Judul: Coffee Ground and Husk as Components of Growing Media for the Production of White Oyster Mushroom (Pleurotus ostreatus)
Abstrak: Jamur tiram memiliki nilai ekonomi, ekologi, dan kesehatan serta dibudidayakan dengan media serbuk kayu dengan campuran dedak. Namun, pemanfaatan dedak bersaing dengan kebutuhan lain, seperti pakan. Padahal, limbah industri kopi banyak tersedia. Oleh sebab itu, penelitian ini bertujuan untuk mengetahui potensi ampas dan kulit kopi sebagai komponen media jamur tiram putih pengganti dedak. Penelitian dilakukan pada dua konsentrasi ampas dan kulit kopi (9% dan 18%), sehingga terdapat empat perlakuan: ampas kopi 9% (A1), ampas kopi 18% (A2), kulit kopi 9% (K1), dan kulit kopi 18% (K2). Media perlakuan ditambah serbuk gergaji 80%, kapur 2%, dan dedak 9% atau 0%. Media kontrol (K) memiliki dedak 18%. Jamur dipanen hingga tiga kali. Setiap perlakuan memiliki rasio C/N dan produksi yang berbeda. Media dengan rasio C/N tertinggi adalah K2, diikuti berturut-turut oleh A2, K1, A1, dan K. Media dengan rasio C/N yang lebih tinggi menunjukkan periode inkubasi yang lebih pendek, kecuali pada K1 dan K2. Sebaliknya, media dengan rasio C/N yang lebih rendah menunjukkan bobot panen total, bobot tubuh buah, jumlah tubuh buah dan primordium (kecuali pada K1), dan nilai efisiensi biologi (EB) yang lebih tinggi. Perlakuan A1 memiliki nilai keberterimaan yang baik dan EB 42.11%, sehingga ampas kopi 9% dapat menjadi alternatif pengganti dedak., Oyster mushrooms have economic, ecological, and health values and are cultivated with sawdust media with a mixture of rice bran. However, the use of rice bran competes with other needs, such as feed. Meanwhile, coffee industry waste is widely available. Therefore, this study aims to determine the potential of coffee grounds and skins as components of white oyster mushroom media to replace rice bran. The study was conducted at two concentrations of coffee grounds and husks (9% and 18%), so that there were four treatments: 9% coffee grounds (A1), 18% coffee grounds (A2), 9% coffee husks (K1), and 18% coffee husks (K2). Added with 80% sawdust, 2% lime, and 9% or 0% rice bran. The control medium (K) had 18% bran. Mushrooms are harvested up to three times. Each treatment has a different C/N ratio and production. The medium with the highest C/N ratio was K2, followed by A2, K1, A1, and K, respectively. The medium with the higher C/N ratio showed a shorter incubation period, except for K1 and K2. On the other hand, media with a lower C/N ratio showed higher total harvest weight, fruiting body weight, number of fruiting bodies and primordium (except for K1), and higher biological efficiency (EB) values. The A1 treatment had a good acceptability value and an EB of 42.11%, 9% coffee grounds could be an alternative to rice bran.
Keyword: antinutrition, biological efficiency, C/N ratio, utilization

Judul: Growth and Production Of Oyster Mushroom (Pleurotus spp.) on Media Containing Sengon Wood, Coffee Skin, and Straw
Abstrak: Jamur tiram merupakan salah satu kelompok jamur kayu yang dapat dimakan (edible). Pemanfaatan limbah hasil kehutanan dan pertanian seperti serbuk gergaji kayu sengon, kulit kopi, dan jerami menjadi salah satu yang dapat dimanfaatkan sebagai media tanam dalam kultivasi jamur tiram guna memaksimalkan limbah yang ramah lingkungan. Penelitian bertujuan untuk menganalisis pengaruh media yang mengandung kayu sengon, kulit kopi, dan jerami terhadap pertumbuhan dan produksi jamur tiram. Penelitian menggunakan Rancangan Acak Lengkap (RAL) faktor tunggal dengan 3 perlakuan media yaitu formula 1 (kayu sengon dan kulit kopi), formula 2 (kayu sengon dan jerami), dan kontrol (kayu sengon). Hasil penelitian menunjukkan bahwa fase vegetatif jamur paling singkat diperoleh pada media formula 2 (15-18 hari). Fase generatif jamur yang membutuhkan waktu paling cepat masa panen diperoleh pada media kontrol (9-11 hari). Total bobot basah jamur terbesar dan nilai efisiensi biologis tertinggi diperoleh pada media kontrol (229,10 g) dengan nilai efisiensi biologis 79,0% pada jamur tiram putih (Pleurotus ostreatus) dan (331,70 g) pada jamur tiram cokelat (Pleurotus cystidiosus) dengan nilai efisiensi biologis 114,4%., Oyster mushroom is a group of edible wood mushrooms. Utilization of forestry and agricultural waste such as sawdust from sengon wood, coffee husks, and straw is one that can be used as a planting medium in oyster mushroom cultivation in order to maximize environmentally friendly waste. This study aims to analyze the effect of media containing sengon wood, coffee skin, and straw on the growth and production of oyster mushrooms. The study used a single factor completely randomized design (CRD) with 3 media treatments, namely formula 1 (sengon wood and coffee husk), formula 2 (sengon wood and straw), and control (sengon wood). The results showed that the shortest fungal vegetative phase was obtained in formula 2 media (15-18 days). The fungal generative phase wich required the fastest time to harvest was obtained in control media (9-11 days). The highest total wet weight of mushrooms and the highest biological efficiency value obtained on control media (229,10 g) with a biological efficiency value of 79,0% on white oyster mushroom (Pleurotus ostreatus) and (331,70 g) on brown oyster mushroom (Pleurotus cystidiosus) with a biological efficiency value of 114,4%.
Keyword: brown oyster mushroom, coffee husk, sengon wood, straw, white oyster mushroom.

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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