Evaluating Impact Resistance of Aluminum 6061-T651 Plate using Smoothed Particle Hydrodynamics Method

Performing various experimental, theoretical, and numerical investigations for better understanding of behavioural characteristics of metals under impact loading is of primary importance. In this paper, application of smoothed particle hydrodynamics (SPH) method in impact mechanics is discussed and effective parameters on impact strength of an aluminum plate are investigated. To evaluate the accuracy of smoothed particle hydrodynamics method for simulating impact, Recht and Ipson model is first provided thoroughly for both Rosenberg analytical model and smoothed particle hydrodynamics method, and then plots of initial velocity-residual velocity and initial velocity-absorbed energy for target of aluminum 6061-T651 are presented. The derived information and simulation results expresses that the maximum error percentage of smoothed particle hydrodynamics method in compared with Rosenberg analytical model is within an acceptable range. Therefore, the results of smoothed particle hydrodynamics method verify the Rosenberg analytical model with high accuracy. Results reveal that higher initial impact velocity decreases the time of projectile penetration, and so penetration depth and length as well as the local damage rate of plate increases

A critical analysis of Iranian buy-back transactions in the context of international petroleum contractual systems

This research critically examines the Iranian petroleum contractual system from its birth to the present, and considers its future evolution. Initially, it reviews the development of oil contracts, from the early concessions until the annulment of all obligations as the result of two major events; the Nationalisation Movement and the Islamic Revolution of 1979. The constant policy struggle between the need for foreign funding and technology in the oil industry on one hand and the desire to avoid foreign exploitation on the other is analysed in terms of its impact on the current stance towards foreign investment and the formation of the present contractual model. The embodiment of this complex struggle is the buy-back contractual model that has found widespread use in Iranian petroleum transactions since 1989. This scheme is best described as a short term risk service agreement, whereby the foreign investor provides the funds for petroleum Exploration and Exploitation in exchange for a pre-defined, volume-based quantum of remuneration in case of successful production that serves to both compensate and reward the contractor. The adoption of this system is a compromise solution between the need for foreign capital, expertise and services on one hand and wariness of foreign involvement in natural resources on the other, as evident from the Constitutional limitations discussed later in this study. A crucial element of this arrangement is the transfer of the field's operation back to the National Iranian Oil Company following conclusion of the contract; a legal step which distinguishes buyback contracts from alternative systems that may be contrary to the Constitution. Both the structure and the comparative advantages of the buy-back have been discussed at length, with particular attention to the enabling laws and their flaws. Detailed analysis is devoted to the other major international contractual models, including a comparative evaluation of these alternative systems and their suitability for the Iranian oil industry, given the limitations of the Constitution. The buy-back system is scrutinised from both the foreign and the domestic perspective and the issue of whether revision of its terms or an alternative model would be more appropriate considering the grievances of all the participants. The extent to which the Iranian oil industry was and will be affected by increasing international pressure, particularly as the result of US Sanctions, was considered extensively. It appears that Iran is not yielding to such pressure but rather orienting itself towards alternative allies and continuing to sign contracts based on the buy-back. Particularly stringent examination of specific terms and conditions of buy-back has been conducted through a review of various oil fields so as to determine if the model's perceived flaws manifest themselves in reality. The finding of the analysis described above is that the buy-back contract as implemented in Iran is flawed on basis of the limiting nature of its provisions rather than by virtue of the model itself. A number of provisions, such as maximum contract length and method of remuneration, which are needlessly restrictive, are highlighted and the importance of modernising them in light of the current economic environment is noted. Based on the facts and findings throughout the study, the conclusion arises that evolutionary rather than revolutionary reforms are both required and viable, without undermining the current legal framework. Lastly, the study yields a practical recommendation as to the reforms most crucial to the preservation of Iran's attractiveness to investors, in light of the current economic, political and legal environment

Reducing Peak Current and Energy Dissipation in Hybrid HVDC CBs Using Disconnector Voltage Control

This work was supported by the European Union’s Horizon 2020 research and innovation program under grant No. 691714.Peer reviewedPostprin

Identifying Requirements for Vocational Information and Communication Technology Curricula in Afghanistan

This paper examines how ICT (Information & Communication Technology) is taught in vocational institutions in developing countries. If the world is truly flat, ICT education in Afghanistan and Namibia would. In the highly-standardized domain of ICT, the vocational education curricula should be similar to what you might find in Estonia and other developed nations. We focus specifically on what ICT with the consideration to the labour market needs, is the focus of this study. Such comparisons are demanding, because of the multiplicity of educational systems. Yet, there are some lessons we can learn from the international experience. CurrentICT qualification standards in Europe. The paper explores also current challenges in Afghanistan’s ICT Technical Vocational Education curricula, technical vocational institutes which influence the delivery of teaching and learning in ICT domain, as well as potential mismatch between the supply and demand of ICT-skilled workforce in Afghanistan

Detection of infectious bronchitis virus serotypes by reverse transcription polymerase chain reaction in broiler chickens

Infectious bronchitis (IB) is a highly contagious disease of the respiratory and urogenital tract of chickens, caused by infectious bronchitis virus (IBV), a member of the family Coronaviridae. The disease is common throughout the world where chickens are produced commercially. PCR on reverse transcribed RNA is a potent technique for the detection of IBV. In comparison with classical detection methods, PCR-based techniques are both sensitive and fast. Dozens of serotypes and genotypes of IBV have been detected, and many more will surely be reported in future. This research was conducted to identify the infectious bronchitis virus with group specific primers of avian Coronaviruses in Zabol, southeast of Iran. Tracheal swabs were collected from eleven commercial broiler flocks and these swabs were used for RNA extraction. General primers included XCE2+ and XCE2- that amplify all IBV serotypes were used. Primers MCE1+, BCE1+ and DCE1+ was used to amplifying the specific nucleotide sequence of Massachusetts, 4/91 and D274 serotypes, respectively. The results of this study showed that 36.36% of the sampled flocks were positive to IBV by RT-PCR. Moreover, the Massachusetts was the identified serotype of infectious bronchitis virus. The results provide the first molecular evidence for the presence of infectious bronchitis virus and Massachusetts serotype in Zabol. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/2193-1801-2-36) contains supplementary material, which is available to authorized users

Bidirectional Hybrid HVDC CB with a single HV Valve

Funding Information: This work was supported by the European Union’s Horizon 2020 Research and Innovation Program under Grant 691714. Paper no. TPWRD-01506-2018.Peer reviewedPostprin

Using mathematical methods for analyzing financial statements

Increasing in the financing turnover is one of the most important aims of economical organizations and companies management. In fact, by studying the available data and statistics and digits from their financial accounts, these organizations try to get a figure of their organizational production (which is obtained with the use of energy and lots of money) and with analyzing the present condition and considering the strategic and long term organizational aims and also awareness from their strength and weakness points and proper inductions, can be caused to optimal activities and acceptable exploitation from the financing. In this regard, analysis of cost- effective financial accounts can create the necessary ground for recognition of difficulties ahead of the organization and be a way for solving many problems for the future and look into the future decisions. Even though the analysis of financial relationship has been an important issue in so many years, the limitation of the analysis with regarding one factor on the top and the other factor in the bottom, would be evaluated only one dimension and therefore by considering financial ratio in separate form, it usually cannot be a good guide for financers and companies’ managers. To solve this problem, in this article, it has been suggested that we initially analyze the experts and specialists in industries and use the analytic processes because of importance in different financial ratios in comparison to each other. Then combine the ratios with regard to 4 sets of the ratios as a head of each company. Importance and usability of each company in comparison to the other companies have been measured. The mark for each company’s usability with different data mentioned which can be a suitable guide for the financer as well as the managers of the company to notice the primacy of the financing and orientation of the company was determined with more care. The results of the research indicated that in cash flow ratios, speed ratio, and in growth ratios, increase in the salary ratio and in the operational ratios, stock turnover ratio have the highest importance. After using combined indices as received and use of a covering analyzing model, total data of companies insurability mark calculated

Solving Elasto-Static Bounded Problems with a Novel Arbitrary-Shaped Element

A simple method to analysis any arbitrary domain shapes with a single element which based on Decoupled Scaled Boundary Finite Element Method is presented in this paper. The introduced element is based on boundary finite element method which helps to modelling curve and sharp boundaries with acceptable accuracy. Shape functions and mapping functions are similar to Decoupled Scaled Boundary Finite Element Method but locating center origin (LCO) is relocated in this method from corners with direct view to whole domain into shape center and formulation and behavior of the method is developed for the element. The most important advantageous of this technique is ability of solving displacement in domain by solving differential equations which causes more accurate answers in domain.  We also perform well-established numerical tests and show the performance of the new element. Results shown us the accuracy and reliable answers for the introduced element. Also some benchmark examples are solved by this method and answers are compared with correct answers and plotted. High accuracy of answers with low cost of calculations and ability of the method to analysis the curve and sharp boundaries are the most important advantageous of this new element

Using mathematical methods for analyzing financial statements

Increasing in the financing turnover is one of the most important aims of economical organizations and companies management. In fact, by studying the available data and statistics and digits from their financial accounts, these organizations try to get a figure of their organizational production (which is obtained with the use of energy and lots of money) and with analyzing the present condition and considering the strategic and long term organizational aims and also awareness from their strength and weakness points and proper inductions, can be caused to optimal activities and acceptable exploitation from the financing. In this regard, analysis of cost- effective financial accounts can create the necessary ground for recognition of difficulties ahead of the organization and be a way for solving many problems for the future and look into the future decisions. Even though the analysis of financial relationship has been an important issue in so many years, the limitation of the analysis with regarding one factor on the top and the other factor in the bottom, would be evaluated only one dimension and therefore by considering financial ratio in separate form, it usually cannot be a good guide for financers and companies’ managers. To solve this problem, in this article, it has been suggested that we initially analyze the experts and specialists in industries and use the analytic processes because of importance in different financial ratios in comparison to each other. Then combine the ratios with regard to 4 sets of the ratios as a head of each company. Importance and usability of each company in comparison to the other companies have been measured. The mark for each company’s usability with different data mentioned which can be a suitable guide for the financer as well as the managers of the company to notice the primacy of the financing and orientation of the company was determined with more care. The results of the research indicated that in cash flow ratios, speed ratio, and in growth ratios, increase in the salary ratio and in the operational ratios, stock turnover ratio have the highest importance. After using combined indices as received and use of a covering analyzing model, total data of companies insurability mark calculated