Articles
<![CDATA[The analysis of Calsium (Ca), Magnesium (Mg), Sodium (Na) and Posphorus (P) ijn Beluntas (Pluchea indica L.) Leaves ]]>
<![CDATA[Fitriani, Eva]]>;
<![CDATA[Walanda, Daud K.]]>;
<![CDATA[Hamzah, Baharuddin]]>
<![CDATA[ Jurnal Akademika Kimia Vol 8, No 1 (2019) ]]>
Publisher : <![CDATA[Universitas Tadulako ]]>
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<![CDATA[Beluntas are bushes that may consumed as vegetable which mostly founded in Central of Sulawesi. The research purposes to determine the concentration of calcium (Ca), magnesium (Mg), sodium (Na), and posphorus (P) in beluntas leaves (pluchea indica L.). The concentration of Ca, Mg, and Na were obtained using atomic absorption spectrophotometer and the concentration of P was obtained using spectrodirect spectrophotometer. The average concentration of mineral in beluntas leaves are Ca 678.71 mg/100g, Mg 93.38 mg/100g, Na 198.11 mg/100g, and P 29.84 mg/100g.]]>
<![CDATA[Application of STAD Type Cooperative Learning Models Integrated With Camtasia Studio Presentation Media on Student's Motivation and Learning Outcomes Class XI MIPA SMAN 1 Sigi Biromaru ]]>
<![CDATA[Wagiman, Saumadin]]>;
<![CDATA[Walanda, Daud K.]]>;
<![CDATA[Diah, Anang Wahid M.]]>
<![CDATA[ Jurnal Riset Pendidikan MIPA Vol. 2 No. 1 (2018) ]]>
Publisher : <![CDATA[Universitas Tadulako ]]>
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DOI: 10.22487/j25490192.2018.v2.i1.pp64-74
<![CDATA[This research aims to determine the effect of student motivation and outcomes learning through the application of cooperative learning model type of STAD combined with presentation media camtasia studio in class XI MIPA at SMAN 1 Sigi Biromaru. Subject of this research was two classes of XI MIPA1 as much 22 students as the experimental class and XI MIPA2 as much 22 students as a control class determined by Purposive Random Sampling. Data was collected use questionnaire instrument of learning motivation and learning result test. Testing data of research result using t-statistical analysis of t-test (Independent Sample t-Test) with prerequisite test that is normality test and homogeneity test. The average score of students learning motivation in the experimental class was 81 and the average score of students learning motivation in the control class was 67. The average score of students learning outcomes in the experimental class was 85 and the average score of students learning outcomes in the control class was 74. Based on the hypothesis analysis with t-test motivation of learning motivation obtained value tcount = 7.670 and it was located in the region of rejection of H0 between -2.018 and 2.018. Hypothesis analysis with t-test result statistic obtained value tcount = 8.056 and it was located in the region of rejection of H0 between -2,018 and 2.018. The result shows that there is effect of application cooperative learning model type of STAD combined with media presentation of studio camtasia toward the student motivation and outcomes learning in class XI MIPA at SMAN 1 Sigi Biromaru.]]>
<![CDATA[Penerapan Metode Pembelajaran SQ3R Berbantuan Internet Terhadap Hasil Belajar Siswa Kelas X Pada Materi Sistem Periodik Unsur Di SMA Labschool Palu ]]>
<![CDATA[Alep, Boni]]>;
<![CDATA[Walanda, Daud K.]]>;
<![CDATA[Hamzah, Baharuddin]]>
<![CDATA[ Jurnal Akademika Kimia Vol 4, No 1 (2015) ]]>
Publisher : <![CDATA[Universitas Tadulako ]]>
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<![CDATA[Internet is a global network connecting thousands and even millions of computer networks with a personal computer so that the user can obtain a variety of information from wider sources. This internet service is used to assist the implementation of the SQ3R learning method that is expected to enrich the literature. The SQ3R learning method is a method of learning which uses the reading technique intensively and rationally to understand the main ideas, the details of a reading, and a comprehensive understanding of a passage with the steps i.e. surveying, asking, reading, communicating, and reviewing. The aim of this study was to determine the effect of the implementation of SQ3R learning method internet-assisted to the learning outcomes (cognitive) of students in the class X on the material periodic table of elements at Senior High School Labschool Palu. This research was a quasi-experimental with non-randomized pre-test and post-test control groups design. This research was carried out by holding two groups of class X science 1 as the control group (n = 19) and Class X science 2 as the experimental group (n = 18).Testing of research data used t-test statistical analysis one side (right side) with the prerequisite tests: normality and homogeneity tests. The results of the data analysis obtained the average value (X1 ) of experiment class was 83.94 with a standard deviation of 8.24 and (X1 ) of control class was 77.78 with a standard deviation of 8.54. Results of the hypothesis testing using statistical t-test one side (right side) obtained tcount>ttable value was 1.867 > 1.690 with a confidence level (α) = 0.05 and a degree of freedom (df ) = 35. Based on the results of hypothesis testing, then Ho is rejected and H1 is accepted so it can be concluded that the SQ3R learning method internet-assisted on the material Periodic System of Elements has a positive influence on the learning outcomes of students in the class X at Senior High School Labschool Palu.]]>
<![CDATA[Students' Perceptions Of The Inorganic Chemistry Classroom Management Through A Web-Based Instructional System ]]>
<![CDATA[Daud Karel Walanda]]>;
<![CDATA[Mery Napitupulu]]>;
<![CDATA[Detris Poba]]>
<![CDATA[ Jurnal Pendidikan Kimia Indonesia Vol. 6 No. 1 (2022) ]]>
Publisher : <![CDATA[Universitas Pendidikan Ganesha ]]>
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DOI: 10.23887/jpk.v6i1.41404
<![CDATA[Pengelolaan kelas dalam proses pengajaran khususnya mata pelajaran kimia akan menjadi signifikan agar hasil belajar menjadi optimal. Namun kegitan pembelajaran yang dilaksanakan saat ini kurang optimal sedangkan berdampak pada hasil belajar. Penelitian ini bertujuan untuk menganalisis persepsi mahasiswa dalam manajemen kelas mata kuliah kimia anorganik. Jenis penelitian ini yaitu penelitian kuantitatif. Metode dan instrument yang digunakan untuk mengumpulkan data yaitu instrument. Subjek penelitian ini adalah 40 mahasiswa. Teknik yang digunakan untuk menganalsis data yaitu analisis deskriptif kualitati dan kuantitatif. Hasil penelitian menunjukkan bahwa persepsi mahasiswa tentang GC berada pada kategori memuaskan dan merekomendasikan GC untuk digunakan dalam pelajaran lain. Effect size dihitung dari perbedaan rata-rata pre-test dan post-test sebelum dan sesudah pembelajaran dengan menggunakan rumus Cohen dan diperoleh efektivitas GC menurut kriteria Cohen adalah 1,77, yang berarti bahwa ukuran efek Google Classroom luas; maka GC sangat efektif digunakan dalam mengajar mata kuliah kimia anorganik. Disimpulkan bahwa pengelolaan kelas melalui sistem instruksional berbasis WEB efektif digunakan dalam pembelajaran.]]>
<![CDATA[KINETIC TRANSFORMATION OF SPINEL TYPE LiMnLiMn2O4 INTO TUNNEL TYPE MnO2 ]]>
<![CDATA[Daud K Walanda]]>
<![CDATA[ Indonesian Journal of Chemistry Vol 7, No 2 (2007) ]]>
Publisher : <![CDATA[Universitas Gadjah Mada ]]>
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DOI: 10.22146/ijc.21685
<![CDATA[Lithiated phase LiMn2O4 is a potential cathode material for high-energy batteries because it can be used in conjunction with suitable carbon anode materials to produce so-called lithium ion cells. The kinetic transformation of LiMn2O4 into manganese dioxide (MnO2) in sulphuric acid has been studied. It is assumed that the conversion of LiMn2O4 into R-MnO2 is a first order autocatalytic reaction. The transformation actually proceeds through the spinel l-MnO2 as an intermediate species which is then converted into gamma phase of manganese dioxide. In this reaction LiMn2O4 whose structure spinel type, which is packing between tetrahedral coordination and octahedral coordination, is converted to form octahedral tunnel structure of manganese dioxide, which is probably regarded as a reconstructive octahedral-coordination transformation. Therefore, it is a desire to investigate the transformation of manganese oxides in solid state chemistry by analysing XRD powder patterns. Due to the reactions involving solids, concentrations of reactant and product are approached with the expression of peak areas.]]>
<![CDATA[Analysis of Vitamin C and Calcium in Jongi Fruits (Dillenia serrata Thunb) Based on Their Maturity Level ]]>
<![CDATA[Miryam B. Kalase]]>;
<![CDATA[Daud K. Walanda]]>;
<![CDATA[Mery Napitupulu]]>
<![CDATA[ Jurnal Akademika Kimia Vol. 8 No. 3 (2019) ]]>
Publisher : <![CDATA[Universitas Tadulako ]]>
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DOI: 10.22487/j24775185.2019.v8.i3.pp147-152
<![CDATA[Jongi plant (Dillenia serrata Thunb) is one of the plants that found Poso District. The characteristics of this fruit are mainly on the refreshing sour taste and attractive color which is yellow. This study aims to determine the levels of vitamin C and calcium in this fruit based on the level of maturity. The fruit of jongi used as a sample was categorized into there type of maturity namely mature, ripe, and overripe. The method used for vitamin C analysis was iodimetry and for calcium, analysis using spectrophotometry (λ: 422.7 nm). From the results of the analysis, it was obtained that the levels of vitamin C in fruit jongi successively were 81.84, 114.40, and 70.40 mg/100 g, while the calcium levels obtained in the fruits were 5.91, 5.65, and 6.46 mg/100 g. The data above showed that the maximum vitamin C content in jongi fruit when the fruit was in ripe type, while the highest calcium content in jongi fruit was when the fruit in overripe type.]]>
<![CDATA[Antioxidant Activity Test of Red Spinach’s Extract (Blitum rubrum) in Ethanol Solvent and Water Solvent with DPPH ]]>
<![CDATA[Nur A. O. Buhang]]>;
<![CDATA[Siti Nuryanti]]>;
<![CDATA[Daud K. Walanda]]>
<![CDATA[ Jurnal Akademika Kimia Vol. 8 No. 3 (2019) ]]>
Publisher : <![CDATA[Universitas Tadulako ]]>
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DOI: 10.22487/j24775185.2019.v8.i3.pp153-159
<![CDATA[The study of red spinach antioxidants (Blitum rubrum) in two types of solvents i.e ethanol and water has been performed. The purpose of this study was to determine the antioxidant activity of red spinach extract from Tinombo Selatan district, Central Sulawesi. Red spinach was macerated in ethanol and water to obtain variations of extract concentrations of 20, 40, 60, and 80 mg/L. Free radicals used were DPPH reagents while vitamin C was used as a positive control. The measurement of absorbance of red spinach’s extract was conducted by spectrophotometric. The results showed that IC50 extract of red spinach in ethanol and water were 51.404 mg/L and 52.227 mg/L, while the value of IC50 vitamin C in ethanol and water solvent was 43.241 mg/L and 140.507 mg/L. Based on the IC50 red spinach’s extract in ethanol and water have strong antioxidant activity.]]>
<![CDATA[Phytochemical Screening and Antioxidant Activity Test of Red Onion (Allium ascolinicum L.) Extract Variety of Palu Valley ]]>
<![CDATA[Rimah Juwita]]>;
<![CDATA[Daud K. Walanda]]>;
<![CDATA[Supriadi Supriadi]]>
<![CDATA[ Jurnal Akademika Kimia Vol. 9 No. 2 (2020) ]]>
Publisher : <![CDATA[Universitas Tadulako ]]>
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DOI: 10.22487/j24775185.2020.v9.i2.pp63-69
<![CDATA[The red onion of Palu valley variety is a plant that is widely found in Palu area and regarded as a leading commodity in Central Sulawesi. The purpose of this study was to examine the secondary metabolite compounds contained in red onion (Allium ascolinicum L.) of Palu valley variety and its antioxidant activity. Antioxidant activity test in this study used DPPH (1,1-Diphenyl-2-Pikrilhidrazil) as a source of free radical, and vitamin C as the comparison. The antioxidant activity of red onion extract was analyzed using a UV-Vis spectrophotometer. The red onion tuber powder was extracted by maceration using ethanol solvent. Qualitative test of onion powder showed positive results on alkaloids, flavonoids, and tannin compounds. The samples and vitamin C were tested for antioxidant activity in various extract concentrations of 10, 30, 50, 70, and 90 ppm. The results showed that red onion extract of Palu valley variety presented an IC50 value of 38.548 ppm, and vitamin C presented an IC50 value of 22.646 ppm. Based on these values, the red onion (Allium ascolinicum L.) extract is categorized as a very strong class of antioxidant which can be used as a source of natural antioxidant.]]>
<![CDATA[Analysis of Macro Nutrient on Rono Fish (Xenopoecilus oophorus) Freshwater ]]>
<![CDATA[Delviana Melego]]>;
<![CDATA[Mery Napitupulu]]>;
<![CDATA[Daud K. Walanda]]>
<![CDATA[ Jurnal Akademika Kimia Vol. 8 No. 4 (2019) ]]>
Publisher : <![CDATA[Universitas Tadulako ]]>
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DOI: 10.22487/j24775185.2019.v8.i4.pp191-196
<![CDATA[Fish are assumed to have high nutritional value with mineral content, vitamins, fats, and proteins containing essential amino acids that are needed for growth and human intelligence. One type of them is rono fish (Xenopoecilus oophorus) freshwater which is an endemic fish that comes from lake Poso, Central Sulawesi and still found in traditional markets of Tentena city, but the local community is less interested in this type of fish and the lack of literature that informs about the nutritional content of rono fish. The research aims to determine the macronutrient content in rono fish. The nutrient content analyzed in fish was on carbohydrates, proteins, and fats by using the anthrone sulfate method for carbohydrate analysis, Kjeldahl method for protein, and for fat analysis using the soxhlet method. The results of the analysis obtained that macronutrient in freshwater rono fish was followed carbohydrate was 9.26%, the protein was 37.79% and fat was 11.92%.]]>
<![CDATA[The Effect of Copper(II) and Cadmium(II) Ions Against the Percent Mercury Ion Extraction Using Emulsion Liquid Membrane Technique ]]>
<![CDATA[Suhartini Musa]]>;
<![CDATA[Baharuddin Hamzah]]>;
<![CDATA[Daud K. Walanda]]>
<![CDATA[ Jurnal Akademika Kimia Vol. 8 No. 4 (2019) ]]>
Publisher : <![CDATA[Universitas Tadulako ]]>
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DOI: 10.22487/j24775185.2019.v8.i4.pp218-222
<![CDATA[The effect of copper(II) and cadmium(II) ions on the percent of mercury ion extraction using an emulsion liquid membrane technique have been performed. This study used HNO3 as an internal phase, mixed span 80 and span 20 as a surfactant, benzoyl acetone as cation carrier, kerosene as membrane phase, and mercury solution as a sample solution. Variations of concentrations of copper(II) and cadmium(II) ions added were 10, 20, and 30 ppm with mercury concentrations of 30 ppm. The result of the research showed that the addition of copper(II) ion with concentrations of 10 to 30 ppm decreased the percentage of mercury ion extraction 30 ppm by 12.12% and the addition of cadmium(II) ion with the concentration of 10 to 30 ppm decreased the percentage of mercury ion extraction 30 ppm by 11.74%.]]>
