scholarly journals Effect of Uncertainty in Localized Imperfection on the Ultimate Compressive Strength of Cold-Formed Stainless Steel Hollow Sections

2019 ◽  
Vol 9 (18) ◽  
pp. 3827 ◽  
Author(s):  
Yanfei Shen ◽  
Rolando Chacón
Keyword(s):  
Stainless Steel ◽  
Compressive Strength ◽  
Three Dimensional ◽  
Local Buckling ◽  
Cost Effective ◽  
3D Models ◽  
Ultimate Compressive Strength ◽  
Cross Sectional ◽  
Hollow Section

Stainless steel has excellent corrosion resistance properties, considerable long-term durability, and good mechanical strength. Hollow sections are a versatile and efficient form for construction applications. The use of cold-formed stainless steel rectangular hollow section (RHS) and square hollow section (SHS) in construction industry grasps the attention of designers conceiving long-term, cost-effective structures. For cold-formed RHS and SHS, localized imperfection (ω) resulting from rolling and fabrication process is inevitable. ω has inherent variability and has no definitive characterization. In this paper, statistical analysis of the maximum value of ω collected from available experimental data is conducted. A new approach utilizing Fourier series to generate the three-dimensional (3D) models of members with random ω is proposed. Probabilistic studies based on the proposed 3D models are then carried out to evaluate the effect of uncertainty in ω on the ultimate compressive strength of stainless steel columns with cold-formed RHS and SHS. A total of 21 columns that are prone to local buckling reduction are studied. The results show that uncertainty in ω has a considerable influence on the columns with relatively higher cross-sectional slenderness.

scholarly journals 3D-Volume Rendering of the Pelvis with Emphasis on Paraurethral Structures Based on MRI Scans and Comparisons between 3D Slicer and OsiriX®

2021 ◽  
Vol 45 (3) ◽  
Author(s):  
C. M. Durnea ◽  
S. Siddiqi ◽  
D. Nazarian ◽  
G. Munneke ◽  
P. M. Sedgwick ◽  
...  
Keyword(s):  
Image Processing ◽  
Secondary Analysis ◽  
Three Dimensional ◽  
3D Models ◽  
Clinical Role ◽  
Cross Sectional ◽  
3D Slicer ◽  
Mri Scans ◽  
3D Volume ◽  
Good Agreement

AbstractThe feasibility of rendering three dimensional (3D) pelvic models of vaginal, urethral and paraurethral lesions from 2D MRI has been demonstrated previously. To quantitatively compare 3D models using two different image processing applications: 3D Slicer and OsiriX. Secondary analysis and processing of five MRI scan based image sets from female patients aged 29–43 years old with vaginal or paraurethral lesions. Cross sectional image sets were used to create 3D models of the pelvic structures with 3D Slicer and OsiriX image processing applications. The linear dimensions of the models created using the two different methods were compared using Bland-Altman plots. The comparisons demonstrated good agreement between measurements from the two applications. The two data sets obtained from different image processing methods demonstrated good agreement. Both 3D Slicer and OsiriX can be used interchangeably and produce almost similar results. The clinical role of this investigation modality remains to be further evaluated.

scholarly journals Accuracy of 2D modeling approach for performance simulation of noncircular single- and dual-layer monolithic catalysts

2021 ◽  
Author(s):  
Behnam Mozaffari
Keyword(s):  
Cross Sections ◽  
Three Dimensional ◽  
Single Layer ◽  
Flow Region ◽  
3D Models ◽  
Catalytic Performance ◽  
Cross Sectional ◽  
2D Modeling ◽  
Modeling Approach ◽  
Monolithic Catalysts

This study aims to evaluate the accuracy of widely applied approach of modeling noncircular channels and washcoats of monolithic catalysts with equivalent circular geometrical shapes. For this purpose, catalytic performance of equivalent circular and square channel cross-sectional shapes with single-layer Pt/Al2O3 and dual-layer Fe-ZSM-5+Pt/Al2O3 washcoats are investigated. For the noncircular cross-sections, three-dimensional computational fluid dynamics models that consider species gases convection inside the channel bulk flow region, and reaction and diffusion of species inside the washcoat layer(s) are utilized to simulate the performance of one channel of the monolithic catalytic converters. In addition, in order to investigate the amount of inaccuracy of 2D modeling approach for noncircular channels, 2D models are applied to simulate the equivalent monolithic catalysts with circular cross-sections, and the results of the 2D and 3D models are compared together, and also, with the experimental and 1D+1D modeling technique results available in the literature.

scholarly journals Evaluation of grapevine trunk size by use of a handheld camera and three-dimensional modelling

OENO One ◽  
2019 ◽  
Vol 53 (4) ◽  
Author(s):  
Khalil Bou Nader ◽  
Leonard Maximilian Pfahl ◽  
Eric Gomès ◽  
Manfred Stoll
Keyword(s):  
Three Dimensional ◽  
Cost Effective ◽  
Image Resolution ◽  
Vitis Vinifera L ◽  
Cross Sectional ◽  
Carbon Sequestration Potential ◽  
Trunk Diameter ◽  
Lighting Conditions ◽  
Sequestration Potential ◽  
Three Dimensional Models

Background and aims: Measurement of grapevine size is necessary to assess carbon reserves at the level of individual vines and to estimate the carbon sequestration potential of vineyards. Methods of measurement rely mostly on traditional dendrological techniques that may be prone to error. In this study, we examined the use of structure-from-motion with multiview stereophotogrammetry (SfM-MVS) to obtain accurate measurements of vine trunk thickness and volume. SfM-MVS enables the creation of scaled, georeferenced three-dimensional models based on a set of overlapping photographs.Methods and results: The study was conducted using field-grown Vitis vinifera L. cv. Riesling vines aged 5, 22 and 46 years and pruned in a bilateral Guyot. Trunk diameter, cross-sectional area and circumference 10 cm above the grafting point were measured by traditional dendrometry, and the values obtained compared with corresponding estimates from reconstructed three-dimensional SfM-MVS models. SfM-MVS was also used to estimate total trunk volume. Correlation between measured values and modelled estimates was close to unity (0.976 ≤ R2 ≤ 0.988). The estimates for 5-year-old vines had the largest errors.Conclusions: Under adequate lighting conditions and with sufficient image resolution, SfM-MVS is able to produce accurate models of vine trunks.Significance of the study: This work serves as proof of concept for the use of SfM-MVS to measure the trunk size of field-grown grapevines of different ages. This technique, which is relatively new, is cost-effective and easy to implement. Further research is necessary to determine specific applications of SfM-MVS, in which it could supplement or replace traditional dendrological techniques.

scholarly journals A smoking cessation program as a resource for bladder cancer patients

2012 ◽  
Vol 6 (5) ◽  
Author(s):  
Daniel Vilensky ◽  
Nathan Lawrentschuk ◽  
Karen Hersey ◽  
Neil E. Fleshner
Keyword(s):  
Bladder Cancer ◽  
Smoking Cessation ◽  
Cost Effective ◽  
Smoking Cessation Program ◽  
Cross Sectional ◽  
Quit Smoking ◽  
Patients At Risk ◽  
Effective Program ◽  
Managing Stress

Background: Continued tobacco use following a bladder cancer(CaB) diagnosis puts patients at risk for other tobacco-associateddiseases and has also been associated with heightened risks oftreatment-related complications, tumour recurrence, morbidity andmortality. Our aim was to determine if patients with CaB who continueto smoke warrant a smoking cessation program as a resourcefor improving their prognosis and long-term health.Methods: A cross-sectional quantitative questionnaire-based studywas performed between January and April 2009. We surveyedpatients with a pathologically confirmed diagnosis of CaB duringtheir cystoscopy appointments at a single cancer centre.Results: One hundred patients completed the survey with 72% ofthem admitting to smoking in their lifetime. A third of respondentssmoked at the time of their diagnosis; 76% of patients who hadbeen active smokers at the time of their diagnosis (n = 33) reportedsmoking at some point thereafter and 58% continued to smoke. Among continued smokers, they were classified in the following categories: 26% were in “precontemplation,” 5% in “contemplation,”16% in “preparation,” and 53% in “action;” 37% of patientswho continued to smoke were interested in a hospital-based smokingcessation program. Overall, 70% reported smoking as a risk factor for a poor CaB prognosis. The two most common barriersto quitting were “trouble managing stress and mood” and “fear ofgaining weight.”Conclusion: Based on the data from our centre, patients with CaBwho continue to smoke after their diagnosis warrant a smoking cessationprogram as a resource for improving prognosis and long-term health. Further research should focus on establishing an efficacious and cost-effective program that provides these patients with theresources they need to quit smoking.

The Clinker Minerals Effect on the Cement Hardening Kinetic Constants

2019 ◽  
Vol 974 ◽  
pp. 217-223
Author(s):  
Shark M. Rakhimbaev ◽  
Tatiana V. Anikanova ◽  
Igor S. Rakhimbaev ◽  
Alexey S. Pogromsky
Keyword(s):  
Compressive Strength ◽  
Ultimate Strength ◽  
Sharp Decrease ◽  
Ultimate Compressive Strength ◽  
Kinetic Constants ◽  
The Individual ◽  
The Relationship ◽  
Positive Effect

The work is devoted to the study of the relationship between the individual clinker minerals content, the stone compressive strength in different periods of hardening and the binders kinetic hardening constants. It is shown that C3S and C2S affect the cements’ kinetic hardening constants in the early and long-term periods in different ways. There is a positive effect of C2S on the ultimate compressive strength and a sharp decrease in the dependence of the stone ultimate strength on C3S in the later periods. The initial hardening rate in high-cement cement is established to increase sharply with an increase in the C3A content from 5 to 12%. The increase in the C3A content up to 12% in low-cement cement has little effect on the initial hardening rate value.

Highly stable lithium metal battery with an applied three-dimensional mesh structure interlayer

2018 ◽  
Vol 6 (32) ◽  
pp. 15540-15545 ◽  
Author(s):  
Hyunjin Kim ◽  
Yong Jun Gong ◽  
Jeeyoung Yoo ◽  
Youn Sang Kim
Keyword(s):  
Stainless Steel ◽  
Three Dimensional ◽  
Cost Effective ◽  
Effective Strategy ◽  
Lithium Metal ◽  
Stainless Steel Mesh ◽  
Mesh Structure ◽  
Cost Effective Strategy ◽  
Steel Mesh ◽  
Lithium Metal Battery

We propose a facile and cost-effective strategy for stabilizing the lithium metal–electrolyte interface via a three-dimensional stainless steel mesh (SSM) interlayer.

scholarly journals Caudal mandibular fracture repair using three-dimensional printing, presurgical plate contouring and a preformed template to aid anatomical fracture reduction

2018 ◽  
Vol 4 (2) ◽  
pp. 205511691879887 ◽  
Author(s):  
Peter Southerden ◽  
Duncan M Barnes
Keyword(s):  
Stainless Steel ◽  
Plate Fixation ◽  
Three Dimensional ◽  
3D Models ◽  
Fracture Repair ◽  
Mandibular Fractures ◽  
Rigid Fixation ◽  
Patient Morbidity ◽  
Drill Holes ◽  
Mini Plate

Case summary Two cats were presented with mandibular fractures following head trauma. Following a CT scan, both were diagnosed with fractures of the ramus. The CT scans were used to print three-dimensional (3D) models of the mandibular fractures, which were used to pre-contour stainless steel mini-plates. These were fixed to the models and the screw positions used to produce a stainless steel template. The template was used as a pattern during surgery to drill holes in the ramus so that the pre-contoured mini-plates could be fixed in the exact same position as they had been on the 3D model. The fractures healed in both cats achieving normal jaw function and occlusion. Relevance and novel information Conventional techniques used to treat caudal mandibular fractures in cats, such as maxillomandibular fixation and bignathic encircling and retaining device (BEARD), are associated with significant patient morbidity and postoperative complications. Internal rigid fixation is difficult because of small bone size, requirement for considerable plate contouring and difficulty in achieving accurate anatomical reduction of caudal mandibular fractures. These are the first reported cases of mini-plate fixation of caudal mandibular fractures in cats using 3D models, pre-contouring of bone plates and the use of a template to facilitate accurate plate positioning, which may provide an alternative technique suitable for fixing caudal mandibular fractures in cats.

scholarly journals 3D Bioprinted Spheroidal Droplets for Engineering the Heterocellular Coupling between Cardiomyocytes and Cardiac Fibroblasts

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Raven El Khoury ◽  
Naveen Nagiah ◽  
Joel A. Mudloff ◽  
Vikram Thakur ◽  
Munmun Chattopadhyay ◽  
...  
Keyword(s):  
Mechanical Stability ◽  
Cardiac Fibroblasts ◽  
Three Dimensional ◽  
3D Models ◽  
Cardiac Cells ◽  
Junctional Coupling ◽  
Human Cardiac Fibroblasts ◽  
Gap Junctional ◽  
Gap Junctional Coupling

Since conventional human cardiac two-dimensional (2D) cell culture and multilayered three-dimensional (3D) models fail in recapitulating cellular complexity and possess inferior translational capacity, we designed and developed a high-throughput scalable 3D bioprinted cardiac spheroidal droplet-organoid model with cardiomyocytes and cardiac fibroblasts that can be used for drug screening or regenerative engineering applications. This study helped establish the parameters for bioprinting and cross-linking a gelatin-alginate-based bioink into 3D spheroidal droplets. A flattened disk-like structure developed in prior studies from our laboratory was used as a control. The microstructural and mechanical stability of the 3D spheroidal droplets was assessed and was found to be ideal for a cardiac scaffold. Adult human cardiac fibroblasts and AC16 cardiomyocytes were mixed in the bioink and bioprinted. Live-dead assay and flow cytometry analysis revealed robust biocompatibility of the 3D spheroidal droplets that supported the growth and proliferation of the cardiac cells in the long-term cultures. Moreover, the heterocellular gap junctional coupling between the cardiomyocytes and cardiac fibroblasts further validated the 3D cardiac spheroidal droplet model.

scholarly journals Frontal Cryosectioning: An Improved Protocol for Sectioning Large Areas of Fibrous Scaffolds

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Casey P. Grey ◽  
David G. Simpson
Keyword(s):  
Cross Sections ◽  
Imaging Techniques ◽  
Fibrous Tissue ◽  
Three Dimensional ◽  
3D Models ◽  
Spatial Cues ◽  
Tissue Engineering Scaffolds ◽  
Cross Sectional ◽  
Fibrous Scaffolds ◽  
Scaffold Properties

Fibrous tissue engineering scaffolds, such as those produced by electrospinning, cannot achieve their clinical potential until deep cell-scaffold interactions are understood. Even the most advanced imaging techniques are limited to capturing data at depths of 100 µm due to light scatter associated with the fibers that compose these scaffolds. Conventional cross-sectional analysis provides information on relatively small volumes of space and frontal sections are difficult to generate. Current understanding of cellular penetration into fibrous scaffolds is limited predominantly to the scaffold surface. Although some information is available from cross-sections, sections vary in quality, can distort spatial scaffold properties, and offer virtually no spatial cues as to what scaffold properties instigate specific cellular responses. Without the definitive ability to understand how cells interact with the architecture of an entire scaffold it is difficult to justify scaffold modifications or in-depth cell penetration analyses until appropriate techniques are developed. To address this limitation we have developed a cryosectioning protocol that makes it possible to obtain serial frontal sections from electrospun scaffolds. Microscopic images assembled into montage images from serial sections were then used to create three-dimensional (3D) models of cellular infiltration throughout the entire scaffold.

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