Judul: Quality of Eri Silkworm Frass Fertilizer (Samia  cynthia ricini) with EM4 and PGPR Activators
Abstrak: Eri silkworm (Samia cynthia ricini) has the potential to be cultivated in Indonesia. Silkworm cultivation in a year produces 250-300 kg of frass which has potential cause problems for cultivation and environment. Frass has high nutrients so potentially used as fertilizer for agricultural. This study aims to analyze the quality of silkworm frass fertilizer with EM4 and PGPR activators on spinach. The production of fertilizer is accelerated by using activators EM4 and PGPR. The physical and chemical properties of fertilizers were analyzed descriptively. Fertilizer effectiveness experiment on watercress was carried out using a completely randomized design (CRD). At 4th week the physical properties of the fertilizer changed texture and pH according to SNI but still had a slightly sour smell and black color. Using EM4 and PGPR showed increase NPK according to SNI. The usage frass silkworm S. c. ricini fertilizer had significant effect on height, stem diameter, number of leaves, fresh weight, water shoots, water spinach leaves based on Tukey's advanced test on level of 5%. Therefore, Eri silkworm frass fertilizer has potentially used as fertilizer for horticultural in spinach as experimental plant.
Keyword: EM4, Eri silkworm frass, PGPR, Samia cynthia ricini, Spinach

Judul: Microbiological Properties and Antioxidant Activity of Eri Silkworm Pupae (Samia cynthia ricini) Flour with Different Particle Size
Abstrak: Pupa ulat sutra Eri (Samia cynthia ricini) memiliki nilai gizi dan sifat antioksidan yang dapat dijadikan sebagai produk pangan berupa tepung. Sebagai produk pangan, diperlukan uji analisis mikrobiologi sehingga diketahui kelayakannya. Sifat Mikrobiologi dianalisis dengan menghitung Angka Lempeng Total, E. coli, S. aureus dan Salmonella sp. Sementara itu, adanya proses pengayakan tepung dengan tujuan menghomogenkan ukuran partikel dapat memengaruhi aktivitas antioksidan. Maka dari itu, nilai aktivitas antioksidan pada tepung sutra Eri dengan ukuran partikel 80 mesh dan 60 mesh diuji melalui aktivitas penghambatan DPPH (2.2-Diphenyl-1-picrylhydrazyl) dan kapasitas antioksidan. Analisis data menggunakan rancangan acak lengkap (RAL) dan uji T-Independen. Hasil menunjukkan bahwa nilai ALT, E. coli dan Salmonella sp. telah memenuhi ketentuan standar SNI 3751:2009. Jumlah sel S. aureus pada tepung ialah <105 koloni/g, sehingga mengindikasikan bahwa jumlah cemaran tidak melebihi ambang batas. Selain itu, analisis aktivitas antioksidan kedua tepung tergolong kuat meskipun ukuran partikel tepung pupa sutra Eri yang berbeda tidak memberikan pengaruh nyata., Eri silkworm pupae (Samia cynthia ricini) have nutritional and antioxidant values that can be used as food products in the form of flour. As a food product, it is necessary to test its microbiological properties so that its feasibility is known. Microbiological properties were analyzed by calculating the Total Plate Count, E. coli, S. aureus and Salmonella sp. Meanwhile, the process of sifting flour with the aim of homogenizing the particle size will affect the antioxidant activity. Therefore, the antioxidant activity in Eri silk flour with particle sizes of 80 mesh and 60 mesh was tested through DPPH inhibition activity and antioxidant capacity. Data analysis used a completely randomized design (CRD) and independent T-test. The results showed that the value of the TPC, E. coli and Salmonella sp. has met the standard provisions of SNI 3751:2009. The number of S. aureus cells was <105 colonies/g which indicated that the amount of contamination did not exceed the thresholdhe analysis of the antioxidant activity was classified as strong although the different particle size did not have a significant effect.
Keyword: antioxidant, flour, microbiological properties, pupae, Samia cynthia ricini

Judul: : Persamaan Tunggal sebagai Representasi Kurva Komposit
Abstrak: A mathematical method is introduced to represent a composite curve based on an extension of analytic geometry. The representation is given either with a single equation or with two equations, in the case of parametric representation. This method permits the representation of composite curves in similar manner to the conventional representation of non-composite curves. Some mathematical tools, including Heaviside unit step function and periodizer function, are used in the establishment of a single equation. In this paper, regular equations of regular and irregular polygon, as well as composite curves of two dimensions, are implemented using a computer algebraic system, Mathematica.
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