3,017 research outputs found

    Masalah-masalah yang dihadapi dan pengaruhnya terhadap pencapaian pembelajaran di Kolej Universiti Teknologi Tun Hussein Onn: satu tinjauan

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    Kajian kes ini adalah bertujuan untuk meninjau masalah-masalah yang dihadapi oleh pelajar-pelajar tahun dua yang mengambil kursus Ijazah Saijana Muda Kejuruteraan Elektrik di KUiTTHO. Masalah-masalah ini adalah yang berkaitan dengan pencapaian pelajar dalam pembelajaran mereka. Seramai 100 orang pelajar terlibat di dalam kajian kes ini. Kajian kes ini meninjau permasalahan bagi dua pencapaian CPA responden yang mewakili 3.0 ke atas dan 3.0 ke bawah. Responden diminta menjawab soal selidik yang diedarkan. Di dalam borang soal selidik, terdapat hanya enam masalah yang ditinjau untuk tujuan kajian kes. Masalah-masalah yang sering dihadapi oleh pelajar adalah masalah kewangan, masalah kesihatan, masalah keluarga, masalah rakan sebaya, masalah pensyarah dan masalah pengurusan masa. Hasil kajian mendapati masalah kewangan adalah merupakan masalah yang paling banyak dihadapi oleh pelajar berbanding dengan masalah-masalah yang lain. Masalah-masalah yang lain tidak memberikan kesan yang ketara kepada pencapaian dalam pembelajaran pelajar-pelajar ini. Beberapa cadangan telah dikemukakan untuk tindakan pihak yang berkenaan untuk meningkatkan lagi prestasi pelajar yang terlibat. Diharapkan dengan adanya kajian kes ini dapat meningkatkan lagi pembelajaran semua pelajar di KUiTTHO amnya

    Flexural behavior of steel fiber reinforced concrete: testing and modelling

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    In this paper the results of tests performed on specimens and structural elements made of steel fiber reinforced concrete are presented. Fiber content ranged from 0 to 60 kg/m3 of concrete. Using the results of the uniaxial compression tests performed under displacement control condition, a stress strain relationship for fiber concrete in compression was derived. Three point bending tests on notched beams were carried out in order to simulate the post cracking behavior and to evaluate the fracture energy. Based on the constitutive relationships derived from the experiments, a layered model for the analysis of steel fiber reinforced concrete cross sections was developed. The model performance and the benefits of fiber reinforcement on thin slabs reinforced with steel bars were assessed by carrying out tests on slab strips. The main results are presented and discussed

    An experiment on the use of disposable plastics as a reinforcement in concrete beams

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    Illustrated here is the concept of reinforced concrete structures by the use of computer simulation and an inexpensive hands-on design experiment. The students in our construction management program use disposable plastic as a reinforcement to demonstrate their understanding of reinforced concrete and prestressed concrete beams. The plastics used for such an experiment vary from plastic bottles to steel reinforced auto tires. This experiment will show the extent to which plastic reinforcement increases the strength of a concrete beam. The procedure of using such throw-away plastics in an experiment to explain the interaction between the reinforcement material and concrete, and a comparison of the test results for using different types of waste plastics are discussed. A computer analysis to simulate the structural response is used to compare the test results and to understand the analytical background of reinforced concrete design. This interaction of using computers to analyze structures and to relate the output results with real experimentation is found to be a very useful method for teaching a math-based analytical subject to our non-engineering students

    Crack mitigation in concrete : superabsorbent polymers as key to success?

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    Cracking is a major concern in building applications. Cracks may arise from shrinkage, freeze/thawing and/or structural stresses, amongst others. Several solutions can be found but superabsorbent polymers (SAPs) seem to be interesting to counteract these problems. At an early age, the absorbed water by the SAPs may be used to mitigate autogenous and plastic shrinkage. The formed macro pores may increase the freeze/thaw resistance. The swelling upon water ingress may seal a crack from intruding fluids and may regain the overall water-tightness. The latter water may promote autogenous healing. The use of superabsorbent polymers is thus very interesting. This review paper summarizes the current research and gives a critical note towards the use of superabsorbent polymers in cementitious materials

    Interval type‑2 fuzzy aggregation operator in decision making and its application

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    Type-2 fuzzy sets (T2FSs) can deal with higher modeling and uncertainties which exist in the real-world application, specifically in the control systems. Particularly the climate changes are always uncertain and thus, the type-2 fuzzy controller is an effective system to handle those situations. Polyhouse is a methodology used to cultivate the plants. It breaks the seasonal hurdle of the formulation and it is also suitable for the conflictive climate conditions. Controlling and directing internal parameters of the polyhouse play an essential role in the growth of the plant. Among those, humidity is an important element when one deals with the growth of the plant in polyhouse. It affects the weather, as well as the global change of the climate and hence, the inner climate of the polyhouse will be disturbed. In this paper, operational laws for triangular interval type-2 fuzzy numbers and derived triangular interval type-2 weighted geometric (TIT2WG) operator with their desired mathematical properties using Dombi triangular norms. Also, humidity control is analyzed using interval type-2 fuzzy controller (IT2FC) with the use of derived aggregation operator which is the aim of the paper. Further stability of the system has been analyzed by applying four different defuzzification methods and the method is recommended which gives a better response

    Internal curing of cement pastes by superabsorbent polymers studied by means of neutron radiography

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    Autogenous shrinkage is a problem in cementitious materials with a low water-to-binder ratio. When the internal relative humidity decreases due to the ongoing hydration reaction and selfdesiccation, autogenous shrinkage takes place if no external or internal water source is present. This may lead to cracking and eventually cause durability problems in constructions. Ideally, the internal relative humidity should be maintained during hydration of the cement paste. Superabsorbent polymers (SAPs) may be used to mitigate autogenous shrinkage. When self-desiccation occurs, these polymers will release their absorbed additional mixing water due to increasing capillary forces to stimulate internal curing. This release of water towards the cementitious matrix and the effect on the cementitious matrix itself can be studied by means of neutron radiography. In this study, thin samples of cement paste were casted between glass plates and the evolution of the internal water amount was studied as a function of time. In specimens without SAPs and a water-to-binder ratio of 0.30, shrinkage was seen. Furthermore, autogenous shrinkage was reduced in cement pastes when using SAPs and an additional entrained water-to-binder ratio of 0.054. The release of water from smaller SAPs (100 μm dry size) seemed to be more promising compared to bigger SAPs (500 μm) with the same absorption properties. The technique of neutron radiography supports the findings of shrinkage tests where SAPs were already proven to be useful. This opens additional insights towards the application of SAPs in the construction area
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