Yogyakarta, Indonesia

Islamic University of Indonesia

Yogyakarta, Indonesia

The Islamic University of Indonesia is a private university located in Yogyakarta, Indonesia. It was established in 27 Rajab 1364 or in 8 July 1945 as STI by political figures of the day including Dr. Muhammad Hatta, Mohammad Natsir, Mohammad Roem, Wachid Hasyim as well as Abdul Kahar Mudzakir. STI developed into a university called Universitas Islam Indonesia on 14 December 1947. Historically, UII is the first national university in Indonesia, and it is also the oldest private university in the country.The university is located in Sleman, Daerah Istimewa Yogyakarta. Wikipedia.

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Fatimah I.,Islamic University of Indonesia
IOP Conference Series: Materials Science and Engineering | Year: 2017

TiO2-SiO2have been synthesized by the sol-gel method from titanium isopropoxide and varied silica precursors: tetraethyl orthosilicate and tetra methyl ortho silicate. To study the effect of the precursor, prepared materials were characterized by X-ray diffraction, scanning electron microscopy, Diffuse Reflectance UV-vis optical absorption, and also gas sorption analysis. XRD patterns showed the formation of TiO2 anatase in the TiO2-SiO2 composite with different crystallite size from different silica precursor as well as the different surface morphology. The DRUV-vis absorption spectra exhibit similar band gap energy correspond to 3.21eV value while the surface area, pore volume and pore radius of the materials seems to be affected by the precursor. The higher specific surface area contributes to give the enhanced activity in phenol hydroxylation and methylene blue photodegradation. © Published under licence by IOP Publishing Ltd.

Teguh M.,Islamic University of Indonesia
Procedia Engineering | Year: 2017

Masonry infill walls of reinforced concrete frame structures are commonly used for non-engineered and engineered buildings. For this establishment, exterior walls and interior partitions are made of masonry for producing a cost-effective solution for building purposes. Although walls are usually considered as a non-structural element of reinforced concrete frame structures, the masonry infill walls contribute significantly to the seismic building performance. The interaction effect between bounding frame and infill wall is a complicated issue in the experimental test. This paper presents experimental investigations of masonry infill walls of RC frame buildings under cyclic in-plane loads. Three typical reinforced concrete frames with and without infill masonry walls were experimentally conducted to seek their structural behavior in terms of stiffness, strength and ductility of the structures. In this research, tie-beam and tie-column (practical beam and column) components applied to non-engineered buildings were adopted to perform typical reinforced concrete frames. Their hysteretic behavior of RC frames as well as the effect of gaps between the frame and the infill on the structural behavior are briefly discussed. © 2017 The Authors.

Pawirodikromo W.,Islamic University of Indonesia
Procedia Engineering | Year: 2017

A numerical investigation was conducted on the damage potential of 25-low frequency content ground motions (earthquake) normalized to be the maximum of 0.30 g. The damage potential is measured based on several parameters started from the simplest parameter (Level-1) to the complex parameter (Level-5). The global inelastic response of 10-story RC structure subjected to the corresponding ground motions, i.e the base shear, roof horizontal displacement, hysteretic energy and element damage index, have been used as damage indicators. Then, the ground motion parameters were correlated with the damage indicators. Results of the investigation showed that among the damage indicators are well correlated. The A/V ratio is relatively simple parameter (Level-2) and possesses relatively consistent and high correlation coefficient R with the damage indicators. Accordingly, A/V ratio can be stated as simple damage potential to cause severity of the structure under earthquake excitation. © 2017 The Authors.

Muhaimin,Islamic University of Indonesia
Journal of Physics: Conference Series | Year: 2017

Simulation distribution of pollutants (SOx and NOx) emitted from Cirebon power plant activities have been carried out. Gaussian models and scenarios are used to predict the concentration of pollutant gasses. The purposes of this study were to determine the distribution of the flue gas from the power plant activity and differences pollutant gas concentrations in the wet and dry seasons. The result showed that the concentration of pollutant gasses in the dry season was higher than the wet season. The difference of pollutant concentration because of wind speed, gas flow rate, and temperature of the gas that flows out of the chimney. The maximum concentration of pollutant gasses in wet season for SOx is 30.14 μg/m3, while NOx is 26.35 μg/m3. Then, The simulation of air pollution in the dry season for SOx is 42.38 μg/m3, while NOx is 34.78 μg/m3. © Published under licence by IOP Publishing Ltd.

Miranda S.,Islamic University of Indonesia
IOP Conference Series: Materials Science and Engineering | Year: 2017

The purpose of this study is to analyze the variables affecting the determination of the sale price of vegetable which is constant over time in a supermarket qualitatively and quantitavely. It focuses on the non-organic vegetable with a fixed selling price over time such as spinach, beet, and parsley. In qualitative analysis, the sale price determination is influenced by the vegetable characteristics: (1) vegetable segmentation (low to high daily consumed); (2) vegetable age (how long it can last related to freshness); which both characteristic relates to the inventory management and ultimately to the sale price in supermarket. While quantitatively, the vegetables are divided into two categories: the leaf vegetable group that the leaves are eaten as a vegetable with the aging product (a) = 0 and the shelf life (t) = 0, and the non-leafy vegetable group with the aging group (a) = a+1 and the shelf life (t) = t+1. The vegetable age (a) = 0 means they only last for one day when they are ordered then they have to terminate. Whereas a+1 is that they have a longer life for more than a day such as beet, white radish, and string beans. The shelf life refers to how long it will be placed in a shelf in supermarket in line with the vegetable age. According to the cost plus pricing method using full price costing approach, production costs, non-production costs, and markup are adjusted differently for each category. There is a holding cost added to the sale price of the non-leafy vegetable, yet it is assumed a 0 holding cost for the leafy vegetable category. The amount of expected margin of each category is correlated to the vegetable characteristics. © Published under licence by IOP Publishing Ltd.

Harwati,Islamic University of Indonesia
IOP Conference Series: Materials Science and Engineering | Year: 2017

Supplier selection is a decision with many criteria. Supplier selection model usually involves more than five main criteria and more than 10 sub-criteria. In fact many model includes more than 20 criteria. Too many criteria involved in supplier selection models sometimes make it difficult to apply in many companies. This research focuses on designing supplier selection that easy and simple to be applied in the company. Analytical Hierarchy Process (AHP) is used to weighting criteria. The analysis results there are four criteria that are easy and simple can be used to select suppliers: Price (weight 0.4) shipment (weight 0.3), quality (weight 0.2) and services (weight 0.1). A real case simulation shows that simple model provides the same decision with a more complex model. © Published under licence by IOP Publishing Ltd.

Lestari P.,Islamic University of Indonesia
AIP Conference Proceedings | Year: 2017

Humic acid (HA) has been isolated from South Kalimantan (Indonesia) peat soil using alkali extraction method. The isolated HA then was applied on the adsorption process of AuCl4- in solution. Parameters investigated in the adsorption process consisted of the effect of initial pH, adsorption rate constant (k) and the adsorption capacity of AuCl4- on peat soil HA. The adsorption rate constant was determined according to the kinetic model proposed by Santosa (2007). The adsorption of AuCl4- on peat soil HA was optimum at pH 2. The adsorption rate constant (k) was 1.11 × 10-3 min-1. Adsorption of AuCl4- on peat soil HA fitted the Langmuir isotherm with the adsorption capacity of 90.91 mg.g-1. The adsorption of AuCl4- on peat soil HA was accompanied by the reduction of AuCl4- to Au(0), clarified by the existence of several peaks belonging to Au(0) in the XRD pattern of HA after the adsorption process. © 2017 Author(s).

Merdekawati K.,Islamic University of Indonesia
AIP Conference Proceedings | Year: 2017

Two of bachelor of chemical education's competences are having practical skills and mastering chemistry material. Practicum courses are organized to support the competency achievement. Based on observation and evaluation, many problems were found in the implementation of practicum courses. Preliminary study indicated that 5E Learning Cycle can be used as an alternative solution in order to improve the quality of chemistry practicum course. The 5E Learning Cycle can provide positive influence on the achievement of the competence, laboratory skills, and students' understanding. The aim of the research was to describe the feasibility of implementation of 5E Learning Cycle on chemistry practicum courses. The research was based on phenomenology method in qualitative approach. The participants of the research were 5 person of chemistry laboratory manager (lecturers at chemistry and chemistry education department). They concluded that the 5E Learning Cycle could be implemented to improve the quality of the chemistry practicum courses. Practicum guides and assistant competences were organized to support the implementation of 5E Learning Cycle. It needed training for assistants to understand and implement in the stages of 5E Learning Cycle. Preparation of practical guidelines referred to the stages of 5E Learning Cycle, started with the introduction of contextual and applicable materials, then followed with work procedures that accommodate the stage of engagement, exploration, explanation, extension, and evaluation. © 2017 Author(s).

16S rRNA gene analysis of bacteria lactic acid (LAB) isolate from Markisa Kuning Fruit (Passiflora edulis var. flavicarpa) as a producer of protease enzyme and probiotics has been done. The aim of the study is to determine the protease enzyme activity and 16S rRNA gene amplification using PCR. The calculation procedure was done to M4 isolate bacteria lactic acid (LAB) Isolate which has been resistant to acids with pH 2.0 in the manner of screening protease enzyme activity test result 6.5 to clear zone is 13 mm againts colony diametre is 2 mm. The results of study enzyme activity used spectrophotometer UV-Vis obtainable the regression equation Y=0.02983+0.001312X, with levels of protein M4 isolate is 0.6594 mg/mL and enzyme activity of obtainable is 0.8626 unit/ml while the spesific enzyme activity produced is 1.308 unit/mg. Then, 16S rRNA gene amplificatiom and DNA sequencing has been done. The results of study showed that the bacteria species contained from M4 bacteria lactic acid (LAB) isolate is Weisella cibiria strain II-I-59. Weisella cibiria strain II-I-59 is one of bacteria could be utilized in the digestive tract. © 2017 Author(s).

Fatimah I.,Islamic University of Indonesia | Huda T.,Islamic University of Indonesia
Applied Clay Science | Year: 2013

Organo-clays of cetyltrimethylammonium(CTMA)-intercalated montmorillonite from a naturally occurring Indonesian montmorillonite were prepared. Previous research showed that the insertion of surfactants into interlayer spaces in montmorillonite improved the adsorption of hydrophobic chemicals. The current research focused on the effects of preparation variables, the concentration of CTMA surfactant, the cation exchange capacity (CEC) of the montmorillonite clay and their ratio (CTMA/CEC) on the physicochemical characteristics of the organo-clays and adsorption of toluene. X-ray diffraction (XRD), surface area analysis, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were used to compare the physicochemical characteristics of the modified and unmodified montmorillonite clays. The adsorption of toluene was studied in kinetics and isotherm. It was found that the CTMA/CEC ratio strongly affected the physicochemical properties and adsorption capacities of the montmorillonite surfaces. Adsorption kinetics was evaluated by pseudo-first order, pseudo-second order and Elovich models. Adsorption isotherm was assessed with the Langmuir, Freundlich and Temkin isotherms. The data were best fit by the pseudo-second order model and the Langmuir model. © 2012 Elsevier B.V.

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