bluuebunny/crossref_metadata_2025 huggingface dataset:
Consensus Recommendations for Immunosuppressive Treatment of Dogs with Glomerular Disease Based on Established Pathology
Authors:   IRIS Canine GN Study Group Established Pathology Subgroup, Segev G. , Cowgill L.D. , Heiene R. , Labato M.A. , Polzin D.J.
Published: November 2013

The purpose of this report was to provide consensus recommendations for the use of immunosuppressive therapy in dogs with active glomerular diseases. Recommendations were developed based on comprehensive review of relevant literature on immunosuppressive therapy of glomerular disease in dogs and humans, contemporary expert opinion, and anecdotal experience in dogs with glomerular disease treated with immunosuppression. Recommendations were subsequently validated by a formal consensus methodology. The Study Group recommends empirical application of immunosuppressive therapy for dogs with severe, persistent, or progressive glomerular disease in which there is evidence of an active immune‐mediated pathogenesis on kidney biopsy and no identified contraindication to immunosuppressive therapy. The most compelling evidence supporting active immune‐mediated mechanisms includes electron‐dense deposits identified with transmission electron microscopic examination and unequivocal immunofluorescent staining in the glomeruli. For diseases associated with profound proteinuria, attendant hypoalbuminemia, nephrotic syndrome, or rapidly progressive azotemia, single drug or combination therapy consisting of rapidly acting immunosuppressive drugs is recommended. The Study Group recommends mycophenolate alone or in combination with prednisolone. To minimize the adverse effects, glucocorticoids should not be used as a sole treatment, and when used concurrently with mycophenolate, glucocorticoids should be tapered as quickly as possible. For stable or slowly progressive glomerular diseases, the Study Group recommends mycophenolate or chlorambucil alone or in combination with azathioprine on alternating days. Therapeutic effectiveness should be assessed serially by changes in proteinuria, renal function, and serum albumin concentration. In the absence of overt adverse effects, at least 8 weeks of the rapidly acting nonsteroidal drug therapy and 8–12 weeks of slowly acting drug therapy should be provided before altering or abandoning an immunosuppressive trial.
Regulation of toxin production in the pathogenic clostridia
Authors: Carter Glen P. , Cheung Jackie K. , Larcombe Sarah , Lyras Dena
Published: November 2013

The genus Clostridium comprises a large, heterogeneous group of obligate anaerobic, Gram‐positive spore forming bacilli. Members of this genus are ubiquitous in the environment and although most species are considered saprophytic, several are pathogenic to both humans and animals. These bacteria cause a variety of diseases including neuroparalysis, gas gangrene, necrotic enteritis, food poisoning, toxic shock syndrome and pseudomembraneous colitis, which in most cases arise as a consequence of the production of potent exotoxins. Treatment options are often limited, underscoring the need for new treatment strategies and novel therapeutics. Understanding the fundamental mechanisms and signals that control toxin production in the pathogenic clostridia may lead to the identification of novel therapeutic targets that can be exploited in the development of new antimicrobial agents.
Glomerular expression of myxovirus resistance protein 1 in human mesangial cells: Possible activation of innate immunity in the pathogenesis of lupus nephritis
Authors: Watanabe Shojiro , Imaizumi Tadaatsu , Tsuruga Kazushi , Aizawa Tomomi , Ito Tatsuya , Matsumiya Tomoh , Yoshida Hidemi , Joh Kensuke , Ito Etsuro , Tanaka Hiroshi
Published: November 2013

Since viral infections activate type I interferon (IFN) pathways and cause subsequent release of IFN‐dependent proinflammatory chemokines and cytokines, the innate immune system plays an important role in the pathogenesis of lupus nephritis (LN). It has been reported that human myxovirus resistance protein 1 (Mx1), a type I IFN‐dependent transcript, acts against a wide range of RNA viruses. Although the expression of Mx1 in biopsy specimens obtained from patients with dermatomyositis and cutaneous lupus has been described, the expression of Mx1 in human mesangial cells (MCs) has remained largely unknown. We treated normal human MCs in culture with polyinosinic‐polycytidylic acid (poly IC), an authentic double‐stranded RNA, and analyzed the expression of Mx1 by reverse transcription‐polymerase chain reaction and western blotting. To elucidate the poly IC‐signalling pathway, we subjected the cells to RNA interference against IFN‐β. We also conducted an immunofluorescence study to examine mesangial Mx1 expression in biopsy specimens from patients with LN. Poly IC‐induced Mx1 expression in MCs are shown both time‐ and dose‐dependently, and RNA interference against IFN‐β inhibited poly IC‐induced Mx1 expression. Intense glomerular Mx1 expression was observed in biopsy specimens from patients with LN, whereas negative staining occurred in specimens from patients with IgA nephropathy or purpura nephritis. These preliminary observations support, at least in part, the theory of innate immune system activation in the pathogenesis of LN.
Clinical features and mutation of NPHP5 in two Chinese siblings with Senior‐Løken syndrome
Authors: Tong Huajuan , Yue Zhihui , Sun Liangzhong , Chen Huiqin , Wang Weiguang , Wang Haiyan
Published: November 2013

Senior‐Løken syndrome is a rare syndromic form of nephronophthisis that is associated with retinal dystrophy. Presently, seven genes (NPHP1‐6 and NPHP10) have been associated with Senior‐Løken syndrome. NPHP5 mutations are known to cause classical Senior‐Løken syndrome. Here, we report two sisters (II‐4, II‐5) from a Chinese Han ethnic family who presented with classical Senior‐Løken syndrome. Both affected sisters exhibited Leber's congenital amaurosis and juvenile nephronophthisis that progressed to end‐stage renal disease by the age of 16 years and 9 months in patient II‐4 and 12 years and 9 months in patient II‐5. Sequence analysis showed a homozygous truncated mutation in NPHP5, c.1090C>T (p.R364X), in the patient II‐4. This mutation is predicted to introduce a new open reading frame that results in the truncation of the C‐terminal 235 amino acids of nephrocystin‐5 and its consequent loss of function. Both parents carried a single heterozygous mutation in the same position, and no homozygous deletion of NPHP1 was found in this pedigree.
New strategies and findings for behavioral interventions in autism spectrum disorders
Authors: Lord Catherine , Jones Rebecca M.
Published: November 2013

Behavioral interventions are the major source of change for children with autism spectrum disorders and a major cost to families and government. In the last 5 years, a number of carefully designed intervention studies have provided new information about the effects of caregiver training and direct instruction on behavior treatments. Outcomes of these interventions are neither easily assessed nor simple, but are dependent on child characteristics as well as caregiver skills and attitudes. Some interventions aimed at specific skills have similar results, yet there is growing evidence that child interventions may have different effects than caregiver training, although both may affect outcomes in the long term. New research strategies and findings are discussed, with a focus on how underlying behaviors and specific components may contribute to intervention outcomes.
Valuing lively materialities: Bio‐economic assembling in the making of new meat futures
Authors: Henry Matthew , Roche Michael
Published: November 2013

Variable profitability within New Zealand's red meat sector has again led to the problematisation of its constitutive relationships. This problematisation has almost inevitably focused on the structural transformation of the sector. Rather than beginning with structural transformation, we draw on assemblage theory to trace the assembling work associated with three unstable bio‐economic projects: Primera lamb, Wagyu beef and FarmIQ. The paper offers a cautionary assessment of experimentation and innovation in the red meat sector, and suggests that the search for an enduring structural solution will continually be disrupted by the lively materialities upon which the red meat sector relies.
Pediatric invasive streptococcal infection in northern and eastern regions of Hokkaido, Japan from 2010 to 2012
Authors: Sakata Hiroshi
Published: November 2013

Background

The frequency of occurrence of pediatric invasive streptococcal infection in Japan has not been studied, therefore the aim of this study was to survey the northern and eastern regions of Hokkaido from 2010 to 2012.

Method

Survey sheets were sent to the pediatric departments at 17 facilities where children in the subject region can be hospitalized. Responses were obtained from all of the 17 facilities.

Results

Seven patients developed group A streptococcal infection over the 3 years, and their ages ranged from 1 day after the birth to 15 years old. Sepsis was diagnosed in five children, and empyema and arthritis in the knee were found in one child each, respectively. The number of cases in children under 15 years old was six excluding the child who was 15 years old, and the incidence rate per 100 000 population was 1.00. Eight children developed group B streptococcal infection, and their ages ranged from 0 days to 2 months after birth. Two cases were the early onset type (age within 7 days) and six cases were the late onset type. Five children developed sepsis and three children developed meningitis. The frequency of occurrence was 0.24 per 1000 births; which was 0.06 per 1000 births for the early onset type and was 0.18 per 1000 births for the late onset type. No reports for group C or group G hemolytic streptococcal infection were obtained.

Conclusions

The incidence rates identified in the present survey are similar to those in other advanced countries, and appear to be valid.
Asthma management in the Asia–Pacific region
Authors: Beckert Lutz , Moran Angela
Published: November 2013

See article, Volume 18 Number 6 page 957
Chest computed tomography for the diagnosis of Mycoplasma pneumoniae infection
Authors: Miyashita Naoyuki , Akaike Hiroto , Teranishi Hideto , Nakano Takashi , Ouchi Kazunobu , Okimoto Niro
Published: November 2013

We analysed 53 cases of laboratory‐confirmed Mycoplasma pneumoniae infection with cough lasting ≥7 days and chest radiography showing no abnormal findings. Twenty‐two (41%) of those patients showed abnormal findings on chest high‐resolution computed tomography. In the daily clinical setting, for assessment of acute cough, physicians should be aware that it is difficult to confirm bronchiolitis or bronchopneumonia due to M. pneumoniae by chest radiography.
Two novel KIR3DL1 alleles, 3DL1*0150205 and 3DL1*0150206, identified by full‐length DNA sequencing
Authors: Yindom L.‐M. , Wang L. , Rowland‐Jones S. L. , Dong T.
Published: November 2013

KIR3DL1*0150205 and KIR3DL1*0150206 alleles have five and six mutations, respectively, compared with KIR3DL1*0150201.
Hrs‐ and CD63‐Dependent Competing Mechanisms Make Different Sized Endosomal Intraluminal Vesicles
Authors: Edgar James R. , Eden Emily R. , Futter Clare E.
Published: November 2013

Multivesicular endosomes/bodies (MVBs) contain intraluminal vesicles (ILVs) that bud away from the cytoplasm. Multiple mechanisms of ILV formation have been identified, but the relationship between different populations of ILVs and MVBs remains unclear. Here, we show in HeLa cells that different ILV subpopulations can be distinguished by size. EGF stimulation promotes the formation of large ESCRT‐dependent ILVs, whereas depletion of the ESCRT‐0 component, Hrs, promotes the formation of a uniformly sized population of small ILVs, the formation of which requires CD63. CD63 has previously been implicated in ESCRT‐independent sorting of PMEL in MVBs and transfected PMEL is present on the small ILVs that form on Hrs depletion. Upregulation of CD63‐dependent ILV formation by Hrs depletion indicates that Hrs and CD63 regulate competing machineries required for the generation of distinct ILV subpopulations. Taken together our results indicate that ILV size is influenced by their cargo and mechanism of formation and suggest a competitive relationship between ESCRT‐dependent and ‐independent mechanisms of ILV formation within single MVBs.
Phosphatase activity of the voltage‐sensing phosphatase, VSP, shows graded dependence on the extent of activation of the voltage sensor
Authors: Sakata Souhei , Okamura Yasushi
Published: November 2013

Key points

The voltage‐sensing phosphatase (VSP) consists of the voltage sensor and the phosphatase domain. The voltage sensor movement is coupled to the phosphatase activity.

To uncover the coupling mechanisms between the two domains, we made a voltage sensor mutant of VSP. Our analyses showed that this voltage sensor moves in two steps.

Measurements revealed that the phosphatase activity of this mutant is associated with both the first and second step of the voltage sensor movements.

Results suggest that the phosphatase activity of VSP shows graded dependence on the extent of activation of the voltage sensor.

The voltage‐sensing phosphatase (VSP) consists of a voltage sensor and a cytoplasmic phosphatase region, and the movement of the voltage sensor is coupled to the phosphatase activity. However, its coupling mechanisms still remain unclear. One possible scenario is that the phosphatase is activated only when the voltage sensor is in a fully activated state. Alternatively, the enzymatic activity of single VSP proteins could be graded in distinct activated states of the voltage sensor, and partial activation of the voltage sensor could lead to partial activation of the phosphatase. To distinguish between these two possibilities, we studied a voltage sensor mutant of zebrafish VSP, where the voltage sensor moves in two steps as evidenced by analyses of charge movements of the voltage sensor and voltage clamp fluorometry. Measurements of the phosphatase activity toward phosphatidylinositol 4,5‐bisphosphate revealed that both steps of voltage sensor activation are coupled to the tuning of phosphatase activities, consistent with the idea that the phosphatase activity is graded by the magnitude of the movement of the voltage sensor.
Transition between fast and slow gamma modes in rat hippocampus area CA1 in vitro is modulated by slow CA3 gamma oscillations
Authors: Pietersen Alexander N. J. , Ward Peter D. , Hagger‐Vaughan Nicholas , Wiggins James , Jefferys John G. R. , Vreugdenhil Martin
Published: November 2013

Key points

The synchronisation of neuronal activity at gamma frequencies (30–100 Hz) could determine the effectiveness of neuronal communication.

Gamma oscillations in the CA1 region of the hippocampus in vitro was thought to be dependent on gamma oscillations generated in area CA3, but in vivo CA1 can generate gamma oscillations independently.

In this study we found that activating acetylcholine receptors induced stable gamma oscillations in the CA1 local network isolated in slices in vitro that were faster than those in CA3, but relied on similar neuronal circuitry involving feedback inhibition.

Gamma frequency inputs from CA3 (spontaneous in intact hippocampal slices or stimulated in isolated CA1) can suppress the local fast gamma oscillation in CA1 and force it to adopt the slower CA3 oscillation through feed‐forward inhibition.

This modulation could allow CA1 to alternate between effective communication with the entorhinal cortex and CA3, which may regulate memory encoding and memory recall phases.

Hippocampal gamma oscillations have been associated with cognitive functions including navigation and memory encoding/retrieval. Gamma oscillations in area CA1 are thought to depend on the oscillatory drive from CA3 (slow gamma) or the entorhinal cortex (fast gamma). Here we show that the local CA1 network can generate its own fast gamma that can be suppressed by slow gamma‐paced inputs from CA3. Moderate acetylcholine receptor activation induces fast (45 ± 1 Hz) gamma in rat CA1 minislices and slow (33 ± 1 Hz) gamma in CA3 minislices in vitro. Using pharmacological tools, current‐source density analysis and intracellular recordings from pyramidal cells and fast‐spiking stratum pyramidale interneurons, we demonstrate that fast gamma in CA1 is of the pyramidal–interneuron network gamma (PING) type, with the firing of principal cells paced by recurrent perisomal IPSCs. The oscillation frequency was only weakly dependent on IPSC amplitude, and decreased to that of CA3 slow gamma by reducing IPSC decay rate or reducing interneuron activation through tonic inhibition of interneurons. Fast gamma in CA1 was replaced by slow CA3‐driven gamma in unlesioned slices, which could be mimicked in CA1 minislices by sub‐threshold 35 Hz Schaffer collateral stimulation that activated fast‐spiking interneurons but hyperpolarised pyramidal cells, suggesting that slow gamma frequency CA3 outputs can suppress the CA1 fast gamma‐generating network by feed‐forward inhibition and replaces it with a slower gamma oscillation driven by feed‐forward inhibition. The transition between the two gamma oscillation modes in CA1 might allow it to alternate between effective communication with the medial entorhinal cortex and CA3, which have different roles in encoding and recall of memory.
An Experimental Study of the Phenomenon of Surface Alloying by EDM Process Using Inconel Tool Electrode
Authors: Kumar Sanjeev
Published: November 2013

Electrical Discharge Machining (EDM) has emerged as a very important machining process due to its numerous advantages. It is extensively used by the die and toolmaking industry for the accurate machining of complex internal profiles. Although EDM is essentially a material removal process, it has been used successfully for improving the surface properties of the work materials after machining. As the dissolution of the electrode takes place during the process, some of its constituents may alloy with the machined surface under appropriate machining conditions. Additive powders in the dielectric medium may form part of the plasma channel in the molten state and produce similar alloying effect. The breakdown of the hydrocarbon dielectric under intense heat of the spark contributes carbon to the plasma channel. Sudden heating and quenching in the spark region also alters the surface properties. This paper reports the results of an experimental study into electrical discharge machining of H13 hot die steel with Inconel (an alloy of chromium, nickel and iron) tool electrode under machining conditions favouring high electrode wear. The results show improvement in micro-hardness after machining by as much as 88%. Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analysis of the machined surfaces show transfer of chromium and nickel from the tool electrode. Both these elements form intermetallic compounds as well as solid solution with iron and strengthen it. It was found that percentage of chromium increased from 5.39% to 6.52% and that of nickel increased from 0.19% to 4.87%. The favourable machining conditions for surface alloying were found to be low value of peak current, shorter pulse on-time, longer pulse off-time and negative polarity of the tool electrode.
Statistical Cutting Force Model for Orthogonal Cutting of Polytetrafluoroethylene (PTFE) Composites
Authors: Stan Felicia , Vlad Daniel , Fetecau Catalin
Published: November 2013

This paper presents an experimental investigation of the cutting forces response during the orthogonal cutting of polytetrafluoroethylene (PTFE) and PTFE-based composites using the Taguchi method. Cutting experiments were conducted using the L27 orthogonal array and the effects of the cutting parameters (feed rate, cutting speed and rake angle) on the cutting force were analyzed using the S/N ratio response and the analysis of variance (ANOVA). Statistical models that correlate the cutting force with process variables were developed using ANOVA and polynomial regression. The variation of the apparent friction coefficient was analyzed with respect to tool geometry and the cutting process. The results indicated that cutting and thrust forces increase with increasing feed rate, and decrease with increasing rake angles from negative to positive values and increasing cutting speed. A power law relationship between the apparent friction coefficient and the normal force exerted by the chip on the tool-rake face was identified, the former decreasing with an increasing normal force.
Mechanism of Fatigue Performance Enhancement in a Superhard Nanoparticles Integrated Nanocomposites by a Hybrid Manufacturing Technique
Authors: Lin Dong , Ye Chang , Suslov Sergey , Liao Yiliang , Liu C. Richard , Cheng Gary J.
Published: November 2013

A hybrid manufacturing process, which contains Laser Sintering (LS) and Laser shock peening (LSP), is introduced to generate iron-TiN nanoparticle nanocomposites. It is a two-step process including LS followed with LSP. Before LS, TiN nanoparticles mixed with iron powders are coated on samples surface. After LS, TiN nanoparticles are embedded into iron matrix to strengthen materials. Then LSP is performed to introduce work hardening and compressive residual stress. The existed nanoparticles increase the dislocation density and also help to pin the dislocation movement. Better residual stress stability under thermal annealing can be obtained by better dislocation movement stabilization, which is beneficial for fatigue performance.
Mechanics of Modulation Assisted Machining
Authors: Yeung Ho , Guo Yang , Sundaram Narayan K. , Mann James B. , Compton W. Dale , Chandrasekar Srinivasan
Published: November 2013

The controlled application of low-frequency modulation to machining — Modulation Assisted Machining (MAM) — effects discrete chip formation and disrupts the severe contact condition at the tool-chip interface. The role of modulation in reducing the specific energy of machining with ductile alloys is demonstrated using direct force measurements. The observed changes in energy dissipation are analyzed and explained, based on the mechanics of chip formation.
Analytical Cut Geometry Prediction for Free Form Surface During Semi-Finish Milling
Authors: Hendriko  , Duc Emmanuel , Kiswanto Gandjar
Published: November 2013

In five-axis milling, determination of continuously changing Cutter Workpiece Engagement (CWE) is still a challenge. Solid model and discrete model are the most common method used to predict the engagement region. However, both methods are suffering with the long computational time. This paper presents an analytical method to define CWE of toroidal cutter during semi-finishing of sculpture part. The workpiece from 2.5D rough milling is represented by a number of blocks. The length of cut at every engagement angle can be determined by calculating the outermost engagement point called upper CWE point. This point was determined by first assumed that the workpiece surface is flat. A recalculation for CWE correction is then performed for the engagement occurred in two workpiece blocks. The method called Z-boundary and X-boundary are employed to obtain the upper CWE point when the engagement occurred on toroidal side. Meanwhile Cylinder-boundary method was used when the engagement occurred on the cylinder side. The developed model was examined to ensure its accuracy. A sculptured surface part was tested by comparing the depth of cut generated by the simulation developed and the depth of cut measured by Unigraphic. The result indicates that the proposed method is very accurate. Moreover, due to the method is analytically, and hence it is efficient in term of calculation time.
GPGPU Accelerated 3-Axis CNC Machining Simulation
Authors: Konobrytskyi Dmytro , Kurfess Thomas , Tarbutton Joshua , Tucker Tommy
Published: November 2013

GPUs (Graphics Processing Units), traditionally used for 3D graphics calculations, have recently got an ability to perform general purpose calculations with a GPGPU (General Purpose GPU) technology. Moreover, GPUs can be much faster than CPUs (Central Processing Units) by performing hundreds or even thousands commands concurrently. This parallel processing allows the GPU achieving the extremely high performance but also requires using only highly parallel algorithms which can provide enough commands on each clock cycle.

This work formulates a methodology for selection of a right geometry representation and a data structure suitable for parallel processing on GPU. Then the methodology is used for designing the 3-axis CNC milling simulation algorithm accelerated with the GPGPU technology. The developed algorithm is validated by performing an experimental machining simulation and evaluation of the performance results.

The experimental simulation shows an importance of an optimization process and usage of algorithms that provide enough work to GPU. The used test configuration also demonstrates almost an order of magnitude difference between CPU and GPU performance results.
Residual Stress Analysis and Weld Bead Shape Study in Laser Welding of High Strength Steel
Authors: Liu Wei , Kong Fanrong , Kovacevic Radovan
Published: November 2013

The X-ray diffraction (XRD) technique is employed to measure residual stress induced by the laser welding of 6.7 mm thick ASTM A514 high strength steel plates. The distribution of residual stress in the weld bead is investigated. The results indicate that the fusion zone (FZ) has the maximum tensile stress, the transition from tensile to compressive stress tends to appear in the heat affected zone (HAZ), and the initial stress far from the weld center are not influenced by the welding process. Based on the measurement data, the influence of the laser power and the welding speed on residual stress is obtained. The magnitude of residual stress near the weld bead increases with an increase in laser power or a decrease in welding speed. The welds with incomplete penetration have a considerably lower magnitude of residual stress in FZ than ones with full penetration. Post-weld heat treatment is utilized to relieve residual stress in the weld bead. Although residual stress is not completely relieved after the heat treatment, a dramatically reduced magnitude and much more uniform distribution are achieved. In addition, the effects of the laser power, the welding speed, the laser spot diameter, and the gap between two plates on the weld shape are also studied.
Melt Pool Flow and Surface Evolution During Pulsed Laser Micro Polishing of Ti6Al4V
Authors: Ma Chao , Vadali Madhu , Duffie Neil A. , Pfefferkorn Frank E. , Li Xiaochun
Published: November 2013

Extensive experimental work has shown that pulsed laser micro polishing (PLμP) is effective for polishing micro metallic parts. However, the process physics have not been fully understood yet, especially with respect to the melt pool flow. A reliable physical model can be of significant assistance in understanding the fluid flow in the melt pool and its effect on PLμP. In this paper, a two-dimensional axisymmetric transient model that couples heat transfer and fluid flow is described that was constructed using the finite element method. The model not only provided the solutions to the temperature and velocity fields but also predicted the surface profile evolution on a free deformable surface. The simulated melt depth and resolidified surface profiles matched those obtained from optical images of PLμPed sample cross-sections. The model was also used to study the effect of laser pulse duration on the melt pool flow. The study suggests that longer pulses produce more significant fluid flows. The cut-off pulse duration below which minimal fluid flows should be expected was estimated to be 0.66 μs for Ti6Al4V, which also matched well with the experimental results. It is evident that the coupled model offers reliable predictions and thus can be extended for a more complex parametric study to provide further insights for PLμP.
Curvature Estimation for Metrology of Non-Rigid Parts
Authors: Aidibe Ali , Tahan Souheil-Antoine
Published: November 2013

At the end of the manufacturing process, engineers need to know if a manufactured part fits its computer-aided design (CAD) model and how is the amplitude of inherent variation of manufacturing process. Non-rigid parts, at free state condition, may have a significant different form than their CAD model due to gravity loads; residual stresses induced distortion and/or assembly load. Today, a complicated and expensive specialized fixture is needed to conform these parts. To tackle the above challenges, we present in this paper a new approach for metrology of fixtureless non-rigid parts. This approach combines the curvature properties of manufactured parts with the extreme value statistic test as identification method to distinguish profile deviation due to the manufacturing process from part’s deformation due to the flexibility of the part and to determine whether the tolerance fits the CAD model or no. This approach is tested on simulated typical industrial sheet metal giving satisfying results in terms of percentage of errors in defect area and in peak profile deviation estimated.
An Investigation of Sheet Metal Deformation Behavior During Electro-Hydraulic Forming (EHF)
Authors: Rohatgi Aashish , Stephens Elizabeth V. , Davies Richard W. , Smith Mark T.
Published: November 2013

This work describes recent advances in our understanding of sheet metal behavior during electro-hydraulic forming (EHF) process. Two sets of experiments were performed using AA5182-O Al sheet material. In the first set, 1 mm thick sheet samples were subjected to a single pressure-pulse or two consecutive pressure-pulses with the deformation being carried out under free-forming or inside a conical die. In the second set of experiments employing 2 mm sheet samples, a circular region at the center of the sheet was pre-thinned to 1 mm thickness and the sheet was subjected to a single pressure-pulse under free-forming conditions. The sheet deformation history for both sets of experiments was quantified using a recently developed technique that combines high-speed imaging and the digital image correlation (DIC) techniques. The results from the first set of experiments show that the manner in which the discharge is created can influence the strain-rates and hence, the deformation history experienced by the sheet materials. The results of the multi-pulse experiments demonstrate the applicability of the EHF technique for re-strike operations. The results from the second set of experiments show that the pre-thinned region is analogous to a reduced gauge section with the resulting strain-rate (in the pre-thinned region) exceeding that in the adjacent homogeneous sheet by more than 50%.
Die Wear and Galling in Stamping DP980 Steel
Authors: Shih Hua-Chu , Du Changqing , Zhou Dajun
Published: November 2013

Stamping of dual phase (DP) 980 steel creates higher deformation heat, contact pressure and friction force between the tooling and sheet steel. These, in turn, cause higher die wear and galling. Although various countermeasures have been adopted in production to prevent excessive wear associated with forming DP980 steel, the stamping die tryout process has not been revised accordingly to ensure that the die surfaces in contact with sheet metal have been hardened and coated. The effects of die hardness and lubrication conditions on die wear and galling in stamping DP980 steel during the die tryout process were evaluated at different contact pressures using the bending under tension (BUT) tester. A reciprocal cyclic bend test system (CBTS) of modifying bending under tension test was used to investigate wear and galling between a die in the tryout phase and in a production condition. The results indicate that the hardness of the die material dominates the galling and wear behavior in the die tryout phase. A better surface treated die material and an anti-galling strategy was also identified to decrease galling and wear in both die tryout and production.
Line-Based Laser Induced Plasma Micro-Machining (L-LIPMM)
Authors: Malhotra Rajiv , Saxena Ishan , Ehmann Kornel , Cao Jian
Published: November 2013

Recently, the technique of Spot-based Laser Induced Plasma Micro-Machining (Spot-LIPMM) has been developed to address the limitations of conventional ultrashort pulse laser micro-machining. Its main advantages are adaptability to a wide range of materials and superior wall geometries. We propose a variation of the Spot-LIPMM process by creating line plasma instead of spot plasma, with the use of suitable optics. This paper describes the experimental setup used to create line plasma and the process used for micro-machining with L-LIPMM. Optics simulations are developed as a means of guiding the choice of optics to be used for line plasma generation and estimating the energy and shape of the plasma created. It is shown that this Line-based LIPMM (L-LIPMM) process is capable of micromachining channels at a much higher speed than conventional Spot-based laser ablation or spot-based LIPMM. Additionally, the effects of process parameters on machined geometry using L-LIPMM are discussed.
Embedding Information on Metal Surfaces by Micro-Milling
Authors: Thomas Tesswin , Subbiah Sathyan , Kong Adams Wai Kin
Published: November 2013

A new method of storing or embedding information on the surface of metals is presented here. The feed marks left behind by the passing tool in micro-milling are used as a way to embed the information. By simply varying the feed rates during milling in predetermined way information can be stored similar to how an optical storage disc embeds digital information in a binary fashion. Such storage is demonstrated by creating the surface topography using micro-milling and performing information retrieval by extracting and analyzing the surface profiles. Expected applications of this are in steganography and water marking of products for authenticity checks.
Constant Temperature Embossing of PEEK Films
Authors: Kuduva-Raman-Thanumoorthy Ramasubramani , Kim Byung H. , Yao Donggang
Published: November 2013

A new variant of the hot embossing process has been conducted with amorphous PEEK films as a model material. Constant Temperature Embossing (CTE) utilizes the crystallizing nature of amorphous polymers such as poly (ether ether ketone) (PEEK), poly (ethylene terephthalate) (PET) and poly (ethylene naphthalate) (PEN) when heated above their glass transition temperature to eliminate the thermal cycling. The key process parameters such as embossing temperature and embossing time depend on the thermal behavior of the amorphous PEEK film. Embossing studies were conducted using silicon tools with microchannel arrays of different aspect ratios, and the films were characterized using scanning electron microscopy and optical profilometry. The process enables a simple isothermal embossing process for polymers that have a glass transition temperature well above the room temperature and also with a wide temperature gap between the glass transition temperature and melting point.
Cloud Manufacturing Platform: Operating Paradigm, Functional Requirements, and Architecture Design
Authors: Ren Lei , Zhang Lin , Zhao Chun , Chai Xudong
Published: November 2013

Cloud manufacturing is emerging as a new promising business paradigm as well as an integrated technical approach, contributing to the shaping of a highly-collaborative, knowledge-intensive, service-oriented and eco-efficient manufacturing industry. The following research issues concerning cloud manufacturing platform, what users can achieve with the platform, what the platform can do, and how to design it, play crucial roles in this new area. This paper proposes a cloud manufacturing paradigm that depicts a typical scenario which can provide an explanation for the concept of cloud manufacturing and makes the mysterious “cloud” transparent. Then the functional requirements of cloud manufacturing platform are investigated to specify design objectives. Based on these, the paper presents the design of MfgCloud, a cloud manufacturing platform prototype. In discussion of the main components of MfgCloud, the specific concepts different from those corresponding terms in IT area are also defined and given their implementation mechanisms. Consequently, this paper proposes a new point of view for the concept of cloud manufacturing, and accordingly presents a reference design of cloud manufacturing platform.
Picosecond and Nanosecond Pulsed Laser Ablation of Aluminium Foil
Authors: Sozzi Michele , Tragni Katia , Selleri Stefano , Cucinotta Annamaria , Lutey Adrian H. A. , Molari Pier Gabriele , Carmignato Simone
Published: November 2013

The pulsed laser ablation of 20 micron thick aluminium foil is investigated by exposing moving samples to picosecond pulses of wavelength 1064nm and nanosecond pulses of wavelength 515nm and 1030nm. Ablation thresholds and depths are determined for a range of conditions using an optical microscope and 3D optical profiler. Complete three-dimensional crater profiles for single and multiple pulses are presented. The results reveal a variation in ablation threshold with wavelength, pulse duration and the number of pulses; a large reduction is observed for picosecond pulses. Ablation rates per pulse are expressed by general equations and found to vary strongly with both laser type and the number of pulses. The green nanosecond laser is found to ablate most efficiently for fluences above 10J/cm2, whilst the picosecond source is instead advantageous for low fluences. A large reduction in ablation depth per pulse is observed with an increasing number of pulses. The present work affords prediction of scribe and cut parameters for the processing of thin aluminium layers and, more generally, characterises the driving parameters of pulsed picosecond and nanosecond laser ablation of metals.
Effects of Interfacial Geometry on Laser Joining of Dissimilar NiTi to Stainless Steel Wires
Authors: Brandal Grant B. , Satoh Gen , Yao Y. Lawrence , Naveed Syed
Published: November 2013

Joining of the dissimilar metal pair NiTi to stainless steel is of great interest for implantable biomedical applications. Formation of brittle intermetallic phases requires that the joining processes limit the amount of over-melting and mixing along the interface. Thus, laser joining is a preferred method due to its ability to precisely control heat input. This study explores a method of using a cup and cone interfacial geometry, with no filler material, to increase the tensile strength of the joint. Not only does the cup and cone geometry increase the surface area of the interface, but it also introduces a shear component, which is shown to be beneficial to tensile strength of the wire as well. The fracture strength for various cone apex angles and laser powers is determined. Compositional profiles of the interfaces are analyzed. A numerical model is used for explanation of the processing.
Reconciling the Differences Between Tolerance Specification and Measurement Methods
Authors: Vemulapalli Prabath , Shah Jami J. , Davidson Joseph K.
Published: November 2013

The ASME Y14.5M standard has defined different types of tolerances that can be applied to a feature to achieve the required functionality. Each tolerance defines a zone within which the feature under inspection must lie. The conformance of the parts to these tolerances is checked by manual measurements or a CMM. But it has been observed that the measurements between different CMMs do not match. There are two generally accepted reasons for this discrepancy. The first one is the measurement uncertainty in CMM software. This problem was addressed by NIST by developing reference softwares for feature fitting algorithms. And the second one is the distinct choice of algorithms for fitting substitute feature to the data points measured from CMM. Feature fitting algorithms used in CMMs are often based on their mathematical convenience rather than the interpretation of definitions in the GD&T standard. Our research is focused on identifying that normative algorithm that is best to be used for each type of tolerance. Each normative algorithm is identified as the one to best represent the interpretation of geometric control as defined by the Standard and on the manual methods used for the measurement of a specific tolerance type.
The Effect of Warm Accumulative Roll Bonding and Post Process Treatment on Microstructure and Mechanical Behavior of CP-Ti
Authors: Milner Justin L. , Abu-Farha Fadi , Kurfess Thomas
Published: November 2013

Accumulative Roll Bonding (ARB), a severe plastic deformation technique, was used in this study to process commercially pure titanium (CP-Ti) sheets at selected warm temperatures. Post-processing treatments at selected conditions were also performed on the ARB processed material, following each ARB processing cycle. Mechanical characterization and microstructural examination were carried out on the processed and post processed material to track the evolution of the microstructure, the changes in strength and ductility, and their relationships with regard to one another. Though the temperatures and processing conditions covered here are limited, it was found that ARB processing temperature affects the resultant flow behavior of the material. Furthermore, it was shown that post processing treatment of the ARB processed material can increase both strength and ductility of the material; the latter can be used as an effective tool for further controlling the structure and properties of the ARB-processed material.
Optimal Motor Location for the Reduction of Residual Vibrations in Mode-Coupled Ultra-Precision Manufacturing Machines
Authors: Okwudire Chinedum E. , Lee Jihyun
Published: November 2013

Ultra-precision manufacturing (UPM) machines are used to fabricate and measure complex parts having micrometer-level features and nanometer-level tolerances/surface finishes. Therefore, low-frequency residual vibrations that occur during the motion of the machines’ axes must be minimized. Recent research by the authors has revealed that coupling the vibration modes of passively-isolated machines by properly selecting the location of the vibration isolators could lead to a drastic reduction in residual vibrations. However, the effect of motor location on the residual vibrations of mode-coupled UPM machines has not been rigorously analyzed. In this paper, an objective function which minimizes residual vibration energy with respect to motor location is defined and analyzed. It is shown to have a guaranteed global minimum irrespective of the parameters of the UPM machine. Conditions that ensure that the global minimum is located in a practically feasible design space are explored. Finally, the merits of optimal motor placement on residual vibration reduction are demonstrated using simulations conducted on a 5-axis ultra-precision machine tool.
Analysis of Fiber Optic Sensor to Measure Velocity During Electromagnetic Forming and Welding
Authors: Thibaudeau E. , Turner B. , Gross T. , Kinsey B. L.
Published: November 2013

Previous methods of measuring high velocity deformation in electromagnetic forming and magnetic pulse welding include Photon Doppler Velocimetry (PDV), laser micrometers, and high speed photography. In this paper an alternative method is presented, implementing a fiber optic, reflectance dependent displacement sensor. The sensor is shown to be an attractive low cost solution to measurement of high velocities in high voltage, magnetic environments. Data is shown with respect to sensor characterization including various surface reflectivity values, curvatures, and misalignments; implementation in two forming and welding processes; and verification with high velocity measurement in parallel with PDV. The sensor system is one twentieth the cost of a PDV system, and yet measures velocities accurately to at least 140 m/s. Sensor performance is also enhanced by the use of retroreflective tape, which is shown to increase the displacement range by 9×, decrease sensitivity to misalignment, and increase repeatability and ease of implementation.
An Investigation of Anisotropic Behavior on 5083 Aluminum Alloy Using Electric Current
Authors: Pleta Abram D. , Krugh Matthew C. , Nikhare Chetan , Roth John T.
Published: November 2013

Due to more stringent environmental regulations, the demand for strong, lightweight metal alloys, such as AA 5083, has increased. In sheet metal forming, aluminum is preferred over higher density steels to manufacture such parts; however the in-plane anisotropic behavior of AA 5083 alloy greatly affects its formability. Previous researchers have found that mechanical properties of metallic materials can be influenced by DC electrical current, a research area known as Electrically-Assisted Manufacturing (EAM). The research herein is focused on characterizing the in-plane anisotropic behavior of AA 5083 alloy with and without DC current application, while it is loaded in the uniaxial direction. Furthermore, the effects of EAM on Lueder’s banding will also be investigated.
Uncertainty in Peakedness Factor Estimation by JONSWAP Spectral Fitting From Measurements
Authors: Saulnier Jean-Baptiste
Published: November 2013

In offshore engineering, JONSWAP shapes are commonly used to fit wave spectra and characterise the peakedness of the sea state. The latter is defined as γ, the so-called peak enhancement factor, which is as large as the peak is acute, with values generally ranging from ∼1 to 7 (1 and 3.3 being usually adopted for fully-developed and average wind seas respectively). The determination of γ values permit to simulate realistic sea conditions later on, in particular for determining extreme loads on floating structures in severe sea states.

The consistency of the fitting with respect to the actual sea state is subject to — at least — two key, connected aspects, which are: the frequency resolution (i.e., the spacing between two consecutive spectrum estimates) and the sampling error (i.e., the statistical variability of estimates due to both the finiteness of the wave record and the spectral averaging).

Based on realistic sea state spectral simulations, this work addresses the sensitivity of the JONSWAP fitting to these aspects and shows that it systematically results in a bias in the peakedness estimate — the bias being aggravated when the sampling error is large for a given signal length (from 10min to 1h). It is shown, in particular, that the error committed with respect to the true γ value is generally higher than 5% for most types of peaks and may often exceed 30%.

The aim of this work is to emphasize this issue for practical offshore and oceanographic applications for it may, in turn, potentially introduce a bias in the dynamic response of floating structures in numerical simulations and tank tests.