Makara Journal of Science
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PEMBUATAN ARANG AKTIF DARI BATANG JAGUNG MENGGUNAKAN AKTIVATOR ASAM SULFAT DAN PENGGUNAANNYA PADA PENJERAPAN ION TEMBAGA (II)
No full textPreparation of Activated Carbon from Maize Stems by Sulfuric Acids Activation and Their Application in Copper (II) Ion Sorption. Activated carbons were prepared from maize (Zea mays L.) stems by sulfuric acids activation or chemical methods. The dry maize stems are usually used as low-value energy resources in many ountries, burned in the field, or discarded, which are unfavorable to environment. This motivates the investigation of producing value-added products from the dry maize stems, such as activated carbons, as well as solving some environmental problems. The preparation process consisted of sulfuric acid impregnation at different impregnation ratio followed by carbonization at 250–400°C for 1–4 h. The results show that the impregnation ratio was 1.25, the optimum activation temperature was 300°C and the activation time was 1 h. The sorption capacity of the activated carbon was 25.1 mg/g. Keywords: copper (II) ion sorption, maize stems, sulfuric acid activato
THE USE OF ALGAE CONCENTRATES, DRIED ALGAE AND ALGAL SUBSTITUTES TO FEED BIVALVES
No full textMicroalgae has high nutritional value and are used to feed adult and larval stages of bivalves, the larvae of some fish and crustaceans and zooplankton. However, microalgae production for aquaculture animal is very expensive. To overcome this, the use of preserved microalgae such as algae concentrate and dried algae, or algal substitutes has been developed. There are both advantages and disadvantages to this alternative food. For example, even though the cost production for algal substitute yeast-based diet is cheaper, their nutritional value is much lower compared to fresh microalgae. Moreover, there is no significant difference in nutritional value between preserved (concentrated or dried) and fresh microalgae; however, preserving microalgae for long periods will affect their nutritional value. In spite of this problem, preserved microalgae such as algal concentrate and dried algae seem to be more effective to feed bivalves than algal substitutes yeast based diet due to their availability and relatively high nutritional value. Furthermore, algae concentrates are more suitable to replace fresh algae than dried algae.Keywords: algae concentrate, bivalves, dried algae, microalgae, yeas
HUBUNGAN FILOGENETIK SPESIES LIMNONECTES (RANIDAE: AMPHIBIA) ASAL SUMATERA BARAT DAN ASAL ASIA TENGGARA BERDASARKAN GEN 16S RIBOSOMAL RNA
No full textPhylogentic Relationship among Limnonectes (Ranidae: Amphibia) found in West Sumatra with Other Species from South East Asia based on the based on the 16S rRNA Gen. The objective of this research was to study the phylogenetic relationship among Limnonectes species found in West Sumatra and with other species from South East Asia based on the partial DNA sequences16S rRNA sequences. DNA sequences were aligned using ClustalX version 1.64b, and the phylogenetic relationship within samples were analyzed using PHYLIP version 3.5c program. The alignment showed that, from 805 sites, there are 250 parsimony informative polymorphism sites. The phylogenetic tree showed that all of the Limnonectes spesies were divided in two clusters, the L. blythii complex and L. kuhlii complex. L. kuhlii and L. sp1 clustered into L. kuhlii complex and L. shomponerum and L. macrodon were clustered to L. blythii complex. This result showed that L. kuhlii and L. blythii are species complexes that are actually constituted of several species. Keywords: 16S rRNA, Limnonectes, West Sumatr
DETEKSI CEPAT BAKTERI Escherichia coli DALAM SAMPEL AIR DENGAN METODE POLYMERASE CHAIN REACTION MENGGUNAKAN PRIMER 16E1 DAN 16E2
No full textRapid Detection of Escherichia coli in Water Samples by Polymerase Chain Reaction Using 16E1 and 16E2 Primers. The detection of Escherichia coli in various water samples by Polymerase Chain Reaction method using 16E1 and 16E2 primers has been carried out. It was found that four out of ten samples were detected Escherichia coli and revealed the presence of the amplified product of the size 584 base pairs. Confirmation test of PCR result was also done using the conventional culturing method. The results of this study showed that the PCR assay was specific and faster than the conventional culturing method for detection of Escherichia coli. Keywords: 16E1 and 16E2 primers, Escherichia coli, PCR, wate
KOMPOSISI KIMIA MINYAK ATSIRI DAUN AKWAY
No full textChemical Composition of Essential Oil from Akway. Akway (Drimys piperita Hook f.) is a woody, evergreen and aromatic plan that was a member of winteraceae. This plant is used by Sougb tribe lived in Sururey village, District of Manokwari, to heal malaria and to enhance the vitality of body. The objectives of this research were to know the yield of essential oil using water distillation of leaves and its chemical composition using gas chromatography and mass spectroscopy (GC-MS). The results indicated that the yield of leaves essential oil by using water distillation was 0.2%. The essential oil composed by 49 compounds categorized by terpene and its derivatives 83.67%, derivatives of benzene 4.08% and alifatic compounds 8.16%.Keywords: Drimys piperita, essential oil compound
ACTIVITY OF ETHANOLIC EXTRACT FROM Justicia gendarussa Burm. LEAVES ON DECREASING THE URIC ACID PLASMA
No full textThe effect of Justicia gendarussa leaves extract has been investigated using oxonate-induced hyperuricemic male albino rats. In this experiment thirty five male albino rats were divided randomly into seven groups. There were three group doses variations of J. gendarussa extract that were 1.3 g/kg bw, 2.6 g/kg bw and 5.2 g/kg bw; two comparison groups that were allopurinol 0.68 g/kg bw and herbal “X” 0.85 g/kg bw; and two control groups that were induced control potassium oxonate 0.25 mg/kg bw and normal control CMC 0,5 %. Intraperitoneal administration of potassium oxonate 0.25 mg/kg bw was given one hour before administration of test drugs in eight day and plasma uric acid was measured in rats after two hours. Plasma uric acid was measured by spectrophotometric on 520 nm with enzymatic method. The results showed that all extracts could reduced uric acid level of rats. The decreasing potency of uric acid level was equal to doses increase, so the best result that can reduce uric acid level was J. gandarussa extract at a dose 5.2 g/ kg bw. This results indicated that J. gendarussa leaves extract may be effective for the prevention and the treatment of hyperuricemia.Keywords: enzymatics, hyperuricemia, Justicia gendarussa Burm, spectrophotometri
THE DEVELOPMENT OF BIOCHEMICAL OXYGEN DEMAND SENSOR USING LOCAL YEAST: Candida fukuyamaensis, UICC Y-247
No full textIn order to shorten the measurement time of biochemical oxygen demand (BOD), a BOD sensor based on yeast metabolism was developed. Local yeast, Indonesian Origin, Candida fukuyamaensis UICC Y-247, was used as a transducer. The yeast was immobilized as a thin film in agarose matrix with the auxiliary of Nafion® acting as the membrane for ion exchange process. The film was then attached to gold-modified glassy carbons and used as transducer on the working electrodes. The measurements were conducted by observing the depletion of glucose concentration using multipulse amperometric method and then converted to BOD values. Optimum condition was observed in a waiting measurement time of 30 min at an applied potential of 450 mV (vs. Ag/AgCl). Linearity was shown in glucose concentration range of 0.1–0.5 mM, which was equivalent to BOD concentration range of 10–50 mg/L. A detection limit of 1.13 mg/L BOD could be achieved. Good repeatability was shown by a relative standard deviation (RSD) of 2.7% (n = 15). However, decreasing current response of ~50% was found after 3 days. Comparing to the conventional BOD measurement, this BOD sensor can be used as an alternative method for BOD measurements.Keywords: amperometr, BOD sensor, Candida fukuyamaensis UICC Y-247, gold-modified carbon, Indonesian yeas
ANALISIS SENYAWA METABOLIT SEKUNDER DARI EKSTRAK METANOL DAUN SURIAN YANG BERPOTENSI SEBAGAI ANTIOKSIDAN
No full textSecondary Metabolites Analysis of Methanol Extract of Surian (Toona sureni (Bl.) Merr) Leaf as Antioxidant Potential. The study of performed secondary metabolites from the methanol extract of Surian (Toona sureni (Bl.) Merr) leaves have been done by thin-layer chromatography (TLC) method. The result showed that methanol extract of Surian leaves consist of alkaloid, flavonoid, polyphenol and terpenoid. All of them positively have the ability to scavenge 2,2- diphenyl-1-picrylhydrazyl (DPPH). It has IC50 (4.80) are smaller than the ascorbat acid standard (IC50 = 9.23).Keywords: antioxidant, diphenyl picrylhydrazyl, Toona suren
STUDI PERBANDINGAN SIFAT MEKANIK POLYPROPYLENE MURNI DAN DAUR ULANG
No full textComparative Studies on Mechanical Properties of As-received and Recycled Polypropylenes Characteristic of Pure and Recycled Polypropylene. In this study, the mechanical properties and the fracture areas of as-received, recycled, and commercial recycled Polypropylenes (PPs) used for cloth hanger materials were compared. Differential Scanning Calorimetry (DSC) test results showed that recycling process did not cause a significant change to the material’s melting point, which stayed in a range of 160-163 oC. Meanwhile, Fourier Transform Infrared (FTIR) test results showed that the commercial recycled PPs contained of polyethylene (PE), which was not found in the asreceived and recycled PPs. Tensile and hardness tests demonstrated that there were no significant differences between the as-received and recycled PPs. In contrast, tensile test results of the commercial recycled PPs showed that the tensile strength, Young modulus and strain-at-break were lower than those of the as-received PPs by 22.1%, 8.1% and 65.7% respectively. The hardness test results of the commercial recycled PPs showed that the recycling process had a little effect on the material’s hardness. These facts were supported by Scanning Electron Microscope (SEM) observation on the surface that the contour of the commercial recycled PPs was relatively flatter and had smaller grain size than those of the as-received PPs. This indicated that the commercial recycled PPs were more brittle compared to the recycled PPs. To conclude, the recycled PPs have similar properties to the as-received PPs so that recycled PPs are suitable to be applied as cloth hanger application. Keywords: DSC, FTIR, hardness, polypropylene, SEM, tensile strengt
SYNTHESIS AND CHARACTERIZATION OF TiO2(B) NANOTUBES PREPARED BY HYDROTHERMAL METHOD USING [Ti8O12(H2O)24]Cl8.HCl.7H2O AS PRECURSOR
No full textLow-dimensional TiO2-related material has been synthesized by hydrothermal treatment of [Ti8O12(H2O)24]Cl8.HCl.7H2O) crystal as precursor in a 10 M NaOH aqueous solution at 150 °C for 24 h. Characterization of the obtained product was carried out by a range of techniques including X-ray diffraction (XRD), high resolution scanning electron microscopy (HRSEM), high resolution transmission electron microscopy (HRTEM), Raman spectroscopy and nitrogen adsorptiondesorption isotherm (Brunauer-Emmett-Teller (BET)-Barret-Joyner-Halender (BJH)). From HRTEM, XRD and Raman spectra showed that the obtained product has a TiO2(B) structure. According to HRTEM observations, it was found that TiO2(B) has nanotubular structure with approximately 5-8 nm in outer and 3-6 nm in inner diameter. The BET surface area of TiO2(B) nanotubes is quiet large, values of 418.3163 m2/g being obtained. Pore structure analysis by the BJH method showed that the average pore diameter of TiO2(B) nanotubes has 5.5781 nm. Keywords: hydrothermal methodnanotubes, synthesis, TiO2(B), titani