Judul: Effectiveness of water change on Control Media to Growth of Sea Grape Caulerpa lentillifera
Abstrak: Anggur laut termasuk dalam kelompok rumput laut dengan proses pertumbuhannya memanfaatkan arus dalam penyebaran unsur hara. Pergantian air pada budidaya anggur laut dilakukan untuk manipulasi terhadap arus yang akan menciptakan pergerakan air. Penelitian ini bertujuan untuk mengetahui pengaruh pergantian air terhadap rekayasa arus pada pertumbuhan Caulerpa lentillifera yang dilakukan pada kolam terkontrol. Bibit yang digunakan pada masing-masing media tanam yaitu sebanyak 500 gram Penelitian ini terdiri dari empat perlakuan dengan masing-masing tiga ulangan. Perlakuan yang diujikan menggunakan kode yang terdiri dari perlakuan PA5 (pergantian air lima hari sekali), PA3 pergantian air tiga hari sekali), PA2 (pergantian air dua hari sekali), PA1 (pergantian air setiap hari selama 8 jam/hari). Pergantian air yang dilakukan memberikan pengaruh terhadap pertumbuhan C. lentillifera. Hasil laju pertumbuhan bobot spesifik terbaik terdapat pada perlakuan pergantian air setiap hari, selama 8 jam/hari pada media budidaya anggur laut yaitu sebesar 2,78±0,12%., Sea grapes are included in the seaweed group with their growth process utilizing currents in the distribution of nutrients. Water changes in sea grape cultivation are done for manipulation of currents that will create water movement. This study aimed to measure the effect of water change on manipulation flow to the growth of Caulerpa lentillifera on control media. The seeds used for each one planting media were 500 grams. The study consisted of four treatments with three replications each. The treatment was PA5 (no water change for 5 days), PA3 (no water change for three day), PA2 (no water change for one days), and PA1 (daily water change). Water change treatment has an effect on the growth of sea grapes. The best result of spesific growth rate was water change treatment for days as long as 8 hours in sea grape cultivation was 2,78±0,12%.
Keyword: Caulerpa lentillifera, Growth, Current

Judul: Effect of Sea Grapes (Caulerpa lentillifera) Immersion Time in NaCl Solution on Organoleptic Quality and Antioxidant Activity
Abstrak: Anggur laut (Caulerpa lentillifera) memiliki kelemahan cepat mengalami kemunduran mutu. Perendaman anggur laut dalam larutan NaCl dapat memperpanjang tingkat kesegaran. Penelitian ini bertujuan menentukan pengaruh lama perendaman anggur laut dalam larutan NaCl terhadap mutu organoleptik, aktivitas antioksidan dan masa simpan. Perlakuan yang diberikan yaitu perendaman 0, 10, dan 20 menit. Pengamatan setiap 2 hari selama 10 hari terhadap morfologi, rendemen ekstrak, berat, diameter, organoleptik, senyawa bioaktif, dan IC50. Interaksi faktor perendaman dan penyimpanan tidak memengaruhi rendemen ekstrak dan kadar air. Perendaman kembali dengan air tawar mampu mengembalikan berat dan diameter anggur laut. Penerimaan panelis bertahan hingga hari ke-10 pada anggur laut yang direndam larutan NaCl, namun hanya bertahan hingga hari ke-6 pada anggur laut segar. Senyawa alkaloid, steroid, dan saponin hanya terdeteksi pada hari ke-0 dan tidak terdeteksi pada hari selanjutnya hingga hari ke-10. Nilai IC50 mengalami peningkatan hingga hari ke-10 pada seluruh perlakuan., Sea grapes (Caulerpa lentillifera) have the disadvantage which is quickly spoiled. Immersing sea grapes in NaCl solution can extend the freshness qualities. This study aims to determine the effect of sea grapes immersing time in NaCl solution on organoleptic quality, antioxidant activity, and storage time. The treatments given were immersion 0, 10, and 20 minutes. Observations every 2 days for 10 days on morphology, extract yield, weight, diameter, organoleptic, bioactive compounds, and IC50. The interaction of immersion and storage factors did not affect the extract yield and water content. Rehidration in fresh water is able to restore the weight and diameter of sea grapes. Acceptance of panelists lasted up to day 10th on sea grapes immersed in NaCl solution, but only lasted until day 6th on fresh sea grapes. Alkaloids, steroids, and saponins were only detected on day 0 and were not detected on the next day up to day 10th. The IC50 value has increased up to day 10th in all treatments.
Keyword: sea grapes, immersing time, NaCl solution, shelf life

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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