Makara Journal of Science
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IONIC LIQUIDS: PREPARATIONS AND LIMITATIONS
No full textIonic liquids are considered as an ideal alternative to volatile organic solvents and chemical industries in the future, because they are non-volatile. Ionic liquids are also considered as new novel chemical agents and widely regarded as a greener alternative to many commonly used solvents. Ionic liquids have been studied for a wide range of syntheticapplications and have attracted considerable interest for use as electrolytes in the areas of organic synthesis, catalysis, solar cell, fuel cells, electrodeposition and supercapacitors. However, some ionic liquids suffer from more or less some drawbacks such as toxicity, preparation and high cost in the process for use. Most recently, three types of ionic liquids are attracted much attentions specifically traditional ionic liquid, protic ionic liquid and deep eutectic solvent, where their preparation, mechanism and limitation were differentiated. However, those liquids are having their ownadvantages and limitations based on applications. Traditional ionic liquid and protic ionic liquid are highly cost and toxic for applied engineering research, but they consist of micro-biphasic systems composed of ionic compounds which have more varieties in the applications. The deep eutectic solvent is very economic for large-scale possessing but there are only limited ionic mixtures to certain application such as electrochemistry.Keywords: deep eutectic solvent, ionic liquids, protic ionic liquids, volatile organic solvent
ENKAPSULASI KETOPROFEN DENGAN KITOSAN-ALGINAT BERDASARKAN JENIS DAN RAGAM KONSENTRASI TWEEN 80 DAN SPAN 80
No full textEncapsulated Ketoprofen by Chitosan-Alginat based on Type and Variation of Tween 80 and Span 80 Concentration. Ketoprofen has been encapsulated by chitosan-alginate based on types of surfactant and it’s concentration. The variations of concentration either Tween 80 (polietilena sorbitanmonooleat) or Span 80 (sorbitanmonooleat) that used were around (1- 3)% concentrations with stirring around (15-60) minutes. The using of Tween 80 resulted efficiency of encapsulated ketoprofen and nano particle size (100-1000) nm are higher than Span 80.Keywords: encapsulated ketoprofen, chitosan-alginate, Span 80, Tween 8
DETEKSI INTEGRITAS GENOMIK PISANG HASIL IRADIASI IN VITRO BERDASARKAN PENANDA MIKROSATELIT
No full textPenelitian ini bertujuan mendeteksi integritas genomik pisang hasil iradiasi in vitro berdasarkan penanda mikrosatelit. Kajian integritas genomik ini dilakukan pada pisang Mas yang telah diiradiasi dengan sinar gamma 15 Gy. DNA inti diisolasi dari setiap aksesi mengikuti metode Dixie, diamplifikasi dengan Perkin Elmer Gene Ampl PCR 2400 menggunakan sepuluh primer, kemudian dielektroforesis pada gel agarose 1%. Terakhir dilakukan elektroforesis pada gel poliakrilamid secara vertikal, dan pewarnaan silver untuk visualisasi alel yang muncul. Hasilnya menunjukkan bahwa diantara sepuluh primer yang dipakai, delapan diantaranya menghasilkan pita-pita yang jelas, konstan, dan dapat diulang. Jumlah pita bervariasi, dari satu sampai dua, mengikuti tingkatan ploidi pisang Mas berupa diploid AA. Jumlah satu pita menunjukkan alel homozigot, sedangkan jika jumlah pitanya dua, menunjukkan alel heterozigot. Diantara delapan primer yang menunjukkan hasil yang jelas tersebut, enam diantaranya menghasilkan pita-pita yang berbeda diantara tanaman hasil iradiasi, kultur in vitro, dan kontrol, sedangkan pada dua primer lainnya menunjukkan alel yang sama untuk semua aksesi yang diuji. Perubahan genomik terlihat pada semua tanaman hasil iradiasi yang nampak mempunyai pita yang berbeda jumlah dan ukurannya dibandingkan dengan tanaman kontrol. Perubahan dapat terjadi pada zigositas alel tertentu, misalnya dari heterozigot ke homozigot atau sebaliknya. Perubahan alel menunjukkan adanya ketidakstabilan genomik yang dapat timbul akibat berbagai peristiwa seperti delesi, insersi, dan amplifikasi nukleotida
COMPUTATION OF NATURAL CONVECTION IN A POROUS PARALLELOGRAMMIC ENCLOSURE WITH A MAGNETIC FIELD
No full textDetailed numerical calculations are presented in this paper for natural convection in a porous parallelogrammic enclosure with a magnetic field. The inclined walls are maintained isothermally at different temperatures. The top and bottom horizontal straight walls are kept adiabatic. To simplify the effort in matching the grid mesh with the inclined walls of the parallelogrammic region/geometry, the computational domain is mapped onto a rectangular shape using a non-linear axis transformation. Transport equations are modeled by a stream-vorticity formulation then expressed in them new coordinate system and solved numerically by a finite difference method. Based upon the numerical predictions, we found the convection modes within the enclosure depended upon the Rayleigh number and the inclination angle. As the value of magnetic field is made larger, the strength of the heat transfer is progressively suppressed. Tuning the inclination angle decreases the heat transfer performance
PERSONALIZATION SISTEM E-LEARNING BERBASIS ONTOLOGY
No full textPersonalization of Ontology Based E-learning System. Today, a form of technology known as Web 2.0 thatthoroughly supports web-to-web interactions is present. Interactions, such as information sharing in the forms of document sharing (slideshare), picture sharing (flickr), video sharing (youtube), Wikis, and online networking (weblog and web-forum) are principally accomodating community empowerment services. These factors cause the appearance of social interaction through Internet as well as learning interaction and anywhere anytime training which is recently called e-Learning. Basically, e-Learning needs a self-employed learning method and learning habits that emphasize on the learner as the most important role. However, e-learning system which is expected to boost the intensity of selfemployed learning is uncapable to represent the importance. This is proven with the current e-Learning system in Indonesia that only accomodates the delivery of learning materials identical to all active learners, ignores the cognitive aspects and does not offer any approach or experience of interactive self-learning and disregards the aspect of users’ ability to adapt. The proposed e-learning system which is Web 2.0-based utilizes ontology as the representation of meaning of knowledge formed by the learner
EFEK DOPING Ni (II) PADA AKTIFITAS FOTOKATALITIK DARI TiO2 UNTUK INHIBISI BAKTERI PATOGENIK
No full textInfluence of Co-Doping of Ni (II) on Photocatalytic Activity of TiO2 for Pathogenic Bacteria Inhibition. Nanoparticle titanium dioxide (TiO2) has most attention in the past decade, since it can be applied as alternative material on sterilization photocatalyst process. This research focused on increasing performance of titania such as structure, particles size and surface area through Ni ion doped on TiO2 surface by sol-gel technique. Product were used to design of a photobioreactor for sterilization process from pathogenic bacteria such as Escherichia coli, Staphylococcus aureus and Bacillus subtilis. Product were characterized using Thermogravimetric-Differential Thermal Analysis (TG-DTA), X-ray Diffraction (XRD), Transmition Electron Microscopy (TEM), Scanning Electron Microscopes-Energy Dispersive X-Ray Spectroscopy (SEM-EDX) dan Brunauer-Emmet-Teller (BET). Titanium dioxide with anatase structure have 12.1 nm in particles size and surface area 49.6 m2 / g that have higher inhibition rate to bacteria cell. Photobiocatalytic reaction was carried out in various TiO2-Ni concentration and UV irradiation times. The anti bacteria from TiO2-Ni to all bacteria cell suspension after UV irradiated at λm : 365 nm has good synergistic effect. Effect of mechanical treatment by sonicator showed the increasing inhibition rate around 4% for 120 minute irradiation. Inhibition rate optimization for each bacteria gave different efficiency inhibition to TiO2-Ni concentration 1.5-2.0 g/L. TiO2-Ni powder inhibited growth of Escherichia coli, Staphylococcus aureus around ≥ 95% for 120 minute irradiation, while Bacillus subtilis resistance with inhibition percentage rate only 88.1%. Keywords: activity, inhibition, pathogenic, photocatalytic, TiO
DOWNSIZED CHELATING RESIN-PACKED MINICOLUMN PRECONCENTRATION FOR MULTIELEMENT DETERMINATION OF TRACE METALS BY ICP-MS
No full textChelating resin-packed minicolumn preconcentration was used for multielement determination of trace metals in seawater by inductively coupled plasma mass spectrometry (ICP-MS). The chelating resin-packed minicolumn was constructed with two syringe filters (DISMIC 13HP and Millex-LH) and an iminodiacetate chelating resin (Chelex 100, 200-400 mesh), with which trace metals in 50 mL of original seawater sample were concentrated into 0.50 mL of 2 M nitric acid, and then 100-fold preconcentration of trace metals was achieved. Then, 0.50 mL analysis solution was subjected to the multielement determination by ICP-MS equipped with a MicroMist nebulizer for micro-sampling introduction. The preconcentration and elution parameters such as the sample-loading flow rate, the amount of 1 M ammonium acetate for elimination of matrix elements and the amount of 2 M nitric acid for eluting trace metals wasoptimized to obtain good recoveries and analytical detection limits for trace metals. The analytical results for V, Mn, Co, Ni, Cu, Zn, Mo, Cd, Pb, and U in three kinds of seawater certified reference materials (CRMs; CASS-3, NASS-4, and NASS-5) agreed well with their certified values. The observed values of rare earth elements (REEs) in the above seawater CRMs were also consistent with the reference values. Therefore, the compiled reference values for the concentrations of REEs in CASS-3, NASS-4, and NASS-5 were proposed based on the observed values and referencedata for REEs in these CRMs.Keywords: chelating resin-packed minicolumn, ICP-MS, micro-sampling introduction, seawater certified referencematerial, trace metal
TOKSISITAS AKUT DAUN Justicia gendarussa Burm.
No full textAcute Toxicity of Justicia gendarussa Burm. Leaves. Preminelary experiment showed that ethanolic extract of gandarusa leaves (Justicia gendarussa Burm.) could decreased uric acid blood level on rats. The aim of this experiment was to determine of the value LD50 and liver function based on activities of aminotransferase. Animals test which were used in this experiment were 50 males and 50 females white mice. They were divided into 5 groups. Group 1 as control group was given aquadest. Group 2-5 were treated by ethanolic extract of gandarusa leaves with dosage 4, 8, 16, and 32 g/kg bw. The LD50 value was determined by the amount of death in group during 24 hours after giving a single dose of test substance. The result showed that the highest dose was practically non toxic with LD50 value of 31.99 g/kg bw (male groups) and 27.85 g/kg bw (female groups). Measurement of aminotransferase activity was done by using colorimetric method. The result of ANOVA analysis for liver function showed that the giving test substance 4 g/kg bw –16 g/kg bw was not significantly different between treated groups and control group
OPTIMASI BIODEGRADABILITAS DAN UJI TOKSISITAS HASIL DEGRADASI SURFAKTAN LINEAR ALKILBENZENA SULFONAT (LAS) SEBAGAI BAHAN DETERJEN PEMBERSIH
No full textOptimization of Biodegradability and Toxicity Testing of Degradation Product from Linear Alkyl Benzene Sulfonate (LAS) Surfactant as Cleaning Detergent Agent. Linear Alkyl Benzene Sulfonate (LAS) is a surfactant used in laundry detergent as cleaning agent and toxic to aquatic organisms. Results shows, with the LAS concentration used (20 ppm) in medium, adaptation time and Acinetobacter sp. growth has shown better biodegradation ability than three other bacteria used Pseudomonas putida, Pseudomonas fluorescence, Bacillaria spp. Thus, Acinetobacter sp is used further for biodegradation process of LAS. Based on its biodegradation half-life using Acinetobacter sp, and with mixed culture (± 52.32% and ± 46.82% respectively) could be achieved in 4 (four) days, LAS could be categorized as a biodegradable compound. The toxicity assay is based on tetrazolium dye reduction with Rhizobium meliloti as indicator organism. LAS is more toxic than its intermediate product from biodegradation, with IC50 = 34.35 ppm, and the intermediate product, Ac and Cm, has IC50 = 446.19 ppm and 111.28 ppm respectively. Identification of intermediate products using IR and LC-MS analysis shows that the degradation product contains chemicals compounds with functional group as follows: benzene, benzoic acid, hydroxyl, and aliphatic carbons with large molecule weight. Until its half-time degradation time, LAS biodegradation process only occurs at the aliphatic carbon chain, and have not yet reached the stage of aromatic ring opening. Keywords: biodegradation, linear alkylbenzene sulfonate (LAS), Rhizobium meliloti, tetrazolium dy
PERHITUNGAN POLARISASI SPONTAN DAN MOMEN QUADRUPOL POTENSIAL LISTRIK BAHAN PIZT (PbInxZryTi1-x-yO3-x/2)
No full textThe Calculation Spontaneous Polarization and Quadrupole Moment of Electric Potential PIZT (PbInxZryTi1-x-yO3-x/2). PZT (PbZr1-xTixO3) is a perovskite crystal that can be used for IR sensor. Small amount of dopant can drastically change the specific characteristic of ferroelectric ceramic such as spontaneous polarization, dielectric constant, electromechanical and also electro-optic properties. The addition of In3+ ion (called as hard doping) has been applied in this research. Thin film of PIZT (PbInxZryTi1-x-yO3-x/2) has been deposited on Si(100) substrate with Chemical Solution Deposition (CSD) method. The concentration of solution is 0,5 M and the angular speed applied of spin coating is 3000 rpm. The PIZT sample has been analyzed with x-ray diffraction method. Rietveld analyses using GSAS-EXPGUI software resulted lattice parameter of crystal and phase compositions of PIZT samples. The values of all sample PIZT spontaneous polarization (Ps) have been calculated lower than PZT. The optimally Ps was reached at 0,5% to 1% In2O3 doping. Quadrupole moment of electric potential (θQ(r)) at point P (0,0,2a) reached optimum at 6% In2O3 doping and they also showed that PIZT thin film have θQ(r) higher value than their bulk form for In2O3 doping >1%.Keywords: PZT, PIZT, XRD, Rietveld analyses, spontaneous polarization, quadrupole moment of electric potentia