PENERAPAN MODEL PEMBELAJARAN KOOPERATIF TIPE NUMBERED HEAD TOGETHER UNTUK MENINGKATKAN KEMAMPUAN KERJA SAMA SISWA SEKOLAH DASAR

Penelitian ini dilatarbelakangi oleh kemampuan kerja sama yang kurang muncul pada kelas V A di salah satu SD Negeri Kecamatan Sukajadi Kota Bandung. Hal ini ditandai dengan kurangnya kontribusi siswa pada saat pembelajaran kelompok. Ketika mengadakan pembelajaran kelompok, guru cenderung memberikan tugas pada kelompok tanpa membimbing kelompok tersebut selama proses pembelajaran. Tujuan dari penelitian ini adalah untuk meningkatkan kemampuan kerja sama dengan menerapkan model pembelajaran kooperatif tipe Numbered Head Together. Metode dalam penelitian ini adalah Penelitian Tindakan Kelas (PTK) dengan mengadaptasi model PTK dari Kemmis dan Mc. Taggart. Penelitian ini dilaksanakan dalam dua siklus. Subjek dari penelitian ini adalah siswa kelas V A yang berjumlah 25 orang. Hasil dari siklus I menunjukkan kemampuan kerja sama mencapai 62,28% dengan kategori cukup, sedangkan pada siklus II kemampuan kerja sama siswa meningkat, hingga hasil yang diperoleh mencapai 87,14% dengan kategori baik. Berdasarkan hasil penelitian tersebut maka dapat disimpulkan bahwa penerapan model pembelajaran Kooperatif tipe NHT (Numbered Head Together) pada kelas V A terbukti dapat meningkatkan kemampuan kerja sama pada diri siswa dalam mata pelajaran IPA. Maka dengan itu diharapkan model pembelajaran ini dapat dijadikan suatu alternatif dalam pembelajaran guru untuk meningkatkan kemampuan kerja sama siswa. ; The research was distributed by the ability of less cooperation appeared in class V A at one elementary school Sub Sukajadi Bandung. It is characterized by the lack of contributions to the students at the time of the learning group. When organising a group learning, teachers tend to give a task to a group without guide such groups during the learning process. The purpose of this research is to improve the ability of cooperation by implementing cooperative learning model of type Numbered Head Together. The method in this research is the Research Action class and adapt the model action research of Kemmis and Mc. Taggart. This research was conducted in two cycles. The subject of this research is the grade V A of 25 people. Results from the I-cycle demonstrates the ability of cooperation reached 62.28% with enough categories, while on cycle II cooperation capabilities of students increased, the results obtained up to achieve 87.14% with the good category. Based on the results of the study it can be concluded that the application of the Cooperative learning model type NHT (Numbered Head Together) on a class V with proven capabilities can improve teamwork in students in Science subjects. Thus it is hoped this learning model can be used as an alternative in the learning of teachers to improve the student's cooperation

Kajian Penanganan Tumpahan Minyak Menggunakan Oil Skimmer Tipe Rotary disc pada Jenis Bahan Bakar Berbeda

Oil spills are a source of pollutants that can spread quickly in water. Therefore this effort to deal with oil spills has attracted the attention of many broad communities. In this paper, we developed a tool for handling oil spills called an oil skimmer with a rotary disc as a component for taking oil spills on the surface of the water. The oil skimmer is designed to float above the surface of the water and can be controlled in the direction of its movement from a distance by using a joystick. To achieve this goal, the oil skimmer is equipped with a propeller driven by a DC motor which is connected to the Arduino Mega 2560 as the controller. The testing process is carried out by varying the speed of the rotary disc on three different types of fuel spills (pertalite, pertamax, and diesel). The amount of oil collected by the oil skimmer is then determined in volume using a measuring cup for each experiment. Finally, the characteristics and the effect of the rotary disc speed on the oil skimmer on the volume of oil collected is examined to determine the performance of the oil skimmer.Tumpahan minyak merupakan salah satu sumber pencemar yang dapat menyebar secara cepat di perairan. Oleh karena itu upaya penanganan tumpahan minyak ini mengundang perhatian banyak komunitas luas. Dalam paper ini, kami mengembangkan salah satu alat untuk menangani tumpahan minyak yang disebut dengan oil skimmer dengan rotary disc sebagai komponen untuk mengambil tumpahan minyak yang terdapat pada permukaan air. Oil skimmer dirancang dapat terapung diatas permukaan air dan dapat dikontrol arah pergerakannya dari jarak jauh dengan menggunakan sebuah joystick. Untuk mencapai tujuan tersebut, oil skimmer dilengkapi dengan propeller yang digerakkan oleh motor DC yang dihubungkan dengan Arduino Mega 2560 sebagai kontrolernya. Proses pengujian dilakukan dengan melakukan variasi kecepatan pada rotary disc pada tiga jenis tumpahan bahan bakar berbeda (pertalite, pertamax, dan solar). Jumlah minyak yang terkumpul oleh oil skimmer kemudian ditentukan volumenya menggunakan gelas ukur untuk setiap percobaanya. Akhirnya karakteristik dan pengaruh kecepatan rotary disc pada oil skimmer terhadap volume minyak yang terkumpul dikaji untuk mengetahui performa dari oil skimmer

Waterless purification using oil palm biomass-derived bioadsorbent improved the quality of biodiesel from waste cooking oil

The utilization of adsorbents produced from biomass for tertiary treatment of industrial wastes has gained much interest compared to the conventional methods such as flocculation and coagulation. In the present study, a bioadsorbent produced from pressed-shredded oil palm empty fruit bunch was used to remove impurities from crude biodiesel derived from waste cooking oil. The purification process was performed using 1 to 5 wt% bioadsorbent loadings under continuous stirring at 500 rpm for 1 h. After purification using 5 wt% of bioadsorbent loading, 89.7% of residual methanol, 81.7% of water, 36.7% of free fatty acid and 98.6% of potassium were successfully removed. This met the European Biodiesel Standard (EN14214). In comparison to commercial adsorbents and the water washing method, purification using the oil palm empty fruit bunch derived bioadsorbent resulted in higher removal of free fatty acids, potassium, water impurities and a smaller loss of fatty acid methyl esters. It was found that the use of the bioadsorbent improved the biodiesel quality besides its benefits of ease of operations and avoidance of waste water production

Kinetic and thermodynamic of heterogeneously K₃PO₄/AC-catalysed transesterification via pseudo-first order mechanism and eyring-polanyi equation

The use of carbon-based catalysts has drawn so much interest in biodiesel production due to improved reaction performance. However, there was lack of comprehensive studies in term of its kinetic and thermodynamic perspective. Therefore, a methodical study is essential to uncover the influence of the carbon catalyst with respect to reaction rate and yield. This study represents kinetic and thermodynamic of heterogeneously K₃PO₄/AC-catalysed transesterification. It was done correspondingly via pseudo-first order mechanism and Eyring-Polanyi equation, whereby, under the optimal reaction temperature of 333.15 K, all data have fitted satisfactorily in both models with resulted R² of 0.99, respectively. Activation energy (Ea) and Gibbs free energy (ΔG) were calculated as 34.2 kJ mol⁻¹ and −33.68 kJ mol⁻¹, indicating the reaction was exergonic and spontaneous at high temperature

Enhanced coal bed methane (ECBM) recovery: optimization of CBM production using different injected gas composition and rate for south sumatra CBM field, Indonesia

Indonesia, whose 453 TCF potential coal bed methane (CBM) reserves, rank the 6th largest CBM reserves around the world. However, the technical limitation is amongst the major issues slowing down the exploitation progress of the resources which current national CBM production only reach up to 1 MMSCFD. This paper provides a newly enhanced coal bed methane (ECBM) recovery method to improve the methane production. Scenarios of nitrogen (N2) and carbon dioxide (CO2) injection were used in this study to perform 25 years production simulation and compared with CBM primary production. Created hypothetical model based on the characteristic of coal seams CBM field in South Sumatra, Indonesia, was used to analyze the increasing methane production by using N2 and CO2 injection with different compositions and rates. The result observed about 3,52% incremental methane production by injecting N2 into CBM reservoir. In other words, this new method has an impact on enhancing the CBM national production, particularly South Sumatra CBM field, which could be useful for further CBM development in Indonesia. Mixture injection seemed to be unfavorable for the field due to the difference of gas mechanism. Thu

Enhanced coal bed methane (ECBM) recovery: optimization of CBM production using different injected gas composition and rate for south sumatra CBM field, Indonesia

Indonesia, whose 453 TCF potential coal bed methane (CBM) reserves, rank the 6th largest CBM reserves around the world. However, the technical limitation is amongst the major issues slowing down the exploitation progress of the resources which current national CBM production only reach up to 1 MMSCFD. This paper provides a newly enhanced coal bed methane (ECBM) recovery method to improve the methane production. Scenarios of nitrogen (N2) and carbon dioxide (CO2) injection were used in this study to perform 25 years production simulation and compared with CBM primary production. Created hypothetical model based on the characteristic of coal seams CBM field in South Sumatra, Indonesia, was used to analyze the increasing methane production by using N2 and CO2 injection with different compositions and rates. The result observed about 3,52% incremental methane production by injecting N2 into CBM reservoir. In other words, this new method has an impact on enhancing the CBM national production, particularly South Sumatra CBM field, which could be useful for further CBM development in Indonesia. Mixture injection seemed to be unfavorable for the field due to the difference of gas mechanism. Thu