Judul: Effectivity Malang Apple (Malus sylvestris Mill) Peels Infuse as Antidiarrheal for Mice (Mus musculus)
Abstrak: Kulit apel memiliki berbagai manfaat kesehatan sebagai antioksidan, antibakteri, dan antiproliferatif. Penelitian ini bertujuan untuk mengetahui kandungan metabolit sekunder apel malang dengan skrinning fitokimia dan kemampuannya sebagai antidiare menggunakan metode proteksi intestinal, serta mengetahui konsentrasi yang efektif sebagai antidiare pada mencit. Penelitian menggunakan 30 ekor mencit yang dibagi menjadi lima kelompok yaitu kelompok kontrol (-), kontrol (+), dan tiga kelompok percobaan dengan tingkat konsentrasi 25%, 50%, dan 100% diberikan secara peroral. Parameter yang diamati berupa frekuensi defekasi, konsistensi feses, onset, durasi, serta waktu persembuhan diare mencit setiap 30 menit selama 9 jam. Hasil skrinning fitokimia kulit apel menunjukkan adanya senyawa metabolit sekunder berupa alkaloid, flavonoid, dan saponin. Hasil pengamatan pada onset, durasi, dan waktu persembuhan diare menunjukkan sediaan infusa kulit apel pada setiap konsentrasi dapat mempersingkat durasi diare. Hasil pengamatan konsistensi, frekuensi, dan durasi menunjukkan infusa kulit apel malang memiliki efek antidiare pada setiap konsentrasi dengan konsentrasi 100% memiliki tingkat efektivitas paling baik sebagai antidiare., Apple peels have various health benefits as antioxidants, antibacterials, and antiproliferative agent. This study aimed to determine the secondary metabolite content of unfortunate apples by phytochemical screening and its ability as antidiarrheal using the intestinal protection method, as well as to determine the effective concentration as antidiarrheal in mice. The study used 30 mice divided into five groups, namely the control group (-), control (+), and three experimental groups with concentration levels of 25%, 50%, and 100% given orally. Parameters observed were frequency of defecation, consistency of feces, onset, duration, and recovery time of mice diarrhea every 30 minutes for 9 hours. The results of apple peel phytochemical screening showed the presence of secondary metabolite compounds in the form of alkaloids, flavonoids, and saponins. The results of observations on the onset, duration, and recovery time of diarrhea showed that apple peel infuse preparations at each concentration could shorten the duration of diarrhea. Observations on consistency, frequency, and duration showed that apple peel infuse had an antidiarrheal effect at each concentration with 100% concentration having the best level of effectiveness as antidiarrheal.
Keyword: antidiare, infusa, proteksi intestinal, apel hijau, kulit apel

Judul: Effectiveness Test of Watery Rose Apple Leaves  Decoction (Syzygium samarangense Blume) as Antidiarrheal in Mice (Mus  musculus)
Abstrak: Tanaman jambu air telah banyak digunakan sebagai obat herbal dalam mengatasi penyakit, akan tetapi belum ada penelitian mengenai aktivitas antidiare pada tanaman ini. Penelitian ini bertujuan mengetahui aktivitas antidiare dari daun jambu air dengan dua metode yakni metode proteksi intestinal dan transit intestinal. Penelitian ini menggunakan 30 ekor mencit jantan yang dibagi menjadi enam kelompok perlakuan: kelompok kontrol positif (Loperamide HCl), kelompok kontrol negatif (Tween-80 [1%]), dan empat kelompok perlakuan dekok daun jambu air dengan konsentrasi 12,5%, 25%, 50%, dan 100%. Parameter yang diamati pada metode proteksi intestinal yaitu frekuensi defekasi dan konsistensi feses, sedangkan pada metode transit intestinal yaitu rasio lintasan penanda usus. Berdasarkan kedua metode tersebut, dekok daun jambu air dengan konsentrasi 12,5%, 25%, 50%, dan 100% mempunyai aktivitas antidiare. Dekok daun jambu air dengan konsentrasi 12,5% menunjukkan aktivitas antidiare yang paling efektif., Watery rose apple plants have been widely used as herbal medicine in overcoming diseases, but there has been no research on the antidiarrheal activity of this plant. This study aims to determine the antidiarrheal activity of watery rose apple leaves with two methods, namely intestinal protection and intestinal transit methods. This study used 30 male mice which were divided into six treatment groups : the positive control group (Loperamide HCl), the negative control group (Tween-80 1%), and four treatment groups of watery rose apple leaf decoction with concentrations of 12.5%, 25%, 50%, and 100%. The parameters observed for intestinal protection method were defecation frequency and stool consistency, while for intestinal transit method intestinal were marker passage ratio. Based on both methods, watery rose apple leaves decoction with concentrations of 12.5%, 25%, 50%, and 100% had antidiarrheal activity. Watery rose apple leaves decoction with a concentration of 12.5% showed the most effective antidiarrheal activity.
Keyword: antidiarrheal, intestinal protection, intestinal transit, watery rose apple

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
Keyword: