Developing Students' Ability of Mathematical Connection Through Using Outdoor Mathematics Learning

The Purpose of this study is to determine the achievement and improvement of students' mathematical connectionability through using outdoor mathematics learning. 64 students from the fifth grade of Primary School at SDN 65 and SDN 67 Bengkulu City were taken as the sample of this study. While the method of the research used in this research is experiment with quasi-experimental designs non-equivalent control group. The results of the study are as follows: (1) There is an increasing ability found in mathematical connection of students whom taught by using outdoors mathematics learning is 0,53; (2) Based on statical computation that achievement of students' ability of mathematical connection is taught by using outdoor mathematics learning score is 71,25. It is higher than the students score 66,25 which were taught by using the conventional learning. So as to improve students' mathematical connection, teachers are suggested to use the outdoors mathematics learnin

The influence of fuel structure on CO and NOx formation in lean premixed hydrocarbon flames

A study is made of the influence chemical structure of fuel has upon combustion performance through tracing the generation of carbon monoxide and oxides of nitrogen in lean, premixed, hydrocarbon-air flames. The study includes both analytical and experimental investi- gations. On the analytical side, a kinetic model is developed to predict both CO and NO time-histories in one-dimensional, premixed flames. The model is based upon the assumption of partial equilibrium in the post-flame zone while the fuel oxidation in the main reaction zone is allowed for by using a global oxidation rate equation. NO formation is assumed to be entirely via the Zeldovitch mechanism and to start in the post-flame zone. The utility of the model is judged through comparison between theoretical results and experimental data. On the experimental side, a simple burner system, supporting a one-dimensional premixed flame was designed and built. All fuels selected for investigation were pure hydrocarbons representing the main hydrocarbon types usually found in practical fuels; namely paraffins, olefins, naphthenes and aromatics. The hydrogen-to-carbon ratio ranged from 1 to 2.67 and the carbon number from 3 to 12. The experiments were performed at 1,2 and 3 atm pressure levels and 140°C inlet temperature, while the equivalence ratio was in the range 0.6 to 0.9. Flames were sampled for most stable species by a water- cooled stainless steel sampling probe. The experimental results show that the fuel structure signifi- cantly affects CO time-histories in the investigated flames mainly through influencing its generation rather than its burnout. CO burnout is shown to be mainly controlled by radical recombination processes, and the experimentally derived CO global oxidation rate equations are found not to be universally applicable. The results also show that the fuel structure influences prompt NOx formation within, and very near, the main reaction zone but that it does not influence post-equilibrium NOx formation if account is taken of differences in the flame temperatures. N02 is found to constitute a large percentage of total NOx measured especially at lower temperature and equivalence ratios. Comparison between experimental and theoretical results show that the prescribed kinetic model can satisfactorily predict CO levels for different fuels and under different conditions if the fuel oxidation global rate equation is correctly defined for different fuels. On the other hand, agreement between predicted and measured NO profiles has been obtained at atmospheric pressure only. At high pressure, the predicted levels were much smaller than those measured experimentally, and this disagreement is attributed to the fact that proper account is not taken of the NO and N02 formation kinetics in the main reaction zone

Synthesis of Supported Catalysts by Dry Impregnation in Fluidized Bed

The synthesis of catalytic or not composite materials by dry impregnation in fluidized bed is described. This process can be carried out under mild conditions from solutions of organometallic precursors or colloidal solutions of preformed nanoparticles giving rise to reproducible metallic nanoparticles containing composite materials with a high reproducibility. The adequate choice of the reaction conditions makes possible to deposit uniformly the metal precursor within the porous matrix or on the support surface. When the ratio between the drying time and the capillary penetration time (tsec/tcap) is higher than 10, the impregnation under soft drying conditions leads to a homogeneous deposit inside the pores of the particles of support. The efficiency of the metal deposition is close to 100%, and the size of the formed metal nanoparticles is controlled by the pores diameter. Finally, some of the presented composite materials have been tested as catalysts: iron-based materials were used in carbon-nanotubes synthesis, while Pd and Rh composite materials have been investigated in hydrogenation reactions

Stochastic Production Frontier Models to Explore Constraints on Household Travel Expenditures Considering Household Income Classes

This paper explores the variation of household travel expenditure frontiers (HTEFs) prior to CC reform in Jakarta. This study incorporates the variation of household income classes into the modeling of HTEFs and investigates the degree to which various determinants influence levels of HTEF. The HTEF is defined as an unseen maximum (capacity) amount of money that a certain income class is willing to dedicate to their travel. A stochastic production frontier is applied to model and explore upper bound household travel expenditure (HTE). Using a comprehensive household travel survey (HTS) in Jakarta in 2004, the observed HTE spending in a month is treated as an exogenous variable. The estimation results obtained using three proposed models, for low, medium and high income classes, show that HTEFs are significantly associated with life stage structure attributes, socio-demographics and life environment factors such as professional activity engagements, which is disclosed to be varied across income classes. Finding further reveals that considerable differences in average of HTEFs across models. This finding calls for the formulation of policies that consider the needs to be addressed for low and medium income groups in order to promote more equity policy thereby leading to more acceptable CC reform

Membangun Kemandirian Belajar Siswa Melalui Pembelajaran Matematika Realistik

The Purpose of this study is to determine the achievement and improvement of self regulated learning student through realistics mathematics learning. This study use a quasi-experimental design by the non-equivalent control group. The results are realistics mathematics learning more effectively in the achievement and improvement of self regulated learning student is compared conventional learning. Differences achievement and improvement in both groups is significant. The magnitude of the achievement of self regulated learning student is taught through realistics mathematics learning is 176.85, while self regulated learning student is taught through conventional learning is 172.96. While, the magnitude of the increase in self regulated learning student is taught realistic mathematics learning is 0.1, if it is compared with conventional learning

Peningkatan Kemampuan Komunikasi Matematik Melalui Pembelajaran Matematika Realistik

Tujuan penelitian ini adalah untuk mengetahui pencapaian dan peningkatan kemampuan komunikasi matematik siswa Sekolah Menengah Pertama Kota Bengkulu melalui Pembelajaran Matematika Realistik. Metode penelitian yang digunakan adalah kuasi eksperimen dengan non-equivalent control group design. Hasil penelitian sebagai berikut. Pembelajaran Matematika Realistik lebih efektif dalam pencapaian dan peningkatan kemampuan komunikasi matematik siswa dibandingkan pembelajaran konvensional. Besarnya pencapaian kemampuan komunikasi matematik siswa yang diajar melalui pembelajaran matematika realistik adalah 63,96 dan pembelajaran konvensional adalah 47,46. Sementara itu, besarnya peningkatan kemampuan komunikasi matematik siswa yang diajar melalui pembelajaran matematika realistik adalah 0,51 dan pembelajaran konvensional 0,24. The purpose of this study is to determine the achievement and improvement of students' mathematical communication ability in Bengkulu City Junior High School through realistic mathematics learning. The method used is a quasi-experimental non-equivalent control group design. The results of this study as follows. The realistic mathematics learning is more effective in the achievement and improvement of students' mathematical communication ability than conventional learning. The magnitude of the achievement of students' mathematical communication ability in realistic mathematics learning is 63,96 and conventional learning is 47,46. Meanwhile, the magnitude of the improvement of students' mathematical communication ability is realistic mathematics learning is 0,51 and conventional learning is 0,2

Pengaruh Tunjangan Kinerja Terhadap Kinerja Pegawai Pada Bauk Universitas Negeri Makassar

Penelitian ini bertujuan untuk mengetahui: 1) Gambaran persepsi pengawai mengenai pemberian tunjangan kinerja pada BAUK Universitas Negeri Makassar; 2) Gambaran kinerja pegawai pada BAUK Universitas Negeri Makassar 3) Pengaruh tunjangan kinerja terhadap kinerja pegawai BAUK Universitas Negeri Makassar. Pendekatan yang digunakan adalah pendekatan kuantitatif dengan jenis penelitian korelasional. Variabel dalam penelitian ini yaitu pemberian tunjangan kinerja sebagai variabel bebas dan kinerja pegawai sebagai variabel terikat. Populasi dalam penelitian ini sebanyak 107 dengan sampel sebanyak 50% (54 orang) yang diambil dengan menggunakan teknik proportinale random sampling. Teknik pengumpulan data yang dilakukan yaitu teknik angket observasi dan teknik dokumentasi. Data yang diperoleh melalui instrument angket, dianalisis dengan menggunakan statistik deskriptif dan inferensial setelah diuji persyaratan analisis.Hasil penelitian menunjukkan bahwa: 1) Persepsi pegawai mengenai pemberian tunjangan kinerja termasuk sangat tinggi; 2) Kinerja pegawai termasuk kategori sangat tinggi; 3) Terdapat pengaruh positif dan signifikan antara pemberian tunjangan kinerja terhadap kinerja pegawai. Oleh karena itu disarankan kepada pimpinan pada BAUK Universitas Negeri Makassar, kiranya berupaya mempertahankan kinerjanya dan bahkan lebih ditingkatkan

IR optical fiber-based noncontact pyrometer for drop tube instrumentation

The design of a two color pyrometer with infrared optical fiber bundles for collection of the infrared radiation is described. The pyrometer design is engineered to facilitate its use for measurement of the temperature of small, falling samples in a microgravity materials processing experiment using a 100 meter long drop tube. Because the samples are small and move rapidly through the field of view of the pyrometer, the optical power budget of the detection system is severly limited. Strategies for overcoming this limitation are discussed