1,827 results match your criteria volume curvature

Self-reconfigurable high-weight-per-volume-gelatin films for all-solution-processed on-skin electronics with ultra-conformal contact.

Biosens Bioelectron 2021 Apr 15;184:113231. Epub 2021 Apr 15.

Department of Electronic Materials Engineering, Kwangwoon University, Seoul, 01897, South Korea. Electronic address:

Although conventional skin-attachable electronics exhibit good functionalities, their direct attachment (without any adhesive) to human skin with sufficient conformal contact is challenging. Herein, all-solution-processed on-skin electronics based on self-reconfigurable high-weight-per- volume-gelatin (HWVG) film constructed using an effective, biocompatible water absorption-evaporation technique are demonstrated. Completely conformal contact of self-reconfigurable HWVG films is realized by rapidly inducing anisotropic swelling in the perpendicular direction and covering any curvature on the skin without spatial gap or void after shrinking. Read More

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The topology of ventricle surfaces and its application in the analysis of hydrocephalic ventricles: a proof-of-concept study.

Neuroradiology 2021 Apr 15. Epub 2021 Apr 15.

Department of Neurosurgery, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore.

Purpose: The cerebral ventricles deform in a non-uniform fashion in response to increased CSF volume and/or pressure in hydrocephalic syndromes. Current research is focused on volumetric analyses, while topological analysis of ventricular surfaces remains understudied. We developed a method of quantitatively modeling the curvature of ventricular surfaces to analyze changes in ventricular surfaces in normal pressure hydrocephalus (NPH) and Alzheimer's disease (AD), using the left frontal horn as an example. Read More

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Separating the influences of late talking and dyslexia on brain structure.

J Abnorm Psychol 2021 Apr;130(3):286-296

Laboratory of Language Neurobiology, Nencki Institute of Experimental Biology, Polish Academy of Sciences.

Being a late talker constitutes a risk factor for later neurodevelopmental disorders; however, its neurobiological basis remains unexplored. We aimed to determine the unique and mutual correlates of late talking and developmental dyslexia on brain structure and behavioral outcomes in a large sample of 8- to 10-year-old children in a between-groups design ( = 120). Brain structure was examined using voxel-based morphometry (to measure gray matter volume) and surface-based morphometry (to measure gray matter volume, cortical thickness, surface area, and curvature of the cortex). Read More

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Dosimetric comparison of volumetric modulated arc therapy (VMAT) and high-dose-rate brachytherapy (HDR-BT) for superficial skin irradiation with significant curvature in one or more planes.

Strahlenther Onkol 2021 Mar 31. Epub 2021 Mar 31.

Mount Vernon Cancer Centre, East and North Hertfordshire NHS Trust, London, UK.

Purpose: This study compares the plan quality of high-dose-rate brachytherapy (HDR-BT) and volumetric modulated arc therapy (VMAT) for superficial irradiation of large areas of skin with significant curvature in one or more planes.

Methods: A total of 14 patients from two centres previously treated with either HDR-BT or VMAT were retrospectively replanned using the alternative technique. Sites included scalp and lower limbs. Read More

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Neuroimage Biomarker Identification of the Conversion of Mild Cognitive Impairment to Alzheimer's Disease.

Front Neurosci 2021 19;15:584641. Epub 2021 Feb 19.

Department of Electrical Engineering, National Cheng Kung University, Tainan, Taiwan.

An efficient method to identify whether mild cognitive impairment (MCI) has progressed to Alzheimer's disease (AD) will be beneficial to patient care. Previous studies have shown that magnetic resonance imaging (MRI) has enabled the assessment of AD progression based on imaging findings. The present work aimed to establish an algorithm based on three features, namely, volume, surface area, and surface curvature within the hippocampal subfields, to model variations, including atrophy and structural changes to the cortical surface. Read More

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February 2021

Stable and Efficient Nanofilm Pure Evaporation on Nanopillar Surfaces.

Langmuir 2021 Mar 17;37(12):3731-3739. Epub 2021 Mar 17.

School of Engineering and Materials Science, Queen Mary University of London, London E1 4NS, United Kingdom.

Molecular dynamics simulations were conducted to systematically investigate how to maintain and enhance nanofilm pure evaporation on nanopillar surfaces. First, the dynamics of the evaporation meniscus and the onset and evolution of nanobubbles on nanopillar surfaces were characterized. The meniscus can be pinned at the top surface of the nanopillars during evaporation for perfectly wetting fluid. Read More

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Spongiosum-combined glanuloplasty reduces glans complications after proximal hypospadias repair.

Asian J Androl 2021 Mar 12. Epub 2021 Mar 12.

Department of Urology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai 200040, China.

We aim to design a new glanuloplasty procedure combined with spongiosum to reduce the incidence of glans dehiscence and coronal fistula after proximal hypospadias repair. Patients who underwent urethroplasty by dorsal preputial island flap for proximal hypospadias between January 2014 and December 2016 were reviewed in this retrospective cohort study. Those who underwent spongiosum-combined glanuloplasty comprised the new-maneuver group, whereas those who underwent conventional glanuloplasty comprised the control group. Read More

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Quantitative and Qualitative Sex-Modulations in the Brain Anatomy of Autism.

Biol Psychiatry Cogn Neurosci Neuroimaging 2021 Mar 10. Epub 2021 Mar 10.

Neurosciences & Mental Health Program, SickKids Research Institute, Toronto, Ontario, Canada; Department of Psychiatry, Hospital for Sick Children, Toronto, Ontario, Canada; Margaret and Wallace McCain Centre for Child, Youth & Family Mental Health, Azrieli Adult Neurodevelopmental Centre, and Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, Canada; Autism Research Centre, Department of Psychiatry, University of Cambridge, Cambridge, UK; Department of Psychiatry, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan. Electronic address:

Background: Sex-based neurobiological heterogeneity in autism is poorly understood. Research is disproportionately biased to males, leading to an unwarranted presumption that autism neurobiology is the same across sexes. Previous neuroimaging studies using amalgamated multi-center datasets to increase autistic female samples are characterized by large statistical noise. Read More

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Predictors of Depression in Men With Peyronie's Disease Seeking Evaluation.

J Sex Med 2021 Mar 9. Epub 2021 Mar 9.

Sexual & Reproductive Medicine Program, Urology Service, Memorial Sloan Kettering Cancer Center, New York, NY, USA. Electronic address:

Background: Peyronie's disease (PD) has negative impacts on the psychosocial status of men including depression warranting clinical evaluation in up to 50% of men.

Aim: To examine predictors of depression in patients with early PD seeking evaluation.

Methods: All PD patients at a high-volume PD practice underwent screening and curvature assessment after intracavernosal injection. Read More

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Morphological Analysis of the Right Ventricular Endocardial Wall in Pulmonary Hypertension.

J Biomech Eng 2021 Mar 11. Epub 2021 Mar 11.

University of Texas at San Antonio, UTSA/UTHSA Joint Graduate Program in Biomedical Engineering, San Antonio, TX 78249; University of Texas at San Antonio, Department of Mechanical Engineering, San Antonio, TX 78249.

Pulmonary hypertension (PH) is a chronic progressive disease diagnosed when the pressure in the main pulmonary artery, assessed by right heart catheterization, is greater than 25 mmHg. Changes in the pulmonary vasculature due to the high pressure yield an increase in the right ventricle (RV) afterload. RV models were obtained from segmentation of cardiac magnetic resonance images at baseline and 1-year follow up for a pilot study that involved 12 PH and 7 control subjects. Read More

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Patient Attitudes Towards Surgical Management of Peyronie's Disease Prior to Men's Health Consultation.

Urology 2021 Mar 4. Epub 2021 Mar 4.

Department of Urology, Mayo Clinic, Rochester, MN.

Objective: To evaluate clinical characteristics associated with patient attitudes toward surgical treatment of Peyronie's disease (PD) prior to consultation in a high-volume male sexual health clinic.

Methods: From 2014-2018 a prospective database was created of patients presenting to the sexual health clinic at our institution. Multivariable regression analysis was conducted to determine factors associated with pre-visit consideration of surgery. Read More

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Ferumoxytol-enhanced ultrashort TE MRA and quantitative morphometry of the human kidney vasculature.

Abdom Radiol (NY) 2021 Mar 5. Epub 2021 Mar 5.

Northeastern University, Boston, MA, USA.

Purpose: To evaluate the feasibility of Quantitative Ultrashort-Time-to-Echo Contrast-Enhanced (QUTE-CE) MRA using ferumoxytol as a contrast agent for abdominal angiography in the kidney.

Methods: Four subjects underwent ferumoxytol-enhanced MRA with the 3D UTE Spiral VIBE WIP sequence at 3 T. Image quality metrics were quantified, specifically the blood Signal-to-Noise Ratio (SNR), blood-tissue Contrast-to-Noise Ratio (CNR) and Intraluminal Signal Heterogeneity (ISH) from both the aorta and inferior vena cava (IVC). Read More

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On the Role of Curved Membrane Nanodomains, and Passive and Active Skeleton Forces in the Determination of Cell Shape and Membrane Budding.

Int J Mol Sci 2021 Feb 26;22(5). Epub 2021 Feb 26.

Faculty of Electrical Engineering, University of Ljubljana, SI-1000 Ljubljana, Slovenia.

Biological membranes are composed of isotropic and anisotropic curved nanodomains. Anisotropic membrane components, such as Bin/Amphiphysin/Rvs (BAR) superfamily protein domains, could trigger/facilitate the growth of membrane tubular protrusions, while isotropic curved nanodomains may induce undulated (necklace-like) membrane protrusions. We review the role of isotropic and anisotropic membrane nanodomains in stability of tubular and undulated membrane structures generated or stabilized by cyto- or membrane-skeleton. Read More

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February 2021

Tactile acuity of fingertips and hand representation size in human Area 3b and Area 1 of the primary somatosensory cortex.

Neuroimage 2021 May 27;232:117912. Epub 2021 Feb 27.

Functional Imaging Unit, Center for Diagnostic Radiology, University Medicine of Greifswald, Walther-Rathenau-Str.46, D-17475 Greifswald, Germany. Electronic address:

Intracortical mapping in monkeys revealed a full body map in all four cytoarchitectonic subdivisions of the contralateral primary somatosensory cortex (S1), as well as positive associations between spatio-tactile acuity performance of the fingers and their representation field size especially within cytoarchitectonic Area 3b and Area 1. Previous non-invasive investigations on these associations in humans assumed a monotonous decrease of representation field size from index finger to little finger although the field sizes are known to change in response to training or in disease. Recent developments improved noninvasive functional mapping of S1 by a) adding a cognitive task during repetitive stimulation to decrease habituation to the stimuli, b) smaller voxel size of fMRI-sequences, c) surface-based analysis accounting for cortical curvature, and d) increase of spatial specificity for fMRI data analysis by avoidance of smoothing, partial volume effects, and pial vein signals. Read More

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Three-dimensional analysis of the root canal preparation with Reciproc Blue®, WaveOne Gold® and XP EndoShaper®: a new method in vivo.

BMC Oral Health 2021 Feb 25;21(1):88. Epub 2021 Feb 25.

Endodontics Department, Universidad de San Carlos, Guatemala, Guatemala.

Background: The purpose of this study was to evaluate the changes in canal volume after root canal preparation in vivo with 3 different single-file techniques (Reciproc-Blue®, WaveOne-Gold® and XP-EndoShaper®), with a new method using CBCT and 3D reconstruction.

Methods: In this prospective study, thirty human lower premolars from healthy patients were used, in which extraction was indicated for orthodontic reasons. All the teeth used were caries- and restoration-free with complete root development, without signs of periodontal disease or traumatic occlusion, and with only one straight canal (up to 25º curvature). Read More

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February 2021

Finite element-based method for determining an optimal offloading design for treating and preventing heel ulcers.

Comput Biol Med 2021 Apr 9;131:104261. Epub 2021 Feb 9.

Biorobotics and Biomechanics Lab (BRML), Faculty of Mechanical Engineering, Technion-Israel Institute of Technology, 32000, Haifa, Israel.

Diabetic heel ulceration, a serious, destructive, and costly complication of diabetes, is often treated by custom-made offloading footwear. One common offloading device is a custom-made insole designed with a hole under the damaged site that is intended to reduce local mechanical loads on the ulcer. However, current devices do not take into account the increasing loads at the wound peripheries, and quantitative assessments and scientific guidelines for the optimal design of the offloading hole are lacking. Read More

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Femtosecond laser-assisted stromal keratophakia for keratoconus: A systemic review and meta-analysis.

Int Ophthalmol 2021 Feb 20. Epub 2021 Feb 20.

Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore, Singapore.

Purpose: Femtosecond lasers have revived the possibility of stromal keratophakia or tissue additive keratoplasty, a technique originally introduced by Prof. Jose Ignacio Barraquer in the 1960s. The surgical technique offers a unique solution to treat keratoconus. Read More

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February 2021

Semi-automatic micro-CT segmentation of the midfoot using calibrated thresholds.

Int J Comput Assist Radiol Surg 2021 Mar 19;16(3):387-396. Epub 2021 Feb 19.

Department of Orthopaedics, University of Utah, 590 Wakara Way, Salt Lake City, UT, 84108, USA.

Purpose: In the field of skeletal research, accurate and reliable segmentation methods are necessary for quantitative micro-CT analysis to assess bone quality. We propose a method of semi-automatic image segmentation of the midfoot, using the cuneiform bones as a model, based on thresholds set by phantom calibration that allows reproducible results in low cortical thickness bones.

Methods: Manual and semi-automatic segmentation methods were compared in micro-CT scans of the medial and intermediate cuneiforms of 24 cadaveric specimens. Read More

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Electrically driven nematic flow in microfluidic capillary with radial temperature gradient.

Phys Rev E 2021 Jan;103(1-1):012702

Russian Technological University (MIREA), Moscow 119454, Russia.

An electrically driven fluid pumping principle and a mechanism of kinklike distortion of the director field n[over ̂] in the microsized nematic volume has been described. It is shown that the interactions, on the one hand, between the electric field E and the gradient of the director's field ∇n[over ̂], and, on the other hand, between the ∇n[over ̂] and the temperature gradient ∇T arising in a homogeneously aligned liquid crystal microfluidic channel, confined between two infinitely long horizontal coaxial cylinders, may excite the kinklike distortion wave spreading along normal to both cylindrical boundaries. Calculations show that the resemblance to the kinklike distortion wave depends on the value of radially applied electric field E and the curvature of these boundaries. Read More

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January 2021

Systolic reserve maintains left ventricular-vascular coupling when challenged by adverse breathing mechanics and hypertension in healthy adults.

J Appl Physiol (1985) 2021 Apr 11;130(4):1171-1182. Epub 2021 Feb 11.

Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada.

Augmented negative intrathoracic pressures (nITP) and dynamic hyperinflation (DH) are adverse breathing mechanics (ABM) associated with chronic obstructive pulmonary disease (COPD) that attenuate left ventricular (LV) preload and augment afterload. In COPD, hypertension (elevated systemic arterial load) commonly adds additional afterload to the LV. Combined ABM and hypertension may profoundly challenge ventricular-vascular coupling and attenuate stroke volume (SV), particularly if LV systolic reserve is limited. Read More

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Isolated human crystalline lens three-dimensional shape: A comparison between Indian and European populations.

Exp Eye Res 2021 Apr 3;205:108481. Epub 2021 Feb 3.

Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL, USA.

There have been many studies on lens properties in specific populations (e.g. in China, Europe, Singapore, etc. Read More

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Are the Morphological Indices of the Vertebrobasilar System Heritable? A Twin Study Based on 3D Reconstructed Models.

Medicina (Kaunas) 2021 Feb 1;57(2). Epub 2021 Feb 1.

Medical Imaging Centre, Semmelweis University, 78/A Üllői Street, 1082 Budapest, Hungary.

: The asymmetrical vertebral artery (VA) flow and diameter are common findings, which can result in an asymmetrical blood flow in the basilar artery (BA), leading to bending of the artery over time. This study investigated whether the variation of the different vertebrobasilar morphological indices that influence flow characteristics might be inherited. We analyzed 200 cerebral magnetic resonance imaging (MRI) scans of healthy Caucasian twins (100 pairs) who underwent time-of-flight MRI. Read More

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February 2021

Thermal Management and Modeling of Forced Convection and Entropy Generation in a Vented Cavity by Simultaneous Use of a Curved Porous Layer and Magnetic Field.

Entropy (Basel) 2021 Jan 26;23(2). Epub 2021 Jan 26.

Department of Mechanical Engineering, Technology Faculty, Fırat University, Elazığ 23119, Turkey.

The effects of using a partly curved porous layer on the thermal management and entropy generation features are studied in a ventilated cavity filled with hybrid nanofluid under the effects of inclined magnetic field by using finite volume method. This study is performed for the range of pertinent parameters of Reynolds number (100≤Re≤1000), magnetic field strength (0≤Ha≤80), permeability of porous region (10-4≤Da≤5×10-2), porous layer height (0.15H≤tp≤0. Read More

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January 2021

Influence of rotational speed on torque/force generation and shaping ability during root canal instrumentation with continuous rotation and optimum torque reverse motion.

Int Endod J 2021 Feb 1. Epub 2021 Feb 1.

Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan.

Aim: To evaluate how different rotational speeds affect the torque/force generation and shaping ability of rotary root canal instrumentation using JIZAI (MANI, Japan) nickel-titanium instruments in continuous rotation and optimum torque reverse (OTR) motion.

Methodology: Mesial root canals of mandibular molars were instrumented up to size 25, .04 taper using JIZAI instruments, and anatomically matched canals were selected based on geometric features of the canal [canal volume (mm ), surface area (mm ), length, 15°-20° curvature and radius of curvature (4-8 mm)] after micro-computed tomographic scanning. Read More

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February 2021

Ab initio predictions of graphite-like phase with anomalous grain boundaries and flexoelectricity from collapsed carbon nanotubes.

J Chem Phys 2021 Jan;154(4):044701

Department of Mechanical Engineering, University of Minnesota, Twin Cities, Minnesota 55455, USA.

Although large-radius carbon nanotubes (CNTs) are now available in macroscopic quantities, little is known about their condensed phase. Large-scale density functional theory calculations predict a low energy phase in which the same-diameter "dog-bone" collapsed CNTs form a graphite-like phase with complex, anomalous grain boundaries (GBs). The excess GB volume does not prevent the strong van der Waals coupling of the flattened CNT sides into AB stacking. Read More

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January 2021

A Numerical Analysis of Resin Flow in Woven Fabrics: Effect of Local Tow Curvature on Dual-Scale Permeability.

Materials (Basel) 2021 Jan 15;14(2). Epub 2021 Jan 15.

Department of Materials, The University of Manchester, Manchester M13 9PL, UK.

Permeability is a crucial flow parameter in liquid composite moulding (LCM), which is required to predict fibre impregnation, void formation and resin back flow. This work investigates the dual-scale (micro- and meso-) nature of permeability during resin infusion into woven fabric by incorporating the intra tow flow where the degree of local tow curvature (tow/yarn undulation) is taken into account. The mesoscopic permeability of a dual-scale porous media in a unit cell is estimated using Darcy's law, where the Gebart analytical model is applied for the intra tow flow in longitudinal and transverse directions with respect to distinct fibre packing arrangements. Read More

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January 2021

Static interface profiles for contact lines on an elastic membrane with the Willmore energy.

Phys Rev E 2020 Dec;102(6-1):062803

Department of Mathematics, National University of Singapore, Singapore 119076.

We consider a fluid interface in contact with an elastic membrane and study the static profiles of the interface and the membrane. Equilibrium conditions are derived by minimizing the total energy of the system with volume constraints. The total energy consists of surface energies and the Willmore energy; the latter penalizes the bending of the membrane. Read More

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December 2020

Probing the adsorption of nonionic micelles on different-sized nanoparticles by scattering techniques.

Phys Rev E 2020 Dec;102(6-1):062601

J-PARC Center, High Energy Accelerator Research Organization, Tokai, Ibaraki 319-1106, Japan.

The interaction of nanoparticles with surfactants is extensively used in a wide range of applications from enhancing colloidal stability to phase separation processes as well as in the synthesis of noble functional materials. The interaction is highly specific depending on the charged nature of the surfactant. In the case of nonionic surfactants, the micelles adsorb on the surface of nanoparticles. Read More

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December 2020

Clinically detectable structural abnormalities in pediatric-onset multiple sclerosis: A large-scale magnetic resonance imaging analysis.

Int J Dev Neurosci 2021 Apr 29;81(2):200-208. Epub 2021 Jan 29.

Division of Newborn Medicine, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.

Background: Multiple Sclerosis is characterized by neural demyelination. Structural magnetic resonance imaging (MRI) provides soft tissue contrast, which forms the basis of techniques for extracting regional biomarkers across a participant's brain.

Objectives: To investigate the clinical presentation of multiple sclerosis in a large-scale MRI analysis that includes thorough consideration of extractable structural measurements (average and variability of regional cortical thicknesses, cortical surface measurements, and volumes). Read More

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Analysis of two-phase air-water annular flow in U-bends.

Heliyon 2020 Dec 28;6(12):e05818. Epub 2020 Dec 28.

McDougall School of Petroleum Engineering, The University of Tulsa, Tulsa, USA.

This paper presents an experimental and numerical study of gas-liquid annular flow in horizontal 180 U-bends. The paper aims to study the effect of bend curvature radius and superficial gas velocity in the liquid film's behavior and annular flow characteristics. The study is divided into three sections. Read More

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December 2020