Establishment of Testing Methodology for Forge Welded Tubular Products

2012 ◽  
Author(s):  
Ganesan S. Marimuthu ◽  
Per Thomas Moe ◽  
Bjarne Salberg ◽  
Jan Inge Audestad
Keyword(s):  
Material Flow ◽  
Large Scale ◽  
Flow Behavior ◽  
Treatment Options ◽  
Full Scale ◽  
International Standards ◽  
Small Scale ◽  
Test Plan ◽  
Welding Machine

A state-of-the-art small-scale solid state forge welding machine has been fabricated for checking weldability by Shielded Active Gas Forge Welding (SAG-FW) of tubular products applicable predominantly for, but not limited to offshore Industries. Effective, fast and inexpensive welding and testing of joints make this small-scale method suitable for evaluating weldability of a material before starting regular qualification and fabrication in a full-scale welding machine normally located in spool base or offshore. The small-scale machine provides a complete package for pre-qualification studies, including assessment of welding conditions, material flow behavior, heat treatment options. However, there are considerable challenges relating to application of international standards of testing as well as interpretation and use of results in the context of large-scale welding. In this paper results from small-scale welding and weld characterization of an API 5L X65 quality are presented. First, a detailed test plan for analyzing the weld is outlined. This procedure is subsequently applied for checking the welds to be produced in the full-scale machine. Short-comings in using the small-scale process as well as the possible remedies are discussed in detail.

Coupled Thermo-Hydro-Geochemical Models of Engineered Barrier Systems: The Febex Project

2000 ◽  
Vol 663 ◽  
Author(s):  
J. Samper ◽  
R. Juncosa ◽  
V. Navarro ◽  
J. Delgado ◽  
L. Montenegro ◽  
...  
Keyword(s):  
Large Scale ◽  
Reference Model ◽  
Numerical Models ◽  
Full Scale ◽  
Small Scale ◽  
Model Parameters ◽  
In Situ Test ◽  
Wide Range ◽  
Engineered Barrier

ABSTRACTFEBEX (Full-scale Engineered Barrier EXperiment) is a demonstration and research project dealing with the bentonite engineered barrier designed for sealing and containment of waste in a high level radioactive waste repository (HLWR). It includes two main experiments: an situ full-scale test performed at Grimsel (GTS) and a mock-up test operating since February 1997 at CIEMAT facilities in Madrid (Spain) [1,2,3]. One of the objectives of FEBEX is the development and testing of conceptual and numerical models for the thermal, hydrodynamic, and geochemical (THG) processes expected to take place in engineered clay barriers. A significant improvement in coupled THG modeling of the clay barrier has been achieved both in terms of a better understanding of THG processes and more sophisticated THG computer codes. The ability of these models to reproduce the observed THG patterns in a wide range of THG conditions enhances the confidence in their prediction capabilities. Numerical THG models of heating and hydration experiments performed on small-scale lab cells provide excellent results for temperatures, water inflow and final water content in the cells [3]. Calculated concentrations at the end of the experiments reproduce most of the patterns of measured data. In general, the fit of concentrations of dissolved species is better than that of exchanged cations. These models were later used to simulate the evolution of the large-scale experiments (in situ and mock-up). Some thermo-hydrodynamic hypotheses and bentonite parameters were slightly revised during TH calibration of the mock-up test. The results of the reference model reproduce simultaneously the observed water inflows and bentonite temperatures and relative humidities. Although the model is highly sensitive to one-at-a-time variations in model parameters, the possibility of parameter combinations leading to similar fits cannot be precluded. The TH model of the “in situ” test is based on the same bentonite TH parameters and assumptions as for the “mock-up” test. Granite parameters were slightly modified during the calibration process in order to reproduce the observed thermal and hydrodynamic evolution. The reference model captures properly relative humidities and temperatures in the bentonite [3]. It also reproduces the observed spatial distribution of water pressures and temperatures in the granite. Once calibrated the TH aspects of the model, predictions of the THG evolution of both tests were performed. Data from the dismantling of the in situ test, which is planned for the summer of 2001, will provide a unique opportunity to test and validate current THG models of the EBS.

scholarly journals Topophilia, Placemaking, and Boundary Work

2022 ◽  
Vol 6 (GROUP) ◽  
pp. 1-33
Author(s):  
Janghee Cho ◽  
Samuel Beck ◽  
Stephen Voida
Keyword(s):  
Large Scale ◽  
Methodological Approach ◽  
Work Practice ◽  
Small Scale ◽  
Work From Home ◽  
Humanistic Geography ◽  
Working From Home ◽  
Long Term Impact

The COVID-19 pandemic fundamentally changed the nature of work by shifting most in-person work to a predominantly remote modality as a way to limit the spread of the coronavirus. In the process, the shift to working-from-home rapidly forced the large-scale adoption of groupware technologies. Although prior empirical research examined the experience of working-from-home within small-scale groups and for targeted kinds of work, the pandemic provides HCI and CSCW researchers with an unprecedented opportunity to understand the psycho-social impacts of a universally mandated work-from-home experience rather than an autonomously chosen one. Drawing on boundary theory and a methodological approach grounded in humanistic geography, we conducted a qualitative analysis of Reddit data drawn from two work-from-home-related subreddits between March 2020 and January 2021. In this paper, we present a characterization of the challenges and solutions discussed within these online communities for adapting work to a hybrid or fully remote modality, managing reconfigured work-life boundaries, and reconstructing the home's sense of place to serve multiple, sometimes conflicting roles. We discuss how these findings suggest an emergent interplay among adapted work practice, reimagined physical (and virtual) spaces, and the establishment and continual re-negotiation of boundaries as a means for anticipating the long-term impact of COVID on future conceptualizations of productivity and work.

INVESTIGATION INTO THE INFLUENCE OF IMPREGNATION ON PINE TIMBER COMBUSTION USING A CONE CALORIMETER AND LARGE SCALE TESTS

2011 ◽  
Vol 3 (3) ◽  
pp. 91-104 ◽  
Author(s):  
Jerzy Gałaj ◽  
Zbignev Karpovič ◽  
Waldemar Jaskółowski
Keyword(s):  
Cone Calorimeter ◽  
Large Scale ◽  
Experimental Studies ◽  
Fire Retardant ◽  
Full Scale ◽  
Lower Amount ◽  
Small Scale ◽  
Fire Retardants ◽  
Co Concentration ◽  
Piloted Ignition

Fire safety is one of the main requirements with respect to the regulations on the buildings involved into the category of human hazards. Human safety measures are applied equally to inhabitants, users, customers, spectators, etc., as well as to fire brigades taking part in the activities connected with rescue actions. Methods for emission research were applied to estimate thermo-kinetic parameters related to smoke and toxic gases. The methods fall into two types: full scale methods reflect fire conditions and small laboratory scale methods having a significantly lower degree of reflection. This paper presents the results of studies on the influence of BAK-1 and Flamasepas-2 fire retardants produced in Lithuania and applied for timber on the selected parameters of the fire environment. Experimental studies were conducted using a cone calorimeter (small scale) in the closed compartment equipped with measuring devices (full scale). The undertaken studies have demonstrated that considering some parameters, such as heat release rate (HRR), a positive effect of the lower amount of the released heat can be obtained. Unfortunately, in case of the major part of the studied parameters, including time to ignition, CO concentration and extinction parameter reflecting smokiness, worse results (shorter time, higher CO values and higher extinction coefficient) have been observed for the treated timber rather than for the non-impregnated one. The obtained results have showed combustion with piloted ignition. In case of no piloted ignition, the results were slightly different. For all studied specimens treated with fire retardants, no ignition was observed and tests were terminated following 15 minutes. CO concentration and extinction parameter (smokiness) were higher for non-impregnated timber. Full scale experiments have confirmed the above provided information; moreover, it has been found that the application of fire retardant has no significant impact on temperatures in the compartment.

scholarly journals Geometry and the deformation of pack ice: II. Simulation with a random isotropic model and implication in sea-ice rheology

2000 ◽  
Vol 31 ◽  
pp. 323-326 ◽  
Author(s):  
Jinro Ukita ◽  
Richard E. Moritz
Keyword(s):  
Large Scale ◽  
Yield Curve ◽  
Maximum Shear Stress ◽  
Small Scale ◽  
Pack Ice ◽  
Line Process ◽  
Scale Characterization ◽  
Poisson Line Process ◽  
Realistic Geometry

AbstractIn this paper, we extend the analysis of geometry and deformation of pack ice initiated in part I by considering random isotropic geometry using the Poisson line process. The model is used to estimate opening, ridging and sliding coefficients for more realistic geometry than the idealized simple and regular geometry considered in part I. We then derive the shape of yield curves by applying minimization of the maximum shear stress to a linear combination of the estimated ridging and sliding coefficients. It is found that isotropic crack geometry results in a sine-lens shape for the yield curve if sliding makes no contribution to the energy dissipation. By contrast, when sliding contributes, the shape of the yield curve becomes teardropped. These results suggest the presence of a consistent relationship between large-scale characterization of inter-floe interactions and small-scale (crack and lead) ridging processes.

scholarly journals Unmanned Aerial Vehicle Propagation Channel over Vegetation and Lake Areas: First- and Second-Order Statistical Analysis

Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 65
Author(s):  
Deyvid L. Leite ◽  
Pablo Javier Alsina ◽  
Millena M. de Medeiros Campos ◽  
Vicente A. de Sousa ◽  
Alvaro A. M. de Medeiros
Keyword(s):  
Secure Communication ◽  
Large Scale ◽  
Communication Channel ◽  
Channel Model ◽  
Path Loss ◽  
Doppler Frequency ◽  
Unmanned Aircraft ◽  
Small Scale ◽  
Log Normal

The use of unmanned aerial vehicles (UAV) to provide services such as the Internet, goods delivery, and air taxis has become a reality in recent years. The use of these aircraft requires a secure communication between the control station and the UAV, which demands the characterization of the communication channel. This paper aims to present a measurement setup using an unmanned aircraft to acquire data for the characterization of the radio frequency channel in a propagation environment with particular vegetation (Caatinga) and a lake. This paper presents the following contributions: identification of the communication channel model that best describes the characteristics of communication; characterization of the effects of large-scale fading, such as path loss and log-normal shadowing; characterization of small-scale fading (multipath and Doppler); and estimation of the aircraft speed from the identified Doppler frequency.

Prediction of Brownout Inception Beneath a Full-Scale Helicopter Downwash

2012 ◽  
Vol 57 (4) ◽  
pp. 1-13 ◽  
Author(s):  
Gregory Jasion ◽  
John Shrimpton
Keyword(s):  
Boundary Layer ◽  
Large Scale ◽  
Aerodynamic Force ◽  
Dust Cloud ◽  
Full Scale ◽  
Small Scale ◽  
Wall Region ◽  
Analytical Prediction ◽  
Characteristic Particle ◽  
Near Wall

Dust entrained by low flying helicopters leads to the degraded visual environment, brownout. Particle inception is a critical stage in the development of the dust cloud. Here, near-wall Lagrangian particle forces are considered through analyzing an approximate time-averaged full-scale rotor flow. This simplified flow does not attempt to predict brownout, instead it provides scales and velocity data in the near-wall region, compares the role of particle-fluid forces, and provides a foundation for Lagrangian entrainment models. The analysis shows that three characteristic particle sizes are exposed to different physics in different boundary layer zones, a function of the distance from the helicopter. Drag is the dominant aerodynamic force, cohesion is large for small particles, but wall-bounded lift is sufficient to entrain medium-sized particles. A complementary analytical prediction of tip vortices found that both large-scale inviscid features and small-scale viscous features of the boundary layer are significant.

Flow behavior downstream of two side-by-side circular cylinders in shallow water

2016 ◽  
Vol 94 (10) ◽  
pp. 975-981
Author(s):  
Mustafa Atakan Akar ◽  
Burcu Oguz ◽  
Huseyin Akilli ◽  
Besir Sahin
Keyword(s):  
Shallow Water ◽  
Large Scale ◽  
Flow Behavior ◽  
Circular Cylinders ◽  
Small Scale ◽  
Piv Method ◽  
Gap Ratio ◽  
Image Velocimetry ◽  
The Right ◽  
Bistable Flow

Investigations of bistable flow structure past a pair of cylinders positioned side-by-side in shallow water is conducted experimentally applying dye observation and the particle image velocimetry (PIV) method. For the gap ratio of G/D = 1.25, the jet-like flow between cylinders deflects asymmetrical flow structures forming a large-scale wake as well as a small-scale wake downstream of cylinders. The small vortices around the right cylinder get closer to each other forming a larger vortex in the large-scale wake region, which leads the jet-like flow to changeover side to side. The small frequency (f = 0.352 Hz) associated with frequency of vortex shedding of cylinder with wider wake and the higher frequency (f = 0.793 Hz) which depicts the smaller wakes frequency.

scholarly journals Turkish Chemical Industry and Environmentally Friendly Technologies

2017 ◽  
Vol 3 (4) ◽  
pp. 257 ◽  
Author(s):  
A. Nilgün Akin ◽  
Z. Ilsen Önsan
Keyword(s):  
Large Scale ◽  
Pollution Abatement ◽  
Forest Products ◽  
International Standards ◽  
Small Scale ◽  
Marmara Region ◽  
Marmara Sea ◽  
Industrial Companies ◽  
Long Time ◽  
Metal Products

Turkey has been manufacturing chemicals for a long time, being a producer of many basic and intermediate chemicals, petrochemicals and plastics. Among ca. 6000 companies manufacturing various<br />chemicals, 95 are large scale, 208 are medium scale, and the rest are all small size companies. The southern coast of the Marmara Sea is the home of Turkey’s densest population and industrial centers. Most<br />companies in chemical industries, especially private sector companies, are situated in the Marmara Region which, therefore, also generates large amounts of solid and liquid wastes from industrial areas, along with municipal solid waste and sewage as well as air pollution from gas emissions. Large scale industrial companies place a great deal of importance on international standards in production and comply with<br />environmental legislation and regulations. Although Turkey has made great progress over the last fifteen years in creating mechanisms to address its environmental problems, air and water pollution abatement problems still exist due to small scale enterprises generally using old technologies in sub-sectors including highly polluting activities such as textiles/clothing/leather, metal products/machinery/equipment, food/beverages/tobacco, forest products/furniture.

scholarly journals Scale Effects of Footings on Geocell Reinforced Sand Using Large-Scale Tests

2018 ◽  
Vol 4 (3) ◽  
pp. 497
Author(s):  
A. Shadmand ◽  
Mahmoud Ghazavi ◽  
Navid Ganjian
Keyword(s):  
Large Scale ◽  
Initial Conditions ◽  
Scale Effects ◽  
Friction Angle ◽  
Full Scale ◽  
Small Scale ◽  
Granular Soils ◽  
Initial State ◽  
The Difference ◽  
Mean Stresses

The scale effect on bearing capacity of shallow footings supported by unreinforced granular soils has been evaluated extensively. However, the subject has not been addressed for shallow footings on geocell-reinforced granular soils. In this study, load-settlement characteristic of large square footings is investigated by performing large-scale loading tests on unreinforced and geocell-reinforced granular soils. The effects of footing width (B), soil relative density of soil (Dr), and reinforcement depth (u) have been investigated. The test results show that the scale effects exist in geocell-reinforced soils, like unreinforced soils, and the behavior of small-scale models of footings cannot be directly related to the behavior of full-scale footings due to the difference between initial conditions of tests and the initial state of mean stresses in the soil beneath the footings having different dimensions. Large footings create higher mean stresses in the soil, resulting in low soil friction angle and initial conditions of the test approach to the critical state lines. The results of tests indicate that model experiments should be conducted on low-density soil for better prediction of the behavior of full-scale footings, otherwise, the predicted behavior of full-scale footings does not seem conservative.

Scale-Up Correlation for the Flow of Surfactant-Based Fluids in Circular Coiled Pipes

2010 ◽  
Vol 132 (8) ◽  
Author(s):  
Ahmed H. Ahmed Kamel ◽  
Subhash N. Shah
Keyword(s):  
Power Law ◽  
Large Scale ◽  
Flow Behavior ◽  
Scale Up ◽  
Deborah Number ◽  
Small Scale ◽  
Power Law Model ◽  
Flow Data ◽  
Coiled Tubing ◽  
Fluid Elasticity

This study involves experimental investigation on the flow properties of aqueous surfactant-based (SB) fluids in small and large-scale coiled tubing. It aims at understanding the viscoelastic properties and its effect on the flow behavior of SB fluids in coiled tubing. In spite of SB fluids wide use as friction reducer and/or fracturing fluid in the oil and gas industry, the flow data in large pipe sizes as well as coiled tubing are very scarce. Majority of the available flow data are gathered in straight pipes with small sizes. The scale-up of small-scale flow data is questionable due to the pronounced diameter effect. Furthermore, previous studies have correlated flow behavior of these fluids only through simple power-law model parameters. Limited work with polymeric fluids has been reported that includes fluid elasticity in scale-up procedure and it is nonexistent for highly elastic SB fluids. In this study, the properties of widely used Aromox APA-T, a highly active surfactant used as gelling agent in aqueous and brine base fluids, are thoroughly investigated. Rheological measurements are conducted using Bohlin rheometer for SB fluid concentration of 1.5 vol %, 2 vol %, 3 vol %, and 4 vol %. Flow data are gathered using 1.27 cm, 3.81 cm, 6.03 cm, and 7.30 cm OD coiled tubing with various curvature ratios. This study presents the first attempt to investigate the flow behavior SB fluids in large-scale coiled tubing. The results show that SB fluids exhibit non-Newtonian pseudoplastic behavior. Elastic and viscous properties of SB fluids are very sensitive to surfactant concentration. Friction losses in coiled tubing are significantly higher than those in straight pipes due to secondary flow effect. Increasing curvature ratio yields higher friction pressure loss. Also, small-scale data correlations using only simple power-law model fluid rheological parameters lead to erroneous results when scaled-up to large pipe sizes. New technique, based on the modified Deborah number, which includes fluid elasticity and pipe shear effect, has been developed to correlate data from the small laboratory-scale tubing and large field-scale pipes. Correlation to predict Fanning friction factor of SB fluids in coiled tubing as a function of Deborah number and fluid flow behavior index is presented. Correlation is validated by comparing predictions with the experimental data. It is shown that the new correlation accurately predicts friction factor of SB fluids and thus alleviates the scale-up issue.

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