This paper deals with finding an approximate solution to the index-2 time-varying linear differential algebraic control system based on the theory of variational formulation. The solution of index-2 time-varying differential algebraic equations (DAEs) is the critical point of the equivalent variational formulation. In addition, the variational problem is transformed from the indirect into direct method by using a generalized Ritz bases approach. The approximate solution is found by solving an explicit linear algebraic equation, which makes the proposed technique reliable and efficient for many physical problems. From the numerical results, it can be implied that very good efficiency, accuracy, and simplicity of the pre

In most recent studies, long-term retention after orthodontic treatment has been hypothesized that may be necessary to maintain the stability of the dentition and avoid post-treatment changes. The bonded fixed retainer is characterized by its clinical effectiveness, patient acceptance, and lack of patient complaints as compared with a removable retainer. An electronic database (such as PubMed, PubMed Central, Web of Science, Science Direct, Cochrane Library, Scopus, and ResearchGate) has been collected using specific keywords. Of the 152 articles, only randomized clinical trials that investigated different types of fixed retainers or compared fixed with removable retainers were illustrated in tables and included in this review. The

The purpose of this paper is to introduce and study the concepts of fuzzy generalized open sets, fuzzy generalized closed sets, generalized continuous fuzzy proper functions and prove results about these concepts.

The construction project is a very complicated work by its nature and requires specialized knowledge to lead it to success. The construction project is complicated socially, technically and economically in its planning, management and implementation aspects due to the fact that it has many variables and multiple stakeholders in addition to being affected by the surrounding environment. Successful projects depend on three fundamental points which are cost-time, performance and specifications. The project stakeholder's objective to achieve best specifications and the cost-time frame stipulated in the contract.

The question is, was the optimum implementation accomplished? The provision for the success of the project

The propagation of laser beam in the underdense deuterium plasma has been studied via computer simulation using the fluid model. An appropriate computer code “HEATER” has been modified and is used for this purpose. The propagation is taken to be in a cylindrical symmetric medium. Different laser wavelengths (1 = 10.6 m, 2 = 1.06 m, and 3 = 0.53 m) with a Gaussian pulse type and 15 ns pulse widths have been considered. Absorption energy and laser flux have been calculated for different plasma and laser parameters. The absorbed laser energy showed maximum for  = 0.53 m. This high absorbitivity was inferred to the effect of the pondermotive force.

 The present study introduces description of a new species of class Ostracoda genus Hemicypris Sars, 1903. External morphological characters particularly shape, size and structure of left and right valves of carapace and body appendages were discussed and illustrated. Locality and date of collection were given.

The reduction to pole of the aeromagnetic map of the western desert of Iraq has been used to outline the main basement structural features. Three selected magnetic anomalies are used to determine the depths of their magnetic sources. The estimated depths are obtained by using slope half slope method and have been corrected through the application of a published nomogram. These depths are compared with previous published depth values which provide a new look at the basement of the western desert in addition to the thickness map of the Paleozoic formations. The results shed light on the important of the great depths of the basement structures and in turn the sedimentary cover to be considered for future hydrocarbon exploration

The Gullfaks field was discovered in 1978 in the Tampen area of the North Sea and it is one of the largest Norwegian oil fields located in Block 34/10 along the western flank of the Viking Graben in the northern North Sea. The Gullfaks field came on stream in 1986 and reached a peak of production in 2001. After some years, a decrease in production was noticed due to the decrease in pressure in the well. The goal of this paper is to improve the production of a well located in Gullfaks field by injecting CO₂ through coiled tubing. The use of the CO₂ injection method is due to the fact that it is a greenhouse gas, and its production in the atmosphere contributes to global warming. It is important to reduce its emission

This study examined the imperative construction: the command, the interrogative, the prohibition, the call, and the wish. In the Diwan of Al-Shamakh bin Dirar; where the poetic verses were monitored in each of the topics of the student's creation, and the rhetorical meanings that he came out with. What is new in this study is that it is the first to study the demanded composition in the poetry of a glorious poet, Al-Shammakh bin Dirar Al-Dhubyani. As his poetry did not receive such a study, it sought to employ what was written by rhetoric scholars, in an attempt to explore the demanded composition in the poetry of Al-Shamakh. The study adopted the descriptive analytical approach, which is based on counting the number of times the poet us