Lateral Configuration Research Articles

Measurement of longitudinal displacement using lateral shearing cyclic path optical configuration setup and phase shifting interferometry

We present a technique for the measurement of longitudinal displacement using a lateral shearing cyclic path optical configuration (CPOC) setup and phase shifting interferometry. In the technique, a plane mirror mounted on a linear translation stage, placed slightly away from the focal plane of a lens, introduces a longitudinal focal shift to the incident focusing beam. The resulting spherical wavefront emerging from the lens is sheared into two orthogonally polarized beams using the CPOC setup. By applying polarization phase shifting interferometry (PPSI), the longitudinal focal shift of the beam focus is calculated by determining the slope of the optical path difference variation between the sheared beams. Similarly, the additional focal shift introduced due to longitudinal translation of the mirror, by an unknown amount, is determined using PPSI. Half of the difference between the two longitudinal focal shifts measured gives the longitudinal displacement of the mirror. The technique can be used for an extended range of distance measurement. The novelty of the technique is the introduction of CPOC for the distance measurement. The advantages of the technique compared to other related methods are discussed.

Parameters influencing seismic response of horizontally curved, steel, I-girder bridges

This study examines the influence of curved, steel, I-girder bridge configuration on girder end reactions and cross frame member forces during seismic events. Simply-supported bridge finite element models were created and examined under seismic events mimicking what could be experienced in AASHTO Seismic Zone 2. Bridges were analyzed using practical ranges of: radius of curvature; girder and cross frame spacings; and lateral bracing configuration. Results from the study indicated that: (1) radius of curvature had the greatest influence on seismic response; (2) interior (lowest radius) girder reactions were heavily influenced by parameter variations and, in certain instances, uplift at their bearings could be a concern; (3) vertical excitation more heavily influenced bearing and cross frame seismic response; and (4) lateral bracing helped reduce seismic effects but using bracing along the entire span did not provide additional benefit over placing bracing only in bays adjacent to the supports.

Thickness measurement of transparent glass plates using a lateral shearing cyclic path optical configuration setup and polarization phase shifting interferometry

We present a measurement technique to determine the thickness of a transparent glass plate (GP) by using a lateral shearing cyclic path optical configuration (CPOC) setup and polarization phase shifting interferometry (PPSI). In the technique, the GP introduces a longitudinal shift in the focus of the beam and, as a result, a spherical wavefront emerges from the lens, which is otherwise set for producing a collimated beam. Using CPOC, two laterally sheared orthogonally polarized beams are generated from the incident spherical wavefront. By applying PPSI, the slope of the optical path difference variation between the laterally sheared interfering beams is evaluated, and the radius of the spherical wavefront and the longitudinal shift of the beam focus are calculated. The thickness of the GP is determined from the standard relation between the longitudinal shift of the focus introduced by the GP and the thickness of the GP. Results obtained for a GP of 9.810mm thickness are presented.

A Lateral Microfluidic Cell for Imaging Electrodeposited Zinc near the Shorting Condition

The morphology evolution of zinc electrodeposited from alkaline ZnO/KOH is imaged in situ using a microfluidic cell. Working and counter electrodes are in a lateral configuration, separated by a flow channel with a height of , resulting in quasi-two-dimensional zinc layers. At a flow rate of 0.3 cm/s, zinc packing in the channel is highest at a current density just above the transition from porous to dense zinc, . When deposited, compact zinc is approximately 3 times as dense as porous zinc, as determined by image analysis of the layer. The dense mode invariably leads to ramifications and critical growth, causing cell shorting. Greater zinc packing is possible at a flow rate of 3.1 cm/s, although flow rates of this order are impractical for flow-assisted zinc batteries. Ramified zinc tips approach a kinetically limited rate, independent of electrolyte flow rate. Therefore, increased flow rate cannot control critical growth once it begins. Increased flow rate results in a higher density of ramified tips at equivalent cell potential. The zinc deposition reaction has a Tafel slope of 130 mV below and 50 mV in the second Tafel region . The second Tafel region is relevant to zinc secondary batteries.

Development of a nonlinear finite element model of the type II odontoid fracture

Objective To develop an anatomic detailed finite element model of the type Ⅱ odontoid fracture. Methods The finite element model was constructed by the software Mimics 8. 1 with CT images. Fracture of the base of den was modeled with reference to type Ⅱ odontoid fracture. The meshed model was acquired and finished with Ansys 9. 0. The ligaments were added to the model based on data from the literature. To validate the model of type Ⅱ odontoid fracture, the predicted kinematic data, in term of the range of motion ( ROM) , under different static loading configurations were analyzed and compared against the experimental data. In the analysis, the weight of the skull was simulated by applying vertical load of 40 N on the occiput, and the inferior surface of the C3 vertebral body was fully constrained. Pure moment loading of 1. 5 Nm was applied to the occiput along the various anatomical planes to simulate various movements of the cervical spine under flexion, extension, axial rotation and lateral bending configurations. Results The model consisted of 229 047 nodes and 152 475 elements. The ROM of Cl-2 was; flexion-extension 38. 3° , lateral bending 20. 4° , rotation 74. 2°, and correlated well with the experimental data. Conclusion The anatomic detailed finite element model of the model of type Ⅱ odontoid fracture realistically simulates the complex kinematics of the craniocervical region which can simulate the natural condition and facilitate the further biomeehanical research. Key words: Cervical spine; Biomechanics; Odontoid; Fracture

Iatrogenic Ulnar Nerve Injury After the Surgical Treatment of Displaced Supracondylar Fractures of the Humerus: Number Needed to Harm, A Systematic Review

Supracondylar fractures of the humerus are common pediatric elbow injuries. Most displaced or angulated fractures are treated by closed reduction and percutaneous pinning, with either a crossed pin or lateral pin configuration. The purpose of this study was to conduct a systematic review to determine if there is an increased risk of iatrogenic nerve injury associated with the crossed pin configuration. Relevant articles were identified by searching electronic databases and hand searching-related journal and conference proceedings. Within each trial, the risk of iatrogenic ulnar nerve injury was calculated for each pinning technique. For studies comparing crossed versus lateral pinning, the resulting trial-based differences in risk estimates were pooled using a random effects meta-analysis. A number needed to harm was determined using the pooled risk difference. Thirty-two trials consisting of 2639 patients were used in the pooled analysis. The pooled risk difference of iatrogenic ulnar nerve injury is 0.035 (95% confidence interval, 0.014-0.056), with a higher incidence of injury in the crossed pinning group. The weighed number needed to harm for the crossed pinning is 28 (95% confidence interval, 17-71). The results of this review suggest that there is an iatrogenic ulnar nerve injury for every 28 patients treated with the crossed pinning compared with the lateral pinning. Further research is necessary to ensure that the optimal pinning technique is chosen to treat these factors. Level III.

The effect of lateral flooding on the coolability of irregular core debris beds

The coolability of ex-vessel core debris is an important issue in the severe accident management strategy of, e.g. the Nordic boiling water reactors. In a core melt accident, the molten core material is expected to discharge into the containment and form a porous debris bed on the pedestal floor of a flooded lower drywell. The debris bed generates decay heat which must be removed by boiling in order to stabilize the debris bed and to prevent local dryout and possible re-melting of the material. The STYX test facility which consists of a cylindrical bed of irregular alumina particles has been used to investigate the effect of lateral coolant inflow on the dryout heat flux of the particle bed. The lateral flow was achieved by downcomers attached on the sides of the test rig. The downcomers provide coolant into the lower region of the bed by natural circulation. Both homogenous and stratified bed configurations have been examined. It was observed that the dryout heat flux is increased by 22–25% for the homogenous test bed compared to the case with no lateral flooding. For the stratified configuration with a fine particle layer on top of the bed, no significant increase in the dryout heat flux was observed. The experiments have been analyzed by using the MEWA-2D code. Models which include explicit consideration of gas–liquid friction were used in the calculations in order to realistically capture the lateral flow configuration.

Three-Dimensional Semianalytical Solutions of Groundwater Flow to a Well in Fractured Wedge-Shaped Aquifers

The three-dimensional Laplace domain solutions of groundwater flow to a well in fractured double porosity confined, unconfined, and leaky wedge-shaped aquifers are developed. Three wedge boundary configurations: (1) two constant head zero drawdown; (2) two impermeable; and (3) one constant head zero drawdown and one impermeable wedge boundary are considered. Dimensionless drawdowns are obtained for different wedge boundary configurations to investigate flow system behavior. Lateral boundary dimensionless flux at a representative line is also calculated for two constant head zero drawdown configuration and its sensitivity to the matrix hydraulic parameters are investigated. Results of our study are presented in the form of dimensionless flux-dimensionless time and dimensionless drawdown-dimensionless time, type curves. The results are useful for evaluating the role of matrix hydraulic parameters on lateral boundary depletion rate and investigation of flow system behavior in double porosity wedge-shaped aquifers with different lateral boundary configurations. The presented analytical solutions can also be used in parameter identification, stream depletion rate estimation and numerical models verification.

Biomechanical Analysis of Lateral Pin Placements for Pediatric Supracondylar Humerus Fractures

Several clinical studies have shown that lateral pinning alone is of equal stability to crossed pins in the treatment of supracondylar fractures. The aim of this study was to compare the stability of parallel and varied divergent lateral pin configurations to provide an easily reproducible technique for optimal pin placement. Twelve third-generation synthetic composite humeri were osteotomized at the level of the coronoid and olecranon fossae to simulate a humeral supracondylar fracture. Each fracture was reduced and fixed using two 1.6 mm (0.062 inches) Kirschner wires (1 fixed, 1 varied) in 4 different positions (from parallel to divergent with respect to fixed wire), and sequentially tested in extension, varus, and valgus as well as internal and external rotations using an MTS 858 Minibionix materials testing load frame (MTS Corporation, Eden Prairie, MN). A 2-way analysis of variance was carried out to compare construct stiffness in all 5 modes of testing according to both pin position and testing sequence. A level of P<0.05 was considered statistically significant. The best torsional, valgus, and extension resistances were found with position 4, which was the most divergent configuration. For both internal and external rotations, position 4 showed statistically higher stiffness as compared with all other configurations (P<0.05). In resistance to extension, both positions 3 and 4 were stiffer than either position 1 or 2 (P<0.05). For resistance in varus testing, position 3 showed statistically greater stiffness than all other pin positions (P<0.05). Although there was no statistical difference between all the 4 positions in valgus testing, position 4 showed greater resistance when compared with other positions. The lateral pin placed parallel to the metaphyseal flare of the lateral humeral cortex, in combination with a second diverging pin crossing the fracture site at the medial edge of the coronoid fossa (position 4), provided the optimum fixation for supracondylar fractures of the humerus. Using these readily available landmarks, the treating surgeon can reproducibly provide appropriate pinning treatment for most of these fractures.

Interplay of bulk and interface effects in the electric-field-driven transition in magnetite

Contact effects in devices incorporating strongly correlated electronic materials are comparatively unexplored. We have investigated the electrically driven phase transition in magnetite (100) thin films by four-terminal methods. In the lateral configuration, the channel length is less than $2\text{ }\ensuremath{\mu}\text{m}$, and voltage-probe wires $\ensuremath{\sim}100\text{ }\text{nm}$ in width are directly patterned within the channel. Multilead measurements quantitatively separate the contributions of each electrode interface and the magnetite channel. We demonstrate that on the onset of the transition contact resistances at both source and drain electrodes and the resistance of magnetite channel decrease abruptly. Temperature-dependent electrical measurements below the Verwey temperature indicate thermally activated transport over the charge gap. The behavior of the magnetite system at a transition point is consistent with a theoretically predicted transition mechanism of charge gap closure by electric field.

Accuracy of Predissection Assessment of the Lower Lateral Cartilage Configuration: A Cadaveric Study

Preoperative planning of nasal tip surgery requires an accurate assessment of the nasal tip cartilages configuration. The current literature lacks any evidence on the accuracy of preoperative assessment of the lower lateral cartilages (LLC) shape. This study was designed to determine the accuracy of the LLC shape and configuration assessment prior to dissection. The configuration of the lateral, middle, and medial crura was assessed on 42 LLC (21 cadavers) prior to dissection by way of observation and palpation. The findings were then compared with those observed after LLC exposure through an open-approach dissection. The accuracy of predissection LLC shape assessment was 42 of 42 (100%), 32 of 42 (76%), and 12 of 42 (29%) for medial, middle, and lateral crus, respectively. The configuration of the lateral crus of LLC cannot be accurately assessed prior to exposure of the cartilage. A rhinoplastic surgeon who embarks on nasal tip surgery should be familiar with a number of techniques to address any tip deformity encountered after exposure, as the preoperative clinical and photographic assessments cannot reliably demonstrate the type of LLC deformity.

Low Thermal Budget Monolithic Integration of Evanescent-Coupled Ge-on-SOI Photodetector on Si CMOS Platform

The design and fabrication of a monolithically integrated evanescent-coupled Ge-on-silicon-on-insulator (SOI) photodetector and CMOS circuits were realized on common SOI platform using an ¿electronic-first and photonic-last¿ integration approach. High-performance detector with an integrated Si waveguide was demonstrated on epitaxial Ge-absorbing layer selectively grown on an ultrathin SOI substrate. Performance metrics of photodetector designs featuring vertical and lateral PIN configurations were investigated. When operated at a bias of -1.0 V, a vertical PIN detector achieved a lower <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dark</sub> of ~ 0.57 ¿A as compared to a lateral PIN detector, a value that is below the typical ~ 1 ¿A upper limit acceptable for high-speed-receiver design. Very high responsivity of ~ 0.92 A/W was obtained in both detector designs for a wavelength of 1550 nm, which corresponds to a quantum efficiency of ~ 73%. Impulse response measurements showed that the vertical PIN detector gives rise to a smaller full-width at half-maximum of ~ 24.4 ps over a lateral PIN detector, which corresponds to a -3 dB bandwidth of ~ 11.3 GHz. <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RC</i> time delay is shown to be the dominant factor limiting the speed performance. Eye patterns (pseudorandom binary sequence 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> -1) measurement further confirms the achievement of high-speed and low-noise photodetection at a bit rate of 8.5 Gb/s. Excellent transfer and output characteristics have also been achieved by the integrated CMOS inverter circuits in addition to the well-behaved logic functions. The introduction of an additional thermal budget (800 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> C) arising from the Ge epitaxy growth has no observable detrimental impact on the short-channel control of the CMOS inverter circuit. In addition, we describe the issues associated with monolithic integration and discuss the potential of Ge-detector/Si CMOS receiver for future optical communication applications.

Camera and trocar placement for robot-assisted radical and partial nephrectomy: which configuration provides optimal visualization and instrument mobility?

Proper camera and trocar placement is critical to the success of minimally invasive procedures. For robot-assisted renal surgery, two basic trocar configurations have been described. The medial approach, using a 30° downward-angled lens mimics a traditional transperitoneal laparoscopic configuration. An alternative configuration, using a 0° or 30° upward-angled lens approach locates the camera laterally, evoking a position sense similar to a retroperitoneal approach. Our objective is to compare the differences between these two standard approaches for robot-assisted renal surgery. After performing a review and analysis of available literature, our group tested both the medial and lateral camera approaches during robotic renal surgery performed in human patients. The medial approach provides a wide field of view, because of the relatively greater distance to the target structures and a horizon line closer to the patient's midline. The lateral configuration offers significantly different visualization. The relative proximity to the target structures and a higher horizon line results in a comparatively restricted field of vision. Instrument mobility is comparable between the two approaches. Meta-analysis of the literature reveals that both approaches provide comparable overall operative times for both radical and partial nephrectomy, though there is a trend towards shorter overall operative times for partial nephrectomy performed through a medial approach. The medial trocar configuration provides a familiar working environment for both surgeon and assistant; the wide-angle view enables enhanced visualization of surrounding structures and tracking of the instruments inserted by the assistant. The lateral approach offers the potential advantage of a closer view of the kidney, but does so at the expense of a significantly restricted field of view. In our experience, a medial trocar configuration offers significant advantages over the lateral trocar configuration, and is, therefore, the standard approach at our high-volume center.

Fontan hemodynamics: Importance of pulmonary artery diameter

We quantify the geometric and hemodynamic characteristics of extracardiac and lateral tunnel Fontan surgical options and correlate certain anatomic characteristics with their hemodynamic efficiency and patient cardiac index. The study was conducted retrospectively on 22 patients undergoing Fontan operations (11 extracardiac and 11 lateral tunnel operations). Total cavopulmonary connection geometric parameters such as vessel areas, curvature, and offsets were quantified using a skeletonization method. Energy loss at the total cavopulmonary connection junction was available from previous in vitro experiments and computational fluid dynamic simulations for 5 and 9 patients, respectively. Cardiac index data were available for all patients. There was no significant difference in the mean and minimum cross-sectional vessel areas of the pulmonary artery between the extracardiac and lateral tunnel groups. The indexed energy dissipation within the total cavopulmonary connection was strongly correlated to minimum cross-sectional area of the pulmonary arteries (R(2) value of 0.90 and P < .0002), whereas all other geometric features, including shape characteristics, had no significant correlation. Finally, cardiac index significantly correlated with the minimum pulmonary artery area (P = .006), suggesting that total cavopulmonary connection energy losses significantly affect resting cardiac output. The minimum outlet size of the total cavopulmonary connection (ie, minimum cross section of pulmonary artery) governs the energy loss characteristics of the total cavopulmonary connection more strongly than variations in the shapes corresponding to extracardiac and lateral tunnel configurations. Differences in pulmonary artery sizes must be accounted for when comparing energy losses between extracardiac and lateral tunnel geometries.

Capacitor-embedded 054 pJ/bit silicon-slot photonic crystal waveguide modulator

A high-speed compact silicon modulator based on the lateral capacitor configuration is experimentally demonstrated with low-power consumption and 3 dB modulation depth. The capacitor layout is introduced to scale down the total modulator capacitance to 30x10(-15) F, which effectively reduces the rf power consumption to 0.54 pJ/bit. Exploiting the slow group velocity of light in the slot photonic crystal waveguides, the device reported herein exhibits higher modulation efficiency than conventional capacitor modulator and provides a V(pi)L figure of merit of 0.18 Vcm at the wavelength of 1548 nm.

Three-year-old child head-neck finite element modelling: simulation of the interaction with airbag in frontal and side impact

This study proposes to assess the interaction between the three-year-old child head-neck system and a typical airbag, a protective system frequently used in the automotive field. Two separated models (head and neck) developed at the Strasbourg University (UDS) were coupled in order to estimate the injury risk during this type of impact. The first model developed is a three-year-old child finite element neck model (FEM) based on a realistic geometry. This FEM was validated in four directions against an original method based on scaling method. The second FEM is a three-year-old child head FE model published by Roth et al (2008). This model proposed an injury criterion in terms of Von Mises stress in the brain for moderate neurological injuries. After a coupling of these two FE models two impacts a frontal and lateral impact configuration are simulated. These impacts consisted of an airbag deployment at different gaps in order to calculate and estimate child brain injury risks.

Development of a vacuum packaged nanodiamond lateral field emission device

The authors report the development of a monolithic diamond field emission device in lateral configuration operating in a vacuum package. Nanocrystalline diamond is applied in the microfabrication of planar lateral emitter diodes on a silicon-on-insulator substrate. A feasible packaging process has been developed for the device, where the diodes are die attached, wire bonded, and vacuum sealed in a cavity package. Field emission characterization measurements performed on the packaged diamond lateral vacuum devices indicate a practical construct and package for vacuum micro/nanoelectronic applications.

Radiographic evaluation of frontal talar edge configuration for osteochondral plug transplantation

For successful reconstruction of osteochondral lesions of the talus, the anatomic configuration of the talar edge must be respected. This study evaluated the radiographic configuration of the talar edge in the anterior-posterior (AP) view by analyzing medial and lateral talar edge angles and radii in 81 patients with a true AP view and without ankle pathology. The mean lateral talar edge angle was 91.8 degrees , and the mean medial talar edge angle was 110.0 degrees . The medial frontal talar edge radius was 4.8 mm and the lateral 3.5 mm, respectively. No correlation between angle and radius was found. These results revealed a significant difference between the medial and the lateral talar edge configuration. This may be due to the three-dimensional function of the human ankle joint. No study so far has addressed these differences radiologically. These differences should be addressed in the reconstruction of osteochondral lesions and be included in the preoperative planning.

Nanocrystalline diamond lateral vacuum microtriode

A vacuum field emission microtriode in lateral configuration utilizing nanocrystalline diamond is presented. The nanodiamond lateral triode is a completely integrated device comprising a fingerlike emitter geometry with an ∼15nm tip radius of curvature, built-in gate, and anode with gate-cathode spacing of 3μm and anode-cathode spacing of 12μm. Triode characteristics, demonstrating gate-controlled emission current modulation with an anode current of 4μA and high transconductance of 0.3μS from a single emitter-finger at low device voltages (Vg&amp;lt;40V and Va∼65V), are obtained. The anode-induced electron emission conforms to Fowler–Nordheim tunneling. These observations from the first diamond lateral vacuum microtriode demonstrate a robust device for integrated circuit-compatible, temperature-, and radiation-insensitive vacuum micro-nanoelectronics.

Experimental and Numerical Investigation of R-134a Flow through a Lateral Type Diabatic Capillary Tube

This paper presents the performance of R-134a through a diabatic capillary tube with lateral configuration. The paper is divided into two sections: (1) an experimental investigation of straight and helical diabatic capillary tubes and (2) a numerical investigation of the straight diabatic capillary tube. In the experimental investigation, the effects of parameters such as capillary tube diameter, capillary tube length, coil pitch, and inlet subcooling on the refrigerant mass flow rate through a diabatic capillary tube were studied. In addition to the parameters mentioned above, the mass flow rate through a diabatic helical capillary tube was also found to be a function of suction-line inlet superheat and heat exchange length. The suction-line inlet superheat in the present investigation is not a controlled parameter. A comparison of the results of diabatic helical capillary and adiabatic helical capillary tubes was also made. On the basis of acquired experimental data, a correlation to predict the refrigerant mass flow rate was proposed. It was found that the predictions of the proposed correlation are within ±5% agreement with the experimental data. In the numerical investigation, a mathematical model was developed by applying laws of conservation of mass, momentum, and energy to a straight diabatic capillary tube. These differential equations were solved numerically using a finite difference method. The developed model was validated with experimental data from previous and present research. Further, a comparison was also made between the proposed model and the models of Sinpiboon and Wongwises (2002) and Valladares (2007).