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Aurantiochytrium sp. is a marine protist that is highly ecologically relevant in the mangrove environment. This species of microalgae has long been known to produce high concentration of Docohexanoic acid (DHA, omega-3, 22:6n-3). DHA has a beneficial role for maintenance of normal brain function, visual acuity as well as prevention of cardiovascular and neurological diseases in humans. Although Indonesia is known to have the largest mangrove forest in the world, unfortunately, research on the isolation, potential observation and use of Aurantiochytrium microalgae has been still rarely published. Therefore, this research aims to promote the importance of research field using microalgae Aurantiochytrium from Indonesian strain for future biochemical production processes. In this work, the samples of targeting microalgae were isolated from Kulonprogo mangrove, Yogyakarta using the direct plating method. The isolation medium contained 50% (v/v) seawater, 1% (w/v) agar, 0.5% (w/v) glucose, 0.1% (w/v) peptone, and 0.1% (w/v) yeast extract, without the addition of streptomycin and penicillin. Morphological characteristics were observed. The observation results confirmed the availability of Aurantiochytrium isolates in prepared medium. Therefore, future isolation of Aurantiochytrium microalgae from other Indonesian mangrove forests can use the direct planting methods presented in this paper. In addition, this paper presented future important applicability of Indonesian Aurantiochytrium strains for uses in strategic industrial sectors, including pharmaceuticals, nutraceuticals and biofuel companies. [ABSTRACT FROM AUTHOR]

Due to increased development and population growth, the high demand for land in urban areas often results in unsuitability land use. Urban areas should minimize the negative impact of this mismatch by establishing a control mechanism for land use. This mechanism benefits for maintaining sustainable land use and ensuring new developments do not interfere with the spatial plan. This paper aims to analyze the existing spatial pattern of land use toward the spatial plan as an initial mechanism for controlling land use. The study applied a spatial pattern audit approach using a Geographic Information System (GIS) to determine the suitability between the existing spatial pattern recorded in 2019 toward the spatial plan stated in the Detailed Spatial Plan (RDTR) of Yogyakarta 2015-2035. The satellite imagery-based map has been confirmed through field surveys then presented in a GIS-based map. The analysis is carried out by overlaying the map of 2019 and detailed spatial plan GIS-based maps released in 2015 to obtain the spatial utilization discrepancy. The audit analysis found that 21.55% of the current land use is unsuitable according to the spatial plan. [ABSTRACT FROM AUTHOR]

The supply chain for halal chicken meat in Indonesia is a unique and more complex than in other countries since there are so many actors who take a part in each chain. Study on behaviour for breeders, distributors, sellers and customers become essential to be carried out to obtain a comprehensive understanding of the critical point of halal chicken supply chain. The common study only discusses segmentation behaviour on the customer's perspective, while the critical point of halal lies more crucially on the sellers. Therefore, reviewing the sellers becomes important in the halal chicken meat supply chain. This paper presents a computational segmentation of halal chicken meat's sellers using a clustering method. The clustering is based on demographic and behavioural attributes. The essential attributes of demographic cover gender, age, education, selling location, selling quantity, selling duration, and source of chicken while behaviour attributes are adapted from Theory of Planned Behaviour framework that involves knowledge, attitude, intention, and action. Data were collected through a quantitative questionnaire from 249 chicken meat's sellers in Yogyakarta province in Indonesia. K-means cluster is used to group seller with the same interest in attributes and the number of clusters is optimized using the Elbow Method. From the calculation of Elbow Method, there is a sharp decline and shapes an angle between k=2 and k=3, so chicken meat sellers are grouped into three clusters. The composition shows that about 23.2% is included in the apathetic cluster, 45.7% belongs to religious, and 31.1% fits to rationalist. Cluster 1 and 3 have insignificant difference in halal behaviour but not with cluster 2. Based on analysis, the level of education is the most important demographic sub attributes in configuring halal behavioural pattern. [ABSTRACT FROM AUTHOR]

PV has been used throughout the year in several areas in Indonesia due to the high potential for solar radiation. It is currently being used both in stand-alone models and in energy generation models where photovoltaic cells are connected to an existing grid. PV can be used and developed in the Yogyakarta region, especially in the GI Medari because it has a radiation value of approximately 1608/kWh/m2/year. With high enough iradiation, the placement of PV in the right location in the system will maintain the voltage utility, but if PV is placed in the wrong location, it will affect the stability of the system. When PV is connected to a strategic location, the system will be more stable. The purpose of this paper is to analyze the effect of PV entering the system with different penetrations by looking at the load flow and short circuit system before and after adding PV to the GI Medari system, the 3rd feeder (MDI3) with 217 buses, using ETAP (Electrical Transient Analyser Program) 12.6.0 [ABSTRACT FROM AUTHOR]

The liquefactions phenomena have been reported after a shocking 6.5Mw earthquake hit Yogyakarta province in the morning at 27 May 2006. Several researchers have reported the damage, casualties, and soil failure due to the quake, including the mapping and analyzing the liquefaction phenomena. Most of them based on SPT test. The study try to draw the liquefaction susceptibility by means the shear velocity profiling using modified Multichannel Analysis of Surface Waves (MASW). This paper is a preliminary report by using only several measured MASW points. The study built 8-channel seismic data logger with 4.5 Hz geophones for this purpose. Several different offsets used to record the high and low frequencies of surface waves. The phase-velocity diagrams were stacked in the frequency domain rather than in time domain, for a clearer and easier dispersion curve picking. All codes are implementing in Matlab. From these procedures, shear velocity profiling was collected beneath each geophone's spread. By mapping the minimum depth of shallow water table, calculating PGA with soil classification, using empirical formula for saturated soil weight from shear velocity profile, and calculating CRR and CSR at every depth, the liquefaction characteristic can be identify in every layer. From several acquired data, a liquefiable potential at some depth below water table was obtained. [ABSTRACT FROM AUTHOR]

Coastal area of Gunungkidul Regency is one of the areas prone to tsunami in Indonesia. In contrary, currently, this area is very intensively developed as one of the favourite tourism destination. This paper is aimed at explaining tsunami risk and a mitigation type in Gunungkidul Area, Yogyakarta. Digital elevation model (DEM) and coastal morphology were used to generate tsunami hazard map. Vulnerability was analysed by utilizing land use data. Information from previous studies (e.g. from GTZ) were also considered for analysis. Tsunami risk was classified into three classes, i.e. high risk, medium risk, and low risk and visualized in the form of tsunami risk map. Tsunami risk map is a tool which can be used as disaster reduction instrument, such as for evacuation routes planning. Based on the preliminary results of this research, it is clear that tsunami risk in this area is varied depend on the morphological condition of the location. There are five coastal area selected as the location, i.e. Ngrenehan, Baron, Sepanjang, Pulang Sawal, and Sadeng. All locations have the high risk zone to tsunami, especially for bay area. Evacuation routes were generated for all locations by considering the local landscape condition. There are several differences of evacuation ways for each location. [ABSTRACT FROM AUTHOR]

Waste generated from various construction activities (construction waste), directly or indirectly, has an impact on the environment such as reduction of natural resources and environmental pollution due to its disposal. In addition, poor construction waste management can cause huge financial losses to construction companies. As reported by several countries, construction waste can account for 20-30% of all waste disposed in landfills. Factors causing construction waste generation include human error factors, poor project management, incomplete design documents, incorrect material selection, improper implementation methods, and several external factors. Large-scale construction projects need to adopt a waste management plan to reduce losses from construction waste. Learning from the implementation of waste management planning in developed countries, by applying a system of reduce, reuse, recycle, and classifying waste materials according to their types, waste management will provide optimum results. Since in Indonesia,especially in Yogyakarta, construction waste management is still not implemented optimally, this study aims to: (1) identify the types of construction waste and the factors that cause construction waste using the construction processes of the 4th and 5th floors of the Teaching Industry Learning Center (TILC) Building of Universitas Gadjah Mada as a case study, (2) find out the largest wastage level generated, and (3) conduct an analysis on how to handle construction waste from structural work at the project site. This research is a correlation study using a survey method with a research sample of 5 people determined by purposive sampling technique. The survey data were analyzed using descriptive analysis with Pareto diagrams and fishbone diagrams. From the results of the study, it was found that the type of construction waste in the TILC Building project was direct waste generated from concrete work, formwork wood, and reinforcement bar materials. This was influenced by the activities of material delivery, material storage, the alteration process of the material, and other residual waste. The dominant type of waste material in the construction project was fc' 30 MPa concrete with a wastage level value of 7.194%. The waste management of the TILC UGM Building construction project has implemented a waste management hierarchy system with the most dominant stages being the waste reuse and reduce. [ABSTRACT FROM AUTHOR]

Indonesia has potential geothermal energy reaching 28,617 MegaWatt which is 40 of the total world geothermal potential. There are many areas with geothermal potential in Indonesia that have not been explored, especially exploitation related to their utilization. One area on Java Island that requires further investigation is Telomoyo Volcano. This study aims to look at the geothermal system and estimate the reservoir temperature using the geothermometer. Geothermometer methods are used for temperature calculations involving the concentrations of Na, K, Ca. The results of the analysis show that the type of fluid is Chloride water. The results of plotting the concentrations of sodium (Na), potassium (K), and magnesium (Mg) show that they are all in the immature water zone. The estimated temperature of the subsurface reservoir of Pakis Dadu hot spring is ± 188 °C and Dukuh Temple hot spring is ± 171 °C. 5. The geothermal system in the study area is classified as a liquid-dominated system. According to the lineament analysis and the fault fracture density map indicate that the manifestations emerge on the surface from the outflow zone, which is controlled by the existence of geological structures. The utilization of geothermal potential in the research area as hot spring baths and high-temperature reservoirs that are good for being developed into geothermal power plants. [ABSTRACT FROM AUTHOR]

Guntur Spring provides clean domestic and agricultural irrigation water and is the only water source in Girijati Village (Gunungkidul Regency) and Sorotopo Village (Bantul Regency), Yogyakarta Indonesia. The research was designed to analyze the multitemporal suitability of an epikarst spring water in the tropics for irrigation, with Guntur Spring as an example. It employed Na% analysis, Sodium Adsorption Ratio (SAR) calculation, and hydrogeochemical data plotting on the USSL and Wilcox diagrams. The observed elements were Ca2+, Na+, Mg2+, K+, and electrical conductivity. Based on the Na% and SAR values, all samples of the Guntur Spring were excellent (S1). The USSL plot classified them as moderate to good (S2-C1), and the Wilcox diagram indicated excellent to good attributes. Guntur Spring has higher water suitability parameter values for irrigation (Na% and SAR) than other springs in the Gunungsewu Karst Area that receive allogenic recharges. However, such a difference does not necessarily place these springs in different classes. Likewise, although extreme events like the tropical cyclone Savannah diminish the water quality, it does not lower the water suitability class for this purpose. [ABSTRACT FROM AUTHOR]

Earthquakes are one of the most destructive natural disasters on earth, which are the result of surging tectonic stress, and it extremely difficult to predict due to a lack of different statistical patterns required to model future occurrences. Indonesian Meteorology, Climatology, and Geophysics Agency (BMKG) said that there were 11.920 earthquakes happen in 2018 and 11.473 earthquakes in 2019. In 2018, there were 29 destructive earthquakes and one earthquake followed by a tsunami that caused 4047 people dead or lost, 6.439 people injured, 704.849 people evacuated, and thousand public facilities damage. While in 2019, there were 147 people injured, 5.025 homes damaged, and a hundred public facilities damage caused by 13 destructive earthquakes. Earthquakes prediction is necessary to reduce the risk caused by earthquakes. The purpose of this research was to predict when the earthquake would happen from the instrumentation system based on the telemonitoring of radon concentration anomaly to provide an early warning system alarm before an earthquake occurs. The methodology used in this research was built radon concentration monitoring systems that were placed near the fault around Yogyakarta-Indonesia. Radon concentration is measured every hour. Then, the author analyzed the correlation between radon gas concentration and the earthquakes happen from Sumatra until NTT. The data of earthquakes were taken from the Indonesian Meteorology, Climatology, and Geophysics Agency (BMKG) and Postdam Geofon. After measuring the radon gas concentration for 9 months and doing analysis, it was found that the prediction of an earthquake could be decided when 4 of 5 algorithms were confirmed. Based on the algorithm that was determined, there were 34 of 51 earthquakes that were successfully predicted and 34 of 66 true algorithms. So, the correctness of the prediction is 51,52% with an accuracy of 66,67% that the earthquake will happen 1 until 3 days later. [ABSTRACT FROM AUTHOR]

The study of low molecular weight organic acids (LMWOA) effects on Zn2+ desorption from the soil around the illegal landfills in Yogyakarta was conducted. The aims of this research are to analyze the physico-chemical properties of soil, investigate the presence of metal contamination in the soil and evaluate the effect of LMWOA (citric acid, tartaric acid, and oxalic acid) on the desorption of Zn2+ from soil samples taken from illegal landfill area in Yogyakarta. The soil samples used in this study were collected from three different locations. The characterization of the soil samples was conducted by analyzing its water content, ash content, cation exchange capacity, total organic carbon, and conductivity. Metal content was analyzed by atomic absorption spectrophotometry (AAS), while soil functional groups were investigated by using Fourier transform infrared spectrometry (FTIR). In desorption studies, the effect of LMWOA concentration and pH level are investigated. The result showed that the soil samples I, II and III had the content of Zn2+ at 263.5, 478.1, and 181.9 mg kg-1. In the Zn desorption processes there is a tendency that Zn2+ easily desorbed at acid condition. In addition, citric acid had the highest effect on metal desorption process compared to tartaric and oxalic acids. [ABSTRACT FROM AUTHOR]

Porous materials have been applied for various applications, mainly as adsorbent and catalyst. One of them is zeolite, particularly in a synthetic form which has excellent performance but has some drawbacks of high cost, complex processing, and waste production. Meanwhile, natural zeolite is available in abundant amount and has low-cost provisioning, so it has prospective room for developed. Some of the common types of natural zeolites are mordenite and clinoptilolite; one of the availabilities is located in Gunungkidul, Yogyakarta, Indonesia. The typical modification of zeolite is dealumination which was also applied to the natural zeolite. Dealumination was carried out to improve the natural zeolite properties, particularly Si/Al ratio. The various types of dealumination process were conducted in variable of acid concentration (0 to 12 N HCl), volume ratio (1:1, 1:2, 1:4), soaking time studies (1, 2, 4, 24 hours), agitation (stirring and no stirring), and multi-stage dealumination (1 to 10 stages). XPS analysis determined the Si/Al ratio, then supported by XRD and BET to explore the other characteristics transformation of crystal structure and specific surface area. In the single stage dealumination, the highest Si/Al ratio of 16.2 was produced at 12 N HCl, 1:4 volume ratio, 24 hours soaking time and stirring action. Meanwhile, the multi-stage dealumination has the evidence to improve the Si/Al ratio sequentially than others variable in single stage dealumination; the highest Si/Al ratio attained over than 120 at the most upper stage of dealumination. Moreover, dealumination treatment also increases the specific surface area over than 220 m²/g, but the multi-stage variable was not affected much. The multi-stage dealumination effect provides prospective application of mordenite-clinoptilolite natural zeolite, particularly in the high Si/Al ratio, as hydrophobic surface porous adsorbent or catalyst. [ABSTRACT FROM AUTHOR]