Development of an analytical reference stress equation for inner-diameter defected curved plates in tension

2011 ◽  
Vol 88 (5-7) ◽  
pp. 256-261 ◽  
Author(s):  
Stijn Hertelé ◽  
Wim De Waele ◽  
Rudi Denys
Keyword(s):  
Stress Equation ◽  
Reference Stress ◽  
Inner Diameter ◽  
Analytical Reference

Limit Load and Reference Stress for Curved Wide Plates

2010 ◽  
Author(s):  
Stijn Hertele´ ◽  
Wim De Waele ◽  
Rudi Denys ◽  
Jeroen Van Wittenberghe ◽  
Matthias Verstraete
Keyword(s):  
Experimental Validation ◽  
Limit Load ◽  
Plastic Collapse ◽  
Test Results ◽  
Finite Element Analyses ◽  
Flat Plates ◽  
Stress Equation ◽  
Reference Stress ◽  
Plate Curvature ◽  
Girth Welds

Curved wide plates are a valuable tool in the assessment of defective pipeline girth welds under tension. Throughout the years, Laboratory Soete collected an extensive database of curved wide plate test results. In an effort to investigate these results through FAD analysis, the authors recently developed a reference stress equation for curved plates. The approach followed is similar to the development of the Goodall and Webster equation for flat plates. This paper elaborates finite element analyses of the equation’s capability to predict plastic collapse. It is found that, although overestimated, the influence of plate curvature is correctly predicted in a qualitative way. For all simulations, the curved plate reference stress equation produced conservative estimations. This indicates that the proposed equation is suited to safely predict the plastic collapse of defective pipeline girth welds. An experimental validation is underway.

Comparison of the Aditus ad Antrum Diameter on CT between Patients with Chronic Otitis Media and Healthy Individuals

2019 ◽  
Vol 15 (10) ◽  
pp. 990-993 ◽  
Author(s):  
Elif Gündoğdu ◽  
Uğur Toprak
Keyword(s):  
Computed Tomography ◽  
Otitis Media ◽  
Middle Ear ◽  
Healthy Subjects ◽  
Normal Values ◽  
Chronic Otitis Media ◽  
Healthy Individuals ◽  
Inner Diameter ◽  
Male Patients ◽  
The Right

Background: The middle ear cavity is ventilated through the aditus ad antrum. Aditus blockage contributes to the pathology of otitis media. Objective: To determine the normal values of the aditus ad antrum diameter on computed tomography and to investigate its relationship with chronic otitis media and related pathologies (tympanosclerosis and myringosclerosis). Methods: The temporal CT images of 162 individuals were evaluated retrospectively. In the axial sections, the inner diameter of the aditus was measured at the narrowest point at the cortex. The differences in diameter were compared between diseased and healthy ears. Results: In healthy individuals, the diameter was narrower in women. There was no difference between the right and left ears in healthy subjects. No correlation was found between age and diameter. In male patients with myringosclerosis, the diameter was slightly narrower on both sides but more marked on the left. In female patients with myringosclerosis, the diameter in both ears was slightly narrower. In cases of otitis media and tympanosclerosis, the diameter was less than that of healthy individuals, despite the lack of statistically significant result in all cases. Conclusion: The aditus ad antrum was narrower in diseased ears, indicating that a blocked aditus may contribute to the development of otitis media, as well as mucosal diseases.

Dynamic Processes During Pulsed Gas Injection Into Liquid Column

2016 ◽  
Author(s):  
P. D. Lobanov ◽  
O. N. Kashinsky ◽  
A. S. Kurdyumov ◽  
N. A. Pribaturin
Keyword(s):  
Liquid Metal ◽  
Gas Phase ◽  
Gas Injection ◽  
High Amplitude ◽  
Metal Alloy ◽  
Dynamic Processes ◽  
Flow Parameters ◽  
Liquid Metal Alloy ◽  
Inner Diameter ◽  
Gas Volume

An experimental study of dynamic processes during pulsed gas injection into quiescent liquids was performed. Both water and low melting temperature metal alloy were used as test liquids. Air and argon were used as gas phase. The test sections were vertical cylindrical columns 25 and 68 mm inner diameter. Measurements of flow parameters during gas injection were performed. Water – air experiments were performed at room temperature, the temperature of liquid metal alloy was 135 deg C. Time records of pressure in the liquid and in gas phase above the liquid were obtained. Measurements of liquid temperature and level of liquid surface were performed. It was shown that at pulse gas injection into liquid metal high amplitude pressure fluctuation may arise. Also the fluctuation variation of the free surface of the liquid may appear which are connected with the oscillations of the gas volume. Experimental data obtained may be used for verification & validation of modern CFD codes.

scholarly journals Synergistic Effects of Fe2O3 Nanotube/Polyaniline Composites for an Electrochemical Supercapacitor with Enhanced Capacitance

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1557
Author(s):  
Farkhod Azimov ◽  
Jihee Kim ◽  
Seong Min Choi ◽  
Hyun Min Jung
Keyword(s):  
Electrode Materials ◽  
High Efficiency ◽  
Electrochemical Impedance ◽  
Synergistic Effects ◽  
Structural Development ◽  
Anodized Aluminum ◽  
Anodized Aluminum Oxide ◽  
Inner Diameter ◽  
Polyaniline Composites ◽  
Fe2o3 Nanotubes

α-Fe2O3, which is an attractive material for supercapacitor electrodes, has been studied to address the issue of low capacitance through structural development and complexation to maximize the use of surface pseudocapacitance. In this study, the limited performance of α-Fe2O3 was greatly improved by optimizing the nanotube structure of α-Fe2O3 and its combination with polyaniline (PANI). α-Fe2O3 nanotubes (α-NT) were fabricated in a form in which the thickness and inner diameter of the tube were controlled by Fe(CO)5 vapor deposition using anodized aluminum oxide as a template. PANI was combined with the prepared α-NT in two forms: PANI@α-NT-a enclosed inside and outside with PANI and PANI@α-NT-b containing PANI only on the inside. In contrast to α-NT, which showed a very low specific capacitance, these two composites showed significantly improved capacitances of 185 Fg−1 for PANI@α-NT-a and 62 Fg−1 for PANI@α-NT-b. In the electrochemical impedance spectroscopy analysis, it was observed that the resistance of charge transfer was minimized in PANI@α-NT-a, and the pseudocapacitance on the entire surface of the α-Fe2O3 nanotubes was utilized with high efficiency through binding and conductivity improvements by PANI. PANI@α-NT-a exhibited a capacitance retention of 36% even when the current density was increased 10-fold, and showed excellent stability of 90.1% over 3000 charge–discharge cycles. This approach of incorporating conducting polymers through well-controlled nanostructures suggests a solution to overcome the limitations of α-Fe2O3 electrode materials and improve performance.

Discussion of “Unified Effective Stress Equation for Soil” by Chao Zhang and Ning Lu

2021 ◽  
Vol 147 (2) ◽  
pp. 07020003
Author(s):  
Sakineh Fazli Ghiyasabadi ◽  
Ehsan Nikooee ◽  
Ghassem Habibagahi
Keyword(s):  
Effective Stress ◽  
Stress Equation

scholarly journals Carbon Fiber Reinforced Multi-Phase Epoxy Syntactic Foam (CFR-Epoxy-Hardener/HGMS/Aerogel-R-Hollow Epoxy Macrosphere(AR-HEMS))

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 683
Author(s):  
Xinfeng Wu ◽  
Yuan Gao ◽  
Tao Jiang ◽  
Ying Wang ◽  
Ke Yang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Carbon Fiber ◽  
Deep Sea ◽  
Impact Resistance ◽  
Syntactic Foam ◽  
Low Density ◽  
Expandable Polystyrene ◽  
Two Factors ◽  
Inner Diameter ◽  
Multi Phase

Because the aerogel has ultra-low density and good impact resistance, the aerogel material, epoxy-hardener system, and expandable polystyrene beads (EPS) were used to prepare the lightweight aerogel reinforced hollow epoxy macro-spheres (AR-HEMS). The multi-phase epoxy syntactic foam (ESF) was manufactured with the epoxy-hardener system, HGMS (EP-hardener-HGMS), and AR-HEMS by “the compression modeling method.” In this experiment, in order to enhance the strength of the ESF, some different kinds of the carbon fiber (CF) were added into the EP-hardener-HGMS system (CFR-EP). The influence of the volume stacking fraction, inner diameter, and layer of the AR-HEMS and the content and type of the CF in the EP-HGMS (CFR-EP) system on the compressive strength of the ESF were studied. Weighing the two factors of the density and compressive strength, the ESF reinforced by 1.5 wt% CF with 90% AR-HEMS has the better performance. This kind of the ESF has 0.428 g/cm3 nd 20.76 Mpa, which could be applied in 2076 m deep sea.

scholarly journals Morphological Changes in Lamellar Macular Holes According to SD-OCT Examination over a Long Observation Period

Diagnostics ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1145
Author(s):  
Magdalena Kal ◽  
Izabela Chojnowska-Ćwiąkała ◽  
Mateusz Winiarczyk ◽  
Monika Jasielska ◽  
Jerzy Mackiewicz
Keyword(s):  
Retinal Thickness ◽  
Morphological Changes ◽  
Outer Diameter ◽  
Corrected Visual Acuity ◽  
Macular Holes ◽  
Kolmogorov Smirnov ◽  
Inner Diameter ◽  
Observation Period ◽  
Sd Oct

Background: The aim of this study was to evaluate the quantitative morphological changes in lamellar macular holes (LMHs) based on SD-OCT examinations and to assess the correlations among minimal retinal thickness (MRT), reading vision (RV), and best corrected visual acuity (BCVA) over a 36-month follow-up period. Methods: A group of 40 patients (44 eyes) with LMH was evaluated, with an average age of 69.87 (SD = 10.14). The quantitative parameters monitored in the follow-up period (at 0, 3, 6, 12, 18, 24, 30, and 36 months) were tested for normality of distribution by Shapiro–Wilk and Kolmogorov–Smirnov tests. Results: The RV and BCVA values were stable, and no significant changes were found at any of the check-ups during the 36-month follow-up period (BCVA p = 0.435 and RV p = 0.0999). The analysis of individual quantitative LMH parameters during the 36-month follow-up period did not demonstrate statistically significant differences: MRT (p = 0.461), Max RT temporal (p = 0.051), Max RT nasal (p = 0.364), inner diameter (ID) (p = 0.089), and outer diameter (OD) (p = 0.985). Conclusions: The observations at 0, 6, 12, 18, 24, 30, and 36 months revealed moderate and significant correlations between RV and MRT. No significant correlation between BCVA and MRT was observed.

Influence of fully submerged permanent magnets in the evaluation of heat transfer and performance analysis of single slope glass solar still

2021 ◽  
pp. 095765092110310
Author(s):  
Ajay Kumar Kaviti ◽  
Akkala Siva Ram ◽  
Amit Kumar Thakur
Keyword(s):  
Heat Transfer ◽  
Permanent Magnets ◽  
Outer Diameter ◽  
Solar Still ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Inner Diameter ◽  
Evaporative Heat Transfer ◽  
And Performance ◽  
Depth Water

In this experimental study, permanent magnets with three different sizes (M-1: 32 mm inner diameter, 70 mm outer diameter and 15 mm thick, M-2: 25 mm inner diameter, 60 mm outer diameter and 10 mm thick, M-3: 22 mm inner diameter, 45 mm outer diameter and 9 mm thick) are fully submerged in the single-slope glass solar still. The performance of magnetic solar stills (MSS) with three different sizes at 2 cm depth water to ensure that magnets are fully submerged is compared with conventional solar still (CSS) at the location 17.3850°N, 78.4867°E. Tiwari model is adapted to calculate the heat transfer coefficients (HTC), internal and exergy efficiencies. MSS with M-1, M-2 and M-3 significantly enhanced the convective, radiative, and evaporative heat transfer rate for the 2 cm depth of water. This is due to the desired magnetic treatment of water, which reduces the surface tension and increases the hydrogen bonds. The MSS's total internal HTC, instantaneous efficiencies led CSS by 25.52%, 28.8%, respectively, with M-1. Having various magnetic fields due to different magnets sizes increases MSS's exergetic efficiency by 33.61% with M-1, 33.76% with M-2, and 42.25% with M-3. Cumulative yield output for MSS with M-1, M-2, and M-3 is 21.66%, 17.64%, 15.78% higher than CSS. The use of permanent magnets of different sizes in the MSS is a viable, economical and straight forward technique to enhance productivity.

Sign in / Sign up

Export Citation Format

Share Document