bluuebunny/crossref_metadata_2025 huggingface dataset:
Customer churn factors detection in Indonesian postpaid telecommunication services as a supporting medium for preventing waste of IT components
Authors: Saputro B , Ma’mun S , Budi I , Santoso A B , Putra P K
Published: March 2021

One of the most important tasks in the telecommunication company is to maintain the customer churn rate and customer satisfaction level. These things can be maintained by evaluating the churn customer factors. The results of this evaluation can certainly be used to improve the services of the company, so that customers will be stopped from churn and customer satisfaction level will be increased. This condition indirectly provided positive effect on the environment by preventing e-waste of IT components. In this research study, customer churn factors from customer feedback were evaluated by using text mining, by targeting the postpaid customers in one of telecommunication company in Indonesia. In this research we used 3 classification methodology, Fast Large-Margin, Naïve Bayes, and Support Vector Machine. Fast Large-Margin classification methodology was the most accurate model in this research, was used to classify the customer feedback for five following customer churn factors in telecommunication industry: poor customer service, poor network, high cost of services, billing errors, and promotion seeking. The result shows that promotion seeking was the most factor that caused customer to churn during January and December 2019 period.
Comparison of testing load cell sensor data sampling method based on the variation of time delay
Authors: Hastawan A F , Haryono S , Utomo A B , Hangga A , Setiyawan A , Septiana R , Hafidz C M , Triantino S B
Published: March 2021

Load Cell Sensors are transducers (transducers, electronic components that can measure physical quantities into electrical signals) that can convert the pressure by the load into an electrical signal. IC HX711 is a weighing module, which has a working principle of converting the measured changes in resistance changes and converting them into voltage quantities through the existing circuit. Load cell and HX7411 are used to obtain data of weight which will be compared with a commercial digital weight scale that the accuracy has been verified. In collecting data of weight, there are several calculation methods including the mean, modus, and median method. This study aims to provide test results for the three methods with different variations in delay. Delay is used to avoid errors in taking data from the sensor directly and also to provide pauses for the sensor in real time data collection. The test was conducted with four human subjects who have differences in body weight. The variation of delay used is 250ms, 500ms, 750ms, and 1000ms. The test results show that when testing variations in body weight with a delay time of 250ms, the mean method has the best results with a value of nmean
= 2. In the 500ms delay test, the median method has the best results with the value nmedian
= 3. In the 500ms delay test, the mean and median methods have the same good results with values of nmean
= 2 and nmedian
= 2. In the 1000ms delay test, the median method has the best results with a value of nmedian
= 2. The results of the whole test show that the values of Nmean
= 6, Nmedian
= 8, and Nmodus
= 2 which indicate that the median method is the method that has the best level of precision.
Online learning in higher education during the Covid-19 pandemic: A case study in the Department of Electrical Engineering, Universitas Negeri Semarang
Authors: Sunardiyo S
Published: March 2021

The Covid-19 pandemic that hit the world has posed significant challenges for the world of higher education globally. The main challenge that is very urgent and inevitable for lecturing at the university is face-to-face in class but must be taught online. Online teaching and learning implies a certain pedagogical content knowledge, especially related to designing and organizing for a better learning experience and creating a different learning environment, and the role of information technology. This article, concludes that five things play a role in online learning, namely first, a reliable information technology facility to support access to online learning; Second, the need for teachers to make variations and innovations to deliver teaching material so that it attracts students; Third, it needs an in-depth study in practicum lectures; Lecturers can do a practicum with simulations. Fourth, there is a need for material to be delivered based on light, clear, concise and interactive principles. Fifth, there is an increase in student participation in online learning.
Usability evaluation of assignment and monitoring information learning system of internship students based on SMS Gateway with Raspberry Pi
Authors: Setiyawan A , Priyanto  , Prasetya T A , Hastawan A F
Published: March 2021

There are obstacles in the delivery of information during pre-engineering activities at the Vocational High School. There needs to be a system that makes it easy to deliver information from schools to students who carry out internship. The purpose of this study was to evaluate the usefulness of the evaluation of the usefulness of the task information learning system and the monitoring of student labor based on the SMS gateway with raspberry pi. The instrument used in usability testing is the Computer Usability Satisfaction Questionnaires: Psychometric Evaluation and Instructions for Use questionnaire developed by IBM for software usability measurement standards. The instrument for testing usability aspects with the Computer System Usability Questionnaires (CSUQ) questionnaire developed by IBM uses a Likert scale as a measurement scale. The data for the trial were 20 respondents consisting of adaptive normative subject teachers, internal engineering committee and smartschool developers. Based on the results of testing the quality of software developed on the usability aspect has a percentage of 85% or has a high quality scale and based on alpha cronbach calculations has a calculation result of 0.851 or has a “good” category. The SMS Gateway system with Raspberry Pi for Internship Assignment and Monitoring meets the usability aspect and is suitable for use.
Production of Brachiaria mutica as natural dyes powder for textile application: characterisation study
Authors: Kusumastuti A , Fardhyanti D S , Anis S , Kamis A
Published: March 2021

Innovation of synthetic dyes successfully eliminated the utilisation of natural materials as textile dyes. Simplicity as well as variety of colours strongly increased the application of synthetic dyes. Nevertheless, environmental concern has lately forced the use of natural dyes. To simplify the usage of natural dyes, production of natural dyes powder is inevitable. Investigation was carried out to examine the effects of solvent and filler types on the yield, chromaticity, flavonoid content, and water content of natural dyes powder. In this work, Brachiaria mutica was used as a sample source. It was crushed and grinded before extracted using mixture of methanol and water as solvents at various methanol concentration of 25%, 50%, 75%, and 100%. Extraction was carried out at a ratio of raw materials to solvent of 1:10. The filler of maltodextrine or gum arabic was added into dye extract before then converted into powder form by the aid of spray dryer. It was found that among the provided solvents, system using 50% methanol was considered to be optimal in resulting high yield as well as flavonoid content, while maltodextrine is chosen as providing better result than that of gum Arabic. Moreover, methanol concentration of 50% and 5% maltodextrine filler generated greyish yellow colour with the lowest water content of 0.9%.
Kinetic study of adsorption carboxylic acids of used cooking oil using mesoporous active carbon
Authors: Rengga W D P , Seubsai A , Roddecha S , Azizah S Y N , Rosada D F
Published: March 2021

This study investigates the reduction of free fatty acids from the problem of used cooking oil in the food industry with bio-waste adsorbents such as banana peels—experimental conditions at the activation temperature of making activated carbon. Adsorption kinetics and temperature of activated effects were studied. Bio-char activated at 600, 650, and 700°C. The used cooking oil and activated carbon were analyzed using Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray energy-dispersive, and BET analysis. Activated carbon has a surface area of 548 m2/g, with an average pore diameter of 35 nm (range of mesophore). As a result, bio-char activated at 700°C is best presented by a linear pseudo-second-order kinetic model suitable for describing the adsorption kinetic. The maximum adsorption capacity was 62 mg/g at 303 K. Carboxylic groups as free fatty acid was removed from used cooking oil used surface of activated carbon. Models best described the experimental data as with the higher values of the correlation coefficient (R2). The results of this study prove that the banana peel bio-waste ingredient, which is food waste, is a potential adsorbent to reduce free fatty acid levels to the standard of 0.3
Study of the water hyacinth extract concentration to the characteristics of gel hand sanitizer
Authors: Prasetiawan H , Ayuningtyas F S , Pebrianti H , Megawati  , Astuti W , Kusumaningtyas M
Published: March 2021

Hand hygiene is one of the most important things in the spread of bacteria and virus. The spread of this organism can be stopped by cleaning hands either by washing or sanitizing. Water hyacinth extract contain high flavonoid and tannin which can be used as an active agent in hand sanitizer. Three different extract concentration were examined which are 8, 10 and 12%. Organoleptic test were conducted to examine the shape, colour and scent of the hand sanitizer. Biological test were performed to find the effectiveness of the hand sanitizer against the bacteria. The results showed that hand sanitizer product with 8% water hyacinth extract have better potential in killing the bacteria compared to the other concentration.
The use of yellow velvetleaf (Limnocharis flava) as a natural color for colet technique using cold wax
Authors: Musdalifah M , Marfiana E , Nurmasitah S
Published: March 2021

Yellow velvetleaf is a fast-growing plant. It cannot be optimally used, particularly the old leaves. Old yellow velvetleaf waste has not been used appropriately, even though it has more benefits and value. The leaves of yellow velvetleaf contain natural color of carotenoids and flavonoids which can be used for natural dyes. The potential color produced can possibly be applied for textile coloring colet technique using cold wax. The research method was carried out through experiments and data analysis using descriptive analysis. The results show that yellow velvetleaf can be used for colet coloring technique using cold wax, and the resulted colors differs depending on the mordant used. Color aging test shows that during the process of nglorod (wax exfoliating) using water, the darkest color was found in tunjung mordant with a color different of 81-100, belongs to “very dark” category. The test of fastness to rubbing shows score of 4 (good) for all samples. The highest result for motif sharpness test is found in the process of nglorod with water and tunjung mordant with color different of 81-100, which is categorized as “very sharp”.
Production of hydrocarbon based solvent with low aromatic content using ASPEN Plus
Authors: Fardhyanti D S , Prasetiawan H , Hisyam A , Kusumaningtyas R D , Mulya S T S , Findriyani M A R , Sasongko N A
Published: March 2021

The solvent is a liquid that can dissolve or extract specific materials. Solvents are needed for most chemical transformations to increase contact between reagents and catalysts. It also holds an important role in many studies, industrial chemical processes, coatings, and formulations of consumer products, however, most of the hydrocarbon-based solvents based still contain high aromatic content of benzene, toluene, and xylene which are carcinogenic chemicals. The separation of aromatic hydrocarbons from a mixture of C4-C10 aliphatic hydrocarbons is a complex process, due to its close boiling points and some combinations can form azeotropes. The general distillation process is not the right choice for the separation of aromatic hydrocarbons from a mixture of C4-C10 aliphatic hydrocarbons. Possible processes are liquid-liquid extraction, extractive distillation, and azeotropic distillation. In this study, extractive distillation using ASPEN Plus was performed to simulate the process. The crude feed composition used contains 77.13% aromatic compounds so that the separation technology used uses the extractive distillation process using sulfolane as a solvent. The variables used are the ratio of the crude feed to sulfolane (1:10, 1:15, 1:20), the number of stages (30, 40, 50), feed stage (15,20,25). Based on the simulation results, the best result was obtained by using the ratio of the crude feed to sulfolane of 1:10, with the number of stages 30, and the feed stage on the 25th stage.
Synthesis and characterization of magnetic activated carbon from Ceiba pentandra fiber for zinc ion removal
Authors: Astuti W , Trisyani A , Biladudin M , Sulistyaningsih T , Prastiyanto D
Published: March 2021

One of the heavy metals contained in the electroplating industrial wastewater is zinc. Adsorption is found to be one of the most effective methods for zinc ion removal from aqueous solution due to low cost and simple to operate. The main purpose of this study was to use cotton (Ceiba pentandra) fiber as a precursor to developing a magnetic activated carbon (MAC) for zinc ion removal. The activation process was carried out using potassium hydroxide (KOH) by conventional heating using a tubular furnace at a temperature of 500°C for 2 hours under a stream of nitrogen (N2), while the magnetization process was carried out using co-precipitation method. The adsorption of zinc ion onto MAC was recorded to be 96% at a solution pH of 5 and contact time of 180 min. The adsorption of zinc onto AC is fitted well by the Freundlich isotherm model, while the zinc-MAC system is described well by the Langmuir isotherm model. Meanwhile, the pseudo second order kinetic model is suitable for AC and MAC. Owing to low cost and high efficiency, MAC prepared from Ceiba pentandra fiber can be used as an effective adsorbent for zinc ion removal from industrial wastewater.
The use of laban (Vitex pinnata L) leaf as a silk pigment
Authors: Prasetyaningtyas W , Wati S , Buang R
Published: March 2021

Synthetic dyes are usually carcinogenic, therefore it is necessary to use alternative dyes to reduce the use of synthetic dyes, namely by using natural dyes. This study aims at determining the potential of Laban leaves as a natural dye in silk fabrics. Extraction was done by boiling the leaves for 1 hour. The dyeing of the mordanted cloth was done 4 times. The dyed fabrics were treated with post mordanting using alum, calcium oxide and tunjung with a concentration of 50gr/l. Fabric testing was carried out by testing the color strength and color fastness to washing with soap. The results of the color strenght test showed that the highest value was obtained by the use of tunjung with a T% value of 88.96 for very dark criteria, then followed by calcium oxide mordant with a value of 30.20 and the lowest value on the use of alum mordant with a value of 20.97 for light criteria. The color fastness test to washing generated an average value of 4 which was in the good category.
The coloring of batik stamp using songgolangit (Tridax procumbens) weeds with different fixation
Authors: Dwicahya K N , Musdalifah M , Nurmasitah S
Published: March 2021

Natural dyes are from parts of plant, such as leaves, fruit, flowers, seeds, roots and bark. Weed is one of the plants that can be used as natural dyes. This study aims to determine the potential of Songgolangit weeds as natural dyes on batik stamp. This research is an experimental research. The objects of this study are Songgolangit weeds, batik stamp and the fixation (tunjung, alum, and quicklime). The data was collected by looking at the catalog of textile dyes to find out the direction of the resulting color. The sharpness of the motif was tested by using organoleptic tests. The result of the color direction analysis of alum fixation is Hazelwood. The quicklime fixation result is Bone and the tunjung fixation result is Hazelnut. The sharpest motif is produced from tunjung fixation. In conclusion, Songgolangit weeds can be used as natural dyes of batik stamp. The direction of the color produced differs depending on the fixation substance used.
Risk assessment for occupational health and safety of Soekarno-Hatta international airport accessibility project through HIRARC method
Authors: Fauziyah S , Susanti R , Nurjihad F
Published: March 2021

Statistic based on BPJS data in 2019 have shown that the number of work accident recorded 77.295 cases and the construction sector is still the highest contributor to work accident cases in comparison to other sectors. Soekarno-Hatta International Airport accessibility project connects the northern perimeter road with the southern perimeter road with a total length of 4 km. This study focuses on the flyover construction, considering that is the highest risk on construction activities. Risk assessment tool on this research using HIRARC method. In general, there are three major steps of HIRARC; hazard identification, risk assessment and risk control. Identifying hazard is a process to determine the risks of hazards that occure in construction work. Assessing risk of construction work calculated using likelihood and severity index. Then, the result of hazard identification and risk assessment, risk control are taken to mitigate the hazard risk. This study instrument used interviews and observations both used risk assessment sheet which filled by safety officers, safety supervisors, site engineers and site supervisors. There were 45 hazards identified for five construction work which are, (i) survey (ii) land clearing, (iii) excavation work, (iv) pilling work, and (v) bored pile work. The conclusion that can be drawn is that there are seven extreme risk at this project, i.e. (i) Workers fall into lake; (ii) Workers get hit by road users; (iii) The operator is exhausted; (iv) Crane wire rope failure; (v) Vibro hummer failure; (vi) Workers pinched by bracket formwork and (vii)Workers injured by pieces concrete pile cutting.
What causes cost overrun in highway strategic project in Indonesia?
Authors: Susanti R , Nurdiana A , Kurnianto Y.F.
Published: March 2021

In 2016, Indonesia is concerning about the acceleration of public infrastructure projects through the existence of government strategy projects that spread across several project sectors, including in highway projects. Totally, there is a 44 highway strategic project in Indonesia and several of them are currently in Central Java. Unfortunately, as a national strategic project, even though all of these projects are prioritized in their construction process, the implementation of the national strategic projects are faced up problems especially related to high pressure from the government that has an impact to project cost even causing cost overrun including in highway strategic project. The research aim is to analyze factors causing cost overrun in highway strategic project from owner and contractor perspectives. This study is limited to a case study in Pemalang-Batang Highway Strategic Project. The analysis of the study is using Risk Breakdown Structure to identify risk factors causing cost overrun. From a total of 14 risks identify, both parties agreed to design change as the most risk factor in causing cost overrun in highway strategic project in Indonesia.
Interior design study of lecturer rooms at E12 building 2nd floor UNNES – learn from COVID-19 pandemic
Authors: Purnomo A
Published: March 2021

The covid-19 pandemic case has changed the structure of life in all aspects throughout the world. The field of man-made environment or architecture is no exception. The interior arrangement of a building, as part of the man-made environment, is also affected. The interior design of a building today seems to be obliged to participate in following the standards of new health-protocols in the new normal era.What about the interior of the building that has already been utilized? Of course it requires further study to find out whether the interior of a building can be said to be healthy or not. This study aims to examine the interior design of the lecturer room E12 building 2nd floor UNNES in terms of health that is emphasized from the behavior of its users by referring to the situation of the covid-19 pandemic and its future prospects. The research method used is by field observations to search visual data, observing user behavior and textual data. Those who are categorized as users of the lecturer room E12 building 2nd floor UNNES are lecturers from the Department of Architecture, students, administrators and guests. The results of this study indicate that based on the pattern of user behavior and associated with the standard requirements of space, area, volume of space, material and infrastructure conditions, interior design of lecturer room E12 building 2nd floor UNNES, is included in healthy category, although there are several minor corrections that can be included as suggestions for improvement in order to adjust to the new normal era during the covid-19 pandemic period and thereafter.
The effect of polypropylene fiber addition to mechanical properties of concrete
Authors: Pangestuti E K , Handayani S , Adila H , Primerio P
Published: March 2021

Concrete is the one of the building construction materials that has a high compressive strength, but it has lower tensile strength. The addition of fibers to concrete is expected to improve its mechanical properties. In this study, the concrete was added with Polypropylene (PP) fiber with a length of 12 mm. The compressive strength of concrete specimens was 20 MPa with the variety of fiber used was 0.5 kg/m3; 1 kg/m3; and 1.5 kg/m3. The test were conducted on 36 specimens in the form of cylinders and cubes. The tests were compressive strength, split tensile strength and water absorption at the age of 28 days. The highest value of the compressive strength of the fiber concrete was the amount of Polypropylene fiber 1 kg/m3, namely 2.92 MPa, increase of 6.92% of the compressive strength of concrete without additional fiber. The highest value for the split tensile strength in the amount of Polypropylene fiber 1 kg/m3 was 2.34 MPa or an increase of 21% from the tensile strength value of concrete without additional fiber. Meanwhile, the lowest water absorption capacity of concrete is the addition of 1.5 kg/m3 of fiber, which is 2.366% or has decreased by 64% from the concrete without fiber.
Toll road maintenance towards minimum service standard
Authors: Suwarto F , Kurnianto Y F , Setiabudi B , Sholeh M N
Published: March 2021

Start at present, investment in toll road construction is conventional investment in the form of investment within a certain period of time to obtain profits from the results of capital loans/financing obtained from toll revenues during toll road operation during the concession period by the BUJT. This means that BUJT has full authority over the implementation of road maintenance at the location of its concession. Hence toll road concessions have the obligation to maintain toll roads in accordance with minimum service standards using the company’s toll road revenues. Thus, each BUJT has their own maintenance policy. Therefore, the management of toll roads that are managed on a concession basis can lead to differences in road damage management programs in each BUJT concession. This research assesses the road maintenance program planning on BUJT toll road concession holders to see the effectiveness BUJT in carrying out road maintenance regarding of the fulfillment of SPM. The result shows that the majority of BUJT has regularly carried out efforts to improve road functions, however they have the inadequacy in conduct conditions surveys by using equipment according to the standards. with “Undertake routine efforts throughout the year to maintain road conditions” being the highest mean whereas “Perform visual assessment on foot” has the lowest mean value. Moreover, it can be determine that the road damage frequency data found is with the an “Adverse Opinion” audit findings result that is conducted by BPJT with the most frequent damage and receive an “Adverse Opinion” of an audit result was potholes with mean value of 2.100 and 2,200 that is followed by Guardrail damage with mean value of 2,1667 and 2,200. While the least frequent damage in the toll road was Drainage cross section with mean value of 2.533 and 2,700 and Rutting with mean value of 2.400 and 2,633 subsequently for damage frequency and Adverse Opinion frequency.
Evaluation of the lighting system in drawing studio at the E12 building, Faculty of Engineering UNNES
Authors: Setiawan M F
Published: March 2021

A room can be said to be a good one if the lighting following the requirements of needs depends on the function of the room. The room studied in this study was a drawing studio room in E12 Building, Faculty of Engineering UNNES. This room has a condition where the spread of light entering from the window is uneven so during the day the lights must always be turned on. The purpose of this study is to measure and evaluate the lighting intensity of the drawing studio space. This research was conducted using descriptive and evaluative methods. The data obtained is sourced from the results of direct light intensity measurements on the object of research conducted in the morning, afternoon, and evening for three days using a lux meter and measurements made referring to SNI 16-7062-2004 about measuring the intensity of lighting at work. The results of the measurement of lighting intensity in the image studio room will be compared with the SNI recommended standards. According to SNI 03-6575-2001, the standard requirement for a lux studio drawing space is 750 lux. The result, both when the lamp is turned on and the lamp turns off the measurement results do not meet the standards. It is recommended to increase the intensity of artificial lighting (lights) in the drawing studio until it meets the SNI 750 lux standard. From the results of calculations with the lumen method, it is recommended to replace each lamp with a lamp that has a light current of 9360 lumens.
The development of a permeable pavement from concrete bricks
Authors: Ulfiana D , Suripin  , Budieny H , Parmantoro PN , Wibowo SA
Published: March 2021

Global climate change is causing an increase in the intensity of rainfall in Indonesia. This causes an increased risk of flooding because it is not supported by changes in infrastructure planning and water resource management. Infrastructure construction, especially roads, sidewalks, and parking lots, still uses waterproof construction such as asphalt and concrete. This waterproof construction causes rainwater to not infiltrate to soil layers and consequently rainwater runoff increases. The increasing intensity of rainfall that is not compensated by an increase in infiltration areas causes an increase in the risk of flooding. Therefore, the design of a mixture of concrete bricks that has a high level of permeability needs to be developed to reduce the risk of flooding. This research was conducted by making test samples of four mixture design. The design approach is carried out by varying the proportions between coarse and fine aggregates, and the water-cement ratio. The infiltration testing method was also conducted to accommodate research needs. Based on the analysis, for paving block with an aggregate-cement ratio of 4 by volume, the optimum water-cement ratio was 0.40 with a permeability level of 630 mm/hour and compressive strength of 21.29 MPa.
The effect of different processes of flour making on the proximate composition of taro (Colocasia esculenta (l.) flour and taro flour cookies
Authors: Paramita O , Fathonah S , Rosidah  , Agustina T , Larasati M
Published: March 2021

This research examined the effect of flour making method using chemicals on the soaking process of taro tubers. Method 1 was done by soaking taro tubers in 500 ppm sodium metabisulfite solution. Method 2 was done by soaking in warm water at 40 ° C for 3 hours followed by immersing in 10% NaCl solution for 1 hour, Method 3 was done by immersing in a brine solution (1 teaspoon in 5 liters of water) for 20 minutes followed by soaking it again in a sodium metabisulfite solution (1 gram per 1 liter of water) for 20 minutes. In related to the proximate composition in taro flour, the result showed that the flour making that uses sodium metabisulfite (Na2S2O5) soaking method produces the best protein and crude fiber content of 3.158% and 4.080%, respectively. The taro cookie making that uses flour that is immersed in sodium metabisulfite (Na2S2O5) produces the best protein, crude fiber and energy content of 2.091%, 2.820% and 588.897% respectively. This is because the first method only uses one immersion process that is using sodium metabisulfite, while the second and third methods go through two immersion processes. It can be concluded that the flour making method using a soaking process with 500 ppm sodium metabisulfite solution can increase the benefit of using taro flour.
The addition of moringa leaf powder into instant porridge as an effort to improve organoleptic quality and nutritional content for the elderly
Authors: Hestiyawati A , Wahyuningsih  , Fathonah S
Published: March 2021

Research objectives: 1) to find result of different percentage Moringa leaf flour addition by 0%, 5%, 10%, 15%. 2) to find the energy content, protein and iron in the instant porridge with Moringa leaf flour addition. 3) to find out the elderly’s acceptability of instant porridge with Moringa leaf flour addition. The experimental design used was the One short case study. The data analysis method used was the single classification variant analysis method followed by the tukey test, while the elderly’s acceptability was analysed by using preference test. The study results are: 1) The tenderness texture of Moringa leaf instant porridge is different and the after taste is bitter. 2) The energy content test result of 0% to 15% Moringa leaf powder addition is ranging from 228.7 to 456.1 kcal. The protein content of instant porridge with 0% to 15% Moringa leaf powder addition ranges from 9.0-19.8 grams and the iron content of instant porridge with 0% to 15% Moringa leaf powder addition ranges from 4.5 to 5.1 mg. 3) The elderly’s acceptability of the sample with 0%, 5% and 10% Moringa leaf powder addition belongs to “like” criteria while for the sample with 15% Moringa leaf powder addition belongs to the criteria “average” criteria. Conclusion: 1) Differences are found in the normal porridge and instant porridge with Moringa leaf flour addition. 2) the highest nutrient content is found in the sample with 15% Moringa leaf flour addition. 3) the highest acceptance of elderly is found in the sample with 0% Moringa leaf flour addition. Based on the research result, it is suggested to use moringa leaves which are often harvested periodically and add salt in the boiling leaves to get rid the bitterness.
Study of glucomannan extraction with hydrochloric acid catalyst and alcohol solvent based on porang tuber flour (Amorphophallus oncophyllus)
Authors: Bahlawan Z A S , Damayanti A , Megawati  , Cahyari K , Andriani N , Hapsari R A
Published: March 2021

Amorphophallus oncophyllus or commonly known as porang is a group of Aracea tubers. Porang has a high economic value and prebiotic source of oligosaccharides because it contains glucomannan. Porang flour contains about 67.5% glucomannan. Glucomannan is used as an emulsifier and stabilizer in the food, beverage and cosmetics products industry and as an ingredient for supplements and food additives because of its high fibres content. In this study, glucomannan purification can be optimized by using chemicals with modified maceration techniques with a stirring and washing machine using ethanol and glucomannan analysis using phenol sulphuric acid test in order to determine the decrease in sugar in porang flour. The purpose of this study was to determine the highest glucomannan content from several parameters such as the concentration of hydrochloric acid catalyst, stirring time, temperature, and the ratio of samples to solvents. The optimum conditions for the extraction process were at 0.7 M hydrochloric acid catalyst concentration, stirring time for 1 hour, temperature at 70°C and the ratio of samples to solvents was 1:5. Therefore, the optimum glucomannan content obtained from extraction using hydrochloric acid catalyst reached 95.85%.
A Review on Utilization of Plastic Wastes in Making Construction Bricks
Authors: Mak Shu-Lun , Wu Tanya Ming Yan , Tang Fanny Wai Fan , Li Jimmy Chi Ho , Lai Chi Wing
Published: March 2021

Plastic waste is spread at an unprecedented speed due to the rapid use of domestic and industrial plastic items. The environmental pollution resulting from the continued disposal of plastic wastes in landfills has not only created land problems but has also heightened the pollution of marine resources. This paper aims to review and investigate the feasibility of utilizing plastic waste in making construction bricks. The use of plastic waste in making the sand-plastic bricks will enhance the protection of the environment from the effects of plastic waste that normally takes several millennials to degrade. Thermostatic plastic waste; that is, those polymers whose recycling may not affect the environment, including polyethylene (PE) and polyethylene terephthalate (PET), is found to implore lightweight, durable, cost-effective, and low thermal conductor bricks. Compressive strength (CS) and water absorption tests are found as the key test methods for measuring the effectiveness of high-volume content of plastic waste in bricks. Notably, a high percentage of plastic waste in proportion to sand is found to improve the compressive strength of the bricks besides allowing negligible water to seep through.
The Evolutionary Game Model of the Multiple Governance System of Chinese Construction Waste
Authors: Chen Huilin , Zhou Hui , Wu Xiang
Published: March 2021

Urban waste crisis is a prominent environmental problem in China, and the regulation of municipal construction waste treatment is a complex system. The evolution game model of government-enterprise-social governance system is constructed by embedding social supervision. The application of Jacobi analysis method explored the game strategy of waste processing enterprises, government regulators and social supervision, in which the multilateral game analysis is introduced into risk strategies of economic efficiency factor. It revealed the inherent influence mechanism of the social supervision on the behavior of the waste management enterprises and the government regulator, and the evolution law of government-enterprise-social governance system has greatly developed with the use of simulation. In addition to supervision by governmental departments, social supervision is more necessary for improving the construction waste management and governance structure effectively.
Application of Ground-Penetrating Radar for Living Trees Detection
Authors: Chen Shong-Loong , Liu Sung-Tien , Lin Chen-Hua , Liu Chun-Chieh
Published: March 2021

In order to evaluate the potential hazards, researchers are working on revealing the inner structural of a living trunk using different diagnostic techniques. Nondestructive techniques (NDTs), such as stress wave method and ultrasonic wave method, have become increasingly convenient and economical in trees detection. To improve forest management and to prevent collapses of trees, it is necessary to investigate the internal part of tree trunks. In order to do it non-invasively, ground-penetrating radar (GPR) appears as a promising inspection device. Each of these NDTs has its pros and cons. Among all, the GPR is capable of multiple measurements with hardly any damage to the body of a tree, perfect for investigations on roots and trunks of living trees. 15 camphor trees are selected and subject to GPR testing for the study. The results of inductive method and GPR wave signals indicate that the GPR image shows “wavy” features when an eccentric void is found inside a tree, meaning that the travel time is the shortest for the return signals when the antenna is closest to the void. However, GPR wave signals appear to be discontinuous and fluctuate when there are irregular cavities. The signal time is defined by using the metal plate to generate strong reflection in the case of on-site monitoring. The internal condition of tree trunk is usually tested based on detecting 2D image of tree trunk by the stress wave method, as to confirm that the application of GPR is feasible to detect the trunk of camphor tree. The method proposed in this paper can realize the accurate localization and imaging distribution of the internal defects of the trees by the radar wave scanning images.
Application of Ground Penetrating Radar in Reservoir Leakage Detection in Complex Geological Areas
Authors: Yan Jun , Bo Wang , Zhao Xiaofang , Cai Hong , Wu Shuaifeng , Xiao Jianzhang , Sun Liming
Published: March 2021

As a typical nondestructive testing method, ground penetrating radar (GPR) has been widely applied in geological detections of highways and coalmines, but rarely in leakage detection of reservoirs. Taking Taohe Reservoir as an example, this paper deploys multiple GPR detection lines on site, and carries out intensive detection in the upstream/downstream of the reservoir, as well as on the left/right abutments of the dam. In this way, leaks were detected on the left and right dam abutments. The detection results provide a reference for subsequent analysis and treatment of reservoir leakage.
GeoDetector Based Research on Spatial Differentiation and Influencing Factors on China Urban Exhibition Development
Authors: Chen Jianbin , Chen Xiuchen , Yang Xilin
Published: March 2021

The author constructed index system, including 4 factors, namely Regional environment, related supporting industries, market openness, urban hierarchy and 17 sub-variables with 69 cities as sample, to analyze the spatial differentiation and factors influencing China urban exhibition development based on Natural Breaking Point and Geographic Detector. The research results show that there is significant spatial differentiation for China urban exhibition development; Factors that have a significant impact on the development of urban exhibition include Related supporting industries, open market, Urban hierarchy and two variables of Regional environment, namely, the Regional GDP and GDP Proportion of Tertiary Industry. The interactions between factors is more influential than factors alone.
Optimal Design of Excitation Systems of Synchronous Condensers for HVDC Systems in Power Grid Environment Based on Variable Universe Fuzzy Adaptive PID Controller
Authors: Shi Fan , Wang Honghua , Lu Tianhang , Wang Chengliang
Published: March 2021

In a gesture to optimize the reactive power properties of synchronous condensers and improve capabilities of condensers to support the voltages of AC systems, the outer loop control of the reactive power of condensers and the outer loop control of the voltages of AC systems are introduced into the conventional design of the main excitation systems of condensers in high voltage direct current (HVDC) systems in this study. Moreover, variable universe fuzzy adaptive PID controller is proposed to serve excitation systems of condensers to improve the response ability of condensers in power grid faults and the recovery speed of condensers after power grid faults, and to reduce overvoltage of power grids generated by condensers in the process of fault recovery. To verify its experimental validation, the model of ±100 kV HVDC system containing a condenser is set up in MATLAB/Simulink. The verified results reveal that the optimal design strategy of excitation systems of synchronous condensers in the proposal can ensure rapid regulation of the voltages of AC systems arising from condensers, and reduce overcompensation of the voltages and reactive power of AC systems arising from condensers when faults recover.
Environmental Engineering with Software Environment Modelling Based on Threat Model
Authors: Li Qiuying , Sun Ruize
Published: March 2021

The influence of software environment and its changes on software safety are becoming more and more important. This paper analyzes the relationship between software environment and software safety requirement, and builds software environment model related to safety requirement based on threat model from a conceptual hierarchy. Finally, an application is given for case study.
Energy Saving Design and Optimization of suspension System in Baja Competition for College Students
Authors: Ning Taiyu , Chen Wengang , Chen Jifei
Published: March 2021

The suspension design and optimization of Baja car were carried out on the premise of meeting the rules of the race in order to improve the handling stability and ride smoothness of the car. Firstly established the 3 d modelling software UG in suspension system 3 d model, the according to the design of the frame model of hard point ADAMS motion simulation model of motion simulation analysis and optimization selection of parameters, stress suspension system was analyzed by ANSYS, ensure the strength of the car, according to the four-wheel positioning parameters of suspension system and, along with the change of wheel parallel to beat curve using ADAMS/Insight module for parametric curves were optimized. Combined with the design and optimization, the front wheel camber angle changed from 0.81 to 0.68, the caster angle changed from 5.66 to 5.84, the caster angle changed from 6.35 to 6.42, and the front wheel toe angle changed from-1.48 to 0.99, jumping up and down in front wheel track changes reduced from 100 mm to 50 mm, swing arm to connect hard point rise of the front suspension arm Angle smaller, ultimately achieve steering the car light, effectively improve the performance of the car.
Molecular Dynamics Simulation of Ceramic Polyolefin for Fire Resistant Cable
Authors: Yang Changlong , Gong Min , Yang Fan , Liang Jiaming , Jin Peng
Published: March 2021

In order to study the mechanism of high temperature environment’s influence on the mechanical properties and interparticle interactions of ceramic polymer materials for fire-resistant cables, the typical models of three ceramic polyolefin Formulations were established according to the distribution proportion of each material. With the assistance of molecular simulation software, molecular dynamics simulation was carried out. The results show that with the increase of temperature, the intermolecular interaction weakens, the mechanical modulus decreases, and the FFV increases. The Formulation with the most significant intermolecular interaction at high temperature, the one with the largest mechanical modulus at the same temperature and the one with the slowest increase of FFV with temperature’s increase is the mixture system of ceramic ethylene butene copolymer and 28% EVA. The simulation results can provide reference for the selection of polyolefin ceramic materials for fire resistant cables.
Microwave-assisted Degradation of Poultry Feather to Synthesize Protein-based Surfactant
Authors: Hong Xiaomin , Chen Jinyang , Ma Guoli , Li Jinrui , Yang Yunfan , Yang Dingqing
Published: March 2021

Poultry feather is hydrolyzed into peptides and amino acids in sub-critical water without any acid or alkali as catalyst under microwave-assisted heating to produce protein-based surfactant. The optimal hydrolysis condition is as follows: temperature 200 °C, time 60 min, and the yield of peptides and amino acids 84.31%. The critical micelle concentration (CMC) and surface tension of the product of peptides and amino acids are 2.6 g/L and 48.2 mN/m. In order to increase lipophilicity, subsequently anionic protein-based surfactant was synthesized by acylation reaction between the hydrolysis product of peptides and amino acidsand oleoyl chloride. The CMC and surface tension decreased greatly with linkage with oleoyl. The synthesized anionic surfactant with weight ratios of 10% (wt.%) hydrolysis liquid/oleoyl chloride of 3:1, 4.5:1 and 6:1 are 0.5, 0.7 and 0.8 g/L and corresponding surface tension are 30.1, 34.0 and 35.7mN/m.
Effect of Maize Straw Composite Substrate on Tomato Seedlings Growth
Authors: Li J Q , Li Y , Liu C J , Fan Y T , Du Q J , Xiao H J , Wang Jiqing
Published: March 2021

In order to make full use of the agricultural waste resource maize straw, the alternative organic matrix of peat was studied to realize agricultural recycling. In this study, with peat: vermiculite = 2:1(v/v) as the control, the physicochemical properties of the matrix of maize straw fermentation after mixed with vermiculite in different volumes (3:1, 2:1, 3:2, 1:1) and the effect of applying the composite substrate to the tomato seedling were studied. The results showed that the effect of vermiculite contents on dry bulk density of mixing substrate was positive, however the effect of vermiculite contents on total porosity of mixing substrate was negative; The pH value of maize stalk fermented substrate treatments were among 7.01-7.21, but the pH value of peat was acidic; the treatment, fermented maize stalk substrates: vermiculite=1:1 (v/v), can nurse strong tomato plug seedling after sowed 42 d, it does not differ significantly between the treatment and peat on plant height, number of leaves, shoot dry weight and dry weight of whole tomato plant; Also it did not differ significantly among all treatments on content of chlorophyll, chl a/b, and root system vigor of tomato seedlings. Therefore, it is suggested that in the production practice, corn stalk fermentation matrix and vermiculite 1:1 mix to carry out seedling, compared with peat seedling, sowing 3-5 days in advance, so as to achieve the effect of peat seedling.
Optimization of Flame Retardant Amount for Epoxy Anti-Sliding Surface Layer
Authors: Sheng Jingliang , Zhu Bin
Published: March 2021

To improve the flame retardant ability of anti-skid epoxy surface material in the tunnel, the paper conducted study on influence of inorganic flame retardant magnesium hydroxide (abbrev. MH), organic flame retardant decabromodiphenylethane (abbrev. DBDPE) and antimony trioxide (abbrev. AO) on the performance after they were applied in anti-skid epoxy surface material. The mechanical properties, rheological properties, combustion properties and thermal stability of epoxy surface with different flame retardants were tested. After optimizing the blending amount to determine the optimal proportion, flame retardant efficiency of those was evaluated. The analysis showed that organic flame retardant DBDPE and AO have a better performance at the same dosage. The oxygen index of DBDPE/AO epoxy cement increased much faster than MH with the amount of flame retardant. When content reached 16%, the oxygen index of the DBDPE/AO reached 31.8%, which meant that it was a flame retardant material and had little effect on other properties of the cement. It is not a good treatment to add too much flame retardant in the epoxy anti-sliding surface, otherwise the rheological properties and mechanical properties would be influenced largely. When the content of composite flame retardant DBDPE/AO got to 12%, each performance index would meet the design requirements. The excessive content of MH was unsuitable because it would greatly reduce the mechanical properties and the ease of construction of epoxy cement. Based on comprehensive performance analysis, 9% DBDPE/AO is recommended as the flame retardant for anti-skid epoxy surface.