Judul: Analysis Evapotranspiration In The Wet Tropic: South Lampung and North Jakarta In 1998-2017
Abstrak: Analisis Evapotranspirasi di Daerah Tropika Basah: Lampung Selatan dan Jakarta Utara Tahun 1998-2017. Evapotranspirasi (ETo) merupakan gabungan dari proses evaporasi dari permukaan tanah dan tanaman, serta proses transpirasi melalui kanopi tanaman. Evapotranspirasi merupakan komponen penting dalam memengaruhi keseimbangan hidrologi di suatu wilayah, karena nilainya menduduki porsi fase air yang cukup besar. Penelitian ini bertujuan untuk mendapatkan gambaran perubahan nilai evapotranspirasi selama 20 tahun di Jakarta Utara dan Lampung Selatan. Metode penelitian ini dilakukan dengan menggunakan analisis tren iklim historis dan evapotranspirasi. Nilai evapotranspirasi diperoleh dengan menggunakan metode Penman-MonteithMetode ini merupakan metode paling baik untuk menghitung nilai evapotranspirasi. Hal tersebut dikarenakan nilai korelasi (r) dari hasil penghitungan evapotranspirasi metode Penman-Monteith dengan pengukuran menggunakan lisimeter lebih dari 97 % untuk seluruh bulan. Selain itu, nilai standard error dari metode ini juga menunjukkan angka terkecil yakni 32 % dibanding dengan metode lain.. Evapotranspirasi tahunan di Lampung Selatan dan Jakarta Utara menunjukkan garis tren naik dalam 20 tahun terakhir, dengan kemiringan garis tren yang lebih besar di wilayah Jakarta Utara dibandingkan dengan di wilayah Lampung Selatan. Dalam kurun waktu 20 tahun nilai evapotranspirasi pada periode musiman di wilayah Lampung Selatan dan Jakarta Utara memiliki nilai evapotranspirasi tertinggi pada periode SON (September-Oktober-November) dan nilai terendah ada pada periode JJA (Juni-Juli-Agustus)., Analysis of Evapotranspiration in Wet Tropics: South Lampung and North Jakarta 1998-2017. Evapotranspiration (ETo) is a combination of the evaporation process from the soil surface and plants, as well as the transpiration process through the plant canopy. Evapotranspiration is an important component in influencing the hydrological balance in an area, because its value occupies a fairly large portion of the water phase. This study aims to obtain an overview of changes in the value of evapotranspiration for 20 years in North Jakarta and South Lampung. This research method is carried out using historical climate trend analysis and evapotranspiration. The evapotranspiration value was obtained using the Penman-Monteith method. This method is the best method for calculating the evapotranspiration value. This is because the correlation value (r) from the calculation of evapotranspiration using the Penman-Monteith method with measurements using a lysimeter is more than 97% for the entire month. In addition, the standard error value of this method also shows the smallest number, which is 32% compared to other methods. Annual evapotranspiration in South Lampung and North Jakarta shows an upward trend line in the last 20 years, with a greater slope of the trend line in the North Jakarta area. compared to the South Lampung region. In a period of 20 years, the evapotranspiration value in the seasonal period in South Lampung and North Jakarta has the highest evapotranspiration value in the SON period (September-October-November) and the lowest value is in the JJA period (June-July-August).
Keyword: ETo, evapotranspiration, South Lampung, North Jakarta, temperature, trend

Judul: Analysis of Air Temperature Changes and Evapotranspiration Rate Estimation due to Urban Heat Island in Jakarta, Bogor, and Tangerang
Abstrak: Pertumbuhan penduduk di DKI Jakarta yang mengakibatkan peningkatan kawasan terbangun akan memberikan dampak negatif berupa peningkatan suhu permukaan dan berdampak pada laju evapotranspirasi di DKI Jakarta. Oleh karena itu, perlu dilakukan analisis dampak urban heat island (UHI) terhadap perubahan suhu permukaan dan estimasi terhadap laju evapotranspirasi di DKI Jakarta sebagai daerah urban dibandingkan dengan Kabupaten Bogor, dan Kota Tangerang sebagai daerah sub-urban. Penelitian ini dilakukan dari bulan Mei-Juni 2021 menggunakan data sekunder dari BMKG yang diolah menggunakan model Blaney-Criddle, Linacre, Kharuffa, serta Hargreaves-Samani dan data citra Landsat untuk wilayah DKI Jakarta. Berdasarkan hasil perhitungan, laju evapotranspirasi keempat model untuk ketiga berkisar antara 1.61 mm/hari hingga 9.43 mm/hari. Perubahan luas RTH menjadi kawasan terbangun di DKI Jakarta sebesar 7.4% dari tahun 2011-2020 mengakibatkan kenaikan suhu sebesar 0.3-0.5°C per tahun. Peningkatan suhu di DKI Jakarta dibandingkan Kabupaten Bogor, dan Kota Tangerang mengakibatkan peningkatan laju evapotranspirasi pada model Blaney-Criddle, Linacre, dan Kharuffa namun mengakibatkan penurunan laju evapotranspirasi pada model Hargreaves-Samani. Rata-rata intensitas UHI di DKI Jakarta dibandingkan dengan Kabupaten Bogor, dan Kota Tangerang yaitu berkisar antara 0.37 °C– 2.89°C., The population growth of DKI Jakarta has increased the built-up area caused a negative impact, which is an increase in surface temperature and the evapotranspiration rate. Therefore, it is necessary to analyze the impact of urban heat island (UHI) on air temperature changes and estimate the evapotranspiration rate in DKI Jakarta as an urban area compared to Bogor Regency, and Tangerang City as a suburban area. This research was conducted from May to June 2021 using secondary data obtained from BMKG processed with Blaney-Criddle, Linacre, Kharrufa, Hargraves-Samani models and Landsat images for DKI Jakarta area. Based on the results, it was found that evapotranspiration rate estimation using four models is in the range of 1.61 mm/day to 9.43 mm/day. The change in the area of green open space into a built area in DKI Jakarta by 7.4% from 2011-2020 increased temperature by 0.3-0.5 °C/year. The increased air temperature between Jakarta-Tangerang and Jakarta-Bogor causes increased evapotranspiration in the Blaney-Criddle, Linacre, and Kharrufa models but decreased evapotranspiration in the Hargreaves and Samani model. The average intensity of UHI in DKI Jakarta compared to Bogor Regency and Tangerang City is in the range of 0.37°C – 2.89°C.
Keyword: land cover, reference evapotranspiration, urban heat island

Judul: Hydroxyapatite-Chitosan Composite Coating on Stainless Steel 316 to Improve Corrosion Resistance
Abstrak: Metals that were used in bone implantation should have good corrosion resistance that were not easily corroded when implanted into the body. Metal corrosion resistance of stainless steel 316 can be enhanced through the metal coating by hydroxyapatite-chitosan composite with composition ratio of hydroxyapatite (gram) and chitosan 3% (mL) 0.2:0, 0.2:0.1, 0.2:0.5, 0.2:1.0, and 0.2:1.5. Besides improving the corrosion resistance of metal, the presence of chitosan also maintain the position of hydroxyapatite on metal surfaces. Corrosion resistance increases with increasing amount of chitosan added and the best composition of hydroxyapatite-chitosan composite was 0.2:1.0.
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