338 research outputs found
Settlement reduction of dredged marine soils (DMS) admixed with cement & waste granular materials (WGM): 1-D compressibility study
Dredged marine soils (DMS) are considered as geo-waste and commonly disposed far into the sea. Environmental impacts raised from dredging such as turbidity and disturbance of marine ecosystem had increased the social demand to reuse DMS in engineering application. Typically, DMS have low shear strength and low bearing capacity. Hence, the DMS could be strengthened up by soil solidification. In present study, waste granular materials (WGM) such as coal bottom ash (BA) and palm oil clinker (POC) were utilized as additional binder to cement. The DMS were solidified with 3 series of admixtures; namely cement and/or WGM. The factor that influenced the compressibility of the soil sample such as percentages of admixtures were considered. Proportioned samples of 10, 15 and 20 % of cement, and/or 50 and 150 % of WGM of dry weight of DMS were subjected to one-dimensional oedometer test. The test samples were cured for 7 days in room temperature. Results show that cement- and WGM-admixed DMS have reduced the soil’s compressibility considerably than the untreated sample. As expected, the cemented soil had significantly reduced the settlement better than WGM-admixed soil. Hence, homogeneous samples of 15C50BA and 10C100POC produced almost similar reduction of compressibility as sample 20C. Therefore, reusing WGM as partial replacement of cement in DMS could provide beneficial reuse of these materials
Physicochemical characterization of chitosan/agar blend gel beads prepared via the interphase method with different drying techniques.
In this study, natural and biodegradable chitosan/agar blend gel-beads were prepared via the interphase method. Agar was added to chitosan dissolved in aqueous acetic acid and stirred homogenously under a controlled temperature. With a syringe, the gel solution were added and dropped wisely to the oily phase. The gel-beads were dried at
two different conditions: in the oven at 60°C, and in the freeze dryer for 12 hours. The physicochemistry of the resulting materials were subsequently characterized by fourier transforms infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). FTIR results confirmed the formation of intermolecular hydrogen bonding between the amino and hydroxyl groups of chitosan and the hydroxyl groups of the agar. From the TGA results, we noticed that heat stability of the chitosan/agar blend beads was high compared to its individual components. SEM micrographs showed regular shaped chitosan beads with spherical forms and rough
surfaces with pores
Penyingkiran boron daripada larutan akuas menggunakan penjerap komposit berasaskan karbon-mineral (Boron removal from aqueous solutions using composite adsorbent based on carbon-mineral)
Penyingkiran boron dalam larutan akuas secara penjerapan telah dikaji dengan menggunakan penjerap komposit yang menggabungkan zeolit, batu kapur, karbon teraktif dan buangan arang sekam padi. Parameter optimum seperti pH, masa sentuhan optimum dan dos bahan penjerap dikaji. Kajian isoterma penjerapan dan kinetik penjerapan turut dijalankan. Hasil penyelidikan menunjukkan penyingkiran boron paling optimum berlaku pada pH5 dan masa sentuhan optimum ialah pada minit ke 120. Dos optimum bagi penyingkiran boron dalam larutan akuas ialah pada dos 280 g/L dan penyingkiran yang dapat dilakukan ialah sebanyak 50.49%. Dalam kajian isoterma, model isoterma Langmuir dan Freundlich telah diaplikasikan dan hasil kajian membuktikan bahawa kajian isoterma penjerapan adalah mematuhi model isoterma Langmuir (R2 = 0.8792). Nilai kapasiti penjerapan maksimum (qm) yang diperoleh daripada model isoterma Langmuir adalah 1.8985 mg/g. Kajian kinetik penjerapan dijalankan untuk mengetahui mekanisme proses penjerapan dan hasil kajian menunjukkan kadar kinetik bagi penjerapan boron ini adalah mematuhi model kinetik tertib kedua. Pekali korelasi yang diperoleh untuk model kinetik tertib kedua ini adalah 0.9929. Ini mencadangkan bahawa kinetik penjerapan boron adalah dipengaruhi oleh proses kimia
Sikap Terhadap Sains Siswa Dalam Penerapan Pembelajaran Inkuiri Terbimbing (Guided Inquiry Approach)
This research aims to determine the increase attitudes toward science of students in physics learning by the implementation of guided inquiry approach in class X IPA4 SMA Muhammadiyah 1 Pekanbaru. The subjects are students of class X IPA4. This class has fewer than 35 students, consists of 13 male students and 22 female students. The data collection instrument in this study is questionnaire of attitudes towards science which consists of 24 statements. Analysis of the data in this study is a descriptive analysis using the Gain (increase). If G>0.3, so the attitudes towards science of student is increase by the implementation of guided inquiry approach. The results showed: Gain attitudes towards science of students on aspects of interest in the science of 0.15 with a low category, aspects of science and learning activities of 0.17 with a low category, the importance of science aspects of 0.20 with a low category, and environmental aspects of the view science of 0.18 with a lower category. So that the average gain attitudes toward science of students in the amount of 0.18 to a low category. Application of guided inquiry approach the material and application of Newton\u27s laws have low gain to improve attitudes toward science of students in class X SMA Muhammadiyah 1 pekanbaru
Experimental Evaluation on Physical and Mechanical Properties of Concrete Containing Green Mussel Shell (Perna viridis) Powder as an Admixture
Mussel shell is a type of waste that is generated abundantly. However, the presence of chemical components such as calcium (CaCO3) in mussel shells has shown its potential as filler materials in concrete designing. Therefore, this paper presents the experimental result for the physical and mechanical properties of concrete containing 1%, 2%, 3% and 4% Mussel Shell Powder (MSP) as additional material under 2.73% sodium chloride solution. The MSP has been cleaned, grinded and sieved 75μm sizes in order to obtain its final product. Compressive strength, split tensile, and capillary water absorption were determined. Statistical analysis was performed to investigate the correlation and level of significance using IBM SPSS in determining the optimal mix design for modified concrete. The performance of MSP concrete and control specimens are the main factor that been observed in this study. The increment percentages of MSP in concrete had led to reduce on its mechanical strength, however improved in its absorption rates. According to statistical analysis, it shows that low MSP percentages giving a significant value for compressive strength and very strong correlation coefficient compared to control specimens, thus it indicated minimum MSP percentages are more potential in improving concrete physical and mechanical performance
Hasil Belajar Kognitif IPA Fisika Siswa melalui Penerapan Strategi Bowling Campus di Kelas Viii6 SMPN 15 Pekanbaru
This research aims at describe cognitive learning outcomes science of physics through the implementation strategy Bowling Campus on light subject at SMPN 15 Pekanbaru. The expected benefits of this research is for students implementation Bowling Campus strategy can improve the cognitive learning to become a better student. For teachers can be used as an alternative teaching strategies to improve the quality of science physics teaching. This research was conducted in SMP 15 Pekanbaru precisely in March 2015 until June 2015 in class VIII6 totaling 39 students. The design of the research is Pre-experimental design shapes One Shot Case study. From the research results obtained by the average value of absorption of students by 76.53% and categorized as good. Based on the average value of absorption was also found that the effectiveness of learning by applying Bowling Campus declared effective strategy. Based on 20 indicators of achievement of competencies in a given light material, 14 indicators declared complete with a percentage of 70%. It can be concluded that the application of Bowling Campus strategy can be used as an alternative in order to achieve the learning outcomes of cognitive learning better students in the classroom VIII6 SMP 15 Pekanbaru
Forecasting wind speed data by using a combination of ARIMA model with single exponential smoothing
Wind serves as natural resources as the solution to minimize global warming and has been commonly used to produce electricity. Because of their uncontrollable wind characteristics, wind speed forecasting is considered one of the best challenges in developing power generation. The Autoregressive Integrated Moving Average (ARIMA), Simple Exponential Smoothing (SES) and a hybrid model combination of ARIMA and SES will be used in this study to predict the wind speed. The mean absolute percentage error (MAPE) and the root mean square error (RMSE) are used as measurement of efficiency. The hybrid model provides a positive outcome for predicting wind speed compare to the single model of ARIMA and SES
Bonding Strength between Geopolymer Fly Ash to Ordinary Portland Cement Concretes using Mohr-Coulomb Theory
This paper presents an experimental study to analyse the bonding strength between geopolymer concrete (GC) and normal concrete (NC) bond substrate. Three different strengths of GC which were 80 MPa, 85 MPa and 90 MPa were bonded to 30 MPa NC and denoted as NC30-GC80, NC30-GC85 and NC30-GC90. Slant shear and split tensile tests were conducted to investigate the bonding strength between two different substrates. The effect of bonding was then determined by using Mohr-Coulomb theory where critical bonding condition (smooth surface) was created. From the analysis, it was found that NC30-GC80 had the most powerful self-adhesion between GC towards NC. This result indicated the highest bonding strength of GC to NC at critical condition. Such strong bond was obtained by the effect of self-adhesive from GC to NC. The self-adhesive characteristic which represented by pure shear strength was obtained from Mohr-Coulomb theory
Analysis of EMG based Arm Movement Sequence using Mean and Median Frequency
This paper present the studies of analysis arm movement sequence which dedicated for upper limb rehabilitation after stroke. The recovery of the arm could be optimized if the rehabilitation therapy is in a right manner. Upper limb weakness after stroke is prevalent in post-stroke rehabilitation, many factors that can deficit muscle strength there are neural, muscle structure and function change after stroke. Rehabilitation process needs to start as soon as after a stroke attack, repetitive and conceptualized. On the other hand monitoring of muscle activity also need in the rehabilitation process to evaluate muscle strength, motor function and progress in the rehabilitation process. The objective of this research is to analysis arm movement sequence using the feature frequency domain. In this study deltoid, biceps and flexor carpum ulnaris (FCU) muscles will be monitored by surface electromyography (sEMG). Five healthy subjects male and female become participants in data recording. Mean frequency (MNF) and median frequency (MDF) domain are two signals processing technique used for arm movement sequence analyzing. The analysis result showed that MNF is better than MDF where MNF produced higher frequency than MDF from each segment. From the data analysis, this movement sequence design more focuses on deltoid and FCU muscles treatment. This movement sequence has five condition movements. First undemanding, second difficult, third moderate, fourth moderate and the last cool-down movements. The best movement sequence minimum has four condition movements warming up - moderate - difficult - cool-down
Expression of segment a of infectious bursal disease virus in pichia pastoris
Recombinant plasmid containing segment A open reading frame 2 (ORF2) gene of infectious bursal disease virus (IBDV) of a very virulent subtype from local outbreak (strain 3529/92) was constructed. The gene encoding the IBDV structural polyprotein (N-VP2-VP3-VP4-C) was inserted into an expression vector, pPICZ prior to its transformation into Pichia pastoris by electroporation. After the induction of P. pastoris transformant with 0.5% methanol, the production of IBDV polyprotein was observed using Western blot. In P. pastoris, co- or post-translational processing of the large polyprotein occurred, generating a stable C-terminal product (VP3) of correct size, but without any detectable N-terminal product (VP2). The failure to observe the VP2 protein in Western blot analysis was probably due to the conformational epitope problem
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