Judul: The addition of calcium to increase the survival and growth of juvenile giant freshwater prawn (Macrobrachium rosenbergii de man) on the medium salinity
Abstrak: Mineral calcium plays a role in the process of osmoregulation and the formation of the exoskeleton of shrimp. This study aimed to determine the optimal calcium levels that can support the survival and growth of prawns and evaluate the role of calcium for the survival and growth of prawns on the medium salinity. The study consisted of two steps, the first to determine the range of calcium concentrations. The next steps evaluated the role of calcium on the frequency of molting, osmotic work rate, oxygen consumption rate, growth rate, survival and feed efficiency. This study used a completly randomized design with four treatments and three replications (A.salinity of 4 ppt + 0 mg/L Ca(OH)2 B. salinity of 4 ppt + 25 mg/L Ca(OH)2, C.salinity of 4 ppt + 50 mg /L Ca(OH)2 and D. salinity of 4 ppt + 75 mg/L Ca(OH)2 ). Results showed that adding calcium to the medium salinity can decrease levels of osmotic work and oxygen consumption and increasing the frequency of molting, growth rate, survival rate and feed efficiency. The addition of calcium to the medium salinity with a concentration of 50 mg/L Ca(OH)2) is the best medium for growth of juvenile giant freshwater prawn.
Keyword: 

Judul: Effect of osmotic load on survival, larval development time, and growth potential of freshwater giant prawn post-larvae
Abstrak: The production of freshwater giant praw n through rearing should be increased continuously considering the ever-incre asing market demand. Acceleration in increasing production has been constrained by limitation of seed quality and quantity. The problem has been in effectiveness of salinity management without taking into consideration larval osmotic load in a ha tchery. Hence, the research aimed at understanding osmotic compartment that pot entially plays an important role in survival, larval development, and the potential growth of post-larva of freshwater giant prawns. The basic principal used as determining base was minimizing osmotic load through adaptation and efficiency of energy utilization. The experimental method was causal comparative conditional; while the experimental design used was a complete randomized design with four salinity treatmen ts and three replications. The research consisted of three experiments, covering effects of osmotic load on: (1) larval development, (2) rate of oxygen consumption, and (3) growth potential of freshwater giant prawn post-larvae. Observation was c onducted on those critic al stadium based on preliminary experiment; comprising those of 6 th , 8 th , 11 th and post-larva using the design of complete random type with four tr eatments of salinity and three replications.
Keyword: 

Judul: Invers Drazin dari Matriks Toeplitz Singular
Abstrak: Matriks Toeplitz adalah matriks yang setiap unsur pada diagonal utama bernilai sama dan setiap unsur pada subdiagonal yang bersesuaian dengan diagonal utama juga bernilai sama. Matriks singular adalah matriks yang tidak bisa ditentukan inversnya. Akan tetapi, dapat diupayakan untuk ditentukan inversnya menggunakan invers matriks yang diperumum. Invers Drazin merupakan salah satu jenis invers matriks yang diperumum. Pada karya ilmiah ini ditentukan invers Drazin dari matriks Toeplitz singular dengan menggunakan metode Leverrier Faddeev. Kemudian, ditentukan invers Drazin dari matriks Toeplitz singular yang direpresentasikan sebagai penjumlahan segitiga bawah dan segitiga atas matriks Toeplitz berdasar pada teorema Gohberg dan Semencul., Toeplitz matrix is a matrix in with element on the main diagonal has the same value and on the subdiagonal corresponding to the main diagonal also has the same value. Singular matrix is a matrix that has no inverse. However, it can be attempted to determine the inverse using a generalized inverse matrix. Inverse Drazin is a type of generalized matrix inverse. This paper discussed the inverse Drazin for a singular Toeplitz matrix using the Leverrier Faddeev method. Then, the Drazin inverse of the singular Toeplitz matrix which is represented as a sum of products of lower and upper triangular Toeplitz matrix based on Gohberg and Semencul theorem.
Keyword: inverse Drazine, singular Toeplitz matrix