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Teacher Upgrading Skill in Preparing Materials and Examination Based on Images in Sibolga City Andriayani Andriayani; Cut Fatimah Zuhra; Awan Maghfirah; Maulida Yanti; Saharman Gea; Khatarina Meldawati Pasaribu; Averrous Fazlurrahman Piliang
ABDIMAS TALENTA: Jurnal Pengabdian Kepada Masyarakat Vol. 5 No. 2 (2020): ABDIMAS TALENTA : Jurnal Pengabdian Kepada Masyarakat
Publisher : Talenta Publisher

There are 61 primary/ibtidaiyah schools, 18 junior high schools, and 18 senior high schools in the city of Sibolga, which is located in Teluk Tapian Nauli, with a total number of teachers of about 2000. This is in line with the vision of Sibolga city (2016-2021) in order to create a stable, advanced, and successful Sibolga City by producing highly competitive quality human beings in order to create a harmonious, peaceful, secure and unified society. As mentioned above, one of its mission points is to prepare human resources (HR) that have integrity, reliable, competitive, expert in science and technology so that they able to compete in the global job market. As the education stakeholder, Sibolga Education and Culture Official has plan many outstanding work programs such as made a collaboration in partnership with the Universitas Sumatera Utara community service team. As a result, based on field observations and discussions, it was known that one of the obstacle that facing by the teachers in Sibolga is not being able to provide teaching materials and also picture-based examination questions as contained in the question grid. Currently, there are several technology-driven applications that can be used to make images or graphics creating process easier. Two of them are, GeoGebra Classic that used to create graphics and images in mathematics and Chemdraw that used to create structure images that related to chemistry. In addition word optimization training was also conducted to optimize teacher on preparing teaching materials with Ms. word.

Enhancement Mechanical Properties of Simalambuo Wood (Loppophetalum spp) Delignified using NaOH in The Thermomechanical Densification Method Nur Azizah; Febri Sindika; Andriayani Andriayani; Saharman Gea
Jurnal Akademika Kimia Vol. 11 No. 4 (2022)
Publisher : Universitas Tadulako

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One of the problems with fast-growing wood is the low density, which causes poor mechanical properties, so a densification process is carried out to increase the wood's density, surface hardness, and strength. In this study, the delignification process using NaOH was carried out at variations of 12.24, and 48 hours and then continued with the thermomechanical densification process. This study decreased lignin content in delignification simalambuo wood from 30% to 4%. The value of the Modulus of Rupture, Modulus of elasticity, and surface hardness increases with increasing immersion time during the delignification process. The highest values of Modulus of Rupture, Modulus of elasticity, and surface hardness were obtained by simalambuo wood soaked for 48 hours, namely, 2828.23 kg/cm2, 97.47 kg/cm2, and 256.73 kg/cm2.

Synthesis of Fluorescent Carbon Dots from Soybean Residuals Using Hydrothermal Method Dinda G. Ayu; Saharman Gea; Andriayani Andriayani; Ronn Goei
Jurnal Akademika Kimia Vol. 12 No. 2 (2023)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2023.v12.i2.pp71-77

Soybean residuals are biowaste composed of carbon chains and amine groups bounded in peptide linkages. The component was identified through FTIR analysis which showed the vibration of the diamide bond (N=C=N) at wave number 2132cm-1. Owing to the existence of these components, soybean has the potential to be used as a precursor to synthesize carbon nano-material, such as Carbon Dots (C - Dots). In this study, the synthesis of C - Dots material from soybean residuals was carried out using the facile hydrothermal method at a temperature of 200 oC for 6 hours. Afterward, the as-synthesized C - Dots were analyzed for their optical property, structure, and morphology. Based on the analysis of the UV - Vis and photoluminescent spectra, C - Dots exhibited absorbance peaks of 292 nm and 301 nm in the UV light region, and fluorescence emission peaks of 468 nm, with blue luminescence characteristics. The observation was supported by the morphological analysis using the HR - TEM, C - Dots exist in a spherical shape with an average particle size of 3.467 nm and a lattice distance of 0.363 nm. Besides, the C - Dots exhibited a good quantum yield of 28.15 %. From the results of the analysis, it is known that the synthesis of C - Dots material has been successfully carried out with particle size < 10 nm.

Karakterisasi Silikon dari Sekam Padi Terdoping dengan Kobalt: Analisis Struktur dan Sifat Magnetoelektrik Kurniawan, Rizky; Andriayani, Andriayani; Gea, Saharman; Kurniawan, Hadi
Jurnal Ilmu Fisika Vol 16 No 2 (2024): September 2024
Publisher : Jurusan Fisika FMIPA Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jif.16.2.97-106.2024

The development of Si-based materials has attracted increasing attention, particularly for application in semiconductors, batteries, sensors, and optical technology. Silicon has abundant availability, high energy storage capacity, and low work potential. However, it faces compatibility challenges due to its low electrical conductivity and extremely small magnetic susceptibility. This research aimed to investigate the influence of Co dopants on the structure, morphology, electrical conductivity, and magnetic susceptibility of silicon. Silicon was synthesized using the magnesiothermic reduction method, and silicon was modified with Co metal dopants at 0.1% and 0.5% concentrations through the impregnation method. XRD analysis results showed that Si, 0.1% Co/Si, and 0.5% Co/Si exhibit silicon diffraction patterns at 2θ = 28.42º; 47.28º; 56.11º; 69.13º; and 76.36º. The morphology of Si and Co/Si revealed a rough, uneven, and porous surface with particles appearing spherical. Electrical conductivity increases with Co concentration: Si = 1223 µS/cm, 0.1% Co/Si= 1376 µS/cm, and 0.5% Co/Si= 1529 µS/cm. Magnetic susceptibility measurements indicated that Si, 0.1% Co/Si, and 0.5% Co/Si are paramagnetic at a range of 1.18 x10-6 to 1.25 x10-5 SI. These characterization results confirmed that the modification with Co dopants can enhance the magnetoelectric properties of silicon.

Functionalization Mesoporous Silica using Aminopropyltriethoxysilane (APTES) as Adsorbent for Removal Ni (II) from Aqueous Solution Hidayani, Ega; Andriayani, Andriayani; Taufik, Muhammad
JKPK (Jurnal Kimia dan Pendidikan Kimia) Vol 9, No 1 (2024): JKPK (Jurnal Kimia dan Pendidikan Kimia)
Publisher : Program Studi Pendidikan Kimia FKIP Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/jkpk.v9i1.85597

This study successfully synthesized mesoporous silica using the template methyl ester ricinoleate (MS-TMR) and further functionalized the MS-TMR surface with 3-aminopropyltriethoxysilane (APTES). The functionalization of MS-TMR with APTES was achieved through a 48-hour grafting method. For the adsorption experiments, 20 mg of both MS-TMR and MS-TMR-APTES adsorbents were employed to remove Ni(II) from aqueous solutions at a concentration of 30 mg/L and pH 6. The objective was to assess the adsorption capacity and to characterize the synthesized adsorbents. Characterization was conducted using Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD). FTIR analysis revealed that the MS-TMR adsorbent possessed silanol (Si-OH) and siloxane (Si-O-Si) groups. Conversely, the MS-TMR-APTES adsorbent exhibited additional amine (N-H) and C-H groups after the APTES grafting. XRD results indicated that both samples were amorphous. The concentration of Ni(II) ions was determined using Atomic Absorption Spectroscopy (AAS), which facilitated the calculation of removal percentages and adsorption capacities. MS-TMR achieved a mere 3.54% removal of Ni(II) ions, corresponding to an adsorption capacity of 3.21 mg/g. In contrast, MS-TMR-APTES demonstrated significantly enhanced performance, removing 54.23% of Ni(II) ions with an adsorption capacity of 48.81 mg/g. The findings suggest that APTES-functionalized MS-TMR has considerable potential for removing Ni(II) ions and could be explored further for the adsorption of other heavy metal ions.

Karakterisasi Silikon dari Sekam Padi Terdoping dengan Kobalt: Analisis Struktur dan Sifat Magnetoelektrik Rizky Kurniawan; Andriayani Andriayani; Saharman Gea; Hadi Kurniawan
Jurnal Ilmu Fisika Vol 16 No 2 (2024): September 2024
Publisher : Jurusan Fisika FMIPA Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jif.16.2.97-106.2024

The development of Si-based materials has attracted increasing attention, particularly for application in semiconductors, batteries, sensors, and optical technology. Silicon has abundant availability, high energy storage capacity, and low work potential. However, it faces compatibility challenges due to its low electrical conductivity and extremely small magnetic susceptibility. This research aimed to investigate the influence of Co dopants on the structure, morphology, electrical conductivity, and magnetic susceptibility of silicon. Silicon was synthesized using the magnesiothermic reduction method, and silicon was modified with Co metal dopants at 0.1% and 0.5% concentrations through the impregnation method. XRD analysis results showed that Si, 0.1% Co/Si, and 0.5% Co/Si exhibit silicon diffraction patterns at 2θ = 28.42º; 47.28º; 56.11º; 69.13º; and 76.36º. The morphology of Si and Co/Si revealed a rough, uneven, and porous surface with particles appearing spherical. Electrical conductivity increases with Co concentration: Si = 1223 µS/cm, 0.1% Co/Si= 1376 µS/cm, and 0.5% Co/Si= 1529 µS/cm. Magnetic susceptibility measurements indicated that Si, 0.1% Co/Si, and 0.5% Co/Si are paramagnetic at a range of 1.18 x10-6 to 1.25 x10-5 SI. These characterization results confirmed that the modification with Co dopants can enhance the magnetoelectric properties of silicon.

Green Synthesis of Barium Doped Titanium Dioxide Using Palm Leaf Extract (Elaeis guineensis Jacq.) Andriayani, Andriayani; Hutapea, Henny Dumarta; Taufik, Muhammad
Journal of Chemical Natural Resources Vol. 7 No. 1 (2025): Journal of Chemical Natural Resources (JCNaR)
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jcnar.v7i1.20178

Conventional synthesis of titanium dioxide (TiO₂) nanoparticles often involves the use of toxic chemicals, high costs, and extreme operating conditions. This research aims to develop a cost-effective and environmentally friendly green synthesis method for TiO₂ by utilizing oil palm leaf (Elaeis guineensis Jacq.) extract as a reducing and stabilizing agent. Subsequently, doping with barium (Ba) was carried out to enhance the photocatalytic, optical, and electrical properties of the resulting TiO₂. Phytochemical analysis revealed that oil palm leaf extract contains alkaloids, flavonoids, terpenoids, saponins, and tannins, which play a role in the reduction and stabilization processes of TiO₂ nanoparticles. Characterization using Fourier Transform Infrared Spectroscopy (FTIR) identified Ti-O bonds in pure TiO₂ at a wavenumber of 588 cm⁻¹, and a shift in absorption peaks in the range of 548-595 cm⁻¹ in Ba-doped TiO₂ indicated the formation of the barium titanate phase. X-ray Diffraction (XRD) analysis showed that Ba doping increased the crystallite size of TiO₂ from 1.17 nm to 1.65 nm, which may have implications for photocatalytic applications.

Validation Method of 3,4-Methylenedioxymethamphetamine (MDMA) Analysis Using Gas Chromatography Mass Spectroscopy Taufik, Muhammad; Miranda, R.A. Fani; Andriayani, Andriayani
Journal of Chemical Natural Resources Vol. 7 No. 1 (2025): Journal of Chemical Natural Resources (JCNaR)
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jcnar.v7i1.21032

MDMA is known as a narcotic and stimulant is a drug that is often abused, both in pill and powder form. Therefore, it is important to have an accurate and sensitive analysis method to detect the presence of MDMA especially in urine samples of drug users. In this work, optimization of the GC-MS method was carried out to obtain the best separation conditions and the highest sensitivity using the GCMS instrument. This study aims to develop a validation method for the analysis of 3,4-methylenedioxymethamphetamine (MDMA) using the Gas Chromatography-Mass Spectrometry (GCMS) technique. The results of the analysis showed that the accuracy, precision, linearity, limit of detection, limit of quantification and selectivity were respectively: 97.53%, 3.66%, R² ≥ 0.99, LOD 0.7 ppm, LOQ 2.35 ppm, and Rs 19.83. The results of the study showed that this method has good accuracy with acceptable precision values and low enough LOD and LOQ to detect MDMA at appropriate concentrations. Thus, this validated GC-MS method can be effectively applied for the analysis of MDMA in various urine sample matrices, especially in the development of the field of analytical chemistry.

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