Judul: The Effectiveness of Oil as a Slow Release Urea Nitrate Coating Material on Fermentability, Digestibility and In Vitro Gas Production
Abstrak: Penelitian ini bertujuan untuk mengevaluasi efektivitas minyak sebagai coating slow release urea nitrat secara in vitro. Penelitian ini menggunakan rancangan acak kelompok (RAK) dengan 5 perlakuan dan 4 kelompok. Perlakuan terdiri dari P0 = ransum kontrol; P1 = P0 + urea; P2 = P0 + urea nitrat; P3 = P0 + urea nitrat dengan coating minyak sawit; P4 = P0 + urea nitrat coating minyak ikan. Parameter yang diamati yaitu pH, konsentrasi ammonia (NH3), volatile fatty acid (VFA), sintesis protein mikroba (SPM), koefisien cerna bahan kering (KCBK), koefisien cerna bahan organik (KCBO), produksi gas, dan gas metan. Analisis data menggunakan sidik ragam dengan perlakuan berbeda nyata dilakukan uji lanjut menggunakan uji Duncan menggunakan software SPSS versi 25. Hasil penelitian menunjukkan bahwa penggunaan slow release urea nitrat dengan coating minyak ikan dan minyak sawit tidak berpengaruh nyata (P>0,05) terhadap pH, NH3, SPM, VFA, KCBK, KCBO, total produksi gas, dan gas metan. Penggunaan SRUN dengan bahan coating minyak sawit dan minyak ikan belum efektif memengaruhi fermentabilitas, kecernaan dan produksi gas in vitro., This study aimed to evaluate the effectiveness of oil as a slow release urea nitrate coating in vitro. This study used a randomized block design (RBD) with 5 treatments and 4 groups. The treatment consisted of P0 = control ration; P1 = P0 + urea; P2 = P0 + urea nitrate; P3 = P0 + urea nitrate with palm oil coating; P4 = P0 + urea nitrate coating of fish oil. Parameters observed were pH, concentration of ammonia (NH3), volatile fatty acids (VFA), microbial protein synthesis (SPM), dry matter digestibility coefficient (KCBK), organic matter digestibility coefficient (KCBO), gas production, and methane gas. Data analysis using analysis of variance (ANOVA) and significantly different treatments were tested with the Tukey's test using SPSS software version 25. The results showed that the use of slow release urea nitrate with fish oil and palm oil coatings had no significant effect (P>0.05) on pH, NH3, SPM, VFA, KCBK, KCBO, amount of gas production and methane gas. The use of SRUN with palm oil and fish oil coatings has not effectively influenced in vitro fermentability, digestibility, and gas production.
Keyword: Coating, urea nitrate, in vitro, oil, slow release

Judul: Slow Release Urea Nitrate with Acetaldehyde and Formaldehyde Coating Techniques against Fermentability and In Vitro Digestibility
Abstrak: Penelitian ini bertujuan mengevaluasi pengaruh pemberian coating asetaldehid dan formladehid terhadap fermentabilitas, kecernaan, serta produksi gas dalam rumen secara in vitro. Penelitian ini menggunakan rancangan acak lengkap (RAL) untuk menguji parameter pH, kecernaan bahan kering (KcBK), kecernaan bahan organik (KcBO), konsentrasi amonia, produksi gas, gas metan dan volatile fatty acid (VFA) total serta uji lanjut Tukey HSD. Data yang diperoleh dianalisis dengan menggunakan software SPSS versi 25. Hasil penelitian tersebut menunjukkan bahwa pemberian coating urea nitrat berlapis asetaldehid dan formladehid tidak berpengaruh nyata terhadap pH, KCBK, KCBO, VFA, gas metan dan konsentrasi amonia di dalam rumen. Akan tetapi berpengaruh nyata (P <0,05) dalam menurunkanproduksi gas. Dapat disimpulkan bahwa Penggunaan slow release urea nitrat (SRUN) dengan bahan coating asetaldehid lebih efektif memperlambat laju degradasi amonia dari pada bahan coating formaldehid, namun bahan coating asetaldehid dan formaldehid tidak berdampak terhadap fermentasi rumen, kecernaan, dan produksi metana., This study aimed evaluate the effect of coating acetaldehyde and formaldehyde on fermentability, digestibility, and gas production in the rumen in vitro. This study used a completely randomized design (CRD) to test the parameters of pH, dry matter digestibility (DMD), organic matter digestibility (OMD), ammonia concentration, gas production, methane gas and volatile fatty acid (VFA) ) and differences among mean values were examined using Tukey HSD test. The data obtained were analyzed using SPSS software version 25. The results showed that the coating of urea nitrate coated with acetaldehyde and formaldehyde had no significant effect on pH, DMD, OMD, VFA, methane gas and ammonia concentration in the rumen. However, it had a significant effect (P <0.05) in reducing gas production. The use of slow release urea nitrate (SRUN) with acetaldehyde coating materials is more effective in slowing the rate of ammonia degradation than formaldehyde coating materials, but acetaldehyde and formaldehyde coating materials have no impact on rumen fermentation, digestibility, and methane production.
Keyword: ammonia, acetaldehyde, formaldehyde, urea nitrate coatings

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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