Short Plate Research Articles

Total Spondylectomy of C2

A report on 3 patients undergoing total spondylectomy of the C2 vertebra for tumor and the technique for C1-3 reconstruction. To illustrate the feasibility of complete resection of the C2 vertebra with preservation of the vertebral arteries and cervical nerve roots. Total spondylectomy provides improved progression free survival in many patients with locally aggressive spinal tumors. However, the perceived technical demands of effectively preserving both vertebral arteries, maintaining cervical nerve roots, and biomechanical reconstruction of the cranial-cervical junction often dissuades surgeons from carrying out total spondylectomy of the C2 vertebra. A review of 3 patients undergoing total C2 spondylectomy for tumor (thyroid adenocarcinoma, chordoma, and solitary plasmocytoma) was done. The surgical procedure that was undertaken and the technique used are described. Postoperatively, all 3 patients had uneventful postoperative recovery with gradual improvement in their neurologic functions. Preservation of bilateral vertebral arteries and all cervical nerve roots is feasible when carrying out intralesional total spondylectomy in patients with C2 vertebral body tumors and should be considered in patients thought to benefit from total C2 vertebra excision. In an attempt to augment construct stability and provide anterior column load sharing, we have used mesh cage and iliac crest graft between C1 and C3 held in place with a short cervical plate without complications.

Caracterização anatômica, química e física da madeira de candeia (Eremanthus erythropappus (DC.) Macleish)

Neste trabalho, objetivou-se a caracterização anatômica, química e física da madeira de candeia (Eremanthus erythropappus (DC.) Macleish). Coletaram-se cinco árvores na região de Carrancas-MG, e retirados discos ao DAP para confecção dos corpos-deprova. Realizou-se a descrição e mensuração dos principais elementos anatômicos da madeira (fibras, vasos e parênquima radial). Para a análise química, determinou-se a quantidade de extrativos totais, holocelulose, lignina e constituintes inorgânicos. O estudo físico consistiu na determinação da densidade básica e aparente da madeira e assim como a determinação das contrações tangencial, radial e volumétrica total, dos coeficientes de anisotropia e de retratibilidade. Os principais resultados encontrados para características macroscópicas foram: odor desagradável, decorrente da presença de óleo-resina, grã revessa e dura ao corte; características microscópicas: parênquima axial escasso e radial bastante fino, elementos de vasos com pontoações numerosas e muito pequenas, placas de perfuração simples, fibras libriformes curtas com parede celular espessa e presença de células de óleo no raio. Composição química: 20,89% de extrativos totais; 50,52% de holocelulose; 28,59% de lignina e 0,39% de constituintes inorgânicos. A densidade aparente foi de 0,98 g/cm³ e a básica de 0,79 g/cm³. O coeficiente de anisotropia foi igual a 1,91 e o coeficiente de retratibilidade volumétrica, 0,28%.

Effect of H-BN Content on Microstructures of the Laser Cladding Self- Lubricant Coatings

Self-lubricating Ni+h-BN coatings were prepared by CO2 laser cladding with powder mixtures of Ni60 and h-BN. The chemical compositions and microstructures of the coatings were analyzed using SEM and XRD. The microhardness of the coatings was measured on a microhardness tester. It was found that the morphology of CrB was changed from irregular block-like shape (in Ni60+5%h-BN coating) →short–plate structure (in Ni60+10%h-BN coating)→dendritic-plate structure(in Ni60+15%h-BN coating) with increasing the content of h-BN. The microhardness of the 5,10 and 15% h-BN coatings ranged from 650～800HV0.2, 800～1010HV0.2 and 1000～1200HV0.2, which was higher than that of Ni60 coating and substrate.

Buckling of axially loaded composite plates with restrained edges

Approximate expressions to determine the lowest buckling load of short and long composite plates are presented. The plate is subjected to uniaxial compressive load. All the four edges of the plate are elastically restrained by springs or stiffeners. Explicit expressions for the calculation of the lowest buckling load are presented as a function of the plate’s length. The derived expressions were compared to numerical solutions investigating the entire parameter range.

Design of an embedded-feed type microstrip patch antenna for UHF radio frequency identification tag on metallic objects

The design of an embedded-feed type microstrip patch antenna, which can be mounted on metallic objects for radio frequency identification (RFID), is presented. The structure consists of an embedded feed with T-matching networks and a symmetrical radiating rectangular loop patch. The proposed antenna has no shorting plate or via hole and consists of a very thin structure of microstrip patch antenna compared with the conventional metallic tag antennas. The impedance of the presented antenna can be changed to match the impedance values of tag chips by using the T-matching network. The gain radiation pattern performance of the proposed antenna on metal surface is improved so that it can be used for a tag antenna mountable on metal surface in ultra-high frequency (UHF) band RFID applications. The antenna is analysed by full wave simulations, and experimental results are provided for the manufactured prototype.

Punching shear resistance of flat plate connection under monotonic load

This research studies the response of flat plate–column connections consisting of various types of shear reinforcement and steel plate subjected to gravity loadings using structural experiments and numerical analysis in tall buildings. The four test specimens were prepared to model the interior bay flat plate slab–column connections in a typical flat plate slab building. The base specimen has no shear reinforcement, and the other specimens have shear stud rails, shear studs with short steel plates under the slab and on the top portion of the column, and shear studs with long steel plates under the slab and on the top portion of the column. The base specimen failed due to punching shear generated from the gravity loading. The three other types of slab shear reinforcement using stud rails, shear studs with short steel plates and shear studs with long steel plates were shown to be efficient in resisting punching shear in the connections under gravity loading. The specimens containing studs with steel plates showed the most ductile behaviour under the gravity loading. The structural behaviour of the four specimens has been tested using the structural experiment and numerical analysis.

Effects of twisting and bending on the performance of a miniaturized truncated sinusoidal printed circuit antenna for wearable biomedical telemetry devices

In this paper, we present a miniaturized Truncated Sinusoidal Printed Circuit Antenna (TSPCA) consisting of a thin conductive film of copper mounted on a flexible substrate for wearable biomedical telemetry and smart clothes applications on the premises of health care and sport medicine facilities. The fundamental resonant mode of the proposed TSPCA is 611 MHz. The flat antenna operates over the frequency range from 608 to 614 MHz (−10 dB return-loss bandwidth of 1.7%) with a bore-sight gain of −29 dBi when operating in a free-space environment. The antenna size has been miniaturized to a 10 mm × 10 mm × 0.5 mm using a shorting plate on a substrate with a relative permittivity of 6.15 and loss tangent of 0.00134. The effects of twisting and bending on the performance of the TSPCA are investigated. It has been found that the maximum change in bore-sight gain, resonant frequency, and S 11, with respect to the flat case, is −8.5 dBi, 0.2%, and −4 dB, respectively, with respect to the flat case for bend angles ranging from −45° to 45°. Twisting of the antenna, on the other hand, in the range from −45° to 45° showed a maximum change of −16 dBi, 1%, and −17 dB in the bore-sight gain, resonant frequency, and S 11, respectively. The bandwidth remains virtually unaffected for both cases. The performance of the TSPCA is investigated when the antenna is mounted parallel to and at a distance of 0.5 mm from the arm, leg, thigh, and head. It has been found that maximum change in bore-sight gain, resonant frequency, and S 11 is −3.5 dBi, 2.5%, and −6.5 dB, respectively with respect to the isolated antenna.

Da Vinci System: clinical experience with complex proximal humerus fractures

The purpose of this study is to report the clinical and radiographic outcomes after open reduction and internal fixation of displaced proximal humerus fractures with the "Da Vinci System". It is a triangle-shaped cage whose opposite faces are pierced, and it represents the evolution of a triangle-shaped bone block technique performed in a previous series of 33 patients. The new device is an interesting innovation to treat the difficult problem of fracture fragments reconstruction and stability, metaphyseal bone loss and proximal humerus revascularization. According to the technique, authors position the correct size titanium cage into the metaepiphysis, so that the fragments are reduced upon the cage, and they are stabilized with a minimal osteosynthesis by Kirschner wires, titanium screws or transosseous sutures. If the fracture line involves the proximal portion of the diaphysis, it is possible to use a short low profile plate. Between May 2005 and November 2009, we treated 71 patients (34 men and 37 women), even though we included in our study only 59 patients, who had a minimum follow-up of 12 months. The first patient has been treated in May 2005 and the last one in September 2008. The mean age was 60.8 years (minimum 27, maximum 78). There were 8 displaced 3-part fractures, 20 displaced 4-part fractures, 10 4-part fracture-dislocations, 5 head splitting, 12 unclassified multifragmentary fractures, 1 2-part fracture with multifragmentary calcar and 3 malunions of 4-part fracture. The functional results were evaluated by the Constant score. With a mean follow-up of 24 months (minimum 12, maximum 36 months), the mean Constant score was 80.25. The results were excellent or good in 48 cases, bad in 2 cases and satisfactory in 9; the mean active anterior elevation (AAE) was 160 degrees . All fractures but one healed; in one case, we had a deep infection after 80 days since the operation, treated with a preformed cement spacer.

One Stage Urethroplasty in Severe Hypospadias -Buccal Mucosa Inlay with Penile Island Skin Flap Onlay

Purpose Severe forms of Hypospadias are usually associated with chordee and short or even absent urethral plate that result in a small and curved penis. In this case, the urethral plate should be divided for penile straightening and lengthening. In such cases the missing urethral plate needs to be augmented. Material and Methods We present the case of a 14 month old boy with a perineal Hypospadias, a 90° ventral penile curvature and a bifid scrotum.After completion of penile degloving, artificial erection reveals a severe ventral penile curvature.The short urethral plate is mobilised in the plane of Buck’s-Facia. The urethral plate is divided at the coronal level.The dorsal neurovascular bundle is carefully mobilised. With another artificial erection, the point of the maximal curvature is revealed and the intended correction marked with an Ellis-Clump.In order to straighten the penis, the marked area is incised longitudinally and sutured transversally. Renewed erection demonstrates the straightened penis.The distance between the original hypospadic meatus and the distal end of the divided urethral plate shows a 4cm gap that needs to be bridged.Buccal mucosa is harvested from the inner cheek and brought to the ventral aspect of the penis to be used as an inlay graft to fill in the gap of the missing urethral plate.After complete fixation of the buccal mucosa, the inlay is quilted to the tunica albuginea.Dorsal penile and preputial skin was used for creating the longitudinal island flap.The island flap is transposed ventrally with the buttonhole technique to be used as the onlay flap.The glanular wings are trimmed and the glans reconstructed.The bifid scrotum is corrected in the same session. Results A severe Hypospadias was corrected as a one-stage-procedure. No complications occurred. Conclusions Combined longitudinal island skin flap and buccal mucosa graft could be a good choice for urethral reconstruction in most severe Hypospadias repairs.

Interaction of circular cylinder wake with a short asymmetrically located downstream plate

This study reveals the interaction patterns of separated shear layers from a circular cylinder with a short downstream plate and their reflection on the frequency and the formation length of the vortices from the cylinder as a function of plate location relative to the cylinder. The effect of horizontal (G/D) and vertical (Z/D) distances between the cylinder and the plate on the near wake is studied via Digital Particle Image Velocimetry (DPIV) in a water channel for Reynolds numbers of 200, 400 and 750, based on the cylinder diameter D. It is shown that the interaction of wake with the plate of length D can be categorized depending on the horizontal and the vertical distances between the cylinder and the plate. For the vertical distance range of Z/D ≤ 0.7, there is a critical horizontal spacing before which the shear layers from the cylinder are inhibited to form vortices in front of the plate. Resulting elongated recirculation region between the plate and the cylinder suggests modification of the absolutely unstable near wake of free circular cylinder in favor of convective instability. Z/D = 0.9 provides a passage from Z/D ≤ 0.7 to ≥1.1 and is associated with a dominant effect on the near-wake characteristics of interaction of shear layers from the cylinder with those from the downstream plate. For Z/D ≥ 1.1, there is again, yet a smaller critical horizontal spacing after which vortices interact with decreased downstream plate interference. In this vertical separation distance range, a gap flow between the plate and the cylinder plays a determining role on the formation length and St number of vortices for small horizontal spacing values.

On the larval morphology and ecology of the limoniid Microlimonia machidai (Diptera, Limoniidae)

The morphology of Microlimonia machidai (Al.) larvae is described for the first time. The main diagnostic characters are the following: the presence of five well-developed stigmal lobes, which are sclerotized internally; the massive head capsule with a short frontal plate; the presence of creeping welts on abdominal segments III-VII and the absence of cone-like tooth on the anterior margin of the labium and hypopharynx. The most typical habitat is the juicy bast fibers in decaying trunks of coniferous and deciduous trees.

Stacked Rectangular Microstrip Antenna with a Shorting Plate and a Helical Pin for Triple Band Operation in ITS

A stacked rectangular microstrip antenna with a shorting plate and a helical pin is proposed as a car antenna for triple band operation in ITS. The proposed antenna operates as a conventional stacked microstrip antenna at the highest frequency band. At the middle and the lowest frequency bands, the antenna radiates at low elevation angles from the helical pin and the shorting plate. In this paper, as an example of triple band antennas in the ITS, an antenna is designed that supports PHS, VICS and ETC. The proposed antennas have the proper radiation pattern for each application and are small in size.

G223 平板列挿入による自然対流層流熱伝達の促進に関する数値解析(一般講演)

Heat transfer enhancement for a laminar natural-convection boundary layer along a vertical flat plate with short flat plates standing in line 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 shows that 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.

Comparative studies on the effect of duct height on heat transfer and flow behavior between co-angular and co-rotating type finned surface

This paper presents the comparative studies on the effect of duct height on heat transfer and flow behavior between co-angular and co-rotating type finned surface in duct. Experiments were performed to investigate the effect of duct height on heat transfer enhancement of a surface affixed with arrays (7 × 7) of short rectangular plate fins of a co-angular and a co-rotating type pattern in the duct. An infrared imaging system with the camera of TVS 8000 was used to measure the temperature distributions to calculate the local heat transfer coefficients of the representative fin regions. Pressure drop and heat transfer experiments were performed for both types of fin pattern varying the duct to fin height ratio (Hd/Hf) of 2.0–5.0. The friction factor calculated from the pressure drop shows that friction factor decreases with increasing the duct to fin height ratio (Hd/Hf) regardless of fin pattern and this is expected because the larger friction occurs for smaller duct to fin height ratios. Detailed heat transfer distribution gives a clear picture of heat transfer characteristics of the overall surface as well as the influence of the duct height. In addition, different flow behavior and flow structure developed by both patterns were visualized by the smoke flow visualization technique.

Three-dimensional multi-scale plate assembly for maximum heat transfer rate density

This paper extends the design concept for generating multi-scale structures in forced convection for a finite-size flow system to a three-dimensional heat-generating plate with the objectives of maximising heat transfer rate density, or the heat transfer rate per unit volume. The heat-generating plates, arranged in a stack form channels in which the fluids are forced through by an applied pressure difference. The first stage of this work consists of numerical simulation of the flow and heat transfer in a large number of flow configurations, to determine the optimum plate spacing, and the maximum heat transfer rate density. In the subsequent stages, shorter plates are inserted in the centers at adjacent (longer) plates in the entranced region were the boundary layer are thin and there is a core of unused fluid. The heat transfer density is further increased by progressively inserting another set of even shorter plates between the plates and then optimizing the whole structure. The resulting structure is an optimized multi-scale and multi channel structure with horizontal equidistant heated plates of decreasing lengths scales. Further more the effects of plate thickness and dimensionless pressure drop number on the multi-scale structure was investigated. The numerical results are found to be in good agreement with predicted analytical results.

Effect of a biplanar osteotomy on primary stability following high tibial osteotomy: a biomechanical cadaver study

Open-wedge high tibial osteotomy (HTO) is becoming increasingly popular for the treatment of varus gonarthrosis in the active patient. The various implants used in HTO differ with regard to its design, the fixation stability and osteotomy technique. It is assumed that the combination of a plate fixator with a biplanar, v-shaped osteotomy supports bone healing. So far, there are no biomechanical studies that quantify the stabilizing effect of a biplanar versus uniplanar osteotomy. We hypothesized that a significant increase in primary stability of bone-implant constructs is achieved when using a biplanar as opposed to a uniplanar osteotomy. Twenty-four fresh-frozen human tibiae were mounted in a metal cylinder, and open-wedge osteotomy (12 mm wedge size) was performed in a standardized fashion. Proximal and distal tibial segments were marked with tantalum markers of 0.8 mm diameter. Two different plates with locking screws were used for fixation: a short spacer plate (group 1, n = 12) and a plate fixator (group 2, n = 12). In six specimens of each group, a biplanar V-shaped osteotomy with a 110 degrees angulated anterior cut behind the tuberosity parallel to the ventral tibial shaft axis was performed. In the remaining six specimens of each group, a simple uniplanar osteotomy was performed in an oblique fashion. Axial compression of the tibiae was performed using a material testing machine under standardized alignment of the loading axis. Load-controlled cyclical staircase loading tests were performed. The specimens were radiographed simultaneously in two planes together with a biplanar calibration cage in front of a film plane with and without load after each subcycle. Radiostereometry allowed for serial quantification of plastic and elastic micromotion at the osteotomy site reflecting the stability provided by the combination of implant and osteotomy technique. No significant additional stabilizing effect of a biplanar osteotomy in craniocaudal and mediolateral plane was found. However, additional stability was achieved in anteroposterior (AP) and all rotational planes in those specimens fixated with a short spacer plate. In this biomechanical set-up with axial load, the additional stabilizing effect of a biplanar osteotomy did not come into effect in the presence of a long and rigid plate fixator. However, biplanar osteotomy increased the fixation stability significantly in AP and rotational planes when a short spacer plate was used. Clinically, the biplanar osteotomy promotes bone healing regardless of the implant used. Biomechanically, biplanar osteotomy is advantageous for shorter plate designs to increase primary stability of the bone-implant construct.

Design of a Circularly Polarized Tag Antenna for Increased Reading Range

We introduce a novel circularly polarized tag antenna, consisting of a truncated patch, a shorting plate, and a ground plane, to increase the reading range while remaining in compliance with EIRP regulations. The reading range of the proposed tag is twice that of linearly polarized tags, due to the decreased polarization mismatch between the reader and tag antennas. An additional parasitic patch is loaded onto the structure to boost the reading range in the UHF RFID band. As a result, an average reading range of 8 m is achieved between 860 MHz and 960 MHz, compared to a range of about 3 m with conventional dipole tags.

Urethral Lengthening in Metoidioplasty (Female-to-male Sex Reassignment Surgery) by Combined Buccal Mucosa Graft and Labia Minora Flap

To develop a technique for urethral reconstruction using a combined labia minora flap and buccal mucosa graft. Urethral lengthening is the most difficult part in female transsexuals and poses many challenges. From April 2005 to February 2008, 38 patients (aged 19-53 years) underwent single-stage metoidioplasty. The technique starts with clitoral lengthening and straightening by division of both clitoral ligaments dorsally and the short urethral plate ventrally. The buccal mucosa graft is quilted to the ventral side of the corpora cavernosa between the native orifice and the tip of the glans. The labia minora flap is dissected from its inner surface to form the ventral aspect of the neourethra. All suture lines are covered by the well-vascularized subcutaneous tissue originating from the labia minora. The labia majora are joined in the midline and 2 silicone testicular implants are inserted to create the scrotum. The neophallus is covered with the remaining clitoral and labial skin. The median follow-up was 22 months (range 11-42). The median neophallic length was 5.6 cm (range 4-9.2). The total length of the neourethra was 9.4-14.2 cm (median 10.8). Voiding while standing was reported by all 38 patients, and temporary dribbling and spraying were noted by 12. Two fistulas and one urethral erosion resulted from the testicular implant and required secondary revision. A combined buccal mucosa graft and labia minora flap present a good choice for urethral reconstruction in female-to-male transsexuals, with minimal postoperative complications.

Film boiling heat transfer and vapour film collapse on spheres, cylinders and plane surfaces

An experimental study of transient film boiling was conducted, with different coolant velocities, on two spheres with different diameters, two cylindrical specimens of different lengths in parallel flow, a cylinder in cross flow and two flat plates with different lengths. A frame by frame photographic study on the nature of the vapour/liquid interface and the collapse modes has revealed a new mode for film collapse, in which an explosive liquid–solid contact is followed by film re-formation and the motion of a quench front over the hot surface. Steady state tests were carried out on a plate similar to the short plate used in the transient experiments and the heat transfer, film stability and collapse results are compared with those of the transient investigation. Heat transfer coefficients and heat fluxes during film boiling were found essentially to depend on specimen temperature and water subcooling. In contrast, the influences on heat transfer of specimen size and water velocity were relatively small for the ranges studied. A theoretical model predicted heat transfer coefficients to within 10% of experimental values for water subcoolings above 10 K and within 30% in all cases.

Evolution of flat-plate wakes in sink flow

Evolution of flat-plate wakes in sink flow has been studied both analytically and experimentally. For such wakes, a similarity solution is derived which considers simultaneous presence of both laminar and turbulent stresses inside the wake. This solution utilizes an additional Reynolds-stress term which represents the fluctuations similar to those in wall-bounded flows, accounting for the fluctuations originating from the plate boundary layer. In this solution, it is shown that the total stress, the sum of laminar and Reynolds shear stresses, becomes self-similar. To investigate the accuracy of the analytical results, the wake of a flat plate located at the centreline of a planar contraction is studied using hot-wire anemometry. Wakes of both tapered and blunt edges are considered. The length of the plates and the flow acceleration number K = 6.25 × 10−6 are chosen such that the boundary-layer profiles at the plate edge approach the self-similar laminar solution of Pohlhausen (Z. Angew. Math. Mech., vol. 1, 1921, p. 252). A short plate in which the boundary layer at the edge does not fully relaminarize is also considered. The development of the turbulent diffusivity used in the analysis is determined empirically for each experimental case. We have shown that the obtained similarity solutions, accounting also for the initial conditions in each case, generally agree well with the experimental results even in the near field. The results also show that the mean velocity of the transitional wake behind a tapered edge becomes self-similar almost immediately downstream of the edge.