Study of the process of formation of tubes end sections during longitudinal rolling in grooves formed by a different number of rolls

2021 ◽  
pp. 44-48
Author(s):  
D. A. Akhmerov ◽  
◽  
A. V. Vydrin ◽  
Keyword(s):  
Wall Thickness ◽  
Stretch Ratio ◽  
External Diameter ◽  
Continuous Rolling ◽  
Elongation Ratio ◽  
Longitudinal Rolling ◽  
Rolling Mills ◽  
Advantages And Disadvantages ◽  
Hollow Billets ◽  
The Relationship

The work substantiates the relevance and highlights the degree of development of the research topic. The main advantages and disadvantages of the process of rolling hollow billets with the use of modern longitudinal rolling mills with 2 and 3 roll grooves are noted. With the help of physical and computer modeling, a study of the process of longitudinal rolling of pipes using 2 and 3 roll passes was carried out, for the formation of end sections (scrap). Established and numerically reflected the relationship between the size of the reduction of passes of a continuous rolling mill with 3-roll and 2-roll stands and the length of the end sections of the pipes. It is clear that the use of 3 rolls, forming a groove, allows to reduce the total end cut by 1.5 times, in contrast to 2 rolls. It has been determined that the main technological factors influencing the formation of the end sections are the ratio of the external diameter to the wall thickness of the strip (D/S), the reduction along the wall thickness, the elongation ratio, and the number of rolls required to form the groove. An empirical formula has been obtained for calculating the length of the end trim, which makes it possible to evaluate the influence of the number of rolls in the stand, the D/S ratio and the stretch ratio.

Reduction in longitudinal wall-thickness variation on tubes rolled on TPA-140 longitudinal rolling mills at the Sinarskii Pipe Plant

Metallurgist ◽  
1986 ◽  
Vol 30 (8) ◽  
pp. 293-294
Author(s):  
M. B. Bisk ◽  
A. I. Brizhan ◽  
G. A. Kaspirovich ◽  
A. I. Nechiporenko ◽  
Yu. I. Pustovoichenko ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Thickness Variation ◽  
Pipe Plant ◽  
Longitudinal Rolling ◽  
Rolling Mills ◽  
Longitudinal Wall ◽  
Wall Thickness Variation

Influence of Roll Speed Schedule on Transverse Wall Thickness Evenness of Shell Elongated by Mandrel Mill

2010 ◽  
Vol 654-656 ◽  
pp. 1311-1314 ◽  
Author(s):  
Sheng Zhi Li ◽  
Zhi Chao Zhang ◽  
Hai Yan Bao ◽  
Zhi Yang Zhou
Keyword(s):  
Wall Thickness ◽  
Rolling Process ◽  
Steel Tube ◽  
Transverse Wall ◽  
Data Reliability ◽  
Continuous Rolling ◽  
Roll Speed ◽  
Seamless Steel Tube ◽  
The Relationship ◽  
Seamless Steel

The seamless steel tube continuous rolling process with 8-stand full-floating mandrel is simulated with the aid of commercial FE code MSC. SuperForm. The relationship is analyzed between the distribution of the transverse wall-thickness and the speed schedule of the rollers. The result shows that the transverse evenness of the wall thickness of the tubes can be enhanced by optimizing the speed schedule. Furthermore, by adopting meliorated method to measure the wall-thickness of the shell, the error is reduced while data reliability is increased. When using the existing equipments (mandrel mill), it is an effective way to improve the transverse wall-thickness accuracy of the shell tube by adjusting the speed schedule. Compared with present roll speed schedule, the transverse wall-thickness accuracy can be increased by 10% for the rolling of elongated shell with 152.5mm in OD and 6mm in wall thickness tube under the 3# speed schedule put forward in this paper.

scholarly journals Theoretical and Methodological Approaches to Ecological Changes, Social Behaviour and Human Intergroup Tolerance 300,000 to 30,000 BP

2021 ◽  
Vol 28 (1) ◽  
pp. 53-75 ◽  
Author(s):  
Penny Spikins ◽  
Jennifer C. French ◽  
Seren John-Wood ◽  
Calvin Dytham
Keyword(s):  
Social Behaviour ◽  
Environmental Variability ◽  
Raw Materials ◽  
Modern Human ◽  
Resource Exploitation ◽  
Agent Based ◽  
Advantages And Disadvantages ◽  
Ecological Changes ◽  
The Relationship ◽  
Social Behaviours

AbstractArchaeological evidence suggests that important shifts were taking place in the character of human social behaviours 300,000 to 30,000 years ago. New artefact types appear and are disseminated with greater frequency. Transfers of both raw materials and finished artefacts take place over increasing distances, implying larger scales of regional mobility and more frequent and friendlier interactions between different communities. Whilst these changes occur during a period of increasing environmental variability, the relationship between ecological changes and transformations in social behaviours is elusive. Here, we explore a possible theoretical approach and methodology for understanding how ecological contexts can influence selection pressures acting on intergroup social behaviours. We focus on the relative advantages and disadvantages of intergroup tolerance in different ecological contexts using agent-based modelling (ABM). We assess the relative costs and benefits of different ‘tolerance’ levels in between-group interactions on survival and resource exploitation in different environments. The results enable us to infer a potential relationship between ecological changes and proposed changes in between-group behavioural dynamics. We conclude that increasingly harsh environments may have driven changes in hormonal and emotional responses in humans leading to increasing intergroup tolerance, i.e. transformations in social behaviour associated with ‘self-domestication’. We argue that changes in intergroup tolerance is a more parsimonious explanation for the emergence of what has been seen as ‘modern human behaviour’ than changes in hard aspects of cognition or other factors such as cognitive adaptability or population size.

Material Properties and Design Aspects of Folding Bicycle Frame

2011 ◽  
Vol 264-265 ◽  
pp. 777-782 ◽  
Author(s):  
M.A. Maleque ◽  
M.S. Hossain ◽  
S. Dyuti
Keyword(s):  
Material Properties ◽  
Raw Material ◽  
New Materials ◽  
Materials Properties ◽  
Advantages And Disadvantages ◽  
Bicycle Frame ◽  
Successful Design ◽  
Future Direction ◽  
The Relationship ◽  
Comprehensive Study

successful design of folding bicycle should take into account the function, material properties, and fabrication process. There are some other factors that should be considered in anticipating the behavior of materials for folding bicycle. In order to understand the relationship between material properties and design of a folding bicycle and also for the future direction in new materials with new design, a comprehensive study on the design under different conditions are essential. Therefore, a systematic study on the relationship between material properties and design for folding bicycle has been performed. The advantages and disadvantages matrix between conventional bicycle and folding bicycle is presented for better understanding of the materials properties and design. It was found that the materials properties of the folding bicycle frame such as fatigue and tensile strength are the important properties for the better performance of the frame. The relationship between materials properties and design is not straight forward because the behavior of the material in the finished product could be different from that of the raw material. The swing hinge technique could be a better technique in the design for the folding bicycle frame.

ON INTERACTION OF MATERIAL AND PROCEDURAL LAW IN THE CONTEXT OF REFORMING THE NOMENCLATURE OF SCIENTIFIC SPECIALTIES IN JURISPRUDENCE

2021 ◽  
Vol 3 (3) ◽  
pp. 214-231
Author(s):  
S.I. Suslova
Keyword(s):  
Civil Law ◽  
Scientific Research ◽  
Civil Procedure ◽  
Dialectical Logic ◽  
Advantages And Disadvantages ◽  
Procedural Law ◽  
Depth Study ◽  
Civil Science ◽  
Substantive Law ◽  
The Relationship

Introduction: the influence of the material branches of law on the content and development of procedural branches has long been substantiated in the legal literature. At the same time, civil law scholars, limited by the scope of the nomenclature of scientific specialties in legal sciences, do not have the opportunity to conduct dissertation research aimed at identifying the influence of procedural branches on the norms of substantive law. With regard to scientific research, the study of such an impact is currently permissible only within the specialty 12.00.15. Reforming the nomenclature of scientific specialties towards its enlargement creates the basis for the development of the scientific theory of intersectoral relations, developed by M.Iu. Chelyshev. An in-depth study of the intersectoral interaction of civil law and civil procedure will contribute not only to the development of scientific knowledge, but also will allow solving practical problems at a different methodological level. Purpose: to analyze the stages of the formation of scientific specialties in the context of the relationship between civil law and procedure, to identify the advantages and disadvantages of uniting and dividing civil law and procedure in scientific research, to analyze dissertations in different periods of development of the science of civil law and the science of civil procedure, to formulate ways to improve directions of research to bridge the gap between the science of civil law and procedure. Methods: empirical methods of description, interpretation; theoretical methods of formal and dialectical logic. The legal-dogmatic private scientific method was used. Results: identified the main views on the ratio of material and procedural branches in legal science; it is illustrated that the intersectoral approach is currently admissible only for dissertations in the specialty 12.00.15, which led to an almost complete absence of scientific research on this topic in civil science; substantiated the need to establish the bilateral nature of the relationship and interaction of material and procedural block. Conclusions: reforming the nomenclature of scientific specialties by right in the direction of their enlargement should have a positive effect on bridging the gap that has developed between works on civil law and civil law procedure in the last years of their separate existence. This is especially true of civil science, which developed its own scientific theories in isolation from the possibilities of their implementation within the framework of procedural law. The methodological basis for solving these problems has already been formed – this is an intersectoral method, the application of which is justified and demonstrated in the works of M.Iu. Chelyshev.

659Left atrial wall thickness evaluation during atrial fibrillation redo procedures

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
C Teres ◽  
D Soto ◽  
B Jauregui ◽  
D Penela ◽  
A Ordonez ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Wall Thickness ◽  
Atrial Wall ◽  
Ablation Procedure ◽  
Left Atrial Wall ◽  
Local Distance ◽  
The Mean ◽  
The Right ◽  
The Relationship ◽  
Funding Acknowledgements

Abstract Funding Acknowledgements Dr Teres was funded by Swiss Heartrhythm Foundation Introduction pulmonary vein (PV) reconnections due to gaps on circumferential ablation lines are responsible for atrial fibrillation recurrences after catheter ablation. We sought to analyze the local left atrial wall thickness (LAWT) of PV line gaps at AF redo ablation during real-time catheter positioning. LAWT was measured on the MDCT 3D reconstruction and fused with the LA anatomy using CARTO-merge. Objective To analyze the relationship between local reconnection gaps and the LAWT during AF redo procedures. Methods Single-Center cohort study that included 41 consecutive patients referred for AF redo procedure. All patients had a MDCT prior to the ablation procedure. LAWT maps were semi-automatically computed from the MDCT as the local distance between the LA endo and epicardium. Each PV line was subdivided into 8 segments and mean LAWT was computed. During the procedure, the local gap was defined as the earliest activation site at the reconnected segment of the circumferential PV line (Figure 1A & 1B). Results 41 patients [31 (75.6%) male, age 60 ± 10 years] were included. Mean LAWT was 1.36 ± 0.20 mm. Mean PV circumferential line WT was higher in left PVs than in the right PVs 1.68 ± 0.57 vs. 1.31 ± 0.39 mm p < 0.001 respectively. Mean WT of the reconnected points was 44% higher than the mean WT of the segment where the reconnection was located. Mean reconnection point WT was at the 87th percentile of the circumferential line in the LPVs and at the 76th percentile in the RPVs. The reconnected point WT was higher in the LPVs than RPVs 2.13 ± 1.14 vs. 1.47 ± 0.48 mm p < 0.001 respectively.  The most frequent location for reconnections was the left anterior carina (71%), with a mean WT of 2.24 ± 0.91mm; and the right anterior carina (56%) with a mean WT of 1.57 ± 0.62mm (Figure 2A & 2B). Conclusions Reconnection points were more frequently present in the thicker segments of the PV circumferential line. The most frequently reconnected segment was the anterior carina in both right and left PVs. Atrial wall thickness maps derived from MDCT are useful to guide AF redo procedures. Abstract Figure. 1) Activation & WT map; 2) Segment WT

scholarly journals Optimization of Superplastic Forming Process of AA7075 Alloy for the Best Wall Thickness Distribution

2021 ◽  
Vol 6 (4) ◽  
pp. 251-261
Author(s):  
Manh Tien Nguyen ◽  
Truong An Nguyen ◽  
Duc Hoan Tran ◽  
Van Thao Le
Keyword(s):  
Wall Thickness ◽  
Deformation Temperature ◽  
Numerical Optimization ◽  
Thickness Distribution ◽  
Superplastic Forming ◽  
Forming Process ◽  
Wall Thickness Distribution ◽  
Surface Method ◽  
Series Of Experiments ◽  
The Relationship

This work aims to optimize the process parameters for improving the wall thickness distribution of the sheet superplastic forming process of AA7075 alloy. The considered factors include forming pressure p (MPa), deformation temperature T (°C), and forming time t (minutes), while the responses are the thinning degree of the wall thickness ε (%) and the relative height of the product h*. First, a series of experiments are conducted in conjunction with response surface method (RSM) to render the relationship between inputs and outputs. Subsequently, an analysis of variance (ANOVA) is conducted to verify the response significance and parameter effects. Finally, a numerical optimization algorithm is used to determine the best forming conditions. The results indicate that the thinning degree of 13.121% is achieved at the forming pressure of 0.7 MPa, the deformation temperature of 500°C, and the forming time of 31 minutes.

scholarly journals The Method for Product Design Selection with Incomplete Linguistic Weight Information Based on Quality Function Deployment in a Fuzzy Environment

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Ming Li
Keyword(s):  
Product Design ◽  
Quality Function Deployment ◽  
Design Development ◽  
Quality Function ◽  
Advantages And Disadvantages ◽  
Fuzzy Environment ◽  
Design Requirements ◽  
Design Selection ◽  
The Given ◽  
The Relationship

The selection of a design for the given product is a critical problem in product design development. Focuses of the designers and customers on the design are not identical. In order to bridge the gap and provide a more relaxing way to select the design, a new method based on quality function deployment (QFD) is proposed. In such a method, customers are required to give their linguistic preferences on the design with respect to the customer requirements (CRs). In the rating of the weight of CRs, they are allowed to provide incomplete linguistic weight information and the objective optimization model is proposed to derive the exact linguistic weight information. Designers are required to rate the correlation between design requirements (DRs) and the relationship between the CRs and DRs to construct the house of quality. Opinions given by the customers are translated into the opinions with respect to the DRs based on the QFD. Afterwards, the priorities of the designs and design requirements are determined. The assessment results not only show the contribution of each design requirement to the customer satisfaction but also show the advantages and disadvantages of each design from the designers’ perspective clearly and directly. An example is provided to validate the applicability of the proposed method.

scholarly journals The Relationship between Maxillary Sinus Lateral Wall Thickness, Alveolar Bone Loss, and Demographic Variables: A Cross-Sectional Cone-Beam Computerized Tomography Study

2018 ◽  
Vol 28 (2) ◽  
pp. 109-114 ◽  
Author(s):  
Tuba Talo Yildirim ◽  
Güliz Nigar Güncü ◽  
Mehmet Colak ◽  
Tolga Fikret Tözüm
Keyword(s):  
Bone Loss ◽  
Maxillary Sinus ◽  
Computerized Tomography ◽  
Wall Thickness ◽  
Alveolar Bone ◽  
Lateral Wall ◽  
Cone Beam ◽  
Cone Beam Computerized Tomography ◽  
And Gender ◽  
The Relationship

Objectives: Sinus floor elevation and augmentation surgery is widely used as a reliable procedure to increase insufficient bone height in the posterior maxillary area. The purpose of the present clinical study was to determine the associations between periodontal bone loss (PBL), maxillary sinus lateral bone wall thickness, age, and gender using cone-beam computerized tomography (CBCT). Materials and Methods: The current retrospective study consists of 716 maxillary sinus CBCT images of 358 patients. The CBCT scans were assessed to detect the relationship between lateral wall thickness and PBL. ANOVA and Student t test analysis were used to determine the influence of PBL on sinus lateral wall thickness. Results: Sinus lateral wall thickness was significantly associated with PBL (p < 0.05) at 3, 13, and 15 mm height. There was no significant association between lateral wall thickness and gender (p > 0.05). However, there was a significant association between lateral wall thickness at 3 and 13 mm and age (p < 0.05). There were significant associations between PBL and age (p < 0.001), and PBL and gender (p < 0.05). Conclusions: PBL might have an association with maxillary sinus lateral bone wall thickness. Further studies are needed to confirm this possible relationship.

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