This paper investigate a sensorless speed control of a separately excited dc motor fed from a buck type dc-dc converter. The control system is designed in digital technique by using a two dimension look-up table. The performance of the drive system was evaluated by digital simulation using Simulink toolbox of Matlab.
Internal control is system,defined and implemented under its responsibility , which aims to ensure that; laws and regulations are complied with; the instructions and directional guidelines fixed by Executive Management or the Management Borad are applied; the company internal processes are functioning correctlly , particularly those implicating the security of its assets; Financial Information is reliable; and generally contributes to the control over its activities , to the efficiency of its operation and to the efficient utilisation of its Resources. By helping to anticipate and control the risks involved in not meeting the objectives the company has set for itself, the internal control system plays akey role in conducting & monito
... Show MoreT-joints are common structures encountered in the assemblage of many industrial applications due to their advantages. However, joining these structures when using Friction Stir Welding (FSW) could be prone to defects that cause severe consequences like loss of strength and fracture. The current paper implements an experimental procedure to assess the effect of geometrical tool shape on void formation in friction stir welded AA 6061-T6 T-joint configuration. Taguchi optimization method was put into service to minimize the number of experiments and fulfil the goal of discovering the optimal FSW parameters that allow the manufacturing of such configurations with high mechanical properties. X-ray radiography and micrograph images were u
... Show MorePolitical terminology differs from any other type of terminology not only in the presence of political terminology, but also in content, structure, functions and the recipient who perceives it. Taking this into account, it is inappropriate to consider the semantic difficulties of translating Russian-language political terms solely at the semantic level. In our opinion, it is inextricably linked with the lexical, syntactic and grammatical levels. If we combine all 4 levels, then the following translation techniques can be distinguished: lexical borrowing (transcription / transliteration, tracing); modulation; generalization / concretization; omission / addition; descriptive translation; conversion [Komissarov 2013]. One of the most
... Show MoreThis paper tackles methods of teaching conversation in Russian to students speaking Arabic. It analyses the differences between the two languages, as well as the difficulties and major errors faced by Arabic speakers studying Russian. Particularly, it looks at the difficulty of transforming spoken language. Finally, the paper suggests ways for teaching spoken language and treating the reasons behind making errors.
Аннотация
Данная статья рассматривает методы преподавания говорения на русском языке для носителей арабского яз
... Show MoreIncremental Sheet Metal Forming (ISMF) is a modern sheet metal forming technology which offers the possibility of manufacturing 3D complex parts of thin sheet metals using the CNC milling machine. The surface quality is a very important aspect in any manufacturing process. Therefore, this study focuses on the resultant residual stresses by forming parameters, namely; (tool shape, step over, feed rate, and slope angle) using Taguchi method for the products formed by single point incremental forming process (SPIF). For evaluating the surface quality, practical experiments to produce pyramid like shape have been implemented on aluminum sheets (AA1050) for thickness (0.9) mm. Three types of tool shape used in this work, the spherical tool ga
... Show MoreThe current study was designed to investigate the alterations in the ultrastructure of orgenelles and cellular activity of exocrine pancreatic acini of experimentally induced-diabetic rats and to assess the usefulness of herbal combination supplementation in improving the ultrastructure and cellular activity of exocrine pancreas. The number of albino male rats used were 24 which divided into equally 4 groups; group I: control group, group II: alloxan-induced diabetes mellitus (single intraperitoneal dose of alloxan 120 mg/kg for 3 days), group III: herbal combination treatment composed from the extracts of fenugreek seeds (Trigonella foenum-graecum), black cumin (Nigella sativa) seeds, rhizomes
... Show MoreThe results show the inability to apply the Taylor rule within inflation and GDP Gaps because the monetary behave is elated from the Iraqi economy.
When applying the Taylor rule to exchange rate with the inflation and the output gap, the results do not match the nominal price announced by the central thing, which proves the lack of commitment by the Central Bank by using the Taylor rule, whether short-run interest rate or exchange rate (Nominal Anchor), so it did not stay to the Iraqi Central Bank only using the principle of Taylor with the expected inflation rate below the level of output (Macro activity) for the separation of monetary behavior from the real one o
... Show MoreIn this study, the effects of different loading doses of cerium in the prepared NaY zeolite from Iraqi kaolin were investigated. Al-Duara refinery atmospheric residue fluid catalytic cracking was selected as palpation reaction for testing the catalytic activity of cerium loading NaY zeolite. The insertion of cerium in NaY zeolites has been synthesized by simple ion exchange methods. Three samples of modified zeolite Y have been obtained by replacing the sodium ions in the original sample with cerium and the weight percent added are 0.35, 0.64, and 1.06 respectively. The effects of cerium loading to zeolite Y in different weight percent on the cracking catalysts were studied by employing a laboratory fluidized
... Show MoreStick- slip is the continuous stopping& release of the Bit/BHA due to the irregular down-hole rotation prompted by the existing relationship between the friction torque and the torque applied from the surface to free the bit.
Friction coefficient between BHA and wellbore is the main player of stick slip amount, which can be mitigated by support a good lubricators as additives in drilling mud.
Mathematical (or empirical) solves should be done through adjusting all parameters which supposed to reduce stick- slip as low as possible using different models, one of the main parameters is drilling mud. As per Nanoparticles drilling fluid is a new technology that offers high performance
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