54 research outputs found

    Evaluating Instrument Quality: Rasch Model – Analyses of Post Test of Curriculum 2013 Training

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    The main purpose of this study was to evaluate the quality of post test utilized by LPMP Central Kalimantan Indonesia in curriculum 2013 training for X grade teachers. It uses Rasch analysis to explore the item fit, the reliability ( item and person), item difficulty, and the Wrigh map of post test. This study also applies Classical Test Teory (CTT) to determine item discrimination and distracters. Following a series of iterative Rasch analyses that adopted the “data should fit the model” approach, 30 items post test of curriculum 2013 training was analyzed using Acer Conquest 4 software, software based on Rasch measurement model. All items of post test of curriculum 2013 training are sufficient fit to the Rasch model. The difficulty levels (i.e. item measures) for the 30 items range from –1.746 logits to +1.861 logits. The item separation reliability is acceptable at 0.990 and person separation reliability is low at 0.485. The wright map indicates that the test is difficult for the teachers or the teachers have low ability in knowledge of curriculum 2013. The post test items cannot cover all the ranges of the teachers\u27 ability levels. Items discrimination of post test of curriculum 2013 training grouped into fair discrimination (item 2, 4, 5, 8, 11, 18) and poor discrimination (1, 3, 6, 7, 9, 10,12, 13, 14, 15, 16, 17, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30). Some distracters from item 1, 2, 6, 7, 8, 9, 11, 13, 16, 17, 18, 19, 20, 22, 24, 25, 27, 28, 29 and 30 are problematic. These distracters require further investigation or revision.   Key words: Rasch analysis, training, curriculum 2013, post tes

    Pembuatan Bahan Bakar Padat dari Pelepah Sawit Menggunakan Proses Torefaksi pada Variasi Suhu Waktu Torefaksi

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    Oil Palm Fronds can be used as alternative energy source by using torrefaction process. Oil Palm Fronds has a calorific value of 15439.39 kJ/kg. The calorific value can be increased by torrefaction. Torrefaction is a pre-treatment process of biomass into solid fuel within temperature range of 200 - 300 oC in an inert condition. This research aims to produce solid fuel from oil palm fronds and study the effect of variation in temperature and time torrefaction towards characteristic of solid fuel resulted. Torrefaction of oil palm fronds was using fixed bed horizontal reactor at temperature of 250 - 300 oC and time of 20 - 40 minutes. Product quality resulted was calorific value, mass yield, energy yield and proximate. The result obtained for calorific value in range was 18152.26 - 24060.32 kJ/kg, mass yield was 45.22 - 75.04 %, and energy yield was 70.49 - 88.23 %. Proximate analysis resulted in the form of moisture content was 3.42 - 5.44 %, ash content was 4.67 - 6.89 %, volatile content was 38.63 - 65.34 %, and fixed carbon was 24.55 - 51.06 %

    Karbonisasi Pelepah Sawit dengan Variasi Temperatur dan Waktu Karbonisasi

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    Palm fronds only used as a source of raw materials for animal feed, compost and organic fertilizer in the garden area so far. The heating value of palm fronds is 15,184 MJ/kg. The heating value can be improved by conducting carbonization process. Carbonization is a method to process biomass into solid fuel without oxygen where the temperature range is between 400-600 °C.The aim of this study is to produce a solid fuel from palm fronds by using carbonization process and studied the effect of variations in temperature (450-550 °C) and carbonization time (3-4 hours) on the quality of fuels from waste palm frond.Carbonization temperature used were 450, 500, 550oC, carbonization time used were 3, 3.5, 4hours. Particle size used were < 850 μm (20 mesh).The highest result of heating value was 27,177MJ/kg at 450oC for 3.5hours. The lowest result of volatile matter content was 7,01 %-wt at 550oC for 3hours. Significant process condition affecting the heating value was temperature and carbonization time

    Bahan Bakar Padat dari Tandan Kosong Sawit Menggunakan Proses Torefaksi; Variasi Suhu dan Ukuran Bahan Baku

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    Palm Empty Fruit Bunches (EFB) can be used as alternative energy source by using torrefaction process. Torrefaction is a pre-treatment process of biomass into solid fuel within temperature range of 200-300 oC in an inert condition. The aim of this research was producing solid fuel from oil palm EFB and studyng the effect of process variabel towards characteristic of solid fuel that was resulted. Torrefaction of EFB was using fixed bed horizontal reactor with temperature (225-275 oC) and particle size (5-15 mm). The quality of product that analyzed was calorific value, mass yield, energy yield and proximate (moisture content, ash content, volatile content and fixed carbon). The result of research was obtained for calorific value was 18362.17-20113.19 kJ/kg, mass yield was 52.15-77.85% and energy yield was 65.82-90.00%. The result proximate analysis such as moisture content was 1.22-1.35%, ash content was 6.97-13.59%, volatile content was 35.71-56.64%, and fixed carbon was 33.45-52.13%. From the result that was obtained, the effect of rising temperature given increasing to the calorific value, energy yield, ash content, and fixed carbon

    Bahan Bakar Padat dari Pelepah Sawit Menggunakan Proses Karbonisasi dengan Variasi Ukuran Bahan Baku dan Suhu

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    Palm frond so far only used as a source of raw materials for animal feed, compost and organic fertilizer in the plantation. Palm frond has a calorific value of 15,184.05 kJ/kg. Utilization of palm frond as main material of solid fuel production with carbonization process can reduce the problem of oil palm plantations waste and can be increased the calorific value of product. The aims of this study is to produce solid fuel from palm fronds by using carbonization process and analyze solid fuel quality from palm frond with variation of raw material size and temperature. Variation of carbonization temperature were 450°C, 500°C and 550°C. Variation of raw material size 1.68 – 2.38 mm (-8 +10 mesh), 0.84 – 1 mm (-16 +20 mesh) and 0.42 – 0.5 mm (-32 +35 mesh). Water content were 3.66 – 4.86%, ash were 9.39 – 16.17%, volatile were 9.45 – 28.60% and fixed carbon were 57.26 – 70.01%. The highest caloric value was 28,410.94 kJ/kg for 550°C of carbonization temperature and 0.42 – 0.5 mm (-32 +35 mesh) of raw material size
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