Judul: The Study of Overland Flow Management Practices in the Arboretum of Jagorawi Toll Road, Bogo
Abstrak: Jalan raya diketahui merupakan salah satu sumber pencemaran air permukaan yang berasal dari polutan kendaraan berupa emisi gas buang dan bahan lain. Aliran permukaan yang melalui jalan raya sebagian akan meresap ke dalam tanah di sekitar jalan dan sebagian dapat berakumulasi menjadi genangan. Proses tersebut berjalan terus menerus menyebabkan adanya akumulasi bahan emisi kendaraan di dalam tanah. Salah satu metode untuk meminimalisir hal tersebut adalah dengan menerapkan teknik bioretensi. Arboretum tol Jagorawi idealnya berfungsi sebagai sistem bioretensi yang dapat mengontrol kualitas aliran permukaan dan mengalirkannya dengan aman ke daerah sekitarnya. Penelitian ini bertujuan mengkaji pengelolaan aliran permukaan di arboretum tol Jagorawi, mengkaji keterkaitan antara selang kejadian hujan, tinggi dan lama hujan, serta volume kendaraan yang melewati jalan tol Jagorawi dengan sifat-sifat fisik dan kimia pada air hujan dan air permukaan, mengetahui kemampuan tanah sebagai sistem bioretensi dan mengkaji kemampuan sistem bioretensi melalui karakter sifat kimia air sumur di pemukiman warga. Hasil penelitian menunjukkan bahwa air permukaan dengan selang kejadian hujan paling panjang memiliki kadar TDS paling tinggi sejalan dengan tingginya volume kendaraan. Nilai pH air hujan dan air permukaan sekitar 6,1-6,7, tergolong aman dan tidak berpotensi mencemari air tanah. Kadar P-total air hujan sekitar 0,2-0,33 mg/l, tergolong tidak aman bagi air minum, akan tetapi kandungan P-total dalam air sumur warga tergolong rendah dan tidak menunjukkan adanya pencemaran. Kandungan nitrat pada air permukaan sekitar 10,33-14,47 mg/l, tergolong tidak aman untuk air minum dan berpotensi mencemari air tanah, akan tetapi kandungan nitrat pada air tanah tergolong rendah dan tidak menunjukkan adanya pencemaran. Kadar Pb pada air hujan dan air permukaan sekitar 0,003-0,013 mg/l, tergolong aman bagi air minum dan tidak berpotensi sebagai pencemar, akan tetapi contoh air sumur 3 menunjukkan kandungan Pb yang melebihi batas ambang kualitas air minum yaitu sebesar 0,018 mg/l. Arboretum tol Jagorawi sudah memenuhi syarat sifat fisik sistem bioretensi kecuali tekstur. Tekstur tanah di lokasi penelitian mengandung liat ≥ 50%.
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Judul: Evaluasi jalur hijau jalan sebagai penyangga lingkungan sekitarnya dan keselamatan pengguna jalan bebas hambatan jagorawi
Abstrak: The traffic problems have been increasing in recent few years. In many big cities, the volume of vehicle causes air pollutions and noises that are disturbing the comfortably of men activities. Highway is the most contributing factor in traffic problems. From many solutions, the greenery in highway is the one of solutions against negative effects of traffic as environment buffer, especially for communities and for supporting users safety. The objectives of this study are to evaluate roadside greenery in Jagorawi Highway as a buffer and for supporting of users safety in three major functions, there are air pollutants reduction, noises abatement, and space barrier. Fieldwork researches were conducted onto three segments road: Bogor’s - Ciawi’s tollgates to Sentul’s ramp as 1st segment (± 15,4 km length); Sentul’s ramp to Cimanggis’s ramp as 2nd segment (± 13,5 km length); and Cimanggis’s ramp to Taman Mini’s tollgate as 3rd segment (± 15 km length). Every segment was divided into two sections: East side and West side. The comparative method was used to measure suitability and compatibility plants in roadside greenery in Jagorawi according to the regulations and principles of landscape architecture science. The comparative method result that all segments and sections on fieldwork indicate that plants selection, structures, patterns and configurations were not suitable and compatible enough for supporting the three major functions of road greenery (assessment ranged from bad to moderate grades). The greenery at first segment achieves moderate grade (44,26% requirements fulfilled) in air pollutants reduction, bad to moderate grade (32,67% - 41,67% requirements fulfilled) in noises abatement, moderate grade (56,00% - 57,33% requirements fulfilled) in space barrier function and moderate grade (56,00% - 58,17% requirements fulfilled) in aesthetic function. The second segment achieves moderate grade (47,54% - 50,32% requirements fulfilled) in air pollutants reduction, bad grade (30,0% requirements fulfilled) in noises abatement, moderate grade (57,69% - 58,85% requirements fulfilled) in space barrier function and moderate grade (57,50% - 58,46% requirements fulfilled) in aesthetic function. The third segment achieves moderate grade (49,35% - 50,74% requirements fulfilled) in air pollutants reduction, moderate to good grade (59,33% - 69,67% requirements fulfilled) in noises abatement, good grade (62,83% - 69,67% requirements fulfilled) in space barrier function and moderate grade (59,42% requirements fulfilled) in aesthetic function. According to the above analysis result, the study proposes a concept of appropriate plants selecting, according its structure and performance and so pattern and configuration to achieve the effectiveness of roadside greenery as environment buffer and supporting the safety in Jagorawi Highway.
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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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