Angle Configuration Research Articles

Angled-tip vs. straight-tip guidewire in ERCP: a randomized, multicenter study

Background Endoscopic retrograde cholangiopancreatography (ERCP) is the mainstay for interventional treatment of biliopancreatic diseases, and guidewires are decisive for successful treatment. Methods A randomized, multicenter, open-label study was conducted in patients in whom a guidewire was required in ERCP. Success rate and duration of the investigation were evaluated by randomly applying hydrophilic guidewires with a straight tip (ST) or an angled tip (AT) configuration, with normal (type NF) or enhanced (type EF) flexibility. Randomization was stratified by indication, i.e., stricture of the intra-hepatic bile ducts, stricture of the extrahepatic bile ducts, obstruction by bile duct stones, or interventions involving the pancreas. Cross-over was allowed if the initially allocated guidewire did not result in treatment success. Results Four hundred fifty-three patients were included, and 422 were finally analyzed. In 363 procedures (86%), the initially allocated wirés use resulted in treatment success. The success rate for using a guidewire with an angled tip configuration was 87.5 vs. 79.9% in a straight tip configuration (p = 0.049), and in negotiating an intrahepatic stricture the success rate was 90.7 vs. 69.1%, respectively (p = 0.008). No significant differences were observed in other indications. Procedural duration time did not differ in between the treatment groups. Conclusion ERCP guidewires with an angled tip were more frequently successful when compared to straight tipped wires and most successful in treating intrahepatic strictures. Guidewires with standard vs. enhanced tip flexibility showed equal success rates in all indications.

Free vibration analysis of grid-stiffened composite truncated spherical shells

In this paper, the vibrational behavior of grid-stiffened truncated composite spherical shells has been studied. Using a smeared stiffener technique, the stiffness contribution of the non-uniform grid structures are superimposed with those of the shell. The helical stiffeners have been considered as truss, which are able to bear the axial forces. The equations of motion have been derived within the framework of the classical Donnell’s thin shell theory and then solved by means of Galerkin method in order to extract the natural frequencies and vibration modes. The simply supported, clamped and combination of these two boundary conditions have been considered for the shell ends. In order to validate the semi-analytical results and also conduct an extensive parametric study, a 3-D finite element model has been built using ABAQUS CAE software. Comparing the results obtained via the two approaches, good agreement has been achieved. The effects of spherical shell’s geometrical parameters, lamination angle and different configurations of the stiffening structure have been examined as well. The results are new and can be considered as a benchmark for further studies.

Influence of torsional stiffness in double-angle open-web joist and joist girder chords

The double angle chords of open-web steel joists are often designed to efficiently support loading with relatively slender sections, which introduces buckling instabilities that are treated differently by various design standards. This study investigates the buckling behavior of double angles, focusing on the importance of flexural–torsional buckling. A theoretical inelastic buckling investigation considering current design practices and known steel behavior demonstrates how flexural–torsional buckling does not control for all double angle configurations. Subsequent investigation focuses on double angles theoretically susceptible to flexural–torsional buckling, while implementing finite element modeling of full joist structures and isolated chord segments. The resulting elastic eigenbuckling analysis and geometrically and materially nonlinear analysis with imperfections captures significant twisting of individual angles in the built-up section; however, global flexural–torsional buckling was not observed to control. Most double angle configurations are controlled by flexural buckling due to an increased flexural–torsional buckling capacity. This result is attributed to the observed increased torsional stiffness of the chords, which is typically not considered in design. A supplementary investigation indicated this torsional stiffness was primarily a result of torsion being transferred through the stiff chord-to-chord connections, which do not exist in all double angle members. Accounting for the additional torsional stiffness in a theoretical inelastic buckling calculation leads to flexural–torsional buckling not controlling the design of most double angle cross sections considered in this study. Overall, this study indicates that designing double angles in joist structures by only considering flexural buckling with local buckling is reasonable with current industry practices.

Numerical analysis of hydrodynamic and thermal characteristics of three inside channel configurations of a plate and shell heat exchanger (PSHE)

The Plate and Shell Heat Exchanger (PSHE) is a variation of the Plate Heat Exchanger (PHE) with a more compact and robust geometry. This paper presents the analysis of the flow in the inner channel formed by a pair of plates of a PSHE employing computational fluid dynamics to determine the hydrodynamic and thermal characteristics for three Chevron angle configurations, 15° × 15° (High/High-HH), 45° × 45° (Low/Low-LL) and 15° × 45° (High/Low-HL). The ANSYS CFX software was employed with the application of the Standard k-ε and the SST (Shear-Stress-Transport) turbulence models for comparison. Experimental pressure drop data and flow streamlines were used to validate the numerical model and to analyze simplifications in the geometric model. Pressure drop, friction factor, and Nusselt number were evaluated for the three geometries studied. A local analysis of the parameters that describe the channels was also performed in this study.

Predicting the growth of middle cerebral artery bifurcation aneurysms using differences in the bifurcation angle and inflow coefficient.

Growing intracranial aneurysms (IAs) are prone to rupture. Previous cross-sectional studies using postrupture morphology have shown the morphological or hemodynamic features related to IA rupture. Yet, which morphological or hemodynamic differences of the prerupture status can predict the growth and rupture of smaller IAs remains unknown. The purpose of this longitudinal study was to investigate the effects of morphological features and the hemodynamic environment on the growth of IAs at middle cerebral artery (MCA) bifurcations during the follow-up period. One hundred two patients with MCA M1-2 bifurcation saccular IAs who underwent follow-up for more than 2 years at the authors' institutions between 2011 and 2019 were retrospectively identified. During the follow-up period, cases involving growth of MCA IAs were assigned to the event group, and those with MCA IAs unchanged in size were assigned to the control group. The morphological parameters examined were aneurysmal neck length, dome height, aspect ratio and volume, M1 and M2 diameters and their ratio, and angle configurations among M1, M2, and the aneurysm. Hemodynamic parameters were flow rate and wall shear stress in M1, M2, and the aneurysm, including the aneurysmal inflow rate coefficient (AIRC), defined as the ratio of the aneurysmal inflow rate to the M1 flow rate. Those parameters were compared statistically between the two groups. Correlations between morphological and hemodynamic parameters were also examined. Eighty-three of 102 patients were included: 25 with growing MCA IAs (event group) and 58 with stable MCA IAs (control group). The median patient age at initial diagnosis was 66.9 (IQR 59.8-72.3) years. The median follow-up period was 48.5 (IQR 36.5-65.6) months. Both patient age and the AIRC were significant independent predictors of the growth of MCA IAs. Moreover, the AIRC was strongly correlated with sharper bifurcation and inflow angles, as well as wider inclination angles between the M1 and M2 arteries. The AIRC was a significant independent predictor of the growth of MCA IAs. Sharper bifurcation and inflow angles and wider inclination angles between the M1 and M2 arteries were correlated with the AIRC. MCA IAs with such a bifurcation configuration are more prone to grow and rupture.

Numerical modeling of imposed magnetohydrodynamic effects in hypersonic flows

Weakly ionized plasmas, formed in high enthalpy hypersonic flows, can be actively manipulated via imposed magnetic fields—a concept termed magnetohydrodynamic (MHD) flow control. Imposed MHD effects, within flows that exhibit multiple shock interactions, are consequential for emerging aerospace technologies, including the possibility of replacing mechanical control surfaces with magnetic actuation. However, numerical modeling of this flow type remains challenging due to the sensitivity of feature formation and the real gas modeling of weakly ionized, electrically conductive, air plasma. In this work, numerical simulation capabilities have been developed for the study of MHD affected, hypersonic flows, around two-dimensional axisymmetric non-simple geometries. The validated numerical methodology, combined with an advanced 19 species equation of state for air plasma, permits the realistic and efficient simulation of air plasmas in the equilibrium regime. Quantitative agreement is achieved between simulation and experiment for a Mach 5.6 double cone geometry with applied magnetic field. In the context of the magnetic actuation concept, numerical studies are conducted for varied conical surface angle and magnetic field configuration. For simple geometries with an elemental shock type, the MHD enhancement effect produces a self-similar shock structure. This paper demonstrates how, for hypersonic flows with complex shock interactions, the MHD affected flow is not only augmented in terms of shock position but may exhibit topological adaptations in the fundamental flow structure. A classification system is introduced for the emergent flow topologies identified in this work. Fluid-magnetic interactions are explored and explained in terms of the coupled mechanisms leading to (1) differences in magnitude of MHD enhancement effect and (2) structural adaptations of the flow topology. The applied numerical studies examine why increased conical surface angle does not amplify the MHD enhancement effect as expected from the base flow conditions, and the mechanisms by which the magnetic field configuration influences the MHD augmented shock structure. Most critically, classes of conditions are identified that produce topological equivalence between the magnetic interaction effects and a generalized mechanical control surface.

On the wake of a large depth ratio wall-mounted prism at a normal incident angle

The wake characteristics of a large depth-ratio (depth-to-height) prism at the incident angle of 90° is numerically examined at Reynolds number of 250. An arc type, symmetric vortex shedding is observed in the wake with periodicity of St=0.087. The flow periodicity reduced with increasing incidence angle to 90°. A Hexapole-type cross-sectional wake topology is observed in the wake, corresponding to the formation of two downwash inducing pairs and a single upwash inducing (base vortex) pair. The base-vortex dominate the wake, resulting in a strong upwash flow, while a relatively smaller tip-vortex induced downwash flow is limited to the near vicinity of the prism. The unsteady flow is attributed to fluctuations that arise from the lateral positioning of the prism by means of changing incidence angle, and consecutively increased projected width of the prism. The multiple downwash inducing vortices are formed due to the shear layer detachment from the side and top surfaces of the prism, which itself is attributed to the large depth-ratio in normal incident angle configuration and the base vortex that originated from the legs of the arc-type structure. This constitutes a new wake topology that differs with previous observations at lower incidence angles.

Flow distribution in the air cooler of HTGR passive cavity cooling system

Passive Cavity Cooling System (PCCS) is an important safety related system for High Temperature Gas-cooled Reactor (HTGR). Air cooler is one of the key components of this system. The non-uniform flow distribution is a common issue encountered in similar Parallel Tube Heat Exchanger (PTHX). Improving flow uniformity is favorable for both thermal hydraulic performance and structure safety. In this work, the flow distribution characteristics of a compact parallel tube air cooler with U-type header arrangement are theoretically and numerically investigated. First, a theoretical discrete model is proposed for flow distribution in PTHX. It reveals that the static pressure distributions in the headers are influenced by static pressure recovery, friction resistance and local pressure drop, which is directly related with flow uniformity. Then, the flow uniformity of Z-type and U-type header arrangements is numerically investigated and compared in detail. Moreover, the effects of thermal hydraulic parameter and geometrical parameter on flow uniformity are successively evaluated. Numerical results show that the flow uniformity of PCCS air cooler with U-type header arrangement is more excellent than that of Z-type header arrangement. Thermal hydraulic parameters, such as tube-side water temperature and mass flow rate, have little impact on flow uniformity. Nevertheless, the flow distribution characteristics are very sensitive to the geometrical parameters, including the insertion angle configuration, the flow area ratio of header to parallel heat transfer tubes (AR) and the cross-sectional area ratio of distribution header to collection header (DCR). Reasonable insertion angle configuration and decreasing AR can effectively enhance the flow uniformity of PCCS air cooler. For header match, it should be avoided that the distribution header diameter below the collection header diameter. As a result, the optimal structure design determined in this work is an air cooler with U-type header arrangement, where the inlet insertion angle is 0°, the outlet insertion angle is 180°, and the diameters of distribution header and collection header are both 120 mm. Its flow uniformity is improved by more than 50% compared with present design. This work reports a promising design modification, as the potential structure optimization for HTGR PCCS air cooler.

SPR based refractive index modulation of nanostructured SiO2 films grown using GLAD assisted RF sputtering technique

Low refractive index materials have always gained attention for avoiding optical losses in numerous devices like Light emitting diodes (LEDs), Distributed Bragg Reflectors (DBRs) etc. Glancing angle deposition (GLAD) has proven to be an effective method for depositing porous nanostructures with low refractive index. SiO2 has the lowest refractive index in comparison to most of the materials present in nature and is therefore utilized extensively in the fabrication of optical devices with minimum optical losses. The present work focuses on the SiO2 nanostructured thin films grown using glancing angle (GLAD) configuration in RF Sputtering technique under varying deposition conditions (glancing angle and pressure) at fixed thickness. The deposited porous SiO2 nanostructured layers have well-defined nanorods of feature size smaller than 100 nm. The refractive index corresponding to all the deposited SiO2 nanostructured films came out to be smaller than the corresponding value (1.49) mentioned in the literature for bulk SiO2. The refractive index has been observed to vary in a wide range (1.05 to 1.40). Characterization of the deposited SiO2 nanostructured films was carried out using Fourier Transform Infrared (FTIR) spectroscopy, Energy Dispersive X-Ray (EDS) analysis, and Atomic Force Microscopy (AFM) to assess the qualitative properties of the deposited nanostructured SiO2 films. Surface Plasmon Resonance (SPR) and Ellipsometry studies are performed to determine the refractive index value of the deposited nanostructured SiO2 thin films. A refractive index value as low as ∼ 1.05 at a wavelength of 633 nm is achieved for SiO2 nanostructured thin film deposited at 30 mTorr deposition pressure and 80° glancing angle.

Effect of Strong Azimuthal Swirl on Ignition and Light-Around in an Annular Combustor

Abstract In this paper, we investigate the effect of strong azimuthal swirl on ignition dynamics in a laboratory-scale annular combustor. Bulk azimuthal swirl was produced by a novel angled injector configuration, producing swirling jet flames oriented downwards toward the combustor backplane and in the azimuthal direction, replicating a simplified version of the SAFRAN spinning combustor concept. To provide more realistic flow conditions, the design included rich-quench-lean (RQL) staging via a circumferential distribution of dilution ports and an effusion cooled combustor backplane. High-speed imaging and an azimuthal array of photomultipliers to measure OH* chemiluminescence were used to characterize the ignition dynamics for different injector velocities and global equivalence ratios. The mass flows through the injectors, dilution ports, and effusion cooled backplane were independently metered so that the injector equivalence ratio and global equivalence ratio could be separately controlled. The light-around times were found to have no clear correlation with the injector velocity since the rich injector equivalence ratio meant the flame burned in a nonpremixed mode even though the global equivalence ratio was lean due to the RQL staging. However, it was found that lower injector velocities extended the lean ignition limit based on the global equivalence ratio. The ignition sequence during light-around (order in which the injectors are ignited) was found to be highly repeatable, igniting each consecutive injector in the anticlockwise direction (the direction of bulk swirl). In rare cases, the ignition sequence was observed to branch in both directions. Finally, in an effort to extend the lean ignition limit, the effect of azimuthal staging was investigated. Two configurations were tested. In the first configuration, the injectors on one half of the annulus were operated at a fixed equivalence ratio whereas the other half of the annulus was operated at a different equivalence ratio. In the second configuration, every second injector had the same equivalence ratio. Both configurations extended the lean extinction limit but the first configuration was the most effective.

Propagation Methods Decide Root Architecture of Chinese Fir: Evidence from Tissue Culturing, Rooted Cutting and Seed Germination.

The root is the main organ of a plant for absorbing resources and whose spatial distribution characteristics play an important role in the survival of seedlings after afforestation. Chinese fir (Cunninghamia lanceolata) is one of China’s most important plantation species. To clarify the effects of propagation methods on root growth and spatial distribution characteristics of Chinese fir trees, sampled trees cultivated by seed germination, tissue culture, and asexual cutting of Chinese fir were taken as the research objects. The root morphology, geometric configuration, and spatial distribution characteristics of different trees were analyzed. The influence of geometric root morphology on its spatial distribution pattern was explored by correlation analysis, and the resource acquisition characteristics reflected by the roots of Chinese fir trees with different propagation methods are discussed. The main results showed that the root mean diameter (1.56 mm, 0.95 mm, and 0.97 mm), root volume (2.98 m3, 10.25 m3, and 4.07 m3), root tip count (397, 522, and 440), main root branch angle (61°, 50° and 32°) and other geometric configurations of Chinese fir under seed germination, tissue culture and rooted cutting respectively, were significantly different, which resulted in different distribution characteristics of roots in space. Chinese fir seed germination had noticeable axial roots, and the growth advantage was obvious in the vertical direction. A fishtail branch structure (TI = 0.87) was constructed. The shallow root distribution of tissue culture and rooted cutting was obvious, and belonged to the fork branch structure (TI = 0.71 and 0.74, respectively). There was a tradeoff in the spatial growth of the root system of Chinese fir trees with different propagation methods to absorb nutrients from heterogeneous soil patches. A negative correlation was present between the root system and root amplitude. There was an opposite spatial growth trend of Chinese fir trees with different propagation methods in the vertical or horizontal direction. In conclusion, selecting suitable propagation methods to cultivate Chinese fir trees is beneficial to root development and the “ideal” configuration formation of resource acquisition to improve the survival rate of Chinese fir afforestation.

Evaluating the corrosion behaviour of AA6061-T6 alloy and its friction stir welded joints

ABSTRACT The cold rolled aluminium alloy (AA6061-T6) and its friction-stir welded joints (with varied tool-tilt angle and joint configuration) were investigated for their corrosion performance using a corrosion immersion test in two stages. First, the influence of corrosion conditions on the performance of base metal was investigated using the design-of-experiments approach with the central composite design of response surface methodology. Among the three input corrosion variables (namely time, temperature and NaCl-concentration) selected at three levels each, the contribution of temperature to corrode the base metal was found to the order of ≈50%, followed by time (21%) and NaCl-concentration (7%). Further, parameters were optimised to attain minimum and maximum corrosion rate conditions. In the second-stage, the optimised corrosion conditions were used to study the corrosion behaviour of the welded joints. Among all welds, the single-pass joint fabricated with 0° tilt angle showed minimum corrosion rate but possessed 96% higher mass-loss compared to the base metal. Moreover, the corrosion rate was found to increase with the increase in tool-tilt angle, as-well-as with the change in joint configuration from single-pass to double-pass. The optical and scanning electron microscopy revealed the pitting and intergranular corrosion to be the dominating corrosion mechanisms for the base metal and welded joints.

Vapor condensation on micropillar structured surface with lattice Boltzmann method

Pure vapor condensation process and heat transfer on micropillar structured surfaces with various wettabilities are simulated numerically based on an improved three-dimensional phase-change lattice Boltzmann method (LBM). Condensed droplet dynamic behaviors containing nucleation, growth and departure are mainly explored. Two preferable droplet nucleation sites are detected successfully: at the corner between micropillar sides and subcooled substrate, and at the center of substrate. The effects of contact angle, micropillar spacing and height on droplet nucleation time, departure diameter and departure frequency are investigated quantitatively. Results indicate that as the contact angle increases, nucleation of condensate is delayed, while the departure diameter is reduced and departure frequency is increased. The increase in micropillar spacing, height and contact angle changes droplet from Wenzel state to partial wetting state. Moreover, it is also shown that the highest temperature and maximum local heat flux appear at the three-phase contact line. Despite the very complex roles of micropillar structures and wettability on condensation heat transfer, an optimal heat transfer surface with configurations of contact angle of 90°, micropillar spacing of 12 and height of 18 is presented. This study provides a fundamental understanding in regards to vapor condensation on microscale structured surface from numerical view.

Outcomes of medical and surgical management in eyes with idiopathic elevated episcleral venous pressure.

Idiopathic elevated episcleral venous pressure (IEEVP) is a rare cause of secondary glaucoma and is a diagnosis of exclusion. The aim of this study was to describe the clinical presentation and analyze the outcomes of medical and surgical management in eyes diagnosed with idiopathic elevated episcleral venous pressure. A retrospective analysis of eyes diagnosed with IEEVP over a 5-year period between April 2012 and March 2016 was performed. The demographic details, medical history, and clinical course of the cases were obtained from the medical records. Data pertaining to the severity of glaucomatous damage, response to medical management, need for surgical intervention, and their outcomes were analyzed. Fifteen eyes of 13 patients were included. Thirteen eyes (86.6%) had open angle configuration. Among the 13 eyes that had glaucoma, eight eyes (61.5%) had severe glaucoma, four eyes (30.7%) had moderate glaucoma, and one eye (7.6%) had mild glaucoma. The median follow-up was 210 days. Seven of the 15 eyes (46.6%) required a glaucoma filtration procedure, and three underwent prophylactic sclerotomies. 71.4% of these eyes had complete success. One out of the seven operated eyes required choroidal drainage post-operatively. IEEVP is an extremely rare condition and presents with raised intra-ocular pressure and tortuous episcleral vessels. The management of IEEVP is similar to that of primary open angle glaucoma. Uveal effusion is to be anticipated, and hence, combining trabeculectomy with prophylactic sclerotomies is advisable.

On the use of Brazilian disk specimen for measuring mixed-mode I/II translaminar fracture toughness of notched glass/epoxy composite laminates: A comprehensive study

In this work, a comprehensive experimental and theoretical study is performed on laminated composites containing V- and U-notch to evaluate the last-ply-failure (LPF) load in mixed-mode I/II loading conditions. Numerous tests are conducted on the composite laminates using the Brazilian disk specimen for the first time. The samples are fabricated of E-glass/epoxy in three different lay-up configurations, namely unidirectional, cross-ply, and quasi-isotropic. Three notch opening angles of 2α = 30°, 60°, and 90° are considered for the V-notched samples, while for both V- and U-notches three notch tip radii of ρ= 1, 2, and 4 mm are taken into account. Four mixed-mode I/II loading angles of β = {0°, 10°, 20°, mode II} and three repetitions for each notch opening angle and composite lay-up configuration lead to an overall of 432 fracture tests in the experimental section of the paper, which can provide a good amount of experimental data set for other researchers. Subsequently, in the analytical section, two stress-based fracture criteria accompanied by the virtual isotropic material concept (VIMC) are employed to estimate the fracture loads theoretically. It is demonstrated that using the VIMC approach can yield accurate predictions, while it has much less computational costs compared to the traditional approaches in the literature.

Influence of oblique angle variations on the thermo-hydraulic characteristics of the oblique fin heat sink with Al2O3 water nanofluid

The flow mixing through secondary flow is critical for improving the heat transfer of microchannel heat sinks. This study investigates oblique fin heat sinks (OFHSs) under forced convection conditions with Al2O3-water nanofluid under the Re 100–500. The study is referenced with a straight channel heat sink for benchmarking purposes. Five oblique angle configurations (15°, 25°, 35°, 45°, and 55°) were investigated at the constant fin pitch and constant width ratio (primary width-to-secondary width ratio) of 2:1. The RNG k-ε model has been employed with enhanced thermofluidic effect and wall treatment. The findings revealed that secondary flow generation leads the thermal boundary layer to redevelop at each fin, resulting in continuous fluid flow development. Pressure drop increment has been noticed with oblique angles 15° to 25°, and the variation is almost insignificant among the 35°, 45°, and 55° OFHS. The secondary flow rates were found to have a profound effect in all the cases. The 25° degree shows a higher average convection coefficient among all the OFHSs. Also, the convection coefficient varied in the following order for both water and nanofluid: 15° < 25° > 35° > 45° > 55°. The 25° OFHS enables a more uniform water/nanofluids temperature to build up in the streamwise direction than the 35°, 45°, and 55° OFHS. The thermofluidic analysis suggests that the proposed designs have superior heat convection performance than their flow resistance penalty. Therefore, the 25° OFHS offers a promising option for further parametric research in the future.

Numerical Analysis of Unidirectional GFRP Composite Mechanical Response Subjected to Tension Load using Finite Element Method

Composite material is a well-known structural material which is increasingly adopted as an engineering structure material. Glass fiber reinforced polymer offers the lightweight and high strength characteristics that is required for the modern industry, such as aviation, automotive, wind power, and marine technology. One of the important mechanical characteristics of the composite materials are the tensile properties, because it is well known as the material strength. Therefore, the investigation of mechanical response on the glass fiber reinforced polymer (GFRP) tensile test using numerical analysis is important for the estimation of structural response of the GFRP complex structure, such as boat construction. The objective of this research is to assess and estimate the mechanical response of the GFRP composite material subjected to tension load using finite element method. The linear transversely isotropic model is developed to estimate the unidirectional glass fiber GFRP with the configuration of fiber orientation angles of 0°, 30°, 45°, 60° and 90°. The results show that FE simulation are capable to detect the specimen response during the tensile test. The maximum discrepancy of the estimated stress strain diagram is about 16.5% to 32% compared to experimental data. The larger orientation angle has shown the larger discrepancy value. It is found that the increment of discrepancy value is generated by the nonlinearity behavior of the material due to the domination of polymer material behavior on the large orientation angle. Otherwise, the FE models have estimated accurately the ultimate strength, maximum displacement and fracture load. It can be concluded that the linear transversely isotropic model is adequately accepted as the estimation method of the GFRP composite structure response.

Classifications of Qualitative Characteristics on Angle Configurations via Ultrasound Biomicroscopy in Acute Primary Angle Closure.

PurposeTo study the classifications of qualitative characteristics on the angle configurations in the acute primary angle closure (APAC) and fellow eyes by ultrasound biomicroscopy (UBM).MethodsA total of 131 patients (262 eyes) were researched retrospectively. The qualitative parameters from UBM images were classified into iris form (IF), ciliary body configuration (CBC), basal iris thickness (BIT), iris convexity (IC), iris insert (II), iris angulation (IA), ciliary body size (CBS) and ciliary body position (CBP). Comparative analyses between the APAC (case group) and fellow (control group) eyes were performed.ResultsThere were significant differences in IF, CBC, IC, II, CBS, CBP between the case group and control group in all quadrants (P<0.001). The IA of the case group and control group presented significant difference in all quadrants (P=0.001). However, there was not a significant difference in BIT between the case group and control group in all quadrants (P=0.495). The case group had fewer parallelogram-like and mushroom-like and more cone-like and hook-like CBCs than the control group (P<0.001).ConclusionMultiple ciliary body configurations can influence the stability of the lens and the anatomic configuration of the anterior chamber angle indirectly. New qualitative classification system of UBM may be more intuitionistic and refined to reflect the angle configurations to help clinical practice.

Daylighting Performance of Integrated Light Shelf with Horizontal Light Pipe System for Deep Plan High-Rise Office in Tropical Climate

Tropical countries such as Malaysia receives a significant amount of daylight. The utilisation of this renewable resource in a high-rise office building leads to opportunities and challenges. Deep plan spaces in such buildings provide challenges to create a uniform daylight distribution across the room. An integrated light shelf (LS) with horizontal light pipe (LP) offers a solution to cater to this problem. Seven (7) different types of LS angle configurations were simulated through Integrated Environment Solution Virtual Environment to assess their daylight performance with integrated LP using overcast and intermediate sky with four orientations. The results showed that the integration of LS to LP improved the daylight uniformity across the room. LS5 with an angle of -15° performed best when compared to a room with only LP installed for all the design days and orientations. The integration of LP and LS5 was able to shade the front portion of the room while providing illumination at the rear spaces. The findings of this study promote the use of integrated LS and LP in deep open-plan high-rise office buildings for building designers.

Evaluation of anatomical variations with morphological measurements and their relationship with rotator cuff tear and acromion types

Introduction: There many more anatomical measurements such as the acromiohumeral distance and lateral acromion angle and acromial configuration was reported as might be associated with rotator cuff tear. In our study, we aimed to reveal the effect of acromion index, acromiohumeral distance, lateral acromion angle, critical shoulder angle values and the acromion type in the development of rotator cuff tear. &#x0D; Material and Method: In our retrospective study, 58 patients and 29 asymptomatic volunteers who underwent shoulder magnetic resonance imaging examinations were examined. acromion index, acromion humaral distance, lateral acromion angle and critical shoulder angle were measured and their relationship with rotator cuff tear and acromion types were evaluated. &#x0D; Results: Type III (hooked) of acromial shapes, higher acromion index and critical shoulder angle values, lower acromiohumeral distance and lateral acromion angle values are more frequently seen in rotator cuff tear patients, in our study. &#x0D; Conclusion: Thus, we revealed anatomical malformations that predispose to rotator cuff tear concerning the shoulder joint.