bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of dustfall pollution on chlorophyl content of polyalthea longifolia leaves
Authors: Asis S A , Suryani S , Assegaf A H 
Published: February 2021

Abstract
Dust has a size of 0.001 - 10000 µm. Dust from motor vehicle exhaust emissions generally has a size of 1 - 150 µm, and flying dust due to vehicle traffic has a size of 100 µm. This dust when it falls on the leaves will cover the stomata. The length of stomata is 80 µm and a maximum width of 50 µm, which is smaller than the size of the dust. As a result, the stomata will be covered by dust, and the leaves cannot absorb CO2, an important ingredient in photosynthesis. The leaf samples used in this study were Polyalthea Longifolia leaves located near the highway, around the cement factory, and in plantations as a control. Then, the leaves were measured for the content of total chlorophyll using the Wintermans and de Mots equation, and mineral content using X-ray Fluorencence (XRF). The results showed that the leaves around the cement factory had a yellow color, small, lower chlorophyll content, and had low absorptivity on minerals than the leaves from near the highway and control.
Effect of extraction method of the eel fish albumin levels of Anguilla marmorata (Q.) gaimard and Anguilla bicolor
Authors: Jamaluddin  , Hasnawati  , Yuyun Y , Pitriani  , Widodo A 
Published: February 2021

Abstract
This study aims to determine the effect of the extraction method based on the type and weight of the sample to the albumin levels, which can produce the highest albumin levels. The extraction method used is heating (hotplate) at heat temperature 60°C for 30 minutes using 0,1 M HCl solvent and steam (water bath) at heat temperature of 60°C (the sample temperature is 45°C) for 30 minutes with distilled water solvent. The weight of the sample used is 0,5 kg and 0,7 kg. Testing of the albumin levels using the Bromocresol green (BCG) method by photometer with a wavelength (λ) 546 nm. According to statistical data the highest albumin levels contained in the extraction of steaming water bath with a value of 0,156 g/100 g. Based on the type of eel, Anguilla marmorata (Q.) Gaimard with the highest albumin levels of 0,143g/100 g. The highest albumin levels of the Anguilla marmorata (Q.) Gaimard on the weight of 0,5 kg and 0,7 kg are 0,132 g/100 g and 0,153 g/100g.
The effect of learning realistic mathematics education (RME) Approach to improve students’ mathematical communication
Authors: Darto  
Published: February 2021

Abstract
Teaching and learning mathematics have predisposition to be conducted mechanically. Teacher prefers to teach algorithm directly, give examples, and then ask the students to finish the tasks similar to those illustrated by the teacher. The students solve a mathematical problem by memorizing without understanding. As a result, the students only master the simple mathematics concepts, but very weak in communication mathematics. This condition can be solved by implementing Realistic Mathematics Education (RME) approach. In the RME approach, there is no special teaching methods required, but from a risen variety of characteristics. This research concludes the learning approach Realistic Mathematics Education (RME) loaded with math activities (doing mathematics), investigation, discussion, and reflection. The research’s subject was 25 students at grade 6 SD Negeri 1 Kecamatan Bunga Raya Kabupaten Siak Riau, Indonesia. Data were collected through observations, interviews, checklist, and analyzing the students’ works .Learning Realistic Mathematics Education (RME) is not a teacher explaining, giving examples,and then the students imitate the example of the teacher, but requiring students to work in groups, investigate, experiment, discuss and share. Realistic Mathematics Education (RME) approach contributes not only to the cognitive development of students but also the affective and psychomotor of students.
Construction Scheme of Proof Based on Assimilation and Accommodation Processes: Theorem of Number Theory
Authors: Hamdani Deni , Subarinah Sri , Triutami Tabita Wahyu , Arjudin  , Sripatmi  
Published: February 2021

Abstract
Number theory is a branch of mathematics that deals with the properties of natural numbers, aimed at finding interesting and unexpected relationships of various types of numbers, then proving that the relationship is true. Problem solutions and proof theorems of number theory often require a strong mathematical background. Weak background, such as: giving examples only applies to definitions not to theorems and lemmas, understanding of the definitions and proven theorems, ways of looking at new theorems built on definitions, and previous theorems, and knowledge of when a definitions or lemma-theorems can be used; enough to affect the ability to solve the problem of number theory. So it is necessary to explore the possibility of other problems in the activity of constructing proof, which in this study uses the framework of the process of assimilation and accommodation, followed by interviews based on student responses. The results obtained are 3 groups of construction schemes, namely: 1) schemes using definitions and theorems, 2) schemes using theorems, and 3) schemes using definitions. Within the three groups there are variations of the problem found that the diantranya occurs is dis-equilibrium in the construction scheme group with theorems and definitions; and group construction schemes by definition only. His advice is to reflect on the ability to understand definitions, theorems and lemmas; and the development of lecture designs that can make the activity of constructing proof into routine activities.
Mathematical Problem-Solving Heuristics Used by Students in College Algebra Class
Authors: Desyarti Safarini TLS , Nurashari Regina , Lie Margaretha Weryana 
Published: February 2021

Abstract
This study is intended to describe heuristics are known and utilized by the first-year university students to solve mathematical problem-solving. Thirty participants were asked to solve two problems. We used the answer sheets to analyze students’ step by step solutions and conduct interview sessions with six selected participants to obtain more in-depth information. 66.67% of the participants were able to solve the first problem and most of them use equation. The other 20% of the participants were able to perform heuristic but fail to get the correct solution, and most of them also used equation heuristic. Some participants also used guess and check and act-it-out heuristic to solve problem 1. In contrast, only 36.67% of participants who were able to solve the second problem, and most of them used guess and check heuristic. About 33.33% of participants were able to perform heuristics but failed to find the correct solution. It was found that most of the participants tend to use heuristics that they had learned when they were in senior high school. They are lack of confidence to use other heuristics.
The need analysis of mathematics module based on problem-based learning to improve reasoning ability
Authors: Lestari Puji , Mardiyana  , Slamet I 
Published: February 2021

Abstract
This study aims to determine how students ‘needs for mathematics modules based on problem-based learning to improve students’ reasoning ability. The research method used is qualitative method. The subjects of this study were teachers and class VIII students in the junior high school even semester of the academic year 2019/2020 which contained 28 students of Junior High School 2 Jumapolo. The analysis was carried out in 3 stages, namely preliminary analysis, student analysis, material teaching analysis. Data collection using non-test methods using interviews and open questionnaires with 10 questions. The results of interviews with mathematics teachers in Junior High School 2 Jumapolo, it is known that students often experience difficulties in learning mathematics. The results of the open questionnaire showed that 82.15% of students stated that the development of mathematics modules based on problem-based learning was needed. The result of teaching materials showed that aspects manipulating mathematics, checking the validity of an argument, drawing conclusions are still not adequate, then for indicators make a conjecture and make generalizations there are still no match. The development of mathematics modules based on problem-based learning is needed to overcome the problem of textbooks that have not yet maximized reasoning ability.
Scaffolding as a strategy to help student difficulties in proving group problems
Authors: Warli  , Rahayu P , Cintamulya I 
Published: February 2021

Abstract
This study aims to describe the use of scaffolding as a teaching strategy in helping students difficulties in proving group problems. To achieve that goal, learning is done with scaffolding strategies on group topics. Then the problem proving test is given on a group topic, then the interview is based on the student’s proof answers. For this reason, this research is qualitative descriptive research. The subjects were students of Unirow Tuban Mathematics education who were taking Algebra Structure Courses. Scaffolding strategy design refers to the mapping of proof indicators, and the level of scaffolding developed by [1] explaining, reviewing and restructuring, and developing conceptual thinking, then associated with the scaffolding strategy developed by [2], including offering explanations, inviting student participation, verifying and clarifying student understanding, modeling desired behavior, and inviting students to contribute instructions. To explore the ability to prove, interview guidelines refer to indicators of construction proof. The results showed that the ability of students in the initial steps of proof, proof of flow, using related concepts, the argument of proof, and the language of proof had a very good increase. So the ability of students to prove after using a strategy to pursue scaffolding has increased. The implication of scaffolding as a strategy becomes an alternative teaching choice in abstract algebra subjects.
Forecasting dengue incidence in Bali by means latent Bayesian count data model
Authors: Chadidjah Anna , Jaya I G N M 
Published: February 2021

Abstract
Dengue disease is a viral infectious disease caused by DENV-1, DENV-2, DENV-3, and DENV-4. It does not only cause a public health problem. However, it may also cause social and economic conditions. Forecasting dengue incidence is a crucial part of an early warning system (EWS), which is needed in controlling and preventing dengue disease. Forecasting is a statistical tool used to obtain future information based on historical data. However, the models had been developed commonly applied for continuous data. It was very rare in modeling count data. We develop a model based on a Poisson log-linear model to accommodate count data. We use the Latent Bayesian approach to estimate the parameters model. We apply the model for forecasting dengue incidence in Bali. We used data from 2011 to 2016 to forecast the dengue incidences in periods 2017-2020. We found a Poisson model with Random Walk order one prior and Half Cauchy hyperprior distribution is the bet model for forecasting dengue incidence in Bali. We found the dengue incidence decrease from 2017 to 2020 where the highest incidence rates always occur from January to May. This condition is thought to be related to the rainfall period.
An Empirical Bayesian Model in Disease Mapping of TB in Regency Bandung
Authors: Marhamah Elin , Padmadisastra S , Suprijadi J 
Published: February 2021

Abstract
In this paper we proposed an Empirical Bayesian model in estimating the relative risk of people getting a Tuberculosis (TB) diseases in a small area.. Which is one of the top rank diseases causing death in Indonesia. It is considered that the proposed model will alleviate some of the draw back that exist in the Standardized Mortality Ratio (SMR) method in estimating relative risk. It is shown that the proposed EB method produce an estimate of the risk which is a weighting averegae of SMR and EB estimate. To give a complete insight into the paper, we give an illustration concerning the case of Tuberculosis (TB), which is still considered as a killer disease in Indonesia.
Applied of feed-forward neural network and facebook prophet model for train passengers forecasting
Authors: Pontoh Resa Septiani , Zahroh S , Nurahman H R , Aprillion R I , Ramdani A , Akmal D I 
Published: February 2021

Abstract
Train is public transportation that is widely used by people in Indonesia. Due to the high level of comfort at a low price relatively. Based on released data by PT KAI, the number of train passengers has increased in almost every holiday season, thereby, it is suspected that there are seasonal patterns with fixed and random periods. In 2013, the government issued a policy related to infrastructure development, then, it caused the number of passengers significantly increasing in the following year. Thus, we need a model that can accommodate these patterns to forecast the number of train passengers accurately. The use of neural network methods such as Feed Forward Neural Network (FFNN), nowadays, becomes popular in facing big data including unexpected fluctuation on the data. Additionally, recently, Facebook announced an accurate method of forecasting, called Prophet model, for data which have trend, seasonality, holidays, and missing data. Hence, the forecast for monthly train passengers on this research is modelled by FFNN and Facebook Prophet. The result shows that Prophet performs better than FFNN. However, the difference in the value of MAPE is not too large.
Design and fabrication of an E-whisker using a PVDF ring
Authors: Jiang Yani , Li Jialing , Wang Zhi , Qin Yongbin , Guo Guangming , Zheng Zaixiang , Bian Yixiang 
Published: February 2021

Abstract
Mammalian whiskers can perceive obstacles and airflows. In this study, an electronic whisker (E-whisker) sensor was designed and fabricated by setting a PVDF ring with symmetrical electrodes on the root of a fiber beam. Vibration displacements with different waveforms were applied at the free end of the E-whisker beam to study the relationship between the vibration displacements and the output signals. The E-whisker protrusion sensing ability was investigated by driving it to sweep through the surface of a base platform. A static E-whisker beam and a swinging E-whisker were then separately placed in a wind tunnel to detect the airflow perception of the sensor. The experimental results suggested that the E-whisker could sense the frequencies and amplitudes of displacements at its free end, the height and width of a platform or the heights of other irregular protrusions; the static E-whisker could sense the magnitude or direction of an impact airflow, while the swinging E-whisker could sense the magnitude of a constant airflow. Thus, this kind of E-whisker could perceive the environment and airflow through touch sensation and could be used as a physical model to study the principles and abilities of animal whiskers to perceive obstacles and airflows.
Mitigating sustainability tradeoffs as global fruit and vegetable systems expand to meet dietary recommendations
Authors: Stratton Anne Elise , Finley John W , Gustafson David I , Mitcham Elizabeth J , Myers Samuel S , Naylor Rosamond L , Otten Jennifer J , Palm Cheryl A 
Published: February 2021

Abstract
Recent analyses indicate that global fruit and vegetable (F&V) production will need to increase by 50%–150% by 2050 in order to achieve sustainable and healthy diets for 10 billion people. Although global production of F&V has grown by 50% during the last two decades alone, simply scaling up current systems of F&V production, supply chains, and consumption will inevitably worsen environmental and socioeconomic tradeoffs. This article examines three examples of important F&V—avocados, leafy greens, and tomatoes—to assess the global challenge of meeting dietary recommendations at affordable prices to consumers while sustaining producer livelihoods and minimizing environmental damage. These three cases highlight key characteristics of F&V systems that make the challenge of sustainable expansion especially difficult: knowledge-, input-, and labor-intensive production, high rates of food loss and waste, and low affordability to consumers relative to less nutrient-dense food groups. Our analysis shows that only by investing in innovations that increase diversity, integrate technology, and improve equity will truly sustainable expansion of F&V systems be possible.
Dominant contribution of nitrogen compounds in precipitation chemistry in the Lake Victoria catchment (East Africa)
Authors: Bakayoko Adama , Galy-Lacaux Corinne , Yoboué Véronique , Hickman Jonathan E , Roux Frank , Gardrat Eric , Julien Frédéric , Delon Claire 
Published: February 2021

Abstract
This work provides a complete chemical characterization of rains collected in the tropical rural site of Mbita (Kenya) on the shores of Lake Victoria (annual rainfall 1259.3 mm). We present a wet nitrogen deposition budget including inorganic and organic dissolved nitrogen in relation with atmospheric sources of gases and particles, precipitation rate and air mass transport. A unique 2 yr monitoring data set (2017–2019), providing 183 rain samples was collected and analyzed according to international standards (WMO/GAW). Considering that precipitation represents the largest contributor of water to the Lake Victoria (80%), this study gives new insights in the seasonality of nutrients wet deposition (WD) inputs in the unique natural resource represented by Lake Victoria and its catchment. Four main contributions to the chemical composition of precipitation, were identified: (a) a 28% terrigenous contribution related to crustal and biomass sources, (b) a 14% marine contribution related to Indian ocean air masses intrusion, (c) a 15% organic contribution due to volatile organic carbon emissions from biomass burning and vegetation and (d) a predominant nitrogenous contribution of 39% due to livestock and fertilizers, biomass burning and neighboring agricultural fires. Ammonium and nitrate volume weighed mean concentrations are 36.75 and 8.88 μeq l−1, respectively. Rain in Mbita is alkaline (pH = 5.8) highlighting neutralization by heterogeneous chemistry. Total nitrogen WD is 8.54 kgN ha−1 yr−1, 58 760 tN yr−1 for the entire lake, with 26% attributed to dissolved organic nitrogen. A total atmospheric deposition of 15 kgN ha−1 yr−1 is estimated taking into account dry deposition estimate from literature, showing that the Lake Victoria ecosystem is exposed to eutrophication. An extensive and regular monitoring of wet and dry nitrogen deposition is highly recommended both in-shore and off-shore to help improving the efficiency of nitrogen use in agricultural areas and reduce nitrogen losses around Lake Victoria.
Network analysis of the food–energy–water nexus in China’s Yangtze River Economic Belt from a synergetic perspective
Authors: An Rihui , Liu Pan , Cheng Lei , Yao Minglei , Li He , Wang Yibo 
Published: February 2021

Abstract
Economic development, resource scarcity and climate change pose enormous challenges to the food–energy–water (FEW) nexus, calling for integrative resources governance to improve the synergy between subsystems. However, it is unclear about the synergy evolution of the FEW nexus in temporal and spatial scales. This paper uses the network analysis to explore the FEW nexus in China’s Yangtze River Economic Belt. First, the comprehensive index system containing subsystems, order parameters and eigenvectors are determined in causal paths. Second, the synergetic network among order parameters is developed, and the centrality analysis is then conducted to identify the influencing factors. Third, the Bayesian network among eigenvectors is constructed to analyze the sensitivity of the dominant influencing factors. The results show that: (a) Energy subsystem has the highest centralities and dominates the FEW nexus. (b) From the perspective of time variability, the network centralization reaches the highest in 2007, but reaches the lowest in 2013, showing a downward trend, so we should adhere to the national strategy of synergetic development to realize the resource sustainability. (c) From the perspective of spatial sensitivity, upper reach (UR) is sensitive to food-related factors while lower reach (LR) is sensitive to energy-related factors. Therefore, the development of agriculture in upper UR should focus on protection, and the development of industry in LR should focus on remediation. The significance of the research is to construct a network analysis framework for better understanding the spatio-temporal variability of the FEW nexus in Yangtze River Economic Belt.
Fast classification of rice (Oryza sativa) cultivars based on fragrance and environmental origins by means of near infrared spectroscopy
Authors: Munawar A A , Sabaruddin Z 
Published: February 2021

Abstract
Presented paper aimed to investigate the application of near infrared spectroscopy as a fast and robust approach in distinguishing two different rice cultivars based on their fragrance character. Spectra data of rice samples were acquired and recorded in wavenumbers range of 4000-10 000 cm−1 with co-added of 32 scans and 4x optical gain. Further, multivariate analysis in form of principal component analysis (PCA) was employed to classify those samples based on near infrared optical properties. The result showed that both rice cultivars can be precisely clustered and discriminated with total explained variance of 100% using first two principal components (PC). The respective chemical parameters of these differences are fiber content, carbohydrates, amylose content and fragrance. The mentioned three parameters were vibrated strongly in wavenumbers 4260, 7512 and 7900 cm−1 for carbohydrates, amylose and fragrance, while for fiber content, it vibrated at 5183 cm−1 respectively. Based on obtained results, it may conclude that near infrared spectroscopy approach is able to classify and discriminate rice cultivars based on their fragrance by means of spectral optic properties in near infrared region.
Chemical contents and thermal stability of Madu bamboo (Gigantochloa albociliata) for natural-bonded fiber composites
Authors: Yusoff M S R , Bahari S A , Haliffuddin R M A A , Zakaria M N , Jamaluddin M A , Rashid N H M N 
Published: February 2021

AbstractThe objective of this study was to evaluate the chemical contents and thermal stability of young (3 years old or less) and matured (more than 5 years old) Madu Bamboo (Gigantochloa albociliata). The comprehensive knowledge of these properties will help to promote the uses of this bamboo’s fiber for natural-bonded composite products. The different age levels of bamboo can be an indicator in evaluating the significant difference of the chemical contents and thermal stability of bamboo. The chemical contents were determined in accordance to the standard outline in Technical Association of Pulp and Paper Industry (TAPPI) test method, while thermal stability was conducted in accordance to Shimadzu TGA 50 analyzer. The culm exhibited different chemical contents between young and old age, in which, young bamboo showed higher hot water extractives and ash contents compared to mature bamboo. On the other hand, matured bamboo contained higher alcohol-toluene extractives, holocellulose, a-cellulose and lignin than young ones. Hence, more resin and possible wood gum in matured bamboo that is beneficially in natural bonded composite product. The thermal analysis of extracted bamboo fiber indicated the thermal degradation behavior of both young and matured bamboo with the same species. The maximum temperature degradation of both young and matured bamboos was 413°C and 404°C. Therefore, matured bamboo was degraded at lower temperature compared to young bamboo, which indicates lower thermal stabilities. The result of this study reported that young bamboo ofG. albociliataspecies is acceptable to be harvested at young ages for reinforcement in natural bonded composite board, according to their thermal stabilities and chemical contents.