Abdul Wahidin Nuayi

1. Graphene growth on transition metal catalysts is governed by a complex interplay between carbon diffusion, surface energetics, and thermal history. Among commonly used catalysts, nickel (Ni) has...

This study synthesized multi-layer graphene on a glass substrate using the high-frequency plasma-enhanced vapor deposition method with a hot wire in plasma. In the growth process, plasma was generated from methane gas (CH₄) using an RF power generator at 70 MHz frequency and nickel (Ni) as the catalyst, which is deposited and annealed beforehand. This study aims as a preliminary to obtain optimum parameters for MLG growth using the HW IP-VHF-PECVD method. Raman spectroscopy, utilizing a 532 nm laser and an 1800 g/mm grating, detected distinctive D-band, G-band, and 2D-band peaks at wave numbers of 1335.31, 1607.74, and 2660.99 cm⁻¹, respectively, in unannealed catalyst samples. Raman analysis, incorporating the I_2D/I_G ratio, revealed the presence of multi-layer graphene exhibiting diverse ratios (0.07 – 0.22) and crystal sizes (15.62 – 20.70 nm). SEM analysis demonstrated enhanced homogeneity in grain size and uniformity in thickness following Ni catalyst annealing. EDS confirmed the successful growth of graphene with carbon identified as the primary element. The annealing process at 400 °C for two hours resulted in graphene with a higher mass percentage and a more significant percentage of carbon atoms. These findings underscore the potential of the HW IP-VHF-PECVD method for producing multi-layer graphene, particularly in the context of solar cell applications, with further optimization of parameters.

This KKN-Thematic Activity Program aims as an effort to improve health in the village of Dunggala especially during the Covid-19 pandemic to minimize / reduce and break the chain of spread of Covid-19. In the current pandemic, sufficient and good immunity is needed. Traditional medicine plays a role in maintaining the body's immunity. When compared to chemical drugs, folk remedies tend to be safer because the active substances in folk remedies are lower than those of chemical drugs. Therefore, the cultivation of medicinal plants is considered important. The method used in the KKN-Thematic program is the provision of examples of making live pharmacies and community development through socialization. This activity was held in Dunggala Village, Batudaa Subdistrict, Gorontalo Regency, and was integrated with Real Work Lecture (KKN), Research and Community Service Institute (LPPM) of Gorontalo State University (UNG) in 2021. This activity is supported directly by the Dunggala Village apparatus, led by the Dunggala Village Chief as a partner in this program.

This study is aimed at determining the piezoelectric configuration for generating electricity from wave power through the design of a prototype model named Cov-TOTal. The study was carried out in Tomini Bay, Lopo Village, Batudaa Pantai District, Gorontalo Regency, located at approximately ±50 meters from the shoreline, while the piezoelectric construction was arranged in parallel with varying numbers of 28, 70, and 90 pieces. The result showed that the amount of piezoelectric configuration affects the value of the voltage and electric current generated by the Cov-TOTal model. Furthermore, the average electric voltage values were 17.58, 20.76, and 29.85 volts, while the average current was 1.16, 1.73, and 2.01 mA for each piezoelectric amount. Therefore, the largest values of power and electrical energy for each piezoelectric are 16.65 mW and 0.56 joules, 31.82 mW and 1.20 joules, and 44.59 mW and 1.77 joules, respectively. This study concluded that the amount of piezoelectric configuration has a significant effect on the voltage, current, power, and electrical energy produced.

PENGARUH PENERAPAN MICROSOFT TEAMS TERHADAP KEMAMPUAN PEMECAHAN MASALAH SISWA DENGAN MENGGUNAKAN MODEL PEMBELAJARAN PROBLEM BASED LEARNING PADA MATERI GETARAN HARMONIS

This experiment aimed to measurenment of the electricity and dielectric characteristic of onion (Allium cepa). In this study, the onion have been done through the variation of frequency and temperature. The frequency was setup in 30 different values from 100 Hz -1 MHz with the temperature are from 26 0 C up to 40 0C with each increase of 2 0C. The measurement was performed on AC current in 1 kHz and input voltage is one volt. The ions through to the membrane was measured as a conductance value by using LCRmeter that connected with two pieces of AgCl electrodes on both side of the membrane. Beside that, the conductance (G) was measured by the variation temperature of the solution. The results based on the electric characteristics variation of the frequency shows that the electricity of the onion membrane from the conductance itself is tend to increase and the capacitance is decrease due to increasing of the frequency. However, the conductance and the capacitance of the soaked onion membrane is increase doe to increase of the temperature than the original onion membrane. In adddition, the increasing of conductance to temperature was plotted on ln G to 1/T curve. The slope or gradient of the curve is used to determine the change of the self-energy of the membrane and its pore radius. Self-energy of ion which obtained from non-washed and washed and soaked (with distilled water) membrane is respectively 7,66967 x 10-21 J or 0,04787 eV dan 1,2156 x 10-19 J or 0,7869 eV ( 1 joule = 6,2415 x 1018 eV) and the average of pore membrane radius is 2,00 x 10-9 meter (2,00 nm) and 1,26 10-10 meter (0,126 nm). Based on the results the onion membrane could be a good membrane for established the electrisity anf the dielectricity.

The research aims to determine the effect of using cooperative learning model type STAD on learning science to students’ performance in rational thinking skills and learning outcome. The point of view of this influence is seen from the presence or absence of improvement rational thinking skills activity of cognitive learning outcomes after treatment. The research used experimental method with the design One Shot Case Study and took place in SMPN 3 Gorontalo. The data obtained were students’ performance in rational thinking skill and learning outcome gathered by observation sheet of students’ activity and test sheet. The result show that increase in average score of students’ performance in rational thinking in the third meeting compared to the first meeting by indicators of information digging, information processing, problem solving, and conclusion formulating. The overall result shows that the students’ performance in rational thinking skills achieves good criteria; additionally, the students’ learning outcomes achieve average score of 83.81, categorized as B (good).Penelitian ini bertujuan melihat pengaruh penggunaan model kooperatif tipe STAD pada pembelajaran IPA terhadap kecakapan berfikir rasional dan hasil belajar kognitif siswa. Pengaruh ini dilihat dari ada atau tidaknya peningkatan aktivitas kecakapan berfikir rasional dan hasil belajar kognitif siswa setelah diberikan perlakuan. Penelitian ini menggunakan metode eksperimen dengan desain One Shot Case Study yang dilaksanakan di SMP Negeri 3 Gorontalo. Data yang diperoleh berupa aktivitas kecakapan berfikir rasional siswa dan hasil belajar kognitif yang dijaring dengan menggunakan lembar pengamatan aktivitas siswa dan lembar tes. Hasil yang diperoleh menunjukkan terjadi peningkatan rerata skor aktivitas siswa untuk kecakapan berfikir rasional pada pertemuan ketiga bila dibandingkan dengan pertemuan pertama untuk masing-masing indikator menggali informasi, mengolah informasi, memecahkan masalah dan membuat kesimpulan. Hasil penelitian secara keseluruhan menunjukkan perolehan dengan kriteria sangat baik untuk kecakapan berfikir rasional siswa, dan untuk hasil belajar kognitif siswa diperoleh rerata skor sebesar 83.81 dengan predikat B (baik).

This research aims to investigate clay silt reserve in brick farmer area. This research applies geoelectricity by using Schlumberger configuration conducted by doing injection of electric current with low frequency to surface of earth. Value of resistance will bring information about structure and materials across by it.Research site is in four stations and based on the geographical location in the station I at coordinate N 00 ° 35'43.7 ", E 123 ° 03'41.6" directed to east west, station 2 in coordinate N 00 ° 35'43.8 ", E 123 o 03'41.4 "directed to north south, station 3 in coordinate N 00 ° 35'42.4", E 123 ° 03'41.5 "directed to north south and station 4 in coordinate N 00 ° 35'45.4", E 123 ° 03 '42 .1 "directed to south north. Research finding reveals that depth or density of clay silt ie in S1 is 8 m, in S2 is 2.5 m, in S3 is 7 m while in S4 is 8,5 m. Density in S2 is the thinnest is the river thinnest gravel and sand are found there. Then, based on the four points after straight line is drawn, it shapes geometry which makes the volume of clay silt reserve can be calculated. And based on finding of measurement and calculation, it obtains volume of clay silt reserve in the village of Dulohupa for 15000 m3.