Design and operating parameters of a fulidized bed for the combustion of municipal solid waste using standpipes air distributors

Hydrodynamic studies and combustion of simulated and actual municipal solid waste were carried out in a fluidized bed system. A wide range of parameters was investigated in hydrodynamic study after which the optimum parameters were implemented in the combustion studies. A newly fabricated standpipes air distributor (primary air inlet) was designed based on findings of the optimum orifice diameter, orifice distance and distance between pipes. Orifice diameter, orifice distance and distance between pipes of 3 mm, 10 mm and 70 mm were used in the hydrodynamic studies of circular and rectangular columns (CHS and RHS). The operating parameters investigated in the CHS and RHS included the effect of sand sizes and aspect ratios on the fluidization profile. Standpipes air distributors having the same orifice diameter and distance but with a wider pipe distance of 200 mm were used in the hydrodynamic studies of a bigger rectangular (big scale) column. Different air flow strategies were implemented to ensure good mixing between sand and samples and to investigate the penetration of the incombustibles into the sand bed. Parameters studied in the combustion of municipal solid waste included the effect of fluidizing velocity and air factor on the combustion profile in the bed as well as the freeboard region with standpipe air distributor design and dimension established from the hydrodynamic studies of a bigger scale rectangular column. Findings from the CHS and RHS showed that sand particles with mean size of 0.34 mm performed good fluidization profile compared to other coarser sand sizes. The ratio of the bed height over diameter of column (Dc) for good fluidization was determined at cDH?for the circular column whereas the ratio of the bed height (H) over the length (L) of column was observed at H<L for the rectangular columns. A two side air flow was seen as the best air flow strategy for good mixing in a bigger rectangular column. The range of fluidization number and air factor for the combustion of simulated municipal solid waste in a rectangular fluidized bed combustor was 5 – 7 mfUin which 5 mf U was found to be the optimum with air factor of 0.8 (primary air). Air factor of 0.4 (secondary air) was observed to show good temperature profile in the freeboard region for the combustion of municipal solid waste. The optimum total combined air factor for the combustion of municipal solid waste was 1.2 in which inlet primary air factor and inlet secondary air factor were 0.8 and 0.4, respectively

Supporting Student’s Thinking In Addition Of Fraction From Informal To More Formal Using Measuring Context

One of reasons why fractions are a topic which many students find difficult to learn is that there exist many rules calculating with fractions. In addition, students have been trained for the skills and should have mastered such procedures even they do not ‘understand’. Some previous researcher confirmed that the problem which students encounter in learning fraction operations is not firmly connected to concrete experiences. For this reason, a set of measuring context was designed to provide concrete experiences in supporting students’ reasoning in addition of fractions, because the concept of fractional number was derived from measuring. In the present study we used design research as a reference research to investigate students’ mathematical progress in addition of fractions. In particular, using retrospective analysis to analyze data of fourth graders’ performance on addition of fractions, we implemented some instructional activities by using measuring activities and contexts to provide opportunities students use students’ own strategies and models. The emergent modeling (i.e. a bar model) played an important role in the shift of students reasoning from concrete experiences (informal) in the situational level towards more formal mathematical concept of addition of fractions. We discuss these findings taking into consideration the context in which the study was conducted and we provide implications for the teaching of fractions and suggestions for further research. Key word: measuring context, addition of fractions, design research, emergent modelin

ANALYZING CORONAL MASS EJECTION OF JULY 10, 2005 AND ITS EFFECT ON THE EARTH’S MAGNETOSPHERE

Abstract A large coronal mass ejection (CME) was occurred on July 10, 2005 08:54 UT at the South‐West solar limb. This was a partial type of CME as the ejected coronal plasma covered partially around the occulting disk of coronagraph. The Large Angle and Spectrometric Coronagraph (LASCO) aboard Solar and Heliospheric Observatory (SOHO) data were used in detecting CME. The data taken by the Extreme‐ultraviolet Imaging Telescope (EIT) as well as Michelson Doppler Imager (MDI) that observes the active regions in white‐light wavelength and maps the magnetic field of the photosphere are used to identify the source region of CME. The projected speed of CME perpendicular the Sun‐Earth line is determined to estimate the arrival time at the Earth’s orbit. The speed and location of the source region of CME are used to study the effect of CME to the Earth’s magnetosphere (geo‐effectiveness). It is concluded that the CME’s effect to the Earth’s space environment was relatively small (Dst index greater than –100 nT) due to the source region was located close to the West solar limb. This work supports the efforts in establishing space weather service at LAPAN. Keywords: coronal mass ejection, geo‐effectiveness, space environment, space weather

INTERACTIVE LEARNING MEDIA DEVELOPMENT ON EDUCATION PNEUMATIC USING MACROMEDIA FLASH 8 CLASS STUDENT XI ELECTRONIC INDUSTRY SKILLS COMPETENCY SMK MUHAMMADIYAH PRAMBANAN

The purpose of this thesis final project for developing interactive learning media on subjects pneumatic and determine the level of feasibility Developing interactive learning media on subjects pneumatic class student XI Electronic Industry Skills Competency SMK Muhammadiyah Prambanan. The research method used in this study is a type of research and development. Research Procedures memalui five stages of development, namely: analysis, design, development, implementation and assessment. The fifth stage is called Multimedia System Development Life Cycle in Education. The development of instructional media is using Macromedia Flash 8. Determining the feasibility of interactive learning media pneumatic based on expert validation test media by media expert lecturers of the Faculty of Engineering UNY, subject teachers pneumatic Electronics Industry Skills Competency SMK Muhammadiyah Prambanan and students' opinions through questionnaires. The results of the feasibility study the development of instructional media specialist pneumatic testing revealed through media, material experts and students' opinions. Percentage of assessment by the media expert instructional media expert lecturers of the Faculty of Engineering UNY by 80%, so it can be interpreted that the development of instructional media in the category of pneumatic fit for use as a medium of learning. The percentage of assessments that matter experts pneumatic subject teachers at SMK Muhammadiyah Prambanan 89.23%. These results can be interpreted that the material in the development of instructional media in the category Pneumatic very decent. Students' opinions as the user reaches 79.07%, so that in the category of worth. Students can understand the material and are interested in the use of interactive learning media pneumatic. Keywords: pneumatic, instructional media, interactive, and feasibility