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Jurnal Teknosains
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Core Subject : Engineering,
JOURNAL TEKNOSAINS, is a journal which began publication in 2011, and is published each June and December. JOURNAL TEKNOSAINS is a series of scientific publications in science and technology area from the perspective of a multi and interdisciplinary studies. JOURNAL TEKNOSAINS is an interdisciplinary forum for the publication of original peer-reviewed, contributed and invited articles to improve and enhance science and technology. The journal provides a stimulating and informative variety of papers geared toward theory and practice in the hope that common information shared among a broad coalition of individuals and groups involved in science and technology will facilitate future efforts. JOURNAL TEKNOSAINS published by the Graduate School of Gadjah Mada University. All articles will be subjected to double-blind peer review process following a review by the editors.
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Articles 7 Documents
Search results for , issue " Vol 3, No 2 (2014): June" : 7 Documents clear
CONTACT ANGLE MEASUREMENT OF DENTAL RESTORATIVE MATERIALS BY DROP PROFILE IMAGE ANALYSIS M. Rinastiti, H. D. K. Yulianto dan
Jurnal Teknosains Vol 3, No 2 (2014): June
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (339.292 KB) | DOI: 10.22146/teknosains.6023

Abstract

The capability of initial microbial adhesion to dental restorative composites surface is influenced by the surface wettability of the materials. The common method to evaluate surface wettability of materials is contact angle measurement. The existing conventional method to measure contact angle is by means of a contact angle (CA)-Goniometer device, which is less practically applicable in clinical circumstances. Therefore, a more practical and applicable method is needed to measure contact angle in clinical circumstances. This research was performed to compare between contact angles measured by means of a CA-Goniometer device and a new practical method of drop profile image analysis. In addition, since there were two different formulas that can be used to calculate contact angle value from a drop profile image, then we also need to evaluate which formula is more reliable to be used. Tests were carried out using three composite discs (Clearfill-Kuraray Medical, Inc.) sample and deionised water for different measurement procedures. One drop of 3µl liquid was dropped onto the surface of the composite discs, and the drop profile image was captured by means of a customized home-made device connected to a digital camera. Two different formulas were used to calculate the contact angle value from the drop profile image, namely the “linier gradient equation” and the “tangential line”. The contact angle values obtained from the two different formulas were compared with the value obtained from the conventional method descriptively. Tests were carried out using three composite discs (Clearfill-Kuraray Medical, Inc.) sample and deionised water for different measurement procedures. One drop of 3µl liquid was dropped onto the surface of the composite discs, and the drop profile image was captured by means of a customized home-made device connected to a digital camera. Two different formulas were used to calculate the contact angle value from the drop profile image, namely the “linier gradient equation” and the “tangential line”. The contact angle values obtained from the two different formulas were compared with the value obtained from the conventional method descriptively. The differences in percentage between the contact angle value calculated by the “linier gradient equation” and “tangential line” formulas, and those calculated by means of the CA-Goniometer are 20,56% and 3,51%, respectively. It is obviously demonstrated that the value obtained by the “tangential line” formula has a smaller difference compared to those obtained by the “linier equation gradient” formula. Among the two different formulas, it is confirmed that the contact angle value calculated with the “tangential line” formula has closer similarity with the value obtained from the CA-Goniometer. This result confirms that the new practical method of drop profile image analysis is promising for measuring contact angle values in clinical circumstances. Related to the drop profile image analysis, the “tangential line” formula is more accurate compared to the “linier gradient equation” formula.
TEGANGAN RESIDU KEPING ARESTER SEBAGAI FUNGSI DARI CACAH KEPING ARESTER T. Haryono, Devia Eka Yunida dan
Jurnal Teknosains Vol 3, No 2 (2014): June
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (397.419 KB) | DOI: 10.22146/teknosains.6022

Abstract

Indonesia is a tropical area with a high intensity of repeating lightning strikes. The voltage is produced by lightning by increasing the presence of sensitive loads. Therefore, lightning can easily worsen the quality of consumer power, even if the generated voltage is relatively low. Lightning strikes can cause excessive voltage along the power lines. Its propagation can cause a voltage surge on low voltage systems, which can damage the equipment. Maintenance and protection against lightning strikes are necessary for the prevention of such damage. Arrester is a device that is intensively used nowadays by the general public to protect equipments from lightning strikes. It is used to protect the system from the danger of lightning by flowing current into the ground and leaving a certain resistance value, so that the system does not experience a surge voltage.This research was conducted through laboratory-scale testings using several major equipments, such as a high voltage generator, an impulse voltage generator, and an oscilloscope. Modifications of the tests were done using one to four 220 volt low voltage Merlin Gerin LTD arresters arranged in series, with a maximum current of 6.5 kA . Calculations using equations for low voltage circuit in series were done for more than four arresters. From the test results, it was found that the characteristics of the arrester residual voltage will rise when connected in series. Low voltage arresters can be used for higher voltage requirements by counting the number of arresters needed. The equation for the number of arresters in series required to cut the overvoltage surge is y = 0.694x – 0.106. Therefore, if more than 4 arresters will be needed, the residue voltage can be estimated through this formula. 
DAMPAK DAN KENDALA WISATA WADUK SERMO DARI ASPEK LINGKUNGAN HIDUP DAN RISIKO BENCANA dan M. Widyastuti, Sudarmadji
Jurnal Teknosains Vol 3, No 2 (2014): June
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (406.798 KB) | DOI: 10.22146/teknosains.6027

Abstract

Sermo Reservoir is a multipurpose reservoir. Due to its natural beauty and being the only reservoir in Yogyakarta Special Region, it is visited by many tourists. Tourism activities in the reservoir may cause environmental impacts and disaster risks for the tourists. This study aims to determine the potential of Sermo Reservoir as a natural tourism object and, in general, analyze the environmental impacts and disaster risks caused by tourism activities. The study was conducted by field surveys, observations and interviews with the local community. Reservoir water samples were collected for physical and chemical parameter analysis and were evaluated against the standard requirements of water for tourism activities. Data analysis was performed using descriptive qualitative and quantitative methods, using tables and diagrams of the processed data. In general it was found that the Sermo Reservoir has high potential for tourism. However, due to the lack of supporting facilities, the number of tourist coming to the Sermo Reservoir is still not yet optimal. The environmental impacts caused by tourism activities have occurred. The positive impacts that arise are the emerging business opportunities and the increased revenue of the local people, while the negative impacts are the pollution caused by solid waste and the water quality degradation. The risk of disaster may come from accidents when conducting activities in the reservoir, and it should be considered in the development of Sermo Reservoir for tourism.
PERKEMBANGAN LAYANAN TRANSPORTASI PERDESAAN PADA WILAYAH BERBUKIT Achmad Djunaedi, Dewanti, Danang Parikesit, dan
Jurnal Teknosains Vol 3, No 2 (2014): June
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (358.455 KB) | DOI: 10.22146/teknosains.6021

Abstract

Transport service development generally indicates some development problems and transport troubles in particular. This research analyses the development of rural transport services in Kemalang Sub-district, Klaten District, Central Java Province using qualitative research method and Case Study research approach. Primary data were collected by in-depth interviewing of 26 respondents, which was supported by secondary data from institutional survey. Transport service development was reviewed in three development stages; those are before 1990, 1990-2005 and 2005-2010. There have been alterations in the dominant transport service used during those three periods, from non-motorized private transport service to motorized public transport services, and then to private transport services of motorcycles. That development has led to positive changes in the character of transport services, such as the increase of transport service availability, flexibility and capability in solving nature’s restrictions, so that they promote mobility and accessibility. One negative change is the decrease of traffic safety. 
ADSORPSI PENCEMARAN LIMBAH CAIR INDUSTRI PENYAMAKAN KULIT OLEH KITOSAN YANG MELAPISI ARANG AKTIF TEMPURUNG KELAPA Lasindrang, Musrowati
Jurnal Teknosains Vol 3, No 2 (2014): June
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (303.343 KB) | DOI: 10.22146/teknosains.6026

Abstract

Chitosan has been used as biosorbent. In addition to having advantages, chitosan as biosorbent also has disadvantages. Chitosan is very soluble in low pH, so it cannot adsorb Cr (total) at low pH. It is because the active site (amine group) of chitosan undergoes protonation, and its adsorption capability is easily influenced by anions in waters. Therefore, this research studied the use of chitosan coating on active charcoal of coconut shell to increase the adsorption capability of Cr (total), BOD, and COD. This research was done to evaluate the characteristics of the liquid waste quality with or without Wastewater treatment unit (IPAL), and compare them with the Regulation of DIY Governor number 7/2010. It also studied the effect of pH and Concentration of chitosan coating on active charcoal as adsorbent on the decrease of Cr (total), BOD, and COD concentration in the liquid waste of leather tanning. The results indicate that the liquid waste of the leather tanning industry with and without Wastewater treatment unit (IPAL) have exceeded the quality standard for the liquid waste of leather tanning industry. An ANOVA statistical test indicated that Cr (total), BOD, and COD are significant at 0.05 (p < 0.05), with various pH influencing the decrease in Cr (total), BOD, and COD. The highest removal percentage resulting from the effect of chitosan concentration coating on active charcoal is obtained in adsorbent C (K3A1), with Cr (total) (91.9%); BOD (99.5%); and COD (98.47%).;
LANSKAP EKOLOGI KESERASIAN DAN KEMENARIKAN KEPARIWISATAAN ALAM DI WILAYAH YOGYAKARA UTARA muhamad, Muhamad
Jurnal Teknosains Vol 3, No 2 (2014): June
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (343.24 KB) | DOI: 10.22146/teknosains.6024

Abstract

This study examines the extent of landscape ecology and attractiveness of the natural environment in the tourism area in the region north of Yogyakarta. Yogyakarta northern region has objects and natural tourism attractions of the venture capital in its tourism development footprint. The compatibility and attractiveness level of the environment is one of the most important factors to determine the region’s level of potential environmental compatibility and attractiveness, so that the characteristics and the distribution pattern of the attractiveness and harmony of nature in the tourism region can be known. The results showed that the landscape level of ecological harmony and the attractiveness of the environment after the 2010 eruption had a significant amount of the index. The higher the quality of the natural (physical) environment and social (human and socioeconomic) culture is, the higher the level of harmony and attractiveness of the region. Landscape ecology establishes harmony between the social component (population) and the natural environment (bio-physical), suchthat they form a potential tourist attraction at the site of nature tourism in the region north of Yogyakarta. 
OPERATIONS RESEARCH STRATEGI EFISIENSI BERMULA DARI PERANG Masruroh, Nur Aini
Jurnal Teknosains Vol 3, No 2 (2014): June
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (252.728 KB) | DOI: 10.22146/teknosains.6028

Abstract

Penggunaan nama operations research inimemang tidak dapat lepas dari sejarah awalperkembangan ilmu ini. Berawal dari zamanperang dunia kedua, ketika pemerintahanInggris dan Amerika menghadapi permasalahanterbatasnya ketersediaan logistikperang yang harus dialokasikan ke beberapaoperasi militer dan aktivitas lain yangmendukung operasi militer ini sehinggamemerlukan sebuah strategi distribusilogistik yang efektif dan efisien. Gunamerumuskan strategi ini, maka dibentuklahtim yang terdiri dari sejumlah ilmuwanuntuk mengaplikasikan pendekatan ilmiahuntuk memecahkan permasalahan ini. Timini diberi tugas untuk melakukan research on(military) operations. Tim ilmuwan inilah yangselanjutnya dikenal sebagai tim operationsresearch (OR) yang pertama kali. Salah satuhasil dari tim ini adalah hasil risetnya tentangstrategi pengaturan operasi kapal selam yangmenghasilkan kemenangan dalam perang diAtlantik utara.

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