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"Hamburan neutrino dengan materi bintang quark melalui interaksi lemah arus ne- tral telah dipelajari. Untuk menjelaskan keadaan materi quark, digunakan model bag MIT. Struktur bintang quark dapat dipelajari dengan memasukkan persamaan keadaan bintang quark kedalam persamaan TOV. Dalam tulisan ini kami mempela- jari penampang lintang differensial dan lintasan bebas rata-rata neutrino. Perhitun- gan dilakukan menggunakan dua metode; Pertama dengan memperhatikan hambu- ran N-body sebagai N kali hamburan dua partikel, Kedua dengan memperlakukan efek banyak benda dengan baik dalam hamburan N-body. Kedua pendekatan dipela- jari dan dibandingkan pada kasus temperatur nol. Untuk pendekatan pertama, interaksi didominasi oleh quark down, sedangkan untuk pendekatan kedua quark down dan quark strange memberikan kontribusi yang sama. Lintasan bebas rata- rata neutrino menurun dengan meningkatnya kerapatan, temperatur dan energi awal neutrino. Untuk kasus temperatur berhingga, terdapat beberapa faktor yang perlu diperhatikan, seperti; faktor retardasi, Pauli blocking dan detailed balancing. Pauli blocking dan detailed balancing secara signifikan mengurangi nilai lintasan bebas rata-rata neutrino. Sedangkan faktor retardasi menunjukkan sifat yang tidak biasa dari lintasan bebas rata-rata neutrino-quark strange. Selain itu, efek penangkapan neutrino secara signifikan menyebabkan fraksi elektron meningkat. Kontribusi elek- tron menurunkan lintasan bebas rata-rata neutrino. Lebih lanjut, lintasan bebas rata-rata neutrino dari pusat bintang quark hingga ke permukaan bintang semakin meningkat.

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The scattering of neutrino with quark star matter through neutral current weak interaction is studied. To describe the quark matter state, MIT bag model is used. The quark star structures can be studied by inserted the quark star equation of state into TOV equation. Here we study the neutrino differential cross section and mean free path. The calculation is performed by using two method; First by considering N-body scattering as N times two body scattering, Second by treating the many body effect properly in N-body scattering. Both approach are compared and studied for the case zero temperature, where we have found that for the first approach, interaction are dominated by the one from down quark, while the second approach the down and strange quarks provide similar contribution. Neutrino mean free path decreases with increasing density, temperature and initial energy neutrino. For finite temperatur case are several factors should be considered, i.e, retardation, Pauli blocking and detailed balancing factors. Pauli blocking and detailed balancing significantly reduce the value of the neutrino mean free path. While the retardation factor indicates unusual behavior of neutrino-strange quark mean free path. In addition, the effect of neutrino trapping is significantly increased the fraction of electrons. Contribution of electrons reduces the value neutrino matter mean free path. Therefore, the neutrino mean free path from the center of quark star to the stellar surface increases."

"Penelitian ini bertujuan untuk mendeskripsikan dan mengaji signifkansi peningkatan nilai rata-rata hasil ujian nasional (UN) SMP di kabupaten Garut dari tahun 2004sampai 2006 Data sekunder yang di gunakan dalam penelitian ini berasal dari Pusat Penilaian Pendidikan

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"ABSTRAKPeatland fires encourage the government to restore peat function as natural water storage. One of the measures taken is to build a circumference dike to hold water to reduce excessive drainage. However, there is no study yet of the planned average water level that has to be maintained from the construction of circumference dike. Therefore, the aim of this study is to calculate the average water level on peatlands inside the circumference dike. The methods used consist of hydrological analysis, spatial analysis, and water level analysis. The results of the analysis shows that the average water level in normal years tends to be above the surface, except in the second half of August to the first half of November. In the second half of September to the second half of October, the peat has the potential to be burned. In a dry season the water tends to fall decline to the drainage boundary of peatland which is at -1.5 m which occurs in the second half of March to December. In the second half of February until December peatland has potential to be burned. From this research, it can be concluded that the calculations using this method is similar with in-situ observation data and can be used to calculate the average water level of peat with the same conditions in other locations."