Iradiasi Neutron Pada Bahan Ss316 Untuk Pembuatan Endovascular Stent

Neutron Irradiation on SS316 Material for Radioactive Endovascular Stent Production. It was reported thatrestenosis could be prevented by radioactive endovascular stent. SS316 material of endovascular stent has beenirradiated at pneumatic rabbit system of G.A. Siwabessy reactor for 5 minutes for producing radioactive stent byneutron activation. After 10 days of decay, the irradiated SS316 was measured by gamma spectrometer. Theradioisotopes of 51Cr, 59Fe and 60Co were detected in the irradiated SS316 with radioactivity of 5990, 107 and 109Bq/mg respectively. The Calculation results showed that radioisotopes of 51Cr, 59Fe and 55Fe were produced by neutronactivation. The radioactivity of 51Cr, 59Fe and 55Fe were 6051, 70 and 110 Bq/mg respectively. In the irradiatedmaterials, the 55Fe was not detected because the radioisotope emitted radiation with very low energy (5.9 keV). It isconsidered that radioisotope of 60Co was produced from cobalt impurity in the SS316

Aspek Yuridis Renegosiasi Kontrak Karya di Indonesia (Studi Kontrak Karya antara Pemerintah Republik Indonesia dengan PT.Freeport Indonesia)

Mining is one of sources the country and religional incomes. That is why the presence of mining company truly help country and region /local development. Renegotiation is based on the acts number 4 year 2009 about mineral coal, of wich statement should be adjudted to the recent acts. The bill number 4 year 2009 stated the mining conservation based on utility, equality and nationality. The creation-contract negotiation has strong law foundation, even though its content clashes with the contarct which already been signed. Renegiatation does not deny the content of contract, but adption of current condiotion and the rules of certain country. It is imposible to keep the content compeletely the same after long years because that condition will be harmful for one side. Even worse that contract is full of political and foreign needs as the main consideration

Synchrotron Polarization at High Galactic Latitude

We present preliminary results from mapping the high-latitude Galactic polarization with the Effelsberg Telescope at $\lambda$21 cm. Structures on the resulting maps are mostly on the scale of several degrees. The results show detection of polarization over most of the field, at the level of tens of percent of the synchrotron emission. The evidence of more structure in Stokes Q and U rather than in $\sqrt{Q^2+U^2}$ suggests the existence of Faraday rotation.Comment: To be published in the proceedings of "The Cosmic Microwave Background and its Polarization", New Astronomy Reviews, (eds. S. Hanany and K.A. Olive

Geothermal Reservoir Characterization for Steam Field Management in Kamojang Geothermal Field-West Java

Kamojang is the first geothermal field in Indonesia with a vapor dominated system reservoir. Kamojang has been exploited for over 20 years producing about 1100 tons/hour of steam which is equivalent to 140 Mwe electricity energy. This research is aimed to study the reservoir character after 20 years of exploitation and to investigate the effect of reinjection as a artificial recharge for steam input in the future and also the nature of secondary processes in the reservoir using isotope geochemistry tools. The research is conducted by natural isotopes (18O, 2H and 3H) analysis of many sources of water (meteoric, cold spring, fumaroles and shallow groundwater) in the surrounding of Kamojang field and also fluid reservoir to establish fluid reservoir origins and isotopic composition. Gas analysis and isotopes monitoring on the 25 production wells have been conducted every 2-3 years intervals for more than 10 years to investigate the effect of exploitation to the reservoir performance. Tritium radiotracer test with 370 GBq (10 Ci) activity was conducted at the KMJ 15 reinjection well to determine qualitatively and quantitatively the flow of reinjection water to its surrounding producing well (KMJ 11, 14, 17, 18, 26, 17 and 30). Data interpretation and evaluation to determine reinjection water mass recovery and cooling prediction modeling were conducted using ICEBOX program package (TRINV and TRCOOL). Interpretation and evaluation of data concluded that reservoir fluid of Kamojang geothermal field was originated from meteoric water which infiltrated through fault structures at elevation of 1350 m –1650 m above sea level. There is no evidence that the fluid was originated from magmatic water. Reservoir fluid moved both laterally and vertically (deep fluid) with lateral fluid movement from west to the east. The isotope data analysis indicated there is water entry in west-northwest reservoir boundary. Water entry gradually moved from northwest to the southeast (through wells of KMJ 42, 40, 27, 26 and 28). Exploitation effect to ten of the observation wells shows a decrease in w/r ratio and liquid saturation from 35 % in the beginning to about 20,5 % on the average after 20 years of operation. Evaluation with TRINV and TRCOOL program shows that 13,5 % of water reinjected into KMJ 15 reinjection well was recovered in the surrounding production wells. The program model of the reservoir temperature cooling shows that water reinjection with flow rate of 10 kg/sec is very save. After 20 years of reinjection activity, the model predicts a production wells will be cooling of about 6.8oC.Received: 15 January 2009; Revised: 1 May 2009; Accepted: 5 May 200

Pengaruh Faktor-faktor Teknikal Terhadap Harga Saham (Studi Pada Harga Saham Idx30 Di Bursa Efek Indonesia Periode Tahun 2012-2015)

The purpose of this study is to examine the effect of bid volume, past stock price and trading volume partially and simultaneously to the stock price by using multiple linear regression analysis. Selection of the samples in this study using purposive sampling method, generating 17 companies as sample. Results from this study indicate that; 1) Volume bid partially does not effect on stock prices; 2) Past stock price partially is positively significant effect on stock prices; 3) Trading volume partially is negatively effect on stock prices; 4) Volume bid, past stock price and trading volume simultaneously significant effect on stock prices. According from determinant test show variability of dependent variable stock price can be explain from independent variable from regression model about 85%, the percentage out from value is 15% that can be affect dependent variable. The results of this study can be used as one card at a practical investment analysis in doing stock trading for investors and traders

Dampak Bantuan Sosial Penguatan Lembaga Distribusi Pangan Masyarakat (P-ldpm) terhadap Kinerja Gapoktan di Kecamatan Natar Kabupaten Lampung Selatan

This research aims to assess the impact of P-LDPM on Gapoktan performances and rice farmers incomes member of Gapoktan in Natar District South Lampung Regency. The sample of this research includes two Gapoktan's chairman, and 26 rice farmers from Gapoktan Pendowo (P-LDPM recipient) and Gapoktan Mekar Sari (non P-LDPM recipient). The data collection was conducted from April to May 2015. Performance of Gapoktan was analyzed by quantitative descriptive analysis; income of rice farmers was analyzed by independent t-test of two samples. The result of this research showed that P-LDPM gave impact on Gapoktan performance. This could be seen from the recipient of P-LDPM Gapoktan performance that showed a good performance, in two performance indicators set by the Ministry of Agriculture in 2013. While, non recipients P-LDPM Gapoktan only showed good performance in one indicator. Income of the farmer was not impacted by P-LDPM yet, this could be seen from the results of independent t-test of two samples analysis that showed no significant difference in the average income per hectare between recipients and non-recipients of Gapoktan members

Growth and yield of chilli (Capsicum annuum L.) in response to mulching and potassium fertilization

A field experiment was canducted 10 study the influence of levels of potassium fertilizer (0, 66 and 132 kg ha-1) and types of mulching (black plastic, reflective plastic and coconut fronds) on growth and yield of chilli. Plant height, yield, fruit number and dry weight of plant increased with increasing K levels and mulching. Yields were increased by 89% and 142% with K levels of 66 and 132 kg ha-1, respectively. Highest yield was obtained from plant grown under reflective plastic mulch. Nitrogen, P, K and Ca content in leaf tissues, soil temperature and moisture under mulched conditions were higher than without mulch. There was a positive correlation between plant dry weight with soil temperature and moisture