Samarinda, Indonesia

Mulawarman University
Samarinda, Indonesia

The Universitas Mulawarman is a public university located in Samarinda, East Kalimantan, Indonesia. It was established on September 27, 1962, making it the oldest tertiary education institution in East Kalimantan. With more than 35,000 students, Universitas Mulawarman is the university with the most students in Kalimantan. Its main campus is in Gunung Kelua, while other campuses are in Pahlawan Road, Banggeris Street and Flores Street of Samarinda.Universitas Mulawarman is striving to be the world-class university which is able to play a role in development through education, research and community service which relies on natural resources, especially the tropical rainforest and its environment. Wikipedia.

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Nurhadi M.,Mulawarman University
AIP Conference Proceedings | Year: 2017

Titania supported sulfonated coal was created as heterogeneous catalyst for epoxidation of 1-octene with aqueous hydrogen peroxide as oxidant at room temperature. The catalysts were prepared from coal that was sulfonated with H2SO4 (97%) and impregnated 7.2%wt with titanium(IV) isopropoxide (Ti(PrO)4). All catalysts coal (C), CS, Ti(7.2)-CS and Ti(7.2)-CSC were characterized by FTIR. The catalytic performance was tested for epoxidation of 1-octene with H2O2 aqueous as oxidant. It is found that Ti(7.2)-CS possessed the best catalytic performance and it gave the highest 1,2 epoxyoctene 322 μmol. © 2017 Author(s).

Akhsan N.,Mulawarman University | Vionita,Mulawarman University
AIP Conference Proceedings | Year: 2017

An experiment aimed to determine the effect of application of several types of local microorganisms (MOL) and the number of doses to the development of fungi and bacteria on soybean planting media, have been conducted in Samarinda for 3 (three) months. Factorial experiment arranged in a completely randomized design and repeated three times, was used in this experiment. The first factor was the type of MOL consisted of cow dung (m1), snails (m2), banana peel (m3) and bamboo roots (m4), and the second factor was the dose MOL zero mL (d0), 100 mL (d1), 200 mL (d2), 300 mL (d3), 400 mL (d4) analyzed with Anova and Least Significance Difference (LSD) at 5%. Fungi and bacteria contained in the local microorganisms (cow dung, snails, banana peel and bamboo root) are: fungus Aspergillus sp, Penicillium sp., Trichoderma sp., cellulotic and lignolitic bacteria. An increase in the type and amount of fungus is happened for some genus. The dominant bacteria in the planting medium is a gram-negative bacteria. Cow dung seemed the best source at the dosages level of 400 ml. © 2017 Author(s).

Astuti I.F.,Mulawarman University | Cahyadi D.,Mulawarman University
AIP Conference Proceedings | Year: 2017

Thesis is one of major requirements for student in pursuing their bachelor degree. In fact, finishing the thesis involves a long process including consultation, writing manuscript, conducting the chosen method, seminar scheduling, searching for references, and appraisal process by the board of mentors and examiners. Unfortunately, most of students find it hard to match all the lecturers' free time to sit together in a seminar room in order to examine the thesis. Therefore, seminar scheduling process should be on the top of priority to be solved. Manual mechanism for this task no longer fulfills the need. People in campus including students, staffs, and lecturers demand a system in which all the stakeholders can interact each other and manage the thesis process without conflicting their timetable. A branch of computer science named Management Information System (MIS) could be a breakthrough in dealing with thesis management. This research conduct a method called clustering to distinguish certain categories using mathematics formulas. A system then be developed along with the method to create a well-managed tool in providing some main facilities such as seminar scheduling, consultation and review process, thesis approval, assessment process, and also a reliable database of thesis. The database plays an important role in present and future purposes. © 2017 Author(s).

One of the coal combustion ashes is coal bottom ash. Low rank coal bottom ash can act as TiO2 catalyst's support which was calcined at varying temperature, has been created. The low rank coal bottom ash model was collected from low rank coal which burned in muffle furnace at 800 °C for 2 h. Subsequently, the low rank coal bottom ash was impregnated with titanium(IV) isopropoxide (Ti(PrO)4) 500 μmol, and then calcined at variation temperature of 300, 400, 500, 600 and 700 °C. The modified physiochemical property of catalysts were determined UV-vis spectroscopy, N2 adsorption-desorption and hydrophobicity test. The performances of the catalysts were tested for styrene oxidation with H2O2 aqueous as oxidant. It is found that the low rank coal bottom ash was as good catalyst support, whereby TiO2 supported low rank coal bottom ash which calcined at 400 °C possessed the best catalytic activity with styrene conversion 45% and selectivity 87%. © 2017 Trans Tech Publications, Switzerland.

The modified coal char from low-rank coal by sulfonation, titanium impregnation and followed by alkyl silylation possesses high catalytic activity in styrene oxidation. The surface of coal char was undergone several steps as such: modification using concentrated sulfuric acid in the sulfonation process, impregnation of 500 mmol titanium(IV) isopropoxide and followed by alkyl silylation of n-octadecyltriclorosilane (OTS). The catalysts were characterized by X-ray diffraction (XRD), IR spectroscopy, nitrogen adsorption, and hydrophobicity. The catalytic activity of the catalysts has been examined in the liquid phase styrene oxidation by using aqueous hydrogen peroxide as oxidant. The catalytic study showed the alkyl silylation could enhance the catalytic activity of Ti-SO3H/CC-600(2.0). High catalytic activity and reusability of the o-Ti-SO3H/CC-600(2.0) were related to the modification of local environment of titanium active sites and the enhancement the hydrophobicity of catalyst particle by alkyl silylation. Copyright © 2017 BCREC GROUP. All rights reserved.

Rayadin Y.,Ecology and Conservation Center for Tropical Studies | Rayadin Y.,Mulawarman University | Spehar S.N.,University of Wisconsin - Oshkosh
American Journal of Physical Anthropology | Year: 2015

Body mass is a key determinant of a species' ecology, including locomotion, foraging strategies, and energetics. Accurate information on the body mass of wild primates allows us to develop explanatory models for relationships among body size, ecology, and behavior and is crucial for reconstructing the ecology and behavior of fossil primates and hominins. Information on body mass can also provide indirect information on health and can be an important tool for conservation in the context of increasingly widespread habitat disturbance. This study reports body mass data recorded for wild Northeast Bornean orangutans (Pongo pygmaeus morio) during relocation efforts in forestry and oil palm plantations in East Kalimantan, Indonesia. The average mass of flanged adult males (n = 12, 74 ± 9.78 kg) and adult females (n = 7, 35.29 ± 7.32 kg) from this study were 13.6% and 9% lower, respectively, than the only other published wild Bornean orangutan body mass measurements, but the range of weights for both males and females was larger for this study. This pattern could be due to sampling error, data collection differences, or the influence of habitat disturbance, specifically a lack of access to resources, on individual health. When necessary relocations present the opportunity, we encourage researchers to prioritize the collection of body size data for the purposes of understanding ecology but also as an indirect means of monitoring population viability. As primate habitat becomes increasingly fragmented and altered by humans such data will become critical to our ability to make informed conservation decisions. © 2015 Wiley Periodicals, Inc.

Hadibarata T.,Ehime University | Hadibarata T.,Mulawarman University | Tachibana S.,Ehime University
Journal of Environmental Sciences | Year: 2010

Polyporus sp. S133, a fungus collected from contaminated soil, was used to degrade phenanthrene, a polycyclic aromatic hydrocarbon, in a mineral salt broth liquid culture. A maximal degradation rate (92%) was obtained when Polyporus sp. S133 was cultured for 30 days with agitation at 120 r/min, as compared to 44% degradation in non-agitated cultures. Furthermore, the degradation was affected by the addition of surfactants. Tween 80 was the most suitable surfactant for the degradation of phenanthrene by Polyporus sp. S133. The degradation rate increased as the amount of Tween 80 added increased. The rate in agitated cultures was about 2 times that in non-agitated cultures. The mechanism of degradation was determined through the identification of metabolites; 9,10-phenanthrenequinone, 2,2′-diphenic acid, phthalic acid, and protocatechuic acid. Several enzymes (manganese peroxidase, lignin peroxidase, laccase, 1,2-dioxygenase and 2,3-dioxygenase) produced by Polyporus sp. S133 were detected during the incubation. The highest level of activity was shown by 1,2-dioxygenase (187.4 U/L) after 20 days of culture. © 2010 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences.

Rustam,Mulawarman University
Raffles Bulletin of Zoology | Year: 2016

Little is known about the ecology of the rare marbled cat Pardofelis marmorata on Borneo. In addition, the little information that is available on the species often comes from incidental sightings. Here we use the MaxEnt algorithm to produce a habitat suitability map for this species based on a compilation of existing data. We collected 105 marbled cat occurrence records for Borneo, of which 27 (Balanced Model) or 69 (Spatial Filtering Model) were used to estimate potential habitat suitability. The resulting relative habitat suitability map showed key conservation areas in Borneo. According to these results it appears that the most suitable habitats for marbled cat are lowland forests, but these forests are most threatened by deforestation and other anthropogenic activities. It is imperative to develop appropriate conservation strategies for the marbled cat on Borneo, including long-term research and monitoring, reduction of human disturbances in lowland forests, increased data-sharing and research networking, and stakeholder involvement for conservation planning and activities. © 2016 National University of Singapore.

Hindryawati N.,Universiti Malaysia Pahang | Hindryawati N.,Mulawarman University | Maniam G.P.,Universiti Malaysia Pahang
Ultrasonics Sonochemistry | Year: 2015

This study demonstrates the potential of Na-silica waste sponge as a source of low cost catalyst in the transesterification of waste cooking oil aided by ultrasound. In this work an environmentally friendly and efficient transesterification process using Na-loaded SiO2 from waste sponge skeletons as a solid catalyst is presented. The results showed that the methyl esters content of 98.4 ± 0.4 wt.% was obtainable in less than an hour (h) of reaction time at 55 °C. Optimization of reaction parameters revealed that MeOH:oil, 9:1; catalyst, 3 wt.% and reaction duration of 30 min as optimum reaction conditions. The catalyst is able to tolerant free fatty acid and moisture content up to 6% and 8%, respectively. In addition, the catalyst can be reused for seven cycles while maintaining the methyl esters content at 86.3%. Ultrasound undoubtedly assisted in achieving this remarkable result in less than 1 h reaction time. For the kinetics study at 50-60 °C, a pseudo first order model was proposed, and the activation energy of the reaction is determined as 33.45 kJ/mol using Arrhenius equation. © 2014 Elsevier B.V. All rights reserved.

Erwin. 2016. Microscopic decay pattern of yellow meranti (Shorea gibbosa) wood caused by white-rot fungus Phlebia brevispora. Biodiversitas 17: 417-421. The anatomical changes of wood decaying caused by white-rot fungus Phlebia brevispora could provide the basis for evaluating and analysis of decay on yellow meranti (Shorea gibbosa) heartwood. By using soil-block test procedure of JIS K-1571 and microscopic analysis, a progressive decay in vitro of S. gibbosa wood caused by P. brevispora was well characterized. The percentage of wood weight loss was ranged from 0.91% to 12.34%in 2-12 weeks' incubation. On the first 6 weeks of incubation of S. gibbosa infected with P. brevispora, the early stages decay, in which pit erosion and slight erosion of cell walls facilitated by hyphal spreading among cells. The intermediate decay features of numerous and conspicuous holes as well as erosion troughs in cell walls were found after 8 weeks' incubation. Furthermore, complete degradation of wood cell components, defined as the advanced stage of decay, was found in some areas of wood after 12 weeks' incubation. The pattern of wood decay was similar to those of the decayed xylem of S. gibbosa stem canker in field conditions. © 2016, Society for Indonesian Biodiversity. All right reserved.

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