bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protease production by soil bacteria for green technology: Screening and optimization
Authors: Ratnaningrum D , Kosasih W , Endah E S , Lathifa A K N , Diwan A M , Nida V , Saraswaty V , Risdian C 
Published: June 2023

Abstract
Protease is a type of enzyme that hydrolyzes proteins into peptides and amino acids. The demand for protease for green technology in some industries like detergent, food, and leather is increasing nowadays. Some soil bacteria, especially the Bacillus strains, are known to have the ability to produce protease. Compared to other sources like plant and animal origin, microbial protease has more advantages as it can be produced at an industrial scale, short cultivation time, and are easy to harvest. This research aimed to screen the proteolytic bacteria from the bulk soil samples collected under mango trees and to study the optimum condition for protease production using the response surface methodology (RSM). Three bacterial strains (SH2CR, SH3CR, and SC4CR) were isolated and shown to have proteolytic activity. Based on 16S rRNA gene analysis, the strain SH2CR was close to Priestia megaterium NBRC 15308T (96.97% similarity), while the strains SH3CR and SC4CR were related to Bacillus zanthoxyli strain 1433T (100% similarity). One of them, SH2CR, was further studied using a fermenter at a one-liter production scale with the medium containing skim milk at 30°C. The best condition for protease production by SH2CR was achieved at 48 h incubation time, 300 rpm of agitation, and 1.25% skim milk.
Determination of antioxidant activity, total phenolic, and total flavonoid contents from avocado seeds (Persea americana)
Authors: Kurniawan K , Rahmat A 
Published: June 2023

Abstract
In this study, the antioxidant activity, total phenolics, and total flavonoids of avocado seed extract were determined. The evaluation was observed towards methanol and ethyl acetate fractions by using the spectrophotometric method. The antioxidant activity of the avocado seed extract was determined by calculating the 50% of inhibition concentration of free radical scavenging activity towards DPPH radicals. The results showed that the IC50 of methanol and ethyl acetate fractions were 66 mg/mL and 63 mg/mL, respectively. The total phenolic content of the methanol fraction and the ethyl acetate fraction were almost similar at 48.6–48.7 mg/g dry weight of extract (gallic acid equivalent). Whereas the total flavonoid content of the methanol and ethyl acetate fractions was determined as 41.2–41.4 mg/g dry weight of the extract (quercetin equivalent). The phenolic and flavonoid compounds present in the fractions seemed to account for the antioxidant activity. Therefore, avocado seeds are a potential source of antioxidant compounds.
Preliminary study of microplastic in bottled drinking water
Authors: Syuhada  , Radini F A , Rusmana D , Liza C , Nur I M Z , Rifathin A 
Published: June 2023

Abstract
Microplastic is widely discussed and has become growing attention because of its negative impact on the environment and the well-being of living organisms. Some international studies have found microplastics in some foods and beverages, such as honey, beer, table salt, and drinking water. However, there are few accurate analytical techniques for identifying and analysing microplastics, especially in beverages and foods. This preliminary study investigates microplastics that might contaminate bottled drinking water, their physical properties, and their types of material. Five local brands of 120 ml bottled drinking water were used for this research, collected from a traditional market in South Tangerang. The samples were observed visually for microplastic’s presence, sizes, and shapes using a digital microscope. Furthermore, material identification using a Microscope - Fourier transform infra-red (μ-FTIR) was conducted to analyse the types of material present in the samples. The results show that all examined samples were contaminated, and the major pollutants were fibres with lengths between 0.042 and 3.668 mm. According to the material identification result using μ-FTIR, materials found in most samples are cellulose-based polymers, which are used widely for natural textiles (e.g., cotton) and synthetic fibres. In the five brands of the analysed bottled drinking water, neither the packaging material polypropylene nor the bottle caps made of polyethylene were detected. These findings indicate that the analysed bottled drinking water was not contaminated by microplastic, but by micro debris of natural cellulose-based polymers.
Distribution of Escherichia coli and coliform in groundwater at Leuwigajah and Pasirkoja Areas, West Java, Indonesia
Authors: Naily W , Sunardi S , Asdak C , Dida E N , Hendarmawan H 
Published: June 2023

Abstract

Escherichia coli and coliform are frequently detected in groundwater, and their abundant presence indicates that the groundwater has been contaminated. Several variables, including population density and well construction, contribute to the growth of E. coli and coliforms in groundwater. This is caused by domestic waste as a source of pollution being close to clean water sources (wells). This study aims to map the distribution of E. coli and coliform. The study was conducted at Pasirkoja and Leuwigajah in Greater Bandung, West Java, Indonesia. E. coli and coliform counts from 36 wells were carried out using the Petrifilm method with a 3MTM PetrifilmTM Rapid E. coli/Coliform Count Plate. The distribution of E. coli and coliform is represented by Quantum Geographic Information System (QGIS) software. The results showed that the number of E. coli and coliform mostly exceeded the quality standard. The distribution of E. coli and coliform is to the east of Leuwigajah and to the west of Pasirkoja.
Evaluation of ammonium issues in Indonesian groundwater: Potential sources and removal methods
Authors: Fahmi M A , Rohman A , Ahsan S A , Firmansyah F , Perdananugraha G M , Rusydi A F 
Published: June 2023

Abstract
Elevated concentration of ammonium (NH4
+) has been identified as one of the problems with groundwater because it indicates anthropogenic disturbance. In this study, we evaluated the NH4
+ presence in Indonesian groundwater and the land-use conditions possibly related to the issues. In addition, this research presents practical strategies for reducing NH4
+ concentrations in groundwater. The spatial distribution shows that high levels of NH4
+ are found in densely populated areas. Furthermore, land-uses analysis reveals that considerable concentrations of NH4
+ were found in several land-uses, including settlement, agricultural, fishpond, industrial, and garbage disposal, reaching 24.16, 7.73, 16.7, 7.42, and 84.9 mg/L, respectively. However, the statistical analysis shows that not all land-uses types significantly correlated with groundwater NH4
+ contents. Based on the p-value and confidence interval of 95%, NH4
+ concentrations are significantly correlated with settlements, brackishwater ponds, and garbage disposal. Similarly, industrial and agricultural land-uses have positive correlations with NH4
+ concentrations, although these correlations are insignificant. Finally, the promising methods for NH4
+ removal are the adsorption and ion exchange methods using zeolite or biochar, which could reduce NH4
+ levels by 90% and more. Furthermore, these methods do not require complicated application procedures.
Analysis of silica gel desiccant application in fuel storage tanks model to reduce palm oil-based biodiesel degradation
Authors: Azhad M F R , Fathallah A Z M 
Published: June 2023

Abstract
The need for a cleaner and more efficient engine arises as regulations on emissions become more stringent. besides increasing pollution and inefficiency concerns, manufacturing expenses are also on the upswing. As around 20% of all the energy used goes toward reducing friction, effective lubrication is a potential solution to the issues of efficiency, emissions, and engine wear. Several nanoparticles are being tried as potential performance-enhancing additions for engine oils. By sliding, polishing, rolling, and forming a third body, nanoparticles can improve liquid lubrication and lessen the contact between sliding surfaces. Because of its unusual characteristics, hexagonal boron nitride proven itself as a viable substitute for traditional inorganic solid lubricants. There has been a lot of study on how adding hBN nanoparticles to lubricating oil affects internal combustion engines. The impact of hBN as oil nano additions on engine fuel consumption, pollutants, and wear rate is the subject of this review study. Several studies show that hexagonal boron nitride, when added to engine oil, decreases the oil’s coefficient of friction (COF) and raises its thermal conductivity. From these improvements, lower fuel consumption, higher engine performance, lower exhaust gas emission, and prolonged moving parts wear rate are achieved for an internal combustion engine. This improvement will be beneficial to both operational and economic aspects.
Particulate Matter Concentration in Healthcare Facilities: The Influence of Natural Ventilation
Authors: Savanti Fisa , Wicaksono Dimas 
Published: June 2023

Abstract
Particulate Matter (PM) is an air pollutant that harms human health. Therefore, there is a particular concern about reducing indoor air pollutants. Natural ventilation supplies clean air into the room to reduce indoor pollutants and create good air quality. This research aims to determine the influence of natural ventilation on the particulate matter’s concentration in the room. First, the physical indoor air quality, including particulate matter, was measured using research instruments to obtain the primary data in healthcare facility buildings. Quantitative analysis is then carried out following the applicable recommended standards. The results indicate that natural ventilation can affect particulate matter concentration in the room and play an essential role in reducing it. Therefore, a building must consider good ventilation design to create better indoor air quality.
Characteristics and Antioxidant Activities of Three ‘Beras Kencur’ Effervescent Formulations
Authors: Astuti W , Hayati S , Dinata M A , Yonifasari C D , Wardania N R , Fitri Z A 
Published: June 2023

Abstract
This study aimed to evaluate the physical characteristics and antioxidant activities of beras kencur effervescent tablet formulations. Beras kencur was prepared in 7 different concentrations to assess the percent inhibition. The highest inhibition potency (76.2%) was found in beras kencur 10 mg/mL. This concentration was used to obtain the formulation of the effervescent tablet, which differed in definite proportions of citric acid (C6H8O7), tartaric acid (C4H6O6), and sodium bicarbonate (NaHCO3). When dispersed in water, the tablet produces a bubbling reaction by releasing CO2. The tablets were evaluated for pH, soluble time, total phenolic content (TPC), and antioxidant activity. These observations demonstrated that the higher proportion of NaHCO3 led to the higher solubility of the effervescent tablet. The antioxidant activity of formulations was evaluated using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and total phenolic content was determined using Folin-Ciocalteau. The outcomes suggested that the phenolics might become unstable at high acid conditions. In contrast, an increase in alkaline pH increased the ability of effervescent tablets to produce reactive oxygen species (ROS). The tablet with an equal proportion of acid and base showed the highest antioxidant activity (IC50 = 20.8), in line with the total phenolic content (5.772 mg GAE/mL).
Effect of Applying Strong Column Weak Beam to the Laboratory’s Artificial Lighting System
Authors: Hangga Arimaz , Nisa Alim Muanifatin , Triantino Septiandi Budi , Khoirunnisa Fitriana , Wulan Anissa Purnama , Khoerunnisa Anissa 
Published: June 2023

Abstract
Lighting is one of the crucial experiment factors in the laboratory. Laboratory’s lighting system that follows the Indonesian National Standard (SNI) can improve visual comfort during experiments. This research aims to determine the effect of strong column weak beam (SCWB) on illuminance in the laboratory according to SNI 6197:2011. The results were expected to provide recommendations for the implementation of SCWB in the laboratory so that the laboratory lighting system was more optimal. Digital Electronics Laboratory, E8 Building, Universitas Negeri Semarang had dimensions of 12m x 7m x 4m. The measurement of illuminance used general measurement and task measurements according to SNI 7062-2019. Illuminance data retrieval was carried out in two ways, namely observation and simulation. Measurement of laboratory’s illuminance by observation has been carried out for 10 days with repetition 10 times. The simulation of illuminance measurement used Dialux 10. Based on the results of observations and simulations, it can be seen that the Digital Electronics Laboratory did not follow SNI 6197:2011 with an illuminance of 31.3 – 137 lux. The simulation used the modifying lamp layout and applying TL LED (Philips Master LEDTube HO) so that the illuminance distribution of the Digital Electronics Laboratory followed SNI 6197: 2011 of 500 – 769 lux. The simulation results of the SCWB dimension variation showed that the recommended thickness of the SCWB was between 10 cm – 30 cm to obtain a more optimal illuminance.
Passenger’s Level of Satisfaction with and Loyalty to Trans Semarang Bus Services
Authors: Haryadi Bambang , Damayanti Ervina , Alam Monacella Lieta , Narendra Alfa , Purnomo Andi 
Published: June 2023

Abstract
The rapid development of motorization in the city of Semarang caused an increase in congestion. This prompted the City of Semarang Government to provide adequate, safe and comfortable public transportation for the community. The public transportation service introduced in 2009 was a rapid transit system called the Trans Semarang Bus Rapid Transit (BRT). This study aims to measure the passenger’s level of satisfaction with and loyalty to Trans Semarang bus services. We measured satisfaction using the Customer Satisfaction Index (CSI) method. The satisfaction index is based on five dimensions of service quality, namely: physical, reliability, responsiveness, assurance, and empathy. The results showed the value of the CSI of 69.17 percent. This means that overall passenger satisfaction with the Trans Semarang bus service is still low. The level of passenger loyalty to Trans Semarang buses was measured by their intention to use the service in a sustainable manner is 78 percent. This means that if there is another alternative, the probability of leaving the Trans Semarang bus is 22 percent. The quality of Trans Semarang bus services still needs to be improved to increase passenger satisfaction with and loyalty to the bus services.
Parking Tracking System Using Ultrasonic Sensor HC-SR04 and NODEMCU ESP8266 Based IoT
Authors: Sulistyawan Vera Noviana , Salim Nur Azis , Abas Faizal Ghozali , Aulia Najma 
Published: June 2023

Abstract
Generally, many parking systems have not implemented a tracking intelligent system with the help of sensor technology and applications combined with the Internet of Things. This creates a lot of problems with the unexpected and irregular overflow of parking volumes. In overcoming the above problems, a study was made that discusses the parking tracking system design with the HC-SR04 ultrasonic sensor intelligent working system using a smartphone and an Internet of Things (IoT) based web application. This parking tracking system will use the main component, namely the ultrasonic sensor and several other components, namely the NODEMCU ESP8266. The Internet of Things will be used in this parking smart work system to provide information to parking users through a web system about the location of vacant parking slots. With this web system, users will be able to use the booking model and see which parking positions are available. The model used is a chip that is programmed and placed in each parking lot so that it can transmit digital information signals to a server that can be accessed in real-time by the user. With the planning of a parking tracking intelligent work system, it is hoped that it can help management of parking usage by users.
Application of multilayer perceptron (MLP) method for streamflow forecasting (case study: Upper Citarum River, Indonesia)
Authors: Enung  , Kasyanto Heri , Sari Risna Rismiana , Lubis Muhammad Fauzan 
Published: June 2023

Abstract
Flood forecasting is a critical component of flood early warning. The discharge that occurs is one of the parameters that can be used as a reference for predicting flooding. Various discharge forecasting models based on physically based models or data-driven models have been developed. One of the flood forecasting methods that can be considered for forecasting discharge on watersheds with limited physical data is the Artificial Neural Network (ANN). Furthermore, the ANN method allows the analysis process to be completed in less time and with fewer resources. One of the ANN models employed in this work is the multilayer perceptron (MLP). The MLP model was developed in this study to predict streamflow at the Citarum river, particularly at the Dayeuhkolot hydrological station at 2, 4, 6, 8, 10, 12, and 24 hours ahead. Two data input scenarios were used in the modeling scene. First, input data in the form of station rainfall data and discharge data. The second is regional rainfall and discharge data. Before predicting the discharge in the coming hours, the hyperparameters model is optimized using the GridSearchCV method. The model’s performance is assessed using the RMSE, NSE, and R2 values. The MLP method produced satisfactory results for both scenarios when predicting discharge in less than 4 hours with the NSE and R2 value higher than 0.9. Scenario 2 input data produces a slightly better prediction model than scenario 1. Based on NSE and R2 values, discharge prediction with a prediction time of more than 6 hours produces less accurate results.
Identification of Landslide Potential at UNNES Conservation Park Based on Rainfall and Soil Geology Parameters
Authors: Pambudi K.A. , Kusumawardani R. 
Published: June 2023

Abstract
Semarang city has a unique morphology with hilly in the south and lowland in the north area. UNNES Conservation Park as aa study area located at the hilly area has a potential of landslide susceptibility with the various level of slope and the type of soil. Furthermore, in the wet season, high intensity of rainfall in this area be considered as the factor for landslides triggering. This article focused analyse the potential for landslides in the study area. A cross section in north area which has steep slope was taken to be analysed. Comparison the manual method using Fellenius and Bishop and a numerical method for SF computation was applied for landslide potential identification. The results of analysis revealed the SF number was 1.746 with the Fellenius method and 1.786 with the Bishop method. Meanwhile, using the numerical method, the SF number is 1.440-1.471. From the result could be concluded the UNNES Park was categorized as stable class for Fellenius and Bishop method and critical class category for numerical method.
Design Criteria for Chicken Slaughterhouse Wastewater Treatment with Granular Activated Sludge in Sequencing Batch Reactor
Authors: Audelia P , Ratnaningsih  , Tazkiaturrizki  
Published: June 2023

Abstract
Chicken Slaughterhouse (RPA) is a business in the field of slaughtering and processing chicken into parts that are ready to sell to customers, where the waste water which contains high levels of organic matter can pollute the environment. Therefore, it is necessary to treat wastewater that is efficient and easy to use such as Granunlar Activated Sludge (GAS) using Sequencing Batch Reactor (SBR). The study was conducted on a laboratory scale to determine the effect of aeration time and settling time using different aeration (7 L/min and 10 L/min). The formation of GAS was cultured by reacting the activated sludge with slow stirring for 28 days, after which it was acclimatized by 50%, 75%, and 100%, then entered into the main study. The results obtained from the processing results are the level of COD removal to 25, 66 mg/L with 97.49% efficiency; BOD became 107.61 mg/L with an efficiency of 85.29%; and removal of TSS to 64 mg/L with an efficiency of 60%. The optimum processing time is 1 hour aeration with 40 minutes of precipitation using an aeration rate of 10 L/min. The design criteria obtained were BOD Load 0.671 kg BOD/m3.day, F/M ratio 0.145 kg BOD/kg MLVSS.day, HRT 26 hours, and SRT 28 days.
Highest and Best Use (HBU) Analysis on Vacant Land in Jakarta Garden City, East Jakarta
Authors: Laena H , Raflis  
Published: June 2023

Abstract
Land availability in the capital of Indonesia, Jakarta, is dwindling. However, its population is growing. This growth affects population density and activity to rising, as well as the need for land, especially for housing purposes. Moreover, land prices are also escalated over time. Hence, to optimize the available land utilization and value, it is necessary to find the best designation and produce the highest land value. The Highest and Best Use Analysis is used to achieve this goal. By evaluating several aspects, namely, physical, legal, financial, and maximum productivity. This research was applied to an asset of vacant land in Asoca Street, Jakarta Garden City, Cakung, East Jakarta with an area of 3.725,68 m2. After the analysis, it is obtained that apartment is the best designation, producing the highest increase in land value of Rp 131.366.494/m2 and productivity after developed by 591,04%. It is also feasible to develop, because with an investment period of 10 years, the designation produces a net present value greater than zero, which is Rp 418.641.935.213, an internal rate of return greater than the minimum attractive rate of return of 7% which is 22,76%, and a payback period of 4 years, 3 months, and a day.
Redesign of Trans-Semarang Bus Stop at Prof. Soedarto Segment Using an Accessibility Approach
Authors: Pratiwi I , Wibowo A A , Savanti F , Yulianto D I , Setiyawan A 
Published: June 2023

Abstract
Bus rapid transit, which was established in the city of Semarang in 2009, is expected to be a solution for the transportation needs of the people of the city of Semarang. With good service and economical prices, bus rapid transit is quite a favorite form of transportation for the citizens of Semarang. However, the current design of the Trans-Semarang bus stop is still far from easy for its users to access. The need for public services in the form of easy accessibility of users, both disabled and elderly. There needs to be a review from the Semarang City government, regarding the fulfillment of bus shelter facilities and designs that are still less than standard. This study uses a descriptive method using qualitative techniques. The research subjects were bus stops and users of the Trans-Semarang bus stop. Data collection techniques used are observation and documentation. The results of the research obtained on the design of the Trans-Semarang bus stop indicate that there are several shortcomings in the design of the Trans-Semarang bus stop along the Prof. Soedarto. To achieve the standard of comfort in terms of accessibility, it is necessary to redesign the bus stop design following the standards of building design regulations. Some of these shortcomings have been improved by redesigning the Trans Semarang bus stop with an accessibility approach. In addition, it is necessary to add several facilities that are not yet available so that the function of the Trans-Semarang bus stop can be used optimally and sustainably by the residents of Semarang.