Judul: Magic Strength pada Graf Path, Bistar, dan Cycle Ganjil
Abstrak: Karya ilmiah ini membuktikan teorema-teorema untuk memperoleh magic strength pada graf path, graf bistar, dan graf cycle ganjil. Magic strength pada suatu graf adalah nilai minimum dari semua bilangan konstan yang diperoleh dari semua magic labeling pada graf tersebut. Magic labeling pada suatu graf merupakan pelabelan total pada simpul dan sisi suatu graf dengan labelnya adalah bilangan asli, dimana jumlah label-label pada sebuah sisi yang incident dengan dua simpul adalah suatu bilangan konstan. Terdapat empat pembuktian teorema yang dibahas dalam karya ilmiah ini. Misalkan n merupakan suatu bilangan asli. Teorema pertama membuktikan bahwa nilai magic strength dari graf path berderajat 2n adalah 5n+1. Teorema kedua membuktikan bahwa nilai magic strength dari graf path berderajat 2n+1 adalah 5n+3. Teorema ketiga membuktikan bahwa nilai magic strength dari graf bistar berderajat n adalah 5n+6. Teorema keempat membuktikan bahwa nilai magic strength dari graf cycle berderajat 2n+1 adalah 5n+4.
Keyword: graph labeling, magic labeling, magic strength

Judul: Beberapa Sifat pada Graf a-Vertex Consecutive Magic dan Graf b-Edge Consecutive Magic
Abstrak: Suatu pelabelan total simpul ajaib 𝜆����� dari graf 𝐺����� = (𝑉�����, 𝐸�����) dengan himpunan simpul 𝑉����� = 𝑉�����(𝐺�����) dan himpunan sisi 𝐸����� = 𝐸�����(𝐺�����) disebut pelabelan total a-vertex consecutive magic jika himpunan label dari simpul 𝐺����� adalah 𝜆�����(𝑉�����) = {𝑎����� + 1, 𝑎����� + 2, … , 𝑎����� + 𝑛�����} dengan 𝑎����� ∈ {0,1,2, … , 𝑒�����}. Pelabelan tersebut merupakan pelabelan total b-edge consecutive magic jika himpunan label dari sisi 𝐺����� adalah 𝜆�����(𝐸�����) = {𝑏����� + 1, 𝑏����� + 2, … , 𝑏����� + 𝑒�����} dengan ∈ {0,1,2, … , 𝑛�����} . Dinotasikan 𝑒����� adalah banyaknya sisi dan 𝑛����� adalah banyaknya simpul. Terdapat empat teorema yang akan dibahas dalam karya ilmiah ini. Teorema pertama menunjukkan magic constant dari graf a-vertex consecutive magic. Teorema kedua menunjukkan bahwa jika 𝐺����� adalah suatu graf a-vertex consecutive magic yang memiliki satu simpul terisolasi, maka 𝑎����� = 𝑒����� dan order 𝑛����� serta size 𝑒����� memenuhi persamaan (𝑛����� − 1)2 + 𝑛�����2 = (2𝑒����� + 1)2. Teorema ketiga menunjukkan bahwa jika 𝐺����� adalah suatu graf a-vertex consecutive magic yang memiliki order 𝑛����� dan size 𝑒����� = 𝑛����� − 1, maka 𝑛����� adalah bilangan ganjil dan 𝑎����� = 𝑛����� − 1. Teorema keempat menunjukkan magic constant dari graf b-edge consecutive magic.
Keyword: pelabelan total simpul ajaib, graf a-vertex consecutive magic, graf bedge consecutive magic

Judul: Utilization of hydrolized duckweed (Lemna minor) meal as a soybean replacement in Nile tilapia (Oreochromis niloticus) diet,
Abstrak: Tilapia is a fast growing fish widely cultured in many tropical and sub tropical countries. The recent production figures reported our global production estimates for 2015 is 5,576.8 metric tons. In developing countries the major challenges facing aquaculture industry is high cost of production associated with fish feeds. Feed represents 40-70% of operating costs for aquaculture operations, increasing expenses and potential declining supplies soybean meal have led scientists to search for less expensive but compatible alternative protein sources for fish feed; most of which are based on animal or plant protein sources. The objectives of study was to determine the incubation period for hydrolysis of duckweed and to evaluate the use of hydrolized duckweed as aprotein source for the growth performance of Nile tilapia Three experiments were conducted to determine the composition and digestibility of hydrolyzed duckweed meal by sheep rumen liquor as the replacement of soybean meal in the diet of Nile tilapia. The first trial examined the effectivity of sheep rumen liquor enzyme to decrease crude fiber contents of (DWM), the added volume of sheep rumen liquor was 100 ml/kg DWM and then it was incubated for 0, 12, 24 hr . The second trial was to evaluate the apparent digestibility of hydrolyzed DWM for Nile Tilapia, apparent digestibility were determined using chromic oxide indicator added to both reference diet and test diets. The feed ingredients used in the trial were hydrolyzed DWM (HDWM) and unhydrolyzed DWM (DWM). Ten fish with an average weight of 18±0.36g were used in the trial and reared in the aquarium of size 30×40×50cm for 15 days; feces were collected from three replicates using a fecal collection column attached to the aquarium. Third trial was to evaluate the growth performance of Tilapia fed test diet with hydrolyzed Duckweed meal (HDWM). The experimental design was set according to completely randomized design with four treatments and three replicates of HDWM inclusion levels that is 0%, 15%, 30% and 45%. Nile tilapia fish with initial body weight of 18±0.36g was kept in 12 units aquarium size of 30×40×50cm at stocking density of 10fish/aquarium, the fish were fed two times a day at 08:00am and 16:00pm to apparent satiation for a period of 60 days. The results indicated that duckweed meal (DWM) hydrolyzed with 100 mL/kg and incubated for 24 hrs showed the lowest crude fiber contents of 13.68% compared to other treatments. Total digestibility of hydrolyzed duckweed (HDWM) meal was 87.3% compared with unhydrolyzed duckweed (DWM) which was 66.8%. Total final weight (TFW), survival rate (SR), specific growth rate (SGR), feed conversional rate (FCR) and protein retention (PR) shows growth performance at 15% inclusion. The results of this study showed that 100mL/kg sheep rumen liquor at incubation period of 24 hr can be suitable for hydrolysis of duckweed to reduce crude fiber also hydrolyzed duckweed can substitute soybean meal at an incubation rate of 15% in the diet of Nile tilapia and had the same growth and FCR with control diet
Keyword: Digestibility, Duckweed meal, Growth performance, Sheep rumen