Judul: Design Modification of Parallel Infiltration Wells to Reduce Land and Roof Runoff in the New Lecture Building of Dramaga IPB
Abstrak: Salah satu upaya pengurangan limpasan hujan yang mencakup konservasi air tanah adalah sumur resapan. Perancangan sumur resapan pada gedung kuliah baru IPB sudah pernah dilakukan. Sumur resapan hanya meresapkan limpasan dari atap sehingga efektivitas sumur dalam meresapkan limpasan lahan total sebesar 17.77%. Penelitian ini bertujuan merancang, menghitung Rencana Anggaran Biaya (RAB) dan merekomendasikan teknis pengelolaan sumur resapan paralel yang meresapkan limpasan dari lahan dan atap gedung kuliah baru IPB. Penelitian dilaksanakan pada bulan April-Juli 2021. Pengambilan data dilakukan di gedung kuliah baru IPB. Perencanaan sumur resapan mengacu pada SNI 8456:2017. Sumur resapan direncanakan berpenampang lingkaran dengan dinding buis beton berporous, berdiameter 1 m dan kedalaman 2 m. Sumur resapan direncanakan meresapkan 50% beban volume limpasan sehingga dibutuhkan 116 sumur dengan luas lahan 1456.96 m2. RAB satu unit sumur resapan adalah Rp 5,565,728.00 sehingga untuk membangun 116 unit sumur resapan dibutuhkan biaya sebesar Rp 645,624,435.00. Sumur resapan yang direncanakan dapat meresapkan limpasan dari lahan dan atap secara alami tanpa bantuan pompa., One of the efforts to reduce rain runoff which includes groundwater conservation is infiltration wells. The design of infiltration wells in the new lecture building of IPB has been carried out. Infiltration wells only absorb runoff from the roof so that the effectiveness of the well in absorbing the total land runoff is 17.77%. This study aims to design, calculate the budget plan and recommend the technical management of parallel infiltration wells that absorb runoff from the land and roof of the new lecture building of IPB. The research was carried out in April-July 2021. Data collection was carried out in the new lecture building of IPB. Infiltration well planning refers to SNI 8456:2017. The infiltration well is planned to have a circular cross-section with a porous concrete buis wall, 1 m in diameter and 2 m deep. Infiltration wells are planned to absorb 50% of the runoff volume load so that it takes 116 wells with the required land area of 1456.96 m2. The budget plan for one unit of infiltration well is Rp. 5,565,728.00, so to build 116 units of infiltration well, it costs Rp. 645.624,435.00. The planned infiltration well can absorb runoff from the land and roof naturally without the help of a pump.
Keyword: atap, lahan, limpasan, permeabilitas, sumur resapan

Judul: Rancangan Sistem Penampungan Air Hujan Pada Bangunan Hijau Di Kampus IPB Dramaga Bogor
Abstrak: Indonesia merupakan negara beriklim tropis dengan curah hujan rata-rata yaitu antara 2.000-4.000 mm/tahun (KLH 2009). Potensi air hujan yang tinggi belum termanfaatkan secara optimal. Siklus hidrologi memegang peranan penting dalam menjaga ketersediaan air di permukaan bumi. Penelitian ini bertujuan menyusun desain penampungan air hujan, menghitung kebutuhan air domestik, dan menghitung persentase kebutuhan air domestik yang disuplai dari air hujan pada gedung kuliah baru IPB. Penelitian ini menggunakan data curah hujan harian 10 tahun terakhir, yaitu dari tahun 2010-2019 dengan acuan SNI 03-7065-2005 dan SNI 8153:2015. Hasil penelitian ini berupa Ground Water Tank (GWT) berukuran 6 x 4,5 x 4,5 x 0,3 m dengan kapasitas 121,92 m3 yang dapat memenuhi kebutuhan air gedung sebesar 78,90 %. Penelitian ini menggunakan sistem atap sebagai catchment area dari ground water tank. Debit andalan yang didapat berdasarkan luas area atap sebesar 53,65 m3. Penilaian Greenship kategori aspek konservasi air memperoleh poin sebesar 17 poin dari total 21 poin yang tersedia dengan dua tolak ukur prasyarat. Rancangan Anggaran Biaya (RAB) pembuatan ground water tank di gedung kuliah baru IPB sebesar Rp 347.905.662., Indonesia is a tropical country with an average rainfall of 2,000-4,000 mm/year (KLH 2009). The high potential of rainwater has not been utilized optimally. The hydrological cycle plays an important role in maintaining the availability of water on the earth's surface. This study aims to develop a rainwater storage design, calculate domestic water needs, and calculate the percentage of domestic water needs supplied from rainwater in the new IPB lecture building. This study uses daily rainfall data for the last 10 years, namely from 2010-2019 with reference to SNI 03-7065-2005 and SNI 8153:2015. The results of this study are Ground Water Tank (GWT) measuring 6 x 4,5 x 4,5 x 0.3 m with a capacity of 121,92 m3 which can meet the building's water needs of 82,90%. This study uses a roof system as a catchment area of the ground water tank. The mainstay discharge obtained based on the roof area is 53,65 m3. The Greenship assessment in the water conservation aspect category received 17 points out of a total of 21 points available with two prerequisite benchmarks. The Draft Budget (RAB) for the construction of a ground water tank in the new lecture building of IPB amounted to Rp 347.905.662.
Keyword: clean water needs, water conservation, rainwater storage

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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