Judul: Analisis IPK Rendah Mahasiswa TPB IPB Tahun Akademik 2009/2010
Abstrak: Keberhasilan studi mahasiswa baru di IPB dapat diamati melalui IPK pada TPB. Berdasarkan rangkuman data IPK populasi mahasiswa baru IPB Tahun Akademik 2009/2010 dengan beracuan pada kriteria pemeringkatan sekolah dalam Peringkat Riwayat Akademik Sekolah di IPB (PERAK SLTA-IPB), terdapat sekitar 11% (342 orang) mahasiswa TPB memiliki IPK kurang dari 2.10 atau tergolong memiliki IPK rendah, dengan persentase terendah ada pada jalur USMI dan tertinggi ada pada jalur BUD. Ada 2 kelompok mahasiswa dengan IPK rendah, yaitu mahasiswa DO (IPK ≤ 1.50) dan mahasiswa tidak DO ( 1.50 < IPK ≤ 2.10). Keberhasilan studi mahasiswa baru mungkin dipengaruhi oleh faktor lingkungan dan budaya serta faktor sosial ekonomi. Faktor lingkungan budaya diwakili oleh daerah asal SLTA, peringkat asal SLTA, jalur masuk IPB, prioritas pilihan masuk IPB, tingkat popularitas mayor, nilai Pengantar Matematika, Kalkulus, Kimia, Fisika, dan Biologi. Sedangkan faktor sosial ekonomi diwakili oleh jenis kelamin, penghasilan orang tua / wali, pekerjaan orang tua / wali. Dari model regresi logistik biner dengan peubah respon adalah mahasiswa TPB Tahun Akademik 2009/2010 dengan IPK rendah terungkap bahwa hanya faktor lingkungan dan budaya yang berpengaruh terhadap mahasiswa DO, yaitu prioritas pilihan masuk IPB, nilai Kalkulus, Kimia, dan Biologi. Nilai Kalkulus paling dominan mengakibatkan DO mahasiswa TPB dengan IPK rendah. Model regresi logistik biner yang dibangun pada penelitian ini memiliki tingkat ketepatan klasifikasi sebesar 91.5%.
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Judul: Evaluasi Faktor Sosial dan Ekonomi terhadap IPK<2.10 di TPB IPB
Abstrak: IPB admit students through the SNMPTN Undangan, written test (SNMPTN Ujian Tertulis and Ujian Talenta Masuk IPB), Beasiswa Utusan Daerah, and Prestasi Internasional-Nasional. The majority of admissions is from SNMPTN Invitation, which is about 67%. Selection method on the SNMPTN Undangan based on school quality that is reflected in PERAK SLTA-IPB, academic potential applicants, and principle of student diversity IPB as a miniature of Indonesia. Academic potential applicants are represented by the value of science and math, and students in the school rankings. The distribution of grade point average (GPA) TPB is negative skew. Total of 9.1% of students in TPB IPB academic year 2011/2012 have GPA<2.10 with unequal percentages in each selection and 16% of them is drop out. PTN is essentially trying to get students with the best academic potential as much available capacity, certainly it is not a random process. Relationship between GPA and social and economic factors with quantile regression shows that SNMPTN Undangan, female student, study program BPIF category 1, and area from Central Java - Yogyakarta - East Java provides a low failure rate in the TPB. Electric power and income of parents has not effect on the low GPA. In addition, the UN does not affect the value of a low GPA then the UN has not been able to reflect the value of school quality and academic potential high school graduates to succeed in the TPB.
Keyword: Quantile Regression, PERAK SLTA-IPB, GPA

Judul: Sintesis Nanokristal Magnetit Menggunakan Urea sebagai Penjerap Cr(VI)
Abstrak: The study was to synthesize and characterize magnetite nanocrystal. Magnetite powder was synthesized using hydrothermal method from FeSO4 as precursor and sodium hydroxide and urea as the base sources. Characterization of the obtained powder was carried out using X-ray diffraction, scanning electron microscope, and energy dispersive X-ray analyzer. The crystallite size of magnetite by X-ray diffraction was obtained from 18,23 to 67,34 nm. The scanning electron microscope observations showed that magnetite particles underwent agglomeration. Magnetite powder was used as Cr(VI) adsorbent. The results showed that adsorption capacity for urea-based magnetite at pH 1-5 in 2 hours were 1.92; 1.91; 1.59; 1.20; and 1.21 mg/g, respectively. Adsorption capacity for sodium hydroxide-based magnetite (pH 1-5, 2 hours) were 1.74; 1.83; 0.64; 0.69; and 0.77 mg/g. The results indicated that urea-based magnetite is able to increase adsorption capacity.
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