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This study presents the development of a stochastic modelling system and a laboratory works on the greenhouse scale for estimating the concentration of boron in controlled irrigated-paddy plants. The model was developed based on Object Oriented Programming (OOP) Python 3.6. The stochastic model is developed to predict boron concentration through different treatments (different inflow and interval irrigation) inside the greenhouse. There were three treatments of the experiment in greenhouse scale: the buckets filled using full of open inflow in bucket one, the buckets filled using a half of open inflow in bucket two, the buckets filled using a quarter of open inflow in bucket three. The study used integration data using Odeint python package, Hargraves model, and chemical kinetics to estimate the boron concentration. The result shows that bucket two and bucket three have higher boron concentration than bucket one based on laboratory experiment. In this study, the simulation approaches show performances which are satisfactory to predict boron concentration up to three second in the buckets.

Extreme waves are an important factor in coastal structures both offshore structures and onshore structure design. However, due to the difficulty of measuring ocean waves, many areas still do not have measured wave height data. Data processing is required to transform the measured wind data into wind-wave value in order to solve this issue. This study aims to analyze extreme waves based on wind data from BMKG Panjang and BMKG Radin Inten II stations. For analysis of determination of extreme waves can be done by using Fisher Tippet Type I (Gumbel) and Weibull methods. The result show that Weibull method gives the higher value than Gumbel method, with the maximum percentage of 43.04% at the 2-year return period.

Rice cultivation using substrate hydroponic system on the building’s rooftop is an alternative way to improve rice production. This research aimed to study the effect of growth media compositions on rice growth with substrate hydroponic system. The experiment used Completely Randomized Block Design with five treatments of growth media composition i.e. 100% rice husk charcoal; 100% cocopeat; 50% rice husk charcoal: 50% cocopeat; 25% rice husk charcoal: 75% cocopeat; and 75% rice husk charcoal: 25% cocopeat. The result showed that composition of 75% rice husk charcoal : 25% cocopeat significantly affected plant height. Otherwise, reformulating nutrient composition for hydroponic rice cultivation supported the growth media to perform better. The addition of NH 4 + as a source of nitrogen improved plant growth in vegetative stage. In addition, the ratio between K: Ca (1.25: 1) applied to complete requirement of those nutrients and considered as environmental stress defence. The use of a container becomes an alternative to maintain media relative humidity and nutritional EC value. Either in the rainy or dry season, relative humidity and nutrient EC of media must be checked frequently to maintain the optimum conditions for rice growth.

The development of environmentally friendly technology for water ecosystem rehabilitation has become a challenge in solving pollution control problems in water bodies. Ecotechnology is a technology to improve water quality using an ecosystem approach, including the technology of constructed treatment wetlands and natural adsorbents. This study aims to produce an alternative ecotechnology for textile industrial waste remediation, on-site treatment of water bodies contaminated with textile waste, using a constructed treatment wetlands system and natural adsorbents. The result was conducted for 6 months using a reactor on a pilot scale with a continuous system. The result showed that CTWs’ ability effectively reduced ammonia in textile wastewater with a 20% dilution of up to > 80% and > 90% respectively using plants Vetiveria zizanioides and Heliconia psittacorum . Meanwhile, at 50% textile wastewater dilution, CTW with Heliconia psittacorum was more effective in reducing ammonia (> 80%) than CTW with Vetiveria zizanioides (> 60%). CTW with Vetiveria zizanioides and Heliconia psittacorum was able to reduce the dye content up to < 69.68% and < 54.39%, respectively. The natural adsorbent ability of bentonite has a higher ability to reduce dyes and ammonia, which is up to < 64.84% and < 91.12%. Good performance in these two eco-technology systems will result in better waste disposal by combining these two systems into one ecotechnology system.

This research goal was to investigate the antioxidant activity of methanol extract of kecombrang (Etlingera elatior) flowers and leaves. Extraction processes by using maceration technique. Dried samples were extracted by using commercial methanol for 48 h. Antioxidant activity was measured as DPPH radical scavenging activity. The results showed that IC50 of the methanol extract of kecombrang shoot leaves was 14.53 ppm; the methanol extract of kecombrang mature leaves was 28.97 ppm; and the methanol extract of kecombrang flowers was 105.90 ppm. It is indicated that the extracts can be used as an agent to scavenging free radicals.

The hydrological system of tropical peatland has been changed due to drainage. The condition caused prone to peatland burning. Forest fire affected the vegetation composition in peatland. Repeated fire causes more severe impact on vegetation and the change the peatland characteristics. The aim of the study is to obtain species composition on peatland after fire in Central Kalimantan. The research was conducted on several plots of vegetation observation on peatland that burned in 2015 (three years after fire and forth fire frequency). The plot sizes were depending on vegetation stage (seedling, sapling, poles, and trees) of 2 Ha or 50 observation plots. The measurements of parameter were species, density, frequency, and important value index. The species composition was described by ecological indices such as Shannon wiener index, Simpson index, and evenness index. The results showed that species diversity and ecological index were very low. That condition indicated that the fire has changed the species composition and the natural regeneration has been obstructed. Combretocarpus Rotundatus and Cratoxylon glaucum were presented on overall tree stage as pioneer species, but the climax species didn’t found on three years after forest fire. Based on the results, the repeated fires caused an extreme decrease of natural regeneration so the ability of recovery is not running well. The parameters can be used in determining the priority of revegetation program on large scale.

This study aims to explore the increase of students’ problem solving ability as the impact of the application of experiential learning using STEM approach. This study use a pre experiment method that is applying the one group pretest-posttest learning design. The participants are 40 students (18 male and 22 female) of second grade Science program in one high school in Province of West Java. The selection of the participants is using random class sampling technique. The data are collected based on the questions that are given to the participants. The questions are divided into five indicators of problem solving ability in Pascals’ principle learning material. According to the result of this study, that using normalized gain, it shows the increase of students’ problem solving ability that can be categorized in high level. The highest score for the students’ problem solving ability is in describing problem and planning a solution, whereas the lowest score is in giving evaluation for the solution of the problem. The result of this study shows that the experiential learning using STEM approach can be used as an alternative to improving students’ problem solving ability, especially in Pascals’ principle.

Kopyor coconut is a type of Indonesian coconut with a unique flavor and texture, which makes it attractive to consumers. Kopyor coconut is commonly consumed as a fresh fruit and has a short shelf life. Therefore, innovation in kopyor coconut product development is needed to extend its shelf life; one potential method is pasteurization. This study aims to extend the shelf life of kopyor coconut by determining the optimum thermal pasteurization process for kopyor coconut flesh products and evaluating the impact on product quality during storage at room temperature. Thermal adequacy assessment includes two test steps: the appliance’s thermal distribution test and the product’s thermal penetration test conducted at boiling water temperature (98°C). Kopyor coconut was formulated with citric acid as an acidity regulator and sugar as a sweetener and then packaged in boil-pack plastic packaging. Product characteristics observed included pH value, free fatty acid (FFA), total soluble solids (°Brix), and microbial contamination. Based on the thermal adequacy test results, the minimum time for the pasteurization process of kopyor coconut products is 17 min. The kopyor coconut products exhibited satisfying quality as no microbes were detected from the TPC analysis, which means no microbial growth during storage. The pH value during eight weeks of storage was 3.68-3.91 and is still within the requirements of acidified foods. The FFA content was 1.59-2.27%, while the total soluble solids were constant at 19 °Brix. In conclusion, pasteurization treatment maintained the product quality of kopyor coconut flesh during eight weeks of storage at room temperature.

Sei Gesek Reservoir is located in Bintan Regency, Riau Island Province. The reservoir is one source of water for the community in Tanjungpinang City. One of the freshwater fish that inhabit the Sei Gesek Reservoir is the belida fish ( Notopterus notopterus ). The objective of this study was to the Relative Length of the Gut (RLG), type and food composition of belida fish ( N. notopterus ), and food comparative in the digestive tract of the belida fish ( N. notopterus ) with food resources in the substrate Sei Gesek reservoir, Bintan Regency, Riau Island. The method used in this research was the survey method. A sampling of belida fish ( N. notopterus ) was carried out in three months according to the fishing grounds. The data analysis used is Relative Length of the Gut (RLG), Index of Preponderance (IP), and Index of Electivity (E). The result showed that the total fish caught was 30, there were 16 males and 14 females. The relative length of the gut female and male belida fish ( N. notopterus ) were 0.21 and 0.25 respectively. Based on the relative length of the gut value, belida fish ( N. notopterus ) was classified as a carnivore. The food types of belida fish ( N. notopterus ) were fish, crustaceans, microalgae, macrophytes, annelids, nematodes, and detritus. Index of preponderance showed that the main food of belida fish ( N. notopterus ) in Sei Gesek Reservoir was small fish based on sex, the month of capture, and body length measurement. Index of electivity showed that the food type from the microalgae is Asterionella sp. and Closterium sp. not selected by belida fish ( N. notopterus ) as food.

Graphene oxide and reduced graphene oxide attract a lot of attention due to graphene provides some properties that suitable for wider application. Properties of graphene are unique since it can be tuned regarding to its controlled synthesis method and several treatments. This work, graphene oxide was synthesized from used graphite electrode by modified Hummer's method in which oxidation process controlled. Zinc was used to produce reduced graphene oxide. Graphene oxide and reduced graphene oxide were characterized by SEM, EDS, FT-IR, UV-vis, and XRD. Effective strategy was studied to produce graphene oxide and reduced graphene oxide by controlling its oxidation process. These results prove that chemical and structural properties of graphene oxide and reduced graphene oxide depend on oxidation duration. Furthermore, carbon/oxygen ratio was studied to evaluate effective oxidation process.