Judul: Cluster analysis and biplot analysis of pressure plant pest organisms in West Java Province
Abstrak: Jawa Barat merupakan provinsi dengan produksi tanaman pangan padi terbesar kedua di Indonesia. Adanya organisme pengganggu tanaman (OPT) pada tanaman padi menyebabkan produksi tanaman padi dapat menurun termasuk di provinsi Jawa Barat. Analisis gerombol dapat digunakan untuk melihat jumlah gerombol kabupaten di Jawa Barat yang terbentuk berdasarkan persentase luas lahan yang terserang OPT, informasi tersebut dapat digunakan untuk memperoleh kriteria tingkat serangan OPT. Analisis biplot dapat mengidentifikasi karakteristik antara persentase luas lahan yang terserang OPT dengan kabupaten di Jawa Barat. Hasil analisis gerombol menunjukkan terdapat tipe penggerombolan untuk masing-masing OPT yang berbeda per musimnya, dengan gerombol yang terbentuk antara 2 sampai 4 gerombol. Hasil analisis biplot menunjukkan terdapat kabupaten-kabupaten tertentu yang terserang oleh OPT tertentu yang berbeda tiap musimnya., West Java is the province with the production of food crops in Indonesia's second largest rice. The presence of plant pests (OPT) in rice plants led to decreased production of rice plants can include in the province of West Java. Analysis of clusters can be used to see the number of districts in West Java clusters are formed based on the percentage of land area affected pest, such information can be used to obtain the level of pest attack criteria. Biplot analysis can identify characterize about the percentage of land area affected by the pest districts in West Java. The results of the analysis showed that there were clusters penggerombolan type for each different pest per season, with clusters formed between 2 to 4 clusters. Biplot analysis results showed that there were certain districts were affected by the particular pest that is different each season. Keywords: Biplot Analysis, Cluster Analysis, OPT
Keyword: Analisis Biplot, Analisis Gerombol, OPT

Judul: Pengaruh Keragaman Iklim terhadap Serangan Empat Organisme Pengganggu Tumbuhan Utama Tanaman Padi Di Jawa Barat
Abstrak: Pada tanaman padi, terdapat 4 hama yang sering menurunkan produksinya yaitu hama penggerek batang padi (PBP), wereng batang coklat (WBC), hawar daun bakteri (HDB), dan blast (Pyricularia oryzae Cav.). Tingkat serangan keempat OPT tersebut sensitif terhadap perubahan suhu udara, kelembaban dan curah hujan. Penelitian ini bertujuan untuk mengetahui hubungan antara keragaman ketiga variabel iklim terhadap luas serangan 4 hama utama padi di Provinsi Jawa Barat. Penelitian ini menggunakan data sekunder luas areal serangan hama padi dari Badan Perlindungan Pangan dan Hortikultura (BPTPH) dan data iklim (suhu, kelembaban, dan curah hujan) dari Badan Meteorologi, Klimatologi dan Geofisika (BMKG) periode 1990 - 2018. Pengaruh keragaman iklim terhadap luas serangan 4 OPT utama diuji dengan menggunakan analisis regresi linier. Hasil penelitian menunjukkan bahwa suhu udara memberikan kontribusi yang nyata terhadap peningkatan luas serangan keempat hama utama padi, sedangkan kelembapan relatif hanya memberikan kontribusi yang nyata terhadap peningkatan luas serangan blas dan curah hujan tidak memberikan kontribusi yang nyata terhadap perubahan luas serangan 4 hama tersebut., In rice crops, there are 4 pests that often reduce their production, namely rice stem borer (RSB), brown planthopper (BPH), bacterial leaf blight (BLB), and blast (Pyricularia oryzae Cav.). The invasion level of the four pests is sensitive to changes in air temperature, humidity and rainfall. This study was aimed to examine the relationship between the diversity of the three climate variables on the invasion area of the 4 main pests of rice in West Java Province. This research used secondary data on the area of rice pests invasion from the Food and Horticultural Protection Agency (BPTPH) and climate data (temperature, humidity and rainfall) from the Meteorology, Climatology and Geophysics Agency (BMKG) in the period 1990 - 2018. The impact of climate variability on invasion area of 4 major rice pests was examined using a linear regression analysis. The results showed that air temperature contributed significantly to the increase in invasion area of the four main rice pests, while relative humidity only contribute significantly to the increase in invasion area of blast, and rainfall did not significantly contribute to changes in the invasion area of the four pests.
Keyword: climate change, regression linear analysis, rice pests

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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