correction, in both LASIK and photorefractive keratectomy (PRK) treatments.

Methods:  Seventy‐four refractive surgery candidates were recruited prospectively in a non‐randomized trial. Only one eye from each candidate was randomly enrolled in the study. Of them, 40 eyes underwent LASIK treatment (LG group), while 34 eyes underwent PRK treatment (PG group). Preoperatively, the ocular residual astigmatism (ORA) was calculated for each eye, according to which each astigmatism fault was characterized as primarily anterior or non‐anterior. Twenty LG eyes and 16 PG eyes presented primarily anterior astigmatism (LG‐A and PG‐A subgroups, respectively), while 20 LG eyes and 18 PG eyes demonstrated primarily non‐anterior astigmatism (LG‐NA and PG‐NA subgroups, respectively). Postoperatively, vector analysis of astigmatism correction was conducted. The following indexes were calculated: (i) correction index (CI), (ii) difference vector (DV) and (iii) index of success (IOS).

Results:  Preoperatively, mean differences between manifest and topographic astigmatisms for the LG and the PG subgroups were significant (p:0.006 and p < 0.001, respectively), while postoperatively, aforementioned differences were non‐significant (p:0.18 and p:0.09, respectively). Regarding vector analysis in the LG group, mean CI, IOS and DV were 1.39 ± 1.26, 0.37 ± 1.06 and 0.30 ± 0.51, respectively. Differences in CI, IOS and DV between LG‐A and LG‐NA subgroups were non‐significant. Regarding vector analysis in the PG group, mean CI, IOS and DV were 1.22 ± 0.33, 0.47 ± 0.46 and 0.27 ± 0.25, respectively. Differences in CI, IOS and DV between PG‐A and PG‐NA subgroups were non‐significant.

Conclusions:  Our results suggest that the Allegretto Wave and WFO profile seem to be equally effective in both anterior and non‐anterior astigmatism correction, regardless of treatment type.
Furin mRNA expression in peripheral blood correlates with chronic hepatitis B virus infection
Authors: Chen Yan , Xie Xia , Gu Lin , Huang Xiao‐Hui , Peng Xiao‐Mou
Published: June 2012

Aim:  The mechanisms underlying development of chronic hepatitis B virus (HBV) infection are related to immune tolerance, but are as yet incompletely understood. Furin has been found to be essential for maintenance of peripheral immune tolerance mediated by regulatory T cells (Treg). Such effect of furin on chronic HBV infection was investigated in this study.

Methods:  Peripheral blood from 40 individuals with self‐limited HBV infection, 40 patients with asymptomatic persistent HBV infection and 40 patients with chronic hepatitis B (CHB) was collected and mRNA expression levels of furin, transforming growth factor (TGF)‐β1 and the Treg‐function‐related forkhead transcription factor FoxP3 were detected using quantitative real‐time polymerase chain reaction. CD4+CD25+FoxP3+ Treg were detected using flow cytometry.

Results:  Furin mRNA expression in peripheral blood was significantly higher in patients with persistent HBV infection than in individuals with self‐limited infection (P < 0.01), and was much higher in CHB patients than in those with asymptomatic persistent infection (P < 0.01). Furthermore, furin mRNA was relatively higher in patients with positive hepatitis B e antigen and higher levels of serum HBV DNA (>10 000 copies/mL). In patients with CHB, furin mRNA expression was found to correlate with TGF‐β1 mRNA and FoxP3 mRNA expression using Spearman's rank correlation coefficient test. It was 5.7‐times higher in CD4+CD25+ T cells than in CD4+CD25– T cells and correlated with the frequency of Treg (P < 0.05).

Conclusion:  Furin mRNA expression in peripheral blood correlates with chronic HBV infection and liver damage, and seems to participate in immune inhibitory and anti‐inflammatory mechanisms in HBV infection, mediated by TGF‐β1 and/or Treg.
Vibration Suppression Device Having Variable Inertia Mass by MR-Fluid
Authors: Matsuoka Taichi
Published: June 2012

Authors have proposed a new type of vibration suppression device that utilizes variable inertia mass by fluid which acts as a series inertia mass. The series inertia mass is proportional to not only square of a ratio between a diameter of a piston cylinder and a by-pass pipe, and also a density of the fluid. The resisting force characteristics in case of water or turbine oil were measured. To confirm the proposed theory and investigate effects of vibration control, vibration tests of frequency response and seismic response of one-degree-of-freedom system with the test device were carried out. The experimental results were compared with the calculated results, and the effects of vibration suppression are confirmed experimentally and theoretically. In this paper, in order to derive the effect of a variable inertia mass by using a magnet-rheological fluid, resisting force characteristics of the test device are measured in several cases of magnetic field. The orifice of the by-pass pipe can be changed in virtual, since some rare-earth magnets are installed around the by-pass pipe. It can be seen from experimental results that the inertia force is increasing as stronger magnetic fields. It is pointed out that the variable inertia mass can be derived since clustered magnetic particles in the by-pass pipe act as a virtual orifice under strong magnetic field. The relation between magnetic flux and variable inertia mass are estimated experimentally.
On the Use of 2 DOF Planetary Gears as “Speed Increasers” in Small Hydros and Wind Turbines
Authors: Saulescu Radu , Jaliu Codruta , Climescu Oliver , Diaconescu Dorin Valentin
Published: June 2012

A specific issue both for small hydropower plants and wind turbines refers to the discrepancy between the relatively low speed of the water turbine / wind rotor and relatively high speed of the electric generator: the turbine / rotor has higher performances at lower speeds, while the generator performances are increasing with the speed. Usually, this problem can be solved connecting a proper speed increaser between the turbine and generator. This paper aims to model and simulate a new solving variant for this issue. The solution uses 2 turbines and a generator, connected through a planetary gear with 2 inputs (the turbines) and 1 output (generator). The counter-rotating system functioning is based on the property of the 2 DOF planetary gear sets about summing 2 input motions into an output motion. The transmissions running conditions are modeled in the paper, with examples in relevant applications; the numerical simulation results are comparatively analyzed to those of classical solutions and recommendations concerning their use are settled.
Numerical Simulation of Tread Effects on the Interaction Between Cellular Shear Band Based Non-Pneumatic Tire and Sand
Authors: Ma Jeff , Summers Joshua David , Joseph Paul F.
Published: June 2012

To optimize the design of the non-pneumatic tire for NASA’s new Moon mission, Finite Element Method (FEM) is used to investigate the tread effects on the interaction between cellular shear band-based non-pneumatic tire and sand. The cellular shear bands, which are made of an aluminum alloy (AL7075-T6), are designed to have the same effective shear modulus of 6.5E+6 Pa. The Lebanon sand found in New Hampshire is used and Drucker-Prager/Cap plasticity constitutive law with hardening is employed to model the sand. The tires and tread are treated as deformable elastic bodies. Penalty contact algorithm is used to model the tangential behavior of the contact between the tread and sand and Coulomb’s law is considered for the friction between tire and sand. Numerical results show the deformation of sand and tire. The stress (strain) distribution in sand, tire, and along the interface between them are also presented. The effect of the tread on the contact pressure between tire and sand is explored. Numerical results show that the shear band with cellular geometry of (θ = −65°, h = 21) is the most promising for use in the non-pneumatic tire.
Numerical Investigation of Effect of Membrane Thickness on the Performance of Cellular Shear Band Based Non-Pneumatic Tire
Authors: Ma Jeff , Summers Joshua David , Joseph Paul F.
Published: June 2012

Several treaded cellular shear bands have been investigated and it is found that the shear band with cellular geometry of (θ = −65°, h = 21) is the most promising to give us best contact pressure profile. To further optimize the design of the pneumatic tire made with this cellular geometry for NASA’s new moon mission, the Finite Element Method is used to investigate the effect of the thickness of membranes on the performance of the cellular shear band based non-pneumatic tire. In this research, we use the Lebanon sand found in New Hampshire and employ the Drucker-Prager/Cap plasticity constitutive law with hardening to model the sand. Penalty contact algorithm is used to model the tangential behavior of the contact between the tread and sand and Coulomb’s law is considered for the friction between tire and sand. The tires and tread are treated as deformable elastic bodies. Numerical results show the deformation of sand and tire, the stress (strain) distribution in sand, tire, and along the interface between them for different thickness of the membranes and hub. The effect of membrane thickness on the contact pressure between tire and sand is explored and it reveals that the tire with thickness t = 0.2mm for inner and outer membranes is not acceptable in terms of the elastic deformation of tire and contact pressure profile and the tire with thickness t = 1.0mm gives us best contact pressure profile.
Deformation Prediction of Mouse Embryos in Cell Injection Experiment by a Feedforward Artificial Neural Network
Authors: Abbasi Ali A. , Ahmadian M. T. , Vossoughi G. R.
Published: June 2012

In this study, neural network models have been used to predict the mechanical behaviors of mouse embryos. In addition, sensitivity analysis has been carried out to investigate the influence of the significance of input parameters on the mechanical behavior of mouse embryos. In order to reach these purposes two neural network models have been implemented. Experimental data earlier deduced-by [Flu¨ckiger, M. (2004). Cell Membrane Mechanical Modeling for Microrobotic Cell Manipulation. Diploma Thesis, ETHZ Swiss Federal Institute of Technology, Zurich, WS03/04] –were collected to obtain training and test data for the neural network. The results of these investigations show that the correlation values of the test and training data sets are between0.9988 and 1.0000, which are in good agreement with the experimental observations.
A Protective Structure, Saver During Structural Collapse
Authors: Heidari Alireza , Galishnikova Vera V. , Kani Iradj Mahmoudzadeh
Published: June 2012

In this paper a new protective structure is designed to save human life, in the event of the structural collapse due to an earthquake, terrorist attack or other catastrophic events. The life-saver device discussed here is a moment resisting 3-D steel or composite frames that encapsulates a single or double bedstead, board in the kitchen, worktable in the office or other cases as appropriate. The frame consists of a number of beam-columns of angle cross-section bolted together by gusset plates and topped with a thin steel plate or a rectangular rebar mesh. The collapse of walls and ceiling on top of this structure will result in large plastic deformations in various sections of the frame whereby the energy of the falling debris is dissipated. Despite these large deflections, no harm is inflicted upon the people sleeping inside the frame. The physical behavior of this new life-saving device under real situation of structural collapse also is modeled in ANSYS LS-DYNA software. Combined nonlinear analysis of the frame is performed under dynamic loads developed; the stresses and deformations are carried out. Austenitic twinning induced plasticity (TWIP) steel which has a good combination of both strength and ductility also has been used for modeling and designing this structure and the results has been compared with ordinary steels. The design is verified for the emergency limit state considering the safety of people inside the protective structure.
Return on Investment Analysis for Implementing Barriers to Reverse Engineering
Authors: Knight Darren C. , Mattson Christopher A.
Published: June 2012

Reverse engineering (extracting information about a product from the product itself) is a competitive strategy for many firms and is often costly to innovators. Recent research has proven metrics for estimating the reverse engineering time and barrier and has shown that products can strategically be made more difficult to reverse engineer, thus protecting the innovator. Reverse engineering, however, is only the first phase of attempting to duplicate a product. Imitating — the process of discovering how to physically reproduce the performance of the reverse engineered product in one or more of its performance areas — is the second and final phase. This paper presents metrics for the time and barrier to imitating and shows how they can be joined with reverse engineering metrics to estimate a total time and total barrier to duplicate a product. As there is a cost associated with the design of barriers to reverse engineering and imitating it is important that a return on investment analysis be performed to ensure a profitable endeavor. Details of such an analysis are presented here.
A Novel Approach for Designing Parabolic Mirrors Using Optimized Compliant Bands
Authors: Li Lifang , Kecskemethy Andres , Arif A. F. M. , Dubowsky Steven
Published: June 2012

Parabolic concentrator mirrors are an important component of many solar energy systems, particularly solar mirror collectors. Precision parabolic mirrors are expensive to fabricate and to transport. Here, a new concept for designing and fabricating precision parabolic mirrors is presented. The mirror is formed from a thin flat very flexible metal sheet with a highly reflective surface. Attached to the rear surface of the mirror sheet is a backbone band whose figure is optimized to form the reflective sheet into a precision parabola when its two ends are pulled toward each other. An analytical model to optimize the shape of the band is presented. The validity of the concept is demonstrated using Finite Element Analysis and laboratory experiments. The concept would permit flat mirror elements to be easily fabricated and efficiently packaged and shipped to field sites and assembled into the parabolic trough concentrators with potentially substantial costs reductions compared with conventional methods.
On Measuring Engineering Risk Attitudes
Authors: Van Bossuyt Douglas , Carvalho Lucila , Dong Andy , Tumer Irem Y.
Published: June 2012

Theories of rational decision making hold that decision makers should select the best alternative from the available choices, but it is now well known that decision makers employ heuristics and are subject to a set of psychological biases. Risk aversion or risk seeking attitude has a framing effect and can bias the decision maker towards inaction or action. Understanding decision-makers’ attitudes to risk is thus integral to understanding how they make decisions and psychological biases that might be at play. This paper presents the Engineering-Domain-Specific Risk-Taking (E-DOSPERT) test to measure the risk aversion and risk seeking attitude that engineers have in four domains of engineering risk management: identification, analysis, evaluation and treatment. The creation of the instrument, an analysis of its reliability based on surveying undergraduate engineering students in Australia and the United States, and the validity of the four domains are discussed. The instrument is found to be statistically reliable to measure engineering risk aversion and risk seeking, and to measure engineering risk aversion and risk seeking to risk identification and risk treatment. However, factor analysis of the results suggest that four other domains may better describe the factors in engineers’ attitude to risk.
Computerized Design and Tooth Contact Analysis of Spiral Bevel Gears Generated by the Duplex Helical Method
Authors: Gonzalez-Perez Ignacio , Fuentes Alfonso , Hayasaka Kenichi
Published: June 2012

The duplex helical method, among the different generation methods of spiral bevel gears, has shorter times of manufacturing since both sides of the gear tooth are generated simultaneously. The duplex helical method is based on the application of a helical motion of the cradle respect to the gear blank during the infeed of the sliding base on which the work spindle is mounted. Computerized design and generation of spiral bevel gears by the duplex helical method is a complex problem since the machine-tool settings are specific for each hypoid generator and optimization of the contact pattern and the function of transmission errors is not straightforward. The proposed goals in this research paper are as follows: (i) conversion of the specific machine-tool settings of a given hypoid generator to the so-called neutral machine-tool settings that can be applied at any hypoid generator, (ii) computerized generation of the generated spiral bevel gears by the duplex helical method considering the neutral-machine tool settings, (iii) illustration of results of tooth contact analysis of a spiral bevel gear drive where the pinion has been generated by the duplex helical method for investigation of the contact pattern and the function of transmission errors, and (iv) adjustment of the contact pattern by considering parabolic profiles on the blades of the head-cutter. A numerical example is represented considering a spiral bevel gear drive generated at the Hypoid Generator 106 of Gleason.
3-Dimensional Force Curve and Dissipation Model Acquisition Using the Spectral Inversion Method in Tapping Mode AFM
Authors: Williams Jeffrey C. , Solares Santiago D.
Published: June 2012

Atomic force microscopy (AFM) has been a field driving at exploring nanoscale surfaces and measuring both topography as well as material properties. One of the phenomena that has attracted significant interest is tip-sample dissipation, which was initially investigated by Cleveland and coworkers [Appl. Phys. Lett. 72, 2613–2615 (1998)]. In this paper we expand on that work by developing a method to map the total conservative and non-conservative forces simultaneously in space and as a function of relative tip-sample velocity. This is accomplished through Fourier analysis performed on the response of a torsional harmonic cantilever (THC) probe, previously developed by Sahin and coworkers [Nature Nanotechnology 2, 507–514 (2007)]. The effect of a select group of AFM parameters (cantilever resonant frequency, force constant, quality factor, amplitude set point and excitation amplitude) is simulated in a feasible range of experimental conditions, which maximizes the spatial and velocity range of the oscillating tip, such that useful maps of the total force as a function of tip velocity and position can be acquired. We analyze the observed trends and propose an approach to acquire analytical models of the local tip-sample dissipative and conservative forces.
Simulation of Actuation in Micro-Thermal Switches
Authors: Maghsoudi Elham , Martin Michael James
Published: June 2012

The opening and closing of a RF MEMS switch is simulated using the governing thermal and structural equations. The system is a bridge with a length of 250 microns, a width of 50 microns, and a thickness of 1 micron, in air with a pressure of 5 kPa. Simulations are performed for two different materials: silicon and silicon nitride. Three heating models are used: Distributed heat, concentrated heat at the center, and concentrated heat at the sides of the top plate. The steady state results show that the maximum deflection variation at the center of the bridge versus the total heat changes at the top corresponds to a linear system. For distributed heat, for a specific deflection at the center, closed bridge needs less heat at the top than the free bridge. Variation in the length of the contact results in negligible changes in the maximum deflection. Transient results show that silicon nitride has faster response in comparison with silicon. Silicon nitride has a smaller closing time and opening time in comparison with silicon for the same value of heat, due to the larger expansion coefficient of silicon nitride. Adding concentrated heat at the center yields a larger displacement than adding heat to the sides and show better dynamic behavior. When the heating is changed to a concentrated heat load at the center the required heat is an order of magnitude less than heat added to the sides.
Analytical Modeling of Squeeze Film Damping in Micromirrors
Authors: Moeenfard Hamid , Ahmadian Mohammad Taghi , Farshidianfar Anoushiravan
Published: June 2012

In the current paper, Extended Kantorovich Method (EKM) has been utilized to analytically solve the problem of squeezed film damping in micromirrors. A one term Galerkin approximation is used and following the extended Kantorovich procedure, the solution of the Reynolds equation which governs the squeezed film damping in micromirrors is reduced to solution of two uncoupled ordinary differential equation which can be solved iteratively with a rapid convergence for finding the pressure distribution underneath the micromirror. It is shown that the EKM results are independent of the initial guess function. It is also shown that since EKM is highly convergent, practically one iterate is sufficient for obtaining a precise response. Furthermore using the presented closed form solutions for the squeezed film damping torque, it is proved that when the tilting angle of the mirror is small, the damping is linear viscous one. Results of this paper can be used for accurate dynamical simulation of micromirrors under the effect of squeezed film damping.
An Experimental Investigation of the Efficiency of Planetary Gear Sets
Authors: Talbot David C. , Kahraman Ahmet , Singh Avinash
Published: June 2012

In this paper, results from an experimental study on power losses of planetary gear sets are presented. The experimental set-up includes a specialized test apparatus to operate a planetary gear set under tightly-controlled speed, load and oil temperature conditions, and instrumentation for an accurate measurement of power losses. The test matrix consisted of gear sets having 3 to 6 planets under loaded and unloaded conditions in order to separate load independent (spin) and load dependent (mechanical) power losses. The test matrix also included tests with planet gears having two levels of tooth surface roughness amplitudes as well as tests at varying oil inlet temperature. The results clearly indicate that spin power loss decreases with both reduction of number of planets and increase in oil temperature. Meanwhile, the mechanical power loss decreases with a decrease in oil temperature and reduction in gear surface roughnesses. Results also indicate that mechanical losses can be described by the power transmitted and lost by each planet branch.
Comparison of Gene Expression Programming and Common Metamodeling Techniques in Engineering Design
Authors: Xiao Mi , Gao Liang , Shao Xinyu , Qiu Haobo , Nie Li
Published: June 2012

To reduce the tremendous computational expense of implementing complex simulation and analysis in engineering design, more and more researchers pay attention to the construction of approximation models. The approximation models, also called surrogate models and metamodels, can be utilized to replace simulation and analysis codes for design and optimization. Commonly used metamodeling techniques include response surface methodology (RSM), kriging and radial basis functions (RBF). In this paper, gene expression programming (GEP) algorithm in evolutionary computing is investigated as an alternative technique for approximation. The performance of GEP is examined by its innovative applications to the approximation of mathematical functions and engineering analyses. Compared to RSM, kriging and RBF, GEP is demonstrated to be more accurate for the small sample size. For large sample sets, GEP also shows good approximation accuracy. Additionally, GEP has the best transparency since it can provide explicit and compact function relationships and clear factor contributions. Overall, as a novel metamodeling technique, GEP exhibits great capabilities to provide the accurate approximation of a design space and will have wide applications in engineering design, especially when only a few sample points are selected for approximation.