Ade Gafar Abdullah

Synthesis of silica particles from rice straw waste using a simple extraction method

The purpose of this study was to synthesize silica particles from rice straw waste using a simple extraction method. The experiment was conducted by heating and extracting rice straw waste into basic solution. To get silica particles, the extracted solution was then put into acid solution and heated to remove the remained solvent. The experimental results showed that the aggregated silica particles with sizes of about 200 nm were successfully produced. The XRD and FTIR analysis showed that the final product was silica and free of graphite. However, we found that some KCl component in the final product in which this was possibly from the use of KOH as the extraction agent. Therefore, further studies are still required to synthesize high purity silica particles from rice straw waste.

Decomposition Behavior of Curcumin during Solar Irradiation when Contact with Inorganic Particles

Curcumin is one of materials which have been widely used in medicine, Asian cuisine, and traditional cosmetic. Therefore, understanding the stability of curcumin has been widely studied. The purpose of this study was to investigate the stability of curcumin solution against solar irradiation when making contact with inorganic material. As a model for the inorganic material, titanium dioxide (TiO2) was used. In the experimental method, the curcumin solution was irradiated using a solar irradiation. To confirm the stability of curcumin when contact with inorganic material, we added TiO2 micro particles with different concentrations. The results showed that the concentration of curcumin decreased during solar irradiation. The less concentration of curcumin affected the more decomposition rate obtained. The decomposition rate was increased greatly when TiO2 was added, in which the more TiO2 concentration added allowed the faster decomposition rate. Based on the result, we conclude that the curcumin is relatively stable as long as using higher concentration of curcumin and is no inorganic material existed. Then, the decomposition can be minimized by avoiding contact with inorganic material.

Synthesis of Potassium Silicate Nanoparticles from Rice Straw Ash Using a Flame-assisted Spray-pyrolysis Method

The purpose of this study was to synthesize potassium silicate nanoparticles from rice straw ash using a flame-assisted spray-pyrolysis method. Rice straw, as one of the agricultural wastes, was used as a source of silica. In the experimental procedure, rice straw was burned at 700°C for 3 hours to produce rice straw ash. Then, the rice straw ash was extracted using an alkaline method. We used potassium hydroxide (KOH) as an alkaline chemical agent as well as a source of potassium. The solution was then put into the flame-assisted spray-pyrolysis apparatus to produce potassium silicate nanoparticles. The results showed that the spray method can assist the production of spherical potassium silicate nanoparticles with sizes of about 50 nm.

Extraction of Curcumin Pigment from Indonesian Local Turmeric with Its Infrared Spectra and Thermal Decomposition Properties

Curcumin is one of the pigments which is used as a spice in Asian cuisine, traditional cosmetic, and medicine. Therefore, process for getting curcumin has been widely studied. Here, the purpose of this study was to demonstrate the simple method for extracting curcumin from Indonesian local turmeric and investigate the infrared spectra and thermal decomposition properties. In the experimental procedure, the washed turmeric was dissolved into an ethanol solution, and then put into a rotary evaporator to enrich curcumin concentration. The result showed that the present method is effective to isolate curcumin compound from Indonesian local turmeric. Since the process is very simple, this method can be used for home industrial application. Further, understanding the thermal decomposition properties of curcumin give information, specifically relating to the selection of treatment when curcumin must face the thermal-related process.

Neutron Distribution in the Nuclear Fuel Cell using Collision Probability Method with Quadratic Flux Approach

To solve the integral neutron transport equation using collision probability (CP) method usually requires flat flux (FF) approach. In this research, it has been carried out in the cylindrical nuclear fuel cell with the spatial of mesh with quadratic flux approach. This means that the neutron flux at any region of the nuclear fuel cell is forced to follow the pattern of a quadratic function. The mechanism may be referred to as the process of non-flat flux (NFF) approach. The parameters that calculated in this study are the k-eff and the distribution of neutron flux. The result shows that all parameters are in accordance with the result of SRAC.

Preparation of Potassium-Posphate-embedded Amorphous Silicate Material from Rice Straw Waste

Rice straw is one of the agricultural wastes that increased every year. Since rice straw ash contains 74.6% of silica, this material is potentially used to produce silica. Thus, the purpose of this study was to investigate the possibility process for generating potassium-phosphate-embedded amorphous silica material. To extract silica from rice straw waste, we used potassium hydroxide solution followed by an acid precipitation treatment. Based on the experimental results, the proposed method is potential to be used as an alternative technique for getting silica material. In addition, the method has a positive impact on the environment because this is potential for reducing the amount of rice straw waste, whereas at the same time this provides an added value to the rice straw waste itself.

Electrical Load Profile Analysis Using Clustering Techniques

Data mining is one of the data processing techniques to collect information from a set of stored data. Every day the consumption of electricity load is recorded by Electrical Company, usually at intervals of 15 or 30 minutes. This paper uses a clustering technique, which is one of data mining techniques to analyse the electrical load profiles during 2014. The three methods of clustering techniques were compared, namely K-Means (KM), Fuzzy C-Means (FCM), and K-Means Harmonics (KHM). The result shows that KHM is the most appropriate method to classify the electrical load profile. The optimum number of clusters is determined using the Davies-Bouldin Index. By grouping the load profile, the demand of variation analysis and estimation of energy loss from the group of load profile with similar pattern can be done. From the group of electric load profile, it can be known cluster load factor and a range of cluster loss factor that can help to find the range of values of coefficients for the estimated loss of energy without performing load flow studies.

Anomalous STLF for Indonesia power system using Artificial Neural Network

This paper presents the research results of Short Term Load Forecasting (STLF) on the power distribution systems in the West Java, Indonesia. Forecasting is executed using Artificial Neural Network (ANN), with back propagation algorithms. Experiments conducted on the data load holidays (anomalous load). To obtain optimal prediction accuracy, then conducted the experiment by changing the number of input learning and learning rate value. The simulation results verify that the ANN method performs more accurate than the conventional method used Indonesia Power Company. Results of this study are expected to be used as an alternative method based on soft computing.

Perangkat Penilaian Kinerja untuk Pembelajaran Teknik Pemeliharaan Ikan

This paper shows the study result of performance assessment instrument development for the learning of fish-rearing technique. The study was intended to develop the new performance assessment instrument and to determine teachers’ and students’ responses toward its using. The study adapted development research procedures by selecting 27 students as the sample. Before the instrument was applied, it was tested by some experts. The result of feasibility test showed that the performance assessment instrument was categorized very good, thus revision was not required. After that, the instrument was experimented to several students. The findings showed that according to the teachers, the media attainment level was classified very good; however, the students argued that the instrument was good. Therefore, it was concluded that the performance assessment instrument was able to improve students’ interest toward practical work, to motivate students in learning, and to help them in scoring. The researchers hope that the study can contribute to the quality improvement of performance assessment instrument in the learning process at vocational secondary school.

MODUL VIRTUAL: MULTIMEDIA FLIPBOOK DASAR TEKNIK DIGITAL

Perkembangan teknologi informasi dan komunikasi, berpengaruh juga terhadap kemaj uan i novasi media pembel aj aran. Makal ah i ni mengekspl orasi hasi l perencanaan, pembuatan dan implementasi modul virtual pembelajaran dasar teknik digital. Tujuannya adalah untuk menguji validitas produk sehingga memenuhi kelayakan sebagai media pembelajaran. Prosedur penelitian dilakukan melalui langkah-langkah penelitian pengembangan, dengan metode evaluatif. Hasi l penelitian membukti kan bahwa modul virtual i ni memi l i ki tampil an yang menari k, mudah di pahami dan mudah digunakan. Di harapkan hasi l pengembangan modul virtual i ni berdampak terhadap peni ngkatan penguasaan peserta didi k dal am mempelaj ari dasar tekni k digital.