9,211 research outputs found

    Corrosion study of pipeline material for seabed sediment in tropical climate

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    Corrosive environments such as marine sediments can cause corrosion to steel pipelines at any time when certain conditions are met. Seabed sediment could cause severe corrosion damage due to its corrosiveness to the pipelines buried under it. Many consequences could take place in case if there is incident in oil/gas pipelines. Successfully identifying elements of corrosion in marine sediment would enhance the future of steel structure protection and monitoring systems. This article focuses on the behaviour of corrosion rate of steel located near shore environment and the aim is to determine the effect of sediment on corrosion of steel. To investigate that, simulated near shore sediment conditions have been used where the steel coupons buried in sediments which have different characteristics. Weight loss technique has been implemented to determine the weight loss rate of the steel specimens. Based on the results of this study, metal weight loss increases as the duration of exposure to seabed sediment environment become longer. The sea sediment simulated condition has given significant levels of corrosion. Conclusively, the corrosion rate of steel in seabed sediment located in tropical region is complicated and further studies are suggested

    Finite element analysis of protective bicycle helmet & dummy head under dynamic loading

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    Cycling is a good activities particularly for recreation, exercise, and transportation. However, cycling related to the head injury is a significant contributor to hospitalization and death. Previous literatures indicates that the available helmets have less effective in preventing head injuries among cyclists. Moreover, most of the available helmets have been tested for only a few loading conditions. Therefore, the purpose of this study is to use finite element models to evaluate the protective effect of a helmet against various impact velocities. The head and helmet model has been developed using computational software. This study focus on the explicit dynamic analysis which performed in ANSY-WORKBENCH with loading condition in term of various impact velocity impacted on front and side of the head model. The results indicates the differences between the frontal and side simulations. They have been compared to identify the protective effect of the helmet and head

    Design of Thermal Equipment Milling for Fabricating the Tio2 Photocatalysts Coated Grain Polymers

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    Organic waste water treatment can be conducted with technique of photocatalytic. Photocatalytic activity involves factors light intensity and amount of catalyst. In order this process can take place optimally, the catalyst material coating on the surface of the material buffer such as polymer shaped grains can be an alternative method. Setting the temperature and the duration of heating automatically is very efficient in controlling the physical characteristics of the photocatalyst materials. In this experiment, modification done on of the two types of thermal equipment milling namely cylindrical equipment milling equipped with heater and equipment milling based electric oven. The testing process of the thermal equipment milling performed with controlled temperature in the range of 110 ° C and setting the timer to 60 minutes. In testing the thermal characteristics of milling equipment, it takes as long as 220 minutes for each immobilization process using cylindrical milling and 65 minutes when using an electric oven. Setting the temperature and time in the electric oven milling can be performed automatically, which can not be performed using cylindrical milling. Milling equipment based electric oven has also been used in the selection of buffer polymer materials and fabricate TiO2 photocatalysts which tested on photodegradation of organic compound of methylene blue (MB).Penjernihan air limbah organik dapat dilakukan dengan teknik fotokatalisis. Agar aktivitas fotokatalitik yang melibatkan faktor intensitas cahaya dan jumlah katalis dapat berlangsung secara optimal, pelapisan material katalis pada permukaan material penyangga berupa bulir polimer termoplastik dapat menjadi salah satu alternatif. Pengaturan temperatur dan lamanya pemanasan secara otomatis sangat efisien dalam mengendalikan karakteristik fisis material fotokatalis Dalam penelitian ini dilakukan modifikasi terhadap dua jenis peralatan thermal millng, yaitu peralatan milling cylinder yang dilengkapi dengan komponen pemanas dan peralatan miling berbasis oven listrik. Proses pengujian milling dilakukan dengan temperatur terkontrol pada kisaran 110 °C dan pengaturan timer 60 menit. Dalam pengujiankarakteristik termal kedua alat tersebut, dibutuhkan waktu selama 220 menit untuk setiap proses imobilisasi menggunakan milling cylinder dan 65 menit bila menggunakan peralatan berbasis oven listrik. Pengaturan temperatur dan waktu pada alat berbasis oven listrik dapat dilakukan secara otomatis, yang tidak dapat dilakukan menggunak milling cylinder. Peralatan milling berbasis oven listrik ini juga telah digunakan dalam pemilihan polimer penyangga material fotokatalis TiO2 serta pabrikasi fotokatalis TiO2 yang diujikan dalam fotodegradasi senyawa organik metilen biru (MB)

    Penerapan Metode Pembelajaran Aktif Cooperative Script untuk Meningkatkan Prestasi Belajar Siswa pada Pokok Bahasan Struktur Atom di Kelas X Mia SMA Negeri 1 Kepenuhan Kabupaten Rokan Hulu

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    Research on the application of active learning Cooperative Script method has been done in class X of SMAN Kepenuhan Kabupaten Rokan Hulu on the subject of atomic structure. Based on the results of observations conducted by researchers at the SMAN1Kepenuhan Kabupaten Rokan Hulu do known that learning is teacher centered, so that students become less active and negatively affect student achievement. The objective was to determine the increase in student achievement and increase student achievement category. The research form is an experimental research with pretest-posttest design. The sample consisted of two classes, namely class X MIA1 as the experimental group and the class X MIA2 as the control group. The experimental group is the group of students who were treated by applying the active learning of Cooperative Script method, while the control group was treated with information discussion methods. Data analysis technique used is the t-test. The results showed tarithmetic>ttable (2,07 > 1,68) and N-gain of the experimental group is 0,754 which includes the high category. Therefore, it can be concluded that the application for active learning Cooperative Script method can increase student achievement in the subject of anatomic structure in SMAN 1 Kepenuhan Kabupaten Rokan Hulu

    An enhanced segmentation technique for smokers RBC rouleax coin stacking

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    Smoking is one of the major factors of having coin stacking formation of Red Blood Cell or commonly known as RBC that can cause blood clots and can lead to stroke. Smokers tends have thicker, high count, and overlapping of RBC compared to non-smokers. Blood cell detection plays significant part in biomedical field. There are two methods in detection of RBC, manual inspection by medical experts and automated machines. The manual inspection process is detection of blood cells under a microscope that is more prone to human error and time consuming, while automated hardware solutions like automated haematology machines are available, due to high cost it is not widely available to poor and developing countries who have a high statistic of smokers. Smokers have a high tendency of overlapping RBC or commonly known as rouleaux coin stacking cell formation. This study presents an enhanced segmentation technique that can detect the high degree of overlapping RBCs of smokers using digital image processing that can be helpful in the medical field

    Application of a hybrid of least square support vector machine and artificial bee colony for building load forecasting

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    Accurate load forecasting is an important element for proper planning and management of electricity production. Although load forecasting has been an important area of research, methods for accurate load forecasting is still scarce in the literature. This paper presents a study on a hybrid load forecasting method that combines the Least Square Support Vector Machine (LSSVM) and Artificial Bee Colony (ABC) methods for building load forecasting. The performance of the LSSVM-ABC hybrid method was compared to the LSSVM method in building load forecasting problems and the results has shown that the hybrid method is able to substantially improve the load forecasting ability of the LSSVM method

    Metacognitive skills of Malaysian students in non-routine mathematical problem solving

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    Metacognitive skills play an important role in solving mathematical problems. However, there is a lack of empirical studies on the role of metacognitive skills in solving mathematical problems, particularly non-routine ones. Therefore, this study was undertaken to identify students' metacognitive skills and the impact of such skills on non-routine mathematical problem solving. By using a quantitative method, a total of 304 students in Johor Bahru district were involved in the study. A Self-Monitoring Questionnaire (SMQ) and a mathematical test were used in data collection. Data were analysed using descriptive and inferential statistics such as frequency, percentage, mean, the Mann-Whitney U test, and the Kruskal-Wallis H test. Results showed that the level of the students' performance in solving non-routine mathematical problems was very low. There was also a significant difference in the metacognitive skills among students with different performance levels in solving non-routine mathematical problems, and we concluded that these metacognitive skills should be emphasised in this process

    Ionosphere: A Month Campaign over Sipitang and Parit Raja Stations, Malaysia

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    Ionospheric scintillations, which cause significant effects on satellite signals for communication and navigation, often takes place in equatorial region such as Malaysia. However, this disturbance are not fully understand due to few studies performed. This research reports the study and monitoring activity on Total Electron Content (TEC) and ionospheric scintillation in Malaysia using GPS measurements. Approach: One dual-frequency GPS receiver was positioned at the main station in Parit Raja, West Malaysia (1.86° N, 103.8° E) and Sipitang, East Malaysia (5.10° N, 115.56° E) respectively. Dual-frequency GPS data collected during the one-month ionospheric experimental campaign was used for TEC and scintillation computation and analysis. The TEC with 15 sec interval were computed from combined L1 and L2 code-pseudorange and carrier phase measurements. Whereas, the scintillation parameter S4 index was computed as a standard deviation of the received signal power normalized to average signal power every 60 sec on L1. A corrected S4 (without noise effects) was also computed and used in the analysis. Results: It was found that the daily maxima vTEC for Parit Raja (PR) ranged from 38-100 TECU, which is generally higher than those of Sipitang, which ranged from 30-42 TECU. However, a general consistency for both stations can be seen during the 1 month campaign period. Conclusions/Recommendations: In conclusion, these results show good agreement in the existence of the equatorial anomaly observed during moderate solar flux conditions and undisturbed geomagnetic condition. This will contributes to the knowledge of equatorial ionosphere and help in space weather condition. However, to better understand and characterize the ionosphere over Malaysia, more campaigns should be encouraged

    F3TM: flooding factor based trust management framework for secure data transmission in MANETs

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    Due to the absence of infrastructure support, secure data dissemination is a challenging task in scalable mobile ad hoc networks (MANETs) environment. In most of the traditional routing techniques for MANETs, either security has not been taken into account or only one aspect of security concern has been addressed without optimizing the routing performance. This paper proposes Flooding Factor based Framework for Trust Management (F3TM) in MANETs. True flooding approach is utilized to identify attacker nodes based on the calculation of trust value. Route Discovery Algorithm is developed to discover an efficient and secure path for data forwarding using Experimental Grey Wolf algorithm for validating network nodes. Enhanced Multi-Swarm Optimization is used to optimize the identified delivery path. Simulations are carried out in ns2 to assess and compare the performance of F3TM with the state-of-the-art frameworks: CORMAN and PRIME considering the metrics including delay, packet delivery ration, overhead and throughput. The performance assessment attests the reliable security of F3TM compared to the state-of-the-art frameworks
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