bluuebunny/crossref_metadata_2025 huggingface dataset:
Develop cooperative capacity for students in STEM modelation model
Authors: Nhung Van Thi Thanh , Hanh Pham Thi Hong
Published: April 2021

STEM is an educational model which is being concerned by countries around the world and Vietnam. With the goal of developing career capacities and orientations for students, STEM education model helps connect schools, communities, workplaces and global organizations by learning through action. Students experience and apply the integrated knowledge in the areas of Science, Technology, Engineering and Maths to solve practical problems and create products. The nature of STEM education is collaborative teaching. Collaboration in STEM teaching is expressed in the content of the subject, in the learning activities, in the learners and in the cooperative learning results in the education model. STEM is the development of professional-oriented competencies for students.
Hacking STEM - a solution to teaching natural science subjects in secondary schools for STEM-oriented education
Authors: Thu Nguyen Diu Th i , Hoang Giang
Published: April 2021

In the new general school curriculum, the Natural Science subject is taught in an integrated way according to the STEM-oriented education. However, it is not simple to build a topic of teaching Natural Science subject towards STEM standards. In this context, Hacking STEM is one of the ideal solutions to solve the aforementioned problem. The paper focuses on analyzing what Hacking STEM is, the advantages and disadvantages of Microsoft Hacking STEM when applied in Vietnam, the process of using Microsoft Hacking STEM projects, analyzing a specific project, the relationship between these projects with the Natural Science subject in the new general school curriculum and with the subjects of Natural Sciences being taught in the current period.
Designing experiential learning activities for students in directions of STEM education at primary schools
Authors: Thanh Nguyen Thi , Duong Ngo Thi Thuy
Published: April 2021

STEM is a new educational model in the world which integrated many subjects and skills helping students to develop and integrate well in their lives. STEM education is basically understood to equip students with the necessary knowledge and skills related to the fields of science, technology, engineering and mathematics. Experiential learning activities for students in directions of STEM education help students combine the scientific and mathematical knowledge to solve the practical problems. In Experiential learning activities, students based on combining the knowledge of various education fields and skills to apply in reality and participate in the service activities for communities under the guidance and organization of their teachers. This paper focuses on the designing of experiential learning activities to develop the core skills of primary students with some main contents such as: overview of STEM education, experiential learning activities and experiential learning activities for students in directions of STEM education; designing the experiential learning activities in direction of STEM education at primary schools; for example about the experiential activities in direction of STEM education at primary schools,…
Development of STEM education learning unit in context of Vietnam Tan Cuong Tea village
Authors: Tinh Phan Thi , Duc Nguyen Mau , Yuenyong Chokchai , Kieu Nguyen Thi , Nguyen Tien-Trung
Published: April 2021

The paper will clarify STEM learning activities using team teaching approach by the Physics, Chemistry, and Biology through Sutaphan nad Yuenyong [11] context based STEM education learning approach. The activity will be started by identification of social issues that science teacher raises the social issue about the tea production process in Tan Cuong, Thai Nguyen, Vietnam. The context may engage students to learn concept on heat transfer, chemical composition, ecosystem, and so on in order to practice among concepts in science, technology, engineering and mathematics. The decision making stage, lets the students decide on how they are going to make the required prototype for Physics, Chemistry and Biology aspect as possible solutions to the problem. The development of prototype or product stage, students are given enough time to create the Tea dryer machine, fertilizers or system of growing the tea plant, short flim for advertising the Tan Cuong tea village STEM education tourist place. Test and evaluation of the solution stage, students will apply their knowledge related to their prototype or product for test and evaluation of the solution. The socialization and completion decision stage, the students? will have an exhibit of their output. The paper will discuss how to provide students chance to applying STEM knowledge through these activities.
Practical investigating of STEM teaching competence of pre -service chemistry teachers in Vietnam
Authors: Trang Nguyen Thi Thuy , Oanh Dang Thi , Binh Pham Thi , Ninh Tran Trung , Anh Mai The Hung , Dung Le Van , Duc Nguyen Mau
Published: April 2021

The Vietnam’s new general education curriculum is transferring from content orientation to students’ capacity and quality development orientation. STEM (is acronym words of Science, Technology, Engineering, and Mathematics) education contributes to the development of 21st century skills of students. In order to successfully implement STEM education, in addition to leaders, managers and programmers, teachers have an important role in directly building and organizing STEM education. And pre-service teachers need to be trained to deal with complexities of education. The purpose of this research is to assess the pre-service chemistry teachers? existing STEM teaching capacity in Vietnam. Research method was survey through a set of unstructured and structured questions, and participants of this research are 57 pre-service chemistry teachers (who are 3rd and 4th grade learners of 5 Universities of Education representing all three regions of Vietnam). Content analysis was used to analyze the data from unstructured questions while the data from structured questions were transformed into frequency, percentage and descriptive statistic analyze. The findings indicated that most of participants have conceptualized the aspects of STEM in accordance with a number of researches in the world. However, they were less capable in designing their teaching STEM and performing teaching STEM in the classroom, beside assessment abilities were not good and lack diversity. They also suggested that there should be a specific guide material on how to design and conduct STEM teaching. Therefore, the study also suggested measures to develop STEM teaching competences for pre - service chemistry teachers in Vietnam: 1) redesign the teacher training program to include STEM educational modules, 2) provide STEM teaching instruction modules from STEM fields in Chemistry, and 3) combine Blended Learning approach to enhance their ICT ability.
Status and solutions of STEM intergrated teaching competence of the natural science teaching staffs at secondary schools in central coast and central highlands regions of Vietnam
Authors: Duyen Em Vo Van
Published: April 2021

Integrated teaching is one of the main orientations in changing the general education curriculum at secondary schools in Vietnam. STEM education which is responsible for providing skills for the 21th century students, is also a abilities to meet the demand of the modern society. Add, STEM education is tasked with early detection, stimulating interest and educating the younger generation in competencies in the fields of mathematics, sciences, engineering, technology and informatics in order to prepare human resources to meet the requirements of socio-economic development. However, in the reality, STEM intergrated teaching competence of the natural science teaching staffs at secondary school are a worrying problem. The writing mentions to the status of STEM intergrated teaching competence of natural science teachers in secondary schools at Central Coast and Central Highlands regions of Vietnam and solution of their teaching competence improvement.
The application of web-3d and augmented reality in e-learning to improve the effectiveness of arts teaching in Vietnam
Authors: Son Nguyen Duc
Published: April 2021

Nowadays, the development of information technology in the context of industrial revolution 4.0 has quickly transformed Vietnamese education in general and arts education in particular. Moreover, the process of globalization raises many forms of non-traditional education. E-learning is one of the non-traditional education form that has the ability to bring knowledge across space, time and borders to all over the world. In the context of the industrial revolution 4.0, e-learning is also constantly developing to meet the practical society needs. The paper not only shows e-lecturer roles but also discusses e-learning development in art teaching by applying web-3D technology and augmented reality in innovating art teaching and learning methods in Vietnam. The paper uses interdisciplinary approaching method such as: education, arts, science and technology… Thereby, the article is going to propose solutions to improve the effectiveness of art teaching in Vietnam by implementation e-learning using web-3D and augmented reality in Vietnamese universities.
Utilization of ICT-integrated STEM lessons on biodiversity for grade 8 learners
Authors: Salic-Hairulla Monera A.
Published: April 2021

The purpose of this study is to determine the effect of the utilization of an ICT-integrated STEM lessons on biodiversity for grade 8 learners. The study used the quasi-experimental design. There were eighty (80) participants that were match sampled in terms of their average grades in Grade 8. The experimental group which composed of forty (40) participants were exposed to the developed technology based instructional material (TBIM) while another forty (40) participants were exposed to the traditional method of teaching (TMOT). Both the control group (TMOT) and the experimental group (TBIM) pretest scores lies to the Beginning (B) level of understanding. In the post-test, the experimental group scores results to Advance (A) level of understanding while the control group has a Proficient (P) level of understanding. The p-value of the control group, 0.019, is closer to the boundary (0.05) while the p-value of the experimental group, 0.000, was very far from it. This infers that the experimental group had recorded a higher difference than the control group. Thus, the utilization of an ICT-integrated STEM lessons on biodiversity for grade 8 learners were found to be effective in enhancing conceptual knowledge of the participants.
The use of elearning tools in blended learning approach on students’ engagement and performance
Authors: Etom R , Pabatang Jr. O , Dapanas KMM , Consolacion R , Iniego JM , Jumao-as AM , Pabua AM , Tee KC
Published: April 2021

Industry 4.0 offers new opportunities in teaching and learning with the emergence of new ideas and technology. Face-to-face instruction becomes an obsolete method and does not cater to the needs of millennial learners. Distance learning is not widely adopted by schools in third world countries. Thus, school policies, facilities, and teacher is not yet ready to adapt full online learning instruction. However, Blended learning mediates the transition of face-to-face and online learning approach. This study examines the 180 senior high school students in Science, Technology, Engineering and Mathematics Strand on their perception on the use of eLearning tools and the impact of blended learning on their learning process. This study used the descriptive correlational design using a questionnaire in gathering data. Results show that respondents preferred the blended learning approach for its flexibility in accessing content online and highly adept in using digital devices. The use of eLearning tools is highly engaging and efficient; however, blended learning model has a moderate impact on students’ performance in doing activities online.
Development of the analytic geometry flipped classroom teaching model through Google Classroom
Authors: Suanse Ketsaraporn , Yuenyong Chokchai
Published: April 2021

The paper clarified the development of the analytic geometry flipped classroom teaching model through Google Classroom. The model of teaching was developed based on the significant definition of flipped classroom that reverses the traditional teaching method. The flipped classroom was known as the active learning that provided lecture before the classroom via video recorded or online and then face-to-face teacher guiding for practicing, doing projects, or problem solving in classroom. The flipped classroom, therefore, probably allow students to learn productively active learning about mathematics (e.g. analytic geometry) with teacher in classroom. And, the open online instructional platform Google Classroom could be used by all teachers to provide the online lecture before practicing, doing projects, or problem solving in classroom. The paper clarified the development of the analytic geometry flipped classroom teaching model through Google Classroom regarding on 5 strategies of effective flipped classroom including plan, introduce concepts in class, use math apps, video, and student teaching. Then, the paper explained more details of the analytic geometry flipped classroom learning activities. The paper may have implications for developing mathematics active learning via the flipped classroom.
Developing science learning activities using online gamification
Authors: Teemueangsa Sanit , Jedaman Pornchai
Published: April 2021

The developing science learning activities using online gamification is a method of teachers instructional to students for effectiveness learning. This become a documentary study and interview with the key informant of science teachers to collection data for analyzed factors and learning strategies. Five key factors included gamification, collaborative learning, scaffolding learning, assessment, and learning resources. And, learning strategies of 5th steps include activation, arrangement, adventure, approval, and assertion.
Meta-analysis of STEM Education approach effected on students’ learning achievement in Thailand
Authors: Lueangsuwan T , Srikoon S
Published: April 2021

STEM Education is an area of study that intergrates the four principles of science, technology, engineering, and mathematics through coherent and active teaching and learning approaches which base on problem-based learning in the real-world. Thus, the purpose of this study is to synthesize the research on STEM Education Approach effected on students’ learning achievement in Thailand. There are two sets of variables. The first set is the description of research and the second set is the effect size of research. Data collection and analysis tools are the recording data form for research synthesis, frequency, percentage and meta-analysis. The results showed that (1) description of researches dated by 2009-2019, STEM Education research was mostly published in 2017 (68.18%), Rajabhat Mahasarakham University often produced STEM Education research (59.09%), Sciences Education major usually produced the STEM Education research (68.18%), researchers from the Office of the Basic Education Commission commonly produced the research (72.72%), most of the researchers were female (72.72%), common research objectives found was to compare (35.19%), research design most found was One group pretest-posttest design (77.27%), frequent sampling method found was purposive sampling (59.09%), sampling level of research was upper secondary school (68.18%) and analyzing method largely found was descriptive analysis (48.89%). (2) the effect size (d) from STEM Education on Learning Achievement = 0.445 which means STEM Education can affect the scores of the experimental group more than the control group.
Research synthesis of STEM Education effected on science process skills in Thailand
Authors: Apaivatin R , Srikoon S , Mungngam P
Published: April 2021

STEM stands for Science, Technology, Engineering and Mathematics integrated to be an educational management approach. It also enhances students’ thirteen science process skills including observing, classifying, measuring, using numbers, using space/time relationship, inferring, predicting, communicating, identifying and controlling variables, defining variables operationally, formulating hypotheses, experimenting, interpreting data and drawing conclusion. These are divided into two groups: basic process skills consisting of the first eight processes and integrated process skills consisting of the last five processes. Nowadays, there are plenty of studies concerning the STEM Education effected on students’ science achievements in Thailand but not many focusing on science process skills. Therefore, the objective of this research is to synthesize the STEM Education effected on Thai students’ science process skills. The variables consist of two sets which are the description of research, and the effect sizes of research. The tool for collecting data is the recording data form for research synthesis. Data were analysed by frequency, percentage and meta-analysis. The results showed that 1) the description of research found that from 2010 until 2019 research referring to students’ science process skills on STEM Education published ten reports, mostly in 2016 and 2018 (40%), Maha Sarakham University and Rajabhat Maha Sarakham University equally usually produced the research referring to the students’ science process skills on STEM Education (30%), most researchers from the Office of the Basic Education Organization produced the research (90%), most were female researchers (80%), the research type was thesis in master degree (100%), the objective commonly found was to compare (44%), most of the research design found was in experimental design using One Group Pretest - Posttest Design (80%), always found sampling methods using cluster random samplings (50%), sample found mainly was students (100%), samples’ research level was equally both lower and upper secondary (50%),used largely in science (50%) and repeated analyzing method found was descriptive statistics (27.02%), and most of the science process skills were integrated skills (60%). 2) The effect sizes (d) of STEM Education effected on students’ science process skills was 1.69. The Standard Deviation (Sd) was 1.99. This means that the STEM Education can influence students’ science process skills.
Validation of a design thinking mindset questionnaire with Thai elementary teachers
Authors: Ladachart Luecha , Ladachart Ladapa , Phothong Wilawan , Suaklay Narissara
Published: April 2021

Due to a recent educational reform in Thailand, elementary teachers are challenged to use an engineering design process as an instructional approach to STEM education. This would require them to have a design thinking mindset (DTM) as a basic requirement. However, it has been argued that it is difficult to measure DTM using a questionnaire. Therefore, there has been little information if Thai elementary teachers possess DTM. This study aimed to develop and validate a Thai version of DTM questionnaire with two groups of Thai elementary teachers (N=138). Successively determinding Cronbach’s alpha values with each group of the teachers, six components of DTM were suggested. These components included (1) Being comfortable with problems, (2) User empathy, (3) Mindfulness of the process, (4) Collaborative working with diversity, (5) Orientation to learning, and (6) Creative confidence. While this result may need to be comfirmed with a larger population of teachers, a Thai version of the questionnaire can be potentially used to explore Thai elementary teachers’ DTM in other contexts.
Capacity Building in Teaching Mathematics through Problem Solving
Authors: Buan Amelia T. , Medina Joneil B. , Liwanag Grace P.
Published: April 2021

Drawing from the national evaluation of the DOST-SEI’s project STAR, this paper presents the case of the Northern Mindanao. Teaching Mathematics through Problem Solving (TMPS), interdisciplinary contextualization, and Lesson Study are the main training content of the project STAR. A good mixture of theory presentation, demonstration, practice, feedbacking and coaching compose the typical training design of the project. This evaluation study revealed that the training from 2014-2017 have applied the training content in different settings, mostly in the classroom and among small group of teachers The participants’ teaching practice are impacted by the training evidenced by the change of their beliefs, attitudes and roles in the classroom Teacher participants also claimed to have gained professional skills as they continue on their implementation but have also encountered various challenges such as the lack of monitoring and feedback. Form the insights on student interviews and class observations, there are evidences that students indeed benefitted from the teachers’ implementation of the training content. Recommendations based from the results are also discussed..
Raising environmental awareness through local-based environmental education in STEM lessons
Authors: Tadena Maria Theresa G. , Salic-Hairulla Monera A.
Published: April 2021

Republic Act 9512 mandates the promotion of environmental awareness through and by integrating environmental education in both public and private schools. Seeing STEM education in new light that seeks in helping learners use the local environment as a vehicle for developing understanding various environmental issues. Providing adequate STEM and environmental education will make everyone appreciate their relationship with the environment which lead toenvironmental awareness and in developing a sustainable future. This study aimed to develop Local-Based Lessons on Environmental Education through integrationto STEM lessons to raise environmental awareness among grade 8 learners. The study employed Quasi-experimental qualitatively supported with two-group pre-test-post-test design to examine the effectiveness of the Developed Local-Based Lessons on Environmental Education. T-test analysis between post-test scores of the control and experimental groups revealed to be significantly different at t (75.108) = -17.595, p=0.000 with the experimental group (M=24.49,SD=4.98) scoring higher than control group (M=8.99, SD=3.20). Similar result was found between the two groups gain score at: control and experimental, t(56.207) = -19.408, p(0.000)<.05, two-tailed with the experimental group gaining score higher than the control group. This implies that the Developed Local-Based Lessons on Environmental Education integrated to STEM lessons has increased the environmental awareness of the learners.
Comparison of active learning models (ALM) on the achievement and retention of teaching mathematics
Authors: Dapin Ana Mae S. , Buan Amelia T. , Mendoza Josie Vic
Published: April 2021

Mathematics education can be daunting for students — due to a variety of societal factors and abilities in mathematics that are often seen as fixed. Teachers expressed that student – centered approaches promote active learning in the classroom. Active learning requires students to do meaningful learning activities and think about what they are doing. This study sought to find out the comparison of three active learning models (ALM) in relation to the achievement and retention in mathematics among Grade 11 students. This study was conducted in one of the private schools in Cagayan de Oro City during the first semester of 2018-2019 among 84 students under Science, Technology Engineering and Mathematics (STEM) strand. The results of the study revealed that the respondents from each model had significantly increased results of their achievement scores within the two weeks implementation. Furthermore, the three models had the same effect in terms of retention of mathematics concepts. During the focus group discussion students expressed that clear directions and giving feedback on their work helped them solve the problem. In addition, they also conveyed that listening to peers ideas motivated them to be successful in solving a problem.
Analyze confirmatory factors of science and mathematics professional characteristics teacher in Thailand
Authors: Kalam Saengchan , Wijakkanalan Santi , Kuroda Ariyabhorn
Published: April 2021

The study aimed to study factor of professional teachers teaching Science and Mathematics in Thailand through the second-order confirmatory factor analysis. The samples were 132 Science and Mathematics teachers during 2019 academic year in Thailand. They were selected by using the Multi-stage random sampling. Research instrument included 86 items of the questionnaire asking professional teacher’s characteristic, the 5 Level Rating Scale with reliability of total issue = 0.943. Data were analysed by using the second-order confirmatory factor analysis. The findings were as follows: The second-order confirmatory factor analysis model regarding to characteristics of professional teachers in Science and Mathematics in Thailand, was fit and congruent the empirical data. (%2
= 83.490, df = 64, p-value = 0.0514, CFI = 0.989, TLI = 0.981, RMSEA = 0.048, SRMR = 0.049, and x
2 / df = 1.304 )Every factor and indicator in the model, was significant and supportive with each other.
Science educational management of “SIAOE model” for sustainability the quality improving a Thai’s Basic education, Thailand
Authors: Mungchu Adisak , Teemueangsa Sanit , Jedaman Pornchai
Published: April 2021

Framework of education in Thailand 4.0 on policies as six qualities of teachers and ten focus points of the spatial support performance and management that leads to concrete action. Administration of education relates to the development of educational quality. This study aimed to analyzed the factors of educational management of “S IAOE model” for sustainability the quality improving Thai’s basic education and to confirmatory factor analysis associated with factors of educational management of “SIAOE model”. The collection, first to involved synthesizing documentary and interview questionnaire with 30 directors and 50 teachers to study for the factors of educational management of “SIAOE model”, second to survey by questionnaire with 1,200 sampling were the directors and teachers to study the levels of the factors of educational management of “SIAOE model”, third to confirmatory factor analysis (CFA) of educational management of “SIAOE model” in the data. The study revealed that the factors of educational management of “SIAOE model” in 5th factors including sufficiency economy, involvement, achievement organization, effectiveness, and the CFA showed that 5th factors the composition of all the variables are statistically significant at a level of .01
Awareness of education university’s preschool students about the impact of 4.0 industrial revolution in education and role of STEM education in teaching
Authors: Hanh Hoang Thi My , Khue Hoang Thi , Hai Do Manh , Hoi Dinh Duc
Published: April 2021

The article talks about the awareness of preschool students about the impact of the 4.0 industrial revolution in education. Research results show that: Most of the students in the University and College of Education are aware of the importance and impacts of the 4.0 industrial revolution in education in general and in the changes of goals, contents, methods, and forms from the impact of 4.0 industrial revolution. However, there still have been sparities between students of Universities and Colleges of Education, which show that students at universities of education are better aware of the others at the College of Education. And, there are still some students who are not really aware of the changes in the goals, contents, methods and forms of education from the impacts of the 4.0 industrial revolution. However, STEM education also significantly affects the change of teaching methods, towards interdisciplinary teaching and development of learners skills through many experiential activities to adapt and integrate.
Effects of salinity on the respirometric activities of mixed culture bacteria from activated sludge process
Authors: Madmanang Romsan , Sriwiriyarat Tongchai
Published: April 2021

Salinity or saltiness is dissolved in water by the relative proportion of salt in a solution. All organisms have to keep their cells alive a water balance in their bodies. The activated sludge process (ASP) containing aerobic microorganisms located nearby the coastal area may be faced the problems of salinity from sea water. In this research, the effects of salinity on the respirometric activities of mixed culture bacteria from activated sludge process were evaluated at different levels of NaCl concentrations ranging between 0-25 g/L in the OxiTop system at the temperature of 20 °C. The oxygen uptake rate (OUR) was used to reveal the effects of salinity. The experiments results indicated that the OURs decreased as the NaCl concentrations increased, resulting in the failures of bacterial osmotic pressure systems and causing the lysis of bacteria. The COD and nitrification were failed because the nitrogen and COD loadings to the systems were increased by the lysis of bacteria.
Latex Factory Effluent Treatment Using Biomass Power Plant Fly Ash
Authors: Kaewmanee Jutamas
Published: April 2021

This research aims to study Latex Factory Effluent Treatment Using Biomass from power plant fly ash. The purpose of the study is to compare treated latex factory effluent using fly ash from power plant with that of industrial effluent standard issued by Thailand’s Pollution Control Department. The experiments used Coagulation as chemical treatment method. The experiments were carried out using fly ash with 0, 2, 3, 4, 5 and 6 grams dry weight. The agitation times were 10, 30, 45 and 60 minutes, respectively with the settling time of 30 minutes. The treated water was analysed for the following parameters: pH, turbidity, turbidity, sulfate and conductivity, respectively. The results shown that the best experimental set is Experiment 6, with 6 g fly ash, 60 minutes stirring time and settling time of 30 minutes. The treated turbidity value is 456 NTU COD equivalent to 28000 mg/L, the sulfate content is 23100 mg / L, conductivity is 19590 μs / cm, respectively. The pH value is 5.47 in the experiment 6 with the highest corrected pH possible in this study by adding 6 grams of fly ash with stirring time of 60 minutes. However, other parameters of treated effluent still not meet with industrial effluent standards. Further study and improvement are needed.
Watermelon Rind-Ponkan Marmalade: A Physico-chemical Analysis
Authors: Zabala Vanessa B. , Goles Charess E.
Published: April 2021

Today’s consumers are becoming health conscious and this has led to the demand of fruits and vegetable which wastes like the rinds, skins or peels from such are also produced. This study aimed to divert wastes into an innovative food product. Specifically it aimed to utilize watermelon rind and ponkan peelings into marmalade. A quantitative research method is used in the analysis of this study. Four treatments of marmalade were prepared and the most acceptable treatment was analyzed for physicochemical properties. Research results showed that the four treatments of marmalade are acceptable and do not have significant differences in terms of its characteristics and general acceptability. Among the four treatments, T 277 and 482 are the most acceptable with a computed value of 7.73 which means liked very much. The physicochemical analysis of T 277 results (pH-5.39, TA-0.360, WA- 26.66%, TSS-66.3%, Vit. C-below DL, Ash-0.53, Fat-0.85%) are more acceptable as compared with T 482 (pH-5.398, TA-0.354, WA-31.32%, TSS-56.4%, Vit. C-below DL, Ash- 0.71 Fat-0.36%). Furthermore, for the sample’s microbial load count, treatment 277 has lesser microbial load which is 70 and 60 CFU respectively while treatment 482 has 70 and 100 CFU in the two batches of samples which were analyzed. Thus in terms of physicochemical properties and microbial analysis, T 277 is more ideal. From the results of the study conducted, it is concluded that the acceptable ratio should be 2:1 that is 400 grams watermelon rind to 200 grams ponkan juice. Specifically, the measurement of ingredients is found to be within a good proportion for marmalade making. A techno-guide on Watermelon Rind Marmalade was then developed showcasing its physico-chemical properties, recipe and costs.
Dynamic Mechanical Properties of High Nitrogen Steel under Combined Loading
Authors: Yang Zizhen , Miao Cheng , Wu Hailing , Zhong Tao , Bai Lihong , Lu Ruijiao , Yuan Wei , Wu Xin
Published: April 2021

High speed collision is the main feature of armored service environment. It is very important for armor structure design to study the dynamic response of armor material under high strain rate loading. Based on Hopkinson bar techniques, dynamic performance experiments of high-nitrogen steel under combined loading were carried out in this paper. The stress-strain curves of high nitrogen steel under different loading conditions were obtained. The results show that with the increase of shear stress ratio, the anti-failure ability of high nitrogen steel decreases significantly. When the loading angle was 90° and 60°, the fracture surfaces and stress-strain curves of the samples were significantly different under the same loading conditions. With the decrease of the loading angle, the fracture surface and the stress-strain curve of the sample under the same loading condition tend to be the same. In the process of combined loading, with the reduction of the loading angle, the tensile force of the sample at the yield stage decreases gradually.
Investigation on the Damage Mode and Anti-penetration Performance of B4C/UHMWPE Composite Targets for Different Incident Velocities and Angles
Authors: Wang Hongfei , Wang Jinxiang , Tang Kui , Chen Xingwang , Li Yuanbo
Published: April 2021

To found out the effects of incident velocity and incident angle on the damage mode and anti-penetration performance of ceramic composite targets, and provide a certain basis for optimizing the structural design of ceramic composite armor. The penetration of 7.62 mm bullet into oblique boron carbide (B4C)/UHMWPE composite target was investigated by ballistic testing and numerical simulation. The effects of incident velocity and incident angle on the fragmentation degree of bullet and ceramic panel were analyzed, also the damage mode of bullet penetrating ceramic composite target was developed preliminarily to estimate the anti-penetration performance of ceramic composite targets. Based on the testing and simulation results, it was found that the fragmentation degree of bullet and ceramic panel increases gradually with the increase of incident velocity and incident angle, but the fragmentation degree of bullet and ceramic panel decreases obviously when the incident velocity exceeds the ballistic limit; the damage mode of UHMWPE laminate is mainly tensile failure when the bullet’s incident velocity is lower than the ballistic limit, and the increase of incident velocity or incident angle makes UHMWPE laminate more prone to shear failure and delamination failure. With the increase of incident angle, the ballistic limit of B4C/UHMWPE composite target increases significantly, the deflection angle of bullet increases similarly, and the optimal thickness ratio of ceramic panel and backplate tends to decrease with the increase of incident angle.
Analysis on Injury for Light Armored Vehicle Occupant by the After-effect Fragments of Rifle Projectile
Authors: Li Jinming , Yan Wenmin , Wang Shu , Lu Dabin , Mai Ruimin
Published: April 2021

Armor-piercing projectile is one of the main threats faced by light armored vehicles. The after-effect fragments formed by projectile penetrating armor will cause injuries to the occupants. It is an important reference for evaluating the impact of the armor-piercing projectile on light armored targets. The characteristics of after-effect fragments have a great influence on the lethal efficiency of internal occupants, especially those wearing bulletproof vests. In order to study the injury effect of the after-effect fragments on occupants, the 12.7 mm multifunctional bullet was tested to 10 mm armored steel to obtain the mass distribution of after-effect fragments at different speeds, and then a finite element model of the effect of after-effect fragments on the human thorax FEM with soft body armor was established. Through numerical simulation, the impact of different after-effect fragments of bullets was obtained. The stress changes, pressure changes and etc. of human model after the impact of different after-effect fragments were obtained that provides a basis for further evaluation of the injury effect of fragments on occupants in light armored vehicles.
Experimental Study on Ballistic Performance of Lateral Constraint Ceramic Structures
Authors: Wu Hailing , Zhang Shengjun , Cui Xinzhong , Li Daji , Zhong Tao , Miao Cheng , Wu Xin
Published: April 2021

Thermal Bush restraint technology was used to control the thickness of the restraint layer by applying the restraint layer on the ceramic lateral. Different thickness of circular SiC ceramic was confined lateral with steel Bush of 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm and 3.5 mm thickness according to the characteristics of thermal expansion and cold contraction of steel bushing, and lateral restraint of which was calculated. Ballistic resistance of lateral constraint ceramic structure was studied by firing 105 mm armor-piercing simulated projectile with 25 mm ballistic gun. And it turns out: the greater the lateral restraint on the ceramics, the smaller the penetration depth of the projectile into the after-effect target the higher the ballistic resistance of the target with increase of thickness of lateral restraint layer. In the design of armor structure, thickness of lateral restraint layer should be reduced as much as possible considering requirement of light weight under the condition of achieving the required ballistic performance to improve the overall ballistic performance of lateral restraint ceramic armor structure.
Simulation Study on the Performance of Kevlar Fibre Reinforced Composites Under the Penetration of Fragment
Authors: Li Shuhu , Wang Ronghui , Zhang Dashun , Du Juan , Xu Jingli , Zhang Haiyun , Liu Fangbiao
Published: April 2021

Aiming at the problem of Kevlar fibre reinforced composite target anti penetration of wedge-shaped fragment, the finite element models of Kevlar fibre reinforced composite targets with different thickness and the fragments are established. The simulation calculation of Kevlar fibre reinforced composite target against penetration of different velocity fragments is carried out. The anti-ballistic V50 of Kevlar fibre reinforced composite target with different thickness is obtained, and the damage failure mode of the Kevlar fibre reinforced composite target in the process of anti fragment penetration is analyzed, and the simulation results are verified by experiments. This simulation provides scientific basis and data support for the optimization design of composite structure armor and armor lining.
Research Progress of Numerical Simulation Method Based on the Protection Performance of STF-Kevlar Fabric Liquid Armor Composites
Authors: Li Shuhu , Xu Jingli , Zhang Jianqin , Wu Lianqi , Zhang Haiyun , Wei Huazhen , Wang Danyong , Chen Yiwei , Gao Yingying
Published: April 2021

In this paper, the numerical simulation method for the protection performance of liquid armor based on STF can be roughly summarized into two ways, containing the shell element simulation method based on the inter-yarns friction coefficient and the coupled Euler-Lagrangian simulation method. The shell element simulation method of inter-yarns friction coefficient has a single consideration for STF performance, but it has high calculation efficiency and low calculation cost. The coupled Euler-Lagrangian simulation method fully considers the shear thickening characteristics of STF, and comprehensively considers the characteristics of STF. The simulated performance gets closer to the actual situation, and it can also reveal the effect of STF in improving the protection performance.
Research on Penetration Performance of Tandem Damage Elements to Oblique Reactive Armor
Authors: Chang Bianhong , Yin Jianping , Zhang Yu , Shi Zhixing
Published: April 2021

In order to study the penetration performance of the tandem warhead against the oblique reactive armor target, ANSYS/LS-DYNA finite element simulation software was used to simulate the penetration process of the tandem warhead against the oblique reactive armor target when the front liner of the tandem warhead was made of different materials. The results show that when the front liner material is copper, the formed jet penetrates the reactive armor and will detonate it. The rear jet is greatly affected by the reactive armor, and the final penetration depth is 550 mm; when the front liner material is material is polytetrafluoroethylene (PTFE), the formed low-density jet penetrates the reactive armor and does not detonate it. The rear jet directly penetrates the main target plate along the low-density jet penetration hole, and the final penetration depth is 646 mm, compared with the tandem warhead As far as the front liner uses copper jet, the penetration depth is increased by 17.45%.
Study on Prediction Technique for Fragments of Counterattack Projectiles for Active Protection
Authors: Kang Zhenyu , Lv Juan , Yuan Shuqiang , Li Yazhe , Du Juan
Published: April 2021

This paper aims to predict the distribution of mass and number of natural fragments based on the Payman method and using the fragmentation similarity relation and the correction relation of geometric factors that influence fragmentation. The results showed that the prediction accuracy of the fragment mass and number distribution was up to over 90%. The shape, explosive, material and heat treatment process of a projectile can be optimized through simulation tests to realize the reasonable matching of the projectile material, explosive and structure, thus shortening the development cycle and providing reliable technical means for improving the power of fragmentation munitions in China.
Effects of Environment Temperature on The Attenuation of Quasi-Spherical EFP Velocity
Authors: Li Yue , Niu Shengjun , Shi Haicheng , Ji Xuesong , Hu Xuecen , Li Mingjian
Published: April 2021

A comparison of multiple quasi-spherical EFP warhead tests conducted during different seasons of the year revealed that EFP velocities in the cold season were low. In this paper, the experimental phenomenon is analyzed theoretically base on the principles of EFP and flight dynamics. Due to the difference of air density caused by the different temperature, the aerodynamic drag of EFP with the same aerodynamic shape and initial velocity is obviously different. Because of the hypervelocity of EFP, The impact velocity of EFP on target is also significantly affected after flying over 100 meters. In the paper, the flight velocities of a quasi-spherical EFP at different temperatures is calculated by MATLAB, which is in good agreement with the experimental results. It is necessary to consider the change of environment temperature in engineering practice of quasi-spherical EFP warhead in order to improve kinetic energy margin.
Experimental Research on Igniting the Aviation Kerosene by W-Zr Reactive Fragment
Authors: Liu Kai , Liu Guitao , Chen Min , Liang Dong , Wang Zhiwei , Ge Wenyan , Li Delin
Published: April 2021

Taking W-Zr reactive fragment as the research object, the influence of fragment density, shape and size parameters on the armor-piercing ignition fuel tank was studied through the simulated target test of 12.7mm ballistic gun launch. Combined with high-speed camera, the armor-piercing ignition behavior of the reactive fragment and ignition mechanism were revealed. The results show that the ignition fuel tank with low and medium density activity fragments has better effect, and the ignition speed of the fragments with high density decreases about 26%. The cube shape fragments have the best ignition performance, followed by cylindrical fragments and spherical fragments. The ignition ability of 7mm and 8mm fragments is equivalent, while the ignition ability of 8mm fragments is slightly stronger. The ability of W-Zr fragment to ignite aviation kerosene is closely related to the content of active components and the degree of breakage when it hits the target plate. Under the action of high-speed impact on the target plate, the fragments ware quickly broken into fragments with a certain flying Angle and high temperature combustion. Under the coupling action of the impact kinetic energy of the fragments and the chemical reaction heat, the critical ignition condition of fuel is reached, and the fuel tank is ignited.
Observation of Debris Clouds Generated by Hypervelocity Impact of Copper Jets with Thin Aluminum Plats
Authors: Jiao W J , Chang L H , Yuan J F , Su J J , Gan Y D , He H , Xiong C Z
Published: April 2021

With high kinetic energy and excellent penetration performance, metal jets have been widely used in the defence industry. When a thin plate is impacted by a metal jet with a velocity higher than 3 km/s, debris clouds will be generated at both sides of the plates. However, compared with the debris clouds generated by hypervelocity impact of projectiles, debris clouds generated by hypervelocity jets is rarely observed. In this paper, the utility of ultrahigh-speed simultaneous framing and streak photography technology is applied in the experiment of copper jets impact thin aluminum plates at hypervelocity. Debris clouds and front edges of shock waves are clearly observed and recognized after using newly developed technology to effectively restrain excessive exposure caused by intensive self-illumination in the experiment. From framing and streak pictures, the process of jets impact targets is comprehensively and completely recorded and the velocities of the jet and the debris cloud are obtained using the methods of data processing developed in present paper.
Photothermal effect of Copper Sulfide Nanoparticles in Skin Defects in mice
Authors: Gao Ying , Deng Feifan , Shan Xiaoqian
Published: April 2021

Photothermal therapy is a non-invasive or minimally invasive, controllable, and has with good antimicrobial efficiency, while the main thing about skin defects is the prevention of bacterial infection as well as rapid repair and healing. Compared with drug therapy, photothermal therapy has the advantages of convenience and no side effects. In this paper, we mainly synthesize a copper sulfide nanoparticle with photothermal effect and wrap it in biocompatible mesoporous silica to make it work to the maximum extent. We It can be concluded from the data obtained from the defect experiments in mice animals that the skin defects in the mice after irradiated with NIR light take took less time to repair and heal than those mice not irradiated with NIR, so it can be shown that Photothermal photothermal treatment plays an important role here.
High Order Semi-Implicit WCNS for 1D Isentropic and Full Euler Equations
Authors: Chen Xun , Zhang Xu , Jiang Yanqun
Published: April 2021

This paper designs a high order semi-implicit weighted compact nonlinear scheme (WCNS) to solve 1D isentropic and full Euler equations. The Euler equations are split into stiff and non-stiff terms that are solved by the implicit and explicit time discretization method, respectively, in order to improve the computational efficiency for low Mach flows. The fifth-order WCNS is applied for the spatial discretization. Several numerical examples are given to demonstrate the performance of the designed method.