162 research outputs found

    Seismic response evaluation of RC tower connected to short rigid buildings.

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    In urban construction with the presence of tall buildings adjacent to short buildings, civil engineers have tried to connect low-rise rigid buildings to tall buildings in order to enhance the rigidity of the towers and decrease seismic response induced by earthquake excitation. From recent developments in earthquake energy dissipation systems, the application of viscous dampers for coupling of parallel and adjacent buildings to reduce earthquake effect has been considered by civil engineers, and many investigations have been conducted. In the present study an attempt has been made to evaluate the effect of connecting reinforced concrete towers to short rigid building through viscous damper devices. For this purpose, a 10-story RC tower connected to two short RC buildings by viscous damper was modeled and analyzed under Elcentro (1940) earthquake record excitation by using the finite element technique. In addition, the effect of various viscous damper damping coefficients on seismic response of the tower was evaluated by analyzing the aforementioned tower with various damper damping coefficient to the short building. The results showed improvement of seismic response of the tall building which was supported by short RC buildings through viscous damper device during earthquake. Moreover by increasing damper damping coefficient response of the tower structure the displacement was effectively reduced

    Strength correlation between individual block, prism and basic wall panel for load bearing interlocking mortarless hollow block masonry

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    This paper focuses on the development of the compressive strength correlation between the individual block, prism and basic wall panel for load bearing interlocking hollow mortarless blocks. The interlocking blocks used were developed by the Housing Research Centre at Universiti Putra Malaysia. The blocks consisted of stretcher, corner and half blocks. Forty individual block units from each type were tested under compression. The compressive strengths of 10 prisms assembled by stacking two stretcher blocks and two half blocks were evaluated. In addition, four wall panels each having a dimension of 1.2 × 1.2 m were assembled and tested under axial compressive loads. The results obtained were compared with those found in bonded masonry. BS 5628 Part 1:1992 were used for predicting of the compressive capacity of the bonded masonry. The interlocking mechanism, crack patterns and failure mechanism of the interlocking masonry specimens are highlighted and discussed. The correlations between the compressive strength of the interlocking masonry individual block (fcb), prism (fcp) and standard panel (fcw) found in this analysis were fcp = 0.47fcb, fcw = 0.83fcp and fcw = 0.39fcb. Test results indicate that the interlocking mechanism and strength of the block in the load-bearing wall was satisfactory

    Peningkatan Hasil Belajar Siswa pada Pembelajaran IPA Menggunakan Metode Demonstrasi di Kelas III

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    The formulation of a problem for this study is whether there is an increase in student learning outcomes using a method demonstration on learning of Natural Sciences of objects and nature in Class III Elementary School No. 21 Muan?. The purpose this study was to describe the improvement of student learning outcomes in learning by using a method demonstration on learning of Natural Sciences and the nature of the objects in the class III Elementary School No. 21 Muan. Research results obtained is the ability of teachers in preparing lesson plans in the first cycle of 2.58 and 3.77 for the second cycle. The observation of the teacher 's ability to implement the learning in the first cycle of 3.06 and 3.88 for the second cycle. Student learning outcomes in material objects and nature is the first cycle of 48.18, increased in the second cycle of 86.36. This means learning by demonstration method can improve the learning outcomes of students of class III SDN 21 Muan

    Peningkatan Keterampilan Menulis Menggunakan Media Gambar Komik Siswa SMA Santo Fransiskus Asisi Pontianak

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    This study aims to increase the students write a narrative paragraph using drawing of comics. This research is motivated poor writing skills of high school students of Santo Fransiskus Asisi Pontianak. Values ​​obtained student does not reach KKM 75 set by the school. The method used in this research is descriptive and qualitative forms of research. The data source of this research is the teacher, students of class XC and related documents. The data in this study is the RPP, the observation of teachers and value to write a paragraph of narrative. The technique used in this research is measurement techniques, observation and documentary studies. The average value of student learning outcomes before implementation action is 66.94. In the first cycle using media images of comics, the learning outcomes of students has increased by an average of 72. Furthermore, the value of the second cycle increased again to an average of 7.571. Based on these results an increase in the value of students in writing a narrative paragraph using media images of comics

    Development of an innovative interlocking load bearing hollow block system in Malaysia

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    The paper describes the development of a new interlocking hollow block masonry system appropriate for load bearing masonry wall construction. The developed system is an alternative to the traditional bonded masonry system where the blocks in the wall are integrated through mortar layers. In the system developed, the blocks are stacked on one another and three-dimensional interlocking protrusions are provided in the blocks to integrate the blocks into walls. This paper includes the background, concept and procedure used to develop an efficient interlocking hollow block system, which may be used in the construction of load bearing walls. Twenty-one different block models have been investigated and analysed with respect to weight, bearing and shear areas, shape, ease of production, ability to accommodate vertical and horizontal reinforcing stabilising ties and efficiency of the interlocking mechanism under imposed loads. The blocks, developed under the name ‘PUTRA BLOCK’, have been used to construct a single-storey house at Universiti Putra Malaysia. The system provides a fast, easy and an accurate building system

    Temporal Diversity of the Nymphalids in Kubah National Park, Sarawak, Malaysia

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    Unique microhabitats caused temporal-space separation which also indicates that animals are constrained in their flexibility to adapt to the environment. Arthropods was recorded to be temporally patchy within seasons, and in the tropical region, rainfall fluctuations are somewhat varied although only in a considerable range. These minute variations are still however observed to provide unique microhabitats to the insects and thus knowledge on the effects of the rainfall is still much required. To determine any distribution patterns of the nymphalid butterflies, bait-trapping was conducted from May to November 2009 in Kubah National Park, Sarawak. Even though there was a linear relationship between the total rainfall and numbers of nymphalids, there was no significant correlation between the nymphalids and rainfall distribution (p-value > 0.05). Rainfall in the preceded month could increase the overall nymphalids abundance which coincides with the leaf-flushing peak, suitably for the larval stages. In contrast, heavy rainfall during the data collection could also lead to larval mortality. Rainfall parameter and possibly many more environmental variables are important, as the distribution pattern of the nymphalids are strongly related to the environment

    Roles of Heterogeneous Habitat for Conservation of Nymphalidae in Sarawak (East Malaysia)

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    Species diversity characterises an area or a targeted habitat and provides information on the species assemblages, which is a primary reflection of habitat diversity. It incorporates both species richness and abundance and may rely on factors, such as host-plant availability and food resources. Kubah National Park is a lowland mixed dipterocarp forest, and uniquely offers various vegetation types, which includes heath and submontane forests. In the present study, four contrasting forest habitats were selected along forest trails, namely, primary forests, secondary forests, heath forests and forest edges. Forty baited traps were used within a six-months of sampling period. The highest abundance was recorded at the heath forest while the least was at the secondary forest. However, there was no significant difference in terms of species abundance between forest habitats for subfamilies, as well as for the 15 most abundant nymphalid species sampled, except for Mycalesis mnasicles. This satyrine was regarded as being able to differentiate habitat, apart from sensitive to canopy openings. Secondary forest provides a heterogeneous habitat for nymphalids, and thus highest diversity was observed here. This study implies that habitat association of the family is crucial, as it will provide information for both species inventory as well as the fluctuation patterns of the nymphalids diversity. Similar study is suggested to be carried out in the future, which incorporates more than one habitat types and in a more extensive period

    Finite element modeling of crack propagation in RC beam by using energy approach

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    In present study interface element with nonlinear spring is used to simulate cohesive zone model (CZM) in reinforced concrete beam in Mod I of crack propagation. Modified crack closure integral method is implemented to model propagation of fracture process zone (FPZ). This model, energy can calculate energy release rate in concrete by using new method in energy approach. Energy dissipation rate by steel bars is obtained to affect on crack propagation criterion to implement in finite element method. The results show that proposed model does not depend on mesh size

    Protein and amino acid composition of different quinoa (Chenopodium quinoa willd) cultivars grown under field conditions in Ethiopia, Kenya, Uganda, and Zambia

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    Protein-energy malnutrition (PEM) remains a public health concern in most developing nations. In Africa, PEM can be attributed to monotonous diets based on cereals, roots, and tubers, with little or no protein of animal origin. Diversifying cropping systems to include protein dense pseudo-cereals such as Quinoa (Chenopodium quinoa Willd.) could help provide more protein in the diet of vulnerable populations. Quinoa is a crop with potential for biodiversification because it has a high nutritional value; however, it is underutilized in Africa, and information about the nutritional quality of the grain grown in contrasting environments is limited. Within the framework of FAO’s commemoration of 2013 as the ‘The International Year of the Quinoa’ (IYQ), a Technical Cooperation Programme (TCP) project was developed with some African countries to assess the capacity of quinoa to adapt to different agro-ecological regions and the nutritional quality of the resulting grain. For this study, we evaluated the protein content and amino acidprofile of three genotypes of quinoa that had been grown under diverse altitudes, soil, and climate conditions in Ethiopia, Kenya, Uganda, and Zambia. The mean protein content (g/100g) of Kancolla, Titicaca and BBR varieties grown in Africa ranged from 14.33 ±0.20 to 17.61 ±0.55, 14.23 ±0.25 to 16.65 ±0.55, and 13.13 ±0.2 to 16.23 ±0.49, respectively. On the other hand, the protein content (g/100g) of Kancolla, Titicaca, and BBR seeds grown in Peru was 13.80 ±0.10, 17.43 ±0.31, and 17.07 ±0.11, respectively. The Kancolla variety [grown in Ethiopia and Kenya] had a significantly higher protein content than that obtained from Peru [P < 0.001]. Regarding the profile of essential amino acids, Quinoa is essentially richer in methionine than most cereals. Levels of methionine were lower in the seeds grown in Africa compared to those from Peru [P < 0.001]. In terms of environmental influences, the protein content was relatively higher in quinoa seeds grown in high-altitude areas, where soils have a low pH and high nitrogen content. We conclude that Quinoa can be introduced to Africa, especially to high altitudes and warm regions where the soil has a low pH and high nitrogen content. Thecrop would be ideal for diversifying local diets. Key words: Africa, Agro-ecology, Chenopodium quinoa, protein, amino acid content, biodiversity, diet
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