Article Per Year (5 Year)
p-Index From 2021 - 2026
5.393
P-Index
This Author published in this journals
All Journal Jurnal Pendidikan Kimia Indonesia Jurnal Matematika & Sains Jurnal Penelitian Pendidikan IPA (JPPIPA) Jurnal Akademika Kimia Jurnal SOLMA Indonesian Journal of Chemistry JMM (Jurnal Masyarakat Mandiri) Jurnal Ilmiah Kanderang Tingang Journal of Educational Chemistry (JEC) Patria : Jurnal Pengabdian Kepada Masyarakat Jurnal Riset Pendidikan MIPA Jurnal Abdimas Ilmiah Citra Bakti (JAICB) Mattawang: Jurnal Pengabdian Masyarakat JSEP (Journal of Science Education and Practice) Jurnal Akademika Kimia Jurnal Ilmu Pendidikan Indonesia JIPI (Jurnal IPA dan Pembelajaran IPA) Mitra Sains Jurnal Akademika Kimia Jurnal Pendidikan MIPA Jurnal Abdimas Ilmiah Citra Bakti
Daud Karel Walanda
Pendidikan Kimia FKIP Universitas Tadulako Palu Indonesi 94119
Agriculture, Biological Sciences & Forestry Arts Humanities Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Computer Science & IT Education Engineering Environmental Science Health Professions Languange, Linguistic, Communication & Media Law, Crime, Criminology & Criminal Justice Materials Science & Nanotechnology Mathematics Physics Public Health Social Sciences Other

Published : 73 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 73 Documents
Search

 4   5   6   7   8 
Extraction of Nickel from Morowali Laterite Ore with Hydrochloric Acid (HCl) I Komang Jati Purnawan; Daud K. Walanda; Mery Napitupulu
Jurnal Akademika Kimia Vol. 11 No. 3 (2022)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2022.v11.i3.pp134-139

Abstract

This study aims to determine the influence of temperature, leaching time, and the influence of hydrochloric acid concentration in the nickel extraction process, as well as to determine the optimum conditions of the laterite nickel extraction process using the Taguchi method which is influenced by hydrochloric acid concentration, temperature and leaching time. The laterite samples used came from the Bahodopi District, Morowali Regency, Central Sulawesi Province. Quantitative analysis using AAS (Atomic Absorption Spectrophotometer) with variables studied including acid concentrations of 0.5 M, 1 M, and 2 M, temperatures with levels of 30oC, 60oC, and 95oC, and leaching times of 3 hours, 6 hours, and 12 hours. The optimum conditions obtained from the results of the study were at a temperature of 95oC, a leaching time of 12 hours and a concentration of 2 M with the optimum absorbance obtained, namely 0.1635, the optimum concentration of 5.9693 mg /L with a percent of nickel recovery obtained of 1.41%.
Utilization of Hyperdocs in Online Learning Models on Student Learning Outcomes Hasmawati Hasmawati; Daud K. Walanda; Afadil Afadil; Kasmudin Mustapa; Detris Poba
Jurnal Akademika Kimia Vol. 11 No. 4 (2022)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2022.v11.i4.pp261-265

Abstract

This study aims to improve student learning outcomes through online learning models by utilizing hyperdocs on buffer solution material in class XI MAN 1 Palu City. This type of research uses a quasi-experiment with a pretest and posttest Group Design. Quantitative descriptive research with mixed methods and sampling by purposive sampling. The sample in this study were students of class XI MIPA 1 as the experimental class and XI MIPA 3 as the control class. The instrument used in this study was a learning achievement test totaling 16 multiple-choice question numbers. The research results were obtained from both classes, namely for the experimental class of 81.14 and the control class of 77.05. Learning outcomes were analyzed by testing the effect size for the experimental class, namely 1.2 (Very Large) and 1.0 (Large) for the control class. Based on the results of the study it can be concluded that the online learning model by utilizing hyperdocs in class XI MAN 1 Palu City students can improve student learning outcomes.
Pemanfaatan Hyperdocs Bagi Guru Dalam Merancang Project-Based Learning Walanda, Daud Karel; Napitupulu, Mery; Poba, Detris
Patria : Jurnal Pengabdian Kepada Masyarakat Vol 5, No 2: September 2023
Publisher : Universitas Katolik Soegijapranata

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24167/patria.v5i2.9819

Abstract

Ketika pembelajaran harus dilaksanakan dari rumah dan tidak dapat melakukan pembelajaran secara normal maka platform hyperdocs dapat digunakan untuk merancang lembar kerja yang transformatif dan interaktif. Fitur yang disedikan oleh hyperdocs sangat mendukung guru untuk merencanakan langkah-langkah belajar project-based learning namun tetap terorganisir. Tujuan pengabdian ini adalah untuk memberikan pelatihan kepada guru-guru SMA mengenai bagaimana cara merancang project-based learning dengan menggunakan hyperdocs. Pembelajaran berbasis proyek yang akan dirancang oleh guru-guru SMA diharapkan dapat menggantikan lembar kerja tugas manual. Hasil rancangan juga akan lebih menarik karena akan menumbuhkan kreativitas guru, serta menciptakan kolaboratif baru antara siswa. Subjek sasaran adalah guru SMA Labschool UNTAD Palu (n = 15). Metode pelaksanaannya diawali dengan melakukan observasi untuk mendapatkan informasi awal mengenai mitra. Selanjutnya, dilakukan pelatihan yang terdiri dari presentasi, bimbingan teknis, evaluasi, dan pengolahan data. Kuisioner (15 item) dan instrumen wawancara terbuka (6 item) yang telah divalidasi digunakan untuk mengetahui persepsi guru. Hasil pelatihan menunjukan respon positif guru terhadap materi, kegiatan dan manfaat dari pelatihan mengenai pemanfaatan HyperDocs dalam merancang project-based learning. Pengabdian ini memberikan manfaat bagi guru-guru dalam memanfaatkan platform hyperdocs untuk merancang instrumen yang dapat digunakan dalam pembelajaran.
Application Of The Problem Based Learning Model On Salt Hydrolysis Materials To Improve Science Process Skills And Metacognition Awareness Of Class XI MIPA Students At SMA Ismail, Ismail; Walanda, Daud K.; Ratman, Ratman
Jurnal Ilmiah Kanderang Tingang Vol 15 No 2 (2024): Jurnal Ilmiah Kanderang Tingang
Publisher : FKIP Universitas Palangka Raya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37304/jikt.v15i2.367

Abstract

This study aims to determine the effect of the problem-based learning model on science process skills and metacognitive awareness of class XI MIPA students at SMA Negeri 1 Dampal Selatan. This type of research is quasi-experimental by using the Pretest-Posttest control group design. The study population was (N = 129) students of class XI MIPA SMA Negeri 1 Dampal Selatan. The sampling technique is simple random sampling. Class XI MIPA 1 (n = 32) students as the experimental class and class XI MIPA 4 (n = 32) students as the control class. The research data was collected by using an essay test to measure science process skills and questionnaires to measure the metacognitive awareness of students on the salt hydrolysis materials. Data were analyzed descriptively with the statistic application. The science process skills of students with the problem-based learning implementation model had (M = 71.84, SD = 7.956) with an effect size value of 8.92 while the discovery learning model had (M = 72.34, SD = 7.872) with an effect size value of 8.33. Metacognition awareness of students with problem-based learning implementation model has (M = 77.03, SD = 3,961) with an effect size value of 5.56 while the discovery learning model has (M = 77.62, SD = 2.738) with an effect size value of 6.46. Research result show that: (1) the problem-based learning model affects the science process skills of students on the salt hydrolysis materials; (2) the problem-based learning model affects the metacognitive awareness of students on the salt hydrolysis materials; (3) there is a positive relationship between science process skills and metacognitive awareness of students on the salt hydrolysis materials. Key words: Problem-based learning, science process skills, metacognition awareness
Impact of Visual Audio Media on Learning Results on Class XI Reaction Speed Material Ratman, Ratman; Walanda, Daud Karel; Amalia, Maryam
JEC Vol. 6 No. 2 (2024)
Publisher : Department of Chemistry Education, Faculty of Science and Technology, Universitas Islam Negeri Walisongo Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21580/jec.2024.6.2.19895

Abstract

The study aims to describe the impact of the use of audiovisual media in the form of video learning on the learning results of students at Sigi District State High School 10. The research method is quantitative research with a type of quasi-experimental research or experimental experiment with a design pretest-posttest control group design. The differences in learning results on reaction speed between experimental and control classes are shown by the results of Wilcoxon and Mann Whitney's statistical analysis tests. The results of the Wilcoxons and Mann whitney statistical analytics tests on the post-test values of experimental classes and the control classes both show the significance values Asymp.Sig.(2-tailed) = <0,000. Because of the signification values Asymp.Sig.(2-tailed) = 0,000 < 0,05. Then from the two results of these statistical analyses it can be concluded that there is an influence of the use of audiovisual media in the form of video learning on the learning outcomes of students in SMAN 10 Sigi.
PELATIHAN PENDEKATAN KOLABORATIF DAN INKLUSIF DALAM IMPLEMENTASI KURIKULUM MERDEKA DI SMAN 4 PALU Napitupulu, Mery; Walanda, Daud K; Poba, Detris; Napitupulu, Nurasyah D; Walanda, Ryka M
Jurnal Abdimas Ilmiah Citra Bakti Vol. 6 No. 1 (2025)
Publisher : STKIP Citra Bakti

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.38048/jailcb.v6i1.4569

Abstract

Implementasi Kurikulum Merdeka menekankan pembelajaran yang inklusi, kolaboratif, dan berpusat pada peserta didik, sehingga diperlukan peningkatan pemahaman dan keterampilan pendidik dalam mengimplementasikannya secara optimal. SMA Negeri 4 Palu, sebagai salah satu sekolah inklusi di Kota Palu, telah menerapkan Kurikulum Merdeka sejak tahun 2022 dengan pembelajaran berdiferensiasi. Oleh karena itu, desain strategi pembelajaran inklusif dan kolaboratif perlu terus diperbarui agar sesuai dengan perkembangan pendidikan. Kegiatan pelatihan ini bertujuan untuk meningkatkan pemahaman guru mengenai konsep, tujuan, dan strategi Kurikulum Merdeka, serta melatih mereka dalam mengembangkan model pembelajaran yang responsif dan partisipatif. Program pelatihan dirancang berdasarkan kebutuhan dan karakteristik peserta, dengan menggunakan pendekatan kolaboratif dan inklusif. Pelaksanaan kegiatan dilakukan secara interaktif dan partisipatif, melalui diskusi, simulasi, serta praktik langsung. Hasil evaluasi menunjukkan bahwa pelatihan ini berkontribusi signifikan dalam meningkatkan berbagai aspek keterampilan pendidik, dengan peningkatan pemahaman konsep pembelajaran inklusif sebesar 82%, keterampilan pembelajaran kolaboratif 76%, rasa percaya diri dalam mengelola kelas inklusi 52%, kemampuan mengidentifikasi kebutuhan individu siswa 67%, penggunaan metode pengajaran inklusif 88%, dan kemampuan menciptakan lingkungan kelas yang inklusif 61%. Dengan demikian, pelatihan ini terbukti efektif dalam meningkatkan kompetensi guru dalam mengimplementasikan Kurikulum Merdeka secara lebih inklusif dan kolaboratif.
Nickel Extraction from Morowali Laterite Ore with Chloride Acid (HCl) – Nitric Acid (HNO3) Solution Leonardo, Leonardo; Walanda, Daud K.; Napitupulu, Mery; Ningsih, Purnama
Jurnal Akademika Kimia Vol. 13 No. 1 (2024)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2024.v13.i1.pp1-6

Abstract

Nickel is a metal of high strategic value for human needs to make stainless steel, batteries, and other products. The amount of nickel reserves in the world is about 72 % in rock oxides, and the rest is in sulfide rocks. However, only about 42 % of total nickel production in the world comes from laterite ore, while nickel sulfide is mainly produced. Research was conducted to determine the optimum nickel extraction parameters in a mixture of nitric acid and hydrochloric acid, and to determine the effect of the solvent volume ratio, temperature, and leaching time parameters on the nickel leaching results from laterite samples. This study uses the taguchi¬larger the better method with each factor having three levels of conditions, namely the volume ratio of the solvent using variations of 1: 1, 1: 2, and 2: 1 then variations in temperature of 30°C, 60 °C, and 90 °C as well as variations in the leaching time of 3 hours, 6 hours, and 12 hours. The optimum conditions for nickel extraction are a parameter ratio of 1:1, a temperature of 90 °C, and a leaching time of 6 hours. The results of atomic absorption spectrophotometer analysis showed that the concentration of Ni2+ at optimum conditions was 10.7895 ppm, and the recovery value was 2.54 %.
Analysis of Metal Content in Rocks Using X-Ray Fluorescence (XRF) Napitupulu, Mery; Maharani, Tiara; Walanda, Daud K.; Said, Irwan
Jurnal Akademika Kimia Vol. 13 No. 1 (2024)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2024.v13.i2.pp7-13

Abstract

Rocks in mining have different types and levels of metal from one another. This study aims to determine the levels of metals present in rocks found in illegal mining areas in the Dongi-Dongi region. The parameters tested are the type of metal contained in rocks from unlawful mining in the Dongi-Dongi area and the amount of metal content in rocks from illegal mining in the Dongi-Dongi area. The results showed that the metals contained in the five rock samples from gold mining in Dongi - Dongi were, respectively, iron (Fe), potassium (K), silicon (Si), calcium (Ca), titanium (Ti), arsenic (Ar), zirconium (Zr), manganese (Mn), rubidium (Rb), niobium (Nb), molybdenum (Mo), indium (In), strontium (Sr), tin II (Sn), and rubidium (Ru) with the highest metal percentage found in the fifth rock sample (E), namely iron (Fe) at 62.89 % and potassium (K) at 54.7 %. The high content of iron and potassium in Dongi-Dongi mining rocks has the potential to be utilized by the community, as these metals are widely used in various industrial fields.
Effect of Solvent Differences on Flavonoid Levels and Antioxidant Activity of Hass Avocado Peel (Persea Americana Hass) Napitupulu, Mery; Nurhikma, Nurhikma; Walanda, Daud K.; Poba, Detris
Jurnal Akademika Kimia Vol. 14 No. 1 (2025)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2025.v14.i1.pp51-57

Abstract

The Hass avocado fruit (Persea Americana Hass) comes from Australia. The color of the Hass avocado skin when it is still raw is green, and when it is ripe, it is black. This study aims to see the effect of different solvents in determining the levels of flavonoids and the antioxidant activity of Hass avocado peel extract. Determination of flavonoid levels using UV-Vis spectrophotometry and for antioxidant activity using 2,2-diphenyl-1-pikrihydrazyl (DPPH) as a source of free radicals, and vitamin C as a positive control, and UV-Vis spectrophotometry to measure the absorbance of Hass avocado peel extract. The results showed that the flavonoid content in the ethanol extract of avocado peel was 2.078 mg/100 mg extract, and for the methanol extract of Hass avocado peel was 1.995 mg/100 mg extract. For the antioxidant activity test, the IC50 value of the ethanol extract of avocado peel was 134.181 mg/L, while the IC50 value of vitamin C was 19.815 mg/L. For the methanol extract of Hass avocado rind, the IC50 value was 149.611 mg/L, while for vitamin C, the IC50 value was 37.093 mg/L. Ethanol extract and methanol extract of Hass avocado peel (Persea Americana hass) are classified as moderately strong antioxidants based on IC50 values.
Biochar from Kapuk Randu (Ceiba pentandra) Seeds for Adsorption of Remazol Blue Dye in Wastewater Napitupulu*, Mery; Walanda, Daud Karel; Nakazawa, Koyomi; Poba, Detris; Tiwow, Vanny M A; Nurmayanti, Yuli; Rahma, Sri
Jurnal IPA & Pembelajaran IPA Vol 9, No 3 (2025): SEPTEMBER 2025
Publisher : Universitas Syiah Kuala

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24815/jipi.v9i3.47600

Abstract

The use of synthetic dyes such as remazol by textile companies can harm the environment because they are toxic, long-lasting, and hard to break down. This study aims to find out how well biochar made from randu kapuk seeds can absorb colors in water by determining the best weight, contact time, and pH level. The study's findings indicate that the moisture content of biochar made from randu kapuk seeds at temperatures of 400C, 450C, and 500C is 5.7%, 5.1%, and 4.3%, respectively. The ash concentration at temperatures of 400, 450, and 500 was 7.7%, 6.8%, and 6.3%, respectively. The best amount of biochar tested was 100 mg, which could absorb 25 mg of remazol Blue, giving it an adsorption capacity of 1.65 mg/g. The best time for biochar made from kapuk seeds to absorb remazol Blue was 30 minutes, with an absorption ability of 1.59 mg/g. The optimal pH for the adsorption of remazol Blue was 4, with a capacity of 5.39 mg/g. The results showed that biochar made from kapuk seeds was excellent at soaking up substances and followed certain patterns that suggest it works through a single layer of chemical bonding. This study highlights how effective biochar made from kapuk seeds is as a safe and eco-friendly material for cleaning dye-polluted water, which helps promote sustainable water management in line with SDG 6: clean water and sanitation
Co-Authors AA Sudharmawan, AA Afadil Alam Anshary Alep, Boni Alizah, Nur Almahdali, Khafifah Amalia, Maryam Anang Wahid M.Diah Anggraini Anggraini Anggraini, Windi Arwansyah Arwansyah Baharuddin Hamzah Baloga, Hendra Bau Ratu Berlin, I Dewa Gede Darsikin Darsikin Dasi, Alfina D. A. Delviana Melego Detris Poba Dewi, Evie Kurnia Maya Dewijayanti, Putu W. Djahir, Ahmad Rifaldi Djulia Onggo Eka Dewi Ellak I. von Nagy-Felsobuki Emi Sulmeni Enar, Rohmala Finta Amalinda Finta Amalinda Fitriani, Eva Geoffrey A. Lawrance Griffiths, Zoe Hasmawati Hasmawati I Ketut Suada I Komang Jati Purnawan I Komang werdhiana I W. A. Wirawan Irwan Irwan Irwan Said Ismail Ismail Kasmudin Mustapa Kusuma, I Gede Yoga Nata Leonardo Leonardo Marungkil Pasaribu Mery Napitupulu Miryam B. Kalase Mohammad Jamhari Muhammad Agus Muljanto Mustakim, Sartika MUSTAMIN IDRIS Nakazawa, Koyomi Napitupulu*, Mery Napitupulu, Nurasyah D Ni Luh Cicik Fitriani Novianti Patiung Nur A. O. Buhang Nurasyah Dewi Napitupulu Nurdin Rahman Nurhikma, Nurhikma Poba, Detris Podala, Katherina Pongenda, Rudy Christiyanto Purnama Ningsih Putra, Iim E. Rahma, Sri Ratman Ratman Razni, Razni Reny, Reny Rimah Juwita Rita Lefrida Robert C. Burns Rukmawati Rukmawati Ryka Marina Walanda Setiawan, I Ketut Ardi Siang Tandi Gonggo Siang Tandi Gonggo Siti Nuryanti Sitti Aminah Sitti Rahmawati Solfarina, Solfarina Sri Hastuti Virgianti Pulukadang Sri Mulyani Sabang Suciati, Indah Suhartini Musa Supriadi Supriadi Susilawati, Niluh Eka Syamsiar, Syamsiar Tahril Taslima Tiara Maharani, Tiara Tiwow, Vanny M A Trisnawati Trisnawati Tudjuka, Mora Delfita Uswatun Hasanah Wagiman, Saumadin Walanda, Richard Albert Walanda, Ryka M Walanda, Ryka M. Yeyet Sri Rahmi Yuli Nurmayanti Yulianti, Iluh Devi