This paper examines the effectiveness of the social and political factors as the determinants of antidumping duties against the transition economies. The empirical evidence shows…
Abstract
This paper examines the effectiveness of the social and political factors as the determinants of antidumping duties against the transition economies. The empirical evidence shows that protectionist pressures tend to be strengthened against them with low labor standards, although protectionist tendencies with respect to social dumping are not so apparent in actual impositions of antidumping duties. There is a weak evidence that the different degrees of democraticness influenced the protectionism against the transition economies during the late 1990s, while such an effect is not found during the period of 2002-2006, as the concerned countries passed the initial stage of transition.
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This paper aims to clarify the role that economic methodology and approach can help the World Trade Organization (WTO) Appellate Body (AB)make better decisions. The author…
Abstract
Purpose
This paper aims to clarify the role that economic methodology and approach can help the World Trade Organization (WTO) Appellate Body (AB)make better decisions. The author discusses two prominent disputes to demonstrate how economics could have resulted in improved AB decision. First, there is the question of whether countervailing duties can continue to be imposed subsequent to privatization of state-owned enterprises. Second, there is the frequently challenged zeroing issue.
Design/methodology/approach
The author uses a case study method. He reviews the details of specific disputes and explains how standard microeconomic methods would have produced greater clarity in the determinations and hence promoted a more efficient dispute resolution process.
Findings
In this commentary, however, the author addresses a frustration with the AB, namely, the reluctance of the AB to embrace economics in its decision-making. He argues that economic methods would produce superior determinations.
Originality/value
This paper fulfils an identified need to document how economic methods would have led to better AB decisions.
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Connie Rae Bateman, Neil C. Herndon and John P. Fraedrich
This paper represents a discussion of transfer pricing (TP). Key factors are identified and propositions developed from tax accounting and other perspectives. Stages of the TP…
Abstract
This paper represents a discussion of transfer pricing (TP). Key factors are identified and propositions developed from tax accounting and other perspectives. Stages of the TP decision process are identified along with the critical factors directly affecting sales and a TP audit. Propositions are derived which show relationships among these variables and tax rates, competition, and TP methodologies. Finally, academic research implications are suggested.
The U.S. antidumping legislation provides protection to domestic industries that face dumped imports. Restricting imports by imposing antidumping duties protects domestic firms…
Abstract
The U.S. antidumping legislation provides protection to domestic industries that face dumped imports. Restricting imports by imposing antidumping duties protects domestic firms from predatory pricing by foreign firms. At the same time it reduces competition in the domestic market. In cases where the industry consists only of one or two firms, import restriction can drastically reduce competition faced by domestic firms. This paper looks at the cases filed by the chemical industry to illustrate this possibility. The concentration of industries asking for protection and the impact of import restriction on domestic competition is studied.
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Antonio Lanzotti, Marzio Grasso, Gabriele Staiano and Massimo Martorelli
This study aims to quantify the ultimate tensile strength and the nominal strain at break (ɛf) of printed parts made from polylactic acid (PLA) with a Replicating Rapid prototyper…
Abstract
Purpose
This study aims to quantify the ultimate tensile strength and the nominal strain at break (ɛf) of printed parts made from polylactic acid (PLA) with a Replicating Rapid prototyper (Rep-Rap) 3D printer, by varying three important process parameters: layer thickness, infill orientation and the number of shell perimeters. Little information is currently available about mechanical properties of parts printed using open-source, low-cost 3D printers.
Design/methodology/approach
A computer-aided design model of a tensile test specimen was created, conforming to the ASTM:D638. Experiments were designed, based on a central composite design. A set of 60 specimens, obtained from combinations of selected parameters, was printed on a Rep-Rap Prusa I3 in PLA. Testing was performed using a JJ Instruments – T5002-type tensile testing machine and the load was measured using a load cell of 1,100 N.
Findings
This study investigated the main impact of each process parameter on mechanical properties and the effects of interactions. The use of a response surface methodology allowed the proposition of an empirical model which connects process parameters and mechanical properties. Even though results showed a high variability, additional ideas on how to understand the impact of process parameters are suggested in this paper.
Originality/value
On the basis of experimental results, it is possible to obtain practical suggestions to set common process parameters in relation to mechanical properties. Experiments discussed in the present paper provide a variety of data and insight regarding the relationship among the main process parameters and the stiffness and strength of fused deposition modeling-printed parts made from PLA. In particular, this paper underlines the shortage in existing literature concerning the impact of process parameters on the elastic modulus and the strain to failure for the PLA. The experimental data produced show a good degree of compliance with analytical formulations and other data found in literature.
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Ana Elisa Costa, Alexandre Ferreira da Silva and Olga Sousa Carneiro
The performance of parts produced by fused filament fabrication is directly related to the printing conditions and to the rheological phenomena inherent to the process…
Abstract
Purpose
The performance of parts produced by fused filament fabrication is directly related to the printing conditions and to the rheological phenomena inherent to the process, specifically the bonding between adjacent extruded paths/raster. This paper aims to study the influence of a set of printing conditions and parameters, namely, envelope temperature, extrusion temperature, forced cooling and extrusion rate, on the parts performance.
Design/methodology/approach
The influence of these parameters is evaluated by printing a set of test specimens that are morphologically characterized and mechanically tested. At the morphological level, the external dimensions and the voids content of the printed specimens are evaluated. The bonding quality between adjacent extruded paths is assessed through the mechanical performance of test specimens, subjected to tensile loads. These specimens are printed with all raster oriented at 90º relative to the tensile axis.
Findings
The best performance, resulting from a compromise between surface quality, dimensional accuracy and mechanical performance, is achieved with a heated printing environment and with no use of forced cooling. In addition, for all the conditions tested, the highest dimensional accuracy is achieved in dimensions defined in the printing plane.
Originality/value
This work provides a relevant result as the majority of the current printers comes without enclosure or misses the heating and envelope temperature control systems, which proved to be one of the most influential process parameter.
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J.P. Barbosa Mota and E. Saatdjian
Natural convection in a porous layer between two horizontal, concentriccylinders is investigated numerically by solving the 2‐DDarcy‐Boussinesq equations on a very fine grid…
Abstract
Natural convection in a porous layer between two horizontal, concentric cylinders is investigated numerically by solving the 2‐D Darcy‐Boussinesq equations on a very fine grid. The parabolic‐elliptic system was solved by a second order finite difference scheme based on the implicit alternating direction method coupled with successive under relaxation. The calculations show that for radius ratios above 1.7, the functional relationship between the mean Nusselt number and the Rayleigh number exhibits a closed hysteresis loop associated with the transition from a two to a four cell flow pattern. For very small radius ratios, steady state regimes containing 2, 4, 6, and 8 cells are progressively obtained as the Rayleigh number is increased, but no hysteresis behaviour is observed. For a radius ratio of 2, the numerical results are in good agreement with the experimental data. Multi‐cellular regimes and hysteresis loops have also been reported in the literature for fluid annuli but some differences between the two cases exist and are fully explained below.
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Taha Sheikh and Kamran Behdinan
This paper aims to present a hierarchical multiscale model to evaluate the effect of fused deposition modeling (FDM) process parameters on mechanical properties. Asymptotic…
Abstract
Purpose
This paper aims to present a hierarchical multiscale model to evaluate the effect of fused deposition modeling (FDM) process parameters on mechanical properties. Asymptotic homogenization mathematical theory is developed into two scales (micro and macro scales) to compute the effective elastic and shear modulus of the printed parts. Four parameters, namely, raster orientation, layer height, build orientation and porosity are studied.
Design/methodology/approach
The representative volume elements (RVEs) are generated by mimicking the microstructure of the printed parts. The RVEs subjected to periodic boundary conditions were solved using finite element. The experimental characterization according to ASTM D638 was conducted to validate the computational modeling results.
Findings
The computational model reports reduction (E1, ∼>38%) and (G12, ∼>50%) when porosity increased. The elastic modulus increases (1.31%–47.68%) increasing the orthotropic behavior in parts. Quasi-solids parts (100% infill) possess 10.71% voids. A reduction of 11.5% and 16.5% in elastic modulus with layer height is reported. In total, 45–450 oriented parts were highly orthotropic, and 0–00 parts were strongest. The order of parameters affecting the mechanical properties is porosity > layer height > raster orientation > build orientation.
Originality/value
This study adds value to the state-of-the-art terms of construction of RVEs using slicing software, discarding the necessity of image processing and study of porosity in FDM parts, reporting that the infill density is not the only measure of porosity in these parts.
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Maximilian Kunovjanek and Christian Wankmüller
The COVID-19 pandemic caused global supply disruptions and shortages that resulted in countries battling over desperately needed (medical) supplies. In this mayhem, additive…
Abstract
Purpose
The COVID-19 pandemic caused global supply disruptions and shortages that resulted in countries battling over desperately needed (medical) supplies. In this mayhem, additive manufacturing (AM) provided relief to the strained healthcare systems and manufacturing environments by offering an alternative way to rapidly produce desired products. This study sheds light on how AM was used globally in response to the COVID-19 pandemic.
Design/methodology/approach
The study undertakes a systematic and content-centric review of 289 additively manufactured products made in response to the COVID-19 pandemic. Additionally, quantitative frequency-based text mining and various descriptive analyses were applied that support the investigation of the subject under regard.
Findings
Results show that AM was primarily used in the medical domain for the production of standard medical items, such as personal protective equipment (PPE) but also for non-obvious and new applications (e.g. swab simulator, rapid diagnostic kits, etc.). Also, certain paradigm shifts were observed, as the effective move to mass production and the mitigation of problems related to certification and standardization emerged as prominent management prospects. Nevertheless, various obstacles arose and remained in the path of lasting AM success, especially with respect to print quality, raw material supply and technological versatility.
Originality/value
Due to the actuality of the topic under investigation, no comparable study has so far been conducted. The systematic review provides a conclusive and precise foundation for further analysis and subsequent discussions. Additionally, no comparable study mapping such a wide array of different AM products exists today.
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Taha Sheikh and Kamran Behdinan
This paper aims to present a geometrical void model in conjunction with a multiscale method to evaluate the effect of interraster distance, bead (raster) width and layer height…
Abstract
Purpose
This paper aims to present a geometrical void model in conjunction with a multiscale method to evaluate the effect of interraster distance, bead (raster) width and layer height, on the voids concentration (volume) and subsequently calculate the final mechanical properties of the fused deposition modeling parts at constant infill.
Design/methodology/approach
A geometric model of the voids inside the representative volume element (RVE) is combined with a two-scale asymptotic homogenization method. The RVEs are subjected to periodic boundary conditions solved by finite element (FE) to calculate the effective mechanical properties of the corresponding RVEs. The results are validated with literature and experiments.
Findings
Bead width from 0.2 to 0.3 mm, reported a decrease of 25% and 24% void volume for a constant layer height (0.1 and 0.2 mm – 75% infill). It is reported that the void’s volume increased up to 14%, 32% and 36% for 75%, 50% and 25% infill by varying layer height (0.1–0.2 and 0.3 mm), respectively. For elastic modulus, 14%, 9% and 10% increase is reported when the void’s volume is decreased from 0.3 to 0.1 mm at a constant 75% infill density. The bead width and layer height have an inverse effect on voids volume.
Originality/value
This work brings values: a multiscale-geometric model capable of predicting the voids controllability by varying interraster distance, layer height and bead width. The idealized RVE generation slicer software and Solidworks save time and cost (<10 min, $0). The proposed model can effectively compute the mechanical properties together with the voids analysis.