Development of a Simplified PWR Fuel Assembly Nonlinear Model

This paper proposes a computation technique to develop a simplified nonlinear model for a typical nuclear fuel assembly. Because more than a hundred fuel assemblies are packed in the reactor, simplistic model generation is critical to evaluate the motion during an anticipated event such as earthquake. Two straight beams are introduced to simplify the fuel assembly, and the beam properties are moderately defined to represent the skeleton structure and a bundle of slender fuel rods. Because nonlinearity is caused by the interaction between the rods and the spacer grids in the skeleton structure, the two beams are connected with multilinear joints that characterize the mechanical interaction between them. An equation of motion for the model is provided, and the degree of the freedom of the model can be reduced by using a few major modes of the beams. Significant mechanical parameters must be defined reasonably, so a method is proposed to identify unknown parameters through a deterministic calculation and an optimization process. All the information, including the identified parameters, are utilized to develop a nonlinear finite element model with a commercial code. The performance of the model is compared with the test results.

Evaluation of hydrodynamic behavior of biosand filters using computational fluid dynamics combined with the design of experiments

Biosand filters (BSFs) are widely used in rural and urban areas where access to drinking water is limited or non-existent. This study applies computational fluid dynamics in the assessment of hydrodynamic characteristics considering changes in the design of two BSF models to make construction options available to communities, without losing hydrodynamic efficiency. The commercial code ANSYS-CFX 20.1 together with a central composite design of experiments methodology to simulate the flow was used under different combinations of porosities, permeabilities, pipe diameters, and filter diameters and heights. These parameters were combined statistically from Statistica 13.3. Our results have shown that combining greater filter depths with smaller pipe diameters has played a key role in the BSF best performance, and the CAWST V10 model has performed better than HydrAid, with lower velocities and longer hydraulic retention times.

Skazane na zapomnienie — prawo handlowe w PRL

The post-war history of Polish commercial law is not a frequent subject of interest in the literature. Historical reflection is usually limited to indicating that the civil code entering into force on 1 January 1965 and, on the same day, the repeal of the pre-war commercial code from 1934 formally ended the era of Polish private law’s duality — the coexistence of two equal branches of law: civil law, regulating common relations, and commercial law, regulating economic relations. However, it was the last symbolic chord in the history of commercial law during the communist period. In fact, it had been extinguished several years earlier and replaced by a socialist substitute in the form of economic law, intended to regulate the centrally planned, socialist trading, in which there was no space for individual economic activity. The article discusses the mechanism of dismantling commercial law in the political and economical order of the totalitarian state, which Poland became after the Second World War. This mechanism was implemented not on the normative level, by repealing the norms of commercial law, but on the factual one, by eliminating — through administrative, fiscal, and penal pressure methods — addressees of commercial law (already existing and potential entrepreneurs) and taking them away, e.g. by nationalizing the most essential components of their enterprises. In this way, the necessary (personal and property) background of commercial law was destroyed, making its norms irrelevant. Thus, commercial law was condemned to a dozen or so years of non-existence and oblivion before the legislator decided to make a formal decision, which was to repeal most provisions of the commercial code. Only those regulations remained in force that were needed by the communist authorities, e.g. to conduct foreign trade. The effects of several-decades-long systemic non-existence of commercial law are still noticeable today. Despite the systemic transformation in 1989 and the return of the Polish economy to free market rules, Polish commercial law — relegated to the role of a specialized discipline of civil law and formally distinguished only for research and teaching activities — has not yet regained its rank as an independent branch of private law.

Economic and legal methodology of regulation of economic relations: no alternative phenomenon

The article is devoted to the problem of a legally secured attempt to repeal the Commercial Code of Ukraine and thus undermine the legal economic order, exaggerating the importance of certain civil structures of property regulation for the economy. In this regard, the article attempts to present a range of arguments in favor of comprehensive, organic and effective regulation of economic market relations, as well as in favor of effective legal support for the implementation of the state's own economic policy which is economic and legal regulation. Hypothetically, the abolition of the Commercial Code of Ukraine cannot be equated with the abolition of only certain forms of property rights and certain organizational and legal forms of economic organizations. Such an action will lead to the undermining of the entire legal economic order by the universal basic algorithm of which the Commercial Code of Ukraine serves. After all, only it formed the types of economic relations, types of economic activity - commercial and non-commercial management, economic policy and legal principles of its implementation, state regulation of economic activity and a certain classification of its main legal means of influence, the system of economic entities, which provides ample opportunities choose a specific organizational and legal form from a wide range of options, features of the legal status of state and municipal enterprises - the basis of special legal regimes of the state and municipal sectors of the national economy and many other socially significant aspects. Accordingly, the article raises the question of the economic effect of the introduction of the proposed bill, which should be taken into account and proposed for discussion, as its destructive potential is obvious. The article also draws attention to the need for criminological examination of this civil bill, one of the large-scale results of which should be the transfer of ownership from the state and local communities to the ownership of legal entities - companies to the relevant public property

A Novel Improved Coupled Dynamic Solid Boundary Treatment for 2D Fluid Sloshing Simulation

In order to achieve stable and accurate sloshing simulations with complex geometries using Smoothed Particle Hydrodynamic (SPH) method, a novel improved coupled dynamic solid boundary treatment (SBT) is proposed in this study. Comparing with the previous SBT algorithms, the new SBT algorithm not only can reduce numerical dissipation, but also can greatly improve the ability to prevent fluid particles penetration and to expand the application to model unidirectional deformable boundary. Besides the new SBT algorithm, a number of modified algorithms for correcting density field and position shifting are applied to the new SPH scheme for improving numerical stability and minimizing numerical dissipation in sloshing simulations. Numerical results for three sloshing cases in tanks with different geometries are investigated in this study. In the analysis of the wave elevation and the pressure on the tank, the SPH simulation with the new SBT algorithm shows a good agreement with the experiment and the simulations using the commercial code STAR-CCM+. Especially, the sloshing case in the tank with deformable bottom demonstrates the robustness of the new boundary method.

Impacts of Double V-Rings in the Heat Exchanger Duct on Heat Transfer and Flow Behaviors: A Numerical Study

The impacts of the double V-rings (DVR) in the heat exchanger duct (HED) on heat transfer and flow structures are numerically analyzed. The general configuration of the DVR is called “type I,” while the discrete DVR can be split into two structures, which are called “types II and III.” The influences of the DVR sizes, DVR types and flow directions on heat transfer rate, friction loss, and thermohydraulic performance are considered. The Reynolds numbers in the range around 100–2000 (laminar regime at the entrance condition) are selected for the present investigation. The numerical problem of the HED installed with the DVR is solved with the finite volume method (a commercial code). The flow structure, heat transfer mechanism, and performance analysis in the HED that fitted the DVR are reported. The flow and heat transfer profiles in the HED fitted with the DVR are an important knowledge to develop the thermohydraulic performance of compact heat exchangers. As the numerical results, it is seen that the heat transfer ability of the tested duct improves around 1.05–16.62 times upper than the smooth duct. Additionally, the greatest value of the thermal enhancement factor in the HED fitted with the DVR is seen to be around 4.17 at a/H = 0.025, b/H = 0.10, Re = 2000, and V-upstream direction for the type I.

ADEQUATE ASSURANCE OF PERFORMANCE UNDER THE UN CONVENTION ON CONTRACTS FOR THE INTERNATIONAL SALE OF GOODS AND THE UNIFORM COMMERCIAL CODE

This article compares and contrasts the doctrine of adequate assurance of performance under the US Uniform Commercial Code (the UCC) and the UN Convention on Contracts for the International Sale of Goods (the CISG). The article argues that, in the context of the CISG, the mechanism of adequate assurance found in the UCC is a faux ami. Despite some similarities, the doctrine of adequate assurance regulated in the CISG is distinct and serves different functions to its UCC counterpart.

A Rationalised CFD Design Methodology for Turgo Turbines to Enable Local Manufacture in the Global South

In the Global South, pico- and micro-hydropower turbines are often made by local workshops. Despite several advantageous features, e.g., a high power density and capacity to handle silt, there is no commonly available Turgo turbine design appropriate for local manufacture. Technological developments including the internet, CAD, and additive manufacturing increase the opportunity to precisely transfer designs around the world. Consequently, design improvements can be shared digitally and used by manufacturers in their local context. In this paper, a rationalised CFD approach was used to guide simple design changes that improve the efficiency of a Turgo turbine blade. The typical manufacturing capacity of the micro-hydropower industry in Nepal was used to rationalise the variation of potential design changes. Using the geometry and operational parameters from an existing design as a benchmark, a two-blade, homogenous, multiphase model was developed and run using the commercial code ANSYS CFX. Initially, it was identified that the jet aim position had a significant effect on the efficiency. A design of experiments’ approach and subsequent analysis of numerical and visual results were used to make design changes that resulted in an improvement in efficiency from 69% to 81%. The design changes maintained the simple profile of the blade, ensuring that the resulting design was appropriate for manufacture in a local workshop.

PAST AND PRESENT OF THE ULTRA-VIRES PRINCIPLE IN TURKISH COMPANIES LAW

Abolished Commercial Code No. 6762 art. 137 limited the entitlement of commercial companies to the “subject of activity” included in the company's articles of association. Transactions exceeding the scope of operation written in the company's articles of association were deemed to be ultra vires transactions and were deemed null and void. Since the transactions that were deemed null and void were not available in the legal world, it was not possible to make them valid again. Because, a legal transaction that does not exist is invalid from the very beginning; even if the interests of all parties require it, it is not possible to validate the transaction with approval or authorization. Therefore, since transactions outside the scope of business of commercial companies were also considered null and void, there was no approval or ratification procedure that could make them valid. The only way to carry out the aforementioned transaction in a valid manner was to change the articles of association, regulate the company's field of activity to include the aforementioned transaction, and re-do the transaction from the beginning. In the Turkish Commercial Code no. 6102 art. 125 provision emphasized that commercial companies have legal personality, as in article 137 of the abolished Commercial Code no. 6762. However, unlike the abolished one, by eliminating the ultra vires principle, which is a limit to the competence of commercial companies. It has been widely accepted in the meaning of Turkish Civil Code art. 48. This issue was also included in the Turkish Commercial Code no:6102 art. 125 justification, and it was stated that the ultravires principle was abolished. Therefore, it is understood that the ultravires principle was abandoned as a result of the conscious choice of the Lawgiver. The subject of business is no longer a limiting element of the legal capacity of commercial companies. Despite this, the subject of business still maintains its importance for trading companies. Turkish Commercial Code no:6102 art. 213, which regulates the mandatory elements of the articles of association of commercial companies, in the provisions of 339 and 5 76, the subject of activity continues to maintain its place as a mandatory element that should be included in the articles of association. In the aforementioned provisions, among the mandatory elements to be included in the articles of association, as a common expression in the aforementioned company types, the phrase "business subject in a specified and defined manner" is used. The subject of operation is also in the Turkish Commercial Code no. 6102 art. 233 and in the provisions of art. 371, it remains as a factor limiting the representation authority of those authorized to represent the company. When these provisions are evaluated, it is understood that although the ultra vires principle has been abandoned in terms of the competence of commercial companies, the principle continues to be preserved in terms of representation. In the study, the provisions of abolished Commercial Code no:6762 art. 137, which limits the license of commercial companies to the subject of activity and art. 128, which defines the license in the broadest sense, were determined as the starting point, and the provisions regulating the authority of representation of commercial companies were examined. Thus, the effects of the ultra vires principle on the competence and representation of commercial companies have been comparatively examined within the framework of the abolished Commercial Code No. 6762 and the current Turkish Commercial Code No. 6102.