Short Plate Research Articles

Multipacting simulation and analysis of a taper quarter wave cavity by using Analyst-PT3P

Since the tapered quarter wave resonator (QWR) cavity is proven to have a much lower peak surface magnetic field in the short plate and a lower peak surface electric field near the beam tube compared with the straight outer conductor QWR, it has been recommended for the separated sector cyclotron linac injector system in the heavy ion research facility in Lanzhou. This paper is focused on the multipacting (MP) analysis for the tapered QWR with a frequency of 80.5 MHz and beta of 0.085. Using the Analyst program, MP bands can be simulated and analyzed with the Particle Tracking module to identify potential problems in the cavity design. This paper will present the simulation results of MP for the tapered QWR cavity.

Calculation of the Arc Velocity Along the Polluted Surface of Short Glass Plates Considering the Air Effect

To investigate the microphysics mechanism and the factors that influence arc development along a polluted surface, the arc was considered as a plasma fluid. Based on the image method and the collision ionization theory, the electric field of the arc needed to maintain movement with different degrees of pollution was calculated. According to the force of the charged particle in an arc plasma stressed under an electric field, a calculation model of arc velocity, which is dependent on the electric field of the arc head that incorporated the effects of airflow around the electrode and air resistance is presented. An experiment was carried out to measure the arc velocity, which was then compared with the calculated value. The results of the experiment indicated that the lighter the pollution is, the larger the electric field of the arc head and arc velocity is; when the pollution is heavy, the effect of thermal buoyancy that hinders arc movement increases, which greatly reduces the arc velocity.

Activation of gold decorated carbon nanotube hybrids for targeted gas adsorption and enhanced catalytic oxidation

Free standing assemblies of carbon nanotubes (CNTs), known as bucky-paper (BP), have been functionalised through the in situ plating of gold nanoparticles within the interstitial spaces in the BP. The nanoparticles are extremely small and well distributed at short plating times, so much so that the specific surface area of the BP is actually increased by the gold incorporation. These well distributed nanoparticles exhibit high enthalpy hydrogen storage and selective carbon dioxide adsorption over other gases, in particular methane. In concert with the conductive BP substrate, it has been demonstrated that these materials can also act as high turnover heterogeneous catalysts.

Through-Silicon-Via (TSV) for silicon package: ″via-bridge″ approach

We present in this paper an alternative Through-Silicon-Via approach that can meet the new requirements of Si package. In this wafer level packaging scheme, a thick silicon interposer (200 to 300μm) is directly reported on a PCB. In 200mm Si wafers, we made a two steps TSV composed of two vias: a top via and a bottom via. The top via is etched with DRIE (diameter 60μm, depth 180 μm, Aspect Ratio = AR>3), and insulated with high temperature dielectric. After dry film lithography, the TSV is partially plated with Cu limiting the process costs (short plating time, no CMP) and the stress inside the TSV. After temporary carrier bonding, the wafer is backgrinded so that 15μm remains below the bottom of the main TSV. Backside lithography and DRIE process create the bottom via (four different diameters: 10-20-30 and 40μm) to contact main TSV. A final backside Cu plating of the opening completed the process. This via bridges the gap between via-last (AR<2) and via-middle (AR>7) and combines high temperature process from via-middle and low-cost processing from via-last. The mechanical simulations show that this ″TSV bridge″ has reduced residual stresses inside the TSV. Our electrical measurements exhibit an average single TSV resistance below 10mOhms with excellent yield (∼95% on Kelvin and 82 TSV chains), and low contact resistances (4.7×10−9 Ω.cm2) extrapolated on 4 different contact diameters. This 200μm deep TSV seems therefore very promising for low-cost thick interposer applications.

Dinoflagellate Vulcanodinium rugosum identified as the causative organism of pinnatoxins in Australia, New Zealand and Japan

Rhodes L., Smith K., Selwood A., McNabb P., Munday R., Suda S., Molenaar S. and Hallegraeff G. 2011. Dinoflagellate Vulcanodinium rugosum identified as the causative organism of pinnatoxins in Australia, New Zealand and Japan. Phycologia 50: 624–628. DOI: 10.2216/11-19.1The producers of pinnatoxins E and F were first identified through systematic light microscopy-mass spectrometry (LC-MS) screening of New Zealand (NZ) dinoflagellate isolates. Pinnatoxins E, F and G were subsequently detected for South Australian (AUS) isolates, and a pinnatoxin G producer was recently identified from Okinawa, Japan. The NZ, AUS and Japanese isolates appear morphologically identical to Mediterranean field samples recently described as Vulcanodinium rugosum. Motile forms (24–32 µm long, 20–30 µm wide) have a wide, deeply incised cingulum displaced by 17% of the cell length and a deep sulcus. Photosynthetic motile cells have the same distinctive apical pore complex with raised collar and short canal plate. The reticulate thecal ornamentation resembles that of Bysmatrum because the three intercalary plates are connected. The posterior sulcal plate Sp does not touch the cingulum (as in Bysmatrum, Pentapharsodinium and Ensiculifera). The plate formula for the NZ, AUS and Japanese isolates is Po, X, 4′, 3a, 7″, 6c (5c + T), 5s, 5′″, 2″″. The dominant non-motile life-cycle stage comprises clusters of brown to black, spherical, unornamented, non-calcareous division cells (30–35 µm diameter). Genetically these isolates fall within the Peridiniales, closely related to the calciodinellid genera, Pentapharsodinium, Ensiculifera and Scrippsiella. The large subunit (LSU) rDNA and internal transcribed spacer (ITS) sequences exhibit sequence differences compared to each other and to the French field material (96–97% LSU and 84–88% ITS similarity, respectively). This variation and pinnatoxin profile differences suggest a possible species complex.

Complete Penile Disassembly for Epispadias Repair in Postpubertal Patients

To present the outcomes of complete penile disassembly in 14 postpubertal patients. Complete penile disassembly is widely used for epispadias repair. From July 2001 to May 2008, a total of 14 postpubertal patients underwent complete penile disassembly epispadias repair. The median age at surgery was 18 years (range 14-34). Of the 14 patients, 3 patients had isolated penopubic epispadias (all with failure of previous repairs) and 11 had bladder exstrophy with no previous attempts at epispadias repair. Of the 11 patients with exstrophy, 6 had undergone previous cystectomy and rectal diversion and 5 had undergone bladder neck closure, ileocystoplasty, and creation of a continent outlet. A urethral stent was used only for patients with isolated epispadias. The first postoperative follow-up examination was at 6 weeks. Later, the patients were followed up every 3 months for 1 year. All patients had an orthotopic meatus. However, the short urethral plate was lengthened with a penile skin flap in 5 (36%) of the 14 patients to achieve an orthotopic meatus. No patient had glans/corporal ischemia. All patients had normal conical symmetric glans/corpora. Of the 3 patients undergoing redo surgery, 1 had sloughing of the distal neourethra and ended up with a coronal hypospadias. All 11 de novo patients had an orthotopic meatus with no fistula, stenosis, or dehiscence. All neourethras were easily calibrated with a 14F sound. All patients had normal straight erections with normal forward ejaculation. Complete penile disassembly is safe and effective surgery for epispadias repair in postpubertal patients. Lengthening of the urethral plate with a penile skin flap was required in one third of patients. The erection/ejaculatory functions were preserved in all patients.

Field Plated AlGaN/GaN-on-Si HEMTs for High Voltage Switching Applications

In this study, we fabricated AlGaN/GaN-on-Si high electron mobility transistors (HEMTs) for high voltage switching applications where both the field plate length and the gate-to-drain distance were varied for structural optimization. A tapered gate was fabricated in conjunction with the field plate in order to eectively suppress the high electric field at the gate edge. Regardless of the gate-to-drain distance, which was varied from 7 to 20 µm, the highest breakdown voltage was obtained with a short field plate length (i.e., 2 ‐ 3 µm), and the breakdown voltage monotonically decreased with increasing field plate length. A breakdown voltage of 1200 V with an on-resistance of 3.7 m ·cm 2 was achieved using a gate-to-drain distance of 20 µm and a field plate length of 3 µm.

Transcriptional Profiling of Chondrodysplasia Growth Plate Cartilage Reveals Adaptive ER-Stress Networks That Allow Survival but Disrupt Hypertrophy

Metaphyseal chondrodysplasia, Schmid type (MCDS) is characterized by mild short stature and growth plate hypertrophic zone expansion, and caused by collagen X mutations. We recently demonstrated the central importance of ER stress in the pathology of MCDS by recapitulating the disease phenotype by expressing misfolding forms of collagen X (Schmid) or thyroglobulin (Cog) in the hypertrophic zone. Here we characterize the Schmid and Cog ER stress signaling networks by transcriptional profiling of microdissected mutant and wildtype hypertrophic zones. Both models displayed similar unfolded protein responses (UPRs), involving activation of canonical ER stress sensors and upregulation of their downstream targets, including molecular chaperones, foldases, and ER-associated degradation machinery. Also upregulated were the emerging UPR regulators Wfs1 and Syvn1, recently identified UPR components including Armet and Creld2, and genes not previously implicated in ER stress such as Steap1 and Fgf21. Despite upregulation of the Chop/Cebpb pathway, apoptosis was not increased in mutant hypertrophic zones. Ultrastructural analysis of mutant growth plates revealed ER stress and disrupted chondrocyte maturation throughout mutant hypertrophic zones. This disruption was defined by profiling the expression of wildtype growth plate zone gene signatures in the mutant hypertrophic zones. Hypertrophic zone gene upregulation and proliferative zone gene downregulation were both inhibited in Schmid hypertrophic zones, resulting in the persistence of a proliferative chondrocyte-like expression profile in ER-stressed Schmid chondrocytes. Our findings provide a transcriptional map of two chondrocyte UPR gene networks in vivo, and define the consequences of UPR activation for the adaptation, differentiation, and survival of chondrocytes experiencing ER stress during hypertrophy. Thus they provide important insights into ER stress signaling and its impact on cartilage pathophysiology.

Heat transfer from a short plate behind an obstacle in tandem

Heat transfer from a heated plate placed behind an obstacle in cross-flow was investigated in this experimental study. In the experiment three types of obstacles were investigated circular; rectangular and triangular cross-sectioned, in order to test the effects of geometrical shape of the obstacle on heat transfer from the test plate for various orientation angles of the plate ( β = 0°, +45°, 90° and −45°). The experiments have been conducted for three different obstacle sizes of each geometry. During the study the effects of obstacle size, and separation between the obstacle and test plate for different orientation angles were examined for range of Reynolds number 2700 < Re l < 13,000, dimensionless separation number P ranging from 1.81 to 13.82 and flow blockage ratio varied of ζ = 9.33%, ζ = 18.66%, and ζ = 28% for D = l , 2 l and 3 l respectively. Based on the measurements, average Nusselt number was determined using lump heat capacitance method. From the results, it was found that the shape and size of the obstacle and plate orientation angle significantly affect the heat transfer from a plate in the wake flow region.

Nucleation and growth characteristics of electroplated Cu on plasma enhanced atomic layer deposition-grown RuTaN direct plate barriers

A study has been carried out to understand the mechanism that enables plasma enhanced atomic layer deposition (PEALD)-grown RuTaN barriers to support direct (seedless) copper electroplating. In particular, the effects of changing the liner surface chemistry on the subsequent plated copper nucleation behavior have been evaluated. Amperometric measurements and short pulse plating experiments were carried out directly on PEALD-grown RuTaN barriers. To enhance copper nucleation, a liner surface cleaning protocol was developed and evaluated. In order to understand the effect of intrinsic liner composition and conductivity on the film microstructure and subsequent plated copper nucleation, a study of copper nucleation density as it relates to the Ru:Ta ratio in the liner was carried out. The thickness extendibility of these direct plate liners was also explored. These liners were also tested for potential use in sub-45-nm copper metallization applications.

Buckling and postbuckling behavior of unstiffened slender curved plates under uniform shear

Buckling and postbuckling behavior of curved plates under in-plane shear are investigated. After revisiting classic elastic buckling results, the elastoplastic postbuckling behavior and the effects of curvature parameter and aspect ratio are simulated via geometrical and material nonlinear analyses. Imperfection sensitivity is studied for various imperfection shapes and magnitudes. An increase in curvature parameter raises the elastic buckling load, produces unstable buckling and reduces postbuckling reserves. The buckling load and shear capacity are higher in shorter plates. Small initial imperfections are found to have severe effects on the initial buckling load of plates with large curvature parameter, but little effect on ultimate postbuckling capacity.

Biomechanical Comparison of 2 Different Locking Plate Fixation Methods in Vancouver B1 Periprosthetic Femur Fractures

Locking plates are commonly used to treat fractures around a well-fixed femoral component. The optimal construct should provide sufficient fixation while minimizing soft-tissue dissection. The purpose of the current study was to determine whether plate length, working length, or bone mineral density affects survival of locking plate fixation for Vancouver type B1 periprosthetic hip fractures. A transverse osteotomy was created just distal to cemented femoral prostheses in 9 pairs of cadaveric femurs. Fractures were stabilized with long (20-hole) or short (12-hole) locking plates that were secured proximally with cables and screws and distally with screws only. Specimens were then cycled 10000 times at 2500 N of axial force and 15 Nm of torque to simulate full weightbearing. A motion capture system was used to record fracture displacement during cycling. Failure occurred in 5 long and 3 short plates, with no significant differences found in the number of cycles to failure. For the specimens that survived, there were no significant differences found between long and short plates for displacement or rotation observed at the fracture site. A shorter working length was not associated with increased failure rate. Lower bone mineral density was significantly associated with failure (P = .02). We concluded that long locked plates do not appear to offer a biomechanical advantage over short locking plates in terms of fixation survival, and that bone mineral density was a better predictor of failure than was the fixation construct type.

Low Reynolds number flow over a square cylinder with a splitter plate

Flows over a square cylinder of side length D with and without a splitter plate are numerically investigated at a Reynolds number of 150. The length of the splitter plate is varied systematically from L=0.5D to L=6D so the sensitivity of the flow structure to the inclusion of the splitter plate can be inspected. It is found that the splitter plate introduces a strong hydrodynamic interaction to the near wake of the cylinder and the length of the plate affects significantly the flow structure. The behavior of the flow can be grouped into three regimes. For short plate lengths (0≲L≲D), the free shear layers are convected further downstream before rolling up when the plate length is increased. For intermediate plate lengths (1.25D≲L≲4.75D), a secondary vortex is clearly visible around the trailing edge of the splitter plate and the shear layers begin to roll up closer to the trailing edge. For long plate lengths (L≳5D), a regime is observed in which the free shear layers reattach to the splitter plate. The study also proposes the minimum wake half-width as the length scale for a possible universal Strouhal number, which is found to be valid for 0≤L≤4D.

Mechanical damage to Gram-negative bacteria by surface plating with the Drigalski-spatula technique

Colony counting by spreading bacterial suspensions on plating media by various techniques is of general concern. Comparative studies between hand plating (Drigalski-spatula technique) for different time intervals and spiral plating resulted in significant differences in colony counts. Lower counts of Gram-negative bacteria were obtained by using hand plating for more than 10s, compared with short time hand plating (5s) or spiral plating. Colony counting of Gram-positive bacteria showed no differences between both techniques. Further characterisation of Escherichia coli cells spread with the Drigalski-spatula technique by electron microscopy revealed a large number of damaged cells compared to control samples. The data clearly shows that the mechanical forces during hand plating are sufficient to damage E. coli cells.

Vulcanodinium rugosumgen. et sp. nov. (Dinophyceae), un Nouveau Dinoflagellé Marin de la Côte Méditerranéenne Française

Abstract Vulcanodinium rugosum gen. nov., sp. nov. (Dinophyceae): a new marine dinoflagellate from the French Mediterranean coast. A new armoured marine dinoflagellate, Vulcanodinium rugosum Nezan et Chomerat, gen. nov., sp. nov. is described from water samples of Mediterranean lagoons. The thecal plate formula is Po, X, 4′, 3a, 7″, 6c, 6s, 5′″, 2″″. The apical pore plate Po is very large and a mucous matrix is extruded from its centre. The plate X is rather long and just below is the narrow and short first apical plate 1′. The intercalary anterior plates are contiguous. The first cingular c1 plate is narrow. The number, the shape of plates and the presence of lists characterize the sulcus. The thecal surface is covered by longitudinal striae with often cross reticulations and is perfored by large pores. According to the studied feature, the morphology of Vulcanodinium rugosum looks like, either a peridinioid or a gonyaulacoid species. A phylogenetic study, based on LSU rDNA sequence data, confirms that t...

Preparation of Wood-Based EMI Shielding Composite via a Short Process Electroless Plating

A short electroless Ni-P plating process for preparing EMI shielding wood-based composite was studied. Birch and Fraxnus madshurica veneers were used as the substrate. It is a simple method that Ni-P coating was easily deposited on the surface of two kinds of veneers. The plated specimens were observed by SEM that the films are uniform, compact and continuous. EDS results shows that the coating contains 4wt% phosphorus and 96wt% nickel. It is indicated by XRD analysis that the film on the two kinds of veneers are crystalline. It was measured that the two wood-based composites have better electromagnetic shielding performance if more than 60dB in the frequency ranges from 9k to 1.5GHz.

Electrodeposition of the Sn-58 wt.%Bi layer for low-temperature soldering

The electroplating characteristics and deposition layer of a Sn-Bi eutectic alloy applicable to low-temperature soldering were investigated. A methane sulphonate electrolyte was fabricated and the current density was focused in order to achieve an eutectic Sn-Bi composition. The electroplating characteristics, including the polarization curve and deposition thickness with plating time, were also studied. As experimental results, a polarization curve showed a Sn-Bi codeposition occurred under a −0.5 V electropotential. The Bi content in the Sn-Bi deposit decreased with an increasing current density, such as 99.42 wt.% for −10 mA/cm2 and 42.27 wt.% for −40 mA/cm2. The thickness of the electroplated layer increased with the plating time, while a relatively uniform thickness was obtained in a short plating time, such as less than 40 min. The eutectic deposition of Sn-58.2 wt.%Bi was successfully fabricated by plating at −30 mA/cm2 for 30 min.

Numerical Analysis for Heat Transfer Enhancement in a Laminar Natural-Convection Boundary Layer by Inserting Short Flat Plates Set in Array

Heat transfer enhancement for a laminar natural-convection boundary layer along a vertical flat plate by inserting short flat plates set in array at fixed intervals (split heat transfer promoter) has been numerically analyzed to comprehend the mechanism originating the increase in heat transfer rates. The calculated results impressively reproduce visualized fluid motions obtained in the previous experiment, and it is again confirmed that the remarkable heat transfer enhancement is due to the synergetic effect of low temperature fluid flow detouring the inclined plates and the longitudinal vortexes generating at the edge faces of inclined plates. For the heated surface of 0.3 m height, the use of 7 column split heat transfer promoters conduces to an increase in average heat transfer rate of approximately 50 % compared with that without promoter.

Urethral reconstruction in severe hypospadias using buccal mucosa graft and penile skin flap

Hypospadias represents the most frequent penile anomaly. The most challenging part of hypospadias surgery is urethral reconstruction. Many various tissues are used (local skin flaps, bladder mucosa grafts, buccal mucosa grafts etc.) for the reconstruction of the neourethra. Our aim was to evaluate advantages and disadvantages of combined buccal mucosa graft and penile skin flap in urethral reconstruction in severe hypospadias repair. Between December 2005 and August 2009, 48 patients with severe hypospadias, aged from nine months to 12 years (mean age 23 months) underwent surgery. Thirty-four (71%) had penoscrotal and 14 (29%) scrotal hypospadias. Ventral penile curvature was present in all cases, and was corrected by incision of the short urethral plate. Urethroplasty was performed a buccal mucosa graft combined with dorsal penile skin flap. Mean follow-up was 22 months (range from 9 months to 3 years). Satisfactory functional and aesthetic results were achieved in 40 (83%) patients. Fistula was noted in six cases and was solved by minor revision. Urethral stenosis in two cases was resolved by simple dilatation. Urethral reconstruction using the buccal mucosa graft and dorsal penile skin flap in severe hypospadias repair could be the method of choice. Using this technique, single stage urethral reconstruction is possible with satisfactory esthetical and functional results.

Three-dimensional design optimisation of patient-specific femoral plates as a means of bone remodelling reduction

Previous investigations into the optimisation of internal plates have mostly focused on the material properties of the implant. In this work, we optimise the shape, size and placement of the plate for successfully minimising bone remodelling around the implant. A design optimisation algorithm based on strain energy density criterion, combined with the finite element analysis, has been used in this study. The main optimisation goal was to reduce this change and keep it close to the conditions of an intact femur. The results suggest that the anterolateral side of the bone would be the optimum location for the plate, as for the geometry, the optimum moves towards having a thick, wide and short plate. These important results could be directly applicable to orthopaedic surgeons treating a femur fracture with internal plates. Since the optimisation algorithm remains the same for any patient, this advancement provides the surgeon with a tool to minimise the post surgery remodelling by trying to maintain the natural structure of the bone.