bluuebunny/crossref_metadata_2025 huggingface dataset:
Geospatial Analysis of Coastline Erosion Along Pulau Tuba, Langkawi
Authors: Aizam Adnan Nor , Qistina binti Shahibul Fadilah Farah , Maisara Ahmad Idzdihar Raihan , Amry Mohd Fazly , Rauf Abdul Rasam Abdul , Suhana Mokhtar Ernieza
Published: January 2021

The erosion in Malaysia has brought attention to many authorities especially the coastline in the eastern part of Peninsular Malaysia. Although the erosion in the northern part of Peninsular Malaysia does not receive as much attention as the eastern part of Peninsular Malaysia, however, the issue should not be neglected. High spatial resolution satellite imageries were used for the extraction of coastline and classification level of erosion rate along with the Pulau Tuba. The coastline data was extracted using two different methods known as Maximum Likelihood (ML) and On-Screen Digitizing (OSD) in the determination of the best approach of coastline detection from the Sentinel-2 data of the year 2016 and 2019. Furthermore, the level of erosion is made based on the physical and economic parameters outlined by the National Coastal Erosion Study 2015 (NCES). Due to some inevitable constraints of Movement Control Order by the Malaysian government due to the COVID-19 pandemic, physical observation data of Pulau Tuba were collected via Google Maps. The information acquired includes type of coastal geomorphology, land use, development on the area, activities conducted, and adaptation of erosion if any. These data were utilized to determine the erosion rate and categories using the proposed model by NCES for five divided management units (MU) of the Pulau Tuba areas utilizing Erdas Imagine and ArcGIS software. The analysis found that the ML approach has under-detected the coastline length between 3.19% to 45.0% as compared to OSD for both years of 2016 and 2019. Rate of erosion for Pulau Tuba based on the NCES approach found that the highest erosion rate occurred at the MU1 (Pulau Dayang Bunting- Pulau Tuba causeway) with 2.91% and classified as K1 (critical erosion category) with a value of 4.39 m/yr−1 and the highest accretion rate at the MU3 with 3.06%. The critical erosion category was associated with the MU that has significant development and on-going activities that occurred in the area especially in MU 4 (Pulau Tuba) and MU 5 (Teluk Berembang). Other than that, the high number of erosions occurred in that section is due to the exposure of waves, wind, currents, and tides.
Mapping Immigrant Populations: A GIS-Based Public Perception Exploratory Analysis
Authors: Sumping A , Abdul Rasam A R , Adnan N A , Md Saad N
Published: January 2021

Mapping and analysis of the immigrant population are one of the GIS-based society contributions related to spatial community matters. The difficulty in getting a detailed map of the immigrant population in Malaysia is the main concern in this study. This exploratory socio-spatial study is conducted to analyse the external immigrant’s population distribution pattern in Shah Alam by using GIS and public perception approach. Selection of the study area, data collection, data processing and analysis are the main steps carried out in a GIS framework. A GIS map was derived from the questionnaires that were distributed among the 81 local citizens and immigrants. Most of the immigrant population occupied in the area of Section 7, Section 25 and Section 24 especially in the central part of the main city. The locals agreed that the majority of the immigrant influenced to a negative impact on society, but the immigrants believed that their presence led to a positive impact on the local physical development. Mapping the external immigrant will assist the authority in decision making and handling immigrant-related concerns
Initial investigation of hydraulics engineering for flood mitigation: A case study in Krueng Aceh Sub-watershed
Authors: Saputra A A , Saputro D D , Prastica R M S
Published: January 2021

Problem of flooding in the Krueng Aceh Sub-watershed occurs almost every year, thus, the study is conducted. This article aims at the initial study of flood mitigation investigations in the Krueng Aceh Sub-watershed, which consists of an analysis of existing channel hydraulics and an ideal design plan at the study site for hydrological analysis of the Sub-watershed. In addition to the analysis of channel hydraulics, analysis of the safety factors of existing channel cliffs and plans is also carried out. In addition to flood mitigation in the form of redesigning existing canals, this article proposes the construction of an earth-embankment dam. In the analysis of this existing channel, discharge is obtained by 1098.857 m3/s. When compared with the design flood discharge for a period of 100 years, the channel discharge capacity cannot accommodate flood discharge. With the redesign of the channel, the storage capacity can accommodate the flood discharge with a safety factor of 2.804, greater than the existing channel of 2.711. Earth-embankment dam is proposed with a safety factor of 3.497. Further studies need to be done flood routing to find out how much the contribution of the dam reservoir to the reduction of flooding in the study area.
The development of smoothed particle hydrodynamics (SPH) method for modeling the interaction movement of fluid layers in between two soil layers in flat surface condition
Authors: Saffanah H , Bahsan E , Marthanty R R D R
Published: January 2021

The liquefaction phenomenon most often happens in saturated, loose, and low density such as sandy soils. When the bearing capacity drops, loose sand tends to become compressed and behaves like a liquid. This behavior generates an interaction between sandy soils and clay soils which has a higher permeability and include its water content. Therefore, it required a method that can model large deformation movements, namely the free particle method, Smoothed Particle Hydrodynamics (SPH). The SPH Method is used to determine the layer of water formed during the cyclic load to approach the liquefaction phenomenon. The model use clay soils as solid and water layers as fluid with model geometry 0.1x0.1x0.05 m. Program parameters represent clay soils with stiffness coefficient, solid volume, and critical shear strength also fluid layers with damping coefficient, fluid volume, and viscosity. The calculation is done with Fortran Program and visualized in 2 Dimension and 3 Dimension with Gnuplot. Both will be evaluated from the movement of solid and fluid also numeric stability. In the final model the parameters Ks = 20000 N/m, Ks = 53.3 Ns/m, dan x particle = 50 reach numeric stability and all fluid particles can recognize the solid layer.
Analysis of potential liquefaction using cone penetration test data and grain size distribution test with case study of liquefaction in Lolu Village
Authors: Rahayu W , Yuliyanti I , Bahsan E
Published: January 2021

Liquefaction is a rare natural disaster and is very closely related to geotechnical engineering, where it occurred i\n the city of Palu in 2018 ago. One of the Palu liquefaction areas is Lolu Village, which experiences a sizeable lateral movement of up to 150 m. The research aims to identify the potential liquefaction in Lolu Village using the Cone Penetration Test (CPT) data and grain size distribution test. In evaluating liquefaction potential, the CPT data is processed with the Idriss-Boulanger method, referring to the value of soil safety factors based on the ratio between ground resistance to liquefaction (CRR) and earthquake (CSR). Whereas grain size distribution tests are carried out based on ASTM, referring to soil type composition’s influence on the level of liquefaction potential. The results from eight CPT in Lolu village shows that liquefaction potential occurs at a depth of 5 to 10 m with varying end resistance and friction ratio values of the soil. Likewise, grain size distribution tests indicate that soil types are dominated by sandy soils vulnerable to liquefaction.
The effect of rainfall on the slope stability with numerical simulation on Tawaeli-Toboli road, Central Sulawesi
Authors: Pontoh A N
Published: January 2021

Tawaeli-Toboli is an arterial road that often experiences landslides due to rainfall, which increases pore water pressure and thus, decreases the soil’s shear strength. This research analyzes the effect of rainfall on Tawaeli-Toboli road with numeric simulation to determine the characteristics such as changes in pore pressure and slope stability. Frequency analysis with HAVARA software was used to determine the maximum rainfall, while the dominant rain duration was analyzed using WindRose. Furthermore, the SoilVision software was used to fit grain size distribution, and the results are used to estimate the soil-water characteristic curve (SWCC). Analysis of pore water pressure changes was carried out using the SEEP/W program. The results were used as input data to determine the slope stability analysis using the SLOPE/W program. The frequency analysis result showed that the maximum amount of rainfall on Tawaeli-Toboli road is 205.698 mm after 11 days. During normal rainfall (20 mm/day), the Western slope remains stable with a safety factor value of 1.50. Simultaneously, in heavy rains, it decreases significantly to 1.350 after 11 days of rain. The eastern slope is quite stable because it has a safety factor value of 1.721 during heavy rain conditions.
The vehicle type effect to the mixed traffic flow performance (case of study: Soleh Iskandar road, Bogor, Indonesia)
Authors: Sudibyo Tri , Erizal  , Fauzan Muhammad
Published: January 2021

Many cities in developing South East Asia countries face a traffic congestion problem due to the enormous number of private vehicles operating on urban roads. Various traffic management policies are implemented to minimize any loss of congestion problems. Traffic management policies and strategies are established based on traffic analysis and calculation from field observation data which commonly use passenger car units (PCU) as the calculation approach. However, this approach becomes more challenging in an area with mixed traffic where the passenger car is not the majority of the traffic proportion, e.g. in many SEA cities. This study emphasizes the understanding of the hypothesized changes in the traffic performance on the same number of vehicles under the different proportion of motorcycles as a fundamental understanding for PCU application. To achieve the study goal, a traffic microsimulation-based analysis was conducted. The model was built based on the Soleh Iskandar road geometric and traffic data in Bogor, West Java, Indonesia. The motorcycle flows were simulated from 45% to 90% of total flow proportions that consistently affected the overall traffic performance. The consistent changes in traffic performance indicator swift in the 85% and 90% of motorcycles.
Forest fires and carbon emission release in semi-arid regions of Indonesia: the evidence from medium resolution of satellite imagery
Authors: Armanto AN , Perdinan  , Dasanto BD , Hidayati R
Published: January 2021

Forest fires are one of the causes of forest degradation and deforestation in Indonesia. Tropical savanna forests are one of the forest ecosystems found in the Indonesian region with a semi-arid climate type prone to drought and fire. Forest fires contribute to the release of greenhouse gas emissions into the atmosphere. The calculation method to estimate the burnt area is still an obstacle in calculating greenhouse gas emissions due to forest fires. This research aims to assess the burnt area in tropical savanna forest cover type using medium resolution satellite imagery data by utilizing the Normalized Burn Ratio index in four villages in East Sumba Regency and estimating greenhouse gas emissions these activities. The results showed that the NBR method does not produce an estimate of the burned area with a fair degree of accuracy because the characteristic of channel 7 (SWIR) is sensitive to vegetation moisture content. The savanna forest cover type is the type of land cover identified as the most dominant burned area. It produces the highest greenhouse gas emissions compared to other land cover types.
Application of SWAT in selecting soil and water conservation techniques for preparing management recommendation of Cilemer watershed, Banten, Indonesia
Authors: Rachman L M , Nursari E , Baskoro D P T
Published: January 2021

The quality of watershed ought to be maintained because of its function as a life buffer of living things, especially in water and other material needs provision. From the indication result, Cilemer watershed was degraded, therefore, it demanded planning efforts to restore watershed quality. This study aimed to determine watershed management directives and selecting some alternatives of soil and water conservation techniques by using Soil Water Analysis Technique (SWAT) method. Six scenarios were applied, there were: strip cropping (Scenario 1), agroforestry (Scenario 2), reservoir or small reservoir (Scenario 3), strip cropping and agroforestry combination (Scenario 4), strip cropping and reservoir combination (Scenario 5), and strip cropping, agroforestry, and reservoir combination (Scenario 6). The result showed Scenario 6 was the most effective to maintain watershed quality. Compared to the existing conditions, Scenario 6 could decrease Qmax-Qmin ratio by 34.57%, decreased the surface flow by 33.64%, so, the runoff coefficient decreased from 0.25 to 0.16. Moreover, Scenario 6 also increased the base flow by 52.16% (from 357.55 mm to 544.07 mm), water yield by 4.16% (from 904.55 mm to 943.68 mm). However, Scenario 2 was the most optimal scenario since its input was lighter and involving a smaller restored area.
Study of inelastic behaviour steel structure of special moment frame (SMF) and eccentrically braced frame (EBF) with pushover analysis
Authors: Mentari S
Published: January 2021

High rise buildings should be made as sufficient seismic performance, so it won’t immediately collapse when an earthquake occurs. Therefore, lateral strengthened stories are required in high rise buildings to enhance the lateral rigidity of structure. The use of lateral strengthening has a great effect on the entire seismic performance. A 20-stories high rise steel structure building was evaluated on this research comparing the structures’ inelastic behaviour using two seismic force-resisting system, i.e., special moment frame and eccentrically braced frame. The analysis of inelastic behaviour in this research using static non-linear analysis, i.e., pushover analysis. By using pushover analysis, the inelastic behaviour of structures, including story drift, shear story, displacement, plastic joint formation, and ductility, were obtained. In the elastic condition, the shear story of the eccentrically braced frame system is smaller than the special moment frame system. While in plastic condition, the shear story of the eccentrically braced frame system is larger than the special moment frame system. The story drift and the displacement of the special moment frame system are indicated to be larger than the eccentrically braced frame system. These results show that the eccentrically braced frame system has better rigidity than the special moment frame system.
Comparison of bearing capacity pile foundation base on pile dynamic analyzer test and conventional analysis (Case on foundation bridge in Cikampek)
Authors: Somantri A K , Tarigan P J S
Published: January 2021

The foundation as the base of construction work must be able to bear the structural load from above and carry it down. Thus, the foundation analysis needs to be done for designed and build to determine the stability value of the foundation due to load and deformation. This research will be carried out in two different ways: analyzing PDA test results and calculating the bearing capacity of the foundation using Mayerhoff, Poulos Davis and Tomlinson’s method. Those two different ways will have resulted in a comparison of dynamic analysis. So it can be concluded through the regression results that will be determined in a linear and logarithmically. Based on the Mayerhoff method, bearing capacity regression values linearly ranged from 0.77 to 0.86 while logarithmically is 0.8. For the Paulos Davis method, the linear and logarithmic regression values range between 0.7 to 0.88. The Tomlinson method produces regression values ranging from 0.65 to 0.88 in a linear and logarithmic. This study shows differences in the value of regression from various conventional analyzes that have been carried out.
Effect of heat curing on early strength of high-performance mortar containing ferronickel slag as cement replacement
Authors: Edwin R S , Kimsan M , Pramono B , Masud F
Published: January 2021

High-performance mortar (HPM) is a new material in construction projects which requires a huge amount of cement on its production. As a consequence, the cost of this material will increase. This problem can be solved by utilizing alternative binders combined with the latest curing technology to obtain a low cost of HPM without loss of quality. This study aims to examine the effect of heat curing on the compressive strength of HPM containing FNS as cement replacement in early days (7 days). The FNS was ground using a ball mill to achieve a fineness similar or higher than cement. A low water-to-cement ratio of 0.35 was chosen in this research. The series of HPM mixtures containing FNS used in this study were 0%, 5%, 10%, 15%, 20% and 30%. Heat curing at 75 °C was used to assess the performance of the HPM compared to normal curing. The particle size distribution of binders was determined using a laser diffractometer. The results showed that the presence of FNS in the HPM had a positive effect on the compressive strength at 7 days after applying heat curing. The use of heat curing at 75 °C increased the strength of HPM at 7 days.
Application of soybean powder as urease enzyme replacement on EICP method for soil improvement technique
Authors: Pratama G B S , Yasuhara H , Kinoshita N , Putra H
Published: January 2021

Many researchers have confirmed the application of calcite precipitation method by urease enzyme induction as a potential soil improvement technique. However, this method needs an expensive investment due to the urease enzyme issue. The enzyme itself brings 90% of the total materials cost. It means that finding new inexpensive material for replacing the enzyme is considered essential for the development of this method. In this study, a potential material, which is soybean powder, was evaluated through several experimental tests. A comparison of urease activity value between EICP using soybean powder and commercial urease as a catalyst for hydrolysis of urea compound was made through a series of conductivity tests. It was found that EICP using soybean urease can be a potential alternative to a commercial product in terms of urease activity. The precipitation materials were analysed using a microscale test to analyses the minerals type. Besides, the reinforcing effect of EICP solution on soil specimens was evaluated by conducting unconfined compressive strength (UCS) test and acid leaching test. The results of the UCS test were indicated that the soybean powder is a potential material to be used in soil improvement technique.
Identification of non-volcanic geothermal manifestation in North Konawe Regency Indonesia using land surface temperature of Landsat satellite image
Authors: Jaya L M G , Suprayogi A , Sudarsono  , Hasbi M
Published: January 2021

Energy needs are increasing from year to year. However, in many countries, fossil energy is utilized in a large portion even though the country has a lot of potential for new and renewable energy. Geothermal is renewable energy has an important role in Indonesia besides other potential renewable energy such as water, wind, solar, and ocean tidal. This study aimed to identify non-volcanic geothermal manifestation in North Konawe Regency, South East Sulawesi Province, based on Landsat Enhanced Thematic Mapper (ETM) remote sensing satellite image. Land Surface Temperature (LST) method was conducted using thermal band processing of Landsat ETM. For this purpose, the single-window algorithm was applied. Validation was also conducted through a ground survey. The result of this study showed that at least two geothermal manifestations were founded in two separate locations in Wawolesea village and Toreo respectively. From the LST analysis, we found that the temperature reached 26.35 to 37.42 Celsius Degree in both locations, where hot water spring as geothermal manifestation exist. According to the ground check, the temperature correlation between in situ and LST is enough which R2=0.5155.
Rainfall modeling based on early predicted and season zone characteristic in the BMKG season zone over Lombok river basin
Authors: Noviadi S C
Published: January 2021

Planning water resources for long-term (annual, monthly) and operational (daily) requires a more accurate analysis of water availability calculations. The Meteorology, Climatology and Geophysics Agency (BMKG) publishes bulletin of forecasting every year in the form of the early wet season and the characteristics of the wet and dry season in each Season Zone (ZOM). BMKG conducts analysis and forecasting with complex climate parameters. Thomas Fiering analysis with the help of Excel Visual Basic Application (VBA) software is used to forecast rainfall at each rainfall station in BMKG Season Zone. The average error of forecasting rainfall during the wet season on the BMKG season zone in 2015/2016, 2016/2017 and 2017/2018 were 20%, 30% and 26%. While the average error for the dry season on the BMKG season zone is 44%, 34% and 52%. The existence of this deviation is caused by several factors including the uncertain season changes every year, as well as the influence of “El Nino.”.
Design and implementation of solar pump irrigation systems for the optimization of irrigation and increase of productivity
Authors: Rejekiningrum P , Apriyana Y
Published: January 2021

The irrigation solar water pump system is a technological innovation using water pumps that are more efficient and economical. The aims of this study are: (1) to design an efficient solar pump irrigation system for shallots and red chili, and (2) to measure the irrigation efficiency of the solar pump irrigation system. The configuration of the solar water pump irrigation system should be determined on the basis of (1) the pump performance curve, (2) the irrigation system performance curve and (3) the pump discharge and the operating pressure curve. Our results show that the operational duration of the pump for 7.59 hours/day in Playen Sub-District, Gunungkidul was able to irrigate 2,333 m2, while in Imogiri Sub-District, Bantul a regime of 5.42 hours/day could irrigate 3,630 m2. Irrigation techniques using Impact Sprinklers for shallots and Streamlines for red chili, when combined with mulch could increase the growth and yield of shallots and red chili crops compared to the patterns and methods practiced by farmers. The efficiency of the solar water pump irrigation system should be further improved by a more detailed calculation of water supply pumping power calculation in order to increase the planting capacity of farm.
Developing IT infrastructure of evaporative irrigation by adopting IOT technology
Authors: Arif C , Setiawan B I , Saptomo S K , Taufik M , Wiranto  , Mizoguchi M
Published: January 2021

The primary key to the modernization of irrigation is the effectiveness of agricultural water use that should be supported by good infrastructure, including information technology (IT). The objective was to evaluate the performance of IT infrastructure in collecting weather data for evaporative irrigation. The system was set up under a natural environment since 10 July 2020 in the Kinjiro Farm, Bogor. The system consisted of three parts, i.e., integrated sensors suite (ISS), console (data logger), and the server, including the dashboard system. The ISS involved several sensors, namely:Pyrsolar radiation, rain gauge, air temperature, and humidity sensors, together with wind speed and direction. All data were collected through the console and data logger and then transferred into a local computer server to the dashboard system using an internet connection. The users can access all data from the dashboard system as numerical and graphical data. The system showed a reliable performance, as all data were well properly sent to the server every 30 minutes. The weather parameters, including rain events, were correctly monitored every 30 minutes. All observed data were found to directly affect the reference evapotranspiration, a parameter that will be used for further consideration in determining irrigation scheduling.
The effect of chlorpyrifos exposure on carp fish at twin lakes of West Sumatra Indonesia
Authors: Ihsan T , Edwin T , Paramita D , Frimeli N
Published: January 2021

This study was conducted to analyze the sublethal effect of chlorpyrifos on the Feed Conversion Ratio (FCR), Sustainable Growth Rate (SGR), and carp behaviors. The concentration used 1/7 and 1/14 of the LC50 carp. The study was conducted with the number of fish per aquarium was five fishes, and the testing exposure time was 14 days. The results of the FCR and the SGR at a concentration of 1/7 and 1/14 LC50 was 0.2907 and 0.3031, and 1.551% and 1.9581%, respectively. Changes in behavior during exposure, a decline in appearance such as being alone in the corner of the aquarium, moving irregularly and stress (r = 0.75-1), lots of mucus (r = 0.800-1), anal excretion (r = 0.6-0.799), and breathe to the surface (r = 0.800-1). This situation happened because chlorpyrifos begins to affect the nervous system of carp to reduce other body functions. The FCR and SGR had a significant effect through the statistical test due to the chlorpyrifos concentration. Whereas in carp’s physiological behavior changes, there was no significant effect due to the level of concentration provided.
Prediction of land cover changes in Penajam Paser Utara Regency using cellular automata and markov model
Authors: Permatasari R J , Damayanti A , Indra T L , Dimyati M
Published: January 2021

Development and economic growth in an area can cause land cover changes. Penajam Paser Utara Regency, as a new capital candidate, is also predicted to experience in land cover changes. Land cover changes that are not following the land’s potential will cause environmental problems, so it is necessary to predict land cover changes by looking at patterns of land cover changes in the past and the factors that influence it. The purpose of this study is to analyze and predict the land cover change in Penajam Paser Utara Regency in 2031. The method used in this study is modeling using Cellular Automata - Markov. The driving factor of land cover change is used in making prediction models such as distance from the center of activity, distance from the road, distance from the river, elevation, and slope. The prediction land cover changes show that there has been an increase in plantation area and a decrease in forest area, while the development of the built-up area is not visible. The kappa test for predicted land cover showed perfect results. The resulting land cover model can be used to formulate land-use policies.
Investigation of air pollution dispersion from kiln stacks based on seasonal using multi-model integration (WRF/CALPUFF)
Authors: Pratama A
Published: January 2021

Air pollution is one of the environmental problems that have a bad impact on human life. Air pollution sources come from various sources such as industry, mining, transportation activities, etc. This study aims to identify the seasonal dispersion of Sulfur Dioxide produced by kiln stacks in PT Semen Padang, Tbk. The Dispersion model used in this study is CALPUFF (For air pollution model) integrated with WRF (Weather Research Forecasting) (For meteorological model). CALPUFF requires the wind field generated by the CALMET model and the WRF model. From the simulation, the direction of SO2 dispersion on the wet season and the dry season is influenced by meteorological phenomena such as sea breeze and land breeze. The dispersion of Sulfur Dioxide in the dry season passes the urban area more than in the wet season, with the highest concentration is 122 µg/m3. On the other hand, in the wet season, the highest concentration is 120 µg/m3. These results are below of national quality standard in Indonesia (365 µg/m3). The statistic also shows that the correlation and error (RMSE) between the model and observed data are 0.63 and 5.49 in the wet season, whereas the correlation and error (RMSE) in the dry season are 0.74 and 2.89.
Analysis of multimedia filter effectiveness to improve the quality of rainwater runoff in fulfilling urban raw water supply
Authors: Oktaviani A , Suwartha N
Published: January 2021

Rainwater is recommended as a clean water supply through several water treatment methods. Based on preliminary data test results, several parameters exceed the sanitary hygiene water standard. This research aimed to improve the quality of rainwater runoff using the multimedia filter, which combined filtering and physical adsorption process. The combination of silica sand, activated carbon, and zeolite media was simulated into a pilot-scale of 1:2 reactor. Based on the first experimental results, the use of proposed media has a significant effect (p-value≅0) on several parameters. The best improvement in effluent quality reaches 100% in nitrites removal, 29% in nitrates removal, and 94.4% in total coliform removal. However, the media thickness variation factor has an insignificant effect (p-value 0.616) to effluent quality. Based on the second experiment results, hydraulic loading rate (HLR) variation shown a significant effect (p-value 0.01) on several parameters. Effluent quality improvement reaches 71.4% in nitrites removal, 100% in nitrates removal, and 91.9% in total coliform removal. However, variation in HLR gave an insignificant effect (p-value 0.769) on improving effluent quality.
Novel helical or coiled flocculator for turbidity reduction in drinking water treatment: a performance study
Authors: Cahyana G H , Suwandhi P , Mulyani T
Published: January 2021

Helical or spiral coiled flocculator have not been applied in drinking water treatment yet in Indonesia. Only a few articles discussed it with different themes like hydrodynamic, floc characteristics, and performance. This study was done to know the efficiency (performance) of helical flocculator with parameters velocity gradient, pipe, helical diameter, flowrate, detention time, and coagulant dose. The study was divided into two steps: Jar test to determine the optimum dosage of coagulant and flocculation experiments to evaluate the helical flocculator efficiency. Efficiencies were in the range of medium to high. On flowrate, 13 ml/second was obtained good results for two pipe sizes but different in helical diameters. In a 0.5 inch pipe with 0.8 m helical diameters, the turbidity reduction efficiencies were 72.4% and 73.9%, and sediment volume was 18.3 ml and 20.0 ml. In a 0.625 inch pipe with 0.4 m helical diameters, the turbidity reduction efficiencies were 76.7% and 78.5%, and sediment volume was 14.3 ml and 19.7 ml. The optimum velocity gradient about 64.9–69.6 per second, and detention time about 438–649 seconds. The results showed that helical flocculator was effective for floc formation. Flowrate, pipe diameter, helical diameter were three key parameters to perform helical flocculator.
Analysis of performance and testing of 1215 WP rooftop solar power plants with on-grid system household scale with the case study of Sambiroto Asri Housing Semarang City
Authors: Windarta J , Denis  , Silaen J S , Satrio D A
Published: January 2021

This research is conducted to examine the on-grid system to the solar module and analyze the consequences of on-grid solar power plant implementation towards the daily electrical energy consumption. The data retrieval is conducted for three days, from 29thto 31stJuly 2020 and this research provides real-time data by considering the weather conditions of each day. According to the result, the solar module has an efficiency value of 15.13%. This value is lower than the nameplate due to the higher solar module surface temperature than the optimal operating temperature. Subsequently, based on the implementation impact analysis, it is stated that on-grid system implementation in the solar power plant could produce electrical energy of 4.32 kWh. It is also found that the daily output of on-grid system implementation in a solar power plant could operate the load of 1.86 kWh and it could export the electrical energy to the grid of 2.46 kWh. In this way, the system could use a load of 2.45 kWh and export electrical energy of 1.87 kWh to the grid on the weekend. Therefore, it can be concluded that a solar power plant with an on-grid system could export the electrical energy to the grid.
Personal characteristic, occupational, work environment and psychosocial stressor factors of musculoskeletal disorders (MSDs) complaints on bus driver: literature review
Authors: Zulkarnain M A , Setyaningsih Y , Wahyuni I
Published: January 2021

Musculoskeletal disorders (MSDs) complaints is an accumulation of injuries and pain in the musculoskeletal system. It is characterized by injuries on muscles, tendons, cartilages, ligaments, and vascular and nervous structures. Bus drivers are high-risk workers that experience MSDs complaints. MSDs on bus drivers can disrupt drivers’ performance, endanger drivers, passengers, and public road users. This study aims to review the literature on factors of MSDs complaints among bus drivers. The literature review method is used by compilation, tabulation, comparing the research results, and then summarizing it. The research was obtained from an accredited journal site (PubMed, Research Gate, Science Direct, Scopus) and the google scholar journal search page. After searching for keywords and screening with the research inclusion criteria, 15 studies were obtained. It was found that smoking habits, age, years of work, driving duration, work posture, vibration, work stress, and job dissatisfaction were the main factor of MSDs complaints on the bus driver. Several studies also show that bus drivers with a low level of physical activity, long driving duration, high driving frequency, unergonomic seats, feelings of anxiety and confusion during driving had a higher risk for experiencing MSDs complaints.
Metal industry waste desiccation behavior with the addition of bentonite as a landfill liner
Authors: Ramadan B S , Alfanti L K , Sutrisno E , Budihardjo M A , Wardhana I W , Yumaroh S
Published: January 2021

The existence of garbage in the environment can cause pollution. Therefore, it is necessary to carry out waste management, one of which is by building a landfill. Landfill liner should have a permeability coefficient <10−6 cm/sec to prevent contamination. Currently, the affordable material used as landfill liner is clay, but it is quite rare. An alternative material we can use is metal industrial waste, which has not been utilized. Metal industrial waste has a permeability coefficient, namely 25.34560 x 10−6 cm/s. In order to reduce the permeability coefficient value, metal industrial waste is added with bentonite material, which has a low permeability value with variations of 0%, 5%, 10%, 15%, 20%, and 25% addition of bentonite. Digital image processing techniques are used to calculate crack intensity factor (CIF) values using the Matlab 2019 software. The results showed that the permeability value that fulfilled was the variation of 20% bentonite addition of 0.8059 x 10−6 cm/s and 25% of 0.5059 x 10−6 cm/s. While the CIF results showed that only the variation of 25% bentonite addition were not eligible because they had a crack area >4%. Thus it can be concluded that the best composite is metal industrial waste with 20% bentonite.
Electrocoagulation for drinking water treatment: a review
Authors: Al-Hanif E T , Bagastyo A Y
Published: January 2021

In this era, raw water pollution often occurs, and conventional processing can sometimes not treat it. Raw water as a water source for drinking water has to meet physical, chemical, and biological parameters in accordance with a predetermined standard. One of the parts of the advanced electrochemical process is electrocoagulation, which has been widely used to treat various types of wastewater and water. Chemical coagulation and electrocoagulation had the same process but a different mechanism. The way aluminum or iron is delivered is the difference in the mechanism. This article focuses on the effects of various operating parameters and recent developments in the electrocoagulation for the drinking water treatment process. Their optimum ranges for maximum pollutant removal and various pollutants removed by this process are observed.
The effect of amylase and cellulase enzymes on biogas production from rice husk waste using solid-state anaerobic digestion (SS-AD) method
Authors: Nugraha W D , Wafiroh H , Syafrudin  , Junaidi  , Budihardjo M A , Safitri R P
Published: January 2021

Biogas comes from an anaerobic biological decomposition process. Biogas is an alternative energy that potential to be developed in Indonesia. One of the various raw materials that can be used in biogas production is rice husk waste. This study analyzes the effect of pretreatment using amylase and cellulase enzymes on the production of biogas from rice husk waste in the Solid-State Anaerobic Digestion (SS-AD) method. Rice husk waste was used as a substrate with a C/N ratio of 25%, and the total solids used was 21%. Rice husk is biomass that is difficult to degrade because it has high lignin content; therefore, pretreatment is necessary. One of them is biological pretreatment using enzymes. The enzymes used are amylase and cellulase enzymes with various concentrations of 9%, 12%, 15%, and 18%. The biogas produced was then measured every two days for 40 days of the study with the volume of biogas as the observed parameter. The results showed that pretreatment with the addition of amylase and cellulase enzymes could increase biogas production. The highest biogas production was obtained by pretreatment of 18% amylase enzyme, namely 1466 mL, and by pretreatment of 18% cellulase enzyme, namely 1075 mL.
Cultivation process of microalgae using wastewater for biodiesel production and wastewater treatment: a review
Authors: Padri M , Boontian N , Piasai C , Phorndon T
Published: January 2021

Combining microalgae cultivation with nutrient removal is a promising technique as it enables renewable energy generation with the additional potential removal of wastewater contaminants in a single process. Performance and total yield of this process are still below the standard for industrialization. Thus, optimization is needed to reach the feasibility and actualize the concept. Cultivation conditions and reactor design play essential roles in the application and feasibility of this process. Both aspects have been developed through the years to enable the industrial application of this concept. Cultivation conditions are usually categorized into trophic conditions in which each situation has its specific function and target of removal. These conditions, however, are also applied in various reactor systems. Closed photobioreactor and open pond are two central systems for the reactor. Two of the most applied reactor models in wastewater are reviewed here to create a broad picture of the algae cultivation process by emphasizing biomass production and considering different aspects.
Spatial quality of shallow groundwater in DAS Cijurey Regency of Majalengka, West Java
Authors: Mutiara T , Kusratmoko E , Marko K
Published: January 2021

Considering when the water needs to surge, an alternative is required to obtain clean water—one of them by utilizing the presence of shallow groundwater. However, not all shallow groundwater has good quality to consume. Thus, the study aims to describe the groundwater quality spatial pattern and describe the link between the spatial pattern of groundwater quality with lithology, land use, and groundwater in DAS Cijurey, Majalengka regency. There are two types of parameters used, namely physical and chemical. The shallow groundwater Quality measurement was carried out in November 2019. The results showed the territorial distribution of groundwater quality and the connection between groundwater and the three influence factors at DAS Cijurey. The number of samples used is 41 points, groundwater quality sampling with a purposive random sampling method. As the parameters measured will be compared to 3 quality standards, namely, Ministerial Regulation No. 492/Menkes/PER/IV/2010, Government regulation of the Republic of Indonesia No. 82 2001, and Regulation of the Minister of Health RI No. 01/birhukmas/1975. After that, a decent water quality result (6 samples) is not feasible (35 samples) for consumption. The dominating factors of land use, i.e., settlement, for the dominating lithology are the unraveling volcanic rock and the depth of the water in its depths of 0-5 meters.
Spatial distribution of rice productivity utilizes sentinel-2A and NDVI algorithm in Nagrak Sub-district, Sukabumi Regency
Authors: Rahmanida Y , Shidiq I P A , Rokhmatuloh  , Supriatna
Published: January 2021

Rice is a commodity of rice-producing food crops that plays a vital role in the Indonesian economy. For anticipating increased food needs, accurate information about the amount of harvest becomes very important. Information on the number of harvests, one of which can be known by estimating rice productivity. Rice productivity estimation can be monitored by remote sensing. This study used a remote sensing approach by employing satellite imagery from Sentinel-2A sensors to generate vegetation index. This study used NDVI (Normalized Difference Vegetation Index) to determine rice plants’ age and estimate rice productivity. This study analyzes rice productivity and the spatial distribution of rice crop productivity in the Nagrak Sub-district, Sukabumi Regency. The results of this study are Sentinel 2-A and algorithm could provide rice productivity estimation and know the range of the largest rice productivity is greater than 6 ton per hectare, which is widely spread at an altitude of 500 -1000 meter above sea level and a slope of 8 to 15 percent, and a distance of 0 - 150 meters from the river.
Measurement of water availability: understanding the relationship between the physics of water and the level of community welfare at Bumiaji District, Batu City, Indonesia
Authors: Ari I R D , Hariyani S , Waloeya B S
Published: January 2021

This research attempts to be part of the Sustainable Development Goals movement goal, especially pillar number six. Bumiaji District Batu City, Indonesia is chosen as an empirical case, with the basic assumption that putting together physical and social infrastructures is a crucial success for poverty alleviation. Total respondents are 552 households proportionally distributed at nine villages classified into poor and non-poor families. Primary data was conducted through a face-to-face interview questionnaire. The first aim found that the non-poor households have better access to safe water than the poor by measuring the five components of Water Poverty Index (WPI), in range the WPI value of 55.26 – 80.12 44.98 – 64.91, respectively. However, the two have one similarity wherein the environment indicates the worst component (25.04 – 37.78). For the second question, applying Social Network Analysis with two indexes of participation and density index also depicts a similar result that the non-poor households have higher social ties than the poor. In conclusion, putting together the balanced development between physical infrastructure and human resources is indispensable, particularly on how important environmental education to prevent land-use conversion from green areas to the built-up area.
Carbon emission report: a review based on environmental performance, company age and corporate governance
Authors: Solikhah B , Wahyuningrum I F S , Yulianto A , Sarwono E , Widiatami A K
Published: January 2021

This research aims to explore the practice of carbon emission disclosure in the manufacturing company. This paper also examines the factors that influence the disclosure of carbon emissions. The factors tested are environmental performance, company age, managerial ownership, institutional ownership, and independent commissioners. This study uses a sample of 40 manufacturing companies listed on the Indonesia Stock Exchange in 2012 - 2015. The data analysis methods included were descriptive statistical analysis and panel data regression analysis. The carbon emission disclosure level in Indonesia’s manufacturing companies is low because companies are less concerned about environmental reporting problems. The results of this study indicate that company age, institutional ownership, and independent commissioners have a positive effect on the disclosure of carbon emissions, while environmental performance and managerial ownership do not affect the disclosure of carbon emissions.
Spatial distribution and characteristics of destructive activities in Tahura Gunung Menumbing, West Bangka
Authors: Pratama M R , Marhaento H
Published: January 2021

Taman Hutan Raya (Tahura) Gunung Menumbing is a well-known protected area in West Bangka, Indonesia for its uniqueness of plants and animals that represent the low-land forest ecosystems of Bangka-Belitung Island. However, the biodiversity of Tahura Gunung Menumbing is currently facing threats from illegal encroachments. This research aims to map the spatial distribution of those illegal encroachments and investigate their characteristics such as dominances, frequencies, and time of activity. We interviewed 48 respondents that were selected by the snowball sampling technique. These respondents consisted of farmers, illegal tin miners, and poachers. The results showed that the spatial distribution of illegal encroachments such as illegal tin mining, wildlife hunting, and illegal agriculture mainly occurred on the west side of Tahura Gunung Menumbing. Illegal agriculture practices for rubber and oil palm were the most dominant activities (69%), while illegal tin mining and wildlife hunting contributed 25% and 6%, respectively. Illegal tin mining and agriculture practices almost occurred every day throughout the day. The findings of our study showed that Tahura Gunung Menumbing is facing serious threats and thus the biodiversity is potentially declining in the future. Therefore, conservation actions to preserve the biodiversity in Tahura Gunung Menumbing are urgently needed.
Evaluation of community-based drinking water supply in Manyar Sub-District, Gresik Regency
Authors: Marsono B D , Pitaloka K D
Published: January 2021

The differences of topography in Indonesia causes drinking water distribution by Municipal Waterworks (PDAM) can’t reach up some rural areas which are far from urban area, one of them is in the Manyar Subdistrict, Gresik Regency. In fact, this subdistrict has the potential for economic growth because it is close to the north coast and there is a national port. About 10,67% of drinking water supply in rural area is held through the Community-based Drinking Water Supply which is managed and maintained by Himpunan Penduduk Pemakai Air Minum (HIPPAM). The research aim to evaluate the system and make recommendation’s from the evaluation analysis for more optimal system performance. The evaluation consist of technical and non-technical aspects were conducted by the scoring and weighting method. Tanggulrejo Village got the highest score, 4,28 (85,50%), with a very good category, while Pongangan Village got the lowest score, 2,65 (53%), with a moderate category. In general, optimal performance for this evaluation can be obtained by optimizing the existing water treatment; involving the community as meter recorder; and improving the administrator knowledge and skills through HIPPAM training.