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Jakarta, Indonesia

Trisakti University is a private university located in west Jakarta, Indonesia. Founded on 29 November 1965, the university has more than 30,000 students. Wikipedia.

Moore T.A.,Cipher Consulting Ltd. | Moore T.A.,University of Canterbury | Bowe M.,Ephindo Energy Pte Ltd. | Nas C.,Trisakti University
International Journal of Coal Geology | Year: 2014

The Balikpapan Formation (Miocene age) in Sangatta, East Kalimantan is thick (>1500m) containing abundant coal seams that range in thickness from less than a meter to over 5m. Coal seams are distributed throughout the section and may represent 5 to 7% of the total formation thickness. Measured gas contents range from <1 to 13m3/t (as received basis). The variation is both stratigraphically and geographically controlled. In samples from three drill cores, trends of vitrinite reflectance, calorific value, and moisture content indicate that rank increases down hole. Measured gas content also increases down hole in each core locations. However the rate of change down hole for all of those parameters increases with proximity to the southwestern corner of a geological feature known locally as the Pinang Dome. The Sangatta area has a higher geothermal gradient (50°C/km) than most other parts of East Kalimantan (25-40°C/km). It is well documented that the southwest part of the Pinang Dome has elevated organic maturation levels. It is concluded that there is higher heat flow in this area and thus coal beds in proximity have been thermally altered. This is evident not just in the increased rank and measured gas contents but also in the higher CO2 and C2+ gas composition found adjacent to the southwest corner of the Pinang Dome. It is hypothesized that the gas origin in the higher rank area could be thermogenic while gas isotopes from the well furthest from the Pinang Dome, with the lowest rank coals, indicate biogenic origins. © 2014 Elsevier B.V. Source

Julian E.S.,Trisakti University
Telkomnika | Year: 2012

Bipolar transistor performances can be characterized by figures of merit such as cut-off frequency, maximum frequency of oscillation and Emitter Coupled Logic gate delay. We studied the required figures of merit for digital application and the effects of lateral and vertical scaling to the figures of merit of SiGe Heterojunction Bipolar Transistor. With lateral scaling, the width of emitter finger is scaled down from 0.25 to 0.12 μm while with the vertical scaling, the base width is scaled down to reduce the base delay. We also observed the effects of Ge profile and Ge fraction to the devices performances. Bipole3 5.3.1G is used to help us in the study. We found that high frequency cut-off and maximum frequency of oscillation as well as low Emitter Coupled Logic gate delay are all important for digital applications. Scaling down the emitter finger width enhanced the maximum frequency of oscillation and reduced Emitter Coupled Logic gate delay significantly while scaling down the base width increased the cutoff frequency and current gain. Source

Nurrohman H.,Tokyo Medical and Dental University | Nurrohman H.,Trisakti University | Nikaido T.,Tokyo Medical and Dental University | Takagaki T.,Tokyo Medical and Dental University | And 3 more authors.
Dental Materials | Year: 2012

Objectives: Interaction between specific functional groups and apatite crystals may contribute to adhesion. The present study investigated effects of four adhesives with different compositions on protection of crystals beneath the hybrid layer against acid-attack using transmission electron microscopy (TEM) and selected area electron diffraction (SAED). Methods: Human dentin was bonded with four adhesives; two with a carboxylic-based functional co-polymer (PAA): three-step etch-and-rinse Scotchbond Multi-Purpose (SMP, 3M ESPE) and one-step self-etch Adper Easy Bond (AEB, 3M ESPE), and two with a phosphate-based functional monomer (MDP): two-step etch-and-rinse Clearfil Photo Bond (CPB, Kuraray Medical) and two-step self-etch Clearfil SE Bond (CSE, Kuraray Medical). The specimens were the either left untreated (control) or subjected to acid-base challenge with demineralizing solution (pH 4.5) and 5% NaClO. All specimens were processed and observed by TEM. SAED was used to identify the presence or absence of apatite crystallites at the base or beneath hybrid layer before and after acid-base challenge. Results: An apatite-rich zone was observed beneath the partially demineralized hybrid layer of CSE. The zone was thinner in AEB, but a demineralization-susceptible area was found beneath it. The etch-and-rinse adhesives (SMP and CPB) demonstrated completely or predominantly demineralized hybrid layers, which were devoid of the acid-resistant apatite-rich zone. Significance: TEM/SAED evidence disclosed that the preserved dentin apatite crystals beneath the thin hybrid layer of the mild self-etch adhesives were protected against acid. Diffusion of reactive components beyond the hybrid layer, and their chemical bonding potential with the remaining crystals created the acid-base resistant zone. © 2012 Academy of Dental Materials. All rights reserved. Source

Trihandini I.,University of Indonesia | Wiradidjaja Adiwoso A.,Rehabilitation Center | Erri Astoeti T.,Trisakti University | Marks L.,Ghent University
International Journal of Paediatric Dentistry | Year: 2013

Background: Data on the oral situation of young people with intellectual disabilities are scarce, especially data of children from a developing country. Aim: To describe and to evaluate the oral treatment needs of Special Olympics Special Smiles Athletes in Indonesia between 2004 and 2009. Design: A cross-sectional study data were collected through interviews and clinical examinations using the Special Olympics Special Smiles CDC protocol. Participants: Indonesian Special Smiles athletes; their mean age was 13.46 years ± 2.97. Results: More than 70% of athletes had visible untreated decay. Almost 30% (29.8%) of the athletes had gingival inflammation. Pain in the oral cavity was reported by 28.6%. Athletes who had untreated decay reported 6.67 times (95% CI OR; 4.00-11.14) more pain compared to those who did not have untreated decay. Athletes living in provinces on Java Island had 1.54 times (95% CI OR; 1.15-2.07) more untreated decay compared to the athletes who live in provinces in outer Java Island. 21.63% of the screened athletes were referred to the dentist for urgent treatment. Conclusion: The results suggest that there is an elevated oral treatment need in Indonesian Special Smiles population. © 2012 John Wiley & Sons Ltd, BSPD and IAPD. Source

Hyland C.W.K.,Hyland Fatigue Earthquake Engineering | Wijanto S.,PT. Gistama Intisemesta | Wijanto S.,Trisakti University
Bulletin of the New Zealand Society for Earthquake Engineering | Year: 2010

The Padang earthquake is a timely reminder to New Zealand structural engineers of a number of things with respect to seismic design and construction practice of steel structures. These include: The importance of implementing the latest seismic loadings and design technology into new and existing structures without undue delay; The need to maintain an effective Building Code enforcement and audit process, including the keeping of publicly transparent compliance records; The important role of the design engineer in observing and auditing the interpretation and implementation of the design is essential, to prevent improper substitution of materials and illconsidered design changes; The need for ongoing continuing professional development and education for design, construction and building code enforcement officials to develop and maintain technical competency; The separation of non-structural elements from interfering with the primary seismic resisting system needs to be carried through diligently from design and into construction. Where structural separation is not achieved then design models for integrating unreinforced brickwork panels within moment resisting frames need to be developed, particularly for retrofit situations; The design for weak-axis bending of two way moment resisting steel frames requires careful attention to secondary effects, and should be avoided where possible; Non-self centring structural elements need to be identified at design stage and designed to minimise inelastic behaviour during ultimate limit state earthquakes; Diagonal bracing rods should be designed to avoid failure within couplings. Consideration should also be given to the dynamic response of the roof level bracing system to heavy wall induced lateral loads; Connections at the interface of steel work with concrete and masonry sub-trades need to be carefully monitored to ensure intended design performance is achieved; Unreinforced masonry without lateral tiebacks should be avoided on lintels over egress-ways; A guide of typical structural repair methods would also be a useful tool for post-earthquake use, to quickly identify appropriate repair strategies and allow repair estimates to be developed. At a philosophical level, should a post-earthquake repair be required to simply allow a resumption of functionality? Alternatively should the repair be required to reinstate the structural performance to its pre-earthquake strength? Or should the repair improve the seismic resisting performance of the structure in line with current earthquake engineering knowledge? Source

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