Judul: Analisis Variabel Evaporasi di Perairan Terbuka dan  Variabel Evaporasi Penman-Monteith Menggunakan Ridge Regression [Studi  Kasus Model Kebakaran Hutan].
Abstrak: Kebakaran hutan dan lahan (karhutla) dipengaruhi oleh tingkat evapotranspirasi aktual (act), evaporasi dari perairan terbuka (pev) dan evaporasi Penman-Monteith (et0). Tujuan penelitian ini adalah menganalisis karakteristik data, data spasial dan temporal ketiga variabel tersebut serta membandingkan performa variabel pev dan et0 untuk memodelkan kebakaran hutan menggunakan Ridge Regression. Penelitian ini menggunakan data terkait karhutla yang diperoleh dari metode Empirical Orthogonal Function berbasis Singular Value Decomposition. Analisis yang dilakukan antara lain teoritis, karakteristik, temporal, spasial, dan regresi ridge. Analisis regresi melibatkan data hotspot sebagai indikator karhutla. Hasilnya adalah variabel pev membutuhkan indikator perhitungan yang paling sedikit. Karakteristik variabel act lebih menyerupai variabel et0. Ketiga variabel memiliki keserupaan pola spasial dan temporal pada data terkait karhutla. Selanjutnya, performa variabel pev lebih baik dari variabel et0. Namun, performa variabel act lebih mendekati variabel et0., Forest and land fires are a disaster that influenced by the actual evapotranspiration (act), evaporation from open water (pev) and Penman-Monteith evaporation (et0). The purpose of this study is to analyze the characteristics of data, spatial and temporal data of these three variables and compare the performance of pev and et0 variables to model forest fires using Ridge Regressions. In this study, forest fire related data will be used and it is obtained from the Empirical Orthogonal Function method based on Singular Value Decomposition. The analysis carried out include theoretical, characteristic, temporal, spatial, and ridge regressions. The regression analysis is involving hotspot data as an indicator of forest and land fires. The results shows that the pev variable has the least number of computation indicator. The characteristics of the act variable are more like the et0 variable. All three variables have similar patterns of spatial and temporal in forest fire-related data. Furthermore, the performance of the pev variable is better than the et0 variable. However, the performance of the act variable is closer to the et0 variable.
Keyword: evaporation, forest and land fires, characteristics, performance, regression

Judul: Analisis Perbandingan Metode Perhitungan Evapotranspirasi dan  Kaitannya dengan Kebakaran Hutan dan Lahan di Indonesia
Abstrak: Kebakaran hutan dan lahan (karhutla) ditetapkan sebagai bencana alam nasional di Indonesia. Salah satu faktor alami karhutla adalah El-Niño yang dapat menyebabkan kemarau berkepanjangan sehingga kekeringan terjadi. Standardized Precipitation-Evapotranspiration Index (SPEI) adalah salah satu indeks kekeringan yang memperhatikan evapotranspirasi potensial (PET) dan presipitasi. PET dapat dihitung dengan berbagai metode antara lain Penman-Monteith, Thornthwaite dan Stephens-Steward. Penelitian ini bertujuan untuk menentukan metode perhitungan PET yang paling efektif dalam jumlah variabel, kemiripan sebaran dan selisih dengan data asli/catat untuk menyatakan karhutla di Indonesia. Metode Thornthwaite membutuhkan variabel yang paling sedikit dibandingkan kedua metode lainnya. Berdasarkan DTW dan Euclidean Distance, Thornthwaite memiliki sebaran yang paling mirip dengan data asli. Selain itu, selisih data Thornthwaite paling kecil terhadap data asli. Oleh karena itu, metode Thornthwaite merupakan metode yang paling efektif dibandingkan Penman Monteith dan Stephens-Steward bagi Indonesia., Forest and land fires are set as a national natural disaster in Indonesian. One of natural factors of forest and land fires is El-Niño that can cause long dry season so that droughts occur. One of the droughts index is Standardized Precipitation-Evapotranspiration Index (SPEI). This index examines potential evapotranspirations (PET) and precipitations. PET can be calculated by various methods including Penman-Monteith, Thornthwaite and Stephens-Steward. This study aims to determine the most effective PET calculation method in number of variables, similarity of distribution and difference with recorded data for declaring forest and land fires in Indonesia. Thornthwaite method requires the fewest variables compared to the other two methods. Based on DTW and Euclidean Distances, the data distribution of Thornthwaite is most similar to the original data. In addition, the difference of the Thornthwaite's data and the original data is the smallest. Because of that, the Thornthwaite method is the most effective method compared to Penman-Monteith and Stephens-Steward for Indonesian.
Keyword: evapotranspiration, forest and land fires, Standardized Precipitation-Evapotranspiration Index, Thornthwaite

Judul: Optimization of Alginate-Chitosan Microcapsules Formation for Leydig Cells Encapsulation
Abstrak: Hypogonadism is a clinical condition characterized by low concentrations of testosterone. It is caused by malfunction of Leydig cells in producing testosterone. Encapsulation method will protect the transplanted cells from the immune system rejection. The aims of this study was to optimize the formation of microcapsules for Leydig cells encapsulation. The microcapsules were made of alginate and chitosan as the first and the second coating agents, respectively. The result showed that the minimum concentration of alginate was 1.5% (w/v) with a viscosity of 33.8 cPs, resulted spherical microcapsules with diameters of 230-270 µm. The optimum concentration of chitosan as the second coating agent was 0.5% (w/v), resulted spherical microcapsule with mechanical stability in 4 hours. Leydig cells can be trapped inside the capsule with a density that proportional with concentration of cells used in the encapsulation.
Keyword: