Polycyclic aromatic hydrocarbons (PAHs) contaminants have toxic, carcinogenic, and mutagenic properties. Screening bacteria from different sources capable of carrying out the biodegradation of (PAHs) is essential for mapping and mobilization purposes and applying them to polluted hydrocarbon environments. The study aims to compare the capacity of PAH biodegradation by two types of bacteria isolated from different sources. The method applied is the interaction between bacterial suspension and pyrene-contaminated waste for 30 days. Biodegradation products in organic compounds were analyzed using gas chromatography/mass spectroscopy (GC/MS) and Fourier transform infrared spectroscopy (FTIR). The analysis results found several indications of the performance of bacterial biodegradation: The capacity of pyrene degradation by Bacillus licheniformis strain ATCC 9789 (Bl) bacteria against pyrene was relatively more dominant than Sphingobacterium sp. strain 21 (Sb) bacteria. The percentage of total bacterial biodegradation for product type Sb was (39.00%), and that of the product of bacterial degradation type Bl (38.29%). The biodegradation products of the test bacteria (Bl and Sb) were relatively similar to pyrene in the form of alcohol and carboxylic acid organic compounds. There was no significant difference in the pyrene biodegradation between Bl and Sb bacteria.

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This research was completed using mixed qualitative and quantitative methods. Field surveys were executed in sugar cane plantation throughout South Sulawesi Indonesia. Land suitability analyses were performed using a parametric approach with Storie’s index equation followed up with  correlation analysis using the Pearson correlation. Results revealed that the period for sugarcane crop growth in the humid tropic relatively dry regions of South Sulawesi Indonesia lasted for the months of November to July.  The land suitability for sugar cane in the research location was moderately suitable (S2c) and marginally suitable (S3c, S3s, S3s,f and S3c,w) with limiting factors such as relative humidity during crop maturation phase, the duration of sunlight, soil depth, soil texture, soil pH and soil drainage. Land suitability index at the research location ranged from 25.2 to 55.0; sugar cane yields ranged from 30.3 to 62.0 Mg ha-1 year-1. Pearson correlation coefficient (r) between LSI with cane and sugar productivity were 0.81 and 0.84 respectively, signifying the strength of the correlation between the two values. This also indicates that land suitability index can be estimating the potential crop yield in the humid tropicsthat relatively dry climate regions.

The area of agricultural land, especially paddy fields, is related to the level of rice production. Conversion of agricultural land to non-agriculture will have an impact on the availability of rice supply. This study aims to identify changes in paddy field land use in 2005 - 2016 using high-resolution satellite imagery and calculate the need for rice per capita in Pallangga District. This research utilizes the application of geographic information systems in monitoring changes in paddy field use. The method used in the classification of land use is digitizing on screen. The conversion of paddy fields to non-paddy fields was obtained from the results of overlapping maps of Pallangga District land use maps in 2005 and 2016 and presented in the form of cross tabulations. The accuracy test results obtained the overall accuracy value of 98.04%, and the kappa accuracy value of 0.98. This study shows that paddy field area has decreased by 305.25 ha. The change consisted of 17.68 ha into a water body, turned into a garden of 132.86 ha and became a settlement of 154.71 ha. The conversion of paddy fields in Pallangga District in 2005-2016 affected rice production. The results of the analysis of the needs of rice per capita per year show that in 2017 Pallangga District is surplus in the supply of rice to its population. However, based on population projection, the decrease in land area and rice production in Pallangga Subdistrict in 2020 was unable to meet the rice needs of its population of 1,027 tons

The purpose of this study was to: (1) finding out the difficulties experienced by mathematics education students in solving geometric reasoning problems based on van Hiele's theory; (2) identifying the factors causing difficulties experienced by students in solving geometric problems based on van Hiele’s theory; and (3) determining the steps that need to be taken to overcome the students' difficulties in solving geometric reasoning problems based on van Hiele's theory in the Transformation Geometry Course. The students' difficulties in solving geometric reasoning problems based on van Hiele's levels will give an idea of the indicators of geometrical reasoning abilities that are still low, so that the right alternative solutions are obtained. This type of research is descriptive research with a qualitative approach.  The research subjects were 28 students who programed geometry transformation courses. The instrument in this study was a test instrument, namely geometric reasoning abilities of students as many as 5 questions consisting of 5 levels of ability, namely visualization, analysis, abstraction, formal deduction, and rigor. While the data analysis techniques in this study used descriptive analysis. Collecting data in this study used interview techniques and written tests. The results showed that from the five indicators of geometric reasoning ability, for the visualization level, there were 26 people who achieved the optimal score with a percentage of 92.9. Seen at the level of analysis still not reached optimally with a percentage of 21.4 or only 6 people who achieved the optimal score, while the level of abstraction, formal deduction, and rigor has not been achieved. Difficulties experienced by students at the level of analysis, abstraction, formal deduction, and rigor. The causal factors experienced by students based on the results of interviews obtained information that students have difficulty answering questions due to several things including; students have forgotten about the material being taught, when they learn they understand but are less interested in developing, feel unsatisfied so they expect concrete media, need to be trained in many questions, and follow up to students. From this information, an appropriate alternative is needed, for example using van Hiele's theory to familiarize students with reasoning skills.