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EFEK DOPANT TERHADAP STRUKTUR DAN KARAKTER DARI FOTOKATALIS POWDER TITANIA Rilda, Yetria; Dharma, Abdi; arief, Syukri; Alif, Admin
Jurnal Riset Kimia Vol 2, No 1 (2008): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v2i1.145

Abstract

 ABSTRACT The structure and characterization of the titania (M-TiO2) can be modified by metal doped and calcinations temperatures variation by sol-gel method. Characterization of gel and M-TiO2 powder realized by FT-IR, TGA, XRD, Photo Optic and SEM. Titania has two crystal structures such as anatase and rutile. Anatase structures shown higher photocatalytic properties than rutile. The crystal structure was characterized to JCPS reference no. 21-1272, 2Ө : 25.3° identically as anatase structure and 2Ө : 27.3° as rutile. Structure modification is depend on calcinations temperature change. At 400°C the anatase structure was formed. The anatase intensity was increased at 500°C and at 600°C anatase transportation to rutile was found and anatase mixture was obtained. Several types of dopant can inhibit anatase to rutil transformation process at temperature ≥ 600°C. Park et al.,[1] reported that calcinations temperature and valence ion dopant influence the crystal size. Based on Scherrer’s equation the crystal size can be calculated by using the XRD  data. The crystal size of maximum intensity which was identified as anatase structure at 500°C as following Fe-TiO2 10.6 nm, MoTiO2 16.8 nm.  M-TiO2 character through inhibition of E. Coli bacteria growth was great infulenced by particle size and dopant ion type. This character shown by MIC value (Minimal Inhibition Concentration)) of each Fe, Mo-TiO2 between 0.35 – 0.45%. Keywords : crystal structure, characterization, titania, sol-gel
Modifikasi dan Karakterisasi Titania (M-TiO2) Dengan Doping Ion Logam Transisi Feni dan Cuni Rilda, Yetria; Arief, Syukri; Dharma, Abdi; Alif, Admin
Jurnal Natur Indonesia Vol 12, No 2 (2010)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (632.25 KB) | DOI: 10.31258/jnat.12.2.178-185

Abstract

Structure and size of titania nanoparticles have been modified with doping the transition metal (FeNiand CuNi) and controlling the calcinations temperature. Gel and M-TiO 2 powder were characterized byFT-IR showed the changed in intensity at 4000-400 cm-1. TG-DTA curve show the weigh of sample wasdecreased with the increasing of temperature 25-800°C. XRD pattern used to identify the titania structureshows the highest intensity of anatase at temperature calcination as 500°C. XRD of FeNi-TiO 2 and CuNi-TiO2 FeNi 10.5-41.9 nm and CuNi 12.1-33.5 converted using Debye-Scherrer’s equation and TEM analysisthe distribution of crystal size as FeNi-TiO2 and CuNi-TiO2 10-15 nm. SEM has shown that morphology ofdifferent surface from the FeNi-TiO 2 and CuNi-TiO 2 at different calcinations temperatures. Titaniacomposition can be determined by EDX analysis give as FeNi-TiO2 1:1, 97.01% and CuNi-TiO2 1:1, 94.63%respectly. The surface area has been determined by BET as FeNi-TiO 2 was 64.38 m2/g and CuNi-TiO2was 40.9 m2/g.
The Thermophilic Bacterial Growth Curve Irdawati Irdawati; Ilsa Septia Putri; Syamsuardi Syamsuardi; Anthoni Agustien; Yetria Rilda
Bioscience Vol 2, No 2 (2018): Biology
Publisher : UNIVERSITAS NEGERI PADANG

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (577.485 KB) | DOI: 10.24036/0201822100819-0-00

Abstract

Thermophilic bacteria are bacteria that can produce thermostable enzymes and used in various industries. Thermostable enzymes that can be produced by thermophilic microorganisms one of them is xylanase enzyme. Xylanase produced by microbes has optimum temperature characteristics and more diverse optimum pH on various substrates, which will affect the activity of the resulting xylanase enzyme. The influence of temperature greatly determines the activity of the enzyme at the time of catalyzing a reaction. At optimum pH conditions, the enzyme has an active side conformation that is substrate-like so that it can form a complex of appropriate enzymes and produce the product to its full potential. One of the thermophilic bacterial habitats of hot springs in West Sumatera is the Aro Sapan River hot spring located in Koto Parik Gadang Subdistrict in Ateh, South Solok District. The Saw Aro River hot spring has a temperature of 75 ° C and is pH 8 or alkaline. The aim to this research was to know the profile of the growth of thermophilic bacteria. This research is a descriptive method. The data obtained were analyzed descriptively. The conclusion is the best activity of xylanase thermophilic bacteria was at the sixth time incubation.
EFEK DOPANT TERHADAP STRUKTUR DAN KARAKTER DARI FOTOKATALIS POWDER TITANIA Yetria Rilda; Abdi Dharma; Syukri arief; Admin Alif
Jurnal Riset Kimia Vol. 2 No. 1 (2008): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v2i1.145

Abstract

 ABSTRACT The structure and characterization of the titania (M-TiO2) can be modified by metal doped and calcinations temperatures variation by sol-gel method. Characterization of gel and M-TiO2 powder realized by FT-IR, TGA, XRD, Photo Optic and SEM. Titania has two crystal structures such as anatase and rutile. Anatase structures shown higher photocatalytic properties than rutile. The crystal structure was characterized to JCPS reference no. 21-1272, 2Ө : 25.3° identically as anatase structure and 2Ө : 27.3° as rutile. Structure modification is depend on calcinations temperature change. At 400°C the anatase structure was formed. The anatase intensity was increased at 500°C and at 600°C anatase transportation to rutile was found and anatase mixture was obtained. Several types of dopant can inhibit anatase to rutil transformation process at temperature ≥ 600°C. Park et al.,[1] reported that calcinations temperature and valence ion dopant influence the crystal size. Based on Scherrer’s equation the crystal size can be calculated by using the XRD  data. The crystal size of maximum intensity which was identified as anatase structure at 500°C as following Fe-TiO2 10.6 nm, MoTiO2 16.8 nm.  M-TiO2 character through inhibition of E. Coli bacteria growth was great infulenced by particle size and dopant ion type. This character shown by MIC value (Minimal Inhibition Concentration)) of each Fe, Mo-TiO2 between 0.35 – 0.45%. Keywords : crystal structure, characterization, titania, sol-gel
Rancang Bangun Sensor Kelembaban Udara menggunakan Plastic Optical Fiber (POF) dengan Cladding TiO2-SiO2 dan Data Transmisi F Febrielviyanti; H Harmadi; Dahyunir Dahlan; Yetria Rilda
Jurnal Fisika dan Aplikasinya Vol 15, No 1 (2019)
Publisher : Lembaga Penelitian dan Pengabdian Kepada Masyarakat, LPPM-ITS

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (405.479 KB) | DOI: 10.12962/j24604682.v15i1.4358

Abstract

Serat optik merupakan media transmisi berupa kabel yang terbuat dari kaca atau plastik yang digunakan untuk mentransmisikan sinyal cahaya dari satu titik tempat ke titik tempat lainnya. Prinsip kerja dari serat optik memanfaatkan prinsip pemantulan sempurna dengan memanfaatkan perbedaan indeks bias antara core dan cladding. Serat optik juga dapat dijadikan sensor dengan menggunakan sistem instrumentasi. Sistem instrumentasi terdiri dari input, proses, dan output. Input atau masukan menggunakan laser dioda, karena laser mempunyai spektrum sangat sempit yang cocok dijadikan sumber cahaya pada serat optik. Proses pentransmisian data menggunakan serat optik sebagai pandu gelombang, dimana serat optik yang digunakan sebanyak lima variasi panjang pengupasan. Perekaman data transmisi kelembaban udara menggunakan Arduino Uno dan Ethernet Shield. Output dihasilkan berupa tegangan keluaran yang di tampilkan pada LCD atau PC. Hasil terbaik diperoleh dari variasi panjang pengupasan 2 cm dengan pelapis TiO2-SiO2 sebagai pengganti cladding, dimana menunjukkan nilai R2 = 0,982. Rata-rata error yang diperoleh dari rancangan alat kelembaban udara sebesar 3,06 %. Hal ini menunjukkan ketidak sesuaian antara pembacaan alat yang dirancang dengan alat ukur standarnya, karena sensor yang dirancang tersebut masih sangat rentan terhadap kesalahan sistematik. Tetapi sudah cukup baik untuk dapat mendeteksi kelembaban udara dari suhu 86oC-100oC.
MIKOALGA SPIRULINA PLATENSIS SEBAGAI SUPLEMEN UNTUK MENINGKATKAN GIZI DAN IMUNITAS BALITA DI POSYANDU ANGGREK 2 KELURAHAN SEBERANG PADANG, KOTA PADANG Armaini Armaini; Yetria Rilda; Netti Suharti
Jurnal Hilirisasi IPTEKS Vol 3 No 4 (2020)
Publisher : LPPM Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jhi.v3i4.473

Abstract

Patients with malnutrition mostly were golden age toddlers under 2 years. Based on the survey conducted, it was found toddler of the Posyandu Anggrek 2 experienced malnutrition. The community partnership program provides solutions to improve nutrition, especially for toddlers by utilizing the nutrient-rich Spirullina platensis microalgae as a nutritional supplement in the toddler's diet. The main objective of the community partnership program implemented at Posyandu Anggrek 2 is to provide Spirullina platensis capsule supplements to improve nutrition in under-fives with malnutrition and malnutrition, to increase knowledge of mothers of toddlers about highly nutritious foods, especially Spirullina platensis microalgae to improve nutrition, immunity and health toddlers during the current Covid-19 epidemic. The application of Spirullina platensis cultivation technology which is transferred to housewives who are members of Posyandu Anggrek 2. The success of this program shows that giving Spirullina platensis capsules to 10 toddlers for 6 weeks can increase toddler nutrition as measured based on the WHO standard Anthropometric index. The increase in body weight and height after administration of Spirullina platensis was seen in all toddler, and there was an increase in health and immunity in toddler. It can be concluded that giving Spirullina platensis capsules is beneficial for improving nutritional status and immunity in toddlers.
Synthesis of Graphene Oxide Enriched Natural Kaolinite Clay and Its Application For Biodiesel Production Syukri Syukri; Fadhil Ferdian; Yetria Rilda; Yulia Eka Putri; Mai Efdi; Upita Septiani
International Journal of Renewable Energy Development Vol 10, No 2 (2021): May 2021
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2021.32915

Abstract

A heterogeneous catalyst is one type of catalyst which is very effective for biodiesel production; thus, in this study, a novel heterogeneous bifunctional catalyst was prepared by kaolinite clay obtained from Padang of West Sumatera and impregnated with graphene oxide and potassium hydroxide (KOH) for the simultaneous esterification and transesterification reactions of palm oil into biodiesel. For comparison, two other catalysts were also prepared. The first catalyst was the same clay which was heated at 450ºC for 4 hours, and the second catalyst was the same clay which was impregnated with potassium hydroxide (KOH) only. The three catalysts were characterized using X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), and Fourier Transform Infra-Red (FTIR). XRF analysis showed that the clay sample’s main composition consisted of 54% silica, 35% alumina, and 7% hematite. The XRD analysis results showed that the most dominant crystal composition was quartz, kaolinite, and hematite. The analysis results using FTIR showed a change in intensity and shift in wave numbers indicating a cation exchange. The catalytic activity test was carried out with a ratio of oil and methanol 1:6, catalyst amount 5%, 60ºC reaction temperature, and 4 hours of reaction time.The results showed that the catalytic activity of clays impregnated with graphene oxide and potassium hydroxide was better with a yield of 58% compared to clays without impregnation and other clays that were only impregnated with KOH under the yields of 0.8% and 0.4%, respectively
Evaluation of Lipid Profile and Liver Function After Administration of Scenedesmus dimorphus in Obese Mice Armaini Armaini; Siti Hajir; Yetria Rilda
Jurnal Riset Kimia Vol. 13 No. 2 (2022): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v13i2.503

Abstract

Obesity is a major public health problem in developing countries and is a significant risk factor for metabolic disorders. Microalgae Scenedesmus dimorphus (S. dimorphus) contains bioactive compounds such as pigment function as antioxidants, and omega-3 and omega-6 PUFAs have potential as nutraceuticals. The study aimed to evaluate the lipid profile and liver function after the administration of S. dimorphus in obese mice. The research design uses mice which are divided into 6 groups; Group 1 (G1) normal control, G2 control Obesity, G3 treatment with Orlistat, G4 treatment S. dimorphus (0.25mg/g BW), G5 treatment S. dimorphus (0.5 mg/g BW) and G6 treatment S. dimorphus (0.75 mg/g BW) each group consisted of 5 mice and 21 days of observation time. The parameters observed were lipid profile and liver function of mice. Based on the results of the study, the effective dose for treating obesity is a dose of S. dimorphus 0.75 mg/g (BW) can reduce cholesterol, triglycerides, and LDL levels, respectively 67.7 mg/dl, 49.2 mg/dl, 10 , 2 mg/dl, and increased HDL, 68.32 mg/dl compared to control of obesity (G2), respectively 108.7 mg/dl, 139.1 mg/dl, 20.6 mg/dl and HDL 60, 28 mg/dl, this dose is also effective for improving the function of blood pressure by reducing AST and ALT 15.6 U/L and 18.8 U/L, respectively, compared to the obesity group (G2), which is 26.6 U/L, and 29,7 U/L. Based on the results of the study it can be concluded that S. dimorphus is useful for anti-obesity for mice (Mus musculus).
Pengaruh Modifikasi Fisika pada Komposisi, Struktur Kristal dan Sifat Katalitik Lempung Solok Admi Admi; Florencia Tri Angellika; Yetria Rilda; Syukri Syukri
Jurnal Fisika Unand Vol 11, No 4 (2022)
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (367.308 KB) | DOI: 10.25077/jfu.11.4.548-555.2022

Abstract

Mineral lempung yang diperoleh dari Kabupaten Solok, Sumatera Barat, telah dimodifikasi secara fisika melalui pemanasan pada 105°C, 450°C dan 850°C. Aktivitas katalitiknya telah diuji dalam transesterifikasi minyak jelantah untuk menghasilkan metil ester asam lemak. Komposisi utama lempung ditemukan terdiri dari Si, Al dan Fe serta unsur-unsur minor lainnya seperti K, Ti, Na, Ca Mg, dan Mn (pengukuran XRF). Jenis mineral utama sampel lempung adalah kaolinite dan illite (karakterisasi XRD). Kalsinasi pada suhu 850 °C mengakibatkan penurunan fasa kaolinit yang menandakan telah terjadi transformasi parsial menjadi metakaolin (analisis XRD). Pengujian aktivitas katalitik di bawah kondisi reaksi tertentu dari semua lempung menunjukkan bahwa lempung yang dikalsinasi pada 850°C menghasilkan dua jenis senyawa biodiesel yaitu metil ester asam palmitat dan metil ester asam oleat (analisis GC-MS). Tanah liat yang dipanaskan pada suhu 110 dan 450 oC sama sekali tidak menunjukkan aktivitas katalitik
Pengaruh Gas CO2 Terhadap Pertumbuhan, Kandungan asam lemak, lipid dan Karotenoid Total Chlorella emersonii Rahmatika Yani; Abdi Dharma; Yetria Rilda
Jurnal Ilmu Lingkungan Vol 21, No 2 (2023): April 2023
Publisher : School of Postgraduate Studies, Diponegoro Univer

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jil.21.2.245-250

Abstract

Karbon dioksida (CO2) yang berasal dari kegiatan industri, merupakan salah satu penyebab gas rumah kaca yang berkontribusi terhadap pemanasan global. Belakangan ini mikroalga banyak diminati karena kemampuannya dalam biofiksasi CO2, sebagai sumber karbon pada proses fotosintesis. Mikroalga memiliki potensi untuk mengurangi emisi CO2, serta biomassa yang dihasilkan dapat dimanfaatkan sebagai bahan baku obat, maupun bahan baku biodiesel. Penelitian ini bertujuan untuk mengetahui kemampuan mikroalga Chlorella emersonii dalam menghasilkan karotenoid dan lipid akibat pengaruh paparan gas CO2 tinggi. Waktu pemaparan CO2 99,90% dilakukan setiap 5; 10; 15; 20 menit per hari selama 28 hari. Biomassa yang dihasilkan, diekstrak karotenoid total dan lipid total yang diukur menggunakan analisis spektrofotometri dan gravimetri. Lipid diesterifikasi dengan metode modifikasi metanol-HCl-transesterifikasi dan dikarakterisasi menggunakan Gas Chromatography-Mass Spectroscopy (GC-MS). Hasil penelitian menunjukkan bahwa, stres lingkungan yang disebabkan paparan gas CO2 selama 10 menit, menurunkan biomassa sebesar 45,17%, disertai peningkatan lipid dan kandungan asam lemak sebesar 52,31% dan 73,42%, dengan kandungan karotenoid total optimal 8,54 µg/mL. Budidaya Chlorella emersonii merupakan solusi yang efisien dan berkelanjutan untuk mengatasi masalah cemaran gas CO2, efek stres yang dihasilkan dapat menjadi strategi untuk meningkatkan kandungan karotenoid, lipid dan asam lemak yang berpotensi untuk biodiesel.