Article Per Year (5 Year)
p-Index From 2020 - 2025
3.444
P-Index
This Author published in this journals
All Journal Jurnal Periodic Jurusan Kimia UNP Jurnal Penelitian Pendidikan IPA (JPPIPA) Pelita Eksakta SAINTI: Majalah Ilmiah Teknologi Industri
Nizar, Umar Kalmar
Unknown Affiliation
Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Control & Systems Engineering Education Energy Engineering Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mathematics Physics Other

Published : 26 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 26 Documents
Search

 1   2   3 
Esterifikasi Palm Fatty Acid Distillate Menggunakan Katalis Karbon Kulit Buah Kakao (Theobroma Cacao) Tersulfonasi Agustin, Andre; Nizar, Umar Kalmar
Periodic Vol 13, No 1 (2024): PERIODIC
Publisher : Departemen Kimia FMIPA UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/periodic.v13i1.120001

Abstract

Catalyst is a substance that plays an important role in biodiesel production because the reaction for biodiesel formation is slow. This catalyst can be synthesized by utilizing organic waste such as cocoa pods. This study aimed to study the physicochemical properties and catalytic activity of sulfonated cocoa pod carbon catalyst for biodiesel production from PFAD. This catalyst was synthesized through a calcination process at temperatures of 250 0C, 300 0C, 350 0C, 400 0C, 450 0C for 1 hour and sulfonation with H2SO4 p.a then characterized using FTIR, XRD, and acid site test. The catalyst is then applied in the manufacture of biodiesel through an esterification reaction between PFAD and methanol with a mole ratio of 1:15. The biodiesel produced was tested for its physicochemical properties in the form of density test, flow rate, acid number, and percent conversion. The results showed that the highest number of carbon catalyst sites for cocoa pod shells was KKBK-450. Based on the FTIR analysis, there are absorption bands at wave numbers of 1036 cm-1 and 1181 cm-1 indicating the presence of an O=S=O group which proves that the sulfonate group was successfully substituted onto the carbon surface of the cocoa pod. Characterization using XRD showed the results in the form of a carbon catalyst of cocoa pods having an amorphous structure. Based on the test results of the physicochemical properties of the catalyst from the biodiesel produced, KKBK-450 showed the optimum catalytic activity with the percent conversion of FFA to FAME of 52.28%.
Analisis Beberapa Sifat Fisikokimia dari Minyak Goreng Kemasan Hasil Penggorengan Ubi Jalar (Ipomea batatas) Sabrina, Joya; Dewata, Indang; Oktavia, Budhi; Pernadi, Niza Lian; Farhan, Muhammad; Rahmi, Fathaniah Raviqa; Nizar, Umar Kalmar
Periodic Vol 13, No 2 (2024): PERIODIC
Publisher : Departemen Kimia FMIPA UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/periodic.v13i2.124356

Abstract

Cooking oil is a biological mixture derived from plants and consists of a mixture of esters derived from glycerol with fatty acids. The most commonly used cooking oil for cooking by the community is palm oil, because it is easy to obtain and the price is relatively affordable. The main composition of palm oil is triglycerides more than 95% and several other components such as monoglycerides, diglycerides, free fatty acids, phosphatides and sterols. Sweet Potatoes have the main content, namely carbohydrates. In addition to carbohydrates, there are other ingredients such as protein and fat. The purpose of this study was to determine the physicochemical properties of packaged cooking oil from sweet potato frying at a certain time and temperature and to use packaged cooking oil without heating as a comparison. The physicochemical properties of the oil determined include density, flow rate, acid number and saponification number. Bimoli cooking oil from sweet potato frying has a density value of 0.9369 gr/ml, a flow rate of 3.662 ml/s, an acid number of 8.143 mgKOH/gr and a saponification number of 14.305 mgKOH/gr. The results of this study indicate that the results of the physicochemical properties test of packaged cooking oil have a better value than the test results of sweet potato frying oil.
Pengaruh Penjernihan Minyak Jelantah Menggunakan Nasi Terhadap Sifat Fisikokimia Minyak Sidiq, Aqil Marsya; Putra, Ananda; Amelia, Fitri; Pernadi, Niza Lian; Rizki, Suci Yulia; Nizar, Umar Kalmar
Periodic Vol 13, No 1 (2024): PERIODIC
Publisher : Departemen Kimia FMIPA UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/periodic.v13i1.124355

Abstract

The increased demand for cooking oil has led to a corresponding rise in its consumption. To address this situation, individuals often resort to reusing cooking oil, despite its unsuitability for consumption. The repeated use of cooking oil at high temperatures induces the hydrolysis of triglycerides into free fatty acids. Consequently, this research aims to refine the quality of used cooking oil through its purification using rice, rendering it suitable for reuse. Rice is rich in amylose and amylopectin, both of which feature -OH groups that can interact with -COOH groups present in free fatty acids within used cooking oil. In the process of used cooking oil purification, rice serves as an adsorbent. The findings of this study exhibit an improvement with an increase in the amount of rice used in the purification of cooking oil. Furthermore, the utilization of rice as an adsorbent during the cooking oil purification process leads to a reduction in density to 0.9454 g/mL, a decline in the acid number to 2.0797 mg KOH/g, an augmentation of flow rate to 0.3141 mL/s, and an elevation of the hoarding number to 77.1842 mg KOH/g within the used cooking oil.
Studi Pengaruh Rasio Mol Silika terhadap Titania dalam Pembentukan Koordinasi Titanium Tetrahedral dalam Silika-Titania dengan Metoda Solid State Yuliani, Amelinda; Veronita, Silvi; Pernadi, Niza Lian; Nizar, Umar Kalmar
Periodic Vol 12, No 3 (2023): PERIODIC
Publisher : Departemen Kimia FMIPA UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/periodic.v12i3.117884

Abstract

Titanium tetrahedral coordination shows high activity as a catalyst so that it attracts attention to be researched and developed. In this study, tetrahedral titanium coordination was studied and produced through the Si-O-Ti bond between solid silica precursors and solid titania. Both precursors are mixed in toluene and sonicated for homogeneity. The resulted mixture was calcined at a temperature of 400oC for 8 hours and then characterized with DRS UV-Vis, XRD and FESEM. The results showed that the synthesis sample experienced an increase in tetrahedral titanium fraction from 27% to almost 34%. Characterization with XRD indicates that the diffraction pattern of the resulting sample is very similar to the titania precursor with a crystalline pattern with an anatase and rutile phases. The morphology of the resulting sample showed that silica samples that did not react with titania experienced agglomeration
Pengaruh Variasi Konsentrasi NaOH Terhadap Xerogel dari Kulit Durian (Durio zibethinus Murr.) Anjelia, Mariza; Nasra, Edi; Kurniawati, Desy; Nizar, Umar Kalmar
Periodic Vol 13, No 1 (2024): PERIODIC
Publisher : Departemen Kimia FMIPA UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/periodic.v13i1.124374

Abstract

The objective of this study was to synthesize xerogel from durian peel waste by determining the optimal NaOH concentration for the synthesis process. The sol-gel method was employed, utilizing SiO2 as the main component and Na2SiO3 as the precursor. The sodium silicate precursor was obtained by reacting SiO2 derived from durian shell ash with NaOH solutions of various concentrations: 2 M, 5 M, 8 M, 11 M, and 14 M. The surface area of the resulting xerogel was tested, and the optimal NaOH concentration was found to be 8 M, yielding a surface area of 6637.8 m2/g. The synthesized xerogel was further characterized using FTIR analysis within the wave number range of 4000-600 cm-1. The FTIR data revealed the presence of silanol at a wave number of 3253.30 cm-1 and siloxane at a wave number of 1060.18 cm-1, confirming the successful synthesis of the xerogel.
Degradasi Zat Warna Malachite Green Menggunakan Katalis TiO2 dengan Metode Fotolisis Miftahurrahmi, Miftahurrahmi; Sanjaya, Hary; Oktavia, Budhi; Nizar, Umar Kalmar
Periodic Vol 12, No 3 (2023): PERIODIC
Publisher : Departemen Kimia FMIPA UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/periodic.v12i3.118388

Abstract

The research that has been done on the photolysis of the degradation of Malachite Green using TiO2 catalyst aims to determine the effect of the percentage degradation of the Malachite Green solution. The results of UV-Vis spectrophotometer measurements obtained a wavelength of 617nm. The results showed that the highest percentage of degradation was 99.05% at 210 minutes using TiO2 catalyst, while 65.45% with TiO2 catalyst mass of 0.25 grams. This study shows that the hydroxyl radical (∙OH) is the main control in degrading Malachite Green.
Pengaruh Lebar dan Ketebalan Komposit C/CuO Berbasis Karbon Aktif Pelepah Kelapa Sawit Terhadap Karakteristik Material Termoelektrik Novriansyah, Edo; Putra, Ananda; Azhar, Minda; Nizar, Umar Kalmar
Periodic Vol 13, No 3 (2024): PERIODIC
Publisher : Departemen Kimia FMIPA UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/periodic.v13i3.125697

Abstract

Abstract -Electrical energy is energy that is really needed by humans, one way to save electrical energy is to use the thermoelectric method. Thermoelectric materials are materials that can convert heat energy into electrical energy through the Seebeck effect. This research aims to determine the effect of the size of the Active Carbon/Cuo composite material with a high Seebeck coefficient and apply it as a thermoelectric generator. In this study, variations in the size of the mold material were carried out with thickness (0.5 0.8 1 1.3 and 1.5) cm, width (1 1.3 1.6 2.5) and length 5 cm. From the research results, it can be seen that materials with sizes of 0.5 cm and 1 cm have the highest thermal conductivity, namely 0.195 mS.cm-1 and 0.0964 mS.cm-1, the lowest thermal conductivity is 0.06J/s and 0.08J/s, and the highest electrical voltage (Seebeck effect), namely 0.02 mV/K and 0.012 mV/K. Furthermore, applying this material to a generator is capable of producing an electrical voltage of 1.7V at a temperature of 80℃.
Sintesis Tetraetil Ortosilikat (TEOS) dari Silika Hasil Kalsinasi Sekam Padi Rahmi, Rahmi; Nizar, Umar Kalmar; Khair, Miftahul; Althof, Hasnah Sausan; Azzahra, Wenalda Hanifah; Beri, Deski
Periodic Vol 13, No 3 (2024): PERIODIC
Publisher : Departemen Kimia FMIPA UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/periodic.v13i3.125501

Abstract

Indonesia is an agricultural country. Where agriculture makes an important contribution to the economy and the fulfillment of people's basic needs. It is known that every 1 kg of rice produced, is able to produce 0.28 kg of rice husk. Rice husk is an agricultural waste that is abundant in nature. In this research, the effect of calcination time on silica obtained from rice husk has been determined. The purity level of the extracted silica is 99%. Silica that has been successfully extracted is then used in the TEOS synthesis process by varying the reaction time. A total of 1 mole of ethanol (58.4 ml) and 0.25 ml (7 grams) of silica powder were added to 250 ml neck flask 3 and the addition of alumnia catalyst as much as 1 gram, then the mixture was refluxed using 800C for 5, 7, 10, 15 and 20 hours. The TEOS obtained was then subjected to several parameter tests that provide information about the physical and chemical conditions, so that this can provide information regarding the quality of the resulting solution. The measurements carried out are, Densiats solution testing, Viscosity and refractive index. From the data obtained the density value of TEOS is 0.986 g/ml - 0.995 g/ml, the viscosity value of TEOS is 0.8176 cps - 0.9337 cps and the refractive index value of TEOS is 1.356 - 1.360. While the yield obtained is from 82.11% - 54.74%.
Pengaruh Variasi Ukuran Lebar Material Terhadap Karakteristik Termoelektrik Sistem C/CuO Wulandari, Yolanda; Putra, Ananda; Nizar, Umar Kalmar; Riga, Riga
Periodic Vol 13, No 3 (2024): PERIODIC
Publisher : Departemen Kimia FMIPA UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/periodic.v13i3.125757

Abstract

One of the factors that can affect the quality and characteristics of thermoelectric materials is the size of the material.. This study aims to determine how the effect of material size is varied in width and thickness. The material used is activated carbon obtained from previous research that has met the SNI No. 06-3720-1995 content test. The activated carbon is then composited with Copper (II) Oxide. Based on the tests that have been carried out, the best material obtained is the material with a width size variation of 1 cm. With a high electrical conductivity value of 0.0909 MΩ-.cm-, low thermal conductivity of 0.2418 J/s and has a high Seebeck coefficient of 0.0166 mV/K. Thermoelectricity offers sustainable energy to maintain energy needs, namely by converting wasted heat energy into electrical energy that can overcome the current global warming problem.
PELATIHAN PENGGUNAAN LIVE WORSHEETS SEBAGAI LKPD INTERAKTIF DENGAN PENEKANAN PADA TIGA LEVEL REPRESENTASI KIMIA BAGI GURU KIMIA DI SMAN 1 LEMBAH GUMANTI DAN SMA DI KABUPATEN SOLOK BAGIAN SELATAN Nizar, Umar Kalmar; Azhar, Minda; Mukhaiyar, Riki; Zulhendra, Zulhendra; Suryelita, Suryelita; Ningsih, Sherly Kasuma Warda
Pelita Eksakta Vol 7 No 2 (2024): Pelita Eksakta, Vol. 7, No. 2
Publisher : Fakultas MIPA Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/pelitaeksakta/vol7-iss2/245

Abstract

SMA Negeri 1 Lembah Gumanti is one of the schools in Southern Solok Regency that’s actively spurring the development of its school by completing the infrastructure and quality of education for both students and teachers. ICT training especially for teachers to support the quality learning process. One of the uses of this facility is to create interactive LKPD on LiveWorksheets. The purpose of the service activity is to increase the knowledge and skills of chemistry teachers using various learning resources on websites on the internet, increase chemistry teachers' knowledge of the three levels of representation and their interconnections, increase chemistry teachers' knowledge and skills in combining learning resources for making interactive LKPD on the LiveWorksheets web with an emphasis on the three levels of chemical representation. The methods used in this activity are lecture, demonstration and practice. Training participants were asked to present the results of their activities.
Co-Authors Afrilia, Yoni Agustin, Andre Akmar, Reza Althof, Hasnah Sausan Anjelia, Mariza Auzakiyah, Sabella Azzahra, Wenalda Hanifah Budhi Oktavia Charles Banon Della Rosalynna Stiadi Deski Beri Desy Kurniawati Edi Nasra Fadhila, Radhiatul Fika, Miva Hemalia Fitri Amelia Fitriani Fitriani Gusvita, Nola Hapzi Ali Harahap, Aprilia Silviani Hardeli Hardeli Hary Sanjaya Indang Dewata Istiqamah, Siti Sarah Izanel, Rezi Ananta Karsa, Dion Randi Khaliq, Feni Kurnia Mawardi Miftahul Jannah Miftahul Khair Miftahurrahmi, Miftahurrahmi Minda Azhar Muhammad Farhan Mukhaiyar, Riki Novel, Dheo Shalsabilla Novela, Riana Novriansyah, Edo Pernadi, Niza Lian Putra, Ananda Putri, Natasya Alya Putri, Yunisa Anugrah R, Yoanatul Hasanah Rahadian Zainul Rahmi Rahmi Rahmi, Fathaniah Raviqa Rahmi, Maulidia Arsyta Riga, Riga Risma Sari, Risma Rizki, Suci Yulia Sabrina, Joya Sari, Trisna Kumala Sherly Kasuma Warda Ningsih Sidiq, Aqil Marsya Simbolon, Ranita Sri Benti Etika Suryani, Okta Suryelita, Suryelita Syafri, Vanny Sofiana Syafriadi, Riko Veronita, Silvi Wulandari, Yolanda Yuliani, Amelinda Zulhendra, Zulhendra Zuyyina, Himla