bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Encryption Techniques of Distance Measurement in Laser Fuze
Authors: Yiyan Lei , Kang Yi , Yuting Zhao
Published: June 2019

To improve the anti-interference performance of laser fuze, the polarized properties of laser in the laser fuze is used. By controlling the polarized properties of laser, the target and get the information of distance can be recognized. According to the polarized properties of scattering light, the laser fuze distinguishes the target from the background, which can weaken the influence of the background light and active interference. At the same time, some key technologies of laser fuze, such as rotation of bomb and information encryption and so on, are also studied.
Multi-mode Dynamic Aggregation Strategy for Mobile Edge Resources
Authors: Wang Weihong , Zhou Fuxiang , Feng Qian , Cao Yuhui , Lv Hongyan
Published: June 2019

In view of the problem of network service delay and low resources utilization caused by frequent resources failure in mobile network service processing, this paper proposed a multi-mode dynamic aggregation strategy for mobile edge resources (MDDAS). Firstly, the definitions and expressions of mobile edge resources were given in the paper by the form of resource vectors, and a two-layer resource aggregation model was proposed. After that, the parameters and operators required for resources aggregation are defined. Then, the resource aggregation schemes and the construction of the resources view are described by applying definition formulas and calculation parameters. Finally, it is verified by experiments that the MDDAS achieves the purpose of reducing the processing delay of network services and improving the utilization of network resources to a certain extent.
Research on Text Mining of Railway Safety Supervisors Performance Based on BiLSTM and CRF
Authors: Gao Fan , Wang Shisheng , Li Xinqin , Cao Hongfei , Cai Xiaolei
Published: June 2019

In the era of big data with unstructured data, the potential value of unstructured data mining is an effective way to solve the industry problem. Based on a large number of data recorded from the actual text of the performance plan of railway security supervisors, this paper proposes a text similarity calculation method based on text mining technology to calculate whether the personnel performance plan matches the reality. First, the text Named Entity Recognition(NER) is realized by using the combination of Bi-directional Long Short Term Memory (BiLSTM) and the Conditional Random Fields (CRF). Then based on the concept similarity calculation of HowNet, we designed the method of calculating the similarity between the same named entity. After that, different weights are given according to the importance of named entity, and a method of computing similarity between named entities is designed.. Finally, according to the given threshold, to obtain whether planning and realistic matching, and the actual personnel working situation, provide the basis for personnel assessment for the management personnel.
The characteristics of WC based cemented carbide using nonmagnetic Ni(W) solid solution derived from ammonium paratungstate as the binder
Authors: Hong Myongson , Sun Xudong , Xiu Zhimeng , Kim Donggil
Published: June 2019

An effective technique for making nonmagnetic WC based cemented carbide by using Ni(W) solid solution manufactured from ammonium paratungstate(APT) as the binder was developed. It was found that powder particles using APT as the W source had larger contact area between W and Ni and higher activity, which was conducive to the mutual diffusion between Ni and W, leading to a faster solid phase reaction and higher content of W diffused into Ni. And the mechanical and nonmagnetic properties of WC based cemented carbide derived from nonmagnetic Ni(W) solid solution as the binder are much better than those derived from pure Ni as the binder.
Synthesis, Characterization and Property of Amphiphilic Copolymer
Authors: Han Nianfeng , Zhou Dejie , Hu Xiuying , Wang Qingzhao
Published: June 2019

Atom transfer radical polymerization (ATRP) has been employed for the synthesis of an amphiphilic diblock copolymer MeOPEO-b-PBMA. The macroinitiator was prepared by poly(ethylene oxide) monomethyl ether with 2-Bromoisobutyryl bromide. The amphiphilic diblock copolymer was obtained by the macroinitiator and monomer n-Butyl methacrylate (BMA). The block copolymer was characterized by means of proton nuclear magnetic resonance (1H NMR). The honeycomb-patterned polymer films was obtained by the breath figure method. Water contact angle measurements revealed that a hydrophobic surface is obtained. The amphiphilic polymers expected to the application as the hydrophobic materials.
A Novel Method for Reducing Springback of Hot Stretch Bending Parts
Authors: Cao Fengchao , Zeng Yuansong , Liu Baosheng , Wu Wei
Published: June 2019

Due to the impact of temperature on springback in hot stretch bending(HSB) process, this paper proposed a modified hot stretch bending(MHSB) process in which a reheating process was added before post stretching. The reheating process was realized by controlling the current distribution in the straight region and the bent region of titanium extrusion. Prior to HSB tests, uniaxial tensile tests were carried out to determine the deformation behavior of extrusion under the temperature condition similar to the HSB processes investigated. The results of the tensile tests provided supporting evidence for that the temperature of post stretching strongly affected the forming accuracy of hot stretch bending parts. Particularly, much more joule heat generated in the bent region than in the straight region successfully reheated it to initial forming temperature by increasing current before post stretching. Accordingly, the springback was significantly reduced via the novel method compared to conventional hot stretch bending(CHSB) process. This method is proved to be an efficient and lower cost solution for reducing springback in HSB.
Condition Monitoring Technology for Bearing Ring Groove Grinding
Authors: Zhi Hou , Jie Zeng
Published: June 2019

Bearing is the most important basic components of mechanical equipment, and its machining quality directly affects the equipment quality. The ring is a main part of the rolling bearing, its groove is the working surface of rolling bearing, and its accuracy will directly affect performance and lifecycle of rolling bearing. Grinding method is often used to ensure the machining quality of ring groove, and grinding processing is crucial to final quality of bearing products. Therefore, in order to research and understand the quality assurance technology of grinding process for ring groove, three technologies such as grinding technology, condition monitoring technology and ring groove grinding state monitoring technology are discussed and analysed.
Research on the handling stability of four-wheel steering vehicle
Authors: Liu T , Jia L N , Yang N , Li C S
Published: June 2019

Now days, people have higher and higher requirements on automobile performance. As an important performance of a vehicle, the handling stability not only affects the driver’s driving experience, but also relates to the safety of the occupants. In order to improve the handling stability of vehicles, a simulation of the four-wheel-steering system in the linear range based on the time domain was conducted in this paper. Sideslip angle and yaw rate were taken as control targets. Proportional feedback control and PID control were integrated in the control system. The comparison of the front-wheel-steering system and the four-wheel-steering system indicated that the four-wheel-steering system had obvious effect on improving the handling stability of the vehicle.
Real-time defect detection of laser additive manufacturing based on support vector machine
Authors: Liu Tao , Huang Lei , Chen Bo
Published: June 2019

Laser additive manufacturing is an advanced digital manufacturing technology used to build or repair metal parts layer by layer. However, monitoring and in-process defect diagnosis lag behind advances in other key technologies, which makes product quality control a challenging problem. In this paper, a novel real-time monitoring system is proposed to automatically detect defects using principal component analysis and support vector machine. A camera is used in the image acquisition system to capture molten pool image. Ten molten pool features were extracted and principal component analysis was used to reduce the dimensions of the feature set. Support vector machine is used to build a classifier to detect defects in the deposited layer. The experimental results show that the SVM method can achieve high defect detection rate when identifying both slag and bulge defects. The support vector machine has a more satisfactory performance than the RBF neural network method. It is proved that the support vector machine method can be used more accurately and more universally in the in-situ monitoring system of laser additive manufacturing for defect diagnosis.
Experimental study of the physical and mechanical properties of pervious concrete with recycled and gravel aggregate
Authors: Zhang Yangang , yang Chuanjun , Shi Yunxing , Ni Kun , Li Yanwen , Zhang Peng
Published: June 2019

A experiment research on pervious concrete using recycled and gravel as aggregate was carried out. The effects of aggregate binder ratio and water cement ratio on compressive strength of the concrete were studied. The results show that the water cement ratio has different influence on the compressive strength of the two kinds of concretes, while the influence rule of the aggregate binder ratio is approximately the same, but the degree is different, moreover, the compressive strength of the concrete (using gravel as aggregate) in 28 days is basically the same as that in 56 days.
Interfacial intermetallic developments of Sn-3.0Ag-0.5Cu-2.0ZnO lead free solder
Authors: Qu Min , Cao Tianze , Cui Yan , Liu Fengbin , Jiao Zhiwei
Published: June 2019

The interfacial intermetallic compound growth behavior of Sn-3.0Ag-0.5Cu lead free solder joints with 2.0wt.% ZnO of micrometer was investigated in this study. Solder joints were fabricated in F4N reflow furnace at 255°Cfor less than 5min and thereafter aged at 150°C up to 240h. Results showed that the IMCs layer were almost layer type and grew thicker with extended aging time. The IMCs of Sn-3.0Ag-0.5Cu-2.0ZnO composite solder was diffusion controlled mechanism by diffusion growth kinetics analysis, moreover, the diffusion coefficient of Sn-3.0Ag-0.5Cu-2.0Zn0 composite solder was 0.31 μm2/h and smaller than that of Sn-3.0Ag-0.5Cu plain solder, it revealed that ZnO powder can reduced the diffusion coefficient of interfacial intermetallic compound.
A Survey of Traceback Based on Probabilistic Packet Marking Under DDoS Attacks
Authors: Zhou Linna , Jiang Hui , Zhou Xinli
Published: June 2019

DDoS attacks are mostly adopted by attackers in the network. This attack is malicious on the network protocol, resulting in the object not working properly. At present, the Packet Marking is the main method to trace back the attackers under DDoS attacks, especially the Probabilistic Packet Marking (PPM) of Packet Marking. Therefore, the two main types of Probabilistic Packet Marking are studied in this paper: Advanced Packet Marking and Authenticated Packet Marking (APM) and Adjusted Probabilistic Packet Marking (APPM).
Short-term Traffic Flow Prediction based on Data-Driven Knearest neighbour Nonparametric Regression
Authors: Chen Ken , Zhao Shasha , Zhang Dengyin
Published: June 2019

In order to solve the problem that the KNN algorithm is not accurate enough in the short-term traffic forecasting process and the prediction efficiency is not high caused by the search for past observations, a short-term traffic flow prediction model based on data-driven K-nearest neighbor non-parametric regression is proposed. The model is developed based on two-step search algorithm. Firstly, in the non-predictive period of time, the candidate input data similar to the current state is searched from the historical data for the system. Then, the optimal decision input data for prediction is identified from the candidate input data at the predictive point. Finally, the best decision input data is used to generate the prediction through the prediction algorithm. The simulation results show that the algorithm can effectively reduce the time for searching historical data on the premise of ensuring the accuracy of system prediction, thus reducing the execution time in the process of system prediction and improving the prediction efficiency of the system.
Application of Space Co-location Mining in Urban Construction
Authors: Lv Guoshuai
Published: June 2019

with the continuous development of the world economy, people’s living quality has been improved significantly, but meanwhile a series of urban construction problems have occurred. Due to the increasing population, the number of residential areas, schools, hospitals and other facilities is increasing, and unreasonable distribution will inevitably take place. The main purpose of urban planning is to coordinate the specific arrangement of urban spatial layout and various concrete construction by rationally utilizing the urban land according to the determined nature, scale and development direction of the city. From this point of view, by planning the city to make the population of the city rationally distributed, and fully analyzing the factors of people’s gathering according to the existing layout of the city, these elements can be planned and constructed in a centralized manner so as to solve the problems of transportation, environment, etc. in the city. This paper analyzes the reasonable and advanced urban layout and extracts useful knowledge from the spatial data, thus helping the relevant agencies of the government to plan and develop the new urban area.
Application research of the partial discharge automatic detection device and diagnostic method based on the ultrasonic in long distance GIL equipment
Authors: Wei Xu , Teng Yun , Liu Zi-quan , Deng Jie-qing , Jia Yong-yong
Published: June 2019

Gas-insulated transmission lines are very long with the length over 100 meters for each single chamber and there are no non-metal connection parts between two chambers, which leads to a poor detect effect when using the UHF method. Because of the attenuation of the propagation process, the ultrasonic detection method has many measuring points and a large workload of manual detection. To solve these problems, an automatic detection device and diagnostic location method based on ultrasonic method for the partial discharge of GIL were proposed in this paper. By combining the ultrasonic partial discharge detection device with the inspection robot, the robot performs the partial discharge inspection and transmits the data to the background diagnostic system for analysis. The overall structure of the system, the method of automatic diagnostic and location are introduced. The effectiveness of detection, diagnostic and location of the system is verified by simulation of the discharge signal in the laboratory. The application of the system can avoid the possible limitations of manual inspection in GIL Partial Discharge Ultrasonic testing, improve the work efficiency and guarantee the safe operation of power system.
Optimizing Semiconductor Laser PIDNN Decoupling Control Base on CPSO
Authors: Xia Peng , Lin Yao , Zhang Li-Hua
Published: June 2019

The coupling model of semiconductor laser is established for optical port components. The decoupling controller is designed by PIDNN, which enables the controller to response quickly and set parameter. The initial value of PID parameter is optimized by CPSO, and the appropriate initial value can make the system stable and reach expected value. CPSO can effectively prevent weight parameter search from falling into local optimal, and has a fast search speed.
Fabrication and evaluation of a printhead with integrated electrodes for electrohydrodynamic jet printing on insulating substrate
Authors: Pan Yanqiao , Zeng Liangcai
Published: June 2019

Printhead with integrated electrodes plays an important role in electrohydrodynamic jet (E-jet) printing, which can remove the effect of substrate and may be potentially used in fabrication of microelectrodes for flexible electronics. In this paper, we propose a printhead with integrated electrodes to achieve E-jet printing on insulating substrate. Evaluation of the printhead is performed by E-jet printing tests of ethylene glycol in order to validate correctness of design and feasibility of printing on insulating substrate. The printing tests on silicon indicate that the design of proposed printhead with integrated electrodes is correct which can work normally. However, influence of repulsive force by remaining electric charges on substrate is the main cause for failure tests on PET substrate. This research can provide a lesson to implement E-jet printing on insulating substrate in future.
Computer-Assisted Assessment Model to Decrease Math Anxiety And Increase Mathematical Self Efficacy of Junior High School Students
Authors: Nasution S H , Qohar A , Susiswo
Published: June 2019

The purpose of this research was to produce a computer-assisted assessment model as valid, practice, and effective to decrease math anxiety and increase mathematical selfefficacy of junior high school students. The product that would be gained was assessment computer-assisted that using Moodle and GeoGebra Software. This research referred to ADDIE development model that had five stages, they were Analysis, Design, Develop, Implementation, and Evaluation. The data collection techniques of this research were using students’ anxiety questionnaire and students self-efficacy questionnaire. The validator stated that the product which was developed was valid without revision. Product trials was done to 30 trials subject and gained that there was a decrease in anxiety level from medium anxiety (the anxiety average score 23,73) to lowest anxiety (the anxiety average score 10,3) and there was an increase to the self-efficacy average score from 27,13 (medium self-efficacy) became 37,36 (high self-efficacy).
Students’ Mathematical Communication in Solving Combination Problems
Authors: Sukoriyanto
Published: June 2019

The purpose of this study was to describe students’ mathematical communication ability in solving combination problems. This study involved 27 students majoring in mathematics, Mathematics and natural science faculty who took discrete mathematics subject. Students were asked to solve combination problems. Based on students’ works results, the ability of students were categorized into three categories, namely high ability, medium ability, and low ability. From each ability group, one student was chosen to describe their mathematical communication ability. The research results showed that the student with high ability was able to do written text well, do mathematical expressions well, and gave the correct final answer. while the student with medium ability was only able to do mathematical expressions. The student with low ability was not able to do written text, was unable to do mathematical expressions, and was unable to provide the correct final answer.
Mathematics Learning Difficulties of Slow Learners on A Circle
Authors: Metikasari S , Mardiyana  , Triyanto
Published: June 2019

Slow learners are children who have low intelligence in which these children need more time to study than normal children. The aim of this research was to analyze some mathematics learning difficulties of the slow learner on a circle and the strategies to overcome the difficulties. This exploratory study research used qualitative approach. The subjects were two of the 8th grade’s slow learner students in Islam Diponegoro Junior High School Surakarta. Data collection was done using documentation, testing, and interview method. Based on the data analysis, the results showed that the subjects dominantly had mathematics difficulties on a circle that were categorized in ideognostic dyscalculia, in which they had difficulties in understanding mathematical ideas and relationships towards the circle especially in the new situations (variety of problems), because of difficulty in recalling mathematical ideas after learning it; and operational dyscalculia, in which they got difficulties in performing arithmetic operations and mathematical principle, because they did not comprehend the algebraic concepts. The strategies to overcome these difficulties were encourage the students have clear conception by using teaching aids such as paper-circular or cylindrical cans so that the students could find out the value of phi, circumference, area, radius, diameter of the circle.
Development of Math Comic Learning Media on The Subject of Algebraic Expressions for Seventh Grade of Junior High School Students
Authors: Hidayah I N , Fathimatuzzahra
Published: June 2019

This development research aimed to 1) know the development process of mathematical comic learning media on the subject of algebraic expression that was valid, practical, and effective for grade VII of Junior High School students, 2) obtain mathematical comic learning media on the subject of algebraic expression which was valid, practical, and effective for grade VII of Junior High School students. The development model was using a modification of 4-D development model from Thiagarajan, Dorothy S. Semmel, and Melvyn I. Semmel became a 3-D development model. The procedure of this development consisted of three stages, namely 1) define, 2) design, and 3) develop. The results of this study were 1) The process of developing comic learning media that was valid, practical and effective was found. 2) The mathematical comic learning media products on the subject of algebraic expression that was valid. From the validity data analysis, a validity of learning media score is 3,3, lesson plans obtain a validity of lesson plan score is 3,66. a validity of knowledge assessment instrument score is 3,46, a validity of the students’ responses questionnaire score is 3,84. 3) The mathematical comic learning media products on the subject of algebraic expression was practical with practicality score is 3.3214 and 4) The mathematical comic learning media products on the subject of algebraic expression was effective were obtained. The products produced were two comic books with the subject of introduction to algebraic expressions and addition, subtraction and multiplication operations of algebraic expressions. The subject was presented in the form of stories with illustrations of black-and-white images and was equipped with practice questions.
CAKA as Physics Learning Media Based on Android Apps on Smartphones
Authors: Kurniawan H D , Kuswanto H
Published: June 2019

In this research, we aimed to design physics learning media based on Android apps on smartphones. The media were tested to ensure their validity, practicality and efficiency for learning activities. We used the Analysis, Design, Development, Implementation and Evaluation (ADDIE) model as the model of development. The media were tested through three steps: peer, expert and small group test. Data were collected via questionnaires, interviews and observations. This research produced physics learning media based on an application named CAKA (Becak Fisika). CAKA contains some senior high school physics topics such as work and energy, Newton’s laws and circular motion. The results showed that the CAKA learning media had good compatibility and there were no significant problems when they were used. The CAKA application was tested, and the result was found to be valid, practical and efficient for learning activities.
Students’ Energy Awareness Profile of High, Mid, and Low Levels Junior High School Student in Sragen
Authors: Nugroho W A , Sajidan  , Maridi
Published: June 2019

Energy awareness needs to be owned by students because environmental and energy problems in the 21st century become more complicated. This research was conducted to describe the profile of students’ energy awareness. The descriptive analysis method was used as the research method. Eighty-four junior high school students in Sragen Regency were selected as the subject. The subjects were selected through purposive sampling technique. The energy awareness instrument was adapted from Climate Literacy and Energy Awareness Network (CLEAN) by National Science Foundation and modified based on energy awareness model from Muhammad G. Hassan which included Environmental Concern, Visibility of Consumption, and Educational aspects. The results showed that the students’ energy awareness on visibility consumption was 52.72% with enough category acquisition while 23.76% on the environmental concern and 21.41% on the education aspects indicate quite low criteria. Based on the results, it can be concluded the students’ energy awareness in Sragen was relatively low, so need to be improved.
Climatic factors, Habitat Conditions and Nesting Behavior of White-Headed Munia (Lonchura maja) Birds
Authors: Ciptono  , Pramudihasan Aghnan , Aji Pangestu Wicak , Surya Fathoni Alfian
Published: June 2019

Scaly-breasted and white-headed Munia bird (Lonchura maja), is one of three species of Lonchura birds that live arround UNYcampus. Life habit and behavior is not well known. This study was done by observing the natural behavior without giving treatment to the object of research. The process of observations conducted from June to August 2017. This study aims to determine the condition of vegetation and climatic environment arround UNY and the behavior of Lonchura birds, and determine ideal conditions for nesting. All data collected by visual observation. These results indicate that the vegetation condition arround UNY related to Lonchura wildlife on campus, divided into 6 different locations. Each location has climatic conditions and different environmental carrying capacity resulting in species of birds that inhabit it any different. Scaly-breasted bird requires fairly dry location with an ideal temperature for the activity in the range of 27ºC, humidity is above 50% and the intensity of light that tends to light. Nesting sites of Lonchura made amid a clump of tree stands with a height at the top of the half-height of the tree. The most ideal conditions for Lonchura is the availability of feed such as grass seeds, the availability of dry grass for nest materials and also stands at over 4 meters high as nesting sites.
Population dynamics of Auricularia delicata fruit bodies in Bingungan forest, Turgo
Authors: Prasetiya D. , Aminatun T.
Published: June 2019

We have already done describing clearly enough about the particular substrates as Auricularia delicata habitat. Along with that research, another study was population dynamics of Auricularia delicata fruit bodies, among density and all measured environmental factors (temperature, air humidity, light intensity, pH, and water content of the substrates) which were carried out in Bingungan forest for eight months, 136 sampling from rainy season began to early dry season. Those data were analyzed using time series analysis which visualized in FIR (Finite Impuls Response) graphs and discriminant analysis (LDA) to classify similarity among plots and samplings. The population dynamics of Auricularia delicata fruit bodies might be modeled using GEE (Generalized Estimating Equation) analysis for forecasting purpose. Therefore, we have representation about when the best timing of Auricularia delicata did fruiting process in what conditions really were.
Fern Diversity in Taman Nasional Gunung Merapi and Its Potency as a Biology Learning Resource
Authors: Ayu Din Illahaqi Aza , Aloysius Suyitno
Published: June 2019

In the kingdom of Plantae, fern (Pteridophyte) is one of the largest and diverse plant group. They are dominant on the forest floor in warm temperatures and high humidity. This research aims: (1) to present the diversity of fern in Taman Nasional Gunung Merapi (TNGM), (2) to analyze the potency of fern diversity in TNGM as biological learning resources and (3) the feasibility of Pteridophyte Photo Sequence as learning media. The research was carried out through observation for identifying anykinds of fern and analyzing the potency of fern diversity as a learning resource, especially to study the Pteridophyte. In order to develop media photo sequence, this research used the ADDIE model (Analysis, Design, Development, Implementation, and Evaluation), but it was limited to the step of Development. The result showed that seventy five species of fern have been found in TNGM which is included in the 3 of 4 classes i.e. Lycopsida (8 species), Equisetopsida (1 species), and Pteropsida (66 species). It could be used as learning resource on subtopic of Pteridophyte for high school students in 10th grade based on Biology Curriculum 2013. The feasibility value for media photo sequence of pteridophyte in TNGM showed “very good” category.
Development of Bio-Monopoli of Human Musculoskeletal System as Learning Media for High School Students
Authors: Suwarno R N , Suratsih
Published: June 2019

The purpose of this study are: (1) to develop Bio-Monopoli, an educational game as learning media of Human Musculoskeletal System topic for High School students; (2) to find out the appropriateness of the Bio-Monopoli; and (3) to identify whether there is any difference in student’s learning motivation pra-experimental and post-experimental using Bio-Monopoli. This was a ‘Research and Development’ (R & D) study referring to 10 Borg & Gall’s stages (1983). The study’s subjects are theorist, Biology teacher, media experts, and students of XI IPA of MAN 1 Sleman. Data collected by purposive random and incidental sampling technique using questionnaire. The data of the media’s appropriateness were analyzed descriptively. The data of student’s learning motivation were analyzed by Wilcoxon Signed Rank Test and N-gain calculation. The result shows that Bio-Monopoli is very good and effective according to the respondents based on media engineering, visual communication, and learning aspect. There is a significant difference of student’s learning motivation pra-and post-experimental using Bio-Monopoli. Learning motivation’s increase included in moderate criteria with 0.424 in N-gain score.
Instructional technique questions in the planning phase of project based learning to increase the score of concept map
Authors: Arya Widatama Dita , Widoretno Sri , Dwiastuti Sri , Sajidan  , Maridi
Published: June 2019

The study aimed to improve student’s Concept map (CM) scores through the application of instructional techniques questions in the form of planning investigation according to driving questions (planning) in Project Based Learning. Research is a Class Action Research with 3 Cycles, including: planning to compile the lesson plan and its completeness, implementation of actions, observation, reflection and construct of expert CM. The research subjects consist of 35 high school students. Validation data use triangulation method: verification of CM scores suitability and documentation based on CM experts and interviews. Data analysis is done with qualitative descriptive: reducing, presenting data and drawing conclusions based on complete CM data. The results showed that the teacher’s questions functioned as instructional techniques that increased the CM scores of students but variation presented in component CM.
Development of Biology Learning Media Based on Adobe Flash to Increase Interest and Conceptual Understanding
Authors: Astuti Esti , Nurcahyo Heru
Published: June 2019

This research aims to know the feasibility and effectivity of interactive biology learning media product of human reproduction system based on adobe flash and to know the influence of application of learning media developed to increase interest and conceptual understanding. This development research refers to the developmental step by Borg & Gall. The field trial subjects in the experimental and the control class consisted of 35 students science second grade 5 and 3 Kota Mungkid High School. Collecting data used questionnaires, interview guides, evaluation media product sheets, interest questionnaire sheets, and concept comprehension tests. Quantitative data analysis techniques used independent t-test. The results showed that the learning media viewed from media experts and material experts categorized good. The result of independent t-test significance value is <0,05 and interest learners have increased was categorized as medium, the early learning interest is 65.1 and the final learning interest is 83.7 in treatment class . So it can be concluded that the learning media used is feasible and effective for use in biology learning process to increase interest and conceptual understanding.
Problems in learning biology for senior high schools in Lombok Island
Authors: Hadiprayitno G , Muhlis  , Kusmiyati
Published: June 2019

This survey was aimed to assess the student’s difficulties in senior high school for learning particular topics in Biology and the problems in the learning process. The survey was conducted in senior high school all around the Lombok island by using questionnaire and surveyed 568 students and 24 biology teachers which then analyzed by using qualitative and quantitative statistics. This survey revealed the difficult topics are bacteria and viruses (18.64%), endocrine system (10.63%), cell structure (8.81%), genetics (8.41%), and nervous system (8.28%). The student’s major problems in learning the topics are the use of the scientific name, the complexity of the topics, and the students learning habits. The survey also revealed the teacher’s problems in the teaching process in the planning stage (23.27%), implementation stage (48.63%) and evaluation stage (28.10%).
Misconceptions on Photosynthesis and Plant Respiration Topics Based on Thinking Styles
Authors: Pamungkas M S H , Saputro S , Mulyani S
Published: June 2019

Photosynthesis and plant respiration is an important science concept included in the curriculum in many countries, one of which is Indonesia. This topic is repeatedly taught at different age levels from elementary until tertiary education. Students who have misconceptions will assume that the concept they believe is true, but in reality does not conform to the existing scientific concept. Misconceptions will affect students’ knowledge. This knowledge will then be brought continuously to the next level of education and affect the learning achievement. Students’ thinking styles are one of the factors causing misconceptions. This study aimed to identify misconceptions based on the thinking styles of the seventh grade students about photosynthesis and plant respiration. The method used in this study was survey method. The data were collected by employing Matching Familiar Figure Test (MFFT) and Four Tier Test in three schools with high, medium, and low grades. The result showed that the students with impulsive and slowly imprecise thinking style had a higher percentage of misconception than those with reflective and quickly precise thinking styles. This study can be used as a reference to do remediation of misconceptions to improve the quality of learning.
Treatment of organic resources before soil incorporation in semi-arid regions improves resilience to El Niño, and increases crop production and economic returns
Authors: Smith Jo , Nayak Dali , Albanito Fabrizio , Balana Bedru , Black Helaina , Boke Shiferaw , Brand Alison , Byg Anja , Dinato Mengistu , Habte Mulugeta , Hallett Paul , Lemma Argaw Thomas , Mekuria Wolde , Moges Awdenegest , Muluneh Alemayehu , Novo Paula , Rivington Mike , Tefera Tewodros , Vanni May , Yakob Getahun , Phimister Euan
Published: June 2019

The use of limited organic resources to build resilience to drought in semi-arid regions was investigated using systems modelling. The study focused on Halaba in Ethiopia, drawing on biophysical and socio-economic data obtained from a survey of farms before, during and after the 2015/16 El Niño event. Using a simplified weather dataset to remove noise from weather fluctuations, a ten yearly El Niño was demonstrated to cause significant long-term degradation of soil, reducing crop yields by 9%–14% and soil carbon by 0.5%–4.1%; more frequent droughts would increase this impact. Farmers in Halaba usually apply manures to soils untreated. Counteracting the impact of El Niño on soil degradation is possible by increasing application of untreated manure, but would result in a small net cost due to loss of dung as fuel. By composting manure its recalcitrance increases, allowing soil degradation to be counteracted without cost. The best option investigated, in terms of both food and fuel security, for households with access to water and finances needed for anaerobic digestion (500–2000 US$), is to use manure to produce biogas and then apply the nutrient-rich bioslurry residue to the soil. This will result in a significant benefit of over 5000 US$ per decade from increased crop production and saved fuel costs. However, many households are limited in water and finances; in that situation, the much cheaper pyrolysis cook-stove (50 US$) can provide similar economic benefits without the need for water. The biochar residue from pyrolysis is highly recalcitrant, but pyrolysis results in loss of nutrients, so may result in lower yields than other uses of manures. This may be countered by using biochar to capture nutrients from elsewhere in the farm, such as from animal housing or compost pits; more work is needed to quantify the impact of treated biochar on crop yields.
Activated carbon characteristics of tabah bamboo that physically activated under different activation time
Authors: Negara D N K P , Nindhia T G T , Surata I W , Sucipta M , Hidajat F
Published: June 2019

Activated carbon is a versatile porous material that widely applied to purify, deodorize, decolorize, remove or reduce some gases harmful constituents and storage of gas. For different application different characteristics of activated carbon is required. This paper concerns to find out the characteristics of activated carbons derived from tabah bamboo (Gigantochloc nigrociliata) that physically activated with different activation holding time. Prepared tabah bamboo was carbonized by heating up to the temperature of 800 °C for two hours. The char produced was powdered and then activated physically by heating up to 800 °C, soaked at that temperature during each 1, 1.5 and 2 hours under 100 mL/min N2flow. Activated carbons manufactured were characterized by proximate and ultimate analyses and SEM observation. The results show that the highest fix carbon (82.52%) and lowest ash (5.91 %) was obtained at 1 hour soaking time with moisture and volatile contents were 3.56% and 8.00 % respectively; the highest carbon (C) content of 84.16 % was yielded at soaked time of 1.5 hours; SEM observation shows that there were significant differences of morphology structure between raw material and activated carbons for all of the soaking time variations. The pores structures have been formed in the activated carbons produced.
Experimental study on combustion characteristics of an indirect injection diesel engine fuelled by biodiesel blends
Authors: Ghurri A , Keun S K
Published: June 2019

An experimental investigation was conducted to evaluate the performance of an indirect injection (IDI) diesel engine using diesel (D100) and diesel-biodiesel blends (BD25, BD45, BD65) separately. The engine was run in various engine loads at constant engine speed ranging from 1000 to 2400 rpm with an interval 200 rpm. The results showed that the maximum pressure inside a cylinder of D100 is slightly higher than that of BD65 and other biodiesel blends. The biodiesel blends exhibited higher pressure change rate at a moment before peak pressure inside the combustion chamber. It was also clearly observed that the heat release rate of D100 is higher than those of biodiesel blends. This result is consistent with the higher engine power delivered by D100 compared to the biodiesel blends. In related to the combustion period, it was recorded that BD65 started the combustion slightly earlier than that of D100. This resulted in the shorter ignition delay of BD65 compared to D100. On the other hand, from the burnt mass data it was found that the BD65 ended the combustion later than the D100. This means the combustion duration of biodiesel blends are longer than that of diesel fuel which is worse combustion condition.
Sea water absorption on corrosion and hardness properties of lining brake with hybrid particulates composites
Authors: Subagia I D G A , Suardana N P G
Published: June 2019

This work is focused on study water absorption behavior on hybrid particle reinforcement for phenolic resin composites. This experiment works subjected to investigates corrosion and hardness properties effect of seawater absorption. Hybrid composites were constructed by three types of particles such as basalt, seashell, and alumina were mixed for reinforcement, and the phenolic resin was employed as a matrix. Specimens were manufactured by using the hot-press process on temperatures and pressure of 150°C and 2000N. Water absorption test was carried out by immersing specimens in seawater at room temperature for different time durations (3, 14, 24, 30, and 60 days) according to ASTM D 570 standard. The morphology of hybrid particles composites was investigated by SEM. The result showed that the increasing weight fraction of basalt powder has increased the hardness of specimens. Water absorption was shown monotonous trend on all hybrid composites configuration. In addition, hybrid composite immersion in seawater made hybrid particle composites corrosive.
Utilization plastic waste using pyrolysis fixed bed
Authors: Swamardika I B A , Winaya I N S , Hartati R S
Published: June 2019

This investigative research aims to convert urban non-organic waste fuels such as plastic waste into energy using fixed bed pyrolysis technology. Pyrolysis fixed bed (PFB) is one of the most efficient technologies for converting various types of undegradable solid waste into thermal energy and liquid fuels with high efficiency. The study was conducted on a lab-scale PFB reactor with dimensions of 15 cm and 55 cm in diameter and bed height respectively. The reactor is equipped with a cooling and decomposition system to accommodate liquid and gas products. Reactor temperature variations using an external heater were tested and quartz sands were selected as a bed material to improve the temperature function of the PFB reactor so as the maximum quality and quantity of liquid product were obtained. The fuel properties of the derived oil were tested including their physical properties, calorific value, elemental measurement (CHNOS) analysis. The results of the study showed that the increase in temperature resulted in an increased pyrolysis performance which was indicated by the increased volume and liquid caloric value.
Two water wheels performance in series for empowerment of irrigation
Authors: Asral  , Huda F , Akbar M
Published: June 2019

Irrigation system especially in Riau Province are widely available in around of agriculture area. The water flow of irrigation seems to provide continuous energy however many people ignored. The source can be used to drive some water wheels to generate electricity. The head of flow is relatively low with long enough area as the reason many water wheel in series like undershot type was appropriate to apply. This study aims to investigate the possibility of using many water wheels in a canal by installing two units of water wheel together i.e picohydro with series. Then, doubling the amount of energy might be utilized from the resources. For manufacture the corrosion resistant and lightweight material are selected to maintain the wheel from damage. The water wheel was tested from the ground up irrigation keep constant, various level of water to determine the characteristics of water wheel achievement. Power output and efficiency of the water wheel are among other of the results present in this study. Single water wheel produce that the maximum electrical power of about 1300 Watt. However the installation of two water wheel in series caused a decrease the total output power of the system approximately 1065 watt.
The effect of fiber volume fraction on tensile and impact properties of eleusine indica grass reinforced polypropylene bio composite
Authors: Lokantara I P , Suardana N P G , Surata I W , Winaya I N S
Published: June 2019

The purpose of this research was to investigate the tensile strength and impact strength of eleusine indica grass fiber-reinforced polypropylene recycle composite. In this study, the fiber was treated with alkali at 5% NaOH for 2 hours. The eleusine indica grass fiber cut with a length of 3 cm and the matrix used recycle polypropylene. In this research, the volume fraction of eleusine indica grass fiber varied by 20%, 25%, and 30% respectively. The composite molded with a hot press at temperature 200°C with a holding time for 2 hours. Tensile test used ASTM D3039 and impact test used ASTM D256. The highest tensile and impact strength results on fiber volume fraction 30%.
Smoldering combustion propagation of subtropic peat; case study on pelalawan peat
Authors: Martin A , Orion H , Sandhyavitri A , Palamba P , Nugroho Y S
Published: June 2019

Smoldering combustion was categorized as a very dangerous combustion and considered as a main cause to haze problem during wildland fires in Sumatera, Indonesia. This study aims to determine the characterized of the spread of peat fire, so the mitigation can be done. This study was used experimental methods. In this case, peat from Riau were analyzed and the samples to be used were peat that has been dried in the oven during 24 hours at 100 °C of temperature, moisture content after interaction with air was 7.09%;. This study was resulted the maximum combustion temperature of 508.72 °C. The rate of propagation of peat fires was determine from the difference of time when the combustion temperature reaches 300°C and 365°C. The rate of smoldering propagation at temperature of 300°C of 14.3 cm/h on the vertical direction and 6.31 cm/h on horizontal direction. The rate of smoldering propagation at temperature of 365oC of 19.76 cm/h on the vertical direction and 5.17 cm/h on horizontal direction.
Analysis of transient elastohydrodynamic lubrication of point contact subjected to sinusoidal dynamic loads
Authors: Cupu D R P , Stratmann A , Jacobs G
Published: June 2019

Vibration is inevitable from all machine elements operations since the load, surface velocities or contact radii change in time. In the case of a ball bearing application, the load changes as the ball elements rotate around the track. This change will be more rapidly when the external load changes. The vibrations induce a sinusoidal dynamic load working on the contact. On the other hand, the imperfect waviness on the contacting surfaces causes the vibration effects on the film thickness to become more pronounced. This paper numerically investigates the influence of the sinusoidal varying loads due to vibrations on the film thickness and pressure profile of the isothermal, elastohydrodynamically lubricated point contact with a wavy surface. For that purpose, a single contact between ball element and inner raceway is modeled as a contact between a spherical ball and a flat plate. The results reveal that the external sinusoidal dynamic load induces the modulations on the film thickness and pressure profile. The waviness on one contacting surface causes the changes in the EHL behaviors to become more pronounced.