Judul: Analisis Pengaruh Faktor Cuaca Untuk Prediksi Serangan Organisme Pengganggu Tanaman (OPT) pada Tanaman Bawang
Abstrak: Pest and disease are the main factors which cause low onion productivity in Brebes. The aim of this reasearch was to find out the effect of weather parameter and pest predator toward the intensity of pest attack (Spodoptera exigua, Liriomyza sp dan Thrips tabaci) using Correlation, Stepwise Regression and Principal Component Regresion technique in two regions. The intensity of Spodoptera exigua, Liriomyza sp and Thrips tabaci attack were influenced by various weather variables from at least one of the combined data of Tmax, Tmin, RH and rain , one until three weeks before the attack period. The intensity of the Spodoptera exigua’s attack showed significant positive correlation with the intensity of the attack in the previous week and predator, while Tmax, RH and rain showed significant negative relationship. The intensity of the Liriomyza sp’s attack showed a significant negative correlation with Tmax, Tmin, RH and rain. Thrips tabaci particularly showed significant negative correlation with Tmax and Tmin. The regression result using Stepwise method for predicting the intensity of Spodoptera exigua's pest attack in region 1 (Karangbale and Pamulian) and region 2 (Kedungbokor, Larangan and Sitanggal) based on intensity attack data from previous week, the predator and weather elements showed a high R2 value if it is analyzed for each areas, that are 99,7% and 100% and for Lyriomiza sp with the R2 value are 45,9% and 94,8%. Particularly for Thrips tabaci, attack analysis based on weather element got a good value if both areas are combined, that is 39,6%. Used of the data, though the obtained linear regression equation get high values of R 2 but has not shown the consistency of weather influenced between sites, the weather and other physical factors observed were no different. For each region and each pest’s cases, the affected weather elements are different.
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Judul: Analisis hubungan faktor iklim dengan tingkat serangan wereng batang cokelat (Nilaparvata lugens Stal.) sebagai landasan prediksi serangan: studi kasus pada 3 Kabupaten di Provinsi Jawa Tengah
Abstrak: Pests are organisms that can cause damage to plants and can adversely affect the economy. Rice is the most important staple food in Indonesia. One of destructive pest of rice plants which can reduce the production is brown planthopper (Wereng Batang Coklat – WBC). One of the triggers widespread increase in attacks of WBC is the climatic factor. Climatic factors can influence the level of attacks of the pest. Therefore, the influence of climate on broad attack WBC is important to be analyzed. This study aims to analyze the relationship between climatic factors with a broad attack WBC as a basis for prediction of attack. The areas of studies covered 3 district of Central Java Province,e.g., Cilacap, Pekalongan, and Tegal. The method used for analysis linear regression method for rainfall, quadratic regression to other climatic factors, and multiple linear regression to all the climatic factors that possible influence. Analysis of climatic factors with broad WBC relationships attacks carried out at different time delay (lag time) those are without lag, lag 1 and lag 2. The highest determinate coefficient results between regions of WBC attacks and climatic factors is 20.2%. These results obtained when the analysis is done in lag 1 with the equation of LS (Area Of Attack) = - 38 + 90.2 Tavg - 36.0 Tmax - 61.6 Tmin - 0146 R + 3.11 RH. Climatic factor is one of the factors that influence the broad attack of WBC, there are several other factors that need to be included in the analysis to improve results and get a better prediction.
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Judul: Membran Komposit Kitosan-Zeolit untuk Aplikasi Direct Methanol Fuel Cell
Abstrak: Direct methanol fuel cell (DMFC) is a fuel cell that utilize methanol as the fuel source. The electrolyte membrane used in the DMFC system in this research was chitosan-zeolite composite membrane. The composite membrane was synthesized with chitosan-zeolite composition variation of 1:1, 1:2, 1:3, and 2:1. The membranes were analyzed by Fourier transform infrared spectrophotometer (FTIR) and scanning electron microscope, and for the specific gravity. Membrane performances were tested with methanol uptake, methanol permeability, conductivity, and potential difference in the DMFC system. The FTIR spectrum showed no formation of new functional groups inducating that the composite membrane was a result of physical mixing. Morphological analysis showed that the membrane was nonporous. Chitosan-zeolite 1:3 composite membrane had the highest specific gravity and methanol uptake, 1.4226 g/mL and 41.44%, respectively. The highest proton conductivity was showed by the 1:2 chitosanzeolite composite membrane, namely 7.2946× 10-7 S/cm. Based on this research results, chitosan-zeolite composite membrane can be applied in DMFC system.
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