Judul: Aktivitas Antibakteri Ekstrak Kulit Petai (Parkia speciosa Hassk.) Terhadap Bakteri Escherichia coli dan Staphylococcus aureus
Abstrak: Parkia speciosa Hassk. is one of edible plants that not developed as medicinal plants yet.The purpose of this research is to study antibacterial activity of peel extract to Staphylococcus aureus and Escherichia coli bacteria with gel diffusion (well method). Peel extract that used in this research were from extraction of n-hexane, ethyl acetate, and ethanol 70%. The concentration were 50, 100, 150, 200, 250, and 300 mg/mL for every solvent. The result of this research showed that ethyl acetate extract has the highest antibacterial activity with 404,25% of 10 mg/mL streptomycin’s antibacterial activity agains Staphylococcus aureus, and 279,12% of 10 mg/mL streptomycin’s antibacterial activity agains Escherichia coli. TLC result showed that ethyl acetate extract with toluene:ethyl acetate (93:7) as solvent has eight spots under 254 nm UV that was mean ethyl acetate extract of petai peel consisted of eight compound. The result of Analysis of Variance with SPSS 16 program for windows showed that variance of solvents and concentration were significantly different for inhibition areas
Keyword: Bogor Agricultural University (IPB), TLC, Staphylococcus aureus, Parkia speciosa Hassk, Escherichia coli, antibacteria

Judul: Aktivitas Antibakteri Ekstrak Daun Sengon (Falcataria moluccana (L) Nielsen) terhadap Bakteri Staphylococcus aureus dan Escherichia coli
Abstrak: Disease by infection is most suffered by people and developed from time to time in medicines. The last research showed that Falcataria moluccana leafs had fitochemical compounds and potential as antibactery. The research aimed to study the antibacterial compounds activity of Falcataria moluccana leafs extract at S. aureus and E. coli with gel diffusion (well method). The leafs used in this research were leaf extract from extraction of aquades, ethanol 70%, ethanol 96%, and ethyl acetate. The concentrations were 50, 100, 150, 200, 250, and 300 mg/mL for each solvents. The result showed that aquades extract could not inhibit the growth of bacteria, while ethyl acetate and ethanol extracts showed antibacterial activity. The largest antibacterial activity showed by ethyl acetate extract at concentration 300 mg/mL with inhibiton areas 6.90 and 4.97 mm for S. aureus and E. coli. This values included in medium category. The result of Analysis of Variance with SPSS 16. program for windows showed that variance of solvents and concentration were significantly difference for inhibition areas.
Keyword: Falcataria moluccana (L) Nielsen, S. aureus, E. coli, antibactery

Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular