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Sintesis Codoped-Sr2TiO4 Fasa Ruddlesden-Popper dengan Metoda Lelehan Garam dan Sifat Hantaran Listriknya
Get PDFIn this research, undoped-Sr2TiO4 and codoped-Sr2TiO4 Ruddlesden-Popper (RP) phase compounds have been synthesized with mole variations of Sr:Ti and dopants. Double substitution with Sm3+ for Sr2+ sites and Nb5+ for Ti4+ sites forming Sr2-xSmxTi1-yNbyO4 (x = 0.0125; 0.025; 0.05; 0.1 and y = 0.0125) aimed to increase the number of electrons carrier, so that the electrical conductivity enhanced. The XRD patterns showed that the highest purity of prepared Sr2TiO4 RP phase sample was obtained at the mole ratio of Sr:Ti of 2:1 with specific peaks at 2θ: 31.35°, 46.73°, and 57.33°. Then, this mole ratio was used to prepare the codoped-samples, and the XRD patterns showed the Sr1.95Sm0.05Ti0.9875Nb0.0125O4 sample has the highest purity. SEM images showed that the undoped-Sr2TiO4 and codoped-Sr2TiO4 samples have a plate-like particles with micrometer size. The electrical conductivity of Sr1.95Sm0.05Ti0.9875Nb0.0125O4 sample was measured to be a 17-fold increase compared to that of undoped-Sr2TiO4 sample.Â
Pembuatan Protokol Penapisan Virtual Berbasis Stuktur (pvbs) untuk Identifikasi Ligan Inhibitor Reseptor Platelet-Activating Factor (PAF-r) sebagai Target Terapeutik Asma menggunakan YASARA
Get PDFPlatelet-activating factor receptors (PAF-r) is known as one of the receptors that affect asthma, while the Y-21480 ligand is reported as an effective, specific, and active PAF-r antagonist for asthma patients. Research in building structure-based virtual screening protocol (SBVS) for identification of PAF-r ligand inhibitors has been performed, the receptor crystal structure was obtained from the Protein Data Bank (PDB ID: 5zkp), while the ligand used as a leading compound is Y-24180, obtained from U.S. National Library of Medicine. Interactions between ligands and receptors are observed through molecular dynamics simulations using the YASARA program at intervals up to 20 nanoseconds, ligand-receptor binding stability occurs after a time interval of 2 nanoseconds, the lowest ligand-receptor binding energy occurs at a time interval of 1,401 picoseconds. Internal validation by re-docking 1,000 times the ligand to receptor resulted in a value of Root Mean Square Deviation (RMSD) of 0.6037 Å, confirmed that SBVS protocol was accurately able to reproduce the Y-24180 ligand pose on the 5zkp crystal structure, the protocol can be used as a new approach for investigation or design of compounds that have therapeutic potential as anti-asthma
Adsorpsi Asam Humat pada Zeolit Alam yang Dimodifikasi dengan TiO2
Get PDFThis research modified natural zeolite with TiO2 synthesized by the sol-gel process which was applied as a humic acid adsorbent. The purpose of this study was to coat natural zeolites with TiO2 to increase the adsorption capacity of natural zeolites as humic acid adsorbents. The natural zeolite powders were obtained from Kabupaten Solok, West Sumatra, based on X-ray Fluorescence (XRF) analysis, the ratio of silica/alumina (Si/Al) was 4.35, indicating that natural zeolite was clinoptilolite zeolite. Scanning Electron Microscopy (SEM) analysis showed natural zeolite has a rough surface with closed pores while zeolite coated with TiO2 (zeolite/TiO2) has a homogeneous, smooth surface with open pore. The results of the Energy Dispersive X-Ray Spectroscopy (EDS) analysis showed that the level of TiO2 was 7.1%, this result showed that TiO2 has been coated on the surface of the zeolite. Natural zeolite and zeolite/TiO2 were applied as humic acid adsorbents. Maximum adsorption capacity of natural zeolites and zeolites/TiO2 were 0.2787 mg/g and 1.199 mg/g, respectively
Uji Aktivitas Sitotoksik dan Antibakteri Ekstrak Daun Tumbuhan Rengas (Gluta renghas L)
Get PDFGenerally, Gluta renghas L. is known because of its very toxic latex which can cause hard irritations to skin. Although, rengas latex has efficacy as an antibacterial agent. Related to previous research, it has been reported that there are urisol, rengol, glutarengol, laccol, and thitsiol in rengas latex. The woody trunk was reported to contain flavonoid, benzenoid, lipid, and steroid compounds. The leaves, were reported shows that the leaves of G. renghas contain an anticholinesterase substance and can be reduced the rate of hydrolysis of acetylcholine. Extraction of rengas leaves has been carried out. It has been shown phenols, steroids, and coumarins compounds in methanol extract, flavonoids, phenols, saponins and alkaloids compounds in ethyl acetate extract, steroids and alkaloids compounds in hexane extract. In the present, cytotoxicity and antibacterial activity have been tested. The results show that the great cytotoxicity activity by ethyl acetate extracts which have an LC50 value is 123,718 µg/mL (R2 0.9822), while the great antibacterial activity shown by methanol extract 1,000 µg/mL with a diameter of inhibition zone 19.02 mm (S. aureus) and 16.06 mm (E. coli).Â
Perbandingan Efektivitas Dekolorisasi Fotokatalitik Metilen Biru dan Metil Jingga menggunakan Semikonduktor ZnO pada Variasi pH
Get PDFThe comparison of photocatalytic decolorization of Methylene Blue and Methyl Orange using ZnO Semiconductor under UV-LED radiation has been studied at varied pH. ZnO have been synthesized using co-precipitation method. The Scanning Electron Microscopy (SEM) result showed that the synthesized ZnO has a hexagonal structure with the particle size range 0.125 to 0.5 µm. The BET isotherm characterization showed the synthesized ZnO has a specific surface area (SBET), mesoporous volume and micropore volume of 60.20 m2/g, 0.541 cm3/g and 0.02 cm3/g, respectively. The observation of the effect of pH to the photocatalytic activity showed that the highest removal percentage occurred at pH 9 with the value of 95.64% for methylene blue and occurred at pH 3 with the value of 6.236% for methyl orange.Â
Identifikasi Senyawa Metabolit Sekunder, Uji Antimikroba dan Antioksidan Ekstrak Akar Gantung Hornstedtia Scyphifera Var. Fusiformis Holttum (Sijangkang)
Get PDFHornstedtia scyphifera var. fusiformis Holttum is endemic plant of Zingiberaceae family that distributed in Sumatera. Hornstedtia scyphifera var. fusiformis Holttum contained some secondary metabolite such as phenolic, saponin, triterpenoid and alkaloid. The biological activity of methanol, ethyl acetate, and n-hexane extracts from Hornstedtia scyphifera var. fusiformis Holttum suspended roots was tested for antibacterial and antioxydant activity. Antioxidant activity was analized by DPPH method. The antibacterial activity was tested by used disk difussion method againts Staphylococcus aureus bacteria (gram-positive bacteria) and Escherichia coli (gram-negative bacteria). Almost all of Hornstedtia scyphifera var. fusiformis Holttum suspended roots extract were given antibacterial activity, nonetheless the biggest inhibition zone of Escherichia coli that was inhibited by n-hexane and ethyl acetate extracts which have inhibtion zone 10 mm at concentration 500 mg/L and also againts Staphylococcus aureus, the biggest inhibition by ethyl acetate and n-hexane extracts which have inhibition zone 10.30 mm at concentration 500 mg/L. Among all extracts tested, methanol extract of the possessed moderate free radical scavenging activity with IC50 = 51.89 mg/L
Sintesis Senyawa Aurivillius Lapis Empat PbBi4Ti4O15 dan PbBi3NdTi4O15 dengan Metode Lelehan Campuran Garam NaCl-KCl dan Karakterisasi Struktur
Get PDFFour-layered Aurivillius phases PbBi4Ti4O15doped with Nd3+ with formula PbBi3NdTi4O15 were synthesized by molten-salt technique using NaCl and KCl (1:1 molar ratio) as the flux. Precursors were weighed stoichiometrycally and grinded with salts mixture in 1:7 ratio (product : salts mixture) until homogenous. The samples were heated at temperature 600oC, 700oC, 800oC, and 900oC for 5 hours for each temperature. The products were characterized by X-ray diffractometer (XRD), Scanning Electron Microscope (SEM) and LCR-meter. XRD data were refined by Rietica program using Le Bail technique. Refinement results showed the best structure as the A21am of space group for both samples. Surface analysis for each samples morphology is the plate-like by SEM characterization. Dielectric constants measured at room temperature show that the sample doped Nd3+ has lower value than sample without containing Nd3+ cation
STUDI OPTIMASI EKSTRAKSI KANDUNGAN SENYAWA FENOLIK TOTAL DAN UJI AKTIVITAS ANTIOKSIDAN DARI DAUN MANGGIS (Garcinia mangostana Linn.)
Get PDFThis study aims to determine antioxidant activity and total phenolic content of mangosteen leaves in several different solvents. The antioxidant activity test of the extract was determined by the DPPH method and the total phenolic content was determined by the Folin-Ciocalteu method. The phytochemical test of mangosteen leaves showed the presence of phenolic compounds, saponins, triterpenoids and alkaloids. The extraction results increase with increasing water content in methanol, ethanol and acetone. The highest amount of extract was obtained using 50% acetone solvent (34.98 ± 0.17%). Extraction using 100% ethanol showed the highest total phenolic content (614.25 ± 5.58 mg GAE / g extract) and the lowest IC50 value (5.81 mg / L). The results of this study indicate that the use of 50% acetone solvent can optimize the amount of extract and 100% ethanol can optimize the content of total phenolic compounds and antioxidant activity of mangosteen leaves
PENJERNIHAN AIR SUMUR MENUJU AIR LAYAK MINUM DENGAN METODA LAPISAN MULTI MEDIA ( LMM )
Get PDFThe Multi Soil layering (MSL) system is a liquid waste treatment method with the use of soil as the main medium and the organic material formed in brick and arranged in layers with a homogeneous zeolite layer. The MSL system is made of acrylic (50 x 15 x 50) cm containing a brick (4 x 9 x 15) cm and (4 x 5 x 15) cm of volcanic soil mixture as the main medium mixed with charcoal, rice husk, and iron powder (70 : 10 : 10 : 5)%, permiable layer is used zeolite (2-3) mm. The sample came from the well water of one of villager at Jati, Padang. Efficiency of SML system for aeration process on turbidity parameter with flow rate variation of 2, 4, 6, 8 mL/min reach 99,8 %, for non aeration process efficiency of turbidity decrease 88,14 %. While for the flow rate of 10, 20, 40, 80 mL/min, the efficiency of decrease for aeration at parameters Mn 66,44 %, nitrite 59,74 %, nitrate 58,34 %, turbidity 54,63 %, while in non aeration efficiency decrease turbidity reach 44,04 %, Mn 47,26 %, nitrite 49,74 %, nitrate 45,57 %. Of all efficiency values decreasing all parameters already complied drinking water quality standard according to Permenkes RI No. 492/Menkes/Per/IV/2010
Pengaruh Pemberian Variasi pH terhadap Produksi Trigliserida Total dan Komposisi Asam Lemak dari Chlorella Vulgaris Air Tawar
Get PDFChlorella vulgaris is a microalgae that has high lipid content and potential as raw material for biofuel production. This study aims are to determine the effect of pH on growth, lipid production and fatty acid composition of C. vulgaris by using Growmore 32-10-10 fertilizer as a culture medium. Microalgae were cultured in medium Growmore 32-10-10 for 10 days. Afterward, pH of medium was varied into pH 5, 7, 8.2 and 9 and continued cultivate for 3 days. C. vulgaris cultured at pH 8.2 which is a control pH reached optimum growths. The GC-MS analysis for lipid productivity of C. vulgaris was 0.5020 g/L/day and 0.2902 g/L/day for microalgae grew at pH 8.2 and 9, respectively. Cultures at pH 8.2 and 9 produce methyl hexadecanoate, methyl 9-octadecanoate, methyl octadecanoate, methyl 9,12-octadecadienoate, methyl 9,11-octadecadienoate. Additional fatty acid methyl nonadecanoate was also found in C. vulgaris grew at pH 9. The low and high pH stress of C. vulgaris culture medium did not affect culture growth but altered lipid production and fatty acid composition