99 research outputs found
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Kinetic and Thermodynamic Adsorption of Cr(VI) onto Dried Oscillatoria Splendida in Aqueous Solution
Full text linkKinetic and thermodynamic adsorption study of Cr(VI) ion in aqueous solutions by dried Oscillatoria Splendida biomass was investigated in the batch system. The Oscillatoria Splendida was isolated and cultured from algae swamp ecosystem in South Sumatera. The adsorption properties of Cr(VI) onto dried Oscillatoria Splendida biomass was studied by the influences of contact time, initial Cr(VI) ion concentration and temperature of reaction. The experimental results were the rate of adsorption followed the second-order kinetic model with the rate of reaction k2 is 0.00181 mg g-1 min-1 and the adsorption thermodynamic agree to the Langmuir’s model with amount of Cr(VI) removed from aqueous solution increased with increasing Cr(VI) concentration with the higher adsorption energy was 8.46 kJ/mol at 50 °C
Characterization and Optimization of Capryol-90, Polysorbate-80, And Peg-400 Proportion in Mefenamic Acid Self Nanoemulsifying Drug Delivery System (SNEDDS) With Simplex-Lattice-Design
Full text linkMefenamic acid as pain relief drug belongs to the biopharmaceutics classification system (BCS) class II which is practically insoluble in water causing extremely low dissolution in gastrointestinal tract. The self nanoemulsifying drug delivery system (SNEDDS) is a new innovation pharmaceutical dosage form that has effectively known to increase solubilization of hydrophobic drug in polar solvent. In this study the capryol-90 was selected as oil phase in SNEDDS as it showed maximal solubility of mefenamic acid (20 mg/mL). Combination of polysorbate-80 and PEG-400 as a generally regarded as safe (GRAS) excipient were used as surfactant and co-surfactant in SNEDDS due to its high HLB property that can increase mefenamic acid solubility in water. The ternary phase diagram of capryol-90, polysorbate-80, and PEG-400 was constructed in advance to obtain the component concentration of spontaneous nanoemulsion region. Model simplex-lattice-design cooperated in Design-Expert®10 was used to define SNEDDS mefenamic acid formula. Optimized mefenamic acid SNEDDS formula consisted of 20% capryol-90, 31.62% polysorbate-80, and 48.38% PEG-400. Characterization study of Optimized mefenamic acid SNEDDS formula showed improvement of drug content (102.820 ± 4.950)%, emulsification time (421.015 ± 1.290) second, and viscosity (0.927 ± 0.017) mm2/s 30oC. One way ANOVA statistical analysis result of optimal formula SNEDDS (105.210 ± 4.425)% of drug content, commercial generic caplet (0.917 ± 0.094)%, and mefenamic acid powder capsule (10.446 ± 0,333)% gave significant value (sig*) below than 0.05. Optimal formula proved that SNEDDS can significantly increase mefenamic acid dissolution of pH 7.4 (ileum fluid). The optimal formula of mefenamic acid SNEDDS successfully formed an uniformity droplet size (PDI 0.18) with mean size 241.9 nm and the surface charge has a value of -16.5 mV respectively
Synthesis of Alkyd Resin Modified with Waste Palm Cooking Oil as Precursor Using Pretreatment with Zeolite Adsorbent
Full text linkResearch on synthesis of alkyd resin (AR) modified with waste palm cooking oil (WPCO) as precursor using alcoholys-polyesterification method was successfully conducted. The modified alkyd resin was characterized using Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetry-Differential Thermal Analysis (TG-DTA). The pretreatment was carried out for WPCO by applying adsorption technique using zeolites to remove free fatty acid (FFA). Modified alkyd resin was synthesized with the main ingredients composition consisting of WPCO, glycerol, anhydrous phthalate with the oil length of 40% at the total weight of 27.54 grams, and a small amount of CaO as catalyst. The characterization result using FTIR showed the presence of typical alkyd resin compound group at the absorption peaks 1597.06 and 1651.07 consecutively as the vibration of benzene ring from the phthalate and C=C stretching of unsaturated fatty acids. The thermal characterization was performed by using TG-DTA analysis showing that the transition glass and recrystallization at the temperature 390.25 °C and 482.46 °C respectively
Morphological Diversity of Lansium domesticum Corr in South Sumatra
Full text linkResearch on the Morphological Diversity of Lansium domesticum Corr in South Sumatra aims to examine the morphological diversity of L. domesticum in South Sumatra. The research was conducted in April 2017 to June 2017. This research was conducted by means of exploration carried out in seven districts covering, East Ogan Komering Ulu District, South Ogan Komering Ulu District, Ogan Komering Ulu District, Musirawas District, Ogan Komering Ilir District, Muara Enim District and Musi Banyuasin District. Sampling was done using purposive sampling method. Observation of morphological diversity was done by characterization of morphology and analyzed by the descriptive method. The result of this research shows that in South Sumatera, there were two variants of L. domesticum namely L. domesticum variant duku and L. domesticum variant langsat. Morphological characters that distinguish between duku and langsat variants were found under canopy conditions, the presence of hair on top and bottom surfaces of leaves, fruit shape, fruit skin thickness, fruit taste, and the presence of sap on ripe fruit
Analysis of Potential Landslides Using Geographic Information System (GIS) on Rail Tunnel in Gunung Gajah Village, Lahat Regency of South Sumatra
Full text linkLahat Regency is one of the cities which is prone to geological disasters such as landslides. The landslide is caused by a varied topography such as flat, hilly or mountainous. On January, 23rd 2016, the landslide occurred on the mouth of a railway tunnel in Gunung Gajah Village, Lahat Regency. The purpose of this study is to determine the influence of geological factor on the slope stability. The method of research is a survey method based on geographic information systems in the form of interpretation and analysis of the causes and triggers of landslides with a direct approach in the field by doing scoring an overlay technique. The analysis obtained the parameters of landslides such as: slope, lithology/physical properties of rocks, geological structure and land use. The results and conclusions of this research are the landslide potential distribution map in Gunung Gajah Village, Lahat Regency consisting of three classes of landslide vulnerability: low, medium and high and in the focus areas of research entering the high level of vulnerability
Development of Audit Energy Application for Residential Sector
Full text linkThe residential sector is the biggest electric energy user in Indonesia. In this sector, there is a potential electricity saving of up to 30%. This savings can be obtained by implementing energy conservation. Energy use intensity (EUI) is a measure in assessing the efficiency of a building. From the EUI value can then be determined the efficiency criteria of a residential building, is it very efficient, efficient, moderately efficient or wasteful. An energy audit application was developed to facilitate in assessing the efficiency of a residential building in consuming electricity. The efficiency assessment in the model building shows that there is a significant electricity saving after the conservation efforts conducted, even though the model building is included efficient in the use of electrical energy
Analysis of Vegetation in Green Open Space of Gasing Industrial Area
Full text linkThe study aims to determine the diversity of vegetation in the Green Open Space of the Gasing Industrial Area. The study was conducted from April to July 2017. The method of analysis used quadratic method with 2 plots at different location with three repetitions, quantitative data analysis was done on density value, dominance, frequency, important value and diversity index of each plant species. The results showed that vegetation consists of 16 tribes and 19 species, dominated by Pteridophyta and Spermatophyta. Value of vegetation diversity (2,24) and uniformity value 0,30. The higher number of the species, the higher diversity index of the species. Such characteristics are caused by environmental influences such as organic matter content and low pH and factors derived from human intervention.
Keywords: Vegetation, Diversity, industrial are
The Property of Continuity And Positively Definite Characteristic Function of Compound Poisson Distribution As The Sum of Geometric Distribution
Full text linkThe compound Poisson distribution as the sum of independent and identically random variables from geometric distribution is characterized by using characteristic function. The characteristic function of this compound distribution is obtained by Laplace-Stieltjes transform. It is provided a characterization of this compound distribution employing the properties of characteristic function as continuous and positively definite function
Diversity of Phytophagous and Entomophagous Insect on Yellow Alder Flower (Turnera subulata J.E SM and Turnera ulmifolia L.) Around the Palm Oil (Elaeis guineensis J.) Plantations
Full text linkYellow alder flower, with Indonesian name bunga pukul delapan, can influence the existence of phytophagous and entomophagous insect around any crops. The existence of these phytophagous and entomophagous insects would affect the diversity of predator and parasitoid insect species that come to these crops. This research was aimed to study the role of yellow alder flower in their influence of the presence of predatory and parasitoid insect that active in the Turnera subulata dan Turnera ulmifolia. The research was conducted at July to August 2017 in palm oil plantation of PT. Tania Selatan branch Burnai Timur 1. The results showed that phytophagous insect found in the yellow alder flower belonging to 6 orders and 25 families. Meanwhile for the entomophagous insect, it was belonging to the 7 orders and 15 families. The diversity index in Turnera subulate and Turnera ulmifolia was in range of 0.063 and 2.912 or higher than 2. The dominant index was low (in range of 0.091 to 0.125) and the evenness index was high enough in range 0.738 – 0.752