bluuebunny/crossref_metadata_2025 huggingface dataset:
Realistic mathematics education: an alternative to improve students’ understanding of fraction concept
Authors: Cendekiawaty T , Sugiman S
Published: July 2020

Mathematics is a material that is considered difficult by students in learning mathematics so that students find difficulties in understanding concepts, especially the concept of fraction. Some students see fraction as whole numbers but only as a symbol that needs to be manipulated in various ways. The main factors that led to students’ difficulties in understanding the concept of fraction are more frequent student to memorize than to build an understanding of the concept. Another factor is the approach used by the teacher is not oriented to the real world where the situation can be imagined by the students. Alternative approaches that can be used as a solution is a realistic mathematics education approach. This study tries to examine students’ understanding of fraction concept through a realistic mathematic education approach by reviewing literatures. Through a realistic mathematics education approach, students had a chance to develop their knowledge by expressing their ideas during the learning process. Students were also able to imagine various situations occurred in a mathematical problems because those problems were in a real situation problems related to students’ life
The effectiveness of inquiry-based learning on computational thinking skills and self-efficacy of high school students
Authors: Sulistiyo M A S , Wijaya A
Published: July 2020

The aim of this research was to investigate the effectiveness of Inquiry-Based Learning (IBL) on computational thinking skills and self-efficacy of 11thgrade students with derivative as the learning topic. The type of this research was quasi experimental research. The population of this research was 191 of 11thgrade students in a public high school in Yogyakarta. The sample was 42 students from class XI Natural Science 1 and XI Natural Science 3 which were chosen by random sampling. The data were collected from pre-test and post-test for computational thinking skills and survey for self-efficacy. The results showed that: (1) IBL was effective toward computational thinking skills, (2) IBL was effective toward self-efficacy, (3) scientific learning was effective toward computational thinking skills, (4) scientific learning was effective toward self-efficacy, (5) IBL was not more effective than Scientific Learning toward computational thinking skills, (6) IBL was more effective than Scientific Learning toward self-efficacy. IBL failed to become learning model that was more effective than scientific learning toward computational thinking skills because of the failure in developing asking skills, but succeed to be more effective than scientific learning on improving self-efficacy because IBL provided more diverse sources of self-efficacy.
Schema of competencies for mathematics junior high school based in Indonesian curriculum
Authors: Maharani N A D , Retnowati E
Published: July 2020

The objective of this research was to develop a Schema of Competencies for Mathematics Junior High School Based in Indonesian Curriculum, specifically for VII and VIII grades and thus, to describe the assessment results given by mathematics education experts and teachers on the product with regard to feasibility of implementation. The research method is qualitative/descriptive using the 4D development model. The subject of this research was a Junior High School mathematics teacher in Yogyakarta and mathematics education experts. Qualitative data was obtained from development notes, suggestions from supervisors, mathematics education experts, and teachers. After that, the data were analyzed using descriptive analysis that is used to revise the products. The quantitative data collection was carried out by questionnaire and analyzed using Aiken’s V. This research produces a schema of competency achievement, which is diagram that describes the order of achievement of a defined competency. There are 23 knowledge and skill basic competencies that contain 19 mathematical topics. There are 9 topics studied in 7th grade and 10 topics studied in 8th grade. The following things that are done in developing a scheme is calculation the number of effective weeks, translation of Indicators from basic competencies, compilation of the semester program, determine competency prerequisites, preparation of product assessment sheets, make a scheme systematics, expert validation and then revise the scheme, after that do a product feasibility assessment. The content-validity coefficient for each material in the range of 0,819 – 0,917 on very high criteria. Therefore, the schema of competency achievement is feasible to implement.
Polygons in hyperbolic geometry using Beltrami-Klein models
Authors: Patmaningrum R , Lestari H P
Published: July 2020

Hyperbolic geometry was a geometry based on Hyperbolic Parallel Postulate. The purpose of this research was to describe the model of basic objects, concepts of triangles and polygons, as well explain types of polygons in hyperbolic geometry used the Beltrami-Klein model. The research method was literature study, it studied the definition and axiom were related to Euclid geometry and hyperbolic geometry such as point, line, triangle, and polygon. The result of this study was: 1) The plane model for Beltrami-Klein model is a γ circle. The object of geometry such as Klein points was expressed as a dot, Klein lines was expressed as part of Euclid lines that contained in a γ circle, Klein distances and Klein angles has the same presentation as Euclid distances and Euclid angles. 2) The Klein triangles have different concepts from the Euclid triangles. 3) The Klein polygons were defined as a combination of Klein segments, Klein rays, or Klein lines that was foreign to each other and have n different Klein points that was not collinearities. 4) The Klein polygons were divided into two types, the ordinary Klein polygons and the asymptotic Klein polygons.
Learning achievement of Elementary School student of mathematics using the Testlet model instrument: A comparison between the 2006 Curriculum and the 2013 Curriculum
Authors: Hamdi S , Kartowagiran B
Published: July 2020

This study aims to describe and compare elementary school students’ achievement in mathematics using the 2006 curriculum and 2013 curriculum with a testlet model. The research used a survey method and a quantitative approach. The participants were 552 from 14 elementary schools consisting of 273 students from elementary schools applying the KTSP curriculum and 279 from elementary schools applying the 2013 curriculum. The instruments used a testlet model test instruments that had met valid and reliable criteria. The data were analyzed using independent sample t-test. The results of the analysis show that there were not significant differences in the two curricula with t value with equal to 1.246 on the significance level of 0.118. The data obtained using a testlet model were more detailed related to students’ difficulties, students’ ability to answer questions and the level of guessing from students. The results can be used as a basic in enhancing student mathematics learning.
Can augmented reality improve problem-solving and spatial skill?
Authors: Guntur M I S , Setyaningrum W , Retnawati H , Marsigit
Published: July 2020

Spatial and problem-solving skill are two essential skills that are needed by students to deal with the industrial revolution 4.0. Spatial and problem-solving skills certainly are not genetically obtained but are the result of a long learning process. Augmented reality technology is one of the solutions to improve problem-solving and spatial skills. The purpose of this study is to explain why AR can improve problem-solving and spatial skills based on the study of theory and results from previous research. The method used is a literature review. Data was obtained from scientific journals and books that have been published in reputable publishers. The results show that augmented reality can improve problem-solving and spatial skill because there are interrelated relationships between these two skills and augmented reality which is a technology that combines the real world and cyberspace that has been tested in several studies which can improve both of these skills.
The readiness of junior high school mathematics teachers in implementing Permendikbud No. 37 of 2018
Authors: Murdiyani N M , Jailani  , Susanti M
Published: July 2020

The purpose of this study was to describe the readiness of Junior High School mathematics teachers in Yogyakarta in implementing Permendikbud no. 37 of 2018. This is because as a component as well as an executor of the curriculum, teachers need to be prepared to implement the new Permendikbud. The type of this research is a mix of quantitative and qualitative study using survey technique and interview. From the results of the questionnaire and interview sheet, data were obtained that most schools had syllabus, teacher manuals, student textbooks, assessment rubrics, and lesson plan for each Basic Competency. However, there are some schools that still lack in learning resources and learning media so it must be prepared by the teacher himself. In general, some teachers still have difficulties in several aspects when designing Lesson Plan based on The Core Competency and The Basic Competency set by the government i.e. in creating innovative learning media, in practicing various learning strategies and in carrying out holistic assessments. So, it can be concluded that there are still a number of Junior High School mathematics teachers who are not ready to implement Permendikbud no. 37 of 2018.
What are the roles of technology in improving student statistical literacy?
Authors: Suhermi  , Widjajanti D B
Published: July 2020

The use of technology in the learning process has provided positive benefits in improving students’ abilities. One of the abilities of students that can be improved through the application of technology in statistical learning is statistical literacy. Technology in statistical learning is a tool used in the teaching and learning process of statistics that aims to improve student statistical literacy. This literature research aims to examine what are the roles of technology that can be used in the statistical learning process so as to increase student statistical literacy. The key word in the study literature is technology in statistical learning. The literature used in this study is 22 articles written in the last 5 years that examine the use of technology in statistical learning. The results of this study conclude that the use of technology in the form of computers and smartphones makes it easy for teachers and students to access websites, online learning sites and statistical software that can be used in the statistical learning process to improve student statistical literacy. The use of websites and online learning sites in the process of learning statistics can act as a source of learning and a source of data that can improve students’ ability to understand and interpret statistical data. While the software plays a role in presenting and processing data that can improve students’ abilities in presenting and communicating statistical information.
The role of mathematics teacher in the digital era
Authors: Wijaya A
Published: July 2020

The complex characteristics of the digital era requires more than just conceptual knowledge. In addition to a so called 21st century skills, ‘digital literacy’ has been raised to highlight a set of important competencies to cope with the demands of the future era. Digital literacy comprises practical and functional skills, critical thinking and evaluation, creativity, e-safety, proficient communication, collaboration, cultural and social understanding, and information processing. Developing such competencies since early education requires a big role of teacher. By putting the idea of technological pedagogical content knowledge (TPACK) into practice, there are three important areas of consideration. First, preparation stage for which teacher should design or prepare technology-based or technology-assisted tasks that focus on exploratory activities. Second, during the implementation stage teachers needs to give proper scaffolding to bring from technical exploration to mathematical exploration. Lastly, the assessment stage for which teachers could use technology to improve efficiency and accessibility.
Integrating technology into learning mathematics: the special place of the scientific calculator
Authors: Kissane B
Published: July 2020

Technology for learning mathematics and for STEM more generally can take many forms, but this paper argues that the most likely technology to have an impact for all students in many ASEAN countries is the scientific calculator. Integration of technology into mathematics education in the twenty-first century requires good technology, an appropriate curriculum, well-educated teachers and an assessment regime that recognizes how important technology is for mathematical activity. While popular misconceptions that a calculator is only helpful for arithmetic persist, a four-part model for understanding the educational potential of scientific calculators is described and exemplified, recognising the significance of representation, computation, exploration and affirmation. Alternatives to scientific calculators include online calculators with visual and computer algebra capabilities, which might be appropriate provided the educational environment supports their use in all aspects of education, including formal assessment. The paramount significance of the teacher for successful integration is highlighted.
Acoustical Analysis of Circular Straight Mufflers with Bias Inlet/outlet Ducts
Authors: Chiu Min-Chie , Cheng Ho-Chih , Chang Ying-Chun , Lin Ding-Yao
Published: July 2020

In order to overcome the drawback of the accuracy for the Plane wave theory in the muffler’s acoustical calculation in the region of higher frequencies, we use a theoretical analysis of eigen function in conjunction with a four-pole system matrix to evaluate the TL of a circular straight muffler with bias inlet/outlet duct. With this method, the acoustical calculation can be speeded up comparing to traditional simulation of FEM and BEM method. Consequently, results reveal that the bias effect will tremendously influence the acoustical performance of the muffler.
The High-payload Manipulator Development Based on Novel Two-stage Cycloidal Speed Reducers and Hub Motors
Authors: Huang Jung-Tang , Li Chia-Wei
Published: July 2020

Collaborative robots such as Universal Robotics and KUKA are well developed and well known throughout the world. Nowadays, the manipulator structure uses a brushless motor with an RV reducer, or a harmonic reducer, and has a built-in driver to form a joint module and is composed of a connecting rod. This paper proposes a four-axis manipulator based on the novel two-stage cycloidal reducers and hub motors. The traditional two-stage cycloidal speed reducer requires two cycloidal gears through the first-stage speed reducer. Therefore, the traditional two-stage cycloidal reducer has four cycloidal gears. The novel two-stage cycloidal speed reducer simplifies this design. The design of the secondary deceleration is achieved by connecting two different numbers of cycloidal teeth and a phase difference of 180 degrees to the intermediate central disc so that the two-stage speed reduction can be achieved, and the reduction ratio is 136. Use this type of speed reducer, with a 200W hub motor, to build a four-axis manipulator and place a driver in the rod to save space. The proposed manipulator specifications: 4 degrees of freedom, the maximum payload is 18kg, the total weight is 37kg, the maximum working space is 0.7 meters, the efficiency of the reducer is 73.657% and the backlash of the reducer is 1.135°. The features of this four-axis manipulator are lightweight, low power, low cost, high-payload, and long life. This type of reducer is also a new option in addition to RV reducer and harmonic reducer for driving manipulator’s joint.
A Novel Mechatronic Kit of Variable Stiffness Manipulators – Design and Implementation
Authors: Lin Jonqlan , Hsu Wu-Hsiang , Liu Chia-Chang
Published: July 2020

In the developing fields of wearable devices, rehabilitation, and humanoid robotics, variable stiffness actuators (VSAs) are attracting increasing attention. VSA can minimize forces that are exerted by shocks, and can be safely interacted with by their users. They can store and release energy as passive elastic elements. The main goal of this work is to design a variable stiffness mechanism with a lightweight articulated robot arm. The proposed variable stiffness mechanism is based on lever kinematics. An RC servo motor is used to manipulate the leverage and to adjust the stiffness of the mechanism to control the position of a robot arm. Two spring elements absorb the output force from the lever. Such a design can reduce the number of sensing elements that are used in the robotic system and the damage force that is caused by unpredictable external forces. The designed articulated robotic arm uses a worm gear with a 1:40 high gear ratio to increase the payload capacity and reduce the weight of the robot arm. The worm gear has a self-locking function, which reduces the sliding step of the stepping motor. The advantages of the design in this study are the retention of the strength and loading capacity of the robot arm. The software package LabVIEW is used to build the control and measurement environment in which several control syntheses are tested. Numerous experimental results confirm that the design is reliable and has a low cost of implementation in a shock test. The novel mechatronic kit is ideally suitable for use in advanced mechatronic courses for university students. The discussion of the broad issues deliberated in this investigation will be applied to various systems that require variable stiffness manipulators.
A Novel Robotic Automated Optical Inspection System for on the Fly Production Lines
Authors: Lin Hsien-I , Wibowo Fauzy Satrio , Wahyudi Yuda Risma
Published: July 2020

Automated optical inspection (AOI) is getting popular in quality of control in manufacturing. There is a huge demand to install AOI systems in production lines seamlessly. Usually, a conveyor is used in a product line to carry work-pieces. Thus, it becomes difficult to inspect the quality of products by images when work-pieces are moving. This paper proposed a robotic AOI system which is able to track moving objects in a conveyor to take clear images. This system can be installed into production lines on the fly. To achieve this, the system estimates the pose of the coming work piece using a camera before the work-piece arrives the inspection spot, and adjust the poses of the inspection cameras to align with the work piece. Then, the robot moves along the conveyor at the same speed and the system requires the correct calculation of image Field of View (FOV). By doing this, the robotic AOI system can take clear images of the work piece. We validated the system on a Denso RC8-series industrial robot equipped with eye-in-hand cameras to capture clear images while the work-piece is moving. The results show that the proposed system is able to take clear images when the conveyor speed is up to 10cm/sec.
The Study on System Stability and Power Compensation in the Distributed Grid-connected Photovoltaic System
Authors: Hsu Weitai , Ding Sida , Huang Chiwei
Published: July 2020

New energy technologies are gradually matured and are being put into construction. The operation of conventional power grids is not able to meet the management of new energy generation and grid connection. When it comes to the distributed generation of electricity, the most representative is a photovoltaic system. It is essential to study the impact of the distributed grid-connected photovoltaic system on the stability, power, and voltage of the existing power grid. This paper mainly examines the effect of the distributed photovoltaic system on the balance of the power system and the optimization of reactive power compensation inspects the stability of the system through voltage fluctuations, and verifies the power compensation effect of the three-phase LCL photovoltaic grid-connected inverter combined with the photovoltaic system.
Deep-learning Object Detection for Resource Recycling
Authors: Lai Yeong-Lin , Lai Yeong-Kang , Shih Syuan-Yu , Zheng Chun-Yi , Chuang Ting-Hsueh
Published: July 2020

Recent years have seen a growing concern over global warming, as well as environmental pollution and protection issues. Resource recycling helps the effective reduction of greenhouse gases and environmental pollution, and improves the quality of life for many people. This paper proposes a deep-learning object detection system for resource recycling. The resource recycling of the objects including paper cups, plastic bottles, and aluminum cans was conducted by artificial intelligence. Single shot multibox detector (SSD) and faster region-based convolutional neural network (Faster R-CNN) models were utilized for the training of the deep-learning object detection. With regard to data set images and training time, the accuracy, training steps, and loss function of the SSD and Faster R-CNN models were studied. The accuracy and loss characteristics of the deep-learning object detection system for resource recycling were demonstrated. The system exhibits good potential for the applications of resource recycling and environmental protection.
Influence of Fly Ash and Recycled AAC Waste for Replacement of Natural Sand in Manufacture of Autoclaved Aerated Concrete
Authors: Lam N N
Published: July 2020

Currently in Vietnam, the source of natural sand used in construction in general and in production of autoclaved aerated concrete (AAC) in particular is increasingly exhausting, so finding new sources of raw materials to replace natural sand has important role to ensure the maintenance of construction material production activities as well as towards sustainable construction development. Autoclaved aerated concrete (AAC) is one of the lightweight concretes that commonly used in construction. AAC is relatively light in weight, having lower thermal conductivity, higher heat resistance, lower shrinkage, and faster in construction process when compared to the conventional concretes. This paper aims to research, use and compare the use of recycled AAC waste and fly ash to replace natural sand in AAC concrete brick production factory. The new developed AAC was conducted by replacing sand with recycled AAC and fly ash in ratio of 0%, 5%, 10%, 15%, 20%, 30%, 40% and 60, 80 and 100%. Mechanical tests such as density, compressive strength have been carried out. Research results show that it is possible to take advantage of recycled AAC waste products with a maximum content of 5% and fly ash with a content of up to 100% to replace the natural sand in the manufacture of AAC bricks. In terms of economic and technical efficiency, the use of fly ash is more optimal, because it allows reducing the volumetric density, enhancing compressive strength and minimizing the grinding cost as well as contributing to environmental protection, aiming to sustainable construction.
A Study on Using Crushed Sand to Replace Natural Sand in High-Strength Self-compacting Concrete Towards Sustainable Development in Construction
Authors: Lam N N
Published: July 2020

In recent years, the use of natural sand to produce concrete has led to increased demand for sand quarrying, resulting in this valuable resource exhaustion. Therefore, there should be synchronous solutions to limit the use of resources that are gradually depleted, contributing to environmental protection. One of the solutions is to use crushed sand to replace natural sand as aggregate in concrete, especially the study of using crushed sand to make high-strength self-compacting concrete. Crushed sand is an aggregate of angular shape and surface roughness that hinders the self-compacting of the concrete mixtures. Combination with fine mineral admixtures will be a good solution to improve the rheological properties of the concrete, i.e. reducing the internal friction between the angular particles in the paste system, increasing the ability to “lubricate” the aggregate particles, thereby creating excellent workability and self-compacting ability for concrete with slump flow of 820 mm and flow time of 4.5s, the ability to flow through reinforcing steel meets the technical requirements of EFNARC and compressive strength at the age of 28 days reaches over 85MPa.
Environmental Friendly Low Mass 20g-Sn58Bi/Cu Solder Alloy as an Alternative to Lead SnPb and Its Properties Study
Authors: Amares S. , Rajkumar D.
Published: July 2020

The SnBi solder system are argued to be the possible replacement for the lead and hazardous SnPb solder alloy. The features that differs in this study from the other types of Sn58Bi/Cu is the low mass usage of 20g. This low mass serves as to preserve materials and reduce waste. Yet, the main objectives to provide substantial data in term key properties of melting temperature, hardness and contact area properties of this Sn58Bi solder. The melting point of the Sn58Bi solder alloy is 142.25°C, close to the eutectic temperature. The average Vickers hardness value produced by the Sn58Bi was 28.8Hv, considerably high and close to the SnPb. The spreading area of the Sn58Bi solder alloy on the Cu substrate was calculated to 14.85mm2, at the soldering temperature 230°C. These properties are based on 20g of SB that can be predicted to be quite standout, and at the same time provides less waste of materials. Insight discussions are elaborated in this paper.
Energy-efficient Lighting and Biophilic Design Concept to Boost Reading Interest in Social Facilities’ Library
Authors: Dewi OC , Ismoyo AD , Felly R , Aisyah  , Yohardi L
Published: July 2020

Library in public and social facilities such as schools, mosques, churches and training centers has never become the main priority service unless it is intended accordingly. The good thing is, the library in such facilities always merges with other social functions such as special classes, gathering room or even dining room which is an addition to its original function: the reading room. Department of Architecture Universitas Indonesia, together with “Smandel 95 Berbagi Kasih Program” has conducted (has been conducting kalau aktivitasnya masih berlangsung) community engagement program, funded by the Directorate of Research and Community Engagement Universitas Indonesia, in an orphanage in Jakarta, namely Yayasan Tanjung Barat. The aim of this activity is to increase the occupant’s hobby in reading without renouncing the original activities through an energy-efficient and biophilic concept. Software-based lighting simulation and biophilic intervention concept were conducted to get the optimum result, a part of the design development through multi-discussions with the occupants and observations. Through this study, the energy efficiency from lighting intervention and the biophilic design presence in this library can be increased by 59% and 69% respectively.
Preliminary Calculation of the Potential Solar Power from the Second-floor+ Houses in Hung Vuong Street, Hue city, Vietnam
Authors: Binh Minh Hoang Thi , Giao Chau Trinh Thi , Zschiesche Michael , Cuong Cung Trong , Cuong Pham Viet
Published: July 2020

This is the preliminary calculation about the potential of solar power from second-floor+ houses along Hung Vuong Street, Hue city. Research team organized field trips to inventory the houses and areas, number of floors, sunshine direction of the house in accordance with its adjacent houses. We calculated the number of solar panels needed to install and the potential of solar power can be generated from each house from the second floor and more. Research team has chosen photovoltaic solar cell technology (PV) to calculate the actual solar power achieved. The calculated results of solar power reserves are 3GWh/year with an investment of 57 billion VND (not including inverter). This reserves can help to reduce 4.17 million tons of CO2, 19.08 million tons of nitrogen oxide, 0.06 million tons of sulfur dioxide, 3.12 million tons dust, 1.14 million tons of ash, 9.12 million m3 of water and 2.55 million tons of coal annually, if the lifetime of the solar system is 25 years, the emissions will decrease significantly. This research shows that the potential for solar power conversion is feasible to address the green growth needs of the economy and climate protection in Thua Thien Hue province.
Wood Modification for Under-Utilised Hardwood Species
Authors: Németh R , Horváth N , Fodor F , Báder M , Bak M
Published: July 2020

The different wood modification processes give the opportunity to improve the applicability of such wood materials, which due to their lower biological resistance and/or weather resistance and/or dimension stability have a limited application field. Beside several plantation grown species (e.g. poplars or black locust), there are some species that are not plantation grown but available in considerable quantities, but with low added value during their utilization. These species are mainly used for energy recovery, but they have also the potential for the utilization with higher added value (e.g. furniture, claddings, etc.). These hardwood species are Turkey oak (Quercus cerrisL.), hornbeam (Carpinus betulusL.) and tree-of-heaven (Ailanthus altissimaMill.). They have in general high density, strength values and surface hardness. By improving of the properties their application could be widened by substituting more valuable wood species. Different modification techniques were used for the improvement of the properties of these wood species, namely heat treatment and oil heat treatment. In this paper selected wood properties were investigated which are important by the specification of the application fields of the treated material.
Relationship between the Fixation Period and Some Mechanical Properties of Pleated Wood
Authors: Németh R , Báder M
Published: July 2020

Longitudinally compressed wood (or pleated wood) is much easier bendable compared to untreated wood, even to much smaller curves. Its properties make pleated wood both an economically and environmentally friendly product for performing curved wood products. As a result of longitudinal compression, modulus of elasticity and required bending stress highly decrease, while bendability coefficient increases threefold. The longitudinal compression is usually followed by the fixation process: the degree of compression is held constant for a certain amount of time to relax the internal stresses in the wood. Fixation strengthens the effects of the treatment and it is used by the industry, but unfortunately, there is very slight literary knowledge available in this topic. We try to fill this gap by using different times of fixation and bending tests. The first minute of fixation is the most effective, but for example fixation for more than 10 hours results in a maximum deflection during 4-point bending tests of 675%, in a decrease of modulus of elasticity to 18.6% and in a decrease in bending stress at 5 mm crosshead displacement to 29.3%, compared to untreated specimens. Finally, pleated wood can undergo significant plastic deformation before fracture.
Role of Electrical Conductivity on Salinity and Mineralization due to Groundwater Level Fluctuations in Kolkata City
Authors: John B , Das S
Published: July 2020

This paper attempts to explain the relationship between the falling Groundwater level and the rising electrical conductivity of the Kolkata Metropolitan City. The groundwater level of the city is on the fall, and if it further depreciates, then it will lead to the flow of toxic elements from the Dhapa areas leading to increased minerals and dissolved salts in the groundwater, rendering the groundwater unfit for consumption. It is seen that the salinity of the groundwater is on the rise in Kolkata. The salinity or the degree of dissolved salts was tested using electrical conductivity parameter. The water level and electrical conductivity data was collected from different Government organisation and the EC for post 2018 was collected through field measurement using a TLC metre. Maps were prepared using GIS techniques and both the parameters (groundwater level and electrical conductivity) were correlated. It shows a positive correlation between groundwater level and electrical conductivity and maximum fall in the level is seen in the northern part of the city. If artificial recharge is done in the trough areas then only the problem can be solved to a greater extent.
Experimental Analysis and Numerical Simulation of Hydraulic Jump
Authors: Nandi B , Das S , Mazumdar A
Published: July 2020

Saint Venant equations are numerically solved to simulate the formation of hydraulic jump in a rectangular channel having a small bed slope. The MacCormack’s scheme is used for the solution by applying specified initial and boundary conditions until a steady state flow is reached. The location of the hydraulic jump is determined as a part of these computations. The artificial viscosity technique should be used in the computations to dampen the superior oscillations near the steep gradient of the simulated hydraulic jump. Twenty laboratory experiments were carried out for verification of the numerical model. The upstream Froude number for these experiments ranged from 2.17 to 7.0 in three different bed slopes 0, 0.02174, 0.0475. The simulated hydraulic jump profiles using the MacCormack’s scheme shows a good agreement with the experimental data. An empirical equation was developed to determine the location of hydraulic jump using regression analysis based on simulated data. Software based on Computational Fluid Dynamics (CFD) was also used to simulate two of these experiments. The results obtained from CFD analysis matched fairly with the experimental results.
Energetic Assessment of Biogas Plant Projects Based on Biowaste and Maize Silage Usage
Authors: Dach J , Pulka J , Janczak D , Lewicki A , Pochwatka P , Oniszczuk T
Published: July 2020

Maize silage, in spite of its rising prize and technological problems of monoculture in Eastern Germany, is still the most popular substrate for biogas plants. However waste materials often generate income, because of the potential technological or ecological problems they cause. Such an approach seems to be more profitable even considering lower biogas yield of dose waste substrates. To compare these different scenarios energetic and economical assessment of waste fermentation processes such be conducted. In this paper, three different substrates will be evaluated to determine their suitability for agricultural biogas plant feedstock.The research was based on the modified German standards DIN and VDI, while chemical and physical analytical methods were based on the Polish Standard System. Economic analysis was performed using standard prices in the polish biogas market. The calculation was conducted for 500 kW installation. Based on the obtained results, it was proven that refood was characterized by the highest methane and biogas yield from the analyzed substrate group. Maize silage fermentation in the Polish condition is least profitable due to the approximately 50 % income reduction by the costs of obtaining silage. However due to the price received for treating waste materials, refood fermentation is the most economically feasible option.
Growth and Nutritional Performance of Black Soldier Fly (Hermetia illucens) Larvae Reared in Fermented Rice Straw and Duck Manure
Authors: Pamintuan Kristopher Ray S. , Agustin Hanika Angel T. , Deocareza Ericka D.
Published: July 2020

Black soldier fly larvae (BSFL) are known to convert organic wastes into useful biomass, of which the composition depends on the substrate. It is of interest whether feed protein can be sustainably obtained from waste materials by feeding them to BSFL. This study aimed to convert rice straw and duck manure into BSFL biomass for conversion of waste into animal feed. The growth parameters of BSFL fed with pure fermented rice straw, pure duck manure, and an equal parts mixture of the two as well as its nutritional composition was determined. The larvae’s efficiency to consume and convert the different substrates was also evaluated. Results showed that BSFL fed with duck manure had significantly higher average individual weight of 0.0619±0.004 g, followed by mixture of duck manure and rice straw (0.0614±0.001 g), while those fed solely with rice straw did not accumulate the same biomass (0.0415±0.002 g). Correlations were also made for mass-length, mass-width, and length-width. Mass-length connection was the most reliable correlation (r = 0.732). The harvested BSFL protein was the highest for those fed with rice straw at 34.62%. Feed conversion ratio ranging from 3.71 to 11.3 was achieved for the substrates used. The availability of the waste substrate in large quantities coupled with efficient biomass conversion makes BSFL a sustainable organic matter converter primarily useful as additive to animal feed.
Removal Persistent Organic Pollutant in the Leachate by Subsurface Horizontal Flow Construction Wetland in Lab Scale CWs
Authors: Huong Quynh Pham , Cuong Vo Kim
Published: July 2020

Hard organic compounds such as humic, fulvic in leachate which require treatment to make it dischargeable into the water stream. CWs is designed in the dimension of DxRxH = 2.5x0.8x0.5m. The filter materials used are small pebbles, crushed stone, and large pebbles. In this work, the effectiveness of removing colour and COD from leachate with Canna Lily CWs with activated sludge. Removal of COD and colour by CWs were 75.2% and 80.0% after 5 days, COD removal and colour increase were 9.7%, 5.6%, when adding 200mg of activated sludge to CWs. The quality of leachate is up to standard with HTR of 6 days with COD and 7 days with colour. The treatment time for leachate meets QCVN 40:2011/BTNMT standards is 7 days.
Research on Industrial Hazardous Waste Generation in China Based on Combination Forecasting Model
Authors: Liang Xuedong , Yan Fuhai , Yang Xu
Published: July 2020

As the largest developing country, with the rapid development of society and economy, China’s industrial hazardous waste generation is constantly increasing.. In order to promote the scientific and effective management of industrial hazardous wastes, it is necessary to carry out reliable prediction research on industrial hazardous wastes generation. In view of the analysis of existing studies, firstly, this article considers the trend model, gray model, support vector machine model, and ARIMA model based on the sample data amount and the applicability of the prediction method to predict the hazardous waste production data separately; Then, the entropy weight method is used to evaluate independent models through multiple error indicators to determine the combined weight of each independent model; Finally, a combination forecasting model was established to study the production of industrial hazardous waste, and the application of the combination forecasting model to the forecast of industrial hazardous waste production in China was explored.
Study of Ecotourism Sustainable Development Strategy of the Cinsibu Atayal Tribe in Taiwan
Authors: Chang Hsiao-Ming , Lin Chi-Jen , Hung Chien-Jen
Published: July 2020

This study aims to analyze the processes and measures of the sustainable tourism development of indigenous tribes, and explores the policies of governmental departments, in order to serve as reference for the development of tribal tourism. This study treats the Cinsibu Atayal Tribe in Taiwan as the subject and conducts qualitative research. According to the findings: (1) Policy guidance of the government and clergymen in the tribe are the main forces to promote sustainable tribal ecotourism development. (2) Tribal ecotourism can effectively carry out ecological conservation and maintain and pass on culture. (3) By the creation of job opportunities in the tribe, the people can be self-sufficient, which results in sustainable development in the tribe. According to the results, this study proposes suggestions for the development of tribal ecotourism.
Relationships between Sustainable Campus Partial Renovation Project and Disaster Prevention Indices
Authors: Kuo Jhun-Iuan , Chuko Cheng , Chih Tung Huang , Huang Wei-Cher , Chao Fang-Lin
Published: July 2020

The relationship between sustainability and campus disaster prevention was investigated. From understanding the characteristics of campus, ecology, and energy, people can establish a diverse campus environment and create an eco-education demonstration zone. Descriptive statistics and one-way ANOVA were utilized to investigate the operation and money flow of “Sustainable Campus” by the Ministry of Education. Through comparing multiple criteria decision, we verified factors from “Instruction of Disaster Management for Campus.” The results indicated: north Taiwan has the most ecology and health indicators, along with the most frequent natural water purification processing. Middle and south areas have the most permeable pavements, and the east region is notable for its multilayer ecological greening projects. By the result of the Delphi method questionnaire, we established six main applications for sustainability and disaster management: “building materials and natural resources,” “permeable pavements.” The global actions indicated more resourced placed on aspects of “indoor environment improvements” and “rainwater recycling.”
Autonomous Electrical System Monitoring and Control Strategies to Avoid Oversized Storage Capacity
Authors: Hong T T Vu , Delinchant Benoit , Ferrari Jérôme , Nguyen Quang D
Published: July 2020

A significant solution to achieve energy efficiencies and stability of the electrical network is upgrading auto-consumption in a single PV system. In this paper, we presented a methodology to implement low-cost sensors and actuators to have better monitoring and control for a feasibility solution. This approach has been conducted through a case study on Greenhouse’s PV system in Grenoble, France. We proposed a minimal set of sensors to reduce system complexity while giving us enough information to make decisions. Some technical issues were analyzed as accuracy, sampling rate, response-ability of our system. The influences of inverter operation mode to system losses were considered. After that, we figured out energy problematics in our system based on available design data and simulation data from PVSyst. A PV production prediction model was investigated with input as forecast cloudiness data collected from web service, updated every 3 hours. This model, combined with real-time monitoring data and setting mode on an off-grid inverter, was used to identify control strategies with objectives of avoiding oversize storage capacity and maximizing the autonomous duration of the PV system.
Impact of Pluvial First Flush – Application to Danang City, Vietnam
Authors: Quy An Nguyen Phuoc , Gourbesville Philippe , Audra Philippe , Duong Vo Ngoc , Ngoc Khoi Vo Diep
Published: July 2020

As cities in Vietnam, a combined drainage system has been building in Danang City. In recent years, Danang City has been extensively developing. However, additional wastewater treatment plants have not been built. As a result, wastewater and rainwater are discharged directly into the coastal areas. The initial period of the runoff after first rainfall events can be called the first flush, which has higher pollutants. So the contribution of pollutants from the first flush must be considered in order to correctly make an environmental preservation method for the coastal area. This study uses Mike Urban with modelling water quality to analysis the sensitivity of the NH4
+ concentration in the first flush of the areas. In addition, rainfall intensity and Antecedent Dry Weather Period are two key factors influencing the pollutants of the first flush. Through the results of the simulation, the NH4
+ concentration increase follows the rainfall intensity with maximum concentration appearing when rainfall intensity reaches 19 mm/h. However, NH4
+ concentration then decreases even when rainfall intensity increases. NH4
+ concentration reaches up to around 15 mg/l every 5 days dry period with 30 mm/h rainfall intensity.
Development and Design of Hot Spring Filter and Sterilization Device
Authors: Hsu Jui-Liang , Yen Ke-Tien , Yeh An-Chi
Published: July 2020

Hot springs are not easy to generate, how to deal with the used hot spring water and make it recycled has become a very important topic in this industry. The purpose of this study was to develop a hot spring filtration and sterilization device, to provide hot spring industry in hot spring water quality management has good results. The problem to be solved in this research and design was to use Titanium dioxide nano silver Antibacterial cloth for antibacterial dyeing and finishing powder the filter sterilization device was made of filter material structure, aiming at the spring quality of Carbonated spring or Sodium bicarbonate spring), The hot spring pool water is filtered and sterilized and re-introduced, so that the hot spring water could be reused without the doubt of hygienic safety. In order to solve the above problems, this research and development designed department discloses a hot spring pool water filtration and sterilization device, applicable to carbonated spring or sodium bicarbonate spring Its structure included: 1. barrel 2. central filter 3. filter material structure.
Development and Design of Water Surface Type Filtration and Sterilization Device
Authors: Hsu Jui-Liang , Yen Ke-Tien , Yeh An-Chi
Published: July 2020

Some lighter foreign matters or dust will float on the water surface. The existing filter device can not effectively filter these floating foreign matters or dust. Therefore, the purpose of this study is to design a surface filtration and sterilization device, hoping to provide hot spring, massage pool and swimming pool operators with good performance in water quality management. The structure of the design content includes: the tank body, which has a movable hatch cover, a central filter pipe and a filter screen layer, the filter material structure which is detachable, and a purified water output pipe connecting the holding space and the outside, and the water outlet is arranged at the bottom of the tank body, and the filtered and sterilized pool water is led into the purified water pipe for transmission through the central filter pipe and the filter material structure through the suction of the motor And then discharged into the pool water.
Residue Pesticides (Pyrethroid Group) in Vegetable and Their Health Risk Assessment via Digestion on Consumers in Ha Nam Province, Vietnam
Authors: Huong D T V , Nga T T H , Ha D T T
Published: July 2020

Pyrethroid group are insecticides recommended for protection against insects by governed organization such as World Health Organization (WHO) and the European Union (EU). They are widely used in agriculture, households, forestry, horticulture, medicine and veterinary medicine. In Vietnam, these pesticides were used with huge amount in crops, especially in vegetable. The residues of λ- cyhalothrin, permethrin, cypermethrin, deltamethrin in four vegetable head mustard, leaf mustard, choy sum, bok choy were detected by GC/MS technique. 84 samples of four leafy vegetable in Brassicaceae family were colleted from seven places (farms, stores, markets) in Ha Nam Province. The levels of λ- cyhalothrin in three samples, cypermethrin in four samples, deltamethrin in four samples were above the maximum residue limit of Vietnam Government. There were no significant of health risk by these pesticides via digestion vegetable but the risk for kid was higher than for adult. Their health risk on cosumers using these vegetable were evaluated.