bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensitivity Analysis to Optimise the Microstructural Properties of an Inconel 718 Component Manufactured by Rotary Forging
Authors: Mangas Ángela , Santos Maite , Zarazua Jose Ignacio , San José Juan , Atxaga Garbiñe , Adarraga Olatz
Published: June 2013

Microstructural behaviour of Inconel 718 using rotary forging as forming process is presented in this paper. This work is the continuation of a previous one, presented in ESAFORM 2012, in which the numerical model was described and previous results about microstructural behaviour were shown. Several simulations are carried out in order to investigate the effect of initial grain size, temperature and strain rate in microstructure. Experimental tests are done in order to validate the numerical results, analyzing the final microstructure. Preparation of the experimental equipment is shown: heating tool system, thermal isolation technique, tool design for the integration of the heating and the isolation system. Heat loss during the transfer operation between furnace and rotary forging machine is measured experimentally, in order to obtain a precise initial temperature value of the part at the beginning of the process. The experimental tests allow validating the simulation work, obtaining the real input parameters for the numerical calculation. Two ways of forming are obtained depending on the initial grain size. The optimal combination of the rotary forging process parameters listed above is determined in achieving a fine and homogeneous microstructure.
Numerical Modeling and Digital Image Correlation Strain Measurements of Coated Metal Sheets Submitted to Large Bending Deformation
Authors: Duchêne Laurent , Ben Bettaieb Amine , Tuninetti Victor , Habraken Anne Marie
Published: June 2013

The recently developed SSH3D solid-shell element [1], which is based on the Enhanced Assumed Strain (EAS) and the Assumed Natural Strain (ANS) techniques, is utilized for the modeling of a severe bending sheet forming process. To improve the element's ability to capture the through thickness gradients, a specific integration scheme was developed. In this paper, the performances of this element for the modeling of the T-bent process were assessed thanks to comparison between experimental and numerical results in terms of the strain field at the outer surface of the sheet. The experimental results were obtained by Digital Image Correlation. It is shown that a qualitative agreement between experimental and numerical results is obtained but some numerical parameters should be optimized to improve the accuracy of the simulation predictions. In this respect, the influence of the penalty coefficient of the contact modeling was analyzed.
Dramatic Speed-Up in FEM Simulations of Various Incremental Forming Processes Thanks to Multi-Mesh Implementation in Forge®
Authors: De Micheli Pascal , Perchat Etienne , Ducloux Richard , Digonnet Hugues , Fourment Lionel
Published: June 2013

Improvements in parallel computing and adaptive remeshing have permitted to simulate a wide range of metal forming processes within few hours or days on modern multi-core workstations. However, they do not tackle the issues encountered in incremental forming processes, making them very challenging. Multi-mesh methods opens very interesting doors in this domain, making possible to take advantage of adaptive remeshing techniques (optimizing the ratio precision/cost) without its usual drawbacks (loss of information and diffusion issues).We present in this article a fully parallel Dual-Mesh implementation in the commercial FEA software FORGE®, compatible with a wide range of other FEM facilities. Speed-up larger than 4 are common for incremental forming simulations, and speed-up larger than 10 can be reached in favorable cases. Parallel efficiency is the same than for our standard computations (>80% for more than 2000 nodes per core).
Deformations in Idealized 2D Extrusion Welding
Authors: Valberg Henry , Nolte Dirk , Torabzadeh Khorasani Sepinood
Published: June 2013

Metal flow inside the container and in the metal behind a butt-ended die bridge in idealized aluminum extrusion welding has been investigated by FEA and experiment with respect to the deformation of the material flowing around the bridge and into the layers close the extrusion seam weld. Along the mid-axis of the extrusion process the effective strain subjected to the extrusion material can be determined in three different ways. One way is to determine the strains from grid pattern experiments that reveal the real deformations. When it comes to FEA there are two options; the strains can be determined from the initial and final positions of a number of material points distributed along the mid-axis of the material, where after traditional theoretical strain-equations can be used to calculate the effective strain distribution along the axis. Another possibility is to use the post-processor of the software to calculate the strain distribution. In this work the effective strain distribution along the mid-axis of the billet inside the container volume were determined by all these three methods. The effective strain in the thin layer of the squeeze zone ahead of the dead zone in front of the die bridge determined from the experiments was found to be much larger than the strains elsewhere along this axis. The same was the case when effective strain was determined by FEA from the computed position of the points, but this strain value was predicted approximately 10% lower than the corresponding value from the experiments in the layer with the heaviest strains. However, when this effective strain distribution was calculated by the post-processor of the software the high-strain layer in the squeeze zone was not revealed at all, instead the effective strains were predicted rather even over the whole length of the mid-axis. Corresponding effective strain distributions were determined along the mid-axis of the extrusion material in the weld chamber also, and after outflow of this material into the extrusion seam weld of the resulting profile where no experimental information is available. When this effective strain distribution was computed by FEA, based on initial and final position of points, very different strain values were obtained as compared to when same strains were collected directly from the post-processor. It is believed that the first results, i.e., the effective strains computed from the points are quite accurate, while those values calculated by the post-processor are less reliable.
Analysis of the Deformation Behavior of Ti-6Al-4V at Elevated Temperatures
Authors: Merklein Marion , Hagenah Hinnerk , Kaupper Markus , Schaub Adam
Published: June 2013

Titanium alloys, such as Ti-6Al-4V, offer favorable characteristics as significant strength, biocompatibility and metallurgical stability at elevated temperatures. These advantages afford the application of parts out of Ti-6Al-4V in a wide field within aerospace, astronautic and medical technologies. Most applied shaping operations for parts out of titanium alloys are forging, casting, forming and machining. In order to develop and improve forming operations numerical simulations are applied during preprocessing. For that purpose mechanical properties of the material such as yield stress and Lankford parameter have to be determined. Due to the two-phase (α + β) microstructure of Ti-6Al-4V, forming operations have to be carried out at elevated temperatures to reduce the required forming force and extend forming limits. Taking the temperature and stress state dependency of the material into consideration, uniaxial tensile and compression tests are accomplished at elevated temperatures, ranging from 400 to 600 °C. Furthermore, the experimentally determined yield stress and Lankford parameter are approximated with the yield loci model proposed by Barlat 2000. The model predicts the flow response of the material, thus provides input data for the finite element analysis of forming processes at different temperature levels.
Finite Element Simulation as a Tool to Evaluate Gear Quality after Gear Rolling
Authors: Khodaee Alireza , Melander Arne
Published: June 2013

Gear rolling is a manufacturing technique for gears with many advantages like reduced material consumption, reduced scrap generation, fast cycle times, good surface quality and improved final properties of the gear wheels compared to conventional production technology based on machining. In order to make use of all these advantages it is desired to reach the final shape of the gear wheel already after rolling. This means that post treatments like grinding should be avoided. This puts high requirements on the shape accuracy after gear rolling. In this paper it was studied if finite element simulation could be used to evaluate the shape accuracy after gear rolling. The measurement of shape accuracy of gear wheels is specified in standards like ISO1328-1. The allowed deviations from nominal shape are often of the order of 10-30 μm for very good qualities. So if such evaluation shall be possible from a finite element simulation the accuracy must be of the same order. In order to have sufficient accuracy of the finite element simulation 2D simulations were performed on a spur gear. The FE code DEFORM was utilized. The shape accuracy was evaluated for gear rolling of two cases. One case had gears with the module of 1 mm. The other case involved gears with a significantly larger module of 4 mm. This was an interesting case since it is known that it is more difficult to roll the gear with good accuracy in large modules.
Time-Efficient and Precise FEM/BEM Simulation of a Cold Forging Process Verified by Tool Load Determination
Authors: Schongen Fabian , Klocke Fritz , Mattfeld Patrick , Rjasanow Sergej , Fleck Marvin , Grzhibovskis Richards
Published: June 2013

Developing green processes establishes new possibilities for cold forging industry. Current technological developments require automotive parts with less mass, but higher material-efficiency. To achieve these goals, high-strength steels and complex geometries are used. The rising process forces lead to increased tool loads and subsequently elastic tool deformation resulting in early tool failure or dimensional deviations. A numerical determination of tool loads during process enables their reduction by a load-dependent design of the tool geometry. Aim of this work is a time-efficient and precise determination of tool loads considering the complete tool system using the example of a lateral extrusion process. By domain decomposition into Finite Element Method (FEM) and Boundary Element Method (BEM) domains and subsequently an integrated FEM/BEM simulation, a significant computation time reduction towards a conventional FEM model is achieved. Experiments of the examined lateral extrusion process provide data for the verification of the investigated process simulation models. In order to be able to validate the simulated elastic tool deformations, strain gauges are installed on the die insert and allow an experimental measurement of the elastic radial die strains. Additionally the simulated process force development and the final workpiece geometry of the simulation models are compared with experimental results.
Speed Roll Laws Influence in a Ring Rolling Process
Authors: Giorleo Luca , Ceretti Elisabetta , Giardini Claudio
Published: June 2013

Ring Rolling is a complex hot forming process used for the production of shaped rings, seamless and axis symmetrical workpieces. The main advantage of workpieces produced by ring rolling, compared to other technological processes, is given by the size and orientation of grains, especially on the worked surface which give to the final product excellent mechanical properties. In this process different rolls (Idle, Axial, Guide and Driver) are involved in generating the desired ring shape. Because each roll is characterized by a speed law that could be set independently by the speed law imposed to the other rolls an optimization is more critical compared with other deformation processes. Usually in industrial environment a milling curve is introduced in order to correlate the Idle and Axial roll displacement, however it must be underlined that different milling curves lead to different loads and energy for ring realization.In this work an industrial case study was modeled by a numerical approach: different milling curves characterized by different Idle and Axial roll speeds laws (constant, linear and quadratic) were designed and simulated. The results were compared in order to identify the best set of Idle and Axial roll speed laws that guarantee a good quality produced ring (lower fishtail) with lower manufacturing loads and energy.
Effect of Tow Meander on the Shear Compliance of Woven Engineering Fabrics Measured Using the Biaxial Bias Extension Test
Authors: Abdiwi Farag , Harrison Philip , Yu Woong Ryeol
Published: June 2013

In this paper, a non-orthogonal constitutive model [1] is used to investigate the effect of sample misalignment due to ‘tow meander’, across the initial blank sheet on the shear compliance of a woven glass fabric, as measured using the biaxial bias extension test with various transverse loads applied [2]. The same statistical distribution and spatial correlations of shear angles observed in the woven glass fabric have been automatically reproduced using ‘VarifabGA’ [3]. The effect of realistic tow directional variability is investigated by generating blanks using VarifabGA and then simulating the biaxial bias extension test using the finite element software, Abaqus ExplicitTM. In order to assign the initial fiber orientation to each element in the mesh, a unique element set is assigned to each element. A MatlabTM code 'InitialAngle.m' has been written to produce two input files; the first 'Mat.inp' includes the material property parameters of each element and the second 'Sec.inp' includes the sections of those elements. Finally, a comparison between the experimental and predicted shear compliance shows the effect of tow directional variabilityorientation to each element in the mesh, a method is introduced which involves assigning a unique element set to each element in the mesh. A Matlab code 'InitialAngle' has been written to produce two input files; the first input file 'Mat.inp' includes the material property parameters of each element and the second input file 'Sec.inp' includes the sections of those elements. Finally, a comparison between the experimental and predicted shear compliance shows the effect of tow misalignment on the shear compliance.
Rheology of Blast Furnace Slags Admitted High Concentration of Titanium Oxides
Authors: Migas Piotr , Korolczuk-Hejnak Marta
Published: June 2013

The applying of burden materials containing titanium compounds in the blast furnace process and the processes of forming titanium carbides and nitrides has a directly impact on the physical and chemical properties of slag and pig iron. Thereby affecting the course of the process, its efficiency and economy. It is known that the dynamic viscosity coefficient of slag – with an increased titanium compounds content in the reducing conditions of the blast furnace - may rapidly change. The products of the reduction reaction, precipitation and separation of titanium compounds are responsible for the thickening effect of the slag and the problems of permeability of blast furnace, causing anomalies in the functioning of the unit. The presence of solid components (particles) in the melts determines the rheological character of the entire system. Authors have performed a rheological study of synthetic furnace slag concentration of TiO2 in the range of 6% to 30%. The measurements were performed at temperatures in the range between 1310-1490oC. The obtained results made it possible to carry out the rheological characteristics of analyzed liquid and semi-solid slag systems and draw of flow curves. Identifying the rheological character of semi-solid slag systems provides opportunities for the development of mathematical modeling of liquid phase flows in a dripping zone of the blast furnace, allowing e.g to indentify the unstable parts of a metallurgical aggregate.
Laser Surface Modification of AISI 1025 Low Carbon Steel Using Pulsed Nd:YAG Laser for Enhance Surface Properties
Authors: Fauzun Fazliana , Aqida Syarifah N. , bin Wahab Md. Saidin
Published: June 2013

This paper presents laser surface modification of AISI 1025 low carbon steel for enhance surface hardness properties. An Nd:YAG laser system with pulse mode was used in order to modify 10mm thick plate surface. Three controlled parameters were laser power, pulse duration and overlap percentage which ranged from 100W to 200W, 0.4 to 1.0ms and 50% to 90% respectively. The treated samples was characterised for metallographic study and hardness. Metallographic study was conducted using optical microscope for laser modified layer thickness and grain size. Hardness properties were measured using Vickers indenter. The result show that hardness of laser treated area increased due to fine grain size produced in the laser modified layer. The overlapping rates increase significantly with decreasing laser scanning speed. These findings are important high wear applications.
Energy-Efficient Solid Forward Extrusion through Hybridization Based on Process-Integrated Resistance Heating
Authors: Terhorst Michael , Klocke Fritz , Niebes Stefan , Schongen Fabian , Mattfeld Patrick
Published: June 2013

In this paper a hybridized solid forward extrusion process is proposed that uses a process-integrated resistance heating for the energy-efficient heating of the workpiece material in order to avoid the occurrence of chevron cracks. As for the process-integration of the resistance heating two variations are regarded: the preheating of the wrought material prior to the forming process as well as a resistance heating concurrent with the extrusion process. Based on a three-shouldered solid forward extrusion of Cf53 with emerging chevron cracks the broad temperature interval for crack elimination is derived from experiments where the wrought material is preheated in a furnace. With this derived temperature a numerical approach for the dimensioning of a resistance heating of both prior to the forming process and during extrusion is shown. The approach is based on solving the Fourier heat transfer equation using both numerical algorithms in MATLAB and finite element method (FEM) in Deform-2D. In a final step the two scenarios heating prior to and during the extrusion process are evaluated in terms of their energy-efficiency using FEM.
Hot Stretch Forming of a Titanium Alloy Component for Aeronautic: Mechanical and Modeling
Authors: Astarita Antonello , Armentani Enrico , Ceretti Elisabetta , Giorleo Luca , Mastrilli Pasquale , Paradiso Valentino , Scherillo Fabio , Squillace Antonino , Velotti Carla
Published: June 2013

The development of Hot Stretch Forming (HSF) by the Cyril Bath Company was in response to airframe designers needing to use Titanium airframe components in new commercial aircraft. Many of the airframe component structures are designed to fit against the inside radius of the fuselage curvature. By combining traditional stretch forming technology with hot titanium forming techniques, the HSF guarantees a saving in material and machining time, which are two serious cost issues for today’s aircraft manufacturers. In addition, the process allows for consistent quality in a productively efficient manner, assuring the sustainable attainment of delivery and build schedules. The HSF is an innovative process on the cutting edge of the technologies, so focused research is needed in order to better understand this technology and develop new applications for this process. in this paper the HSF process is investigated: the machine and the different steps that characterized the process were described and the results of a preliminary experimental campaign was discussed focusing the attention on the metallurgical aspect. Moreover a modeling of the process was executed in order to study the stresses and strains undergone by the material among the deformation.
3D Modelling of Doped and Multi-Materials during Sintering of a Granular Packing
Authors: Tossoukpe Howatchinou , Valdivieso François , Bruchon Julien , Drapier Sylvain
Published: June 2013

This paper presents a level set framework for the modelling of doping effect during surfacediffusion phenomena in a granular packing. The molecular flux of the doped compound is related tothe chemical potentials of all the diffusion species. The evolution of the grain compact is simulatedin three dimensions, based on the resulting kinetic law relating the surface diffusion velocity to thethermodynamic driving force. An anisotropic adaptive mesh, based on the level set function propertiesis used to refine the mesh in the surroundings of the grain surface. The simulations have been perfomedby using parallel computing strategy.
Electromagnetic Sheet Bulging: Analysis of Process Parameters by FE Simulations
Authors: Correia Joao Pedro M. , Ahzi Saïd
Published: June 2013

Electromagnetic forming is a non-conventional forming process and is classified as a high-speed forming process. It provides certain advantages as compared to conventional forming processes: improved formability, high repeatability and productivity, reduction in tooling cost and reduction of springback and of wrinkling. However, various process parameters affect the performance of the electromagnetic forming system. Finite element simulations are very useful to optimize a process because they can reduce time and costs. With the aim of investigating the effects of the process parameters on the deformed blank geometry, finite element simulations of an electromagnetic sheet bulging test have been performed in this work. Furthermore the role of first impulse of discharged current is also investigated.
Achieving High Strains in Sheet Metal Characterization Using the In-Plane Torsion Test
Authors: Yin Qing , Kolbe Jörg , Haupt Marco , Tekkaya A. Erman
Published: June 2013

The in-plane torsion test is used to determine plastic flow curves for sheet metals. Very high strains of up to an equivalent strain of 1.0 can be measured since there are no edge effects in a plane torsion specimen. In combination with optical strain measurement, an efficient evaluation method for this test was developed. However, the achievable strain varies for each material. The slippage between the inner clamps and the specimen was found to be one main limiting effect. In order to improve the clamping capability, different surface corrugations are applied at the inner clamping tool. Four sheet materials, DC06, DP600, AA6016, and AA5182 are selected for testing this new clamping setup. While the flow curve of DC06 is determined until a strain of 1.0 and above, such high values cannot be achieved for the other materials. It can be shown that the measurable strain can be increased by the choice of the surface corrugation features at the inner clamping. For the DP steel and the aluminum alloys, the flow curve can be determined until equivalent plastic strains of 0.5 to 0.6, which is also a significant improvement compared to many other sheet metal testing methods.
Modeling Approach for the Determination of Material Flow and Welding Conditions in Porthole Die Extrusion with Gas Pocket Formation
Authors: Schwane Martin , Gagliardi Francesco , Jäger Andreas , Khalifa Nooman Ben , Tekkaya A. Erman
Published: June 2013

The material flow in porthole dies is of crucial importance with regard to the seam weld quality in aluminum extrusion. Thus, experimental as well as numerical investigations on the effect of die geometry on the material flow were conducted. The experimental tests were performed on a 10 MN laboratory extrusion press. During the experimental trials, the extrusion ratio was varied by means of exchangeable die plates. Since the modular die allows removal of the aluminum in the welding chamber as well as in the feeders after the process, the material flow could be inspected in detail. The experimental results were used to improve the accuracy of FEA simulations, which were also conducted by commercial software. An attempt was made to improve the result quality of Eulerian FEA model regarding the simulation of an extrusion process with a gas pocket in the welding chamber. The influence of the modeling approach on the predicted material flow and on the contact pressure was analyzed and finally linked to the seam weld quality.
Design Criteria in Numerical Design of Profile Extrusion Dies
Authors: Siegbert Roland , Elgeti Stefanie , Behr M. , Kurth K. , Windeck C. , Hopmann C.
Published: June 2013

Abstract. The rather unintuitive and non-linear behavior of plastics melts is a well-known obstacle in the design and manufacturing cycle of profile extrusion dies. This is reflected, for example, in the so-called running-in experiments, in which the already manufactured die is modified up to 15 times until the final product, shaped by the die, matches the quality requirements. Besides a homogeneous outflow velocity and thus homogeneous material distribution, an appropriate die swell is a second design objective which complicates the reworking of the manufactured die. We are conducting work to shorten the manual running-in process by the means of numerical shape optimization, making this process significantly less costly and more automatic. From a numerical point of view, the extrusion process is not as challenging as high-speed flows, since it can be described by steady Stokes equations without major loss of accuracy. The drawback, however, is the need for ac- curate modeling of the plastics behavior, which generally calls for shear-thinning or even viscoelastic models, as well as for 3D computations, leading to large computational grids. The intention of this paper is to investigate the application of specific geometry features in extrusion dies and their influence on objective functions in an optimization framework. However, representative objective functions concerning die swell and the incorporation of known geometry features, as used by experienced die designers, into the optimization framework still remain a challenge. Hence, the topics discussed are the influence of the mentioned geometry features on existing objective functions as well as an outlook on an algorithmic implementation into the optimization process with regard to representative objective functions.
Composite Extrusion of Thin Aluminum Profiles with High Reinforcing Volume
Authors: Pietzka Daniel , Ben Khalifa Nooman , Gerke Stephanie , Tekkaya A. Erman
Published: June 2013

Extruded aluminium profiles with a variety of different cross-sections are mainly used in lightweight structures for transportation means. Examples are stringer profiles in the fuselage of airplanes or profiles in chassis of trains and cars. Nowadays, the mass reduction of a lightweight structure is an important issue to achieve lower fuel consumption and CO2 emissions. With an increased portion of aluminium profiles the mass of structures can be reduced considerably in contrast to the application of steel parts, due to the lower density of aluminium. However, this is coupled with disadvantages such as the lower specific stiffness and strength of the material. One possibility to improve the mechanical properties of aluminium profiles without a considerable increase of their weight is the embedding of reinforcing elements during the extrusion process. Special porthole extrusion dies are used to feed reinforcing elements in form of high strength steel wires separate from the aluminium material flow. In the welding chamber of the die both materials bond together to a composite profile. To achieve a high advantage of the technology for lightweight applications a high reinforcing volume of aluminium profiles is targeted. A comparatively high reinforcing volume can be reached either by a high number of reinforcing elements or through a reduction of the profile wall thickness. A high number of reinforcing elements leads to a small distance between the single elements in the profile cross-section. The paper will show the results of an experimental and numerical analysis which were carried out to determine the minimum distance between the reinforcing elements as well as the minimum profile thickness. In the trials different arrangements of the elements in the profile cross-section and profile thicknesses were considered. Main parameters which have an influence on the process stability were analyzed and a process window for the manufacture of thin profiles with high reinforcing volume was deduced.
Sequential Optimization of Strip Bending Process Using Multiquadric Radial Basis Function Surrogate Models
Authors: Havinga Jos , Klaseboer Gerrit , van den Boogaard A.H.
Published: June 2013

Surrogate models are used within the sequential optimization strategy for forming processes. A sequential improvement (SI) scheme is used to refine the surrogate model in the optimal region. One of the popular surrogate modeling methods for SI is Kriging. However, the global response of Kriging models deteriorates in some cases due to local model refinement within SI. This may be problematic for multimodal optimization problems and for other applications where correct prediction of the global response is needed. In this paper the deteriorating global behavior of the Kriging surrogate modeling technique is shown for a model of a strip bending process. It is shown that a Radial Basis Function (RBF) surrogate model with Multiquadric (MQ) basis functions performs equally well in terms of optimization efficiency and better in terms of global predictive accuracy. The local point density is taken into account in the model formulation.
Deferasirox in Indian children with thalassemia major: 3 years experience
Authors: Dhamija Mayank , Mahajan Amita , Kalra Manas , Virmani Anju
Published: June 2013

Objective: To evaluate the efficacy and safety of the oral iron chelator deferasirox in treating transfusional hemosiderosis in a cohort of Indian children with thalassemia major with high iron load. Materials and Methods: The first 50 children (age 2-18 yrs) with thalassemia major to commence deferasirox at our center were enrolled and followed up for a period of 36 months between April 2008 and March 2011. The dose of deferasirox was determined by their baseline serum ferritin and was adjusted to a maximum of 40 mg/kg/day depending on response. Ferritin levels, SGOT, SGPT, serum creatinine and urine albumin were regularly monitored. Results: Of the 50 patients, 76% documented a significant decline in serum ferritin ( P<0.05). Seven (14%) patients had a stable ferritin whilst 5 patients (10%) documented an increase over the study period. The mean serum ferritin at baseline, 12, 24 and 36 months was 4354, 3260, 3290 and 3042, respectively ( P<0.05). The median serum ferritin at the same time points was 3555, 2810, 2079 and 2271, respectively ( P<0.05). No severe toxicity was seen. Conclusions: Deferasirox, when given in doses ≥30 mg/kg, was found to be an effective and safe drug in reducing transfusional hemosiderosis. Thirty five (70%) needed dose escalation upto 40 mg/kg/day. Fifteen (30%), however did not achieve a negative iron balance despite maximally permissible doses.
Case of childhood laryngeal papillomatosis with metastatic carcinoma esophagus in adulthood
Authors: Shetty Nishitha , Prabhash Kumar , Joshi Amit , Sayed Suhail I. , Sharma Shilpi , Noronha Vanita , Deshmukh Anuja , Chaukar Devendra , Kane S , D′cruz Anil K. ,   Gopal
Published: June 2013

A young male patient was diagnosed to have laryngeal papillomas at the age of 3 years for which he underwent permanent tracheostomy and also multiple surgical and laser excision procedures. Then, later in life, the patient had progressive breathlessness and dysphagia. On examination, he had supraclavicular lymphadenopathy showing squamous carcinoma pathology. Since laryngeal papillomas have a high propensity to transform into laryngeal squamous cell carcinoma, he was first evaluated for laryngeal carcinoma which was negative. Esophagoscopy showed a growth in the esophagus, the biopsy of which was positive for squamous malignant cells. Patient was then started on palliative chemotherapy with combination of paclitaxel and carboplatin, and at progression with weekly nanoxel with stable disease. This is a rare case of childhood laryngeal papillomatosis progressing to metastatic esophageal carcinoma. This case has been presented to highlight the fact that patients with laryngeal papillomas are not only at high risk of progressing to laryngeal carcinoma but can also have other malignancies of the upper aerodigestive tract and lung. Most of them have been correlated to human papilloma virus (HPV), but in our patient HPV DNA was negative.
Spontaneous Collapse of Bilateral Bullae with Conservative Management
Authors: Shariff Masood A , Singh Vijay A , Daniele Edward D , Goyal Nikhil , Peykova Deliana , Nabagiez John P , Rosell Frank M
Published: June 2013

We report a case of bilateral apical lung bullae that collapsed following an episode of community-acquired pneumonia with bilateral air fluid levels. With standard treatment for community-acquired pneumonia, management of a patient that may have qualified for bullectomy, (as in our case) showed complete resolution of all pathology without surgical intervention. Conservative management took precedence in alleviating pathology over surgical intervention.
Effects of automated immunization registry reporting via an electronic health record deployed in community practice settings
Authors: Phillips A. , Keeling J. , Kaushal R. , Senathirajah Y. , Merrill J.
Published: June 2013

Background: Among the expected benefits of electronic health records (EHRs) is increased reporting of public health information, such as immunization status. State and local immunization registries aid control of vaccine-preventable diseases and help offset fragmentation in healthcare, but reporting is often slow and incomplete. The Primary Care Information Project (PCIP), an initiative of the NYC Department of Health and Mental Hygiene, has implemented EHRs with immunization reporting capability in community settings.

Objective and Methods: To evaluate the effect of automated reporting via an EHR on use and efficiency of reporting to the NY Citywide Immunization Registry, we conducted a secondary analysis of 1.7 million de-identified records submitted between January 2007 and June 2011 by 217 primary care practices enrolled in PCIP, pre and post launch of automated reporting via an EHR. We examined differences in records submitted per day, lag time, and documentation of eligibility for subsidized vaccines.

Results: Mean submissions per day did not change. Automated submissions of new and historical records increased by 18% and 98% respectively. Submissions within 14 days increased from 84% to 87%, and within 2 days increased from 60% to 77%. Median lag time decreased from 13 to 10 days. Documentation of eligibility decreased. Results are significant at p<0.001.

Conclusions: Significant improvements in registry use and efficiency of reporting were found after launch of automated reporting via an EHR. A decrease in eligibility documentation was attributed to EHR workflow. The limitations to comprehensive evaluation found in these data, which were extracted from a registry initiated prior to widespread EHR implementation suggests that reliable evaluation of immunization reporting via the EHR may require modifications to legacy registry databases.

Citation: Merrill J, Phillips A, Keeling J, Kaushal R, Senathirajah Y. Effects of automated immunization registry reporting via an electronic health record deployed in community practice settings. Appl Clin Inf 2013; 4: 267–275

http://dx.doi.org/10.4338/ACI-2013-02-CR-0009
Newly observed peroxides and the water effect on the formation and removal of hydroxyalkyl hydroperoxides in the ozonolysis of isoprene
Authors: Huang D. , Chen Z. M. , Zhao Y. , Liang H.
Published: June 2013

Abstract. The ozonolysis of alkenes is considered to be an important source of atmospheric peroxides, which serve as oxidants, reservoirs of HOx radicals, and components of secondary organic aerosols (SOAs). Recent laboratory investigations of this reaction identified hydrogen peroxide (H2O2) and hydroxymethyl hydroperoxide (HMHP) in ozonolysis of isoprene. Although larger hydroxyalkyl hydroperoxides (HAHPs) were also expected, their presence is not currently supported by experimental evidence. In the present study, we investigated the formation of peroxides in the gas phase ozonolysis of isoprene at various relative humidities on a time scale of tens of seconds, using a quartz flow tube reactor coupled with the online detection of peroxides. We detected a variety of conventional peroxides, including H2O2, HMHP, methyl hydroperoxide, bis-hydroxymethyl hydroperoxide, and ethyl hydroperoxide, and interestingly found three unknown peroxides. The molar yields of the conventional peroxides fell within the range of values provided in the literature. The three unknown peroxides had a combined molar yield of ~ 30% at 5% relative humidity (RH), which was comparable with that of the conventional peroxides. Unlike H2O2 and HMHP, the molar yields of these three unknown peroxides were inversely related to the RH. On the basis of experimental kinetic and box model analysis, we tentatively assigned these unknown peroxides to C2−C4 HAHPs, which are produced by the reactions of different Criegee intermediates with water. Our study provides experimental evidence for the formation of large HAHPs in the ozonolysis of isoprene (one of the alkenes). These large HAHPs have a sufficiently long lifetime, estimated as tens of minutes, which allows them to become involved in atmospheric chemical processes, e.g., SOA formation and radical recycling.
An inverse modeling method to assess the source term of the Fukushima nuclear power plant accident using gamma dose rate observations
Authors: Saunier O. , Mathieu A. , Didier D. , Tombette M. , Quélo D. , Winiarek V. , Bocquet M.
Published: June 2013

Abstract. The Chernobyl nuclear accident and more recently the Fukushima accident highlighted that the largest source of error on consequences assessment is the source term including the time evolution of the release rate and its distribution between radioisotopes. Inverse modeling methods, which combine environmental measurements and atmospheric dispersion models, have proven efficient in assessing source term due to an accidental situation (Gudiksen, 1989; Krysta and Bocquet, 2007; Stohl et al., 2012a; Winiarek et al., 2012). Most existing approaches are designed to use air sampling measurements (Winiarek et al., 2012) and some of them also use deposition measurements (Stohl et al., 2012a; Winiarek et al., 2013) but none of them uses dose rate measurements. However, it is the most widespread measurement system, and in the event of a nuclear accident, these data constitute the main source of measurements of the plume and radioactive fallout during releases. This paper proposes a method to use dose rate measurements as part of an inverse modeling approach to assess source terms. The method is proven efficient and reliable when applied to the accident at the Fukushima Daiichi nuclear power plant (FD-NPP). The emissions for the eight main isotopes 133Xe, 134Cs, 136Cs, 137Cs, 137mBa, 131I, 132I and 132Te have been assessed. Accordingly, 103 PBq of 131I, 35.5 PBq of 132I, 15.5 PBq of 137Cs and 12 100 PBq of noble gases were released. The events at FD-NPP (such as venting, explosions, etc.) known to have caused atmospheric releases are well identified in the retrieved source term. The estimated source term is validated by comparing simulations of atmospheric dispersion and deposition with environmental observations. The result is that the model-measurement agreement for all of the monitoring locations is correct for 80% of simulated dose rates that are within a factor of 2 of the observed values. Changes in dose rates over time have been overall properly reconstructed, especially in the most contaminated areas to the northwest and south of the FD-NPP. A comparison with observed atmospheric activity concentration and surface deposition shows that the emissions of caesiums and 131I are realistic but that 132I and 132Te are probably underestimated and noble gases are likely overestimated. Finally, an important outcome of this study is that the method proved to be perfectly suited to emergency management and could contribute to improve emergency response in the event of a nuclear accident.
Relation of zonal plasma drift and wind in the equatorial F region as derived from CHAMP observations
Authors: Park J. , Lühr H.
Published: June 2013

Abstract. In this paper we estimate zonal plasma drift in the equatorial ionospheric F region without counting on ion drift meters. From June 2001 to June 2004 zonal plasma drift velocity is estimated from electron, neutral, and magnetic field observations of Challenging Mini-satellite Payload (CHAMP) in the 09:00–20:00 LT sector. The estimated velocities are validated against ion drift measurements by the Republic of China Satellite-1/Ionospheric Plasma and Electrodynamics Instrument (ROCSAT-1/IPEI) during the same period. The correlation between the CHAMP (altitude ~ 400 km) estimates and ROCSAT-1 (altitude ~ 600 km) observations is reasonably high (R ≈ 0.8). The slope of the linear regression is close to unity. However, the maximum westward drift and the westward-to-eastward reversal occur earlier for CHAMP estimates than for ROCSAT-1 measurements. In the equatorial F region both zonal wind and plasma drift have the same direction. Both generate vertical currents but with opposite signs. The wind effect (F region wind dynamo) is generally larger in magnitude than the plasma drift effect (Pedersen current generated by vertical E field), thus determining the direction of the F region vertical current.
Processing and analysing an ensemble of climate projections for the joint research project KLIWAS
Authors: Imbery F. , Plagemann S. , Namyslo J.
Published: June 2013

Abstract. The research programme KLIWAS, funded by the German Federal Ministry of Transport, Building and Urban affairs is focussed on climate change and its impacts on waterways and navigation for Germany in the 21th century. In order to derive sound statements about the range of possible future climate changes, KLIWAS use hydro-meteorological information derived from a wide variety of global and regional climate models. In the framework of KLIWAS emphasis is taken on the quantification of uncertainties in climate model output. Therefore, a 19-member ensemble of climate model runs was used. On the basis of the SRES-scenario A1B the probabilities of changes in air temperature, precipitation amount, global radiation and several climate indices were computed for near (2021 to 2050) and distant (2071–2100) scenario horizons. Furthermore, statistical downscaling techniques, including approved bias correction methods, were used to provide a spatial high-resolution sub-ensemble of eight climate model simulations for climate change impact investigations.
Natural and Fukushima-derived radioactivity in macroalgae and mussels along the Japanese shoreline
Authors: Baumann Z. , Casacuberta N. , Baumann H. , Masqué P. , Fisher N. S.
Published: June 2013

Abstract. Following the failure of the nuclear power plant in Fukushima Prefecture in March 2011, peer-reviewed publications describing radioactivity levels in organisms inhabiting coastal environments are scarce. This paper reports on elevated levels of 134Cs and 137Cs in macroalgae and mussels (up to ~ 800 Bq kg−1 dry wt.) in June 2011. Cs concentrations in biota sampled in early June 2011 were higher in areas south of Fukushima than sampled in the last third of the month north of Fukushima. Activity concentrations from 134+137Cs in organisms south of Fukushima were comparable to or lower than those from the naturally occurring 40K in the same samples. While 210Pb and 210Po concentrations were generally lower than these other radionuclides, 210Po as an α-emitter is more significant from a radiological viewpoint than γ-emitters as it can inflict greater biological damage. By applying known bioconcentration factors of Cs in biota, measured biota concentrations of Cs were also used to estimate Cs concentrations in coastal seawater to be in the range of 102–103 Bq m−3. These estimates show that, 3 months after the accident and maximal release of radioactive Cs, levels of Cs persisted in coastal waters, although at levels that were two orders of magnitude lower than at the time of release. These June coastal seawater Cs levels were four orders of magnitude above Cs concentrations off Japan prior to the Fukushima disaster.
UV-induced carbon monoxide emission from living vegetation
Authors: Bruhn D. , Albert K. R. , Mikkelsen T. N. , Ambus P.
Published: June 2013

Abstract. The global burden of carbon monoxide (CO) is rather uncertain. In this paper we address the potential for UV-induced CO emission by living terrestrial vegetation surfaces. Real-time measurements of CO concentrations were made with a cavity enhanced laser spectrometer connected in closed loop to either an ecosystem chamber or a plant-leaf scale chamber. Leaves of all examined plant species exhibited emission of CO in response to artificial UV-radiation as well as the UV-component of natural solar radiation. The UV-induced rate of CO emission exhibited a rather low dependence on temperature, indicating an abiotic process. The emission of CO in response to the UV-component of natural solar radiation was also evident at the ecosystem scale.
Response of benthic foraminifera to ocean acidification in their natural sediment environment: a long-term culturing experiment
Authors: Haynert K. , Schönfeld J. , Schiebel R. , Wilson B. , Thomsen J.
Published: June 2013

Abstract. Calcifying foraminifera are expected to be endangered by ocean acidification, However, the response of a complete community kept in natural sediment and over multiple generations under controlled laboratory conditions has not been constrained to date. During six month incubation, foraminiferal assemblages were treated with pCO2 enriched seawater of 430, 907, 1865 and 3247 μatm pCO2. The fauna was dominated by Ammonia aomoriensis and Elphidium species, whereas agglutinated species were rare. After 6 months incubation, pore water alkalinity was much higher in comparison to the overlying seawater. Consequently, the saturation state of Ωcalc was much higher in the sediment than in the water column in all pCO2 treatments and remained close to saturation. As a result, the life cycle of living assemblages was largely unaffected by the tested pCO2 treatments. Growth rates, reproduction and mortality, and therefore population densities and size-frequency distribution of Ammonia aomoriensis varied markedly during the experimental period. Growth rates varied between 25 and 50 μm per month, which corresponds to an addition of 1 or 2 new chambers per month. According to the size-frequency distribution, foraminifera start reproduction at a diameter of 250 μm. Mortality of large foraminifera was recognized, commencing at a test size of 285 μm at a pCO2 ranging from 430 to 1865 μatm, and of 258 μm at 3247 μatm. The total organic content of living Ammonia aomoriensis has been determined to be 4.3% of dry weight. Living individuals had a calcium carbonate production rate of 0.47 g m−2 yr−1, whereas dead empty tests accumulated at a rate of 0.27 g m−2 a−1. Although Ωcalc was close to 1, some empty tests of Ammonia aomoriensis showed dissolution features at the end of incubation. In contrast, tests of the subdominant species, Elphidium incertum, stayed intact. This species specific response could be explained by differences in the elemental test composition, in particular the higher Mg-concentrations in Ammonia aomoriensis tests. Our results emphasize that the sensitivity to ocean acidification of endobenthic foraminifera in their natural sediment habitat is much lower compared to the experimental response of specimens isolated from the sediment.