scholarly journals К статической устойчивости трубопровода

2020 ◽  
Vol 90 (4) ◽  
pp. 612
Author(s):  
А.Г. Хакимов
Keyword(s):  
Pipe Wall ◽  
Initial Stresses ◽  
Compression Force ◽  
Static Interaction ◽  
External Pressures

Based on the assumption of the initial deformed shape of the pipeline without initial stresses, the critical compression force is determined. The pipeline was under the influence of internal and external pressures, compressive forces. A fluid with a given density flowed through the pipeline. The axisymmetric expansion of the pipe and its longitudinal shortening, changes in the temperature of the pipe wall, and the formation of an ejection arch were taken into account. The static interaction of instabilities under the influence of the above factors is studied.

Development of a mathematical model of the influence of wall thickness on the strain rate when profiling pipes by drawing

2020 ◽  
pp. 49-52
Author(s):  
R.A. Okulov ◽  
N.V. Semenova
Keyword(s):  
Mathematical Model ◽  
Strain Rate ◽  
Wall Thickness ◽  
Pipe Wall ◽  
Strain Intensity ◽  
Thickness Strain ◽  
Pipe Wall Thickness

The change in the intensity of the deformation of the pipe wall during profiling by drawing was studied. The dependence of the strain intensity on the wall thickness of the workpiece is obtained to predict the processing results in the production of shaped pipes with desired properties. Keywords drawing, profile pipe, wall thickness, strain rate. [email protected]

Conclusion

2018 ◽  
Author(s):  
Dirk van Miert
Keyword(s):  
Natural Science ◽  
Biblical Text ◽  
The Bible ◽  
External Pressures ◽  
History Of

In the conclusion, the intrinsic deconstructive power of philology is contrasted with external pressures moving philology in different political and religious directions. The positions of the main protagonists differed widely, but they show that the less they were institutionalized, the more freedom they had to present unorthodox theories. As in the case of natural science, biblical philology was a handmaiden of theology, but it could also be used against certain theologies. In the end, the accumulation of evidence regarding the history of the Bible and the transmission of its texts, could not fail to impinge on the authority of Scripture. The problems in the transmission of the biblical text were widely discussed in the decade leading up to the publication of the Theological-political Treatise. Readers of Spinoza were already familiar with the type of reasoning which Spinoza employed in the central chapters of his notorious work.

scholarly journals Why do informal markets remain informal: the role of tacit knowledge in an Indian footwear cluster

2021 ◽  
Author(s):  
Yugank Goyal ◽  
Klaus Heine
Keyword(s):  
Tacit Knowledge ◽  
Informal Markets ◽  
Market Institutions ◽  
Market Structures ◽  
Long Run ◽  
External Pressures ◽  
Propositional Form ◽  
The City

AbstractWhy do informal markets resist formalizing, even when the gains of doing so outweigh its costs in the long run? While a number of responses to this question have been advanced, we discover that part of the reason could be located in the tacit knowledge (attributed to Polanyi, Hayek) embedded in the marketplace, on which market institutions run. This factor is not fully explored yet. Tacit (idiosyncratic, inarticulate, nonconscious) knowledge is acquired personally through experience and cannot be transferred or conveyed to anyone. This is the knowledge we use to act without knowing it in a propositional form. We present the case of one of India’s largest informal footwear cluster, located in the city of Agra. We show that informal markets, hinged on tacit knowledge, cannot evolve easily and therefore may remain locked-in, despite external pressures or incentives to formalize. The study shows that efforts to overcome informality and reaping the benefits of formalized market structures cannot be done without taking cognizance of the sticky intangible knowledge on which these markets rest.

scholarly journals Trade-Control Compliance in SMEs: Do Decision-Makers and Supply Chain Position Make a Difference?

2021 ◽  
Author(s):  
Christian Hauser
Keyword(s):  
Decision Making ◽  
Decision Makers ◽  
Behavioral Ethics ◽  
Managerial Decision ◽  
Organizational Responses ◽  
Control Laws ◽  
Compliance Programs ◽  
External Pressures ◽  
Compliance Program ◽  
Trade Control

AbstractIn recent years, trade-control laws and regulations such as embargoes and sanctions have gained importance. However, there is limited empirical research on the ways in which small- and medium-sized enterprises (SMEs) respond to such coercive economic measures. Building on the literature on organizational responses to external demands and behavioral ethics, this study addresses this issue to better understand how external pressures and managerial decision-making are associated with the scope of trade-control compliance programs. Based on a sample of 289 SMEs, the findings show that the organizational responses of SMEs reflect proportionate adjustments to regulatory pressures but only if decision-makers are well informed and aware of the prevailing rules and regulations. Conversely, uninformed decision-making leads to a disproportionate response resulting in an inadequately reduced scope of the compliance program. In addition, the results indicate that SMEs that are highly integrated into supply chains are susceptible to passing-the-buck behavior.

scholarly journals Finite Element Analysis of Composite Repair for Damaged Steel Pipeline

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 301
Author(s):  
Jiaqi Chen ◽  
Hao Wang ◽  
Milad Salemi ◽  
Perumalsamy N. Balaguru
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Hoop Stress ◽  
Pipe Wall ◽  
Von Mises Stress ◽  
Repair System ◽  
Composite Repair ◽  
Steel Pipeline ◽  
Von Mises ◽  
Infill Material

Carbon fiber reinforced polymer (CFRP) matrix composite overwrap repair systems have been introduced and accepted as an alternative repair system for steel pipeline. This paper aimed to evaluate the mechanical behavior of damaged steel pipeline with CFRP repair using finite element (FE) analysis. Two different repair strategies, namely wrap repair and patch repair, were considered. The mechanical responses of pipeline with the composite repair system under the maximum allowable operating pressure (MAOP) was analyzed using the validated FE models. The design parameters of the CFRP repair system were analyzed, including patch/wrap size and thickness, defect size, interface bonding, and the material properties of the infill material. The results show that both the stress in the pipe wall and CFRP could be reduced by using a thicker CFRP. With the increase in patch size in the hoop direction, the maximum von Mises stress in the pipe wall generally decreased as the maximum hoop stress in the CFRP increased. The reinforcement of the CFRP repair system could be enhanced by using infill material with a higher elastic modulus. The CFRP patch tended to cause higher interface shear stress than CFRP wrap, but the shear stress could be reduced by using a thicker CFRP. Compared with the fully bonded condition, the frictional interface causes a decrease in hoop stress in the CFRP but an increase in von Mises stress in the steel. The study results indicate the feasibility of composite repair for damaged steel pipeline.

scholarly journals Cultural Influences on the Regulation of Energy Intake and Obesity: A Qualitative Study Comparing Food Customs and Attitudes to Eating in Adults from France and the United States

Nutrients ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 63
Author(s):  
Maria Carlota Dao ◽  
Sophie Thiron ◽  
Ellen Messer ◽  
Camille Sergeant ◽  
Anne Sévigné ◽  
...  
Keyword(s):  
United States ◽  
Qualitative Study ◽  
Social Interactions ◽  
Weight Management ◽  
Food Consumption ◽  
Eating Behavior ◽  
The United States ◽  
Food Culture ◽  
External Pressures ◽  
The U.S

(1) Background: The influence of food culture on eating behavior and obesity risk is poorly understood. (2) Methods: In this qualitative study, 25 adults in France with or without overweight/obesity participated in semi-structured interviews (n = 10) or focus groups (n = 15) to examine attitudes to food consumption and external pressures that influence eating behavior and weight management. Results were compared to an equivalent study conducted in the United States, thereby contrasting two countries with markedly different rates of obesity. Emerging key themes in the French data were identified through coding using a reflexive approach. (3) Results: The main themes identified were: (1) influence of commensality, social interactions, and pleasure from eating on eating behavior, (2) having a balanced and holistic approach to nutrition, (3) the role of environmental concerns in food consumption, (4) relationship with “natural” products (idealized) and food processing (demonized), (5) perceptions of weight status and management. Stress and difficulties in hunger cue discernment were viewed as important obstacles to weight management in both countries. External pressures were described as a major factor that explicitly influences food consumption in the U.S., while there was an implicit influence of external pressures through eating-related social interactions in France. In France, products considered “natural” where idealized and juxtaposed against processed and “industrial” products, whereas this was not a salient aspect in the U.S. (4) Conclusions: This first comparative qualitative study assessing aspects of food culture and eating behaviors across countries identifies both common and divergent attitudes to food and eating behavior. Further studies are needed to inform the development of effective behavioral interventions to address obesity in different populations.

Dynamic water fill level measurement using a phantom-dependent adaptive electrical capacitance tomography (ECT) method

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Christoph Kandlbinder-Paret ◽  
Alice Fischerauer ◽  
Gerhard Fischerauer
Keyword(s):  
Pipe Wall ◽  
Electrical Capacitance Tomography ◽  
Electrical Capacitance ◽  
Capacitance Measurements ◽  
Level Measurement ◽  
Element Simulation ◽  
Fill Level ◽  
Capacitance Tomography ◽  
Low Permittivity ◽  
Adaptation Scheme

Abstract In electrical capacitance tomography (ECT), the resolution of the reconstructed permittivity distribution improves with the number of electrodes used whereas the number of capacitance measurements and the measurement time increases with the number of electrodes. To cope with this tradeoff, we present a phantom-dependent adaptation scheme in which coarse measurements are performed with terminal electrodes interconnected to form a synthetic electrode ring with fewer but larger electrodes. The concept was tested by observing the sloshing of water inside a pipe. We compare the reconstructed results based on eight synthetic electrodes, on 16 elementary electrodes, and on the adaptation scheme involving both the eight synthetic electrodes and some of the elementary capacitances. The reconstruction used the projected Landweber algorithm for capacitances determined by a finite-element simulation and for measured capacitances. The results contain artefacts attributed to the influence of the high permittivity of water compared to the low permittivity of the pipe wall. The adaptation scheme leads to nearly the same information as a full measurement of all 120 elementary capacitances but only requires the measurement of 30 % fewer capacitances. By detecting the fill level using a tomometric method, it can be determined within an uncertainty of 5 % FS.

scholarly journals Perspective on the Response of Turbulent Pipe Flows to Strong Perturbations

Fluids ◽  
2021 ◽  
Vol 6 (6) ◽  
pp. 208
Author(s):  
Liuyang Ding ◽  
Tyler Van Buren ◽  
Ian E. Gunady ◽  
Alexander J. Smits
Keyword(s):  
Pipe Flow ◽  
Abrupt Change ◽  
Pipe Wall ◽  
Surface Condition ◽  
Initial Response ◽  
Body Of Revolution ◽  
Future Directions ◽  
Pipe Flows ◽  
Roughness Elements ◽  
Pipe Geometry

Pipe flow responds to strong perturbations in ways that are fundamentally different from the response exhibited by boundary layers undergoing a similar perturbation, primarily because of the confinement offered by the pipe wall, and the need to satisfy continuity. We review such differences by examining previous literature, with a particular focus on the response of pipe flow to three different kinds of disturbances: the abrupt change in surface condition from rough to smooth, the obstruction due to presence of a single square bar roughness elements of different sizes, and the flow downstream of a streamlined body-of-revolution placed on the centerline of the pipe. In each case, the initial response is strongly influenced by the pipe geometry, but far downstream all three flows display a common feature, which is the very slow, second-order recovery that can be explained using a model based on the Reynolds stress equations. Some future directions for research are also given.

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