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This study aims to analyze the analytical thinking skills of prospective teacher students in scientific learning of energy materials by applying a Research-Based Learning model (RBL). This study used a mixed method with a sequential explanatory design. The respondents selected through purposive sampling were 70 students, and 2 of them were for interview data. The research data was collected using a test instrument in the form of 10 essay questions and a non-test in the form of open interviews to students. The average pre-test score for the essay test was 45.71, the post-test score was 68.71, and the N-gain value was 42.37%. These results provide information about analytical thinking skills on energy concepts which are still in the moderate category, so alternative learning strategies are needed to improve the ability of prospective teachers in science learning. This research has recently developed five indicators of analytical thinking skills based on quantitative and qualitative studies on energy materials in science learning. Abstrak: Penelitian ini bertujuan untuk menganalisis keterampilan berpikir analitis mahasiswa calon guru dalam pembelajaran saintifik materi energi dengan menerapkan model pembelajaran berbasis penelitian (RBL). Penelitian ini menggunakan mixed method dengan desain sequential explanatory. Responden yang dipilih melalui purposive sampling sebanyak 70 siswa, dan 2 diantaranya untuk data wawancara.. Data penelitian dikumpulkan dengan menggunakan instrumen tes berupa 10 soal essay dan non-test berupa wawancara terbuka kepada siswa. Rata-rata nilai pretest tes esai adalah 45,71, nilai posttest 68,71, dan nilai N-gain 42,37%. Hasil tersebut memberikan informasi tentang keterampilan berpikir analitis pada konsep energi yang masih dalam kategori sedang, sehingga diperlukan alternatif strategi pembelajaran untuk meningkatkan kemampuan calon guru dalam pembelajaran sains. Penelitian ini memiliki kebaruan mengembangkan lima indikator kemampuan berpikir analitis berdasarkan kajian kuantitatif dan kualitatif pada materi energi dalam pembelajaran IPA.

Analytical thinking skills are critical thinking skills and higher-order thinking skills that meet students’ demands in the 21st century. This study aims to analyze the student’s analytical thinking skills in the natural sciences, particularly in new and renewable energy. This study was a sequential explanatory design with quantitative and qualitative methods. Data was obtained from the interview, observation, and essay test to students of the Madrasah Ibtidaiyah Teacher Education Program Study at IAIN Surakarta (Indonesia) to determine a characteristic of the students’ analytical thinking skills. The results showed that the mean scores of the pre-test, post-test, and effect size were 54.34, 74.91, and 2.91, respectively. These results revealed that analytical thinking skills in the concept of new and renewable energy in the experimental group were higher than the control group. Innovative learning like PBL had a potential as the alternative method to increase the analytical thinking skills of student. These findings were expected to provide a general characteristic to lecturers and researchers on the students’ analytical thinking skills in higher education in the natural sciences, particularly in the concept of new and renewable energy by implementing the Problem Based Learning (PBL) model.

Abstract Molybdenum-based materials have been intensively investigated for high-performance gas sensor applications. Particularly, molybdenum oxides and dichalcogenides nanostructures have been widely examined due to their tunable structural and physicochemical properties that meet sensor requirements. These materials have good durability, are naturally abundant, low cost, and have facile preparation, allowing scalable fabrication to fulfill the growing demand of susceptible sensor devices. Significant advances have been made in recent decades to design and fabricate various molybdenum oxides- and dichalcogenides-based sensing materials, though it is still challenging to achieve high performances. Therefore, many experimental and theoretical investigations have been devoted to exploring suitable approaches which can significantly enhance their gas sensing properties. This review comprehensively examines recent advanced strategies to improve the nanostructured molybdenum-based material performance for detecting harmful pollutants, dangerous gases, or even exhaled breath monitoring. The summary and future challenges to advance their gas sensing performances will also be presented.

Cahaya matahari memiliki sifat polikromatik bila dibiaskan akan menghasilkan cahaya-cahaya monokromatik. Cahaya-cahaya monokromatik inilah yang ditangkap oleh klorofil dan digunakan dalam proses fotosintesis. Dalam suatu percobaan diketahui bahwa gelombang cahaya biru dan cahaya merah adalah yang paling efektif dalam melakukan proses fotosintesis. Kesimpulan: 1). Gelombang cahaya biru dan cahaya merah adalah yang paling efektif dalam melakukan proses fotosintesis. Cahaya merah mempunyai energi foton 1.65-2.00 eV, sedangkan cahaya biru mempunyai energi foton 2.5-2.75 eV. 2). Pada fotosintesis terdapat dua reaksi yaitu reaksi terang dan reaksi gelap. Reaksi terang terjadi Pemecahan air (H2O) menjadi ion Hidrogen (H+) dan molekul air menggunakan energi cahaya, menghasikan O2, ATP, dan NADP H2. Reaksi gelap terjadi pengikatan karbondioksida (CO2) dan mengkombinasikannya dengan ion hidrogen (H+) sehingga membentuk gula. 3). Dalam fotosintesis berlaku hukum kekekalan energi yaitu Energi radiasi sinar matahari ditangkap oleh klorofil kemudian diubah menjadi energy kimia melalui proses fotosintesis. Dalam hal ini tidak ada energi yang musnah. Energy kimia tersebut digunakan untuk mensintesis CO2 dan H2O menjadi glukosa dan senyawa kompleks lainnya yang tersimpan dalam bentuk senyawa karbohidrat. Sunlight has polychromatic properties when refracted will produce monochromatic light. This monochromatic light is captured by chlorophyll and used in the process of photosynthesis. In an experiment it was found that blue light and red light are the most effective in carrying out photosynthesis. Conclusion: 1). Blue light and red light are the most effective in carrying out photosynthesis. Red light has a photon energy of 1.65-2.00 eV, while blue light has a photon energy of 2.5-2.75 eV. 2). There are two reactions in photosynthesis, namely the light reaction and the dark reaction. The light reaction occurs The splitting of water (H2O) into Hydrogen ions (H+) and water molecules using light energy, producing O2, ATP, and NADP H2. The dark reaction occurs when carbon dioxide (CO2) is bound and combines with hydrogen ions (H+) to form sugars. 3). In photosynthesis, the law of conservation of energy applies, namely the energy of solar radiation captured by chlorophyll and then converted into chemical energy through the process of photosynthesis. In this case no energy is lost. The chemical energy is used to synthesize CO2 and H2O into glucose and other complex compounds that are stored in the form of carbohydrate compounds.

Due to its harmful nature, carbon monoxide (CO) should be detected at low temperature and in a wide range of CO concentration. A sensor based on WO3–graphene nanocomposite synthesized by the solvothermal method has been developed. Based on material characterizations, the synthesized monoclinical WO3 has a nanowire shape. The presence of graphene interestingly promoted the formation of the WO3 hexagonal structure as a minor phase in the composite. The gas sensor measurements were carried out at three different temperatures, 300 °C, 150 °C, and room temperature. It was found that at 300 °C, the composite with ratio WO3:graphene 2:1 or WG21 produces a 21.5 response value to 10 ppm of CO, which is higher than the other composites. The response and recovery times of WG21 are 16 and ∼4.4 min, respectively. The WG21 nanocomposite was also found to show a good sensitivity in the range concentration of 10–300 ppm.

In this work, wearable resistive gas sensors based on hybrid graphene/zinc oxide (ZnO) nanocomposites were fabricated on a flexible cotton fabric and employed to monitor odorless and colorless carbon monoxide (CO). Dip-coating and chemical bath deposition (CBD) was used to deposit the graphene layer and grow the ZnO nanorods, respectively. The films were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-Ray diffraction (XRD) to investigate their morphological structures, elemental composition, and crystal phase, respectively. Those characterizations were also confirming the growth of ZnO nanorods on the already-deposited graphene layer on fabrics. From the gas sensor measurements at room temperature, it was revealed that these graphene/ZnO nanocomposites were highly sensitive and selective towards CO gas at low concentration down to 10 ppm. The shortest response and recovery times of the sensors were measured to be 280 s and 45 s, respectively. Moreover, in comparison to bare graphene sensors, the surface modification by ZnO nanorods could obviously enhance the sensing response by up to 40% (i.e., doubled sensitivity). These flexible hybrid sensors are therefore expected to be a promising alternative for the existing rigid CO sensors in the market by offering unique nanostructures, low-cost fabrication, high flexibility, and good sensing performances.

Thermochemistry as one of sub-subject in chemistry subject which is taught in senior high school. This subject has considered as one of the most difficult subject to be learn by student. In understanding thermochemistry, students often experience misconception because this subject is containing abstract concept and requires representation at the macroscopic, submacroscopic, and symbolic levels. This study was intended to determine the level of student understanding of thermochemical subject after going through the teaching and learning process as an evaluation material for students and teachers. The used research method was descriptive quantitative using a three-tier multiple choice (TTMC) diagnostic test instrument. The subjects of this study were students of class IX IPA 1 Madrasah Aliyah Negri 1 East Lampung in the academic year 2019/2020 with a sample size of 33 students. The obtained results exhibited that student misconception toward the tested subject, including exothermic and endothermic reaction, thermochemistry equation, enthalpy changes, Hess Law, and bonding energy, were 90, 78, 45, 66, and 18%, respectively. The results of the analysis are expected to be an evaluation material for teachers to be able to convey thermochemical material more conceptually to improve student understanding.

Test of English as a foreign Language or TOEFL is a standardized test of English for non-native speaker. It consists of three parts or three sections of tests. In Reading Comprehension test, it consists of vocabulary test. To get better result of score, it needs strategies. The purposes of this study are to know the strategies used by the students to answer the vocabulary test on reading section of TOEFL, to know the most strategy used by the students, to know the least strategy used by the students and to know the distribution of strategies used by the students to answer the Vocabulary test of Reading Comprehension of the TOEFL. The researcher used descriptive qualitative research. The subject was twelve students. The instrument was questionnaire that consisted of thirty questions. Data analyzes technique was by using mean score. The result of the research showed that; (1) students used all strategies to answer the vocabulary test of reading comprehension of TOEFL. (2) the most strategies used by the students was ‘Looking for contextual clues to the meaning of unknown words.(3) the least strategy used by the students to answer vocabulary test was ‘Developing a new vocabulary study system, and (4) the distribution of the strategy number 1 was 3.88,strategy number 2 was 3.61, number 3 was 2.94, number four was 2.91, strategy number 5 was3.88, strategy number six was 3.47, strategy number seven was 3.69, strategy number eight was 3.02, strategy number nine was 3.00 and the last strategy was 3.13.

Based on documentation of pgmi mentioned that college students are derived from background science class is 36,98 % , less than 50 % of the student PGMI .This has led consequence that lecture believe in science ranging from the base and supported by the laboratory adequate .The laboratory adequate will build real kosep students in understand science.Steps analysis needs research laboratory PGMI in lecture ipa is as follows: 1) analysis of need assessment, 2) the literature study, 3) study komparasi , 4) expert judgment, 5) improvement. Based on analysis of the data can pull conclusions as follows: 1) The lab PGMI FITK IAIN Surakarta especially for science laboratory having 85 set equipment consisting of 737 the tools and can be used to 121 title science experiments. 2) Additional needs necessary the 25 set equipment science experiments, with details as follows: kit science less 24 set, consisting of the balance KIT 4 sets, mineral KIT 5 sets, Sound KIT 4 sets, coal KIT 6 sets, and heat engine KIT 5 sets, and science integrated KIT less 1 set, and 5 the microscopes.

Present-day science indicates that developing sensors with excellent sensitivity and selectivity for detecting early signs of diseases is highly desirable. Electrochemical sensors offer a method for detecting diseases that are simpler, faster, and more accurate than conventional laboratory analysis methods. Primarily, exploiting non-noble-metal nanomaterials with excellent conductivity and large surface area is still an area of active research due to its highly sensitive and selective catalysts for electrochemical detection in enzyme-free sensors. In this research, we successfully fabricate Metal-Organic Framework (MOF) FeBDC-derived Fe3O4 for non-enzymatic electrochemical detection of glucose. FeBDC synthesis was carried out using the solvothermal method. FeCl2.4H2O and Benzene-1,4-dicarboxylic acid (H2BDC) are used as precursors to form FeBDC. The materials were further characterized utilizing X-ray Powder Diffraction (XRD), Scanning Electron Microscopy (SEM), and Fourier-Transform Infrared Spectroscopy (FTIR). The resulting MOF yields good crystallinity and micro-rod like morphology. Electrochemical properties were tested using Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV) with a 0.1 M of Phosphate Buffer Saline (PBS pH 7.4) solution as the supporting electrolyte. The measurement results show the reduction and oxidation peaks in the CV curve of FeBDC, as well as Fe3O4. Pyrolysis of FeBDC to Fe3O4 increases the peak of oxidation and reduction currents. The Fe3O4 sample obtained has a sensitivity of 4.67 µA mM−1.cm−2, a linear range between 0.0 to 9.0 mM, and a glucose detection limit of 15.70 µM.

http://dx.doi.org/10.17014/ijog.vol2no3.20074The investigated area is a region prone to liquefaction hazards since it consists of loose, saturated Quaternary deposits. The Quaternary deposits were deposited in several sediment environments such as swamp, estuary, near shore, off shore, and fluvial (flood plain, flood basin and paleo channel). Among those Quaternary deposits, the paleo channel and estuary deposits which mainly consist of fine - to medium - sand have high susceptibility to liquefaction. An earthquake-source zone which is able to trigger earthquake and to cause liquefaction hazards is known to be thrust fault and subduction zones. Earthquakes produced by thrust fault activities are classified as shallow earthquakes while earthquakes produced by a subduction zone are deep earthquakes. The investigated area is divided into low liquefaction susceptibility, moderate susceptibility and high liquefaction susceptibility zones. This division has been made based on physical characteristic of the sand deposits, grain size, thickness of sand and its position to groundwater level as well as the physical character of overburden layer.

The adsorption characteristic of natural dye has been studied on harvesting light using purification process. The purification process used for separation pigment photosynthesis of syngonium leafs was called fractionation. The first fractionation of the dye contains pigment of β- carotene . The absorpton spectrum of β-carotene has been investigated by using Uv-Vis spectroscopy. The Fourier Transform Infrared revealed that the binding of the dye was on the surface of TiO2. Analysis absorbance and energy gap of the dye has been investigated by using Uv-Vis spectroscopy and Tauc relation. The cells were illuminated under 100 mW/cm2 AM 1.5 condition. The performance of the cells with sensitized the fractionation dye has a short circut current density (Jsc) of 0.27 mA/cm2, an open circuit photovoltage (Voc) of 0.4V, and Fill Factor (FF) of 68.89%. Furthermore, the overall efficiency of DSSC is 0.074%. The low efficiency for the fractionation cell based dye sensitized solar cells due to the weakness of interaction between dye molecule and the surface of TiO2.

This study aimed to analyze the Research-Based Learning (RBL) model implementation in the natural sciences in improving students' analytical thinking skills. This study employed a mixed-method with a sequential exploratory design. Data collection began with qualitative data and then continued with quantitative data. Qualitative data collection techniques used observation and interviews, while quantitative data collection used essay tests. Sampling was carried out before the research implementation. The samples were students of the PGMI IAIN Surakarta Study Program, Indonesia, which consisted of 34 pre-service elementary school teachers. The research was conducted in the odd semester of the 2019/2020 academic year. Quantitative data analysis techniques used a quasi-experimental design with one group pretest-posttest. Based on the results of four observations on the research treatments, the mean was 3.714, in which the values of preliminary activities were 3.625, core activities were 3.714, and closing activities were 3.75, used a rating scale (1-4) with the very good category. The RBL model implementation in the natural sciences in the concept of energy can improve the analytical thinking skills of students, as evidenced by the N-gain value was 56.57%in the medium category. This increase was obtained from the mean of the pretest score (46.84) and the post-test score (76.9), by using a rating scale (0-100). The research findings provide ideas to lecturers and researchers in improving the student's analytical thinking skills through the application of innovative learning models in the topic of the concept of energy.