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Search Results: 1 - 10 of 352 matches for " TRI PRARTONO "
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Growth and Extracellular Carbonic Anhydrase Activity of Zooxanthellae Symbiodinium sp. in Response of Zinc Enrichment
HAYATI Journal of Biosciences , 2011,
Abstract: Coral reef communities contain a wide variety of mutualistic associations none more important than the relationship between corals and their symbiotic dinoflagellates of the genus Symbiodinium sp., commonly referred to as zooxanthellae. The function of Zinc (Zn) as cofactor of several enzyme systems such as extracellular carbonic anhydrase (extracellular CA) which catalyzes the interconversion of HCO3- and CO2. Concentrations of dissolved Zn in oligothropic waters are often very low therefore may limit the growth of zooxanthellae and their ability to fix CO2 from seawater via the carbonic anhydrase. The aim of this research is to investigate the effect of various concentrations of Zn on the growth and extracellular CA activity in zooxanthellae. Cell density was monitored daily by enumeration with hemocytometer-type chamber (0.1 mm). Extracellular CA was measured in homogenized intact whole cell by a pH drift assay. Results revealed that Zn status strongly influences the growth rate and extracelullar CA activity in zooxanthellae. The specific growth rate and cell density increased two-fold whilst extracelullar CA activity increased 10.5 times higher than that in control with increasing concentrations of Zn from 0 to 80 nM, but decreased when Zn was over 80 nM. Under a concentration of 80 nM was not Zn limited culture, consequently the growth rate of zooxanthellae not dependent on CO2 concentration yet offset by extracelullar CA activity.
Fatty Acid Content of Indonesian Aquatic Microalgae
HAYATI Journal of Biosciences , 2010,
Abstract: High utilization of fossil fuel increases the level of carbon dioxide in the atmosphere and results in global warming phenomenon. These things establish the world’s thought to look for the other alternative energy that can reduce the use of fossil fuel even to be replaced by the substitute. Recently, Indonesia has been doing the research of microalgae as a feedstock of an alternative biofuel. Fatty acid content that microalgae have is also high to produce biofuel. The steps used in this research is a 7 days cultivation, harvesting, extraction using hexane, and fatty acid identification using Gas Chromatography of microalgae species. Fatty acid component in some species such as Chlorella sp., Scenedesmus sp., Nannochloropsis sp., and Isochrysis sp. is between 0.21-29.5%; 0.11-25.16%; 0.30-42.32%; 2.06-37.63%, respectively, based on dry weight calculation. The high content of fatty acid in some species of microalgae showed the potential to be the feedstock of producing biofuel in overcoming the limited utilization from petroleum (fossil fuel) presently.
Vertical Distribution and Flux of Nutrients in the Sediments of the Mangrove Reclamation Region of Muara Angke Kapuk, Jakarta
Anna Ida Sunaryo Purwiyanto,Tri Prartono,Alan Frendy Koropitan
Makara Seri Sains , 2012,
Abstract: The reclaimed mangrove estuary in Muara Angke Kapuk is a reclaimed area that has not evaded the impacted of pollution and waste in the areas surrounding Cengkareng, Jakarta. This is apparent from the fact that almost all sediments under the mangrove trees are buried under heaps of plastic trash. However, the reclaimed region still has variety of organism, which indicating that the region still has an internal carrying capacity, especially nutrients from sediment. The purpose of this research was to examine the condition of sediment nutrients in this mangrove reclamation region. The research was conducted by taking water samples using a modification of the stratified cup at a sediment depth of 0-15 cm with depth intervals of 2.5 cm, and taking sediment samples using the sediment ring. Pore water samples were measured for dissolved oxygen (DO) and concentrations of ammonia, nitrite, nitrate, and phosphate. Sediment samples were used to obtain porosity values. The data obtained is used to make vertical concentration profiles and analysis of vertical nutrient flux. Vertical nutrient flux analysis was performed with the aid of QUAL2K software version 2.11. The results showed different vertical distributions and flux of nutrients, where influx for ammonia and phosphate and an increase in line with increasing sediment depth, while nitrate efflux and a decreased concentration. The flux calculation of nitrite as transitory nutrient was not done, but the concentration decreased after a depth of 2.5 cm. This indicates that the high contamination on the surface does not prevent the natural chemical processes so the reclaimed region can still provide nutritional support for its organism.
Tri Margono
Jurnal Akuntansi dan Keuangan , 2000,
Abstract: The value of information depends on its content, how to find it, and how to utilize it to support user's activities. It means that the value of information can only be determined until the information has been received. First step for analyzing such cost are to identify and classify them properly. This classification should be based on the total costs of entire service activities such as direct costs, indirect costs, and some instances of additional costs. The important elements for determining costs that are burdened to users are salaries, raw materials or collection costs, and unexpected costs. The strategy for determining cost of information service in library depends on the aim for offering the services, price of service/product, and the fitness between the needs and the information provided as well as the demand for the services being offered. Although the cost and price of information services could be determined by five approaches -(those are optimal pricing, pricing according to value, pricing for full cost recovery, marginal cost pricing, and free distribution of services information)- provider must consider the content of information. It means that the calculation of information service cost should be based not only by fixed and variable costs, but also by the information contents and depreciation of each collection. Abstract in Bahasa Indonesia : Nilai informasi sangat tergantung dari isi, cara perolehan, dan manfaatnya bagi pengguna dalam mendukung aktivitas yang sedang dilakukan. Hal tersebut menunjukkan bahwa nilai informasi baru dapat ditentukan kemudian setelah informasi itu diperoleh. Langkah awal yang harus ditempuh untuk melakukan analisis biaya adalah dengan mengidentifikasi dan mengklasifikasi biaya yang dimaksud. Klasifikasi lebih didasarkan pada biaya total dari keseluruhan aktivitas jasa, yang terdiri atas biaya langsung, biaya tidak langsung, dan biaya tambahan. Elemen-elemen yang harus diperhatikan oleh pengelola informasi dalam menentukan besarnya biaya informasi yang akan dibebankan kepada pengguna adalah biaya kerja/upah, biaya bahan atau koleksi, dan biaya tak terduga. Strategi penentuan biaya jasa informasi di perpustakaan sangat ditentukan oleh tujuan jasa yang ditawarkan, harga jasa/produk dan kebutuhan informasi yang berhubungan dengan data yang dicari serta tingkat kebutuhan pasar terhadap jasa yang telah dilakukan. Walaupun sebenarnya besarnya biaya dan harga jasa informasi dapat juga ditentukan melalui lima pendekatan utama, yaitu optimal pricing, pricing according to value, pricing for full cost recovery, marginal c
Tri Ratnawati
Jurnal Akuntansi dan Keuangan , 2007,
Abstract: Purpose of the study is to examine direct and indirect effect of the external factor, investment opportunity, assets growth on financial decisions that firms listed in Jakarta Stock Exchange. Structural Equation modeling use to proof direct and indirect effect, this result of the models is acceptable (fit). Amount of the sample is 195 analysis unit for before crisis and 196 analysis unit for that moment of the crisis. Before crisis, direct effect external factors to financial decision are positive significance and indirect effect pass through investment opportunity is negative significance, direct effect exceed of indirect effect. Financial decision does not direct effect to asset growth and does not indirect effect pass through investment opportunity. Abstract in Bahasa Indonesia : Penelitian ini bertujuan menguji pengaruh langsung dan pengaruh tidak langsung faktor eksternal, kesempatan investasi, pertumbuhan assets terhadap keputusan pendanaan perusahaan yang terdaftar di Bursa Efek Jakarta dengan menggunakan Structural Equation Modeling. Sampel yang digunakan adalah 195 unit analisis sebelum krisis dan 196 unit analisis pada saat krisis. Hasil studi menunjukkan bahwa sebelum krisis pengaruh langsung faktor eksternal adalah positif signifkan dan pengaruh tidak langsung melalui kesempatan investasi adalah negatif signifikan. Pada saat krisis, faktor eksternal tidak mempunyai pengaruh langsung terhadap keputusan pendanaan, bagaimanapun pengaruh tidak langsung adalah negatif signifikan. Pengaruh langsung faktor eksternal terhadap kesempatan investasi. kata kunci : faktor eksternal, pertumbuhan assets, kesempatan investasi
Tri Krianto
Makara Seri Kesehatan , 2009,
Abstract: Not of all Schoolchildren Knows about Dengue Hemorrhagic Fever. More than 30% dengue patients in Depok City were school age children. Infection does not always happened in school in which a child spend their time 25% of his time a day. School has strategic role in dengue control. It means that schoolchildren must have to adequate information so that its positive behavior. This quantitative study aims to assess information exposed and their knowledge in dengue vector control. Mean difference and correlation analyze were used in this study. Result of this study indicated that information exposed among schoolchildren and dengue knowledge were still lower.
Comparative Advantage: Theory, Empirical Measures And Case Studies
Review of Economic and Business Studies (REBS) , 2009,
Abstract: This paper consists of three main parts i.e. theory, analytical tool and case studies of comparative advantage. Firstly, we review the theory and various empirical measures of comparative advantage. We would argue that for the catching-up economies, like ASEAN countries, the meaning of “leading exported products” could be examined from the two points of view i.e. international competitiveness and country’s trade balance. Secondly, we combine two indexes of comparative advantage, i.e. Revealed Symmetric Comparative Advantage (RSCA) index by Dalum et al. (1998) and Laursen (1998), and Trade Balance Index (TBI) by Lafay (1992), which represent well the two points of view, to propose an analytical tool, namely “products mapping”. Thirdly, this analytical tool is applied to analyze exported products (defined as 3-digit SITC Revision 2) of the ASEAN countries. This paper concludes that in the cases of ASEAN countries, the higher the comparative advantage for a specific product, the higher the possibility of the country as a net-exporter becomes. This finding strongly supports the theory of comparative advantage.
Crouch, Harold. Political Reform in Indonesia after Soeharto.
Tri Ratnawati
Journal of Indonesian Social Sciences and Humanities , 2011,
Abstract: Review of Crouch, Harold. (2010). Political Reform in Indonesia after Soeharto. Singapore: Institute of Southeast Asian Studies. 390 pp (including bibliography and index) ISBN 9789812309204 and 9812309209
Quantum-Classical System: Simple Harmonic Oscillator
Tri Sulistiono
Physics , 1997,
Abstract: Problems concerning with application of quantum rules on classical phenomena have been widely studied, for which lifted up the idea about quantization and uncertainty principle. Energy quantization on classical example of simple harmonic oscillator has been reviewed in this paper.
Notes on free fall of a particle and bouncing on a reflecting surface
Tri Sulistiono
Physics , 1997,
Abstract: Considerable progress has recently been made in controling the motion of free atomic particles by means of light pressure exerted by laser radiation. The free fall of atoms and bouncing on a reflecting surface made from evanescent wave formed by internal reflection of a quasiresonant laser beam at a curved glass surface in the presence of homogeneous gravitational field has been observed. In this paper we present the energy quantization of this system by making use the asymptotic expansion method. It is shown that for large $n$ the levels go like $n^{2/3}$ which may be compared with $n^2$ for the infinite square well.
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